Method for manufacturing lithium secondary battery, method for manufacturing stacked battery, and method for manufacturing composite body   
The whole of a conductive material layer is formed on a bonding surface of an outer film having flexibility and barrier properties to prepare a composite body in which the conductive material layer is integrated with the outer film. A current collector is located within an application region, and at least a part of an electrode terminal is located outside the application region. A positive electrode active material precursor layer, an electrolyte precursor layer, and a negative electrode active material precursor layer are added to the composite body with plane positions thereof aligned with that of the current collector. These precursor layers are subjected to a crosslinking process. The application regions are applied, and the outer films are bonded, to seal a cell. The crosslinking process may be omitted.
          Yamaha : YZF-R   
Web: http://www.store-168.com MSN/Email:yousupplier@hotmail.com 路1 GP tech trickles down: Revised rigidity of the main frame between the engine mounts and steering head, a new, more rigid lower triple clamp, a 20mm-longer swingarm produce the best-handling R1 ever. 路2 Shorter valve guides and other revisions increase intake flow and reduce friction, for more power. 路3 Gold-colored forks look great. 路4 Revised clutch boss provides increased oil flow for excellent durability. Engine: 路1 Short-stroke 998cc DOHC, 20-valve, liquid-cooled inline four-cylinder engine. 路2 Dual-valve fuel injection system uses motor-driven secondary throttle valves and 32-bit ECU for super-responsive, instantaneous power delivery. 路3 Two-piece ergonomically designed fuel tank carries fuel in the rear section, for good centralization of mass, while the front half contains a Ram-Air-fed airbox for increased power. 路4 Lay-down design cylinder head鈥?0 degrees forward鈥?optimizes weight distribution, straightens intake tracts for improved cylinder filling, and allows frame to pass over instead of around the engine for great strength and a narrow chassis. 路5 Closed-deck cylinder block increases strength and allows a narrow engine in spite of big, 77mm bores. 路6 Narrow-angle five-valve combustion chambers produce a highly efficient 12.4:1 compression ratio. Big valves and high-lift cams flow plenty of air. 路7 Carburized connecting rods with fractured big ends produce a quick-revving engine with excellent high-rpm durability. 路8 High silicon-content ceramic-composite cylinder sleeves ensure great heat dissipation for consistent power delivery and reduced friction. 路9 Strong, yet lightweight clutch and close-ratio six-speed gearbox with triangulated shaft layout for great strength, compactness, and quicker acceleration. 路10 Titanium underseat exhaust system (with stainless steel midpipe and catalyst) contains a titanium EXUP valve for a broad, seamless powerband. 路11 High-efficiency curved radiator and an aluminum liquidcooled oil cooler maintain stable operating temperature. 路12 Direct ignition coils, dual-electrode spark plugs and highoutput magneto deliver extremely accurate, reliable firing. 路13 AC generator behind cylinder block produces a narrow engine with excellent cornering clearance. Chassis/Suspension: 路1 Overall frame width of only 15.6 inches produces comfortable ergonomics as well as efficient aerodynamic penetration. 路1 Controlled Fill die cast, truss-type swingarm is very strong and longer, for optimal traction and feedback. 路2 Controlled Fill die cast, detachable aluminum subframe is light, strong and allows easy rear shock access. 路3 Dual 320mm front disc brakes; light/strong, forged one-piece radial-mount calipers and Brembo radial-pump front master cylinder with adjustable lever delivers amazing braking power and controllability. 路4 Fully adjustable KYB inverted telescopic front fork with 43mm tubes provides 4.7 inches of travel. 路5 Piggyback rear shock gives 5.1 inches of wheel travel, full adjustability and a lightweight, accessible aluminum preload adjustment collar. 路6 Light, five-spoke wheels enhance acceleration, deceleration, handling and suspension action. Additional Features: 路1 Two multi-reflector and two projector beam headlights provide great illumination and distinctive style. 路2 Adjustable LCD illumination and multi-function digital gauges: adjustable shift light, odometer, dual tripmeters, water temperature, air temperature, full-time clock, lap timer and large 15,000 rpm analog tachometer. 路3 Aggressive bodywork with twin Ram-Air intakes for increased engine performance. 路4 LED taillight is light, bright and highly efficient. 路5 Sticky 120/70-ZR17 and 190/50-ZR17 radial tires for incredible grip and precise handling. 路6 Forged footpegs are extra durable and light. 路7 Extensive use of hollow bolts and lightweight fasteners helps trim overall weight. 路8 8.2 AH battery is compact and light. 路9 Durable #530 O-ring鈥搒ealed drive chain. 路10 Standard toolkit located in convenient storage compartment under passenger seat Engine Type 998cc, liquid-cooled, 20-valve, DOHC, in-line four-cylinder Bore x Stroke 77 x 53.6mm Compression Ratio 12.4:1 Carburetion Fuel injection, dual-valve throttle bodies with motor-driven secondary valves Ignition Digital TCI Transmission 6-speed w/multi-plate clutch Final Drive #530 O-ring chain Chassis Suspension/Front 43mm inverted telescopic fork w/adjustable preload, compression damping, rebound damping; 4.7" travel Suspension/Rear Single shock w/adjustable preload, compression damping, rebound damping, spring preload; 5.1" travel Brakes/Front Dual 320mm discs; radial-mount forged 4-piston calipers Brakes/Rear 220mm disc w/single-piston pin-slide caliper Tires/Front 120/70-ZR17 Tires/Rear 190/50-ZR17 Dimensions Length 82.1" Width 28.3" Height 43.5" Seat Height 32.9" Wheelbase 55.7" Rake (Caster Angle) 24.0掳 Trail 3.8" Fuel Capacity 4.75 gal. Dry Weight 381 lbs. Other Main Jet Not Applicable Main Air Jet Not Applicable Jet Needle Not Applicable Needle Jet Not Applicable Pilot Air Jet 1 Not Applicable Pilot Outlet Not Applicable Pilot Jet Not Applicable Primary Reduction Ratio 65/43 (1.512) Secondary Reduction Ratio 45/17 (2.647) Gear Ratio - 1st Gear 38/15 (2.533) Gear Ratio - 2nd Gear 33/16 (2.063) Gear Ratio - 3rd Gear 37/21 (1.762) Gear Ratio - 4th Gear 35/23 (1.522) Gear Ratio - 5th Gear 30/22 (1.364) Gear Ratio - 6th Gear 33/26 (1.269)
          Circuit protective device and method for manufacturing the same   
A circuit protecting element includes insulating substrate (11), a pair of surface electrodes (12) provided to both ends of a top face of insulating substrate (11), element (13) bridging the pair of surface electrodes (12) and electrically connected to the pair of surface electrodes (12), base layer (14) formed between element (13) and insulating substrate (11), and insulating layer (15) covering element (13). Base layer (14) is formed of a mixture of diatom earth and silicone resin. The structure discussed above allows stabilizing the blowout characteristics of the circuit protecting element.
          Connectivity in ictal single photon emission computed tomography perfusion: a cortico-cortical evoked potential study   
Abstract
Subtraction ictal and interictal single photon emission computed tomography can demonstrate complex ictal perfusion patterns. Regions with ictal hyperperfusion are suggested to reflect seizure onset and propagation pathways. The significance of ictal hypoperfusion is not well understood. The aim of this study was to verify whether ictal perfusion changes, both hyper- and hypoperfusion, correspond to electrically connected brain networks. A total of 36 subtraction ictal and interictal perfusion studies were analysed in 31 consecutive medically refractory focal epilepsy patients, evaluated by stereo-electroencephalography that demonstrated a single focal onset. Cortico-cortical evoked potential studies were performed after repetitive electrical stimulation of the ictal onset zone. Evoked responses at electrode contacts outside the stimulation site were used as a measure of connectivity. The evoked responses at these electrodes were compared to ictal perfusion values noted at these locations. In 67% of studies, evoked responses were significantly larger in hyperperfused compared to baseline-perfused areas. The majority of hyperperfused contacts also had significantly increased evoked responses relative to pre-stimulus electroencephalogram. In contrast, baseline-perfused and hypoperfused contacts mainly demonstrated non-significant evoked responses. Finally, positive significant correlations (P < 0.05) were found between perfusion scores and evoked responses in 61% of studies. When the stimulated ictal onset area was hyperperfused, 82% of studies demonstrated positive significant correlations. Following stimulation of hyperperfused areas outside seizure onset, positive significant correlations between perfusion changes and evoked responses could be seen, suggesting bidirectional connectivity. We conclude that strong connectivity was demonstrated between the ictal onset zone and hyperperfused regions, while connectivity was weaker in the direction of baseline-perfused or hypoperfused areas. In trying to understand a patient’s epilepsy, one should consider the contribution of all hyperperfused regions, as these are likely not random, but represent an electrically connected epileptic network.

          Nanotube Superbatteries   
http://www.technologyreview.com/energy/21938/?a=f Friday, January 09, 2009 Dense films of carbon nanotubes store large amounts of energy. By Katherine Bourzac Pure power: Pure thin films of carbon nanotubes can store and carry large amounts of electrical charge, making them promising electrode materials. This scanning-electron-microscope image shows a film made up of 30 layers of the nanotubes on […]
          Bedol Water Powered Clock – Blue   
List Price: N/A Get it For $19.00 at Amazon.com Expiry Date: Limited Time Offer HOT DEAL! HURRY UP! The Bedol Water Clock keeps perfect time without batteries or electricity. Just open the fill cap and add water. Cutting-edge technology enables the amazing Bedol Water Clock to generate it own clean energy. Electrodes within the water [...]
          uso de los videos en las tic   
La galvanoplastia es el proceso basado en el traslado de iones metálicos desde un ánodo a un cátodo en un medio líquido, compuesto fundamentalmente por sales metálicas y ligeramente acidulado.
Desde el punto de vista de la física, es la electrodeposición de un metal sobre una superficie para mejorar sus características. Con ello se consigue proporcionar dureza, duración, o ambas.
Otra de las importantes aplicaciones de la galvanoplastia es la de reproducir por medios electroquímicos objetos de muy finos detalles y en muy diversos metales

          RECUBRIMIENTOS METALICOS   
La galvanoplastia es el proceso basado en el traslado de iones metálicos desde un ánodo a un cátodo en un medio líquido, compuesto fundamentalmente por sales metálicas y ligeramente acidulado.
Desde el punto de vista de la física, es la electrodeposición de un metal sobre una superficie para mejorar sus características. Con ello se consigue proporcionar dureza, duración, o ambas.
Otra de las importantes aplicaciones de la galvanoplastia es la de reproducir por medios electroquímicos objetos de muy finos detalles y en muy diversos metales

          DESCARGA ENTREVISTA: Diputada Maya Fernández valora mesa de trabajo por personas electrodependientes   
La autora del proyecto que busca la gratuidad en las cuentas de la luz para estas familias afirmó que “llegará un momento que necesitaremos el patrocinio del Ejecutivo”.
          Comisión de Salud pide a ministerio de energía impedir corte de suministro a pacientes electrodependientes.   
Los parlamentarios acordaron, también, establecer una mesa de trabajo con los ministros de salud y energía, además de las empresas distribuidoras, para abordar la problemática de manera integral y sacar adelante un proyecto de ley que se haga cargo de las necesidades básicas de este grupo de la población.
          Transcutaneous Electrical Nerve Stimulation   

Transcutaneous Electrical Nerve Stimulation


INTRODUCTION


Transcutaneous electrical nerve stimulation (TENS) currently is one of the most commonly used forms of electroanalgesia. Hundreds of clinical reports exist concerning the use of TENS for various types of conditions such as low back pain (LBP), myofascial and arthritic pain, sympathetically mediated pain, bladder incontinence, neurogenic pain, visceral pain, and postsurgical pain. Because many of these studies were uncontrolled, there has been ongoing debate about the degree to which TENS is more effective than placebo in reducing pain.

The currently proposed mechanisms by which TENS produces neuromodulation include the following:

  • Presynaptic inhibition in the dorsal horn of the spinal cord
  • Endogenous pain control (via endorphins, enkephalins, and dynorphins)
  • Direct inhibition of an abnormally excited nerve
  • Restoration of afferent input

The results of laboratory studies suggest that electrical stimulation delivered by a TENS unit reduces pain through nociceptive inhibition at the presynaptic level in the dorsal horn, thus limiting its central transmission. The electrical stimuli on the skin preferentially activate low- threshold myelinated nerve fibers. The afferent input from these fibers inhibits propagation of nociception carried in the small unmyelinated C fibers by blocking transmission along these fibers to the target or T cells located in the substantia gelatinosa (laminae 2 and 3) of the dorsal horn.

The mechanism of the analgesia produced by TENS is explained by the gate control theory proposed by Melzack and Wall in 1965. The gate usually is closed, inhibiting constant nociceptive transmission via C fibers from the periphery to the T cell. When painful peripheral stimulation does occur, the information carried by C fibers reaches the T cells and opens the gate, allowing pain transmission centrally to the thalamus and cortex, where it is interpreted as pain. The gate control theory postulated a mechanism by which the gate is closed again, preventing further central transmission of the nociceptive information to the cortex. The proposed mechanism for closing the gate is inhibition of the C-fiber nociception by impulses in activated myelinated fibers.

 

TECHNICAL CONSIDERATIONS


A TENS unit consists of one or more electric signal generators, a battery, and a set of electrodes. The units are small and programmable, and the generators can deliver trains of stimuli with variable current strengths, pulse rates, and pulse widths. The preferred waveform is biphasic, to avoid the electrolytic and iontophoretic effects of a unidirectional current. The usual settings for the stimulus parameters used clinically are the following:

  • Amplitude - Current at low intensity, comfortable level, just above threshold
  • Pulse width (duration) - 10-1000 microseconds
  • Pulse rate (frequency) - 80-100 impulses per second (Hz); 0.5-10 Hz when stimulus intensity is set high

When TENS is used for pain control, patients are instructed to try different frequencies and intensities to find those that provide the best pain control for that individual. Optimal settings of stimulus parameters are subjective and are determined by trial and error. Electrode positioning is quite important. Usually, the electrodes are placed initially on the skin over the painful area, but other locations (eg, over cutaneous nerves, trigger points, acupuncture sites) may give comparable or even better pain relief.

The 3 options for the standard settings used in different therapeutic methods of TENS application include the following:

  • Conventional TENS has a high stimulation frequency (40-150 Hz) and low intensity, just above threshold, with the current set between 10-30 mA. The pulse duration is short (up to 50 microseconds). The onset of analgesia with this setup is virtually immediate. Pain relief lasts while the stimulus is turned on, but it usually abates when the stimulation stops. Patients customarily apply the electrodes and leave them in place all day, turning the stimulus on for approximately 30-minute intervals throughout the day. In individuals who respond well, analgesia persists for a variable time after the stimulation stops.
  • In acupuncturelike settings, the TENS unit delivers low frequency stimulus trains at 1-10 Hz, at a high stimulus intensity, close to the tolerance limit of the patient. Although this method sometimes may be more effective than conventional TENS, it is uncomfortable, and not many patients can tolerate it. This method often is considered for patients who do not respond to conventional TENS.
  • Pulsed (burst) TENS uses low-intensity stimuli firing in high frequency bursts. The recurrent bursts discharge at 1-2 Hz, and the frequency of impulses within each burst is at 100 Hz. No particular advantage has been established for the pulsed method over the conventional TENS method.

Patient comfort is a very important determinant of compliance and, consequently, the overall success of treatment. The intensity of the impulse is a function of both pulse duration and amplitude. Greater pulse widths tend to be more painful. The acupuncturelike method is less tolerable because the impulse intensity is higher.

The amount of output current depends on the combined impedance of the electrodes, skin, and tissues. With repetitive electrical stimuli applied to the same location on the skin, the skin impedance is reduced, which could result in greater current flow as stimulation continues. A constant current stimulator, therefore, is preferred to minimize sudden uncontrolled fluctuations of current intensity related to changes in impedance. An electroconductive gel applied between the electrode and skin serves to minimize the skin impedance. Skin irritation can occur in as many as 33% of patients, at least in part, due to drying out of the electrode gel. Patients need to be instructed in the use and care of TENS equipment, with particular attention to the electrodes.

Medical complications arising from use of TENS are rare; however, skin irritation is a frequent problem and often is due partly to the drying out of the electrodes. Sometimes individuals react to the tape used to secure the electrodes. Skin irritation is minimized by using self-adhesive disposable electrodes and repositioning them slightly for repeated applications. The use of TENS is contraindicated in patients with demand-type pacemakers because their stimulus outputs may drive or inhibit the pacemaker.

A variety of newer transcutaneous or percutaneous electrical stimulation modalities recently has emerged.

  • Interferential current therapy (IFC) is based on summation of 2 alternating current signals of slightly different frequency. The resultant current consists of cyclical modulation of amplitude, based on the difference in frequency between the 2 signals. When the signals are in phase, they summate to an amplitude sufficient to stimulate, but no stimulation occurs when they are out of phase. The beat frequency of IFC is equal to the difference in the frequencies of the 2 signals. For example, the beat frequency and, hence, the stimulation rate of a dual channel IFC unit with signals set at 4200 and 4100 Hz is 100 Hz.
  • IFC therapy can deliver higher currents than TENS. IFC can use 2, 4, or 6 applicators, arranged in either the same plane for use on regions such as the back or in different planes in complex regions (eg, the shoulder).
  • Percutaneous electrical nerve stimulation (PENS) combines advantages of both electroacupuncture and TENS. Rather than using surface electrodes, PENS uses acupuncturelike needle probes as electrodes, placed at dermatomal levels corresponding to local pathology. The main advantage of PENS over TENS is that it bypasses the local skin resistance and delivers electrical stimuli at the precisely desired level in close proximity to the nerve endings located in soft tissue, muscle, or periosteum.

 

APPLICATIONS OF TENS IN CLINICAL PRACTICE


Literature on the use of TENS in a variety of medical conditions reports a wide range of outcomes, from very positive to negative effectiveness. Currently, there is an overall consensus favoring the use of TENS, with authorities differing on its value in different clinical situations. Generally, TENS provides initial relief of pain in 70-80% of patients, but the success rate decreases after a few months or longer to around 20-30%. To exclude a false-negative response, a trial of TENS for at least 1 hour should be given to confirm potential benefit from subsequent continuous use.

According to Johnson, the time from the start of stimulation to the onset of analgesia varies from almost immediate to hours (on average 20-30 minutes in over 75% of patients and 1 hour in 95% of patients). The duration of analgesia also varies considerably, continuing only for the duration of stimulation in some patients and providing considerable prolonged poststimulation relief in others. The same TENS protocol may have different degrees of antinociception in acute experimental pain compared with chronic clinical pain in patients with chronic LBP.

Patients differ in their stimulus preferences and in their rates of compliance. In Johnson's study of compliance in patients who benefited from TENS, 75% used the device on a daily basis. Patients showed individual preferences for particular pulse frequencies and patterns and consistently adjusted their stimulators to these settings on subsequent treatment sessions.

 

Indications for the use of TENS

  • Neurogenic pain (eg, deafferentation pain, phantom pain), sympathetically mediated pain, postherpetic neuralgia, trigeminal neuralgia, atypical facial pain, brachial plexus avulsion, pain after spinal cord injury (SCI)
  • Musculoskeletal pain: Examples of specific diagnoses include joint pain from rheumatoid arthritis and osteoarthritis, acute postoperative pain (eg, postthoracotomy), and acute posttraumatic pain. After surgery, TENS is most effective for mild-to-moderate levels of pain, and it is ineffective for severe pain. The use of TENS in chronic LBP and myofascial pain is controversial, as placebo-controlled studies fail to show statistically significant beneficial results. Uncertainty also exists about the value of TENS in tension headache.
  • Visceral pain and dysmenorrhea are other conditions in which TENS has been applied successfully.
  • Other disorders: TENS has been used successfully in patients with angina pectoris and urge incontinence, as well as in patients requiring dental anesthesia. Reports discuss use of TENS to assist patients in regaining motor function following stroke, to control nausea in patients on chemotherapy, as an opioid-sparing modality in postoperative recovery, and in postfracture pain.

Contraindications for the use of TENS

  • TENS should not be used in patients with a pacemaker (especially of the demand type).
  • TENS should not be used during pregnancy because it may induce premature labor.
  • TENS should not be applied over the carotid sinuses due to the risk of acute hypotension through a vasovagal reflex.
  • TENS should not be placed over the anterior neck because of possible laryngospasm due to laryngeal muscle contraction.
  • The electrodes should not be placed in an area of sensory impairment (eg, in cases of nerve lesions, neuropathies), where the possibility of burns exists.
  • A TENS unit should be used cautiously in patients with a spinal cord stimulator or intrathecal pump.

 


          Weight Loss Diet Radiofrequency Assisted Lipoplasty A Liposuction Alternative   
One popular alternative to liposuction is Radiofrequency Assisted Lipoplasty. This new medical procedure for treating fat and cellulite is a way for patients to see dramatic results in a relaxing way with no downtime.





Using a form of radio frequency to deliver volumetric heat without damaging the epidermis, the procedure works to melt both subcutaneous and unhealthy visceral fat (that even liposuction cannot treat), reduce cellulite, reshape problem areas, tighten skin and reduce wrinkles. There is no invasive surgery, painful needle injections, inflammation, scars and no downtime for recovery. Patients should not be surprised to see results of up to 3 inches in circumference loss and up to 10 pounds of weight loss in just 6 weeks.





RFAL produces results 560% faster than other forms of non-surgical treatment currently available. The world has waited a long time for an easier solution for unwanted fat reduction, and RFAL literally melts fat extremely quickly and without discomfort.








Good candidates are:





- People who have already tried diet and exercise but have problem areas of excess fat in specific areas, such as the hips, buttocks, thighs, inner knee, back, abdomen, upper arms, cheeks, jowls, chest, and waist.








- People who don't want to undergo invasive liposuction surgery








- People who have had a liposuction surgery and need maintenance





The treatment procedure is like thermal therapeutic massage which is very comfortable to the patient and operator.





During the treatment many people feel little or no sensation at all. Some people feel a tingling or warm sensation under the applicator or electrodes. This feeling usually decreases or disappears after a few hours as the person becomes used to the sensation. This sensation can vary depending upon the site being treated.


Bob Masters is author of this article. More info about:

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          Thick film silver paste and its use in the manufacture of semiconductor devices   
The present invention is directed to an electroconductive silver thick film paste composition comprising Ag, a glass frit and rhodium resinate, Cr2O3 or a mixture thereof all dispersed in an organic medium. The present invention is further directed to an electrode formed from the paste composition and a semiconductor device and, in particular, a solar cell comprising such an electrode. The paste is particularly useful for forming a tabbing electrode.
          Aqueous ink for producing high-temperature electrochemical cell electrodes   
The invention aims at an aqueous ink for high-temperature electrochemical cell electrodes and/or electrolyte containing particles of at least one mineral filler, at least one binder, and at least one dispersant. It also concerns the electrode and the electrolyte using such an ink.
          Elon Musk’s tipped Neuralink wants to put chips in the human brain   
Elon Musk has launched a new company called Neuralink, according to sources, and it aims to develop a technology that could connect human brains with computers. This connection would allegedly be facilitated via small electrodes implanted in the brain, enabling the individual to download and upload thoughts. Though the existence of the company has been confirmed, Musk’s precise role within … Continue reading
          Defibrillation Disposable Medical Electrodes Market: Preference To Disposable Electrodes Attributed To Their User Friendly Nature And Low Manufacturing Costs   
Global Defibrillation Disposable Medical Electrodes Market Research Report 2017 Disposable electrodes play an important role in the diagnosis as well as treatment of several diseases. According to MarketIntelReports “Global Defibrillation
          Bacteria-Coated Nanofiber Electrodes Clean Pollutants in Wastewater   
Cornell University materials scientists and bioelectrochemical engineers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.
          Dissertation Defense: Electrode Integration of Nanostructured Metal and Metal Oxide Materials Based on in-situ Growth Methods for Environmental Sensors   
Announcing the Final Examination of Xiaochen Wang for the degree of Doctor of Philosophy

In the past decades, increased human population and activities have introduced a large amount of pollutants into the environment. Various types of traditional analytical instruments were used for monitoring the emitted chemicals with low detection limit, high accuracy, and discrimination power. However, many of these methods are laboratory-based which require sample collection, transportation, extraction, and purification steps.

To make real-time on-site monitoring possible, miniaturized sensors with various integrated elements were developed. One of the most well-known strategies is to utilize nanostructured materials with enhanced sensing properties for those devices. For a majority of the current state of art devices, the synthesis of nanostructured materials and device integration are done separately, that is, "synthesis first and then integration" approach which involves two separate process steps. However, this approach comes with some disadvantages such as misalignment, contamination, as well as disconnection between nanomaterials and electrodes.

To overcome the aforementioned technical challenge, several synthesis methods were developed and validated for in-situ integration of nanostructured metal and metal oxide materials for environmental sensors in this work. The electroplating technique combined with photolithography was used to make the predefined metal electrodes. Then, with subsequent post-treatments, nanostructured metals and metal oxides could be produced in-situ and directly integrated in the electrodes without any extra transfer process steps.

In the development of a phosphate sensor, nanostructured Co and Co alloy electrodes were prepared by alloying and dealloying methods and a template (glass fiber filter paper and ZnO nanowires) assisted electroplating method. Both potentiometric and amperometric responses to phosphates in the concentration range of 10-6 to 10-2 M were obtained, showing an improvement in the detection limit and interference suppression. A sensing mechanism was proposed to elucidate the behavior of a Co electrode in aqueous solutions with varying pH conditions and optimum pH ranges for working devices were proposed.

For the flammable gas sensor development, the in-situ oxidation of Cu was utilized to form nanowires for sensing electrode fabrication. Multiple CuO nanowires were synthesized in-situ on the electroplated interdigitated Cu electrodes on a hotplate at 500 ℃ in air. The nanowires were successfully integrated as a sensing element into the device, forming bridges between two electrodes. The sensor's behavior was characterized by a current-voltage measurement. Simple processing parameters could be utilized for controlling the electrode morphologies and determining the characteristics of contacts - Schottky or Ohmic - at the electrode interface. A hypothesis was proposed to explain the transition phenomenon between Schottky and Ohmic contact modes, providing important baseline for future device design and fabrication. Finally, the fabricated sensor was tested for a flammable gas detection using saturated ethanol vapor at room temperature, which implicates a low power consumption gas sensor without elevating the sensor temperature unlike traditional gas sensors.

Committee in Charge: Hyoung Jin Cho (Chair), Jiyu Fang, Linan An, Zhai Lei, Andrew Dickerson

          Dissertation Defense: Spray-Deposited Titanium-Oxide Films for Infrared Optics, Photonics and Solar Cell Applications   
Announcing the Final Examination of Sarmad Alhasan for the degree of Doctor of Philosophy

Self-assembled TiO2 foam-like films, were grown by the water based Streaming Process for Electrodeless Electrochemical Deposition (SPEED). The morphology of the 1 m thick films consists of a tangled ropy structure with individual strands of 200 nm diameter and open pores of 0.1 to 3 micron dimensions. Such films are advantageous for proposed perovskite solar cell comprising CH3NH3PbI3 absorber with additional inorganic films as contact and conduction layers, all deposited by SPEED. Lateral film resistivity is in the range 20 - 200 k -cm, increasing with growth temperature, while sheet resistance is in the range 2 �� 20 108 /Sq. Xray diffraction confirms presence of TiO2 crystals of orthorhombic class (Brookite). UV-vis spectroscopy shows high transmission below the expected 3.2 eV TiO2 bandgap. Transmittance increases with growth temperature. This is a Ropy TiO2 thin film. We prepared Smooth TiO2 and Evaporated TiO2 thin film. Self-assembled TiO2 film deposited by aqueous-spray deposition was investigated to evaluate morphology, crystalline phase, and infrared optical constants. The 130 nm thick film has Anatase nano-crystalline structure with 10 nm characteristic surface roughness sparsely punctuated by defects of not more than 200 nm amplitude. The film is highly transparent throughout the visible to wavelengths of 12 m. The optical band gap was determined to be 4.18 eV. Important for long-wave infrared applications is that dispersion is weak compared with the more commonly used dielectic in planer structures SiO2. The low-cost, large-area, atmospheric-pressure, chemical spray deposition method would allow conformal fabrication on flexible substrates for long-wave infrared (LWIR) photonics.

Committee in Charge: Robert Peale (Chair), Kalpathy Sundaram (Co-Chair), Wasfy Mikhaell, Reza Abdolvand, Aravinda Kar

          Sodium Carboxymethyl Starch   
SODIUM CARBOXYMETHYL STARCH (CMS / SCMS / SODIUM STARCH GLYCOLATE) is a starch ether derivative derived from starch. It is soluble in water at room temperature and forms a transparent to light milky & viscous solution. CMS is an important modified starch with unique properties due to the presence of negatively charged functional group (CH2COO-). The introduction of carboxymethyl groups interrupts the ordered structure of native starch and intervenes with the re-association of gelatinized starch. This modification yields starch with decreased gelatinization temperature, increased solubility and improved storage stability. CAS NUMBER: 9063-38-1. CMS is chemically processed carbohydrate typically derived from Native starch viz. Maize, Potato, Tapioca & Rice. CMS are widely used in Oil Well Drilling, Textile, Paper & Corrugated Board, Detergent, Welding Electrodes, Food, Pharmaceutical, Pesticides, Cosmetic, Toothpaste, Paint, Mining and Ceramic Industries.
          Sodium Carboxymethyl Cellulose   
SODIUM CARBOXYMETHYL CELLULOSE (CMC or SCMC or Na-CMC) or Cellulose Gum is an anionic water soluble polymer; It is derived from cellulose, which is made water soluble by a chemical reaction. The water solubility is achieved by introducing carboxymethyl groups (-CH2-COOH) along the cellulose chain, which makes hydration of the molecule possible. CAS NUMBER: 9004-32-4. CMC is a white to creamish coloured powder consisting of very fine particles, fine granules. It is odor less and tasteless. It is a hygroscopic powder readily dissolves in water to form colloidal solution. It is insoluble in many organic solvents such as methanol, ethanol, propanol, acetone and so on. APPLICATIONS: Widely use in Foods, Pharmaceuticals, Cosmetics, Textiles, Papers & Corrugated Boards, Detergents, Paints, Oil Well Drillings, Welding Electrodes, Pesticides, Ceramics, Tobacco, Mosquito Repellent Incense, Explosives, Batteries, Pencils, Leathers & other industries.
          Sodium Carboxymethyl Cellulose (CMC)   
SODIUM CARBOXYMETHYL CELLULOSE (CMC or SCMC or Na-CMC) or Cellulose Gum is an anionic water soluble polymer; It is derived from cellulose, which is made water soluble by a chemical reaction. The water solubility is achieved by introducing carboxymethyl groups (-CH2-COOH) along the cellulose chain, which makes hydration of the molecule possible. CAS NUMBER: 9004-32-4. CMC is a white to creamish coloured powder consisting of very fine particles, fine granules. It is odor less and tasteless. It is a hygroscopic powder readily dissolves in water to form colloidal solution. It is insoluble in many organic solvents such as methanol, ethanol, propanol, acetone and so on. APPLICATIONS: Widely use in Foods, Pharmaceuticals, Cosmetics, Textiles, Papers & Corrugated Boards, Detergents, Paints, Oil Well Drillings, Welding Electrodes, Pesticides, Ceramics, Tobacco, Mosquito Repellent Incense, Explosives, Batteries, Pencils, Leathers & other industries.
          Sodium Carboxymethyl Starch (CMS)   
SODIUM CARBOXYMETHYL STARCH (CMS / SCMS / SODIUM STARCH GLYCOLATE) is a starch ether derivative derived from starch. It is soluble in water at room temperature and forms a transparent to light milky & viscous solution. CMS is an important modified starch with unique properties due to the presence of negatively charged functional group (CH2COO-). The introduction of carboxymethyl groups interrupts the ordered structure of native starch and intervenes with the re-association of gelatinized starch. This modification yields starch with decreased gelatinization temperature, increased solubility and improved storage stability. CAS NUMBER: 9063-38-1. CMS is chemically processed carbohydrate typically derived from Native starch viz. Maize, Potato, Tapioca & Rice. CMS are widely used in Oil Well Drilling, Textile, Paper & Corrugated Board, Detergent, Welding Electrodes, Food, Pharmaceutical, Pesticides, Cosmetic, Toothpaste, Paint, Mining and Ceramic Industries.
           Selectivity for Specific Cardiovascular Effects of Vagal Nerve Stimulation With a Multi-Contact Electrode Cuff    
Ordelman, S.C.M.A. and Kornet, L. and Cornelussen, R. and Buschman, H.P.J. and Veltink, P.H. (2012) Selectivity for Specific Cardiovascular Effects of Vagal Nerve Stimulation With a Multi-Contact Electrode Cuff. IEEE transactions on neural systems and rehabilitation engineering, 21 (1). pp. 32-36. ISSN 1534-4320
           Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation    
Sankarasubramanian, V and Buitenweg, J.R. and Holsheimer, J. and Veltink, P. (2011) Electrode alignment of transverse tripoles using a percutaneous triple-lead approach in spinal cord stimulation. Journal of Neural Engineering, 8 (1). 016010. ISSN 1741-2560
           Multi-electrode nerve cuff recording - model analysis of the effects of finite cuff length    
Veltink, P.H. and Tonis, T. and Buschman, H.P.J. and Marani, E. and Wesselink, W.A. (2005) Multi-electrode nerve cuff recording - model analysis of the effects of finite cuff length. In: 3rd European Medical and Biological Engineering Conference EMBEC'05 , 20-25 November 2005, Prague, Czech Republic (pp. pp. 1-5).
           Multielectrode intrafascicular and extraneural stimulation    
Veltink, P.H. and Alste, J.A. van and Boom, H.B.K. (1989) Multielectrode intrafascicular and extraneural stimulation. Medical and biological engineering and computing, 27 (1). pp. 19-24. ISSN 0140-0118
          Senior Product Manager - Electrodes & Solutions - Thermo Fisher Scientific - Chelmsford, MA   
Job Description How You Will Make A Difference: The Senior Product Manager position drives the value of the product portfolio with the development and
From Thermo Fisher Scientific - Wed, 19 Apr 2017 10:29:52 GMT - View all Chelmsford, MA jobs
          Metrohm 871 Bioscan System (818 Pump, 871 Bioscan, Gold Electrode, Computer/Software)   
The system includes a Metrohm 818 pump, a Metrohm 871 Bioscan with Gold Electrode (used for sugar and carbohydrate analysis),  computer cables, and a computer preloaded with IC Net software.  The system will need a few pieces of tubing, bottl
          Metrohm 894 Professional CVS Semiautomated   
894 Professional CVS semiautomated is a convenient high-end routine analyzer for determinations of organic additives in electroplating baths with "Cyclic Voltammetric Stripping" (CVS). The proven Metrohm electrode technique in combination wit
          Electrochemical system and method for electropolishing superconductive radio frequency cavities   
An electrochemical finishing system for super conducting radio frequency (SCRF) cavities including a low viscosity electrolyte solution that is free of hydrofluoric acid, an electrode in contact with the electrolyte solution, the SCRF cavity being spaced apart from the electrode and in contact with the electrolyte solution and a power source including a first electrical lead electrically coupled to the electrode and a second electrical lead electrically coupled to the cavity, the power source being configured to pass an electric current between the electrode and the workpiece, wherein the electric current includes anodic pulses and cathodic pulses, and wherein the cathodic pulses are interposed between at least some of the anodic pulses. The SCRF cavity may be vertically oriented during the finishing process.
           Non-invasive measurement of hepatic oxygenation by an oxygen electrode in human orthotopic liver transplantation    
Seifalian, AM; Mallett, S; Piasecki, C; Rolles, K; Davidson, BR; (2000) Non-invasive measurement of hepatic oxygenation by an oxygen electrode in human orthotopic liver transplantation. MED ENG PHYS , 22 (5) 371 - 377.
           Non invasive measurement of hepatic oxygenation by an oxygen electrode in human orthotopic liver transplantation    
(2000) Non invasive measurement of hepatic oxygenation by an oxygen electrode in human orthotopic liver transplantation. Medical Engineering and Physics , 22 (5) pp. 371-377.
          Shielded Metal Arc Welding Process- Advantages and Disadvantages    
Shielded Metal Arc Welding Process- Advantages and Disadvantages  Shielded Metal Arc Welding: (SMAW) It is also known as Manual metal arc welding; stick welding or electric arc welding. It is a fusion welding process. Welding is performed with the heat of an electric arc that is maintained between the ends of a coated metal electrode and the work piece. The electric energy from the arc
          ARRAY SUBSTRATE AND FABRICATING METHOD THEREOF, AND METHOD AND DEVICE FOR TESTING ELIGIBILITY OF DATA LINE   
The present disclosure provides for a method for fabricating an array substrate. The method includes forming a continuous and complete annular common electrode pattern surrounding a pixel.
          Device for analyzing biological Substances in a Test Solution and Production Method   
The invention relates to a device (100; 200; 300; 400) for analysing biological substances in a test solution, comprising a test substrate (101; 203; 303; 401) which is transparent at least in part, having a test region (107a, 108a, 109a, 110a; 211; 411) for receiving the test solution, a plurality of electrodes (111, 106; 201, 202; 301, 302; 402, 403) which are arranged on the test substrate (101; 203; 303; 401) and extend into the test region (107a, 108a, 109a, 110a; 211; 411), wherein in each case, at least one portion of the electrodes (111, 106; 201, 202; 301, 302; 402, 403) is made of a transparent material.
          Charge sensors using inverted lateral bipolar junction transistors   
A sensor includes a collector, an emitter and a base-region barrier formed as an inverted bipolar junction transistor having a base substrate forming a base electrode to activate the inverted bipolar junction transistor. A level surface is formed by the collector, the emitter and the base-region barrier opposite the base substrate such that when the level surface is exposed to charge, the charge is measured during operation of the bipolar junction transistor.
          A System for Electrotactile Feedback Using Electronic Skin and Flexible Matrix Electrodes: Experimental Evaluation   
Myoelectric prostheses are successfully controlled using muscle electrical activity, thereby restoring lost motor functions. However, the somatosensory feedback from the prosthesis to the user is still missing. The sensory substitution methods described in the literature comprise mostly simple position and force sensors combined with discrete stimulation units. The present study describes a novel system for sophisticated electrotactile feedback integrating advanced distributed sensing (electronic skin) and stimulation (matrix electrodes). The system was tested in eight healthy subjects who were asked to recognize the shape, trajectory, and direction of a set of dynamic movement patterns (single lines, geometrical objects, letters) presented on the electronic skin. The experiments demonstrated that the system successfully translated the mechanical interaction into the moving electrotactile profiles, which the subjects could recognize with a good performance (shape recognition: $86\pm 8\%$ lines, $73\pm 13\%$ geometries, $72\pm 12\%$ letters). In particular, the subjects could identify the movement direction with a high confidence. These results are in accordance with previous studies investigating the recognition of moving stimuli in human subjects. This is an important development towards closed-loop prostheses providing comprehensive and sophisticated tactile feedback to the user, facilitating the control and the embodiment of the artificial device into the user body scheme.
          Task-Specific Somatosensory Feedback via Cortical Stimulation in Humans   
Cortical stimulation through electrocorticographic (ECoG) electrodes is a potential method for providing sensory feedback in future prosthetic and rehabilitative applications. Here, we evaluate human subjects’ ability to continuously modulate their motor behavior based on feedback from direct surface stimulation of the somatosensory cortex. Subjects wore a dataglove that measured their hand aperture position and received one of three stimuli over the hand sensory cortex based on their current hand position as compared to a target aperture position. Using cortical stimulation feedback, subjects adjusted their hand aperture to move towards the target aperture region. One subject was able to achieve accuracies and R2 values well above chance (best performance: R2 = 0.93; accuracy = 0.76/1). Performance dropped during the catch trial (same stimulus independent of the position) to below chance levels, suggesting that the subject had been using the varied sensory feedback to modulate their motor behavior. To our knowledge, this study represents one of the first demonstrations of using direct cortical surface stimulation of the human sensory cortex to perform a motor task, and is a first step towards developing closed-loop human sensorimotor brain-computer interfaces.
          A Multi-User Surface Visuo-Haptic Display Using Electrostatic Friction Modulation and Capacitive-Type Position Sensing   
This paper proposes a visuo-haptic feedback system that can provide haptic feedback to multiple users on an LCD monitor using electrostatic adhesion and built-in capacitive sensors. The prototype system consists of a 40-inch LCD monitor, an ITO electrode sheet arranged on the monitor, and multiple contact pads for electrostatic adhesion. By applying low-frequency haptic voltage and high-frequency sensing voltage to each pad, the system realizes passive haptic feedback, as well as position sensing using the same components. The passive haptic feedback force exceeds 1 N at 300 V$_\mathrm{rms}$ . The performance of the sensing system is investigated in terms of interference, which shows the haptic voltage and existence of multiple pads can affect the sensing and can shift the output by a few millimeters. A pilot application, virtual hockey game, successfully demonstrates the sensing and haptic rendering capability of the proposed system. The effect of the interference on the demonstration is discussed.
          Mixing and kneading machine for continual compounding and method of implementing continual compounding by means of a mixing and kneading machine   
A mixing and kneading machine (1) for continual compounding comprises a screw shaft (3) rotating in a casing (2) and simultaneously moving axially translationally. To sustainably enhance the efficiency of the machine as regards its material thruput per unit of time the screw shaft (3) comprises at least four groups of radial screw vanes (4a, 4b, 4c, 4d) evenly distributed circumferentially, each group consisting of a plurality of screw vanes in axial sequence. The outer diameter (Da) of the screw shaft ranges from 400 to 800 millimeters. The rotary speed of the screw shaft (3) ranges from 30 to 80 rpm. A mixing and kneading machine (1) engineered as such is particularly suitable for compounding an anodic mass in the production of electrodes—anodes—for the aluminum industry.
          Thousands Of Welding Equipment Offerings Now Available At ForeignTradeExchange.com   

International manufacturers, exporters and importers of welding equipment and supplies grows to thousands of companies on the ForeignTradeExchange.com Web site.

Westborough, MA -- (ReleaseWire) -- 07/25/2006 -- The global industrial import and export trade forum, ForeignTradeExchange.com, today announced its new welding equipment directory has swelled to over 3,000 offerings from companies selling a broad range of welding supplies, equipment and machines.

The directory, according to the company, is intended to help companies involved in all forms of welding source for more competitive priced equipment and supplies. Including, metal and plastic fabricators, engineers, welding contractors, foundries, ironworkers, machine shops, steel manufacturing plants, ship builders, auto body technicians, tank manufacturers, heavy construction firms and other industries.

Welding equipment and supplies available in the directory include, among others, welding helmets, hats, mask, gloves, vests, caps, jackets and blankets. Welding machines include mig, arc, electric, ultrasonic, spot, stick, pipe, seamless, plastic as well as automated welders, most of which are available in both new, used and rebuilt condition.

Welding accessories include welding electrodes, rods, wires, torches, tanks, underwater welding equipment, welding tables, carts, specialty tools, chemicals, grinding products, welding videos and training materials.

Applications include, carbon steel, stainless steel, aluminum, sheet metal, cast iron, silver, plastic, bronze, brass, copper and other metals and alloys.

A briefing of each offering can be viewed on the site with no registration requirement at,

http://www.ForeignTradeExchange.com/suppliers/welding_supplies.html

According to Mark Hamilton, business director of ForeignTradeExchange.com, the directory is used by companies all over the world to locate established manufacturers and distributors of welding products. "Price conscious companies know how to source the world when they need welding equipment and supplies. We all prefer to buy domestically, but sometimes foreign countries just offer a better deal without any decline in quality," says Hamilton.

He added, "Sometimes companies that utilize welding supplies have no choice but to cut costs if they want to remain competitive. Often that means sourcing the global marketplace using online resources like our welding equipment directory to locate suppliers in North America, United Kingdom, Australia, Asia and many European Union countries.

About ForeignTradeExchange.com

ForeignTradeExchange.com is an international Web based industrial supply trade directory and forum for buyers and sellers of industrial products, including manufacturers, exporters, importers, distributors, engineers and IT professionals.

Companies seeking to enter or expand into foreign markets are welcome to post and explore trade leads on the company's World Trade Forum at, http://www.ForeignTradeExchange.com/forum/

For more information on this press release visit: http://www.releasewire.com/press-releases/release-7276.htm

Media Relations Contact

Mark Hamilton
ForeignTradeExchange.com
Telephone: 206-333-0355
Email: Click to Email Mark Hamilton
Web: http://www.ForeignTradeExchange.com


          Fully integrated three-dimensional textile electrodes   
There is described herein a knitting technique for creating a garment having one or more 3D textile electrodes integrated therein. The knitting technique involves knitting the item with integrated electrodes and transmission channels in one single step. The electrode is knit using conducting thread while a base fabric is knit using non-conducting thread. The electrode is knit on a first needle bed and the base fabric is knit on a second needle bed opposite to and facing the first needle bed, the two needle beds being separated by a few millimeters. During the knitting process, the surface knit on the first needle bed and the surface knit on the second needle bed may be linked using an isolating thread network that is simply deposited, without forming a mesh, on the fabric, in order to provide the three-dimensional effect.
          Comment on On-board reformer turns exhaust fumes into fuel by James Stewart   
Once again the superlative properties of hydrogen as fuel are made clear. Hydrogen has the highest burning flame velocity of any fuel, thus allows a more complete burn of the injected hydrocarbon to begin with, and obtaining the necessary hydrogen from the exhaust is a win-win. There should also be the possibility of retro-fitting existing engines to hydrogen injection/re-injection (as part of the intake air stream). Using alternating current, and iron (not steel) electrodes, one can generate the needed hydrogen with very little oxygen by-product, since most of the oxygen is converted to iron oxides at the electrodes.
          Door handle device for vehicle   
A door handle device for a vehicle includes a door handle configured to be supported by a door panel, the door handle including a first handle case arranged to have a void relative to the door panel, a second handle case fixed to the first handle case at a side opposite from the door panel, and a lock command detection sensor including a lock detection signal processing circuit fixed to an inner side of the first handle case, a circuit connection portion electrically connected to the lock detection signal processing circuit, and a lock detection electrode assembled on the second handle case in a state to be arranged along an inner surface of the second handle case, the lock detection electrode being electrically connected to the circuit connection portion in a state where the second handle case is fixed to the first handle case.
          Bacteria-coated nanofiber electrodes clean pollutants in wastewater   
Researchers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.
          Lattice Energy LLC - Neutron production and nucleosynthesis in electric discharges - from lightning bolts to batteries - May 3 2016   

LENR transmutations can occur all around us. Neutrons can be created when Hydrogen atoms (protons) are present within many different types of electric discharges that can include among diverse other things: atmospheric lightning on earth and other planets, arcs between electrodes in air, water, hydrocarbons, as well as in nano-arcs (internal shorts) that can occur in electrochemical batteries.
          Galeri Kimpalan Arka & Gas   



PERALATAN KIMPALAN (Welding Equipments)


Peralatan keselamatan (Safety equipments)

Mesin tekanan tinggi (high pressure machine)

Mesin tekanan (Pressure machine)

Pemotong plasma (Plasma cutter)

Mesin pengilangan menegak (Vertical milling machine)

Mesin pelarik (Lathe machine)

Pemotong besi (Iron cutter)

Mesin hidraulik (Hydraulic jack)

Silinder gas (Gas cylinder)

Elektrod (Electrode)

Mesin gerudi dengan panduan laser (Drill bits with laser guided)

Mesin kimpalan arka (Arc welding machine)

Pemampat udara (Air compressor)


KERJA-KERJA KIMPALAN (Processes of welding)







          Peralatan Kimpalan (Welding Equipments)   
1. Mesin kimpal (welding machine)


Berfungsi sebagai pengubah untuk menyesuaikan volatan dan arus dalam kerja kimpalan.

2. Pemegang elektrod (Electrode holder)


Disalut dengan penebat dan digunakan untuk memegang rod elektrod secara menyepit.

3. Elektrod (Electrode)


Merupakan rod logam yang disalut dengan lapisan bahan lakur dan berfungsi untuk mengalirkan arus elektrik bagi membentuk arka.

4. Pengapit bumi (Grounding clamp)


Berfungsi untuk penyambungan logam asas dengan bekalan kuasa mesin kimpal bagi mengelakkan renjatan elektrik.

5. Tukul penyerpih (Chipping hammer)


Untuk menyerpih dan membersihkan kesan-kesan percikan logam serta jermang kumai yang terhasil pada permukaan bahan logam yang dikimpal.

6. Berus dawai (Steel brush)


Untuk membersihkan kesan-kesan percikan logam serta jermang kumai yang terhasil pada permukaan bahan logam yang dikimpal.



          Automobile mould door panel die   

Automobile mould > Door panel die Mold process: the trial map -- preparation - processing - mold processing -- core processing -- electrode processing -- the mold parts processing - check - assembly - fly mold - mold trial - Production Processing equipment: automatic coordinate measuring standard CNC machining center high precision CNC machining center five axis CNC machining center, EDM deep hole drill combined mill Beijing high-speed milling high-speed carved drilling wire cutting machine etc. Cooling system: optimize the design of circulating water, improve the survival efficiency, reduce your cost. Intermediate treatment: quenching and tempering, improve hardness. Post processing: nitriding treatment of low temperature, deformation is very small, no longer need to be quenched will have a high surface hardness and wear resistance. Mold life: P20 normal use of not less than 500 thousand times. Mode of transport: Izumo in the mold must be installed before clamping piece, packing firm, antirust, logistics and transport. Detail information of automobile lamp mould The main processing equipment: CNC milling, EDM, grinding, drilling, carving, line cutting Number of processing equipment: 38 Processing ability: excellent Process type: injection molding Mold parting surface number: two Cavity number: single cavity mold Mold installation method: semi fixed mold Scope of application: Automotive Quality system: ISO9001 Arrangement: vertical Company address: Guangdong province Dongguan city Sha Tau District Hexing Road No. 38, Copyright: Dongguan Wei a mold technology Co., Ltd. all, Wei an official website: www.moldv1.com, Email: caroline.moldv1@outlook.com, Business: +86 13570038696
          A Burned Child... and a Blessing.   
I am beyond words mortified by the events that have enfolded about this family in the last couple of days. These revolutions of a globe have been horrifying and tragic at best. To help wrap my own mind around the developments of what happened last Tuesday I seek to tell the story just one more time. A story that has been uttered with an increase in volume, and strength with each rendition of it. A story that with each slow playback becomes less surreal and more a clinical reverberation of the events.
The day was Tuesday, July 28th, 2009. It started out as all the others before it. Leaving for work early in the morning and with the same amount of harassing phone calls from bored children at home. Eager for school to start, they played with the same toys, the same games, the same pets that they had spent all summer with. My 15 year old had a friend come over. Mainly staying in his room they watched TV and listened to music.
After lunch the boys became restless, and the swamp cooler was doing little to keep the house cool in the 115 degree heat. They all were sweating and needed a cool down. Colton, my oldest and most responsible son, took his friend and his two younger brothers into the backyard to play in the sprinklers. Upon turning on the water they spayed themselves, the water was cool, but not cold. So he started spraying down the two younger boys with squeals of delight filling the backyard... the game was a foot. Colton being the bigger brother, grabbed his youngest brother and shoved the hose down the back of his shorts. Brotherly games of playful torture... no harm no foul.
Except, that is when tragedy struck. The light green hose, 150 feet in length, had been laying half under the protective shade of the tree in back, and half on the radiating sand of the Mojave Desert. The water was cool to the touch from the comfortable shade of the tree, but once it was in the back of Dustin's cotton shorts, it turned scalding hot from the portion that had been laying in the sand and sun. An innocent hose, a lazy summer day, a playful group of young boys, and tragic accident.
Dustin began to scream a blood curdling scream, one that Colton knew was wrot with terror, fear, and pain. He grabbed for the hose yanked it from his young brother's pants and rushed the 6 year old from his feet, whisking him into the house, down the hall, and into a cold shower. With the cool water raining down on him he seemed to be fine for the moment. Dustin was calm and quiet. Colton ran back outside to turn off the water so that the shower would have greater water pressure. He knew he was hurt, but not how bad. As he finished turning off the water spicot, the screams of terror and pain came flooding back to him from inside the house. He grabbed the phone and frantically called me at work... no answer. "Come on Mom! Pick Up, PLEASE Pick Up!!!" He in a frenzied panic dialed again.... MOM PLLLEEEAAASSSEEE! No answer. I was in a meeting. By this time the blister were starting to form and breaking in the cool water, and Dustin was really hurting bad. The terror and panic was getting thicker by the minute, Colton knew this could not wait until I could be reached. He ran across the street and got a good family friend and neighbor the boys affectionately call Grampy. He ran over, and soon had Dustin out of his shorts, keeping him in the shower for as long as he could stand it. He was freezing, shivering, within the cool water flowing down his little body. And Yet his flesh was burning still from within. Donnie (Grampy) Called me twice more, but this time left messages on my work phone, which Colton in his heightened state of dealing with the situation was unable to do.
10 min. later I got out of my meeting and got my messages. Grampy's voice was cold, and stern, more direct then I was use to. The words did not immediately register but the tone of voice did. Someone was hurt. I listened to that message and I got only two words... call immediately. My heart sank, and ever thankful for the missed call button on my phone I immediately redialed his cell. Grampy was curt and direct. The words were a jumble of my own heart beat ringing in my ears and muffled sounds coming from a phone. The whole office where I work seemed to get deafening silent, and the whole world began to slow down. My arms took so much more time to move, my feet were heavy and planted to the ground. In trying to run I found myself in a slow frame of a bionic man movie, waiting in the back of my mind for the music to begin. My thoughts became s rush of who to call, what to say, how to get approval to go. I chased down Rob and Ken, my bosses, who had moments before walked out the door to go to another meeting in another building on the NASA Dryden site. They granted me leave and asked me to check in to give a status update later on. I agreed, ran to grab my things, shut down my computer, and run as fast as I could, stuck in slow motion hell, to my car. Once inside I drove the speed limit for about 2 min. and then could clearly not care if they took my license away or not. I drove like a bat out of hell... easily reaching 100 miles an hour on the short stretch of freeway between the Edwards AFB exit and Clay Mine Road. It was amazing as if God himself had cleared me a path. Cars and Big Rigs ran side by side in front of me far from the exit, and again in my rear view mirror... but nothing and no one was around me. OK, so it was not the parting of the sea, but it was the right mini miracle that I needed for the moment.
Once on Clay Mine Road it was the gates wide shut, stuck behind an old man going 5 miles an hour in a beat up mini van... I glance to the on coming lane... no cars. I take the hop. This is not in my nature... I would rather wait and make my trip 45 min longer then ever pass another vehicle. It is unsafe, and it is scary. This moment, I did not care... one of my sons was hurt and they needed me. I did not know how bad, or if there was anything that I could do, but I needed to be there... and I needed to be there NOW! The drive while only moments long was hard and tedious. When I got there and saw him, I thought for a moment on what I should do. A million thoughts flooded through my mind. Do I take him to the ER? Do I call an ambulance? Do we have insurance? Does it freaking matter? What do I do, What do I do, What do I do. I grab the phone and pause looking at it unsure if I should or should not call. Silently arguing to myself. Until finally a voice from deep within me cuts though the voices. IT IS YOUR BABY JUST CALL!!! So I did...
911 what is your emergency? My son has been burned. Where is he now? He is on the bedroom floor. Is he coherent? I uh ummm. Is he answering you when you talk to him? Yes, Yes, he is fine, answering fine. Put him in the shower, cold water Mame. OK, I hand the phone to Colton... And I begin to mobilize the troops... My voice is calm and steady... My thoughts are clearer and more direct... Colton, I need you to play relay tell me what they say and tell them what I say. All the while scooping my son, Dusty Joe, scared, wet, and hurting into my arms. I carry him to the bathroom and place him back into the cold water of the tub, he just got free of. He begins to cry softly. I ask George to get me two cups, I begin pouring water over each butt cheek one at a time. It is blistering and the skin is falling away from his body. I keep repeating this process over and over and over again. Not daring to stop until help arrives. I tell George to go out front and wait for the ambulance to wave them in. I lean into him closely and as softly and calmly as I can I tell him he is going to be OK. I tell him that I love him, and that I remind him that I have never left him before and I am not about to start now. I ask him if he trusts me... He says yes. I ask him if he believes me... He says a little stronger...yes. Good, I tell him, this is my job, this is what I do... I take care of you. Just do as I say and it is going to work out... I promise. He seems comforted now, still cold and afraid...
Donnie comes in and asks if he can take over pouring cold water on his poor burned bum. I, grateful for the relief, say yes. I leave the room pacing waiting for help to arrive. I place blankets on the front room floor for when the paramedics arrive, a pillow too. Dustin will need to be comfortable while they stabilize him. Symptoms of shock are racing through my head... Cold clamy skin ( He is wet in a cold shower), what else? Hypotension (like I have a blood pressure cuff his size), next! ummmmm irregular breathing, rapid pulse... I run back into the crowded bathroom looking at the veins in his neck... and the rise and fall of his chest from the back... all the while changing a toilet paper roll that somehow got neglected to hide my true intentions for being there. A little elevated, but not much, in fact I think mine is more rapid then his. He is doing well... where are the paramedics? I make my way back to the front yard... no sign of them. I hear sirens off in the distance... they are coming... coming for Dustin... what a wonderful sound... sirens...a moment of time when seconds turn into minutes. And there is a feeling of peace. But before you can get comfortable or even take a breath you are snapped within an instant back into reality. What are some other signs? Weakness, confusion, anxiety, loss of consciousness. I mentally review Dustin's condition. OK, so far so good... A big truck rolls up... my first thought was, you aren't the ambulance... then it dawns on me. Duhhh it is the fire department, they get here first. Moments before the paramedics... within the flash of an eye they are off the truck and coming into my home... Do you want him out of the tub? So you can get to him easier? I ask in half relief and half pleading for help. Yes was all I heard before I was running back to the bathroom to swoop and scoop my son once more to the front room. By now more people were swarming about... So many different uniforms, partnered teams, stretchers... I had to get out of their way. Mom Mode kicks into high gear... Colton, George get back, get out of here so they can work. The boys move to the far wall just beyond the couch, but still within close view of their brother. Fear in both their eyes, my heart bleeding for both of them, but more intent on making sure Dustin was stable. Then out of the corner of my eye I see Tyler Irish. A young man from the church who just weeks before was sitting having a late dinner of homemade tacos and corn chips at our very own dinner table with his sister and my children. He was working on the Hall Ambulance rig today, and Dustin was his call. I hear Grampy talking to Dustin; Dusty, you know Tyler don't you? You remember Jessica's brother? Little man turns his head to look over his shoulder and recognized a face in a sea of would be rescue heroes. Yes, Hi Tyler. He says before resting his face back onto the pillow. Hey little guy, I am going to take good care of you OK? I am right here. Dustin's body relaxes and he knows he is going to be OK. In the blink of an eye, the stretcher comes in and so many hands are on it, it seems out of some movie scene. He is only 55 lbs. soaking wet, I could pick him up. Within the moment, too quick for my mind to registe the thought, he was on the stretcher, burn blankets were already in place, and discreet blankets draped his tiny frame as he was being belted in for the ride. Dustin was scared for just a second... his eyes wide with panic. Don't worry, I am not leaving you. I am coming with you. He is put into the rig, and I in the front seat. There is a little square window that allows the paramedic and the driver to communicate. Dustin is wildly looking about. I call out to him. I am right here son, I am right here... he searches for my voice and upon seeing me settles down and relaxes. Tyler the paramedic is busy placing electrodes, taking vitals, starting two IV's. He works silently, quietly, efficiently. A graceful dance of life saving ebbs and flows as the rig sways gently with the road. Dustin is at ease. He is calm. Tyler the driver trys to calm me down with small talk, and then the rig becomes silent. The road becomes long, and the stillness, the unknowing of how bad it is, and where will he be going, how long will he be gone, how far away will the hospital be from the rest of the boys, how am I ever going to make this happen? All these flooded thoughts drowning me. I don't know the answers. I say a little prayer... Dearest Heavenly Father, I don't know your reason for his trial, I just know that it is for his greater good, please let your will be done, take care of us. Amen. Tyler offers a tissue, as tears stream down my cheeks. I agree. He hollers for the medic to get me one.... no, no, no I grab for some left over napkins from one of their lunches... this is good. Tyler smiles. Good Enough.
I think to myself...yes, good enough. I begin in that moment to see the many blessings. How well he is doing, how calm he is. How well taken care of he is. I call the pair of Ambulance guys Tyler Squared. Young men, both doing an excellent job. I am amazed at the way his little boy is designed to tighten up to the pain of the burn and his vital areas are left unscathed by the searing heat of the water. How he takes no meds on the way there and only a single cc of morphine upon getting to the ER. This kid is a trooper. He talks to the nurses and tells him his pain level is a 6 on a scale of one to ten. A 6! I know some women who would complain that their own menstrual cycles are a 6, and his entire butt cheeks are bubbled and blistered and nearly gone. Is he serious? Yes, a 6. They give him the morphine shot.
Colton had offered before I left to go with Dustin to the hospital. I told him, I had to be the one to go now to do the insurance paperwork , but if he is admitted he will be staying with Dustin if he liked it or not. This thought comes to me... our family is blessed. Richly and deeply blessed. My immediate family is not close. And I have often wondered how I could teach my own children about having each others backs, and the meaning of family when mine is such a loose interpretation of that word. And yet, today, going trough the trials and tribulations set before us this day. Amongst the painful dressing changes, and the truly bleak financial situation this places us within... we are blessed. Blessed beyond measure, because we are wealthier then most. We are a family by every definition of the word. In times of strife and tragedy we can and will mobilize all of our talents and abilities to rise to the challenge, meet any hardship, and overcome any obstacle. This road is not an easy one, but the right roads never are... so I take solice in knowing we are on the right path... going in the right direction, and this team I call family is only growing tighter and stronger with each day.

          Scientists: Prenatal Exercise May Boost Baby’s Brain   
generic, pregnancyResearchers in Canada have discovered that expectant moms can give their babies a boost in life just by keeping fit while pregnant – and all it takes is a half hour a day. According to researchers at the University of Montreal, low-impact work-outs, like swimming and walking actually help a newborn's brain develop faster. For most pregnant women, 20 to 30 minutes of moderate exercise is recommended on most, if not all, days of the week. Scientists placed electrode caps on babies who were 8- to 12-days old and measured activity as their brains' responded to different sounds.
          Liquid crystal display device   
A liquid crystal display device comprising a backlight and a pixel portion including first to 2n-th scan lines, wherein, in a first case of expressing a color image, first pixels controlled by the first to n-th scan lines are configured to express a first image using at least one of first to third hues supplied in a first rotating order, and second pixels controlled by the (n+1)-th to 2n-th scan lines are configured to express a second image using at least one of the first to third hues supplied in a second rotating order, wherein, in a second case of expressing a monochrome image, the first and second pixels controlled by the first to 2n-th scan lines are configured to express the monochrome image by external light reflected by the reflective pixel electrode, and wherein the first rotating order is different from the second rotating order.
          Tuning display devices   
A technique comprising: determining a correction to a drive voltage for the front plane common electrode of a first display device according to the result of one or more measurements of an optical property for the first display device and the result of one or more measurements of said optical property for one or more other devices including an optical medium having the same optical response as the first display device.
          Shift register, semiconductor device, display device, and electronic device   
The invention provides a semiconductor device and a shift register, in which low noise is caused in a non-selection period and a transistor is not always on. First to fourth transistors are provided. One of a source and a drain of the first transistor is connected to a first wire, the other of the source and the drain thereof is connected to a gate electrode of the second transistor, and a gate electrode thereof is connected to a fifth wire. One of a source and a drain of the second transistor is connected to a third wire and the other of the source and the drain thereof is connected to a sixth wire. One of a source and a drain of the third transistor is connected to a second wire, the other of the source and the drain thereof is connected to the gate electrode of the second transistor, and a gate electrode thereof is connected to a fourth wire. One of a source and a drain of the fourth transistor is connected to the second wire, the other of the source and the drain thereof is connected to the sixth wire, and a gate electrode thereof is connected to the fourth wire.
          Method for driving display device   
An object is to provide a convenient display device which consumes sufficiently small amount of power and a method for driving such a display device. The display device can be in an off state with a still image displayed in a still image display mode in which a pixel electrode and a common electrode which are for applying a voltage to the display element are brought into a floating state so that a voltage applied to the display element is held, and a still image is displayed without further supply of a potential. The display device is put to an off state with a desired image displayed in the still image display mode, whereby the display device can have a higher level of security and can be more convenient.
          Light-emitting device and driving method thereof   
Charge corresponding to a potential difference between electrodes of an electroluminescence element is accumulated in a period in which the electroluminescence element emits light; the potential difference is detected without decrease in the luminance at the time of light emission of the electroluminescence element; and a reference potential of one electrode of the electroluminescence element is changed based on the detected potential difference, so that reduction in luminance of the electroluminescence element due to deterioration of the electroluminescence element is compensated.
          Display device   
A display device of which frame can be narrowed and of which display characteristics are excellent is provided. In a display device including a switch portion or a buffer portion, a logic circuit portion, and a pixel portion, the pixel portion includes a first inverted staggered TFT and a pixel electrode which is connected to a wiring of the first inverted staggered TFT, the switch portion or the buffer portion includes a second inverted staggered TFT in which a first insulating layer, a semiconductor layer, and a second insulating layer are interposed between a first gate electrode and a second gate electrode, the logic circuit portion includes an inverter circuit including a third inverted staggered thin film transistor and a fourth inverted staggered thin film transistor, and the first to the fourth inverted staggered thin film transistors have the same polarity. The inverter circuit may be an EDMOS circuit.
          Display apparatus including a shutter   
A display apparatus includes a first substrate, a second substrate facing the first substrate, and a plurality of pixels including a first pixel. The first substrate includes first openings through which a light is transmitted. The pixels are disposed on at least one of the first substrate and the second substrate. The first pixel includes a first flexible electrode, a second flexible electrode, and a shutter including second openings and disposed between the first and second flexible electrodes. The first flexible electrode receives a first voltage. The second flexible electrode receives a second voltage different from the first voltage. The shutter receives a third voltage. The shutter moves to the first flexible electrode or the second flexible electrode according to a level of the third voltage, thereby controlling the position of the second openings relative to the first openings to control the transmission of the light.
          Medical Assembler   
A majority of the work will be done in a clean room, using microscopes, UV bonding tools, hand assemblies and some laser welding under a microscope Some of the main competencies include: Catheter Reflow, electrode attachment, Wire stringing (into a catheter shaft or lead shafts), steerable handle assembly Candidates will most ...
          (USA-WA-Seattle) Sleep Technologist - Registered   
Job Number: 171370 Department: Sleep Disorders Center Hours: 7:00pm - 7:30am/variable Located in Seattle, WA, Virginia Mason is an internationally recognized leader in the continuous improvement of health care. With an extensive list of awards and distinctions that includes our recognition as Top Hospital of the Decade by The Leapfrog Group, Virginia Mason offers you the opportunity to partner with exceptionally talented peers at every level. You will contribute to the strength of our Team Medicine approach to collaborative medicine and benefit from the changes enacted through our Virginia Mason Production System, a model that has transformed health care by providing patients with easier access to care, reducing errors, and continuously innovating patient safety and quality that has been adopted by other organizations here and abroad. Join us, and find out how many ways Virginia Mason offers you the chance to focus on what really matters - our patients. The PSG Tech (Registered) III reviews, qualifies, quantifies, and verifies all physiologic data collected on all polysomnograms in accordance with the guidelines established by the American Sleep Disorders Association. Additionally, this position generates statistical reports which are utilized by the Sleep Disorders Center physicians for appropriate diagnosis and treatment of patients. + This position requires RPSGT or eligibility, with 3 years of experience in an accredited sleep disorder center. + Working knowledge of respiratory physiology, neurological physiology and comprehensive knowledge of various medical monitors, sensors/electrodes, transducers, and artifacts that they can produce. + The ability to perform accurate analysis of all polysomnograms. + Working knowledge and recognition of sleep architecture, respiratory events, periodic limb movements of sleep, parasomnias, seizures, cardiac dysrhythmias, and hypoxemia. + The ability to implement and document continuous quality improvement. + The ability to recognize artifacts in raw data regardless of the source of origin. + Advanced decision making skills regarding medical recommendations and outcomes. + Excellent communication skills; and the ability to work independently. Virginia Mason offers much more than competitive compensation and benefits. With continuing education opportunities and the added potential of relocation assistance, you will find our commitment to your well-being is both rewarding and refreshing. We are an equal opportunity/affirmative action employer. Virginia Mason Medical Center is an equal opportunity, affirmative action employer. Virginia Mason provides healthcare without regard to race, color, religion (creed), sex, gender identity or expression, sexual orientation, national origin (ancestry) or disability. Disability Accommodation: To request disability accommodation in the application process, contact the Recruiting Offices at 866-422-2275 (voice) or 206-515-5891 (fax). Virginia Mason makes every effort to honor disability accommodation requests. Requests can be responded to most effectively if received as far in advance as possible.
           Growth and ferroelectric properties of Bi2VO5.5 thin films with metallic LaNiO3 electrodes    
Prasad, KVR and Raju, AR and Varma, KBR and Satyalakshmi, KM and Mallya, RM and Hegde, MS (1993) Growth and ferroelectric properties of Bi2VO5.5 thin films with metallic LaNiO3 electrodes. In: Applied Physics Letters, 63 (14). 1898 -1900.
           Growth and ferroelectric properties of $Bi_2VO_{5.5}$ thin films with metallic $LaNiO_3$ electrodes    
Prasad, KVR and Varma, KBR and Raju, AR and Satyalakshmi, KM and Mallya, RM and Hegde, MS (1993) Growth and ferroelectric properties of $Bi_2VO_{5.5}$ thin films with metallic $LaNiO_3$ electrodes. In: Applied Physics Letters, 63 (14). pp. 1898-1900.
          EMG sensor device proto typing - Bio medical engineer needed - Upwork   
Looking for a Bio medical engineer who experience in making emg sensor system, prefer experience in conductive rubber dry electrodes sensor. He/she just need to make a emg sensor system that able to communicate with smart phone through ble4.0, coder and designer are all in place already.

Posted On: June 29, 2017 03:21 UTC
ID: 210609552
Category: Engineering & Architecture > Electrical Engineering
Skills: Electrical Engineering
Country: Hong Kong
click to apply
          Defibrillation Disposable Medical Electrodes Market: Preference To Disposable Electrodes Attributed To Their User Friendly Nature And Low Manufacturing Costs   
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          模具词汇英语翻译   

模具词汇英语翻译(汇总)特全

landed plunger mold 有肩柱塞式模具
burnishing die 挤光模
landed positive mold 有肩全压式模具
button die 镶入式圆形凹模
loading shoe mold 料套式模具
center-gated mold 中心浇口式模具
loose detail mold 活零件模具
chill mold 冷硬用铸模
loose mold 活动式模具
clod hobbing 冷挤压制模
louvering die 百叶窗冲切模
composite dies 复合模具
manifold die 分歧管模具
counter punch 反凸模
modular mold 组合式模具
double stack mold 双层模具
multi-cavity mold 多模穴模具
electroformed mold 电铸成形模
multi-gate mold 复式浇口模具
expander die 扩径模
offswt bending die 双折冷弯模具
extrusion die 挤出模
palletizing die 叠层模
family mold 反套制品模具
plaster mold 石膏模
blank through dies 漏件式落料模
porous mold 通气性模具
duplicated cavity plate 复板模
positive mold 全压式模具
fantail die 扇尾形模具
pressure die 压紧模
fishtail die 鱼尾形模具
profile die 轮廓模
flash mold 溢料式模具
progressive die 顺序模
gypsum mold 石膏铸模
protable mold 手提式模具
hot-runner mold 热流道模具
prototype mold 雏形试验模具
ingot mold 钢锭模
punching die 落料模
lancing die 切口模
raising(embossing) 压花起伏成形
re-entrant mold 倒角式模具
sectional die 拼合模
runless injection mold 无流道冷料模具
sectional die 对合模具
segment mold 组合模
semi-positive mold 半全压式模具
shaper 定型模套
single cavity mold 单腔模具
solid forging die 整体锻模
split forging die 拼合锻模
split mold 双并式模具
sprueless mold 无注道残料模具
squeezing die 挤压模
stretch form die 拉伸成形模
sweeping mold 平刮铸模
swing die 振动模具
three plates mold 三片式模具
trimming die 切边模
unit mold 单元式模具
universal mold 通用模具
unscrewing mold 退扣式模具
yoke type die 轭型模

模具词汇英语翻译(模具常用成形方式)

accurate die casting 精密压铸

powder forming 粉末成形

calendaring molding 压延成形

powder metal forging 粉末锻造

cold chamber die casting 冷式压铸

precision forging 精密锻造

cold forging 冷锻

press forging 冲锻

compacting molding 粉末压出成形

rocking die forging 摇动锻造

compound molding 复合成形

rotary forging 回转锻造

compression molding 压缩成形

rotational molding 离心成形

dip mold 浸渍成形

rubber molding 橡胶成形

encapsulation molding 注入成形

sand mold casting 砂模铸造

extrusion molding 挤出成形

shell casting 壳模铸造

foam forming 泡沫成形

sinter forging 烧结锻造

forging roll 轧锻

six sides forging 六面锻造

gravity casting 重力铸造

slush molding 凝塑成形

hollow(blow) molding 中空(吹出)成形

squeeze casting 高压铸造

hot chamber die casting 热室压铸

swaging 挤锻

hot forging 热锻

transfer molding 转送成形

injection molding 射出成形

warm forging 温锻

investment casting 精密铸造

matched die method 对模成形法

laminating method 被覆淋膜成形

low pressure casting 低压铸造

lost wax casting 脱蜡铸造

matched mould thermal forming 对模热成形模

模具词汇英语翻译(成形不良用语)

aberration 色差

bite 咬入

blacking hole 涂料孔(铸疵)

blacking scab 涂料疤

blister 起泡

blooming 起霜

blow hole 破孔

blushing 泛白

body wrinkle 侧壁皱纹

breaking-in 冒口带肉

bubble 膜泡

burn mark 糊斑

burr 毛边

camber 翘曲

cell 气泡

center buckle 表面中部波皱

check 细裂痕

checking 龟裂

chipping 修整表面缺陷

clamp-off 铸件凹痕

collapse 塌陷

color mottle 色斑

corrosion 腐蚀

crack 裂痕

crazing 碎裂

crazing 龟裂

deformation 变形

edge 切边碎片

edge crack 裂边

fading 退色

filler speak 填充料斑

fissure 裂纹

flange wrinkle 凸缘起皱

flaw 刮伤

flow mark 流痕

galling 毛边

glazing 光滑

gloss 光泽

grease pits 污斑

grinding defect 磨痕

haircrack 发裂

haze 雾度

incrustation 水锈

indentation 压痕

internal porosity 内部气孔

mismatch 偏模

mottle 斑点

necking 缩颈

nick 割痕

range peel 橘皮状表面缺陷

overflow 溢流

peeling 剥离

pit 坑

pitting corrosion 点状腐蚀

plate mark 模板印痕

pock 麻点

pock mark 痘斑

resin streak 树脂流纹

resin wear 树脂脱落

riding 凹陷

sagging 松垂

saponification 皂化

scar 疤痕

scrap 废料

scrap jam 废料阻塞

scratch 刮伤/划痕

scuffing 深冲表面划伤

seam 裂痕

shock line 模口挤痕

short shot 充填不足

shrinkage pool 凹孔

sink mark 凹痕

skin inclusion 表皮摺叠

straightening 矫直

streak 条状痕

surface check 表面裂痕

surface roughening 橘皮状表皮皱摺

surging 波动

torsion 扭曲

warpage 翘曲

waviness 波痕

webbing 熔塌

weld mark 焊痕

whitening 白化

wrinkle 皱纹

模具词汇英语翻译(塑胶原料)

acrylic 压克力

casein 酪素

cellulose acetate 醋酸纤维素CA

cellulose acetate butyrate 醋酸丁酸纤维素CAB

composite material 复合材料

cresol resin 甲酚树脂CF

dially phthalate 苯二甲酸二烯丙酯

disperse reinforcement 分散性强化复合材料

engineering plastics 工程塑胶

epoxy resin 环氧树脂EP

ethyl cellulose 乙基纤维素

ethylene vinylacetate copolymer 乙烯-醋酸乙烯EVA

ethylene-vinlacetate copolyme 醋酸乙烯共聚物EVA

fiber reinforcement 纤维强化热固性/纤维强化复合材料

high density polyethylene 高密度聚乙烯HDPE

high impact polystyrene 高冲击聚苯乙烯HIPS

high impact polystyrene rigidity 高冲击性聚苯乙烯

low density polyethylene 低密度聚乙烯LDPE

melamine resin 三聚氰胺酚醛树脂MF

nitrocellulose 硝酸纤维素

phenolic resin 酚醛树脂

plastic 塑胶

polyacrylic acid 聚丙烯酸PAP

polyamide 耐龙PA

polybutyleneterephthalate 聚对苯二甲酸丁酯PBT

polycarbonate 聚碳酸酯PC

polyethyleneglycol 聚乙二醇PFG

polyethyleneoxide 聚氧化乙烯PEO

polyethyleneterephthalate 聚乙醇对苯PETP

polymetylmethacrylate 聚甲基丙烯酸甲酯PMMA

polyoxymethylene 聚缩醛POM

polyphenylene oxide 聚硫化亚苯

polyphenyleneoxide 聚苯醚PPO

polypropylene 聚丙烯PP

polystyrene 聚苯乙烯PS

polytetrafluoroethylene 聚四氟乙烯PTFE

polytetrafluoroethylene 聚四氟乙烯

polythene 聚乙烯PE

polyurethane 聚氨基甲酸酯PU

polyvinylacetate 聚醋酸乙烯PVAC

polyvinylalcohol 聚乙烯醇PVA

polyvinylbutyral 聚乙烯醇缩丁醛PVB

polyvinylchloride 聚氯乙烯PVC

polyvinylfuoride 聚氟乙烯PVF

polyvinylidenechloride 聚偏二氯乙烯PVDC

prepolymer 预聚物

silicone resin 矽树脂

thermoplastic 热塑性

thermosetting 热固性

thermosetting plastic 塑胶

unsaturated polyester 不饱和聚酯树脂

模具词汇英语翻译(射出成形)

activator 活化剂

bag moulding 气胎施压成形

bonding strength 黏合强度

breathing 排气

caulking compound 填隙料

cell 气孔

cold slug 半凝式射出

colorant 著色剂

color matching 调色

color masterbatch 色母料

compound 混合料

copolymer 共聚合体

cull 残料废品

cure 凝固化

cryptometer 不透明度仪

daylight 开隙

dry cycle time 空料试车周期时间

ductility 延性

elastomer 弹性体

extruded bead sealing 压出粒涂层法

feed 供料

filler 充填剂

film blowing 薄膜吹制法

floating platen 活动模板

foaming agent 发泡剂

gloss 光泽

granule 颗粒料

gunk 料斗

hot mark 热斑

hot stamping 烫印

injection nozzle 射出喷嘴

injection plunger 射出柱塞

injection ram 射出冲柱

isomer 同分异构物

kneader 混合机

leveling agent 匀涂剂

lubricant 润滑剂

matched die method 配合成形法

mould clamping force 锁模力

mould release agent 脱模剂

nozzle 喷嘴

oriented film 取向薄膜

parison 吹气成形坏料

pellet 粒料

plasticizer 可塑剂

plunger 压料柱塞

porosity 孔隙率

post cure 後固化

premix 预混料

purging 清除

reciprocating screw 往复螺杆

resilience 回弹性

resin injection 树脂射出法

rheology 流变学

sheet 塑胶片

shot 注射

shot cycle 射出循环

slip agent 光滑剂

take out device 取料装置

tie bar 拉杆

toggle type mould clamping system 肘杆式锁模装置

torpedo spreader 鱼雷形分流板

transparency 透明性

void content 空洞率

模具词汇英语翻译(表面处理)

age hardening 时效硬化

ageing 老化处理

air hardening 气体硬化

air patenting 空气韧化

annealing 退火

anode effect 阳极效应

anodizing 阳极氧化处理

atomloy treatment 阿托木洛伊表面

austempering 奥氏体等温淬火

austenite 奥斯田体/奥氏体

bainite 贝氏体

banded structure 条纹状组织

barrel plating 滚镀

barrel tumbling 滚筒打光

blackening 染黑法

blue shortness 青熟脆性

bonderizing 磷酸盐皮膜处理

box annealing 箱型退火

box carburizing 封箱渗碳

bright electroplating 辉面电镀

bright heat treatment 光辉热处理

bypass heat treatment 旁路热处理

carbide 炭化物

carburized case depth 浸碳硬化深层

carburizing 渗碳

cementite 炭化铁

chemical plating 化学电镀

chemical vapor deposition 化学蒸镀

coarsening 结晶粒粗大化

coating 涂布被覆

cold shortness 低温脆性

comemtite 渗碳体

controlled atmosphere 大气热处理

corner effect 锐角效应

creeping discharge 蠕缓放电

decarburization 脱碳处理

decarburizing 脱碳退火

depth of hardening 硬化深层

diffusion 扩散

diffusion annealing 扩散退火

electrolytic hardening 电解淬火

embossing 压花

etching 表面蚀刻

ferrite 肥粒铁

first stage annealing 第一段退火

flame hardening 火焰硬化

flame treatment 火焰处理

full annealing 完全退火

gaseous cyaniding 气体氧化法

globular cementite 球状炭化铁

grain size 结晶粒度

granolite treatment 磷酸溶液热处理

graphitizing 石墨退火

hardenability 硬化性

hardenability curve 硬化性曲线

hardening 硬化

heat treatment 热处理

hot bath quenching 热浴淬火

hot dipping 热浸镀

induction hardening 高周波硬化

ion carbonitriding 离子渗碳氮化

ion carburizing 离子渗碳处理

ion plating 离子电镀

isothermal annealing 等温退火

liquid honing 液体喷砂法

low temperature annealing 低温退火

malleablizing 可锻化退火

martempering 麻回火处理

martensite 马氏体/硬化铁炭

metallikon 金属喷镀法

metallizing 真空涂膜

nitriding 氮化处理

nitrocarburizing 软氮化

normalizing 正常化

oil quenching 油淬化

overageing 过老化

overheating 过热

pearlite 针尖组织

phosphating 磷酸盐皮膜处理

physical vapor deposition 物理蒸镀

plasma nitriding 离子氮化

pre-annealing 预备退火

precipitation 析出

precipitation hardening 析出硬化

press quenching 加压硬化

process annealing 制程退火

quench ageing 淬火老化

quench hardening 淬火

quenching crack 淬火裂痕

quenching distortion 淬火变形

quenching stress 淬火应力

reconditioning 再调质

recrystallization 再结晶

red shortness 红热脆性

residual stress 残留应力

retained austenite 残留奥

rust prevention 防蚀

salt bath quenching 盐浴淬火

sand blast 喷砂处理

seasoning 时效处理

second stage annealing 第二段退火

secular distortion 经年变形

segregation 偏析

selective hardening 部分淬火

shot blast 喷丸处理

shot peening 珠击法

single stage nitriding 等温渗氮

sintering 烧结处理

soaking 均热处理

softening 软化退火

solution treatment 固溶化热处理

spheroidizing 球状化退火

stabilizing treatment 安定化处理

straightening annealing 矫直退火

strain ageing 应变老化

stress relieving annealing 应力消除退火

subzero treatment 生冷处理

supercooling 过冷

surface hardening 表面硬化处理

temper brittleness 回火脆性

temper colour 回火颜色

tempering 回火

tempering crack 回火裂痕

texture 咬花

thermal refining 调质处理

thermoechanical treatment 加工热处理

time quenching 时间淬火

transformation 变态

tufftride process 软氮化处理

under annealing 不完全退火

vacuum carbonitriding 真空渗碳氮化

vacuum carburizing 真空渗碳处理

vacuum hardening 真空淬火

vacuum heat treatment 真空热处理

vacuum nitriding 真空氮化

water quenching 水淬火

wetout 浸润处理

模具词汇英语翻译(模具常用刀具工作法)

adjustable spanner 活动扳手

angle cutter 角铣刀

arbour 心轴

backing 衬垫

belt sander 带式打磨机

buffing 抛光

chamfering machine 倒角机

chamfering tool 去角刀具

chisel 扁錾

chuck 夹具

compass 两角规

concave cutter 凹面铣刀

convex cutter 凸形铣刀

cross joint 十字接头

cutting edge clearance 刃口余隙角

drill stand 钻台

edge file 刃用锉刀

file 锉刀

flange joint 凸缘接头

grinder 砂轮机

hammer 铁锤

hand brace 手摇钻

hatching 剖面线

hexagon headed bolt 六角头螺栓

hexagon nut 六角螺帽

index head 分度头

jack 千斤顶

jig 治具

kit 工具箱

lapping 研磨

metal saw 金工锯

nose angle 刀角

pinchers 钳子

pliers 铗钳 plug 柱塞头

polisher 磨光器

protable driller 手提钻孔机

punch 冲头

sand paper 砂纸

scraper 刮刀

screw driver 螺丝起子

scribing 划线

second out file 中纹锉

spanner 扳手

spline broach 方栓槽拉刀

square 直角尺

square sleeker 方形镘刀

square trowel 直角度

stripping 剥离工具

T-slot T形槽

tool for lathe 车刀

tool point angle 刀刃角

tool post 刀架

tosecan 划线盘

trimming 去毛边

waffle die flattening 压纹效平

wiper 脱模钳

wrench 螺旋扳手

模具词汇英语翻译(冲模加工)

barreling 滚光加工

belling 压凸加工

bending 弯曲加工

blanking 下料加工

bulging 撑压加工

burring 冲缘加工

cam die bending 凸轮弯曲加工

coining 压印加工

compressing 压缩加工

compression bending 押弯曲加工

crowning 凸面加工

curl bending 卷边弯曲加工

curling 卷曲加工

cutting 切削加工

dinking 切断蕊骨

double shearing 叠板裁断

drawing 引伸加工

drawing with ironing 抽引光滑加工

embossing 浮花压制加工

extrusion 挤制加工

filing 锉削加工

fine blanking 精密下料加工

finish blanking 光制下料加工

finishing 精整加工

flanging 凸缘加工

folding 折边弯曲加工

folding 摺叠加工

forming 成形加工

impact extrusion 冲击挤压加工

indenting 压痕加工

ironing 引缩加工

knurling 滚花

lock seaming 固定接合

louvering 百叶窗板加工

marking 刻印加工

necking 颈缩加工

notching 冲口加工

parting 分断加工

piercing 冲孔加工

progressive bending 连续弯曲加工

progressive blanking 连续下料加工

progressive drawing 连续引伸加工

progressive forming 连续成形加工

reaming 铰孔加工

restriking 二次精冲加工

riveting 铆接加工

roll bending 滚筒弯曲加工

roll finishing 滚压加工

rolling 压延加工

roughing 粗加工

scrapless machining 无废料加工

seaming 折弯重叠加工

shaving 缺口修整加工

shearing 切断加工

sizing 精压加工/矫正加工

slitting 割缝加工

spinning 卷边?接

stamping 锻压加工

swaging 挤锻压加工

trimming 整缘加工

upsetting 锻粗加工

wiring 抽线加工

模具词汇英语翻译(冲压机械及周边)

back shaft 支撑轴

blank determination 胚料展开

bottom slide press 下传动式压力机

board drop hammer 板落锤

brake 煞车 buckle 剥砂面

camlachie cramp 铸包

chamotte sand 烧磨砂

charging hopper 加料漏斗

clearance 间隙

closed-die forging 合模锻造

clump 夹紧

clutch 离合器

clutch brake 离合器制动器

clutch boss 离合器轮壳

clutch lining 离合器覆盖

coil car 带卷升降运输机

coil cradle 卷材进料装置

coil reel stand 钢材卷料架

column 圆柱

connection screw 连杆调节螺钉

core compound 砂心黏结剂

counter blow hammer 对击锻锤

cradle 送料架

crank 曲柄轴

crankless 无曲柄式

cross crank 横向曲轴

cushion 缓冲

depression 外缩凹孔

dial feed 分度送料

die approach 模口角度

die assembly 合模

die cushion 模具缓冲垫

die height 冲压闭合高度

die life 模具寿命

die opening 母模逃孔

die spotting press 调整冲模用压力机

double crank press 双曲柄轴冲床

draght angle 逃料倾斜角

edging 边锻伸

embedded core 加装砂心

feed length 送料长度

feed level 送料高度

filling core 埋入砂心

filling in 填砂

film play 液面花纹

fine blanking press 精密下料冲床

forging roll 辊锻机

finishing slag 炼後熔渣

fly wheel 飞轮

fly wheel brake 飞轮制动器

foot press 脚踏冲床

formboard 进模口板

frame 床身机架

friction 摩擦

friction brake 摩擦煞车

gap shear 凹口剪床

gear 齿轮

gib 滑块引导部

gripper 夹具

gripper feed 夹持进料

gripper feeder 夹紧传送装置

hammer 槌机

hand press 手动冲床

hand rack pinion press 手动齿轮齿条式冲床

hand screw press 手动螺旋式冲床

hopper feed 料斗送料

idle stage 空站

inching 微调尺寸

isothermal forging 恒温锻造

key clutch 键槽离合器

knockout 脱模装置

knuckle mechanic 转向机构

land 模具直线刀面部

loader 供料器 unloader 卸料机

loop controller 闭回路控制器

lower die 下模

micro inching device 微寸动装置

microinching equipment 微动装置

moving bolster 活动工作台

notching press 冲缺口压力机

opening 排料逃孔

overload protection device 防超载装置

pinch roll 导正滚轮

pinion 小齿轮

pitch 节距

pressfit 压入

progressive 连续送料

pusher feed 推杆式送料

pusher feeder 料片押片装置

quick die change system 快速换模系统

regrinding 再次研磨

releasing 松释动作

reversed blanking 反转下料

robot 机器人

roll forming machine 辊轧成形

roll forming machine 辊轧成形机

roll release 脱辊

roller feed 辊式送料

roller leveler 辊式矫直机

rotary bender 卷弯成形机

safety guard 安全保护装置

scrap cutter 废料切刀

scrap press 废料冲床

seamless forging 无缝锻造

shave 崩砂

shear angle 剪角

sheet loader 薄板装料机

shot 单行程工作

shrinkage fit 收缩配合

shut height 闭合高度

sieve mesh 筛孔

sintering of sand 铸砂烧贴

slide balancer 滑动平衡器

slug hole 逃料孔

spin forming machine 旋压成形机

spotting 合模

stack feeder 堆叠拨送料机

stickness 黏模性

straight side frame 冲床侧板

stretcher leveler 拉伸矫直机

strip feeder 料材送料装置

stripping pressure 弹出压力

stroke 冲程

take out device 取料装置

toggle press 肘杆式压力机

transfer feed 连续自动送料装置

turrent punch press 转塔冲床

two speed clutch 双速离合器

uncoiler 闭卷送料机

unloader 卸载机

vibration feeder 振动送料机

wiring press 嵌线卷边机

模具词汇英语翻译(线切割放电加工关连用语)

abnormal glow 不规则辉光放电

arc discharge 电弧放电
belt 皮带
centreless 无心
chrome bronze 铭铜
clearance angle 後角
corner shear drop 直角压陷
deflection 桡曲度
discharge energy 放电能量
dressing 修整
dwell 保压
flange 凸缘
gap 间隙
graphite 石墨
graphite contraction allowance 电极缩小余量
graphite holder 电极夹座
hair crack 发裂
horn 电极臂
jump 跳刀
magnetic base 磁性座
master graphite 标准电极
pipe graphite 管状电极
pulse 脉冲
rib working 肋部加工
roller electrode 滚轮式电极
rotary surface 旋转面
shank 柄部
sharp edge 锐角部
tough bronze 韧铜
traverse 摇臂
tungsten bronze 钨青铜
waviness 波形起伏
working allowance 加工余量
working dischard 加工废料

模具相关词汇英语翻译(锻铸造关连用语)
accretion 炉瘤
acid converter 酸性转炉
acid lining cupola 酸性熔铁炉
acid open-hearth furnace 酸性平炉
aerator 松砂机
air set mold 常温自硬铸模
airless blasting cleaning 离心喷光
all core molding 集合式铸模
all round die holder 通用模座
assembly mark 铸造合模记号
back pouring 补浇注
backing sand 背砂
base bullion 粗金属锭
base permeability 原砂透气度
belling 压凸
billet 坏料
bleed 漏铸
blocker 预锻模膛
blocking 粗胚锻件
blow hole 铸件气孔
board drop hammer 板落锤
bottom pour mold 底浇
bottom pouring 底注
boxless mold 脱箱砂模
break-off core 缩颈砂心
brick molding 砌箱造模法
buckle 剥砂面
camber 错箱
camlachie cramp 铸包
cast blade 铸造叶片
casting flange 铸造凸缘
casting on flat 水平铸造
chamotte sand 烧磨砂
charging hopper 加料漏斗
cleaning of casting 铸件清理
closed-die forging 合模锻造
core compound 砂心黏结剂
core template 砂心模板
core vent 砂蕊排气孔
corner gate 压边浇口
counter blow hammer 对击锻造
counter lock 止口镶嵌方式
depression 外缩凹孔
die approach 模口角度
draw out 锻造拔长
draw plate 起模板
draw spike 起模长针
dummying 预锻
embedded core 加装砂心
erosion 冲砂
fettling 铸件清理
filling core 埋入砂心
filling in 填砂
film play 液面花纹
finishing slag 炼後熔渣
flash gutter 锻模飞边槽
flask molding 砂箱造模
forging roll 辊锻机
formboard 进模口板
gutter 锻模飞边槽
hammer man 锻工
heading machine 顶镦机
impacter 卧式锻造机
inblock cast 整体铸造
ingot 铸锭
ingot blank 铸坯
inlay casting 镶铸法
investment casting 失模铸造
isothermal forging 恒温锻造
loose piece 木模活块
molding pit 铸模地坑
pouring process 浇注法
recasting 重铸
roll forging 轧锻
rolled surface 轧制表面
rough sand 粗砂
roughing forge 粗锻
sand crushing 塌箱
seamless forging 无缝锻造
separate 分离
shave 崩砂
shrinkage fit 收缩配合
shut height 闭合高度
sieve mesh 筛孔
sintering of sand 铸砂烧贴
slag 熔渣
slag inclusion 夹渣
stickness 黏模性
strip layout 带状胚料排样法
tap casting 顶注
top gate 顶注浇口
unworked casting 不加工铸件
upender 翻转装置
upending 顶锻
uphill casting 底铸
white cast iron 白口铸件

模具词汇相关英语翻译(砂轮用语)
abrasive 砂轮
Al2O3 氧化铝
borazon 氧化硼立方晶
buffing wheel 抛光布轮
diamond 钻石
dresser 砂轮整修机
dressing 修整
endless grinding belt 循环式研磨带
finishing allowance 加工余量
grain 磨粒
grinding disc 研磨盘
jamp up 孔眼堵塞
mesh 网筛目
resinoid grinding wheel 半树脂型砂轮 slitting 切缝量
vitrified 陶瓷的


模具加工方法词汇的英语翻译
barrel 滚筒(加工)
bending 波纹加工
broaching 拉刀切削
centering 定中心
cutting 切削
cylindrical lathe cutting 外圆车削
electric discharge machine 放电加工
electrolytic grinding 电解研磨
embossing 压花加工
facing 面车削
filing 锉刀修润
hand finishing 手工修润
hemming 卷边加工
hobbing 滚齿加工
joggling 摇动加工
lapping 抛光/研磨修润
laser beam machining 雷射加工
lathe cutting 车床车削
planning 刨削加工
polishing 抛亮光
reaming 铰孔修润
rough machining 粗切削
rounding 圆形加工
sawing 锯削
scaling 清除钢碇缺陷
shaping 成形加工
skiving 表面研磨 slotting 切缝切削
taper turning 锥度车削
thread cutting 螺纹切削
ultrasonic machining 超音波加工
up cut milling 逆铣加工


          Electrochemical synthesis of diverse sulfonamide derivatives depending on the potential electrode and their antimicrobial evaluation   
New J. Chem., 2017, Accepted Manuscript
DOI: 10.1039/C7NJ01188A, Paper
Fahimeh Varmaghani, Maryam Hassan, Davood Nematollahi, Shadpour Mallakpour
Electrochemical synthesis of two different series of sulfonamides has been performed using same precursors, 4-(4-nitrophenyl) urazole and arylsulfinic acids, by controlling potential during electrolysis. Electrochemical reduction of 4-(4-nitrophenyl) urazole has...
The content of this RSS Feed (c) The Royal Society of Chemistry

          Direct aqueous solution synthesis of an ultra-fine amorphous nickel-boron alloy with superior pseudocapacitive performance for advanced asymmetric supercapacitors   

New J. Chem., 2017, Advance Article
DOI: 10.1039/C7NJ00222J, Paper
Wei Li, Shaolan Wang, Ming Wu, Xiangjian Wang, Yi Long, Xiaojie Lou
This study reports a facile aqueous solution synthesis of an ultrafine amorphous nickel-boron alloy and its applications as a novel positive electrode material for asymmetric supercapacitors.
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          Brain on a Chip   
Full Title: 
The Brain on a Chip: The Future of Neural Experimentation
Presenter: 
Jackson, Max
When: 
2 Oct 2013 - 19:00 - 20:30
Venue: 
Taste
Where: 
Taste
Street:
717 W. Smith Street
City:
Orlando
,
Province:
Florida
Postal Code:
32804
Country:
United States

Advances in cell culture technology have enabled researchers to grow neural material outside of the brain. This neural material can be shaped into neural networks through chemical patterning techniques, networks which can be grown on electrode grids called Micro Electrode Arrays. These networks can then be used as drug testing beds and as research tools to explore plasticity with a high degree of finesse and granularity. The techniques provide important opportunities to move away from the practical and moral challenges associated with human and animal models in neuroscience research.

Max Jackson is a masters student in BioTechnology at the University of Central Florida where he focuses his research on neural-machine interfacing. He is President of the UCF Synthetic Biology Club, and the Graduate President of the Central Florida Society for Neuroscience. Prior to graduate school, Max worked for a mobile-learning application development company. He enjoys reading the classics and philosophy literature in his free time.


          Fokker-Planck for Disordered Systems   
To get the cost of photovoltaic (PV) systems down, we will have to learn how to efficiently use crappy materials. By crap I mean that mass-produced PV materials will end up getting rolled or extruded or organically grown. Unless we perfect the process, most everything will turn out non-optimal. We already know the difference between clean-room cultivated single crystal semiconducting material and the defect-ridden and often amorphous materials that nature and entropy drives us to. For performance sensitive applications such as communications and computing we would only rarely consider disordered material as a candidate semiconductor. Certainly, the performance of these materials makes them unlikely candidates for high speed processing -- yet for solar cell applications, they may serve us well. In the end, we just have to learn how to understand and deal with crap.

The following will revisit a couple of previous posts where I outlined a novel way to analyze the behavior of disordered semiconducting material. I know for certain that no one has proposed the particular approach before. If it does exist, I certainly can't find it in the literature. From one perspective, this analysis sets forth a baseline for the characterization of a maximally disordered semiconductor.

Background

The prehistoric 1949 Haynes-Shockley experiment first measured the dynamic behavior of charged carriers in a semiconducting sample. It basically confirmed the solution of the diffusion (Fokker-Planck) equation and it demonstrated diffusion, drift, and recombination in a conceptually simple setup. This animated site gives a very interesting overview of PV electrical behavior.

Figure 1: Apparatus for the Haynes-Shockley experiment

This setup works according to theory for an ordered semiconductor with uniform properties but apparently gets a bit unwieldy for any disordered or non-uniform material sample. I inferred this as conventional wisdom since most scientists either punt or use heuristics partially derived from the inscrutable work of a select group of random-walk theorists (see Scher & Montroll).

I had previously applied a very straightforward interpretation to the problem of carrier transport in disordered material. My dispersion analysis essentially set aside the Fokker-Planck formalism for a mean value approximation where I tactically applied the Maximum Entropy Principle. In particular, I really like the MaxEnt solution because I can recite the solution from memory. It matches intuition in a conceptually simple way once you get into a disordered mind-set.

In the real Haynes-Shockley experiment, a pulse gets injected at one electrode, and a nearly pure time-of-flight (TOF) profile results. The initial pulse ends up spreading out in width a bit, but the detected pulse usually maintains the essential Gaussian sigmoid shape.

Adding Disorder

For the time-of-flight for a disordered system, the Maximum Entropy solution looks like:
q(t) = Q * exp(-w/(sqrt((μEt)2 + 2Dt))
This essentially states that the expected amount of charge accumulated at one end of the sample (at a distance w) at time t, follows a maximum entropy probability distribution. The varying rates described by μ and D disperse the speed of the carriers so that a broadened profile results from the initial pulse spike.

The equation above formed the baseline for the interpretation I described initially here.

For completeness, I figured to test my luck and see if I can bull my way through the basic diffusion laws. If I could produce an equivalent solution by applying the Maximum Entropy Principle directly to the Fokker-Planck equation, then this would give a better foundation for the "inspection" result above.

The F-P diffusion equation gets expressed as a partial differential equation with a conservation law constraint:
In this case D1=μ* (carrier mobility) and D2=D* (diffusion coefficient), and f(x,t)=n(x,t) (carrier concentration). With recombination, the solution in one-dimension looks like:

This of course works for well-ordered semiconductors, but D* and μ* will likely vary for disordered material. I made the standard substitution via the Einstein Relation for
D* = Vt μ*
where Vt = β/q stands for the chemical or thermal potential at equilibrium (usually β equals kT where k is Boltzmann's constant and T is absolute temperature). At equilibrium, the stochastic force of diffusion exactly balances the electrostatic force F = qE.

From the basic physics, we can generate a maximum entropy density function for D
p(D*) = 1/D * exp(-D*/D)
then
n(x,t) = Integral p(D*) * nmean(x,t) over all D*
This looks hairy but the integral comes out straightforwardly as (ignoring the constant factors)
n(x,t) = 1/sqrt(t*(4D+t*(Eμ)2)) * exp(-x*R(t)) / R(t)
where
R(t) = sqrt(1/(Dt) + E/(2Vt)2) - E/(2Vt)

If we evaluate this for carriers that have reached the drain electrode at x=w, the total charge collected q is:
q(t) = Q/sqrt(t*(4D+t*(Eμ)2) * exp(-w*R(t)) / R(t)

The measured current is
I(t) = mean of dq(t)/dt from 0 to w
The simple entropic dispersive expression and the Fokker-Planck result obviously differ in their formulation, yet the two show the same asymptotic trends. For an arbitrary set of parameters, one can't detect a practical difference. Use whichever you feel comfortable with.

I show the dynamics of the carrier profile in the animated GIF to the right. The initial profile starts with a spike at the origin and then the profile broadens as the mean starts drifting and diffusing to the opposing contact. You don't see much from this perspective as it looks completely like mush. Yet, when plotted on a log-log scale, it does take on more character.

The collected current profile looks like the following

Figure 2: Typical photocurrent trace showing the initial diffusional spike, a plateau for relatively constant collection from the active region, and then a power-law tail produced from the entropic drift dispersion.



Organic Semiconductor Applications

The photocurrent profile displayed above came from from Andersson's "Electronic Transport in Polymeric Solar Cells and Transistors" (2007) wherein he analyzed the transport in a specific organic semiconducting material, the polymer APFO.

The blue line drawn through the set of traces follows the entropic dispersion formulation. The upper part of the curve describes the diffusive spike while the lower part generates the fat-tail due to the drift component (this shows an inverse square power law in the tail).

Figure 3: Universal profile generated over a set of applied electric field values. For this set, scaling of transit time with respect to the applied field holds, indicative of a constant mobility. However, carrier diffusion causes the initial transient and this does not scale, as the electric field has no effect on diffusion, as shown in the lower set of blue curves.

As I stated in the previous post, most scientists when discussing this shape have either (1) referred to Scher/Montroll and the vague heuristic α, (2) dismissed these features, or (3) labelled them as uninteresting. Andersson follows suit:
At best this transient, as the high α value indicates, might be possible to evaluate in a meaningful way with a bit of error and at worst it is of no use. Either way the amount of material and effort required is rather large compared to the usefulness of the results. APFO-4 is also the polymer that, among the investigated, gives the ”nicest” transients. The conclusion from this is that if alternative measurement techniques can be used it is not worthwhile to do TOF.
Not to dismiss the hard work that went into Andersson's experiment, but I would beg to differ with his assessment of the worthiness of the approach. When characterizing a novel material, every measurement adds to the body of knowledge, and as the interpretation of the aggregation of data becomes more cohesive, we end up learning much more of the internal structure. As I have learned, if someone does not understand a phenomena, they tend to dismiss it (myself included).

By their very nature, disordered systems contain a huge state space and we really can't afford to throw out any information.

Which brings up another interesting set of TOF experiments that I dug up. These also deal with organic semiconducting materials -- the polymers with the abbreviations ANTH-OXA6t-OC12 and TPA-Cz3d. The following figures show the TOF results for various applied voltages. I superimposed the entropic dispersion equation form as the red line with the derived mobility in the caption below each figure. The original researcher had applied the Scher&Montroll Continuous Time Random Walk (CTRW) heuristic as indicated by the intersecting sloped lines. The CTRW model clearly fails in this situation as the slopes need quite a bit of creative interpretation. Note that we don't observe the diffusive spike; I integrated the charge from 10% to 100% of the width instead of 0% to 100%.










ANTH-OXA6t-OC12
μ = 0.0025
TPA-Cz3d
μ = 0.0013
μ = 0.00155
μ = 0.0004
μ = 0.00125
μ = 0.0005
μ = 0.00085
μ = 0.0006






The number of papers I find, especially when dealing with organic semiconductors, that cannot apply the Scher/Montroll theory indicates that it truly lacks any generality. In other words, it works crappily for describing disorderly crap. I will also say the theory has some very serious flaws, including the claim that an α = 1 defines a non-dispersive material. How could a power-law of -2 be anything but dispersive?

The fact that the entropic dispersion formulation works on any disordered material makes it much more general. Several years ago Scher wrote a popular article for Physics Today extolling the wonders of his theory, and how it seemed to fit a variety of disordered systems. He mentioned how well it fit amorphous silicon based on the number of orders of magnitude that his piece-wise line segments matched. Well, the entropic dispersion does just as well:

And nothing mysterious about that slope of 0.5; that results from the diffusion having a square root dependence with time.
          Are we closer to a game-changing device for Parkinson’s disease?   

University of Washington researchers say they’ve developed an advanced deep brain stimulation system to treat essential tremor and Parkinson’s without constantly being “on,” allowing for longer battery life and better treatment. The system utilizes electrodes on top of the brain to sense movement in parts of the body that experience essential tremor, alongside a deep

The post Are we closer to a game-changing device for Parkinson’s disease? appeared first on Medical Design and Outsourcing.


          Lessons Learned from Open‐label Deep Brain Stimulation for Tourette Syndrome: Eight Cases over 7 Years   
Background Deep brain stimulation (DBS) remains an experimental but promising treatment for patients with severe refractory Gilles de la Tourette syndrome (TS). Controversial issues include the selection of patients (age and clinical presentation), the choice of brain targets to obtain optimal patient‐specific outcomes, and the risk of surgery‐ and stimulation‐related serious adverse events. Methods This report describes our open‐label experience with eight patients with severe refractory malignant TS treated with DBS. The electrodes were placed in the midline thalamic nuclei or globus pallidus, pars internus, or both. Tics were clinically assessed in all patients pre‐ and postoperatively using the Modified Rush Video Protocol and the Yale Global Tic Severity Scale (YGTSS). Results Although three patients had marked postoperative improvement in their tics (>50% improvement on the YGTSS), the majority did not reach this level of clinical improvement. Two patients had to have their DBS leads removed (one because of postoperative infection and another because of lack of benefit). Discussion Our clinical experience supports the urgent need for more data and refinements in interventions and outcome measurements for severe, malignant, and medication‐refractory TS. Because TS is not an etiologically homogenous clinical entity, the inclusion criteria for DBS patients and the choice of brain targets will require more refinement.
          Gesture recognition with Arduino   

Pinned onto Open Electronics

  With the board described here, we will interface the electrode board for gesture recognition to Arduino.   To take advantage of the potential of the MGC3130 integrated circuit, we thought of developing a new electrode having the possibility to connect (in addition to our demo board, that we saw in the previous episode), even […]

          Gesture recognition with Raspberry Pi and GestIC   

Pinned onto Open Electronics

  Let’s couple the 3D gesture recognition electrode to Raspberry Pi, in order to create an application with which the pictures can be scrolled on a HDMI screen, by means of gestures.   In an another post we described a new GestIC electrode, which has been developed and created for the purpose of interfacing the Arduino Uno […]

          Amorphous Metal Polysulfides: Electrode Materials with Unique Insertion/Extraction Reactions   

TOC Graphic

Journal of the American Chemical Society
DOI: 10.1021/jacs.7b03909

          High-Throughput Selective Capture of Single Circulating Tumor Cells by Dielectrophoresis at a Wireless Electrode Array   

TOC Graphic

Journal of the American Chemical Society
DOI: 10.1021/jacs.7b03288

          Welder   
We are in need of Welders!!!

Job Title : Certified Welder

Function : Manufacturing

Client Overview - 30,000 employees strong. We work around the globe to deliver industry-leading products, service and solutions for our customers? diverse needs in water and other fluids, thermal management and equipment protection. Our inventive thinking, collaborative spirit, disciplined work ethic and breadth of experts allows us to deliver Inspired Solutions for a Changing World. Through our capabilities as a company, our innovative products and our Win Right values, we have the opportunity to define a clear and compelling role for us in the global community. Everything we do is driven by our passion to help people live better, and we are committed to creating inspired solutions for a changing world. Everything we do is driven by our passion to help people live better.
Business Unit Overview - Our Filtration & Process business is a global leader in the residential, commercial, municipal and industrial markets, providing solutions for the toughest filtration, separation and fluid process management challenges, as well as delivering water treatment, softening, and specialty pumps systems to customers worldwide. Specific end-markets include oil and gas, power generation, chemical, food and beverage, pharmaceutical, foodservice, medical and municipal and industrial desalination, water and wastewater treatment. Additionally, our products are used in the manufacturing of water softeners, filtration and deionization systems, and commercial and residential water filtration applications.

JOB SUMMARY
JOB PURPOSE
This position welds a variety of materials including steel, stainless steel, cast iron and iron alloys. In accordance with ASME Boiler & Pressure Vessel Code (2012 ed.), Sec. 8, Div. 1, sets up and operates basic welding equipment to fuse and connect parts together as specified in engineering drawings. Grinds excess material to specified finish. Reads and interprets engineering drawings. Lays out, fits up, and welds complex fabrications.

ESSENTIAL JOB FUNCTIONS
-Performs basic welding work related to the manufacturing of products.
-Utilizes engineering drawings and / or verbal instructions to lay out, position, and weld a variety of pre-cut steel parts to fabricate industrial filtration housings and components.
-Must pass an ASME 1G and 6G Code Test with GMAW and a 1G with SAW.
-Plans sequence of welding operations to insure optimal work flow and proper attachment of structure, supports, components and equipment when welding job is complete.
-Sets up welding unit (MIG, TIG, Sub-Arc) to desired settings. Obtains specified electrode based on bead, type and thickness of metal.
-Operates welding machine or guides electrode, maintaining length of arc and speed of movement, to form fusion as judged from color of metal and size of molten puddle.
Participates actively in the Site Safety Program
-Performs other duties and responsibilities as necessary.

Job Requirements & Skills
MINIMUM QUALIFICATIONS
1.High School Diploma
2.5 years of related experience preferred.
3.Must be able to read and use a tape measure.
4.Must be able to read and interpret engineering blueprints / drawings.
5.AWS Certified Welder certification preferred.
6.Must be able to read and understand Weld Symbols and Joint Design Diagrams
DESIRED CHARACTERISTICS
-Drives for results -Detail oriented -Works efficiently -Promotes teamwork and collaboration -Capacity for learning -Adaptability to change and ambiguity -Persists in the face of difficulties -Develops oneself -Works with minimal supervision -Uses sound judgment

Qualifed Applicants Apply Online
EEO Statement
Pentair is an Equal Opportunity Employer-Welds along vertical or overhead lines as required.
-Manually applies filler rod, or cleans work piece with wire brush or portable grinder as required. Positions work with clamps and/or jigs prior to welding, and may flame-cut metal plates or other support members.
-Utilizes material handling equipment to move material into, around and out of the department.
-Follows all 5S practices and supports lean activities, as well as safety regulations policies and procedures
          Senior Product Manager - Electrodes & Solutions - Thermo Fisher Scientific - Chelmsford, MA   
Job Description How You Will Make A Difference: The Senior Product Manager position drives the value of the product portfolio with the development and
From Thermo Fisher Scientific - Wed, 19 Apr 2017 10:29:52 GMT - View all Chelmsford, MA jobs
          NCERT Physics Question Paper (Class - 12)   

NCERT Physics Question Paper (Class - 12)


:: Chapter 1 - Electric Charges And Fields ::


List of Physics Formula

EXERCISE

Question 1: What is the force between two small charged spheres having charges of 2 × 10−7 C and 3 × 10−7 C placed 30 cm apart in air?

Question 2: The electrostatic force on a small sphere of charge 0.4 µC due to another small sphere of charge − 0.8 µC in air is 0.2 N. (a) What is the distance between the two spheres? (b) What is the force on the second sphere due to the first?

Question 3: Check that the ratio ke2/G memp is dimensionless. Look up a Table of physical constants and determine the value of this ratio. What does the ratio signify?

Question 4: (a) Explain the meaning of the statement ‘electric charge of a body is quantised’.
(b) Why can one ignore quantisation of electric charge when dealing with macroscopic i.e., large scale charges?

Question 5: When a glass rod is rubbed with a silk cloth, charges appear on both. A similar phenomenon is observed with many other pairs of bodies. Explain how this observation is consistent with the law of conservation of charge.

Question 6: Four point charges qA = 2 µC, qB = −5 µC, qC = 2 µC, and qD = −5 µC are located at the corners of a square ABCD of side 10 cm. What is the force on a charge of 1 µC placed at the centre of the square

Question 7: (a) An electrostatic field line is a continuous curve. That is, a field line cannot have sudden breaks. Why not? (b) Explain why two field lines never cross each other at any point?

Question 8: Two point charges qA = 3 µC and qB = −3 µC are located 20 cm apart in vacuum. (i) What is the electric field at the midpoint O of the line AB joining the two charges? (ii) If a negative test charge of magnitude 1.5 × 10−9 C is placed at this point, what is the force experienced by the test charge?

Question 9: A system has two charges qA = 2.5 × 10−7 C and qB = −2.5 × 10−7 C located at points A: (0, 0, − 15 cm) and B: (0, 0, + 15 cm), respectively. What are the total charge and electric dipole moment of the system?


:: Chapter 2 - Electrostatic Potential and Capacitance ::


EXERCISE

Question 2.1 Two charges 5 × 10–8 C and –3 × 10–8 C are located 16 cm apart. At what point (s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.

Question 2.2 A regular hexagon of side 10 cm has a charge 5 μC at each of its vertices. Calculate the potential at the centre of the hexagon.

Question 2.3 Two charges 2 μC and –2 μC are placed at points A and B 6 cm apart.
(a) Identify an equipotential surface of the system.
(b) What is the direction of the electric field at every point on this surface?

Question 2.4 A spherical conductor of radius 12 cm has a charge of 1.6 × 10–7C distributed uniformly on its surface. What is the electric field
(a) inside the sphere
(b) just outside the sphere
(c) at a point 18 cm from the centre of the sphere?

Question 2.5 A parallel plate capacitor with air between the plates has a capacitance of 8 pF (1pF = 10–12 F). What will be the capacitance if the distance between the plates is reduced by half, and the space between them is filled with a substance of dielectric constant 6?

Question 2.6 Three capacitors each of capacitance 9 pF are connected in series.
(a) What is the total capacitance of the combination?
(b) What is the potential difference across each capacitor if the combination is connected to a 120 V supply?

Question 2.7 Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected in parallel.
(a) What is the total capacitance of the combination? (b) Determine the charge on each capacitor if the combination is connected to a 100 V supply.

Question 2.8 In a parallel plate capacitor with air between the plates, each plate has an area of 6 × 10–3 m2 and the distance between the plates is 3 mm. Calculate the capacitance of the capacitor. If this capacitor is connected to a 100 V supply, what is the charge on each plate of the capacitor?

Question 2.9 Explain what would happen if in the capacitor given in Exercise2.8, a 3 mm thick mica sheet (of dielectric constant = 6) were inserted between the plates,
(a) while the voltage supply remained connected.
(b) after the supply was disconnected.

Question 2.10 A 12pF capacitor is connected to a 50V battery. How much electrostatic energy is stored in the capacitor?

Question 2.11 A 600pF capacitor is charged by a 200V supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. How much electrostatic energy is lost in the process?

ADDITIONAL EXERCISES QUESTIONS

Question 2.12 A charge of 8 mC is located at the origin. Calculate the work done in taking a small charge of –2 × 10–9 C from a point P (0, 0, 3 cm) to a point Q (0, 4 cm, 0), via a point R (0, 6 cm, 9 cm).

Question 2.13 A cube of side b has a charge q at each of its vertices. Determine the potential and electric field due to this charge array at the centre of the cube.

Question 2.14 Two tiny spheres carrying charges 1.5 μC and 2.5 μC are located 30 cm apart. Find the potential and electric field: (a) at the mid-point of the line joining the two charges, and (b) at a point 10 cm from this midpoint in a plane normal to the line and passing through the mid-point.

Question 2.15 A spherical conducting shell of inner radius r1 and outer radius r2 has a charge Q.
(a) A charge q is placed at the centre of the shell. What is the surface charge density on the inner and outer surfaces of the shell?
(b) Is the electric field inside a cavity (with no charge) zero, even if the shell is not spherical, but has any irregular shape? Explain.

Question 2.16 (a) Show that the normal component of electrostatic field has a discontinuity from one side of a charged surface to another given by 2 1 0 ( ) ˆ σ ε E − E n = where ˆn is a unit vector normal to the surface at a point and σ is the surface charge density at that point. (The direction of ˆn is from side 1 to side 2.) Hence show that just outside a conductor, the electric field is σ ˆn /ε0.
(b) Show that the tangential component of electrostatic field is continuous from one side of a charged surface to another. [Hint: For (a), use Gauss’s law. For, (b) use the fact that work done by electrostatic field on a closed loop is zero.]

Question 2.17 A long charged cylinder of linear charged density λ is surrounded by a hollow co-axial conducting cylinder. What is the electric field in the space between the two cylinders?

Question 2.18 In a hydrogen atom, the electron and proton are bound at a distance of about 0.53 Å:
(a) Estimate the potential energy of the system in eV, taking the zero of the potential energy at infinite separation of the electron from proton.
(b) What is the minimum work required to free the electron, given that its kinetic energy in the orbit is half the magnitude of potential energy obtained in (a)?
(c) What are the answers to (a) and (b) above if the zero of potential energy is taken at 1.06 Å separation?

Question 2.19 If one of the two electrons of a H2 molecule is removed, we get a hydrogen molecular ion H+ 2.In the ground state of an H+ 2, the two protons are separated by roughly 1.5 Å, and the electron is roughly 1 Å from each proton. Determine the potential energy of the system. Specify your choice of the zero of potential energy.

Question 2.20 Two charged conducting spheres of radii a and b are connected to each other by a wire. What is the ratio of electric fields at the surfaces of the two spheres? Use the result obtained to explain why charge density on the sharp and pointed ends of a conductor is higher than on its flatter portions.

Question 2.21 Two charges –q and +q are located at points (0, 0, –a) and (0, 0, a), respectively.
(a) What is the electrostatic potential at the points (0, 0, z) and (x, y, 0) ?
(b) Obtain the dependence of potential on the distance r of a point from the origin when r/a >> 1.
(c) How much work is done in moving a small test charge from the point (5,0,0) to (–7,0,0) along the x-axis? Does the answer change if the path of the test charge between the same points is not along the x-axis?

Question 2.22 Figure2.34 shows a charge array known as an electric quadrupole. For a point on the axis of the quadrupole, obtain the dependence of potential on r for r/a >> 1, and contrast your results with that due to an electric dipole, and an electric monopole (i.e., a single charge).

Question 2.23 An electrical technician requires a capacitance of 2 μF in a circuit across a potential difference of 1 kV. A large number of 1 μF capacitors are available to him each of which can withstand a potential difference of not more than 400 V. Suggest a possible arrangement that requires the minimum number of capacitors.

Question 2.24 What is the area of the plates of a 2 F parallel plate capacitor, given that the separation between the plates is 0.5 cm? [You will realise from your answer why ordinary capacitors are in the range of μF or less. However, electrolytic capacitors do have a much larger capacitance (0.1 F) because of very minute separation between the conductors.]

Question 2.25 Obtain the equivalent capacitance of the network in Fig. 2.35. For a 300 V supply, determine the charge and voltage across each capacitor.

Question 2.26 The plates of a parallel plate capacitor have an area of 90 cm2 each and are separated by 2.5 mm. The capacitor is charged by connecting it to a 400 V supply.
(a) How much electrostatic energy is stored by the capacitor?
(b) View this energy as stored in the electrostatic field between the plates, and obtain the energy per unit volume u. Hence arrive at a relation between u and the magnitude of electric field E between the plates.

Question 2.27 A 4 μF capacitor is charged by a 200 V supply. It is then disconnected from the supply, and is connected to another uncharged 2 μF capacitor. How much electrostatic energy of the first capacitor is lost in the form of heat and electromagnetic radiation?

Question 2.28 Show that the force on each plate of a parallel plate capacitor has a magnitude equal to (½) QE, where Q is the charge on the capacitor, and E is the magnitude of electric field between the plates. Explain the origin of the factor ½.

Question 2.29 A spherical capacitor consists of two concentric spherical conductors, held in position by suitable insulating supports (Fig2.36). Show that the capacitance of a spherical capacitor is given by 0 1 2 1 2 4 – r r C r r πε = where r1 and r2 are the radii of outer and inner spheres, respectively.

Question 2.30 A spherical capacitor has an inner sphere of radius 12 cm and an outer sphere of radius 13 cm. The outer sphere is earthed and the inner sphere is given a charge of 2.5 μC. The space between the concentric spheres is filled with a liquid of dielectric constant 32.
(a) Determine the capacitance of the capacitor.
(b) What is the potential of the inner sphere?
(c) Compare the capacitance of this capacitor with that of an isolated sphere of radius 12 cm. Explain why the latter is much smaller.s the magnitude of electrostatic force between them exactly given by Q1 Q2/4πε0r 2, where r is the distance between their centres?
(b) If Coulomb’s law involved 1/r3 dependence (instead of 1/r2), would Gauss’s law be still true ?
(c) A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point?
(d) What is the work done by the field of a nucleus in a complete circular orbit of the electron? What if the orbit is elliptical?
(e) We know that electric field is discontinuous across the surface of a charged conductor. Is electric potential also discontinuous there?
(f ) What meaning would you give to the capacitance of a single conductor?
(g) Guess a possible reason why water has a much greater dielectric constant (= 80) than say, mica (= 6).

Question 2.32 A cylindrical capacitor has two co-axial cylinders of length 15 cm and radii 1.5 cm and 1.4 cm. The outer cylinder is earthed and the inner cylinder is given a charge of 3.5 μC. Determine the capacitance of the system and the potential of the inner cylinder. Neglect end effects (i.e., bending of field lines at the ends).

Question 2.33 A parallel plate capacitor is to be designed with a voltage rating 1 kV, using a material of dielectric constant 3 and dielectric strength about 107 Vm–1. (Dielectric strength is the maximum electric field a material can tolerate without breakdown, i.e., without starting to conduct electricity through partial ionisation.) For safety, we should like the field never to exceed, say 10% of the dielectric strength. What minimum area of the plates is required to have a capacitance of 50 pF?

Question 2.34 Describe schematically the equipotential surfaces corresponding to
(a) a constant electric field in the z-direction,
(b) a field that uniformly increases in magnitude but remains in a constant (say, z) direction,
(c) a single positive charge at the origin, and
(d) a uniform grid consisting of long equally spaced parallel charged wires in a plane .

Question 2.35 In a Van de Graaff type generator a spherical metal shell is to be a 15 × 106 V electrode. The dielectric strength of the gas surrounding the electrode is 5 × 107 Vm–1. What is the minimum radius of the spherical shell required? (You will learn from this exercise why one cannot build an electrostatic generator using a very small shell which requires a small charge to acquire a high potential.)

Question 2.36 A small sphere of radius r1 and charge q1 is enclosed by a spherical shell of radius r2 and charge q2. Show that if q1 is positive, charge will necessarily flow from the sphere to the shell (when the two are connected by a wire) no matter what the charge q2 on the shell is.

Question 2.37 Answer the following:
(a) The top of the atmosphere is at about 400 kV with respect to the surface of the earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth, the field is about 100 Vm–1. Why then do we not get an electric shock as we step out of our house into the open? (Assume the house to be a steel cage so there is no field inside!)
(b) A man fixes outside his house one evening a two metre high insulating slab carrying on its top a large aluminium sheet of area 1m 2.Will he get an electric shock if he touches the metal sheet next morning?
(c) The discharging current in the atmosphere due to the small conductivity of air is known to be 1800 A on an average over the globe. Why then does the atmosphere not discharge itself completely in due course and become electrically neutral? In other words, what keeps the atmosphere charged?
(d) What are the forms of energy into which the electrical energy of the atmosphere is dissipated during a lightning? (Hint: The earth has an electric field of about 100 Vm–1 at its surface in the downward direction, corresponding to a surface charge density = –10–9 C m– 2. Due to the slight conductivity of the atmosphere up to about 50 km (beyond which it is good conductor), about + 1800 C is pumped every second into the earth as a whole. The earth, however, does not get discharged since thunderstorms and lightning occurring continually all over the globe pump an equal amount of negative charge on the earth.)


:: Chapter 3 - Current Electricity ::


Question 3.1 The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4 Ω, what is the maximum current that can be drawn from the battery?

Question 3.2 A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?

Question 3.3 (a) Three resistors 1 Ω, 2 Ω, and 3 Ω are combined in series. What is the total resistance of the combination? (b) If the combination is connected to a battery of emf 12 V and negligible internal resistance, obtain the potential drop across each resistor.

Question 3.4 (a) Three resistors 2 Ω, 4 Ω and 5 Ω are combined in parallel. What is the total resistance of the combination?
(b) If the combination is connected to a battery of emf 20 V and negligible internal resistance, determine the current through each resistor, and the total current drawn from the battery.

Question 3.5 At room temperature (27.0 °C) the resistance of a heating element is 100 Ω. What is the temperature of the element if the resistance is found to be 117 Ω, given that the temperature coefficient of the material of the resistor is 1.70 × 10–4 °C–1.

Question 3.6 A negligibly small current is passed through a wire of length 15 m and uniform cross-section 6.0 × 10–7 m2, and its resistance is measured to be 5.0 Ω. What is the resistivity of the material at the temperature of the experiment?

Question 3.7 A silver wire has a resistance of 2.1 Ω at 27.5 °C, and a resistance of 2.7 Ω at 100 °C. Determine the temperature coefficient of resistivity of silver.

Question 3.8 A heating element using nichrome connected to a 230 V supply draws an initial current of 3.2 A which settles after a few seconds to a steady value of 2.8 A. What is the steady temperature of the heating element if the room temperature is 27.0 °C? Temperature coefficient of resistance of nichrome averaged over the temperature range involved is 1.70 × 10–4 °C–1.

Question 3.9 Determine the current in each branch of the network shown in Fig. 3.30:

Question 3.10 (a) In a metre bridge [Fig. 3.7], the balance point is found to be at 39.5 cm from the end A, when the resistor Y is of 12.5 Ω. Determine the resistance of X. Why are the connections between resistors in a Wheatstone or meter bridge made of thick copper strips?
(b) Determine the balance point of the bridge above if X and Y are interchanged.
(c) What happens if the galvanometer and cell are interchanged at the balance point of the bridge? Would the galvanometer show any current?

Question 3.11 A storage battery of emf 8.0 V and internal resistance 0.5 Ω is being charged by a 120 V dc supply using a series resistor of 15.5 Ω. What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?

Question 3.12 In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35.0 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 6 3.0 cm, what is the emf of the second cell?

Question 3. 13 The number density of free electrons in a copper conductor estimated in Example 3.1 is 8.5 × 1028 m–3. How long does an electron take to drift from one end of a wire 3.0 m long to its other end? The area of cross-section of the wire is 2.0 × 10–6 m2 and it is carrying a current of 3.0 A.

ADDITIONAL EXERCISES QUESTIONS

Question 3. 14 The earth’s surface has a negative surface charge density of 10–9 C m–2. The potential difference of 400 kV between the top of the atmosphere and the surface results (due to the low conductivity of the lower atmosphere) in a current of only 1800 A over the entire globe. If there were no mechanism of sustaining atmospheric electric field, how much time (roughly) would be required to neutralise the earth’s surface? (This never happens in practice because there is a mechanism to replenish electric charges, namely the continual thunderstorms and lightning in different parts of the globe). (Radius of earth = 6.37 × 106 m.)

Question 3.15 (a) Six lead-acid type of secondary cells each of emf 2.0 V and internal resistance 0.015 Ω are joined in series to provide a supply to a resistance of 8.5 Ω. What are the current drawn from the supply and its terminal voltage?
(b) A secondary cell after long use has an emf of 1.9 V and a large internal resistance of 380 Ω. What maximum current can be drawn from the cell? Could the cell drive the starting motor of a car?

Question 3.16 Two wires of equal length, one of aluminium and the other of copper have the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables. (ρAl = 2.63 × 10–8 Ω m, ρCu = 1.72 × 10–8 Ω m, Relative density of Al = 2.7, of Cu = 8.9.)

Question 3.17 What conclusion can you draw from the following observations on a resistor made of alloy manganin?

Question 3.18 Answer the following questions:
(a) A steady current flows in a metallic conductor of non-uniform cross-section. Which of these quantities is constant along the conductor: current, current density, electric field, drift speed?
(b) Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
(c) A low voltage supply from which one needs high currents must have very low internal resistance. Why?
(d) A high tension (HT) supply of, say, 6 kV must have a very large internal resistance. Why?

Question 3.19 Choose the correct alternative:
(a) Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
(b) Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
(c) The resistivity of the alloy manganin is nearly independent of/ increases rapidly with increase of temperature.
(d) The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (1022/103).

Question 3.20 (a) Given n resistors each of resistance R, how will you combine them to get the
(i) maximum
(ii) minimum effective resistance? What is the ratio of the maximum to minimum resistance? (b) Given the resistances of 1 Ω, 2 Ω, 3 Ω, how will be combine them to get an equivalent resistance of (i) (11/3) Ω (ii) (11/5) Ω,
(iii) 6 Ω, (iv) (6/11) Ω? (c) Determine the equivalent resistance of networks shown in Fig. 3.31.

Question 3.22 Figure 3.33 shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02 V (for very moderate currents upto a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of 600 kΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf ε and the balance point found similarly, turns out to be at 82.3 cm length of the wire.
(c) Is the balance point affected by this high resistance?
(d) Is the balance point affected by the internal resistance of the driver cell?
(e) Would the method work in the above situation if the driver cell of the potentiometer had an emf of 1.0V instead of 2.0V? (f ) Would the circuit work well for determining an extremely small emf, say of the order of a few mV (such as the typical emf of a thermo-couple)? If not, how will you modify the circuit?

Question 3.23 Figure 3.34 shows a potentiometer circuit for comparison of two resistances. The balance point with a standard resistor R = 10.0 Ω is found to be 58.3 cm, while that with the unknown resistance X is 68.5 cm. Determine the value of X. What might you do if you failed to find a balance point with the given cell of emf ε ?

Question 3.24 Figure 3.35 shows a 2.0 V potentiometer used for the determination of internal resistance of a 1.5 V cell. The balance point of the cell in open circuit is 76.3 cm. When a resistor of 9.5 Ω is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. Determine the internal resistance of the cell.
 


:: Chapter 4 - Moving Charges and Magnetism ::


Question 4.1 A circular coil of wire consisting of 100 turns, each of radius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil?

Question 4.2 A long straight wire carries a current of 35 A. What is the magnitude of the field B at a point 20 cm from the wire?

Question 4.3 A long straight wire in the horizontal plane carries a current of 50 A in north to south direction. Give the magnitude and direction of B at a point 2.5 m east of the wire.

Question 4.4 A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?

Question 4.5 What is the magnitude of magnetic force per unit length ?

Question 4.6 A 3.0 cm wire carrying a current of 10 A is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be 0.27 T. What is the magnetic force on the wire?

Question 4.7 Two long and parallel straight wires A and B carrying currents of 8.0 A and 5.0 A in the same direction are separated by a distance of 4.0 cm. Estimate the force on a 10 cm section of wire A.

Question 4.8 A closely wound solenoid 80 cm long has 5 layers of windings of 400 turns each. The diameter of the solenoid is 1.8 cm. If the current carried is 8.0 A, estimate the magnitude of B inside the solenoid near its centre.

Question 4.9 A square coil of side 10 cm consists of 20 turns and carries a current of 12 A. The coil is suspended vertically and the normal to the plane of the coil makes an angle of 30º with the direction of a uniform horizontal magnetic field of magnitude 0.80 T. What is the magnitude of torque experienced by the coil?

Question 4.10 Two moving coil meters, M1 and M2 have the following particulars: R1 = 10 Ω, N1 = 30, A1 = 3.6 × 10–3 m2, B1 = 0.25 T R2 = 14 Ω, N2 = 42, A2 = 1.8 × 10–3 m2, B2 = 0.50 T (The spring constants are identical for the two meters). Determine the ratio of (a) current sensitivity and (b) voltage sensitivity of M2 and M1.

Question 4.11 In a chamber, a uniform magnetic field of 6.5 G (1 G = 10–4 T) is maintained. An electron is shot into the field
with a speed of 4.8 × 106 m s–1 normal to the field. Explain why the path of the electron is a circle. Determine the radius of the circular orbit. (e = 1.6 × 10–19 C, me = 9.1×10–31 kg)

Question 4.12 In Exercise 4.11 obtain the frequency of revolution of the electron in its circular orbit. Does the answer depend on the speed of the electron? Explain.

Question 4.13 (a) A circular coil of 30 turns and radius 8.0 cm carrying a current of 6.0 A is suspended vertically in a uniform horizontal magnetic field of magnitude 1.0 T. The field lines make an angle of 60º with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning.
(b) Would your answer change, if the circular coil in
(a) were replaced by a planar coil of some irregular shape that encloses the same area? (All other particulars are also unaltered.)

ADDITIONAL EXERCISES QUESTION

Question 4.14 Two concentric circular coils X and Y of radii 16 cm and 10 cm, respectively, lie in the same vertical plane containing the north to south direction. Coil X has 20 turns and carries a current of 16 A; coil Y has 25 turns and carries a current of 18 A. The sense of the current in X is anticlockwise, and clockwise in Y, for an observer looking at the coils facing west. Give the magnitude and direction of the net magnetic field due to the coils at their centre .

Question 4.15 A magnetic field of 100 G (1 G = 10–4 T) is required which is uniform in a region of linear dimension about 10 cm and area of cross-section about 10–3 m2. The maximum current-carrying capacity of a given coil of wire is 15 A and the number of turns per unit length that can be wound round a core is at most 1000 turns m–1. Suggest some appropriate design particulars of a solenoid for the required purpose. Assume the core is not ferromagnetic.

Question 4.16 For a circular coil of radius R and N turns carrying current I, the magnitude of the magnetic field at a point on its axis at a distance x from its centre is given by, ( ) 2 0 2 2 3/2 2 IR N B x R μ = +
(a) Show that this reduces to the familiar result for field at the centre of the coil.
(b) Consider two parallel co-axial circular coils of equal radius R, and number of turns N, carrying equal currents in the same direction, and separated by a distance R. Show that the field on the axis around the mid-point between the coils is uniform over a distance that is small as compared to R, and is given by, 0.72 0 NI B R μ = , approximately. [Such an arrangement to produce a nearly uniform magnetic field over a small region is known as Helmholtz coils.]

Question 4.17 A toroid has a core (non-ferromagnetic) of inner radius 25 cm and outer radius 26 cm, around which 3500 turns of a wire are wound. If the current in the wire is 11 A, what is the magnetic field (a) outside the toroid, (b) inside the core of the toroid, and (c) in the empty space surrounded by the toroid.

Question 4.18 Answer the following questions:
(a) A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflectedalong a straight path with constant speed. What can you say about the initial velocity of the particle?
(b) A charged particle enters an environment of a strong and non-uniform magnetic field varying from point to point both in magnitude and direction, and comes out of it following a complicated trajectory. Would its final speed equal the initial speed if it suffered no collisions with the environment?
(c) An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.

Question 4.19 An electron emitted by a heated cathode and accelerated through a potential difference of 2.0 kV, enters a region with uniform magnetic field of 0.15 T. Determine the trajectory of the electron if the field
(a) is transverse to its initial velocity,
(b) makes an angle of 30º with the initial velocity.

Question 4.20 A magnetic field set up using Helmholtz coils (described in Exercise 4.16) is uniform in a small region and has a magnitude of 0.75 T. In the same region, a uniform electrostatic field is maintained in a direction normal to the common axis of the coils. A narrow beam of (single species) charged particles all accelerated through 15 kV enters this region in a direction perpendicular to both the axis of the coils and the electrostatic field. If the beam remains undeflected when the electrostatic field is 9.0 × 10–5 V m–1, make a simple guess as to what the beam contains. Why is the answer not unique?

Question 4.21 A straight horizontal conducting rod of length 0.45 m and mass 60 g is suspended by two vertical wires at its ends. A current of 5.0 A is set up in the rod through the wires.
(a) What magnetic field should be set up normal to the conductor in order that the tension in the wires is zero?
(b) What will be the total tension in the wires if the direction of current is reversed keeping the magnetic field same as before? (Ignore the mass of the wires.) g = 9.8 m s–2.

Question 4.22 The wires which connect the battery of an automobile to its starting motor carry a current of 300 A (for a short time). What is the force per unit length between the wires if they are 70 cm long and 1.5 cm apart? Is the force attractive or repulsive?

Question 4.23 A uniform magnetic field of 1.5 T exists in a cylindrical region of radius10.0 cm, its direction parallel to the axis along east to west. A wire carrying current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if,
(a) the wire intersects the axis,
(b) the wire is turned from N-S to northeast-northwest direction,
(c) the wire in the N-S direction is lowered from the axis by a distance of 6.0 cm?

Question 4.24 A uniform magnetic field of 3000 G is established along the positive z-direction. A rectangular loop of sides 10 cm and 5 cm carries a current of 12 A. What is the torque on the loop in the different cases shown in Fig. 4.28? What is the force on each case? Which case corresponds to stable equilibrium?

Question 4.25 A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the
(a) total torque on the coil,
(b) total force on the coil,
(c) average force on each electron in the coil due to the magnetic field? (The coil is made of copper wire of cross-sectional area 10–5 m2, and the free electron density in copper is given to be about 1029 m–3.)

Question 4.26 A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windings of 300 turns each. A 2.0 cm long wire of mass 2.5 g lies inside the solenoid (near its centre) normal to its axis; both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of 6.0 A in the wire. What value of current (with appropriate sense of circulation) in the windings of the solenoid can support the weight of the wire? g = 9.8 m s–2.

Question 4.27 A galvanometer coil has a resistance of 12 Ω and the metre shows full scale deflection for a current of 3 mA. How will you convert the metre into a voltmeter of range 0 to 18 V?

Question 4.28 A galvanometer coil has a resistance of 15 Ω and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A? 


:: Chapter 5 - Magnetism and Matter ::


Question 5.1 Answer the following questions regarding earth’s magnetism:
(a) A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field.
(b) The angle of dip at a location in southern India is about 18º. Would you expect a greater or smaller dip angle in Britain?
(c) If you made a map of magnetic field lines at Melbourne in Australia, would the lines seem to go into the ground or come out of the ground?
(d) In which direction would a compass free to move in the vertical plane point to, if located right on the geomagnetic north or south pole?
(e) The earth’s field, it is claimed, roughly approximates the field due to a dipole of magnetic moment 8 × 1022 J T–1 located at its centre. Check the order of magnitude of this number in some way.
(f ) Geologists claim that besides the main magnetic N-S poles, there are several local poles on the earth’s surface oriented in different directions. How is such a thing possible at all?

Question 5.2 Answer the following questions:
(a) The earth’s magnetic field varies from point to point in space. Does it also change with time? If so, on what time scale does it change appreciably?
(b) The earth’s core is known to contain iron. Yet geologists do not regard this as a source of the earth’s magnetism. Why?
(c) The charged currents in the outer conducting regions of the earth’s core are thought to be responsible for earth’s magnetism. What might be the ‘battery’ (i.e., the source of energy) to sustain these currents?
(d) The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth’s field in such distant past?
(e) The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?
(f ) Interstellar space has an extremely weak magnetic field of the order of 10–12 T. Can such a weak field be of any significant consequence?

Question 5.2 is meant mainly to arouse your curiosity. Answers to some questions above are tentative or unknown. Brief answers wherever possible are given at the end. For details, you should consult a good text on geomagnetism.]

Question 5.3 A short bar magnet placed with its axis at 30º with a uniform external magnetic field of 0.25 T experiences a torque of magnitude equal to 4.5 × 10–2 J. What is the magnitude of magnetic moment of the magnet?

Question 5.4 A short bar magnet of magnetic moment m = 0.32 JT–1 is placed in a uniform magnetic field of 0.15 T. If the bar is free to rotate in the plane of the field, which orientation wou

Question 5.5 A closely wound solenoid of 800 turns and area of cross section 2.5 × 10–4 m2 carries a current of 3.0 A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?

Question 5.6 If the solenoid in xercise 5.5 is free to turn about the vertical direction and a uniform horizontal magnetic field of 0.215 T is applied, what is the magnitude of torque on the solenoid when its axis makes an angle of 30° with the direction of applied field?

Question 5.7 A bar magnet of magnetic moment 1.5 J T–1 lies aligned with the direction of a uniform magnetic field of 0.22 T. (a) What is the amount of work required by an external torque to turn the magnet so as to align its magnetic moment:
(i) normal to the field direction , (ii) opposite to the field direction?
(b) What is the torque on the magnet in cases (i) and (ii)?

Question 5.8 A closely wound solenoid of 2000 turns and area of cross-section 1.6 × 10–4 m2, carrying a current of 4.0 A, is suspended through its centre allowing it to turn in a horizontal plane.
(a) What is the magnetic moment associated with the solenoid?
(b) What is the force and torque on the solenoid if a uniform horizontal magnetic field of 7.5 × 10–2 T is set up at an angle of 30º with the axis of the solenoid?

Question 5.9 A circular coil of 16 turns and radius 10 cm carrying a current of 0.75 A rests with its plane normal to an external field of magnitude 5.0 × 10–2 T. The coil is free to turn about an axis in its plane perpendicular to the field direction. When the coil is turned slightly and released, it oscillates about its stable equilibrium with a frequency of 2.0 s–1. What is the moment of inertia of the coil about its axis of rotation?

Question 5.10 A magnetic needle free to rotate in a vertical plane parallel to the magnetic meridian has its north tip pointing down at 22º with the horizontal. The horizontal component of the earth’s magnetic field at the place is known to be 0.35 G. Determine the magnitude of the earth’s magnetic field at the place.

Question 5.11 At a certain location in Africa, a compass points 12º west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points 60º above the horizontal. The horizontal component of the earth’s field is measured to be 0.16 G. Specify the direction and magnitude of the earth’s field at the location.

Question 5.12 A short bar magnet has a magnetic moment of 0.48 J T–1. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on (a) the axis,(b) the equatorial lines (normal bisector) of the magnet.

Question 5.13 A short bar magnet placed in a horizontal plane has its axis aligned along the magnetic north-south direction. Null points are found on the axis of the magnet at 14 cm from the centre of the magnet. The earth’s magnetic field at the place is 0.36 G and the angle of dip is zero. What is the total magnetic field on the normal bisector of the magnet at the same distance as the null–point (i.e., 14 cm) from the centre of the magnet? (At null points, field due to a magnet is equal and opposite to the horizontal component of earth’s magnetic field.)

Question 5.14 If the bar magnet in exercise 5.13 is turned around by 180º, where will the new null points be located?

Question 5.15 A short bar magnet of magnetic moment 5.25 × 10–2 J T–1 is placed with its axis perpendicular to the earth’s field direction. At what distance from the centre of the magnet, the resultant field is inclined at 45º with earth’s field on (a) its normal bisector and (b) its axis. Magnitude of the earth’s field at the place is given to be 0.42 G. Ignore the length of the magnet in comparison to the distances involved.

ADDITIONAL EXERCISES QUESTIONS

Question 5.16 Answer the following questions:
(a) Why does a paramagnetic sample display greater magnetisation (for the
(c) If a toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?
(d) Is the permeability of a ferromagnetic material independent of the magnetic field? If not, is it more for lower or higher fields?
(e) Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?
(f ) Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?

Question 5.17 Answer the following questions:
(a) Explain qualitatively on the basis of domain picture the irreversibility in the magnetisation curve of a ferromagnet.
(b) The hysteresis loop of a soft iron piece has a much smaller area than that of a carbon steel piece. If the material is to go through repeated cycles of magnetisation, which piece will dissipate greater heat energy?
(c) ‘A system displaying a hysteresis loop such as a ferromagnet, is a device for storing memory?’ Explain the meaning of this statement.
(d) What kind of ferromagnetic material is used for coating magnetic tapes in a cassette player, or for building ‘memory stores’ in a modern computer?
(e) A certain region of space is to be shielded from magnetic fields. Suggest a method .

Question 5.18 A long straight horizontal cable carries a current of 2.5 A in the direction 10º south of west to 10º north of east. The magnetic meridian of the place happens to be 10º west of the geographic meridian. The earth’s magnetic field at the location is 0.33 G, and the angle of dip is zero. Locate the line of neutral points (ignore the thickness of the cable). (At neutral points, magnetic field due to a current-carrying cable is equal and opposite to the horizontal component of earth’s magnetic field.)

Question 5.19 A telephone cable at a place has four long straight horizontal wires carrying a current of 1.0 A in the same direction east to west. The earth’s magnetic field at the place is 0.39 G, and the angle of dip is 35º. The magnetic declination is nearly zero. What are the resultant magnetic fields at points 4.0 cm below the cable?

Question 5.20 A compass needle free to turn in a horizontal plane is placed at the centre of circular coil of 30 turns and radius 12 cm. The coil is in a vertical plane making an angle of 45º with the magnetic meridian. When the current in the coil is 0.35 A, the needle points west to east.
(a) Determine the horizontal component of the earth’s magnetic field at the location.
(b) The current in the coil is reversed, and the coil is rotated about its vertical axis by an angle of 90º in the anticlockwise sense looking from above. Predict the direction of the needle. Take the magnetic declination at the places to be zero.

Question 5.21 A magnetic dipole is under the influence of two magnetic fields. The angle between the field directions is 60º, and one of the fields has a magnitude of 1.2 × 10–2 T. If the dipole comes to stable equilibrium at an angle of 15º with this field, what is the magnitude of the other field?

Question 5.22 A monoenergetic (18 keV) electron beam initially in the horizontal direction is subjected to a horizontal magnetic field of 0.04 G normal to the initial direction. Estimate the up or down deflection of the beam over a distance of 30 cm (me = 9.11 × 10–19 C). [Note: Data in this exercise are so chosen that the answer will give you an idea of the effect of earth’s magnetic field on the motion of the electron beam from the electron gun to the screen in a TV set.]

Question 5.23 A sample of paramagnetic salt contains 2.0 × 1024 atomic dipoles each of dipole moment 1.5 × 10–23 J T–1. The sample is placed under a homogeneous magnetic field of 0.64 T, and cooled to a temperature of 4.2 K. The degree of magnetic saturation achieved is equal to 15%. What is the total dipole moment of the sample for a magnetic field of 0.98 T and a temperature of 2.8 K? (Assume Curie’s law

Question 5.24 A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A?

Question 5.25 The magnetic moment vectors μs and μl associated with the intrinsic spin angular momentum S and orbital angular momentum l, respectively, of an electron are predicted by quantum theory (and verified experimentally to a high accuracy) to be given by: μs = –(e/m) S, μl = –(e/2m)l Which of these relations is in accordance with the result expected classically? Outline the derivation of the classical result


:: Chapter 6 - Electromagnetic Induction ::


Question 6.1 Predict the direction of induced current in the situations described by the following Figs. 6.18(a) to (f ).

Question 6.2 Use Lenz’s law to determine the direction of induced current in the situations described by Fig. 6.19:
(
a) A wire of irregular shape turning into a circular shape;
(b) A circular loop being deformed into a narrow straight wire.

Question 6.3 A long solenoid with 15 turns per cm has a small loop of area 2.0 cm2 placed inside the solenoid normal to its axis. If the current carried by the solenoid changes steadily from 2.0 A to 4.0 A in 0.1 s, what is the induced emf in the loop while the current is changing?

Question 6.4 A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the loop. What is the emf developed across the cut if the velocity of the loop is 1 cm s–1 in a direction normal to the (a) longer side, (b) shorter side of the loop? For how long does the induced voltage last in each case?

Question 6.5 A 1.0 m long metallic rod is rotated with an angular frequency of 400 rad s–1 about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant and uniform magnetic field of 0.5 T parallel to the axis exists everywhere. Calculate the emf developed between the centre and the ring.

Question 6.6 A circular coil of radius 8.0 cm and 20 turns is rotated about its vertical diameter with an angular speed of 50 rad s–1 in a uniform horizontal magnetic field of magnitude 3.0 × 10–2 T. Obtain the maximum and average emf induced in the coil. If the coil forms a closed loop of resistance 10 Ω, calculate the maximum value of current in the coil. Calculate the average power loss due to Joule heating. Where does this power come from?

Question 6.7 A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 m s–1, at right angles to the horizontal component of the earth’s magnetic field, 0.30 × 10–4 Wb m–2.
(a) What is the instantaneous value of the emf induced in the wire?
(b) What is the direction of the emf?
(c) Which end of the wire is at the higher electrical potential?

Question 6.8 Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s. If an average emf of 200 V induced, give an estimate of the self-inductance of the circuit.

Question 6.9 A pair of adjacent coils has a mutual inductance of 1.5 H. If the current in one coil changes from 0 to 20 A in 0.5 s, what is the change of flux linkage with the other coil?

Question 6.10 A jet plane is travelling towards west at a speed of 1800 km/h. What is the voltage difference developed between the ends of the wing

ADDITIONAL EXERCISES QUESTIONS

Question 6.11 Suppose the loop in Exercise Question 6.4 is stationary but the current feeding the electromagnet that produces the magnetic field is gradually reduced so that the field decreases from its initial value of 0.3 T at the rate of 0.02 T s–1. If the cut is joined and the loop has a resistance of 1.6 Ω, how much power is dissipated by the loop as heat? What is the source of this power?

Question 6.12 A square loop of side 12 cm with its sides parallel to X and Y axes is moved with a velocity of 8 cm s–1 in the positive x-direction in an environment containing a magnetic field in the positive z-direction. The field is neither uniform in space nor constant in time. It has a gradient of 10 –3 T cm–1 along the negative x-direction (that is it increases by 10 – 3 T cm–1 as one moves in the negative x-direction), and it is decreasing in time at the rate of 10 –3 T s–1. Determine the direction and magnitude of the induced current in the loop if its resistance is 4.50 mΩ.

Question 6.13 It is desired to measure the magnitude of field between the poles of a powerful loud speaker magnet. A small flat search coil of area 2 cm2 with 25 closely wound turns, is positioned normal to the field direction, and then quickly snatched out of the field region. Equivalently, one can give it a quick 90° turn to bring its plane parallel to the field direction). The total charge flown in the coil (measured by a ballistic galvanometer connected to coil) is 7.5 mC. The combined resistance of the coil and the galvanometer is 0.50 Ω. Estimate the field strength of magnet.

Question 6.14 Figure 6.20 shows a metal rod PQ resting on the smooth rails AB and positioned between the poles of a permanent magnet. The rails, the rod, and the magnetic field are in three mutual perpendicular directions. A galvanometer G connects the rails through a switch K. Length of the rod = 15 cm, B = 0.50 T, resistance of the closed loop containing the rod = 9.0 mΩ. Assume the field to be uniform.
(a) Suppose K is open and the rod is moved with a speed of 12 cm s–1 in the direction shown. Give the polarity and magnitude of the induced emf. experience magnetic force due to the motion of the rod. Explain.
(d) What is the retarding force on the rod when K is closed?
(e) How much power is required (by an external agent) to keep the rod moving at the same speed (=12 cm s–1) when K is closed? How much power is required when K is open?
(f ) How much power is dissipated as heat in the closed circuit? What is the source of this power?
(g) What is the induced emf in the moving rod if the magnetic field is parallel to the rails instead of being perpendicular?

Question 6.15 An air-cored solenoid with length 30 cm, area of cross-section 25 cm2 and number of turns 500, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10–3 s. How much is the average back emf induced across the ends of the open switch in the circuit? Ignore the variation in magnetic field near the ends of the solenoid.

Question 6.16 (a) Obtain an expression for the mutual inductance between a long straight wire and a square loop of side a as shown in Fig. 6.21.
(b) Now assume that the straight wire carries a current of 50 A and the loop is moved to the right with a constant velocity, v = 10 m/s. Calculate the induced emf in the loop at the instant when x = 0.2 m. Take a = 0.1 m and assume that the loop has a large resistance.

Question 6.17 A line charge λ per unit length is lodged uniformly onto the rim of a wheel of mass M and radius R. The wheel has light non-conducting spokes and is free to rotate without friction about its axis (Fig. 6.22). A uniform magnetic field extends over a circular region within the rim. It is given by, B = – B0 k (r ≤ a; a < R) = 0 (otherwise) What is the angular velocity of the wheel after the field is suddenly switched off?


:: Chapter 7 - Alternating Current ::


Question 7.1 A 100 Ω resistor is connected to a 220 V, 50 Hz ac supply.
(a) What is the rms value of current in the circuit?
(b) What is the net power consumed over a full cycle?

Question 7.2(a) The peak voltage of an ac supply is 300 V. What is the rms voltage?
(b) The rms value of current in an ac circuit is 10 A. What is the peak current?

Question 7.3 A 44 mH inductor is connected to 220 V, 50 Hz ac supply. Determine the rms value of the current in the circuit.

Question 7.4 A 60 μF capacitor is connected to a 110 V, 60 Hz ac supply. Determine the rms value of the current in the circuit.

Question 7.5 In Exercises 7.3 and 7.4, what is the net power absorbed by each circuit over a complete cycle. Explain your answer.

Question 7.6 Obtain the resonant frequency ωr of a series LCR circuit with L = 2.0H, C = 32 μF and R = 10 Ω. What is the Q-value of this circuit?

Question 7.7 A charged 30 μF capacitor is connected to a 27 mH inductor. What is the angular frequency of free oscillations of the circuit?

Question 7.8 Suppose the initial charge on the capacitor in Exercise

Question 7.7 is 6 mC. What is the total energy stored in the circuit initially? What is the total energy at later time?

Question 7.9 A series LCR circuit with R = 20 Ω, L = 1.5 H and C = 35 μF is connected to a variable-frequency 200 V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?

Question 7.10 A radio can tune over the frequency range of a portion of MW broadcast band: (800 kHz to 1200 kHz). If its LC circuit has an effective inductance of 200 μH, what must be the range of its variable capacitor? [Hint: For tuning, the natural frequency i.e., the frequency of free oscillations of the LC circuit should be equal to the frequency of the radiowave.]

Question 7.11 Figure 7.21 shows a series LCR circuit connected to a variable frequency 230 V source. L = 5.0 H, C = 80μF, R = 40 Ω.
(a) Determine the source frequency which drives the circuit in resonance.
(b) Obtain the impedance of the circuit and the amplitude of current at the resonating frequency.
(c) Determine the rms potential drops across the three elements of the circuit. Show that the potential drop across the LC combination is zero at the resonating frequency.

ADDITIONAL EXERCISES QUESTIONS

Question 7.12 An LC circuit contains a 20 mH inductor and a 50 μF capacitor with an initial charge of 10 mC. The resistance of the circuit is negligible. Let the instant the circuit is closed be t = 0 .
(a) What is the total energy stored initially? Is it conserved during LC oscillations?
(b) What is the natural frequency of the circuit?
(c) At what time is the energy stored
(i) completely electrical (i.e., stored in the capacitor)?
(ii) completely magnetic (i.e., stored in the inductor)?
(d) At what times is the total energy shared equally between the inductor and the capacitor?
(e) If a resistor is inserted in the circuit, how much energy is eventually dissipated as heat?

Question 7.13 A coil of inductance 0.50 H and resistance 100 Ω is connected to a 240 V, 50 Hz ac supply.
(a) What is the maximum current in the coil?
(b) What is the time lag between the voltage maximum and the current maximum?

Question 7.14 Obtain the answers (a) to (b) in Exercise 7.13 if the circuit is connected to a high frequency supply (240 V, 10 kHz). Hence, explain the statement that at very high frequency, an inductor in a circuit nearly amounts to an open circuit. How does an inductor behave in a dc circuit after the steady state?

Question 7.15 A 100 μF capacitor in series with a 40 Ω resistance is connected to a 110 V, 60 Hz supply.
(a) What is the maximum current in the circuit?
(b) What is the time lag between the current maximum and the voltage maximum?

Question 7.16 Obtain the answers to (a) and (b) in Exercise 7.15 if the circuit is connected to a 110 V, 12 kHz supply? Hence, explain the statement that a capacitor is a conductor at very high frequencies. Compare this behaviour with that of a capacitor in a dc circuit after the steady state.

Question 7.17 Keeping the source frequency equal to the resonating frequency of the series LCR circuit, if the three elements, L, C and R are arranged in parallel, show that the total current in the parallel LCR circuit is minimum at this frequency. Obtain the current rms value in each branch of the circuit for the elements and source specified in Exercise 7.11 for this frequency.

Question 7.18 A circuit containing a 80 mH inductor and a 60 μF capacitor in series is connected to a 230 V, 50 Hz supply. The resistance of the circuit is negligible.
(a) Obtain the current amplitude and rms values
(b) Obtain the rms values of potential drops across each element.
(c) What is the average power transferred to the inductor?
(d) What is the average power transferred to the capacitor?
(e) What is the total average power absorbed by the circuit? [‘Average’ implies ‘averaged over one cycle’.]

Question 7.19 Suppose the circuit in Exercise 7.18 has a resistance of 15 Ω. Obtain the average power transferred to each element of the circuit, and the total power absorbed. Physics 268

Question 7.20 A series LCR circuit with L = 0.12 H, C = 480 nF, R = 23 Ω is connected to a 230 V variable frequency supply.
(a) What is the source frequency for which current amplitude is maximum. Obtain this maximum value.
(b) What is the source frequency for which average power absorbed by the circuit is maximum. Obtain the value of this maximum power.
(c) For which frequencies of the source is the power transferred to the circuit half the power at resonant frequency? What is the current amplitude at the

          Fluoride levels in Beers and Stouts sold in Ireland   









Beer can contain significant levels of fluoride and can in themselves depending on consumption be a significant contribution to the dietary intake of fluoride. For many adults especially those with alcohol addictions or for individuals who consumer relatively large volumes of beers or stouts regularly, the dietary intake of fluorides from this source may significantly exceed that of consuming drinking water.

No accurate database is available providing comprehensive data on fluoride content of beverages, foodstuffs or medications in Ireland. Prior to 2011 no data was available from the Food Safety Authority of Ireland (FSAI) on fluoride levels in foods and beverages. This is despite the fact that the World Health Organisation recommend that prior to commencement of water fluoridation programmes the total dietary exposure of the population for all sectors must be accurately determined, so as to avoid over chronic exposure of the population to fluoride. The WHO Guidelines for Drinking Water recommend that “when setting national standards for fluoride that it is particularly important to consider volume of water intake and intake of fluoride from other sources.”[i] 

The WHO has consistently and correctly stated that "in the assessment of the safety of a water supply with respect to the fluoride concentration, the total daily fluoride intake by the individual must be considered." Similarly the WHO have advised  “that in countries with large water-fluoridation programmes, fluoridated water may be used in food processing, raising the fluoride content of the processed food above that of products for which unfluoridated water has been used. This is particularly important when baby foods are prepared and means that details of the nutrients, including fluoride, should be printed on the packages.”[ii]


It is deeply worrying that despite this recommendation from the WHO no proper dietary fluoride risk assessment has been undertaken in the ROI and that no database is readably available for the public to examine or calculate their fluoride exposure form foodstuffs and beverages.  As with any foodstuff or beverage such as tea, any product produced in Ireland that uses public water supplies will have elevated fluoridated levels. This includes soft drinks, alcoholic beverages and fruit drinks. Despite the warning of the WHO no data on the fluoride content is provided on any packaging in Ireland.

The first attempt to measure the fluoride exposure of the Irish population was undertaken by the  FSAI in 2011. The Total Diet Survey reported fluoride levels in beers sold in Ireland of less than 0.05mg per litre. No data was provided on the brands of beverages tested.
 
To check the accuracy of the data provided in the FSAI report independent scientific testing of forty two alcoholic beverages was undertaken following the American Society of Testing and Material (ASTM) and EPA standard methodologies for fluoride determination. The results conclusively demonstrated that the levels of fluoride reported by the FSAI were grossly inaccurate. A literature review of published data supported this observation.
In contrast to the data provided by the FSAI, Warnakulasuriya et al. (2002) reported mean fluoride concentrations of 0.08–0.71mg/L in beers available in Great Britain; with one Irish beer contained fluoride at 1.12mg/L.[iii] 

The authors of the latter study concluded that beers brewed in locations with high fluoride water levels may contribute significantly to the daily fluoride intake, particularly in alcohol misusing subjects and this may contribute to alcohol-associated bone disease. Marier and Rose (1996) reported that the fluoride content of beer varies according to the fluoride content of process water.[iv]At 0-0.2 ppm fluoride in drinking/process water the fluoride content of beer has been measured at 0.3mg/L. For 1ppm process water 0.7ppm was recorded. 

 The U.S Department of Agriculture (2005) similarly published measured fluoride levels in beers and wines; the mean  concentrations for beers was 0.45 mg/l, 1.05mg/l for red wine and 2.01mg/l for white wine respectively.[v] 

The NRC scientific committee (2006) reported that the typical fluoride levels in beers ranged from 0.08 - 1 mg/L and wine 0.2 – 3.0 mg/L.[vi]

Similarly the WHO reported that Dabeka and Mckenzie (1995)[vii]measured fluoride level of beers in Canada with a range from 0.2mg/l to 0.96mg/L. [viii]
Independent testing of alcoholic beverages undertaken for this study measured the fluoride content in approximately 40 beers and stouts available on the Irish market. The highest fluoride levels in beers produced were as expected from fluoridated countries (Ireland and New Zealand) or countries

FLUORIDE MEASUREMENT PROCEDURE

Fluoride content of all samples was determined by direct potentiometric methods using a fluoride ion selective electrode. The potentiometric technique is considered the simplest and most reliable for fluoride determination. This method utilizes a fluoride selective membrane (Europium doped lanthanum fluoride single crystal cell) immersed in the solutions after buffering with TISAB (Total Ionic Strength Adjustment Buffer) reagent. Readings on the ion analyzer (Extech EXFL700 fluoride meter) were recorded after 3 min of infusion. 

The EXFL700 allows the users to follow the American Society of Testing and Material (ASTM) and EPA standard methodology using TISAB reagents and certified standard solutions. The accuracy of the instrument is ± 3% of reading or ± 0.1ppm (whichever is greater). Calibration standards were prepared using fluoride standard solution (certified 100ppm Eutech fluoride standard) added to plastic labware and diluted with deionized water. All samples and standards used were at the same temperature for precise measurement.

RESULTS

 




Gambar 1. Mesin Las Busur Rendam
Perlu adanya pengaturan kecepatan pengumpanan kawat las yang dapat diubah-ubah untuk mendapatkan panjang busur yang diperlukan. Bila menggunakan sumber listrik DC dengan tegangan tetap, kecepatan pengumpanan dapat dibuat tetap dan biasanya menggunakan polaritas balik (DCRP). Mesin las dengan listrik DC kadang-kadang digunakan untuk mengelas pelat tipis dengan kecepatan tinggi atau untuk pengelasan dengan eletroda lebih dari satu.
Keuntungan Las Busur Rendam:
Kualitas Las baik
Penetrasi cukup
Bahan las hemat
Tidak perlu operator trampil
Dapat memakai arus yang tinggi
Kerugian Las Busur Rendam:
Sulit menentukan hasil seluruh pengelasan
Posisi pengelasan hanya horisontal
Penggunaan sangat terbatas
Tungsten Inert Gas
Pengelasan ini pertama kali ditemukan di USA (1940), berawal dari pengelasan paduan untuk bodi pesawat terbang.
Prinsip : Panas dari busur terjadi diantara elektrode tungsten dan logam induk akan meleburkan logam pengisi ke logam induk di mana busurnya dilindungi oleh gas mulia (Ar atau He)
Las ini memakai elektroda tungsten yang mempunyai titik lebur yang sangat tinggi (3260 C) dan gas pelindungnya Argon/Helium. Sebenarnya masih ada gas lainnya, seperti xenon. Tetapi karena sulit didapat maka jarang digunakan.
Dalam penggunaannya tungsten tidak ikut mencair karena tungsten tahan panas melebihi dari logam pengisi. Karena elektrodanya tidak ikut mencair maka disebut elektroda tidak terumpan.
Keuntungan : Digunakan untuk Alloy Steel, Stainless Steel maupun paduan Non Ferrous: Ni, Cu, Al (Air Craft). Disamping itu mutu las bermutu tinggi, hasil las padat, bebas dari porositas dan dapat untuk mengelas berbagai posisi dan ketebalan.
Dibandinkan dengan Carbon Arc Welding, tungsten memiliki beberapa keunggulan. Pada umumnya Tungsten Arc Welding hampir sama dengan Carbon Arc Welding.
Persamaannya:
Sumber arusnya sama (Power Supply/Welding Circuit)
Memakai Elektroda kawat
Dikhususkan Hanya untuk las
Perbedaannya:
Carbon Arc Welding memakai fluks (Coating), TIG memakai gas pelindung.
Elektroda pada Carbon Arc Welding ikut mencair sebagai logam pengisi, TIG elektrodanya tidak ikut mencair.
Carbon Arc Welding tidak perlu filler metal, TIG diperlukan filler metal.

          Single-molecule spectroelectrochemical cross-correlation during redox cycling in recessed dual ring electrode zero-mode waveguides   

Chem. Sci., 2017, Advance Article
DOI: 10.1039/C7SC02250F, Edge Article
Open Access Open Access
Creative Commons Licence  This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
Donghoon Han, Garrison[space]M. Crouch, Kaiyu Fu, Lawrence P. Zaino III, Paul W Bohn
The ability of zero-mode waveguides (ZMW) to guide light into subwavelength-diameter nanoapertures has been exploited for studying electron transfer dynamics in zeptoliter-volume nanopores under single-molecule occupancy conditions.
To cite this article before page numbers are assigned, use the DOI form of citation above.
The content of this RSS Feed (c) The Royal Society of Chemistry

          Light Me Up!   
Technology for off-the-shelf power generating clothes is here
  • Female jogger standing in field with hands on hips
A lightweight, comfortable jacket that can generate the power to light up a jogger at night may sound futuristic, but UMass Amherst materials scientist Trisha Andrew could make one today. She and colleagues have invented a way to apply breathable, pliable, metal-free electrodes to fabric and off-the-shelf clothing so it feels good to the touch and also transports enough electricity to power small electronics.

Andrew says, “Our lab works on textile electronics. We aim to build up the materials science so you can give us any garment you want, any fabric, any weave type, and turn it into a conductor. Such conducting textiles can then be built up into sophisticated electronics. One such application is to harvest body motion energy and convert it into electricity in such a way that every time you move, it generates power.” Powering advanced fabrics that can monitor health data remotely are important to the military and increasingly valued by the health care industry, she notes.

Generating small electric currents through relative movement of layers is called triboelectric charging, explains Andrew, who trained as a polymer chemist and electrical engineer. Materials can become electrically charged as they create friction by moving against a different material, like rubbing a comb on a sweater. “By sandwiching layers of differently materials between two conducting electrodes, a few microwatts of power can be generated when we move,” she adds.

In the current early online edition of Advanced Functional Materials, she and postdoctoral researcher Lushuai Zhang in her lab describe the vapor deposition method they use to coat fabrics with a conducting polymer, poly(3,4-ethylenedioxytiophene) also known as PEDOT, to make plain-woven, conducting fabrics that are resistant to stretching and wear and remain stable after washing and ironing. The thickest coating they put down is about 500 nanometers, or about 1/10 the diameter of a human hair, which retains a fabric’s hand feel.

The authors report results of testing electrical conductivity, fabric stability, chemical and mechanical stability of PEDOT films and textile parameter effects on conductivity for 14 fabrics, including five cottons with different weaves, linen and silk from a craft store.

“Our article describes the materials science needed to make these robust conductors,” Andrew says. “We show them to be stable to washing, rubbing, human sweat and a lot of wear and tear.” PEDOT coating did not change the feel of any fabric as determined by touch with bare hands before and after coating. Coating did not increase fabric weight by more than 2 percent. The work was supported by the Air Force Office of Scientific Research.

Until recently, she and Zhang point out, textile scientists have tended not to use vapor deposition because of technical difficulties and high cost of scaling up from the laboratory. But over the last 10 years, industries such as carpet manufacturers and mechanical component makers have shown that the technology can be scaled up and remain cost-effective. The researchers say their invention also overcomes the obstacle of power-generating electronics mounted on plastic or cladded, veneer-like fibers that make garments heavier and/or less flexible than off-the-shelf clothing “no matter how thin or flexible these device arrays are.”

“There is strong motivation to use something that is already familiar, such as cotton/silk thread, fabrics and clothes, and imperceptibly adapting it to a new technological application.” Andrew adds, “This is a huge leap for consumer products, if you don’t have to convince people to wear something different than what they are already wearing.”

Test results were sometimes a surprise, Andrew notes. “You’d be amazed how much stress your clothes go through until you try to make a coating that will survive a shirt being pulled over the head. The stress can be huge, up to a thousand newtons of force. For comparison, one footstep is equal to about 10 newtons, so it’s yanking hard. If your coating is not stable, a single pull like that will flake it all off. That’s why we had to show that we could bend it, rub it and torture it. That is a very powerful requirement to move forward.”

Andrew is director of wearable electronics at the Center for Personalized Health Monitoring in UMass Amherst’s Institute of Applied Life Sciences (IALS). Since the basic work reported this month was completed, her lab has also made a wearable heart rate monitor with an off-the-shelf fitness bra to which they added eight monitoring electrodes. They will soon test it with volunteers on a treadmill at the IALS human movement facility.

She explains that a hospital heart rate monitor has 12 electrodes, while the wrist-worn fitness devices popular today have one, which makes them prone to false positives. They will be testing a bra with eight electrodes, alone and worn with leggings that add four more, against a control to see if sensors can match the accuracy and sensitivity of what a hospital can do. As the authors note in their paper, flexible, body-worn electronics represent a frontier of human interface devices that make advanced physiological and performance monitoring possible.  

For the future, Andrew says, “We’re working on taking any garment you give us and turning it into a solar cell so that as you are walking around the sunlight that hits your clothes can be stored in a battery or be plugged in to power a small electronic device.”

Zhang and Andrew believe their vapor coating is able to stick to fabrics by a process called surface grafting, which takes advantage of free bonds dangling on the surface chemically bonding to one end of the polymer coating, but they have yet to investigate this fully.

"We aim to build up the materials science so you can give us any garment you want, any fabric, any weave type, and turn it into a conductor."

-Trisha Andrew


          (USA-DE-Dover) Utility Maintenance Mechanic I   
This job was posted by https://joblink.delaware.gov : For more information, please see: https://joblink.delaware.gov/ada/r/jobs/518732 The City of Dover Public Works Department is seeking qualified applicants for the position of Utility Maintenance Mechanic I in the Wastewater Division. The essential function of the position within the organization is maintenance and repair of the City's 44 wastewater pump stations. The duties of the Utility Maintenance Mechanic I will include the following: inspecting wastewater pump stations daily to ensure proper functioning, performing preventive maintenance and troubleshooting (mechanical, plumbing and electrical), maintaining logs and records for area of responsibility, and preparing routine reports. Problem solving ability and the ability to perform in demanding, high stress, emergency situations that require quick decision making skills is a must. Duties will also include the following: performing preventive maintenance on wastewater pumping stations; washing grease and debris from wet wells, checking valves for proper operation, cleaning check valves, floats, domes, and electrodes, packing glands and pumps, replacing seals, and greasing pump; repairing pumping stations and replacing equipment such as electrical starters, coils, mercury switches, electrodes, sealtrodes, floats, valves, or small compressors; cleaning dry wells and outside of pumping station, including painting building, applying seal coat to parking areas, and escorting weed control contractor; dumping waste container; replacing equipment bulbs and performing seasonal tasks such as snow removal.
          Boat Moves Without an Engine Or Sails w/video   
KeelyNet "Researchers say technology they have developed would let boats or small aquatic robots glide through the water without the need for an engine, sails or paddles. A University of Pittsburgh research team has designed a propulsion system that uses the natural surface tension that is present on the water's surface and an electric pulse to move the boat or robot, researchers said. The Pitt system has no moving parts and the low-energy electrode that emits the pulse could be powered by batteries, radio waves, or solar power, researchers said in a statement." / One of the system's primary applications could be as a cheap, environment-friendly robot that could traverse the world's oceans, gathering research data, Cho said. Pitt researchers said that in their experiments, an electrode attached to a 2-centimeter-long "mini-boat" emitted a surge that changed the rear surface tension direction and propelled the boat at roughly 4 millimeters per second. A second electrode attached to the boat's front side served as the rudder. The Pitt system is similar to the MIT developed robot known as a Robostrider.
          Welder - Texas Hydraulics, Inc - Temple, TX   
Strikes (forms) arc which generates heat to melt and deposit metal from electrode to work piece and join edges of work piece....
From Indeed - Wed, 31 May 2017 18:08:09 GMT - View all Temple, TX jobs
          Gesture recognition with Arduino   

Pinned onto Open Electronics

  With the board described here, we will interface the electrode board for gesture recognition to Arduino.   To take advantage of the potential of the MGC3130 integrated circuit, we thought of developing a new electrode having the possibility to connect (in addition to our demo board, that we saw in the previous episode), even […]

          Gesture recognition with Raspberry Pi and GestIC   

Pinned onto Open Electronics

  Let’s couple the 3D gesture recognition electrode to Raspberry Pi, in order to create an application with which the pictures can be scrolled on a HDMI screen, by means of gestures.   In an another post we described a new GestIC electrode, which has been developed and created for the purpose of interfacing the Arduino Uno […]

          All-printed paper based surface mountable supercapacitors   
Supercapacitors have drawn numerous attentions in recent years since they can deliver relatively high power and energy densities. This article introduces an all-printed paper based surface mountable supercapacitor (SMS), which could withstand the reflow soldering process when integrated into microelectronic systems. The device was fabricated by screen printing and stencil printing processes, contributing to low cost and large-scale fabrication. Furthermore, building electronic devices on ubiquitous paper substrates had advantages of light weight, low cost, and eco-friendliness, etc. Based on activated carbon electrode material and ionic liquid electrolyte, the capacity of the supercapacitor could reach 14 mF at the device volume of 3.2 mm × 2.5 mm × 0.175 mm, besides, the specific volumetric capacity was superior than most of the commercial SMS devices.
          Temperature-dependent surface charge behavior of polypropylene film under DC and pulse voltages   
Film capacitors are constructed with polymer films as the dielectric material, among which polypropylene (PP) has the highest breakdown strength and excellent thermal performance. Accumulation of static charge on the polymer film surface between electrode segments may induce surface discharge causing energy loss and accelerating electrical aging of insulation material in the capacitor. In the application of pulsed power systems, the capacitor faces temperature rise and multiple electrical stresses, which will influence the surface charge behavior of the polymer film. The paper is dedicated to research on the influence of temperature and different voltage waveforms on the surface charge and trap characteristics of PP film. The PP film was corona charged with needle-plate electrodes by DC voltage and combination of DC and pulse voltage, respectively, and the surface potential decay was conducted at different temperature. It is found that the rise of temperature can significantly enhance de-trapping of the surface charge in deep traps, thus accelerating the surface charge decay. Under DC voltage, the accumulation of surface charge shows no relation with temperature, while the decay is dominated by both electric field and temperature. Under multi-stress of DC and pulse voltage, however, the surface charge accumulation is influenced by temperature due to its impact on surface charge coupling. And the decay of surface charge becomes complicated with coupling process as well, in which the electrical field, trap level and density show inconsistency with the decay under different temperature.
          Large-area approach to evaluate DC electro-thermal ageing behavior of BOPP thin films for capacitor insulation systems   
A large-area electro-thermal ageing test setup was developed and utilized to age several laboratory-scale biaxially oriented polypropylene (BOPP)-hydrophobic silica nanocomposite films. The films were aged in test capacitors with self-healing metallized film electrodes, which enabled the ageing test to continue beyond the first breakdowns. Eight different films were aged for 1000 hours under 100 V/μm DC stress at 75 °C, and large-area DC breakdown measurements, dielectric spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and dielectric spectroscopy were used to detect localized and bulk degradation after the ageing period. The effects of antioxidant contents, different PP grades and compounder screw speed were evaluated. Material characterization indicates no bulk degradation had occurred during ageing, which was associated with moderate temperature stress and inert nitrogen atmosphere. On the other hand, low-field breakdowns (weak points) were observed in all but two of the aged materials, indicating that ageing was dominated by localized degradation which may have introduced new breakdown mechanisms. Weak points were also measured in a similarly aged commercial capacitor-grade BOPP film aged at a lower field, supporting this conclusion. The importance of long-term characterization in material development is demonstrated, and it is shown that long-term properties of the evaluated nanocomposites were at least on the same level compared to neat BOPP films.
          Analytical model for determination of the unipolar ionic saturation current during positive corona discharge for geometries comprising cylindrical emitter electrodes   
This paper presents an analytical model for the assessment of the unipolar corona saturation current limit for positive corona discharge in air, based on the determination of the field line lengths and trajectories. The model is applicable to emitter electrodes with a cylindrical surface facing a plane or an identical cylindrical collector electrode, if their spatial characteristics, the ion mobility of the surrounding medium and the applied voltage are known. Experimental investigation is performed to compare the results of the unipolar corona saturation current limit from the proposed model to the actual corona current flow in an experimental setup that comprises cylindrical emitters of various radii, facing a plane electrode. Both the total current amplitude and the current density distribution over the collecting electrode's surface have been examined.
          Experimental study on the movement of non-spherical particles in nonuniform electric field   
The deactivation of free particles is an important issue for improving the insulating capability and reliability of high-voltage systems. In this work, we carry out experiments to investigate the electromechanical behavior of the non-spherical conducting particles for different particle orientations on either bare or coated electrode. Spheroidal and wire-shaped particles are used for the experiments. The particle motion is observed for two principal orientations with respect to the applied electric field in air. The results show that on a bare electrode, both kinds of particles exhibit the liftoff motion when the particle axis is aligned with electric field gradient. The field nonuniformity enhances the upward rotation of the particle tip subjected to the higher electric field. When the particle axis is parallel with a constant field line, the wire-shaped particle is more readily to make a rolling motion to the region of stronger electric field in comparison with the spheroidal particle, which shows higher occurrence rate of liftoff. The motion onset electric field decreases with increasing field nonuniformity. On the insulated electrode, the wire-shaped particle shows exclusively the rolling motion, whereas the spheroidal particle may make a rolling motion or rotate horizontally so as to align its axis with electric field gradient.
          Motion and discharge characteristics of metal particles existing in GIS under DC voltage   
Free particles formed in the discharge process or equipment aging severely threaten the operation security of GIS, which draws great attention of researchers. However, seldom research focuses on disc-type particle, which is the majority of shaped particles in practical GIS. In this paper, an elliptic coordination system is built for obtaining the theoretical lift-off electric field of disc-type particles, and experimental system and observation system are established for studying motion behavior and discharge characteristics of metal particles. Results show that for spherical particles, while the distance between two particles d<;9rs, the downward force caused by impurities on electrodes can be neglected; for wire-type particles, as lengths of particles increase, lift-off electric fields and probabilities of Firefly tend to be larger. Besides, lift-off electric fields grow exponentially with the increases of radius. When length of particle exceeds 3 mm, the gap between practical values and theoretical values becomes larger with the decrease of radiuses; for disc-type particles, with the increase of radiuses, dispersions of lift-off electric field becomes larger; the difference between practical and theoretical values broadens with the fall of radiuses. Besides, lift-off electric fields of disc-type particles are higher than that of wire-type particles with same qualities and with the increase of radius, probabilities of Firefly increase in an unapparent speed in comparison to wire-type particles; in the end, discharge processes in SF6 gap are illustrated. When particles are close to the bottom electrode, the lower end of particles will breakdown first. Then the top end of particles will form streamer discharge. With the continuous development of streamer, the gap will eventually breakdown.
          Effective ionization coefficients and limiting field strength of fluoronitriles-CO2 mixtures   
The density normalized effective ionization coefficients and critical breakdown electric field of the Heptafluoro-iso-butyronitrile (Fluoronitriles), and Fluoronitriles-CO2 mixture are investigated using the steady state Townsend (SST) experimental setup, over a range of the density normalized critical electric field (E/N) from 200-1066 Td (E is the electric field and N the gas density). Breakdown voltage measurements are also performed to plot the Paschen curves for small product values (N×d) (d being the electrode gap), to identify the Paschen minimum, and to validate the density normalized critical electric field (E/N)0 when α=η (α and η are the ionization and attachment coefficients, respectively). The influence of electrode surface roughness is also analyzed.
          A thermo-electrodynamic electric field dependent molecular ionization model to realize positive streamer propagation in a wet-mate DC connector   
Complete subsea factory concept, an equivalent of the full topsides processing facility to be operated on the seabed, is envisaged to power longer, deeper and colder subsea oil and gas fields in the future. This concept has been envisioned through a modular stacked subsea DC transmission and distribution system whose subsea umbilical cables and electrical power component on the seabed can be interfaced with each other by wet-mate (WM) DC connectors. Laboratory and theoretical investigations have been carried out to assess various electrical insulation systems and electrode geometries for a WM DC connector which should operate in the steady state as well as switching transients in a corrosive environment for high reliability and minimum maintenance in its lifetime. In this paper, the electrical insulation performance of a needle-sphere electrode geometry defined by IEC 60897 under a positive step voltage is studied. To approach the complicated solid-liquid insulation system envisaged in a WM DC connector after mating, the electrodes are covered by a dielectric solid and oil is enclosed by the dielectric solid as well. A full thermo-electrodynamic electric field dependent molecular ionization Multiphysics model was developed for the simulation of streamer initiation and growth in the oil while dielectric solid is modeled as a perfect insulator. It is shown that stabilization methods, mesh strategies and time step have a great influence on simulation results and guidelines to choose them properly are presented. Based on simulation results, it was found that the higher relative permittivity of the solid insulation the slower streamer propagation in the oil and the less electrical stress on the solid insulation.
          Comparative analysis of lightning breakdown voltage of natural ester liquids of different viscosities supported by light emission measurement   
This article presents the results of the studies on lightning impulse breakdown voltage measurements performed for two commercial natural ester liquids of different viscosities. These viscosities measured at 100°C were 8.0 mm2/s and 4.6 mm2/s respectively. The dielectric test results presented in this paper concern the measurements performed using the recommendations of the IEC 897 standard where point-to-sphere electrode system is dictated. In addition to measuring the breakdown voltage other experimental techniques were applied such as time to breakdown estimation, light emission registration using the photomultiplier and static photograph collection. The results showed that the differences between the liquids tested concern only positive polarity of lightning impulse voltage. In the case of negative polarity from the standard based calculations and statistical analysis using Weibull distribution the breakdown voltages may be treated as a very similar. In turn the other discharge characteristics such as light waveforms, static photographs and propagation velocities did not showed any differences. In the case of positive lightning breakdown voltage the results were assessed only on the basis of the average values calculated because a deep statistical analysis was not possible due to the small scattering of data. These results indicated on slightly better lightning properties of the natural ester of higher viscosity. Confirmation of this conclusion shall constitute the light waveforms registered where the discharges developing in the low viscosity natural ester are characterized by higher intensity than corresponding discharges developing in the “classical” natural ester. However the static photos did not indicate any differences between the esters tested.
          Calculation model for predicting partial-discharge inception voltage in a non-uniform air gap while considering the effect of humidity   
A calculation model for predicting the inception of partial discharge (PD) in a non-uniform air gap on the basis of theories of electron avalanche and streamer phenomena is proposed. “Partial discharge inception voltages” (PDIVs), under an assumed absolute humidity of less than 20g/cm3, calculated using the proposed model were compared with experimentally measured ones and found to be almost equivalent. Furthermore, the relationship between negative ions and humidity was incorporated into the calculation model, and it was confirmed that the calculated and measured PDIVs tend to be the roughly the same under a wide humidity range under various gap length between electrodes. The proposed partial-discharge inception model based on theories mentioned above was therefore judged to be effective for predicting changes in PDIV when humidity changes.
          Aging characteristics of epoxy resin discharged by very fast transient overvoltage in SF6   
Surface flashover on epoxy resin (EP) materials, as driven by very fast transient-pulse overvoltage, was studied in this research. Flashover experiments were conducted using a nanosecond pulsed power supply in SF6, and then the morphology and the elemental composition of the material surface after different degrees of aging treatment were analyzed. The results show that, the flashover voltage of EP materials driven by nanosecond pulses increases with the increment of SF6 pressure. While, with increasing pulse repetition frequency (PRF), the flashover voltage decreases: this trend is especially significant under a lower PRF. In the aging process, the EP on the material surface in front of the electrodes was cleared by the electrical arc, exposing the alumina particles in the lower layer of the material. As the aging time increases, the organic compounds, which were bubble-shaped and sputtered out by the electrical arc, gradually covered the surface of the alumina particles. In addition, the surface morphology in the area closer to the electrodes changes more significantly, while the material surface below the electrodes, and at the edge of the discharge area, experiences less damage. This research is of significance to those seeking to modify the insulating performance, and aging resistance, of EP insulating materials.
          Influence of temperature on the characteristics of surface charge accumulation on PTFE model insulators   
During the operation of gas insulated switchgear (GIS) and gas insulated line (GIL), the conducting bar generates joule heat, and a non-uniform distribution of temperature forms in the bulk of the insulators. As the load varies, the temperature distribution changes, and it has an influence on the bulk conductivity of the insulators. Moreover, the surface charge accumulation can be affected. In order to clarify this, a surface charge measurement system which could achieve temperature control was constructed, and a model insulator with truncated cone type was employed, as well as two types of high-voltage electrodes, i.e. plate and needle electrodes. It is found that both polarities of charges existed on the insulator surface when a dc high voltage was applied to the plate or needle electrode, and homo-charge density was much higher than that of hetero-one. As for the plate electrode, homo-charges resulted from micro-discharges, while generated by corona in the case with needle electrode. As temperature increased, homo-charge density decreased, kept unchanged and increased for three cases, respectively, i.e. when dc voltage was applied to the plate electrode, and when voltage of 3 and 20 kV was applied to the needle electrode. Moreover, a simulation model involving multi-physics was established, which included heat conduction in solid and transient field changing from the initial capacitive to stationary resistive field distribution. It is proved that the electric conduction of the insulator bulk contributed to the accumulation of hetero-charges, and temperature could enhance this. Besides, when temperature increased, the corona inception voltage reduced, and hence the homo-charge density increased. Due to the effect of neutralization and the differences in the sensitivity of corona with different intensity to temperature, the tendency of homo-charge density changing with temperature for the three cases showed distinct in the experiments.
          Space charge formation in polyimide films and polyimide/SiO2 double-layer measured by LIMM   
For Polyimides (PI) used as insulating inter-layers or passivation layers in microelectronics and power electronics, reliability and failure mechanisms are intimately linked to phenomena such as non-linear conduction, distortion of field distribution and electrical ageing that have all some relation to space charge processes. Knowledge about these space charge distributions is therefore of importance to optimize structures and designs involving PIs. However, in the thickness scale of interest for such applications, of the order of 10 μm, no results were reported for PI, and only scarce studies for other materials. Space charge measurements carried out on PI using the laser intensity modulation method (LIMM) are reported in this work. PI-containing metal-insulator-semiconductor structures were pre-stressed under DC fields up to 2 MV/cm. The impact of the doping type of the substrate (either n-type or, p-type silicon) has been evaluated to address the mechanisms of space charge formation. The nature of electrode substrate substantially impacts the measured charge amount and charge nature, pointing towards charge injection as the origin of space charge build-up. The interpretation is substantiated by results obtained using a SiO2 layer as a barrier against electronic injection from the substrate into the PI layer.
          Charge accumulation patterns on spacer surface in HVDC gas-insulated system: Dominant uniform charging and random charge speckles   
Charge accumulation on a solid insulator surface is one of the critical factors for the development of dc gas-insulated equipment since it will lead to the overstress of polymeric insulation due to local field distortion and enhancement. Therefore, it is important to study the charge accumulation phenomenon on spacer surface under dc field. For decades, researchers have made tremendous progress on this subject by measurement and simulation. However, measurement results are quite different by different researchers due to various electrode configurations and experimental conditions. Further, most researchers use potential to represent charge density, which is not rigorous in that many charge density distribution details are hidden behind the potential. As for pure numerical simulation, reports are rather academic and sometimes cannot accord with the real fact. In this paper, attempts are made to characterize the charge accumulation patterns on spacer surface in HVDC gas-insulated system. Surface charge distributions on a model GIL spacer in 0.1 MPa air under DC voltage are obtained by an advanced measurement method, from which the dominant uniform charging pattern and random charge speckles are separated. Mechanism responsible for the dominant uniform charging pattern is discussed with the aid of a simulation model. Results indicate that, in a well-cleaned system, the electric current through the spacer bulk is the principal factor, but gas conduction is not negligible due to some inevitable ion sources. Highly localized pockets of charge are also observed, which are referred to as speckles. They may originate from micro discharges due to tiny metal particles on the spacer surface or microscopic protrusions on the electrodes.
          Measurement of the electric field strength in transformer oil under impulse voltage   
The electric field distribution of the oil-pressboard structure under impulse voltage provides vital reference for the design of transformer insulation. The electric field distribution under impulse voltage is usually held equivalent to that of the capacitive field and calculated by simulation software. An appropriate margin to the calculation results is then selected according to the allowable strength. The design value identified in such a manner, however, falls short of support and verification of actual measurement. The present paper proposes a non-contact real-time measuring method to explore the electric field distribution of the oil-pressboard structure under impulse voltage, using a created measuring apparatus that is composed of optical system, photoelectric converter device, sealed cavity, and impulse voltage generator. Calibrated and verified by a pair of plate electrodes which generated uniform electric field along the propagating direction of the laser beam, the measured values proved to tally well with the actual values of the electric field in terms of both variation trend and numerical value. The minimum sensitivity of the established measuring apparatus was recorded as 3.5 kV/mm and the maximum deviation was 3.6%.
          The Rumors of My Death Have Been Greatly Exaggerated (Part Deux)   
(When last we left our plucky heroine -- Part I -- she was busy being slapped and wanting to pee, and terribly disappointed at the lack of a Machine That Goes PING. )

As the afternoon wore on, I spent the time mumbling and pushing The Button. They hooked some more things to me -- enough electrode adhesives that I resembled a hyperactive 3-year-old's sticker booklet, a telemetry machine that apparently did something, but did not go PING. Eventually I was introduced to Dr. Napier, who would be my on-call physician overnight. (Of course the first thing I asked Dr. Napier was if he was related to Charles Napier. He looked at me quizzically. "The Blues Brothers?" I said. "Bob's Country Bunker?" Nothing. I gave up.)

If you looked up "tall, dark, and handsome" in a dictionary, there would be a picture of Dr. Napier. He was like a cross between the George Clooney and Johnny Depp of on-call physicians. I imagine that Dr. Napier is tremendously popular with all the nurses and patients, even the semi-conscious ones. Hell, maybe even the unconscious ones. When I talked to one of the nurses about something Dr. Napier had said, she replied, "Oh, yes, Dr. Napier, he's really...nice." Emphasizing "nice" in that way that made it clear that Dr. Napier would be even nicer if he'd take his shirt off. But I digress. He seemed very knowledgeable and competent and sharp, which is the important thing. Mostly.

Dr. Napier took a look at the Foley catheter receptacle and said, "This concerns me." It seems the bag was still mostly empty. If he was concerned, I was concerned. If he had told me they were going to sell me off for medical experimentation, I would have said, "Sure, whatever you want." He then listed a number of steps they would take to address his concerns, something about a bolus of fluids, lasix, and an abdominal CT. He said this all very calmly. They hooked me up to a machine that takes your blood pressure every 10 minutes. After a couple of cycles, he looked even more concerned. "Let's get that CT scan," he said.

They weren't about to have me try to stand up again after the last fiasco, so in some manner involving a sheet they transferred me to a gurney. I don't remember much of that, except the disconcerting feeling that if they weren't careful my abdomen was going to burst open like a pinata and it wouldn't be candy that would come spilling out. We went through a series of doors and elevators and hallways while the theme music from "Get Smart" played in my head. They has sent me with the assistant-assistant nurse, probably so that if anything happened to me on the way, they would have plausible deniability. Finally we ended up at the CT scanner place, which seemed to be somewhere in the bowels of the hospital. It was dark and quiet and soothing, and the scanner was manned by three very pleasant young men in scrubs.

They transferred me to the Scanner Gurney (or whatever it's called) and ran me through a couple times, telling me to put my arms up over my head and hold my breath. When they seemed satisfied, they stopped. One of the scanner guys asked me to sit up. I said, "I don't think that's a good idea." He said it would only be for a minute.  What could it hurt?

I was right, and it was a very bad idea. As soon as I was upright, I felt an intense wave of nausea. I barely had time to register the thought that, "Boy, am I nauseated," before I projectile vomited all over the CT scanner and the pleasant young man standing next to it. And when I say "projectile vomited," I mean Saturday-Night-Live-Will-Ferrell-Parody projectile vomiting. I mean Linda-Blair-Exorcist projectile vomiting. I mean six-foot-distance-several-quarts-of-fluorescent-yellow-goo projectile vomiting. 

There was a slight pause. Then I vomited again. And again. Everyone was rushing around trying to find something for me to vomit in. First try was a partial cardboard box, which proved inadequate. Then there was something like a plastic sleeve, which proved even less adequate than the cardboard box. Finally somebody emptied some kind of a container full of something that made a clattering noise when it hit the floor. I hope it wasn't expensive. Eventually I stopped vomiting. I apologized profusely to the pleasant young man now covered in fluorescent yellow goo. He said, "Don't worry, it's not the worst thing that's happened to me," but he sounded like he was lying. 

Next thing I remember, I'm back up in my room, and Dr. Napier is still looking concerned. He's also looking very disapprovingly at the numbers on the blood pressure machine. I eventually learned that was because numbers that low are considered "incompatible with life." Yikes. Turns out the CT scan had showed I had a large hematoma in my abdomen that had collapsed my bladder, and that event had followed backward up the chain of command until it was throwing my whole system off. Add to that the fact that I was very probably overly dehydrated when I went into surgery (thanks to the bowel prep stuff I drank on Sunday), and the fact that I had spent 20 minutes vomiting on everything, and it was a perfect storm, but not the kind where William Fitchner has the Southie accent.

For a while, it was just fluids, blood pressure readouts where they called out numbers like a really boring game of bingo, a parade of phlebotomists tasked to draw blood every hour, and lots of people looking very concerned. At least until the spiders.....

(This is turning out much longer than I had anticipated. I blame Stephen King. To be continued....)
          Biredox Ionic Liquids: New Opportunities Toward High Performances Supercapacitors   
Faraday Discuss., 2017, Accepted Manuscript
DOI: 10.1039/C7FD00174F, Paper
Charlotte Bodin, Eleonore Mourad, Dodzi Zigah, Steven Le Vot, Stefan A Freunberger, Frederic Favier, Fontaine Olivier
Nowadays, commercial supercapacitors are based on purely capacitive storage and porous carbons are used as electrodes. Unfortunately their energy density is limited, so that many study investigated new materials that...
The content of this RSS Feed (c) The Royal Society of Chemistry

           Investigation of the degradation of the hydrophobic components in low temperature fuel cell electrodes    
Schulze, Mathias und Gülzow, Erich und Reissner, Regine und Christenn, Claudia (2004) Investigation of the degradation of the hydrophobic components in low temperature fuel cell electrodes. In: Conference Proceedings. 2nd France - Deutschland Fuel Cell Conference FDFC-2004, 2004-11-29 - 2004-12-02, Belfort, France.
           PREPARATION OF GAS DIFFUSION ELECTRODES WITH SILVER CATALYSTS FOR ALKALINE FUEL CELLS    
Gülzow, Erich und Wagner, Norbert und Schulze, Mathias (2004) PREPARATION OF GAS DIFFUSION ELECTRODES WITH SILVER CATALYSTS FOR ALKALINE FUEL CELLS. In: First European Workshop on AFC (EWAFC). First European Workshop on AFC (EWAFC), 2004-11-15 - 2004-11-16, Stuttgart, Germany.
           LONG TERM OPERATION OF AFC ELECTRODES WITH CO2 CONTAINING GASES    
Gülzow, Erich und Schulze, Mathias (2004) LONG TERM OPERATION OF AFC ELECTRODES WITH CO2 CONTAINING GASES. In: First European Workshop on AFC (EWAFC). First European Workshop on AFC (EWAFC), 2004-11-15 - 2004-11-16, Stuttgart, Germany.
           INVESTIGATION OF THE CHANGE OF THE HYDROPHOBIC BEHAVIOR OF ELECTRODES FOR LOW TEMPERATURE FUEL CELLS    
Schulze, Mathias und Gülzow, Erich (2004) INVESTIGATION OF THE CHANGE OF THE HYDROPHOBIC BEHAVIOR OF ELECTRODES FOR LOW TEMPERATURE FUEL CELLS. In: First European Workshop on AFC (EWAFC). First European Workshop on AFC (EWAFC), 2004-11-15 - 2004-11-16, Stuttgart, Germany.
           CO2 TOLERANCE AND DEGRADATION OF AFC ELECTRODES    
Gülzow, Erich und Schulze, Mathias (2004) CO2 TOLERANCE AND DEGRADATION OF AFC ELECTRODES. In: First European Workshop on AFC (EWAFC). First European Workshop on AFC (EWAFC), 2004-11-15 - 2004-11-16, Stuttgart, Germany.
           Alteration of the distribution of the platinum catalyst in membrane-electrode assemblies during PEFC operation    
Schulze, Mathias und Schneider, Armin und Gülzow, Erich (2004) Alteration of the distribution of the platinum catalyst in membrane-electrode assemblies during PEFC operation. Journal of Power Sources, 127, Seiten 213-221. Elsevier Science Direct. DOI: 10.1016/j.jpowsour.2003.09.016
           Long-term operation of AFC electrodes with CO2 containing gases    
Gülzow, Erich und Schulze, Mathias (2004) Long-term operation of AFC electrodes with CO2 containing gases. Journal of Power Sources, 127, Seiten 243-251. DOI: 10.1016/j.jpowsour.2003.09.020
          Defect-engineered TiO2 nanotube photonic crystals for the fabrication of near-infrared photoelectrochemical sensor   

J. Mater. Chem. B, 2017, 5,4883-4889
DOI: 10.1039/C7TB01081H, Paper
Wenlong Wu, Zhonghai Zhang
A prototype of near-infrared (NIR) light-responsive PEC analysis platform is first proposed with defect-engineered TiO2 nanotube photonic crystals as photoelectrode and dopamine as target molecule, which opens up a distinctive avenue for promoting NIR PEC analysis to become a versatile detection method.
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          Self-bonding and electrochemical properties of silica-coated nanowire composed of cobalt-coordinated peptide bundles   
J. Mater. Chem. B, 2017, Accepted Manuscript
DOI: 10.1039/C7TB01118K, Paper
Kazuki Murai, Yusuke Yamamoto, Takatoshi Kinoshita, Kenji Nagata, Masahiro Higuchi
We propose a method for self-bonding between electrodes using the self-organizational processes of a silica-coated peptide hybrid nanowire. We designed and synthesized a 23-mer [small alpha]-helical peptide having functional sites that...
The content of this RSS Feed (c) The Royal Society of Chemistry

          Atomistic Simulation Derived Insight on the Irreversible Structural Changes of Si Electrode during Fast and Slow Delithiation   

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Nano Letters
DOI: 10.1021/acs.nanolett.7b01389

          Electrochemical Size Measurement and Characterization of Electrodeposited Platinum Nanoparticles at Nanometer Resolution with Scanning Electrochemical Microscopy   

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Nano Letters
DOI: 10.1021/acs.nanolett.7b01437

          Integrated Hierarchical Cobalt Sulfide/Nickel Selenide Hybrid Nanosheets as an Efficient Three-dimensional Electrode for Electrochemical and Photoelectrochemical Water Splitting   

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Nano Letters
DOI: 10.1021/acs.nanolett.7b01030

          Bacteria-coated nanofiber electrodes digest pollutants   

Cornell materials scientists and bioelectrochemical engineers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.


           Dry Spraying Production Technique for Membrane Electrode Assemblies (MEA's) and Electrochemical Characterization of Polymer Membrane Fuel Cells (PEFC)    
Wagner, N. und Kaz, T. (2004) Dry Spraying Production Technique for Membrane Electrode Assemblies (MEA's) and Electrochemical Characterization of Polymer Membrane Fuel Cells (PEFC). 55th ISE Annual Meeting, Thessaloniki, 19.-24. September, 2004.
          Whole Blood Redox Potential Correlates with Progressive Accumulation of Oxygen Debt and Acts as a Marker of Resuscitation in a Swine Hemorrhagic Shock Model.   
Related Articles

Whole Blood Redox Potential Correlates with Progressive Accumulation of Oxygen Debt and Acts as a Marker of Resuscitation in a Swine Hemorrhagic Shock Model.

Shock. 2017 Jun 27;:

Authors: Daniels RC, Jun H, Tiba MH, McCracken B, Herrera-Fierro P, Collinson M, Ward KR

Abstract
INTRODUCTION: Oxidation-reduction reactions involve electron exchanges that require optimal balance for proper cell function. This balance is measured via redox potential and reflects oxidative stress. Despite the critical role of oxidative stress in critical illness and injury, little is known regarding redox potential. We hypothesize redox potential measurements will correlate with accumulation of O2 debt produced by hemorrhage over time.
METHODS: Ten swine were studied using a polytrauma hemorrhagic shock model. Whole blood and plasma redox potential measures were obtained at defined stages of O2 debt (20, 40, 60, 80 mL/kg), and through resuscitation. Redox potential was determined by measuring open circuit potential using novel gold nanoporous electrodes with Ag/AgCl reference.
RESULTS: Whole blood redox potential showed negative change as O2 debt accumulated, exhibiting positive response during resuscitation, and correlated with O2 debt across all animals (p < 0.001). Redox potential changes throughout O2 debt accrual were significant compared to baseline (p≤0.05), and at end resuscitation compared to O2 debt 60 mL/kg (p = 0.05) and 80 mL/kg (p = 0.02). Whole blood redox potential measures also correlated with oxygen extraction ratio, ScvO2, and lactic acid, appearing very sensitive to acute changes. Plasma RP showed no correlation with O2 debt.
CONCLUSIONS: Whole blood redox potential demonstrates significant correlation to O2 debt at all stages in this model. These results set the stage for further study of redox potential as a direct measure of oxidative stress and potential clinical tool. Given redox potential plasma performance, these measures should be made in whole blood versus plasma.

PMID: 28658006 [PubMed - as supplied by publisher]


          Musical trees   
"Musical trees" is a part of creative arts installation and this project is capable to produce different audio tones by detecting human touch to its attached plants. Existing version of this driver is capable to monitor 8 plants and produce different sounds for each plant.

Prototype version of "Magic Tree" project with 2 plant samples.

This project is build around PIC16F628A 8-bit microcontroller and PT2399 echo processor IC. To drive the sensor electrodes we use pair of CD4011 quad 2-input NAND gate ICs. This prototype use TDA7052 1W audio amplifier IC to drive the speaker(s).

The existing firmware of PIC16F628A is designed to produce tones in between 155Hz to 1244Hz and this range can be change by modifying the supplied firmware source code. In this design PT2399 echo processor IC is used to get more natural (/ deep) sound effect by adding some reverberation to the output.


Schematic and firmware of this project is available to download at elect.wikispaces.com.

          Multimodal Characterization of the Morphology and Functional Interfaces in Composite Electrodes for Li–S Batteries by Li Ion and Electron Beams   

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Langmuir
DOI: 10.1021/acs.langmuir.7b00978

          What Happens to Electrode Shotgun Slugs When Test Fired?   

WATCH THE VIDEO NOW Where does TAOFLEDERMAUS get all these crazy experimental ammo ideas? Now he’s got electrode shotgun slugs… Strange doesn’t fully describe the TAOFLEDERMAUS technique when it comes to testing ammunition. He finds, gets sent, and concocts the wildest, weirdest, most out-there shotgun slugs possibly ever thought of. This time he’s shooting slugs

The post What Happens to Electrode Shotgun Slugs When Test Fired? appeared first on Wide Open Spaces.


          The Chemistry of Electrolyte Reduction on Silicon Electrodes Revealed by in Situ ATR-FTIR Spectroscopy   

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.7b04132

          Electrode/Electrolyte Interface in the Li–O2 Battery: Insight from Molecular Dynamics Study   

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.7b03861

          Capacitive Energy Extraction by Few-Layer Graphene Electrodes   

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The Journal of Physical Chemistry C
DOI: 10.1021/acs.jpcc.7b02827

          CHARACTERISTICS OF STORAGE CELLS SEMINAR REPORT   
                                           Abstract
Charge equalization is a major issue in the service of 
batteries since thay are frequenctly connected in series to obtain the higher output voltage levels for most applications. With series connection, impedance amy happen to the operating batteries during either charging or discharging periods. The imbalance among batteries concerns the operating efficiency and the battery lifetime. The main objective of this seminar to solve the problem of charging and discharging and their protections.With sufficient electricity storage capacity, any power production profile may be mapped onto any desired supply profile. We present a framework to determine the required storage power as a function of time for any power production profile, supply profile, and targeted system efficiency, given the loss characteristics of the storage system. We apply the framework to the electrochemical storage of intermittent renewable power, employing a simplifying linear response approximation that permits the entire efficiency behavior of the system to be described by a single scalar figure of merit—the discharge power capacity. Solid-electrode batteries are shown to have two orders of magnitude too little energy to power ratio to be well suited to the storageof intermittent
                                        
                                    CHAPTER 1                                                                 ELECTROCHEMICAL CELL
Introduction
An electrochemical cell consists of two half-cells. Each half-cell consists ofan electrode and an electrolyte. The two half-cells may use the same electrolyte, or they may use different electrolytes. The chemical reactions in the cell may involve the electrolyte, the electrodes, or an external substance (as in fuel cells that may use hydrogen gas as a reactant). In a full electrochemical cell, species from one half-cell lose electrons (oxidation) to their electrode while species from the other half-cell gain electrons (reduction) from their electrode.A salt bridge (filter paper soaked in KNO3 or some other electrolyte) is often employed to provide ionic contact between two half-cells with different electrolytesand prevent the solutions from mixing and causing unwanted side reactions.Each half-cell has a characteristic voltage. Various choices of substances for each half-cell give different potential differences. Each reaction is undergoing an equilibrium reaction between different oxidation states of the ions. When equilibrium is reached, the cell cannot provide further voltage.                 
                                        Chapter 5
CONCLUSION AND DIRECTION TO FUTURE SCOPE
 In this seminar we learn a lot of new things regarding the battery of cell. In this we lean the basic fundamentals of battery and cell and their options, out voltage and current, capacity of the cell. The discharging methods or charging methods of the storage cells and output characteristics of various cells under different temperature conditions are deeply understood by us. This knowledge of storage cell will help to solar power engineer for selecting the battery of proper rating as per the temperature condition at the site where you are going to install the solar power plant.The some part also not covered in this seminar and after reading this seminar one can go and work on following subtopics related to rechargeable storage cells-F Protection circuit for storage cells and their online monitoring
F Various output characteristics of storage cell can be simulated or drawn with the help of soft-computing tools like MATLAB.
F Optimum rate of discharging of cell under the solar power plant so that life of battery will be better.
  An electrochemical cell is a device capable of either generating electrical energy from chemical reactions or facilitating chemical reactions through the introduction of electrical energy.



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