Search results for " electrode"
showing 10 items of 301 documents
Performance comparison of mono-polar and bi-polar configurations of alkaline electrolysis stack through 3-D modelling and experimental fabrication
2020
Abstract Generation of hydrogen using electrolysis process with integrated renewable energy sources is highly important especially in environmental aspects. In this paper, we demonstrate that the enhancement of electrolysis performance of alkaline electrolysis stacks by diminishing the distance between electrodes, while changing the properties of the Membrane Electrode Assembly (MEA). Prior to that, the performances of mono-polar and bi-polar configurations of alkaline electrolysis stack are compared through 3-D modelling and experimental fabrication. At first, two different single cell alkaline electrolysers are designed using SolidWorks as a design software and the designed cell has been …
CO2 turned into a nitrogen doped carbon catalyst for fuel cells and metal–air battery applications
2021
Heteroatom doped metal-free catalysts are one of the most promising replacements for platinum for the alkaline oxygen reduction reaction (ORR). Due to the lack of metal atoms, they are extremely stable and environmentally friendly. However, production of carbon nanomaterials can have a very high CO2 footprint. In this study, we present ORR catalysts made directly from CO2via molten salt CO2 electrolysis. The deposited carbon powder is doped with nitrogen using pyrolysis in the presence of dicyandiamide. The effect of molten carbonate electrolyte composition towards the final ORR activity in 0.1 M KOH is studied. A thorough physico-chemical study of the starting carbons and N-doped catalysts…
Electrolyses model development for metal/electrolyte interface: Testing with microrespiration sensors
2011
Abstract Initial process of electrolysis is investigated using platinum and tungsten wires as hydrogen electrodes and inductive kickback voltage peak based power unit. Microelectrodes are used to determine concentrations of dissolved hydrogen and pH close to wire electrodes. It is observed that concentration of dissolved hydrogen increases faster on tungsten electrode as on platinum. Authors explain this fact with differences of hydrogen evolution reaction on both materials – inductive kickback voltage peak power unit is supplying very short voltage pulses with limited energy what is enough only for hydrogen adsorption on platinum electrode, but is sufficient for full hydrogen evolution rea…
Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain
2003
Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 microA/cm2 was recorded at a depth of 1 cm from scalp surface with the optimum stimulation orientation used in the experiment and an intensity of 7% of the maximal stimulator output. During TMS we recorded relative current variations under different stimulating coil orientations and at different points…
A Voltammetric Analysis of the Electrochemical Behaviour of Onium Salts at a Mercury Electrode
1980
An analysis of the cyclic voltammograms of the reduction of various onium salt at mercury, produced more detailed information concerning the nature of the reaction pathway, in terms of adsorption, amalgam formation and kinetics of electron transfer, and lead to an interpretation of the characteristic “inverted peak”. An “auto-catalytic” reaction mechanism was indicated, and in conjunction with the preparative experiments [1, 2] a full reduction scheme proposed for the sulphonium salt ([Ph2S+ CH3)]CIO−4) and the phosphonium salt ([Ph2P+ (CH3)2]Br−). Die Analyse der Cyclovoltammogramme der reduktiven Spaltung einiger Phosphonium- und Sulfoniumsaize unterrichtet uber die an der Quecksilberkath…
Dorsal root ganglia neurite outgrowth measured as a function of changes in microelectrode array resistance
2017
Current research in prosthetic device design aims to mimic natural movements using a feedback system that connects to the patient's own nerves to control the device. The first step in using neurons to control motion is to make and maintain contact between neurons and the feedback sensors. Therefore, the goal of this project was to determine if changes in electrode resistance could be detected when a neuron extended a neurite to contact a sensor. Dorsal root ganglia (DRG) were harvested from chick embryos and cultured on a collagen-coated carbon nanotube microelectrode array for two days. The DRG were seeded along one side of the array so the processes extended across the array, contacting a…
VALIDITY, RELIABILITY AND FEASIBILITY OF MEASURING MUSCLE ACTIVITY WITH TEXTILE ELECTRODES EMBEDDED INTO CLOTHING
2007
INTRODUCTION In out-of-laboratory settings the surface EMG measurements are complicated by the requirement of careful electrode placement and skin preparation. The development of washable textile electrodes that can be sowed into sportswear enable muscle activity recordings during normal locomotion without skin preparation and the problem of wires hanging around the body [1]. In this study we performed validity, reliability and feasibility tests of the textile electrodes embedded into shorts against the traditional bipolar surface electrodes.
Simple Circuit Models for Studying Global Earthing Systems
2007
The paper proposes three simple circuit models for the simulation of the behaviour of a global earthing system during different fault events. The models allow one the evaluation of the maximum earth potential rise at every possible fault location and for every possible fault event. The three considered fault events are: single-line-to-earth fault inside a MV/LV substation, double-earth-fault in a MV line, single-line-to-earth fault inside a HV/MV station. After having illustrated the hypotheses at the basis of the study, the circuit models for the three fault events are presented and a numerical example shows how to use them in order to check the "global safety" of the interconnected earthi…
The Quest for Global Safety
2007
The authors present a systematic study on the factors that have influence on the establishment of the safety conditions ensuring the rise of Global Earthing Systems. Starting from the definition of Global Earthing System given by CENELEC Document HD 637 SI and from the results of the studies done on the last years on the interconnected earthing systems inside MV networks, the paper proposes some directions of deepening on the topic of Global Safety. Some of the themes whom the paper deals with are: the correct definition of proximity, interconnection and quasi-equipotentiality of the earth electrodes belonging to a Global Earthing System; the influence of the presence of HV/MV stations on h…
Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line. A Parametric Analysis
2007
When a substation is fed by a combined overhead-cable transmission line, a significant part of the ground fault current flows through the grounded cable sheaths and discharges into the earth at the transition station, where cables are connected to the overhead line. If the transition station is a dead-end steel pole structure, the local ground electrode, small and of high resistance, could be inadequate to maintain the ground potential rise within safety limits in case of a fault to ground at the receiving end substation. Based on a circuit model approach, the paper presents a parametric analysis of the fault current distribution between the faulted substation and the transition station, ta…