China
Africa
Explore chapters and articles related to this topic
Sensor Technologies
Published in Gábor Harsányi, Polymer Films in Sensor Applications, 2017
In cathodic electrochemical deposition, the substance (metal) to be deposited is present in a solution or melt in the form of ions. If two electrodes are inserted into the solution (or melt), the positive ions of the metal will be attracted to the cathode where the metal will be deposited. The mass of the substance deposited is proportional to the electrical charge necessary to be transferred. The proportionality constant is the electrochemical equivalent of the given substance. The properties of the deposited films, for example, its adhesion to the substrate and its crystal structure (the size of microcrystals), may be influenced by the composition of the electrolyte. By this method, it is, of course, possible to deposit films only on conductive substrates, and the films may be contaminated by substances that are present in the electrolyte. This method of deposition is used, for example, in the formation of nickel layers on the surface of other metals (see Section 1.2.2).
F
Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[atomic, general, nuclear, quantum, thermodynamics] The ratio of the electrochemical equivalent of two constituents is directly proportional to the ratio of the atomic weights of the components divided by their respective valences. For instance the valance of silver (A = 108) is unity and the valance of zinc (A = 65) is two, yielding for the electrochemical equivalent for zinc the derived solution from what is known for Silver by means of the mass ratio silver to zinc participating in the electrolysis reaction as (108/1) : (65/2). The quantum explanation states that a material of valence 2 can use halve the quantity to transport the equivalent amount of charge with respect to a material with valence 1. Named after the English chemist and physicist Michael Faraday (1791–1867), from England.
Effect of electrolytic composition on current efficiency and alloy composition in electrowinning of Pr-Mg alloys using chloride electrolyte
Published in Mineral Processing and Extractive Metallurgy, 2021
D. K. Sahoo, M. Anitha, D.K. Singh, V. Kain
The current efficiency of each experiment was determined using Faraday’s law. Current efficiency is the ratio between the actual weights of the material obtained upon the theoretical weight. The following mathematical expression was used to determine current efficiency in the present investigation (Subramanian et al. 2007). where, η is the current efficiency (%), M is the mass of the alloy deposit in (g), ealloy is the electrochemical equivalent of the alloy, Q is the quantity of electricity passed (A sec). The electrochemical equivalent of the alloy was calculated by the following equation:where fMg and fPr are the fractions in the deposit which were obtained from Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) of the alloys. ePr and eMg are the electrochemical equivalents of praseodymium and magnesium respectively.
Micro-electrochemical jet machining of large area microtexturing with tool movement strategy
Published in Materials and Manufacturing Processes, 2022
Where, M is the mass of material dissolved, E is the electrochemical equivalent, W is the flow rate, t is the machining time, h is the interelectrode gap, Am is the molar conductivity, K is the concentration of electrolyte, θ is the voltage, and V is the flow velocity.
Investigation into fabrication of microslot arrays by electrochemical micromachining
Published in Machining Science and Technology, 2019
where, m is the mass of material dissolved or deposited, E is the electrochemical equivalent, W is the flow rate, t is the machining time, h is the inter electrode gap, Am is the molar conductivity, N is the concentration of electrolyte and V is the flow velocity.