Application of pulse current for dissolution of heat-resistant GS32-VI alloy

Objectives. To identify the regularities of electrochemical processing of the heat-resistant GS32-VI alloy in a sulfuric acid electrolyte with a concentration of 100 g/dm3 under the action of a pulsed current in a pulsed mode.Methods. Using the electrochemical technological complex EHK-1012 (developed by IP Tetran) and a non-compensatory method of measuring potential, polarization and depolarization curves with a change in pulse duration and a pause between them were recorded. The current pulses had an amplitude ranging from 0 to 3.5 A (when recording the polarization and depolarization curves), pulse durations ranging from 200 to 1200 ms, and a pause (delay) between pulses ranging from 50 to 500 ms. There were no reverse current pulses.Results. The parameters of the current program that provide the maximum values of the alloy dissolution rate and current output were determined: with a current pulse amplitude of 2 A, a current pulse duration of 500 ms, and a pause duration between pulses of 250 ms, the maximum dissolution rate of the alloy is 0.048 g/h·cm2, while the current output for nickel is 61.6% with an anode area of 10 cm2. The basic technological scheme for processing the heat-resistant GS32-VI alloy, which includes anodic alloy dissolution in a pulsed mode, is proposed.Conclusions. Electrochemical dissolution of GS32-VI alloy under pulsed current action results in an optimal dissolution rate ratio of the alloy components, ensuring the production of a cathode precipitate with a total nickel and cobalt content of 97.5%.

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Skyrmion Creation and Manipulation by Nano-Second Current Pulses

Scientific Reports ◽

10.1038/srep22638 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 37

Author(s):

H. Y. Yuan ◽

X. R. Wang

Keyword(s):

Current Pulse ◽

Data Storage ◽

Current Density ◽

Spin Valve ◽

Free Layer ◽

Fixed Layer ◽

Current Pulses ◽

Zero Current ◽

Current Polarity ◽

A Current

Abstract Easy creation and manipulation of skyrmions is important in skyrmion based devices for data storage and information processing. We show that a nano-second current pulse alone is capable of creating/deleting and manipulating skyrmions in a spin valve with a perpendicularly magnetized free layer and broken chiral symmetry. Interestingly, for an in-plane magnetized fixed layer, the free layer changes from a single domain at zero current to a Neel wall at an intermediate current density. Reverse the current polarity, the Neel wall changes to its image inversion. A properly designed nano-second current pulse, that tends to convert one type of Neel walls to its image inversion, ends up to create a stable skyrmion without assistance of external fields. For a perpendicularly magnetized fixed layer, the skyrmion size can be effectively tuned by a current density.

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Instability of tangential discontinuities in pinching plasmas

Journal of Plasma Physics ◽

10.1017/s0022377899007618 ◽

1999 ◽

Vol 62 (1) ◽

pp. 117-123 ◽

Cited By ~ 3

Author(s):

S. P. TSYBENKO

Keyword(s):

Dispersion Relation ◽

Simple Model ◽

Current Pulse ◽

Current Density ◽

Strong Dependence ◽

Plasma Instability ◽

Tangential Discontinuity ◽

Instability Increment ◽

Tangential Discontinuities ◽

A Current

A new mechanism for the formation of pinching plasma instability related to a tangential discontinuity is discussed. With this in mind we use a simple model of the Davydov–Zakharov class. It appears that there is a strong dependence of the instability increment on current density, resulting from the corresponding dispersion relation. Modulation of a current pulse is shown to be a possible way of stabilizing powerful discharges.

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Creation of a hard microrelief on a titanium surface processed by microplasma discharges with a current amplitude of 200 A and pulse duration of 20 ms

Plasma Physics Reports ◽

10.1134/s1063780x12080144 ◽

2012 ◽

Vol 38 (13) ◽

pp. 1105-1112 ◽

Cited By ~ 5

Author(s):

V. A. Ivanov ◽

M. E. Konyzhev ◽

L. I. Kuksenova ◽

V. G. Lapteva ◽

M. S. Alekseeva ◽

...

Keyword(s):

Pulse Duration ◽

Titanium Surface ◽

Current Amplitude ◽

A Current

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Current Distribution at a Disk Electrode during a Current Pulse

Journal of The Electrochemical Society ◽

10.1149/1.2140681 ◽

2006 ◽

Vol 153 (2) ◽

pp. E17 ◽

Cited By ~ 8

Author(s):

Paul Antohi ◽

Daniel A. Scherson

Keyword(s):

Current Pulse ◽

Current Distribution ◽

Disk Electrode ◽

A Current

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Analytical Modeling and Validation of a Preloaded Piezoceramic Current Output

Micromachines ◽

10.3390/mi12040353 ◽

2021 ◽

Vol 12 (4) ◽

pp. 353

Author(s):

Bin Zhang ◽

Hongsheng Liu ◽

Dezhi Li ◽

Jinhui Liang ◽

Jun Gao

Keyword(s):

Energy Harvesting ◽

Integrated Circuit ◽

Microelectromechanical Systems ◽

Experimental Testing ◽

Current Source ◽

Model Parameters ◽

Current Output ◽

System A ◽

A Current ◽

Piezoelectric Characteristics

Energy harvesting using piezoceramic has drawn a lot of attention in recent years. Its potential usage in microelectromechanical systems is starting to become a reality thanks to the development of an integrated circuit. An accurate equivalent circuit of piezoceramic is important in energy harvesting and the sensing system. A piezoceramic is always considered to be a current source according to empirical testing, instead of the derivation from its piezoelectric characteristics, which lacks accuracy under complicated mechanical excitation situations. In this study, a new current output model is developed to accurately estimate its value under various kinds of stimulation. Considering the frequency, amplitude and preload variation imposed on a piezoceramic, the multivariate model parameters are obtained in relation to piezo coefficients. Using this model, the current output could be easily calculated without experimental testing in order to quickly estimate the output power in energy harvesting whatever its geometric shape and the various excitations.

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Shaper of a current pulse of megaampere level with rise time of 100 ns

2011 IEEE Pulsed Power Conference ◽

10.1109/ppc.2011.6191478 ◽

2011 ◽

Cited By ~ 1

Author(s):

P.V. Duday ◽

E.V. Bochkov ◽

V.I. Dudin ◽

G.I. Dolgachev ◽

V.A. Ivanov ◽

...

Keyword(s):

Current Pulse ◽

Rise Time ◽

A Current

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Current mode sigma-delta modulator designed with the help of transistor’s size optimization tool

Bulletin of the Polish Academy of Sciences Technical Sciences ◽

10.1515/bpasts-2015-0104 ◽

2015 ◽

Vol 63 (4) ◽

pp. 919-922 ◽

Cited By ~ 3

Author(s):

P. Śniatała ◽

M. Naumowicz ◽

A. Handkiewicz ◽

S. Szczęsny ◽

J.L.A. de Melo ◽

...

Keyword(s):

Current Mode ◽

Cmos Technology ◽

Clock Frequency ◽

Mode Structure ◽

Sigma Delta Modulator ◽

Sigma Delta ◽

Current Output ◽

Image Pixels ◽

Time Loop ◽

A Current

Abstract The paper presents a second order current mode sigma-delta modulator designed with the help of a new elaborated tool to optimize the transistor sizes. The circuit is composed of two continuous time loop filters, a current comparator and a one bit DAC with a current output. The resulting circuit, designed in a 65 nm 1.2 V CMOS technology, has a bandwidth of 2 MHz for a clock frequency of 250 MHz. The electrical simulation results show that it achieves a maximum signal-to-noise-plus-distortion ratio (SNDR) of 53.6 dB while dissipating 93 μW, which corresponds to an efficiency of 59.7 fJ/conv. The fully current mode structure makes the circuit suitable to be applied in a current mode signal processing like biosensors or image pixels arrays.

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Measuring the Temperature of Substances upon Fast Heating with a Current Pulse

Bulletin of the Russian Academy of Sciences Physics ◽

10.3103/s1062873818040147 ◽

2018 ◽

Vol 82 (4) ◽

pp. 372-379 ◽

Cited By ~ 6

Author(s):

S. V. Onufriev

Keyword(s):

Current Pulse ◽

Fast Heating ◽

A Current

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Study of the current waveform effect on the formation of cathode deposits during direct electrolysis Part 1. Electrolysis of fresh water

Vodosnabzhenie i sanitarnaia tehnika ◽

10.35776/vst.2021.10.02 ◽

2021 ◽

pp. 18-25

Author(s):

И.В. Пчельников ◽

Т.Т.З. Нгуен ◽

Л.Н. Фесенко

Keyword(s):

Fresh Water ◽

Sodium Hypochlorite ◽

Direct Current ◽

Water Oxidation ◽

Tap Water ◽

Reverse Current ◽

Raw Material ◽

Half Cycle ◽

Current Output ◽

Direct Electrolysis

При электрохимической обработке хлоридсодержащих природных вод в бездиафрагменном электролизере образуются соли хлорноватистой кислоты, проявляющие окислительные свойства. Этот процесс широко используется для производства дезинфицирующих растворов на основе гипохлорита натрия. Сырьем для производства гипохлорита натрия могут быть не только искусственно приготовленные солевые растворы, но и природные минеральные воды, содержащие хлориды. Электролиз таких растворов приводит к образованию на катоде электролизера нерастворимых солей кальция и магния, что препятствует массообмену в межэлектродном пространстве, а также к возникновению аварийных ситуаций. В первой части статьи приведены результаты исследований прямого электролиза постоянным и реверсным током пресной воды г. Донгхой, Республика Вьетнам. В проведенных испытаниях определяли влияние реверсного тока в сравнении с постоянным током на снижение образования нерастворимых веществ на катодах электролизера. Эксперименты показали преимущество реверсного тока над постоянным. Так, при электролизе реверсным током продолжительностью периода до 6 часов масса отложений на электродах не увеличивалась, а на постоянном токе накапливалась с момента начала электролиза. Это связано с тем, что осадок, образующийся в катодный полупериод, растворяется в анодный полупериод кислотой – продуктом окисления воды. Выход хлора по току для водопроводной воды составил не более 23% с плотностью тока 100 А/м2. During the electrochemical processing of chloride-containing natural water in a membraneless electrolyzer, salts of hypochlorous acid are formed that are exhibiting oxidizing properties. This process is widely used for the production of sodium hypochlorite disinfectants. The raw material for the production of sodium hypochlorite can be not only artificially prepared saline solutions, but also natural mineral water containing chlorides. The electrolysis of such solutions results in the formation of insoluble calcium and magnesium salts at the cathode of the electrolyzer thus inhibiting mass transfer in the interelectrode space and the occurrence of emergency situations. The first part of the article presents the results of studies of direct electrolysis of fresh water with constant and reverse current in Dong Hoi city, Republic of Vietnam. In the conducted tests the effect of reverse current in comparison with direct current on the reduction of the formation of insoluble substances at the cathodes of the electrolyzer was determined. The experiments have shown the advantage of reverse current over direct current. So, during the electrolysis with reverse current for a period of up to 6 hours, the amount of deposits on the electrodes did not increase, however, with direct current the deposits accumulated from the very beginning of the electrolysis process. This is due to the fact that the precipitate formed during the cathodic half cycle is dissolved during the anodic half cycle by acid, a product of water oxidation. The current output of chlorine for tap water was no more than 23% with a current density of 100 A/m2.

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