Optimizing the shape and size of a uniform‐current‐density magnet to maximize the field at constant power

1976 ◽  
Vol 47 (4) ◽  
pp. 1657-1661 ◽  
Author(s):  
E. B. Haignere ◽  
W. H. Potter
Keyword(s):  
Current Density ◽  
Constant Power ◽  
Uniform Current ◽  
Shape And Size

Basic properties of anodized porous silicon formed under uniform current density

1994 ◽  
Vol 77 (4) ◽  
pp. 97-105
Author(s):  
Hidekazu Aoyagi ◽  
Akira Motohashi ◽  
Akira Kinoshita ◽  
Tomoyoshi Aono ◽  
Akinobu Satoh
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Basic Properties ◽  
Uniform Current

A study of the non-uniform current density influence in reactive sputtering deposition

2014 ◽  
Author(s):  
Tao Wang ◽  
He Yu ◽  
Chao Chen ◽  
Yang Wang ◽  
Yadong Jiang
Keyword(s):  
Current Density ◽  
Reactive Sputtering ◽  
Sputtering Deposition ◽  
Uniform Current

Modelling the two-phase flow and current distribution along a vertical gas-evolving electrode

2001 ◽  
Vol 428 ◽  
pp. 249-272 ◽  
Author(s):  
ANDERS A. DAHLKILD
Keyword(s):  
Density Distribution ◽  
Current Density ◽  
Molecular Diffusion ◽  
Two Phase Flow ◽  
Current Density Distribution ◽  
Ionic Species ◽  
Phase Flow ◽  
Two Phase ◽  
Uniform Current ◽  
Experimental Findings

The bubbly two-phase flow and electric current density distribution along a single, vertical, gas-evolving electrode are modelled and the results of a boundary layer analysis are presented. Existing empirical models for particle transport in sheared and sedimenting suspensions are adopted for the bubble mixture to close the two-phase model. Ionic species concentrations are shown to be essentially homogeneous as the mixing effect of the bubble suspension usually is much larger than dispersion by molecular diffusion even at laminar flow conditions. The non-uniformity of the bubble distribution along the electrode results in a non-uniform current density distribution, which agrees well with existing experimental findings in the literature.

scholarly journals The effect of temperature on structural changes of NI55CO45 amorphous powder

2004 ◽  
Vol 36 (2) ◽  
pp. 105-112 ◽  
Author(s):  
M. Spasojevic ◽  
Aleksa Maricic ◽  
Lidija Rafailovic
Keyword(s):  
Current Density ◽  
Electrical Resistance ◽  
Structural Changes ◽  
Crystallization Process ◽  
Amorphous Powder ◽  
Solution Temperature ◽  
Specific Chemical ◽  
A Current ◽  
Shape And Size ◽  
Cobalt And Nickel

Cobalt and nickel alloy powders were obtained by electrochemical deposition on a titanium cathode from an ammonium solution of cobalt and nickel sulfate. Powders of a specific chemical structure and composition, particle shape and size were obtained by an appropriate choice of electrolysis parameters, current density, deposit growth rate and solution temperature and composition. Within the current density range of 5 - 450 mAcm-2, the current density did not significantly affect the chemical composition of the powders, but had a significant effect on the particle structure, shape and size. Crystal particles formed at a current density lower than 30 mAcm-2. Amorphous powders were obtained at a current density higher than 50 mAcm-2. Structural changes of the obtained amorphous powder of 55mol.% Ni, 45 mol.% Co, pressed under the pressure of 100 MPa, were investigated by measuring the temperature dependence of electrical resistance in isothermal and non-isothermal conditions varying from room temperature to 750?C. The process of thermal stabilization of defects that appeared during pressing occurred within the temperature range of 200-390?C. The DSC method was used to determine that the powder crystallization process occurred in two stages with peak temperatures of the exothermal maximum in the first and second stage of T1 = 438?C and T2 = 573?C, respectively. A distinct correlation between the change of electrical resistance and the crystallization process was established. The reduction of electrical resistively occurs during each crystallization stage.

Understanding composite negative differential resistance in niobium oxide memristors

2021 ◽  
Author(s):  
Xinjun Liu ◽  
Peng Zhang ◽  
Shimul Kanti Nath ◽  
Shuai Li ◽  
Sanjoy Kumar Nandi ◽  
...  
Keyword(s):  
Current Density ◽  
Negative Differential Resistance ◽  
High Current Density ◽  
Differential Resistance ◽  
Systematic Analysis ◽  
Diverse Range ◽  
Strong Basis ◽  
Lumped Element ◽  
The Core ◽  
Uniform Current

Abstract Volatile memristors, or threshold switching devices, exhibit a diverse range of negative differential resistance (NDR) characteristics under current-controlled operation and understanding the origin of these responses is of great importance for exploring their potential as nano-scale oscillators for neuromorphic computing. Here we use a developed two-zone, parallel memristor model of NDR to undertake a systematic analysis of NDR modes in two-terminal metal-oxide-metal devices. The model assumes that the non-uniform current distribution associated with filamentary conduction can be represented by a high current density core and a lower current-density shell where the core is assumed to have a memristive response due to Poole-Frenkel conduction and the shell is represented by either a fixed resistor or a second memristive region. The detail analysis of the electrical circuits is undertaken using a lumped-element thermal model of the core-shell structure, and is shown to reproduce continuous and discontinuous NDR responses, as well as more complex compound behaviour. Finally, an interesting double-window oscillation behaviour is predicted and experimentally verified for a device with compound NDR behaviour. These results clearly identify the origin of different NDR responses and provide a strong basis for designing devices with complex NDR characteristics.

scholarly journals Grain growth in Pt microheaters subjected to high current density under constant power

2018 ◽  
Vol 51 (26) ◽  
pp. 265303
Author(s):  
Ottó Elíasson ◽  
Gabriel Vasile ◽  
Snorri Ingvarsson
Keyword(s):  
Grain Growth ◽  
Current Density ◽  
High Current Density ◽  
High Current ◽  
Constant Power

The Function Mechanism of Current Density on Antimony Nanopowder Prepared by Electrochemical Method

2011 ◽  
Vol 228-229 ◽  
pp. 639-644 ◽  
Author(s):  
Jian Lin Xu ◽  
Shu Hua Yang ◽  
Li Hui Zhang ◽  
Zhao Kang ◽  
Qiang Guo
Keyword(s):  
Current Density ◽  
Electrochemical Method ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Function Mechanism ◽  
Transmission Electron ◽  
Ft Ir ◽  
Current Densities ◽  
Shape And Size

The nano-antimony particles with different shape, size and stability are prepared by electrochemical method under the dilute hydrochloric acid electrolyte including the surface dispersant OP-10 and different current densities. The influences of current density on the shape and size of nanometer antimony particles prepared by electrochemical method are analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The results show that nano-antimony powder can be prepared by electrochemical method, and the antimony powder possesses the crystal structure with orthorhombic hexahedron. The current density has a significant impact on the agglomeration, shape and size of antimony powder. The size and shape of antimony powder are determined by the nucleation rate of nano-antimony and combination capacity of antimony ions and OP-10 surface dispersing agents affected by current density. When the current density is 25mA/cm2, the average particle size is 12nm or so, the shape is spherical, and the nano-antimony particles are well dispersed and no agglomeration.

Optimal geometry toward uniform current density electrodes

2011 ◽  
Vol 27 (7) ◽  
pp. 075004 ◽  
Author(s):  
Yizhuang Song ◽  
Eunjung Lee ◽  
Eung Je Woo ◽  
Jin Keun Seo
Keyword(s):  
Current Density ◽  
Optimal Geometry ◽  
Uniform Current

scholarly journals Inductance gradient and current density distribution for T-shaped convex and concave rail cross-sections

2018 ◽  
Vol 7 (1.8) ◽  
pp. 237
Author(s):  
M. N. Saravana Kumar ◽  
R. Murugan ◽  
Poorani Shivkumar
Keyword(s):  
Density Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Current Density ◽  
Current Density Distribution ◽  
Design Parameters ◽  
Element Analysis ◽  
Analysis Technique ◽  
Section Shape ◽  
Uniform Current

Rectangular rail was the most widely used cross section shape for the rail gun electromagnetic launching (EML) system. Based on sector assimilation, the rail gun key parameter especially current density (J) and inductance gradient (L’) greatly affected. J decides the efficiency of EML and L’ decides the force acting on the projectile of EML. So, it is mandatory to look upon the sector assimilation of rails. In this paper T shape convex and concave shape rail cross section is proposed and rail gun key design parameters are calculated by varying its dimensions using Ansoft Maxwell 2-D eddy current solver which uses finite element analysis technique to calculate these parameters. The performance of rail gun discussed using the obtained values and it has been observed and that the compared with other considered rail geometries, the T-shaped concave model shows more impact on inductance value which causes uniform current density distribution over the rails.

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