The role of the arc flux and joule heating in the erosion of electrical contacts

An experiment is conducted to investigate the role of surface roughness on the coefficient of friction and contact resistance of sliding electrical contacts. A hemispherical pin is sliding along both smooth and rough 2-meter rail surface. Tests are performed at both low and moderate sliding speed and for a range of electrical current densities, ranging from 0 to about 12 GA/m2. It was found that surface roughness had a significant influence on the coefficient of friction, with the smoother surfaces exhibiting higher coefficients of friction. Contact resistance, on the other hand, did not show as strong an effect of surface roughness, except for a few parameter combinations. At the higher current densities studied (>10 GA/m2), it was found that the contact resistance values tended to be on the order of 1 mΩ, independent of load, speed and roughness. This convergence may be due to presence of liquid metal film at the interface, which established ideal electrical contact.

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A Pendulum Phenomenon in the Visual Perception of Apparent Movement

Quarterly Journal of Experimental Psychology ◽

10.1080/17470215208416610 ◽

1952 ◽

Vol 4 (3) ◽

pp. 109-120 ◽

Cited By ~ 11

Author(s):

K. R. L. Hall ◽

A. E. Earle ◽

T. G. Crookes

Keyword(s):

Experimental Investigation ◽

Visual Field ◽

Visual Perception ◽

Apparent Movement ◽

Electrical Contacts ◽

Perceptual Process ◽

Light Stimuli ◽

Relationship Of ◽

The Relationship

In setting up an apparatus for studying the phenomenon of apparent movement it was noticed that, when a metronome was employed for making the electrical contacts in the light-circuits, the path of apparent movement between the two lights was curved instead of straight. This deviation could not be attributed to the presence of any distorting structure in the visual field, and an experimental investigation of the conditions of the phenomenon was begun. So far five different display conditions have each been observed by ten or eleven subjects individually. No subject saw more than one condition in the experimental series, and their reports indicate that the following factors, in order of importance, are effective in leading to the perception of curved apparent movement: (1) the shape of the light-stimuli, (2) the regularity of the rhythm of presentation, (3) the gradient of brightening and dimming of the lights and (4) the sound of the metronome in synchrony with the appearance of the lights. The possible role of past experience in the perceptual process, and the relationship of this “pendular” phenomenon to Johansson's (1950) “wandering” phenomenon and to normal stroboscopic movement, are briefly discussed.

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Role of Joule Heating in Electro-Assisted Processes: A Boundary Layer Approach for Rectangular Electrodes

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2013-0003 ◽

2013 ◽

Vol 11 (2) ◽

pp. 815-823 ◽

Cited By ~ 2

Author(s):

Mario A. Oyanader ◽

Pedro E. Arce ◽

James D. Bolden

Keyword(s):

Boundary Layer ◽

Heat Generation ◽

Joule Heating ◽

Boundary Layer Thickness ◽

Electrokinetic Remediation ◽

Boundary Layer Flows ◽

Approximation Approach ◽

Convective Mixing ◽

Layer Flow

Abstract An analysis for boundary layer flows caused by natural convection due to heat generation caused by the Joule heating effect is presented. The integral approximation approach developed by Von Karman is used to model the boundary layer flow in the system. Effects of the heat generation on temperature and velocity profiles as well as on the boundary layer thickness are discussed, and their implication for possible convective mixing effects near the electrode region is highlighted. These are important pieces of information when designing applications in electrokinetic remediation and separation of biomolecules.

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Accessing the role of Joule heating on densification during flash sintering of YSZ

Scripta Materialia ◽

10.1016/j.scriptamat.2022.114508 ◽

2022 ◽

Vol 211 ◽

pp. 114508

Author(s):

Subhadip Bhandari ◽

Tarini Prasad Mishra ◽

Olivier Guillon ◽

Devinder Yadav ◽

Martin Bram

Keyword(s):

Joule Heating ◽

Flash Sintering

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Role of Aspect Ratio and Joule Heating within the Fluid Region Near a Cylindrical Electrode in Electrokinetic Remediation: A Numerical Solution based on the Boundary Layer Model

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2012-0007 ◽

2013 ◽

Vol 11 (2) ◽

pp. 687-699

Author(s):

Mario A. Oyanader ◽

Pedro E. Arce

Keyword(s):

Boundary Layer ◽

Numerical Solution ◽

Joule Heating ◽

Navier Stokes ◽

Integral Model ◽

Transfer Model ◽

Layer Model ◽

Navier Stokes Equation ◽

Temperature Development

Abstract This contribution focuses on the analysis of the hydrodynamics taking place near an electrode of cylindrical geometry in electrokinetic applications. Both the temperature development conditions and Joule heating effect are included. A boundary layer approach has been used to model the hydrodynamic in the system. This is based on the heat transfer model, the continuity equation, and the Navier–Stokes equation. The resulting set of two partial differential equations mutually coupled is solved applying the Von Karman integral approximation. A numerical solution of the differential–integral model is used to illustrate the behavior of the systems under a variety of conditions.

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Low-Temperature Removal of Refractory Organic Pollutants by Electrochemical Oxidation: Role of Interfacial Joule Heating Effect

Environmental Science & Technology ◽

10.1021/acs.est.9b05929 ◽

2020 ◽

Vol 54 (7) ◽

pp. 4573-4582 ◽

Cited By ~ 7

Author(s):

Shuzhao Pei ◽

Jie Teng ◽

Nanqi Ren ◽

Shijie You

Keyword(s):

Low Temperature ◽

Electrochemical Oxidation ◽

Organic Pollutants ◽

Joule Heating ◽

Heating Effect ◽

Joule Heating Effect ◽

Refractory Organic Pollutants

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Joule Heating Effects in Electrokinetic Remediation: Role of Non-Uniform Soil Environments: Temperature Profile Behavior and Hydrodynamics

Environments ◽

10.3390/environments5080092 ◽

2018 ◽

Vol 5 (8) ◽

pp. 92

Author(s):

Cynthia M. Torres ◽

Pedro E. Arce ◽

Francisca J. Justel ◽

Leonardo Romero ◽

Yousef Ghorbani

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Joule Heating ◽

Low Voltage ◽

Electrokinetic Remediation ◽

Nusselt Numbers ◽

Heating Effects ◽

Proposed Model ◽

Current Electric Field

Electrokinetic remediation is a process in which a low-voltage direct-current electric field is applied across a section of contaminated soil to remove contaminants. In this work, the effect of Joule heating on the heat transfer and hydrodynamics aspects in a non-uniform environment is simulated. The proposed model is based on a rectangular capillary with non-symmetrical heat transfer conditions similar to those found in non-uniform soil environments. The mathematical and microscopic model described here uses two key parameters in addition to the Nusselt number: the ratio between the Nusselt numbers calculated at both walls of the capillary, named R, and a function of this variable and the Nusselt number, indicated by F(R, Nu). Illustrations describing the five key regimens for the system behavior are presented in terms of ranges for R and F(R, Nu) values, which indicate the key role of the parameter R in controlling the behaviors of the temperature and velocity profiles. Prediction, analysis, and illustration of five different regimes of flow complete the study, and conclusions are given to illustrate how the behavior of the system is affected.

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The Dangling Bond in Undoped Amorphous Hydrogenated Silicon: Trap or Recombination Center?

MRS Proceedings ◽

10.1557/proc-70-125 ◽

1986 ◽

Vol 70 ◽

Cited By ~ 3

Author(s):

M. A. Parker ◽

K. A. Conrad ◽

E. A. Schiff

Keyword(s):

Experimental Data ◽

Response Time ◽

Electrical Contacts ◽

Electron Trap ◽

Recombination Center ◽

Photocurrent Response ◽

Dangling Bond ◽

Hydrogenated Silicon ◽

Amorphous Hydrogenated Silicon

ABSTRACTThe role of the neutral dangling bond defect upon photocarrier processes in undoped amorphous hydrogenated silicon (a-Si:H) is discussed. The evidence that the dangling bond is a simple recombination center is reviewed, and it is shown that this model does not account for photocurrent response time measurements. Experimental data pertinent to the role of electrical contacts upon response time measurements are presented, and it is concluded that contact effects do not account for response-time measurements. The possibility that the dangling bond is primarily an electron trap is discussed.

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