A series of experiments on friction and wear properties of carbon strip rubbing against copper contact wire is performed on high-speed friction and wear tester with electric current. The results show that the friction coefficient is generally maintained between 0.24 and 0.37. In the absence of electric current, the coefficient of friction is higher than that in the presence of electric current....

In the paper are derived analytical expressions for calculation of values of transient resistances of electric arc in the case of interphase short circuits and also is performed numerical MATLAB simulation of electric arc in transient process. Modelling and simulation of electric network and arc was conducted in MATLAB Simulink surrounding, within the mathematical program MATLAB for simulation ...

The influence of welding arc regime on the fumes formation is studied by numerical modeling via description separate processes inside space charge regions near electrodes in with consumable electrode. comprises calculation temperature profiles for electrons and heavy component, distribution gas components’ number densities, particles’ mean free pathes, electric potential field, heat transfer fr...

This paper presents an integrated portable measurement system for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. The system permits direct and non-intrusive measurement of arc light emission images with a capture rate of 1 million images per second (1MHz), and 8 bit intensity resolution. Novel software techn...

This study was conducted in order to evaluate the effects of long term ageing on toughness and resilient modulus of asphalt concrete mixtures containing Electric Arc and Basic Oxygen Furnace steel slags. After initial evaluation of the properties of steel slags using X-ray Diffraction and Scanning Electric Microscope, eleven sets of laboratory mixtures were prepared. Each set was treated replac...

A steady wire-to-plane electric discharge has been modeled in a prolate spheroidal coordinate system with the wire shape taken as a hyperboloid of revolution. A set of continuum conservation equations for the charged particle densities and temperatures together with Poisson’s equation for the self-consistent electric potential describe the steady electric discharge process. These equations have...

Chest radiographs of 661 British electric-arc welders have been examined by three film readers experienced in the radiology of pneumoconiosis. About 7% of the welders showed signs of small rounded opacities of category 0/1 or greater. No definite evidence of large opacities (Progressive Massive Fibrosis) was seen. The prevalence of chest abnormalities other than pneumoconiosis was 7%. A clear a...