Surface barrier diode based on zinc selenide with a passivating zinc oxide film

We propose a method of fabricating surface barrier diodes with overlapped metal junction, which provides for a significant decrease in the reverse currents and an increase in the breakdown voltage.     

Modelling induction skull melting design modifications

Induction Skull Melting (ISM) is used for heating, melting, mixing and, possibly, evaporating reactive liquid metals at high temperatures when a minimum contact at solid walls is required. The numerical model presented here involves the complete time dependent process analysis based on the coupled electromagnetic, temperature and turbulent velocity fields during the melting and liquid shape changes. The simulation is validated against measurements of liquid metal height, temperature and heat losses in a commercial size ISM furnace. The often observed limiting temperature plateau for ever increasing electrical power input is explained by the turbulent convective heat losses. Various methods to increase the superheat within the liquid melt, the process energy efficiency and stability are proposed.     

Surface Activation of Diamond Particles in the Process of Chemical Coppering

The effect of the composition of sensitizing–activating solutions on the activation efficiency and the chemical coppering of diamond powders is studied. The results demonstrate that stabilizing additives improve the stability of the solutions, influence the average coppering rate, and play a key role in determining the morphology and quality of the resultant coatings. The most effective stabilizing additive is synthamid-10, which ensures the deposition of high-quality copper coatings.     

Thermodynamic Properties of Alloys and Phase Equilibria in the In–Sb System

New thermodynamic data for the In–Sb system are obtained and compared with calculation results available in the literature. An isothermal vacuum cell and a procedure for electrolyte preparation are described which ensure high measurement accuracy.     

High-strain-rate superplasticity of nanocrystalline aluminum alloy 1570

The structure and mechanical properties of nanocrystalline aluminum alloy 1570 obtained by means of severe plastic deformation have been studied. Being tested in a temperature range from 300 to 400°C, the alloy exhibits high-strain-rate superplasticity. At 400°C, the superplasticity is manifested in a very broad range of strain rates, extending from 5 × 10^?3 to 1 s^?1.     

An integrated system to remote monitor and control anaerobic wastewater treatment plants through the internet.

The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem.     

The state of stress and strain of an elastic cylindrical shell under acoustic action

The article investigates the state of stress and strain of the surface of an elastic cylindrical shell whose outer part is subjected to the effect of an incident acoustic wave. A qualitative and quantitative analysis of the state of strain of the surface is carried out and recommendations are given for optimizing the functional purpose of the shell and minimizing the arising stresses.Translated from Problemy Prochnosti, No. 4, pp. 43–47, April, 1991.     

Ductile-to-brittle transition temperature of high-strength steel for fastners of power equipment under pressure

The influence of the level of defectiveness of design and service origin (grooves and cracks) of a fastener and an impact specimen on the accuracy of determination of the allowable values of the ductile-to-brittle transition temperature is investigated. An evaluation of the allowable ductile-to-brittle transition temperatures making it possible to impose more soundly based requirements for effectiveness of the material in the stages of design, production, and service in relation to the production condition of the steel, the level of defectiveness of the fastener, and the specified operating life of the threaded joint is proposed.Translated from Problemy Prochnosti, No. 5, pp. 35–37, May, 1991.