Photovoltaic effect in Cd2 SnO4-CdGeP2 heterojunctions

It is shown experimentally to be possible to form rectifying photosensitive heterojunctions by using the method of reactive cathodic sputtering to deposit layers of Cd₂SnO₄ on the surface of nand p-type CdGeP₂ single crystals. It is demonstrated that photosensitivity is seen in the range between the widths of the forbidden bands of CdGeP₂ and Cd₂SnO₄; photosensitivity is 3–4 orders of magnitude greater for n-n junctions than for n-p junctions. The parameters of polarizational photosensitivity were established and analyzed, providing evidence that the investigated system, with an n-n contact, can be used to make polarimetric photodetectors.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 77–82, July, 1988.     

Determination of size and concentration of critical clusters of silicon carbide in the vapour phase in homogeneous nucleation process

The concentrations of clusters of various size in the atmosphere during silicon carbide crystal growth have been calculated on the basis of fundamental ideas of homogeneous nucleation theory, taking into account the specific parameters of silicon carbide. It has been shown that the cluster concentration are sufficiently high to conclude that this is the dominant influence during the initial stages of crystal growth. In this way the assumption of the polymer theory of polytypism, namely that the polytype properties of silicon carbide can be determined from the composition of the gas phase, containing sufficiently large clusters with various polytype structures, has been confirmed.     

Nuclear power pros and cons: A comparative analysis of radioactive emissions from nuclear power plants and thermal power plants

On the basis of the public data statistics of recent years on pollution and emissions from nuclear power plants (NPPs) and thermal power plants (TPPs) in the Russian Federation and the published investigation materials from Russian and foreign experts in this field, a comparative analysis of the radioactive emissions into the environment was performed for NPP emissions, as well as emissions from TPPs that operate using coal. It is shown that the total contents of radioactive nuclides in the TPP emissions substantially exceed those from NPPs, even for modern TPPs that operate using coal with ash contents of not more than 10% equipped with a filtering system that allows the removal of not less than 97.5% of the ash. An especially difficult situation for TPPs is due to long-lived radioactive isotopes, which are disposed practically without monitoring (and have a greater quantity of radioactive waste than NPPs by several orders of magnitude) with slag and are released into the atmosphere with the ash of organic fuels (particularly, shale oil, and coal).     

Investigation of nitrogen solubility process in silicon carbide

On the basis of the epitaxial layers of SiC (N) grown from vapour phase by the sublimation method in a temperature interval (1900–2200) °C and at nitrogen partial pressures from 4 to 760 Torr has been determined the dependence of the nitrogen content in the epitaxial layers of SiC(N) on the nitrogen partial pressure and the temperature of growing. A thermodynamics analysis of the nitrogen solubility process in silicon carbide has been developed taking account of the electron-hole interaction. The experimental and calculation results, we have obtained, allowed us to determine the partial mol solubility heat of nitrogen in SiC.     

Mathematical simulation in enhancing of industrial pyrolysis of hydrocarbon gases and their mixtures with feedback

A general technique was developed for optimal designing pyrolysis with feedback of hydrocarbons C₂-C₄ and their mixtures. Based on this technique, we carried out a study of industrial processes of pyrolysis of propane, ethane, and ethane with the butane-butylene fraction, developed their complete mathematical models that reflected the peculiarities of recycling, and on the basis thereof we defined optimal regimes of governing by these processes that differed significantly from those used in industry. We suggested new ways of governing by all three processes. The use of these ways will allow getting a significant profit by “Ethylene-Polyethylene” plant (Sumgayit). We demonstrated advantages of carrying out pyrolysis of various raw materials with recycling of unreacted raw materials compared with its conducting without recycling.     

Liquid Phase Epitaxy of SiC in the System Si?Tb?SiC by Temperature Gradient Zone Melting (I). Investigation of Solubilities in the System Si?Tb?SiC

In the paper which is divided into three parts the liquid phase epitaxy of SiC by temperature gradient zone melting with the solvent Si Tb is discussed. In the first part the solubility of SiC at different initial compositions of the Si Tb solvent is studied in the temperature range 2000–2500 K.