Optimization models of gas recovery and gas condensate processing

We present a complex of mathematical models that formalize gas recovery and processing. Optimization problems for gas recovery and gas condensate processing are stated and corresponding solution algorithms are suggested. These mathematical models provide a foundation of interactive decision support systems used in gas recovery and gas condensate processing.     

Structure and Properties of B4C - SiC Composites

We have investigated how the composition, grain morphology, and method of preparing the starting mixture affect the processes that form the structure and phase composition of B₄C - SiC composites during hot pressing. We found that, depending on the composition of the initial powder mixtures, which is responsible for different mechanisms of consolidation of ceramic materials during hot pressing, the grain size of the main B₄C phase and its defect content as well as the nature of the SiC phase distribution within the material differ significantly. When B₄C - SiC composites with a low SiC content are made from initial B₄C - B₄Si - B - C powder mixtures those composites have a high cracking resistance because of their fine grain structure.__________Translated from Poroshkovaya Metallurgiya, Nos. 3–4(442), pp. 112–119, March–April, 2005.     

Nature of boron carbonitride I. Conditions of preparation of boron carbonitride

Conclusions A study was made of the preparation of boron carbonitride by various techniques. It is shown that the method of synthesis from simple substances, involving nitriding boron and carbon black in a nitrogen atmosphere at temperatures of 1800–2000°C, yields a product corresponding, according to chemical analysis, to the composition BNC. Standard powder metallurgy techniques appear to be unsuitable for the production of massive boron carbonitride specimens.Translated from Poroshkovaya Metallurgiya, No. 1 (97), pp. 27–33, January, 1971.     

Multicommodity flows in tree-like networks

A problem of finding multicommodity minimum-cost flows in tree-like networks is considered. To solve this problem, an algorithm based on the reduction to a problem of finding a single-commodity flow in a network of arbitrary structure is proposed. For single-commodity flows in tree-like networks, an algorithm using a procedure of border reduction is used.     

An improved method of installing the blank for a drilling bit lap in the machining center

An essentially new method has been developed for installing the blank for a lap in a drilling bit for mechanical machining, which provides guaranteed gaps between the two holes with flat bottoms and the outer cylindrical surfaces of the corresponding fingers. The new method of installing the lap for machining greatly reduces the tolerances for the end and radial slack in the drilling bit and improves the working characteristics. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 1, pp. 46–47, January, 2007.     

A heterocontact in the semiconductor-mumie system

The list of materials that can be used in photosensitive structures has been expanded to include mumie—an organic compound of a biological nature. The current-voltage, capacitance-voltage, and photoelectrical characteristics of n-InSe-mumie heterostructures have been studied. The spectrum of the relative quantum efficiency of these heterostructures exhibits a correlation with the optical absorption spectrum of mumie films deposited from ethanol solutions.