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One of the most important problems in cutting theory is modelling behaviour of cut material accompanied by significant plastic deformations. Determination the chip patterns formation allows to build a theory of entire complex of processes and phenomena occurring in cutting zone. Various schemes, methods and types of processing define a wide variety of implementation schemes with a wide range of orientation cutting edge relative to velocity vector of main working movement. In this regard, it becomes necessary to analyse basic schemes of metal flow around plate. Combination of various schemes can be used to obtain any processing scheme using the principle of superposition. Before, we have developed a new method constructing velocity fields, which is devoid of drawbacks and contradictions of other methods determining the displacements velocity fields. Thus, it becomes necessary to obtain particle velocity fields for basic schemes using the hyperbola method. [ABSTRACT FROM AUTHOR]

Acylation of cloprostenol with acetic anhydride in pyridine, followed by treatment of the exhaustive acetylation product with water, gave 9,11,15-triacetoxy derivative whose reaction with 1,1′-carbonyldiimidazole afforded the corresponding imidazolide. The subsequent condensation with 2-aminoethanol and removal of acetate protecting group lead to the formation of N-(2-hydroxyethyl) cloprostenol amide. Analogous N-ethyl amide was synthesized by reaction of cloprostenol methyl ester with aqueous ethylamine. [ABSTRACT FROM AUTHOR]

The methods for improving the reliability of the cast-welded structure by reducing the deformation of the body of the bowl are proposed. The application of stiffness ribs, secured by welding, reduces the extent of formation of residual strains and increases the reliability and service life of the blast furnace slag cart. [ABSTRACT FROM AUTHOR]

The review covers the literature on the total synthesis of cross-conjugated cyclopentenone prostaglandins (PGs), published from 2000 until present. In view of the specific features differentiating cyclopentenone PGs from prostaglandins of other types, special attention in the review is focused on the biochemistry and physiological functions of the most important representatives of cyclopentenone PGs. Data on analogs of cyclopentenone PGs are presented, and certain aspects of structure-activity correlations and potential practical applications of these compounds are discussed. [ABSTRACT FROM AUTHOR]

The synthesis of acyclic precursors to epothilone D analogs has been explored. Optimal conditions have been found for enolization of (1R)-1-(1,3-dithiolan-2-yl)-1-(methoxymethoxy)-2,2-dimethylpentan-3-one and its aldol condensation with C6‒C21 and C6‒C9 aldehydes. [ABSTRACT FROM AUTHOR]

The main causes for formation of cracks and local sagging in cast large-sized case structures used in metallurgy are considered. Modeling of stress-strain state of the most loaded zones of slag carrier bowls in operation was performed. It is shown that to reduce residual deformations of cast bowls, it is necessary to apply additional stiffeners in the form of welded-on ribs. Calculation was used to determine the required parameters of stiffeners and welds. [ABSTRACT FROM AUTHOR]

The condensation of ethyl 7-(2-oxo-5-formulcyclopentyl)heptanoate by Wittig reaction with the ylide prepared from [(2 E)-3-methylhept-2-en-1-yl]triphenylphosphonium bromide afforded ethyl (±)-(13,15-dideoxy)-16-methyl-9-oxoprosta-13( E,Z),15( E)-dienoate as a mixture of two isomers, 2:1. [ABSTRACT FROM AUTHOR]

A comprehensive study of the polyaniline influence on mineral scaling on the surface of the heterogeneous MK-40 sulfocationite membrane under electrodialysis has been conducted. Current-voltage curves and chronopotentiograms have been obtained and analyzed for the pristine MK-40 membrane and the MK-40 membrane which is surface-modified by polyaniline. The study of the electrochemical behavior of membranes has been accompanied by the simultaneous control of the pH of the solution outcoming from the desalination compartment. The mixture of Na2CO3, KCl, CaCl2, and MgCl2 is used as a model salt solution. Two limiting states are observed on the current-voltage curve of the surface-modified membrane. There is the first pseudo-limiting state in the range of small values of the potential drop. The second limiting current is comparable with that of the limiting current for the pristine membrane. It is shown that chronopotentiometry cannot be used as a self-sufficient method for membrane scaling identification on the surface-modified membrane at high currents. A mineral scale on the surfaces of the studied membranes has been found by scanning electron microscopy. The amount of precipitate is higher in the case of the surface-modified membrane compared with the pristine one. [ABSTRACT FROM AUTHOR]