02.00.00 Chemical sciences
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Description
The stability of strongly basic anion-exchange membranes MA-41-2P (JSC "Schekino-Nitrogen", Russia) and AMX (Tokuyama Soda, Japan) under intensive current regimes was investigated in the current study. The process of water molecules dissociation at current densities above the limiting one in 0.01 M sodium chloride solution was studied in detail. The length of the electroconvective instability at the membrane / solution interface at currents exceeding the limiting current was measured by laser interferometry
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Description
In the article the mathematical model of the space charge region in the bipolar membrane is considered. The structure of the space charge region under passing of electric current, and without electric current is discussed. The results of experimental studies of water dissociation in the bipolar membrane in the presence of chromium(III) are discussed
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ELECTRICAL CONDUCTIVITY OF IONEXCHANGE MEMBRANES IN SOLUTIONS CONTAINING CARBOXYLIC ACIDS
DescriptionThe article presents the experimental results of the study of the concentration dependence of the electrical conductivity of heterogeneous ion-exchange membranes that are in contact with solutions of weak electrolytes - carboxylic acids. It is shown that in this case the membrane conductivity is higher than the conductivity of the solution, wherein the conductivity of cation exchange membranes substantially greater (by an order of magnitude) than the conductivity of anion exchange membranes. This fact must be considered when designing the actual electrodialysis processes of processing solutions containing organic ions. The work identified the need to develop modern ideas about transport and the structural organization of ion-exchange materials, to describe the structure of the ion-exchange membranes that are in contact with weak electrolytes solutions
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KEPLER'S NUMBERS IN THE MODEL OF THE RUTHERFORD-BOHR
DescriptionThe change in the Kepler’s atomic number in the Periodic Table of Mendeleev is studied. It is shown that its values decrease regularly with increasing nuclear charge. An alternative formula for computing the values of the Kepler’s atomic number is proposed. It is shown that the ratio of the atomic number of Kepler’s to the mass of the atom is a constant for each period. The values of these constants are calculated
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Description
A number of thermoreactive oligomers was obtained via the Michael interaction of molar excesses of hexamethylene-bis-maleimide with 5,5’-bisbenzotriazoles in melt. The structure of them was proved by the 13C spectroscopy method. The one-step synthesis in melt, without by-products evolution, in absence of organic solvents, additional reagents, and catalysts is the more acceptable in point of view of technology (a finished reaction product does not require any purification). The process itself is the nucleophile addition across double bond, and so it can be attributed to the atom-saving technologies. According to data of the dynamic scanning calorimetry (DSC) and the thermogravimetry (TG), oligomers fuse at 130.8–135.6 °С, cross-link at 185–250 °С, and begin their thermal destruction in air at temperatures of 400– 420 °С. The tensile strength at shear of the glued joints on base of oligomers (steel plates overlapped) is 14.2– 23.7 MPa (142–237 kgf/cm2 ). The positive effect from the introduce of 5,5’-bis-benzotriazolyl fragments into structure of bismaleimide thermoreactive oligomers on strength of the glued joints between metal plates was revealed
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THEORETICAL FUNDAMENTALS OF ELECTROCHEMICAL TREATMENT OF WATER SOLUTIONS
DescriptionThe present review highlights the theoretical founda-tions of electric activation of aqueous solutions, their characteristics and properties
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Description
In the article we have optimized reaction conditions of furfurilidenatseton with epichlorohydrin in the presence of a catalyst of tin chloride and held hydrogenation of double bond of 2-methylene -2 - [(2-furyl]-X-1,3 – dioxolan; we have also given the biological activity of some unsaturated furan 1,3- dioxolans
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Description
3-Pyrrol-1-ylthieno[3,2-b]pyridin-2-carboxylic acid[(phenyl, 1,3-benzodioxol-5-yl)methylen]-hydrazides were synthesized by the reaction of 3-pirrol-1-ilthieno[2,3-b]pyridine-2-carbohydra-zides with aromatic aldehydes
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Description
In this article the review about the results of syntheses of new derivatives of pyrasoles,I soxazoles and pyridines, containing furan fragment is given. New methods of the syntheses of material are offered and estimation of their biological activity is made
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SYNTHESIS OF SUBSTITUTED PYRIDINE- 3-SULFONYL ISOCYANATES AND PYRIDINE- 3-SULFONYL UREAS
DescriptionAcylation of amides substituted with pyridine-3- sulfonic acids oxalil-chlorides and phosgene was studied. New pyridil-3-sulfonil isocyanates were synthesized. The conditions for this synthesis were optimized by taking into account the detailed understanding of this acylation. The synthesized pyridine-3-sulfonyl isozyanates were converted to pyridine-3-sulfonyl ureas. Biological activity of the new compounds was studied and the substances with high herbicidal effect were found