Scientific Journal of KubSAU

Polythematic online scientific journal
of Kuban State Agrarian University
ISSN 1990-4665
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213 kb

QuЕChERS SAMPLE PREPARATION IN THE DETERMINATION OF PESTICIDES OF DIFFERENT CHEMICAL CLASSES BY HPLC

abstract 1321708011 issue 132 pp. 117 – 127 31.10.2017 ru 0
The method has been developed of simultaneous determination of active ingredients of different kinds of pesticides in biological tissues (fish liver) by applying HPLC with ultra-violet detection and the rapid method of QuEChERS sample preparation. We defined optimum volume and composition of the reagents for the extraction, time of centrifugation and ultrasound treatment, the origin and composition of sorbents that ensure maximum extraction of the substances studied and further cleanup of interfering substances. Acetonitrile was used as a solvent. The extraction was carried out in the presence of a buffering mixture - trisodium citrate dihydrate and disodium citrate hemihydrate. Bondesil PSA bulk sorbents (alkylated amine containing two amine functional groups - secondary and primary) and C18E (reversed-phase sorbent based on silica gel with grafted octadecylsilane groups were used to purify the extract from coextractable substances (fats, proteins, sugars, organic and fatty acids, pigments and other impurities). The degree of extraction of the analyzed active ingredients of pesticides from the liver of fish was 79%. The detectable pesticide concentrations ranged from 0,4 to 0,97 mg/kg. The relative standard deviation of the analysis results amounted to 0,01-0,14
250 kb

ALTERNATIVE MODEL OF CALCULATIONS OF VALUES OF ATOMIC RADIUS

abstract 1321708051 issue 132 pp. 616 – 627 31.10.2017 ru 0
The article presents the results of the development of an alternative model for calculating the values of atomic radius. A formula was derived for calculating the atomic radius of the elements of the Periodic System of DI Mendeleev. The optimal calculation conditions for the proposed model are found. It is shown that the curve of the dependence of the value of the correction coefficient x on the atomic number of the element in form coincides with the dependence of the ionization energy on the charge number
239 kb

STUDY OF EARLY STAGES OF MELANOIDIN’S FORMATION PROCESSES IN MODEL ETHANOLIC D-GLUCOSE – pTOLUIDINE SYSTEM

abstract 1321708057 issue 132 pp. 720 – 727 31.10.2017 ru 0
The results of investigation of melanoidin’s formation early stages in acidic ethanolic D-glucose – p-toluidine model system are presented. Based on the elemental analysis, IR- and UV-spectroscopy data obtained we have shown, that in system studied Amadori rearrangement product undergo the aryl amine elimination during browning to form a nonnitrogenous reductons with antioxidative activity in processes of linoleic acid oxidation. It is also noted, that in system studied inhibition of carbohydrate’s destruction occurs because of non-reactive O-ethylglycosides formation. The data obtained may be useful for technology of carbohydrate-containing raw material
134 kb

SURFACE ENERGY OF POLYMERS (ELASTOMER COMPOSITIONS): A COMPARATIVE ANALYSIS OF THE VALUES OF SURFACE ENERGY PARAMETERS OF DEFECTS IN POLYMERS

abstract 1311707029 issue 131 pp. 301 – 310 29.09.2017 ru 72
Surface energy of polymers determines such important properties of polymers like wetability, adhesion, ability adsorption of low molecular weight substances. Inner organization, the structure of the polymer and the dynamics of interaction between macromolecular chains are shown at last. At the same time, the micro-defects (inhomogeneity) of polymers, which is an integral part of the structure are changed during deformation and must contribute to changing of the surface energy and its components. This article solves the task of detecting changes in the parameters of surface energy of polymers under uniaxial deformation. Data for the quantitative indicators of the surface properties total surface energy and its dispersive and polar components are presented. The calculations showed that the disperse and polar components of all the samples of polymer materials are about 98% of the total and, therefore, is crucial. For the first time experimental data, illustrating the change of surface energy of polymeric materials had been obtained, including elastomeric compositions, when uniaxial deformation. The relative changes of the surface energy vary from 54.5 per cent to 125 %. A decrease of total surface energy and its dispersion component is observed during deformation of polymer samples of different structure and chemical nature
295 kb

DEVELOPMENT OF A NEW MODEL OF CALCULATIONS OF VALUES OF ATOMIC RADIUMS

abstract 1311707047 issue 131 pp. 528 – 546 29.09.2017 ru 65
The article presents the results of studies of changes in the atomic radii of the elements of the periodic table, depending on their atomic masses. It is shown that the appearance of p- and d-orbitals introduces a significant contribution to the value of the atomic radius, and the appearance of f-orbitals makes a significantly smaller contribution to the given value. A radial-mass model of calculations of atomic radii for the elements of the Periodic Table was developed. Optimal conditions for making calculations were chosen. For the first time the values of atomic radii for elements with the order number 103-120 are calculated. It is shown that the values of atomic radii for elements with the order number 103-120 are in the range from 140 to 335 picometers and regularly change in the period
281 kb

APPLICATION OF THE MASS-RADIAL MODEL OF CALCULATION OF ATOMIC RADIUMS FOR ISOTOPES OF CHEMICAL ELEMENTS

abstract 1311707072 issue 131 pp. 872 – 887 29.09.2017 ru 73
The article presents the results of studies of changes in the atomic radii of isotopes of the elements of the periodic table. With using the mass-radial model of calculations, the values of atomic radii for isotopes of chemical elements were obtained. It is shown that the atomic radius of different isotopes of one element is different and depends on the mass and radius of the nucleus. To study the changes in ∆Rav values in the groups and periods of the Periodic Table of Chemical Elements, the ∆Rav dependences on the period number and group number are constructed. It is found that the values depending on the number ∆Rav period / group for the d-elements lie in the low ∆Rav values for selements - in high ∆Rav values, and p-elements - in average values ∆Rav. It is shown that when the atomic nucleus is increased by 1 neutron, the atomic radius increases from 0.01 to 4.76 pm, which is due to the physical effect inside the atom
167 kb

THE STUDY OF ENTEROSORBENT ANTIOXIDANT PROPERTIES OBTAINED OF ADSORPTION ON STARCHES OF ENZYMEANTIOXIDANTS DELIVERED FROM ROOTS OF HORSERADISH

abstract 1301706015 issue 130 pp. 233 – 242 30.06.2017 ru 197
The аrticle is devoted to study of adsorption of enzymes, antioxidants contained in horseradish root on starch to create enterosorbent with anti-oxidant properties. For this goal we have studied adsorption isotherm calculated constants, thermodynamic parameters (change of enthalpy, entropy, and isobaric-isothermal potential); sorption kinetics of enzyme-antioxidants on starch and calculate the main characteristics. The method of producing of enterosorbent - antioxidant on based starches has been developed based on the experimental data. The ready sorbent is a white powder having no taste and smell. In biological fluids and water, it is insoluble. The enterosorbent on starch does not dissolve in water and biological fluids. It is the solid component. This enterosorbent can be used to protect the gastrointestinal tract of humans and animals against a wide variety of oxidants and peroxide. The results of this work will form the basis for the study of the antioxidant properties of the resulting enterosorbent. The results showed that during the tests, the enterosorbent on the starch showed good antioxidant properties. It has high antioxidant activity with respect to hydrogen peroxide
181 kb

RESEARCH IN MICRODEFICIENCY OF POLYMERS (ELASTOMER COMPOSITIONS) UNDER UNIAXIAL DEFORMATION

abstract 1271703062 issue 127 pp. 885 – 894 31.03.2017 ru 312
Macrodeficiency of polymeric materials, including the pervasive one, is a consequence of the development of initial microdefects which appear in polymers both due to external factors and during their processing. This article solves the task of identification the interrelation and interdependence of structural microdefects of various polymeric materials, consisting in the estimation of the structural parameters under uniaxial deformation. It is experimentally shown that the process of changing microdefects in the material bulk begins to flow more intensely during deformation of the material, having anisotropic structures in the bulk. Change of the parameters of microdefects is not observed compared to the starting material at small quantities of the deformation. In the area of deformation corresponding to the transition of the material from isotropic to anisotropic state parameters of microdefects do not depend on the degree of deformation of the sample, and abrupt changes of the parameters of microdefects are observed after completing the formation of anisotropic patterns. It is shown experimentally the identity of the parameters of microdefects in the bulk material (rubber-based natural caoutchouc) during deformation with the quantities of local deformations at the edge of the artificially created macrodefects. Under uniaxial deformation more than 280-300% and the growth of the quantities of local deformations come out at the edge of the artificially created macrodefects and normalized linear dimension k and decrease the total number n of microdefects
190 kb

MATHEMATICAL MODEL OF THE CORRECTION OF PH SOFTENED WATER IN A LONG CHANNEL OF ELECTRODIALYSIS WITH BIPOLAR MEMBRANE

abstract 1261702002 issue 126 pp. 33 – 49 28.02.2017 ru 323
Theoretically and experimentally, we investigated the process of adjusting the pH of natural water of hydrocarbonate class electrodialyzer with bipolar membranes with channel length of 40 cm. We experimentally measured concentration of components, pH of the solutions in alkaline and acid channels of electrodeposition depending on the current density. The article describes a mathematical model for long channels; to scale the mass transfer characteristics of the process there was applied and verified a method of compartmentalization, which gave the possibility to calculate the dependence of the component along the channel length at different velocities of flow of the solution. Numerical calculations were compared with experimental data on electrodialyser of 10 cm and 40 cm length
498 kb

DEVELOPMENT OF A METHOD FOR FIXING PERFTORSULFOPOLIMER MF-4SK ON A HETEROGENEOUS MEMBRANE-SUBSTRATE

abstract 1251701015 issue 125 pp. 223 – 234 31.01.2017 ru 375
The article illustrates the results of the research dedicated to finding a method of combining two polymeric materials - ion-exchange membranes having different chemical nature. It shows a method of applying a homogenous film MF 4SK on the surface of the heterogeneous membrane substrate to produce a chemically and mechanically stable asymmetric bipolar membrane. We have selected membrane substrate ensuring the best electrochemical performance
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