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Fine Chemical Technologies

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Vol 11, No 5 (2016)
View or download the full issue PDF (Russian)
https://doi.org/10.32362/2410-6593-2016-11-5

5-11 115
Abstract
Analysis of the results of the activity of the State Atomic Energy Corporation "Rosatom" and the Federal Service for Ecological, Technological and Nuclear Supervision for preparing the Russian Federation reports at meetings of the contracting parties to fulfil the obligations arising from the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management was performed.The main content of the report refers to the fourth national report of the Russian Federation submitted to the IAEA in May 2015. The main results of the activity for the formation of a unified state system for RW management were considered. Analysis of the questions of the Member States of the Joint Convention to the content of the national report was performed. A review of the activities of the FSUE "RosRAO" in terms of solving the basic problems for the safe management of radioactive waste was presented.
12-20 101
Abstract
This article describes promising technological solutions for the processing, storage and transportation of radioactive waste (RW) implemented by a leading Russian enterprise specializing in the field of radioactive waste management. Federal State Unitary Enterprise "RosRAO" performs nationallevel tasks to ensure nuclear, radiation and environmental safety in the treatment of all types of radioactive waste. To date, FSUE "RosRAO" has a number of ready-made solutions aimed at saving resources while maintaining the radiation and environmental safety by reducing logistics costs due to using large containers for transportation and storage; maximum recycling of waste at the site of its formation or interim storage with the help of mobile systems; creation and operation of easily erected facilities for temporary storage of solid radioactive waste before transferring it for conditioning or disposal. In recent years, we completed a number of major projects focused on improving the radioecological situation on the territory of Russia. The Regional Centre for conditioning and long-term storage of radioactive waste, largest in Russia, was put into operation in Sayda Guba in Murmansk region. Works for state needs were performed to bring radiationhazardous objects to a safe state and to reclaim territories of the Russian Federation subjects exposed to radiation as a result of past activities in the Trans-Baikal and Stavropol territories, Kirov, Moscow, Ivanovo and Orenburg regions.
21-25 133
Abstract
A distinctive feature of enterprises for extracting and processing uranium ore is the inevitable pollution by solid, liquid and gaseous waste. The amount of radioactive waste (RW) is most significant in the nuclear fuel cycle. In spite of its relatively low activity it is the major contributor to the formation of radiation hazards to the people and environment. The radioactivity of uranium ores and of their processing waste is due to natural radionuclides of uranium (238U and 235U) and thorium (232Th) radioactive decay chains.

CHEMISTRY AND TECHNOLOGY OF INORGANIC MATERIALS

26-41 189
Abstract
The review describes the application of solid electrodes based on copper for voltammetric analysis of major classes of organic and inorganic substances over the last fifty years. Despite the fact that there are many reviews of individual solid electrodes this review offers the first comprehensive report on all forms of copper electrodes. The advantages and disadvantages of copper electrodes in comparison with electrodes made of other metals are discussed. Varieties of copper electrodes, their basic physico-chemical properties and some specific characteristics of their surface are described. The electrochemical behavior of copper in aqueous solutions and electrocatalytic mechanisms of transformations of matter on its surface are reported. Examples of the use of electrochemical copper sensors for flow-injection analysis and liquid chromatography are given. Recent trends of the use of copper micro- and nanostructured electrodes in electrochemical analysis are reviewed. The prospects of using copper as a material for the creation of new electrochemical sensors are shown.
42-51 170
Abstract
Tantalum methylate of general formula Ta2(OMe)10 was synthesized by electrochemical synthesis as a precursor for obtaining oxomethylate complexes of tantalum and rhenium. The complex is used to prepare catalysts in reactions of cross-condensation and reductive dehydration of alcohols. The catalysts are based on γ-Al2O3 and TiO2. Ultradisperse and nanosized TiO2 is obtained by the supercritical fluid technology. The sample is characterized by different methods (DTA, XRD, DSC). It is shown that annealing at 340°C allows obtaining anatase modification of TiO2 with a specific urface of 27.3 sq.m/g which can serve as a matrix for drawing active components of catalysts. It is shown that the Ta-Re/Al2O3 catalyst allows transforming ethanol and mixtures of ethanol with glycerin into aliphatic hydrocarbons C3-C11. A technological scheme for obtaining active components of the catalysts for cross-condensation and reductive dehydration of alcohols is suggested.
51-56 101
Abstract
Platinum-palladium/carbon nanjtubes (CNT) carbon nanocomposites were synthesized by chemical reduction of ions in water-organic solutions of reverse microemulsions. Physico-chemical characteristics of the nanocomposites were studied by atomic force microscopy, transmission electron microscopy, photon-correlation spectroscopy, X-ray phase analysis and chronopotentiometry. It was found that the smallest platinum-palladium nanoparticles size is observed when the metal ratio is 3:1 and the water pool size is minimal (ω = 1.5). Testing of catalytic activity in the oxidation of formic acid showed that the platinum-palladium/CNT nanocomposites showed higher corrosion resistance than nanocomposites with pure palladium.

THEORETICAL BASES OF CHEMICAL TECHNOLOGY

57-64 97
Abstract
Standard equipment is a considerable part of modern equipment of chemical plants. In particular, standard heat exchangers are widespread. Possible deviations in the operation of heat exchangers at plants from the preset parameters of their operation can lead to deterioration of the operation of the whole technological system. For this reason an attempt is made in the article to suggest a hypothesis explaining what can lead to disfunction in the operation of heat exchangers. The authors use a method of calculating technological reliability to study the operability of a vertical shell-and-tube heat exchanger. First, the size of the heat transfer surface of the vertical heat exchanger is calculated for specific conditions of work, and a standard device is chosen. Then a method of calculating the technological reliability of the calculated and standard heat exchangers is applied. An operating problem is solved on the assumption that external impacts on the heat transfer process are not fixed, but varied and are within their acceptable intervals. After comparing the probability of the workability of the calculated heat exchanger and of the chosen standard apparatus, a conclusion is made about the expediency of using the standard heat exchanger.
65-69 96
Abstract
When separating multicomponent heterogeneous mixtures in units consisting of a distillation column and a decanter, a fundamental question is the location of phase separation regions with different numbers of liquid phases in the concentration simplex. A solution of this issue is based on data on the vapor-liquid and liquid-liquid equilibria of the mixture and its components, as well as on the general laws of the formation of the topological structure of phase separation areas. A strategy of studying the three-liquid phase equilibrium area in quaternary mixtures is proposed. The strategy is based on the formula of a topological invariant of the separation region and on the mathematical concept of centroid - the intersection point of three medians. The presence of threeliquid phase areas of separation of open and closed types is shown. They differ in the absence (presence) of region of degeneracy via the critical node.

CHEMISTRY AND TECHNOLOGY OF MEDICINAL COMPOUNDS AND BIOLOGICALLY ACTIVE SUBSTANCES

70-80 128
Abstract
The article is devoted to develop of an approach for the identification of new stimulator of ematopoiesis, EPO-Fc fusion protein, which is banned by the World Anti-doping Agency (WADA) to use by athletes since it has become doping. Existing methods of qualitative determination of this substances in routine practice of antidoping laboratories such as polyacrylamide gelelectrophoresis in presence of sodium dodecylsulphate (SDS-PAGE) or lauroylsarcosinate (SARPAGE) are insufficiently specific. The article shows the principal possibility of identification of EPO-Fc fusion protein by means of IEF-PAGE in carrier ampholyte-based gels with a pH range 2-6 after Fc-fragment removal via fermentative hydrolysis.It has been shown that the removing of the crystallizable fragment leads to decrease of molecular weight of whole hybrid molecule and to increase its electrophoretic mobility that allows to detect this banned substances with high specificity by existing methods. During the study the enzyme for hydrolytic cleavage and optimum conditions of hydrolysis of EPO-Fc in serum samples were selected.
81-86 160
Abstract
The conditions of lyophilization of nanoliposomes with encapsulated gentamicin (liposomal gentamicin) were studied. A mode of its safe lyophilization was suggested. A program for eliminating adverse factors was developed. It includes smooth increase of temperature from -70°C (freezing temperature) to room temperature (22±2)°C and gradual reduction of vacuum from 30 to 10 Pa without jumps and drops. The characteristics of the labile nanoliposomal drugs were not lost. The suggested program consisted of 10 steps allowing computer control to attain a slow and uniform increase in the temperature of the frozen product. The precise control of pressure in the chamber was provided by a system of automatic regulation of vacuum supplied with the equipment. After the rehydration the lyophilized preparations completely restored their original shape and properties.

SYNTHESIS AND PROCESSING OF POLYMERS AND POLYMERIC COMPOSITES

87-90 111
Abstract
The research covers rheological characteristics of melts of polysulfones of domestic brand PSF-190 and foreign brand Udel P-1700 at temperatures ranging from 290 to 360°C. The values of activation energy of viscous flow of polysulfone melts at different temperatures are presented. The flow behavior indexes of melts of polysulfones PSF-190 and Udel P-1700 were determined. For the first time thermal stability curves over a wide temperature range were obtained, and formulas for describing them were presented. Temperature modes for processing the studied polysulfones were suggested. The dependency of density and volume in the temperature range from 23 to 320°C were obtained by the dilatometric method. Besides, constants and coefficients of the state equation of linear thermal expansion were calculated.
91-93 112
Abstract
The rheological properties of polyethylene with different molecular weight characteristics were studied. Difference of molecular weight characteristics was found on the basis of melt flow index, and slip effect in the molten polyethylene flow was studied. The presence of slip effect is found in case of flowing polyethylene with a higher molecular weight in contrast to polyethylene with lower molecular weight at different temperatures. Changes of the slip effect parameters upon mixing polyethylenes with very much different molecular weight characteristics were studied.


ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)