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2018

Archives Journal Chemical Bulletin Vol. 1

TO AN ASSESSMENT OF SIZE OF DIFFUSIVE LOSSES OF COOLANT THROUGH A RUBBER CAMERA – COVER

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 18-26 p.
Abstract
In the article the calculation of time of technologically admissible volume of losses of coolant due to diffusive permeability through walls of cameras of branch pipes of refrigerators with the given technical characteristics is executed. The guaranteed resource of work of branch pipes was 14,1 and 7,4 years respectively for one and second machines. Experimental researches of influence of type and structure of fillers on diffusive permeability are carried out on rubbers: 61-202 on the basis of a chloroprene of S-40 and RK-1802 on the basis of the hydrogenated ZETPOL-2000 rubber, at the acceptable technological indicators of processing and production of rubber cameras. The optimum share of filling of rubber mix is experimentally chosen – 20% of mass parts as ground mica. For ensuring long resistance of rubber to influence of coolant as basic it is recommended to use ZETPOL-2000 brand rubber hydrogenated.
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SORPTION-PHOTOMETRIC DETERMINATION OF ANIONIC SURFACTANTS IN THE PRESENCE OF ORGANIC REAGENT

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 27-36 p.
Abstract
The article describes the characteristics of a class of surfactants and the use of substances in the petrochemical industry. The classification of anionic surfactants is considered. The main structural elements of the structure of substances of the considered class are presented. A brief description of the most commonly used methods for the analysis of anionic surfactants is given. Advantages of using photometric, extraction-photometric and spectrophotometric methods for the determination of anionic surfactants using triphenylmethane dyes are described. In the course of the study, the content of the anionic surfactant (sulfonol) in the solution was monitored spectrophotometrically using the indicator reaction with malachite green. The use of the method in question to study sorption processes in a surfactant system is justified by the fact that surfactants are able to form complex compounds (ionic associates) with organic reagents with characteristic light absorption bands.
The results of a photometric determination of an anionic surfactant (sulfonol) using an organic reagent, malachite green, are presented. The effect of the acidity of the environment on the process of adsorption of a component in aqueous solutions is described. A calibration graph for determining the concentration of the component is given.
The main thermodynamic parameters of sulfon adsorption on activated carbon, such as enthalpy (∆H), isobaric-isothermal potential (∆G) and entropy (∆S) sorption were determined during the research. The obtained research results can be used for quantitative determination of the component and modeling of adsorption mechanisms.
The main characteristics of the sorption kinetics of a surfactant (sulfanol) on active coal are calculated. Isotherms of sorption kinetics are given. The possibility of purification from the above-described component using the sorbent under consideration is described.
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APPLICATION OF NANOFLUIDS IN REFRIGERATING ENGINEERING

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 37-40 p.
Abstract
Еlectricity consumption by refrigeration equipment is about 20% of the total energy consumption. Ways to improve the efficiency of refrigeration units is one of the most urgent tasks in the light of the general policy of energy saving in the world. The efficiency coefficient of refrigeration machines depends on the efficiency of heat exchange in the system. In addition to the obvious ways to improve the design of the refrigeration circuit itself, there are a number of alternative solutions to improve the energy efficiency of heat exchange processes. Among them there is the addition of metal oxide nanoparticles to the circuit, which have a high heat transfer coefficient. The article presents a review of the literature on the use of nanoparticles in cooling systems, which describes the energy efficiency from 9.6% to 28% depending on the material of nanoparticles and their concentration. Also, an experimental re-frigeration unit was manufactured, where copper oxide nanoparticles in a concentration of 1% were used. This installation showed a decrease in electricity consumption by 18%, as well as a better dynamics of temperature de-crease.
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ABOUT CONNECTION OF LIQUACTION WITH THE DEBYE TEMPERATURE

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 41-46 p.
Abstract
The article describes the concept of liquation. Within the framework of the research, the definition of the concept described is given. The types of liquation (zonal and dendritic) are given. It is established that a number of parameters characterizing the segregation process are related to the characteristic Debye temperature of a chemical element. The interrelation between the values of the effective atomic radius, intensity, and also the liquation coefficient from the Debye temperature is considered. The role of the values of the maximum supercooling parameter on the Debye temperature is described. The dependence of the content of elements in interdendritic volumes on the Debye temperature is considered. The dependence of the chemical composition of local regions on the Debye temperature is given. A similar trend was observed with the values of the viscosity of the molten metal. The correlation coefficients always exceeded 0.9.
It should be noted that the liquation process adversely affects the steel properties. This can affect the values of the toughness of transverse specimens. The considered dependences of the process parameters can be useful for describing the processes of eliminating the heterogeneity of steels. All this will not only improve its properties, but also describe in more detail the process of eliminating the chemical heterogeneity of steel. In addition, this will allow us considering the melting process with a change in volume. Increased interest causes the content of elements in the axes of the dendrites in the initial cast state. It was found that the distribution of elements in the axes of dendrites in interdendritic microvolumes in the structure of the pressed steel does not depend on the quenching method. For the dependence considered, the values of the correlation coefficient are calculated. The main conditions of the quenching process as well as the content of the elements in percent are given.
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