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Vol. 7 Issue 1

Archives Journal Chemical Bulletin Vol. 7 Issue 1

Composites materials based on natural chrysotile fibers

https://doi.org/10.58224/2619-0575-2024-7-1-4-21
 4-21 p.
Abstract
The article discusses the technology of production, the problems of the development of chrysotile and chrysotile cement industries in the CIS countries. The article provides information on the composition and properties of natural chrysotile fibers, data on the quality of raw materials of cement and chrysotile fibers supplied to chrysotile cement enterprises, characteristics of suspension with them, semi-finished product and properties of solidified chrysotile cement products.
The purpose of the research is to study the influence of external and internal factors, risks on the development of the chrysotile-asbestos industry, on the sales market. Identification of the dependence of the influence of the pa-rameters of chrysotile fiber and cement on the quality of finished chrysotile cement products.
Analysis of scientific literature, analysis of current production, identification and monitoring of the quality of raw materials and finished products, comparative analysis of production and consumption markets.
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Quantum model of anharmonic vibrations of a diatomic molecule with a variable force constant and a small value of the anharmonicity coefficient

https://doi.org/10.58224/2619-0575-2024-7-1-22-31
,
 22-31 p.
Abstract
In this work, vibrations of a diatomic molecule are considered within the framework of quantum mechanics as an anharmonic oscillator with small values of the anharmonicity coefficient. Based on well-known models of quantum harmonic and anharmonic oscillators, a new model with a variable value of the molecule force constant was created here. The force constant depends on the vibrational quantum number n and the anharmonicity coefficient . Mathematical analysis of this model confirmed its physical validity. As an example, the vibrational energy of an oxygen molecule was calculated within the framework of the model presented in the work.
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Application of thermal methods for the analysis of organic matter content in urbanozems

https://doi.org/10.58224/2619-0575-2024-7-1-32-40
, ,
 32-40 p.
Abstract
Objectives: the purpose of the study is to determine the content of organic matter in anthropogenic soils using thermal analysis methods.
Methods. Physico-chemical methods of soil sample analysis were used, the actual acidity, ash content and or-ganic matter were determined according to GOST 26213-2021 and by thermogravimetric analysis.
Results. It is shown that the content of organic substances in soils by thermogravimetry and according to GOST 26213-2021 differ by no more than 15.4%, which, in particular, may be due to the decomposition of inorganic sub-stances during prolonged exposure at a temperature of 525 ° C according to the GOST method. Nevertheless, the thermogravimetry method provides information about the temperatures at which the maximum decomposition rate is observed.
Conclusions. It has been established that the methods of thermogravimetry and according to GOST 26213-2021 give different results of the content of organic carbon in the soil due to different temperatures of maximum decom-position of humic acids. The higher the maximum decomposition temperature, the less organic substances decom-pose when studying soils by thermogravimetry.
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Structural parameters of YBa2Cu3-xO6+y

https://doi.org/10.58224/2619-0575-2024-7-1-41-48
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 41-48 p.
Abstract
the aim of the work is to study the structural parameters of phase 1-2-3 by precision X-ray diffraction method. The refinement of composition and structural parameters to the divergence factor R = 0.008 was carried out. The composition of the substance can be expressed by the formula . Higher values of the mean-square amplitudes of atoms vibrations and vibration anisotropy were obtained for Си1 and О1 located in the basis plane z = 0. Comparison with data obtained at low temperatures suggests that the high mobility of Си1 and O1 is related to static displacements of atoms from their crystallographic positions. There is a correlation between the deviation from the oxygen stehiometry, the lattice period c and the value of the superconducting transition temperature Tc. An increase in the oxygen content is accompanied by an increase in Tc. Dependences of isotropic mean-square amplitudes of atoms-components vibrations of compounds on the oxygen content are plotted. For the O1 atom in the tetragonal phase, a marked growth of mean-square amplitudes of vibrations with increasing oxygen index is observed, which may be associated with an increase in the instability of the structure. It can be concluded that the analysis of precision diffraction studies for yttrium-barium-copper oxides allows us to identify the structural features responsible for the instability of this class of materials.
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