Aleksandra Kalinina

Dr. Aleksandra Kalinina


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
10 February 2023 in Chemengineering
Verified
Journal Article
Open access
PDF file
GMGeorgy Mochalov
Georgy Mochalov
AKAleksandra Kalinina
Aleksandra Kalinina
OZOlesya Zhuchok
Olesya Zhuchok
Currently, the most common method of silane synthesis for electronics and photovoltaics is trichlorosilane (TS) dismutation. TS dismutation proceeds in the form of a reactions cascade, therefore its study is of both practical and scientific interest. The results of calculating the equilibrium composition of the reaction mixture in the vapor phase based on literature data from various sources were not reliable. Therefore, the dependence of the composition of the reaction mixture on the time of contact of the TS vapor with the catalyst under static conditions was experimentally investigated. The stationary composition of the mixture, close to equilibrium, was determined. A good agreement of the obtained results with the literature data in one of the sources was shown. The kinetics of the dismutation reaction of TS and dichlorosilane (DCS) was carried out by the flow method. As a result of regression analysis of experimental data, the rate constants of the direct and reverse dismutation reactions of TS, DCS, and monochlorosilane (MSC) were obtained. The rate constants were used to calculate the equilibrium composition of the reaction mixture. A good agreement between the calculated and experimental data was shown.

9 December 2023 in Microbiology Research
Verified
Journal Article
Open access
PDF file
AKAleksandra Kalinina
Aleksandra Kalinina
VNVladimir Naumov
Vladimir Naumov
AVAlena Verakhina
Alena Verakhina
SOSvetlana Ovchinnikova
Svetlana Ovchinnikova
DYDiana Yakovleva
Diana Yakovleva
PAPolina Afanasieva
Polina Afanasieva
The use of algae for carbon dioxide fixation is based on their natural ability to photosynthesize. Dynamic experiments make it possible to calculate the short-term photosynthetic activity of microalgae strains in photobioreactors. In this study, the effect of temperature and culture time on the intensity of reproduction and on CO2 absorption by some microalgae was evaluated. It was found that the maximum increase in biomass occurred during algae cultivation at 29–32 °C and pH = 8.4. A ratio of ~2.0 was observed between CO2 absorption and the increase in biomass for different microalgae. When using the Chlorella genus, the increase in biomass under comparable conditions was greater than when cultivating microalgae of the Scenedesmus genus.

1 July 2024 in Sci
Verified
Journal Article
Open access
PDF file
OZOlesya Zhuchok
Olesya Zhuchok
YSYegor Stolmakov
Yegor Stolmakov
AKAleksandra Kalinina
Aleksandra Kalinina
VMVitaly Medov
Vitaly Medov
DBDarya Belousova
Darya Belousova
GMGeorgy Mochalov
Georgy Mochalov
Currently, the most common method of silane synthesis for electronics and photovoltaics is trichlorosilane dismutation. Therefore, an experimental study of the kinetics of the dismutation reaction of chlorosilanes is of scientific and practical interest. A catalyst has been proposed that allows the dismutation reaction to be carried out in a wide range of temperatures and pressures. Both kinetic and thermodynamic data on the dependence of the rate of the dismutation reactions of trichlorosilane, dichlorosilane, and monochlorosilane on pressure were experimentally obtained. In addition, the dependence of saturated vapor pressure on temperature for monochlorosilane and dichlorosilane were also experimentally determined. Using the example of TCS, it was experimentally established that increasing the pressure to six atmospheres makes it possible to increase the specific productivity of the reactor by at least an order of magnitude due to the acceleration of the chemical reaction and the increase in the molar concentration of chlorosilanes in the vapor mixture. Consequently, it becomes possible to multiply the reactor’s load on the substance and, accordingly, the performance of the chlorosilane dismutation apparatus in general.

22 November 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
RKRoman Kornev
Roman Kornev
IGIgor Gornushkin
Igor Gornushkin
LSLubov Shabarova
Lubov Shabarova
AEArtur Ermakov
Artur Ermakov
GMGeorgy Mochalov
Georgy Mochalov
AKAleksandra Kalinina
Aleksandra Kalinina
The processes of hydrogen reduction of silicon and germanium chlorides under the conditions of radio-frequency (40.68 MHz) counteracted arc discharge stabilized between two rod electrodes were investigated. The main gas-phase and solid products of plasma-chemical transformations were determined. Thermodynamic analysis of SiCl4 + H2 and GeCl4 + H2 systems was carried out. It is shown that under the implemented experimental conditions, equilibrium components of the products are established. The detected spectra of chemical activity were studied, which gave reason to assume that the molecular mechanism of the hydrogen reduction process is the main one. The impurity composition of gas-phase and solid reaction products was investigated. The possibility of single-stage production of high-purity Si and Ge mainly in the form of compact ingots, as well as high-purity chlorosilanes and trichlorogermane, was shown.

10 March 2025 in Inorganics
Verified
Journal Article
Open access
PDF file
RKRoman Kornev
Roman Kornev
GMGeorgy Mochalov
Georgy Mochalov
NMNikita Maleev
Nikita Maleev
SRSergei Romanov
Sergei Romanov
RKRoman Kornev
Roman Kornev
AKAleksandra Kalinina
Aleksandra Kalinina
The transformation of organochlorine and organic impurities such as CCl4, C2H2Cl2, C2HCl3, C2Cl4, C2H2Cl4, CH4, C3H8, C4H10, and C6H6 in the content range of 10−2–10−6 wt.%, as well as BCl3 impurities at the level of 3 × 10−2 wt.%, was considered. A method has been developed for removing limiting impurities of carbon and boron during the process of the hydrogen reduction of silicon tetrachloride in a high-frequency arc gas discharge at atmospheric pressure. The thermodynamic and gas-dynamic analyses of the reduction process of silicon tetrachloride in hydrogen plasma, along with the behavior of organochlorine impurities, organic substances, and boron trichloride, was conducted. These analyses suggest that under equilibrium conditions, the conversion reactions of impurities result in the formation of silicon carbide and boron silicide. Potential chemical reactions for the conversion of the studied impurities into silicon carbide and boron silicide have been proposed. A new potential for plasma chemical processes has been identified, enabling the effective purification of chlorosilanes from both limiting and limited impurities. The results demonstrate the possibility of significantly reducing the concentrations of organochlorine and organic impurities, as well as boron trichloride, during the reduction of silicon tetrachloride in hydrogen plasma. The maximum conversion rates achieved included 99% for the organochlorine impurity CCl4 to silicon carbide, 91% for benzene impurity to silicon carbide, and 86% for boron trichloride to boron silicide.