Astrakhan State University

About: Astrakhan State University is a education organization based out in Astrakhan, Russia. It is known for research contribution in the topics: Percolation & Carbamate. The organization has 547 authors who have published 565 publications receiving 2367 citations.

Performance Evaluation of On-Grid Solar Power Stations in a Office Building in the Climatic Conditions of Astrakhan Region

Abstract: Solar energy is developing rapidly all over the world. In the Russian Federation the development of solar energy has also been observed in the last 3 years. Mainly network solar power plants with a capacity of 10 to 60 MW are being built. In addition, despite the lack of state support for the development of small renewable energy, in recent years the owners of tourist bases, commercial and office buildings, small enterprises connected to the general power grid have shown increasing interest in grid power plants. In this study the forecast of the development of a small network solar station is carried out using Photovoltaic Geographical Information System program. Full-scale tests of the realized network solar station of 10,5 kW for power supply in the retail and office building showed high accuracy of the forecast of its operation. The average annual self-sufficiency ratio comprised 32%. The results of full-scale testing confirm the economic attractiveness of small grid power projects in the climatic conditions of Astrakhan region.

Theoretical Interpretation of the Vibrational Spectra of Carboxylic-Acid Dimers in the High-Frequency Range

Abstract: An anharmonic band shift in the vibrational spectra of carboxylic-acid dimers is estimated on the basis of ab initio quantum calculations of anharmonic force constants. The implementation of ab initio quantum calculations taking into account the anharmonic nature of vibrations is connected with the choice of the atomic basis in the framework of a specific quantum method. All these factors together with the exclusion principle for bands in the infrared and Raman scattering spectra allow identification of the position of the bands of valence vibrations of CH bonds in the range of 2500–3500 cm–1. The results of model calculations give reason to assert that the fundamental vibrations of the carboxylic fragment are the characteristic frequency and vibrational mode and, for OH bonds, also the characteristic intensity. Small doublet splitting and the exclusion principle for frequencies allow identification of the valence vibrations of CH bonds.

Dynamics of floristic composition of communities dominated by Carex acuta in the northern Volga-Akhtuba floodplain

Abstract: The floristic composition of plant communities dominated by Carex acuta in the northern Volga-Akhtuba floodplain has been analyzed over the period from 1928 to 2009. It has been shown that, in 2008 to 2009, some hygrophytes disappeared from these phytocenoses; simultaneously, their composition was enriched with mesophytes and adventive species. Ramenskii’s ecological scales have indicated a decrease in water supply to habitats of the communities studied.

Apoptosis of hypothalamic neurosecretory cells in stress mice at different stages of ontogenesis.

Abstract: The aim of the present work was to identify the role of cycloferon in the apoptosis of cells in the neurosecretory centers of the hypothalamus in young and old mice in conditions of immobilization stress. Apoptotic cells were identified by staining with ethidium bromide. The optical density of the detection product of the antiapoptotic protein Bcl-2 was also studied in cells of the supraoptic and paraventricular (PVN) nuclei. Cycloferon was found to decrease the level of apoptosis in the neurosecretory centers of the hypothalamus via a Bcl-2-independent pathway. Administration of cycloferon before stress had no effect on the number of apoptotic cells, except in the PVN of old mice, where apoptosis was inhibited.

Structurally-dynamic models of substituted benzoic acids

Abstract: On the basis of modelling not empirical quantum calculations of geometrical and electronic structure of some isomers of substituted benzoic acids are investigated regularity in behaviour of parameters of the adiabatic potential a carboxyl fragment.