PSA-stage Features of the Hybrid Membrane-sorption Oxygen Concentrator

The paper considers the principle of the organization of the hybrid membranesorption oxygen concentrator and the work of the PSA stage of the hybrid system. The use of hybrid membrane-sorption gas separation systems can significantly reduce the energy consumption of plants, as well as to neutralize such disadvantages as contamination of the product flow by the products of abrasion of sorbents, through the use of highly selective polymer membrane, and the restriction on the oxygen concentration when using a single membrane stage, through its use after the PSA stage. In this paper, we propose an arrangement for the operation of the PSA stage of a hybrid system consisting of three adsorbers and providing a constant product flow of the PSA stage necessary to ensure continuous feed flow to the membrane stage of the system. Each of the adsorbers in this system passes through three main stages: filling, displacement (adsorption), and discharge (desorption). Moreover, the filling is not from the compressor, but part of the product flow of the displaced adsorber. The results of the operation of the system organized by the proposed method are compared with the results of the operation of modern gas separation systems on the market.     Keywords: Sorption, air separation, pressure-swing adsorption, PSA, hybrid technologies, oxygen concentrator, recycling, oxyge

Anisotropic magnetic properties and giant magnetocaloric effect in antiferromagnetic RRMnO3_3 crystals (RR=Dy, Tb, Ho and Yb)

We have systematically investigated the magnetic properties and magnetocaloric effect (MCE) in $R$MnO$_3$ ($R$$=$Dy, Tb, Ho and Yb) single crystals. Above a critical value of applied field ($H_c$), $R$MnO$_3$ undergo a first-order antiferromagnetic (AFM) to ferromagnetic (FM) transition below the ordering temperature ($T_{N}^{R}$) of $R^{3+}$ moment and a second-order FM to paramagnetic (PM) transition above $T_{N}^{R}$. Both $H$ and $T$ dependence of $M$ shows that the system is highly anisotropic in the FM as well as PM states and, as a result, the magnetic entropy change ($\Delta S_{M}$) is extremely sensitive to the direction of applied field and can be negative (normal MCE) or positive (inverse MCE). For hexagonal HoMnO$_3$ and YbMnO$_3$ systems, a very small inverse MCE is observed only for $H$ parallel to c axis and it decreases with increasing $H$ and crosses over to normal one above $H_c$. On the other hand, for orthorhombic DyMnO$_3$ and TbMnO$_3$, though the inverse MCE disappears above $H_c$ along easy-axis of magnetization, it increases rapidly with $H$ along hard-axis of magnetization for $T$$\ll$$T_{N}^{R}$. Except for YbMnO$_3$, the values of $\Delta S_{M}$, relative cooling power and adiabatic temperature change along easy-axis of magnetization are quite large in the field-induced FM state for a moderate field strength. The large values of these parameters, together with negligible hysteresis, suggest that the multiferroic manganites could be potential materials for magnetic refrigeration in the low-temperature region.Comment: 10 pages, 11 figure

Ion channel TRPA₁ is a promising therapeutic target for treatment of pain

In the last time information about the role of TRPA₁ in pain and cold sensitivity, as well as in the formation and maintenance of inflammation is increasing in scientific literature. Given this information, the interest for search and study of pharmacological agents, which selectively blocked of TRPA₁ and reduced the severity of pain and inflammation is increasin

EXPERIMENTAL STUDY OF THE ANTIDIARRHOEAL ACTIVITY OF MONTMORILLONITE-CONTAINING ENTEROSORBENT

Aim. To study the antidiarrhoeal activity of montmorillonite-based enterosorbent on the model of serotonin-induced diarrhea.Materials and methods. The study was performed on laboratory mice of both genders, acute diarrhea was induced by intraperitoneal injection of serotonin hydrochloride at a dose of 0.32 mg/kg, enterosorbent as an aqueous suspension was administered orally in a wide range of doses 30 minutes prior to serotonin administration. Within 4 hours, the time of diarrhea onset, the number of defecations, the fluid content in the fecal masses was considered. Morphological examination of the small intestine was carried out. Results. The administration of serotonin led to the development of diarrhea in 100% of animals in 12,8±1,2 minutes, the number of defecations increased 2,5 times compared to intact animals and was 19,5±0,5 times within 4 hours, the fecal masses were predominantly wet and liquid. The use of enterosorbent under the Crim_04 cipher in the maximum dose led to a delay in the development of diarrhea to 73,6±4,1 minutes, a reduction in the number of defecations to 9,4±0,1 and a significant inspissation of stool. The antidiarrhoeal effect of enterosorbent was confirmed morphologically.Conclusions. Montmorillonite-based enterosorbent under the laboratory cipher Crim_04 has a dose-dependent antidiarrhoeal activity in the modeling of serotonin-induced diarrhea

Preclinical study of pharmacological activity of enterosorbente on the basis of montmorillonite

At present, enterosorbents based on mineral raw materials are in high demand among the population. However, there are no enterosorbents on the Russian pharmaceutical market on the basis of domestic mineral raw materials, to study the pharmacological activity of enterosorbent based on montmorillonite of Russian origin under experimental conditions. The methodological approach was based on the implementation of a complex of theoretical, pharmacological, toxicological, histological, biochemical, statistical methods. Models of experimental diarrhea, acute and toxic liver damage, acute experimental pancreatitis were selecte

Measurement of pressure effects on the magnetic and the magnetocaloric properties of the intermetallic compounds R(Co1-xSix)2 [R=Dy and Er]

The effect of external pressure on the magnetic properties and magnetocaloric effect of R(Co1-xSix)2 [R= Er, Dy and x=0, 0.025 and 0.05] compounds has been studied. The ordering temperatures of both the parent as well as the Si substituted compounds are found to decrease with pressure. In all the compounds, the critical field for metamagnetic transition increases with pressure. It is seen that the magnetocaloric effect in the parent compounds is almost insensitive to pressure, while there is considerable enhancement in the case of Si substituted compounds. Spin fluctuations arising due to the magnetovolume effect play a crucial role in determining the pressure dependence of magnetocaloric effect in these compounds. Analysis of the magnetization data using the Landau theory has shown that the magnitude of the Landau coefficient (C3) decreases with Si concentration whereas it is found to increase with pressure. The isothermal magnetic entropy change is found to behave in the same manner as C3, both with Si concentration (at ambient pressure) as well as with the applied pressure.Comment: 15 pages, 5 figure

Hard Magnetic Properties and the Features of Nanostructure of High-Temperature Sm-Co-Fe-Cu-Zr Magnet with Abnormal Temperature Dependence of Coercivity

This paper presents methods and approaches that can be used for production of Sm-Co-Fe-Cu-Zr permanent magnets with working temperatures of up to 550 °C. It is shown that the content of Sm, Cu, and Fe significantly affects the coercivity (Hc) value at high operating temperatures. A decrease in the content of Fe, which replaces Co, and an increase in the content of Sm in Sm-Co-Fe-Cu-Zr alloys lead to a decrease in Hc value at room temperature, but significantly increase Hc at temperatures of about 500 °C. Increasing the Cu concentration enhances the Hc values at all operating temperatures. From analysis of the dependence of temperature coefficients of the coercivity on the concentrations of various constituent elements in this alloy, the optimum chemical composition that qualifies for high-temperature permanent magnet (HTPM) application were determined. 3D atom probe tomography analysis shows that the nanostructure of the HTPM is characterized by the formation of Sm2(Co,Fe)17 (2:17) cells relatively smaller in size along with the slightly thickened Sm(Co,Cu)5 (1:5) boundary phase compared to those of the high-energy permanent magnet compositions. An inhomogeneous distribution of Cu was also noticed in the 1:5 phase. At the boundary between 1:5 and 2:17 phases, an interface with lowered anisotropy constants has developed, which could be the reason for the observed high coercivity values. © 2023 by the authors.Ministry of Education and Science of the Russian Federation, Minobrnauka: 122021000034-9; Ural Federal University, UrFUStudy of magnetic and structural properties was supported by the state assignment of the Ministry of Education and Science of Russia (theme “Magnet”, No. 122021000034-9) and Development Program of the Ural Federal University “Priority-2030”

The impact of Grey Heron (Ardea cinerea L.) colony on soil biogeochemistry and vegetation: a natural long-term in situ experiment in a planted pine forest

Increased anthropogenic pressure including intensification of agricultural activities leads to long-term decline of natural biotopes, with planted forests often considered as promising compensatory response, although reduced biodiversity and ecosystem stability represent their common drawbacks. Here we present a complex investigation of the impact of a large Grey Heron (Ardea cinerea L.) colony on soil biogeochemistry and vegetation in a planted Scots pine forest representing a natural in situ experiment on an engineered ecosystem. After settling around 2006, the colony expanded for 15 years, leading to the intensive deposition of nutrients with feces, food remains and feather thereby considerably altering the local soil biogeochemistry. Thus, lower pH levels around 4.5, 10- and 2-fold higher concentrations of phosphorous and nitrogen, as well as 1.2-fold discrepancies in K, Li, Mn, Zn and Co., respectively, compared to the surrounding control forest area could be observed. Unaltered total organic carbon (Corg) suggests repressed vegetation, as also reflected in the vegetation indices obtained by remote sensing. Moreover, reduced soil microbial diversity with considerable alternations in the relative abundance of Proteobacteria, Firmicutes, Acidobacteriota, Actinobacteriota, Verrucomicrobiota, Gemmatimonadota, Chujaibacter, Rhodanobacter, and Bacillus has been detected. The above alterations to the ecosystem also affected climate stress resilience of the trees indicated by their limited recovery from the major 2010 drought stress, in marked contrast to the surrounding forest (p = 3∙10−5). The complex interplay between geographical, geochemical, microbiological and dendrological characteristics, as well as their manifestation in the vegetation indices is explicitly reflected in the Bayesian network model. Using the Bayesian inference approach, we have confirmed the predictability of biodiversity patterns and trees growth dynamics given the concentrations of keynote soil biogeochemical alternations with correlations R > 0.8 between observations and predictions, indicating the capability of risk assessment that could be further employed for an informed forest management

The integrated exploration of Raifa lake sediments and dendrochronological analysis of Raifa forestry pines

© 2006-2017 Asian Research Publishing Network (ARPN). All rights reserved.The article presents some results of comprehensive research on the properties of Raifa lake bottom sediments and dendrochronological study of Raifa forestry pines (Russia). A preliminary seismic acoustic investigations have been carried out, which allowed to select the sampling site (E 48 ° 43'40.6" N 55 ° 54'21.7"). The length of core sample was 32 cm. Laboratory studies of the core, including the study of the elemental composition, magneto-mineralogical and carcinologic analysis revealed the features of sedimentation mass formation