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Water insoluble calcium hydroxide Ca(OH)2 or calcium carbonate CaCO3 react with aqueous solution of (1-hydroxyethylidene)diphosphonic acid and nitrilotrimethylenephosphonic acid to form poorly soluble calcium (1-hydroxyethylidene)diphosphonate trihydrate and calcium nitrilotrimethylenephosphonate trihydrate, respectively. The reaction of calcium chloride CaCl2 with the disodium salt of ethylenediaminetetraacetic acid afforded poorly soluble calcium ethylenediaminetetraacetate hexahydrate. The reaction of suspensions of complexes of (1-hydroxyethylidene)calcium diphosphonate trihydrate, calcium ethylenediaminetetetraacetate hexahydrate and calcium nitrilotrimethylenephosphonate trihydrate with 2-aminoethanol led to the formation of water-soluble (1-hydroxyethylidene)bis(2-aminoethanol)calcium diphosphonate, tris(2-aminoethanol)calcium nitrilotrimethylenephosphonate, and bis(2-aminoethanol)calcium ethylenediaminetetraacetate, respectively. The molecular structure of calcium ethylenediaminetetraacetate hexahydrate was characterized by single-crystal X-ray diffraction method. [ABSTRACT FROM AUTHOR]

High power impulse magnetron sputtering (HiPIMS) parameters such as the frequency, duration and amplitude of the discharge current pulses can be adjusted over a wide range to change the energy conditions for coating formation. This in turn leads to changes in the structure and properties of the deposited coatings. Measurement of the energy flux onto the substrate during high power pulse magnetron sputtering of copper is the subject of this paper. It is shown that for a fixed peak discharge current and average discharge power, a significant increase in the energy transferred to the coating can be achieved by reducing the duration of the current pulses. In this case, both the total energy flux onto the substrate and the normalized energy transferred per unit volume of the coating will be increased. The reasons for the increase in energy are examined in the paper. The ability to control the energy transferred to the coating by adjusting the HiPIMS pulse parameters is demonstrated. [ABSTRACT FROM AUTHOR]

In the case of loss-of-coolant accidents (LOCAs) at a tokamak fusion reactor (TFR) due to the outflow of water from the cooling system of the first wall/blanket or the divertor into the vacuum vessel, free hydrogen can be released as a result of high-temperature oxidation of beryllium and, to a lesser extent, tungsten and carbon that make up the surface of the vacuum vessel walls and divertor. In a number of accident scenarios, air from the containment rooms can also enter the vacuum vessel. At sufficiently high concentrations of hydrogen in the resulting steam–gas mixture in the vacuum vessel, a fire or explosion can occur, which threatens the structural integrity of the reactor. The most important phenomenon affecting the formation of the region with an increased hydrogen concentration is hydrogen stratification. Therefore, the safety analysis of a TFR, including the promising Russian TFR, should include numerical estimates of the possibility of stratification of hydrogen released during an accident. The article presents a physical model that makes it possible to estimate the characteristic parameters and location of the region with an increased hydrogen content in the LOCA accompanied by the entry of air into the vacuum vessel. [ABSTRACT FROM AUTHOR]

5-Alkyl-substituted derivatives of 1-(2-hydroxyethyl)-4,6-dimethyl-1H-pyrimidin-2-one (1) are synthesized for the first time. Pyrimidine 1 is an active pharmaceutical ingredient of the burn drug Xymedon, which has pronounced hepatoprotective properties. The cytotoxicity and cytoprotective properties of the synthesized pyrimidines against the Chang Liver cell line of hepatocytes are evaluated. It is shown that the introduction of an alkyl substituent into the pyrimidine ring of Xymedon have a significant negative impact on the hepatoprotective properties. [ABSTRACT FROM AUTHOR]

Ti1 – xAlxN coatings with different Al content (x = 0.1–0.43) are grown on WC–Co substrates by dual high-power impulse magnetron sputtering in the Ar/N2 atmosphere. The coating resistance to high-temperature oxidation is determined. For this, the phase composition change is investigated by synchrotron radiation during heating in the air from room temperature to 1100°С. Mechanical properties (hardness, elastic modulus, plasticity index, and plastic deformation resistance) are determined by nanoindentation of coatings before and after heating to 1100°С. X-ray diffraction patterns demonstrate the formation of the TiO2 phase on the surface of all coatings, while the formation temperature and the phase type (brookite or rutile) depend on the Al content in the coating. All coatings are not subject to spinodal decomposition into the TiN and AlN phases after heating to 1100°С. The Ti0.57Al0.43N coating possesses the highest heat resistance; it undergoes the smallest change in the phase composition and mechanical properties after the high-temperature treatment. [ABSTRACT FROM AUTHOR]

Various methods of cluster analysis are used for identifying large-scale atmospheric circulation regimes (weather regimes (WRs)). In this paper we compare the four most commonly used clustering methods: k-means (KM), Ward's hierarchical clustering (HW), Gaussian mixture model (GM), and self-organizing maps (SOMs) to analyze WRs in the Euro-Atlantic (EAT) region. The data used for identifying WRs are 500 hPa geopotential height fields (z500) from the ERA5 reanalysis for 1940–2022. Four classical wintertime WRs are identified by the KM method—two regimes associated with positive and negative phases of the North Atlantic Oscillation (NAO+ and NAO–), a regime associated with the Scandinavian blocking (SB), and a regime characterized by elevated pressure over the Northern Atlantic. For summer months, the KM method gets WRs that are similar in spatial structure to the classical winter ones. The SOM method yields results that are almost identical to the results of the KM method. Unlike KM and SOM methods, HW and GM do not fully catch the spatial structure of all of the four classical winter EAT WRs and their summer analogues. Compared to WRs of the KM and SOM methods, WRs obtained by HW and GM methods explain less z500 variance; they have different occurrences, persistence, and transition features. Summer and winter WRs obtained by HW and GM methods are less similar to each other compared to WRs provided by the KM method. Average spatial correlation coefficients between mean z500 fields of WRs obtained by KM and HW methods are 0.76 in winter and 0.83 in summer; 0.70 in winter and 0.72 in summer for KM and GM methods; and 0.41 in winter and 0.44 in summer for the regimes compared between HW and GM methods, respectively. There are statistically significant trends of the seasonal occurrence of WRs found by some of the studied clustering methods—a positive trend for the occurrence of the NAO+ regime and a negative trend for the occurrence of the NAO-regime. [ABSTRACT FROM AUTHOR]

Studies of the properties of ZnxFe3 –xO4 (x = 0, 0.25, 0.5, 0.75, 1.0) magnetic nanoparticles synthesized by a modified hydrothermal method are presented in comparison with the properties of the same nanoparticles stabilized with polyacrylic acid ZnxFe3 –xO4@PAA. The structure, size, morphology, and magnetic properties of the samples were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR), physical properties measurements (PPMS), and Mössbauer spectroscopy. The synthesized nanoparticles are single-phase, without additional impurities, have a narrow size distribution and are in the superparamagnetic phase. From the (XRD) measurements, it was found that with an increase in the Zn content from x = 0 to x = 1.0, the sizes of the nanoparticles were increasing from 17 to 33 nm. Analysis of the Mössbauer spectroscopy data showed that when doped with Zn ions from x = 0 to x =1.0, the sizes of the nanoparticles were decreasing from 15 to 5 nm. The results of the Mössbauer studies showed that both ZnxFe3 –xO4 and ZnxFe3 –xO4@PAA has a core/shell type structure in which the core is magnetically ordered, whereas the shell does not have magnetic ordering. Mössbauer studies indicate that the coating of citric acid particles leads to their isolation from each other, reducing or eliminating interactions between particles, reducing the thickness of the paramagnetic shell, and thereby increasing the diameter of the core, which is in a magnetically ordered state. [ABSTRACT FROM AUTHOR]

Steam oxidation of beryllium dust, which will inevitably be formed and accumulated in the vacuum chamber of the ITER thermonuclear reactor, can occur in emergency situations associated with the water flow from the cooling system of the first wall or divertor into the vacuum chamber (LOCA-type accident). This process is accompanied by the release of free hydrogen, which creates a risk of fire or explosion when mixing with air. The safety analysis of a thermonuclear reactor should include numerical estimates of the degree of oxidation and the amount of hydrogen released. The paper presents an engineering model that allows, with a given steam content in the volume of the chamber, to determine the rate of hydrogen production during the oxidation of beryllium dust layers and the total amount of hydrogen formed during an accident. An analytical assessment of the oxidation rate of the dust layer is carried out. [ABSTRACT FROM AUTHOR]