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Synthesis of highly porous ceramic materials for catalytic converters based on coarse-dispersed αAl2O3 using a combination of compaction and thermochemical synthesis with the participation of active ultrafine binders is carried out. Using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM), it is established that the morphology of the synthesized material simultaneously includes large pores between filler particles (dominant αAl2O3 phase) and submicron pores in transboundary regions that appeared during the processes of liquid-phase sintering and gas evolution. A significant amount of indialite (Mg2Al4Si5O18) and spinel (MgAl2O4) formed as a result of thermochemical synthesis on surfaces and in the gaps between coarse-dispersed particles is revealed. The dominant pore size (according to the volume of mercury intrusion) is from 20 to 60 μm (about 73%), as well as pores with size from 0.4 to 2 μm (about 6%).The average pore size is about 9 μm. Highly porous materials with these characteristics of the pore space can be effectively used after modification as catalytic converters for the dehydrogenation of alkyl aromatic hydrocarbons with large molecular sizes (about 400 nm) with a long mean free path on the order of ~3–4 μm. [ABSTRACT FROM AUTHOR]

An effective method for processing lignocellulosic raw materials into marketable products is the pyrolysis method. With this method, a water-soluble fraction is formed, which has a rather narrow range of applications. The purpose of this work was to determine the effect of the water-soluble fraction of the pyrolysis liquid and wood vinegar in different dilutions on seed germination and root length and biomass of seedlings of higher plants. The pyrolysis liquid was obtained using the rapid pyrolysis method. Widespread food crops were selected as test crops: white mustard, arugula, radish, dill, curly parsley, lettuce, seed peas and oats. In dilutions of the water-soluble fraction of the pyrolysis liquid (1:200, 1:400 and 1:900), a statistically significant stimulating effect was observed on the germination of radish seeds, and root growth stimulation in radish seedlings was revealed when using dilutions of 1:200, 1:300, 1:400 and 1:900. The 1:900 dilution of the water-soluble fraction of the pyrolysis liquid contributed to the stimulation of seed germination and root growth of seedlings in oats, as well as to arugula seed germination. A statistically significant stimulating effect of wood vinegar was established on the germination of radish seeds using a 1:100 dilution, as well as on the growth of the roots of seedlings and the accumulation of raw biomass by the roots of lettuce seedlings in dilutions of 1:400 and 1:900. [ABSTRACT FROM AUTHOR]

The results of simulation of radiation-chemical transformations in the primary coolant of a water-cooled water-moderated energy reactor (VVER) are presented. It has been shown that under conditions of intense irradiation, molecular nitrogen dissolved in the coolant exhibits chemical activity. The reaction of N2 with the excited hydroxyl radical initiates the formation of ammonia and nitrous acid. Further decomposition of ammonia produces only oxidized forms of nitrogen, with N2 acting as an intermediate product. Maintaining hydrogen and oxygen concentrations within normal limits in the ammonia water chemistry is possible only with constant dosing of NH3 and degassing of the coolant. In the case of water chemistry with H2 dosing (at the initial moment), on the contrary, a stationary regime is quickly established in the absence of disturbances, satisfying the requirements of VVER water chemistry standards. The difference between the two water chemistry systems is due to the presence of nitrogen in the NH3 molecule and its transformations as an element, regardless of the initial chemical form. [ABSTRACT FROM AUTHOR]

The results of testing a xenon gamma spectrometer based on the use of an ionization chamber with compressed xenon are presented. A standard source was used to study the characteristics of the spectrometer. The main characteristics were measured: registration efficiency of 2%, energy resolution of 1.4%. [ABSTRACT FROM AUTHOR]

The Eurasian lynx (Lynx lynx) exhibits geographic variability and phylogenetic intraspecific relationships. Previous morphological studies have suggested the existence of multiple lynx subspecies, but recent genetic research has questioned this classification, particularly in Central Asia. In this study, we aimed to analyse the geographic and genetic variation in Central Asian lynx populations, particularly the Turkestan lynx and Altai lynx populations, using morphometric data and mtDNA sequences to contribute to their taxonomic classification. The comparative analysis of morphometric data revealed limited clinal variability between lynx samples from the Altai and Tien Shan regions. By examining mtDNA fragments (control region and cytochrome b) obtained from Kazakhstani lynx populations, two subspecies were identified: L. l. isabellinus (represented by a unique haplotype of the South clade, H46) and L. l. wrangeli (represented by haplotypes H36, H45, and H47 of the East clade). L. l. isabellinus was recognized only in Tien Shan Mountain, while Altai lynx was likely identical to L. l. wrangeli and found in northern Kazakhstan, Altai Mountain, Saur and Tarbagatai Mountains, and Tien Shan Mountain. The morphological and mtDNA evidence presented in this study, although limited in sample size and number of genetic markers, renders the differentiation of the two subspecies challenging. Further sampling and compilation of whole-genome sequencing data are necessary to confirm whether the proposed subspecies warrant taxonomic standing. [ABSTRACT FROM AUTHOR]

An analysis of modern scientific ideas has shown that there is no consensus on the definition of the energy of organic matter in ecosystems, and current methods need a detailed elaboration. This article presents the results of the application of the method of a component-by-component assessment of the amount of energy of the organic matter of the ecosystem using the energy approach. The methodology is the determination of energy indicators for pools of phytomass, mortmass, and soils, as well as the study of the main energy sources involved in the formation of the ecosystem. The research was carried out on the first above-floodplain terrace of the right coast of the Ushayka River in Tomsk oblast. The materials for testing the technique were obtained in the field on a scale at the level of landscape facies. In laboratory conditions, the energy potential was calculated by methods of determining the heat of combustion during direct combustion using a calorimeter for fractions of model wood, phytomass, and mortmass. According to the results of the study, the main sources of energy for the ecosystem are the sun and precipitation, which provide 3.357 × 109 J/m2/year. The total amount of energy of the organic matter of the ecosystem at the moment, representing its energy potential, is 1.523 × 1013 J/ha, of which the energy potential of grass cover phytomass is 55.01 × 109 J/ha, that of common pine tree stands is 1.29 × 1013 J/ha, that of mortmass is 43.058 × 109 J, and that of soils is 6.754 × 1012 J. The results of the work carried out can be applied to agriculture, territorial zoning, monitoring, recreation, and creation of special ecological zones. [ABSTRACT FROM AUTHOR]

In the interaction of high-molecular ammonium polyphosphate with polyethylene polyamine, thermoplastic polymers with Tg = 46.3–50.7°C, Tsoft = 43–92°C, and Tflow = 85–152°C are obtained. Thermal heat resistance, moisture resistance, and the degree of crystallinity depending on the concentration of polyethylene polyamine are measured. The bending strength of polymers and reinforced composites is measured. A chemical scheme for the formation of a polycomplex is proposed and its structure is considered. [ABSTRACT FROM AUTHOR]

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an increased recognition of its potential to induce neurological complications in the post-infection phase. This paper presents the case study of a 67-year-old male who experienced a severe SARS-CoV-2 infection, followed by the development of myopathy after 11–12 weeks and, subsequently, axonal polyneuropathy associated with IgG monoclonal gammopathies after 30 weeks. Comprehensive laboratory investigations, including serum tests, quantitative electromyography, and muscle biopsies analyzed under light microscopy, were conducted. The patient was followed for a period of 29 months (125 weeks) might offer a more active voice. The investigations unveiled persistent elevations in serum creatine kinase (CK) levels, serum M-protein IgG kappa, myopathic changes in quantitative electromyography, axonal sensorimotor polyneuropathy in nerve conduction studies, and histopathological alterations in muscle biopsies, such as lymphoplasmacytic infiltration and the presence of MHC I, CD4, and CD8 antibodies. Consequently, this paper reviews the clinical and pathological manifestations of polymyositis and polyneuropathy associated with IgG monoclonal gammopathy of clinical significance (MGCS–IgGk polyneuropathy) in the long-term post-COVID-19 period. [ABSTRACT FROM AUTHOR]

Magnetic fields in galaxies are usually originated through the action of a dynamo, which is based on the helicity of turbulent flows (alpha effect) and nonrigid rotation of a galaxy (differential rotation). They are opposed by dissipation, which tends to destroy the regular structures of the field. As a rule, dynamo equations contain averaged turbulence parameters. This approach presents difficulties in the case of galaxies with a highly inhomogeneous interstellar medium, associated, for example, with star formation. One way to solve the problem is to use random coefficients in the field equations. In this case, solutions require separate statistical analysis. This paper examines various statistical moments for the galactic magnetic field within the framework of a model assuming fluctuations of the alpha effect and turbulent diffusion. [ABSTRACT FROM AUTHOR]

Angeli's salt is a nitroxyl donor, due to which it can prevent the negative consequences of hemolysis, such as the vasoconstrictive effect of free hemoglobin in blood plasma. However, the molecular mechanisms of the interaction of nitroxyl with various hemoproteins have not been sufficiently elucidated. It is known that oxoferryl forms of hemoproteins arising from oxidative stress are strong prooxidants. In this study, the reductive nitrosylation of meth- and oxoferryl forms of hemoglobin and myoglobin with nitroxyl was investigated. The experiments were carried out in vitro by detecting nitrosyl forms of hemoproteins using electron paramagnetic resonance spectroscopy. The results indicate the antioxidant effect of Angeli's salt in systems simulating the oxidation of hemoglobin or myoglobin by hydrogen peroxide. As well, the addition of hydrogen peroxide to hemoglobin and myoglobin metforms led to the appearance of an EPR signal of free radicals with g = 2.005 associated with the protein part of these hemoproteins. Thus, nitroxyl acted simultaneously as a reducing and nitrosylating agent, thereby preventing the formation of oxoferryl forms of hemoproteins. The therapeutic properties of Angeli's salt may be largely related to the antioxidant effect exerted on blood components. [ABSTRACT FROM AUTHOR]

The molecular weight distribution of modified amino-formaldehyde resins synthesized at various melamine- and carbamide-to-formaldehyde molar ratios and catalyst modifier and diethylene glycol amounts was studied. Chromatograms of the obtained amino-formaldehyde resins are presented. [ABSTRACT FROM AUTHOR]

Results of experiments on a propagation of a pressure wave with a shock-wave leading front through a gas region excited by a pulsed freely localized discharge of the microwave wavelength range are described. The discharge was realized in air at a pressure from 14 to 100 Torr in the focal region of a quasi-optical electromagnetic beam of the microwave wavelength range. The experiments revealed three types of interaction of the gas-dynamic pulse with the region excited by the discharge in the post-discharge mode. The specific type of interaction is defined by the initial structure of the discharge and the delay time of the gas-dynamic pulse passage through the excited region. [ABSTRACT FROM AUTHOR]

In this paper, the first in a series of four articles, the scientific goals of the Metron project are highlighted, and the characteristics of the cosmic objects available for study within its framework are provided. The Metron interferometer radio telescope should include arrays of meter-range dipole antennas placed on Earth, in outer space, or on the far side of the Moon (or a combination of these options). Working in the meter range will enable the study of the so-called cosmological epoch of the "Dark Ages", which is challenging to observe but highly interesting for understanding the origin of the first stars, galaxies, and black holes, as well as for the search for new cosmological objects and processes. One possibility is to search for absorption in the 21-cm line within the extended halos around early protogalaxies and supermassive primordial black holes, whose existence is predicted in a number of models. Another goal of Metron may be to clarify the anomalous absorption in the 21-cm line previously detected by the EDGES telescopes and to observe radio emissions from the magnetospheres of stars and exoplanets. The Metron project aims to achieve unprecedented resolution in the meter range, which is expected to yield new world-class scientific results. Meter-range antennas and receivers are relatively simple and inexpensive, and the construction of interferometric arrays from them can be accomplished in a relatively short period of time. [ABSTRACT FROM AUTHOR]

The results of studies of the carbohydrate components of birch and pine wood samples torrefied in the temperature range of 200–300°C are presented. An analysis of the monosaccharide composition of carbohydrates hydrolyzed by trifluoroacetic acid has been performed. Resulting from torrefaction, the level of all the monosaccharides except for glucose exhibits a decrease. Already at 200°C, the amount of xylose extracted with the use of trifluoroacetic acid decreases by approximately two times as to compare to the reference sample. Increasing the torrefaction temperature to 250°C results in a decrease in the level of extractable xylose to 1% of the dry weight of initial material. The difference between changes in the monosaccharide composition of pine and birch cell walls is represented by the dynamics of the level of extracted glucose. Owing to torrefaction, a decrease in the amount of carbohydrate components occurs and, consequently, a decrease in the biodegradability of wood is observed, which should be taken into account in the course of composite materials development. [ABSTRACT FROM AUTHOR]

The series of new organotin complexes on the basis of bis(trimethylsilylmethyl)tin diсhloride, 1,1-dichloro-1-stanna-3,3,5,5-tetramethyl-3,5-disila-4-oxacyclohexane, and mono- and bidentate ligands—2,2'-bipyridyl, 1,10-phenanthroline, and 1-methyl-, 1-vinyl-, and 1-allylimidazoles—have been synthesized. The complexes were characterized by elemental analysis; 1Н-, 13С-, and 119Sn-NMR spectrometry; and X-ray data. Cytotoxicity in vitro of the complexes for some lines of human cancer cells was investigated. [ABSTRACT FROM AUTHOR]

When low molecular weight ammonium polyphosphate interacts with polyethylene polyamine, thermoplastic polymers containing fractions with glass transition temperatures Tglass ≥ –95°C are obtained. Their thermal and heat resistance, as well as moisture resistance, is measured at a humidity of 40–50%. The structure and chemical scheme for the formation of interaction products are proposed. [ABSTRACT FROM AUTHOR]

The influence of the preliminary ionization of a combustible mixture and the excitation of its molecules by an electron beam and an external electric field on the intensity of burning of this mixture at diff erent rates of its excitation was considered. Results of calculations of the ignition temperatures of a dry mixture of propane and air as well as of their wet mixture are presented. Recommendations for the exposure of a subsonic flow of such a mixture to an electron beam in an external electric field for increasing the efficiency of burning of the mixture are given. [ABSTRACT FROM AUTHOR]

Abstract—The article considers the efficiency and possibility of introducing into operation of VVER-1000 power units with the lifetime extended owing to the sliding pressure of the second circuit. The history of research by Russian nuclear engineers on VVER lifetime extension is reviewed. It is shown that reduction of fresh steam pressure within the allowed limits will make it possible to release additional reactivity through release of the temperature effect and to generate additional energy during the period of unit operation on the power effect. A mathematical model of changes in the main parameters of the reactor unit, including reactivity balance equations, Stodola–Flugel equation for the turbine, and heat balance and heat transfer equations in the steam generator, is compiled. The expected increase in power generation for modern fuel loadings of VVER-1000 reactors is calculated. The degree of compliance of the proposed mode with the current technological limitations of the large-series VVER-1000 power units is analyzed. The results of the analysis are confirmed by the numerical experiment on the multifunctional analyzer of the VVER-1000 unit modes developed by the National Research Nuclear University MEPhI built on the basis of the ENICAD environment and the certified diffusion neutronic code PROSTOR. Conclusions are drawn about the possibility of introducing the proposed mode into the operational practice of modern VVER-1000 power units. [ABSTRACT FROM AUTHOR]

The possibilities of igniting a combustible mixture in a high-speed flow using a microwave streamer discharge are considered. The results of experimental studies of the streamer discharge structure at various pressures are presented. To quantitatively characterize the intensity of combustion of fuel ignited by a microwave discharge, pressure and temperature measurements are used in various sections of the jet in the discharge wake. The results obtained demonstrate the possibility of igniting a model combustible mixture when propane or its mixture with air is sup-plied to the discharge region. The main physical mechanisms responsible for heating the discharge plasma to the ignition temperature of the combustible mixture and their characteristic time scales are revealed. The change in the dimensions of the combustion zone with a decrease in the initial proportion of propane in the mixture is discussed. The minimum duration and minimum level of microwave radiation required to ignite a model combustible mixture under various conditions are determined. [ABSTRACT FROM AUTHOR]

The hydrogen decrepitation of end-of-life NdFeB magnetic alloys was studied. End-of-life magnets extracted from PC hard drives were taken as a material for the experiments. The choice of these items is governed by their low cost, easy removal from PC, and small size. The magnets were demagnetized at 623 K in a medium vacuum for 4 h, which was followed by three-step cleaning of their surface to remove the electroplated coating, oxidized surface layer, and adsorbed impurities and moisture. The first step of the cleaning was sandblasting with slag shot fed at a pressure of 300 kPa. The second step was chemical etching with solutions of dilute acids (1–3% HCl, HNO3, or H2SO4 in distilled water), followed by washing in acetone. The third step was heat treatment in a vacuum, consisting in rapid heating in a shaft furnace of magnet samples placed after etching in an autoclave, with several exposures in the temperature interval 373–573 K in a medium vacuum. After these operations, the samples were quenched by placing the hot autoclave into a vessel with ice-cold water, preceded by filling the autoclave with argon. Then, alloys of the NdFeB system without removing from the autoclave were subjected to hydrogen decrepitation performed in the temperature interval from 298 to 473 K at an excess hydrogen pressure of 30 to 210 kPa to determine how these parameters influence the properties of the hydride powders obtained and the amount of hydrogen taken up. The hydrogen for the decrepitation was generated by direct desorption from the heated hydride of the LaNi5 alloy. In the pressure range 30–70 kPa and room temperature, alloys of the NdFeB system transform into hydrides. The chemical reaction with hydrogen starts instantaneously without a period of primary hydrogen adsorption. The hydride powders obtained, containing no less than 0.459 wt % hydrogen, are very brittle and can be finely milled (100-g portion) in a planetary ball mill within 6 min to obtain a powder with the particle size smaller than 20 μm. The analysis of the surface of the finely milled hydride powder particles revealed no oxygen (≤1 wt %). [ABSTRACT FROM AUTHOR]

The influence of preliminary ionization and excitation of molecules of a fuel–air mixture when exposed to an electron beam created in an external electric field on increasing the intensity of combustion processes is considered. To study the effect of electron beam plasma on the combustion of a propane–air mixture, a series of experiments were carried out. The characteristics of the propane–air mixture are determined before and after irradiation with an electron beam in the presence and absence of an external electric field. The boundaries of the combined effect of an electron beam and an external electric field are found to increase the efficiency of combustion of a propane–air mixture in a subsonic flow. A physical model of processes in a non-self-sustaining discharge in a subsonic flow of a combustible mixture under known experimental conditions is developed. [ABSTRACT FROM AUTHOR]

The method for visualizing the internal structure of objects (muography method) based on the analysis of the features of passages of atmospheric muons generated in cosmic ray interactions, is based on the spatial distributions of trajectories of penetrating muons recorded by detectors. The method is at the junction of elementary particle physics with many other areas of natural science, e.g., with archaeology. The article presents the results of a muographic study of two objects in the cave complex of a unique historical and archaeological monument, i.e., the Holy Dormition Pskovo-Pechersky Monastery. The experimental technique is based on nuclear emulsion detectors. [ABSTRACT FROM AUTHOR]

The 87Sr/86Sr strontium isotope ratio in skeletal tissues (teeth and bones) gives valuable information about the migrations and origin of humans and animals. In this study, we assess the suitability of various structural elements (enamel and dentin) of a human tooth sample from a burial mound (Early Iron Age, Omsk oblast) for strontium isotope analysis using inductively coupled plasma mass spectrometry (ICP–MS), laser ablation, and electron probe microanalysis. The microelemental mapping of a tooth fragment was conducted. The results indicate the absence of significant diagenetic changes in the tooth enamel, for which the 87Sr/86Sr isotope composition was determined by multicollector ICP–MS after chromatographic separation. This research represents the first isotopic study of materials from archaeological excavations of Sargat culture burial mounds. Furthermore, this approach offers promise in reconstructing taphonomic conditions of burial environments, contributing to the understanding of conditions facilitating the preservation of skeletal tissues and archaeological information. [ABSTRACT FROM AUTHOR]

Due to the development of the chemical industry, the need to obtain high-purity monodisperse nanoparticles is increasing. Therefore, it is necessary to choose the right method for obtaining them. The paper demonstrates a unique method, induction flow levitation, which allows a large list of metal nanoparticles to be obtained using one installation. In this work, magnesium nanoparticles are obtained using this method. The morphology is studied using scanning electron microscopy, where the resulting nanoparticles are clusters of primary particles. Energy-dispersive analysis shows that the surface of magnesium nanoparticles after interaction with atmospheric air is completely covered with a small layer of oxide. Analysis of the phase composition shows that the powder consists of magnesium without traces of oxide. Mass spectrometry with inductively coupled plasma shows a purity of the obtained particles of 99.99%. The characteristics of the porous structure are determined by low temperature porosimetry. The size of the obtained particles does not exceed 40 nm, and the average size is 23 nm. The used method of obtaining nanoparticles demonstrates high productivity (up to 50 g/h) and continuity of the process of obtaining nanoparticles (NP), the ability to control the size of the obtained nanoparticles (NP) in a wide range, noncontact heating, which leads to a high purity of the resulting product confirmed by mass spectrometry with inductively bound plasma. [ABSTRACT FROM AUTHOR]

MgAlON were prepared by self-propagation high temperature synthesis (SHS) using powder and granular mixtures of aluminum, aluminum oxide, magnesium oxide, and magnesium perchlorate. The influence of granulation of starting particles of Al + Al2O3 + MgO + Mg(ClO4)2 powder mixtures on the microstructure and phase composition of combustion products was studied. It was revealed that the granulation of mixtures reduces the combustion temperature and burning velocity. It was found that the combustion products derived from granular mixtures consists of up to four phases (MgAlON, aluminum oxide, aluminum nitride, and unreacted aluminum), while the products of powder mixtures are represented by single MgAlON phase. [ABSTRACT FROM AUTHOR]

The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) was a yearlong expedition supported by the icebreaker R/V Polarstern, following the Transpolar Drift from October 2019 to October 2020. The campaign documented an annual cycle of physical, biological, and chemical processes impacting the atmosphere-ice-ocean system. Of central importance were measurements of the thermodynamic and dynamic evolution of the sea ice. A multi-agency international team led by the University of Colorado/CIRES and NOAA-PSL observed meteorology and surface-atmosphere energy exchanges, including radiation; turbulent momentum flux; turbulent latent and sensible heat flux; and snow conductive flux. There were four stations on the ice, a 10 m micrometeorological tower paired with a 23/30 m mast and radiation station and three autonomous Atmospheric Surface Flux Stations. Collectively, the four stations acquired ~928 days of data. This manuscript documents the acquisition and post-processing of those measurements and provides a guide for researchers to access and use the data products. [ABSTRACT FROM AUTHOR]

This paper studies the dynamics of proton flux in the South Atlantic Anomaly (SAA) region according to ARINA (was operated on the Resurs-DK1 satellite from 2006 to 2015) and VSPLESK (which was mounted on the ISS from 2008 to 2013) satellite experiment data. Both spectrometers have the same scheme. The SAA drift is determined by the position of the maximum flux of high-energy protons with energies in the range from 30 to 100 MeV at the altitude of the Resurs-DK1 satellite (about 580 km) and the ISS (380–420 km). Part of the time the instruments operated simultaneously. [ABSTRACT FROM AUTHOR]

It was shown that the method for the incorporation of a catalytic tungsten component into a porous ceramic converter has a major effect on the activity and selectivity of cumene-to-AMS dehydrogenation. Specifically, the activity of a surface-modified tungsten-containing converter exceeded by more than 2.5 orders of magnitude the activity of a converter with tungsten incorporated by thermochemical sintering of the initial blend. It was further found that the performance of hydrocarbon dehydrogenation in converter channels nearly doubles that of the process occurring over a granular catalyst with an equivalent composition. It was also demonstrated that the process performance can be enhanced by removing extra-pure hydrogen from the reaction system through a palladium-containing membrane. Cumene dehydrogenation in catalytic converters was identified as a zero-order reaction. [ABSTRACT FROM AUTHOR]

A numerical simulation of the conditions for the direct initiation of detonation in the region of a combustible mixture, in which its critical energy is minimum, has been performed using a streamer microwave discharge for the source of detonation initiation. The calculations were conducted on the basis of the model of the two-dimensional detonation in a combustible mixture, flowing in a cylindrical channel, with the use of the system of gas-dynamics and chemical-kinetics equations. The process of detonation initiation was considered as applied to a stoichiometric hydrogen–air mixture flowing in a cylindrical channel at different initial pressures. The requirements for the source of initiation of detonation in a combustible mixture were investigated with respect to the attainment of its critical parameters in practice. [ABSTRACT FROM AUTHOR]

The imaging method based on the absorption and scattering of atmospheric muons (muography method) uses the natural flow of muons formed in the interactions of cosmic rays in the atmosphere. The method is at the junction of elementary particle physics and research in other very diverse fields of natural science, in particular, in archaeology. The paper presents the first results of an experiment to study a unique underground structure in the Holy Dormition Pskov-Caves Monastery, which is a cultural object with a centuries-old history. [ABSTRACT FROM AUTHOR]

One of the effective methods of processing lignocellulosic biomass is pyrolysis, which allows processing it into the liquid product, regardless of the composition of the feedstock. The liquid product obtained as a result of fast pyrolysis (bio-oil) is gaining popularity worldwide as replacing fossil fuels. In the process of processing pyrolysis condensates for fuel and chemical products, wastewater (wood vinegar) is formed, containing organic acids, furans, and phenols. In a large-scale forest chemical production, this waste is formed in large quantities, and its storage or incineration is extremely expensive. Discharge into centralized sewer systems of this drain is impossible due to its high toxicity and mutagenic effect. In this regard, the purpose of this study is to use a set of methods for cleaning WW for further discharge into centralized sewer systems. On the basis of the analysis carried out, a set of methods was proposed as the main methods for the purification of wood pyrolysis by means of sequential purification stages in the form of adsorption with biochar, oxidation with ozone and hydrogen peroxide, and ultrafiltration of the effluent. A high efficiency of 94% in the course of preliminary tests was achieved by the oxidation method under the conditions of the Fenton reaction due to its greater compliance with the conditions relative to other methods, the acidic environment, and the presence of oxidizing substances in the treated wastewater. [ABSTRACT FROM AUTHOR]

To analyze the functioning of servers in a special-purpose information system in different modes of operation, mathematical models are proposed, the formation of which is based on the methods of the theory of mass service systems. These models allow the functioning of the system servers to be analyzed in two modes of request processing—synchronous and asynchronous—and estimating the waiting time of requests that are in the queue. [ABSTRACT FROM AUTHOR]

A numerical simulation of the ignition of a fuel (propane–air) mixture in a combustion chamber by a subcritical streamer discharge, initiated at the wall of the working channel of this chamber in the electric field with a strength lower than the breakdown one, on the basis of the gas dynamics equation defining the propagation of the combustion products in such a channel, the equation for the chemical kinetics of burning of a gas mixture in it, and the relation defining the formation and development of a streamer discharge in this mixture has been performed for different values of the initial pressure in the channel, the excess of the propane in the gas mixture, and the number of streamer-discharge initiators in the channel. The results of the numerical calculations were compared with the available results of the corresponding physical experiment and experiment on the ignition of an analogous gas mixture by a multipoint spark discharge. [ABSTRACT FROM AUTHOR]

This article presents a method for fractionating and separating phenolic compounds from liquid pyrolysis products of lignocellulosic biomass by a three-stage method, in which up to 30% of phenolic compounds can be extracted. The composition of the phenol-substituting fraction was analyzed by the gas chromatography–mass spectrometry (GCMS) method. The isolated phenolic compounds were used in the synthesis of phenol–formaldehyde resins as a phenol-substituting fraction, with the replacement of 40% of the synthetic phenol in the recipe. Various molar ratios of phenol/formaldehyde and phenol/sodium hydroxide in the resin synthesis recipe were considered, as well as their influence on the strength of the adhesive joint and the proportion of free formaldehyde in the finished modified resin. The results of the studies showed that the optimal molar ratio of phenol/formaldehyde is 1:1.98, with a tensile strength of 1.63 MPa and a free formaldehyde fraction of 0.10% in the resin. The phenol/sodium hydroxide molar ratios considered in this paper did not show an optimal molar ratio, but a tendency to reduce the free formaldehyde content in the resin with a decrease in the introduction of an alkaline catalyst into the resin recipe was revealed, while the strength of the adhesive joint remains normal. [ABSTRACT FROM AUTHOR]

One-step gas-phase synthesis of butadiene from formaldehyde and propylene on aluminum (AlP), zirconium (ZrP), and niobium (NbP) phosphates with the pore volumes of 0.51, 0.25, and 0.19 cm3/g, respectively, was studied for the first time. The physicochemical properties of the catalysts were studied by X-ray fluorescence analysis, low-temperature nitrogen adsorption, X-ray diffraction analysis, scanning electron microscopy, temperature-programmed NH3 desorption, IR spectroscopy of adsorbed pyridine, and 31Р MAS NMR. Evaluation of the catalytic properties of the phosphates showed that they can be ranked in the following order with respect to the formaldehyde conversion and target product (butadiene) formation selectivity: AlP < ZrP < NbP, which correlates with metal electronegativity series. The СН2О conversion on the most active NbP was 4.5%, and the molar selectivity of the butadiene formation was 45.3%. [ABSTRACT FROM AUTHOR]

Branched polystyrenes are synthesized by the radical copolymerization of styrene and divinylbenzene with reversible inhibition (in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl) under deteriorating thermodynamic quality of the solvent. The resulting polymers are studied by size-exclusion chromatography combined with static light scattering, ozonolysis, NMR spectroscopy, and differential scanning calorimetry. The branched polymers synthesized by living radical polymerization are characterized by lower intrinsic viscosity values than their linear analogs. Kuhn–Mark–Houwink parameters for these polymers in a tetrahydrofuran solution (а = 0.29) confirm the nonlinear architecture of macromolecules and a high content of pendant double bonds comparable in the order of magnitude with their theoretical content in the absence of the cyclization reaction indicate their branched structure. The glass transition temperature of the branched polystyrenes is 20–35°С lower than the glass transition temperature of the linear polystyrene. [ABSTRACT FROM AUTHOR]

A block spatially cross-linked silicon-oxide copolymer and silicon oxide modified with methyl groups were synthesized catalytically at room temperature using oligomeric methylmethoxysiloxane and zirconium oxychloride (ZOC) octahydrate. The mechanism of curing of siloxane is considered. The thermal stability of compositions containing 5, 10, and 15 wt % of ZOC, which is 450–500°C, was found. Composites reinforced with various fabrics were obtained, and their bending strength was measured. The composition of gaseous products released from the cured composites at 50–700°C was found. The moisture and water resistance of the reinforced composites were tested, and it was shown that there is no change in mass of the samples during soaking in water. The survivability of compositions is considered. Measurements of the oxygen index of the cured polymer showed that spontaneous combustion is not maintained in pure oxygen. There is no improvement in the deformation of binders based on the hybrid polymer. [ABSTRACT FROM AUTHOR]

Gradient materials are of great practical interest for machinery and aviation. Various parts made of these materials can be used at crucially different temperatures, mechanical and chemical conditions. However, obtaining bimetallic materials is sophisticated by various physical and chemical factors. Additive manufacturing allows the creation of complex geometry and produces the parts of different chemical composition. In this article, we demonstrate the fabrication strategy for novel types of "steel-steel" metamaterials of various microhardness and magnetic properties. Direct Energy Deposition of martensite and austenite steels were combined in "metamaterial" components with discrete and continuous layers. An increase in the composition of martensite provides an increase in saturation, which is important for the creation of new generation electric motors. A promising area of use for such parts with gradient transition are reluctance rotors of synchronous motors, in motor assemblies where different properties are required depending on the load and environment. [ABSTRACT FROM AUTHOR]

This paper reports analysis of eddy-covariance data collected during the WFIP2 field campaign in the complex-terrain of the US Pacific Northwest. A 31-day period representative of the region's dry season was used to address the following questions: (1) To what extent does the Constant-Flux Layer (CFL) assumption hold? (2) What is the spatial variability of turbulent and momentum fluxes over km scales? and (3) How skilful are the surface-layer parameterizations of mesoscale models? These questions are directly relevant to subgrid parameterization studies of mesoscale models. Results show that the efficacy of the CFL concept and the spatial variability of turbulent and momentum fluxes are dependent on: (i) the turbulent parameter being analysed, (ii) the measurement's location, (iii) the atmospheric stability regime (determined by the flow and vertical stratification), and (iv) the magnitude of the flux. Finally, the skill of the physics formulation of an often-used surface-layer parameterization scheme available in the Weather Research and Forecasting (WRF) model was also evaluated. Meteorological conditions associated with the highest and the lowest errors were identified. A metric to quantify (time-dependent) flow heterogeneity is proposed, which appears to be a good candidate to predict the skill of idealized surface-layer parameterization schemes in complex terrain. [ABSTRACT FROM AUTHOR]

Samples of monoalkyl and mixed-alkyl phosphine oxides of the hexyl–octyl series were synthesized previously by the Grignard method. Here, the group extraction of rare-earth metals contained simultaneously in their nitrate solutions has been studied using then-synthesized alkyl phosphine oxides. Extraction isotherms for the recovery of the total of lanthanides, scandium, and thorium from nitrate solutions have been obtained. Trihexyl phosphine oxide (THPO) exhibits the highest efficiency under these conditions. Trioctyl phosphine oxide (TOPO) exhibits the best selectivity to heavy-group lanthanides, which makes it useful for the recovery of the heavy-group lanthanide fraction. In addition, scandium and thorium were extracted completely, which in turn indicates the usefulness of phosphine oxides for their extraction. The separation factors have been determined for the entire lanthanides series. [ABSTRACT FROM AUTHOR]

Thermally stimulated processes in mixtures of boric acid (BA) with aluminum after plastic deformation under a pressure of 0.5–4.0 GPa were studied by differential scanning calorimetry (DSC) and thermogravimetry. In the original BC, in the range of 20–200°C, splitting of water occurs, accompanied by an endothermic effect. In deformed mixtures BC–Al = 50–50, the endoprocess was recorded on DSC thermograms in the range of 20–200°С, an exoprocess in the range of 200–550°С, an aluminum-oxidation exoprocess at 620°С, and an aluminum melting endoprocess at 656°С. The baric dependences of the parameters of thermal processes in deformed mixtures exhibited extrema at pressures of 1.0 and 2.5 GPa, which were associated with changes in the electronic structure of aluminum caused by high pressure. Such changes can be retained in deformed mixtures after completion of pressure treatment and manifest themselves upon heating due to the formation of electrical double layers in mixture samples. [ABSTRACT FROM AUTHOR]

A series of tubular porous ceramic converters modified with mono- and bimetallic catalytic systems based on rhenium and tungsten were prepared by a combination of self-propagating high-temperature synthesis and the sol–gel method. These converters were tested in dehydrogenation of ethylbenzene to styrene. Among the tested samples, a monometallic tungsten-containing converter exhibited the optimal properties as it achieved the highest target product production performance. Within the temperature range of 550–600°C, this converter provided a yield of styrene up to about 15 wt % and styrene productivity up to about 22 g h–1 dm–3, with the carbonization of the sample not exceeding 5 wt % over about 6 h of reaction. [ABSTRACT FROM AUTHOR]

The time and energy resolutions were measured for four prototypes of the PHOS electromagnetic calorimeter for the ALICE experiment at the Large Hadron Collider at CERN. Each prototype was made up of nine identical detection elements assembled as a 3 × 3 array. The detection element was based on a lead tungstate (PbWO4) scintillating crystal with a length of 180 mm and a cross section of 22 × 22 mm2, which was viewed from its end face by a photodetector. Avalanche photodiodes and silicon photomultipliers with different active areas (Hamamatsu, Japan) were used as photodetectors. The measurements were made with the electron component of secondary particle beams of the PS proton synchrotron at CERN in the momentum range of 1−10 GeV/c at a temperature of 17.5°C. [ABSTRACT FROM AUTHOR]

Rotation mechanisms of an atomic-molecular particle being into the linearly polarized light field and applied static electric or magnetic fields are for the first time shortly analyzed. Exerting of the particle torque is based on the dynamic molecular Hall effect, distinctive features of which are able to expand the resource of the optical-mechanical manipulation by molecular objects. [ABSTRACT FROM AUTHOR]

This document is a note celebrating the career of Evgeni Fedorovich, the former Editor-in-Chief of Boundary-Layer Meteorology. It highlights his scientific achievements, career milestones, and impacts on the field of boundary-layer meteorology. Evgeni is known for his research on various topics, including entrainment in convective boundary layers, contaminant dispersal in urban settings, and turbulence in slope flows. He has published numerous articles and monographs and has been recognized for his contributions through awards and invitations to collaborate and lead in research and academic communities. Evgeni's career spanned several institutions, including the University of Oklahoma, where he mentored students and conducted research. The authors of the note express their gratitude to Evgeni and wish him a happy retirement. [Extracted from the article]

Flame-retardant and temperature- and water-resistant reinforced composites based on aluminoboro- and aluminochromophosphate inorganic binders modified with metakaolin and polyethylene polyamine are obtained under "soft" conditions. [ABSTRACT FROM AUTHOR]

We present a laboratory study confirming that phenol in phenol–formaldehyde resins can be replaced with deep thermal-processing products of raw wood. Operating conditions of synthesis are described, and a synthetic recipe is given. The synthesized resins were analyzed by physicochemical methods (IR spectroscopy, TGA, and the tensile strength test). The study revealed that such a replacement requires no considerable changes to be made in operating parameters of the current synthetic process for phenol–formaldehyde resins and allows one to obtain a glue based on this resin with a shear strength equal to 1.58 MPa, which meets specifications of the state standard. [ABSTRACT FROM AUTHOR]