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The article addresses serviceability of reinforcement in vertical mine shafts. The mathematical framework is presented for the dynamic processes in the capsule–reinforcement system. The main causes of the dynamic loads in the capsule–reinforcement system are discussed. The importance of the processes in the capsule–reinforcement system during movement of hoists in vertical mine shafts is emphasized. It is asserted that solely computational methods are not enough to analyze processes inside the capsule–reinforcement systems in shafts. It is required to examine actual parameters of shaft reinforcement, in particular, the actual stiffness of shaft guides. The actual measurement procedure of guide stiffness in potash mine shafts is presented. The full-scale tests data are set out in connection with the actual step of reinforcement in shafts. The actual and calculated values of stiffness of shaft guides are compared. Based on the obtained results, the variable stiffness coefficient is derived for the shaft guide stiffness for a few alternative of reinforcement step. Considering the described research findings and the many years-long experience gained in operation of mine shafts, the authors have drawn a conclusion on the necessity to take into account the factor of variable stiffness of guides in shaft design and construction in potash mines in the Upper Kama Potash–Magnesium Salt Deposit, especially in case when the shaft reinforcement step exceeds the project design standards.

Scenarios of the component arrangement of batching plants in the system of a vertical mine shaft are discussed. The features of operation of batching plants in vertical shafts of potash mines are identified. The actual recorded damages generated in the lining of batching plants in the course of their longterm operation in potash mines are described. The geomechanical researches aimed to determine vertical convergence in batching rooms of mine shafts, as well as for monitoring of crack opening and displacements in sidewalls in the batching chambers are presented. The major results of the full-scale geomechanical observations are reported, and the main causes of fractures in concrete and reinforced concrete lining at junctures of shafts and batching rooms and shaft bins are identified. The set of the engineering solutions implemented for the protection of lining in batching facilities during construction of mine shafts is described, and its efficiency is evaluated. The mathematical modeling is carried out to estimate various negative impacts on deformation and fracture of concrete lining in shafts with regard to the time factor. From the modeling results, the dominant cause of concrete lining damage in batching chambers and in mine shaft is found. Based on the accomplished research results and actual long-term experience of operation of mine shafts, the most favorable factors are determined for the best design choices in construction and long-term maintenance-free operation of batching plants in potash mines of the Upper Kama Potash–Magnesium Salt Deposit.

A method of casting surface alloying during casting using gasified models with the formation of a wear-resistant surface layer is considered. The increase in wear resistance is due to formation of boride and carbide components by means of self-propagating high-temperature synthesis between alloyed coating components that occurs during casting manufacture. Results of comparative tests for materials under abrasive wear are presented. Data are given for material composition, structure, and hardness.

The article describes the long-term in-situ observations and inspection of concrete lining in air inlet shaft No. 3 in Uralkali’s mine, which reveal the main causes of the lining failure at intersections with horizontal tunnels and in the areas of instable rocks. Numerical modeling of rock creeping and damage areas in lining at intersections with tunnels is performed in the axially symmetric and three-dimensional formulations. The calculations agree with the observation data, which proves efficiency of mathematical modeling in estimation of deformation and failure of concrete lining during shaft design and operation. Prediction of damage evolution in concrete lining in shaft No. 3 is carried out for the next 10 years.

The possible synthesis of hexagonal titanium carbohydride—copper composites by two- and three-stage mechanical activation of titanium and copper powders in liquid hydrocarbon followed by magnetic-pulse pressing has been studied in this work. Surfactant used for the three-stage synthesis enable one to restrain the formation of intermetallic phases in the process of mechanical activation and reduce the fraction of intermetallic phases in consolidated samples. The density, microhardness, abrasion resistance, and wear parameters under conditions of dry friction with a steel ball have been estimated. Two- and three-stage methods of producing powders have been shown to be preferable, since friction coefficients and wear in friction pairs are much lower than that of composites produced by the one-stage method.

The effect of chemical-thermal treatment (borating) on the structure, composition, depth and hardness of the surface layer of samples from chromium-bearing iron-carbon alloys: 95Kh18 steel and ChKh12 and ChKh32 cast iron is shown. The results of comparative tests of the studied materials on the wear resistance in the conditions of dry friction on fixed abrasive are presented.

This paper presents the results of a total census of inhabited Dalmatian Pelican nests, which was carried out in spring 2017 using a drone aircraft for the waterbodies of the Kurgan and Tyumen regions. The dynamics of the species numbers in the area studied over the last 50–70 years and the factors affecting these dynamics are analyzed.

Several tundra wader species occasionally nesting in the former Orenburg Province in the second half of the 19th century were reported by the prominent researchers of the avifauna of that region E.A. Eversmann, N.A. Zarudnyi, and P.P. Sushkin among others. In most cases, the scientists based their assumptions on circumstantial evidence alone, for instance, summer records of adult birds and migrating broods. Taking into account the specific biology of the species in question, such data could not be regarded as sufficient proof for the species’ nesting. In the middle of the 20th century, these data were revised and quite justly criticized: this led to varying conclusions regarding the nesting of tundra wader species in the region as having been wrong. The matter seemed to be settled. Yet it should be noted that, along with circumstantial data on the nesting of northern waders, the early researchers had also reported very solid facts like finding nests with clutches of eggs and nonflying chicks (including the Red-necked Phalarope and the Little Stint). For certain reasons, those facts were not considered during the revision that followed. Firstly, it was difficult to find an explanation for such outstanding evidence in the middle of the 20th century. Secondly, no new nests of those species were found that could confirm the 19th century researchers as having been right. Furthermore, the idea that long-term cycles of climate changes influence the dynamics of bird nesting areas became widely accepted only by the end of the 20th century. Nowadays when this idea has been thoroughly developed, the possibility of the former nesting of some tundra wader species in arid regions does not seem so incredible. It seems likely that Zarudnyi and Sushkin were the last scientists to witness the nesting of tundra wader populations in the Orenburg region as over time due to climate warming the waders might have left the region for good.

Elastic electron–proton scattering (e–p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, rp. In 2010, a new method using muonic hydrogen atoms1 found a substantial discrepancy compared with previous results2, which became known as the ‘proton radius puzzle’. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen3,4. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e–p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e–p experiments and enabled measurements at very small forward-scattering angles. Our result, rp = 0.831 ± 0.007stat ± 0.012syst femtometres, is smaller than the most recent high-precision e–p measurement5 and 2.7 standard deviations smaller than the average of all e–p experimental results6. The smaller rp we have now measured supports the value found by two previous muonic hydrogen experiments1,7. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant8—one of the most accurately evaluated fundamental constants in physics. A magnetic-spectrometer-free method for electron–proton scattering data reveals a proton charge radius 2.7 standard deviations smaller than the currently accepted value from electron–proton scattering, yet consistent with other recent experiments.

We report a measurement of the π − photoproduction beam asymmetry for the reaction → γ p → π − Δ + + using data from the GlueX experiment in the photon beam energy range 8.2–8.8 GeV. The asymmetry Σ is measured as a function of four-momentum transfer t to the Δ + + and compared to phenomenological models. We find that Σ varies as a function of t : negative at smaller values and positive at higher values of | t | . The reaction can be described theoretically by t -channel particle exchange requiring pseudoscalar, vector, and tensor intermediaries. In particular, this reaction requires charge exchange, allowing us to probe pion exchange and the significance of higher-order corrections to one-pion exchange at low momentum transfer. Constraining production mechanisms of conventional mesons may aid in the search for and study of unconventional mesons. This is the first measurement of the process at this energy.

The GlueX experiment at Jefferson Lab has been designed to study photoproduction reactions with a 9-GeV linearly polarized photon beam. The energy and arrival time of beam photons are tagged using a scintillator hodoscope and a scintillating fiber array. The photon flux is determined using a pair spectrometer, while the linear polarization of the photon beam is determined using a polarimeter based on triplet photoproduction. Charged-particle tracks from interactions in the central target are analyzed in a solenoidal field using a central straw-tube drift chamber and six packages of planar chambers with cathode strips and drift wires. Electromagnetic showers are reconstructed in a cylindrical scintillating fiber calorimeter inside the magnet and a lead-glass array downstream. Charged particle identification is achieved by measuring energy loss in the wire chambers and using the flight time of particles between the target and detectors outside the magnet. The signals from all detectors are recorded with flash ADCs and/or pipeline TDCs into memories allowing trigger decisions with a latency of 3.3 $\mu$s. The detector operates routinely at trigger rates of 40 kHz and data rates of 600 megabytes per second. We describe the photon beam, the GlueX detector components, electronics, data-acquisition and monitoring systems, and the performance of the experiment during the first three years of operation., Comment: Accepted by Nuclear Instruments and Methods A, 78 pages, 54 figures

We report measurements of the photon beam asymmetry Σ for the reaction γp→K+Σ0 (1193) using the GlueX spectrometer in Hall D at Jefferson Lab. Data were collected by using a linearly polarized photon beam in the energy range of 8.2–8.8 GeV incident on a liquid hydrogen target. The beam asymmetry Σ was measured as a function of the Mandelstam variable t , and a single value of Σ was extracted for events produced in the u channel. These are the first exclusive measurements of the photon beam asymmetry Σ for the reaction in this energy range. For the t channel, the measured beam asymmetry is close to unity over the t range studied, − t = ( 0.1 – 1.4 ) ( GeV / c ) 2 , with an average value of Σ = 1.00 ± 0.05 . This agrees with theoretical models that describe the reaction via the natural-parity exchange of the K ∗ (892) Regge trajectory. A value of Σ = 0.41 ± 0.09 is obtained for the u channel integrated up to − u = 2.0 ( GeV / c ) 2 .

Testing the chiral anomaly Pi mesons, also known as pions, consist of a quark and an antiquark and are extremely unstable. Neutral pions have a lifetime of only ∼80 attoseconds, decaying into two photons. Quantum chromodynamics (QCD), the theory of quarks and gluons, predicts this decay and the associated lifetime using the mechanism of broken chiral symmetry—the so-called chiral anomaly. Measuring the lifetime to high precision then provides a benchmark for theories that aim to improve on this original prediction. Larin et al. measured this lifetime with an uncertainty that was half that of the previous most precise result (see the Perspective by Meyer). The measured value was consistent with the original QCD prediction and less consistent with other theoretical approaches. Science , this issue p. 506 ; see also p. 469

An effect of schungite exerted on the degradation of surfaces in the processes of friction and wear is studied. The process is simulated via processing a mixture schungite and iron powders using a high-energy ball mill. Changes in the morphology and structural and phase composition of the milled mixture, as well as in the surface of the grinding balls, are investigated. It is shown that the positive effect of schungite addition to lubricating substances is mainly caused by improvement of the surface quality (roughness reduction) of the contacting bodies after mechanical treatment.

The effect of argon ion irradiation with an energy of 40 keV in the dose range of 1016 - 1018 ion/cm2 on the formation of the surface layers composition, changes in the morphology and mechanical properties (microhardness, and wear resistance) of carbon steel AISI 1020 with a deposited ion-plasma coating Ni80Cr20 was studied. It is shown that irradiation with doses greater than 1017 ion/cm2 leads to the formation of a layer consisting of nickel, chromium and iron. The most optimal treatment mode for improving wear resistance is irradiation with a dose of 5.1017 ion/cm2.

We studied the phenotypic composition of the populations and variability of songs in two bunting species in three localities on the western border of the sympatry zone: in the southern part of Tyumen’ oblast and in the center and southern of Kurgan oblast. Over the last several decades, the zone of contact of the studied species has expanded significantly. The pine bunting started breeding regularly in the area at the end of the 20th century, and at present it is considered a common species comparable in abundance to the yellowhammer. The share of phenotypic hybrids varies from 25 to 50% reaching its maximum at the boundary of the pine bunting’s nesting range. East of this boundary, the hybridization level is reduced, this being seen in a sharp decrease in the share of “leucocephala hybrids.” An analysis of the phenotypic variability of the hybrids shows that they can be divided into two groups similar in coloration to the parental species. The study results let us presume that the hybridization is limited and hybrids return mostly to backcrossing with the parental species. This presumption also finds support in an analysis of the song structure: the yellowhammer and the pine bunting have songs of different, easily distinguishable dialects.

The pharmacotherapy of hypoxia is an important task of modern experimental and clinical pharmacology. The medications with anti-hypoxic effect implemented into clinical practice unfortunately do not meet requirements of physicians due to poor efficiency, narrow range of active dosages and undesirable side effects. The complexes of zinc with N-alkenylimidazole demonstrated anti-hypoxic activity at various models of acute hypoxia within large range of dosage. Therefore, further studying of zinc-contained compounds as possible correctors of hypoxia is of particular interest. The experiments with white nonlinear male mice were used for comparative investigation of ant-hypoxic effect of complex compounds of zinc acetate with N-propargylimidazole and 3-hydroxipyridine, including complexes immobilized on sulfated arabinogalaсtan and also well-known anti-hypoxants and/or anti-oxidants: etomerzol, mexidol, nooglutil and hypoxen. It is demonstrated that anti-hypoxic effect of complex of zinc acetate with N-propargylimidazolein conditions of acute hypobaric hypoxia, acute hypoxia with hypercapnia acute hematic hypoxia by width of active dosages (1-100 mg/kg, intraperitoneally) and degree of expression (19-317% in comparison with control groups of animals) excels the similar effect in well-known anti-hypoxants and/or anti-oxidants: etomerzol (25-100 mg/kg, intraperitoneally), mexidol (100 mk per kg, intraperitoneally), nooglutil (25-100 mg/kg, intraperitoneally) and hypoxen (50-150 mg/kg, intraperitoneally). The protective effect of complex of zinc acetate with 3-hydroxipyridine by width of active dosages (25-100 mg/kg, intraperitoneally) and degree of expression (27-167% in comparison with control groups of animals) in conditions of exogenous hypoxia (acute hypobaric hypoxia and acute hypoxia with hypercapnia) excels similar effect of etomerzol and mexidol ans is comparable with effect of nooglutil and hypoxen. The complexes immobilized on sulfated arabinogalactan were ineffective.

The dynamic development of pharmaceutical field in the Russian Federation requires objective approach to evaluation of manpower component, perspectives of training of modern specialists and changing attitude to profession of druggist. The classical academic principle of The I.M. Sechenov first Moscow state medical university combined with modern approaches to education, continuity of generations of lecturers and historically established role of the University as a leading medical and pharmaceutical university developed highly professional faulty with numbers of scientific schools headed by prominent scientists an pedagogues. The results of pilot survey of opinions of lecturers concerning role of profession of druggist in society and manpower perspectives of the field demonstrate development of vision of pharmacy as a perspective and actively developing direction and related requirements to graduates.

We report on the measurement of the beam asymmetry Σ for the reactions → γ p → p η and → γ p → p η ′ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer − t with significantly higher statistical precision than our earlier η measurements and are the first measurements of η ′ in this energy range. We compare the results to theoretical predictions based on t -channel quasiparticle exchange. We also compare the ratio of Σ η to Σ η ′ to these models as this ratio is predicted to be sensitive to the amount of s ¯ s exchange in the production. We find that photoproduction of both η and η ′ is dominated by natural parity exchange with little dependence on − t .

Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, r

В статье приведен алгоритм обработки сигналов инкрементного датчика для оценки свободных колебаний крутильного маятника при исследовании фрикционных характеристик смазочных материалов применительно к стальным канатам с использованием возможности ПО «PowerGraph». Стальной канат является сложной и гибкой стержневой системой, в которой проволоки имеют форму пространственной спирали (винтовой линии) или двойной спирали. При этом внутренние проволоки стальных канатов находятся внутри и недоступны для прямого исследования, измерения и контроля. Анализ фрикционных характеристик смазочных материалов, используемых в стальных канатах, усугубляется многокомпонентностью и сложной структурой объекта исследования. Экспериментальные методы исследования в этом случае представляют один из наиболее эффективных и достоверных способов оценки эксплуатационных свойств изделия в целом. В основу эксперимента положен процесс затухания вращательных колебаний тяжелого груза, висящего на исследуемом стальном канате. Используемый смазочный материал влияет на такой колебательный процесс, и характеристикой такого влияния является декремент затухания колебательного процесса. В качестве датчика угла использован инкрементный энкодер, установленный соосно исследуемому канату и обеспечивающий разрешение регистрации угла поворота до 0,18 градуса.

The article deals with the important scientific problem of everyday life stories of displaced persons (DPs) in camps in occupied Germany (US zone of occupation, Bavaria). The peculiarities of life and living conditions of displaced persons, their communication practices with the camp administration, the local German population, UNRRA officials and representatives of the Soviet occupation authorities have been analyzed. Main everyday life priorities of DPs have been outlined, character and methods of their employment has been shown. Basic everyday life tactics of DPs in camps has been set using historical sources 1945-1947 (press materials, reports UNRRA officials, reports of non-governmental organizations professionals).It has been proved that life of DPs was based on a few key priorities, among which were the main problems of housing quality, food, clothing, nature of activities and employment. The dynamics of change in the daily life of displaced persons from the primitive forms of survival in 1945-1946, to the «well-fed apathy» 1947-1948 has been described. The difference in politics UNRRA in relation to the two main groups of displaced people: immigrants, who wanted to return to their homeland and potential emigrants who wanted to find a new life outside the sphere of influence of the USSR has been considered and illustrated. Special attention was devoted to gender communication. It has been shown that DPs contacts with the local German population had been an important communication component, which played a key role in the consolidation of the post-war society. The effect of domestic economic cooperation of DPs on the development of «black markets» systems the most popular products: cigarettes, coffee, food delicacies has been elicited. The research is based on the materials of the archive of Kharkov engineer and poet V. Ellis. The main point of which was the magazine «DiPiniada». The magazine was published during the years 1946-1947 in the camp Munich-Pasing (US zone of occupation in Germany). The schedule log (artist V. Odinokov) has been analyzed being a set of historical visual sources, as well as the poetry of W. Ellis 1944-1947 being a literary source. The most common situations in everyday life DPs that had appeared due the difficult circumstances of post-war world order had been described. The complex world of DPs relationship has been shown in the context of the overall historical situation on the territory of occupied Germany and in the whole post-war Europe. It has been proved that the investigation has prospects both in methodological and objective aspects. Particular interesting are the artistic solutions of the magazine, which are interesting not only for historians but also for art critics.

The extraction mechanism has been considered and the crucial role of the dynamic interfacial layer has been noted. The microprocesses that take place in extraction systems and are associated with the Marangoni effect, the loss of hydrodynamic stability, partial dispersion, coalescence, flocculation, the Ostwald ripening of drops, chemical reactions, the emergence of a new phase, adsorption, coagulation, the formation of structures, and polymerization have been described. For LnCl3–H2O–diluent systems (heptane, toluene, tetrachloromethane), data on the shift in the boundaries of the observed transition region over time have been presented. The mechanism of the transfer of the substance in the transition region of the extraction system has been formulated.

Data on the wear tests of the material of a heat exchange tube and a spacer grid of the steam generator of the BREST-OD-300 nuclear reactor plant performed at a high temperature in argon atmosphere are presented. A mathematical model of the wear process based on which the identification of the corresponding wear law is carried out has been proposed. The wear durability of the heat exchange tube has been evaluated.