335 research outputs found
Scalar and Spinor Particles with Low Binding Energy in the Strong Stationary Magnetic Field Studied by Means of Two-and Three-Dimensional Models
On the basis of analytic solutions of Schrodinger and Pauli equations for a
uniform magnetic field and a single attractive -potential the
equations for the bound one-active electron states are discussed. It is vary
important that ground electron states in the magnetic field essentially
different from the analog state of spin-0 particles that binding energy has
been intensively studied at more then forty years ago. We show that binding
energy equations for spin-1/2 particles can be obtained without using of a
well-known language of boundary conditions in the model of -potential
that has been developed in pioneering works. Obtained equations are used for
the analytically calculation of the energy level displacements, which
demonstrate nonlinear dependencies on field intensities. It is shown that in a
case of the weak intensity a magnetic field indeed plays a stabilizing role in
considering systems. However the strong magnetic field shows the opposite
action. We are expected that these properties can be of importance for real
quantum mechanical fermionic systems in two- and three-dimensional cases.Comment: 18 page
The Energy Level Shifts, Wave Functions and the Probability Current Distributions for the Bound Scalar and Spinor Particles Moving in a Uniform Magnetic Field
We discuss the equations for the bound one-active electron states based on
the analytic solutions of the Schrodinger and Pauli equations for a uniform
magnetic field and a single attractive -potential. It is vary
important that ground electron states in the magnetic field differ essentially
from the analogous state of spin-0 particles, whose binding energy was
intensively studied more than forty years ago. We show that binding energy
equations for spin-1/2 particles can be obtained without using the language of
boundary conditions in the -potential model developed in pioneering
works. We use the obtained equations to calculate the energy level
displacements analytically and demonstrate nonlinear dependencies on field
intensity. We show that the magnetic field indeed plays a stabilizing role in
considered systems in a case of the weak intensity, but the opposite occurs in
the case of strong intensity. These properties may be important for real
quantum mechanical fermionic systems in two and three dimensions. We also
analyze the exact solution of the Pauli equation for an electron moving in the
potential field determined by the three-dimensional -well in the
presence of a strong magnetic field. We obtain asymptotic expressions for this
solution for different values of the problem parameters. In addition, we
consider electron probability currents and their dependence on the magnetic
field. We show that including the spin in the framework of the nonrelativistic
approach allows correctly taking the effect of the magnetic field on the
electric current into account. The obtained dependencies of the current
distribution, which is an experimentally observable quantity, can be manifested
directly in scattering processes, for example.Comment: 31 pages, 10 figure
О направлениях развития государственно-частного партнерства в пенитенциарной сфере
The subject. The production sector of the Russian penitentiary system requires development and modernization in order to increase the level of convicts’ employment, to ensure the growth of their labor productivity, which is ultimately aimed at increasing the level of correctional impact of socially useful labour. In modern conditions of market economy development, low efficiency of state production organizations economic activity on competitive markets, as well as the lack of budget funds for the modernization of production assets, the most promising form of organization of penitentiary institutions production activities is public-private partnership. The aim of the article is to develop scientifically based provisions that define the most promising areas for the development of Russian legislation, which will significantly improve the practice of implementing public-private partnership projects in the production sector of the penitentiary system. The methodology. In the course of the study, a complex of general scientific and special methods of scientific search was used, including scientific abstraction, a systematic approach, a dialectical method of cognition, as well as comparative legal and structural-system methods of research. The information base of the study is represented by scientific works of Russian and foreign scientists-penitentiaries, statistical data, regulations, as well as data on legal practice in the field under study. The main results, scope of application. The prerequisites for promising changes in the legislation that determine the need for a significant modernization of the production sector of the penitentiary system are identified. The expansion of the practice of implementing production projects with the involvement of private business initiatives in penitentiary institutions makes it possible to strengthen the corrective impact of socially useful labour, to improve convicts’ food and clothing provision, as well as the communal living conditions of their detention. Conclusion. The article substantiates the need to develop a concept of interaction between the penitentiary system and the business community in order to improve the efficiency of convicts’ employment and their correction, within the framework of which the most relevant directions and stages of the development of public-private partnership should be determined in the future.Выявлены предпосылки перспективных изменений в законодательстве, определяющие потребность существенной модернизации производственного сектора пенитенциарной системы. Расширение практики реализации производственных проектов с привлечением частной предпринимательской инициативы в пенитенциарных учреждениях позволяет усилить корректирующее воздействие общественно-полезного труда, улучшить продовольственное и вещевое обеспечение осужденных, а также коммунально-бытовые условия их содержания. Обоснована необходимость разработки концепции взаимодействия пенитенциарной системы с бизнес-сообществом с целью повышения эффективности трудоустройства осужденных и их исправления, в рамках которой далее следует определить наиболее актуальные направления и этапы развития государственно-частного партнерства
Nut for thread stop
In engineering products, a significant part of the connections are formed using threaded connections, the functioning of which largely determines the reliability of mechanisms and assemblies. To preserve the invariability of the tightening of threaded connections during the operation of vehicles, a nut is presented, in which the internal thread is divided into two parts with different geometric parameters. Nut thread profiles made with different profile heights are described. The first profile height is equal to the height of the initial contour with sharp vertices, and the other one is equal to the standardized height and rounded vertices. When assembling the connection between the increased working height of the nut thread profile and the internal diameter of the bolt thread, the necessary tightness is provided. In the zone of the upper section of the outer diameter of the thread of the nut, the metal is elastically deformed, therefore, when the bolt and nut are connected, an interference is formed with an increase in the coefficient of friction, which determines the operational reliability of the connection.
The optimal ratio of the lengths of sections with different profile heights has been determined to ensure the necessary increase in the locking properties of threaded connections, depending on the specific operating conditions of vehicles.
Conducted laboratory studies on a specially made stand showed the reliability of the initial scientific hypothesis, suggesting that the stability of tightening a threaded connection depends on changes in physical parameters associated with the distortion of the crystal lattice and changes in the density of dislocations that occur in the process of thread formation using a particular technology and during its operation. .
A technique for accelerated testing based on the creation of an additional unscrewing torque has been developed, which can significantly reduce the amount of testing and predict the time after which it is necessary to re-tighten the connection.
The nut is designed for repeated use during reassembly with retention of locking properties during the repair of various technical devices, including cars.
The technology for the production of the proposed nut is simple and economical and involves the use of universal screw-cutting equipment available at any repair company.
In further studies, it is planned to conduct long-term operational tests of vehicles in order to confirm the reliability of the proposed nut for thread locking at the same time as achieving the simplicity of the product and high manufacturability
Effect of Various Infusion Solutions on Microrheology
Objective: to evaluate the in vitro and in vivo effects of various infusion solutions on red blood cell rheology in the early posttraumatic period. Material and methods. The in vitro study assessed crystalloids, albumin, dextrans, modified gelatin, and different generations of hydroxyethyl starches (HES). The preparations were added to blood in a 1:10 dilution; before and after their addition, the values of erythrocyte aggregation and erythrocyte deformability were estimated. The in vivo study covered 59 patients with severe concomitant injury, who were divided into 3 groups: 1) those who received crystalloids only; 2) those who had crystalloids + 6% HES 130/0.42; 3) those who had crystalloids + gelofusine. The same parameters of red blood cell rheology were estimated as in the in vitro study. Results. Albumin, repolyglycan, and HES 130/0.42 were found to have the most pronounced disaggregatory effect in vitro. At the same time, polyglycan, gelofusine, and HES 450/0.7 in particular, enhanced erythrocyte aggregation. In vitro, albumin, HES 130/0.42, and HES 200/0.5 exerted the most beneficial effect on erythrocyte deformability whereas dextrans made the latter worse and HES 450/0.7 and gelofusine failed to have a considerable effect on it. The early posttraumatic period was marked by progressive erythrocyte hyperaggregation and phasic deformability changes. Significant microrheological disorders persisted in the patients on infusion therapy with crystalloid solutions only. Addition of HES 130/0.42 to infusion therapy improved the deformability of erythrocytes and lowered their aggregation. The use of gelofusine as a component of infusion therapy caused a moderate increase in erythrocyte aggregation. Key words: infusion therapy, erythrocyte deformability, erythrocyte aggregation
The Sixth Edition of the WHO laboratory manual for the examination and processing of human semen: is everything new a well-forgotten old?
Despite many shortcomings, the semen analysis remains the leading method of male fertility assessment. For several decades, the WHO has been working on standardisation of the methodology for examining human ejaculate. In 2021, the sixth edition of WHO laboratory manual for the examination and processing of human semen was released, which proposed several concepts for performing and interpreting the results of a semen analysis. Many of these concepts are not new and have already been covered in previous tutorials. At the same time, the rejection of reference values and the transition to “decision limits” raises several questions that have not yet been answered
Modeling of systemic inflammatory response syndrome by chemical induction of colon injury in rats
Our objective was to develop a model of systemic inflammatory response syndrome (SIRS) by chemical induction of colon injury and antibiotic-associated intestinal dysbiosis in rats with primary visceral obesity (PVO) for studies of myocardial resistance to ischemia-reperfusion injury. The experiments were performed with adult Wistar male rats with PVO under improved conditions of a conventional animal clinic. The chemically induced inflammatory colon disease (CIICD) was accomplished by intragastric administration of a mixture of broad-spectrum antimicrobial agents (AMA) for 3 days. Five days later, immunological and biochemical studies were carried out, as follows: composition of the intestinal microbiota in feces and shortchain fatty acids in blood, morphological changes in the structure of the colon, hemodynamic parameters and myocardial stability with modified Langendorff system. In PVO rats, the mass of visceral fat deposits and the content of lipopolysaccharides (LPS) in the blood were significantly increased when giving them fatcarbohydrate diet (FCD). In animals with CIICD, in addition to LPS, there was a significant increase in proinflammatory cytokine concentration (TNF, IL-8, MCP-1), and after oral administration of the AMA mixture, pronounced disturbances of food behavior and evacuatory function of gastrointestinal tract, deep destructive changes in colon, as well as qualitative and quantitative composition of intestinal microbiota with characteristics typical to the first-grade dysbiosis. High levels were shown for IL-8 cytokine only. An increase in acetic and propionic acid concentrations were shown in blood in animals with CIICD, and, to a greater extent, in rats with antibiotic-induced dysbiosis (AID). FCD was followed by significantly reduced levels of lactobacilli and bifidobacteria in colonic contents. CIICD leads to detection of Escherichia coli, and intestinal dysbiosis leads to the manifestation of Proteus. A comorbid combination of pathological changes in the immune and digestive systems caused a significant increase in the area of myocardial necrosis (by 35 percent) in isolated heart by, thus presuming decreased myocardial resistance to ischemia-reperfusion injury (IRI). The SIRS model induced by chemical trauma to large intestine is aggravated by the introduction of AMAs mixture, and it is characterized by a controlled change in inflammatory markers. Deterioration of morphofunctional characteristics in isolated heart included decrease in resistance to IRI seems to correspond to acute inflammatory bowel disease with induced intestinal dysbiosis. This model can be used in experimental medicine in the field of cardiology, endomicroecology, gastroenterology, and immunology
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