Proton configurations in the hydrogen bonds of KH2PO4 as seen by resonant x-ray diffraction

KH2PO4 (KDP) belongs to the class of hydrogen-bonded ferroelectrics, whose paraelectric to ferroelectric phase transition is driven by the ordering of the protons in the hydrogen bonds. We demonstrate that forbidden reflections of KDP, when measured at an x-ray absorption edge, are highly sensitive to the asymmetry of proton configurations. The change of average symmetry caused by the "freezing" of the protons during the phase transition is clearly evidenced. In the paraelectric phase, we identify in the resonant spectra of the forbidden reflections a contribution related to the transient proton configurations in the hydrogen bonds, which violates the high average symmetry of the sites of the resonant atoms. The analysis of the temperature dependence reveals a change of relative probabilities of the different proton configurations. They follow the Arrhenius law, and the activation energies of polar and Slater configurations are 18.6 and 7.3 meV, respectively

The Fermi surface reconstruction in stripe phases of cuprates

Mean-field study of the stripe structures is conducted for a hole-doped Hubbard model. For bond-directed stripes, the Fermi surface consists of segments of an open surface and the boundaries of the hole pockets which appear in the diagonal region of momenta under certain conditions. Segments of the first type are due to one-dimensional bands of states localized on the domain walls. The relation of bands to the doping and temperature dependences of the Hall constant is discussed. In connection with the observation of quantum magnetic oscillations, a systematic search for the electron pockets has been carried out. It is shown that the formation of such pockets in bilayer models is quite possible.Comment: 4 pages, 3 figure

Biomechanical control-based locomotor function rehabilitation technology for children with cerebral palsy

Locomotor functions of children with special needs by the example of infantile cerebral palsy have been studied. The interaction with the support of children with special needs has been examined. It has been proved that during the jump of children of the main group there was an increase in pressure on the support relatively the lateral direction during the repulsion phase, they required more time to perform the initial phase of the jump due to the involvement of additional compensatory mechanisms to ensure the stability when landing. Thus, special attention should be given to the improvement of their coordination abilities and removal of muscle hypertonus. During physical exercises, it is recommended to focus on stretching and to enhance power quality of lower extremities. This approach will improve their motor adaptation. Moreover, the regional hemodynamics reaction to locomotor load among children with special needs has been assessed. It has been shown that children of the main group have a specific functional reserve of regional blood flow in proximal lower extremities. After locomotor load in the main group, there was an increase of pulse blood filling and blood flow velocity in hips, whereas the vegetative maintenance of distal extremities was decreased, which caused venous outflow. It enables us to recommend loading of hip muscles and unloading of shin muscles while forming locomotion adaptive stereotypes

Biomechanical control-based locomotor function rehabilitation technology for children with cerebral palsy

Locomotor functions of children with special needs by the example of infantile cerebral palsy have bee

THE DEVELOPMENT OF LOGICAL THINKING IN JUNIOR STUDENTS THROUGH PROJECT-BASED LEARNING

El artículo da una nueva mirada al método de desarrollo del pensamiento lógico en alumnos de tercer año basado en la correlación entre el modelo original y el que hace posible, a diferencia de los métodos tradicionales, desarrollar el pensamiento del habla, las estructuras intelectuales y las operaciones lógicas de los alumnos de manera más efectiva. . Con la ayuda de los enfoques epistemológico, de actividad sistémica y de entorno, se determina una estrategia para desarrollar el pensamiento lógico de los alumnos a través del aprendizaje basado en proyectos que se basa en la correlación entre el modelo original y el original. Asegura el desarrollo efectivo de a) la actividad intelectual de los escolares b) el pensamiento c) la memoria lógica. El estudio demuestra la efectividad de la tecnología presentada, lo que implica 1) sumergirse en el proyecto, así como especificar sus metas y objetivos; 2) organizar y planificar las actividades de los alumnos; 3) resolver las etapas principales del proyecto; 4) llevar a cabo el proyecto y su presentación; 5) evaluar los resultados. Con base en los datos de la investigación, se destacaron los siguientes criterios: análisis, síntesis, comparación, clasificación, generalización y algunos otros criterios que permitieron determinar tres niveles del desarrollo del fenómeno en cuestión. Nuestro método proporciona una mejora significativa de los resultados de la investigación y garantiza la formación de actividades de investigación, informativas, regulatorias y analíticas de aprendizaje universal (ULA). La evaluación de la efectividad y validez del método propuesto se corrobora mediante cálculos para el criterio de Fisher (criterio φ *). Los resultados comparativos de la investigación antes y después del experimento a alto nivel son 3.564. Los valores empíricos obtenidos de φ * están en el área de significancia. H0 se rechaza (el eje de significancia = 1.64–2.31). Por lo tanto, el método en cuestión tiene un grave impacto en el desarrollo del pensamiento lógico a través del aprendizaje basado en proyectos de alumnos menores.O artigo analisa o método de desenvolver o raciocínio lógico em alunos juniores com base na correlação entre o original e o modelo e possibilita, diferentemente dos métodos tradicionais, desenvolver o raciocínio, estruturas intelectuais e operações lógicas dos alunos de maneira mais eficaz. Com o auxílio das abordagens epistemológicas, de atividade sistêmica e do meio, é determinada uma estratégia para o desenvolvimento do pensamento lógico dos alunos por meio da aprendizagem baseada em projetos, baseada na correlação entre o original e o modelo. Garante o desenvolvimento efetivo de a) atividade intelectual das crianças em idade escolar b) pensamento c) memória lógica. O estudo comprova a eficácia da tecnologia apresentada, que implica 1) imersão no projeto, além de especificar suas metas e objetivos; 2) organização e planejamento das atividades dos alunos; 3) elaboração das principais etapas do projeto; 4) realização do projeto e sua apresentação; 5) avaliando os resultados. Com base nos dados da pesquisa, foram destacados os seguintes critérios: análise, síntese, comparação, classificação, generalização e outros critérios que permitiram determinar três níveis de desenvolvimento do fenômeno em questão. Nosso método fornece uma melhoria significativa dos resultados da pesquisa e garante a formação de atividades de aprendizagem universais (ULAs) informativas, regulatórias e analíticas. A avaliação da eficácia e validade do método proposto é corroborada por cálculos para o critério de Fisher (critério φ *). Os resultados comparativos da pesquisa antes e após o experimento em alto nível são 3.564. Os valores empíricos obtidos de φ * estão na área de significância. H0 é rejeitado (o eixo de significância = 1.64-2.31). Assim, o método em questão tem um sério impacto no desenvolvimento do pensamento lógico através da aprendizagem baseada em projetos de alunos juniores.The article takes a new look at the method of developing logical thinking in junior students based on the correlation between the original and the model and making it possible, unlike traditional methods, to develop students’ speech thinking, intellectual structures, and logical operations more effectively. With the aid of the epistemological, systemic-activity, and milieu approaches, a strategy for developing students’ logical thinking through project-based learning that is premised on the correlation between the original and the model is determined. It ensures the effective development of a) schoolchildren’s intellectual activity b) thinking c) logical memory. The study proves the effectiveness of the presented technology, that implies 1) immersing in the project as well as specifying its goals and objectives; 2) organizing and planning students’ activities; 3) working out the main stages of the project; 4) carrying out the project and its presentation; 5) evaluating the results. Based on the research data, the following criteria were singled out analysis, synthesis, comparison, classification, generalization, and some other criteria, which allowed determining three levels of the development of the phenomenon in question. Our method provides for a significant improvement of the results of the research and ensures the formation of research, informational, regulatory, and analytical universal learning activities (ULAs). The assessment of the effectiveness and validity of the proposed method are corroborated by calculations for the Fisher’s criterion (φ*-criterion). The comparative results of the research before and after the experiment at the high level are 3.564. The obtained empirical values of φ * are in the area of significance. H0 is rejected (the significance axis = 1.64–2.31). Thus, the method in question has a serious impact on the development of logical thinking through project-based learning of junior students

Исследование методов оптимизации сборочных процессов дефибрилляционного оборудования

The electronic medical equipment developing process includes the problems and tasks of medical devices’ technical characteristics improvement, using alternative physical methods of recording medical information. Medical electronic equipment includes defibrillation equipment of various classes, the modernization of which is inextricably connected with scientific and technical research in the field of physics, circuit engineering, design, technology, modeling, characteristics’ measurement, as well as medicine. One of the interdisciplinary research areas at the cardiology and engineering issue is the development of new and modernisation of existing defibrillation devices, improving their functional and operational characteristics, as well as their application efficiency, which is necessary for the provision of extended resuscitation measures. This research is devoted to the research and modeling of defibrillator performance characteristics taking into account components reliability and the operational failure rate determination. The paper also contains study of the production process optimizing methods, in particular assembly operations of high-tech defibrillation products, where the search of optimization solutions was carried out using simulation modeling. Podoliak O. O., Ovchinnikova V. A., Selyahov S. N., Kormin T. G., Korejatov A. V. Optimization methods of assembly processes of defibrillation equipment. Ural Radio Engineering Journal. 2021;5(4):410–431. (In Russ.) DOI: 10.15826/urej.2021.5.4.005. Процесс разработки радиоэлектронного оборудования медицинского назначения включает в себя проблемы и задачи совершенствования технических характеристик медицинских приборов, использования альтернативных физических методов регистрации медицинской информации и так далее. К радиоэлектронному оборудованию медицинского назначения относится деффибрилляционная техника различного класса, модернизация которой неразрывно связана с научными и техническими исследованиями в области физики, схемотехники, конструкции, технологии, моделирования, измерения характеристик, а также медицины. Одно из направлений междисциплинарных исследований на стыке кардиологии и инженерии состоит в разработке новых и совершенствовании существующих деффибрилляционных приборов, повышении их функциональных и эксплуатационных характеристик, а также их эффективности применения, что необходимо для оказания расширенных реанимационных мероприятий. Настоящая статья посвящена исследованию и моделированию эксплуатационных характеристик дефибриллятора с учетом надежности составных частей изделия и определения эксплуатационной интенсивности отказов. Также в статье приведено исследование методов оптимизации производственного процесса, в частности сборочных операций высокотехнологичной дефибрилляционной продукции, где поиск оптимизационных решений проводился с использованием имитационного моделирования. Подоляк О. О., Овчинникова В. А., Селяхов С. Н., Кормин Т. Г., Корежатов А. В. Исследование методов оптимизации сборочных процессов дефибрилляционного оборудования. Ural Radio Engineering Journal. 2021;5(4):410–431. DOI: 10.15826/urej.2021.5.4.005. 

The formation of strategies for effective management of business environment of the region

This study is aimed to explore the opportunities of creating conditions which is necessary for successful development of small and medium enterprises of Russia and the Belgorod region in particular in the chemical industry of leather and footwear sector. The system of criteria for the assessment of the entrepreneurial activity of small and medium enterprises is proposed. The directions of development of small and medium enterprises in the chemical industry of leather and footwear sector are designedyesБелгородский государственный университе

Controlling the topological sector of magnetic solitons in exfoliated Cr1/3_{1/3}NbS2_2 crystals

We investigate manifestations of topological order in monoaxial helimagnet Cr$_{1/3}$NbS$_2$ by performing transport measurements on ultra-thin crystals. Upon sweeping the magnetic field perpendicularly to the helical axis, crystals thicker than one helix pitch (48 nm) but much thinner than the magnetic domain size ($\sim$1 $\mu$m) are found to exhibit sharp and hysteretic resistance jumps. We show that these phenomena originate from transitions between topological sectors with different number of magnetic solitons. This is confirmed by measurements on crystals thinner than 48 nm --in which the topological sector cannot change-- that do not exhibit any jump or hysteresis. Our results show the ability to deterministically control the topological sector of finite-size Cr$_{1/3}$NbS$_2$ and to detect inter-sector transitions by transport measurements.Comment: 7 pages, 8 figure

THE INFLUENCE OF MILK-CLOTTING ENZYMES ON THE FUNCTIONAL PROPERTIES OF PIZZA-CHEESES

The effect of the type and dose of milk-clotting enzymes (Chy-max® M based on recombinant camel chymosin, Fromase® TL based on Rhizomucor miehei protease) on the physicochemical, functional properties and shelf life of pizza-cheeses was studied. When using a low dose of milk-clotting enzymes (MCE) for milk coagulation (250–1100 IMCU per 100 kg of milk), cheeses were obtained with an increased moisture content (55–57%), excessive acidity (pH 4.8–4.9) and texture defects (incoherent, crumbly, with separation of free moisture). This is due to the formation of a weak curd, which releases moisture poorly during processing. The use of an increased dose of MCE makes it possible to obtain a denser curd, better releasing moisture. Cheese produced with a high dose of milk-clotting enzymes (2000–2800 IMCU per 100 kg of milk) had a lower moisture content (52–53%) and lower acidity (pH 5.0–5.1). The protein matrix is more hydrated in these cheeses, which ensures its better water holding capacity and a more homogeneous and cohesive texture. The use of an increased dose of MCE with a high total proteolytic activity (Fromase) gives undesirable consequences in the form of accelerated proteolysis of cheese mass proteins, rapid loss of functional properties of the cheese, and a decrease in the shelf life of cheese (less than 60 days). Cheese production using an increased dose of MCE with a low level of total proteolytic activity (Chy-max M) allows achieving a low level of proteolysis during cheese ripening and increasing its shelf life