Mathematical model and optimization of solder microstructure in a three-layer beam

The studies were carried out with the support of RFBR grant No. 17-03-00720 "Methodology of optimizing micro construction of composite materials for objects of complex shape with enhanced dynamic strength layered by electrotechnological methods"

Kaposi's sarcoma associated with Wegener’s granulomatosi

A case of Kaposi's sarcoma development in a pt with Wegener's granulomatosis during immunosupres- sive treatment with cyclophosphane and prednisolone

Thrombocyte aggregation activity in the conditions of intensive light deprivation

The aim of the research was to study the effect of photoperiodism disturbances on platelet aggregation activity. Material and methods. The experiment was conducted in two stages in 5 groups of male rats: the control group and four experimental groups. At the first stage, the animals were exposed to 24 h/day continuous light (24L:0D) for 10 and 21 days. In the second stage, animals after 10 and 21 days of round-the-clock lighting were returned to natural lighting for a period of 21 days to study the reversibility of changes. Animals were withdrawn from the experiment by intramuscular injection based on body weight of drugs for anesthesia (telazol, xylanite). Blood sampling was performed by puncture of the right heart. The functional activity of platelets was determined no later than 3 hours after the collection of blood. Results and discussion. The results of the experiment indicate a direct effect of light desynchronosis on the increase in platelet aggregation ability, while it was noted that the degree of increase in aggregation activity and reversibility of changes directly depend on the duration of round-the-clock lighting. So, a 10-day stay of animals in conditions of abnormal lighting leads to an increase in aggregation indices, which remain at a high level even when animals return to normal conditions. In animals that were under round-the-clock illumination for 21 days, a more pronounced increase in platelet aggregation values relative to animals on day 10 was noted. In this regard, it can be argued that circadian rhythm disturbances provoke the development of microvasculature disorders

О спектральной задаче, возникающей в механике манипуляционных роботов

A spectral boundary problem of special type containing a spectral parameter in the boundary condition is completely solved in this paper. The characteristic equation for spectrum points determination is obtained, the energy innerproduct is derived, and the orthonormal system of the eigenfunctions is built up.В полном объеме решена спектральная краевая задача специального вида, содержащая спектральный параметр в краевых условиях. Получено характеристическое уравнение для определения точек спектра, выведено энергетическое скалярное произведение, построена ортонормированная система собственных функций

Uranium in man-made carbonates on the territory of Ufa

The paper presents the results of analyzing uranium content in man-made carbonates (scale crusts) on the territory of Ufa based on examination of 42 samples. The median uranium content in the investigated samples stands at 1.44 mg/kg, which is significantly lower than the background values (scales from the Lake Baikal water, a clarke of sedimentary carbonate rocks) and data on other settlements of the Republic of Bashkortostan. Low values of uranium content are probably associated with the effects of the three leading factors, i.e. specific subsurface geology of the territory (gypsum, limestone); types of water supply; water treatment processes for the centralized type of water supply. Spatial distribution of uranium in man-made carbonates is characterized with uniformity, which is disturbed in two cases, i.e. a change of the water supply type (from centralized to individual); and material of the vessels used for boiling the water. No significant differences were detected when comparing samples of man-made carbonates associated with different sources of water supply (the bucket and infiltration types of water intake) and the types of household filters

The Task of Combinatorial Optimization: the Se arch for an Optimal Production and Transport Plan When Organizing Production in New Te rritories

The purpose of this article is to solve one of the tasks of production activities. A company aims to expand individual production facilities and to subsequently determine output and transportation volumes from each of the outlets (local production sites, warehouses, etc.). The hypothesis is that a solution to the production problems can be found in a set of five linear programming problems: the production problem, the center placement problem, the flow problem, the time minimization problem, and the transportation problem. The paper presents the main algorithms for finding optimal solutions, formulates a complex task, builds a model and implements an algorithm for finding optimal solutions. It was shown that such a problem can be formulated in the framework of a complex linear programming problem. The model test is produced on 38 vertices with 16 entry points, 3 exit points. It is shown that such a task can be solved and visualized by means of the Matlab package. Modifications of the model and possible solution algorithms depending on the data sample size are considered. The developed model can be applied at an enterprise or at any production facility where the main task is to search for the optimal combinatorial version of goods, provided that ,first, production costs and the costs of transportation of finished products are minimized and, second, profit is at a maximum. Third, the cost of launching opening new production facilities are kept at a minimum. Such a task corresponds exactly to the economic situation, when the enterprise has yet to expand (open new production sites), and it tries to decide where to produce items from its list of products and determine its output considering the available raw materials and decide on dispatch methods. Such a problem is non-trivial combinatorial in nature.Целью данной статьи является решение одной из нетривиальных задач производственной деятельности, возникшее на предприятии лесной направленности. Предприятие ставит целью расширение отдельных пунктов производства с последующим определением: объемов производства и транспортировки с каждой из точек (мест производства, складов и т. д.). Гипотеза заключается в том, что решение такой производственной проблемы лежит в комплексном решении пяти задач линейного программирования: производственная задача (классическая постановка), задача размещения центров, задача максимального потока, задачи минимизации времени, транспортная задача. В работе представлены основные алгоритмы поиска оптимального решения, сформулирована комплексная задача, построена модель и реализован алгоритм поиска оптимального решения. Было показано, что такую задачу возможно сформулировать в рамках комплексной задачи линейного программирования. Тест модели произведен на 38 вершинах с 16 пунктами входа, 3 пунктами выхода. Показано, что такую задачу возможно решать и визуализировать средствами пакета Matlab. Рассмотрены модификации модели и возможные алгоритмы решения в зависимости от объема выборки данных. Разработанная модель может быть применена на предприятии любой производственной направленности, где стоит главной задачей поиск оптимального комбинаторного варианта вектора товаров при условии, во-первых, минимизации производственных издержек и затрат на транспортировку готовой продукции, во-вторых, получения максимальной прибыли, в-третьих, минимальных издержек при открытии новых пунктов производства. Такая задача в точности подходит к экономической ситуации, когда предприятию еще предстоит расшириться (открыть новые пункты производства), и оно осуществляет попытки по определению мест производства из рассматриваемого списка, объема производства из имеющегося в наличии сырья, способа отправки (как можно больше товара). Такая проблема носит характер нетривиально комбинаторный

EFFECT OF MICROWAVE RADIATION ON STRENGTH CAPPED POLYMER COMPOSITION MATERIALS WITH LIGHTNESS PROTECTIVE RETAINED COATING LOW-CYCLE LOADING

Objectives The analysis of the features of application of fiber-reinforced polymer composite materials (PCM) of different nature in the structural elements of aviation technology and methods of increasing the strength of their products. Method It is indicated on the positive effect on the strength of the bending stress and interlayer shear finish treatment of cured PCM in the microwave electromagnetic field. It is noted that the peculiarity of the elements of the skin of PCM is the presence in the surface layer of the built-in metal mesh, or lightning-proof coating (MFP), necessary to ensure the stability of structural elements to the effects of atmospheric electricity discharges. Result. The tests of the control and processed in the microwave electromagnetic field samples from PCM with MSP on low-cycle fatigue at the number of loading cycles-60 and strain amplitudes-10 mm. it was Found that in the control samples with the grid MEU primary crack appears after 6 cycles. After microwave processing, the samples retain their integrity, but the load causing the set deformation is reduced by 14% already on the 35th cycle. Conclusion Durability of samples with the heat-treated grid "Тekstilmash" and with a grid without heat treatment after influence of microwave electromagnetic field increases respectively by 59,5% and 71%. At the same time, the samples retain their integrity after 60 loading cycles, and the maximum stresses are reduced by 13.7% and 5.8%, respectively, compared to static tests. The limit of low-cycle fatigue increases  after microwave treatment from 37 to 210%

STUDYING THE INFLUENCE OF MICROWAVE RADIATION ON THE THERMOPHYSICAL CHARACTERISTICS OF REVERSED POLYMER COMPOSITION MATERIALS REINFORCED BY CARBON FIBERS

Objectives. The aim of the research is to study the influence of the microwave electromagnetic field on the thermophysical characteristics of PCM reinforced with carbon fibers as one of the factors indicating a certain restructuring of the material, leading to a change in its operational properties.Method. The use of modifying hardening effects that do not lead to excessive destructuring heating of materials.Result. Based on the analysis of scientific and technical literature and trends in the development of technical transport and energy systems, a steady increase in the cons umption of fibrous polymeric composite materials (PCM) in their structures has been revealed. The prospects of applying the effects of microwave radiation (microwave electromagnetic field) on the formation of the required properties of products from PCM and the feasibility of studying the mechanisms of interaction of microwave radiation with the structure of solidified PCM are shown. Experimental studies of the thermophysical interaction of PCM reinforced with carbon fibers with a microwave electromagnetic field with a frequency of 2450 MHz were performed.Conclusion. The fact of more intensive heating of samples of greater thickness and their greater shielding capacity was established. In the study of the thermophysical parameters of PCM subjected to preliminary processing in the microwave electromagnetic field by the modified Parker method, an increase in certain exposure modes of the thermal and thermal conductivities by 20% was observed, which indicates an increase in adhesive bonds in the interfacial zones and an increase in the structure density. This fact can be used in the development of technologies for modifying products from PCM, designed to work in conditions of elevated temperature gradients, which will reduce the magnitude of thermal stresses.Acknowledgment. The research was supported by RFBR grant No. 17-03-00720 «Methodology of optimising microconstruction of composite materials for complex shape objects with increased dynamic strength, formed layer-by-layer by electrotechnological methods»