96 research outputs found

    Elaborating the Strategies for Development of System Important Banks of Ukraine under the Influence of External Environment Factors

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    The aim of the study is a theoretical and methodological generalization of the process of strategic management and determination, through strategic planning, of ways of development of system important banks of Ukraine under conditions of uncertainty of their functioning environment. As a result of the study of foreign and domestic experience, the theoretical and methodological concept of strategic planning of the banking system is formulated. The authors analyze the goals, missions and visions of the strategies of system important banks, assess the state of development of system important banks in Ukraine in the current conditions and identify the key areas of strategic planning. It is found that system important banks of Ukraine occupy a predominant share in the structure of both certain types of banking income and financial performance. In addition, it is determined that strategic planning should be based on the reliability and completeness of economic indicators and non-financial indicators. In particular, the indicators of the bank’s share in the activity among banking structures are important for characterizing its competitive position and the level of efficiency of its strategy among competitors. It is researched that system important banks are predominant in the banking services market, and their network of branches is widely distributed. The strategic development of these banks should be aimed at the possibility of retaining this share of the banking services market. The authors improve the theoretical and methodological approach to the strategic planning process in a bank on the principles of introducing an inclusive component of further development, which will provide for a sustainable accelerated growth of the country’s economic power on the basis of financial inclusion, a radical increase in the welfare of individual members of society and society as a whole. It is specified that such approaches to organizing the formation of strategies of system important banks will also ensure sociopolitical stability and form an appropriate level of national security

    Nonsteady condensation and evaporation waves

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    We study motion of a phase transition front at a constant temperature between stable and metastable states in fluids with the universal Van der Waals equation of state (which is valid sufficiently close to the fluid's critical point). We focus on a case of relatively large metastability and low viscosity, when it can be shown analytically that no steadily moving phase-transition front exists. Numerically simulating a system of the one-dimensional Navier-Stokes and continuity equations, we find that, in this case, the nonsteady phase-transition front emits acoustic shocks in forward and backward directions. Through this mechanism, the front drops its velocity and eventually comes to a halt. The acoustic shock wave may shuttle, bouncing elastically from the system's edge and strongly inelastically from the phase transition front. Nonsteady rarefaction shock waves appear in the shuttle process, despite the fact that the model does not admit steady rarefaction waves propagating between stationary states. If the viscosity is below a certain threshold, an instability sets in, driving the system into a turbulent state. This work was supported by the Japan Society for Promotion of Science.Comment: revtex text file and four eps files with figures. Physical Review Letters, in pres

    Fine-tuning of Silica Coating Procedure for Preparation of Biocompatible and Bright Pbs/Sio2 Qds

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    Near-infrared semiconductor PbS quantum dots (QDs) with emission in biological transparency window are promising material for in vivo biolabelling and deep-tissue imaging of biological specimen. Among various approaches that render initially hydrophobic and toxic QDs biocompatible, the growth of a silica shell on the QD surface represents an efficient method to minimize QD toxicity. Nevertheless, it is important to preserve QDs emission properties after the silica coating procedure. Here we report on the optimal parameters of this procedure which allow to obtain a stable silica shell and maintain the optical properties of initial PbS QDs. Furthermore, we show that PbS QDs with the optimal SiO2 shell retain their luminescence quantum yield even after condensation into a solid film. Thus, our procedure can become a basis in development of bright, receptor-targeted NIR fluorescent probes for in vivo tumor imaging. Keywords: quantum dot, SiO2 shell, bioimagin

    Экспериментальное определение и сравнительный анализ характеристик прочности полимеров PPH030GP, ABS и PLA при различных скоростях деформации

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    Nowadays the field of application of products made from polymer materials is constantly increasing. These products find their wide application in the most high-tech industries such as automotive, aerospace and medical industry. Modern trends in the development of the automotive industry predicts that 75 % of the total car mass will be replaced with polymer materials by 2020 and other industries demonstrate similar trends. Regarding to this information, engineering companies that design parts of the automotive industry should have polymer material characteristics over an entire range of deformations up to destruction for their performance prediction. However, strength characteristics of products from polymers are different and depend not only on a polymer grade but also on technology used for part production. Existing literature review on this problematic area is rather rare. The purpose of this paper is to determine and analyze mechanical characteristics of widely used PPH030GP polymer obtained by extrusion and ABS, PLA polymers applied while manufacturing samples using an additive method (3D-printing) depending on the rate of high-elastic deformation. All the samples have been made according to the requirements of GOST 11262–80 and subjected to uniaxial stretching on a tensile machine UIT STM 050/300 at different speeds of clamp expansion. According to experimental results, stretching diagrams in conditional coordinates s–e have been obtained up to the point of failure for different rates of clamp expansion. It has been shown that while using the additive method, a direction of layers and adhesion between them, which depends on 3D-print parameters, have a significant effect on the part strength. Printing settings are indicated in accordance with the selected mode and a 3D-printer model. As a result of data processing, strength characteristics of PPH030GP polymer and ABS and PLA polymers have been determined to a sufficient extent, depending on the direction of printing layers and rate of high-elastic deformation. These data can be used to calculate strength of products by numerical methods and a finite element method in various software products.Сегодня область применения изделий из полимерных материалов постоянно увеличивается. Такие изделия находят широкое применение в наиболее наукоемких отраслях, таких как автомобильная, аэрокосмическая и медицинская отрасли. Современные тенденции развития автомобильной промышленности прогнозируют к 2020 году 75 % общей массы автомобиля заменить полимерными материалами. Схожие тренды демонстрируют и другие отрасли. В связи с этим инженерным компаниям, проектирующим детали автомобильной промышленности, для прогнозирования их работоспособности необходимо иметь характеристики полимерных материалов во всем диапазоне деформаций – вплоть до разрушения. Однако прочностные характеристики изделий из полимеров различны и зависят не только от марки полимера, но и от технологии производства детали. Подробная информация в отечественной литературе встречается достаточно редко и в сжатом виде. Авторами статьи была поставлена задача определить и проанализировать механические характеристики широко применяемого полимера PPH030GP, полученного экструзивным методом, и полимеров ABS и PLA, применяемых при изготовлении образцов аддитивным методом (3D-печать) в зависимости от скорости деформации. Для этого были выполнены образцы согласно требованиям ГОСТ 11262–80 и подвергнуты одноосному растяжению на разрывной машине UIT STM 050/300 при разных скоростях раздвижения зажимов. По результатам экспериментальных исследований получены диаграммы растяжения в условных координатах s–e вплоть до момента разрушения для различных скоростей раздвижения зажимов. Показано, что при аддитивном методе значительное влияние на прочность изделия оказывают направление слоев и адгезия между ними, которая зависит от параметров 3D-печати. Параметры печати указаны в зависимости от выбранного режима и конструкции 3D-принтера. В результате обработки данных в достаточно полной мере определены прочностные характеристики полимеров PPH030GP, ABS и PLA в зависимости от направления слоев печати и скорости деформации. Эти данные можно применять для расчета прочности изделий численным методом и методом конечных элементов в различных программных продуктах

    Highly Stable, Water-Soluble CdSe/ZnS/CdS/ZnS Quantum Dots with Additional SiO2 shell

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    Quantum dots (QDs) are fluorescent nanocrystals extensively used today in research and applications. They attract much interest due to the high photostability and fluorescence quantum yields close to 100%. The best QDs are made by synthesis in organic media, and they have to be transferred into aqueous solutions if biomedical applications are concerned. An advanced method for rendering QDs water-soluble is to coat them with hydrophilic SiO2 -layer. However, growing a silica shell with a predetermined thickness is a problem, because uncertain values of the molar extinction coefficients (ε) of core/shell QDs made it impossible to calculate precise yields of the chemical reactions involved. Here we suggest an approach to solving this problem by constructing the structural models of per se and silica-coated QDs followed by measuring ε in a course of the QD synthesis, thus carrying out precise quantitative reactions. Proceeding in such a way, we prepared the CdSe/ZnS/CdS/ZnS QDs with the structure predicted by the model and coated by silica shell. Prepared QDs are characterized by a narrow size distribution and the same fluorescence parameters as the original QDs in the organic medium. Developed approach permitted efficient QDs water-solubilisation and preparation of stable nanoparticles for plethora of biomedical applications.     Keywords: Quantum dots, QD, silica shell, core-shel

    Различные методы изучения семантики лексемы

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    The article analyzes the ways of studying the semantics of a word. At the current stage of development of the linguistic science various methods of studying the meaning of a lexeme have been proposed by different linguistic schools. The peculiarities of the component, contrastive and contextual analysis of the lexeme «battle» are described in this article. The undertaken research shows that different methods of linguistic analysis of a word are aimed at different semantic aspects. Due to the component analysis the semantically closest lexemes have been identified. The contrastive analysis has identified the best translation of the lexeme «battle». The contextual analysis has shown how the meaning of the lexeme «battle» changes depending on the context. As a result, all the semantic components, the lexicographic and communicative meanings of the word “battle” have been identified. The research shows that all these methods are interrelated and allow to perform deeper analysis of a lexeme.В статье анализируются различные способы изучения семантики лексической единицы. На данном этапе развития лингвистической науки разными лингвистическими школами предложены различные методы изучения значения лексемы. В данной статье рассматриваются особенности компонентного, контрастивного и контекстуального анализа лексемы “battle”. Исследование показало, что различные методы лингвистического анализа направлены на различные семантические аспекты. В ходе компонентного анализа определены семантически близкие лексемы. Контрастивный анализ помогает выбрать лучший перевод лексемы «battle». Контекстуальный анализ демонстрирует как значение лексемы «battle» меняется в зависимости от контекста. В результате исследования были выявлены все семантические компоненты, лексикографическое и коммуникативное значения лексемы «battle». Исследование показывает, что все методы взаимосвязаны и позволяют осуществить более глубокий анализ слова

    ЭФФЕКТИВНЫЕ ШПОНОЧНЫЕ СОЕДИНЕНИЯ МНОГОПУСТОТНЫХ ПЛИТ ПЕРЕКРЫТИЙ СО СТЕНАМИ В СОВРЕМЕННОМ КРУПНОПАНЕЛЬНОМ ДОМОСТРОЕНИИ

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    The paper considers large-panel constructive system of multi-storey buildings and its industrial basis creates conditions for intensive volume growth in house construction. Application of hollow-core panels are recommended as floor slabs that allows to increase a distance between bearing walls, to improve planning solutions, and also significantly to increase thermal and sound protection properties of floor discs (coatings). Keyed joints having the highest resistance to shearing forces are used to ensure joint action of the slabs with wall panels. A supporting unit of floor elements in the precast-monolithic constructive system ARKOS by means of concrete keys is considered as a prototype of the considered joint. In order to increase a bearing capacity and improve reliability of joints it is envisaged to reinforce keys with space frames. Improvement of joint units is possible to carry out with due account of total number of the factors influencing on strength. Poltava National Technical University named after Yuri Kondratyuk has developed a general methodology for assessment of bearing capacity in keyed joints which is based on the variational method in the theory of concrete plasticity and reflects specificity of stress-strain state of the failure zone. For experimental verification of this methodology investigations have been carried out with the purpose to test operation of keys when they are reinforced in mid-height and reinforcement is distributed in two tiers. The observed experimental fracture pattern in the specimens has confirmed kinematic schemes accepted for calculations and comparative analysis of experimental and theoretical values points to their closeness. Two-level reinforcement significantly improves plastic properties of concrete keys and excludes brittle failure. The proposed design of the joint unit for floor slabs with wall panels is characterized by the ratio of key dimensions and shape of reinforcing cages in the form of hollow cylinders which ensure higher strength and seismic resistance of a joint.Рассмотрена крупнопанельная конструктивная система многоэтажных зданий, индустриальная основа которой создает условия для интенсивного роста объемов домостроения. В качестве плит перекрытий рекомендуется применение многопустотных панелей, что позволяет увеличить расстояние между несущими стенами, улучшить планировочные решения, а также существенно повысить теплои звукозащитные свойства дисков перекрытий (покрытий). Для обеспечения совместной работы плит со стеновыми панелями устраиваются шпоночные стыки, имеющие наибольшее сопротивление действию срезывающих сил. Прототипом рассматриваемого соединения является узел опирания элементов перекрытий сборно-монолитной конструктивной системы «АРКОС» посредством бетонных шпонок. С целью увеличения несущей способности и повышения надежности работы стыков предусматривается армирование шпонок пространственными каркасами. Совершенствование узлов соединений возможно на основе учета полного количества влияющих на прочность факторов. В Полтавском национальном техническом университете имени Юрия Кондратюка разработана общая методика оценивания несущей способности шпоночных соединений, которая базируется на вариационном методе в теории пластичности бетона и отображает специфику напряженно-деформированного состояния зоны разрушения. Для экспериментальной проверки указанной методики выполнено исследование работы шпонок при их армировании посередине высоты и с разнесенной арматурой в два яруса. Наблюдаемая в опытах картина разрушения образцов подтверждает принятые при расчетах кинематические схемы, а сравнительный анализ экспериментальных и теоретических значений предельной нагрузки указывает на их близость. Двухуровневое армирование существенно улучшает пластические свойства бетона шпонок и исключает хрупкое разрушение. Предложенная конструкция узла соединения плит перекрытий со стеновыми панелями отличается соотношением размеров шпонок и формой арматурных каркасов в виде полых цилиндров, которые обеспечивают повышенную прочность и сейсмостойкость стыка

    The evaluation of teeth loosening of the upper jaw in adaptive period of orthodontic treatment by braces

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    Introduction: Tooth loosening is divided into physiological and pathological one, but there is tooth loosening that occurs during orthodontic treatment (OT) and depends on the tissues of parodontium and strength of orthodontic apparatus. The aim of the research is to evaluate teeth loosening of the upper j aw during adaptive period in patients with permanent bite who were treated by braces. Materials and methods: Periostometry (device «Periotest») of teeth to 30 patients who are from 14 to 27 years old with the pathology of the first type based Angle's classification. The evaluation of teeth loosening was done before OT, in 1 month, in 3 months and in 6 months. Results: The average index of teeth loosening before OT in patients included 3,08±1,29, so it corresponded to norm indices. In 1 month after braces fixation indices of tooth loosening were increased. Middle index of teeth loosening on the third month of OT was 5 , 8 4 ± 0 , 7 7 relative units, that in 1,9 times more than periostometric indices before OT. Conclusions: Changes of teeth loosening during OT by braces during the first month after fixation. It should be noted that during the first month of OT data of periostometry determine the enlargement of teeth loosening of all teeth in 1,38, in 3 months there is decrease of teeth loosening for all types of teeth. On the 6'h month of OT indices of teeth loosening continue decreasing but with lesser intensity and not achieve such level which was to the beginning of OT

    Tb(III) complexes with nonyl-substituted calix[4]arenes as building blocks of hydrophilic luminescent mixed polydiacetylene-based aggregates

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    © 2018 The present work for the first time introduces PDA-based vesicles as convenient supporters of luminescent water insoluble Tb3+ complexes. The specific cyclophanic structure of the ligands, where upper and lower calix[4]arene rims are decorated by nonyl- and chelating groups correspondingly provides both complex formation with Tb3+ ions with the coordination of the latter via two 1,3-diketonate groups and self- or mixed aggregation of the complexes. The conditions of the self-aggregation of the Tb3+ complexes are revealed, although the self-aggregates are unstable being converted into the nanosized precipitates which tend to further aggregation and phase separation. The complexes exhibit Tb(III)-centered luminescence which tends to change in time following the phase separation processes. The embedding of the Tb3+ complexes into the PDA-based vesicles results in the mixed aggregates with significant Tb(III)-centered luminescence and significant colloidal stability. The latter arises from high negative electrokinetic potential values due to exterior carboxylic/carboxylate groups of the PDA vesicles

    The Research of Influence of Graphite Quality on Mold Coatings for Low-Pressure Die Casting

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    Изучено влияние содержания активированного в планетарно-центробежной мельнице АГО2 скрытокристаллического графита Курейского месторождения на технологические свойства покрытий пресс-форм, используемых для литья под низким давлением, жидкотекучесть сплава АК12. Установлено, что наиболее оптимальные свойства покрытий достигаются при введении в их состав 15 мас. % активированного графита. Выяснено, что с увеличением содержания графита жидкотекучесть сплава АК12 и шероховатость отливок снижается. Проведённые сравнительные лабораторные и опытно-промышленные испытания покрытий на основе природного, активированного и обогащенного графита показали, что для покрытий пресс-форм могут быть рекомендованы покрытия на основе активированного графитаThe influence of content of cryptocrystalline graphite of Kureysk Field, activated in a planetary centrifugal mill AGO-2, on the technological properties of mold coatings used for low-pressure die casting and castability of AK12 alloy are researched. It was found that the optimum properties of coating are achieved by the introduction into their composition 15 wt. % of activated graphite. Also it was found that with increasing content of graphite, the castability of AK12 alloy and roughness of castings are decreases. The comparative laboratory and pilot testing of coatings based on natural, enriched and activated graphite showed that coatings based on activated graphite can be recommended for mold
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