473 research outputs found

    Modelling and experimental investigation of the fatigue crack kinetics in semitrailer underframe longerons

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    It was developed a system of cyclic trials for investigation of vitality of critic zones of langeron frame ladder constructions and shown the results of tests on low-cycle fatigue of its natural elements in the work

    High-speed time-reversed ultrasonically encoded (TRUE) optical focusing inside dynamic scattering media at 793 nm

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    Time-reversed ultrasonically encoded (TRUE) optical focusing is an emerging technique that focuses light deep into scattering media by phase-conjugating ultrasonically encoded diffuse light. In previous work, the speed of TRUE focusing was limited to no faster than 1 Hz by the response time of the photorefractive phase conjugate mirror, or the data acquisition and streaming speed of the digital camera; photorefractive-crystal-based TRUE focusing was also limited to the visible spectral range. These time-consuming schemes prevent this technique from being applied in vivo, since living biological tissue has a speckle decorrelation time on the order of a millisecond. In this work, using a Tedoped Sn_2P_2S_6 photorefractive crystal at a near-infrared wavelength of 793 nm, we achieved TRUE focusing inside dynamic scattering media having a speckle decorrelation time as short as 7.7 ms. As the achieved speed approaches the tissue decorrelation rate, this work is an important step forward toward in vivo applications of TRUE focusing in deep tissue imaging, photodynamic therapy, and optical manipulation

    Особенности построения электрохимического газоанализатора оксида углерода в атмосферном воздухе

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    Проаналізовано основні джерела викидів оксиду вуглецю в атмосферу. Проведено порівняльний аналіз декількох моделей електрохімічних газоаналізаторів. Описано особливості побудови та експлуатації автоматичного ГА оксиду вуглецю 621ЕХ 20.The basic sources of carbon monoxide emissions in atmosphere are analysed. The comparative analysis of a few models of electrochemical GA is conducted. The features of construction and exploitation of automatic carbon monoxide GA 621EX20 are described.Проанализированы основные источники выбросов оксида углерода в атмосферу. Проведен сравнительный анализ нескольких моделей электрохимических ГА. Описаны особенности построения и эксплуатации автоматического ГА оксида углерода 621ЕХ 20

    Optical focusing deep inside dynamic scattering media with near-infrared time-reversed ultrasonically encoded (TRUE) light

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    Focusing light deep inside living tissue has not been achieved despite its promise to play a central role in biomedical imaging, optical manipulation and therapy. To address this challenge, internal-guide-star-based wavefront engineering techniques—for example, time-reversed ultrasonically encoded (TRUE) optical focusing—were developed. The speeds of these techniques, however, were limited to no greater than 1 Hz, preventing them from in vivo applications. Here we improve the speed of optical focusing deep inside scattering media by two orders of magnitude, and focus diffuse light inside a dynamic scattering medium having a speckle correlation time as short as 5.6 ms, typical of living tissue. By imaging a target, we demonstrate the first focusing of diffuse light inside a dynamic scattering medium containing living tissue. Since the achieved focusing speed approaches the tissue decorrelation rate, this work is an important step towards in vivo deep tissue noninvasive optical imaging, optogenetics and photodynamic therapy

    ВПЛИВ ФІНАНСОВОЇ КРИЗИ В УКРАЇНІ 2014—2015 РОКІВ НА РІВЕНЬ ФІНАНСОВОЇ БЕЗПЕКИ БАНКІВ

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    It has been determined that commercial banks operate in a complex operational environment, which is due to the influence of a number of factors of political, social, economic, which are largely unpredictable and destructive. It is substantiated that external key parameters through which the influence on the process of providing financial security of banks is mediated. The relationship between the size of the rate of mandatory reserve requirements and the level of financial security of the bank is researched. The analysis of the state of assets, liabilities and equity capital by groups of banks during 2012—2016. The role of the central bank in regulating the activities of banks in order to ensure their financial security has been determined. The expediency of imposing sanctions on carrying out of any financial operations of banks with Russian capital in favor of parent structures was substantiated. The key problems that restrain the process of providing financial security of banks in terms of their functional components (capital-resource security, credit-investment, currency and safe level of incomes and expenditures) are determined. The methodical approach to the rating of banks estimation on the level of their financial security is offered on the basis of the analysis of indicators The stimulator / disintegrators of the analyzed banks is based on the rating rating of the bank according to the level of its financial security on the basis of comparison of j-th KB with the «standard» — the bank which The best results for each indicator are the maximum values for stimulators and the minimum for disinfectants. The rating is defined as the arithmetic mean of standardized indicators summed up in the matrix of key indicators. The necessity of grouping the analyzed banks according to their financial security level has been proved. Using the method of grouping of research objects is substantiated as an instrument for streamlining the analyzed banks. It is determined empirically, taking into account qualitative, non-formalized characteristics of four groups of banks for the p vnem their financial security (with a high level of financial security, sufficient, low and critical).Визначено, що комерційні банки функціонують у складному операційному середовищі, а це зумовлено впливом низки факторів політичних, соціальних, економічних, що здебільшого є малопрогнозованими і деструктивними. Обґрунтовано зовнішні ключові параметри, через які опосередковується вплив на процес забезпечення фінансової безпеки банків. Досліджено взаємозв’язок між розміром ставки нормативів обов’язкового резервування і рівнем фінансової безпеки банку. Проаналізовано стан активів, зобов’язань і власного капіталу за групами банків упродовж 2012—2016 рр.. Визначено роль центрального банку в регулюванні діяльності банків щодо забезпечення їхньої фінансової безпеки. Обґрунтовано доцільність запровадження НБУ санкцій на проведення будь-яких фінансових операцій банків із російським капіталом на користь материнських структур. Визначено ключові проблеми, які стримують процес забезпечення фінансової безпеки банків у розрізі і функціональних складових (капітало-ресурсної безпеки, кредитно-інвестиційної, валютної та безпечного рівня доходів і витрат. Запропоновано методичний підхід до рейтингової оцінки банків за рівнем їхньої фінансової безпеки на основі аналізу показників-стимуляторів / дестимуляторів аналізованих банків. Обґрунтовано проведення рейтингової оцінки банку за рівнем його фінансової безпеки на основі порівняння j-го КБ з «еталоном» — банком, який має найкращі результати щодо кожного показника — максимальні значення для стимуляторів і мінімальні — для дестимуляторів. Рейтинг визначено як середнє арифметичне стандартизованих показників, зведених у матрицю ключових показників. Доведено необхідність групування аналізованих банків за рівнем їхньої фінансової безпеки. Обґрунтовано використання методу групування об’єктів дослідження як інструменту упорядкування аналізованих банків. Визначено емпіричним шляхом з обліком якісних, неформалізованих характеристик чотири групи банків за рівнем їхньої фінансової безпеки (з високим рівнем фінансової безпеки, достатнім, низьким і критичним)

    High-speed time-reversed ultrasonically encoded (TRUE) optical focusing inside dynamic scattering media at 793 nm

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    Time-reversed ultrasonically encoded (TRUE) optical focusing is an emerging technique that focuses light deep into scattering media by phase-conjugating ultrasonically encoded diffuse light. In previous work, the speed of TRUE focusing was limited to no faster than 1 Hz by the response time of the photorefractive phase conjugate mirror, or the data acquisition and streaming speed of the digital camera; photorefractive-crystal-based TRUE focusing was also limited to the visible spectral range. These time-consuming schemes prevent this technique from being applied in vivo, since living biological tissue has a speckle decorrelation time on the order of a millisecond. In this work, using a Tedoped Sn_2P_2S_6 photorefractive crystal at a near-infrared wavelength of 793 nm, we achieved TRUE focusing inside dynamic scattering media having a speckle decorrelation time as short as 7.7 ms. As the achieved speed approaches the tissue decorrelation rate, this work is an important step forward toward in vivo applications of TRUE focusing in deep tissue imaging, photodynamic therapy, and optical manipulation

    Средства метрологического обеспечения газоаналитической техники

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    В статті описано особливості розробки засобів метрологічного забезпечення газоаналізаторів. Приведені їх технічні та метрологічні характеристикIn article are described the elaboration peculiarities of measurement standard support of gaz analyzers. Their technical and metrological performances are given.В статье описаны особенности разработки средств метрологического обеспечения газоанализаторов. Приведены их технические и метрологические характеристики

    Автоматический стационарный пост наблюдений за загрязнением атмосферного воздуха “АТМОСФЕРА-10”

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    Проаналізовано стан і проблеми екологічного моніторингу довкілля України. Розглянуто особливості побудови та функціонування автоматизованого посту спостережень за забрудненням атмосферного повітря.The state and problems of the ecological monitoring of environment of Ukraine is analyzed. The features of construction and functioning of the automated station of atmospheric air contamination monitoring are considered.Проанализированы состояние и проблемы экологического мониторинга окружающей среды Украины. Рассмотрены особенности построения и функционирования автоматизированного поста наблюдений за загрязнением атмосферного воздуха

    Nano-colloids of Sn2P2S6 in Nematic Liquid Crystal Pentyl-cianobiphenile

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    It has been shown experimentally that the ferroelectric nano-particles, in common with other molecular additives, shift the clearing temperature, Tc, extending or reducing the two-phase coexistent region and changing the average order parameter of the single-component nematics. An increase of up to 11°C or a smaller decrease of as much as 3°C of Tc, and corresponding changes of the order parameter were observed. In all cases the order parameter of the colloid followed the universal temperature behaviour, which is a characteristic of LCs with molecular additives

    Utility of CD4 cell counts for early prediction of virological failure during antiretroviral therapy in a resource-limited setting

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    BACKGROUND: Viral load monitoring is not available for the vast majority of patients receiving antiretroviral therapy in resource-limited settings. However, the practical utility of CD4 cell count measurements as an alternative monitoring strategy has not been rigorously assessed. METHODS: In this study, we used a novel modelling approach that accounted for all CD4 cell count and VL values measured during follow-up from the first date that VL suppression was achieved. We determined the associations between CD4 counts (absolute values and changes during ART), VL measurements and risk of virological failure (VL > 1,000 copies/ml) following initial VL suppression in 330 patients in South Africa. CD4 count changes were modelled both as the difference from baseline (DeltaCD4 count) and the difference between consecutive values (CD4 count slope) using all 3-monthly CD4 count measurements during follow-up. RESULTS: During 7093.2 patient-months of observation 3756 paired CD4 count and VL measurements were made. In patients who developed virological failure (n = 179), VL correlated significantly with absolute CD4 counts (r = - 0.08, P = 0.003), DeltaCD4 counts (r = - 0.11, P < 0.01), and most strongly with CD4 count slopes (r = - 0.30, P < 0.001). However, the distributions of the absolute CD4 counts, DeltaCD4 counts and CD4 count slopes at the time of virological failure did not differ significantly from the corresponding distributions in those without virological failure (P = 0.99, P = 0.92 and P = 0.75, respectively). Moreover, in a receiver operating characteristic (ROC) curve, the association between a negative CD4 count slope and virological failure was poor (area under the curve = 0.59; sensitivity = 53.0%; specificity = 63.6%; positive predictive value = 10.9%). CONCLUSION: CD4 count changes correlated significantly with VL at group level but had very limited utility in identifying virological failure in individual patients. CD4 count is an inadequate alternative to VL measurement for early detection of virological failure
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