202 research outputs found

    STATE AND PROSPECTS OF BIOENERGY DEVELOPMENT

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    Biofuel is one of the world’s major alternative sources of energy derived from biomass which includes almost all organic substances. In this regard, the state and prospects of development of the world bioenergy have been considered. The positive and negative sides of increasing energy production from biomass have been revealed. The analysis of the countries with the greatest biological resources for the production of liquid and gaseous biofuels has been carried out. The leading countries in the production of various types of biofuels have been determined and the measures of state support, contributing to the development of this direction, have been analyzed. The state and prospects of bioenergy development in Russia have been considered. The export potential of the country in the field of biofuel production and its use in industry has been revealed. It has been established, that despite some successes in the use of biofuel, the development of bioenergy projects in Russia still leaves much to be desired. The reasons, hindering the development of bioenergy in Russia, and measures to stimulate the development of biofuel production have been identified. In this regard, a flexible policy of the state in terms of innovation and energy is necessary, while today the state is focused on traditional energy sources

    Estimation of abrasiveness impact on the parameters of rock-cutting equipment

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    Development of equipment, which provides access to underground mineral deposits and their extraction, requires the use of all the accumulated experience and advanced scientific research in the area of mechanical rock cutting. The most important issues of using mechanical rock cutting tools are their wearability and consumption, which have an impact on technical and economic indicators of project efficiency. The paper describes Russian and foreign practices of estimating tool wear resistance, expressions to determine critical cutting speed, methods to evaluate tool consumption. It is demonstrated that wearability of mechanical tools and associated effects are to a large extent defined by rock abrasiveness. It is highlighted that in Russia the index is calculated using Baron-Kuznetsov method, which is briefly described in the paper. In many countries with a highly-developed mining industry, rock abrasiveness is estimated with a Cerchar  Abrasiveness Index (CAI), recommended by the International Society for Rock Mechanics. Its description is also presented in the paper

    Evaluation of coal export from Russia

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    Dynamics of coal mining in Russia and also export of coal from Russia has been presented. Demand for the Russian coal has been analyzed, reasons for refusal of some countries of extraction of own coal have been revealed. Challenges of the coal industry on medium and long term have been determined and perspectives for its development have been planned. Based on the study, the possible threats to the Russian coal market have been identified and the main competitors of Russia in the field of coal export have been considered

    Selective deposition of polycrystalline diamond films using photolithography with addition of nanodiamonds as nucleation centers

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    A new method of selective deposition of polycrystalline diamond has been developed and studied. The diamond coatings with a complex, predetermined geometry and resolution up to 5 [mu]m were obtained. A high density of polycrystallites in the coating area was reached (up to 32·10{7} pcs/cm{2}). The uniformity of the film reached 100%, and the degree of the surface contamination by parasitic crystals did not exceed 2%. The technology was based on the application of the standard photolithography with an addition of nanodiamond suspension into the photoresist that provided the creation of the centers of further nucleation in the areas which require further overgrowth. The films were deposited onto monocrystalline silicon substrates using the method of "hot filaments" in the CVD reactor. The properties of the coating and the impact of the nanodiamond suspension concentration in the photoresist were also studied. The potential use of the given method includes a high resolution, technological efficiency, and low labor costs compared to the standard methods (laser treatment, chemical etching in aggressive environments)

    The peculiarities of cross-correlation between two secondary precursors - radon and magnetic field variations, induced by stress transfer changes

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    A model of precursor manifestation mechanisms, stimulated by tectonic activity and some peculiarities of observer strategy, whose main task is the effective measurement of precursors in the spatial area of their occurrence on the Earth's daylight, are considered. In particular, the applicability of Dobrovolsky's approximation is analyzed, when an unperturbed medium (characterized by the simple shear state) and the area of tectonic activity (local inhomogeneity caused by the change only of shear modulus) are linearly elastic, and perturbation, in particular, surface displacement is calculated as a difference of the solutions of two independent static problems of the theory of elasticity with the same boundary condition on the surface. Within the framework of this approximation a formula for the spatial distribution (of first component) of magnetic field variations caused by piezomagnetic effect in the case of perturbed regular medium, which is in simple shear state is derived. Cogent arguments in favor of linear dependence between the radon spatial distribution and conditional deformation are obtained. Changes in magnetic field strength and radon concentrations were measured along a tectonomagnetic profile of the total length of 11 km in the surroundings of the "Academician Vernadsky" Station on the Antarctic Peninsula (W 64{\deg}16', S 65{\deg}15'). Results showed a positive correlation between the annual surface radon concentration and annual changes of magnetic field relative to a base point, and also the good coincidence with theoretical calculation.Comment: 27 pages, 11 figures, 3 tables (a substantially revised and extended edition; v3 -- some analysis of recent publications added

    A case report of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease

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    Rendu-Osler-Weber disease is a rare inherited disease of the vasculature, characterized by the development of multiple telangiectasias of the skin and mucous membranes, as well as hemorrhagic syndrome of various localization. We present a case report of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease. In the first part of the article, literature data on the incidence, etiology, pathogenesis, features of clinical manifestations of hereditary hemorrhagic telangiectasia, modern methods of diagnosis and treatment are presented. In the second part of the article, a rare case of recurrent acute ischemic strokes in a young patient with Rendu-Osler-Weber disease, caused by a paradoxical embolism due to pulmonary arteriovenous malformation was demonstrated. The chest CT detected a pulmonary arteriovenous malformation. The data of medical, including anamnesis, a description of the objective and neurological status, the results of laboratory and instrumental methods of examination are presented. The patient was recommended angiopulmonography, during which the pulmonary arteriovenous malformation was successfully embolized. This case indicates the need for targeted examination and monitoring of patients with hereditary hemorrhagic telangiectasia. For the purpose of early detection of vascular malformations in patients with Rendu-Osler-Weber disease and the timely administration of therapy to prevent possible serious cerebrovascular complications, we recommend performing the chest CT.Болезнь Рандю-Ослера-Вебера или наследственная геморрагическая телеангиэктазия представляет собой редкое наследственное заболевание сосудистой системы, характеризующееся развитием множественных телеангиэктазий кожи и слизистых оболочек, а также геморрагическим синдромом различной локализации. Мы представляем клинический разбор случая развития повторных инфарктов головного мозга у молодого пациента с болезнью Рандю-Ослера-Вебера. В первой части публикации приводятся литературные данные о частоте встречаемости, этиологии, патогенезе, особенностях клинических проявлений наследственной геморрагической телеангиэктазии, современных методах диагностики и лечения. Во второй части продемонстрирован редкий случай развития повторных инфарктов головного мозга у молодого пациента с болезнью Рандю-Ослера-Вебера, причиной которых явилась парадоксальная эмболия из легочной артериовенозной мальформации, обнаруженной у пациента при проведении КТ-ангиографии сосудов легких. Представлены данные анамнеза жизни и заболевания пациента, описание объективного и неврологического статуса, результаты лабораторных и инструментальных методов обследований. Пациенту было рекомендована ангиопульмонография, в ходе которой легочная артериовенозная мальформация была успешно эмболизирована. данный случай указывает на необходимость тщательного обследования и наблюдения за пациентами с наследственной геморрагической телеангиэктазией. В целях раннего выявления сосудистых мальформаций у пациентов с болезнью Рандю-Ослера-Вебера и своевременного назначения терапии для предотвращения возможных серьёзных цереброваскулярных осложнений рекомендовано выполнение КТ-ангиографии легких

    Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

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    Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

    Структурные и физико-химические преобразования перикардиальных имплантатов, модифицированных эпоксидной смолой

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    Bovine pericardium samples modified with ethylene glycol diglycidyl ether, designed for surgical correction of congenital heart defects and large blood vessels, were studied by scanning electron microscopy, X-ray diffraction, IR spectroscopy, and differential thermal analysis. It was found that the initial samples of pericardium, before implantation, contain sites of disorganization of the collagen matrix, fragile fracture of collagen fibrils and destruction of the interstitial membranes promoting the penetration of immunocytes into the deep layers of the pericardium. Ossifying calcification with amorphized hydroxyapatite deposition and bone tissue formation as well as multiple erosions and hypertrophic proliferation in the endothelial membrane were detected in the implantation pericardium samples.Методами сканирующей электронной микроскопии, рентгенофазового анализа, ИК-спектроскопии, дифференциально-термического анализа изучены образцы бычьих перикардов, модифицированные диглицедиловым эфиром этиленгликоля, предназначенные для хирургической коррекции врожденных пороков сердца и крупных кровеносных сосудов. В исходных образцах перикардов до имплантации обнаружены дезорганизация коллагеновой матрицы, хрупкий перелом коллагеновых фибрилл и разрушение структуры интерстициальных мембран, способствующих проникновению иммуноцитов в глубокие слои перикарда. В имплантированных образцах перикардов выявлены оссифицирующий кальциноз с отложением аморфизированного гидроксиапатита и формированием костной ткани, а также множественные эрозии и гипертрофические разрастания в эндотелиальной мембране
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