288 research outputs found

    Investigation of diamond biocompatible coatings for medical implants

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    Despite the advantages of diamond-like carbon fi lms that are used as wear-resistant coatings for implants, they may have a number of disadvantages such as the high level of internal tension, low adhesive durability and high sensitivity to environment conditions. These problems can be overcome by application of the new carbon nanocomposite coatings that can be deposited from C60 ionic beam. It was found that the proposed diamond-like nanocomposite coatings increase implant material resistance to electrochemical corrosion processes due to shift of its electrode potential to area of positive values, and also promote a complex of reparative and adaptation and compensatory reorganizations that will allow to accelerate processes of healing and postoperative adaptation of organism in zone of implant inputting.Незважаючи на переваги діамантоподібних вуглецевих покриттів, що використовуються в якості зносостійких захисних покриттів для імплантатів, вони можуть мати ряд недоліків, таких як високий рівень внутрішніх напружень, низька адгезійна міцність, висока чутливість до умов навколишнього середовища. Ці проблеми можуть бути подолані в разі застосування нових вуглецевих нанокомпозитних покриттів, нанесених з іонного пучка С60. Встановлено, що запропоновані діамантоподібні нанокомпозитні покриття підвищують опірність матеріалу імплантату до електрохімічних корозійних процесів за рахунок зміщення його електродного потенціалу в область позитивних значень, а також сприяють комплексу репаративних і адаптаційно-компенсаторних перебудов, що дозволить прискорити процеси загоєння та післяопераційної адаптації організму в зоні введення імплантату

    Features of medical implant passivation using anodic oxide films

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    The passivation ability of metals from groups IV and V of the Periodic Table is considered. Anodic treatment is able to neutralize the increase of metal hardening when comminuting grains to nanometre sizes. The deposition of metal oxide film coatings on a cobalt–chromium alloy surface results in substantial passivation of its surface and prevents cobalt and chromium accumulation in bone tissues. The decrease of surface activity of titanium implants can be achieved both by cleaning the surface during vacuum annealing before oxidation and by the increase of the anodic oxide film thickness, which limits mass and charge transfer through the implant surface. Recommended titanium implant treatment regimens are vacuum annealing at 650 °C and anodic oxidation to attain an oxide thickness less or equal to 300 nm

    Diamond biocompatible coatings for medical implants

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    New carbon (diamond-like) nanocomposite coatings deposited from a C60 ionic beam can be used as a wear-resistant protective coating for implants. It was found that these coatings enhance resistance to тelectrochemical corrosion processes due to a shift of the material’s electrode potential to a zone of positive values. They also promote a complex of reparative, adaptative and compensatory reorganization that accelerates the healing processes in the vicinity of the implant

    Stimulation of calcium phosphate crystal formation by implant surfaces with electret properties

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    Oxide coatings with electret properties are investigated. The possibility of stimulation of the formation of calcium phosphate sediments near the electroactive surface is discussed. The exposure of implants with such coatings to solutions imitating blood plasma showed their high efficiency of biointegration due to activation of an exchange processes in living tissues by a negative superficial charge. The revealed effect amplifies with the growth of the thickness of the anodic oxide film

    Properties of magnetron hydroxyapatite coatings deposited on oxidized substrates

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    Hydroxyapatite (HA) coating were formed on oxidized niobium surfaces by the highfrequency magnetron sputtering method using hydroxyapatite and tricalcium phosphate targets. The structure, substructure and mechanical properties of the Nb–Nb2O5–HA system were investigated by X-ray diffraction, atomic force microscopy and nanoindentation and the stress state was assessed. The synthesized hydroxyapatite film had the following characteristics: thermal expansion coefficient 10–5 K–1; modulus of elasticity 120 GPa; adhesive strength not less than 0.45 kg/mm2; density 2900 kg/m3. The stress magnitude in the metal oxide substrate was from 11 to 14 MPa after hydroxyapatite film deposition

    The conceptual model of sustainable development of the rubal sector

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    On the one hand, the relevance of the studied issue is determined by growing lag of rural territorial units in socioeconomic development, and one the other by their significance in such important aspects of the country, as ensuring food supply security, preservation of the available land, production, ecological, demographic and human potential. The aim of the article is to develop the conceptual model of sustainable development of rural areas, which is based on the system of indicators of quality of living of rural population. The leading method for studying this issue is modeling, which allows to consider it as a targeted and organized process of formation of the concept of sustainable development of the rural sector of the regional economy using the example of the studies of experience of sustainable development of the Kinel-Cherkassky municipal district of the Samara region. The results: the analysis of consistence and tendencies of development of agrarian potential of rural areas of the Samara region was carried out for the purpose of implementation of the conceptual model of sustainable development and assessment of further prospects in the production sphere of the village; the main reasons for disproportion in sustainable development of rural areas of the Samara region are identified. The materials of this article can be used for theoretical conclusions, methodological developments and working knowledge in activities of bodies of the regional government and local self-government when developing the concept and programs of sustainable development of rural municipalities. © 2016 Belyaeva et al

    Zeldovich flow on cosmic vacuum background: new exact nonlinear analytical solution

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    A new exact nonlinear Newtonian solution for a plane matter flow superimposed on the isotropic Hubble expansion is reported. The dynamical effect of cosmic vacuum is taken into account. The solution describes the evolution of nonlinear perturbations via gravitational instability of matter and the termination of the perturbation growth by anti-gravity of vacuum at the epoch of transition from matter domination to vacuum domination. On this basis, an `approximate' 3D solution is suggested as an analog of the Zeldovich ansatz.Comment: 9 pages, 1 figure

    Letters from the Front and Memoires in a Museum Exhibition as the Means of Commemoration and Formation of Historical Memory

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    The article researches the process of historical memory formation and the role of museum spaces in it. The authors consider the use of letters from the front as the means of commemoration. The issues of commemoration and re-commemoration, museum reflection and its influence on historical memory are studied. Special attention is paid to museumification of front letters and memoires of war workers. The authors consider the new possibilities of using them in museum displays using multimedia technologies, emphasizing the higher accessibility of the letters’ content in multimedia. The research novelty consists in the cross-disciplinary view of a historical source through the prism of museum space. The authors show the properties and possibilities of narrative sources which are now available due to modern technologies. The unpublished ego-documents (private letters and memoires) from museum funds were studied and described. The research topicality is due to identification of the influence of written museum exhibits on the formation and socialization of historical memory. It is proved that the personal materials in a museum display using modern technical opportunities enhance the informative effect, stimulating commemoration and facilitating the formation of historical memory. The article employs the experience of fund, exhibition and excursion work of the Museum of the history of Gorky railroad development

    Official and Real Biographies in Context of Soviet Tradition of Non-Material Incentives for Labor during Great Patriotic War

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    The question of the use of the official labor biography in the 30—40s of the twentieth century as a means of instilling a sacred attitude to work in a Soviet person, a method of non-material stimulation of the production process is considered. The relevance of the study is due to the interest in biography in the context of the history of labor, in the authors’ appeal to the problem of forming a new attitude to work during the period of industrialization and the years of the Great Patriotic War. Attention is paid to the role of periodicals. The results of a comparative analysis of the official and real biography, recovered from the materials of the personal file, are presented. The question is raised about the tasks of the official biography of the Hero of Socialist Labor in this period. The novelty of the research is seen in the attraction of unpublished data from the production archive of the Gorky Railway, in the reconstruction of real biographical data. The authors compare the official and real biographies. The possibility of using heroic biography as a method of non-material stimulation of labor has been proved. The author’s reconstruction of the biography of Ivan Georgievich Makarov — Hero of Socialist Labor is presented. The experience of analytical research of documentary historical sources and their comparison with the narrative tradition is described
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