30 research outputs found

    Electro-Conductive Composites Based on Metal Oxides and Carbon Nanostructures

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    Optimal conditions were found for the formation of carbon-oxide composites by the treatment of mixtures of oxides of aluminum or titanium with carbon nanotubes and nanofibers in a planetary ball mill. The dependences of the electrical conductivity of composites on the content of carbon nanomaterials (1-5% by mass) were determined. It is shown that the addition of 3%(wt) of CNT to the oxides leads to a sharp increase in the electrical conductivity: from 5.0Γ—10-8 to 2.8Γ—10-4 S/cm for Al2O3 and from 5.0Γ—10-6 to 2.2Γ—10-2 S/cm for TiO2. It was shown that the carbon-oxide composites are promising carriers of the catalysts of electrode processes in electrochemical devices. It was revealed that Pt/TiO2 - CNT catalyst containing 5% (mass) of carbon nanotubes has the best catalytic activity in oxygen reduction, in an electrode-modeling cathode of a fuel cell. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3512

    Noncomputability Arising In Dynamical Triangulation Model Of Four-Dimensional Quantum Gravity

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    Computations in Dynamical Triangulation Models of Four-Dimensional Quantum Gravity involve weighted averaging over sets of all distinct triangulations of compact four-dimensional manifolds. In order to be able to perform such computations one needs an algorithm which for any given NN and a given compact four-dimensional manifold MM constructs all possible triangulations of MM with ≀N\leq N simplices. Our first result is that such algorithm does not exist. Then we discuss recursion-theoretic limitations of any algorithm designed to perform approximate calculations of sums over all possible triangulations of a compact four-dimensional manifold.Comment: 8 Pages, LaTex, PUPT-132

    Morphology of Nanostructured Alumina and Lanthana Synthesized with the Use of Fibrous Organic Matrix

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    Fibrous aluminum oxide Ξ³-Al2O3 and lanthanum sesquioxide A-type La2O3 were synthesized by the thermal decomposition (700 Β°C, air) of cotton fibers impregnated by aqueous solutions of corresponding nitratesalts. The fibers of alumina consist of 20 nm sized particles, while the particle size of the lanthana ranges within 100–150 nm. The formation of chemisorption products on the lanthana surface is alsodiscussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3504

    Robust Weighted Likelihood Estimation of Exponential Parameters

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    System of key performance indicators as a method for executive decision-making

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    Key performance indicators, KPI are a proven cutting-edge tool for process productivity and staff performance monitoring. Therefore, today it is possible to find the use of this tool in the most varied spheres and industries. However, the system implementation is a long and painstaking process, which requires financial, labor and time expenditures. But in case of its successful implementation, KPI technology will provide the balance of advantage for the company management and contribute to its growth. The article presents the selection mechanism of KPI system development and implementation methods. Using key performance indicators, the organization is able to manage the process and modify it, as well as define objectives for employees and motivate them to achieve their objectives. KPIs are based on measuring quantitative benefits. Control shall be based on comprehensive and reliable information about the company’s process productivity. This is the only way to take quick management decisions, make adjustments to the operation of processes that will contribute to the achievement of strategic objectives as a whole

    The medical social problems and methods of diagnostic of cognitive disorders in patients taking "Spice"

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    The article presents the results of pilot study implemented to determine cognitive disorders in patients taking "Spice". The purpose of research is to identify targets of psychological correction interventions to prevent cognitive deficiency in patients addicted to synthetic cannabinoids. The pilot sampling consisted of 30 patients taking "Spice". The control group consisted of 30 healthy individuals. Along with social consequences, one of the important focuses of the study was investigation of cognitive sphere of patients. A number of pathopsychologic tests was applied. The study established that patients demonstrated disorders of various functions of memory, attention, mental pace and thinking. In particular, disorders of short-term, long-term and mediate memory and mental tempo were revealed. Also, reduced activity of attention took place. The distortion and decreasing of generalization and poor prehension occurred reliably more often as compared with control group. The established cognitive disorders in patients taking "Spice" can be considered as targets for psychological correction interventions to prevent cognitive deficiency in patients addicted to synthetic cannabinoids
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