1,624 research outputs found

    Fuzzy simulation of forest road surface parameters

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    The problem of construction of forest roads with the use of local low-strength substandard materials and industrial waste is considered. To solve the problem, the primary task is to develop a method for estimating the parameters of road surfaces taking into account the conditions of uncertainties in the data. This technique allows us to reasonably clarify some of the regulatory parameters and improve the technology of construction of forest roads, which was the goal of the work. To formalize the task, experimental studies were performed and on the basis of these results, the statement of the task of fuzzy derivation of the function for estimating the bearing capacity of the coating was performed. The synthesis of the output function is performed by means of Matlab. © 2019 IOP Publishing Ltd. All rights reserved

    Planning the forest transport systems based on the principles of sustainable development of territories

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    The article identifies a new method of dynamic modeling in the design of the transport system in the forest fund (TSFF), which is based on economic and mathematical modeling and fuzzy logic tools. The combination of the indicated methods is designed to reduce the disadvantages of their use and increase the benefits. The article substantiates the choice of assessing the forecast level of the impact of risks on the activities of forestry enterprises (the method of expert assessments), using the methodological tools of fuzzy logic. The indicated method makes it possible to take into account a large variety of risk factors of the internal and external environment. At the same time, methodological aspects of fuzzy logic make it possible to formulate a quantitative assessment of qualitative indicators. The article substantiates the choice of tools for economic and mathematical modeling in order to state the design problem of the planned TSFF. Since the indicated method enables the formalization of the functioning of the timber transport system in the given conditions. The article presents a developed model that correctly takes into account the influence of risk factors when planning a TSFF, through the combination of fuzzy logic methods and economic and mathematical modeling. The advantages of the developed model include: considering the multivariance of material flows, vehicles, points of overload, etc.; automated processing of input parameters and effective data; using the model for forecasting, i.e. the possibility of deriving a fuzzy estimate of the efficiency of the timber transport system by identifying cause-effect relationships between the modeling object and the influence of risk factors on its functioning. © 2019 IOP Publishing Ltd

    Cyclotrimerization of 3-R-1,2,4-triazin-5(4H)-ones with cyclic ketones

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    New heterocyclic tetracyclic systems were synthesized. Interaction between 3-R-1,2,4-triazin-5(4H)-ones and cyclic ketones under acidic conditions leads to the formation of zwitterion derivatives of 5,6,7,8,9,10,11,12-octahydro-[1,2,4] triazino[1,6- f ]phenanthridine and 1,2,3,6,7,8-hexahydro-bicyclopenta[b,d] pyrido[1,2- f ][1,2,4]triazine. © 2010 Verlag der Zeitschrift für Naturforschung, Tübingen

    Determining the Young's modulus of a cellular titanium implant by FEM simulation

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    The role of additive manufacturing is noted for the construction of titanium medical implants. The purpose of the study is to determine the Young's modulus of cellular titanium implants, which is based on calculations performed by finite element analysis. A honeycomb structure from intersecting cylinder surfaces is offered for the implant made of the Ti-6Al-4V alloy. Boundary conditions are stated for the loading of the implant structure. It is demonstrated that the Young's modulus can be reduced more than three times comparing to a solid titanium alloy. Zones of strain and stress localization located near the abutment of the cylindrical surfaces. Recommendations for the further improvement of the implant architecture are generated. © 2017 Author(s).Ministry of Education and Science of the Russian Federation, Minobrnauka: 218We hereby acknowledge the support of the Ministry of Science and Education of the Russian Federation, in accordance with the decree of the Government of April 9, 2010, No. 218, project number 03.G25.31.0234

    Mechanical Activation of Ti-2B System: XRD Investigation of Structural Features

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    XRD investigation of Ti-2B system was carried out with the purpose of determining of structural changes in this system during mechanical activation. The size of coherentscattering region (CSR size) and kind II stresses (microstresses) were calculated by diffraction peaks profile analysis. It was determined that initiation of the synthesis reaction directly in mill is taking place at achievement the value of microstresses for titanium approximately equal to its yield point. Spontaneous reaction in a mill indicates that mechanical activation gives essential structural changes in Ti-2B system. So mechanical activation has essential influence on structural condition of Ti-2B system. Titanium diboride synthesized by high-temperature combustion and by mechanosynthesis have approximately equal crystallites size. These results could clarify the processes of materials structural condition after mechanical activation and have a matter for materials science
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