1,014 research outputs found

    Riemann-Hilbert problem, integrability and reductions

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    The present paper is dedicated to integrable models with Mikhailov reduction groups GRDh.G_R \simeq \mathbb{D}_h. Their Lax representation allows us to prove, that their solution is equivalent to solving Riemann-Hilbert problems, whose contours depend on the realization of the GRG_R-action on the spectral parameter. Two new examples of Nonlinear Evolution Equations (NLEE) with Dh\mathbb{D}_h symmetries are presented.Comment: 19 pages, 3 figures, Dedicated to Darryl Holm's 70th birthda

    Research of Wheat Drying in a Microwave and Combined Filter-microwave Dryer

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    The aim of the conducted study is to determine kinetics of the complex effect of microwave energy supply and filter drying of the process of water release from the wheat layer. There is offered a combination of MW and filter drying. A special feature of this combination must be its more effectiveness and high speed of water elimination from surface layers of wet seeds and, as a result, the productivity increase of the drying way, decrease of specific energy consumption.There was determined the influence of the specific load of the material, radiator power on processes of microwave and filter-microwave drying of wheat seeds. There were compared microwave, filter-microwave and convective drying of seeds by parameters of specific energy consumption, drying speed.The specific energy consumption at microwave drying of seeds was 4 MJ/kg, at filter-microwave drying 3.8 MJ/kg that is lower than existent convective dryers. The speed of microwave drying changes from 0,5 to 3 %/min, filter-microwave – from 0.3 to 0.7 %/min. The speed is at the level of standard convective dryers.The conducted studies allow to recommend a new combined way of FMW drying of seeds with low energy consumption.Revealed features of heating and drying are possible to be used at developing industrial dryers.The base of experimental data is possible to be used for optimizing and determining effective conditions of MW and FMW drying

    State policy towards indigenous peoples of Alaska: historical review and contemporary issues

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    The article analyzes main stages of policy development towards indigenous peoples of Alaska and its influence on aboriginal cultures from the beginning of Russian colonization in the 18th century up to present time. The authors conclude that current policy towards indigenous peoples in Alaska can be generally evaluated as successful and supporting development of traditional cultures. The main achievements of this policy are: high level of self-organization and self-government of Alaska natives, legally secured rights for land and resources, progress in conservation of cultural heritage. However, social and economic challenges faced by indigenous people present a potential threat to the political stability in Alaska

    rac-12,14-Dicyclo­propyl-5,8,13,18,21-penta­oxapenta­cyclo­[13.8.0.02,11.04,9.017,22]tricosa-1(15),2(11),3,9(10),16,22(23)-hexa­ene

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    The mol­ecule of the title compound, C24H24O5, has crystallographic twofold symmetry, with the central O atom lying on the rotation axis. The dihedral angle between the best planes of the benzene rings fused to the oxepine fragment is 38.5 (1)°. The dioxine ring adopts a twist form with the ethyl­ene group C atoms deviating by 0.472 (5) and −0.248 (6) Å from the plane defined by the remaining ring atoms
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