1,166 research outputs found

    Processing of basalt fiber production waste

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    The production of mineral rock wool forms a large proportion of off-test waste products. In addition to the cost of their production, there are costs for processing and utilization, such as transportation, disposal and preservation. Besides, wastes have harmful effect on the environment. This necessitates research aimed to study the stress-related characteristics of materials, their recyclability and use in the production of heat-saving product

    Feynman Diagrams and Differential Equations

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    We review in a pedagogical way the method of differential equations for the evaluation of D-dimensionally regulated Feynman integrals. After dealing with the general features of the technique, we discuss its application in the context of one- and two-loop corrections to the photon propagator in QED, by computing the Vacuum Polarization tensor exactly in D. Finally, we treat two cases of less trivial differential equations, respectively associated to a two-loop three-point, and a four-loop two-point integral. These two examples are the playgrounds for showing more technical aspects about: Laurent expansion of the differential equations in D (around D=4); the choice of the boundary conditions; and the link among differential and difference equations for Feynman integrals.Comment: invited review article from Int. J. Mod. Phys.

    Studying the ω\omega properties in pA collisions via the ωπ0γ\omega{\to}\pi^0\gamma decay

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    Within transport calculations we study the production and decay of ω\omega-mesons in pApA reactions at COSY energies including elastic and inelastic ωN{\omega}N rescattering, the ωπ0γ\omega{\to}\pi^0\gamma Dalitz decay as well as π0N\pi^0 N rescattering. The resulting invariant π0γ\pi^0 \gamma mass distributions indicate that in-medium modifications of the ω\omega-meson may be observed experimentally.Comment: 5 pages, espcrc2-style, including 5 ps-figure

    The investigation of dangerous geological processes resulting in land subsidence while designing the main gas pipeline in South Yakutia

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    The number of gas main accidents has increased recently due to dangerous geological processes in underdeveloped areas located in difficult geological conditions. The paper analyses land subsidence caused by karst and thermokarst processes in the right of way, reveals the assessment criteria for geological hazards and creates zoning schemes considering the levels of karst and thermorkarst hazards

    Strength characteristics of sealer devices at design stage

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    The paper deals with strength characteristics of several sealer devices used to seal the inner cavity of an oil pipeline during the replacement of a pipeline section. Construction calculations revealed the stresses related to the pressurized rubber-cord sealing element rupture resulted from an emergency situation. It was concluded that it is necessary to test the operating parameters before applying the sealers. Estimation of the safety factor of existing sealer devices designs was conducted and recommendations for its increase were proposed

    The ion-driven permeation experiment PERMEX

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