5 research outputs found

    Parallel chemistry acceleration algorithm with ISAT table-size control in the application of gaseous detonation

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    In order to improve the computational efficiency of a parallel ISAT (in situ adaptive tabulation)-based chemistry acceleration algorithm in the computations of transient, chemically reacting flows, a control strategy is proposed to maintain the sizes of the data tables in the ISAT computations. The table-size control strategy is then combined with a parallel algorithm to simulate two-dimensional gaseous detonation wave propagation. In the computation of 2H2 + O2 detonation, two sets of tests are conducted to identify the size control strategy. In the first set, the maximum total table size (Mtot) summed over all sub-zones is fixed, while the maximum size of the table on each sub-zone (Msin) is varied. In the second set, a fixed Msin is used for all the tables on the sub-zones while Mtot is varied. A maximum speedup ratio of 4.29 is found in the former tests, while 5.52 is found in the latter. Two parameters, σf and p, are proposed to analyze the load balance and synchronization among table operations in the parallel ISAT computations in the above tests. It is found that both load balance and synchronization have clear influences on the speedup ratio. A parameter pM is defined, and a strategy to choose the optimal maximum table sizes (both Mtot and Msin) based on pM is proposed and is verified to be universal in the computations of both 2H2 + O2 detonation and C2H4 + 3O2 detonation. Finally, the parallel acceleration algorithm enhanced with table-size control is shown to be highly accurate for the detonations in both fuels

    Histology of uterus of Dubska pramenka during sexual season

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    Bosnia and Herzegovina has always had a developed sheep production, at least from the aspect of the number of sheep per capita. Today, the ratio is 1 sheep per 4 persons, because the cattle production, globally looking, is decimated by war. Thanks to the geographic location of the country, the quality of mountain pastures and environment that is still healthy, we believe that with increased investments in sheep production we could increase the number of heads, which would have positive effects on production of meat and milk of exceptional quality. The study involving the uterus of Dubska pramenka during sexual season under nomadic conditions of holding, demonstrated that, in adequate zoo hygiene conditions (holding, feeding, treatment of animal), the sheep showed increased reproductive parameters as well as parameters manifested in meat and milk production. In our studies, microstructure of uterus of Dubska pramenka during sexual season shows extremely positive characteristics for nidation of the egg cell and normal development of the embryo. Epithelium of the uterus is in a form of high-prismatic cells, which points to significant cell activity; perfusion and development of myometrium are visible. The uterine glands are extremely well developed and their histological structure indicates increased secretion and preparation of the uterus for gravidity
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