48,563 research outputs found

    Singularity Free Inhomogeneous Models with Heat Flow

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    We present a class of singularity free exact cosmological solutions of Einstein's equations describing a perfect fluid with heat flow. It is obtained as generalization of the Senovilla class [1] corresponding to incoherent radiation field. The spacetime is cylindrically symmetric and globally regular.Comment: 6 pages, TeX, to appear in Class.Quant.Gra

    Community Engagement, Report 2: The Findings

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    Solar Cell Parameters Extraction from a Current- Voltage Characteristic Using Genetic Algorithm

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    The determination of solar cell parameters is very important for the evaluation of the cell performance as well as to extract maximum possible output power from the cell. In this paper, we propose a computational based binary-coded genetic algorithm (GA) to extract the parameters (I0, Iph and n) for a single diode model of solar cell from its current-voltage (I-V) characteristic. The algorithm was implemented using LabVIEW as a programming tool and validated by applying it to the I-V curve synthesized from the literature using reported values. The values of parameters obtained by GA are in good agreement with those of the reported values for silicon and plastic solar cells. change to “After the validation of the program, it was used to extract parameters for an experimental I-V characteristic of 4 × 4 cm2 polycrystalline silicon solar cell measured under 900 W/m. The I-V characteristic obtained using GA shows excellent match with the experimental one. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100

    Study of Parasite Hosts of the Genus Cuscuta and its Traditional Uses in Planpur Taluka, Gujarat, India

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    Cuscuta is a parasitic plant belonging to family Cuscutaceae. The present paper is an investigation of its various host plant species and its traditional uses in Palanpur Taluka of North Gujarat during 2005-2008. Two species of Cuscuta occur in the Palanpur Taluka. The preservation and documentation of traditional knowledge is a matter of prime importance. This will not only provide recognition of this knowledge but will also help in conservation of such gradually vanishing endangered semi/arid plant species. The present paper provide ethnomedicinal information of 2 species of Cuscuta. For each plant species listed, the botanical name, family, vernacular name, part used, uses/ailments treated, preparations/administrations, use (%) and locality are given

    Profitability of organic and conventional dairy production with different dietary proportions of high-quality grass silage

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    Profitability in milk production was calculated using diets with three different proportions of high-quality grass silage. The treatments consisted of the same feeds, but differed in the dietary proportion of forage: low (L), medium (M) and high (H), representing one conventional and two organic diets. The calculations were based on results in feed intake and milk production from a large dairy cow experiment. In the calculations, three different districts with different conditions for farming were used as models, and calculations were performed on two different herd sizes. In addition, current financial supports were both included and excluded in the calculations. The results showed only minor differences in profitability between using in average 60% or 70% of dry matter (DM) of silage in diets used in organic production. In conventional production, it was profitable to increase the average dietary proportion of silage from 50% to 60% of DM when the prices of concentrate and grains were as high as at the present. The results showed clear economic benefits of increasing the proportion of high-quality silage in conventional Scandinavian dairy cow diets up to levels similar to the standards of the organic production system
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