708 research outputs found

    Household energy and recycling of nutrients and carbon to the soil in integrated crop-livestock farming systems : a case study in Kumbursa village, Central Highlands of Ethiopia

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    Acknowledgements We are grateful to the farmers of Kumbursa village for their wholehearted cooperation in providing genuine responses to interview questions during the household survey. We are also thankful to the Development Agent of Kumbursa village, Mr Dinku Chala, for facilitating our relations with farmers of the study area and for participating in data collection. We are indebted to Addis Ababa University and AUC funded Afri-Flame project (Adaptation of small-scale biogas digesters for use in rural households in Sub-Saharan Africa) for their joint financial support. Our heartfelt gratitude also goes to the staff of Debre Zeit Agricultural Research Center for their cooperation in nutrient content analysis of crop residues and dung cakes. Finally, we owe our heartfelt indebtedness to the two anonymous reviewers for their constructive comments which greatly contributed to the improvement and final refinement of this paperPeer reviewedPublisher PD

    Engine Use In Hybrid Rocket - A Review

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    Despite all the other rocket motors on the market such as solid and liquid. A historically failed motor was in the market which was handicapped in performance but now with technological development in the previous years, hybrid rocket motor is the most influential talk in the market. Deeper in the paper we will discuss the hybrid motor focusing on the fuel used in Hybrid rocket engines and the performance depending on the design. Furthermore, this review paper will help us to study the different materials for the betterment of the engine performance. We will also be focusing on the methods required to improve total impulse. Moreover, will be elaborating on the performance of paraffin wax and its material property

    Verification of a localization criterion for several disordered media

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    We analytically compute a localization criterion in double scattering approximation for a set of dielectric spheres or perfectly conducting disks uniformly distributed in a spatial volume which can be either spherical or layered. For every disordered medium, we numerically investigate a localization criterion, and examine the influence of the system parameters on the wavelength localization domains.Comment: 30 pages, LateX, amstex, revtex styles, 20 figure

    New Approximability Results for the Robust k-Median Problem

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    We consider a robust variant of the classical kk-median problem, introduced by Anthony et al. \cite{AnthonyGGN10}. In the \emph{Robust kk-Median problem}, we are given an nn-vertex metric space (V,d)(V,d) and mm client sets {SiV}i=1m\set{S_i \subseteq V}_{i=1}^m. The objective is to open a set FVF \subseteq V of kk facilities such that the worst case connection cost over all client sets is minimized; in other words, minimize maxivSid(F,v)\max_{i} \sum_{v \in S_i} d(F,v). Anthony et al.\ showed an O(logm)O(\log m) approximation algorithm for any metric and APX-hardness even in the case of uniform metric. In this paper, we show that their algorithm is nearly tight by providing Ω(logm/loglogm)\Omega(\log m/ \log \log m) approximation hardness, unless NPδ>0DTIME(2nδ){\sf NP} \subseteq \bigcap_{\delta >0} {\sf DTIME}(2^{n^{\delta}}). This hardness result holds even for uniform and line metrics. To our knowledge, this is one of the rare cases in which a problem on a line metric is hard to approximate to within logarithmic factor. We complement the hardness result by an experimental evaluation of different heuristics that shows that very simple heuristics achieve good approximations for realistic classes of instances.Comment: 19 page

    AN UPDATED REVIEW ON THE APPLICATION OF DENDRIMERS AS SUCCESSFUL NANOCARRIERS FOR BRAIN DELIVERY OF THERAPEUTIC MOIETIES

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    It’s been nearly 100 y of effort to study the organization and role of the blood brain-barrier and still, we strive to find better techniques to overcome this barrier to deliver the drugs to the brain effectively with reduced systemic side effects. The advances in nanotechnology have given newer horizons in achieving this goal since the nano-scaled systems can modify an existing drug to have a high degree of sensitivity to the physiological conditions and specificity to reach the target organ. Among the various nanocarriers, dendrimers owing to their unique physical and chemical characteristics, represent a potential therapeutic tool in biomedical and pharmaceutical science. Dendrimers, an established polymeric nanocarrier system of the time, can deliver both drugs and genetic material and are being extensively studied to target the brain. The surface modification of dendrimers can reduce their innate toxicity problems and increase the therapeutic efficacy of brain disorders. This review article is an attempt to update on the potential of dendrimers explored in the past five years as a drug delivery avenue that can be considered as a promising solution in the management of a wide range of disorders affecting the central nervous system, including neoplastic, degenerative, and ischemic conditions. The following search criteria were used to expand the review article with the keywords dendrimers, novel drug delivery, nanoparticles, site-specific drug delivery etc

    SUPPORTIVE THERAPY: AN OPTION TO ENHANCE HOST IMMUNITY AGAINST COVID-19

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    The threat posed by COVID 19 outbreak, which is considered to be a global pandemic, is immeasurably affecting all the communities worldwide. COVID-19 is a zoonotic disease, which can affect birds, humans and, other animals. The emergence of this pandemic has been creating a tragic situation worldwide by affecting more people through human-human transmission. The burden (both healthwise and economic) placed by the disease is so huge that any measures to improve the current situation, to fasten up the recovery of already affected patients and, to reduce the risk of death and health deterioration should be considered. Vaccination, being the hope in the scenario, helps in preventing the condition to an extent, but in the absence of availability of a proper drug regimen to fight off COVID 19, the requirement of the need to find a system to control the severity of the infection is a necessity Nutritional supplementation helps in boosting up the immune system especially, vitamins like vitamin C, Vitamin D, Zinc, Omega 3 fatty acids, etc. They also exhibit established immunomodulatory, antiviral as well as anti-inflammatory effects. Pieces of evidence have also highlighted the importance of supportive therapy using nutrient supplements in covid patients as it helps in prominent decreasing of SARS CoV2 load of the virus and also significantly reduces the hospitalization period. Hence the nutritional levels of each of the infected person must be assessed before initiating the anti-viral therapy. The search criteria used were PubMed, Medscape, google scholar, etc. The keywords used to search were COVID 19 Supportive therapy, Vitamin D, Vitamin C, Nutrient supplementation, Host immunity, etc. The range of years is between 1978 and 2021
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