144 research outputs found

    Condition Monitoring Techniques of Power Transformers: A Review

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    Power transformers provide a vital link between the generation and distribution of produced energy. Such static equipment is subjected to abuse during operation in generation and distribution stations and leads to catastrophic failures. This paper reviewed the techniques in the field of condition monitoring of power transformers in recent years. Transformer monitoring and diagnosis are the effective techniques for preventing the eventual failures and contributing to ensure the plan’s reliability. This paper provided a survey on the existing techniques for monitoring, diagnosis, condition evaluation, maintenance, life assessment and possibility of extending the life of the existing assets of power transformers with be appropriate classifications. Thus, this survey could help researchers through providing better techniques for condition monitoring of power transformers

    Influence of different levels of n-3 supplemented (fish oil) diet on performance, carcass quality and fat status in broilers

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    An experiment was conducted to evaluate fish oil as n-3 fatty acids source on some performance, carcass and serum parameters in broilers. One-day old Ross strain male broiler chickens (n = 120) were randomly arranged in four dietary treatments (0, 1.5, 3 and 4.5 percent fish oil), with three replicates for each treatment. Mean live weight and feed intake at the end of starting, growing and finishing periods in fourth treatment was lower than other treatments. All treatments containing fish oil significantlydecreased feed conversion ratio compared to control treatment. There were no significant differences on percent of carcass to live weight and abdominal fat percentage to carcass weight in T2, T3 and T4, but there were significant differences between control diet and the others. Serum triglycerides, cholesterol, LDL-c and VLDL-c concentrations were significantly reduced by fish oil treatments than the control diet, but serum HDL-c concentrations were significantly increased by using of diets containingfish oil. The results of this experiment indicated that dietary  supplementation of fish oil improved feed conversion ratio, carcass quality and HDL-c concentration in serum, but it decreased serum triglycerides, cholesterol, LDL-c and VLDL-c concentrations in serum of broiler chickens

    A structurally distinct TGF-β mimic from an intestinal helminth parasite potently induces regulatory T cells.

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    Helminth parasites defy immune exclusion through sophisticated evasion mechanisms, including activation of host immunosuppressive regulatory T (Treg) cells. The mouse parasite Heligmosomoides polygyrus can expand the host Treg population by secreting products that activate TGF-β signalling, but the identity of the active molecule is unknown. Here we identify an H. polygyrus TGF-β mimic (Hp-TGM) that replicates the biological and functional properties of TGF-β, including binding to mammalian TGF-β receptors and inducing mouse and human Foxp3+ Treg cells. Hp-TGM has no homology with mammalian TGF-β or other members of the TGF-β family, but is a member of the complement control protein superfamily. Thus, our data indicate that through convergent evolution, the parasite has acquired a protein with cytokine-like function that is able to exploit an endogenous pathway of immunoregulation in the host

    QDB: A new database of plasma chemistries and reactions

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    One of the most challenging and recurring problems when modeling plasmas is the lack of data on the key atomic and molecular reactions that drive plasma processes. Even when there are data for some reactions, complete and validated datasets of chemistries are rarely available. This hinders research on plasma processes and curbs development of industrial applications. The QDB project aims to address this problem by providing a platform for provision, exchange, and validation of chemistry datasets. A new data model developed for QDB is presented. QDB collates published data on both electron scattering and heavy-particle reactions. These data are formed into reaction sets, which are then validated against experimental data where possible. This process produces both complete chemistry sets and identifies key reactions that are currently unreported in the literature. Gaps in the datasets can be filled using established theoretical methods. Initial validated chemistry sets for SF 6 /CF 4 /O 2 and SF 6 /CF 4 /N 2 /H 2 are presented as examples

    A Searching Based Method for Locating High Impedance Arcing Fault in Distribution Networks

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