542 research outputs found

    Impact of injecting inert cushion gas into a gas storage reservoir

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    Underground natural gas storage is a process which ensures constant supply of natural gas by storing the excess gas produced and quickly supply when required. The underground storage makes use of depleted reservoirs to store the natural gas. Cushion gas assists in delivering the natural gas (working gas) and maintains the adequate pressure in the reservoir. The key issue is that cushion gas cannot be produced and remains as a permanent inventory which accounts to about 30% of development cost in a typical storage reservoir. A part of cushion gas may be replaced with an inert gas such as nitrogen or carbon dioxide to reduce the investment cost.;The impact of replacing the cushion gas by nitrogen was studied by simulating nitrogen injection into a storage reservoir. The technical difficulty in replacing the cushion by nitrogen is the mixing which would corrupt the quality of natural gas. Some mixing is unavoidable when two dissimilar gases come in contact, but could be controlled with close monitoring and strategic planning. The reservoir parameters such as porosity, permeability and pressure were varied to study the mixing trends. Storage reservoirs are usually considered to serve for long time periods and therefore multiple withdrawal and injection cycles were simulated to study the mixing trend in detail. Different scenarios were considered in simulation by altering well placement, reservoir shape, injection of nitrogen in stages, and distance between the injector and producer wells.;It has been found that the optimum percentage of cushion that can be replaced by nitrogen gas is 20. The degree of mixing is function of withdrawal rate and the fraction of cushion gas replaced in the storage reservoir. Reservoir pressure and permeability may affect the degree of mixing in early cycles but do not have significant impact on mixing. Reservoir porosity appears to have minor impact on the mixing. The mixing effect decreases to a great extent if distance between the producer well and the nitrogen injector is increased

    Machine Tool Crack Detection using Operational Modal Characteristics

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    Machine tool crack detection is to detect any damages in the tool during machining and to predict the breakage of the tool by identifying the appearance of small cracks in the tool during machining. Machine tool state monitoring is critical for controlling the work piece quality and production continuity in the case of mass production. For assessing tool breakage, machine tool vibration monitoring is a suitable means. The results obtained in FE analysis are validated with experimental data. This work gives a methodology for online crack detection in machine tools. This work presents an experimental technique for measuring modal parameters of a rectangular aluminium plate with cantilever boundary condition using only the output data, with the intention to apply the technique to machine tools. Operational modal analysis is be used for damage detection by determining the depth as well as the position of tool cracks. The results obtained are validated with finite element analysis. To locate the crack, 3D graphs of the normalized frequency in terms of the crack depth and location are plotted. The intersection of these contours gives crack location and crack depth. Out of several case studies conducted the results of one of the case study is presented to demonstrate the applicability and efficiency of the method suggested

    Growth and Characterization of Nickel Catalyzed Gallium Oxide Nanowires on Sapphire Substrate

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    Beta gallium oxide (-Ga2O3) nanowires (NWs) were synthesized via chemical vapor deposition in argon atmosphere using gallium as a precursor and sapphire substrate coated with ultra thin film of nickel (Ni). In this report, we report the growth of -Ga2O3 NWs as a function of deposition time. The structure and morphology of grown NWs were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). The results revealed that single crystal growth of the NWs and their crystallinity improved with the increase in the deposition time. The diameter of -Ga2O3 NWs varied in the range between 40-80 nm and their length was observed up to many micrometers. The optical property of NWs was determined using UV-visible spectrophotometer and the bandgap of -Ga2O3 NWs was found to be about 4.30 eV. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3099

    Ferulic Acid: Therapeutic Potential Through Its Antioxidant Property

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    There has been considerable public and scientific interest in the use of phytochemicals derived from dietary components to combat human diseases. They are naturally occurring substances found in plants. Ferulic acid (FA) is a phytochemical commonly found in fruits and vegetables such as tomatoes, sweet corn and rice bran. It arises from metabolism of phenylalanine and tyrosine by Shikimate pathway in plants. It exhibits a wide range of therapeutic effects against various diseases like cancer, diabetes, cardiovascular and neurodegenerative. A wide spectrum of beneficial activity for human health has been advocated for this phenolic compound, at least in part, because of its strong antioxidant activity. FA, a phenolic compound is a strong membrane antioxidant and known to positively affect human health. FA is an effective scavenger of free radicals and it has been approved in certain countries as food additive to prevent lipid peroxidation. It effectively scavenges superoxide anion radical and inhibits the lipid peroxidation. It possesses antioxidant property by virtue of its phenolic hydroxyl group in its structure. The hydroxy and phenoxy groups of FA donate electrons to quench the free radicals. The phenolic radical in turn forms a quinone methide intermediate, which is excreted via the bile. The past few decades have been devoted to intense research on antioxidant property of FA. So, the present review deals with the mechanism of antioxidant property of FA and its possible role in therapeutic usage against various diseases

    Character association and path coefficient analysis for grain yield of parents and hybrids in rice (Oryza sativa L.)

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    An experiment was conducted to study the inter-relationships, direct and indirect effects of various yield attributing characters towards grain yield per plant, at Rice Research Centre, Rajendranagar. Grain yield per plant had significant positive correlation with productivity per day (0.97), panicle weight (0.71), number of filled grains per panicle (0.57), panicle length (0.46), number of productive tillers per plant (0.34), days to 50 per cent flowering (0.23) and plant height (0.16).Path analysis revealed that productivity/ day (0.91) was the major contributor for grain yield followed by, days to 50 per cent flowering (0.19), grain length (0.05), number of productive tillers per plant (0.04), panicle weight (0.04) and number of filled grains per panicle (0.04). It can be concluded from the study that, the above characters can be used as the selection criteria in any rice yield improvement breeding programmes

    Heterosis studies in rice for the identification of better hybrids for Telangana, India

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    In the present study, 23 elite rice genotypes were test crossed with IR 58025A and based on which, 12 restorer lines viz., Rajendra, MTU 1010, IR 64, KNM 118, NLR 33358, Satya, Varalu, RNR 15048, RNR 15038, Tel- lahamsa, RNR(RK) 28 and RNR(RK) 53 were identified during Kharif- Rabi 2013-14. Then, three CMS lines viz., IR 58025A, IR 68902A and IR 72081A were crossed with these identified 12 restorer lines to produce 36 hybrids in line Γ— tester mating design and were evaluated along with standard hybrid check, PA 6129 at Rice Research Centre, Rajendranagar, during Kharif 2014 to find out the best heterotic combinations in terms of grain yield and yield component characters. The degree of heterosis varied from trait to trait. Out of 36 hybrids studied, the significant standard heterosis for grain yield is observed in 3 hybrids, over best check PA 6129, viz., IR 58025A Γ— MTU 1010 (18.25), IR 68902A Γ— RNR 15038 (14.59) and IR 72081A Γ— RNR 15038 (9.57). The best experimental hybrid IR58025A Γ— MTU 1010 recorded average heterosis (78.26) and heterobeltiosis (64.37). These three experimental hybrids can be further evaluated over locations for large scale commercialization in Telangana

    FGF inhibition directs BMP4-mediated differentiation of human embryonic stem cells to syncytiotrophoblast

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    Bone morphogenetic protein (BMP) signaling is known to support differentiation of human embryonic stem cells (hESCs) into mesoderm and extraembryonic lineages, whereas other signaling pathways can largely influence this lineage specification. Here, we set out to reinvestigate the influence of ACTIVIN/NODAL and fibroblast growth factor (FGF) pathways on the lineage choices made by hESCs during BMP4-driven differentiation. We show that BMP activation, coupled with inhibition of both ACTIVIN/NODAL and FGF signaling, induces differentiation of hESCs, specifically to betahCG hormone-secreting multinucleated syncytiotrophoblast and does not support induction of embryonic and extraembryonic lineages, extravillous trophoblast, and primitive endoderm. It has been previously reported that FGF2 can switch BMP4-induced hESC differentiation outcome to mesendoderm. Here, we show that FGF inhibition alone, or in combination with either ACTIVIN/NODAL inhibition or BMP activation, supports hESC differentiation to hCG-secreting syncytiotrophoblast. We show that the inhibition of the FGF pathway acts as a key in directing BMP4-mediated hESC differentiation to syncytiotrophoblast
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