19,260 research outputs found

    Two and three-dimensional shock-shock interactions on the blunt leading edges of the hypersonic inlets

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    The effect of shock impingement on the blunt leading edges of the top and sidewall compression type inlet of a scramjet engine is studied numerically. The impinging shock is caused by the vehicle forebody. The interaction of this forebody shock with the inlet leading edge shock results in a very complex flowfield containing local regions of high pressure and intense heating. This complex flowfield in calculated by solving the Navier-Stokes equations using a finite volume flux splitting technique due to van Leer. To resolve the finer details of the flow structure as well as to predict the surface heat transfer accurately, adaptive grid technique is used in the analysis. Results of the present numerical study are compared with available experimental results

    Determination and expression of genes for resistance to blast (Magnaporthe oryza) in Basmati and non-Basmati indica rices (Oryza sativa L.)

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    One hundred and twenty two (122) genotypes of Basmati and non-Basmati Indica rice genotypes were evaluated for expression of resistance against blast disease under induced epiphytotic conditions. Disease severity (%) and area under disease progress curve (AUDPC) parameters were used for screening the blast resistance. Only 13 genotypes expressed resistance against the blast disease. Nine genotypes carried blast resistance genes but, were susceptible under induced epiphytotic conditions. The rice genotype VLD-61 had no resistance genes; however, it expressed strong resistance against blast. An empirical breeding strategy for development of blast resistant improved varieties of rice was also discussed.Keywords: Magnaporthe oryzae, restriction digestion, molecular breeding, Basmati riceAfrican Journal of Biotechnology Vol. 12(26), pp. 4098-410

    A putative heat-responsive transcription factor (TaHD97) and its targets in wheat (Triticum aestivum) providing thermotolerance

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    214-223Transcription factors (TFs) are protein, which perform their role at transcriptional level by affecting the expression of various genes associated with metabolic pathways, growth and stress-associated genes (SAGs) at different developmental stages. Here, we identified 38 novel heat-responsive transcription factor genes from wheat cv. HD2985 by mining the de novo transcriptome data derived from heat shock (HS) treated wheat. Based on digital gene expression (DGE), a putative transcript (TaHD97) of ~1.1 kbas amplified and cloned from wheat cv. HD2985. The presence of heat stress transcription factor (HSF) DNA binding domain was observed in the amino acid sequence. Differential expression of TaHD97 was observed in HD2985 (thermotolerant) and HD2329 (thermosensitive) under heat stress. Tissue specific expression analysis showed up-regulation of TaHD97 in leaves, stem and endospermic tissues and down-regulation in root under HS. A positive correlation was established between the expression of TaHD97 and its target gene (HSP17 and HSP90) in wheat under heat stress. HSP17 transcripts were observed more in leaves of HD2985, as compared to HD2329. Thermotolerance related biochemical enzymes (SOD, CAT, GPX and TBARS) were observed higher in wheat cv. HD2985 showing maximum expression of TaHD97 under heat stress. There is a need for the functional validation of the gene TaHD97 in order to use it for the regulation of sHSP (catalytic chaperone) - a novel approach towards augmenting thermotolerance in wheat under heat stress

    Strategies to identify muscle fatigue from SEMG during cycling

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    Detection, quantification and analysis of muscle fatigue are crucial in occupational/rehabilitation and sporting settings. Sports organizations, such as the Australian Institute of Sports (AIS), currently monitor fatigue by a battery of tests including invasive techniques that require taking blood samples and/or muscle biopsies, the latter of which is highly invasive, painful, time consuming and expensive. SEMG (surface electromyography) is non-invasive monitoring of muscle activation and is an indication of localized muscle fatigue based on the observed shift of the power spectral density of the SEMG. The success of SEMG based techniques is currently limited to isometric contraction and is not acceptable to the human movement community. The paper proposes and tests a simple signal processing technique to identify the onset of muscle fatigue during cyclic activities of muscles, such as VL and VM, during cycling. Based on experiments conducted with 7 participants, using power output as a measure of fatigue, the technique is able to identify muscle fatigue with 98% significance

    Characterization and Mapping of Halophyte Vegetation Using GIS and Remote Sensing Technique in Kachchh Plane of Gujarat, India

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    One of the pressures of a burgeoning population is need to increase agricultural production through both irrigated agriculture and the development of land that was previously regarded as marginal. About 8.56 m ha land in India is affected by salt. Out of this, about 1.2 m ha land is in Gujarat which is next to Uttar Pradesh (1.295 m ha). Kachchh, the second largest district of the country, has more than 53% of the total geographical area under Ranns (salt-marshy lands). The soil salinity in this region ranges from 3.2 to 32 EC and sodicity from 8.0 to 10.0 pH. The animal husbandry is the major livelihood option of the people of the Banni grassland of this region having an area of about 625 km2. Halophyte grown under the saline ecosystem is the major wild forage source for the animals feed. However, the animals feed mostly on wild forage halophytes grown under the saline ecosystem. Apart from natural salinity, a significant proportion of recently cultivated agricultural land has become saline owing to faulty irrigation practices; this secondary salinization poses direct loss to the crop production. The commercial agriculture now prevalent in the region exploits ground water heavily and encroaches upon grass lands. Heavy grazing pressure on the vegetation including wild halophytes is direct threat to the valuable natural biodiversity of the region. Very meager information on systematic characterization of vegetation in this region is available (Pandya and Sidha, 1987 and GUIDE, 1998). Halophytes have tolerance mechanisms that include ions compartmentalization, and compatible solutes. However, the mechanisms of salt tolerance in these species are not fully understood and not much work is reported in the literature. Halophytes have great potential either for direct agricultural crops uses in saline areas or for the incorporation of their characteristics into existing crop species. They may be useful for grazing or fodder or as ornamental plants and have recently been advocated as a source of oils

    Small Quadrupole Deformation for the Dipole Bands in 112In

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    High spin states in 112^{112}In were investigated using 100^{100}Mo(16^{16}O, p3n) reaction at 80 MeV. The excited level have been observed up to 5.6 MeV excitation energy and spin \sim 20\hbar with the level scheme showing three dipole bands. The polarization and lifetime measurements were carried out for the dipole bands. Tilted axis cranking model calculations were performed for different quasi-particle configurations of this doubly odd nucleus. Comparison of the calculations of the model with the B(M1) transition strengths of the positive and negative parity bands firmly established their configurations.Comment: 10 pages, 11 figures, 2 table

    Force-induced desorption of a linear polymer chain adsorbed on an attractive surface

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    We consider a model of self-avoiding walk on a lattice with on-site repulsion and an attraction for every vertex of the walk visited on the surface to study force-induced desorption of a linear polymer chain adsorbed on an attractive surface and use the exact enumeration technique for analyzing how the critical force for desorption fc(T)f_c(T) depends on the temperature. The curve fc(T)f_c(T) gives the boundary separating the adsorbed phase from the desorbed phase. Our results show that in two dimensions where surface is a line the force fc(T)f_c(T) increases monotonically as temperature is lowered and becomes almost constant at very low temperatures. In case of three-dimensions we, however, find re-entrance, i. e. fc(T)f_c(T) goes through a maximum as temperature is lowered. The behaviour of the polymer chain at different values of temperature and force is examined by calculating the probability distribution of the height from the surface of the vertex at which external force is applied.Comment: Preprint 15 pages with 8figures and two tables. The file table-2d.ps and table-3d.ps lists C_N(Ns,h) for given N with all possible Ns and h in two and three dimension

    Influence of Incomplete Fusion Reaction on Complete Fusion Below 10 Mev/ Nucleon Energies

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    An attempt has been made in the present work to provide an ample opportunity to explore the information about the influence of incomplete fusion (ICF) reaction dynamics on complete fusion in heavy ion induced nuclear reactions. excitation functions for several evaporation residues produced in the interaction of projectile 16O with target 175lu have been measured over the wide projectile energy range ≈ 70-100 MeV. the recoil-catcher activation technique followed by the offline γ-ray spectroscopy has been used for the present measurements. In case of precursor decay, we have made use of Cavinato et al. formulation to calculate the independent cross-section of the identified residues. the measured efs are compared with theoretical predictions of statistical model code PACE-2 and any enhancement in the measured cross-section from theoretical prediction may be due to ICF reaction process. An attempt has been made to estimate the ICf contribution of the cross-section from the measured excitation function data and the dependence of ICf cross-section on projectile energy
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