7,246 research outputs found

    Geomechanical Studies for a Himalayan Tunnel in Jointed Dolomites: A Case History

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    Reported case history of Himalayan tunnel reveals that Barton\u27s and Bieniawski\u27s classification systems provide better assessment of the rock mass behavior. The design and shear strength parameters derived from these classifications provided a preliminary design of the tunnel, which has been critically evaluated with the design, adopted at site. Based on the structural feature and ground water conditions, a number of tunnelling conditions have been predicted. The studies indicated the loosening rock pressures would be occuring at site with an estimated range of 0. 25 kg/cm2 to 3. 58 kg/cm2. Problems of roof collapse, flowing ground condition and cavity formation may occur during the excavation. Multiple drift excavation method is suggested for extremely poor conditions

    Analysis of plant growth promoting potential of endophytes isolated from echinacea purpurea and lonicera japonica

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    Plant endophytes help in maintaining plant health by means of their biofertilizer and biocontrol attributes and, are currently being explored for their ability to produce novel biologically active compounds. Herein, we have isolated beneficial endophytic bacteria from Echinacea purpurea (EF.B3) and Lonicera japonica (LS.B11) that showed phosphate solubilization, siderophore, indole acetic acid and hydrogen cyanide production, and fixation of atmospheric nitrogen. Additionally, the endophytes also conferred antifungal activity against Fusarium sp., Rhizoctonia sp., Pythium sp. and Alternaria sp. When tested in plantae, the LS.B11 and EF.B3 strains were able to promote plant growth and control fungal infections in peaseedlings. Both strains were found to be endophytic as tested by RAPD and viability count. Based on 16S rRNA gene sequencing, we show that the LS.B11 and EF.B3 strains are related to Pseudomonas sp. And Burkholderia sp. By using degenerate primers, we identified genes related to polyketide synthases and non-ribosomal peptide synthetases in EF.B3 and LS.B11, respectively that are typically involved in the production of antimicrobial compounds. Therefore, we conclude that both endophytes can be used for increasing agriculture productivity and in the production of antimicrobial compounds for crop improvement

    Analytical Study of Two Serial Channels with Priority and Reneging

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    Most of the studies of queuing theory, which are useful in our daily life has been investigated by many researchers. The present research is the study of pre-emptive priority queuing system consisting two serial channels in stochastic environment. The impatient behavior of customer’s will be discussed with exponential service distribution and Poisson arrivals. Higher priority customers have pre-emptive priority over the low priority customers. The G.F. technique is used to derive the performance measures of high & low priority queues and assuming FCFS discipline in busy schedule of higher priority class. Also evaluate queue behavior graphically and discussed a special case at the end which shows utilization of channels

    Cosmology with decaying tachyon matter

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    We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show that, under certain conditions, the scale factor represents an accelerating universe, following a phase of decelerated expansion. We make use of a model of dark energy (with p=-\rho) and dark matter (p=0) where a single scalar field (tachyon) governs the dynamics of both the dark components. We show that this model fits the current supernova data as well as the canonical \LambdaCDM model. We give the bounds on the parameters allowed by the current data.Comment: 14 pages, 6 figures, v2, Discussions and references addede

    Soft x-rays absorption and high-resolution powder x-ray diffraction study of superconducting CaxLa(1-x)Ba(1.75-x)La(0.25+x)Cu3Oy system

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    We have studied the electronic structure of unoccupied states measured by O K-edge and Cu L-edge x-ray absorption spectroscopy (XAS), combined with crystal structure studied by high resolution powder x-ray diffraction (HRPXRD), of charge-compensated layered superconducting CaxLa(1-x)Ba(1.75-x)La(0.25+x)Cu3Oy (0<x<0.4, 6.4<y<7.3) cuprate. A detailed analysis shows that, apart from hole doping, chemical pressure on the electronically active CuO2 plane due to the lattice mismatch with the spacer layers greatly influences the superconducting properties of this system. The results suggest chemical pressure to be the most plausible parameter to control the maximum critical temperatures (Tcmax) in different cuprate families at optimum hole density.Comment: 14 pages, 11 figures, accepted for publication in Journal of Physics and Chemistry of Solid

    Direct Visualization of Laser-Driven Focusing Shock Waves

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    Cylindrically or spherically focusing shock waves have been of keen interest for the past several decades. In addition to fundamental study of materials under extreme conditions, cavitation, and sonoluminescence, focusing shock waves enable myriad applications including hypervelocity launchers, synthesis of new materials, production of high-temperature and high-density plasma fields, and a variety of medical therapies. Applications in controlled thermonuclear fusion and in the study of the conditions reached in laser fusion are also of current interest. Here we report on a method for direct real-time visualization and measurement of laser-driven shock generation, propagation, and 2D focusing in a sample. The 2D focusing of the shock front is the consequence of spatial shaping of the laser shock generation pulse into a ring pattern. A substantial increase of the pressure at the convergence of the acoustic shock front is observed experimentally and simulated numerically. Single-shot acquisitions using a streak camera reveal that at the convergence of the shock wave in liquid water the supersonic speed reaches Mach 6, corresponding to the multiple gigapascal pressure range 30 GPa

    Characterization and In Silico Analysis of Pregnancy-Associated Glycoprotein-1 Gene of Buffalo (Bubalus bubalis)

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    Pregnancy-Associated Glycoproteins (PAGs) are trophoblastic proteins belonging to the Aspartic proteinase family secreted by different placental cells of many mammalian species. They play a pivotal role in placentogenesis, foetomaternal unit remodeling, and implantation. The identification of the genes encoding those proteins will be helpful to unravel the intricate embryogenomic functions during pregnancy establishment. Considering importance of these proteins, the present study was undertaken to characterize the pregnancy associated glycoprotein-1 gene of buffalo. An 1181 base pairs buffalo Pregnancy-Associated Glycoprotein PAG-1 gene was PCR amplified from the RNA obtained from the fetal cotyledons. BLAST analysis of the buffalo PAG-1 sequence retrieved a total of 20 cattle, 5 goat, and 4 sheep PAG sequences, exhibiting more than 80% similarity. Buffalo PAG-1 gene contained an uninterrupted open reading frame of 1140 base pairs encoding 380 amino acids that possess a 15 amino acid signal peptide and mature peptide of 365 amino acids. The phylogenetic study of the buffalo PAG-1 gene revealed buffalo PAG-1 is more related to cattle, goat, and sheep PAG-1 sequences. By this study characterization of buffalo PAG-1 gene and its evolutionary relationship was deduced for the first time
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