712 research outputs found

    Maize in India: Production Systems, Constraints, and Research Priorities

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    Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

    Assessment of Ration Scales of the Armed Forces Personnel in Meeting theNutritional Needs at Plains and High Altitudes–I

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    Adequate nutrition is very essential, especially for the Armed Forces, to buildup their nutritional reserveswhile deriving maximum benefits of training/peak performances in operational situations by keeping theirmorale high. The present study reviews/examines the adequacy of the existing ration scales of the ArmedForces personnel stationed under different terrain conditions of the country/recruits at various training centres.Food samples were collected from different strategic locations during different seasons of the year and analysedfor their nutrient composition like proximal constituents, vitamins A, E, B1, B2, C, and dietary fibre. Basedon the data generated, the daily nutrients/energy consumption by the soldiers/recruits, were calculated separatelyboth for personnel in plains and at high altitudes. Soldiers in plains, on an average consumed protein 124.2+ 13.0 g, fat 98.8 + 29.6 g and energy 3632+317 kcal/person/day, while their counterparts at high altitudesconsumed protein 120.4 + 11.2 g, fat 120.1 + 31.1 g, and energy 3906 + 423 kcal/person/day. The study clearlyindicate that the present ration scales for the Service personnel, both in plains and at high altitudes (9000 ftto 15000 ft) is adequate wrt their nutrient density. It is however suggested to ensure adequate supply of goodquality fresh vegetables, fruits, and meat, which inturn would not only help to keep the morale of the soldiers,high and cheerful, especially at high altitudes, but will also enable adequate micronutrient availability. Thefibre levels in the diets of these soldiers have also been found to be well within the limits (20 -35 g/ person/day) recommended for optimal health.Defence Science Journal, 2008, 58(6), pp.734-744, DOI:http://dx.doi.org/10.14429/dsj.58.170

    Anomalous Transient Current in Nonuniform Semiconductors

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    Nonequilibrium processes in semiconductors are considered with highly nonuniform initial densities of charge carriers. It is shown that there exist such distributions of charge densities under which the electric current through a sample displays quite abnormal behaviour flowing against the applied voltage. The appearance of this negative electric current is a transient phenomenon occurring at the initial stage of the process. After this anomalous negative fluctuation, the electric current becomes normal, i.e. positive as soon as the charge density becomes more uniform. Several possibilities for the practical usage of this effect are suggested.Comment: 1 file, 11 pages, RevTex, no figure

    Disordered Bosons: Condensate and Excitations

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    The disordered Bose Hubbard model is studied numerically within the Bogoliubov approximation. First, the spatially varying condensate wavefunction in the presence of disorder is found by solving a nonlinear Schrodinger equation. Using the Bogoliubov approximation to find the excitations above this condensate, we calculate the condensate fraction, superfluid density, and density of states for a two-dimensional disordered system. These results are compared with experiments done with 4He{}^4{\rm He} adsorbed in porous media.Comment: RevTeX, 26 pages and 10 postscript figures appended (Figure 9 has three separate plots, so 12 postcript files altogether

    Elementary excitations of trapped Bose gas in the large-gas-parameter regime

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    We study the effect of going beyond the Gross-Pitaevskii theory on the frequencies of collective oscillations of a trapped Bose gas in the large gas parameter regime. We go beyond the Gross-Pitaevskii regime by including a higher-order term in the interatomic correlation energy. To calculate the frequencies we employ the sum-rule approach of many-body response theory coupled with a variational method for the determination of ground-state properties. We show that going beyond the Gross-Pitaevskii approximation introduces significant corrections to the collective frequencies of the compressional mode.Comment: 17 pages with 4 figures. To be published in Phys. Rev.

    Temperature-induced resonances and Landau damping of collective modes in Bose-Einstein condensed gases in spherical traps

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    Interaction between collective monopole oscillations of a trapped Bose-Einstein condensate and thermal excitations is investigated by means of perturbation theory. We assume spherical symmetry to calculate the matrix elements by solving the linearized Gross-Pitaevskii equations. We use them to study the resonances of the condensate induced by temperature when an external perturbation of the trapping frequency is applied and to calculate the Landau damping of the oscillations.Comment: revtex, 9 pages, 5 figure

    Unitarity Constraints on the B and B^* Form Factors from QCD Analyticity and Heavy Meson Spin Symmetry

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    A method of deriving bounds on the weak meson form factors, based on perturbative QCD, analyticity and unitarity, is generalized in order to fully exploit heavy quark spin symmetry in the ground state (L=0)(L=0) doublet of pseudoscalar (B)(B) and vector (B∗)(B^*) mesons. All the relevant form factors of these mesons are taken into account in the unitarity sum. They are treated as independent functions along the timelike axis, being related by spin symmetry only near the zero recoil point. Heavy quark vacuum polarisation up to three loops in perturbative QCD and the experimental cross sections σ(e+e−→Υ)\sigma(e^+e^- \rightarrow \Upsilon) are used as input. We obtain bounds on the charge radius of the elastic form factor of the BB meson, which considerably improve previous results derived in the same framework.Comment: 13 pages LaTex, 1 figure as a separate ps fil
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