Strategic Analyses of the National River Linking Project (NRLP) of India, Series 4. Water productivity improvements in Indian agriculture: potentials, constraints and prospects

Water productivityWater use efficiencyMultiple useIrrigation practicesIrrigation systemsWater qualityWater allocationCerealsCrop yieldLivestockMilk productionEconomic aspects

Economic value of water in agriculture: comparative analysis of a water-scarce and water-rich region in India

Water productivityEconomic evaluationCrop productionIrrigated farmingWater costsWellsLivestockMilk production

Seeing double: the low-carb diet

No abstract available

Intensity interferometry of thermal photons from relativistic heavy ion collisions

Intensity interferometry of thermal photons, having transverse momenta $k_T \approx$ 0.1 -- 2.0 GeV, produced in relativistic collision of heavy nuclei is studied. It is seen to provide an accurate information about the temporal and spatial structure of the interacting system. The source dimensions and their $k_T$ dependence revealed by the photon interferometry, display a richness not seen in pion interferometry. We attribute this to difference in the source functions, the fact that photons come out from every stage of the collision and from every point in the system, and the fact that the rate of production of photons is different for the quark-gluon plasma, which dominates the early hot stage, and the hadronic matter which populates the last phase of the collision dynamics. The usefulness of this procedure is demonstrated by an application to collision of lead nuclei at the CERN SPS. Prediction for the transverse momentum dependence of the sizes for SPS, RHIC, and LHC energies are given.Comment: 16 pages, 11 figures. Added discussions and references. To appear in Phys. Rev.

On Heatshield Shapes for Mars Entry Capsules

The 70deg sphere-cone - the standard geometry for all US Mars entry missions - is thoroughly examined via flow field simulations at a select few peak heating points along candidate flight trajectories. Emphasis is placed on turbulent heating based on the Baldwin- Lomax turbulence model. It is shown that increased leeward turbulent heating for a 70 sphere-cone flying at angle of attack is primarily due to the discontinuity in curvature between the spherical nose cap and the conical frustum - the attachment of the sonic line at this sphere-cone junction leads to a supersonic edge Mach number over the leeward acreage. In an attempt to mitigate this problem of elevated turbulent heating, alternate geometries, without any curvature discontinuities in the acreage, are developed. Two approaches, one based on nonlinear optimization with constraints, and one based on the use of non-uniform rational B-splines, are considered. All configurations examined remain axisymmetric. The aerothermal performance of alternate geometries is shown to be superior to that of the 70 sphere-cone