GIS-based vulnerability mapping of the coastal stretch from Puri to Konark in Odisha using analytical hierarchy process

Natural Hazards - The 485-km-long coastline of Odisha, a state in the northeastern part of the Indian peninsula, is potentially vulnerable to several disaster events that take place frequently. In...     

Can we constrain the evolution of HI bias using configuration entropy?

We study the evolution of the configuration entropy of HI distribution in the post-reionization era assuming different time evolution of HI bias.We describe time evolution of linear bias of HI distribution using a simple form b(a)=b₀aⁿ with different index n.The derivative of the configuration entropy rate is known to exhibit a peak at the scale factor corresponding to theΛ-matter equality in the unbiasedΛCDM model.We show that in theΛCDM model with time-dependent linear bias,the peak shifts to smaller scale factors for negative values of n.This is related to the fact that the growth of structures in the HI density field can significantly slow down even before the onset ofΛdomination in the presence of a strong time evolution of the HI bias.We find that the shift is linearly related to the index n.We obtain the best fit relation between these two parameters and propose that identifying the location of this peak from observations would allow us to constrain the time evolution of HI bias within the framework of theΛCDM model.     

Influence of Sediment Mobility on Universal von Kármán Coefficient k and Traversing Length of Eddy in Fluvial Streams

Water Resources - Sediment mobility in stream corroborates many significant mechanisms in terms of interactions of transported particles in the carrier fluid flows. In general, the sediment...     

Access to basic amenities and services to urban households in West Bengal: Does its location and size of settlements matter?

GeoJournal - Basic urban services refer to the important civic services required for the citizens of urban areas and for the functioning of cities viz., water supply, sanitation, waste management,...     

Observed daily large-scale rainfall patterns during BOBMEX-1999

A daily rainfall dataset and the corresponding rainfall maps have been produced by objective analysis of rainfall data. The satellite estimate of rainfall and the raingauge values are merged to form the final analysis. Associated with epochs of monsoon these rainfall maps are able to show the rainfall activities over India and the Bay of Bengal region during the BOBMEX period. The intra-seasonal variations of rainfall during BOBMEX are also seen using these data. This dataset over the oceanic region compares well with other available popular datasets like GPCP and CMAP. Over land this dataset brings out the features of monsoon in more detail due to the availability of more local raingauge stations.     

Laser radiation in active amplifying media treated as a transport problem: Transfer equation derived and exactly solved

The flow of laser radiation in a plane-parallel cylindrical slab of active amplifying medium with axial symmetry is treated as a problem in radiative transfer. The appropriate one-dimensional transfer equation describing the transfer of laser radiation has been derived by an appeal to Einstein'sA, B coefficients (describing the processes of stimulated line absorption, spontaneous line emission, and stimulated line emission sustained by population inversion in the medium) and considering the rate equations to completely establish the rational of the transfer equation obtained. The equation is then exactly solved and the angular distribution of the emergent laser beam intensity is obtained; its numerically computed values are given in tables and plotted in graphs showing the nature of peaks of the emerging laser beam intensity about the axis of the laser cylinder.     

On transfer equation in a semi-infinite atmosphere with albedo ω>1

In this note we derive an exact solution of transfer equation in a plane-parallel semiinfinite atmosphere with albedo >1, by the method of Laplace transform and Wiener-Hopf technique. The emergent intensityI(0, ) is obtained in terms of theH ⁰-functionH ⁰() (Das Gupta, 1978) for which some good approximations are given. Intensity at any depth is also obtained.I(0, )/I(0, 0) is plotted in graphs against [0,1], and shows a maximum which drops and shifts towards the origin as increases.     

Computation of mass outflow rate from relativistic quasi-spherical accretion on to black holes

We compute the mass outflow rate R _m˙ from relativistic matter that is accreting quasi-spherically on to the Schwarzschild black holes. Taking the pair-plasma pressure-mediated shock surface as the effective boundary layer (of the black hole) from where the bulk of the outflow is assumed to be generated, computation of this rate is done using combinations of exact transonic inflow and outflow solutions. We find that R _m˙ depends on the initial parameters of the flow, the polytropic index of matter, the degree of compression of matter near the shock surface and the location of the shock surface itself. We thus not only study the variation of the mass outflow rate as a function of various physical parameters governing the problem, but also provide a sufficiently plausible estimation of this rate.