Exploitation of the Gauribidanur array for seismic monitoring     

T.G. Varghese  F. Roy  B.S.S. Rao  M.P. Suryavanshi  R.N. Bharthur 《Physics of the Earth and Planetary Interiors》1979,18(2):87-94

The medium-aperture array at Gauribidanur is in continous operation since 1966. With the recent addition of a 12-bit 16-K computer its potential for the monitoring of underground explosions has improved considerably. The salient aspects of the monitoring system, the present and projected procedures for generation and dissemination of detection data and the long-term storage of data relevant to discrimination research are discussed. An attempt is also made to assess its detection efficiency in the light of the major features of site noise.  相似文献   

Radiative Transfer Models of Dust Shells Around Post-AGB Stars     

R. Surendiranath  M. Parthasarathy  B.A. Varghese 《Astrophysics and Space Science》2002,281(4):751-759

We present a radiative transfer analysis of circumstellar dust shells around the Post-AGB stars HD 179821, HD 56126, HD 101584 and early R star HD 100764, using the code DUSTY. Parameters like mass-loss, shell inner radius, dust temperature, outflow velocity etc., are derived for HD 179821and HD 56126 whose observed SED could be reproduced by our models. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Future projections of Indian Summer Monsoon under multiple RCPs using a high resolution global climate model multiforcing ensemble simulations     

Varghese  Stella Jes  Surendran  Sajani  Rajendran  Kavirajan  Kitoh  Akio 《Climate Dynamics》2020,54(3):1315-1328

Climate Dynamics - Present-day simulations (1983–2003) of a global climate model of 60-km resolution with three deep convection schemes are analysed to find the best scheme for simulation of...  相似文献   

Cylindrical Hall – MHD Waves: A Nonlinear Solution     

V. Krishan  B. A. Varghese 《Solar physics》2008,247(2):343-349

The exact nonlinear cylindrical solution for incompressible Hall – magnetohydrodynamic (HMHD) waves, including dissipation, essentially from electron – neutral collisions, is obtained in a uniformly rotating, weakly ionized plasma such as exists in photospheric flux tubes. The ω – k relation of the waves, called here Hall – MHD waves, demonstrates the dispersive nature of the waves, introduced by the Hall effect, at large axial and radial wavenumbers. The Hall – MHD waves are in general elliptically polarized. The partially ionized plasma supports lower frequency modes, lowered by the factor δ≡ratio of the ion mass density to the neutral particle mass density, as compared to the fully ionized plasma (δ=1). The relation between the velocity and the magnetic field fluctuations departs significantly from the equipartition found in Alfvén waves. These short-wavelength and arbitrarily large amplitude waves could contribute toward the heating of the solar atmosphere.  相似文献   

Effect of Soil Parameters on Dynamic Cone Penetration Indices of Laterite Sub-grade Soils from India     

Varghese George  Ch. Nageshwar Rao  R. Shivashankar 《Geotechnical and Geological Engineering》2009,27(4):585-593

The focus of this study was on correlating the effect of grain-size, maximum dry-density (MDD), field moisture content, and the void ratios on penetration measured using the dynamic cone penetrometer (DCP) for laterite soils blended with fines. Tests were performed on soil samples compacted to MDD for moulding water contents set to the optimum moisture content (OMC), dry of OMC, and wet of OMC un-soaked condition. The results indicated that an increase in the fines-content caused a decrease in the MDD, and an increase in the OMC and the DCP penetration. Regressions were developed correlating various parameters.  相似文献   

Erosion and heavy mineral depletion of a placer mining beach along the south-west coast of India: part III—short- and long-term morphological changes     

R. Prasad  L. Sheela Nair  N. P. Kurian  T. N. Prakash  Tiju I. Varghese 《Natural Hazards》2016,80(2):823-838

  相似文献   

Habitat Suitability Assessment of <Emphasis Type="Italic">Ardeotis nigriceps</Emphasis> (Vigors) in Great Indian Bustard Sanctuary,Maharashtra (India) Using Remote Sensing and GIS     

A. O. Varghese  V. B. Sawarkar  Y. L. P. Rao  A. K. Joshi 《Journal of the Indian Society of Remote Sensing》2016,44(1):49-57

Ardeotis nigriceps, commonly known as Great Indian Bustard (GIB), is a Critically Endangered, Evolutionary Distinct and Globally Threatened (EDGE) and endemic species to the Indian subcontinent. GIB is under tremendous threat in its last strongholds and sliding inextricably towards extinction. The GIB sanctuary in Maharashtra (India) is one of the last refuges of the bird constituting an area of 8496 km² spread over in seven talukas of Solapur and Ahemednagar districts. Major portion of the sanctuary (94.3 %) consists of privately owned lands under a variety of economic vocations and large number of villages and townships. In view of the legal restrictions relating to Protected Area under the Wildlife (Protection) Act of India 1972, the inhabitants of villages and townships faced a very difficult situation regarding use of their lands, development of properties and deriving benefits from planned local and regional development. This created conflict between local people and the forest department over the use of land, which necessitated the rationalization of the sanctuary. The objective of the present study was to map the suitable habitat of GIB in GIB Wildlife Sanctuary as an input for the realignment of the GIB Sanctuary by identifying areas that are important for the GIB. Main parameters considered for the habitat suitability assessments are, habit and habitat of GIB, slope, minimum patch size and disturbance sources. Based on the criteria derived for the ecological and biological requirements of GIB, binary deductive habitat suitability modeling has been done using remote sensing and GIS and prioritized the potential habitats of GIB. The net area of important suitable habitat of GIB in GIB sanctuary is 2304.99 km² out of 8496.44 km². The output of the present study has been used as an input by the committee (set by Honorable Supreme court of India) on rationalization of the GIB Sanctuary and the sanctuary has been rationalized with an area of 1222 km².  相似文献   

Relative performance of different triangular networks in locating regional seismic sources     

Arora  S K  Varghese  T G  Basu  T K 《Journal of Earth System Science》1978,87(11):271-281

Journal of Earth System Science - In regional seismic surveys use of small semipermanent networks of detectors is often made. This study aims at investigating qualitatively the location capability...  相似文献   

Changes in daily maximum temperature extremes across India over 1951–2014 and their relation with cereal crop productivity     

Debasish?Chakraborty  Vinay?Kumar?SehgalEmail authorView author&#;s OrcID profile  Rajkumar?Dhakar  Eldho?Varghese  Deb?Kumar?Das  Mrinmoy?Ray 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(11):3067-3081

This study used gridded daily maximum temperature data (1°?×?1°) for 1951–2014 period to analyze the trend in monthly extreme warm days (ExWD) and changes in its probability distribution in each grid. It also analyzed the trend in spatial spread of annual ExWD over the study period at four exceedance levels and further related the number of ExWDs with cereal crop productivity of India. Extreme warm days have increased throughout India but were statistically significant in 42% grids. The increase was consistent over all the months in north-eastern region, southern plateau and both the coastal plains. It also increased significantly over north-western and central India during April to June summer period. The probability distribution of ExWD also changed significantly in many grids, especially in southern plateau and both the coastal plains. The changes indicated increased frequency in the existing levels of extremes and new occurrences of higher frequency of extremes. The analysis of land area affected by different levels of extremes indicated significant increase, with the rate being highest for higher extremes. In terms of extreme warm day temperatures, the study identified southern plateau, east and west coast plains, and north-eastern India as highly vulnerable. Using copula probability model, study showed that increase in ExWD from 20 to 60% may increase the probability of 5% or more yield loss from 17 to 53% for Kharif cereals, 11 to 43% for Rabi cereals and 19 to 63% for wheat crop. The results may be used for devising zone specific adaptation strategies.  相似文献   

Reflection effect in close binaries: effects of reflection on spectral lines     

M. Srinivasa Rao  B. A. Varghese 《Astrophysics and Space Science》2014,349(2):835-842

Reflection effect phenomenon is studied on the formation of spectral lines in a close binary system when primary component has an extended atmosphere and the secondary component is a point source. Irradiation effect is calculated using one dimensional rod model and self radiation is calculated using continuum radiative transfer equation in spherically symmetric atmosphere. The total radiation is the sum of the radiation of the individual components and the mutually reflected light. Line profiles are also computed along the line of sight observer at infinity for irradiation, self radiation and total radiation and compared in order to study the reflection effect on spectral lines. It is found that the radiation field varies on the primary component when angle of incidence changes from the secondary component. The contour maps show that the radiative interaction makes the outer surface of the primary star warm when its companion illuminates the radiation. The effect of reflection on spectral lines is studied and noticed that the flux in the lines increases at all frequency points and the cores of the lines received more flux than the wings and equivalent width changes accordingly.  相似文献