Amplitudes and Periods of Geomagnetic Micropulsations in the Pc3, 4 Range at Canadian Observatories     

Robert J. Stening  Jagdish C. Gupta 《Geophysical Journal International》1971,23(4):379-386

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Spectrum of average flux of the S-component of solar radio emission     

M. K. Das Gupta  S. K. Sarkar 《Solar physics》1971,18(2):276-283

Spectrum of average flux of the S-component of solar radio emission observed during the peak phase of the present solar cycle has been determined statistically. Daily values of the mean solar flux at 606, 1415, 2695, 4995 and 8800 MHz observed at the Sagamore Hill Solar Radio Observatory have been examined. The superposed epoch method (Chree analysis) has been used for determining the true nature of the S-component at all these frequencies. Spectrum has been obtained after elimination of the basic components at the respective frequencies. The important results obtained from the present statistical investigation are: (1) the basic component increases with frequency, (2) the S-component shows a maximum at 4995 MHz (6 cm), (3) the spectrum is independent of the phase of the 27-day cycle and (4) S-components at all the frequencies have slopes which are both more uniform and higher in the ascending phase than those in the descending phase of the 27-day cycle. In the descending phase slopes increase with frequency.  相似文献   

An exact solution of time-dependent equation of transfer of trapped radiation in a finite absorbing medium     

S. K. Bishnu  S. R. Das Gupta 《Astrophysics and Space Science》1987,134(2):261-299

Milne's time-dependent equation of transfer of trapped radiation in finite absorbing medium has been exactly solved by a combination of Das Gupta's modified form of the Wiener-Hopf technique and method of solving boundary value problems in the theory of heat conduction as adopted by Chandrasekhar (1950) to solve the same equation approximately in combination with his method of discrete ordinates. Milne himself had earlier obtained an approximate solution of his equation.  相似文献   

An algorithm for road enhancement in SAR images using wavelet transform     

Karunesh K. Gupta  Rajiv Gupta 《Journal of the Indian Society of Remote Sensing》2007,35(4):361-367

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Evidence of women’s empowerment in India: a study of socio-spatial disparities     

Kamla Gupta  P. Princy Yesudian 《GeoJournal》2006,65(4):365-380

Various national and international communities have addressed women’s issues and taken various efforts to empower them so as to enhance their social and health status and involve them in developmental activities. The Indian DHS survey (National Family Health Survey, 1998–1999) provides an opportunity to study women’s empowerment in India. The survey collected information on several dimensions of women’s empowerment from 90,303 ever-married women (ages 15–49), from all the states of India. Utilizing these data sets, four indices – household autonomy index, mobility index, attitude towards gender index and attitude towards domestic violence index – are constructed to measure the different dimensions of empowerment. Using these indices, the spatial and socio-economic and cultural disparities that exist within India are analyzed. Finally, an attempt is made to identify some important determinants for women’s empowerment using multiple logistic regression analysis. The results show that at the national level, 43% of the women have high household autonomy; 23% of the women have high freedom to move outside their home; 40% of the women have no gender preference attitude; and only 43% of the women defy domestic violence. But there are significant divergences in these indices of women’s empowerment across the different states and socio-economic and cultural settings within India. Women’s educational levels emerged as an important predictor for all the four dimensions of women’s empowerment. Additionally, media exposure and age have emerged as the important predictors for some dimensions of woman’s empowerment. This paper was presented by Prof. Kamla Gupta at the International Geographical Union Conference (IGU), held in Canada, 2002.  相似文献   

Comparison of Fragmentation Measurements by Photographic and Image Analysis Techniques   总被引：1，自引：0，他引：1  

J. Sudhakar  G. R. Adhikari  R. N. Gupta 《Rock Mechanics and Rock Engineering》2006,39(2):159-168

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Regionalization of constraints on expected watershed response behavior for improved predictions in ungauged basins   总被引：2，自引：0，他引：2  

Maitreya Yadav  Thorsten Wagener  Hoshin Gupta 《Advances in water resources》2007

Approaches to modeling the continuous hydrologic response of ungauged basins use observable physical characteristics of watersheds to either directly infer values for the parameters of hydrologic models, or to establish regression relationships between watershed structure and model parameters. Both these approaches still have widely discussed limitations, including impacts of model structural uncertainty. In this paper we introduce an alternative, model independent, approach to streamflow prediction in ungauged basins based on empirical evidence of relationships between watershed structure, climate and watershed response behavior. Instead of directly estimating values for model parameters, different hydrologic response behaviors of the watershed, quantified through model independent streamflow indices, are estimated and subsequently regionalized in an uncertainty framework. This results in expected ranges of streamflow indices in ungauged watersheds. A pilot study using 30 UK watersheds shows how this regionalized information can be used to constrain ensemble predictions of any model at ungauged sites. Dominant controlling characteristics were found to be climate (wetness index), watershed topography (slope), and hydrogeology. Main streamflow indices were high pulse count, runoff ratio, and the slope of the flow duration curve. This new approach provided sharp and reliable predictions of continuous streamflow at the ungauged sites tested.  相似文献   

Surface heat flow and probable evolution of Deccan volcanism     

Mohan L. Gupta  V.K. Gaur   《Tectonophysics》1984,105(1-4)

In the light of surface heat-flow observations, as well as other related geological and geophysical data, the origin of the Deccan basalts has been examined. The Indian lithosphere, after its detachment from Gondwanaland, apparently traversed a rising plume at La Réunion, which virtually bored through the lithosphere to emerge as the Deccan Trap volcanism on the surface. Subsequent volcanic and plutonic activity appears to have continued not only up to the Oligocene, as is indicated by the alkaline magmatic activity observed near the junction of the three prominent features — the West Coast faults, the Narmada-Son-Tapti lineament, and the Cambay Graben — but also up to the Mio-Pliocene, as indicated by the heat flow and gravity data over the Cambay Graben. The dyke-swarms and sills, which are mostly post-trappean, evolved from the lithosphere after the Indian Plate moved away from the hot spot.  相似文献   

Rotational overthrusting of the northwestern Himalaya: further palaeomagnetic evidence from the Riasi thrust sheet, Jammu foothills, India     

Chris T. Klootwijk  Madan Lal Sharma  Jozef Gergan  S.K. Shah  B.K. Gupta 《Earth and Planetary Science Letters》1986,80(3-4):375-393

Thermal demagnetization results (316 samples) are presented for the Tertiary succession of the Riasi thrust sheet (Jammu foothills, northwestern Himalaya). Primary and secondary magnetization directions of Murree Group red beds (Miocene to Upper Eocene) sampled northeast of Jammu indicate, for this part of the Riasi thrust sheet, a clockwise rotation over about 45° with respect to the Indian shield since Late Eocene/Early Miocene time. This accords with clockwise rotations of similar magnitude observed in the Panjal Nappe and the Krol Belt, and is interpreted as representative for the northwestern Himalaya. Results from the western part of the Kalakot inlier, sampled northwest of Jammu, i.e. basal Murree claystone (Middle Eocene) and carbonate from the Subathu Group (lower Middle to Lower Eocene), indicate an aberrant 20–25° counterclockwise rotation which is of local importance only. Available observations on rotation of Himalayan thrust sheets with respect to the Indian shield, indicate that the Himalayan Arc has formed through oroclinal bending. This supports Powell and Conaghan's and Veevers et al.'s model of Greater India with large-scale intracontinental underthrusting along the Main Central Thrust beneath the Tibetan Plateau. Minimal magnitudes of underthrusting of 550 km in the Krol Belt and 650 km in the Thakkhola region are concluded. Palaeolatitude observations (herein and in [1[) agree with absolute positioning of the Indian plate based on India-Africa relative movement data fixed to a hotspot frame in the Atlantic Ocean, and with palaeolatitude observations from DSDP cores on the Indian plate. Collision-related secondary magnetic components observed both to the north and to the south of the Indus-Tsangpo Suture zone show palaeolatitudes between the equator and 7°N. Comparison of both datasets indicates that initial contact between Greater India and south-central Asia had been established in the Hindu Kush—Karakorum region by about 60 Ma ago whereas eastwards progressive suturing had advanced to the Lhasa Block segment of the Indus-Tsangpo Suture zone before 50 Ma ago.  相似文献   

Estimating surface sensible heat flux using sodar and surface temperature measurements in the evolving convective boundary layer     

K.Sen Gupta  P.K. Kunhikrishnan  V. Radhika  K.Narayanan Nair 《Atmospheric Research》1986,20(2-4)

A simple method is described for estimating the sensible heat flux by using a Doppler sodar system and a thermal probe. This method, which can be applied to a convective boundary layer in morning hours, is based on knowing the zero heat flux level from the reflectivity and the vertical wind speed.  相似文献