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31.
S. K. Deb Inderpreet Kaur C. M. Kishtawal P. K. Pal 《Theoretical and Applied Climatology》2014,115(3-4):693-702
The operational derivation of atmospheric motion vectors (AMVs) using infrared (10.5–12.5 μm) and water vapor (6.3–7.1 μm) channels of successive geostationary satellite images started in the 1980s. Subsequently, AMVs have become an important component for operational numerical weather prediction throughout the globe for the last decade or so. In India, at the Space Applications Centre, Indian Space Research Organisation, the operational derivation of AMVs (infrared winds and water vapor winds) from the Indian geostationary satellite Kalpana-1 has been initiated a few years back. Recently, an L-band radar lower atmosphere wind profiler (LAWP) has been installed at the National Atmospheric Research Laboratory, Gadanki located at (13.58°N, 79.28°E) for continuous high-resolution wind measurements in the lower atmosphere. In this study, a comparison of Kalpana-1 AMVs with wind measurements from LAWP and radiosonde has been carried out for a period of one and a half years. The performances of Kalpana-1 AMVs are also assessed by a separate comparison of Meteosat-7 AMVs, derived at the European Organisation for the Exploitation of Meteorological Satellites, with wind measurements from LAWP and radiosonde. Both sets of comparison show that AMVs from Kalpana-1 and Meteosat-7 are comparable over the Indian Ocean region. 相似文献
32.
S. K. Deb Steve Wanzong C. S. Velden Inderpreet Kaur C. M. Kishtawal P. K. Pal W. P. Menzel 《Journal of the Indian Society of Remote Sensing》2014,42(4):679-687
The real-time operational use of atmospheric motion vectors (AMVs) at numerical weather prediction (NWP) centers in India are being adversely affected due to inaccurate height assignment of cloud tracers, especially in thin semi-transparent clouds. In India, the operational derivation of AMVs from the Indian geostationary satellite Kalpana-1 began few years ago. A statistical empirical method (SEM) of height assignment, based on a genetic algorithm, is currently used to estimate the height of the retrieved vectors from Kalpana-1. This method has many limitations. In this paper, attempts have been made to implement the widely used and well tested height assignment methods such as the infrared window (WIN) technique, the H2O intercept, and the cloud base method in the Kalpana-1 AMV retrieval algorithm. The new height assignment algorithm significantly improves the statistics of the retrieved winds when compared to radiosondes, especially in high and mid levels winds. 相似文献
33.
Pesticide sorption on to the soil has a significant role in deciding the fate and behavior of pesticides in soil and aquatic environment. The present study investigates the adsorption of monocrotophos (MCP) and dichlorvos (DDVP) on the three soils of Malwa region of Punjab, India under different conditions. Batch adsorption experiments were preformed in replicates using 2 g of air‐dried soil and varying concentrations of pesticides and 20 mL of 0.01 M CaCl2 as background electrolyte. The results revealed high adsorption of MCP and DDVP in soil B with kf‐values 0.1261 and 0.0498 and n‐values 2.7345 and 1.831, respectively. The adsorption isotherms obtained were analyzed and the data was subjected to classical Langmuir, Freundlich, and Temkin models. The experimental data best fitted to the logarithm form of Freundlich and Temkin model. Kinetics analyses were performed using pseudo‐first order, pseudo‐second order, and intraparticle diffusion models. The regression results showed that the experimental data fitted very well with the pseudo‐second order kinetic model as correlation coefficient value is very closer to 1 and also followed the intraparticle diffusion model, whereas, diffusion is not only the rate controlling step. The percentages desorption with tap and distilled water is 32–64% for MCP and 25–48% for DDVP. 相似文献
34.
Pitambar Pati B. Parkash A.K. Awasthi Vivekanand Acharya Satvindar Singh 《Journal of Asian Earth Sciences》2011,40(1):315-325
As no evidence for thrusting has yet been reported from the Indo-Gangetic plain so, the Himalayan Frontal Thrust (HFT) has been considered to be the southern most limit of the Siwaliks to the Indo-Gangetic plain. The present study highlights the thrusting activities between the Gandak and Kosi megafan area in the Middle Gangetic plain. As these thrust sheets are concealed beneath thick sediment cover, direct surficial studies of the discontinuity planes are not possible. Further, the topographic breaks formed by the backward erosion of the uplifted thrust faces resemble normal faults with hanging walls to south. Due to gradual decreasing upliftment and/or erosion from north to south, the area shows a step like topographic appearance. Ground penetrating radar (GPR) studies reveal the concealed thrust planes beneath the sediments and the topographic breaks looking like normal faults are interpreted to be the relief created by backward erosion of the thrust sheets along with the overlying sediments. Out of four GPR profiles taken using 100 MHz antennae, three are across the topographic breaks along which most of the terminal fans are formed and one across the basement fault to study its subsurface nature. Initially GPR failed to strike any subsurface discontinuities at the topographic breaks. However, at certain distance to the south of the topographic breaks, GPR was able to strike the northerly dipping subsurface discontinuity planes. By combining the seismological signatures (distribution of earthquake epicenters) with geomorphology, these discontinuities are identified as thrusts. The GPR profiles show a gradual decrease of dip of the thrust planes from north to south across the area. Hence, by the geomorphology, seismological behavior, topography, orientation and continuity, other topographic breaks can be compared with the proven thrusts. GPR study on the basement fault revealed that the NE–SW trending basement faults are not active in the area. The compression between the South Muzaffarpur fault and the peninsular shield led to the generation of the N–S trending extensional Hathauri–Simariaghat fault with downthrown block towards east. Due to depth penetration limit, the GPR study was confined within 15 m depth. The presence of the discontinuity planes up to the base of the GPR profiles indicate their continuity at least up to the base of Holocene sediments. Although this study brought out the presence of concealed thrusts to the south of the HFT, more detailed work is needed further to study their depth extension, relation to the basement and their implication in Himalayan tectonics in a broad manner. At present, we consider these thrusts to be the splays of the HFT. For confirmation, we propose to carryout detail seismic surveys in future research work. 相似文献
35.
D. Kaur N. K. Bhardwaj R. K. Lohchab 《International Journal of Environmental Science and Technology》2018,15(5):1113-1122
Speedy running down of forest cover has put great stress on paper industry for finding new fibrous raw materials. Rice straw is an abundantly available lignocellulosic material especially in wood-short countries and can be utilized as an alternate fibre resource by paper mills. Bleaching is a crucial step in papermaking that involves the chemical reactions to reduce the colour of the pulp and makes it brighter for manufacturing writing and printing grade paper. Contrary to this, bleaching results into the formation of toxic, biorefractory and carcinogenic chlorolignin compounds that pose serious health hazards to aquatic life and human beings. A study was carried out using rice straw soda-AQ pulp for bleaching with sequence based on elemental chlorine (CEOPHH). Further, to reduce the wastewater pollution load, emphasis was given on replacement of elemental chlorine with chlorine dioxide at the first bleaching stage (CD10EOPHH CD30EOPHH and CD50EOPHH) and elemental chlorine-free (ECF) bleaching (DEOPD). The study revealed that generation of chlorophenolic compounds was the highest in CEOPHH sequence followed by CD10EOPHH CD30EOPHH and CD50EOPHH, i.e. 6047, 4765, 4247 and 3864 mg/t, respectively. In DEOPD bleaching sequence, the generation of chlorophenolic compounds in wastewater was reduced to 421 mg/t. ECF bleaching had major impacts on reduction in chloroguaiacols (97%) and chlorophenols (92%) that were in the highest quantity in effluents of CEOPHH bleaching sequence. DEOPD bleaching was found to be a promising option for pulp and paper industry for cutting down the generation of chlorophenolic compounds in bleaching effluents. 相似文献
36.
Birbhum district in West Bengal, India, is one of the most severely affected districts by fluoride-contaminated groundwater. Fluoride content as high as 20.4 mg/L has been reported. Several cases of fluoride-related disorder such as dental fluorosis and skeletal fluorosis have been reported to be endemic in the district. Proper management of groundwater is very crucial. This contribution has been carried out for delineating potential fluoride-contaminated zones (PFCZ) in Birbhum district with the implementation of weighted overlay analysis in GIS environment. Twelve different potentially influential environmental parameters are integrated and evaluated. The final output map was categorised into two subclasses, i.e. ‘low’ and ‘high’, where the low region represents fluoride concentration of 1.5 mg/L and below and the high region represents fluoride concentration above 1.5 mg/L. The outcome reveals that approximately 24.35% of the study area falls under PFCZ, whereas about 75.65% of the study area falls under the safe zone with respect to potential fluoride contamination. On validation of the PFCZ, the reported fluoride contamination data in groundwater shows an overall 87.50% accuracy in prediction via superimposition method and 89.06 and 85.85% success and prediction rates, respectively, when validated with success and prediction rates. 相似文献
37.
Joseph Susmitha Sahai A. K. Shabu Hindhiya Chattopadhyay R. Kaur Manpreet 《Theoretical and Applied Climatology》2022,147(1-2):251-264
Theoretical and Applied Climatology - Monsoon intraseasonal oscillations (MISOs) define a significant proportion of intraseasonal variability of the Indian summer monsoon. In the backdrop of... 相似文献
38.
Ajitpal Kaur N. K. Sood Lakhwant Singh K. D. Singh 《Astrophysics and Space Science》2006,301(1-4):89-96
The effect of differential rotation on the equilibria of self-gravitating filaments has been examined for isothermal and logatropic
equations of state (EOS). Parametric regions for existence of solutions and upper limits for
(the ratio of the rotational kinetic energy to the gravitational potential energy) have been worked out for the different
laws of rotation. Effect of magnetic field has also been discussed. 相似文献
39.
In this problem, one of the primaries of mass m 1 is a Roche ellipsoid filled with a homogeneous incompressible fluid of density ρ 1. The smaller primary of mass m 2 is an oblate body outside the Ellipsoid. The third and the fourth bodies (of mass m 3 and m 4 respectively) are small solid spheres of density ρ 3 and ρ 4 respectively inside the Ellipsoid, with the assumption that the mass and the radius of the third and the fourth body are infinitesimal. We assume that m 2 is describing a circle around m 1. The masses m 3 and m 4 mutually attract each other, do not influence the motions of m 1 and m 2 but are influenced by them. We have extended the Robe’s restricted three-body problem to 2+2 body problem under the assumption that the fluid body assumes the shape of the Roche ellipsoid (Chandrashekhar in Ellipsoidal figures of equilibrium, Chap. 8, Dover, New York, 1987). We have taken into consideration all the three components of the pressure field in deriving the expression for the buoyancy force viz (i) due to the own gravitational field of the fluid (ii) that originating in the attraction of m 2 (iii) that arising from the centrifugal force. In this paper, equilibrium solutions of m 3 and m 4 and their linear stability are analyzed. We have proved that there exist only six equilibrium solutions of the system, provided they lie within the Roche ellipsoid. In a system where the primaries are considered as Earth-Moon and m 3,m 4 as submarines, the equilibrium solutions of m 3 and m 4 respectively when the displacement is given in the direction of x 1-axis or x 2-axis are unstable. 相似文献
40.
A problem of reflection and transmission of shear wave incident upon a corrugated interface between two monoclinic solid half‐spaces have been investigated. Rayleigh's method of approximation is used to investigate the reflection and transmission coefficients for first and second approximation of the corrugation. For a special interface, closed‐form expressions of these coefficients for the first order approximation of the corrugation are obtained. It is found that these coefficients are functions of amplitude of corrugation, elastic parameters of the media, frequency of the incident wave and angle of incidence. The numerical computations are performed for a specific model and the results obtained are presented graphically. It is found that the reflection and transmission coefficients are strongly influenced by the corrugation and the elastic properties of the media. Results of some earlier workers in this field have been reduced as particular case from the present formulation. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献