Photoionization Cross-Section of Chlorine-like Iron     

Sunny Aggarwal  Jagjit Singh  A. K. S. Jha  Man Mohan 《Journal of Astrophysics and Astronomy》2012,33(3):291-301

Semi-relativistic calculations are performed for the photoionization of Fe X (an important coronal ion) from its ground state 3s²3p $^{5}(^{2}P^{0}_{3/2})$ and the first two excited states 3s²3p $^{5}(^{2}P^{0}_{1/2})$ and 3s3p $^{6}(^{2}S_{1/2})$ using the Breit?CPauli R-matrix method. A lowest 41 state eigenfunction expansion for Fe XI is employed to ensure an extensive treatment of auto ionizing resonances that affect the effective cross-sections. In the present calculations, we have considered all the important physical effects like channel coupling, exchange and short range correlation. The present calculations using the lowest 41 target levels of Fe XI in the LSJ coupling scheme are reported and we expect that the present results should enable more accurate modelling of the emission spectrum of highly excited plasma from the optical to the far UV region.  相似文献   

Multivariate statistical approach to identify significant sources influencing the physico-chemical variables in Aerial Bay,North Andaman,India   总被引：1，自引：0，他引：1  

Dilip Kumar Jha  N.V. Vinithkumar  Biraja Kumar Sahu  Apurba Kumar Das  P.S. Dheenan  P. Venkateshwaran  Mehmuna Begum  T. Ganesh  M. Prashanthi Devi  R. Kirubagaran 《Marine pollution bulletin》2014

Aerial Bay is one of the harbor towns of Andaman and Nicobar Islands, the union territory of India. Nevertheless, it is least studied marine environment, particularly for physico-chemical assessment. Therefore, to evaluate the annual spatiotemporal variations of physico-chemical parameters, seawater samples collected from 20 sampling stations covering three seasons were analyzed. Multivariate statistics is applied to the investigated data in an attempt to understand the causes of variation in physico-chemical parameters. Cluster analysis distinguished mangrove and open sea stations from other areas by considering distinctive physico-chemical characteristics. Factor analysis revealed 79.5% of total variance in physico-chemical parameters. Strong loading included transparency, TSS, DO, BOD, salinity, nitrate, nitrite, inorganic phosphate, total phosphorus and silicate. In addition, box-whisker plots and Geographical Information System based land use data further facilitated and supported multivariate results.  相似文献   

Numerical groundwater-flow modeling to evaluate potential effects of pumping and recharge: implications for sustainable groundwater management in the Mahanadi delta region,India   总被引：1，自引：0，他引：1  

Sasmita Sahoo  Madan K. Jha 《Hydrogeology Journal》2017,25(8):2489-2511

Process-based groundwater models are useful to understand complex aquifer systems and make predictions about their response to hydrological changes. A conceptual model for evaluating responses to environmental changes is presented, considering the hydrogeologic framework, flow processes, aquifer hydraulic properties, boundary conditions, and sources and sinks of the groundwater system. Based on this conceptual model, a quasi-three-dimensional transient groundwater flow model was designed using MODFLOW to simulate the groundwater system of Mahanadi River delta, eastern India. The model was constructed in the context of an upper unconfined aquifer and lower confined aquifer, separated by an aquitard. Hydraulic heads of 13 shallow wells and 11 deep wells were used to calibrate transient groundwater conditions during 1997–2006, followed by validation (2007–2011). The aquifer and aquitard hydraulic properties were obtained by pumping tests and were calibrated along with the rainfall recharge. The statistical and graphical performance indicators suggested a reasonably good simulation of groundwater flow over the study area. Sensitivity analysis revealed that groundwater level is most sensitive to the hydraulic conductivities of both the aquifers, followed by vertical hydraulic conductivity of the confining layer. The calibrated model was then employed to explore groundwater-flow dynamics in response to changes in pumping and recharge conditions. The simulation results indicate that pumping has a substantial effect on the confined aquifer flow regime as compared to the unconfined aquifer. The results and insights from this study have important implications for other regional groundwater modeling studies, especially in multi-layered aquifer systems.  相似文献   

Microwave response of green vegetation     

K. K. Jha  K. P. Singh  R. N. Singh 《Journal of Earth System Science》1982,91(3):209-217

The cavity perturbation technique has been used to measure the dielectric constant of vegetation, such as soyabean, grass, corn and green spruce at 9.5 GHz. The dielectric properties of these vegetations are highly dependent upon the moisture content. For freshly plucked specimen the dielectric constant was found to be maximum which decreased gradually as the specimen dried up. The role of these basic physical parameters in microwave scatterometer experiment has been discussed. Some parameters of remote sensing application have been estimated from these measurements and their practical role has been discussed  相似文献   

Model tank experiments for resistivity measurements on non-conducting and conducting sheets     

J. Singh  B. P. Jha  R. P. Gupta 《Pure and Applied Geophysics》1971,85(1):90-106

Summary Model tank experiments for conducting and non-conducting sheets have been described and the results compared with those of other workers.  相似文献   

Studies in the dielectric constant of Indian sandstones as a function of water content,part II     

Jagdeo Singh  B. P. Jha 《Pure and Applied Geophysics》1971,85(1):254-268

Summary Dielectric constants of many sedimentary and metamorphic rocks as a function of water content and frequency have been measured and represented graphically. The results are discussed in the light of known theories. The most significant part of the observations is a type of hysteresis cycle in the values of the dielectric constant for increasing and decreasing water content.  相似文献   

Magnetic survey over Jharia Coal Field     

R. K. Verma  S. N. Prasad  B. P. Jha 《Pure and Applied Geophysics》1973,102(1):124-133

Summary Magnetic survey over Jharia Coal Field has been conducted using Askania torsion magnetometer. Nearly 200 observations were taken over the sedimentary outcrops as well as over crystalline rocks surrounding these. The anomaly map was prepared. The map shows interesting correlation with tectonics of the basin and throws some light on the nature of the underlying basement.  相似文献   

Remote sensing for geology,geomorphology and lineament study of Vindhyan basin,north of Shivpuri,Madhya Pradesh     

V. K. Jha  A. K. Roy  H. P. Jaiswar 《Journal of the Indian Society of Remote Sensing》1985,13(1):39-48

The study area comprises Bundelkhand Granite of Archaean age in the east, unconformably overlain by Upper Vindhyan sequence, ranging from Upper Kaimur Sandstone to Lower Bhander Sandstone Groups, in the west. Geomorphologically, the area has been divided into three geomorphic provinces viz. (1) Bundelkhand inselberg — pediplain, (2) Vindhyan structural plateau, consisting of two major sub-levels of Upper and Lower Bhander Sandstone Groups and two minor sub-levels of Upper and Lower Rewa Sandstone Groups, separated by escarpment and/or valleys, and (3) Chambal alluvial plain. Photo-interpretation and field studies indicate that there are three sets of lineament trends in the area out of which the NNW-SSE trend comes out very strongly on imagery and is correlatable with basement fracture trend of Bundelkhand massif. The synoptic view through imagery also gives the impression that the course of Chambal river towards north and west is controlled by a major lineament, possibly a regional fault trending NE-SW. The NNW-SSE lineament trend mentioned above then probably reflects tension release aspect of the faulting. The field check has brought out some very broad, gentle warps also with NNE-SSW trend in the area. The paper presents the salient observations on geological, structural and geomorphological studies for Shivpuri area based on remote-sensing techniques and their utility for such regional investigations.  相似文献   

Aerial photographs-a useful aid in delineation of the ophiolite belt along indo-burmese border     

V. K. Jha 《Journal of the Indian Society of Remote Sensing》1984,12(2):31-37

The eastern border of India with Burma represents a fairly young tectonic zone. The main rock types of the area belong to the Disang Group of Eocene to Upper Cretaceous age. The Ophiolites have concordant relationship with these rocks. The 200 km long belt of NNE -SSW trending Ophiolite suite of rocks in Manipur and Nagaland is of great academic importance as it has been postulated as probable plate boundary along which ophiolites have been emplaced. It holds immense economic importance too, being the carrier of elements of strategic mineral importance, such as nickel, chromium, platinum etc. Photo-interpretation has been successfully used in delineating the extensions of and location of the important NNE-SSW. lineament along which ophiolite has been emplaced. It has been possible to demarcate .the ophiolite bodies on the basis of their distinct photo-characters from that of sedimentaries. An attempt has also been made to decipher its structural and tectonic relationship with country rocks.  相似文献   

Quantitative treatment of annealing of charged particle tracks in common minerals     

J.N. Goswami  R. Jha  D. Lal 《Earth and Planetary Science Letters》1984,71(1):120-128

A semi-empirical approach has been used to obtain an analytical expression for the annealing of charged particle tracks in minerals as a function of time and temperature. The new formalism allows quantitative evaluation of the extent of annealing in samples for any specified temperature and track production history. The validity of the present approach depends upon the applicability of the Arrhenius equation to the process of annealing of nuclear tracks in solids. Laboratory track annealing studies confirm the predictive aspects of the present approach and also the applicability of Arrhenius' equation to track annealing over a wide time-temperature range (5 seconds/1200 K to 5 × 10⁶ seconds/500 K). The present quantitative treatment of track annealing in rock minerals should permit an in-depth study of a variety of problems in meteoritics and earth sciences.  相似文献