Contamination of Pond with Fluoride and Heavy Metals in the Central India     

B. L. Sahu  S. Ramteke  K. P. Rajhans  K. S. Patel  I. Wysocka  I. Jaron 《Water Resources》2018,45(6):992-1001

The ponds are natural water resources used for drinking, bathing, washing and aqua culture. In this work, the contamination of ponds lied in central India with F^– and heavy metals (As, Sb, Cr, Mn, Fe, Cu, Zn, Cd, Pb, Th and U) is described. The F^– concentration in the pond water and sediment (n = 24) was ranged from 1.6–5.5 mg/L and 210–1430 mg/kg with mean value of 2.3 ± 0.4 mg/L and 599 ± 137 mg/kg, respectively. The concentration variation and sources of the elements in the pond water and sediment are discussed. The health hazards of F^– in the domestic animals are described.  相似文献   

Two-soliton solution of ion acoustic solitary waves in nonplanar geometry     

Biswajit Sahu  Rajkumar Roychoudhury 《Astrophysics and Space Science》2013,345(1):91-98

The nonlinear wave structures of ion acoustic waves (IAWs) in an unmagnetized plasma consisting of superthermal electrons and warm ions are studied in bounded nonplanar geometry. Using reductive perturbation technique we have derived cylindrical and spherical Korteweg-de Vries (KdV) equations for IAWs to study the propagation of two-solitons. The presence of superthermally distributed electrons is shown to influence the propagation of two-solitons in nonplanar geometry.  相似文献   

Forecasting Spontaneous Heating Susceptibility of Indian Coals Using Neuro Fuzzy System     

H. B. Sahu  S. S. Mahapatra 《Geotechnical and Geological Engineering》2013,31(2):683-697

Coal mine fires due to spontaneous heating have been a great concern both for the industry and researchers worldwide. They start in a very small scale and gradually expand in size resulting in environmental, safety and economic concerns. Most of these fires could be averted if suitable preventive measures are taken. Since the spontaneous heating potential of all types of coals are not the same, its accurate forecasting is essential to plan efficient preventive measures, production schedule and storage capabilities of a mine. This study presents a neuro-fuzzy approach for forecasting the auto-oxidation of coals based on laboratory test results on fifty cone coal samples collected from different coalfields of India. Using the constituents of proximate analysis as input parameters, crossing point temperature (CPT) is predicted using adaptive neuro-fuzzy inference system (ANFIS) model. Gaussian membership function has been adopted for describing the input variables. The results indicate that ANFIS model can predict CPT values with reasonable accuracy.  相似文献   

Impact of surface observations on simulation of rainfall over NCR Delhi using regional background error statistics in WRF-3DVAR model     

Dipak K. Sahu  S. K. Dash  S. C. Bhan 《Meteorology and Atmospheric Physics》2014,125(1-2):17-42

In this study, efforts are made to improve the simulation of heavy rainfall events over National Capital Region (NCR) Delhi during 2010 summer monsoon, using additional observations from automatic weather stations (AWS). Two case studies have been carried out to simulate the relative humidity, wind speed and precipitation over NCR Delhi in 48-h model integrations; one from 00UTC, August 20, 2010, and the other from 00UTC, September 12, 2010. Several AWS installed over NCR Delhi in the recent past provide valuable surface observations, which are assimilated into state-of-the-art weather research and forecasting (WRF) model using the three-dimensional variational data assimilation (3DVAR). The quality of background error statistics (BES) is a key component in successful 3DVAR data assimilation in a mesoscale model. In this study, the domain-dependent regional background error statistics (RBS) are estimated using National Meteorological Center method in the months of August and September 2010 and then compared with the global background error statistics (GBS) in the WRF model. The model simulations are analyzed and validated against AWS and radiosonde observations to quantify the impact of RBS. The root mean square differences in the spatial distributions of precipitation, relative humidity and wind speed at the surface showed significant differences between both the global and regional BES. Similar differences are also observed in the vertical distributions along the latitudinal cross section at 28.5°N. Model-simulated fields are analyzed at five different surface stations and one upper air station located in NCR Delhi. It is found that in 24-h model simulation, the RBS significantly improves the model simulations in case of precipitation, relative humidity and wind speed as compared to GBS.  相似文献   

An approach to an integrated micro-watershed management plan of outer Himalayan range of Himachal Pradesh, India     

P. K. Sikdar  Surajit Chakraborty  Paulami Sahu  Tulika Biswas 《Environmental Earth Sciences》2013,68(6):1673-1690

Due to the ever-increasing demand on water resource, the pressure on its judicious utilization is also increasing. Besides being precious, this resource is also complex to manage on account of its dynamic behaviour. In India emphasis is being placed on making the local-level users participate in the management of natural resources at the watershed level. Therefore, it is imperative that local-level organizations be strengthened by providing the integrated watershed management tools which are user-friendly, but still use all the scientific knowledge to arrive at the appropriate decisions. This paper demonstrates the use of GIS-based overlay method for local-level planning, incorporating the sustainability aspects of watershed development. A case study has been taken in the Lower Bhangal Micro-watershed of the outer Himalayan range to demonstrate the approach of matrix/ranking and overlay methods to delineate priority areas for watershed management plan.  相似文献   

Migration of arsenic in multi-aquifer system of southern Bengal Basin: analysis via numerical modeling     

P. K. Sikdar  P. Sahu  S. P. Sinha Ray  A. Sarkar  S. Chakraborty 《Environmental Earth Sciences》2013,70(4):1863-1879

A heterogeneous anisotropic steady-state groundwater flow model for the multi-aquifer system of a part of southern Bengal Basin shows that human intervention has changed the natural groundwater flow system. At present, the shallow groundwater flow is restricted within the aquifer, with very short travel time of tens of years and vertical path length. The deep aquifer is fed by surface water or rainwater from distant locations with travel time of thousands of years and has no hydraulic connection with the arsenic-rich shallow aquifer. Numerical simulations indicate that the future pumping of deep groundwater is not likely to drive in arsenic from the shallow aquifer. Therefore, new wells may be installed in the deep aquifer. High pumping of shallow unpolluted aquifer consisting of brown sand will drive in groundwater containing organic matter from the post-Last Glacial Maximum aquifer-aquitard system. The organic matter drives reduction of manganese oxides at strip interfaces between palaeo-channel and palaeo-interfluve. After the completion of manganese reduction, FeOOH reduction may take place in the marginal palaeo-interfluvial aquifer and release sorbed arsenic. Arsenic then moves into the interior of palaeo-interfluvial aquifer polluting its fresh groundwater. Arsenic migration rates ranges between 0.21 and 6.3 and 1.3 × 10^?2 and 0.4 m/year in horizontal and vertical directions, respectively. Therefore, palaeo-interfluvial aquifer will remain arsenic-free for hundreds to thousands of years to supply safe drinking water.  相似文献   

Massive scalar field in the Bianchi Type I space time     

G. Mohanty  S.K. Sahu  P.K. Sahoo 《Astrophysics and Space Science》2003,288(4):421-427

A class of exact solutions of Eistein's field equations with attractive massive scalar field in LRS Bianchi type I space time is obtained. It is shown that how the dynamical importance of the scalar field and the shear change in the course of evolution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Bianchi type-I cosmological effective stiff fluid model in Saez and Ballester theory     

G. Mohanty  S.K. Sahu 《Astrophysics and Space Science》2004,291(1):75-83

The problem of viscous fluid distribution in Bianchi type I space-time is considered here in a new scalar tensor theory of gravitation proposed by Saez and Ballester (1986). Particular solutions of the field equations are derived assuming the viscous coefficient to be the power functions of energy density. Some physical and geometrical properties of the solutions are also discussed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

ESC observations of SN 2005cf – I. Photometric evolution of a normal Type Ia supernova     

A. Pastorello  S. Taubenberger  N. Elias-Rosa  P. A. Mazzali  G. Pignata  E. Cappellaro  G. Garavini  S. Nobili  G. C. Anupama  D. D. R. Bayliss  S. Benetti  F. Bufano  N. K. Chakradhari  R. Kotak  A. Goobar  H. Navasardyan  F. Patat  D. K. Sahu  M. Salvo  B. P. Schmidt  V. Stanishev  M. Turatto  W. Hillebrandt 《Monthly notices of the Royal Astronomical Society》2007,376(3):1301-1316

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Multigroup discrimination of river, beach, and dune sands using axial-ratio sample statistics of quartz grains     

Basanta K. Sahu 《Mathematical Geology》1982,14(6):577-587

Optimal discrimination among several groups can be achieved by simultaneous diagonalization of pooled within-group, W, and among-group, A, sums of squares and cross-product matrices formed by utilizing axial-ratio sample statistics of quartz grains belonging to different sieve grades. This method maximizes the ratio of among-group cross products to within-group cross product quadratic forms (V'AV/V'WV)and simultaneously yields discriminant scores whose correlation coefficients are zero for group means as well as for within each group. This procedure enables a simple Euclidean distance measure for partitioning the discriminant space for assignment. Although W^–1 and Amatrices are symmetric, the W^–1 Amatrix needed for multigroup discrimination is asymmetric and hence the eigenstructure of W^–1 Ais obtained by simultaneous diagonalization of Wand Amatrices. The first four sample statistics (mean, standard deviation, skewness, kurtosis) of normalized axial-ratios are required for discrimination, although the mean and standard deviation are the most important discriminators.  相似文献