Multivariate canonical correlation techniques: An economic approach for evaluation of pollutants in soil and sediments of Bombay region, India     

D. S. Ratha  B. K. Sahu 《Environmental Geology》1993,21(4):201-207

Multivariate canonical correlation analysis has been carried out taking physical variables (mean, standard deviation, skewness, kurtosis) as predictors and chemical variables (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) as responses from the soils and sediments of Thane Creek and Ulhas River areas in Bombay, India. Soil samples provide the first canonical correlation to the presence of more clay fractions, which controls the concentration of trace elements such as Co, Fe, and Ni. In sediment samples, the first canonical correlation explains the role of mean particle size in controlling the concentration of Pb and Ni. The second correlation shows the role of clay minerals in controlling the concentration of the trace elements such as Fe and Zn. The plot of transformed scores of first canonical correlation for soil illustrate the high correlation between sets of variables as all points are grouped closely within an ellipsoidal field. The plot of transformed scores of first canonical correlation illustrate that there is a clear distinction between the type of sediments collected from Thane creek and the Ulhas river region.  相似文献   

Letters to the editor     

John C. Gower  Norman Gray  M. E. Demina  Basanta K. Sahu 《Mathematical Geology》1973,5(2):203-209

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IOD and ENSO impacts on the extreme stream-flows of Citarum river in Indonesia     

Netrananda Sahu  Swadhin K. Behera  Yosuke Yamashiki  Kaoru Takara  Toshio Yamagata 《Climate Dynamics》2012,39(7-8):1673-1680

Extreme stream-flow events of Citarum River are derived from the daily stream-flows at the Nanjung gauge station. Those events are identified based on their persistently extreme flows for 6 or more days during boreal fall when the seasonal mean stream-flow starts peaking-up from the lowest seasonal flows of June–August. Most of the extreme events of high-streamflows were related to La Ni?a conditions of tropical Pacific. A few of them were also associated with the negative phases of IOD and the newly identified El Ni?o Modoki. Unlike the cases of extreme high streamflows, extreme low streamflow events are seen to be associated with the positive IODs. Nevertheless, it was also found that the low-stream-flow events related to positive IOD events were also associated with El Ni?o events except for one independent event of 1977. Because the occurrence season coincides the peak season of IOD, not only the picked extreme events are seen to fall under the IOD seasons but also there exists a statistically significant correlation of 0.51 between the seasonal IOD index and the seasonal streamflows. There also exists a significant lag correlation when IOD of June–August season leads the streamflows of September–November. A significant but lower correlation coefficient (0.39) is also found between the seasonal streamflow and El Ni?o for September–November season only.  相似文献   

REE-HFSE distribution/partitioning between garnetiferous restites and TTG from Nademavinapura area,Western Dharwar craton     

S. N. Charan  E. V. S. S. K. Babu  S. M. Naqvi  J. G. Rana Prathap  M. Ram Mohan  D. Srinivasa Sarma 《Journal of the Geological Society of India》2009,73(3):371-378

The major part of the Peninsular Gneiss in Dharwar craton is made up of Trondjhemite-Tonalite-Granodiorite (TTG) emplaced at different periods ranging from 3.60 to 2.50 Ga. The sodic-silicic magma precursors of these rocks have geochemical features characteristic of partial melting of hydrated basalt. In these TTGs, enclaves of amphibolites (± garnet) are abundant. These restites are considered to be the residue of a basaltic crust after its partial melting. A detailed study of these (residue) enclaves reveals textures formed due to the process of partial melting. Major, trace and REE analysis of these residue enclaves and the melt TTGs and microprobe analysis of the coexisting minerals show partitioning of REE and HFSE between the precursor melt of TTGs and the upper amphibolite facies residues. Formation of garnetiferous amphibolites with biotite, Cpx and plagioclase consequent to melting, has squeezed the original MORB type of basaltic crust and given rise to the TTGs, depleted in Y, Yb, K₂O, MgO, FeO, TiO₂ and enriched in La, Th, U, Zr and Hf. Coevally during the process of melting, the hydrated basalt was depleted in Na₂O, Al₂O₃, LREE, Th, U and enriched in K₂O, MgO, Nb, Ti, Yb, Y, Sc, Ni, Cr and Co. Mineral chemistry of co-existing garnet-biotite and amphibole-plagioclase in these amphibolitic (restite) enclaves indicates an average temperature of 700 ± 50° C and pressure of 5 ± 1 Kbar. These data are inferred to indicate that during the garnet stability field metamorphism, effective fractionation of HREE and HFSE has taken place between the restites having Fe-Mg silicates, ilmenites and the extracted melt generated from the MORB type of hydrated basalt. These results are strongly substantiated by the reported melting experiments on hydrated basalts.  相似文献   

Ion acoustic solitary and shock waves with nonextensive electrons and thermal positrons in nonplanar geometry     

Biswajit Sahu 《Astrophysics and Space Science》2012,338(2):251-257

The nonlinear wave structures of ion acoustic waves (IAWs) in an unmagnetized plasma consisting of nonextensive electrons and thermal positrons are studied in bounded nonplanar geometry. Using reductive perturbation technique we have derived cylindrical and spherical Korteweg-de Vries-Burgers’ (KdVB) equations for IAWs. The presence of nonextensive q-distributed electrons is shown to influence the solitary and shock waves. Furthermore, in the existence of ion kinematic viscosity, the shock wave structure appears. Also, the effects of nonextensivity of electrons, ion kinematic viscosities, positron concentration on the properties of ion acoustic shock waves (IASWs) are discussed in nonplanar geometry. It is found that both compressive and rarefactive type solitons or shock waves are obtained depending on the plasma parameter.  相似文献   

Magnetoelastic shear wave propagation in pre-stressed anisotropic media under gravity     

Nirmala Kumari  Amares Chattopadhyay  Abhishek K. Singh  Sanjeev A. Sahu 《Acta Geophysica》2017,65(1):189-205

The present study investigates the propagation of shear wave (horizontally polarized) in two initially stressed heterogeneous anisotropic (magnetoelastic transversely isotropic) layers in the crust overlying a transversely isotropic gravitating semi-infinite medium. Heterogeneities in both the anisotropic layers are caused due to exponential variation (case-I) and linear variation (case-II) in the elastic constants with respect to the space variable pointing positively downwards. The dispersion relations have been established in closed form using Whittaker’s asymptotic expansion and were found to be in the well-agreement to the classical Love wave equations. The substantial effects of magnetoelastic coupling parameters, heterogeneity parameters, horizontal compressive initial stresses, Biot’s gravity parameter, and wave number on the phase velocity of shear waves have been computed and depicted by means of a graph. As a special case, dispersion equations have been deduced when the two layers and half-space are isotropic and homogeneous. The comparative study for both cases of heterogeneity of the layers has been performed and also depicted by means of graphical illustrations.  相似文献   

Evaluation of significant sources influencing the variation of physico-chemical parameters in Port Blair Bay,South Andaman,India by using multivariate statistics     

Biraja Kumar Sahu  Mehmuna Begum  M.K. Khadanga  Dilip Kr Jha  N.V. Vinithkumar  R. Kirubagaran 《Marine pollution bulletin》2013,66(1-2):246-251

Port Blair is the capital city of Andaman & Nicobar Islands, the union territory of India. More than 50% of the population of these islands lives around Port Blair Bay. Therefore the anthropogenic effects in the bay water were studied for monitoring purpose from seven stations. Physico-chemical parameters of seawater were analyzed in samples collected once in every 3 months for 2 years from seven sampling stations located in Port Blair Bay, South Andaman Island to evaluate the spatial and tidal variation. Cluster analysis and factor analysis were applied to the experimental data in an attempt to understand the sources of variation of physico-chemical parameters. In cluster analysis, the stations Junglighat Bay and Phoenix Bay having high anthropogenic influence formed a separate group. The factors obtained from factor analysis indicated that the parameters responsible for physico-chemical variations are mainly related to land run-off, sewage outfall and tidal flow.  相似文献   

Emissions of greenhouse and non-greenhouse air pollutants from fuel combustion in restaurant industry     

D. Majumdar  A. Chintada  J. Sahu  C. V. Chalapati Rao 《International Journal of Environmental Science and Technology》2013,10(5):995-1006

Information on emissions from restaurant industry is limited in scientific literature. Emission inventory of greenhouse and non-greenhouse air pollutants from restaurant industry was prepared for two Class 1 Indian cities, viz. Nagpur and Raipur for 2010. Emissions were estimated from a primary database on type and amount of cooking fuel combusted in restaurant industry in the selected cities. Liquefied petroleum gas, charcoal, wood, coal, diesel and candy coal are used in this industry, first three being the major ones. Carbon dioxide emission was highest in both cities and liquefied petroleum gas, charcoal and wood were the major contributors to emissions. Total annual emissions of greenhouse gases, viz. carbon dioxide, methane and nitrous oxide were estimated to be 19,251, 27 and 1 Mg year^?1 in Nagpur and 21,207, 34 and 1 Mg year^?1 in Raipur, whereas total annual emissions of non-methane hydrocarbon (NMHC), carbon monoxide, total suspended particulate (TSP), sulphur dioxide, nitrogen oxides and black carbon (BC) were 96, 959, 31, 12, 19, 3 Mg year^?1 and 87, 1141, 78, 37, 28, 6 Mg year^?1 in Nagpur and Raipur, respectively, from all the fuels used in restaurant industry. Considering the huge growth of Indian restaurant industry in the last decade and the predicted growth in future, emissions from this industry is assumed to grow and will play a major role in governing regional and national emissions in India.  相似文献   

A study on soil physico-chemical, microbial and metal content in Sukinda chromite mine of Odisha, India   总被引：1，自引：1，他引：0  

S. Das  S. S. Ram  H. K. Sahu  D. S. Rao  A. Chakraborty  M. Sudarshan  H. N. Thatoi 《Environmental Earth Sciences》2013,69(8):2487-2497

Soil samples from chromite mining site and its adjacent overburden dumps and fallow land of Sukinda, Odisha, were analysed for their physico-chemical, microbial and metal contents. Chromite mine soils were heterogenous mixture of clay, mud, minerals and rocks. The pH of the soils ranges between 5.87 and 7.36. The nutrient contents of the mine soils (N, P, K and organic C) were found to be extremely low. Analysis of chromite mine soils revealed accumulation of a number of metals in high concentrations (Fe > Cr > Mn > Ni > Zn > Pb > Sr) which exceeded ecotoxicological limits in soil. Correlation and cluster analysis of metals revealed a strong relation between Cr, Ni, Fe, Mn among the different attributes studied. Assessment of different microbial groups such as fungi, actinomycetes and bacteria (heterotrophic, spore forming, free-living nitrogen fixing, phosphate solubilising and cellulose degrading) from mine soils were found to be either extremely low or absent in some soil samples. Further chromium tolerant bacteria (CTB) were isolated using 100 mg/L Cr(VI) enriched nutrient agar medium and were screened for their tolerance towards increasing concentrations of hexavalent chromium and other toxic metals. Out of 23 CTB isolates, three bacteria tolerated up to 900 mg/L, 6 up to 500 mg/L, 20 up to 200 mg/L of Cr(VI). These bacteria were also found to be sensitive towards Cu > Co > Cd and very few CTB strains could show multiple metal tolerance. These strains have great scope for their application in bioremediation of toxic chromium ions in presence of other metals ions, which needs to be explored for their biotechnological applications.  相似文献   

Propagation of two-solitons in an electron acoustic waves in a plasma with electrons featuring Tsallis distribution     

Biswajit Sahu 《Astrophysics and Space Science》2013,345(2):415-420

A first theoretical work is presented to study the propagation of two-solitons in an electron acoustic waves (EAWs) within the theoretical framework of the Tsallis statistical mechanics. For this purpose, cylindrical and spherical Korteweg-de Vries (KdV) equations are derived for electron acoustic solitary waves (EASWs) in an unmagnetized three species plasma system comprised of cold electrons, immobile ions and hot electrons featuring Tsallis statistics by employing the standard reductive perturbation method. The effects of electron nonextensivity and the fractional number density of the hot electrons relative to that of the cold ones number density (α) on the profiles of two-soliton structures are investigated numerically. Results would be helpful for understanding the localized structures that may occur in space plasmas.  相似文献