The Fauna of Different Drinking Water Sources of Bhagalpur,India     

S. Kumar 《洁净——土壤、空气、水》1990,18(6):683-690

In three drinking water sources i. e. river, well and filter water, there were detected 50 taxa of animals: 10 amoebae and 2 ciliates (protozoa), 24 rotifera, 5 cladocerans, and 9 copepods. Chief components of the rotifers population were Brachionus and Keratella, although K. cochlearis is the most common form at all the sites. The presence of Entamoeba histolytica in well water was indicative of faecal contamination which may become a causative agent of amoebiasis in human beings.  相似文献   

Water Quality,Phytoplankton Diversity and Production in G. B. Pant Sagar at Rihand Dam,Pipri     

N. K. Srivastava  R. S. Ambasht  R. Kumar 《洁净——土壤、空气、水》1991,19(5):529-538

The man made reservoir, G. B. Pant Sagar at the dam site (24° 15′ N Lat) in the South Mirzapur district of eastern U. P. was investigated in terms of water quality, phytoplankton diversity and production at monthly intervals between January 1987 and December 1987. The reservoir water showed low to moderate dissolved oxygen (4.3 … 7.5 mg/l) and quite low nutrient contents (0.01-0.2 mg l^?1). Phytoplankton diversity narrowly fluctuated (3.17-3.74) and mean annual production (149.7 g/m³ · aC) showed a meso- to eutrophic condition. A significant positive correlation was obtained between gross production and phytoplankton density (r = 0.79; P < 0.001) Multiple regression equation (GPP = 11.292 + 0.043 BAC + 0.075 CHL + 0.073 CYN) indicates that Chlorophyta contributed more to gross production due to the presence of a higher number of individuals.  相似文献   

Static deformation of two welded half-spaces due to very long strike-slip dislocations     

Raj Kumar Sharma  Nat Ram Garg  Kuldip Singh 《Journal of Earth System Science》1991,100(4):379-388

Closed form analytic expressions for displacement and stresses at any point of either of the two homogeneous, isotropic, perfectly elastic half-spaces in welded contact due to very long strike-slip dislocations are obtained. Both cases of vertical and horizontal strike-slip dislocations are discussed in detail. Variation of the displacement with horizontal distance from the fault and with vertical distance from the interface for a vertical strike-slip fault is studied numerically.  相似文献   

A Leaky Aquifer Model For Hard Rock Aquifers     

M. Sekhar  M. S. Mohan Kumar  K. Sridharan 《Hydrogeology Journal》1994,2(3):32-39

A comparison is made between the unsteady parallel fracture model using the double porosity approach and the anisotropic aquifer-water table aquitard system. The presence of a moving water table in the weathered zone (unconfined block), influenced by recharge from rainfall or other sources and leakage to the fracture zone, is discussed. The effect of fracture skin on the block-fracture interface is studied for both double-porosity and aquifer-water table aquitard systems. Typical type curves are presented. It is found that the effect of both fracture skin and water table is to lead to a flat drawdown behaviour for a large time. The applicability of the present model for parameters estimation is illustrated on a field pumping test of 7 days duration.

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Résumé: Une comparaison a étéétablie entre le modèle de fractures non constamment parallèles utilisant l'approche de la double porosité et une système composé d'un aquifère anisotrope et un bloc de faible perméabilité avec une surface libre. La présence d'une surface libre variable dans la zone d'altération (bloc non captif), inflluencée par la recharge (pluie ou autre) et par l'écoulement vers la zone fracturée, est discutée. L'effet d'une conche superficielle à l'interface bloc-fracture est étudié pour les deux systèmes, celui à double porosité et celui composé d'un aquifère et d'un bloc de faible perméabilité. Des combes typiques sont montrées. Les résultats montrent que les effets d'une conche superficielle et de la surface de la nappe conduisent à une evolution constante en rabattement pour un temps long. L'application du modèle pour l'estimation des paramètres est justifiée par les résultats d'un pompage d'essai de 7 jours.

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Reply to Comments by S. Mishra and S. N. Rajaguru and by G. L. Badam and S. N. Rajaguru on "Toba Ash on the Indian Subcontinent and Its Implication for the Correlation of Late Pleistocene Alluvium"     

Subhrangsu Kanta Acharya  Prabir Kumar Basu 《Quaternary Research》1994,41(3)

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Global features of sea-level pressure distribution in April and July associated with contrasting situations of Indian summer monsoon     

K Rupa Kumar  L S Hingane 《Journal of Earth System Science》1986,95(2):299-309

Global sea-level pressure distribution has been analysed for the months of April and July for 5 years of contrasting situations of Indian summer monsoon, comprising of two drought years (1972 and 1974), a flood year (1975) and two normal monsoon years (1970 and 1973). Mean monthly sea-level pressure data at about 400 stations have been used in the study. Prominent features of pressure departures from long-term normals have also been noted. It is observed that the month of April shows more prominent contrasting features than July. In April, the high pressure centres over USSR and the North Pacific move considerably eastward during poor monsoon years, while a breakaway cell of Icelandic Low goes deep south. Both the high pressure areas over south Indian Ocean and Australia are stronger in good monsoon years. In July, the subtropical high pressure zone over the southern Indian Ocean is stronger and the Australian high is more eastward, in good monsoon years.  相似文献   

Analysis of Hydraulic Conductivity Averaging Schemes for One-Dimensional, Steady-State Unsaturated Flow     

Rajesh Srivastava  Amado Guzman-Guzman 《Ground water》1995,33(6):946-952

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Toxicity of Nickel to a Fresh Water Teleost,Colisa fasciatus     

N. Kumar  K. Nath 《洁净——土壤、空气、水》1987,15(3):313-315

The acute toxicity of nickel sulphate to Colisa fasciatus has been evaluated by static bioassay experiments. The LC 50 values of nickel for 24, 48, 72 and 96 h were computed to be 96.12, 60.18, 24.45 and 16.72 mg/1, respectively. Their 95 % confidence limits have also been investigated.  相似文献   

Toxic Impact of Hexavalent Chromium on the BLOOD Pyruvate of Colisa fasciatus     

Dr. K. Nath  N. Kumar 《洁净——土壤、空气、水》1987,15(5):531-534

The blood pyruvate levels of a freshwater tropical teleost Colisa fasciatus were investigated from 3 to 96 h following sublethal intoxication of 48 ppm hexavalent chromium. The blood pyruvate levels rose at every time period studied from 3… 96 h. A statistically significant elevation is observed from 24 h and progresses up to 96 h. The maximum elevation of 92.86% has been recorded at 72 h (p<0.001).  相似文献   

Gneiss-charnockite relation around Ponmudi,southern Kerala: evidences and implications of prograde charnockite formation in southern India     

C. Srikantappa  G. R. Ravindra Kumar 《Journal of Earth System Science》1987,96(1):1-10

Isochemical conversion of garnet-biotite bearing paragneiss to charnockite in the Precambrian Khondalite belt of southern Kerala is described from Ponmudi area. Petrographic evidences indicate the formation of hypersthene by the breakdown of biotite in the presence of quartz following the reaction: Biotite + quartz → hypersthene + K-feldspar + vapour. The estimated pressure — temperature conditions of metamorphism are around 5–7 kbars and 750° ± 40°C. Presence of CO₂-rich, mixed CO₂-H₂O and H₂O-rich inclusions were noticed in gneiss as well as in charnockites. Charnockites contain abundant CO₂-rich inclusions.  相似文献