Biodegradation of phenanthrene in bioaugmented microcosm by consortium ASP developed from coastal sediment of Alang-Sosiya ship breaking yard     

Vilas Patel  Janki Patel  Datta Madamwar 《Marine pollution bulletin》2013

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Structure of neutron star cores     

V. Canuto  B. Datta  J. Lodenquai 《Astrophysics and Space Science》1975,34(1):223-229

After reviewing the outer and central regions of a neutron star, we discuss the central region and the possibility that the core has a solid structure. We present the work of different groups on the solidification problem, suggesting that the neutron star-cores are indeed solid.  相似文献   

Torsional vibrations of elastic foundations embedded in an elastic half-space     

R. K. N. D. Rajapakse  A. H. Shah  S. K. Datta 《地震工程与结构动力学》1987,15(3):279-297

This paper examines the axisymmetric torsional vibrations of an elastic pile and a hemispherical foundation embedded in a homogeneous elastic half-space. The embedded foundation–half-space system is decomposed into an extended half-space and a fictitious foundation. The deformations of the fictitious system are specified by an admissible function containing a set of generalized coordinates. The Lagrangian equations of motion are used to determine these coordinates associated with the assumed displacement function. Numerical results are presented for torsional impedance of an elastic pile and a hemisphere to illustrate the effects of relative flexibility and geometry. By employing certain simplifications on the pile–half-space system an approximate closed form solution is presented for the torsional impedance of an elastic pile.  相似文献   

Dynamic response of pipelines to moving loads     

S. K. Datta  T. Chakraborty  A. H. Shah 《地震工程与结构动力学》1984,12(1):59-72

Vibration of buried pipelines induced by moving axial and radial loads has been studied in this paper. A thin shell model has been used for the pipeline, which is assumed to be lying in an infinite isotropic homogeneous elastic medium. In order to allow for the possible motion of the pipe out of phase with the surrounding ground a very thin layer of viscoelastic material is assumed to separate the pipe from the ground. Calculations indicate the presence of the interfacial viscoelastic layer does not influence the pipe response in a significant manner. So all the numerical results presented here are for the case when the pipe is assumed to be perfectly bonded. These show that the maximum pipewall displacements and stresses occur in a soft soil at long wavelengths.  相似文献   

Biomarker responses in Macoma nasuta (Bivalvia) exposed to sediments from northern San Francisco Bay     

Werner I  Teh SJ  Datta S  Lu X  Young TM 《Marine environmental research》2004,58(2-5):299-304

Our study investigates biomarker responses and survival of Macoma nasuta exposed to sediments collected from six locations in northern San Francisco Bay. Biomarkers analyzed were stress proteins (hsp70) in gill, mantle and digestive gland, lysosomal membrane damage and histopathologic lesions. Sediments and clam tissues were analyzed for a comprehensive suite of heavy metals and trace organic pollutants. Sediment grain size and organic carbon content were determined. Clams accumulated metals, polyaromatic hydrocarbons (PAHs) and organochlorine pesticides (aldrin and p,p(')-DDT and its metabolites p,p(')-DDD and p,p(')-DDE). Pearson and Spearman correlation analysis revealed that mortality, hsp70 in gill and histopathologic lesion scores in gonads, and lysosomal membrane damage were significantly correlated with tissue concentrations of DDT and/or its metabolites. Tissue concentrations of metals, in particular nickel, chromium, and copper, were associated with macrophage aggregates in digestive gland and germ cell necrosis. Cadmium was linked to mortality and lysosomal membrane damage.  相似文献   

Seasonal variation of antioxidant and biotransformation enzymes in barnacle, Balanus balanoides, and their relation with polyaromatic hydrocarbons   总被引：6，自引：0，他引：6  

Niyogi S  Biswas S  Sarker S  Datta AG 《Marine environmental research》2001,52(1):13-26

Seasonal variations in the antioxidant enzymes (catalase, superoxide dismutase [SOD], NADH-DT diaphorase), biotransformation enzyme, glutathione-S-transferase (GST) and microsomal lipid peroxidation in digestive tissue of barnacle, Balanus balanoides, from polluted and non-polluted populations have been evaluated. Relationships with accumulated polyaromatic hydrocarbon (PAH) concentration in barnacle tissues and environmental parameters (water temperature, salinity, dissolved oxygen concentration, water pH) were determined. As a general trend, maximum antioxidant enzyme and GST activities were detected in the pre-monsoon period or summer (March-June) followed by a gradual decrease during the monsoon (July October) with a minimum in the post-monsoon period or winter (November February). This pattern was similar to tissue concentrations of PAHs, resulting in a significant positive correlation with antioxidant enzymes, mainly catalase and SOD. Microsomal lipid peroxidation exhibited an almost reverse trend of seasonal variation to that of antioxidant enzyme activities indicating an enhanced susceptibility of barnacle tissues to oxidative stress. Among the environmental parameters, only water temperature seemed to have a significant effect on observed variations of antioxidant enzymes and GST activities. The barnacles from polluted and non-polluted populations exhibited seasonal differences in the activities of all the enzymes studied, particularly catalase, SOD and GST, suggesting the possibility of some biochemical adaptation in organisms from a chronically polluted environment. The results indicated that antioxidant defense components, catalase and SOD, are sensitive parameters that could be useful biomarkers for the evaluation of contaminated aquatic ecosystems. The results also suggested the potentiality of barnacle, B. balanoides, as a bioindicator organism against organic pollution.  相似文献   

Elastic wave velocities in rocks     

Satyabrata Datta  K. R. Madhwa Simha 《Pure and Applied Geophysics》1968,70(1):5-11

Summary Compressional wave velocity has been measured in the laboratory by the ultrasonic pulse technique in a number of rock specimens of different geological formations collected from different parts of India. The effect of water saturation on the velocity in some of the porous samples has been investigated. The velocity in some polycrystalline aggregate crystals and in some ores has also been determined. The accuracy of measurements varies from 1 to 2 per cent. The results of measurements with geological details are presented in tabulated form.This paper is published by the kind permission of the Director General, Geological Survey of India.  相似文献   

Interpretations of self potential anomalies due to localised causative bodies     

Mrinal K. Paul  Sukumar Datta  Buddhadeb Banerjee 《Pure and Applied Geophysics》1965,61(1):95-100

Summary Some direct methods of interpretation of SP anomalies that may arise from localised causative bodies have been developed in this paper. The models of the current sources that have been considered here are the cases of 1. single vertical dipole, 2. a pair of similar and similarly situated vertical dipoles and 3. an inclined dipole. A set of three master curves has been prepared in terms of which the interpretation in the first and the third case is complete. With an additional assumption that the distance between the dipoles is small, the second case also is completely solved with the help of the same set of master curves.Published under the kind permission of the Director General, Geological Survey of India, Calcutta.  相似文献   

Saltwater intrusion prediction in coastal aquifers utilizing a weighted-average heterogeneous ensemble of prediction models based on Dempster-Shafer theory of evidence     

Dilip Kumar Roy  B. Datta 《水文科学杂志》2020,65(9):1555-1567

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Geochemistry of groundwater,Burdwan District,West Bengal,India     

S. Gupta  A. Mahato  P. Roy  J. K. Datta  R. N. Saha 《Environmental Geology》2008,53(6):1271-1282

Hydrogeochemical investigations are carried out in the different blocks of Burdwan district, West Bengal, India in order to assess its suitability for drinking as well as irrigation water purpose. Altogether 49 representative groundwater samples are collected from bore wells and the water chemistry of various ions viz. Ca²⁺, Mg²⁺, Na⁺, K⁺, CO₃²⁻, HCO₃⁻, Cl⁻, SO₄²⁻ and NO₃⁻ are carried out. The chemical relationships in Piper and Gibbs diagram suggest that the groundwater mainly belongs to alkali type and Cl⁻ group and are controlled by rock dominance. A comparison of groundwater quality in relation to drinking water quality standards proves that most of the water samples are suitable for drinking water purpose whereas groundwater in some areas of the district has high salinity and high sodium adsorption ratio (SAR), indicating unsuitability for irrigation water and needs adequate drainage.  相似文献