Prediction of the Bioconcentration Factor of Organic Compounds in Fish     

Vishnu Kumar Sahu  Rajesh Kumar Singh 《洁净——土壤、空气、水》2009,37(11):850-857

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Effects of soil layering on the characteristics of basin-edge induced surface waves     

Jay Prakash Narayan  Sanjay Kumar 《Acta Geophysica》2009,57(2):294-310

This paper presents the effects of soil layering on the characteristics of basin-edge induced surface waves and associated strain and aggravation factor. The simulated results revealed surface wave generation near the basin-edge. The first mode of induced Love wave was obtained in models having increasing velocity with depth and a large impedance contrast between the soil layers. Amplitude amplification or de-amplification of body waves was proportional to the impedance contrast between the soil layers. The average aggravation factor was inversely proportional to the impedance contrast between the soil layers in case of increasingvelocity models and proportional in case of decreasing-velocity basinedge models. On the other hand, the maximum strain was inversely proportional to the impedance contrast between the soil layers in both cases. On the average, strain was greater in case of increasing-velocity models but the average aggravation factor was greater in case of decreasingvelocity models.  相似文献   

Environmental isotopes investigation on recharge processes and hydrodynamics of the coastal sedimentary aquifers of Tiruvadanai,Tamilnadu State,India     

U. Saravana Kumar  Suman Sharma  S.V. Navada  A.S. Deodhar 《Journal of Hydrology》2009,364(1-2):23-39

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Morphostratigraphy and fan morphology of doon valley     

R S. Chandel  I B. Singh 《Journal of the Indian Society of Remote Sensing》2000,28(4):265-275

In the present study analysis of Landsat MSS, TM and SPOT imagery and digital analysis of IRS LISS-1 data of Doon Valley was carried out. Various geomorphic features were identified and classified, morphostratigraphy of the area has been established. Main geomorphic units of the area are Mussoorie Hill Range (Denudational), Siwalik Hills (Structural), Remnant Hills (Residual). Siwalik Piedmont. Doon Piedmont, River Terraces and Flood Plain. Three large fan lobes are identified on Doon Piedmont deposits, viz., Western fan lobe, Central fan lobe and Eastern fan lobe. Average slope of these three fan lobes are 2°21′, 2°3′, and 1°24′ for the western, central and eastern fan lobes respectively. Western and central fan lobes have been affected by neotectonic activity which is reflected in transverse profiles.  相似文献   

Application of remote sensing data in characterization and mapping of soil resources for watershed planning in arid Western Rajasthan     

M A Khan  Nepal Singh 《Journal of the Indian Society of Remote Sensing》2000,28(2-3):93-113

Visual interpretation of IRS-L1SS-II (January, 1995) FCC (1:50,000 scale) of spectral bands 2, 3 and 4 was carried out for the identification and mapping of major physiographic units in an arid watershed of Jodhpur district (Rajasthan). Based on image characteristics and field traverses, seven major physiographic units identified are (1) hills (2) pediments, flat to undulating (3) buried pediments, moderately deep to deep, coarse textured (4) buried pediment, shallow to moderately deep and deep, medium to fine textured, saline (5) older alluvial plains, deep and very deep, coarse textured (6) younger alluvial plains, deep to very deep, very coarse textured and (7) dune complexes. Based on physiographicvariatton and soil or site characteristics such as texture, depth, slope, erosion and underneath substrata, 41 soil mapping units were identified and mapped. Final physiography, soil, slope, drainage and landuse maps were prepared on 1:5,000 scale. Taxonomically, the soils of the watershed were classified as Para-Lithic Torriorthents, coarse-loamy, Lithic/Typic Haplocambids, fine-loamy, Lithic/Typic Haplosalids and Typic Torrifluvents and Typic Torripsamments. Land suitability for various mapping units in the watershed have been assessed on the basis of soil physico-chemical characteristics.  相似文献   

Seismotectonics of the Himalaya and its vicinity from centroid-moment tensor (CMT) solution of earthquakes     

D. D. Singh 《Journal of Geodynamics》2000,30(5):159

The centroid-moment tensor solutions of more than 300 earthquakes that occurred in the Himalayas and its vicinity regions during the period of 1977–1996 are examined. The resultant seismic moment tensor components of these earthquakes are estimated. The Burmese arc region shows prominent east–west compression and north–south extension with very little vertical extension. Northeast India and Pamir–Hindu Kush regions show prominent vertical extension and east–west compression. The Indian plate is subducting eastward beneath the northeast India and Burmese arc regions. The overriding Burmese arc has overthrust horizontally with the underthrusting Indian plate at a depth of 20–80 km and below 80 km depth, it has merged with the Indian plate making “Y” shape structure and as a result the aseismic zone has been formed in the region lying between 26°N–28°N and 91.5°E–94°E at a depth of 10–50 km. Similarly, the Indian plate is underthrusting in the western side beneath the Pamir–Hindu Kush region and the overriding Eurasian plate has overthrust it to form a “Y” shape structure at a depth of 10–40 km and below 60 km depth, it has merged with the Indian plate and both the plates are subducting below 60–260 km depth. Further south, the overriding Eurasian plate has come in contact with the Indian plate at a depth of 20–60 km beneath northwest India and Pakistan regions with left lateral strike slip motion.  相似文献   

Computing the 3D in-situ stress field from shut-in pressure data using statistical regression     

Upendra K. Singh  Bharat C. Sahoo 《Geotechnical and Geological Engineering》2000,18(2):119-137

The paper describes a multivariable statistical regression technique for computing the 3D stress tensor applied to the shut-in pressure data obtained on fractures during in-situ stress measurement by hydraulic fracturing in a short borehole. This method computes the mean value of components of the 3D stress tensor and their confidence intervals at a desired confidence level. This has been applied to the data of shut-in pressure from Narwapahar mine, India and Kamaishi mine, Japan. The computed in-situ stress tensor is corroborated with that obtained by other methods.  相似文献   

Abundance and relationship of bacteria with transparent exopolymer particles during the 1996 summer monsoon in the Arabian Sea     

N. Ramaiah  V. V. S. S. Sarma  Mangesh Gauns  M. Dileep Kumar  M. Madhupratap 《Journal of Earth System Science》2000,109(4):443-451

Bacterial abundance and production, numbers, sizes and concentrations of transparent exopolymer particles (TEP) and total organic carbon (TOC) were measured during the 1996 summer monsoon to understand the relationship between TEP, the most labile particulate organic carbon, and bacteria. While high regional variability in the vertical distribution of TOC was discernible, TEP concentrations were high in surface waters at 18–20°N along 64°E with concentrations well over 25 mg alginic acid equivalents I⁻¹ due to upwelling induced productivity. Their concentrations decreased with depth and were lower between 200 and 500 m. Bacterial concentrations were up to 1.99 × 10⁸ I^–1 in the surface waters and decreased by an order of magnitude or more at depths below 500 m. A better relationship has been found between bacterial abundance and concentrations of TEP than between bacteria and TOC, indicating that bacterial metabolism is fueled by availability of TEP in the Arabian Sea. Assuming a carbon assimilation of 33%, bacterial carbon demand (BCD) is estimated to be 1.017 to 4.035 g C m^–2 d^–1 in the surface waters. The observed TEP concentrations appear to be sufficient in meeting the surface and subsurface BCD in the northern Arabian Sea.  相似文献   

Quantification of stability improvement of a dump through biological reclamation     

S. K. Chaulya  R. S. Singh  M. K. Chakraborty  B. K. Srivastava 《Geotechnical and Geological Engineering》2000,18(3):193-207

An integrated study on biological stabilisation of a dump slope has indicated that biological reclamation with grass and tree species should be considered for long term stability of this coal mine dump in India. The grasses have greater soil binding capacity and help to control soil erosion and improve dump stability. Native grasses such as Bamboo (Dendrocalmus strictus) and Kashi (Saccharum spontaneum) are the important constituents of grass species which can stabilise the dump slopes. Field observation of growth performance of grasses have indicated that mean grass height, root depth and below-ground root biomass are 185 cm (±68), 45 cm (±5) and 467 g m^–2 (±170), respectively after three years of grass growth on Mudidih overburden dump slope in India. The growth performance of tree species, namely Sisum (Dalbergia sisoo) and Subabool (Leucena lecocephala), in terms of height, diameter increment, below-ground biomass and root depth have shown mean values of 219 cm (±94), 48 mm (±6), 4.0 kg m^–2 (±1.5) and 1 m (±0.1), respectively. This acts as biological fertility which helps in root proliferation and enhancement of dump stability. From the numerical modelling it is suggested that roots of these grass and tree species have significantly enhanced the factor of safety of dump from 1.4 to 1.8 and therefore have a positive role in maintaining long term stability.  相似文献   

Directional spread parameter at intermediate water depth     

V. Sanil Kumar  M. C. Deo  N. M. Anand  K. Ashok Kumar 《Ocean Engineering》2000,27(8):93

The characteristics of directional spread parameters at intermediate water depth are investigated based on a cosine power ‘2s' directional spreading model. This is based on wave measurements carried out using a Datawell directional waverider buoy in 23 m water depth. An empirical equation for the frequency dependent directional spreading parameter is presented. Directional spreading function estimated based on the Maximum Entropy Method is compared with those obtained using a cosine power ‘2s' parameter model. A set of empirical equations relating the directional spreading parameter corresponding to the peak of wave spectrum to other wave parameters like significant wave height and period are obtained. It shows that the wave directional spreading at peak wave frequency can be related to the non-linearity parameter, which allows estimation of directional spreading without reference to wind information.  相似文献