Simulation studies of satellite spectral radiances for 11·1, 8·3, 7·3, 6·7 μm IR bands     

Agarwal  Vijay K  Ashajayanthi  A V 《Journal of Earth System Science》1981,90(3):327-336

Starting with an outline of spectral radiance calculation for infrared bands, a simulation study has been presented for 11.1, 8.3, 7.3 and 6.7 μm. Detailed response of the spectral radiance to the meteorological parameters has been studied by generating simulated atmospheric temperature and moisture profiles for Indian atmospheres. It has been found that the responses of the 8.3, 7.3 and 6.7 μm bands are maximum for lower troposphere, middle troposphere and upper troposphere respectively, and these spectral radiances are linearly related to the water vapour content of the relevant layers. The thermal IR window at 11.1 μm is found to be sensitive to not only surface temperature and total water vapour content but also to the boundary layer values of mean temperature and water vapour content.

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Alterations in Certain Organic Components and Serum Electrolytes in Notopterus notopterus Chronically Exposed to Phenolic Compounds     

S. R. Verma  Saroj Rani  R. C. Dalela 《洁净——土壤、空气、水》1982,10(1):31-40

• The present investigation was undertaken to evaluate the effects of three sublethal concentrations (1/10th, 1/15th and 1/20th fractions of 96 h LC₅₀) of phenol (P), dinitrophenol (DNP), pentachlorophenol (PCP) and their antagonistic [(PCP + DNP)/P], additive [(DNP + P)/PCP] and synergistic [(P + DNP)/PCP] combinations, on several organic and inorganic components of haemopoetic systems of Notopterus notopterus after 30 d of exposure.
• Glucose, lactate, total phosphorus, non-protein nitrogen, sodium, potassium, magnesium, calcium, iron and chloride were found to be increased in most cases while protein and cholesterol were found to be decreased.
• It has been concluded that these alterations in blood parameters might be due to a damage or hyperactivity of liver, kidney and endocrine glands, the main centres for controlling the tissue metabolism.

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NARX neural network approach for the monthly prediction of groundwater levels in Sylhet Sadar,Bangladesh          下载免费PDF全文

Abdullah Al Jami  Meher Uddin Himel  Khairul Hasan  Shilpy Rani Basak  Ayesha Ferdous Mita 《地下水科学与工程》2020,8(2):118-126

Groundwater is important for managing the water supply in agricultural countries like Bangladesh. Therefore, the ability to predict the changes of groundwater level is necessary for jointly planning the uses of groundwater resources. In this study, a new nonlinear autoregressive with exogenous inputs(NARX) network has been applied to simulate monthly groundwater levels in a well of Sylhet Sadar at a local scale. The Levenberg-Marquardt(LM) and Bayesian Regularization(BR) algorithms were used to train the NARX network, and the results were compared to determine the best architecture for predicting monthly groundwater levels over time. The comparison between LM and BR showed that NARX-BR has advantages over predicting monthly levels based on the Mean Squared Error(MSE), coefficient of determination(R~2), and Nash-Sutcliffe coefficient of efficiency(NSE). The results show that BR is the most accurate method for predicting groundwater levels with an error of ± 0.35 m. This method is applied to the management of irrigation water source, which provides important information for the prediction of local groundwater fluctuation at local level during a short period.  相似文献   

Plane strain deformation of a multi-layered poroelastic half-space by surface loads     

Sarva Jit Singh  Sunita Rani 《Journal of Earth System Science》2006,115(6):685-694

The Biot linearized quasi-static theory of fluid-infiltrated porous materials is used to formulate the problem of the two-dimensional plane strain deformation of a multi-layered poroelastic half-space by surface loads. The Fourier-Laplace transforms of the stresses, displacements, pore pressure and fluid flux in each homogeneous layer of the multi-layered half-space are expressed in terms of six arbitrary constants. Generalized Thomson-Haskell matrix method is used to obtain the deformation field. Simplified explicit expressions for the elements of the 6 × 6 propagator matrix for the poroelastic medium are obtained. As an example of the possible applications of the analytical formulation developed, formal solution is given for normal strip loading, normal line loading and shear line loading.  相似文献   

Walsh spectra of gravity anomalies over some simple sources     

R.K. Shaw  B.N.P. Agarwal  B.K. Nandi 《Journal of Applied Geophysics》1998,40(4):179-186

Walsh transform of gravity anomalies over a point mass, a horizontal and a vertical line mass have been computed to obtain a cyclic shift invariant differential energy density (DED) function. Quantitative relations between DED spectral characteristics with depth to centroid/top of the source have been established. The effects of profile length, sampling interval, random noise and zero padding have been investigated. Applicability of the proposed method has been evaluated through two field examples.  相似文献   

Role　of　Triad　Kinetic　Energy　Interactions　for　Maintenance　of　Upper　Tropospheric　Low　Frequency　Waves　during　Summer　Monsoon　　1988     

D.R. Chakraborty  N.K. Agarwal 《大气科学进展》1996,13(1):91-102

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Terrestrial photogrammetric mapping of the Neh-Nar glacier in Himalaya, India     

N.K. Agarwal 《ISPRS Journal of Photogrammetry and Remote Sensing》1989,44(4)

Terrestrial photogrammetry holds distinct advantages over the conventional theodolite survey or aerial photogrammetry for glacier surveys, on account of inaccessibility of upper reaches of the glaciers and non-suitability of large-scale aerial photography for very high relief areas. The Neh-Nar glacier was mapped with a contour interval of 10 m utilising terrestrial photogrammetric techniques because no large-scale base map of the glacier was available for detailed glaciological studies. This glacier was selected under the International Hydrological Programme. Apart from topographic details various features of glaciological significance like transient snowline, accumulation and ablation zones, bergschrund, icefalls etc., were also mapped.  相似文献   

Rain rate measurements over global oceans from IRS-P4 MSMR     

A. K. Varma  R. M. Gairola  Samir Pokhrel  B. S. Gohil  A. K. Mathur  Vijay K. Agarwal 《Journal of Earth System Science》2002,111(3):257-266

In this paper rain estimation capability of MSMR is explored. MSMR brightness temperature data of six channels corresponding to three frequencies of 10, 18 and 21 GHz are colocated with the TRMM Microwave Imager (TMI) derived rain rates to find a new empirical algorithm for rain rate by multiple regression. Multiple correlation analysis involving various combinations of channels in linear and non-linear forms and rain rate from TMI is carried out, and thus the best possible algorithm for rain rate measurement was identified which involved V and H polarized brightness temperature measurements at 10 and 18 GHz channels. This algorithm explained about 82 per cent correlation (r) with rain rate, and 1.61 mm h^-1 of error of estimation. Further, this algorithm is used for generating global average rain rate map for two contrasting months of August (2000) and January (2001) of northern and southern hemispheric summers, respectively. MSMR derived monthly averaged rain rates are compared with similar estimates from TRMM Precipitation Radar (PR), and it was found that MSMR derived rain rates match well, quantitatively and qualitatively, with that from PR.  相似文献   

On the photo-gravitational restricted four-body problem with variable mass     

Amit Mittal  Rajiv Agarwal  Md Sanam Suraj  Monika Arora 《Astrophysics and Space Science》2018,363(5):109

This paper deals with the photo-gravitational restricted four-body problem (PR4BP) with variable mass. Following the procedure given by Gascheau (C. R. 16:393–394, 1843) and Routh (Proc. Lond. Math. Soc. 6:86–97, 1875), the conditions of linear stability of Lagrange triangle solution in the PR4BP are determined. The three radiating primaries having masses \(m_{1}\), \(m_{2}\) and \(m_{3}\) in an equilateral triangle with \(m_{2}=m_{3}\) will be stable as long as they satisfy the linear stability condition of the Lagrangian triangle solution. We have derived the equations of motion of the mentioned problem and observed that there exist eight libration points for a fixed value of parameters \(\gamma (\frac{m \ \text{at time} \ t}{m \ \text{at initial time}}, 0<\gamma\leq1 )\), \(\alpha\) (the proportionality constant in Jeans’ law (Astronomy and Cosmogony, Cambridge University Press, Cambridge, 1928), \(0\leq\alpha\leq2.2\)), the mass parameter \(\mu=0.005\) and radiation parameters \(q_{i}, (0< q_{i}\leq1, i=1, 2, 3)\). All the libration points are non-collinear if \(q_{2}\neq q_{3}\). It has been observed that the collinear and out-of-plane libration points also exist for \(q_{2}=q_{3}\). In all the cases, each libration point is found to be unstable. Further, zero velocity curves (ZVCs) and Newton–Raphson basins of attraction are also discussed.  相似文献   

Alternating augite‐plagioclase wedges in basement dolerites of Lockne impact structure,Sweden: A new shock wave‐induced deformation feature          下载免费PDF全文

A. Agarwal  B. Reznik  L. M. Alva‐Valdivia  D. C. Srivastava 《Meteoritics & planetary science》2017,52(3):458-470

This paper reports peculiar alternating augite‐plagioclase wedges in basement dolerites of Lockne impact structure, Sweden. The combined microscopic and spectroscopic studies of the micro/nanoscale wedges reveal that these are deformation‐induced features. First, samples showing wedges, 12 out of 18 studied, are distributed in the impact structure within a radius of up to 10 km from the crater center. Second, the margins between the augite and labradorite wedges are sharp and the {110} prismatic cleavage of augite develops into fractures and thereafter into wedges. The fractures are filled with molten labradorite pushed from the neighboring bulk labradorite grain. Third, compared to the bulk labradorite, the dislocation density and the residual strain in the labradorite wedges are significantly higher. A possible mechanism of genesis of the wedges is proposed. The mechanism explains that passing of the shock waves in the basement dolerite induced (i) formation of microfractures in augite and labradorite; (ii) development of the augite prismatic cleavages into the wedges, which overprint the microfracture in the labradorite wedges; and (iii) thereafter, infilling of microfractures in the augite wedges by labradorite.  相似文献