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191.
Munendra Singh Alok Srivastava Amol D. Shinde R. Acharya A. V. R. Reddy I. B. Singh 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(2):241-246
In northern part of Indian sub-continent, As related environmental and health issues receive attention from all over the world. Forty-eight sediment samples were collected from the Ganga Alluvial Plain (GAP) and its weathering products (from the Gomati River) for the study of As distribution and mobilization. These sediment samples were analyzed by Instrumental Neutron Activation Analysis (INAA) method using Cirus Research Reacter of Bhabha Atomic Research Centre, Mumbai. Average As concentrations in the GAP sediments (10.44?mg?kg?1), the Gomati River bed sediments (1.36?mg?kg?1) and the Gomati River suspended sediments (5.30?mg?kg?1) were reported. Significant decrease of As content from the alluvial sediments to the river sediments is a clear indication of its mobilization by chemical weathering processes of mineral biotite. Present study demonstrates the importance of INAA for quantification and mobilization of As and improves our understanding related to As related environmental issues in northern India and elsewhere. 相似文献
192.
This paper presents a method for the evaluation of the capacitance and the charge distribution of a dielectric coated metallic parallelepiped and a dielectric coated metallic hollow cylinder with the top and bottom cover plates using the method of moments (MoM) based on the pulse basis function and the point matching. Boundary conditions for the potential on the conductor surfaces and continuity of the normal component of the displacement density at the dielectric-free space interface is used to generate two integral equations. Two sets of simultaneous equations are formed from the two integral equations using the MoM. The total charge on the conductor surface is found from the solution for the set of simultaneous equations. The validity of the analysis has been justified by comparing the data on the capacitance available in the literature for metallic cube and hollow cylinder with top and bottom cover plates with the data on capacitance, computed by the present method for similar structures considering a very low dielectric constant as well as a very thin dielectric coating. 相似文献
193.
In this article, generation of DWDM-RoF signal utilizing an SOA-MZI multichannel frequency up-conversion is demonstrated. The simulation results of a 16 channel, 10 km DWDM-RoF link at baseband signal of 500 Mbps, over the wavelength range 1545.80–1552.20 nm are reported. BER of the order of e−18 and Q factor above 18 dB over the entire bandwidth signify negligible crosstalk and error free transmission of radio signal. 相似文献
194.
The growth rate of the partial maximum of a stationary stable process was first studied in the works of Samorodnitsky (Ann. Probab. 32:1438–1468, 2004; Adv. Appl. Probab. 36:805–823, 2004), where it was established, based on the seminal works of Rosiński (Ann. Probab. 23:1163–1187, 1995; 28:1797–1813, 2000), that the growth rate is connected to the ergodic-theoretic properties of the flow that generates the process. The results were generalized to the case of stable random fields indexed by ? d in Roy and Samorodnitsky (J. Theor. Probab. 21:212–233, 2008), where properties of the group of nonsingular transformations generating the stable process were studied as an attempt to understand the growth rate of the partial maximum process. This work generalizes this connection between stable random fields and group theory to the continuous parameter case, that is, to fields indexed by ? d . 相似文献
195.
Debasis De Shanker Ram Alok BanerjeeSanat K. Roy 《Journal of magnetism and magnetic materials》2012,324(6):1133-1140
(La0.6Eu0.4)0.67Ca0.33MnO3 has been prepared in the shape of nanoplates of single crystallites (an orthorhombic structure) through polymer templates. HRTEM images reveal 18, 25, and 30 nm thicknesses of plates after heating a precursor powder at 873, 1073, and 1273 K in air for 2 h. These values present average crystallite size determined from broadening of the X-ray diffraction peaks. A spin-glass-like surface (GS) overlayer (3-5 nm thickness) in such plates facilitates a ferromagnetic→ferrimagnetic reordering with markedly suppressed Curie point TC, i.e., as small as 90 K in a 873 K heated sample, from the parent value 268 K. The TC point increases to 103 K (or 120 K) when heating at higher temperature 1073 (or 1273 K), during which the core grows at the expense of the overlayer. The GS tailors as high coercivity Hc as 617 Oe in the zero field cooled (ZFC) sample that is decreased to 500 Oe in the field cooled (FC) sample in the surface spin-freezing along the field direction. The Hc-value (ZFC) that steps down successively to 252 Oe on the overlayer is thinned down by heating at 1273 K. Samples heated at 873, 1073, or 1273 K have regularly increased saturation magnetization 35.3, 63.9, or 69.6 emu/g in ZFC, while 43.7, 70.2, or 75.5 emu/g in FC measured at 10 K. The ferrimagnetic reordering are described based on the scenario of an antiferromagnetic exchange coupling between the Eu3+ and Mn3+ (or Mn4+) sublattices. 相似文献
196.
197.
Arijit Chakrabarty 《Stochastic Processes and their Applications》2012,122(2):623-653
This paper studies the effect of truncation on the large deviations behavior of the partial sum of a triangular array coming from a truncated power law model. Each row of the triangular array consists of i.i.d. random vectors, whose distribution matches a power law on a ball of radius going to infinity, and outside that it has a light-tailed modification. The random vectors are assumed to be Rd-valued. It turns out that there are two regimes depending on the growth rate of the truncating threshold, so that in one regime, much of the heavy tailedness is retained, while in the other regime, the same is lost. 相似文献
198.
Alok Srivastava B. S. Bhadauria P. G. Siddheshwar I. Hashim 《Transport in Porous Media》2013,99(2):359-376
Thermo-rheological effect of temperature-dependent viscous fluid saturating a porous medium has been studied in the presence of imposed time periodic gravity field and internal heat source. Weak nonlinear stability analysis has been performed by using the power series expansion in terms of the amplitude of gravity modulation, which is considered to be small. Nusselt number is calculated numerically using Ginzburg–Landau equation. The nonlinear effects of thermo-mechanical anisotropies, internal heat source parameter, Vadász number, thermo-rheological parameter and amplitude of gravity modulation have been obtained and depicted graphically. Streamlines and isotherms have been drawn for different times. Comparisons have been made between various physical systems. 相似文献
199.
B. S. Bhadauria I. Hashim Jogendra Kumar Alok Srivastava 《Transport in Porous Media》2013,98(3):683-697
Effect of rotation on linear and nonlinear instability of cross-diffusive convection in an anisotropic porous medium saturated with Newtonian fluid has been investigated. Normal mode technique has been used for linear stability analysis, however nonlinear analysis is done using spectral method, involving only two terms. The Darcy model with Coriolis terms, has been employed in the momentum equation. Nonlinear analysis is used to find the thermal and concentration Nusselt numbers. The effects of various parameters, including Soret and Dufour parameters, on stationary and oscillatory convection, have been obtained, and shown graphically. 相似文献
200.
In this paper we try to understand several phenomenological issues related to the mass spectra of P-states quarkonia in a relativistic quark model. We give particular emphasis on understanding the most recent experimental
data within a relativized scalar-vector confining potential. In this paper we extend the previous works on the studies of
quark confinement in non-relativistic QCD, using a formalism which uses a covariant Hamiltonian in the centre of mass frame.
The spin-structure of the potential is obtained from the reduction of Bethe-Salpeter equation into Breit-interaction.
Printed as S Chakrabarty in several papers published earlier e.g. References [1,11] etc. of this paper. 相似文献