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GPU Accelerated Discontinuous Galerkin Methods for Shallow Water Equations

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Communications in Computational Physics 2015年第6期18卷 37-64页

作者： rajesh Gandham David Medina Timothy Warburton Department of Computational and Applied Mathematics Rice University6100 Main StreetMS-134HoustonTX-77005USA

We discuss the development,verification,and performance of a GPU accelerated discontinuous Galerkin method for the solutions of two dimensional nonlinear shallow water *** shallow water equations are hyperbolic partial differential equations and are widely used in the simulation of tsunami wave *** algorithms are tailored to take advantage of the single instruction multiple data(SIMD)architecture of graphic processing *** time integration is accelerated by local time stepping based on a multi-rate Adams-Bashforth scheme.A total variational bounded limiter is adopted for nonlinear stability of the numerical *** limiter is coupled with a mass and momentum conserving positivity preserving limiter for the special treatment of a dry or partially wet element in the ***,robustness and performance are demonstrated with the aid of test ***,we developed a unified multi-threading model *** kernels expressed in OCCA model can be cross-compiled with multi-threading models OpenCL,CUDA,and *** compare the performance of the OCCA kernels when cross-compiled with these models.

关键词： Shallow water equations discontinuous Galerkin positivity preserving slope limiting GPUs accelerators multi-threading

Defect elimination in green sand casting using simulation techniques:A case study

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第5期11卷 1-19页

作者： Sarabjit Singh Neeraj Sharma rajesh Khanna Department of Mechanical Engineering DAV University Jalandhar 144012PunjabIndia Department of Mechanical Engineering Maharishi Markandeshwar(Deemed to be University)Mullana 133207 AmbalaIndia International Tractors Ltd. HoshiarpurPunjabIndia

The Reynolds number of molten metal flowing mold cavity causes bulk turbulence and is the main cause of defects like shrinkage porosity and sand *** housings with shrinkage porosity at critical bearing bores and surface made the casting *** old gating casting areas of perimeters 290mm and 264mm of transmission housing,Reynolds numbers were observed as 16307 and 13806,respectively using simulation *** were collected from experiments to change casting area perimeters from 785mm and 785mm along with the addition of overlap *** Reynolds numbers at two locations were observed as 3705 and 3393,*** metal pressure,velocity and temperature results were related for final shrinkage results of the components on full *** purpose of the study is to reduce shrinkage and porosity defects in green sand casting part using MAGMAS simulation *** outcome was the reduction of casting machining rejection in transmission housing casting from 5.8%0.7%with savings of approximately 0.13 million USD over the period of 14 *** of this work include casting defects study and reduction in different grades and weight range.

关键词： Green sand casting gating system Reynolds number grey cast iron shrinkage porosity MAGMAS software

Transition from radiatively inefficient to cooling dominated phase in two temperature accretion disks around black holes

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Research in Astronomy and Astrophysics 2009年第12期9卷 1331-1342页

作者： Monika Sinha S.R.rajesh Banibrata Mukhopadhyay Astronomy and Astrophysics Program Department of PhysicsIndian Institute of Science

We investigate the transition of a radiatively inefficient phase of a viscous two temperature accreting flow to a cooling dominated phase and vice versa around black holes. Based on a global sub-Keplerian accretion disk model in steady state, including explicit cooling processes self-consistently, we show that general advective accretion flow passes through various phases during its infall towards a black hole. Bremsstrahlung, syn- chrotron and inverse Comptonization of soft photons are considered as possible cooling mechanisms. Hence the flow governs a much lower electron temperature ～10^8 - 10^9.5 K compared to the hot protons of temperature ～10^10.2 - 10^11.8 K in the range of the accretion rate in Eddington units 0.01≤M≤ 100. Therefore, the solutions may potentially explain the hard X-rays and the γ-rays emitted from AGNs and X-ray binaries. We finally compare the solutions for two different regimes of viscosity and conclude that a weakly viscous flow is expected to be cooling dominated compared to its highly viscous counterpart which is radiatively inefficient. The flow is successfully able to reproduce the observed luminosities of the under-fed AGNs and quasars （e.g. Sgr A＊）, ultra-luminous X-ray sources （e.g. SS433）, as well as the highly luminous AGNs and ultra-luminous quasars （e.g. PKS 0743-67） at different combinations of the mass accretion rate and ratio of specific heats.

关键词： accretion accretion disk -- black hole physics -- hydrodynamics -- radia-tive transfer

Gastroprotective effect of Acacia nilotica young seedless pod extract:Role of polyphenolic constituents

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Asian Pacific Journal of Tropical Medicine 2012年第7期5卷 523-528页

作者： Vijay Kumar Bansal rajesh Kumar Goel Department of Pharmaceutical Sciences NIMS UniversityJaipurIndia Department of Pharmaceutical Sciences and Drug Research Punjabi University PatialaIndia

Objective:To systematically evaluate antiulcer potential of Acacia nilotica in different ulcer models in ***:Different extracts[ethanolie,50%hydroethanolic(50:50),70% hydroethanolic(70:30) and aqueous]of young seedless pods were examined in pylorus ligation induced gastric ulcers in *** parameters like,volume of gastric acid secretion,pH,free acidity,total acidity,ulcer index,mucin content and antioxidant studies were determined and were compared between extract treated,standard and vehicle control following ulcer induction. The most active extract was also evaluated in swimming stress induced and NSAID induced gastric ***:Among different extracts of young seedless pods only hydroethanolic extracts showed significant antiulcer activity in pyloric ligation induced *** more the 70%hydroethanolic extract showed better protection as compared to 50%hydroethanolic *** 70%hydroethanolic extract also showed significant mucoprotection in swimming stress induced and nonsteroidal antiinflammatory drugs induced gastric ***: The results of present study concluded that the hydroethanolic extract of young seedless pods of Acacia nilotica has antiulcer activity in pylorus ligation,swimming stress and NSAID induced rat ulcer *** extract containing more amount of phenolic components show high antiulcer activity,indicating the phenolic component of the extract to be responsible for the activity of the extracts.

关键词： Peptic ulcer Acacia nilotica Ulcer index Tannins Flavonoids

Recent advances based on the synergetic effect of adsorption for removal of dyes from waste water using photocatalytic process

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Journal of Environmental Sciences 2018年第3期30卷 201-222页

作者： Subramanian Natarajan Hari C.Bajaj rajesh J.Tayade Inorganic Materials and Catalysis Division (IMCD) CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI)Council of Scientific and Industrial Research (CSIR)

The problem of textile dye pollution has been addressed by various methods,mainly physical,chemical,biological,and *** methods mainly separate and/or remove the dye present in ***,advanced oxidation processes（AOP）have been focused for removal of dye from waste water due to their advantages such as ecofriendly,economic and capable to degrade many dyes or organic pollutant present in *** is one of the advance oxidation processes,mainly carried out under irradiation of light and suitable photocatalytic *** photocatalytic activity of the photocatalytic materials mainly depends on the band gap,surface area,and generation of electron–hole pair for degradation dyes present in *** has been observed that the surface area plays a major role in photocatalytic degradation of dyes,by providing higher surface area,which leads to the higher adsorption of dye molecule on the surface of photocatalyst and enhances the photocatalytic *** present review discusses the synergic effect of adsorption of dyes on the photocatalytic efficiency of various nanostructured high surface area *** addition,it also provides the properties of the water polluting dyes,their mechanism and various photocatalytic materials;and their morphology used for the dye degradation under irradiation of light along with the future prospects of highly adsorptive photocatalytic material and their application in photocatalytic removal of dye from waste water.

关键词： Photocatalysis Dye degradation Adsorption Water pollution Advanced oxidation processes Nanomaterials

Oxidative Stressand Antioxidant Responses in Young Leaves of Mulberry Plants Grown Under Nitrogen, Phosphorus or Potassium Deficiency

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Journal of Integrative Plant Biology 2007年第3期49卷 313-322页

作者： rajesh Kumar Tewari Praveen Kumar Parma Nand Sharma Department of Botany University of LucknowLucknow226007India

The aim of this study was to associate the generation of reactive oxygen species （ROS） with Induced antloxidant responses and disturbed cellular redox environment in the nitrogen-（N）, phosphorus-（P）, or potassium-（K） deftcient mulberry （Morus alba L. var. Kanva-2） plants. The indicators of oxidative stress and cellular redox environment and antioxldant defense-related parameters were analyzed. Oeficlency of N, P or K suppressed growth, accelerated senescence, and decreased concentrations of chloroplastic pigments and glutathione. Lipid peroxidation and activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase were also increased in these N, P, or K deprived plants. Concentration of hydrogen peroxide Increased in plants deficient in N or P. Oeficlency of N or P particularly altered the cellular redox environment as indicated by changes in the redox couples, namely ascorbic acid/total ascorbate decreased in P-, glutathione sulfydryl/total glutathione decreased in N-, and Increased in P-deficient plants. Activity staining of native gels for superoxide dismutase revealed Increased activity as Indicated by Increased intensity of bands, and induction of few new isoforms in P- and K-deficient plants. Oifferences in the patterns of superoxide dismutase isoforms and redox status （ascorbic acid/total ascorbate and glutathlone sulfydryl/total glutathione） Indicate that N-, P-, or K-deficiency altered antioxidant responses to varying extents in mulberry plants.

关键词： antioxidants potassium-deficiency lipid peroxidation Morus alba mulberry nitrogen-deficiency oxidative stress phosphorus-deficiency reactive oxygen species

Abundance of Carbonic Fluid Inclusions in Hira-Buddini Gold Deposit, Hutti-Maski Greenstone Belt, India: Inferences from Petrography and Volume Ratio Estimation of Fluid Components

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Journal of Earth Science 2020年第3期31卷 492-499页

作者： Rajagopal Krishnamurthi Ajit Kumar Sahoo rajesh Sharma Prabhakar Sangurmath Department of Earth Sciences Indian Institute of TechnologyRoorkeeRoorkee-241661India Department of Geology Banaras Hindu UniversityVaranasi-221005India Wadia Institute of Himalayan Geology Dehradun-24S001India Hutti Gold Mines Company Limited Hutti-584115India

Low saline aqueous carbonic fluids are considered to be the ore forming solutions for orogenic lode gold *** separation/fluid immiscibility of the ore fluid is quite common and is one of the major reasons for deposition of gold in these *** carbonic fluid inclusions have been observed in quartz grains of Hira-Buddnini Gold *** estimation indicates that more volume of H2O compared to CO2 is likely to be trapped in inclusions at different P-T *** loss of H2O from fluid inclusions during ductile deformation of quartz grains have been attributed as the suitable reason for abundance of carbonic fluid inclusions.

关键词： orogenic lode gold deposit carbonic fluid inclusions Redlich-Kwong Equation fluid immiscibility Hira-Buddini Gold Deposit

Design and analysis of multi-channel drop filter using dual L defected hexagonal photonic crystal ring resonator

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Digital Communications and Networks 2020年第1期6卷 136-143页

作者： D.Saranya Shoba Mohan A.rajesh school of electronics and engineering vit universityvelloreindia college of science and engineering hamad bin khalifa universitydohaqatar

In this paper,dual L defected hexagonal Photonic Crystal Ring Resonator(PCRR)using Channel Drop Filter(CDF)is designed for Coarse Wavelength Division Multiplexing(CWDM)*** this structure,the external rods of the ring resonator are arranged in a hexagon and the internal rods are removed in L arrangement for introducing *** rods are used to prevent *** using the L defected hexagonal resonator,a multi-channel CDF is designed,which exhibits multiple wavelengths of CWDM(1500 nm–1600 nm)*** addition,the selection of rod size and the position of rods in the proposed multi-channel CDF are validated by varying the radius of coupling and scattering rods,as well as the position of resonators,*** using plane wave expansion and opti Finite Difference Time Domain(FDTD)method,the electromagnetic wave propagation and the photonic band gap are obtained.

关键词： Channel drop filter Photonic crystal ring resonator Coarse wavelength division multiplexing Finite difference time domain

Efficient discrete firefly algorithm for Ctrie based caching of multiple sequence alignment on optimally scheduled parallel machines

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CAAI Transactions on Intelligence Technology 2019年第2期4卷 92-100页

作者： Soniya Lalwani Harish Sharma Abhay Verma rajesh Kumar Department of Computer Science & Engineering Rajasthan Technical University Kota India Department of Electrical Engineering Malaviya National Institute of Technology Jaipur India

This study introduces a two-level strategy for efficient execution of multiple sequence alignment (MSA) of complex heterogeneous sequences. The two levels of the proposed technique are comprised of: designing the discrete firefly algorithm (DFFA) for the formation and implementation of makespan minimisation on parallel machines, followed by performing Ctrie-based caching for pairwise alignment to reduce the load on the data servers for handling multiple queries. The proposed strategy addresses a multi-client problem that aims to acquire the full advantage of the computational power of parallel connected machines. Further, it is shown that the inclusion of Ctrie as caching mechanism successively improves the performance of the system with accretion in several sequences. Performance of proposed DFFA is also compared with discrete versions of four swarm intelligence based algorithms at the criteria of makespan minimisation and the rate of convergence on two kinds of complex and diverse datasets. The work is unique in this sense: it is the first swarm-intelligence-based implementation for the addressed problem;it is so far the first approach for Ctrie based caching of the MSA on the scheduled parallel machines;hybridisation of DFFA with Ctrie for caching the MSA results is also a novel implementation.

关键词： strategy execution machines