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Reflection of three-dimensional plane waves at the free surface of a rotating triclinic half-space under the context of generalized thermoelasticity

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Applied Mathematics and Mechanics(English Edition) 2021年第9期42卷 1363-1378页

作者： p.singh A.K.singh A.CHATTOpADHYAY Department of Mathematics and Computing Indian Institute of Technology(ISM)Dhanbad-826004JharkhandIndia

The reflection of three-dimensional(3D) plane waves in a highly anisotropic(triclinic) medium under the context of generalized thermoelasticity is studied. The thermoelastic nature of the 3D plane waves in an anisotropic medium is investigated in the perspective of the three-phase-lag(TpL), dual-phase-lag(DpL), Green-Naghdi-III(GNIII), Lord-Shulman(LS), and classical coupled(CL) theories. The reflection coefficients and energy ratios for all the reflected waves are obtained in a mathematical form. The rotational effects on the reflection characteristics of the 3D waves are discussed under the context of generalized thermoelasticity. Comparative analyses for the reflection coefficients of the waves among these generalized thermoelastic theories are performed. The energy ratios for each of the reflected waves establish the energy conservation law in the reflection phenomena of the plane waves. The highly anisotropic materials along with the rotation may have a significant role in the phenomenon of the reflection behavior of the 3D waves. Numerical computations are performed for the graphical representation of the study.

关键词： reflection energy ratio triclinic thermoelasticity rotation three-dimensional(3D)wave

Ichnofossils from the Miocene Middle Bhuban Formation, Mizoram, Northeast India and their paleoenvironmental Significance

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Acta Geologica Sinica(English Edition) 2013年第5期87卷 1460-1471页

作者： Kapesa LOKHO Birendra p.singh Wadia Institute of Himalayan Geology (WIHG) Center of Advanced Study in Geology Panjab University

An ichnofossil assemblage is preserved in sediments of the Middle Bhuban Formation, Surma Group, of Miocene age from the Durtlang and Chanmari sections, Aizawl district, Mizoram, northeastern India. The studied sections comprise a thick, bioturbated and thinly bedded sandstone-silty shale facies. The preserved ichnofossils show high density and low diversity with the assemblage represented by feeding and resting traces, i.e., psilonichnus upsilon Frey et al., 1984, Ophiomorpha isp., Teichichnus spiralis Mikulas. 1990, Skolithos isp., palaeophycus isp., and other horizontal burrows. Sedimentary structures associated with these traces are mainly cross bedding, flaser bedding and slump structures. Considering the distribution of the psilonichnus ichnogenus across an integrated ichnological-sedimentological framework, the stratigraphic interval of the Middle Bhuban Formation, in which they occur, are interpreted to have been deposited under a shallow, marginal-marine channel complex dominated by tidal channels developed in quiet, brackish-water portions of a delta plain.

关键词： Ichnology Miocene (Burdigalian) psilonichnus Skolithos Assam-Arakan Basin

Motion through spherical droplet with non-homogenous porous layer in spherical container

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Applied Mathematics and Mechanics(English Edition) 2020年第7期41卷 1069-1082页

作者： p.K.YADAV A.TIWARI p.singh Department of Mathematics Motilal Nehru National Institute of Technology AllahabadPrayagraj 211004India Department of Mathematics Birla Institute of Technology SciencePilani 333031Rajasthan Department of Mathematics National Institute of Technology PatnaPatna 800005India

The problem of the creeping flow through a spherical droplet with a non-homogenous porous layer in a spherical container has been studied ***’s model for the flow inside the porous annular region and the Stokes equation for the flow inside the spherical cavity and container are used to analyze the *** drag force is exerted on the porous spherical particles enclosing a cavity,and the hydrodynamic permeability of the spherical droplet with a non-homogeneous porous layer is *** is placed on the spatially varying permeability of a porous medium,which is not covered in all the previous works related to spherical *** variation of hydrodynamic permeability and the wall effect with respect to various flow parameters are presented and discussed *** streamlines are presented to discuss the kinematics of the *** previous results for hydrodynamic permeability and drag forces have been verified as special limiting cases.

关键词： non-homogenous porous medium Stokes equation Darcy’s law perme-ability parameter wall effect

Seismic analysis of structures with a fractional derivative model of viscoelastic dampers

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Earthquake Engineering and Engineering Vibration 2002年第2期1卷 251-260页

作者： Tsu-sheng Chang Mahendra p.singh Department of Engineering Science and Mechanics.Virginia polytechnic Institute and State Universigy.Blacksburg Virginia24061.USA

Viscoelastic dampers are now among some of the preferred energy dissipation devices used for passive seismic response *** evaluate the performance of structures installed with viscoelastic dampers,different analytical models have been used to characterize their dynamic force deformation *** fractional derivative models have received favorable attention as they can capture the frequency dependence of the material stiffness and damping properties observed in the tests very ***,accurate analytical procedures are needed to calculate the response of structures with such damper *** paper presents a modal analysis approach,similar to that used for the analysis of linear systems,for solving the equations of inotion with fractional derivative terms for arbitrary forcing functions such as those caused by earthquake induced ground *** uncoupled modal equations still have fractional derivatives,but can be solved by numerical or analytical *** numerical and analytical procedures are *** procedures are then used to calculate the dynamic response of a multi-degree of fleedom shear beam structure excited by ground motions. Numerical results demonstrating the response reducing effect of viscoelastic dampers are also presented.

关键词： viscoelastic damper fractioal derivative seismic response

Cambrian Stratigraphy and Faunal Elements Along the Kurgiakh-Surichun La Section(Kurgiakh Valley),Zanskar-Spiti Basin of Northwest Himalaya

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地学前缘 2009年第S1期16卷 265-266页

作者： Birendra p.singh H.No.37 Hari Vihar(Vijay Park)

The Cambrian rocks are well exposed along the Kurgiakh-Surichun La section,situated 78 km SE of the padam Village along a track route at 33°03′787″N and 77°013′647″E in between the Kurgiakh and Surichun La,in Kurgiakh Valley(southeastern Zanskar).Around 715 m thick Cambrian succession was measured along the right and left banks of

关键词： Cambrian ichnofossils trilobites Kurgiakh-Surichun La Lejopyge laeivigata Cruziana-Skolithos ichnofacies

Cropping pattern optimization considering uncertainty of water availability and water saving potential

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International Journal of Agricultural and Biological Engineering 2018年第1期11卷 178-186页

作者： Lina Hao Xiaoling Su Vijay p.singh College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100ShaanxiChina Department of Biological&Agricultural Engineering and Zachry Department of Civil Engineering Texas A&M UniversityCollege StationTX 77843-2117USA

In arid and semi-arid areas,the profitability of irrigated agriculture mainly depends on the availability of water resources and optimal cropping patterns of irrigation *** this study,an integrated agricultural cropping pattern optimization model was developed with considering the uncertainty of water availability and water saving potential in the future,aiming to maximize agricultural net benefit per unit of irrigation *** available water which was based on the uncertainty of runoff was divided into five *** irrigation water-saving potential in the future was quantified by assuming an increase in the rate irrigation water-saving of 10% and 20%.The model was applied to the middle reaches of Heihe River basin,in Gansu province,*** showed that if the irrigation water-saving rate was assumed to increase by 10%,then the net water-saving quantity would increase by 21.5-22.5 million m3 and the gross water-saving quantity would increase by 275.7-303.0 million ***,if the irrigation water-saving rate increased by 20%,then the net water-saving quantity would increase by 43.0-45.1 million m3 and the gross water-saving quantity would increase by 331.7-383.2 million *** the agricultural cropping pattern was optimized,the optimal water and cultivated area allocation for maize would be greater than those for other *** the premise that similar volume of irrigation water quantity was available in different scenarios,results showed differences in system benefit and net benefit per unit of irrigation water,for the distribution of available irrigation water was diverse in different irrigation districts.

关键词： cropping pattern optimization irrigation water-saving potential different scenarios water availability water use efficiency particle swarm optimization(pSO)

Visible light photocatalysis in the synthesis of pharmaceutically relevant heterocyclic scaffolds

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Organic Chemistry Frontiers 2022年第5期9卷 1485-1507页

作者： Vishal Srivastava pravin K.singh Shraddha Tivari praveen p.singh Department of Chemistry CMP Degree CollegeUniversity of AllahabadPrayagraj 211002India Department of Chemistry United College of Engineering&ResearchNainiPrayagraj 211010India

Visible light and photoredox catalysis have emerged as a powerful and long-lasting tool for organic syn-thesis,demonstrating the importance of a variety of chemical bond formation *** products,physiologically active substances,medicines,and agrochemicals all contain heterocyclic *** impact of visible light-promoted chemistry on the functionalization of heterocycles as well as the syn-thesis and modification of heterocyclic compounds of medicinal importance is summarized in this review.

关键词： heterocyclic Visible synthesis

Influence of slope position and aspect on the vegetation attributes and treewater relations in forests of the central Himalayas

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Journal of Mountain Science 2023年第9期20卷 2592-2602页

作者： Vidit TYAGI Surendra p.singh Ripu Daman singh Surabhi GUMBER Rajesh THADANI Rajiv pANDEY Dolphin(pG)Institute of Bio-medical and Natural Sciences Dehra Dun 248007India Central Himalayan Environment Association(CHEA) Dehradun 248007India Department of Forestry and Environmental Science DSB CampusKumaun UniversityNainital 263001India Centre for Ecology Development and Research(CEDAR) A-17 Mayfair GardensNew Delhi 110016India Indian Council of Forestry Research and Education(ICFRE) Dehra Dun 248007India

While the need for understanding the effects of topographical factors on forest structure and function is well recognized,comprehensive studies are *** study evaluates the effect of slope aspect and slope position on water relations and forest attributes across six forest types occurring between 400 m and 2600 m altitude in the Central Himalaya(27°-38°N).We found that predawn tree water potential and soil water potential were generally higher on moist north slope aspect(-0.78±0.05 Mpa and-3.34±0.18 Mpa,respectively)than dry south slope aspect(-0.82±0.18 Mpa and-3.77±0.18 Mpa,respectively).Across six different forests,these values were higher at hill base(-0.71±0.06 Mpa and-2.77±0.19 Mpa,tree predawn water potential and soil water potential,respectively)than other topographical *** favorable effect of north aspect and hill base was also observed in maintaining soil water and tree water potential during the dry *** attributes,such as species richness,unique species and plant density were also generally higher on north slope and hill base than southern aspect and lowest at hill *** forest types,the hill base provided shelter to 46 unique species,compared to 16-18 at the other positions,thus emphasizing its importance as refugia for species to survive climate change induced *** favorable conditions of hill base position not only contribute to increase in alpha diversity,but also to extended species distributional range.

关键词： Hill base Himalaya Refugia Unique species Water relation

A New Stable Algorithm to Compute Hankel Transform Using Chebyshev Wavelets

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Communications in Computational physics 2010年第7期8卷 351-373页

作者： Rajesh K.pandey Vineet K.singh Om p.singh pDpM Indian Institute of Information Technology Design and Manufacturing JabalpurIndia Birla Institute of Technology and Science-pilani Goa CampusGoaIndia Department of Applied Mathematics Institute of TechnologyBanaras Hindu UniversityVaranasiIndia

A new stable numerical method,based on Chebyshev wavelets for numerical evaluation of Hankel transform,is proposed in this *** Chebyshev wavelets are used as a basis to expand a part of the integrand,r f(r),appearing in the Hankel transform *** transforms the Hankel transform integral into a Fourier-Bessel *** truncating the series,an efficient and stable algorithm is obtained for the numerical evaluations of the Hankel transforms of order ν>−*** method is quite accurate and stable,as illustrated by given numerical examples with varying degree of random noise terms εθ_(i) added to the data function f(r),where θ_(i) is a uniform random variable with values in[−1,1].Finally,an application of the proposed method is given for solving the heat equation in an infinite cylinder with a radiation condition.

关键词： Hankel transforms Bessel functions Chebyshev wavelets random noise term