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New exact solutions of the Einstein-Maxwell equations for magnetostatic fields

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Chinese Physics B 2012年第9期21卷 103-108页

作者： nisha Goyal r.K.Gupta School of Mathematics and Computer Applications Thapar University

The symmetry reduction method based on the Frechet derivative of differential operators is applied to investigate symmetries of the Einstein-Maxwell field equations for magnetostatic fields, which is a coupled system of nonlinear partial differential equations of the second order. The technique yields invariant transformations that reduce the given system of partial differential equations to a system of nonlinear ordinary differential equations. Some of the reduced systems are further studied to obtain the exact solutions.

关键词： Einstein-Maxwell equations symmetry reduction method exact solutions

Seismic stratigraphy and the sedimentation history in the Laxmi Basin of the eastern Arabian Sea:Constraints from IODP Expedition 355

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Geoscience Frontiers 2021年第3期12卷 489-502页

作者： nisha Nair Dhananjai K.Pandey Anju Pandey r.Prerna National Centre for Polar and Ocean research(NCPOr) Ministry of Earth SciencesVasco-da-GamaGoa 403804India H-V3-NCPOr Campus Vasco-da-GamaGoa 403804India

Detailed interpretation of seismic stratigraphic sequences in the Laxmi Basin of the eastern Arabian Sea are presented in this study using closely spaced high resolution multi-channel seismic(MCS)*** stratigraphic interpretation is further corroborated using recent drilling results in the Laxmi Basin,derived from the long sediment cores collected during International Ocean Discovery Program(IODP)Expedition *** core-log interpretation discussed in the present study,offer important insights about the lithostratigraphic variations in this *** of multi-channel seismic reflection data reveal five depositional sequences(ranging from Paleocene to recent)that led to the development of this marginal basin since the Cenozoic *** igneous basement is successfully imaged,which was also validated by deep sea coring during the IODP Expedition *** the present study,we primarily focus on the post-rift sedimentation in the Laxmi Basin and its possible *** detailed interpretation in the prevailing tectonic framework of the basin suggests that near-shelf oldest volcaniclastic sedimentation immediately overlying the acoustic basement is linked to the onset of India-Madagascar and India-Seychelles rifting activities during the Late Cretaceous ***,during the Early-Mid to Late Miocene,the basin received maximum sedimentation dominantly through an extensive mass transport mechanism implying possible large-scale deformation on the Indian *** sediment input to the basin appears to have been fed variably via the Indus Fan as well as coastal discharge from the Indian *** total sediment thickness in the Laxmi Basin ranges from 1.1 to 3.5 *** stratigraphic information and sediment isopach maps presented here provide vital information about syn-and post-rift sedimentation pattern in the region and their long term tectonic implications.

关键词： Seismic stratigraphy Laxmi Basin Arabian Sea Site U1456 Site U1457 IODP Expedition 355

Feeding patterns of Indian giant flying squirrel(Petaurista philippensis, Elliot 1839) with reference to seasonal variation in central Gujarat, India

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Journal of Forestry research 2019年第5期30卷 1959-1965页

作者： Singh nisha Dharaiya Nishith Wildlife and Conservation Biology Lab Department of Life Sciences Hemchandracharya North Gujarat University

Indian Giant Flying Squirrel(Petaurista philippensis Elliot 1839)is widely distributed in South Asia and the only species of flying squirrel found in *** studied the seasonal variation in its feeding behaviour at selected sites of Central *** sampling was employed to study the behaviours and mainly feeding *** analyses were consistent with other studies and indicated Madhuca longifolia as an important food *** diet of the species mainly consisted of pith,twig,seed,bark,petiole,young to mature leaves,flower and fruits of 20 species of plants of 15 families along with lichens,Vanda tessellata and Dendrophthoe *** longifolia(25%)contributed most to the squirrel diet,followed by Diospyros melanoxylon(10%)and Terminalia tomentosa(9%).Among the plant parts consumed,pith formed the highest bulk as a food at 23%,followed by fruits(21%),bark(16%),twig(14%),flower(10%),seed(6%),leaf(6%),and bud(4%).The findings reveal the high dependency of flying squirrel on certain tree *** tree species are well represented and distributed throughout central Gujarat,indicating that this area is important for the survival of this species and that the area should be conserved for protection and future management of this species.

关键词： Arboreal rodent Behaviour Madhuca longifolia Phenology Western India

Quark matter properties and fluctuations of conserved charges in(2+1)-flavored quark model

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Chinese Physics C 2022年第6期46卷 46-65页

作者： nisha Chahal Suneel Dutt Arvind Kumar Department of Physics Dr.BR Ambedkar National Institute of TechnologyJalandhar-144011PunjabIndia

In this study,the susceptibilities of conserved charges,baryon number,charge number,and strangeness number at zero and low values of chemical potential are *** series expansion was used to obtain results for the three-flavor Polyakov quark meson(PQM)model and the Polyakov loop extended chiral quark meanfield(PCQMF)***-field approximation was used to study quark matter with the inclusion of the isospin chemical potential,as well as the vector *** effects of isospin chemical potential and vector-interactions on phase diagrams were analyzed.A comparative analysis of the two models was *** of the conserved charges were enhanced in the transition temperature regime and hence provided information about the critical end point(CEP).Susceptibilities of conserved quantities were calculated by using the Taylor series *** of fluctuations in the transition temperature neighborhood provided a clear signature of a quantum chromodynamics(QCD)critical-point.

关键词： quark matter phase diagram conserved charges Taylor’s series fluctuations

Demand-based dynamic bandwidth allocation in multi-beam satellites using machine learning concepts

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Intelligent and Converged Networks 2024年第2期5卷 147-166页

作者： Shwet Kashyap nisha Gupta Department of Electronics and Communication Engineering Birla Institute of Technology MesraRanchi 835215India

In the realm of satellite communication,where the importance of efficient spectrum utilization is growing day by day due to the increasing significance of this technology,dynamic resource management has emerged as a pivotal consideration in the design of contemporary multi-beam satellites,facilitating the flexible allocation of resources based on user *** research paper delves into the pivotal role played by machine learning and artificial intelligence within the domain of satellite communication,particularly focusing on spot beam *** study encompasses an evaluation of machine learning’s application,whereby an extensive dataset capturing user demand across a specific geographical area is subjected to *** analysis involves determining the optimal number of beams/clusters,achieved through the utilization of the knee-elbow method predicated on within-cluster sum of ***,the demand data are equitably segmented employing the weighted k-means clustering *** proposed solution introduces a straightforward yet efficient model for bandwidth allocation,contrasting with conventional fixed beam illumination *** approach not only enhances spectrum utilization but also leads to noteworthy power savings,thereby addressing the growing importance of efficient resource management in satellite communication.

关键词： satellite communications multi-beam satellites machine learning weighted k-means clustering Voronoi tessellation knee-elbow method

An Efficient and Novel Synthesis of Carbamate Esters from the Coupling of Amines, Halides and Carbon Dioxide in the Presence of Basic resin

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Chinese Chemical Letters 2006年第10期17卷 1309-1312页

作者： Devdutt CHATUrVEDI nisha MISHrA Virendra MISHrA Medicinal & Process Chemistry Division Central Drug Research Institute Lucknow-226001 U. P. India Synthetic research Lab Department of Chemistry B. S. A. College Mathura-281004 U. P. India

A convenient, efficient, one-pot, novel process has been developed for the synthesis of carbamates from corresponding alkyl halides and amines using basic resin/CO2 system.

关键词： Basic resin (Ambedite IrA 400) alkyl halides carbon dioxide amines carbamates.

Evaluation of atmospheric corrections on hyperspectral data with special reference to mineral mapping

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Geoscience Frontiers 2017年第4期8卷 797-808页

作者： nisha rani Venkata ravibabu Mandla Tejpal Singh Centre for Disaster Mitigation and Management(CDMM) VIT University OSGST-Lab Department of Environmental.Water Resources EngineeringSchool of Civil and Chemical EngineeringVIT University CSIr-Central Scientific Instruments Organisation

Hyperspectral images have wide applications in the fields of geology,mineral exploration,agriculture,forestry and environmental studies *** to their narrow band width with numerous ***,these images commonly suffer from atmospheric effects,thereby limiting their *** such a situation,atmospheric correction becomes a necessary pre-requisite for any further processing and accurate interpretation of spectra of different surface materials/*** the present study,two very advance atmospheric approaches *** and FLAASH have been applied on the hyperspectral remote sensing *** spectra of vegetation,man-made structure and different minerals from the Gadag area of Karnataka,were extracted from the raw image and also from the QUAC and FLAASH corrected *** spectra were compared among themselves and also with the existing USGS and JHU spectral *** is rigorous atmospheric algorithm and requires various parameters to perform but it has capability to compensate the effects of atmospheric *** absorption curves in any spectra play an important role in identification of the ***,the presence of unwanted absorption features can lead to wrong interpretation and identification of mineral *** also has an advantage of spectral polishing which provides smooth spectral curves which helps in accurate identification of composition of ***,this study recommends that FLAASH is better than QUAC for atmospheric correction and correct interpretation and identification of composition of any object or minerals.

关键词： Atmospheric correction Hyperspectral data radiance reflectance FLAASH QUAC

Utilization of TiO_(2)/gC_(3)N_(4)nanoadditive to boost oxidative properties of vegetable oil for tribological application

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Friction 2021年第2期9卷 273-287页

作者： nisha rANJAN rashmi C.SHENDE Muthusamy KAMArAJ Sundara rAMAPrABHU Department of Physics Indian Institute of Technology MadrasChennai 600036India Department of Metallurgical and Materials Engineering Indian Institute of Technology MadrasChennai 600036India

The emergence of vegetable oil as a promising alternative lubricant in the tribological application space has fueled research for making these oils as useful as mineral *** modification of vegetable oil by the addition of TiO_(2)/gC_(3)N_(4)nanocomposite(as a nanoadditive)was studied *** dispersion of the nanoadditive in the vegetable oil showed good oil dispersion stability without the addition of any *** tribological studies were conducted in a four-ball tester using ASTM standard *** addition,the effect of temperature on tribological performance was also studied to understand the oxidation behavior of vegetable *** results showed a significant improvement in friction and wear properties of the optimized *** mechanism behind the improvement in friction and wear properties is annotated in this paper.

关键词： TiO_(2)/gC_(3)N_(4)nanoadditive vegetable oil oxidation

Nonlinear model predictive control with relevance vector regression and particle swarm optimization

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控制理论与应用（英文版） 2013年第4期11卷 563-569页

作者： M.GErMIN nisha G.N.PILLAI Department of Electrical Engineering Indian Institute of Technology Roorkee

In this paper, a nonlinear model predictive control strategy which utilizes a probabilistic sparse kernel learning technique called relevance vector regression （rVr） and particle swarm optimization with controllable random exploration velocity （PSO-CrEV） is applied to a catalytic continuous stirred tank reactor （CSTr） process. An accurate reliable nonlinear model is first identified by rVr with a radial basis function （rBF） kernel and then the optimization of control sequence is speeded up by PSO-CrEV. Additional stochastic behavior in PSO-CrEV is omitted for faster convergence of nonlinear optimization. An improved system performance is guaranteed by an accurate sparse predictive model and an efficient and fast optimization algorithm. To compare the performance, model predictive control （MPC） using a deterministic sparse kernel learning technique called Least squares support vector machines （LS-SVM） regression is done on a CSTr. relevance vector regression shows improved tracking performance with very less computation time which is much essential for real time control.

关键词： relevance vector regression Least squares support vector machines Nonlinear model predictive control Particle swarm optimization with controllable random exploration velocity