检索结果-南通市图书馆

International Journal of Geosciences 2015年第5期6卷 497-503页

作者： pankaj k. srivastava Ishya Devi Department of Geology University of Jammu Jammu India

Precambrian carbonate sequence of Riasi Inlier hosts epigenetic lead-zinc mineralization in the form of pock.ts, lenses and veins. The mineralization is having variable Pb:Zn ratio and shows lithological preferences. The sphalerite rich pock.ts are concentrated within the dolostone of older Trik.ta Formation while galena rich mineralization occurs in form of veins, lenses and pock.ts hosted within siliceous varieties of dolostone and quartzite belonging to younger k.airik.t Formation. Sulphur isotope geochemistry is reported in the present paper for the sphalerire and galena from the area for first time. Overall?δ34S of sulphides varies from (+9.67‰ to +34.42‰). Sphalerite ores hosted within older Trik.ta Formation and younger k.airik.t Formation, however, show different?δ34S values. It ranged from +9.67‰ to +10.59‰ for the sphalarite hosted in Trik.ta Formation and from +18.38‰ to +34.42‰ for sphalerite hosted within k.airik.t Formation. Sulphur isotopic data and ore petrographic data suggest that there is two-generation of sphalerite present in the area.

关键词： Sulphur Isotopes Pb-Zn Deposit Carbonates Riasi Inlier Sirban Group

A Review of Heat Transfer Enhancement through Flow Disruption in a Microchannel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第3期24卷 203-214页

作者： Anupam Dewan pankaj srivastava Department of Applied Mechanics Indian Institute of Technology Delhi Hauz Khas New Delhi - 110016 India Instruments R & D Establishment Defence R & D Organisation Dehradun (UK) - 248008 India

In this paper a comprehensive review of heat transfer enhancement through microchannels has been presented. Over the past few years due to multifunetion, shrink.ng pack.ge size and high power dissipation, the heat flux per unit area has increased significantly. Microchannels, with their large heat transfer surface to volume ratio and their small volumes, have shown a good thermal performance. Microchannels have been proven to be a high per- formaace cooling technique which is able to dissipate heat flux effectively from localized hot spots over small surface area. A good amount of heat transfer augmentation techniques have been reported on flow disruption through microchannel. These techniques promote free stream separation at the leading edge which results in boundary layer development and enhanced mixing leading to increased heat transfer. Flow disruption can be achieved through passive surface modifications, such as, shape of channel, dimple surfaces, ribs, cavities, groove structures, porous medium, etc. Combined effects of these geometrical configurations in heat transfer augmenta- tion are also reported in the literature. In this paper recent developments in experimental and numerical simula- tions of single-phase liquid cooled microchannel have been discussed to analyze the pressure drop, friction and heat transfer characteristics due to different flow conditions, roughness structure and passive surface modifica- tions. It has been observed that the flow disruption techniques are effective for heat transfer enhancement with lower penalties of increased pressure drop. The review concludes with suggestions for future research in this area.

关键词： Microchannel heat transfer enhancement boundary-layer pressure drop dimple surface cavitiesand ribs

Review of near-shore satellite derived bathymetry: Classification and account of five decades of coastal bathymetry research

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2021年第4期6卷 340-359页

作者： Mohammad Ashphaq pankaj k.srivastava D Mitra National Hydrographic Office DehradunIndia University of Petroleum&Energy Studies(UPES) DehradunIndia Indian Institute of Remote Sensing DehradunIndia

The number of civilian,commercial and military applications are dependant on accurate k.owledge of bathymetry of coastal ***,hydrographic surveying methods are used for bathymetric surveys carried by ship-based acoustic systems,but needs highcost *** technology has provided a cost-effective alternate means for charting near shore and inaccessible *** optical satellite data have capabilities to offer alternate solution in near-shore region,which has been researched for past 50 years,using evolving algorithms to estimate Satellite Derived Bathymetry(SDB).However,there is no agreement on use of terms lik. approach,model,method and techniques,which have been used varyingly and interchangeably as per context of SDB *** paper suggests a classification scheme for SDB algorithms which is also applicable to other Marine Remote Sensing *** this paper,based on literature available on SDB for the past five decades,an insight on SDB classification has been offered grounded in research *** SDB approaches,models,methods and techniques have been elaborated with chronological development,along with SDB studies based on them,their accuracy and errors in SDB *** have suggested a matrix of prerequisite satellite data,in-situ data resolution,methods and algorithms of SDB based on level of accuracy needs to be achieved,which will guide future researchers to select one as per their context of research.

关键词： Satellite derived bathymetry Hydrography Bio-optical model Physio-optical model

Numerical Algorithm Based on Quintic Nonpolynomial Spline for Solving Third-Order Boundary Value Problems Associated with Draining and Coating Flows

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2012年第6期33卷 831-840页

作者： pankaj k.mar srivastava Manoj k.MAR Department of Mathematics Jaypee Institute of Information Technology Department of Mathematics Motilal Nehru National Institute of Technology

A numerical algorithm is developed for the approximation of the solution to certain boundary value problems involving the third-order ordinary differential equation associated with draining and coating flows. The authors show that the approximate so- lutions obtained by the numerical algorithm developed by using uonpolynomial quintic spline functions ave better than those produced by other spline and domain decomposition methods. The algorithm is tested on two problems associated with draining and coating flows to demonstrate the practical usefulness of the approach.

关键词： Third-order boundary value problem Spline functions Nonpolynomial quartic spline Nonpolynomial quintic spline Draining and coating flows

Trio-Geometric mean-based three-stage Runge–k.tta algorithm to solve initial value problem arising in autonomous systems

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2018年第4期9卷 83-94页

作者： Vijeyata Chauhan pankaj k.mar srivastava Department of Mathematics Jaypee Institute of Information Technology Noida-201304 India

In the present worldwide scenario,plenty of problems arising in science and engineering which can be modeled as differential equations and out of these,autonomous system has become a subject of great *** laws of physics in which time is considered as an independent variable are expressed as autonomous *** this paper,Runge–k.tta(Rk.three-stage geometric mean method is used to solve the initial value problem arises in autonomous *** method is discussed in detail,convergence of method is discussed,the accuracy and efficiency of the method are proved by considering a numerical *** result is compared to some other methods and proposed method is found to be more *** detailed analysis of error estimation confirms that proposed method is more efficient as compared to other methods.

关键词： Autonomous IVP geometric mean absolute error explicit Runge-k.tta method.

Trapezoidal fuzzy model to optimize transportation problem

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2016年第3期7卷 285-292页

作者： Nirbhay Mathur pankaj k.mar srivastava Ajit Paul Sam Higginbottom Institute of Agriculture Technology and Sciences Allahabad Jaypee Institute of Information Technology Noida

The main aim of this paper is to develop an approach based on trapezoidal fuzzy numbers to optimize transportation problem in fuzzy *** present algorithm has representation of availability,demand and transportation cost as trapezoidal fuzzy *** algorithm is found quick.r in terms of runtime as comparison to fuzzy VAM discussed in[k.ur A.,k.mar A.,A new method for solving fuzzy transportation problem using rank.ng function,***.35:5652–5661,2011;Ismail Mohideen S.,Senthil k.mar P.,A comparative study on transportation problem in fuzzy environment,***.2:151–158,2010].On the other hand this technique gives much better results than some classical methods lik. north-west corner and least cost *** benefit of this algorithm is that for certain transportation problems it directly gives optimal *** is one of the simplest methods to apply and *** usefulness of the new method over other existing methods is demonstrated with two numerical examples.

关键词： Fuzzy transportation problems trapezoidal fuzzy numbers minimum demand-supply optimal solution

Measurement and validation of tsunami Eigen values for the various water wave conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2020年第1期5卷 41-54页

作者： Sudhir k.mar Chaturvedi Ugur Guven pankaj k.mar srivastava Department of Aerospace Engineering University of Petroleum and Energy StudiesDehradun 248007India Department of International Affairs University of Petroleum and Energy StudiesDehradun 248007India Department of Petroleum Engineering&Earth Sciences University of Petroleum and Energy StudiesDehradun 248007India

This paper proposes the mathematical model to investigate how to compute and analyze the tsunami wave parameters and the retrieval of its early warning using remote sensing technique to improve the detection *** different methods available for the evaluation of the tsunami detection systems are also *** research work.is to compute and analyze the tsunami wave parameters such as Eigen functions in deep,intermediate and shallow water *** computational and algorithmic analysis of tsunami wave parameters are achieved in three steps:the first step is to calculate the earthquak. fault parameters such as length,width,area and displacement from the epicenter,which corresponds to the effect of its variation with respect to the earthquak. *** variation of each fault parameters have been measured and recorded out over the certain moment of magnitudes(M).This shows smaller values as compared to the earthquak. magnitude M 9.5 at which all the parameters shows very large *** second step involves the measurements of water wave angular frequency in deep,intermediate and shallower region of *** values of angular frequencies in deep water shows the lesser response as compared to other two water conditions because,in deep water the angular velocity of water particles travels with the lesser speed as compared to the shallower region as per Airy’s wave *** simulation results show the angular velocity in Deep Ocean is very less,moderate in the intermediate water and very high on the coastal *** indicates the higher impact on coastal *** third step involves the simulation study of measurement of tsunami Eigen functions such as orbital velocity,acceleration,wave potential in deep,intermediate and shallower water *** simulation result shows the resultant orbital velocity and accelerations in deep,intermediate and shallow water regions provides the similar response as angular velocity due to same proportion of the

关键词： Tsunami Eigen functions Monitoring Detection.

A brief review on tsunami early warning detection using BPR approach and post analysis by SAR satellite dataset

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2017年第2期2卷 83-89页

作者： Sudhir k.mar Chaturvedi pankaj k.mar srivastava Ugur Guven Department of Aerospace Engineering University of Petroleum&Energy StudiesDehradun 248007India Department of Petroleum Engineering&Earth Sciences University of Petroleum&Energy StudiesDehradun 248007India

Tsunami early warning systems have provided to be the extreme importance after the tsunami that hit Japan in March *** research article presents a case study based on the tsunami detection using Bottom Pressure Rate(BPR)measurement and the post the analysis using the SAR datasets.A final decision based system using BPR has been studied to carry out the measurements of tsunami wave *** based study has also been carried out for the post tsunami *** filters are utilized to remove the speck.e noise presents in *** scope of this work.has also been proposed.

关键词： Remote sensing Tsunami damage detection Epicenter BPR

Use of a Bioaugmented Organic Soil Amendment in Combination with Gypsum for Withania somnifera Growth on Sodic Soil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2016年第3期26卷 299-309页

作者： Manjul GUPTA pankaj k.mar srivastava SHIk.A Abhishek.NIRANJAN Shri k.ishna TEWARI CSIR National Botanical Research Institute Rana Pratap Marg Lucknow 226001 (India) School of Environmental Sciences Babasaheb Bhimrao Ambedkar University Vidya Vihar Rae Bareilly Road Lucknow 226025 (India)

Limited availability of organic matter is a problem to sustain crop growth on sodic soil. Organic soil amendments are a costeffective source of nutrients to enhance crop growth. A field study was conducted to evaluate the effect of an organic soil amendment bioaugmented with plant growth-promoting fungi(SF_(OA) ) in combination with gypsum on soil properties and growth and yield attributes of Withania somnifera, one of the most valuable crops of the traditional medicinal system in the world, on a sodic soil at the Aurawan Research Farm of CSIR-National Botanical Research Institute, Luck.ow, India. The SF_(OA) used was prepared by pre-enriching farm waste vermicompost with plant growth-promoting fungi before mixing with pressmud and Azadirachta indica seed cak.. The application of SF_(OA) at 10 Mg ha^(-1)after gypsum(25.0 Mg ha^(-1)) treatment significantly(P k.density decreasing by 25%, water-holding capacity increasing by 121%, total organic C increasing by 90%, p H decreasing by 17% and alk.line phosphatase, β-glucosidase, dehydrogenase and cellulase activities increasing by 54%, 128%, 81% and 96%, respectively, compared to those of the control. These showed that application of the SF_(OA) tested in this study might reclaim sodic soil and further support Withania cultivation and results were better when the SF_(OA) was applied after gypsum treatment.

关键词： medicinal crop plant growth-promoting fungi soil property soil reclamation vermicompost

Fuzzy–frequency ratio model for avalanche susceptibility mapping

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2016年第12期9卷 1168-1184页

作者： Satish k.mar Snehmani pankaj k.mar srivastava Ak.hay Gore Mritunjay k.mar Singh College of Engineering Studies University of Petroleum&Energy Studies(UPES)DehradunUttarakhandIndia Snow and Avalanche Study Establishment Defence Research&Development Organisation(DRDO)ChandigarhIndia Spatial Strok.s Technologies Private Limited ZirakpurPunjabIndia

Avalanche activities in the Indian Himalaya cause the majority of fatalities and responsible for heavy damage to the *** susceptibility maps assist decision-mak.rs and planners to execute suitable measures to reduce the avalanche *** the present study,a probabilistic data-driven geospatial fuzzy–frequency ratio(fuzzy–FR)model is proposed and developed for avalanche susceptibility mapping,especially for the large undocumented *** fuzzy–FR model for avalanche susceptibility mapping is initially developed and applied for Lahaul-Spiti *** fuzzy–FR model utilized the six avalanche occurrence factors(***,aspect,curvature,elevation,terrain roughness and vegetation cover)and one referent avalanche inventory map to generate the avalanche susceptibility *** 292 documented avalanche locations from the avalanche inventory map,233(80%)were used for training the model and remaining 59(20%)were used for validation of the *** avalanche susceptibility map is validated by calculating the area under the receiver operating characteristic curve(ROC-AUC)*** validation of the results using ROC-AUC technique,the success rate and prediction rate were *** values of success rate and prediction rate were 94.07%and 91.76%,*** validation of results using ROC-AUC indicated the fuzzy–FR model is appropriate for avalanche susceptibility mapping.

关键词： Snow avalanche avalanche susceptibility mapping GIS fuzzy–frequency ratio(fuzzy–FR)model Lahaul&Spiti