检索结果-南通市图书馆

Bianchi Type-V Bulk Viscous Barotropic Fluid Cosmological Model with Variable G and A

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2008年第8期25卷 3090-3093页

作者： raj.Bali Seema Tinker Department of Mathematics University of Rajasthan 3aipur-302004 India

We investigate the Bianchi type-V bulk viscous barotropic fluid cosmological model with variable gravitational constant G and the cosmological constant A, assuming the condition on metric A/A=B/B=C/C=m/tn potential aswhere A, B, and C are functions of time t, while m and n are constants. To obtain the deterministic mo del, we also assume the relations P = p - 3η H, p = 7P, η = ηop^s, where p is the isotropic pressure, η the bulk viscosity,0≤r≤1 H the Hubble constant, ηo and s are constants. Various physical aspects of the model are *** case of n = 1 is also discussed to compare the results with the actual universe.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Bianchi Type-Ⅲ String Cosmological Models with Time Dependent Bulk Viscosity

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 Physics Letters 2007年第2期24卷 585-588页

作者： BALI raj.PrADHAN Anirudh Department of Mathematics University of Rajasthan Jaipur-302 004 India Department'of Mathematics Hindu Post-Graduate College Zamania-232 331 Ghazipur India

Bianchi type-Ⅲ string cosmological models with bulk viscous fluid for massive string are investigated. To obtain the determinate model of the universe, we assume that the coeffcient of bulk viscosity ξ is inversely proportional to the expansion θ in the model and expansion θ in the model is proportional to the shear g. This leads to B =lC^n, where l and n are constants. Behaviour of the model in the presence and absence of bulk viscosity is discussed. The physical implications of the models are also discussed in detail.

关键词： Cosmological Dependent

Comparison of two-and three-dimensional modeling of invert trap for sewer solid management

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2008年第3期6卷 176-184页

作者： Tsewang Thinglas Deo raj.Kaushal Civil Engineering Department IIT DelhiHauz KhasNew Delhi 110016India

In the present study, five different invert trap configurations （rectangular with and without lids on both sides; trapezoidal, trapezoidal with rectangular base and rectangular with trapezoidal base with lids on both sides） were simulated for both two-dimensional （2D） and three-dimensional （3D） flow conditions for three sediment types （sand, styrocell and plastic beads） at six flow rates （0.35, 0.70, 1.05, 1.35, 4.55 and 9.95 L/s） for each trap. Computational fluid dynamics （CFD）-based modeling using FLUENT software with renormalization Group （rNG） k-e model along with discrete phase model （DPM） were used in the simulations. A hexagonal/tetrahedral and map-type non-uniform grid was chosen to discretize the entire computational domain and a control volume finite difference method was used to solve the governing equations. The flow rates selected in the present study cover the entire range of flow rate expected for dry weather and monsoon. The simulation is capable of differentiating between 2D and 3D modeling of particle traj.ctories, the effects of flow rate and trap geometry on flow patterns developed in the trap. The sediment retention ratio for 2D is higher than that for 3D modeling for all flow conditions, particle types and model geometry due to inclusion of lateral effects in 3D modeling. The invert trap having rectangular shape with trapezoidal base is found to be the most efficient configuration in both 2D and 3D modeling.

关键词： CFD modeling 2D 3D Invert trap Sediment trapping Urban drainage

In-line digital holography for dynamic metrology of MEMS(Invited Paper)

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第12期7卷 1117-1122页

作者： Vijay raj.Singh Anand Asundi School of Mechanical and Aerospace Engineering Nanyang Technological University

In-line digital holography helps to relax the spatial resolution requirement on charge-coupled device sensors for digital recording of holograms and to utilize the full sensing area for image reconstruction which provides larger field of view and better imaging resolution. In this letter, a lensless in-line digital holographic microscopy is presented for dynamic metrology of micro-electro-mechanical system devices. The methodologies of interferometry and time-averaged in-line digital holography are presented for dynamic measurements, which are also useful for simultaneous suppression of in-line waves from real image wave. The experimental results are presented for dynamic thermal characterization of microheater and vibration analysis of cantilevers.

关键词： line MEMS

Three-dimensional computational fluid dynamics （volume of fluid） modelling coupled with a stochastic discrete phase model for the performance analysis of an invert trap experimentally validated using field sewer solids

在线全文

学校读者我要写书评

暂无评论

Particuology 2017年第4期15卷 98-111页

作者： Mohammad Mohsin Deo raj.Kaushal Civil Engineering Department Indian Institute of Technology Delhi New Delhi India

Invert traps are used to trap sewer solids flowing into a sewer drainage system, The performance of the invert trap in an open rectangular channel was experimentally and numerically analysed using field sewer solids collected from a sewer drain. Experiments showed that the free water surface rises over the central opening （slot） of the invert trap, which reduces the velocity near the slot and allows more sediment to be trapped in comparison with the case for the fixed-lid model （assuming closed conduit flow with a shear-free top wall） used by earlier investigators. This phenomenon cannot be modelled using a closed conduit model as no extra space is provided for the fluctuation of the water surface, whereas this space is provided in the volume of fluid （VOF） model in the form of air space in ANSYS Fluent 14.0 software. Additionally, the zero atmospheric pressure at the free water surface cannot be modelled in a fixed-lid model. In the present study, experimental trap efflciencies of the invert trap using field sewer solids were fairly validated using a three-dimensional computational fluid dynamics model （VOF model） coupled with a stochastic discrete phase model. The flow field （i.e., velocities） predicted by the VOF model were compared with experimental velocities obtained employing particle image velocimetry. The water surface profile above the invert trap predicted by the VOF model was found to be in good agreement with the experimentally measured profile. The present study thus showed that the VOF model can be used with the stochastic discrete phase model to well predict the performance of invert traps.

关键词： Computational fluid dynamics mode Invert trap Sedimentation Trap efficiency retention ratio Volume of fluid model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2014年第1期61卷 121-126页

作者： Mukesh Kumar raj.Kumar Department of Mathematics Motilal Nehru National Institute of Technology Allahabad

In the present work, the new exact solutions of the Boiti-Leon-Pempinelli system have been found. The system has extensive physical background. The exact solutions of the Boiti-Leon-Pempinelli system are investigated using similarity transformation method via Lie group theory. Lie symmetry generators are used for constructing similarity variables for the given system of partial differential equations, which lead to the new system of partial differentiaJ equations with one variable less at each step and eventually to a system of ordinary differential equations （ODEs）. Finally, these ODEs are solved exactly. The exact solutions are obtained under some parametric restrictions. The elastic behavior of the soliton solutions is shown graphically by taking some appropriate choices of the arbitrary functions involved in the solutions.

关键词： Boiti-Leon-Pempinelli system similarity transformation method Lie group theory soliton solutions

Automatic Segmentation of Liver from Abdominal Computed Tomography Images Using Energy Feature

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第4期67卷 709-722页

作者： Prabakaran raj.manickam Shiloah Elizabeth Darmanayagam Sunil retmin raj.Cyril raj University Department of Computer Science Engineering Anna UniversityChennai600025India University Department of Information Technology MIT CampusChennai600044India

Liver Segmentation is one of the challenging tasks in detecting and classifying liver tumors from Computed Tomography(CT)*** segmentation of hepatic organ is more intricate task,owing to the fact that it possesses a sizeable quantum of *** paper proposes an algorithm for automatic seed point selection using energy feature for use in level set algorithm for segmentation of liver region in CT *** effectiveness of the method can be determined when used in a model to classify the liver CT images as tumorous or *** involves segmentation of the region of interest(rOI)from the segmented liver,extraction of the shape and texture features from the segmented rOI and classification of the rOIs as tumorous or not by using a classifier based on the extracted *** this work,the proposed seed point selection technique has been used in level set algorithm for segmentation of liver region in CT scans and the rOIs have been extracted using Fuzzy C Means clustering(FCM)which is one of the algorithms to segment the *** dataset used in this method has been collected from various repositories and scan *** outcome of this proposed segmentation model has reduced the area overlap error that could offer the intended accuracy and *** gives better results when compared with other existing *** execution in short span of time is another advantage of this method which in turns helps the radiologist to ascertain the abnormalities instantly.

关键词： Liver segmentation automatic seed point tumor segmentation classification fuzzy C means clustering

水稻“野败”型细胞质雄性不育育性恢复的遗传研究：？

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

农业科技译丛（湖南） 1989年第3期18卷 38-43页

作者： raj.,KG 严钦泉

Towards a self healing information system for digital libraries

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 Zhejiang University-Science A(Applied Physics & Engineering) 2005年第11期6卷 1221-1228页

作者： AMBATI Vamshi rEDDY raj Institute for Software research International Carnegie Mellon University Pittsburgh PA 15213 USAInstitute for Software Research International Carnegie Mellon University Pittsburgh PA 15213 USA

An important area of focus in complex systems development is the capability to adapt to variable runtime environmental resources and to accommodate runtime system failures. The research in this area is broadly termed as “Self Healing” and has recently aroused increasing attention to complex systems. Digital libraries have gained popularity because of the richer features they provide compared to traditional libraries. As more users begin to use digital libraries, addressing downtimes of these valuable resources has become a high priority. Operating and providing access to digital content to anyone, anytime from anywhere in the world, results in a continued rise of administrative overhead for system monitoring and needs continuous human intervention. Given the volume of information and the huge infrastructure of modem libraries, continuous manual system administration is quite costly and not feasible. In this paper we propose a self healing digital library system as the solution to this problem and present the approach of adding self healing capabilities to an existing digital library project, the Digital Library of India （DLI）. We also propose a self healing framework that enables successful reuse of our approach to other architecturally similar digital library systems.

关键词： Digital library Self healing systems Failover Configuration management