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Anisotropic Plane Symmetric Two-Fluid Cosmological Model with Time-Varying G and A

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Chinese Physics Letters 2015年第12期32卷 1-4页

作者： Verma M. K. Chandel S. ram shri Department of Mathematics BBD NITM Lucknow 226028 India Department of Mathematical Sciences Indian Institute of Technology (Banaras Hindu University) Varanasi 221005 India

We investigate a two-fluid anisotropic plane symmetric cosmological model with variable gravitational constant G（t） and cosmological term A（t）. In the two-fluid model, one fluid is chosen to be that of the radiation field modeling the cosmic microwave background and the other one a perfect fluid modeling the material content of the universe. Exact solutions of the field equations are obtained by using a special form for the average scale factor which corresponds to a specific time-varying deceleration parameter. The model obtained presents a cosmological scenario which describes an early acceleration and late-time deceleration. The gravitation constant increases with the cosmic time whereas the cosmological term decreases and asymptotically tends to zero. The physical and kinematical behaviors of the associated fluid parameters are discussed.

关键词： Anisotropic Plane Symmetric Two-Fluid Cosmological Model with Time-Varying G and A FRW

Global Information Resources on Rice for Research and Development

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Rice science 2012年第4期19卷 327-334页

作者： shri ram N.LAXMAN RAO Jaypee University of Information Technology Solan-173 234India Osmania University Hyderabad-50007India

Various issues concerning the progress of rice research are related to ambiguous germplasm identification, difficulty in tracing pedigree information, and lack of integration between genetic resources, characterization, breeding, evaluation and utilization data. These issues are the constraints in developing knowledge-intensive crop improvement programs. The rapid growth, development and the global spread of modern information and communication technology allow quick adoption in fundamental research. Thus, there is a need to provide an opportunity for the establishment of services which describe the rice information for better accessibility to information resources used by researchers to enhance the competitiveness. This work reviews some of available resources on rice bioinformatics and their roles in elucidating and propagating biological and genomic information in rice research. These reviews will also enable stakeholders to understand and adopt the change in research and development and share knowledge with the global community of agricultural scientists. The establishment like International Rice Information System, Rice Genome Research Project and Integrated Rice Genome Explorer are major initiatives for the improvement of rice. Creation of databases for comparative studies of rice and other cereals are major steps in further improvement of genetic compositions. This paper will also highlight some of the initiatives and organizations working in the field of rice improvement and explore the availability of the various web resources for the purpose of research and development of rice. We are developing a meta web server for integration of online resources such as databases, web servers and journals in the area of bioinformatics. This integrated platform, with acronym iBIRA, is available online at http：//***. The resources reviewed here are the excerpts from the resources integrated in iBIRA.

关键词： bioinformatics rice informatics genomic resource proteomic resource agricultural database

Spatially Homogeneous Bianchi Type V Cosmological Model in the Scale-Covariant Theory of Gravitation

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Chinese Physics Letters 2009年第8期26卷 397-400页

作者： shri ram M. K. Verma Mohd. Zeyauddin Department of Applied Mathematics Institute of Technology Banaras Hindu University Varanasi-2210 05 India

We discuss spatially homogeneous and anisotropic Bianchi type-V spacetime filled with a perfect fluid in the framework of the seale-covariant theory of gravitation proposed by Canuto et al. By applying the law of variation for Hubble＇s parameter, exact solutions of the field equations are obtained, which correspond to the model of the universe having a big-bang type singularity at the initial time t = 0. The cosmological model, evolving from the initial singularity, expands with power-law expansion and gives essentially an empty space for a large time. The physical and dynamical properties of the model are also discussed.

关键词： sea surface nonliear interaction numerical method

Bianchi-Type VI_(0) Bulk Viscous Fluid Models with Variable Gravitational and Cosmological Constants

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Applied Mathematics 2011年第3期2卷 348-354页

作者： Manoj K.Verma shri ram Department of Applied Mathematics Institute of TechnologyBanaras Hindu UniversityVaranasiIndia

This paper deals with Bianchi type VI0 anisotropic cosmological models filled with a bulk viscous cosmic fluid in the presence of time-varying gravitational and cosmological constant. Physically realistic solutions of Einstein's field equations are obtained by assuming the conditions 1) the expansion scalar is proportional to shear scalar 2) the coefficient of the bulk viscosity is a power function of the energy density and 3) the cosmic fluid obeys the barotropic equation of state. We observe that the corresponding models retain the well established features of the standard cosmology and in addition, are in accordance with recent type Ia supernovae observations. Physical behaviours of the cosmological models are also discussed.

关键词： Bianchi VI0 Cosmology Bulk viscosity Variable G and A

Linear Plus Linear Fractional Capacitated Transportation Problem with Restricted Flow

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American Journal of Operations Research 2013年第6期3卷 581-588页

作者： Kavita Gupta shri ram Arora Department of Mathematics Hans Raj College University of Delhi Delhi India Department of Mathematics Ramjas College University of Delhi Delhi India

In this paper, a transportation problem with an objective function as the sum of a linear and fractional function is considered. The linear function represents the total transportation cost incurred when the goods are shipped from various sources to the destinations and the fractional function gives the ratio of sales tax to the total public expenditure. Our objective is to determine the transportation schedule which minimizes the sum of total transportation cost and ratio of total sales tax paid to the total public expenditure. Sometimes, situations arise where either reserve stocks have to be kept at the supply points, for emergencies or there may be extra demand in the markets. In such situations, the total flow needs to be controlled or enhanced. In this paper, a special class of transportation problems is studied where in the total transportation flow is restricted to a known specified level. A related transportation problem is formulated and it is shown that to each basic feasible solution which is called corner feasible solution to related transportation problem, there is a corresponding feasible solution to this restricted flow problem. The optimal solution to restricted flow problem may be obtained from the optimal solution to related transportation problem. An algorithm is presented to solve a capacitated linear plus linear fractional transportation problem with restricted flow. The algorithm is supported by a real life example of a manufacturing company.

关键词： Transportation Problem Linear Plus Linear Fractional Restricted Flow Corner Feasible Solution

Root growth dynamics during recovery of tropical mountain forest in North-east India

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Journal of Mountain Science 2019年第10期16卷 2335-2347页

作者： Chalthleng LALNUNZIRA Francis Q.BREARLEY shri Kant TRIPATHI Department of Forestry Mizoram UniversityAizawl 796 004India School of Science and the Environment Manchester Metropolitan UniversityChester StreetManchesterM1 5GDUK

Ever increasing pressures on tropical forests worldwide due to anthropogenic disturbances have greatly affected both above-and belowground functioning of these *** fine roots play major ecological roles in forests through assisting in nutrient and water uptake and returning elements to the soil environment,coarse roots play an important role in C *** studied changes in fine and coarse root biomass,production,turnover and carbon and nitrogen return to the soil in two regenerating forest stands(RFs)following stonemining that were 5 years(RF-5)and 15 years(RF-15)post-disturbance compared with a natural forest stand(NF)in Mizoram,North-east ***(<2mm)and coarse root(2-10 mm)biomass differed significantly among the forest stands and ranged from239(RF-5)to 415(NF)and 230(RF-5)to 436(NF)g m 2,*** root(fine+coarse)biomass increased during stand development but the proportion of very fine root(<0.5 mm)to total root production *** root biomass decreased with increasing soil *** and total root biomass showed strong seasonal correlations with soil moisture,more so than for rainfall and temperature,whereas these relationships were less clear for the coarse root *** amount of N(25-55 kg ha-1)and C(1.9-3.6t ha-1)stored in root biomass increased with stand age with a corresponding increase in production and turnover of C and N to the *** to these tropical forests negatively affected root dynamics,influenced their spatiotemporal patterns,and reduced the production,amount and availability of nutrients returned to the soil along with a strong reduction in the root biomass carbon pool and sequestration in carbon residence *** observed that root growth,especially fine roots,is dependent on abiotic variables,and plays a significant role in early stages of secondary succession by adding organic matter and nutrients through high turnover rates in these forests.

关键词： Total root biomass Element return Regenerating forest Root production and turnover Anthropogenic disturbance

Review on film coolingofliquidrocketengines

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Propulsion and Power Research 2018年第1期7卷 1-18页

作者： S.R.Shine S.shri Nidhi Department of Aerospace Engineering Indian Institute of Space Science and TechnologyThiruvananthapuram 695547India

Film cooling in combination with regenerative cooling is presently considered as an efficient method to guarantee safe operation of liquid rocket engines having higher heat flux densities for long *** paper aims to bring all the research carried out in the field of liquid rocket engine film cooling since *** analytical and numerical procedure followed,experimental facilities and measurements made and major inferences drawn are reviewed in detail,and compared where ever *** has been made through a discussion of the analyses methodologies and the factors that influence film cooling *** effort has also been made to determine the status of the research,pointing out critical gaps,which are still to be explained and addressed by future generations.

关键词： Heat transfer Liquid rocketthrust chamber Film cooling Cooling effectiveness

Totally Anisotropic Cosmological Models with Bulk Viscosity for Variable G and Λ

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Journal of Modern Physics 2012年第1期3卷 9-15页

作者： shri ram Manish K. Singh Manoj K. Verma 不详

Einstein's field equations with variable gravitational and cosmological constants are considered in the presence of bulk viscous fluid for the totally anisotropic Bianchi type II space-time in such a way as to preserve the energy momentum tensor. We have presented solutions of field equations which represent expanding, shearing and non-rotating cosmological models of the universe. The physical behaviours of the models are discussed .We observe that the results obtained match with recent observations of SNIa.

关键词： Bianchi II Cosmology Hubble Parameter Bulk Viscosity Variable G and Λ

Comparative study of solar cycles 22 to 24 in relation to solar output variability

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Natural Science 2012年第6期4卷 349-354页

作者： Sham Singh Divya shrivastava shri ram Lahauriya Adya Prasad Mishra Department of Physics Awadhesh Pratap Singh University Rewa India

The rate of increase in solar activity at the initiation of solar cycle 22 had led the activity during the solar maximum years 1990-1991, be the most severe of any period during the space age. Solar cycle 23 started in May 1996 and ended in December 2008. Total time period of this solar cycle is 12.6 years. The maximum smoothed sunspot number observed during the solar cycle was 120.8 and minimum was 1.7. It is apparent that solar cycle 23 is a long one. Solar cycle 24 (initiated in December 2008) seems to be weak, which will have a slow ramp up, much slower than the late 19th century cycles used for comparison. In the present work, we have considered Sunspot number (Rz) as an index of solar activity, which shows a predominant 11 year cycle. The strength of the solar cycle makes a huge difference to satellite operators. Each solar peak heats and expands the outer atmosphere. The strength of the solar-cycle length, annual average and temperature correlation enables solar cycle length to be used as a climate predictor tool.

关键词： Solar Activity Cosmic Ray Intensity andGeomagnetic Activity