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Bianchi Type-Ⅱ Inflationary Models with Stiff Matter and Decaying Cosmological Term

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Chinese Physics Letters 2014年第7期31卷 27-31页

作者： Shri ram, Priyanka Department of Mathematical Sciences Indian Institute of Technology Banaras Hindu University Varanasi 221 005 India

We deal with einstein＇s field equations with a time-decaying cosmological term of the forms （i） ∧=β（a/a）＋ α/a62 and （ii）∧ = α/a^2, where a is the average scale factor of the universe, α and β are constants for a spatially homogeneous and anisotropic LRS Bianchi type-Ⅱ spacetime. exact solutions of the field equations for stiff matter are obtained by applying a special law of variation for the Hubble parameter. Anisotropic cosmological models are pre.e.ted with a constant negative deceleration parameter which corresponds to the accelerated phase of the pre.e.t universe. The cosmological constant A is obtained as a decreasing function of time that is approaching a small positive value at the pre.e.t epoch, which is corroborated by the consequences from re.e.t supernovae Ia observations. The physical and kinematical behaviors of the models are also discussed.

关键词： INFLATIONARY universe BIANCHI groups PARTICLe decays COSMOLOGY MATHeMATICAL models SPACe & time HUBBLe constant

effect of heavy metals and phenol on bacterial decolourisation and COD reduction of sucrose-aspartic acid Maillard product

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Journal of environmental Sciences 2013年第1期25卷 172-180页

作者： Sangeeta Yadav ram Chandra Department of environmental Microbiology School for Environmental SciencesBabasaheb Bhimrao Ambedkar University (A Central University)

Melanodins are amino-carbonyl complex, predominantly pre.e.t in sugarcane molasses based distillery wastewater as major source of colourant. The microbial decolourisafion of melanoidin is a challenge due to its binding property with other co-pollutants of distillery waste. results re.e.led that the pre.e.ce of Zn2＋（2.00-20.00 mg/L） in melanoidin solution （1200 mg/L） stimulated the bacterial growth and sucrose-aspartic acid Maillard product （SAA） decolourisation as compared to control, while Fe3＋ and Mn2＋ at the same concentration inhibited the process. However, the pre.e.ce of phenol （100 mg/L） along with Zn2＋, Fe3＋ and Mn2＋ suppressed the bacterial growth, SAA decolourisation and MnP activity. The shrinkage and reduced number of bacterial cell count at higher concentration of heavy metals in pre.e.ce of phenol was also observed under scanning electron microscope.

关键词： degradation manganese peroxidase melanoidin

The off-crust origin of granite batholiths

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Geoscience Frontiers 2014年第1期5卷 63-75页

作者： Antonio castro Unidad Asociada de Petrología experimental CSIC-Universidad de Huelva.Campus El Carmen21071 Huelva Spain

Granitod batholiths of I-type features （mostly granodiorites and tonalites）, and particularly those forming the large plutonic associations of active continental margins and intracontinental collisional belts, repre.e.t the most outstanding magmatic episodes occurred in the continental crust. The origin of magmas, however, remains controversial. The application of principles from phase equilibria is crucial to understand the problem of granitoid magma generation. An adequate comparison between rock com- positions and experimental liquids has been addressed by using a projected compositional space in the plane F（Fe ＋ Mg）-Anorthite-Orthoclase. Many calc-alkaline granitoid trends can be considered cotectic liquids. Assimilation of country rocks and other not-cotectic processes are identified in the projected diagram. The identification of cotectic patterns in batholith implies high temperatures of magma segregation and fractionation （or partial melting） from an intermediate （andesitic） source. The com- parison of batholiths with lower crust granulites, in terms of major-element geochemistry, yields that both repre.e.t liquids and solid residues respectively from a common andesitic system. This is compatible with magmas being formed by melting, and eventual reaction with the peridotite mantle, of subducted mOlanges that are finally relaminated as magmas to the lower crust. Thus, the off-crust generation of granitoids batholiths constitutes a new paradigm in which important geological implica- tions can be satisfactorily explained. Geochemical features of Cordilleran-type batholiths are totally compatible with this new conception.

关键词： Batholith Granodiorite Andesite relamination Granulite Lower crust

An Overview of High-Performance Aircraft Structural Al Alloy-AA7085

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Acta Metallurgica Sinica(english Letters) 2015年第7期28卷 909-921页

作者： T.ram Prabhu CeMILAC Defence R&D Organization

AA7085 Al alloy is a new-generation,high-strength,quench-insensitive alloy that features in airframe applications such as massive bulkhead and wing spars structures in Airbus A380 and Joint Strike Fighter *** alloy has a great potential in replacing currently used high-strength AA7 xxx alloys in many international and national military aircraft programs [Hawk,Su-30,Mi G series,light combat aircraft（Tejas）,Hindustan turbo/jet trainer,light combat helicopter,advanced light helicopter,and fifth-generation fighter aircrafts].An effort has been made to highlight the processing,heat treatment,properties and applications of the AA7085 Al alloy from the existing literature on the AA7085 *** potential applications of this alloy are pre.e.ted and compared with the currently used AA7075 Al alloy.A typical process cycle involved in the manufacturing of wrought AA7085 alloy products is described in ***,the precipitation mechanisms involved in the different temper conditions are critically reviewed with the supporting *** mechanical properties with a particular emphasis on tensile,fatigue,and fracture toughness properties are discussed in detail based on the analysis of experimental *** effects of temper conditions on the stress corrosion cracking and exfoliation corrosion have also been reviewed critically.

关键词： Al alloys Heat treatment Material processing Mechanical properties Corrosion

Syntrophic co-culture of Bacillus subtilis and Klebsiella pneumonia for degradation of kraft lignin discharged from rayon grade pulp industry

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Journal of environmental Sciences 2015年第7期27卷 229-238页

作者： Sangeeta Yadav ram Chandra Department of environmental Microbiology School for Environmental Sciences Babasaheb Bhimrao Ambedkar University (A Central University)

In order to search the degradability of kraft lignin, the potential bacterial strains Bacillus subtilis（GU193980） and Klebsiella pneumoniae（GU193981） were isolated, screened and applied in axenic and co-culture conditions. results re.e.led that mixed culture showed better decolorization efficiency（80%） and reduction of pollution parameters（COD 73% and BOD62%） than axenic culture. This indicated syntrophic growth of these two bacteria rather than any antagonistic effect. The HPLC analysis of degraded samples of kraft lignin has shown the reduction in peak area compared to control, suggesting that decrease in color intensity might be largely attributed to the degradation of lignin by isolated ***, the GC-MS analysis showed that most of the compounds detected in control were diminished after bacterial treatment. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized kraft lignin for environmental safety. All these observations have re.e.led that the developed bacterial co-culture was capable for the effective degradation and decolorization of lignin containing rayon grade pulp mill wastewater for environmental safety.

关键词： Degradation GC-MS Kraft lignin Seed germination test Syntropic

Choice of precipitant and calcination temperature of precursor for synthesis of NiCo_2O_4 for control of CO–CH_4 emissions from CNG vehicles

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Journal of environmental Sciences 2018年第3期30卷 62-71页

作者： Suverna Trivedi ram Prasad Department of Chemical engineering &Technology Indian Institute of Technology (BHU)

Compressed natural gas（CNG）is most appropriate an alternative of conventional fuel for ***,emissions of carbon-monoxide and methane from such vehicles adversely affect human health and ***,to abate emissions from CNG vehicles,development of highly efficient and inexpensive catalysts is ***,the pre.e.t work attempts to scan the effects of precipitants（Na2CO3,KOH and urea）for nickel cobaltite（Ni Co2O4）catalysts prepared by co-precipitation from nitrate solutions and calcined in a lean CO-air mixture at 400℃.The catalysts were used for oxidation of a mixture of CO and CH4（1：1）.The catalysts were characterized by X-ray diffractometer,Brunauer–emmett–Teller surface-area,X-ray photoelectron spectroscopy;temperature programmedreductionandScanningelectronmicroscopycoupledwith energy-Dispersive X-Ray *** Na2CO3was adjudged as the best precipitant for production of catalyst,which completely oxidized CO-CH4mixture at the lowest temperature（T（100）=350℃）.Whereas,for catalyst prepared using urea,T（100）=362℃.On the other hand the conversion of CO-CH4mixture over the catalyst synthesized by KOH limited to 97%even beyond 400℃.Further,the effect of higher calcination temperatures of 500 and600℃ was examined for the best *** total oxidation of the mixture was attained at higher temperatures of 375 and 410℃ over catalysts calcined at 500 and 600℃ ***,the best precipitant established was Na2CO3and the optimum calcination temperature of 400℃ was found to synthesize the Ni Co2O4catalyst for the best performance in CO-CH4oxidation.

关键词： CNG vehicular emissions CO-CH4 oxidation NiG0204 Precipitants Calcinations

Unsuitable use of spin and pseudospin symmetries with a pseudoscalar Cornell potential

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Chinese Physics B 2014年第9期23卷 60-61页

作者： L.B.castro A.S.de castro Departamento de Física CFM Universidade Federal de Santa Catarina Departamento de Física Universidade Federal do Maranho Campus Universtitrio do Bacanga Departamento de Física e Química Campus de Guaratinguet Universidade Estadual Paulista

The concepts of spin and pseudospin symmetries has been used as mere rhetorics to decorate the pseudoscalar potential [Chin. Phys. B 22 090301 （2013）]. It is also pointed out that a more complete analysis of the bou... 详细信息

关键词： Dirac equation pseudoscalar Comell potential spin symmetry pseudospin symmetry

Multi-conductor Line Models for Harmonic Load-flow Calculations in LV Networks with High Penetration of PV Generation

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Journal of Modern Power Systems and Clean energy 2022年第5期10卷 1288-1301页

作者： Fernando M.Camilo M.e.Almeida Rui castro V.Fernao Pires Institutode engenhariade Sistemas e Computadores Investigacao eDesenvolvimento(INESC-ID)and TecnicoUniversity of LisbonLisbonPortugal eSTSetubal Polytechnics of SetubalSetuibalPortugal

Low-voltage(LV) distribution networks are unbalanced and pre.e.t loads with nonlinear behavior, which introduce harmonics in the networks. The predictable increase in photovoltaic microgeneration(PV μG) accentuates this unbalanced characteristic, as well as poses new technical problems,namely voltage rise and re.e.se power flow. To accurately account for the distributed PV and loads in the LV network, unbalanced three-phase power flow algorithms should be utilized,where different approaches may be used to repre.e.t lines with various degrees of accuracy. The more accurate algorithm considers the electromagnetic coupling between the line conductors,whereas the simpler algorithm repre.e.ts each conductor of the line as a single-phase line with pure resistive behavior. This paper aims to analyze the influence of the line model on the load flow in a highly unbalanced LV network with a high penetration of PV production, and considers the impact of the harmonics produced by nonlinear loads. Based on the results obtained,it is possible to identify the most suitable model to be used, depending on the study to be performed. Different scenarios of PV generation and loads are addressed in this paper.

关键词： Line model nonlinear loads photovoltaic microgeneration unbalanced distribution network

Mysteries of R^ik=0： A novel paradigm in einstein＇s theory of gravitation

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Frontiers of physics 2014年第1期9卷 98-112页

作者： ram Gopal Vishwakarma Unidad Academica de Matemdticas Universidad Autdnoma de Zacatecas C.P. 98068 Zacatecas ZAC Mexico

Despite a century-long effort, a proper energy-stress tensor of the gravitational field, could not have been discovered. Furthermore, it has been discovered re.e.tly that the standard formulation of the energy-stress tensor of matter, suffers from various inconsistencies and paradoxes, concluding that the tensor is not consistent with the geometric formulation of gravitation [Astrophys. Space Sci., 2009, 321： 151; Astrophys. Space Sei., 2012, 340： 373]. This perhaps hints that a consistent theory of gravitation should not have any bearing on the energy-stress tensor. It is shown here that the so-called ＂vacuum＂ field equations Rik = 0 do not repre.e.t an empty spacetime, and the energy, momenta and angular momenta of the gravitational and the matter fields are re.e.led through the geometry, without including any formulation thereof in the field equations. Though, this novel discovery appears baffling and orthogonal to the usual understanding, is consistent with the observations at all scales, without requiring the Moreover, the resulting theory circumvents the besides explaining some unexplained puzzles. hypothetical dark matter, dark energy or inflation long-standing problems of the standard cosmology

关键词： general relativity and gravitation - fundamental problems and general formalism cos-mological observations