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Stability of LRS Bianchi type-I cosmological models in f(R,T)-gravity

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Research in Astronomy and Astrophysics 2019年第4期19卷 63-76页

作者： Umesh kumar sharma Rashid Zia Anirudh Pradhan Aroon Beesham Department of Mathematics Institute of Applied Sciences & Humanities GLA University Department of Mathematical Sciences University of Zululand

This paper examines the stability of the transition from the early decelerating stage of the Universe to the recent accelerating stage for the perfect fluid cosmological locally rotationally symmetric(LRS) Bianchi-I model in f(R, T) theory. To determine the solution of field equations, the idea of a timevarying deceleration parameter(DP) which yields a scale factor, for which the Universe attains a phase transition scenario and is consistent with recent cosmological observations, is used. The time-dependent DP yields a scale factor a=exp■, where β and k are respectively arbitrary and integration constants. By using the recent cons_traints(H_0 _= 73.8, and q_0 =-0.54) from Type Ia Supernova(SN Ia) data in combination with Baryonic Acoustic Oscillations(BAO) and Cosmic Microwave Background(CMB) observations(Giostri et al.), we obtain the values of β = 0.0062 and k = 0.000016 for which we have derived a cosmological model from the early decelerated phase to the present accelerating phase. By applying_ other r_ecent constraints(H_0 = 73.8, q_0 =-0.73) from SNe Ia Union data(Cunha), we obtain the values of β = 0.0036 and k = 0.000084 for which we have derived a cosmological model in the accelerating phase only. We have compared both models with experimental data. The stability of the background solution has been examined also for the metric perturbations alongside the properties of future singularities in a Universe ruled by dark energy with phantom type fluid. We demonstrate the presence of a stable fixed point with a condition of state ω <-1 and numerically affirm this is really a late-time attractor in the ghost overwhelmed Universe. Some physical and geometric properties of the model are found and examined.

关键词： LRS Bianchi-I Universe Time-dependent deceleration parameter f(R,T) gravity theory Transit universe

Radiation effect on temperature distribution in three-dimensional Couette flow with suction or injection

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Applied Mathematics and Mechanics(English Edition) 2007年第3期28卷 309-316页

作者： Bhupendra kumar sharma Mamta Agarwal R.C.Chaudhary Department of Mathematics University of RajasthanJaipur-302004India

A theoretical analysis of three-dimensional Couette flow with radiation effect on temperature distribution has been analysed, when the injection of the fluid at the lower stationary plate is a transverse sinusoidat one and its corresponding removal by constant suction through the upper porous plate is in uniform motion. Due to this type of injection velocity, the flow becomes three-dimensional. The effect of Prandtl number, radiation parameter and injection parameter on rate of heat transfer has been examined by the help of graphs. The Prandtl number has a much greater effect on *** distribution than the injection or radiation parameter.

关键词： Couette flow three-dimensional heat transfer radiation incompressible

Nonlinear Time Series Analysis of Pathogenesis of COVID-19 Pandemic Spreadin Saudi Arabia

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Computers, Materials & Continua 2021年第1期66卷 805-825页

作者： Sunil kumar sharma Shivam Bhardwaj Rashmi Bhardwaj Majed Alowaidi College of Computer and Information Sciences Majmaah UniversityMajmaah11952Saudi Arabia Maharaja Agrasen Institute of Technology Guru Gobind Singh Indraprastha UniversityDelhi110086India Non-Linear Dynamics Research Laboratory GGS Indraprastha UniversityDelhi110078India

This article discusses short–term forecasting of the novel Corona Virus(COVID-19)data for infected and recovered cases using the ARIMA method for Saudi *** COVID-19 data was obtained from the Worldometer and MOH(Ministry of Health,Saudi Arabia).The data was analyzed for the period from March 2,2020(the first case reported)to June 15,*** ARIMA(2,1,0),we obtained the short forecast up to July 02,*** statistical parameters were tested for the goodness of fit to evaluate the forecasting *** results show that ARIMA(2,1,0)gave a better forecast for the data *** 19 data followed quadratic behavior,and in the long run,it spreads with a high *** is concluded that COVID-19 will follow secondary shock waves,and it is strongly advisable to maintain social distancing with all safety measures as the pandemic situation is not in control.

关键词： COVID-19 short-term forecast ARIMA GIS

Effect of stacking sequence on physical, mechanical and tribological properties of glass-carbon hybrid composites

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Friction 2014年第4期2卷 354-364页

作者： Gaurav AGARWAL Amar PATNAIK Rajesh kumar sharma Jyoti AGARWAL Department of Mechanical Engineering Invertis UniversityBareillyIndia Department of Mechanical Engineering National Institute of Technology(NIT)HamirpurIndia Department of Computer Engineering Rajshree Institute of Management&Technology(RIMT)BareillyIndia

A study was done to determine the effect of best stacking sequence(position and orientation)on the mechanical properties,friction and wear response of hybrid *** main purpose of the study was to determine the best available stacking sequence for which the physical,mechanical and three body abrasive wear rate is *** for mechanical properties(tensile strength,flexural strength,inter laminar shear strength,impact strength and hardness)was done on glass-carbon hybrid *** composites were then subjected to test for three body abrasive wear on a designed experimental *** different factors(sliding velocity,fabric weight percentage,normal load,sliding distance and abrasive particle size)varied in steps to evaluate the friction and three body abrasive wear response of the *** design of experiment using Taguchi’s orthogonal array and analysis of variance(ANOVA)was applied to find out minimum specific wear *** results revealed the significance in arrangement of two different layers of fabric(glass and carbon)and the difference in properties obtained by *** Taguchi experimental analysis it has been observed that three body abrasive wear rate is minimum at 72 cm/s sliding velocity,30 wt.%fabric content,80 N normal load,90 m sliding distance and 125μm abrasive particle *** scanning electron microscope(SEM)studies revealed the dynamics of three‐body abrasive wear and underlying micro‐mechanisms that result in the analysis of three body abrasive wear.

关键词： hybrid composite stacking sequence Taguchi’s method wear mechanism

Natural and artificial small RNAs:a promising avenue of nucleic acid therapeutics for cancer

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Cancer Biology & Medicine 2017年第3期14卷 242-253页

作者： Sunny Yadav Mamta Shekhawat Devashree Jahagirdar Nilesh kumar sharma Cancer and Translational Research Lab Dr.D.Y Patil Biotechnology&Bioinformatics InstituteDr.D.Y.Patil VidyapeethPune 411033MaharashtraIndia

Since the failure of traditional therapy, gene therapy using functional DNA sequence and small RNA/DNA molecules(oligonucleotide) has become a promising avenue for cancer treatment. The discovery of RNA molecules has impelled researchers to investigate small regulatory RNA from various natural and artificial sources and determine a cogent target for controlling tumor progression. Small regulatory RNAs are used for therapeutic silencing of oncogenes and aberrant DNA repair response *** their advantages, therapies based on small RNAs exhibit limitations in terms of stability of therapeutic drugs, precisionbased delivery in tissues, precision-based intercellular and intracellular targeting, and tumor heterogeneity-based responses. In this study, we summarize the potential and drawbacks of small RNAs in nucleic acid therapeutics for cancer.

关键词： Cancer drug targeting gene intracellular therapeutics tumor heterogeneity

Experimental investigation into the effects of Argemone biodiesel/diesel blends on cyclic variations in a multi-cylinder CRDI engine

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Clean Energy 2023年第2期7卷 363-374页

作者： Abhinav sharma Prem kumar Sarbjot Singh Sandhu Mandeep Singh Department of Mechanical Engineering Dr B R Ambedkar National Institute of TechnologyJalandhar-144011PunjabIndia

Internal combustion engines suffer from high cyclic variations that result in higher emissions,lower efficiency,higher fuel consump-tion and poor *** purpose of this study is to investigate how Argemone mexicana biodiesel(AGB)/diesel blended fuels affect the cyclic variability of combustion parameters such as maximum cylinder pressure(Pmax)and indicated mean effective pressure(IMEP)in a four-cylinder turbocharged intercooled common-rail direct injection engine under various engine loading *** chemical and physical properties of AGB produced from *** oil were measured and compared according to the ASTM D6751 *** various volumetric ratios,AGB and diesel fuel were blended as D100,AB10(10%AGB+90%D100),AB20(20%AGB+80%D100)and AB30(30%AGB+70%D100).The IMEP and Pmax time-series data were collected over 200 consecutive cycles at low,partial and high engine loads at a constant engine speed of 2000 *** coefficients of variation(COV)of combustion parameters(Pmax and IMEP)were measured for different AGB/diesel blends and found to be within acceptable *** results show that COV_(Pmax) and COV_(IMEP) decrease as the engine load *** was observed that at low load,AB10 has the lowest COV(Pmax,IMEP),and at partial and high load,AB20 has the lowest COV(Pmax,IMEP)among all the blends.

关键词： indicated mean effective pressure cyclic variations biodiesel diesel engine Argemone mexicana biodiesel

Aerobic bacterial flora of the normal conjunctiva at high altitude area of Shimla Hills in India:a hospital based study

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International Journal of Ophthalmology(English edition) 2013年第5期6卷 723-726页

作者： sharma Parmeshri Dass sharma Neelam Gupta Ravinder kumar Singh Parul Department of Ophthalmology VCSGG Medical Sciences and Research Institute

AIM:To study the normal aerobic conjunctival flora in lower to mid Himalayan region of Shimla ***:Samples from normal conjunctiva of 200 individuals above the age of 13 years who visited Indira Gandhi Medical College Hospital Shimla for refraction or cataract surgery were taken by anaesthetising the conjunctival sac with sterile 4% Xylocaine *** were obtained by gently rubbing lower fornix with a sterile cotton wool swab moistened with normal saline and keeping the eye lids wide apart to avoid contamination from lid *** was immediately inoculated in Brain Heart infusion and subjected to standard aerobic culture and identification ***:Totally,72 eyes(36%) conjunctival sacs were *** aerobes isolated were Staphylococcus *** 120(60%) followed by Haemophilus in 16(8%),diphtheroids in 10(5%),and Escherichia coli(***) in 4(2%).A single aerobe was isolated from 98 eyes(49%) while 30 eyes(15%) yielded more than 1 *** epidermidis(***) was the most common bacterium,found alone in 58 eyes(29%) and in combination with another aerobe in 30 eyes(15%),followed by Staphylococcus aureus(***) in 18(9%) and 10 eyes(5%) ***:*** is the most common commensal organism followed by Haemophilus *** occupied the third position which otherwise are found more abundantly in *** like ***,Staphylococcus citreus and *** were also ***,preoperative administration of topical broad spectrum antibiotics is extremely important in prophylaxis against ocular *** variation in microflora of normal conjunctiva in this part of world can be attributed to geographical,climatic and ethnic characteristics of the population under study.

关键词： normal conjunctival flora high altitude geographic and climatic conditions

Thermally Activated Photoconduction and Alternating-Current Conduction in Se75Ge20Ag5 Chalcogenide Glass： Investigation of Meyer-Neldel Rule

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Chinese Physics Letters 2008年第11期25卷 4079-4082页

作者： R. S. sharma N. Mehta A. kumar Department of Physics Harcourt Butler Technological Institute Kanpur India Department of Physics Banaras Hindu University Varanasi India

We report on the observation of Meyer-Neldel rule in glassy Se75Ge20Ag5 alloy where AE is varied by two different methods. In the first approach, the intensity of light varies while measuring the photoconductivity in amorphous thin films of Se75Ge20Ag5 instead of changing composition of the glassy system. In the second approach, the variation of ac conductivity with temperature is found to be exponential and the activation energy is found to vary with frequency.

关键词： THIN films METALLIC glasses PHOTOCONDUCTIVITY CHALCOGENIDES AMORPHOUS substances

Numerical and analytical investigations of thermosolutal instability in rotating Rivlin-Ericksen fluid in porous medium with Hall current

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Applied Mathematics and Mechanics(English Edition) 2013年第4期34卷 501-522页

作者： S.kumar V.sharma K.KISHOR Department of Mathematics Government College Department of Mathematics Himachal Pradesh University Department of Mathematics Government Senior Secondary School

Numerical and analytical investigations of the thermosolutal instability in a viscoelastic Rivlin-Ericksen fluid are carried out in the presence of a uniform vertical magnetic field to include the Hall current with a uniform angular velocity in a porous medium. For stationary convection, the stable solute gradient parameter and the rota- tion have stabilizing effects on the system, whereas the magnetic field and the medium permeability have stabilizing or destabilizing effects on the system under certain condi- tions. The Hall current in the presence of rotation has stabilizing effects for sufficiently large Taylor numbers, whereas in the absence of rotation, the Hall current always has destabilizing effects. These effects have also been shown graphically. The viscoelastic effects disappear for stationary convection. The stable solute parameter, the rotation, the medium permeability, the magnetic field parameter, the Hall current, and the vis- coelasticity introduce oscillatory modes into the system, which are non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained.

关键词： magnetic field thermosolutal instability Rivlin-Ericksen rotating fluid Hall current porous medium