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Cosmology of a Chaplygin Gas Model Under f(T)Gravity and Evolution of Primordial Perturbations
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作者 Sanjeeda Sultana Surajit Chattopadhyay 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第6期187-198,共12页
This paper reports a detailed study of generalized Chaplygin gas(GCG)with power law form of scale factor and truncated form of the scale factor using binomial expansion in both interacting and non-interacting scenario... This paper reports a detailed study of generalized Chaplygin gas(GCG)with power law form of scale factor and truncated form of the scale factor using binomial expansion in both interacting and non-interacting scenarios along with its cosmological consequences,studied in terms of equation of state(EoS)parameter.In the non-interacting scenario,the EoS parameter behaves as quintessence in both forms of the scale factor.In the interacting scenario,the EoS parameter behaves as phantom and for the truncated form of the scale factor,it violates the constraints of the positive parameterα.The cosmological implementation of GCG interacting with pressureless dark matter is investigated in the framework of f(T)modified gravity,where T is the torsion scalar in teleparallelism.The interaction term is directly proportional to the GCG density with positive coupling constant.In f(T)gravity,the EoS is behaving like phantom.The stability of the reconstructed model is investigated and it is found to be stable against small gravitational perturbations,i.e.,the squared speed of sound is non-negative and an increasing function of cosmic time t.We have observed that our reconstructed f(T)model satisfies one of the sufficient conditions of a realistic reconstructed model and it is consistent with the CMB constraints and primordial nucleosynthesis.Cosmology of primordial perturbations has also been analyzed and the self-interacting potential has been found to be an increasing function of cosmic time t. 展开更多
关键词 (cosmology:)dark energy cosmology:theory (cosmology:)cosmological parameters
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Conservation Strategy for African Medicinal Species: In Vitro Biotechnological Approach 被引量:1
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作者 Priyanka Jha Swati Chahal +3 位作者 Devendra Kumar Pandey Joginder Singh Ram Prasad Vijay Kumar 《Phyton-International Journal of Experimental Botany》 SCIE 2020年第4期779-794,共16页
The use of medicinal plants for different therapeutic values is well documented in African continent.African diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal va... The use of medicinal plants for different therapeutic values is well documented in African continent.African diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal value.The feasible conservation approach and sustainable harvesting for the medicinal species remains a huge challenge.However,conservation approach through different biotechnological tools such as micropropagation,somatic embryogenesis,synthetic seed production,hairy root culture,molecular markers based study and cryopreservation of endemic African medicinal species is much crucial.In this review,an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal species.The present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species. 展开更多
关键词 Biotechnological approach conservation medicinal plant African traditional medicine(ATM) start codon targeted polymorphism(SCoT) somatic embryogenesis
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Viscous holographic f(Q)cosmology with some versions of holographic dark energy with generalized cut-offs
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作者 Gargee Chakraborty Surajit Chattopadhyay Ertan Güdekli 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第12期519-530,共12页
The work reported in this paper demonstrates the cosmology of f(Q)gravity and the reconstruction of various associated parameters with different versions of holographic dark energy with generalized cut-offs,where Q=6 ... The work reported in this paper demonstrates the cosmology of f(Q)gravity and the reconstruction of various associated parameters with different versions of holographic dark energy with generalized cut-offs,where Q=6 H^(2).The Universe is considered to be filled with viscous fluid characterized by a viscous pressureΠ=-3 Hξ,whereξ=ξ0+ξ1 H+ξ2(˙H+H^(2)and H is the Hubble parameter.Considering the power law form of expansion,we have derived the expression of f(Q)under a non-viscous holographic framework and it is then extended to viscous cosmological settings with extended generalized holographic Ricci dark energy.The forms of f(Q)for both the cases are found to be monotonically increasing functions of Q.In the viscous holographic framework,f(Q)is reconstructed as a function of cosmic time t and is found to stay at a positive level with Nojiri-Odintsov cut-off.In these cosmological settings,the slow roll parameters are computed and a scope of exit from inflation and quasiexponential expansion are found to be available.Finally,it is observed that warm inflationary expansion can be obtained from this model. 展开更多
关键词 Holographic dark energy Ricci dark energy f(Q)gravity bulk-viscosity equation of state parameter slow roll parameter
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An Auction-Based Recommender System for Over-The-Top Platform
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作者 Hameed AlQaheri Anjan Bandyopadhay +2 位作者 Debolina Nath Shreyanta Kar Arunangshu Banerjee 《Computers, Materials & Continua》 SCIE EI 2022年第3期5285-5304,共20页
In this era of digital domination,it is fit to say that individuals are more inclined towards viewership on online platforms due to the wide variety and the scope of individual preferences it provides.In the past few ... In this era of digital domination,it is fit to say that individuals are more inclined towards viewership on online platforms due to the wide variety and the scope of individual preferences it provides.In the past few years,there has been a massive growth in the popularity of Over-The-Top platforms,with an increasing number of consumers adapting to them.The Covid-19 pandemic has also caused the proliferation of these services as people are restricted to their homes.Consumers are often in a dilemma about which subscription plan to choose,and this iswhere a recommendation systemmakes their task easy.The Subscription recommendation system allows potential users to pick the most suitable and convenient plan for their daily consumption from diverse OTT platforms.The economic equilibrium behind allocating these resources follows a unique voting and bidding system propped by us in this paper.The systemis dependent on two types of individuals,type 1 seeking the recommendation plan,and type 2 suggesting it.In our study,the system collaborates with the latterwho participate in voting and invest/bid in the available options,keeping in mind the user preferences.This architecture runs on an interface where the candidates can login to participate at their convenience.As a result,selective participants are awarded monetary gains considering the rules of the suggested mechanism,and the most voted subscription plan gets recommended to the user. 展开更多
关键词 Recommendation systems over-the-top platforms subscription allocation auction theory
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Unravelling the Complex Networks of Social Physics:Exploring Human Behavior,Big Data,and Distributed Systems
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作者 Subrata Paul Dhritiman Mukherjee +2 位作者 Anirban Mitra Anuradha Mitra Pushan Kumar Dutta 《Journal of Social Computing》 EI 2024年第2期165-179,共15页
Networks form an integral part of our daily lives, comprising structures known as nodes connected via ties. These networks exhibit a complex interplay of random and structured features. We encounter networks regularly... Networks form an integral part of our daily lives, comprising structures known as nodes connected via ties. These networks exhibit a complex interplay of random and structured features. We encounter networks regularly in our daily activities, whether it is logging into websites, commuting by train, going to work, or attending school. Networks are prevalent in various academic disciplines and practical applications, spanning biology, physics, engineering, social science, and numerous other fields. The early 21st century has witnessed a rapid expansion of techniques facilitating human interaction, significantly impacting behavior and social bonding in both urban and rural settings. The availability and accessibility of extensive population datasets have spurred ongoing research into understanding and shaping human inclinations and sociological phenomena in unconventional ways. This review delves into the nuanced aspects of social physics, exploring the rationale behind choosing this research topic, various conceptual frameworks, categorizations, and distinctions between machine learning and deep learning. The article briefly outlines the advantages of leveraging big data in social physics, highlighting its transformative potential. Lastly, the authors provide insights into several applications of social physics in subsequent sections, offering a glimpse into its real-world implications. 展开更多
关键词 NETWORKS social physics machine learning deep learning social science
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An overlapping grid spectral collocation analysis on a newly developed hybrid nanofluid flow model
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作者 Amir Yaseen Khan Musawenkhosi Patson Mkhatshwa +2 位作者 Sabyasachi Mondal Melusi Khumalo Noor Fadiya Mohd Noor 《Propulsion and Power Research》 SCIE 2024年第1期98-117,共20页
The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by ta... The present study investigates the axisymmetric stagnation point radiativeflow of a Cu-Al2O3/water hybrid nanofluid over a radially stretched/shrunk disk.In this paper,a new mathematical model has been developed by taking into consideration the concept of different nanoparticles concentration in a hybrid nanofluid,which are Brownian motion and thermophor-esis of nanoparticles.A new model for entropy generation has also been provided in the present study.The non-dimensional governing equations of the developed mathematical model are solved using newly developed and efficient overlapping grid spectral collocation method.Numerical stability and residual error test are provided here to show the accuracy of the numer-ical method in this mathematical model.The outcomes offluidflow,temperature,and two different types of concentration profiles are depicted,and described in graphical and tabular forms.For the limiting instances,comparison shows excellent agreement among current and results established in the literature.Increasing the strength of magneticfield is seen to increase the radial component offluid velocity as well as the entropy generated within the system.Two different nanofluid concentration profiles are increasing and decreasing with rising thermophor-esis and Brownian motion parameters,respectively,from a particular height above the disk because of the revised nanofluid boundary condition.Temperature profile increases here with increasing Biot number,and increasing Brinkman number causes higher entropy generation number for both stretching and shrinking disks.The enhanced thermal characteristics of the hybrid nanofluid over the single particle nanofluid has been observed.ª2024 The Authors.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.Ltd. 展开更多
关键词 Axisymmetricflow Hybrid nanofluid Thermal radiation Overlapping grid method Entropy generation
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Bioconvection in Casson nanofluid flow with Gyrotactic microorganisms and variable surface heat flux
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作者 I.S.Oyelakin S.Mondal +1 位作者 P.Sibanda D.Sibanda 《International Journal of Biomathematics》 SCIE 2019年第4期111-135,共25页
This paper presents a two-dimensional unsteady laminar boundary layer mixed convection flow heat and mass transfer along a vertical plate filled with Casson nanofluid located in a porous quiescent medium that contains... This paper presents a two-dimensional unsteady laminar boundary layer mixed convection flow heat and mass transfer along a vertical plate filled with Casson nanofluid located in a porous quiescent medium that contains both nanoparticles and gyrotactic microorganisms. This permeable vertical plate is assumed to be moving in the same direction as the free stream velocity. The flow is subject to a variable heat flux, a zero nanoparticle flux and a constant density of motile microorganisms on the surface. The free stream velocity is time-dependent resulting in a non-similar solution. The transport equations are solved using the bivariate spectral quasilinearization method. A grid independence test for the validity of the result is given. The significance of the inclusion of motile microorganisms to heat transfer processes is discussed. We show, inter alia, that introducing motile microorganisms into the flow reduces the skin friction coefficient and that the random motion of the nanoparticles improves the rate of transfer of the motile microorganisms. 展开更多
关键词 Gyrotactic MICROORGANISMS BIOCONVECTION Casson NANOFLUID VARIABLE heat flux BIVARIATE spectral QUASILINEARIZATION method
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