The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nano...The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nanofluid incorporates the effects of the Brownian motion and thermophoresis in the presence of thermal stratification. The sym- metry groups admitted by the corresponding boundary value problem are obtained by using a special form of Lie group transformations, namely, the scaling group of transfor- mations. An exact solution is obtained for the translation symmetrys, and the numerical solutions are obtained for the scaling symmetry. This solution depends on the Lewis number, the Brownian motion parameter, the thermal stratification parameter, and the thermophoretic parameter. The conclusion is drawn that the flow field, the temperature, and the nanoparticle volume fraction profiles are significantly influenced by these param- eters. Nanofluids have been shown to increase the thermal conductivity and convective heat transfer performance of base liquids. Nanoparticles in the base fluids also offer the potential in improving the radiative properties of the liquids, leading to an increase in the efficiency of direct absorption solar collectors.展开更多
Cloud Computing has become the popular paradigm for accessing the various scalable and on-demand computing services over the internet.Nowadays,individual Cloud Service Providers(CSPs)offering specialized services to t...Cloud Computing has become the popular paradigm for accessing the various scalable and on-demand computing services over the internet.Nowadays,individual Cloud Service Providers(CSPs)offering specialized services to the customers collaborate to form the Cloud Federation,in order to reap the real benefits of Cloud Computing.By collaboration,the member CSPs of the federation achieve better resource utilization and Quality of Service(QoS),thereby increasing their business prospects.When a CSP runs out of resources in the Cloud Federation,in order to offload the customer requests for resources to other CSP(s),identifying a suitable partner is a challenging task due to the lack of global coordination among them.In this paper,we propose the design and implementation of an efficient partner selection mechanism in the Cloud Federation,using the Analytic Hierarchy Process(AHP)and the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)methods,and also considering the trust values of various CSPs in the federation.The AHP method is used to calculate the weights of the QoS parameters used in the TOPSIS method which is used to rank the various CSPs in the Cloud Federation according to the user requirements.Simulation results show the effectiveness of this approach in order to efficiently select the trustworthy partners in large scale federations to ensure the required QoS to the cloud consumers.展开更多
文摘The problem of laminar fluid flow, which results from the stretching of a vertical surface with variable stream conditions in a nanofluid due to solar energy, is in- vestigated numerically. The model used for the nanofluid incorporates the effects of the Brownian motion and thermophoresis in the presence of thermal stratification. The sym- metry groups admitted by the corresponding boundary value problem are obtained by using a special form of Lie group transformations, namely, the scaling group of transfor- mations. An exact solution is obtained for the translation symmetrys, and the numerical solutions are obtained for the scaling symmetry. This solution depends on the Lewis number, the Brownian motion parameter, the thermal stratification parameter, and the thermophoretic parameter. The conclusion is drawn that the flow field, the temperature, and the nanoparticle volume fraction profiles are significantly influenced by these param- eters. Nanofluids have been shown to increase the thermal conductivity and convective heat transfer performance of base liquids. Nanoparticles in the base fluids also offer the potential in improving the radiative properties of the liquids, leading to an increase in the efficiency of direct absorption solar collectors.
文摘Cloud Computing has become the popular paradigm for accessing the various scalable and on-demand computing services over the internet.Nowadays,individual Cloud Service Providers(CSPs)offering specialized services to the customers collaborate to form the Cloud Federation,in order to reap the real benefits of Cloud Computing.By collaboration,the member CSPs of the federation achieve better resource utilization and Quality of Service(QoS),thereby increasing their business prospects.When a CSP runs out of resources in the Cloud Federation,in order to offload the customer requests for resources to other CSP(s),identifying a suitable partner is a challenging task due to the lack of global coordination among them.In this paper,we propose the design and implementation of an efficient partner selection mechanism in the Cloud Federation,using the Analytic Hierarchy Process(AHP)and the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)methods,and also considering the trust values of various CSPs in the federation.The AHP method is used to calculate the weights of the QoS parameters used in the TOPSIS method which is used to rank the various CSPs in the Cloud Federation according to the user requirements.Simulation results show the effectiveness of this approach in order to efficiently select the trustworthy partners in large scale federations to ensure the required QoS to the cloud consumers.
