The Experts below are selected from a list of 58539 Experts worldwide ranked by ideXlab platform
Jing Lin - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear dynamics and Performance Enhancement of asymmetric potential bistable energy harvesters
Nonlinear Dynamics, 2018Co-Authors: Wei Wang, Junyi Cao, Christopher R. Bowen, Ying Zhang, Jing LinAbstract:Bistable system exhibiting complex dynamic behavior has been viewed as an efficient method to overcome the issue of linear energy harvester only performing well near the resonant frequency. Moreover, Performance Enhancement strategies of bistable energy harvesters have been extensively discussed mainly for systems with perfectly symmetric potentials. Due to the presence of imperfections as a result of non-uniform manufacturing of the harvesters, eccentricity of the buckling or magnetic force and uneven gravity, the dynamic characteristics and Performance Enhancement of asymmetric potential energy harvesting remain an open issue. Therefore, this paper investigates the influence mechanism and Performance Enhancement of a cantilever-based bistable energy harvesting system with asymmetric potentials. Bifurcation diagrams of the dimensionless electromechanical equations are employed to discover the effect of asymmetric potentials on the output response. Based on the numerical results, a Performance Enhancement method is proposed by compensating the asymmetric potentials with an appropriate bias of the system to decrease the negative impact of asymmetric potentials on bistable energy harvesting. The optimum bias angle is derived and numerical simulations under constant and sweep frequency excitations demonstrate that the Performance of the asymmetric potential bistable energy harvesters is enhanced in a certain bias angle range around the optimum value. Two bistable energy harvesters with different asymmetric potential energy functions are investigated in the experiments and results verify the effectiveness of the proposed method for improving the energy harvesting Performance.
Manabendra Pathak - One of the best experts on this subject based on the ideXlab platform.
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Performance Enhancement of solar collectors a review
Renewable & Sustainable Energy Reviews, 2015Co-Authors: Siddharth Suman, Mohd Kaleem Khan, Manabendra PathakAbstract:Given rapid depletion of conventional energy sources and environmental degradation caused by their over exploitation, the renewable energy sources are believed to be the future. Technologies utilizing renewable energy sources differ significantly from one another, not only with regard to technical and economic aspects but also in relation to their reliability, maturity, and operational experience in utility scale conditions. Technologies used to harness solar energy have emerged as the most promising and mature since solar energy is abundant, freely available, and it has commercial potential too. This paper presents a review of advancements made in the field of solar thermal technology with a focus on techniques employed for its Performance Enhancement. It also covers the description of different types of solar collectors to facilitate the systematic understanding of solar thermal technology and the novel modifications realized in each category of solar collectors have been highlighted to promote the use of solar energy in routine activities. Performance Enhancement techniques such as geometrical modifications on the absorber plate, use of solar selective coatings and nanofluids have been given a special attention.
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Performance Enhancement of solar collectors—A review
Renewable & Sustainable Energy Reviews, 2015Co-Authors: Siddharth Suman, Mohd Kaleem Khan, Manabendra PathakAbstract:Given rapid depletion of conventional energy sources and environmental degradation caused by their over exploitation, the renewable energy sources are believed to be the future. Technologies utilizing renewable energy sources differ significantly from one another, not only with regard to technical and economic aspects but also in relation to their reliability, maturity, and operational experience in utility scale conditions. Technologies used to harness solar energy have emerged as the most promising and mature since solar energy is abundant, freely available, and it has commercial potential too. This paper presents a review of advancements made in the field of solar thermal technology with a focus on techniques employed for its Performance Enhancement. It also covers the description of different types of solar collectors to facilitate the systematic understanding of solar thermal technology and the novel modifications realized in each category of solar collectors have been highlighted to promote the use of solar energy in routine activities. Performance Enhancement techniques such as geometrical modifications on the absorber plate, use of solar selective coatings and nanofluids have been given a special attention.
S. D. Pohekar - One of the best experts on this subject based on the ideXlab platform.
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Performance Enhancement in latent heat thermal storage system a review
Renewable & Sustainable Energy Reviews, 2009Co-Authors: S. Jegadheeswaran, S. D. PohekarAbstract:Phase change material (PCM) based latent heat thermal storage (LHTS) systems offer a challenging option to be employed as an effective energy storage and retrieval device. The Performance of LHTS systems is limited by the poor thermal conductivity of PCMs employed. Successful large-scale utilization of LHTS systems thus depends on the extent to which the Performance can be improved. A great deal of work both experimental and theoretical on different Performance Enhancement techniques has been reported in the literature. This paper reviews the implementation of those techniques in different configurations of LHTS systems. The influence of Enhancement techniques on the thermal response of the PCM in terms of phase change rate and amount of latent heat stored/retrieved has been addressed as a main aspect. Issues related to mathematical modeling of LHTS systems employing Enhancement techniques are also discussed.
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Performance Enhancement in latent heat thermal storage system: A review
Renewable and Sustainable Energy Reviews, 2009Co-Authors: S. Jegadheeswaran, S. D. PohekarAbstract:Phase change material (PCM) based latent heat thermal storage (LHTS) systems offer a challenging option to be employed as an effective energy storage and retrieval device. The Performance of LHTS systems is limited by the poor thermal conductivity of PCMs employed. Successful large-scale utilization of LHTS systems thus depends on the extent to which the Performance can be improved. A great deal of work both experimental and theoretical on different Performance Enhancement techniques has been reported in the literature. This paper reviews the implementation of those techniques in different configurations of LHTS systems. The influence of Enhancement techniques on the thermal response of the PCM in terms of phase change rate and amount of latent heat stored/retrieved has been addressed as a main aspect. Issues related to mathematical modeling of LHTS systems employing Enhancement techniques are also discussed. © 2009 Elsevier Ltd. All rights reserved.
Yongguang Zhang - One of the best experts on this subject based on the ideXlab platform.
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TCP Performance Enhancement Proxy
Internetworking and Computing Over Satellite Networks, 2020Co-Authors: Yongguang ZhangAbstract:It is commonly perceived that Internet applications, especially those based on TCP protocol, do not perform well over satellite networks. The root of this problem is the latency incurred in a satellite link. To stay competitive, the satellite industry has developed and deployed a practical solution, called TCP Performance-Enhancement Proxy (as known as “TCP Spoofing”) to solve this problem. Although it has gained tremendous success in today’s satellite networks, its use has always been controversial among the Internet community. Its critics blast it for breaking the end-to-end principle, an orthodox of the Internet. Lately, the increasingly pervasive IPsec applications have begun to threaten the Performance of satellite networks by rendering TCP Performance-Enhancement Proxy useless for IPsec-protected traffic.
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A multilayer IP security protocol for TCP Performance Enhancement in wireless networks
IEEE Journal on Selected Areas in Communications, 2004Co-Authors: Yongguang ZhangAbstract:Transmission control protocol (TCP) Performance Enhancement proxy (PEP) mechanisms have been proposed, and in some cases widely deployed, to improve TCP Performance in all-Internet protocol (IP) wireless networks. However, this technique is conflicted with IP-security (IPsec)-a standard IP security protocol that will make inroad into wireless networks. This paper analyzes the fundamental problem behind this conflict and develops a solution called multilayer IP-security (ML-IPsec). The basic principle is to use a multilayer protection model and a fine grain access control to make IP security protocols compatible with TCP PEP. It allows wireless network operators or service providers to grant base stations or wireless routers limited and controllable access to the TCP headers for Performance Enhancement purposes. Through careful design, implementation, and evaluation, we show that we can easily add ML-IPsec to existing IPsec software and the overhead is low. We conclude that ML-IPsec can help wireless networks provide both security and Performance.
Wei Wang - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear dynamics and Performance Enhancement of asymmetric potential bistable energy harvesters
Nonlinear Dynamics, 2018Co-Authors: Wei Wang, Junyi Cao, Christopher R. Bowen, Ying Zhang, Jing LinAbstract:Bistable system exhibiting complex dynamic behavior has been viewed as an efficient method to overcome the issue of linear energy harvester only performing well near the resonant frequency. Moreover, Performance Enhancement strategies of bistable energy harvesters have been extensively discussed mainly for systems with perfectly symmetric potentials. Due to the presence of imperfections as a result of non-uniform manufacturing of the harvesters, eccentricity of the buckling or magnetic force and uneven gravity, the dynamic characteristics and Performance Enhancement of asymmetric potential energy harvesting remain an open issue. Therefore, this paper investigates the influence mechanism and Performance Enhancement of a cantilever-based bistable energy harvesting system with asymmetric potentials. Bifurcation diagrams of the dimensionless electromechanical equations are employed to discover the effect of asymmetric potentials on the output response. Based on the numerical results, a Performance Enhancement method is proposed by compensating the asymmetric potentials with an appropriate bias of the system to decrease the negative impact of asymmetric potentials on bistable energy harvesting. The optimum bias angle is derived and numerical simulations under constant and sweep frequency excitations demonstrate that the Performance of the asymmetric potential bistable energy harvesters is enhanced in a certain bias angle range around the optimum value. Two bistable energy harvesters with different asymmetric potential energy functions are investigated in the experiments and results verify the effectiveness of the proposed method for improving the energy harvesting Performance.
