The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform

Arturo Morales-acevedo - One of the best experts on this subject based on the ideXlab platform.

  • Simulation of hetero-junction silicon solar cells with AMPS-1D
    Solar Energy Materials and Solar Cells, 2010
    Co-Authors: Norberto Hernández-como, Arturo Morales-acevedo
    Abstract:

    Mono- and poly-crystalline silicon solar cell modules currently represent between 80% and 90% of the PV world market. The reasons are the stability, robustness and reliability of this kind of solar cells as compared to those of emerging technologies. Then, in the mid-term, silicon solar cells will continue playing an important role for their massive Terrestrial Application. One important approach is the development of silicon solar cells processed at low temperatures (less than 300 °C) by depositing amorphous silicon layers with the purpose of passivating the silicon surface, and avoiding the degradation suffered by silicon when processed at temperatures above 800 °C. This kind of solar cells is known as HIT cells (hetero-junction with an intrinsic thin amorphous layer) and are already produced commercially (Sanyo Ltd.), reaching efficiencies above 20%. In this work, HIT solar cells are simulated by means of AMPS-1D, which is a program developed at Pennsylvania State University. We shall discuss the modifications required by AMPS-1D for simulating this kind of structures since this program explicitly does not take into account interfaces with high interfacial density of states as occurs at amorphous-crystalline silicon hetero-junctions. © 2009 Elsevier B.V. All rights reserved.

  • Hetero-junction (HIT) silicon solar cell model for AMPS-1D simulation
    2008 5th International Conference on Electrical Engineering Computing Science and Automatic Control, 2008
    Co-Authors: Norberto Hernández-como, Arturo Morales-acevedo
    Abstract:

    Mono and polycrystalline silicon solar cell modules currently represent between 85 and 90% of the PV world market. The reasons are the stability, robustness and reliability of this kind of solar cells as compared to those of emerging technologies. Then, in the mid-term, silicon solar cells will continue playing an important role for their massive Terrestrial Application. One important approach is the development of silicon solar cells processed at low temperatures (less than 300degC) by depositing amorphous silicon layers with the purpose of passivating the silicon surface, and avoiding the degradation suffered by silicon when processed at temperatures above 800deg C. This kind of solar cells are known as HIT cells (Heterojunction with an intrinsic layer) and are already produced commercially (Sanyo Ltd), reaching efficiencies around 23%. In this work we shall find the conditions and parameters needed for the crystalline silicon and amorphous silicon layers that allow high conversion efficiencies. These solar cell are simulated by means of AMPS-1D, which is a program developed at Pennsylvania State University. We shall discuss the modifications required for simulating this kind of structures since this program explicitly does not take into account interfaces with high interfacial density of states as occurs at the amorphous-crystalline silicon interface. Finally, optimization of the HIT cells will also be discussed.

Yves Bertin - One of the best experts on this subject based on the ideXlab platform.

  • Experimental and Numerical Analysis of Start-up of a Capillary Pumped Loop for Terrestrial Applications
    Journal of Heat Transfer, 2019
    Co-Authors: Flavio Accorinti, Vincent Ayel, Nicolas Blet, Sébastien Dutour, Yves Bertin
    Abstract:

    A study on the start-up phases of a Capillary Pumped Loop for Terrestrial Application is proposed in this paper. Experimental analysis and numerical modelling, using a 1-D spatial discretization model based on Navier-Stokes equations and solved by electrical analogy, are presented to study the thermal and hydraulic behavior of the loop for methanol and n-pentane as working fluids, during start-up transient phases. The experimental observations are backed up by the numerical model to help the transient analysis of this kind of loop. The precise numerical study allows us to have a better understanding of the complicated phenomena happening during the start-up and to have a global view of the system during these phases. In this study it will be also showed the influence of vapor line solid walls thermal inertia and its impact on the dynamic behavior and on the success of the start-up of the loop.

  • steady state analysis of a capillary pumped loop for Terrestrial Application with methanol and ethanol as working fluids
    International Journal of Thermal Sciences, 2019
    Co-Authors: Flavio Accorinti, Vincent Ayel, Yves Bertin
    Abstract:

    Abstract This paper aims to study and understand the behaviour of a CPLTA (Capillary Pumped Loop for Terrestrial Applications) in different operating conditions. This CPL, designed for power electronics cooling Applications, has been analysed from two different points of view by comparing its operating behaviour with Ethanol and Methanol as working fluids. The influence of the fluids on CPLTA was experimentally explored by modifying: the thermal characteristics (applied heat flux density on the evaporator walls, saturation temperature in the reservoir and condenser inlet temperature) and the hydraulic characteristics (by acting on a setting valve to generate controlled and increasing pressure losses in the vapour line) in order to show how they impact the behaviour of the loop. Thermal aspects of the loop were analysed, including changes of evaporator conductance. To obtain the thermodynamic cycles and evaporator conductance, based on the real evaporation temperature in the porous wick, a theoretical study was conducted using a specific post-processing tool.

  • Experimental analysis of a capillary pumped loop for Terrestrial Applications with several evaporators in parallel
    Applied Thermal Engineering, 2016
    Co-Authors: Nicolas Blet, Vincent Ayel, Yves Bertin, Cyril Romestant, Vincent Platel
    Abstract:

    Abstract In the context of high-dissipation electronics cooling for ground transportation, a new design of two-phase loop has been improved in recent years: the capillary pumped loop for Terrestrial Application (CPLTA). This hybrid system, between the two standard capillary pumped loop (CPL) and loop heat pipe (LHP), has been widely investigated with a single evaporator, and so a single dissipative area, to know its mean operating principles and thermohydraulic couplings between the components. To aim to extend its scope of Applications, a new experimental CPLTA with three evaporators in parallel is studied in this paper with methanol as working fluid. Even if the dynamics of the loop in multi-evaporators mode appears on the whole similar to that with a single operating evaporator, additional couplings are highlighted between the several evaporators. A decoupling between vapor generation flow rate and pressure drop in each evaporator is especially revealed. The impact of this phenomenon on the conductance at evaporator is analyzed.

  • experimental analysis of a capillary pumped loop for Terrestrial Application
    Journal of Thermophysics and Heat Transfer, 2011
    Co-Authors: Vincent Ayel, Laurent Lachassagne, Yves Bertin, Cyril Romestant, David Lossouarn
    Abstract:

    This paper reports on an experimental study of a capillary pumped loop for Terrestrial Application (CPLTA) that has been tested using ethanol, methanol, and N-pentane as working fluids. This CPLTA, designed for integrated power electronics cooling in railways, is capable of transferring total heat power of more than 5 kWwhen filled with methanol. First, experiments carried out under transient conditions show the high stability of this device for all the conditions tested, particularly with regard to a harsh rail cycle. Second, steady-state results convincingly show that conductance of the evaporator is independent of secondary fluid temperature, but strongly dependent on the nature of the fluid and the saturation temperature at the reservoir. A theoretical analysis has been undertaken in order to establish the thermodynamic operating curves of all tests carried out in steady-state condition by calculating the pressure difference between the reservoir and the evaporator; from these curves onemay determine the evaporation temperature, as well as the conductance restricted to the single evaporator, thereby underscoring the differences between the fluids. Finally, these results confirm that methanol is the maximally performing fluid for such devices, but also that N-pentane is useful with regard to the lowest heat powers applied, due to its lower density when compared with other fluids.

R. Matai - One of the best experts on this subject based on the ideXlab platform.

  • Novel ultra low loss & large effective area G.654.E fibre in Terrestrial Application
    2017 Optical Fiber Communications Conference and Exhibition (OFC), 2017
    Co-Authors: Lei Zhang, Ruichun Wang, Honghai Wang, Jing Li, R. Matai
    Abstract:

    The paper introduced latest ITU-T G.654.E fiber sepecification and typical G.654.E profile design. Our novel ultra low loss & large effective area fiber attenuation and cabling performance were also discussed. In the recent two G.654.E Terrestrial cable projects of china, the PCVD G.654.E fiber shows the huge advantages of link attenuation and effective area than standard G.652.D fiber. G.654.E industry chain is matured and can be promoted in Terrestrial network.

  • novel ultra low loss large effective area g 654 e fibre in Terrestrial Application
    Optical Fiber Communication Conference, 2017
    Co-Authors: Lei Zhang, Ruichun Wang, Honghai Wang, Jing Li, R. Matai
    Abstract:

    The paper introduced latest ITU-T G.654.E fiber sepecification and typical G.654.E profile design. Our novel ultra low loss & large effective area fiber attenuation and cabling performance were also discussed. in the recent two G.654.E Terrestrial cable projects of china, the PCVD G.654.E fiber shows the huge advantages of link attenuation and effective area than standard G.652.D fiber. G.654.E industry chain is matured and can be promoted in Terrestrial network.

Norberto Hernández-como - One of the best experts on this subject based on the ideXlab platform.

  • Simulation of hetero-junction silicon solar cells with AMPS-1D
    Solar Energy Materials and Solar Cells, 2010
    Co-Authors: Norberto Hernández-como, Arturo Morales-acevedo
    Abstract:

    Mono- and poly-crystalline silicon solar cell modules currently represent between 80% and 90% of the PV world market. The reasons are the stability, robustness and reliability of this kind of solar cells as compared to those of emerging technologies. Then, in the mid-term, silicon solar cells will continue playing an important role for their massive Terrestrial Application. One important approach is the development of silicon solar cells processed at low temperatures (less than 300 °C) by depositing amorphous silicon layers with the purpose of passivating the silicon surface, and avoiding the degradation suffered by silicon when processed at temperatures above 800 °C. This kind of solar cells is known as HIT cells (hetero-junction with an intrinsic thin amorphous layer) and are already produced commercially (Sanyo Ltd.), reaching efficiencies above 20%. In this work, HIT solar cells are simulated by means of AMPS-1D, which is a program developed at Pennsylvania State University. We shall discuss the modifications required by AMPS-1D for simulating this kind of structures since this program explicitly does not take into account interfaces with high interfacial density of states as occurs at amorphous-crystalline silicon hetero-junctions. © 2009 Elsevier B.V. All rights reserved.

  • Hetero-junction (HIT) silicon solar cell model for AMPS-1D simulation
    2008 5th International Conference on Electrical Engineering Computing Science and Automatic Control, 2008
    Co-Authors: Norberto Hernández-como, Arturo Morales-acevedo
    Abstract:

    Mono and polycrystalline silicon solar cell modules currently represent between 85 and 90% of the PV world market. The reasons are the stability, robustness and reliability of this kind of solar cells as compared to those of emerging technologies. Then, in the mid-term, silicon solar cells will continue playing an important role for their massive Terrestrial Application. One important approach is the development of silicon solar cells processed at low temperatures (less than 300degC) by depositing amorphous silicon layers with the purpose of passivating the silicon surface, and avoiding the degradation suffered by silicon when processed at temperatures above 800deg C. This kind of solar cells are known as HIT cells (Heterojunction with an intrinsic layer) and are already produced commercially (Sanyo Ltd), reaching efficiencies around 23%. In this work we shall find the conditions and parameters needed for the crystalline silicon and amorphous silicon layers that allow high conversion efficiencies. These solar cell are simulated by means of AMPS-1D, which is a program developed at Pennsylvania State University. We shall discuss the modifications required for simulating this kind of structures since this program explicitly does not take into account interfaces with high interfacial density of states as occurs at the amorphous-crystalline silicon interface. Finally, optimization of the HIT cells will also be discussed.

Mitsuji Matsumoto - One of the best experts on this subject based on the ideXlab platform.

  • Studies on C 2 n and its effects on free space optical communication system
    2010
    Co-Authors: Peng Liu, Kamugisha Kazaura, Kazuhiko Wakamori, Mitsuji Matsumoto
    Abstract:

    With the emergence of new innovative wireless technologies, there is an increased demand for technologies to provide high speed seamless connectivity between two places. Compared with radio frequency communication, free space optical communication has many advantages. It can provide very high speed communication services. But it is deeply influenced by the atmosphere turbulence, when used in Terrestrial Application. It is very important to do some researches on the atmosphere turbulence and its effects on the free space optical communication. We have used an experimental free space optical communication system to measure the characterization of atmosphere turbulence. In this paper we mainly analyze the experiment data of atmosphere turbulence. We also review the theory of atmosphere turbulence and analyze the relation with the characterization of atmosphere turbulence and the receiving power of the free space optical system. From the data we found that the atmosphere turbulence changed with time and weather. And we get some results from analyze the experiment data. The results from the experiment are very important in the design optimization of free space optics system performance in actual operational environments.

  • Studies on C2n and its effects on free space optical communication system
    Information and Telecommunication Technologies (APSITT) 2010 8th Asia-Pacific Symposium on, 2010
    Co-Authors: Kamugisha Kazaura, Kazuhiko Wakamori, Mitsuji Matsumoto
    Abstract:

    With the emergence of new innovative wireless technologies, there is an increased demand for technologies to provide high speed seamless connectivity between two places. Compared with radio frequency communication, free space optical communication has many advantages. It can provide very high speed communication services. But it is deeply influenced by the atmosphere turbulence, when used in Terrestrial Application. It is very important to do some researches on the atmosphere turbulence and its effects on the free space optical communication. We have used an experimental free space optical communication system to measure the characterization of atmosphere turbulence. In this paper we mainly analyze the experiment data of atmosphere turbulence. We also review the theory of atmosphere turbulence and analyze the relation with the characterization of atmosphere turbulence and the receiving power of the free space optical system. From the data we found that the atmosphere turbulence changed with time and weather. And we get some results from analyze the experiment data. The results from the experiment are very important in the design optimization of free space optics system performance in actual operational environments.

  • A Study on Atmospheric Turbulence Effects in Full-Optical Free-Space Communication Systems
    2010 6th International Conference on Wireless Communications Networking and Mobile Computing (WiCOM), 2010
    Co-Authors: Xueying Wu, Mitsuji Matsumoto
    Abstract:

    Next generation free-space optical communication systems have used fiber-optic technology as the seamless connection between free-space and optical fiber. The full-optical free-space optical communication systems use optical fiber as the receiver to get faster communication speed. The atmospheric turbulence deeply influenced on the optical wave propagated in Terrestrial Application. As the active receiving area of the full-optical free-space optical communication systems is very small, it is important to research on the atmospheric turbulence effects on the full-optical free-space optical communication system. In this paper, we discuss about both the turbulence-induced intensity fluctuations and the angle-of-arrival effects in full-optical free-space optical communication systems which are used in a few kilometers communication. We gave the numerical results of the atmosphere turbulence effects on the free-space optical communication systems. In order to minimize the atmospheric turbulence influence on the full-optical free-space optical communications system, we also investigate the use of fine tracking system in the communication system. We have set up a full-optical free-space communication system in Tokyo and received useful data from the experiment. We compared the receiving power of the experiment, when the fine tracking system is On and Off. From the experiment results, we can see that the fine tracking system effectively mitigates the atmospheric turbulence and increases the receiving power of the communication system.