The Experts below are selected from a list of 409842 Experts worldwide ranked by ideXlab platform

Pejman Kazempoor - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of hydrogen and methane fuelled solid oxide fuel cell systems for residential applications system Design Alternative and parameter study
    International Journal of Hydrogen Energy, 2009
    Co-Authors: Pejman Kazempoor, Viktor Dorer, Fathollah Ommi
    Abstract:

    Design-point and part-load characteristics of a solid oxide fuel cell (SOFC) system, fuelled by methane and hydrogen, are investigated for its prospective use in the residential application. As a part of this activity, a detailed SOFC cell model is developed, evaluated and extended to a stack model. Models of all the required balance of plant components are also developed and are integrated to build a system model. Using this model, two system base cases for methane and hydrogen fuels are introduced. Cogeneration relevant performance figures are investigated for different system configurations and cell parameters i.e. fuel utilization, fuel flow rate, operation voltage and extent of internal fuel reforming. The results show high combined heat and power efficiencies for both cases, with higher thermal-to-electric ratio and lower electric efficiency for the hydrogen-fuelled cases. Performance improvements with radiation air pre-heaters and anode gas recycling are presented and the respective application limits discussed.

Fathollah Ommi - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of hydrogen and methane fuelled solid oxide fuel cell systems for residential applications system Design Alternative and parameter study
    International Journal of Hydrogen Energy, 2009
    Co-Authors: Pejman Kazempoor, Viktor Dorer, Fathollah Ommi
    Abstract:

    Design-point and part-load characteristics of a solid oxide fuel cell (SOFC) system, fuelled by methane and hydrogen, are investigated for its prospective use in the residential application. As a part of this activity, a detailed SOFC cell model is developed, evaluated and extended to a stack model. Models of all the required balance of plant components are also developed and are integrated to build a system model. Using this model, two system base cases for methane and hydrogen fuels are introduced. Cogeneration relevant performance figures are investigated for different system configurations and cell parameters i.e. fuel utilization, fuel flow rate, operation voltage and extent of internal fuel reforming. The results show high combined heat and power efficiencies for both cases, with higher thermal-to-electric ratio and lower electric efficiency for the hydrogen-fuelled cases. Performance improvements with radiation air pre-heaters and anode gas recycling are presented and the respective application limits discussed.

Viktor Dorer - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of hydrogen and methane fuelled solid oxide fuel cell systems for residential applications system Design Alternative and parameter study
    International Journal of Hydrogen Energy, 2009
    Co-Authors: Pejman Kazempoor, Viktor Dorer, Fathollah Ommi
    Abstract:

    Design-point and part-load characteristics of a solid oxide fuel cell (SOFC) system, fuelled by methane and hydrogen, are investigated for its prospective use in the residential application. As a part of this activity, a detailed SOFC cell model is developed, evaluated and extended to a stack model. Models of all the required balance of plant components are also developed and are integrated to build a system model. Using this model, two system base cases for methane and hydrogen fuels are introduced. Cogeneration relevant performance figures are investigated for different system configurations and cell parameters i.e. fuel utilization, fuel flow rate, operation voltage and extent of internal fuel reforming. The results show high combined heat and power efficiencies for both cases, with higher thermal-to-electric ratio and lower electric efficiency for the hydrogen-fuelled cases. Performance improvements with radiation air pre-heaters and anode gas recycling are presented and the respective application limits discussed.

Charles J Vath - One of the best experts on this subject based on the ideXlab platform.

  • effect of wire size on the formation of intermetallics and kirkendall voids on thermal aging of thermosonic wire bonds
    Materials Letters, 2004
    Co-Authors: S Murali, Narasimalu Srikanth, Charles J Vath
    Abstract:

    Abstract Thermosonic bonding process is a viable method to make reliable interconnections between die bond pads and leads using thin gold and copper wires. This paper investigates interface morphology and metallurgical behavior of the bond formed between wire and bond pad metallization for different Design and process conditions such as varying wire size and thermal aging periods. Under thermal aging, the fine pitch gold wire ball bonds (0.6- and 0.8-mil-diameter wires) show formation of Kirkendall voids apart from intermetallic compound growth. With 1- and 2-mil-diameter gold wire bonds, the void growth is less significant and reveals fine voids. Studies also showed that void formation is absent in the case of thicker 3-mil wire bonds. Similar tests on copper ball bonds show good diffusional bonding without any intermetallic phase formation (or with considerable slow growth) as well as no voids on the microscopic scale and thus promises to be a better Design Alternative for elevated temperature conditions.

S. Azarm - One of the best experts on this subject based on the ideXlab platform.

  • Multi-objective robust optimization using a sensitivity region concept
    Structural and Multidisciplinary Optimization, 2005
    Co-Authors: S. Gunawan, S. Azarm
    Abstract:

    In multi-objective Design optimization, it is quite desirable to obtain solutions that are “multi-objectively” optimum and insensitive to uncontrollable (noisy) parameter variations. We call such solutions robust Pareto solutions. In this paper we present a method to measure the multi-objective sensitivity of a Design Alternative, and an approach to use such a measure to obtain multi-objectively robust Pareto optimum solutions. Our sensitivity measure does not require a presumed probability distribution of uncontrollable parameters and does not utilize gradient information; therefore, it is applicable to multi-objective optimization problems that have non-differentiable and/or discontinuous objective functions, and also to problems with large parameter variations. As a demonstration, we apply our robust optimization method to an engineering example, the Design of a vibrating platform. We show that the solutions obtained for this example are indeed robust.