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Maximum Output (maximum + output)

Distribution by Scientific Domains
Engineering57%
Life Sciences28%

Terms modified by Maximum Output

  • maximum output power
    		•

    Selected Abstracts

    Computation of locational and hourly maximum output of a distributed generator connected to a distribution feeder

    ELECTRICAL ENGINEERING IN JAPAN, Issue 2 2009
    Yasuhiro Hayashi
    Abstract Recently, the total number of distributed generation such as photovoltaic generation systems and wind turbine generation systems connected to a distribution network has drastically increased. Distributed generation using renewable energy can reduce the distribution loss and emission of CO2. However, the distribution network with the distributed generators must be operated while maintaining the reliability of the power supply and power quality. In this paper, the authors propose a computational method to determine the maximum output of a distributed generator under operational constraints [(1) voltage limit, (2) line current capacity, and (3) no reverse flow to bank] at arbitrary connection points and hourly periods. In the proposed method, a three-phase iterative load flow calculation is applied to evaluate the above operational constraints. The three-phase iterative load flow calculation has two simple procedures: (Procedure 1) addition of load currents from the terminal node of the feeder to root one, and (Procedure 2) subtraction of voltage drop from the root node of the feeder to terminal one. In order to check the validity of the proposed method, numerical simulations are performed for a distribution system model. Furthermore, the characteristics of locational and hourly maximum output of a distributed generator connected to a distribution feeder are analyzed using several numerical examples. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(2): 38,47, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20610 [source]

    Thermodynamic analysis of two-step solar water splitting with mixed iron oxides

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 10 2009
    Martin Roeb
    Abstract A two-step thermochemical cycle for solar production of hydrogen from water has been developed and investigated. It is based on metal oxide redox pair systems, which can split water molecules by abstracting oxygen atoms and reversibly incorporating them into their lattice. After successful experimental demonstration of several cycles of alternating hydrogen and oxygen production, the present work describes a thermodynamic study aiming at the improvement of process conditions and at the evaluation of the theoretical potential of the process. In order to evaluate the maximum hydrogen production potential of a coating material, theoretical considerations based on thermodynamic laws and properties are useful and faster than actual tests. Through thermodynamic calculations it is possible to predict the theoretical maximum output of H2 from a specific redox-material under certain conditions. Calculations were focussed on the two mixed iron oxides nickel,iron-oxide and zinc,iron-oxide. In the simulation the amount of oxygen in the redox-material is calculated before and after the water-splitting step on the basis of laws of thermodynamics and available material properties for the chosen mixed iron oxides. For the simulation the commercial Software FactSage and available databases for the required material properties were used. The analysis showed that a maximum hydrogen yield is achieved if the reduction temperature is raised to the limits of the operation range, if the temperature for the water splitting is lowered below 800°C and if the partial pressure of oxygen during reduction is decreased to the lower limits of the operational range. The predicted effects of reduction temperature and partial pressure of oxygen could be confirmed in experimental studies. The increased hydrogen yield at lower splitting temperatures of about 800°C could not be confirmed in experimental results, where a higher splitting temperature led to a higher hydrogen yield. As a consequence it can be stated that kinetics must play an important role especially in the splitting step. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Is Defibrillation Testing Still Necessary?

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2008
    A Decision Analysis, Markov Model
    Objective: To assess the impact of defibrillation threshold (DFT) testing of implanted cardioverter-defibrillators (ICDs) on survival. Background: DFT testing is generally performed during implantation of ICDs to assess sensing and termination of ventricular fibrillation. It is common clinical practice to defibrillate ventricular fibrillation twice at an output at least 10 J below the maximum output of the device, providing a 10 J safety margin. However, there are few data regarding impact of DFT testing on outcomes. Methods: Decision analysis and Monte Carlo simulation were used to assess expected outcomes of DFT testing. Survival of a hypothetical cohort of patients was assessed according to two strategies,routine DFT testing at time of ICD implant versus no DFT testing. Assumptions in the model were varied over a range of reasonable values to assess outcomes under a variety of scenarios. Results: Five-year survival with DFT and no-DFT strategies were similar at 59.72% and 59.36%, respectively. The results were not sensitive to changing risk estimates for arrhythmia incidence and safety margin. Results of the Monte Carlo simulation were qualitatively similar to the base case scenario and consistent with a small and nonsignificant survival advantage with routine DFT testing. Conclusions: The impact of DFT testing on 5-year survival in ICD patients, if it exists, is small. Survival appears higher with DFT testing as long as annual risk of lethal arrhythmia or the risk of a narrow safety margin is at least 5%, although the incremental benefit is marginal and 95% confidence intervals cross zero. A prospective randomized study of DFT testing in modern devices is warranted. [source]

    A policy tool for establishing a balance between wildlife habitat preservation and the use of natural resources by rural people in South Africa

    AFRICAN JOURNAL OF ECOLOGY, Issue 1 2006
    Oumar Bouare
    Abstract In this paper, a model is set up to determine the size of the wildlife population compatible with the extraction of the maximum output by rural people from natural resources. It is found that when the size of human population increases, to obtain the maximum output of food, the size of wildlife population decreases if the human population is growing faster than or at the same rate as that of the wildlife population; whereas the size of the wildlife population increases if the human population is growing slower than that of the wildlife. Furthermore, in the event that the increase in the size of the wildlife population is unable to reach the level compatible with the extraction of the maximum output of food, the improvement of the wildlife habitat and supplementing rural people's income with the proceeds of tourism are proposed as policies to maintain a balance between the preservation of the wildlife habitat and the use of natural resources by rural people. Résumé Dans cette étude un modèle est établi afin de déterminer la taille de la population faunique compatible avec l'extraction de la quantité maximale des ressources naturelles par les peuples ruraux. Les résultats montrent que quand la taille de la population humaines accroît, afin d'obtenir la quantité maximale de nourriture, la taille de la population faunique décroît si la population humaine augmente plus vite que, ou à la même vitesse que, la population faunique. Tomdis que, la population faunique saccroît si la croissance de la population humaine est plus lente. De plus, si la croissance de la taille de la population faunique n'atteint pas le niveau compatible avec l'extraction de la quantité maximale de nourriture, l'amélioration de l'habitat faunique et le rajout de recettes du tourisme aux revenus des peuples ruraux sont conseillés comme politiques afin de maintenir un équilibre entre la préservation de l'habitat faunique et l'utilisation des ressources naturelles par les peuples ruraux. [source]

    An integrated approach to optimization of Escherichia coli fermentations using historical data

    BIOTECHNOLOGY & BIOENGINEERING, Issue 3 2003
    Matthew C. Coleman
    Abstract Using a fermentation database for Escherichia coli producing green fluorescent protein (GFP), we have implemented a novel three-step optimization method to identify the process input variables most important in modeling the fermentation, as well as the values of those critical input variables that result in an increase in the desired output. In the first step of this algorithm, we use either decision-tree analysis (DTA) or information theoretic subset selection (ITSS) as a database mining technique to identify which process input variables best classify each of the process outputs (maximum cell concentration, maximum product concentration, and productivity) monitored in the experimental fermentations. The second step of the optimization method is to train an artificial neural network (ANN) model of the process input,output data, using the critical inputs identified in the first step. Finally, a hybrid genetic algorithm (hybrid GA), which includes both gradient and stochastic search methods, is used to identify the maximum output modeled by the ANN and the values of the input conditions that result in that maximum. The results of the database mining techniques are compared, both in terms of the inputs selected and the subsequent ANN performance. For the E. coli process used in this study, we identified 6 inputs from the original 13 that resulted in an ANN that best modeled the GFP fluorescence outputs of an independent test set. Values of the six inputs that resulted in a modeled maximum fluorescence were identified by applying a hybrid GA to the ANN model developed. When these conditions were tested in laboratory fermentors, an actual maximum fluorescence of 2.16E6 AU was obtained. The previous high value of fluorescence that was observed was 1.51E6 AU. Thus, this input condition set that was suggested by implementing the proposed optimization scheme on the available historical database increased the maximum fluorescence by 55%. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 274,285, 2003. [source]