WorldWideScience

Sample records for conversion system performance

  1. System Performance Projections for TPV Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    PF Baldasaro; MW Dashiell; JE Oppenlander; JL Vell; P Fourspring; K Rahner; LR Danielson; S Burger; E Brown

    2004-06-09

    TPV technology has advanced rapidly in the last five years, with diode conversion efficiency approaching >30%, and filter efficiency of {approx}80%. These achievements have enabled repeatable testing of 20% efficient small systems, demonstrating the potential of TPV energy conversion. Near term technology gains support a 25% efficient technology demonstration in the two year timeframe. However, testing of full size systems, which includes efficiency degradation mechanisms, such as: nonuniform diode illumination, diode and filter variability, temperature non-uniformities, conduction/convection losses, and lifetime reliability processes needs to be performed. A preliminary analysis of these differential effects has been completed, and indicates a near term integrated system efficiency of {approx}15% is possible using current technology, with long term growth to 18-20%. This report addresses the system performance issues.

  2. Some exploratory considerations of scale effects on the potential performance of wood energy conversion systems

    Science.gov (United States)

    Eggers, A. J., Jr.; Smith, B. A.; Tombaugh, L. W.

    1982-06-01

    Scale effects on the potential performance of wood energy conversion systems whose products might compete in many of the same diverse and dispersed markets as comparable products from fossil fuels are explored. The analytical approach is derived from the average total cost formulation of micro-economics which is configured to account for the factors of total cost rate for wood production, transportation, and conversion in systems with a given conversion efficiency and capacity. The exploratory systems analysis includes: systems elements and cost formulation; area production and associated transportation; point production and associated transportation; conversion system capacity effects; conversion plant learning curve effects; subsystem disaggregation, staging, and production rate effects, and conversion plant financing effects.

  3. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-10-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  4. Two Level Versus Matrix Converters Performance in Wind Energy Conversion Systems Employing DFIG

    Science.gov (United States)

    Reddy, Gongati Pandu Ranga; Kumar, M. Vijaya

    2017-05-01

    Wind power capacity has received enormous growth during past decades. With substantial development of wind power, it is expected to provide a fifth of world's electricity by the end of 2030. In wind energy conversion system, the power electronic converters play an important role. This paper presents the two level and matrix converters performance in wind energy conversion system employing Doubly Fed Induction Generator (DFIG). The DFIG is a wound rotor induction generator. Because of the advantages of the DFIG over other generators it is being used for most of the wind applications. This paper also discusses control of converters using the space vector pulse width modulation technique. The MATLAB/SIMULINK ® software is used to study the performance of the converters.

  5. Experimental and Analytical Performance of a Dual Brayton Power Conversion System

    Science.gov (United States)

    Lavelle, Thomas A.; Hervol, David S.; Briggs, Maxwell; Owen, A. Karl

    2009-01-01

    The interactions between two closed Brayton cycle (CBC) power conversion units (PCU) which share a common gas inventory and heat source have been studied experimentally using the Dual Brayton Power Conversion System (DBPCS) and analytically using the Closed- Cycle System Simulation (CCSS) computer code. Selected operating modes include steady-state operation at equal and unequal shaft speeds and various start-up scenarios. Equal shaft speed steady-state tests were conducted for heater exit temperatures of 840 to 950 K and speeds of 50 to 90 krpm, providing a system performance map. Unequal shaft speed steady-state testing over the same operating conditions shows that the power produced by each Brayton is sensitive to the operating conditions of the other due to redistribution of gas inventory. Startup scenarios show that starting the engines one at a time can dramatically reduce the required motoring energy. Although the DBPCS is not considered a flight-like system, these insights, as well as the operational experience gained from operating and modeling this system provide valuable information for the future development of Brayton systems.

  6. The UTRC wind energy conversion system performance analysis for horizontal axis wind turbines (WECSPER)

    Science.gov (United States)

    Egolf, T. A.; Landgrebe, A. J.

    1981-01-01

    The theory for the UTRC Energy Conversion System Performance Analysis (WECSPER) for the prediction of horizontal axis wind turbine performance is presented. Major features of the analysis are the ability to: (1) treat the wind turbine blades as lifting lines with a prescribed wake model; (2) solve for the wake-induced inflow and blade circulation using real nonlinear airfoil data; and (3) iterate internally to obtain a compatible wake transport velocity and blade loading solution. This analysis also provides an approximate treatment of wake distortions due to tower shadow or wind shear profiles. Finally, selected results of internal UTRC application of the analysis to existing wind turbines and correlation with limited test data are described.

  7. Solar energy conversion systems

    CERN Document Server

    Brownson, Jeffrey R S

    2013-01-01

    Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

  8. Demonstrating Hybrid Heat Transport and Energy Conversion System Performance Characterization Using Intelligent Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ostrum, Lee [Univ. of Idaho and Idaho Falls Center, Idaho Falls, ID (United States); Manic, Milos [Virginia Commonwealth Univ., Richmond, VA (United States)

    2017-09-28

    The debate continues on the magnitude and validity of climate change caused by human activities. However, there is no debate about the need to make buildings, modes of transportation, factories, and homes as energy efficient as possible. Given that climate change could occur with the wasteful use of fossil fuel and the fact that fossil energy costs could and will swing wildly, it is imperative that every effort be made to utilize energy sources to their fullest. Hybrid energy systems (HES) are two or more separate energy producers used together to produce energy commodities. The HES this report focuses on is the use of nuclear reactor waste heat as a source of further energy utilization. Nuclear reactors use a fluid to cool the core and produce the steam needed for the production of electricity. Traditionally this steam, or coolant, is used to convert the energy then cooled elsewhere. The heat is released into the environment without being used further. By adding technologies to nuclear reactors to use the wasted heat, a system can be developed to make more than just electricity and allow for loading following capabilities.

  9. Wind energy conversion system

    Science.gov (United States)

    Longrigg, Paul

    1987-01-01

    The wind energy conversion system includes a wind machine having a propeller connected to a generator of electric power, the propeller rotating the generator in response to force of an incident wind. The generator converts the power of the wind to electric power for use by an electric load. Circuitry for varying the duty factor of the generator output power is connected between the generator and the load to thereby alter a loading of the generator and the propeller by the electric load. Wind speed is sensed electro-optically to provide data of wind speed upwind of the propeller, to thereby permit tip speed ratio circuitry to operate the power control circuitry and thereby optimize the tip speed ratio by varying the loading of the propeller. Accordingly, the efficiency of the wind energy conversion system is maximized.

  10. A System for Retrospective Conversion.

    Science.gov (United States)

    Epstein, Hank

    1984-01-01

    The Apple-based MITINET system uses several forms of technology (Library of Congress MARC file in microfiche, microcomputers, COM vendor) to produce library database and COM catalog. Cost for MITINET software is based on number of branches or buildings performing conversion, and varies from $250 to $85 per building or branch. (EJS)

  11. Design methodology for flexible energy conversion systems accounting for dynamic performance

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Casati, Emiliano; Casella, Francesco

    2014-01-01

    of power systems for base- and part-load operation. Thus, it is crucial to discard, in an early phase of the design process, plant configurations which feature unacceptable dynamic performance. The test case is the preliminary design of an off-grid power plant serving an off-shore platform where one...

  12. Energy conversion system

    Science.gov (United States)

    Murphy, L.M.

    1985-09-16

    The energy conversion system includes a photo-voltaic array for receiving solar radiation and converting such radiation to electrical energy. The photo-voltaic array is mounted on a stretched membrane that is held by a frame. Tracking means for orienting the photo-voltaic array in predetermined positions that provide optimal exposure to solar radiation cooperate with the frame. An enclosure formed of a radiation transmissible material includes an inside containment space that accommodates the photo-voltaic array on the stretched membrane, the frame and the tracking means, and forms a protective shield for all such components. The enclosure is preferably formed of a flexible inflatable material and maintains its preferred form, such as a dome, under the influence of a low air pressure furnished to the dome. Under this arrangement the energy conversion system is streamlined for minimizing wind resistance, sufficiently weathproof for providing protection against weather hazards such as hail, capable of using diffused light, lightweight for low-cost construction and operational with a minimal power draw.

  13. HYDROKINETIC ENERGY CONVERSION SYSTEMS: PROSPECTS ...

    African Journals Online (AJOL)

    eobe

    hydro-to-electric power system, which is being strongly recognized as a unique and unconventional renewable energy solution, is the marine and hydrokinetic energy conversion technology [8]. Hydrokinetic (In Stream, or water current) energy conversion implies the utilization of the kinetic energy of rivers, streams, tidal ...

  14. Robust performance of self-scheduled LPV control of doubly-fed induction generator in wind energy conversion systems

    NARCIS (Netherlands)

    Nguyen Tien, H.; Scherer, C. W.; Scherpen, J. M. A.

    2007-01-01

    This paper describes the design of a self-scheduled current controller for doubly-fed induction generators in wind energy conversion systems (WECS). The design is based on viewing the mechanical angular speed as an uncertain yet online measurable parameter and on subsuming the problem into the

  15. Biological conversion system

    Science.gov (United States)

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  16. Photovoltaic Energy Conversion Systems

    DEFF Research Database (Denmark)

    Kouro, Samir; Wu, Bin; Abu-Rub, Haitham

    2014-01-01

    This chapter presents a comprehensive overview of grid-connected PV systems, including power curves, grid-connected configurations, different converter topologies (both single- and three-phase), control schemes, MPPT, and anti-islanding detection methods. The focus of the chapter has been on the ...

  17. Offshore wind energy conversion systems

    Science.gov (United States)

    Kilar, L. A.; Stiller, P. H.; Anacona, D. F.

    The paper summarizes the findings of a comprehensive assessment of off-shore wind energy conversion systems. Eight generic types of support platforms are discussed, and their conceptual designs are given. Attention is given to the economics of such systems, emphasizing the busbar energy cost measures. Onshore energy costs are developed in terms of controlling environmental parameters, distance from shore and equipment type.

  18. NASA presentation. [wind energy conversion systems planning

    Science.gov (United States)

    Thomas, R. L.

    1973-01-01

    The development of a wind energy system is outlined that supplies reliable energy at a cost competitive with other energy systems. A government directed industry program with strong university support is recommended that includes meteorological studies to estimate wind energy potentials and determines favorable regions and sites for wind power installations. Key phases of the overall program are wind energy conversion systems, meteorological wind studies, energy storage systems, and environmental impact studies. Performance testing with a prototype wind energy conversion and storage system is projected for Fiscal 1977.

  19. HYDROKINETIC ENERGY CONVERSION SYSTEMS: PROSPECTS ...

    African Journals Online (AJOL)

    eobe

    Hydrokinetic energy conversion systems utilize the kinetic energy of flowing water bodies with little or no head to generate other useable forms of energy. In the last few years various research and development efforts have been made to bring out this technology from the proof of concept stage and to demonstrate its ...

  20. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  1. Nominal Performance Biosphere Dose Conversion Factor Analysis

    Energy Technology Data Exchange (ETDEWEB)

    M. Wasiolek

    2004-09-08

    This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standard. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. The objectives of this analysis are to develop BDCFs for the groundwater exposure scenario for the three climate states considered in the TSPA-LA as well as conversion factors for evaluating compliance with the groundwater protection standard. The BDCFs will be used in performance assessment for calculating all-pathway annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle

  2. Nominal Performance Biosphere Dose Conversion Factor Analysis

    Energy Technology Data Exchange (ETDEWEB)

    M. Wasiolek

    2000-12-21

    The purpose of this report was to document the process leading to development of the Biosphere Dose Conversion Factors (BDCFs) for the postclosure nominal performance of the potential repository at Yucca Mountain. BDCF calculations concerned twenty-four radionuclides. This selection included sixteen radionuclides that may be significant nominal performance dose contributors during the compliance period of up to 10,000 years, five additional radionuclides of importance for up to 1 million years postclosure, and three relatively short-lived radionuclides important for the human intrusion scenario. Consideration of radionuclide buildup in soil caused by previous irrigation with contaminated groundwater was taken into account in the BDCF development. The effect of climate evolution, from the current arid conditions to a wetter and cooler climate, on the BDCF values was evaluated. The analysis included consideration of different exposure pathway's contribution to the BDCFs. Calculations of nominal performance BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. BDCFs for the nominal performance, when combined with the concentrations of radionuclides in groundwater allow calculation of potential radiation doses to the receptor of interest. Calculated estimates of radionuclide concentration in groundwater result from the saturated zone modeling. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA) to calculate doses to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain.

  3. Editorial: A Conversation about Performative Social Science

    Directory of Open Access Journals (Sweden)

    Mary Gergen

    2008-05-01

    Full Text Available Conversing by e-mail and mediated by an imaginary cyber-moderator, two of the co-editors of this Special Issue on Performative Social Science (PSS Mary GERGEN and Kip JONES, themselves pioneers of PSS, engage in conversation around such topics as creativity, skill and craft, outputs and outcomes, aesthetics, audience, evaluation, interpretation, scholarship, ambiguity, talking and doing, and inter-disciplinary collaborations. While GERGEN concludes that action is meaningful and rich in symbolic significance, JONES, like Norma DESMOND, speculates that PSS "is big; it's the pictures that got smaller". URN: urn:nbn:de:0114-fqs0802437

  4. Analysis of the performance and cost effectiveness of nine small wind energy conversion systems funded by the DOE small grants program

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Joshua [Univ. of California, Berkeley, CA (United States)

    1982-04-01

    This report presents an analysis of the technical performance and cost effectiveness of nine small wind energy conversion systems (SWECS) funded during FY 1979 by the U.S. Department of Energy. Chapter 1 gives an analytic framework with which to evaluate the systems. Chapter 2 consists of a review of each of the nine projects, including project technical overviews, estimates of energy savings, and results of economic analysis. Chapter 3 summarizes technical, economic, and institutional barriers that are likely to inhibit widespread dissemination of SWECS technology.

  5. Photoelectrochemical based direct conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Kocha, S.; Arent, D.; Peterson, M. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-09-01

    The goal of this research is to develop a stable, cost effective, photoelectrochemical based system that will split water upon illumination, producing hydrogen and oxygen directly, using sunlight as the only energy input. This type of direct conversion system combines a photovoltaic material and an electrolyzer into a single monolithic device. We report on our studies of two multifunction multiphoton photoelectrochemical devices, one based on the ternary semiconductor gallium indium phosphide, (GaInP{sub 2}), and the other one based on amorphous silicon carbide. We also report on our studies of the solid state surface treatment of GaInP{sub 2} as well as our continuing effort to develop synthetic techniques for the attachment of transition metal complexes to the surface of semiconductor electrodes. All our surface studies are directed at controlling the interface energetics and forming stable catalytic surfaces.

  6. Study the performance of photogalvanic cells for solar energy conversion and storage: Rose Bengal-D-Xylose-NaLS system

    Energy Technology Data Exchange (ETDEWEB)

    Gangotri, K.M. [Department of Chemistry, Jai Narain Vyas University, Jodhpur, Rajasthan 342 033 (India); Bhimwal, Mahesh Kumar [Solar Energy Laboratory, Department of Chemistry, Jai Narain Vyas University, Jodhpur, Rajasthan 342 033 (India)

    2010-07-15

    The Rose Bengal is used as photosensitizer with D-Xylose as reductant and sodium lauryl sulphate (NaLS) as surfactant for the enhancement of the conversion efficiency and storage capacity of photogalvanic cell for its commercial viability. The observed value of the photogeneration of photopotential was 885.0 mV and photocurrent was 460.0 {mu}A whereas maximum power of the cell was 407.10 {mu}W. The observed power at power point was 158.72 {mu}W and the conversion efficiency was 1.52%. The fill factor 0.3151 was experimentally determined at the power point of the cell. The rate of initial generation of photocurrent was 63.88 {mu}A min{sup -1}. The photogalvanic cell so developed can work for 145.0 min in dark on irradiation for 165.0 min, i.e. the storage capacity of the photogalvanic cell is 87.87%. A simple mechanism for the photogeneration of photocurrent has also been proposed. (author)

  7. Wind Energy Conversion Systems Technology and Trends

    CERN Document Server

    2012-01-01

    Wind Energy Conversion System covers the technological progress of wind energy conversion systems, along with potential future trends. It includes recently developed wind energy conversion systems such as multi-converter operation of variable-speed wind generators, lightning protection schemes, voltage flicker mitigation and prediction schemes for advanced control of wind generators. Modeling and control strategies of variable speed wind generators are discussed, together with the frequency converter topologies suitable for grid integration. Wind Energy Conversion System also describes offshore farm technologies including multi-terminal topology and space-based wind observation schemes, as well as both AC and DC based wind farm topologies. The stability and reliability of wind farms are discussed, and grid integration issues are examined in the context of the most recent industry guidelines. Wind power smoothing, one of the big challenges for transmission system operators, is a particular focus. Fault ride th...

  8. Performance, Performance System, and High Performance System

    Science.gov (United States)

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  9. Measuring the performance of visual to auditory information conversion.

    Directory of Open Access Journals (Sweden)

    Shern Shiou Tan

    Full Text Available BACKGROUND: Visual to auditory conversion systems have been in existence for several decades. Besides being among the front runners in providing visual capabilities to blind users, the auditory cues generated from image sonification systems are still easier to learn and adapt to compared to other similar techniques. Other advantages include low cost, easy customizability, and universality. However, every system developed so far has its own set of strengths and weaknesses. In order to improve these systems further, we propose an automated and quantitative method to measure the performance of such systems. With these quantitative measurements, it is possible to gauge the relative strengths and weaknesses of different systems and rank the systems accordingly. METHODOLOGY: Performance is measured by both the interpretability and also the information preservation of visual to auditory conversions. Interpretability is measured by computing the correlation of inter image distance (IID and inter sound distance (ISD whereas the information preservation is computed by applying Information Theory to measure the entropy of both visual and corresponding auditory signals. These measurements provide a basis and some insights on how the systems work. CONCLUSIONS: With an automated interpretability measure as a standard, more image sonification systems can be developed, compared, and then improved. Even though the measure does not test systems as thoroughly as carefully designed psychological experiments, a quantitative measurement like the one proposed here can compare systems to a certain degree without incurring much cost. Underlying this research is the hope that a major breakthrough in image sonification systems will allow blind users to cost effectively regain enough visual functions to allow them to lead secure and productive lives.

  10. A System for Electromagnetic Field Conversion

    DEFF Research Database (Denmark)

    2003-01-01

    A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

  11. Hydrokinetic Energy Conversion Systems: Prospects and ...

    African Journals Online (AJOL)

    Hydrokinetic energy conversion systems utilize the kinetic energy of flowing water bodies with little or no head to generate other useable forms of energy. In the last few years various research and development efforts have been made to bring out this technology from the proof of concept stage and to demonstrate its ...

  12. Systems and methods for wave energy conversion

    Science.gov (United States)

    MacDonald, Daniel G.; Cantara, Justin; Nathan, Craig; Lopes, Amy M.; Green, Brandon E.

    2017-02-28

    Systems for wave energy conversion that have components that can survive the harsh marine environment and that can be attached to fixed structures, such as a pier, and having the ability to naturally adjust for tidal height and methods for their use are presented.

  13. Improvements of the One-to-Many Eigenvoice Conversion System

    Science.gov (United States)

    Ohtani, Yamato; Toda, Tomoki; Saruwatari, Hiroshi; Shikano, Kiyohiro

    We have developed a one-to-many eigenvoice conversion (EVC) system that allows us to convert a single source speaker's voice into an arbitrary target speaker's voice using an eigenvoice Gaussian mixture model (EV-GMM). This system is capable of effectively building a conversion model for an arbitrary target speaker by adapting the EV-GMM using only a small amount of speech data uttered by the target speaker in a text-independent manner. However, the conversion performance is still insufficient for the following reasons: 1) the excitation signal is not precisely modeled; 2) the oversmoothing of the converted spectrum causes muffled sounds in converted speech; and 3) the conversion model is affected by redundant acoustic variations among a lot of pre-stored target speakers used for building the EV-GMM. In order to address these problems, we apply the following promising techniques to one-to-many EVC: 1) mixed excitation; 2) a conversion algorithm considering global variance; and 3) adaptive training of the EV-GMM. The experimental results demonstrate that the conversion performance of one-to-many EVC is significantly improved by integrating all of these techniques into the one-to-many EVC system.

  14. Computer-Assisted English Learning System Based on Free Conversation by Topic

    Science.gov (United States)

    Choi, Sung-Kwon; Kwon, Oh-Woog; Kim, Young-Kil

    2017-01-01

    This paper aims to describe a computer-assisted English learning system using chatbots and dialogue systems, which allow free conversation outside the topic without limiting the learner's flow of conversation. The evaluation was conducted by 20 experimenters. The performance of the system based on a free conversation by topic was measured by the…

  15. Optical Energy Transfer and Conversion System

    Science.gov (United States)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

    2015-01-01

    An optical power transfer system comprising a fiber spooler, a fiber optic rotary joint mechanically connected to the fiber spooler, and an electrical power extraction subsystem connected to the fiber optic rotary joint with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, through the rotary joint, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy.

  16. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Neil Todreas; Pavel Hejzlar

    2008-06-30

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  17. Systems Engineering Model for ART Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Mendez Cruz, Carmen Margarita [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rochau, Gary E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, Mollye C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    The near-term objective of the EC team is to establish an operating, commercially scalable Recompression Closed Brayton Cycle (RCBC) to be constructed for the NE - STEP demonstration system (demo) with the lowest risk possible. A systems engineering approach is recommended to ensure adequate requirements gathering, documentation, and mode ling that supports technology development relevant to advanced reactors while supporting crosscut interests in potential applications. A holistic systems engineering model was designed for the ART Energy Conversion program by leveraging Concurrent Engineering, Balance Model, Simplified V Model, and Project Management principles. The resulting model supports the identification and validation of lifecycle Brayton systems requirements, and allows designers to detail system-specific components relevant to the current stage in the lifecycle, while maintaining a holistic view of all system elements.

  18. Energy technology sources, systems and frontier conversion

    CERN Document Server

    Ohta, Tokio

    1994-01-01

    This book provides a concise and technical overview of energy technology: the sources of energy, energy systems and frontier conversion. As well as serving as a basic reference book for professional scientists and students of energy, it is intended for scientists and policy makers in other disciplines (including practising engineers, biologists, physicists, economists and managers in energy related industries) who need an up-to-date and authoritative guide to the field of energy technology.Energy systems and their elemental technologies are introduced and evaluated from the view point

  19. Recent Progress on Integrated Energy Conversion and Storage Systems.

    Science.gov (United States)

    Luo, Bin; Ye, Delai; Wang, Lianzhou

    2017-09-01

    Over the last few decades, there has been increasing interest in the design and construction of integrated energy conversion and storage systems (IECSSs) that can simultaneously capture and store various forms of energies from nature. A large number of IECSSs have been developed with different combination of energy conversion technologies such as solar cells, mechanical generators and thermoelectric generators and energy storage devices such as rechargeable batteries and supercapacitors. This review summarizes the recent advancements to date of IECSSs based on different energy sources including solar, mechanical, thermal as well as multiple types of energies, with a special focus on the system configuration and working mechanism. With the rapid development of new energy conversion and storage technologies, innovative high performance IECSSs are of high expectation to be realised for diverse practical applications in the near future.

  20. Conversion to organic wine production: exploring the economic performance impacts

    OpenAIRE

    Nisén, Pia

    2014-01-01

    This study focuses on understanding the relationship between organic wine production and economic performance. The aim of this study is to clarify, what are the economic impacts that result from the conversion of wine production from conventional to organic. This is an interesting topic to be explored in more detail because despite the increasing demand of organic wine and share of vineyard area used for organic winemaking, the economic consequences of the conversion are still somewhat unclea...

  1. Impact of scan conversion methods on the performance of scalable video coding

    Science.gov (United States)

    Dubois, Eric; Baaziz, Nadia; Matta, Marwan

    1995-04-01

    The ability to flexibly access coded video data at different resolutions or bit rates is referred to as scalability. We are concerned here with the class of methods referred to as pyramidal embedded coding in which specific subsets of the binary data can be used to decode lower- resolution versions of the video sequence. Two key techniques in such a pyramidal coder are the scan-conversion operations of down-conversion and up-conversion. Down-conversion is required to produce the smaller, lower-resolution versions of the image sequence. Up- conversion is used to perform conditional coding, whereby the coded lower-resolution image is interpolated to the same resolution as the next higher image and used to assist in the encoding of that level. The coding efficiency depends on the accuracy of this up-conversion process. In this paper techniques for down-conversion and up-conversion are addressed in the context of a two-level pyramidal representation. We first present the pyramidal technique for spatial scalability and review the methods used in MPEG-2. We then discuss some enhanced methods for down- and up-conversion, and evaluate their performance in the context of the two-level scalable system.

  2. Ocean energy conversion systems annual research report

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    Alternative power cycle concepts to the closed-cycle Rankine are evaluated and those that show potential for delivering power in a cost-effective and environmentally acceptable fashion are explored. Concepts are classified according to the ocean energy resource: thermal, waves, currents, and salinity gradient. Research projects have been funded and reported in each of these areas. The lift of seawater entrained in a vertical steam flow can provide potential energy for a conventional hydraulic turbine conversion system. Quantification of the process and assessment of potential costs must be completed to support concept evaluation. Exploratory development is being completed in thermoelectricity and 2-phase nozzles for other thermal concepts. Wave energy concepts are being evaluated by analysis and model testing with present emphasis on pneumatic turbines and wave focussing. Likewise, several conversion approaches to ocean current energy are being evaluated. The use of salinity resources requires further research in membranes or the development of membraneless processes. Using the thermal resource in a Claude cycle process as a power converter is promising, and a program of R and D and subsystem development has been initiated to provide confirmation of the preliminary conclusion.

  3. Education System Benefits of U.S. Metric Conversion.

    Science.gov (United States)

    Phelps, Richard P.

    1996-01-01

    U.S. metric conversion efforts are reviewed as they have affected education. Education system benefits and costs are estimated for three possible system conversion plans. The soft-conversion-to-metric plan, which drops all inch-pound instruction, appears to provide the largest net benefits. The primary benefit is in class time saved. (SLD)

  4. Systems Requirement Document for the MSRE U-233 Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, R.D.

    2001-01-11

    The fissile material reclamation activities for the MSRE remediation project include the removal and recovery of uranium from the off-gas system, from the stored fuel salt, and finally, from the uranium-laden charcoal in the Auxiliary Charcoal Bed (ACB). Each of these operations produces an uranium/fluoride compound that is not suitable for long-term storage. The uranium-fluoride compounds can be stored for a limited period of time in pressure vessels. The interim-storage vessels are designed to handle the internal pressure buildup from gases formed by radiolysis of the uranium-fluoride compounds. The conversion process will take the pressurized vessels from interim storage and process the materials in a hot cell located at Building 4501. The gas in the vessels will be vented through chemical traps and then the traps will be processed to convert the various uranium-fluoride compounds to a stable uranium oxide form. This will be done one trap at a time. The chemical form of uranium being extracted from the off-gas system and from fuel salt fluorination process is uranium hexafluoride UF{sub 6}. During the operations at MSRE, the UF{sub 6} is chemisorbed onto sodium fluoride (NaF) traps where it forms the complex, 2NaF{center_dot}UF{sub 6}. The conversion process that will be installed in the Building 4501 Hot Cell D will recover the UF{sub 6} from the NaF traps by decomposition of the binary complex at elevated temperatures (>300 C). After the uranium is extracted from the NaF traps, it is collected in the conversion process reaction vessel. The reaction vessel is then hydrolized and heated through several step operations up to 900 C in order to convert the material to a stable uranium oxide. The ACB at MSRE contains uranium-laden charcoal with unstable C{sub x}F compounds. After extraction at MSRE, this material will be delivered to Building 4501 Hot Cell D for processing to a stable oxide. The charcoal conversion process is still under development, with mockup and

  5. Ocean thermal energy conversion (OTEC) power system development utilizing advanced, high-performance heat transfer techniques. Volume 1. Conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-12

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC Demonstration Plant. In turn, this Demonstration Plant is to demonstrate, by 1984, the operation and performance of an ocean thermal power plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the Demonstration Plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibility studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report describes the full-size power system module, and summarizes the design parameters and associated costs for the Demonstration Plant module (prototype) and projects costs for commercial plants in production. The material presented is directed primarily toward the surface platform/ship basic reference hull designated for use during conceptual design; however, other containment vessels were considered during the design effort so that the optimum power system would not be unduly influenced or restricted. (WHK)

  6. Standards for photovoltaic energy conversion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schafft, H. A.

    1980-04-01

    This report provides the results of a search for existing domestic standards and related documents for possible application in the development of a standards base for photovoltaic energy conversion systems. The search resulted in locating about 150 test methods, recommended practices, standards, solar-thermal performance criteria, and other standards-related documents. They are listed by topic areas in the appendix. The listing was prepared to assist those involved in developing performance criteria for photovoltaic systems and in identifying methods to test system performance against these criteria. It is clear from the results of the search that few standards are directly applicable to terrestrial solar photovoltaic systems and that much standards development is required to support the commercialization of such systems.

  7. The Sardinia Radio Telescope conversion, distribution, and receiver control system

    Science.gov (United States)

    Monari, J.; Orfei, A.; Scalambra, A.; Mariotti, S.; Poloni, M.; Fiocchi, F.; Cattani, A.; Maccaferri, A.; Perini, F.; Boschi, M.

    The recent upgrade of the 32-m radio telescope located in Medicina (Bologna - Italy) has allowed us to gain a lot of know-how about ''frequency agility'' management. In this parabolic dish antenna the receiver change is now completely performed only using software controls and avoiding, in this way, human intervention. The acquired experience on this topic has been used to define the framework for the conversion/distribution system design for the SRT (Sardinia Radio Telescope), the new ''64-meter class'' Italian radio telescope. The suitably designed architectures for Local Oscillators (LOs), Intermediate Frequencies (IFs), Ground Unit (GU), Reference (REF) distribution systems and control system will be described in this paper.

  8. Technology assessment of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Meier, B. W.; Merson, T. J.

    1980-09-01

    Environmental data for wind energy conversion systems (WECSs) have been generated in support of the Technology Assessment of Solar Energy (TASE) program. Two candidates have been chosen to characterize the WECS that might be deployed if this technology makes a significant contribution to the national energy requirements. One WECS is a large machine of 1.5-MW-rated capacity that can be used by utilities. The other WECS is a small machine that is characteristic of units that might be used to meet residential or small business energy requirements. Energy storage systems are discussed for each machine to address the intermittent nature of wind power. Many types of WECSs are being studied and a brief review of the technology is included to give background for choosing horizontal axis designs for this study. Cost estimates have been made for both large and small systems as required for input to the Strategic Environmental Assessment Simulation (SEAS) computer program. Material requirements, based on current generation WECSs, are discussed and a general discussion of environmental impacts associated with WECS deployment is presented.

  9. Thermal Noise Can Facilitate Energy Conversion by Ratchet System?

    OpenAIRE

    Takagi, Fumiko; Hondou, Tsuyoshi

    1999-01-01

    Molecular motors in biological systems are expected to use ambient fluctuation. In a recent Letter [Phys. Rev. Lett. {\\bf 80}, 5251 (1998)], it was showed that the following question was unsolved, ``Can thermal noise facilitate energy conversion by ratchet system?'' We consider it using stochastic energetics, and show that there exist systems where thermal noise helps the energy conversion.

  10. Summary of State-of-the-Art Power Conversion Systems for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Atcitty, S.; Gray-Fenner, A.; Ranade, S.

    1998-09-01

    The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for fiture research and development. This report provides an overview of PCS technology, a description of several state-of-the-art power conversion systems and how they are used in specific applications, a summary of four basic configurations for l:he power conversion systems used in energy storage applications, a discussion of PCS costs and potential cost reductions, a summary of the stancku-ds and codes relevant to the technology, and recommendations for future research and development.

  11. Photoelectrochemical solar conversion systems molecular and electronic aspects

    CERN Document Server

    Munoz, Andres G

    2012-01-01

    Providing new insights into the molecular and electronic processes involved in the conversion of sunlight into chemical products, Photoelectrochemical Solar Conversion Systems: Molecular and Electronic Aspects begins with an historical overview and a survey of recent developments in the electrochemistry of semiconductors and spectroscopic techniques. It then provides a comprehensive introduction to the science of conversion cells, reviews current issues and potential directions, and covers a wide range of materials from organic to inorganic cells.Employing a tutorial organization with balanced

  12. Supercritical Carbon Dioxide Brayton Cycle Energy Conversion System

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jae Eun; Kim, S. O.; Seong, S. H.; Eoh, J. H.; Lee, T. H.; Choi, S. K.; Han, J. W.; Bae, S. W

    2007-12-15

    This report contains the description of the S-CO{sub 2} Brayton cycle coupled to KALIMER-600 as an alternative energy conversion system. For system development, a computer code was developed to calculate heat balance of 100% power operation condition. Based on the computer code, the S-CO{sub 2} Brayton cycle energy conversion system was constructed for the KALIMER-600. Using the developed turbomachinery models, the off-design characteristics and the sensitivities of the S-CO{sub 2} turbomachinery were investigated. For the development of PCHE models, a one-dimensional analysis computer code was developed to evaluate the performance of the PCHE. Possible control schemes for power control in the KALIMER-600 S-CO{sub 2} Brayton cycle were investigated by using the MARS code. Simple power reduction and recovery event was selected and analyzed for the transient calculation. For the evaluation of Na/CO{sub 2} boundary failure event, a computer was developed to simulate the complex thermodynamic behaviors coupled with the chemical reaction between liquid sodium and CO{sub 2} gas. The long term behavior of a Na/CO{sub 2} boundary failure event and its consequences which lead to a system pressure transient were evaluated.

  13. Renewable energy systems advanced conversion technologies and applications

    CERN Document Server

    Luo, Fang Lin

    2012-01-01

    Energy conversion techniques are key in power electronics and even more so in renewable energy source systems, which require a large number of converters. Renewable Energy Systems: Advanced Conversion Technologies and Applications describes advanced conversion technologies and provides design examples of converters and inverters for renewable energy systems-including wind turbine and solar panel energy systems. Learn Cutting-Edge Techniques for Converters and Inverters Setting the scene, the book begins with a review of the basics of astronomy and Earth physics. It then systematically introduc

  14. The effect of cerium-based conversion treatment on the cathodic delamination and corrosion protection performance of carbon steel-fusion-bonded epoxy coating systems

    Science.gov (United States)

    Ramezanzadeh, B.; Rostami, M.

    2017-01-01

    The effect of surface pre-treatment of pipe surface by green cerium compound and phosphoric acid solution on the fusion-bonded epoxy (FBE) coating performance was studied. The composition and surface morphology of the steel samples treated by acid and Ce solutions were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), equipped with energy dispersive spectroscopy (EDS). Also, the surface free energy was evaluated on these samples through contact angle measurements. In addition, the effect of Ce and acid washing procedures on the adhesion properties and corrosion protection performance of the FBE was examined by pull-off, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results showed that compared to acid washing, the chemical treatment by Ce solution noticeably increased the surface free energy of steel, improved the adhesion properties of FBE, decreased the cathodic delamination rate of FBE, and enhanced the coating corrosion resistance compared to the acid washed samples.

  15. Conversion of serial holdings into automated library system in ...

    African Journals Online (AJOL)

    Records conversion is a must in a newly automated library system. As a result of the recent development in automation at the University of Ilorin library, almost all the monograph collection have been converted to readable format, while the conversion of the serials records remain dormant. The article discusses the attempt ...

  16. The effect of cerium-based conversion treatment on the cathodic delamination and corrosion protection performance of carbon steel-fusion-bonded epoxy coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), 16765-654, Tehran (Iran, Islamic Republic of); Rostami, M. [Department of Nanomaterials and Nanocoatings, Institute for Color Science and Technology (ICST), 16765-654, Tehran (Iran, Islamic Republic of)

    2017-01-15

    Highlights: • Steel surface was treated by Ce and acid phosphoric solutions. • Ce treatment considerably enhanced the surface energy and produce nanoscale roughness. • Ce treated samples showed enhanced adhesion to FBE coating. • Ce treatment of steel significantly reduced the FBE cathodic delamination rate. • Ce treated sample showed enhanced corrosion resistance. - Abstract: The effect of surface pre-treatment of pipe surface by green cerium compound and phosphoric acid solution on the fusion-bonded epoxy (FBE) coating performance was studied. The composition and surface morphology of the steel samples treated by acid and Ce solutions were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), equipped with energy dispersive spectroscopy (EDS). Also, the surface free energy was evaluated on these samples through contact angle measurements. In addition, the effect of Ce and acid washing procedures on the adhesion properties and corrosion protection performance of the FBE was examined by pull-off, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results showed that compared to acid washing, the chemical treatment by Ce solution noticeably increased the surface free energy of steel, improved the adhesion properties of FBE, decreased the cathodic delamination rate of FBE, and enhanced the coating corrosion resistance compared to the acid washed samples.

  17. Parallel photomask pattern data conversion and verification system

    Science.gov (United States)

    Kanai, Yasunori; Shimada, Toshiji; Sekigawa, Kazunari; Nishi, Makoto; Ishihara, Yasufumi; Mori, Jun-ichi; Akutagawa, Satoshi; Takahashi, Kazuhiko; Miyauchi, Touru

    1996-07-01

    This system is designed to convert and to verify different types of LSI layout design data and EB writer data, such as GDS-II, MEBES, and JEOL, with the help of its original internal format. The internal format data can be processed not only by a single workstation sequentially but also by network-linked workstations or a single workstation having two or more processing units concurrently. This parallel processing mechanism enables the system to reduce total processing time when handling large volume of data. The resultant internal format data produced by the conversion processes including logical operations, magnifications, and re-sizing operations can be immediately verified by built-in DRC program that is driven by a series of user commands, which consequently yields highly reliable output EB writer data. The built-in pattern viewer can graphically visualize any combination of the layout design data, the EB writer data, and the results of each conversion and verification in the same display window to provide users with an intuitive and easy method for verification. The features of the system and the parallel processing performance are described in this paper.

  18. Light distribution system comprising spectral conversion means

    DEFF Research Database (Denmark)

    2012-01-01

    System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side, the sy...... of providing a light distribution system and a method of correcting the spectral transmission characteristics of a light distribution system are disclosed....

  19. Guest Editorial Advanced Distributed Control of Energy Conversion Devices and Systems

    DEFF Research Database (Denmark)

    Davoudi, Ali; Guerrero, Josep M.; Lewis, Frank

    2014-01-01

    The papers in this special issue on advanced distributed control of energy conversion devices and systems are loosely grouped into three categories: 1) ac energy conversion systems; 2) dc energy conversion systems; and 3) optimization and standards....

  20. Energy Storage System with Voltage Equalization Strategy for Wind Energy Conversion

    Directory of Open Access Journals (Sweden)

    Cheng-Tao Tsai

    2012-07-01

    Full Text Available In this paper, an energy storage system with voltage equalization strategy for wind energy conversion is presented. The proposed energy storage system provides a voltage equalization strategy for series-connected lead-acid batteries to increase their total storage capacity and lifecycle. In order to draw the maximum power from the wind energy, a perturbation-and-observation method and digital signal processor (DSP are incorporated to implement maximum power point tracking (MPPT algorithm and power regulating scheme. In the proposed energy storage system, all power switches have zero-voltage-switching (ZVS feature at turn-on transition. Therefore, the conversion efficiency can be increased. Finally, a prototype energy storage system for wind energy conversion is built and implemented. Experimental results have verified the performance and feasibility of the proposed energy storage system for wind energy conversion.

  1. Disk MHD Conversion System for Nerva Reactor

    National Research Council Canada - National Science Library

    Jackson, W

    1992-01-01

    The principal results of the study have been to: (1) confirm that cesium seeded hydrogen plasma disk MHD generator can meet its expected performance while operating in a stable plasma regime; and (2...

  2. Evaluating Performances of Solar-Energy Systems

    Science.gov (United States)

    Jaffe, L. D.

    1987-01-01

    CONC11 computer program calculates performances of dish-type solar thermal collectors and power systems. Solar thermal power system consists of one or more collectors, power-conversion subsystems, and powerprocessing subsystems. CONC11 intended to aid system designer in comparing performance of various design alternatives. Written in Athena FORTRAN and Assembler.

  3. Care and Conversing in Dialogical Systems

    DEFF Research Database (Denmark)

    Steffensen, Sune Vork

    2012-01-01

    This article promotes a point of view on human interaction in terms of dialogical systems. The approach draws on recent, so-called third wave, developments in cognitive science. After an introduction to three waves in cognitive science, and their counterparts in linguistics, the article is placed...... in a tradition that is ecological, embodied and distributed. Its specific take on human interaction pursues these perspectives by claiming that language can neither be reduced to social rules in the micro-sociological domain, nor to biological properties of the individual being. As an alternative to these two...... positions, a theory of dialogical systems is developed, on the basis of current thinking within the enactive program (e.g. De Jaegher and Di Paolo, 2007), the distributed language movement (e.g. Cowley, 2011b), and values-realizing theory (e.g. Hodges, 2009). Dialogical systems are systems of co...

  4. Heat Rejection Concepts for Brayton Power Conversion Systems

    Science.gov (United States)

    Siamidis, John; Mason, Lee; Beach, Duane; Yuko, James

    2005-01-01

    This paper describes potential heat rejection design concepts for closed Brayton cycle (CBC) power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) applications. The Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Space Brayton conversion system designs tend to optimize at efficiencies of about 20 to 25 percent with radiator temperatures in the 400 to 600 K range. A notional HRS was developed for a 100 kWe-class Brayton power system that uses a pumped sodium-potassium (NaK) heat transport loop coupled to a water heat pipe radiator. The radiator panels employ a sandwich construction consisting of regularly-spaced circular heat pipes contained within two composite facesheets. Heat transfer from the NaK fluid to the heat pipes is accomplished by inserting the evaporator sections into the NaK duct channel. The paper evaluates various design parameters including heat pipe diameter, heat pipe spacing, and facesheet thickness. Parameters were varied to compare design options on the basis of NaK pump pressure rise and required power, heat pipe unit power and radial flux, radiator panel areal mass, and overall HRS mass.

  5. Progress on PEP-II magnet power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Bellomo, P.; Genova, L. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Jackson, T. [Lawrence Berkeley National Lab., CA (United States); Shimer, D. [Lawrence Livermore National Lab., CA (United States)

    1996-06-04

    The various power systems for supplying the PEP-II DC magnets rely exclusively on switchmode conversion, utilizing a variety of means depending on the requirements. All of the larger power supplies, ranging from 10 to 200 kW, are powered from DC sources utilizing rectified 480 V AC. Choppers can be used for the series connected strings, but for smaller groups and individual magnets, inverters driving high-frequency transformers with rectifiers comprise the best approach. All of the various systems use a ``building block`` approach of multiple standard-size units connected in series or parallel to most cost-effectively deal with a great range of voltage and current requirements. Utilization of existing infrastructure from PEP-I has been a cost-effective determinant. Equipment is being purchased either off-the-shelf, through performance specification, or by hardware purchase based on design-through-prototype. The corrector magnet power system, utilizing inexpensive, off-the-shelf, four-quadrant switching motor-controllers, has already proven very reliable: 120 of the total of 900 units have been running on the injection system for four months with no failures.

  6. Gate controlled high efficiency ballistic energy conversion system

    NARCIS (Netherlands)

    Xie, Yanbo; Bos, Diederik; de Boer, Hans L.; van den Berg, Albert; Eijkel, Jan C.T.; Zengerle, R.

    2013-01-01

    Last year we demonstrated the microjet ballistic energy conversion system[1]. Here we show that the efficiency of such a system can be further improved by gate control. With gate control the electrical current generation is enhanced a hundred times with respect to the current generated from the zeta

  7. A Prototype Greek Text to Greek Sign Language Conversion System

    Science.gov (United States)

    Kouremenos, Dimitris; Fotinea, Stavroula-Evita; Efthimiou, Eleni; Ntalianis, Klimis

    2010-01-01

    In this article, a prototype Greek text to Greek Sign Language (GSL) conversion system is presented. The system is integrated into an educational platform that addresses the needs of teaching GSL grammar and was developed within the SYNENNOESE project (Efthimiou "et al." 2004a. Developing an e-learning platform for the Greek sign…

  8. Novel, Integrated Reactor / Power Conversion System (LMR-AMTEC)

    Energy Technology Data Exchange (ETDEWEB)

    Pablo Rubiolo, Principal Investigator

    2003-03-21

    The main features of this project were the development of a long life (up to 10 years) Liquid Metal Reactor (LMR) and a static conversion subsystem comprising an Alkali Metal Thermal-to-Electric (AMTEC) topping cycle and a ThermoElectric (TE) Bottom cycle. Various coupling options of the LMR with the energy conversion subsystem were explored and, base in the performances found in this analysis, an Indirect Coupling (IC) between the LMR and the AMTEC/TE converters with Alkali Metal Boilers (AMB) was chosen as the reference design. The performance model of the fully integrated sodium-and potassium-AMTEC/TE converters shows that a combined conversion efficiency in excess of 30% could be achieved by the plant. (B204)

  9. Effects of a cell phone conversation on cognitive processing performances.

    Science.gov (United States)

    Kemker, Brett E; Stierwalt, Julie A G; LaPointe, Leonard L; Heald, Gary R

    2009-10-01

    The ability to apportion cognitive resources to process multiple visual and auditory stimuli is essential for human communication in competing conditions. The purpose of the current research was to examine the effects of a cell phone conversation on a battery of cognitive tests, using both timing (RT) and accuracy (A') as dependent measures. A repeated measures ANOVA was conducted. Forty-two college-age (mean 22 yr) adult females with normal hearing and cognitive function participated in the study. In one condition (quiet), a standardized cognitive assessment battery was administered to participants in a quiet room. In the (cell phone) condition, subjects were formulating and responding to specific questions about their travel experiences during administration of the same cognitive assessment battery. The computer automatically records subject performance. Post-hoc pairwise comparisons were conducted using the Bonferroni approach. The alpha level was set at .05 for all data analysis. This method of analysis was repeated for each of the dependent measures, RT, and A'. The results revealed a consistent, significant effect on reaction time between the two conditions. The same analysis was also conducted to examine the effect of participation in a cell phone discussion on accuracy. As with RT, results revealed a consistent, significant affect on A' between the two conditions. Our study supports the notion that there are differential effects of auditory distracters across cognitive spheres. For simple automatic type visual cognitive tasks, the effect is minimal. However, as visual tasks increase in difficulty, the effect of the auditory distraction is magnified, particularly when the task requires extensive division of language resources.

  10. Tandem filters using frequency selective surfaces for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    Science.gov (United States)

    Dziendziel, Randolph J [Middle Grove, NY; Baldasaro, Paul F [Clifton Park, NY; DePoy, David M [Clifton Park, NY

    2010-09-07

    This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.

  11. Closed Brayton cycle power conversion systems for nuclear reactors :

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Steven A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lipinski, Ronald J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vernon, Milton E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sanchez, Travis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at

  12. Performance analysis of 60-min to 1-min integration time rain rate conversion models in Malaysia

    Science.gov (United States)

    Ng, Yun-Yann; Singh, Mandeep Singh Jit; Thiruchelvam, Vinesh

    2018-01-01

    Utilizing the frequency band above 10 GHz is in focus nowadays as a result of the fast expansion of radio communication systems in Malaysia. However, rain fade is the critical factor in attenuation of signal propagation for frequencies above 10 GHz. Malaysia is located in a tropical and equatorial region with high rain intensity throughout the year, and this study will review rain distribution and evaluate the performance of 60-min to 1-min integration time rain rate conversion methods for Malaysia. Several conversion methods such as Segal, Chebil & Rahman, Burgeono, Emiliani, Lavergnat and Gole (LG), Simplified Moupfouma, Joo et al., fourth order polynomial fit and logarithmic model have been chosen to evaluate the performance to predict 1-min rain rate for 10 sites in Malaysia. After the completion of this research, the results show that Chebil & Rahman model, Lavergnat & Gole model, Fourth order polynomial fit and Logarithmic model have shown the best performances in 60-min to 1-min rain rate conversion over 10 sites. In conclusion, it is proven that there is no single model which can claim to perform the best across 10 sites. By averaging RMSE and SC-RMSE over 10 sites, Chebil and Rahman model is the best method.

  13. The effect of substrate morphological structure on photoelectrical conversion performance of silicon solar cell

    Science.gov (United States)

    Li, Yongtao; Sun, Xiaomeng; Xia, Yang

    2017-03-01

    A novel method is proposed to evaluate electrical characteristics of silicon solar cell at real operating conditions. Silicon solar cells with different substrate morphological structures have various photoelectrical performances. The effect of substrate morphological structure on photoelectrical conversation performance of silicon solar cell has been investigated by illustration analysis, mathematical model and I-V test system. Results show that the solar cell with the porous-sponge like substrate has better electrical characteristics than those with conical like substrate morphological structure. The output power of porous substrate solar cell can exceed by 11% at 40 degree incident angle of sunlight compared to conical substrate solar cell.

  14. Megawatt Class Nuclear Space Power Systems (MCNSPS) conceptual design and evaluation report. Volume 3, technologies 2: Power conversion

    Science.gov (United States)

    Wetch, J. R.

    1988-01-01

    The major power conversion concepts considered for the Megawatt Class Nuclear Space Power System (MCNSPS) are discussed. These concepts include: (1) Rankine alkali-metal-vapor turbine alternators; (2) in-core thermionic conversion; (3) Brayton gas turbine alternators; and (4) free piston Stirling engine linear alternators. Considerations important to the coupling of these four conversion alternatives to an appropriate nuclear reactor heat source are examined along with the comparative performance characteristics of the combined systems meeting MCNSPS requirements.

  15. Correlation between clinical performance and degree of conversion of resin cements: a literature review

    Science.gov (United States)

    DE SOUZA, Grace; BRAGA, Roberto Ruggiero; CESAR, Paulo Francisco; LOPES, Guilherme Carpena

    2015-01-01

    Resin-based cements have been frequently employed in clinical practice to lute indirect restorations. However, there are numerous factors that may compromise the clinical performance of those cements. The aim of this literature review is to present and discuss some of the clinical factors that may affect the performance of current resin-based luting systems. Resin cements may have three different curing mechanisms: chemical curing, photo curing or a combination of both. Chemically cured systems are recommended to be used under opaque or thick restorations, due to the reduced access of the light. Photo-cured cements are mainly indicated for translucent veneers, due to the possibility of light transmission through the restoration. Dual-cured are more versatile systems and, theoretically, can be used in either situation, since the presence of both curing mechanisms might guarantee a high degree of conversion (DC) under every condition. However, it has been demonstrated that clinical procedures and characteristics of the materials may have many different implications in the DC of currently available resin cements, affecting their mechanical properties, bond strength to the substrate and the esthetic results of the restoration. Factors such as curing mechanism, choice of adhesive system, indirect restorative material and light-curing device may affect the degree of conversion of the cement and, therefore, have an effect on the clinical performance of resin-based cements. Specific measures are to be taken to ensure a higher DC of the luting system to be used. PMID:26398507

  16. Correlation between clinical performance and degree of conversion of resin cements: a literature review

    Directory of Open Access Journals (Sweden)

    Grace DE SOUZA

    2015-08-01

    Full Text Available AbstractResin-based cements have been frequently employed in clinical practice to lute indirect restorations. However, there are numerous factors that may compromise the clinical performance of those cements. The aim of this literature review is to present and discuss some of the clinical factors that may affect the performance of current resin-based luting systems. Resin cements may have three different curing mechanisms: chemical curing, photo curing or a combination of both. Chemically cured systems are recommended to be used under opaque or thick restorations, due to the reduced access of the light. Photo-cured cements are mainly indicated for translucent veneers, due to the possibility of light transmission through the restoration. Dual-cured are more versatile systems and, theoretically, can be used in either situation, since the presence of both curing mechanisms might guarantee a high degree of conversion (DC under every condition. However, it has been demonstrated that clinical procedures and characteristics of the materials may have many different implications in the DC of currently available resin cements, affecting their mechanical properties, bond strength to the substrate and the esthetic results of the restoration. Factors such as curing mechanism, choice of adhesive system, indirect restorative material and light-curing device may affect the degree of conversion of the cement and, therefore, have an effect on the clinical performance of resin-based cements. Specific measures are to be taken to ensure a higher DC of the luting system to be used.

  17. Experimental Study of Heat Energy Absorber with Porous Medium for Thermoelectric Conversion System

    Directory of Open Access Journals (Sweden)

    Tzer-Ming Jeng

    2013-12-01

    Full Text Available The thermoelectric conversion system usually consists of the heat absorber, the thermoelectric generator (TEG and the heat sink, while the heat absorber collects the heat to increase the temperature on the hot surface of TEG and enhances the generating electricity. This study experimentally investigated the performance of the brass-beads packed-bed heat absorber for the thermoelectric conversion system. The packed-bed heat absorber is installed in a square channel with the various flow orientation systems and the small ratio of channel width to bead diameter. The flow orientation systems included the straight flow and jet flow systems. This study showed the local and average heat transfer characteristics for various parameters. The experimental results can be the base of designs for the novel porous heat absorber of the thermoelectric conversion system.

  18. Experimental model of a wind energy conversion system

    Science.gov (United States)

    Vasar, C.; Rat, C. L.; Prostean, O.

    2018-01-01

    The renewable energy domain represents an important issue for the sustainable development of the mankind in the actual context of increasing demand for energy along with the increasing pollution that affect the environment. A significant quota of the clean energy is represented by the wind energy. As a consequence, the developing of wind energy conversion systems (WECS) in order to achieve high energetic performances (efficiency, stability, availability, competitive cost etc) represents a topic of permanent actuality. Testing and developing of an optimized control strategy for a WECS direct implemented on a real energetic site is quite difficult and not cost efficient. Thus a more convenient solution consists in a flexible laboratory setup which requires an experimental model of a WECS. Such approach would allow the simulation of various real conditions very similar with existing energetic sites. This paper presents a grid-connected wind turbine emulator. The wind turbine is implemented through a real-time Hardware-in-the-Loop (HIL) emulator, which will be analyzed extensively in the paper. The HIL system uses software implemented in the LabVIEW programming environment to control an ABB ACS800 electric drive. ACS800 has the task of driving an induction machine coupled to a permanent magnet synchronous generator. The power obtained from the synchronous generator is rectified, filtered and sent to the main grid through a controlled inverter. The control strategy is implemented on a NI CompactRIO (cRIO) platform.

  19. Design of video interface conversion system based on FPGA

    Science.gov (United States)

    Zhao, Heng; Wang, Xiang-jun

    2014-11-01

    This paper presents a FPGA based video interface conversion system that enables the inter-conversion between digital and analog video. Cyclone IV series EP4CE22F17C chip from Altera Corporation is used as the main video processing chip, and single-chip is used as the information interaction control unit between FPGA and PC. The system is able to encode/decode messages from the PC. Technologies including video decoding/encoding circuits, bus communication protocol, data stream de-interleaving and de-interlacing, color space conversion and the Camera Link timing generator module of FPGA are introduced. The system converts Composite Video Broadcast Signal (CVBS) from the CCD camera into Low Voltage Differential Signaling (LVDS), which will be collected by the video processing unit with Camera Link interface. The processed video signals will then be inputted to system output board and displayed on the monitor.The current experiment shows that it can achieve high-quality video conversion with minimum board size.

  20. The potential for matrix conversion in marine electric propulsion systems.

    OpenAIRE

    Ciaramella, K. M.

    2006-01-01

    The growing interest in marine electric propulsion is driven by the need to improve ship performance. This thesis presents a review of existing marine electric propulsion technology and potential future variable speed drives. The matrix converter was found to be a promising alternative to existing technology and this thesis describes an investigation into its potential for marine electric propulsion. The matrix converter performs direct AC-AC conversion using a high switching frequency to pro...

  1. Embodied conversational agents: effects on memory performance and anthropomorphisation

    NARCIS (Netherlands)

    Beun, R.J.; Vos, Eveliene de; Witteman, C.L.M.

    2003-01-01

    It is often assumed that the use of Embodied Conversational Agents (ECAs) in human-computer interfaces improves human-computer interaction. Because of their appearance and because they show human-like communicative behaviour, users tend to ascribe human characteristics to ECAs or ‘anthropo-morphize’

  2. Inertial confinement fusion reaction chamber and power conversion system study

    Energy Technology Data Exchange (ETDEWEB)

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  3. Surface plasmon polaritons mode conversion via a coupled plasmonic system

    Science.gov (United States)

    Yang, Fan; Tian, Hao

    2016-05-01

    A coupled plasmonic system for effective mode conversion between single interface surface plasmon polaritons (SPP) in a metal-dielectric waveguide and gap SPP in a metal-dielectric-metal waveguide is proposed. With the modal analysis, it is shown that the interference of the two plasmonic modes in a metal-dielectric-metal-dielectric coupled structure plays the key role in the mode conversion. With typical parameters, the conversion efficiency is as high as 61% (equivalent to 87% of the output total energy flow) at 1μm wavelength, and 1 dB bandwidth is as broad as 300 nm. The proposed structure can be used to implement an SPP mode convertor, router and beam splitter, which enables the interconnection between two important waveguides in plasmonics. The method presented here is fully-analytical, and is tested against fully-vectorial numerical results.

  4. Online optimization of a multi-conversion-level DC home microgrid for system efficiency enhancement

    DEFF Research Database (Denmark)

    Boscaino, V.; Guerrero, J. M.; Ciornei, I.

    2017-01-01

    In this paper, an on-line management system for the optimal efficiency operation of a multi-bus DC home distribution system is proposed. The operation of the system is discussed with reference to a distribution system with two conversion stages and three voltage levels. In each of the conversion...... stages, three paralleled DC/DC converters are implemented. A Genetic Algorithm performs the on-line optimization of the DC network’s global efficiency, generating the optimal current sharing ratios of the concurrent power converters. The overall DC/DC conversion system including the optimization section...... for, such as: components loss parameters, components ageing, load currents, switching frequency and input voltage. Simulation results considering several case studies are presented and the benefits brought by the optimization algorithm in terms of power saving are widely discussed for each case study....

  5. Thermodynamic limits to the conversion of blackbody radiation by quantum systems. [with application to solar energy conversion devices

    Science.gov (United States)

    Buoncristiani, A. M.; Smith, B. T.; Byvik, C. E.

    1982-01-01

    Using general thermodynamic arguments, we analyze the conversion of the energy contained in the radiation from a blackbody to useful work by a quantum system. We show that the energy available for conversion is bounded above by the change in free energy in the incident and reradiated fields and that this free energy change depends upon the temperature of the receiving device. Universal efficiency curves giving the ultimate thermodynamic conversion efficiency of the quantum system are presented in terms of the blackbody temperature and the temperature and threshold energy of the quantum system. Application of these results is made to a variety of systems including biological photosynthetic, photovoltaic, and photoelectrochemical systems.

  6. Physical Limits of Solar Energy Conversion in the Earth System.

    Science.gov (United States)

    Kleidon, Axel; Miller, Lee; Gans, Fabian

    2016-01-01

    Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

  7. Loss comparison of different nine-switch and twelve-switch energy conversion systems

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Loh, Poh Chiang; Qin, Zian

    2014-01-01

    with an answer only available after performing a thorough analysis. For that, it is the intention now to compare the nine-switch and twelve-switch converters when they are used in ac-ac, ac-dc, dc-ac or dc-dc energy conversion systems. Their losses will be compared to identify when the nine-switch converter...

  8. Design of a simple, effective and low cost micro wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Massimiliano; Pucci, Marcello; Vitale, Gianpaolo

    2011-07-01

    The installation of micro-wind energy conversion systems (MWECS) depends on the system's performance and cost. The aim of this study is to present a MWECS developed for low power applications connected to the grid. The system containing a micro-wind turbine, a PMSM machine, a diode bridge, a boost DC/DC converter and a grid connected single phase inverter was developed and then tested. The results showed a good performance of the system, it can deliver up to twice as much energy as a conventional system in the same conditions. This technology is also cheaper and simpler than its concurrents. This study developed a simple effective and low cost micro wind energy conversion system.

  9. System Performance and Testing

    NARCIS (Netherlands)

    Frei, U.; Oversloot, H.

    2004-01-01

    This chapter compares and contrasts the system performance of two widely used solar thermal systems using testing and simulation programs. Solar thermal systems are used in many countries for heating domestically used water. In addition to the simple thermosiphon systems, better designed pumped

  10. Spectral light management for solar energy conversion systems

    Directory of Open Access Journals (Sweden)

    Stanley Cameron

    2016-06-01

    Full Text Available Due to the inherent broadband nature of the solar radiation, combined with the narrow spectral sensitivity range of direct solar to electricity devices, there is a massive opportunity to manipulate the solar spectrum to increase the functionality and efficiency of solar energy conversion devices. Spectral splitting or manipulation facilitates the efficient combination of both high-temperature solar thermal systems, which can absorb over the entire solar spectrum to create heat, and photovoltaic cells, which only convert a range of wavelengths to electricity. It has only recently been possible, with the development of nanofabrication techniques, to integrate micro- and nano-photonic structures as spectrum splitters/manipulators into solar energy conversion devices. In this paper, we summarize the recent developments in beam splitting techniques, and highlight some relevant applications including combined PV-thermal collectors and efficient algae production, and suggest paths for future development in this field.

  11. Integrated bioenergy conversion concepts for small scale gasification power systems

    Science.gov (United States)

    Aldas, Rizaldo Elauria

    microorganisms used to deal with tars are selected and pre-conditioned to the tar environment. Overall, the results provided a basis for operational and design strategy for a combined gasification system but further study is recommended such as determination of the impacts in terms of emissions, power, efficiency and costs associated with the use of producer gas-enriched biogas taking advantage of hydrogen enrichment to reduce NOx and other pollutants in reciprocating engines and other energy conversion systems.

  12. Energy Conversion Loop: A Testbed for Nuclear Hybrid Energy Systems Use in Biomass Pyrolysis

    Science.gov (United States)

    Verner, Kelley M.

    Nuclear hybrid energy systems are a possible solution for contemporary energy challenges. Nuclear energy produces electricity without greenhouse gas emissions. However, nuclear power production is not as flexible as electrical grids demand and renewables create highly variable electricity. Nuclear hybrid energy systems are able to address both of these problems. Wasted heat can be used in processes such as desalination, hydrogen production, or biofuel production. This research explores the possible uses of nuclear process heat in bio-oil production via biomass pyrolysis. The energy conversion loop is a testbed designed and built to mimic the heat from a nuclear reactor. Small scale biomass pyrolysis experiments were performed and compared to results from the energy conversion loop tests to determine future pyrolysis experimentation with the energy conversion loop. Further improvements must be made to the energy conversion loop before more complex experiments may be performed. The current conditions produced by the energy conversion loop are not conducive for current biomass pyrolysis experimentation.tion.

  13. Space-based solar power conversion and delivery systems study. Volume 4: Energy conversion systems studies

    Science.gov (United States)

    1977-01-01

    Solar cells and optical configurations for the SSPS were examined. In this task, three specific solar cell materials were examined: single crystal silicon, single crystal gallium arsenide, and polycrystalline cadmium sulfide. The comparison of the three different cells on the basis of a subsystem parametric cost per kW of SSPS-generated power at the terrestrial utility interface showed that gallium arsenide was the most promising solar cell material at high concentration ratios. The most promising solar cell material with no concentration, was dependent upon the particular combination of parameters representing cost, mass and performance that were chosen to represent each cell in this deterministic comparative analysis. The potential for mass production, based on the projections of the present state-of-the-art would tend to favor cadmium sulfide in lieu of single crystal silicon or gallium arsenide solar cells.

  14. Photoelectrochemical based direct conversion systems for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Kocha, S.; Peterson, M.; Arent, D. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-10-01

    Photon driven, direct conversion systems consist of a light absorber and a water splitting catalyst as a monolithic system; water is split directly upon illumination. This one-step process eliminates the need to generate electricity externally and subsequently feed it to an electrolyzer. These configurations require only the piping necessary for transport of hydrogen to an external storage system or gas pipeline. This work is focused on multiphoton photoelectrochemical devices for production of hydrogen directly using sunlight and water. Two types of multijunction cells, one consisting of a-Si triple junctions and the other GaInP{sub 2}/GaAs homojunctions, were studied for the photoelectrochemical decomposition of water into hydrogen and oxygen from an aqueous electrolyte solution. To catalyze the water decomposition process, the illuminated surface of the device was modified either by addition of platinum colloids or by coating with ruthenium dioxide. These colloids have been characterized by gel electrophoresis.

  15. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    Science.gov (United States)

    Brown, Edward J.; Baldasaro, Paul F.; Dziendziel, Randolph J.

    1997-01-01

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength .lambda..sub.IF approximately equal to the bandgap wavelength .lambda..sub.g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5.lambda..sub.IF to .lambda..sub.IF and reflect from .lambda..sub.IF to about 2.lambda..sub.IF ; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5.lambda..sub.IF.

  16. Designing Energy Conversion Systems for the Next Decade

    Directory of Open Access Journals (Sweden)

    Slobodan N. Vukosavić

    2012-12-01

    Full Text Available Sustainable growth in energy consumption requires transition to clean and green energy sources and energy systems. Environment friendly and renewable energy systems deal with electrical energy and rely on efficient electrical power converters. High power electronics is the key technology to deal with the next generation of electrical energy systems. The door to future breakthroughs in high power electronics is opened by major improvement in semiconductor power devices and their packaging technologies. New materials allow for much higher junction temperatures and higher operating voltages. Most importantly, advanced power semiconductor devices and novel converter topology open the possibility to increase the energy efficiency of power conversion and reduce the amount of heat. Although the waste heat created by high power converters can be put to use by adding on to heating systems, this option is not always available and the conversion losses are mostly wasted. At the same time, wasted heat is a form of pollution that threatens the environment. Another task for high power converters is efficient harvesting of renewable energy sources, such as the wind energy and the sun. Intermittent in nature, they pose a difficult task to power converter topology and controls. Eventually, high power converters are entering power distribution and transmission networks. With their quick reaction, with fast communication between the grid nodes and with advanced controllability of high power converters, a number of innovations can be introduced, facilitating the power system control and allowing for optimizations and loss reduction. Coined smart grid, this solution comprises two key elements, and these are intelligent controls and large static power converters. At virtually no cost, smart grids allow for a better utilization of available resources and it enlarges the stable operating range of the transmission systems. Therefore, it is of interest to review the

  17. Plasma heating due to X-B mode conversion in a cylindrical ECR plasma system

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, V.K.; Bora, D. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat (India)

    2004-07-01

    Extra Ordinary (X) mode conversion to Bernstein wave near Upper Hybrid Resonance (UHR) layer plays an important role in plasma heating through cyclotron resonance. Wave generation at UHR and parametric decay at high power has been observed during Electron Cyclotron Resonance (ECR) heating experiments in toroidal magnetic fusion devices. A small linear system with ECR and UHR layer within the system has been used to conduct experiments on X-B conversion and parametric decay process as a function of system parameters. Direct probing in situ is conducted and plasma heating is evidenced by soft x-ray emission measurement. Experiments are performed with hydrogen plasma produced with 160-800 W microwave power at 2.45 GHz of operating frequency at 10{sup -3} mbar pressure. The axial magnetic field required for ECR is such that the resonant surface (B = 875 G) is situated at the geometrical axis of the plasma system. Experimental results will be presented in the paper. (authors)

  18. Model predictive control of wind energy conversion systems

    CERN Document Server

    Yaramasu, Venkata Narasimha R

    2017-01-01

    The authors provide a comprehensive analysis on the model predictive control of power converters employed in a wide variety of variable-speed wind energy conversion systems (WECS). The contents of this book includes an overview of wind energy system configurations, power converters for variable-speed WECS, digital control techniques, MPC, modeling of power converters and wind generators for MPC design. Other topics include the mapping of continuous-time models to discrete-time models by various exact, approximate, and quasi-exact discretization methods, modeling and control of wind turbine grid-side two-level and multilevel voltage source converters. The authors also focus on the MPC of several power converter configurations for full variable-speed permanent magnet synchronous generator based WECS, squirrel-cage induction generator based WECS, and semi-variable-speed doubly fed induction generator based WECS.

  19. Modeling power electronics and interfacing energy conversion systems

    CERN Document Server

    Simões, Marcelo Godoy

    2017-01-01

    Discusses the application of mathematical and engineering tools for modeling, simulation and control oriented for energy systems, power electronics and renewable energy. This book builds on the background knowledge of electrical circuits, control of dc/dc converters and inverters, energy conversion and power electronics. The book shows readers how to apply computational methods for multi-domain simulation of energy systems and power electronics engineering problems. Each chapter has a brief introduction on the theoretical background, a description of the problems to be solved, and objectives to be achieved. Block diagrams, electrical circuits, mathematical analysis or computer code are covered. Each chapter concludes with discussions on what should be learned, suggestions for further studies and even some experimental work.

  20. System performance analyzer

    Science.gov (United States)

    Helbig, H. R.

    1981-01-01

    The System Performance Analyzer (SPA) designed to provide accurate real time information about the operation of complex systems and developed for use on the Airborne Data Analysis/Monitor System (ADAMS), a ROLM 1666 based system is described. The system uses an external processor to operate an intelligent, simulated control panel. Also provided are functions to trace operations, determine frequency of use of memory areas, and time or count user tasks in a multitask environment. This augments the information available from the standard debugger and control panel, and reduces the time and effort needed by ROLM 1666 users in optimizing their system, as well as providing documentation of the effect of any changes. The operation and state of the system are evaluated.

  1. Evaluation testing of a closed Brayton-cycle electrical-power-conversion system.

    Science.gov (United States)

    Redding, T. E.; Mcgee, J. M.; Luksa, N. C.

    1972-01-01

    Description of the design and testing of a recuperated, closed Brayton-cycle, electrical power conversion system designated the Brayton Cycle Demonstrator (BCD). The system uses electrical heaters as a heat source, argon as the cycle working fluid, and gas-lubricated foil-type bearings. Objectives of the test program include (1) evaluation of the overall system performance characteristics and influences on spacecraft integration, (2) familiarization of personnel with operational methods, and (3) determination of system flexibility by operating at a number of off-design conditions. Results obtained to date are discussed.

  2. Electric utility application of wind energy conversion systems on the island of Oahu

    Energy Technology Data Exchange (ETDEWEB)

    Lindley, C.A.; Melton, W.C.

    1979-02-23

    This wind energy application study was performed by The Aerospace Corporation for the Wind Systems Branch of the Department of Energy. The objective was to identify integration problems for a Wind Energy Conversion System (WECS) placed into an existing conventional utility system. The integration problems included environmental, institutional and technical aspects as well as economic matters, but the emphasis was on the economics of wind energy. The Hawaiian Electric Company utility system on the island of Oahu was selected for the study because of the very real potential for wind energy on that island, and because of the simplicity afforded in analyzing that isolated utility.

  3. Generators for Wind Energy Conversion Systems: State of the Art and Coming Attractions

    OpenAIRE

    Y. Amirat*; M. E. H. Benbouzid; B. Bensaker; R. Wamkeue

    2007-01-01

    Wind Energy Conversion Systems (WECS) have become a focal point in the research of renewable energy sources. This paper provides then a comparative study of past and present generator technologies used in WECS. This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main topologies that are permanent magnet generators, synchronous generators, induction generators and doubly-fed induction generators. The different gener...

  4. High performance systems

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, M.B. [comp.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  5. Nuclear Air-Brayton Combined Cycle Power Conversion Design, Physical Performance Estimation and Economic Assessment

    Science.gov (United States)

    Andreades, Charalampos

    The combination of an increased demand for electricity for economic development in parallel with the widespread push for adoption of renewable energy sources and the trend toward liberalized markets has placed a tremendous amount of stress on generators, system operators, and consumers. Non-guaranteed cost recovery, intermittent capacity, and highly volatile market prices are all part of new electricity grids. In order to try and remediate some of these effects, this dissertation proposes and studies the design and performance, both physical and economic, of a novel power conversion system, the Nuclear Air-Brayton Combined Cycle (NACC). The NACC is a power conversion system that takes a conventional industrial frame type gas turbine, modifies it to accept external nuclear heat at 670°C, while also maintaining its ability to co-fire with natural gas to increase temperature and power output at a very quick ramp rate. The NACC addresses the above issues by allowing the generator to gain extra revenue through the provision of ancillary services in addition to energy payments, the grid operator to have a highly flexible source of capacity to back up intermittent renewable energy sources, and the consumer to possibly see less volatile electricity prices and a reduced probability of black/brown outs. This dissertation is split into six sections that delve into specific design and economic issues related to the NACC. The first section describes the basic design and modifications necessary to create a functional externally heated gas turbine, sets a baseline design based upon the GE 7FB, and estimates its physical performance under nominal conditions. The second section explores the off-nominal performance of the NACC and characterizes its startup and shutdown sequences, along with some of its safety measures. The third section deals with the power ramp rate estimation of the NACC, a key performance parameter in a renewable-heavy grid that needs flexible capacity. The

  6. Energy and data conversion circuits for low power sensory systems

    Science.gov (United States)

    Ghosh, Suvradip

    This dissertation focuses on the problem of increasing the lifetime of wireless sensors. This problem is addressed from two different angles: energy harvesting and data compression. Energy harvesting enables a sensor to extract energy from its environment and use it to power itself or recharge its batteries. Data compression, on the other hand, allows a sensor to save energy by reducing the radio transmission bandwidth. This dissertation proposes a fractal-based photodiode fabricated on standard CMOS process as an energy harvesting device with increased efficiency. Experiments show that, the fractal based photodiodes are 6% more efficient compared to the conventional square shaped photodiode. The fractal shape photodiode has more perimeter-to-area ratio which increases the lateral response, improving its efficiency. With increased efficiency, more current is generated but the open-circuit voltage still remains low (0.3V--0.45V depending on illumination condition). These voltages have to be boosted up to higher values if they are going to be used to power up any sensory circuit or recharge a battery. We propose a switched-inductor DC-DC converter to boost the low voltage of the photodiodes to higher voltages. The proposed circuit uses two on-chip switches and two off-chip Components: an inductor and a capacitor. Experiments show a voltage up to 2.81V can be generated from a single photodiode of 1mm2 area. The voltage booster circuit achieved a conversion efficiency of 59%. Data compression was also explored in an effort to reduce energy consumption during radio transmission. An analog-to-digital converter (ADC), which can jointly perform the tasks of digital conversion and entropy encoding, has also been proposed in this dissertation. The joint data conversion/compression help savings in area and power resources, making it suitable for on-sensor compression. The proposed converter combines a cyclic converter architecture and Golomb-Rice entropy encoder. The

  7. Bisulfite Conversion of DNA: Performance Comparison of Different Kits and Methylation Quantitation of Epigenetic Biomarkers that Have the Potential to Be Used in Non-Invasive Prenatal Testing

    Science.gov (United States)

    Leontiou, Chrysanthia A.; Hadjidaniel, Michael D.; Mina, Petros; Antoniou, Pavlos; Ioannides, Marios; Patsalis, Philippos C.

    2015-01-01

    Introduction Epigenetic alterations, including DNA methylation, play an important role in the regulation of gene expression. Several methods exist for evaluating DNA methylation, but bisulfite sequencing remains the gold standard by which base-pair resolution of CpG methylation is achieved. The challenge of the method is that the desired outcome (conversion of unmethylated cytosines) positively correlates with the undesired side effects (DNA degradation and inappropriate conversion), thus several commercial kits try to adjust a balance between the two. The aim of this study was to compare the performance of four bisulfite conversion kits [Premium Bisulfite kit (Diagenode), EpiTect Bisulfite kit (Qiagen), MethylEdge Bisulfite Conversion System (Promega) and BisulFlash DNA Modification kit (Epigentek)] regarding conversion efficiency, DNA degradation and conversion specificity. Methods Performance was tested by combining fully methylated and fully unmethylated λ-DNA controls in a series of spikes by means of Sanger sequencing (0%, 25%, 50% and 100% methylated spikes) and Next-Generation Sequencing (0%, 3%, 5%, 7%, 10%, 25%, 50% and 100% methylated spikes). We also studied the methylation status of two of our previously published differentially methylated regions (DMRs) at base resolution by using spikes of chorionic villus sample in whole blood. Results The kits studied showed different but comparable results regarding DNA degradation, conversion efficiency and conversion specificity. However, the best performance was observed with the MethylEdge Bisulfite Conversion System (Promega) followed by the Premium Bisulfite kit (Diagenode). The DMRs, EP6 and EP10, were confirmed to be hypermethylated in the CVS and hypomethylated in whole blood. Conclusion Our findings indicate that the MethylEdge Bisulfite Conversion System (Promega) was shown to have the best performance among the kits. In addition, the methylation level of two of our DMRs, EP6 and EP10, was confirmed

  8. Methods for locating ground faults and insulation degradation condition in energy conversion systems

    Science.gov (United States)

    Agamy, Mohamed; Elasser, Ahmed; Galbraith, Anthony William; Harfman Todorovic, Maja

    2015-08-11

    Methods for determining a ground fault or insulation degradation condition within energy conversion systems are described. A method for determining a ground fault within an energy conversion system may include, in part, a comparison of baseline waveform of differential current to a waveform of differential current during operation for a plurality of DC current carrying conductors in an energy conversion system. A method for determining insulation degradation within an energy conversion system may include, in part, a comparison of baseline frequency spectra of differential current to a frequency spectra of differential current transient at start-up for a plurality of DC current carrying conductors in an energy conversion system. In one embodiment, the energy conversion system may be a photovoltaic system.

  9. Efficiency enhancement of the ocean thermal energy conversion system with a vapor–vapor ejector

    Directory of Open Access Journals (Sweden)

    Ho-Saeng Lee

    2015-03-01

    Full Text Available In this article, 20 kW ocean thermal energy conversion with a vapor–vapor ejector is newly proposed. As a vapor–vapor ejector is installed in the system, the pressure difference between the turbine inlet and outlet increases. Therefore, the amount of the working fluid required for the total turbine work of 20 kW is less than when no vapor–vapor ejector is installed. Therefore, installing a vapor–vapor ejector in the system decreases the evaporation capacity and the pump work. The performance analysis considered the outlet pressure of the high-stage turbine, the mass flow ratio of the working fluid at the outlet of a separator just after the high-stage turbine, and the nozzle diameters of the vapor–vapor ejector. As the outlet pressure of high-stage turbine becomes lower, the turbine gross power of high-stage turbine and system efficiency increase although lower outlet pressure of high-stage turbine results in lower ejector performance. Similarly, in terms of mass flow ratio, the highest system efficiency was shown at mass flow ratio of 0.4 at the outlet of a separator just after the high-stage turbine. On the other hand, the performance of the ejector at mass flow ratio of 0.5 at the outlet of a separator was largest. When the nozzle diameters of the vapor–vapor ejector are properly designed, the vapor–vapor ejector shows the highest performance. After the optimization of the operation parameters, system efficiency of the proposed ocean thermal energy conversion power cycle was 2.47%, relatively 15% higher than that of the basic ocean thermal energy conversion power cycle (2.2%.

  10. Performances of an Interleaved High Step-Up Converter with Different Soft-Switching Snubbers for PV Energy Conversion Applications

    Directory of Open Access Journals (Sweden)

    Sheng-Yu Tseng

    2013-01-01

    Full Text Available This paper proposes an interleaved high step-up converter with different soft-switching snubbers for PV energy conversion applications. For the high step-up converter, interleaved and coupled-inductor technologies are used to reduce output ripple current and increase output power level. Simultaneously, two types of snubbers, a single-capacitor snubber and boost type snubber, are introduced separately into the discussed converters for comparing their performances of conversion efficiency and switching losses. For drawing maximum power from the PV arrays, a perturbation-and-observation method realized with the microcontroller is adopted to achieve maximum power point tracking (MPPT algorithm and power regulating scheme. Finally, two prototypes of the interleaved coupled-inductor boost converter with a single-capacitor snubber and with boost type snubber are implemented, respectively. The experimental results obtained are used to verify and compare the performances and feasibilities of the discussed converters with different snubbers in PV conversion applications. The experimental results show that the proposed system is suitable for PV energy conversion applications when the duty ratios of switches of the converter are less than 0.5.

  11. A Floating Ocean Energy Conversion Device and Numerical Study on Buoy Shape and Performance

    Directory of Open Access Journals (Sweden)

    Ruiyin Song

    2016-05-01

    Full Text Available Wave and current energy can be harnessed in the East China Sea and South China Sea; however, both areas are subject to high frequencies of typhoon events. To improve the safety of the ocean energy conversion device, a Floating Ocean Energy Conversion Device (FOECD with a single mooring system is proposed, which can be towed to avoid severe ocean conditions or for regular maintenance. In this paper, the structure of the FOECD is introduced, and it includes a catamaran platform, an oscillating buoy part, a current turbine blade, hydraulic energy storage and an electrical generation part. The numerical study models the large catamaran platform as a single, large buoy, while the four floating buoys were modeled simply as small buoys. Theoretical models on wave energy power capture and efficiency were established. To improve the suitability of the buoy for use in the FOECD and its power harvesting capability, a numerical simulation of the four buoy geometries was undertaken. The shape profiles examined in this paper are cylindrical, turbinate (V-shaped and U-shaped cone with cylinder, and combined cylinder-hemisphere buoys. Simulation results reveal that the suitability of a turbinate buoy is the best of the four types. Further simulation models were carried out by adjusting the tip radius of the turbinate buoy. Three performance criteria including suitability, power harvesting capability and energy capture efficiency were analyzed. It reveals that the turbinate buoy has almost the same power harvesting capabilities and energy capture efficiency, while its suitability is far better than that of a cylindrical buoy.

  12. Catalytic systems used for polymerization, biomass conversion, and enhancing diffusion

    Science.gov (United States)

    Pong, Frances

    A significant amount of research has been dedicated towards the study and improvement of catalysts. A better understanding of how catalysts work can lead to developing more cost-efficient catalytic systems for a variety of applications. My research is focuses on catalytic systems used in three different fields, which are (i) organometallic polymerization catalysts, (ii) molecular motors and (iii) biomass conversion. Researchers have long studied and modified organometallic catalysts for use in the direct co- and homopolymerization of monomers with polar functional groups. The ability to add polar moieties to polymers, which can potentially yield materials with a wider range of physical properties, is highly desirable. In this study (i), a series of naphthoxyimine palladium(II) catalysts -- in which the naphthyl backbone had been functionalized with different moieties -- were synthesized and systematically studied to determine the ligand structure's impact on catalytic activity. The study showed that slight modifications of the naphthyl backbone led to significant changes in the polymer's molecular weight and polydispersity index. The catalysts were also displayed some ability to co-polymerize ethylene and functionalized norbornene. These positive results suggest that further exploration of naphthoxyimine palladium (II) catalysts may be fundamentally interesting. The effect of active, motile particles at the nanoscale has been vigorously researched during the past decade. By understanding how such active suspensions behave, researchers can gain new insights which can potentially provide new applications in many fields. Here (ii) the momentum transfer of active catalysts (Grubbs' 2nd generation catalyst with a hydrodynamic radius of 6A) to their immediate surroundings is observed in an organic suspension. This phenomenon, which has been coined "enhanced diffusion," has not been well studied at the angstrom scale until now. Diffusion-NMR spectroscopy surprisingly

  13. Structure Design and Performance Tuning of Nanomaterials for Electrochemical Energy Conversion and Storage.

    Science.gov (United States)

    Sheng, Tian; Xu, Yue-Feng; Jiang, Yan-Xia; Huang, Ling; Tian, Na; Zhou, Zhi-You; Broadwell, Ian; Sun, Shi-Gang

    2016-11-15

    The performance of nanomaterials in electrochemical energy conversion (fuel cells) and storage (secondary batteries) strongly depends on the nature of their surfaces. Designing the structure of electrode materials is the key approach to achieving better performance. Metal or metal oxide nanocrystals (NCs) with high-energy surfaces and open surface structures have attained significant attention in the past decade since such features possess intrinsically exceptional properties. However, they are thermodynamically metastable, resulting in a huge challenge in their shape-controlled synthesis. The tuning of material structure, design, and performance on the nanoscale for electrochemical energy conversion and storage has attracted extended attention over the past few years. In this Account, recent progress made in shape-controlled synthesis of nanomaterials with high-energy surfaces and open surface structures using both electrochemical methods and surfactant-based wet chemical route are reviewed. In fuel cells, the most important catalytic materials are Pt and Pd and their NCs with high-energy surfaces of convex or concave morphology. These exhibit remarkable activity toward electrooxidation of small organic molecules, such as formic acid, methanol, and ethanol and so on. In practical applications, the successful synthesis of Pt NCs with high-energy surfaces of small sizes (sub-10 nm) realized a superior high mass activity. The electrocatalytic performances have been further boosted by synergetic effects in bimetallic systems, either through surface decoration using foreign metal atoms or by alloying in which the high-index facet structure is preserved and the electronic structure of the NCs is altered. The intrinsic relationship of high electrocatalytic performance dependent on open structure and high-energy surface is also valid for (metal) oxide nanomaterials used in Li ion batteries (LIB). It is essential for the anode nanomaterials to have optimized structures to

  14. Variable-speed systems for higher efficiencies. ALSTOM Power Conversion; Drehzahlvariable Systeme verbessern die Effizienz. ALSTOM Power Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, S. [ALSTOM Power Conversion GmbH, Berlin (Germany)

    2002-07-01

    Variable-speed generators can enhance power generation efficiencies depending on the plant type and site. For example, an offshore wind power system in the North Sea can utilize stronger and more constant winds than a plant in a low inland mountain range, i.e. the demands on the plant itself will differ. A variable-speed drive is recommended which adapts the plant to the available wind and provides optimum power quality with maximum energy yield and availability. Optimum adjustment of the system components is a key prerequisite for this. The central components of the energy conversion system, i.e. the generators and current inverters, convert rotational energy of the rotors into electric power which is supplied to the public grid. Both components have been optimized continually by ALSTOM for many years and have been used successfully in many different systems. [German] Ein drehzahlgeregelter Generator ermoeglicht je nach Anlagentyp und Standort die Steigerung der Energieausbeute. Eine Offshore-Windkraftanlage in der Nordsee kann staerkere und dauerhaftere Winde als eine Anlage, die im Mittelgebirge aufgestellt ist, nutzen. Daraus ergeben sich unterschiedliche Anforderungen an die Windkraftanlage selbst. Gefragt ist eine Steuerung, die das gesamte Antriebssystem, einschliesslich der Rotorblaetter, optimal an die gegebene Windsituation anpasst. Als Loesung bietet sich ein drehzahlgeregeltes Antriebssystem an, das sich auf die jeweilige Windsituation einstellt und bei maximaler Energieausbeute und Verfuegbarkeit die bestmoegliche Stromqualitaet zur Verfuegung stellt. Eine wichtige Voraussetzung dafuer ist die optimale Abstimmung der Systemkomponenten. Die zentralen Komponenten des Energieumwandlungssystems - Generatoren und Stromrichter - sorgen in Windkraftanlagen fuer die Umwandlung der Rotationsenergie in elektrischen Storm, der ins Netz gespeist wird. Beide Komponenten werden von ALSTOM schon seit Jahren kontinuierlich optimiert und haben sich in einer Vielzahl

  15. Construction of biomimetic smart nanochannels with polymer membranes and application in energy conversion systems.

    Science.gov (United States)

    Wen, Liping; Tian, Ye; Ma, Jie; Zhai, Jin; Jiang, Lei

    2012-03-28

    Learning from nature has inspired the creation of intelligent devices to meet the increasing needs of the advanced community and also to better understand how to imitate biology. As one of biomimetic nanodevices, nanochannels or nanopores aroused particular interest because of their potential applications in nanofluidic devices, biosensing, filtration, and energy conversions. In this review we have summarized some recent results mainly focused on the design, construction and application in energy conversion systems. Like biological nanochannels, the prepared smart artificial nanochannels fabricated by ion track-etched polymer membranes and smart molecules show a great potential in the field of bioengineering and biotechnology. And these applications can not only help people to know and understand the living processes in nature, but can also inspire scientists to study and develop novel nanodevices with better performance for the mankind.

  16. Near-infrared (NIR) optogenetics using up-conversion system

    Science.gov (United States)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Yawo, Hiromu

    2015-03-01

    Non-invasive remote control technologies designed to manipulate neural functions for a comprehensive and quantitative understanding of the neuronal network in the brain as well as for the therapy of neurological disorders have long been awaited. Recently, it has become possible to optically manipulate the neuronal activity using biological photo-reactive molecules such as channelrhodopsin-2 (ChR2). However, ChR2 and its relatives are mostly reactive to visible light which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light penetrates deep into the tissues because biological systems are almost transparent to light within this so-called `imaging window'. Here we used lanthanide nanoparticles (LNPs), which are composed of rare-earth elements, as luminous bodies to activate channelrhodopsins (ChRs) since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Neuron-glioma-hybrid ND-7/23 cells were cultured with LNP(NaYF4:Sc/Yb/Er) particles (peak emission, 543 nm) and transfected to express C1V1 (peak absorbance, 539 nm), a chimera of ChR1 and VChR1. The photocurrents were generated in response to NIR laser light (976 nm) to a level comparable to that evoked by a filtered Hg lamp (530-550 nm). NIR light pulses also evoked action potentials in the cultured neurons that expressed C1V1. It is suggested that the green luminescent light emitted from LNPs effectively activated C1V1 to generate the photocurrent. With the optimization of LNPs, acceptor photo-reactive biomolecules and optics, this system could be applied to non-invasively actuate neurons deep in the brain.

  17. Ultra-capacitors in power conversion systems analysis, modeling and design in theory and practice

    CERN Document Server

    Grbovic, Petar J

    2014-01-01

    Divided into five parts, this book is focused on ultra-capacitors and their applications in power conversion systems. It discusses ultra-capacitor analysis, modelling and module design from a macroscopic (application) perspective. It also describes power conversion applications, interface dc-dc converter design and entire conversion system design. Part One covers the background of energy storage technologies, with particular attention on state-of-the-art ultra-capacitor energy storage technologies. In Chapter four of this part, power conversion systems with integrated energy storage is discus

  18. Process systems engineering issues and applications towards reducing carbon dioxide emissions through conversion technologies

    DEFF Research Database (Denmark)

    Roh, Kosan; Frauzem, Rebecca; Gani, Rafiqul

    2016-01-01

    This paper reviews issues and applications for design of sustainable carbon dioxide conversion processes, specifically through chemical conversion, and the integration of the conversion processes with other systems from a process systems engineering (PSE) view-point. Systematic and computer......-aided methods and tools for reaction network generation, processing route generation, process design/optimization, and sustainability analysis are reviewed with respect to carbon dioxide conversion. Also, the relevant gaps and opportunities are highlighted. In addition, the integration of carbon dioxide...... conversion processes with other systems including coexisting infrastructure and carbon dioxide sources is described.Then, the importance of PSE based studies for such application is discussed. Finally, some perspectives on the status and future directions of carbon dioxide conversion technology...

  19. Ultrathin and Ion-Selective Janus Membranes for High-Performance Osmotic Energy Conversion.

    Science.gov (United States)

    Zhang, Zhen; Sui, Xin; Li, Pei; Xie, Ganhua; Kong, Xiang-Yu; Xiao, Kai; Gao, Longcheng; Wen, Liping; Jiang, Lei

    2017-07-05

    The osmotic energy existing in fluids is recognized as a promising "blue" energy source that can help solve the global issues of energy shortage and environmental pollution. Recently, nanofluidic channels have shown great potential for capturing this worldwide energy because of their novel transport properties contributed by nanoconfinement. However, with respect to membrane-scale porous systems, high resistance and undesirable ion selectivity remain bottlenecks, impeding their applications. The development of thinner, low-resistance membranes, meanwhile promoting their ion selectivity, is a necessity. Here, we engineered ultrathin and ion-selective Janus membranes prepared via the phase separation of two block copolymers, which enable osmotic energy conversion with power densities of approximately 2.04 W/m 2 by mixing natural seawater and river water. Both experiments and continuum simulation help us to understand the mechanism for how membrane thickness and channel structure dominate the ion transport process and overall device performance, which can serve as a general guiding principle for the future design of nanochannel membranes for high-energy concentration cells.

  20. Optical digital to analog conversion performance analysis for indoor set-up conditions

    Science.gov (United States)

    Dobesch, Aleš; Alves, Luis Nero; Wilfert, Otakar; Ribeiro, Carlos Gaspar

    2017-10-01

    In visible light communication (VLC) the optical digital to analog conversion (ODAC) approach was proposed as a suitable driving technique able to overcome light-emitting diode's (LED) non-linear characteristic. This concept is analogous to an electrical digital-to-analog converter (EDAC). In other words, digital bits are binary weighted to represent an analog signal. The method supports elementary on-off based modulations able to exploit the essence of LED's non-linear characteristic allowing simultaneous lighting and communication. In the ODAC concept the reconstruction error does not simply rely upon the converter bit depth as in case of EDAC. It rather depends on communication system set-up and geometrical relation between emitter and receiver as well. The paper describes simulation results presenting the ODAC's error performance taking into account: the optical channel, the LED's half power angle (HPA) and the receiver field of view (FOV). The set-up under consideration examines indoor conditions for a square room with 4 m length and 3 m height, operating with one dominant wavelength (blue) and having walls with a reflection coefficient of 0.8. The achieved results reveal that reconstruction error increases for higher data rates as a result of interference due to multipath propagation.

  1. Chart of conversion factors: From English to metric system and metric to English system

    Science.gov (United States)

    ,

    1976-01-01

    The conversion factors in the following tables are for conversion of our customary (English) units of measurement to SI*units, and for convenience, reciprocals are shown for converting SI units back to the English system. The first table contains rule-of-thumb figures, useful for "getting the feel" of SI units or mental estimation. The succeeding tables contain factors accurate to 3 or more significant figures. Please refer to known reference volumes for additional accuracy, as well as for factors dealing with other scientific notation involving SI units.

  2. Generators for Wind Energy Conversion Systems: State of the Art and Coming Attractions

    Directory of Open Access Journals (Sweden)

    Y. Amirat*

    2007-03-01

    Full Text Available Wind Energy Conversion Systems (WECS have become a focal point in the research of renewable energy sources. This paper provides then a comparative study of past and present generator technologies used in WECS. This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main topologies that are permanent magnet generators, synchronous generators, induction generators and doubly-fed induction generators. The different generator-WECS schemes are compared on the basis of topology, cost, efficiency, power consumption and control complexity. Moreover, attempts are made to highlight future issues so as to index some emerging solutions.

  3. Control of modular multilevel converters for grid integration of full-scale wind energy conversion systems

    Science.gov (United States)

    Debnath, Suman

    The growing demand for wind power generation has pushed the capacity of wind turbines towards MW power levels. Higher capacity of the wind turbines necessitates operation of the generators and power electronic conversion systems at higher voltage/power levels. The power electronic conversion system of a wind energy conversion system (WECS) needs to meet the stringent requirements in terms of reliability, efficiency, scalability and ease of maintenance, power quality, and dv/dt stress on the generator/transformer. Although the multilevel converters including the neutral point clamped (NPC) converter and the active NPC converter meet most of the requirements, they fall short in reliability and scalability. Motivated by modularity/scalability feature of the modular multilevel converter (MMC), this research is to enable the MMC to meet all of the stringent requirements of the WECS by addressing their unique control challenges. This research presents systematic modeling and control of the MMC to enable it to be a potential converter topology for grid integration of full-scale WECSs. Based on the developed models, appropriate control systems for control of circulating current and capacitor voltages under fixed- and variable-frequency operations are proposed. Using the developed MMC models, a gradient-based cosimulation algorithm to optimize the gains of the developed control systems, is proposed. Performance/effectiveness of the developed models and the proposed control systems for the back-to-back MMC-based WECS are evaluated/verified based on simulations studies in the PSCAD/EMTDC software environment and experimental case studies on a laboratory-scale hardware prototype.

  4. Assessment of control strategies for fault ride through of SCIG-based wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Manaullah

    2016-01-01

    Full Text Available With increasing penetration of wind energy into the power grid, researchers have started focusing more on control and coordination of wind energy conversion systems (WECS with the other components at system level, especially during fault. It is important to implement a suitable fault ride through control strategy to avoid tripping of the generators when the power system is subjected to voltage dips normally below 90% of nominal voltage. The dips below 90% may lead to a significant loss of generation and frequency collapse, followed by a blackout. This article implements and assesses the methodologies to deal with such situations for squirrel cage induction generator-based wind energy conversion systems employing fully rated power electronic converters. Three distinct control techniques—namely, balanced positive sequence control, positive negative sequence control, and dual current control—have been simulated and applied to grid side converter of SCIG-based WECS. The performance of all the three control strategies has been compared and presented in this work. During this study, the system is subjected to the most common unsymmetrical line to ground (LG fault and most severe symmetrical LLL fault on grid for the purpose of anaysis.

  5. Permanent Magnet Synchronous Generator Driven Wind Energy Conversion System Based on Parallel Active Power Filter

    Directory of Open Access Journals (Sweden)

    FERDI Brahim

    2014-05-01

    Full Text Available This paper proposes a novel application of the instantaneous P-Q theory in a wind energy conversion system (WECS. The proposed WECS is formed by permanent magnet synchronous generator (PMSG wind turbine system connected to the grid through parallel active power filter (PAPF. PAPF uses the generated wind energy to feed loads connected at the point of common coupling (PPC, compensates current harmonics and injects the excess of this energy into the grid using P-Q theory as control method. To demonstrate the feasibility and the performance of the proposed control scheme, simulation of this wind system has been realized using MATLAB/SIMULINK software. Simulation results show the accuracy and validity of the proposed control scheme for the PMSGPAPF system.

  6. Testing of an advanced thermochemical conversion reactor system

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This report presents the results of work conducted by MTCI to verify and confirm experimentally the ability of the MTCI gasification process to effectively generate a high-quality, medium-Btu gas from a wider variety of feedstock and waste than that attainable in air-blown, direct gasification systems. The system's overall simplicity, due to the compact nature of the pulse combustor, and the high heat transfer rates attainable within the pulsating flow resonance tubes, provide a decided and near-term potential economic advantage for the MTCI indirect gasification system. The primary objective of this project was the design, construction, and testing of a Process Design Verification System for an indirectly heated, thermochemical fluid-bed reactor and a pulse combustor an an integrated system that can process alternative renewable sources of energy such as biomass, black liquor, municipal solid waste and waste hydrocarbons, including heavy oils into a useful product gas. The test objectives for the biomass portion of this program were to establish definitive performance data on biomass feedstocks covering a wide range of feedstock qualities and characteristics. The test objectives for the black liquor portion of this program were to verify the operation of the indirect gasifier on commercial black liquor containing 65 percent solids at several temperature levels and to characterize the bed carbon content, bed solids particle size and sulfur distribution as a function of gasification conditions. 6 refs., 59 figs., 29 tabs.

  7. Biomass Feedstock and Conversion Supply System Design and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, Jacob J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Roni, Mohammad S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lamers, Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cafferty, Kara G. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Idaho National Laboratory (INL) supports the U.S. Department of Energy’s bioenergy research program. As part of the research program INL investigates the feedstock logistics economics and sustainability of these fuels. A series of reports were published between 2000 and 2013 to demonstrate the feedstock logistics cost. Those reports were tailored to specific feedstock and conversion process. Although those reports are different in terms of conversion, some of the process in the feedstock logistic are same for each conversion process. As a result, each report has similar information. A single report can be designed that could bring all commonality occurred in the feedstock logistics process while discussing the feedstock logistics cost for different conversion process. Therefore, this report is designed in such a way that it can capture different feedstock logistics cost while eliminating the need of writing a conversion specific design report. Previous work established the current costs based on conventional equipment and processes. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $55/dry ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, low-cost feedstock. The 2017 programmatic target is to supply feedstock to the conversion facility that meets the in-feed conversion process quality specifications at a total logistics cost of $80/dry T. The $80/dry T. target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all conversion in-feed quality targets

  8. High-Performance Operating Systems

    DEFF Research Database (Denmark)

    Sharp, Robin

    1999-01-01

    Notes prepared for the DTU course 49421 "High Performance Operating Systems". The notes deal with quantitative and qualitative techniques for use in the design and evaluation of operating systems in computer systems for which performance is an important parameter, such as real-time applications......, communication systems and multimedia systems....

  9. Line filter design of parallel interleaved VSCs for high power wind energy conversion systems

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus

    2015-01-01

    The Voltage Source Converters (VSCs) are often connected in parallel in a Wind Energy Conversion System (WECS) to match the high power rating of the modern wind turbines. The effect of the interleaved carriers on the harmonic performance of the parallel connected VSCs is analyzed in this paper....... In order to achieve low switching losses, the 60 clamp Discontinuous PulseWidth Modulation (DPWM1) is used to modulate the VSCs. A step-by-step design procedure of the line filter, which ensures the desired harmonic performance under all operating conditions, is presented. The analytical harmonic solution...... limit. In order to achieve the desired filter performance with optimal values of the filter parameters, the use of a LC trap branch with the conventional LCL filter is proposed. The expressions for the resonant frequencies of the proposed line filter are derived and used in the design to selectively...

  10. Recent progress in solution plasma-synthesized-carbon-supported catalysts for energy conversion systems

    Science.gov (United States)

    Lun Li, Oi; Lee, Hoonseung; Ishizaki, Takahiro

    2018-01-01

    Carbon-based materials have been widely utilized as the electrode materials in energy conversion and storage technologies, such as fuel cells and metal–air batteries. In these systems, the oxygen reduction reaction is an important step that determines the overall performance. A novel synthesis route, named the solution plasma process, has been recently utilized to synthesize various types of metal-based and heteroatom-doped carbon catalysts. In this review, we summarize cutting-edge technologies involving the synthesis and modeling of carbon-supported catalysts synthesized via solution plasma process, followed by current progress on the electrocatalytic performance of these catalysts. This review provides the fundamental and state-of-the-art performance of solution-plasma-synthesized electrode materials, as well as the remaining scientific and technological challenges for this process.

  11. Energy Efficiency and Performance Limiting Effects in Thermo-Osmotic Energy Conversion from Low-Grade Heat.

    Science.gov (United States)

    Straub, Anthony P; Elimelech, Menachem

    2017-11-07

    Low-grade heat energy from sources below 100 °C is available in massive quantities around the world, but cannot be converted to electricity effectively using existing technologies due to variability in the heat output and the small temperature difference between the source and environment. The recently developed thermo-osmotic energy conversion (TOEC) process has the potential to harvest energy from low-grade heat sources by using a temperature difference to create a pressurized liquid flux across a membrane, which can be converted to mechanical work via a turbine. In this study, we perform the first analysis of energy efficiency and the expected performance of the TOEC technology, focusing on systems utilizing hydrophobic porous vapor-gap membranes and water as a working fluid. We begin by developing a framework to analyze realistic mass and heat transport in the process, probing the impact of various membrane parameters and system operating conditions. Our analysis reveals that an optimized system can achieve heat-to-electricity energy conversion efficiencies up to 4.1% (34% of the Carnot efficiency) with hot and cold working temperatures of 60 and 20 °C, respectively, and an operating pressure of 5 MPa (50 bar). Lower energy efficiencies, however, will occur in systems operating with high power densities (>5 W/m 2 ) and with finite-sized heat exchangers. We identify that the most important membrane properties for achieving high performance are an asymmetric pore structure, high pressure resistance, a high porosity, and a thickness of 30 to 100 μm. We also quantify the benefits in performance from utilizing deaerated water streams, strong hydrodynamic mixing in the membrane module, and high heat exchanger efficiencies. Overall, our study demonstrates the promise of full-scale TOEC systems to extract energy from low-grade heat and identifies key factors for performance optimization moving forward.

  12. Performance systems and social capital

    DEFF Research Database (Denmark)

    Rasmussen, Grane Mikael Gregaard; Edwards, Kasper

    2014-01-01

    from a study on implementation of a performance system in Danish construction. The results show causalities between implementing the performance system and the emergence of social capital in construction projects. Results indicate that performance systems and social capital is not mutually exclusive......Performance systems and social capital are considered mutually exclusive. Contemporary studies show that social capital is essential in generating performance improvement. This raises an important question: “How do performance systems and social capital correspond?” This study draws on findings...

  13. Debugging the Conversion Process: Lessons from an Administrative Information System Conversion.

    Science.gov (United States)

    Hibbler, Fritz; Mitchell, Linda

    1995-01-01

    The process of reengineering the administrative information system at the University of Idaho required careful planning, development of a set of philosophies, and several strategies for ensuring success. The latter included a humorous symbol (a jitter bug) to express concern, improved institutional communications, and a focus on logistical issues.…

  14. Initial Test Results of a Dual Closed-Brayton-Cycle Power Conversion System

    Science.gov (United States)

    Johnson, Paul K.; Mason, Lee S.

    2007-01-01

    The dual Brayton power conversion system constructed for NASA Glenn Research Center (GRC) was acceptance tested April 2007 at Barber-Nichols, Inc., Arvada, Colorado. This uniquely configured conversion system is built around two modified commercial Capstone C30 microturbines and employs two closed-Brayton-cycle (CBC) converters sharing a common gas inventory and common heat source. Because both CBCs share the gas inventory, behavior of one CBC has an impact on the performance of the other CBC, especially when one CBC is standby or running at a different shaft speed. Testing performed to date includes the CBCs operating at equal and unequal shaft speeds. A test was also conducted where one CBC was capped off and the other was operated as a single CBC converter. The dual Brayton configuration generated 10.6 kWe at 75 krpm and a turbine inlet temperature of 817 K. Single Brayton operation generated 14.8 kWe at 90 krpm and a turbine inlet temperature of 925 K.

  15. Vitrification Facility integrated system performance testing report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.

    1997-05-01

    This report provides a summary of component and system performance testing associated with the Vitrification Facility (VF) following construction turnover. The VF at the West Valley Demonstration Project (WVDP) was designed to convert stored radioactive waste into a stable glass form for eventual disposal in a federal repository. Following an initial Functional and Checkout Testing of Systems (FACTS) Program and subsequent conversion of test stand equipment into the final VF, a testing program was executed to demonstrate successful performance of the components, subsystems, and systems that make up the vitrification process. Systems were started up and brought on line as construction was completed, until integrated system operation could be demonstrated to produce borosilicate glass using nonradioactive waste simulant. Integrated system testing and operation culminated with a successful Operational Readiness Review (ORR) and Department of Energy (DOE) approval to initiate vitrification of high-level waste (HLW) on June 19, 1996. Performance and integrated operational test runs conducted during the test program provided a means for critical examination, observation, and evaluation of the vitrification system. Test data taken for each Test Instruction Procedure (TIP) was used to evaluate component performance against system design and acceptance criteria, while test observations were used to correct, modify, or improve system operation. This process was critical in establishing operating conditions for the entire vitrification process.

  16. 5 CFR 9901.231 - Conversion of positions and employees to NSPS classification system.

    Science.gov (United States)

    2010-01-01

    ... in a pay band based on the level of work of the employee's position in the formerly applicable pay... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of positions and employees to... Provisions § 9901.231 Conversion of positions and employees to NSPS classification system. (a) Introduction...

  17. Performance tuning for high performance computing systems

    OpenAIRE

    Pahuja, Himanshu

    2017-01-01

    A Distributed System is composed by integration between loosely coupled software components and the underlying hardware resources that can be distributed over the standard internet framework. High Performance Computing used to involve utilization of supercomputers which could churn a lot of computing power to process massively complex computational tasks, but is now evolving across distributed systems, thereby having the ability to utilize geographically distributed computing resources. We...

  18. Conversion between EIT and Fano spectra in a microring-Bragg grating coupled-resonator system

    Science.gov (United States)

    Zhang, Zecen; Ng, Geok Ing; Hu, Ting; Qiu, Haodong; Guo, Xin; Wang, Wanjun; Rouifed, Mohamed Saïd; Liu, Chongyang; Wang, Hong

    2017-08-01

    A conversion between the electromagnetically induced transparency (EIT) transmission and Fano transmission is theoretically and experimentally demonstrated in an all-pass microring-Bragg grating (APMR-BG) coupled-resonator system. In this work, the coupling between the two resonators (the microring resonator and the Fabry-Perot resonator formed by two Bragg gratings) gives rise to the EIT and Fano transmissions. The resonant status strongly depends on the round-trip attenuation of the microring and the coupling strength. By tuning the coupling strength, the EIT and Fano transmissions can be controlled and converted. The device performance has been theoretically calculated and analyzed with a specially developed numerical model based on the transfer matrix method. The APMR-BG coupled-resonator systems with different gap widths were designed, fabricated, and characterized on a silicon-on-insulator (SOI) platform. The conversion of resonance was experimentally observed and verified. In addition, this on-chip system has the advantage of a small footprint, and the fabrication process is compatible with the planar waveguide fabrication process.

  19. Power conversion distribution system using a resonant high-frequency AC link

    Science.gov (United States)

    Sood, P. K.; Lipo, T. A.

    1986-01-01

    Static power conversion systems based on a resonant high frequency (HF) link offers a significant reduction in the size and weight of the equipment over that achieved with conventional approaches, especially when multiple sources and loads are to be integrated. A faster system response and absence of audible noise are the other principal characteristics of such systems. A conversion configuration based on a HF link which is suitable for applications requiring distributed power is proposed.

  20. The principles of electronic and electromechanic power conversion a systems approach

    CERN Document Server

    Ferreira, Braham

    2013-01-01

    Teaching the principles of power electronics and electromechanical power conversion through a unique top down systems approach, The Principles of Electromechanical Power Conversion takes the role and system context of power conversion functions as the starting point. Following this approach, the text defines the building blocks of the system and describes the theory of how they exchange power with each other. The authors introduce a modern, simple approach to machines, which makes the principles of field oriented control and space vector theory approachable to undergraduate students as well as

  1. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels: Conversion Pathway: Biological Conversion of Sugars to Hydrocarbons The 2017 Design Case

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J Bonner; Garold L. Gresham; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2013-09-01

    The U.S. Department of Energy promotes the production of a range of liquid fuels and fuel blendstocks from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass collection, conversion, and sustainability. As part of its involvement in this program, the Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL conducted a campaign to quantify the economics and sustainability of moving biomass from standing in the field or stand to the throat of the biomass conversion process. The goal of this program was to establish the current costs based on conventional equipment and processes, design improvements to the current system, and to mark annual improvements based on higher efficiencies or better designs. The 2012 programmatic target was to demonstrate a delivered biomass logistics cost of $35/dry ton. This goal was successfully achieved in 2012 by implementing field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model. Looking forward to 2017, the programmatic target is to supply biomass to the conversion facilities at a total cost of $80/dry ton and on specification with in-feed requirements. The goal of the 2017 Design Case is to enable expansion of biofuels production beyond highly productive resource areas by breaking the reliance of cost-competitive biofuel production on a single, abundant, low-cost feedstock. If this goal is not achieved, biofuel plants are destined to be small and/or clustered in select regions of the country that have a lock on low-cost feedstock. To put the 2017 cost target into perspective of past accomplishments of the cellulosic ethanol pathway, the $80 target encompasses total delivered feedstock cost, including both grower payment and logistics costs, while meeting all

  2. Engrossed in conversation: the impact of cell phones on simulated driving performance.

    Science.gov (United States)

    Beede, Kristen E; Kass, Steven J

    2006-03-01

    The current study examined the effects of cognitively distracting tasks on various measures of driving performance. Thirty-six college students with a median of 6 years of driving experience completed a driving history questionnaire and four simulated driving scenarios. The distraction tasks consisted of responding to a signal detection task and engaging in a simulated cell phone conversation. Driving performance was measured in terms of four categories of behavior: traffic violations (e.g., speeding, running stop signs), driving maintenance (e.g., standard deviation of lane position), attention lapses (e.g., stops at green lights, failure to visually scan for intersection traffic), and response time (e.g., time to step on brake in response to a pop-up event). Performance was significantly impacted in all four categories when drivers were concurrently talking on a hands-free phone. Performance on the signal detection task was poor and not significantly impacted by the phone task, suggesting that considerably less attention was paid to detecting these peripheral signals. However, the signal detection task did interact with the phone task on measures of average speed, speed variability, attention lapses, and reaction time. The findings lend further empirical support of the dangers of drivers being distracted by cell phone conversations.

  3. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  4. An Integrated System for the Treatment of Coal Conversion Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Henry Y. Wang; Keeran R. Srinivasan

    1999-02-25

    Treatment of mixed waste from coal conversion wastewaters involves the degradation of toxic organics and the removal of heavy metals. An integrated and cost-effective treatment scheme that can implement such a process is considered essential to promote continued development and growth of coal conversion processes without any deleterious effects on our ecosystem. We have recently developed a pH-dependent, reversible heavy metal adsorption/desorption process which promises to be a cost-effective alternative to the treatment and disposal options currently in place for these inorganic contaminants. Our work shows that: (1) Polydisperse, industrial-grade surfactants can be used in the development of novel, surfactant-coated smectitic clays containing up to 50% by weight of adsorbed surfactant, (2) Reversible adsorption and resorption of cationic (CU(II) and Cd(II)) and anionic (Cr(VI)) heavy metals from their respective aqueous solutions onto these surfactant-modified smectites can be effected using pH of the medium as a switch, and (3) These surfactant-modified smectites can be repeatedly used (up to 5 times) with only a minimal loss in their adsorption potency and with very little leaching of the adsorbed surfactants.

  5. Nonlinear Predictive Control of Wind Energy Conversion System Using Dfig with Aerodynamic Torque Observer

    Science.gov (United States)

    Kamel, Ouari; Mohand, Ouhrouche; Toufik, Rekioua; Taib, Nabil

    2015-01-01

    In order to improvement of the performances for wind energy conversions systems (WECS), an advanced control techniques must be used. In this paper, as an alternative to conventional PI-type control methods, a nonlinear predictive control (NPC) approach is developed for DFIG-based wind turbine. To enhance the robustness of the controller, a disturbance observer is designed to estimate the aerodynamic torque which is considered as an unknown perturbation. An explicitly analytical form of the optimal predictive controller is given consequently on-line optimization is not necessary The DFIG is fed through the rotor windings by a back-to-back converter controlled by Pulse Width Modulation (PWM), where the stator winding is directly connected to the grid. The presented simulation results show a good performance in trajectory tracking of the proposed strategy and rejection of disturbances is successfully achieved.

  6. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance.

    Science.gov (United States)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy approach points to structural organization at the level of the interaction-such as complementary patterns straddling speech turns and interlocutors. We develop a general, quantitative method to assess lexical, prosodic, and speech/pause patterns related to the two approaches and their impact on collective performance in a corpus of task-oriented conversations. The results show statistical presence of patterns relevant for both approaches. However, synergetic aspects of dialog provide the best statistical predictors of collective performance and adding aspects of the alignment approach does not improve the model. This suggests that structural organization at the level of the interaction plays a crucial role in task-oriented conversations, possibly constraining and integrating processes related to alignment. Copyright © 2015 Cognitive Science Society, Inc.

  7. Development of Electro-Microbial Carbon Capture and Conversion Systems

    KAUST Repository

    Al Rowaihi, Israa S.

    2017-05-01

    Carbon dioxide is a viable resource, if used as a raw material for bioprocessing. It is abundant and can be collected as a byproduct from industrial processes. Globally, photosynthetic organisms utilize around 6’000 TW (terawatt) of solar energy to fix ca. 800 Gt (gigaton) of CO2 in the planets largest carbon-capture process. Photosynthesis combines light harvesting, charge separation, catalytic water splitting, generation of reduction equivalents (NADH), energy (ATP) production and CO2 fixation into one highly interconnected and regulated process. While this simplicity makes photosynthetic production of commodity interesting, yet photosynthesis suffers from low energy efficiency, which translates in an extensive footprint for solar biofuels production conditions that store < 2% of solar energy. Electron transfer processes form the core of photosynthesis. At moderate light intensity, the electron transport chains reach maximum transfer rates and only work when photons are at appropriate wavelengths, rendering the process susceptible to oxidative damage, which leads to photo-inhibition and loss of efficiency. Based on our fundamental analysis of the specialized tasks in photosynthesis, we aimed to optimize the efficiency of these processes separately, then combine them in an artificial photosynthesis (AP) process that surpasses the low efficiency of natural photosynthesis. Therefore, by combining photovoltaic light harvesting with electrolytic water splitting or CO2 reduction in combination with microbiological conversion of electrochemical products to higher valuable compounds, we developed an electro-microbial carbon capture and conversion setups that capture CO2 into the targeted bioplastic; polyhydroxybutyrate (PHB). Based on the type of the electrochemical products, and the microorganism that either (i) convert products formed by electrochemical reduction of CO2, e.g. formate (using inorganic cathodes), or (ii) use electrochemically produced H2 to reduce CO2

  8. Green farming systems for the Southeast USA using manure-to-energy conversion platforms

    Science.gov (United States)

    Livestock operations in the Southeastern USA are faced with implementing holistic solutions to address effective manure treatment through efficient energy management and safeguarding of supporting natural resources. By integrating waste-to-energy conversion platforms, future green farming systems ca...

  9. In-grid solar-to-electrical energy conversion system modeling and testing

    OpenAIRE

    Čorba Zoltan J.; Katić Vladimir A.; Dumnić Boris P.; Milićević Dragan M.

    2012-01-01

    In this study, a simulation model of in-grid solar-to-electrical energy conversion system is presented. In this case, the in-grid solar-to-electrical energy conversion system is small photovoltaic power plant, which was constructed by the Center for Renewable Energy and Power Quality from Faculty of Technical Sciences (FTS). Equivalent circuit diagram of photovoltaic cell is described which was used to develop the simulation model of modules. Possible types...

  10. Total System Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Soo; Kang, Chul Hyung; Lee, Youn Myoung; Han, Ji Woong; Choi, Jong Won; Hahn, Pil Soo; Park, Jeong Hwa; Jeong, Mi Seon

    2007-06-15

    Based on the KAERI FEP list developed through the previous studies, the KAERI FEP Encyclopedia has been developed. Current version is 1.0 which includes all relevant FEPs to compose of two references and all alternative scenarios. Many interaction FEPs between scenario defining FEP(SDF) are created throughout the study. FEPs are classified into many Integrated FEP(IFEP) which eventually become the elements of the RES matrix. The FEAS program one of the component of the KAERI's CYPRUS information system is added to develop the FEP, RES, AC, AMF and finally scenarios. It assists to create transparent way to deal with assessment from the stage of the planning of the R and D to the final stage of the external audit and regulatory body review. Even though MASCOT-K and compartment analysis codes such as AMBER, GoldSim and Ecolego are excellent for TSPA they by in heritage possess a certain limitation especially to identify a proper migration cross sectional area when a relatively big component intersects with a tiny one such as a fracture. It is truly 3D phenomena in nature. MDPSA code is developed which is expected to overcome limitations in compartment models while successfully deals with natural disruptive events. The R and D target for the TSPA is to develop the sufficient scenarios and their variation cases to understand the safety of KRS in every possible aspect. For this, reference scenarios, alternative scenarios covering engineered barrier failure and natural events are developed and assessed respectively for around 100 cases. The stylized template to assess the Korean reference biosphere is developed using the AMBER. Three critical groups, agricultural, freshwater and marine water fishing groups are identified to assess the DCF following the guidelines of ICRP. Based on the QA principles of T2R3, the web based QA system is developed using the procedures in the USNRC 10CFR50 Appendix B. The QA system is combined with the PAID and FEAS to create the

  11. Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, G.L.

    2005-10-03

    This report documents the work performed during the first phase of the National Aeronautics and Space Administration (NASA), National Research Announcement (NRA) Technology Development Program for an Advanced Potassium Rankine Power Conversion System Compatible with Several Space Reactor Designs. The document includes an optimization of both 100-kW{sub e} and 250-kW{sub e} (at the propulsion unit) Rankine cycle power conversion systems. In order to perform the mass optimization of these systems, several parametric evaluations of different design options were investigated. These options included feed and reheat, vapor superheat levels entering the turbine, three different material types, and multiple heat rejection system designs. The overall masses of these Nb-1%Zr systems are approximately 3100 kg and 6300 kg for the 100- kW{sub e} and 250-kW{sub e} systems, respectively, each with two totally redundant power conversion units, including the mass of the single reactor and shield. Initial conceptual designs for each of the components were developed in order to estimate component masses. In addition, an overall system concept was presented that was designed to fit within the launch envelope of a heavy lift vehicle. A technology development plan is presented in the report that describes the major efforts that are required to reach a technology readiness level of 6. A 10-year development plan was proposed.

  12. Contractor Performance Assessment Reporting System

    Data.gov (United States)

    US Agency for International Development — CPARS is a web-based system used to input data on contractor performance. Reports from the system are used as an aid in awarding contracts to contractors that...

  13. Study on Surface Damage and Performance Degradation of Impregnated Catalyst in Dielectric Barrier Discharge Plasma-Assisted Methane Conversion Processes.

    Science.gov (United States)

    Lee, Chung Jun; Lee, Dae Hoon; Kim, Taegyu

    2018-02-01

    This paper describes the performance degradation of impregnated catalyst in the dielectric barrier discharge (DBD) plasma-assisted methane conversion process. Mn and Ni mixed copper-zinc catalysts, and bare γ-Al2O3 support were exposed to the DBD plasma generated at 1 kHz and 9 kV under CH4 direct conversion for 4 hours. The performance degradation due to the surface damage of the catalyst by the plasma was investigated by SEM analysis.

  14. Performance and Fabrication Status of TREAT LEU Conversion Conceptual Design Concepts

    Energy Technology Data Exchange (ETDEWEB)

    IJ van Rooyen; SR Morrell; AE Wright; E. P Luther; K Jamison; AL Crawford; HT III Hartman

    2014-10-01

    Resumption of transient testing at the TREAT facility was approved in February 2014 to meet U.S. Department of Energy (DOE) objectives. The National Nuclear Security Administration’s Global Threat Reduction Initiative Convert Program is evaluating conversion of TREAT from its existing highly enriched uranium (HEU) core to a new core containing low enriched uranium (LEU). This paper describes briefly the initial pre-conceptual designs screening decisions with more detailed discussions on current feasibility, qualification and fabrication approaches. Feasible fabrication will be shown for a LEU fuel element assembly that can meet TREAT design, performance, and safety requirements. The statement of feasibility recognizes that further development, analysis, and testing must be completed to refine the conceptual design. Engineering challenges such as cladding oxidation, high temperature material properties, and fuel block fabrication along with neutronics performance, will be highlighted. Preliminary engineering and supply chain evaluation provided confidence that the conceptual designs can be achieved.

  15. Final Research Performance Progress Report: Geothermal Resource Development with Zero Mass Withdrawal, Engineered Convection, and Wellbore Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard [Louisiana State Univ., Baton Rouge, LA (United States); Tyagi, Mayank [Louisiana State Univ., Baton Rouge, LA (United States); Radonjic, Mileva [Louisiana State Univ., Baton Rouge, LA (United States); Dahi, Arash [Louisiana State Univ., Baton Rouge, LA (United States); Wang, Fahui [Louisiana State Univ., Baton Rouge, LA (United States); John, Chacko [Louisiana State Univ., Baton Rouge, LA (United States); Kaiser, Mark [Louisiana State Univ., Baton Rouge, LA (United States); Snyder, Brian [Louisiana State Univ., Baton Rouge, LA (United States); Sears, Stephen [Louisiana State Univ., Baton Rouge, LA (United States)

    2017-07-07

    This project is intended to demonstrate the technical and economic feasibility, and environmental and social attractiveness of a novel method of heat extraction from geothermal reservoirs. The emphasis is on assessing the potential for a heat extraction method that couples forced and free convection to maximize extraction efficiency. The heat extraction concept is enhanced by considering wellbore energy conversion, which may include only a boiler for a working fluid, or perhaps a complete boiler, turbine, and condenser cycle within the wellbore. The feasibility of this system depends on maintaining mechanical and hydraulic integrity of the wellbore, so the material properties of the casing-cement system are examined both experimentally and with well design calculations. The attractiveness depends on mitigation of seismic and subsidence risks, economic performance, environmental impact, and social impact – all of which are assessed as components of this study.

  16. Ocean Thermal Energy Conversion power system development. Phase I: preliminary design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    Westinghouse has completed the Preliminary Design Phase for the Power System Development of the Ocean Thermal Energy Conversion (OTEC) Demonstration Plant project. This study included the development of a preliminary design for a Modular Application scaled power system (10MWe) and Heat Exchanger Test Articles, both based on the concept developed in the Conceptual Design Phase. The results of this study were used to improve the baseline design of the 50MWe module for the Commercial Size Power System, which was recommended for the demonstration plant by the conceptual design study. The 50MWe module was selected since it has the lowest cost, and since its size convincingly demonstrates that future economically viable commercial plants, having reliable operation with credible anticipated costs, are possible. Additional optimization studies on the size of the power system plus hull continue to identify 50MWe as the preferred minimum cost configuration. This study was limited to a closed cycle ammonia power system module, using a seawater temperature difference of 40/sup 0/F, and a surface platform/ship reference hull. This volume describes system operation, a complete test program to verify mechanical reliability and thermal performance, fabrication and installation operations, and a cost analysis. (WHK)

  17. Enhanced performance in electrochemical energy storage and conversion via carbon-integrated nanostructures

    Science.gov (United States)

    Sheehan, Margaret K.

    Electrochemical energy storage and conversion applications benefit from the integration of nanostructures into the devices, as they have many more active sites per gram which enables excellent mass utilization of the active species. By controlling the surface of fuel cell catalysts, higher activity and efficiency can be achieved as compared to the bulk counterpart, with multiple catalyst facets of varying activity and efficiency. Nanostructured electrochemical capacitors have enhanced electrolyte diffusion over the surface of the electrode, facilitating high rate capability. Nanostructured materials for energy storage and conversion devices, such as electrochemical capacitors and proton exchange membrane fuel cells, can perform even better with the incorporation of carbon. High surface area carbon can enhance the activity of electrochemical capacitors by improving the conductivity of the electrode and/or enhancing the double layer capacitance. Carbon supports for fuel cell catalysts enable proper dispersion of active material without sacrificing conductivity. The work reported in this thesis is aimed toward improving the performance of electrochemical energy storage and conversion devices through novel incorporation of carbon. Carbon was first used to enhance the performance of electrocatalysts. By wrapping fuel cell catalysts in a porous carbon shell, the activity was increased over its bare and CNT-supported counterparts. The carbon shell synthetic method reported here is a good route to the production of a conductive host for Pd electrocatalysts with good contact and in one step with the formation of the Pd nanoparticles. Carbon was also used to enhance the performance of pseudocapacitors, first by incorporating it into the precursor spray solution in the generation of mesoporous metal oxides and then as a metal-organic framework-derived carbon host with dispersed electrochemically active metal oxides. A carbon network was generated from the pyrolysis of pore

  18. Technical and economic performance of integrated bioenergy systems

    Energy Technology Data Exchange (ETDEWEB)

    Toft, A.J.; Bridgwater, A.V. [Aston Univ. (United Kingdom). Energy Research Group; Mitchell, C.P.; Watters, M.P. [Aberdeen Univ. (United Kingdom). Wood Supply Research Group; Stevens, D.J. [Cascade Research, Inc. (United States)

    1996-12-31

    A comprehensive study of biomass production, conversion and utilisation systems has been carried out to examine complete bioenergy systems from biomass in the forest to electricity delivered to the grid. Spreadsheet models have been derived for all of the key steps in an integrated process and these have been compiled into an overall BioEnergy Assessment Model (BEAM). The model has also been used to investigate both the performance of different technologies and the effect of different configurations of the same basic system by manipulating the interfaces between feed production, feed conversion and electricity generation. Some of the results of these analyses are presented here. (orig.)

  19. Characterization of solid-waste conversion and cogeneration systems

    Energy Technology Data Exchange (ETDEWEB)

    Ritschard, R.L.; Haven, K.F.; Henriquez, M.; Kay, J.; Walzer, W.

    1978-08-15

    Recovery of municipal solid wastes (MSW) can reduce the mass of landfilled wastes by as much as 95% and can tap a vast new energy resource. The yearly collection of MSW is estimated to be 125 million tons nationwide. Three basic technologies for recovering energy from MSW are considered, namely: direct combustion using a waterwall incinerator in which heat from burning refuse is converted to steam by circulating water in steel tubes jacketing the interior of the incinerator; manufacture of a relatively uniform shredded, pulverized, or pelleted refuse-derived fuel for supplemental firing in a utility boiler; and pyrolysis or destructive distillation of MSW to extract a low-Btu fuel gas. While resource and energy recovery systems can be installed independently, the processes described here include both energy and resource-recovery systems as well as necessary pollution-control equipment for gaseous emissions. Three end-use applications of cogeneration systems are characterized, including: fluidized-bed cogeneration systems for use in the pulp and paper industry; diesel system using the digested sewage gas of a sewage treatment plant for electricity generation as well as heating and pumping; and an enhanced oil recovery system. Comparisons are made of system inputs per 10/sup 12/ Btu steam output for Landguard pyrolysis, Garrett flash pyrolysis, Union Carbide Purox process, direct combustion, refuse-derived fuels, fluidized-bed cogeneration, diesel cogeneration, and enhanced oil recovery (cogeneration). The RFD system is by far the cheapest to build and is also the most efficient in terms of energy recovery per ton of MSW. The fluidized-bed system has the highest overall system efficiency. However, the PUROX system uses the least ancillary energy and is the only system not requiring an input water flow. Thus the RFD is the most favorable for capital inputs and the PUROX is the most favorable for operational inputs.

  20. Preservice Mathematics Teachers' Solutions to Problems: Conversions within the Metric System

    OpenAIRE

    Jean E. Hallagan

    2013-01-01

    This paper reports on the results of a preliminary investigation to determine if preservice mathematics teachers solve conversion problems within the metric system in multiple ways. Here, four metric conversion problems of escalating difficulty were administered within a mathematics methods course at a comprehensive state university in the Northeastern United States. Results show that preservice teachers solved the problems in the same way that they were taught in high school, and that in hig...

  1. Ocean Thermal Energy Conversion power system development. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    This report covers the conceptual and preliminary design of closed-cycle, ammonia, ocean thermal energy conversion power plants by Westinghouse Electric Corporation. Preliminary designs for evaporator and condenser test articles (0.13 MWe size) and a 10 MWe modular experiment power system are described. Conceptual designs for 50 MWe power systems, and 100 MWe power plants are also descirbed. Design and cost algorithms were developed, and an optimized power system design at the 50 MWe size was completed. This design was modeled very closely in the test articles and in the 10 MWe Modular Application. Major component and auxiliary system design, materials, biofouling, control response, availability, safety and cost aspects are developed with the greatest emphasis on the 10 MWe Modular Application Power System. It is concluded that all power plant subsystems are state-of-practice and require design verification only, rather than continued research. A complete test program, which verifies the mechanical reliability as well as thermal performance, is recommended and described.

  2. Double barrier system for an in situ conversion process

    Energy Technology Data Exchange (ETDEWEB)

    McKinzie, Billy John [Houston, TX; Vinegar, Harold J [Bellaire, TX; Cowan, Kenneth Michael [Sugar land, TX; Deeg, Wolfgang Friedrich Johann [Houston, TX; Wong, Sau-Wai [Rijswijk, NL

    2009-05-05

    A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed around at least a portion of the first barrier. A separation space exists between the first barrier and the second barrier.

  3. Rectenna System Design. [energy conversion solar power satellites

    Science.gov (United States)

    Woodcock, G. R.; Andryczyk, R. W.

    1980-01-01

    The fundamental processes involved in the operation of the rectenna system designed for the solar power satellite system are described. The basic design choices are presented based on the desired microwave rf field concentration prior to rectification and based on the ground clearance requirements for the rectenna structure. A nonconcentrating inclined planar panel with a 2 meter minimum clearance configuration is selected as a representative of the typical rectenna.

  4. Photoelectrochemical based direct conversion systems for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Khaselev, O.; Bansal, A.; Kocha, S.; Turner, J.A. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    With an eye towards developing a photoelectrochemical system for hydrogen production using sunlight as the only energy input, two types of systems were studied, both involving multijunction devices. One set of cells consisted of a-Si triple junctions and the other a GaInP{sub 2}/GaAs tandem cell combination. Additional investigations were carried out on semiconductor surface modifications to move semiconductor band edges to more favorable energetic positions.

  5. 5 CFR 9901.371 - Conversion into NSPS pay system.

    Science.gov (United States)

    2010-01-01

    ... employee's performance warrants the pay increase, and the promotion would have otherwise occurred during... must be reconstructed to reflect any increase that would have otherwise occurred if the employee had... increase adjustment under paragraph (j) of this section, if the employee's base salary exceeds the rate...

  6. Rice Pricing during Organic Conversion of the Honghe Hani Rice Terrace System in China

    Directory of Open Access Journals (Sweden)

    Moucheng Liu

    2018-01-01

    Full Text Available In 2002, the United Nations Food and Agriculture Organization initiated the Globally Important Agriculture Heritage Systems conservation program. Agricultural organic certification, based on traditional environmentally friendly technology, increases farmer income and encourages traditional agricultural heritage. However, during the organic conversion period, farmer income cannot be guaranteed; this period is also a bottleneck for heritage conservation via organic certification. Based on experiences at the Honghe Hani rice terrace system in Yunnan, China, we calculated and compared inputs and outputs of traditional and modern systems during organic conversion and developed a calculation method for determining opportunity costs of agricultural production. We found that the stability of farmer income during conversion can be guaranteed by setting the protective purchasing price at 6.93 CNY/kg, thereby achieving the goal of dynamic conservation of agricultural heritage systems.

  7. Limits to solar power conversion efficiency with applications to quantum and thermal systems

    Science.gov (United States)

    Byvik, C. E.; Buoncristiani, A. M.; Smith, B. T.

    1983-01-01

    An analytical framework is presented that permits examination of the limit to the efficiency of various solar power conversion devices. Thermodynamic limits to solar power efficiency are determined for both quantum and thermal systems, and the results are applied to a variety of devices currently considered for use in space systems. The power conversion efficiency for single-threshold energy quantum systems receiving unconcentrated air mass zero solar radiation is limited to 31 percent. This limit applies to photovoltaic cells directly converting solar radiation, or indirectly, as in the case of a thermophotovoltaic system. Photoelectrochemical cells rely on an additional chemical reaction at the semiconductor-electrolyte interface, which introduces additional second-law demands and a reduction of the solar conversion efficiency. Photochemical systems exhibit even lower possible efficiencies because of their relatively narrow absorption bands. Solar-powered thermal engines in contact with an ambient reservoir at 300 K and operating at maximum power have a peak conversion efficiency of 64 percent, and this occurs for a thermal reservoir at a temperature of 2900 K. The power conversion efficiency of a solar-powered liquid metal magnetohydrodydnamic generator, a solar-powered steam turbine electric generator, and an alkali metal thermoelectric converter is discussed.

  8. Harvesting and Conversation in a Predator-Prey System

    NARCIS (Netherlands)

    Hoekstra, Jeljer; Bergh, van den Jeroen C.J.M.

    2001-01-01

    Optimal harvesting of prey in a predator-prey ecosystem is studiedunder the condition that the existence of the predator has value. Predators (birds) and humans (fishers) compete for prey (shellfish). The behavior of the system is studied and conditions for optimal control are deduced. Various

  9. Solid waste information and tracking system client-server conversion project management plan

    Energy Technology Data Exchange (ETDEWEB)

    May, D.L.

    1998-04-15

    This Project Management Plan is the lead planning document governing the proposed conversion of the Solid Waste Information and Tracking System (SWITS) to a client-server architecture. This plan presents the content specified by American National Standards Institute (ANSI)/Institute of Electrical and Electronics Engineers (IEEE) standards for software development, with additional information categories deemed to be necessary to describe the conversion fully. This plan is a living document that will be reviewed on a periodic basis and revised when necessary to reflect changes in baseline design concepts and schedules. This PMP describes the background, planning and management of the SWITS conversion. It does not constitute a statement of product requirements. Requirements and specification documentation needed for the SWITS conversion will be released as supporting documents.

  10. A Power Supply System with ZVS and Current-Doubler Features for Hybrid Renewable Energy Conversion

    Directory of Open Access Journals (Sweden)

    Jye-Chau Su

    2013-09-01

    Full Text Available In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1 PV-arrays and wind-energy sources can alternatively deliver power to the load during climate or season alteration; (2 maximum power point tracking (MPPT can be accomplished for both different kinds of renewable-energy sources; (3 ZVS and synchronous rectification techniques for the active switches of the forward converter are embedded so as to reduce switching and conducting losses; and (4 electricity isolation is naturally obtained. To achieve an optimally dynamic response and to increase control flexibility, a digital signal processor (DSP is investigated and presented to implement MPPT algorithm and power regulating scheme. Finally, a 240 W prototype power supply system with ZVS and current-doubler features to deal with PV power and wind energy is built and implemented. Experimental results are presented to verify the performance and the feasibility of the proposed power supply system.

  11. Wavelength conversion of optical 64QAM through FWM in HNLF and its performance optimization by constellation monitoring.

    Science.gov (United States)

    Lu, Guo-Wei; Sakamoto, Takahide; Kawanishi, Tetsuya

    2014-01-13

    All-optical wavelength conversion (AOWC) plays an important role in the future transparent optical networks, in order to enhance the re-configurability and non-blocking capacity. On the other hand, high-order quadrature amplitude modulations (QAMs) have been extensively studied for achieving the high-speed and high-spectral-efficiency optical transmission. Since high-order QAMs are more sensitive to phase and amplitude noise, to implement an AOWC sub-system suitable for high-order QAM signals with minimized power penalty, it is important to optimize the operation conditions in order to avoid extra nonlinear distortions co-existed in the AOWC process. Our experimental results show that, constellation monitoring provides a more intuitive and accurate approach to monitor the converted high-order QAM signals, especially in presence of nonlinear phase noise such as self-phase modulation (SPM). We experimentally demonstrate an AOWC of 64QAM signal through four-wave mixing (FWM) in highly-nonlinear (HNLF). The performance of the AOWC is optimized through the constellation monitoring of the converted signal, achieving a negligible power penalty (<0.3 dB at BER of 10(-3)) for 60-Gbps 64QAM after conversion.

  12. Expanding Learning and Social Interaction through Intelligent Systems Design: Implementing a Reputation and Recommender System for the Claremont Conversation Online

    Science.gov (United States)

    Thoms, Brian

    2009-01-01

    In this dissertation I examine the design, construction and implementation of an online blog ratings and user recommender system for the Claremont Conversation Online (CCO). In line with constructivist learning models and practical information systems (IS) design, I implemented a blog ratings system (a system that can be extended to allow for…

  13. Energy harvesting solar, wind, and ocean energy conversion systems

    CERN Document Server

    Khaligh, Alireza

    2009-01-01

    Also called energy scavenging, energy harvesting captures, stores, and uses ""clean"" energy sources by employing interfaces, storage devices, and other units. Unlike conventional electric power generation systems, renewable energy harvesting does not use fossil fuels and the generation units can be decentralized, thereby significantly reducing transmission and distribution losses. But advanced technical methods must be developed to increase the efficiency of devices in harvesting energy from environmentally friendly, ""green"" resources and converting them into electrical energy.Recognizing t

  14. Joint Performance and Planning System

    Data.gov (United States)

    US Agency for International Development — A joint State/USAID system hosted by State that integrates resource and performance information at the program level and enables more flexible and frequent entry of...

  15. Topological Frequency Conversion in Strongly Driven Quantum Systems

    Directory of Open Access Journals (Sweden)

    Ivar Martin

    2017-10-01

    Full Text Available When a physical system is subjected to a strong external multifrequency drive, its dynamics can be conveniently represented in the multidimensional Floquet lattice. The number of Floquet lattice dimensions equals the number of irrationally-related drive frequencies, and the evolution occurs in response to a built-in effective “electric” field, whose components are proportional to the corresponding drive frequencies. The mapping allows us to engineer and study temporal analogs of many real-space phenomena. Here, we focus on the specific example of a two-level system under a two-frequency drive that induces topologically nontrivial band structure in the 2D Floquet space. The observable consequence of such a construction is the quantized pumping of energy between the sources with frequencies ω_{1} and ω_{2}. When the system is initialized into a Floquet band with the Chern number C, the pumping occurs at a rate P_{12}=-P_{21}=(C/2πℏω_{1}ω_{2}, an exact counterpart of the transverse current in a conventional topological insulator.

  16. Foreign Language Tutoring in Oral Conversations Using Spoken Dialog Systems

    Science.gov (United States)

    Lee, Sungjin; Noh, Hyungjong; Lee, Jonghoon; Lee, Kyusong; Lee, Gary Geunbae

    Although there have been enormous investments into English education all around the world, not many differences have been made to change the English instruction style. Considering the shortcomings for the current teaching-learning methodology, we have been investigating advanced computer-assisted language learning (CALL) systems. This paper aims at summarizing a set of POSTECH approaches including theories, technologies, systems, and field studies and providing relevant pointers. On top of the state-of-the-art technologies of spoken dialog system, a variety of adaptations have been applied to overcome some problems caused by numerous errors and variations naturally produced by non-native speakers. Furthermore, a number of methods have been developed for generating educational feedback that help learners develop to be proficient. Integrating these efforts resulted in intelligent educational robots — Mero and Engkey — and virtual 3D language learning games, Pomy. To verify the effects of our approaches on students' communicative abilities, we have conducted a field study at an elementary school in Korea. The results showed that our CALL approaches can be enjoyable and fruitful activities for students. Although the results of this study bring us a step closer to understanding computer-based education, more studies are needed to consolidate the findings.

  17. Modeling of the interplay between single-file diffusion and conversion reaction in mesoporous systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jing [Iowa State Univ., Ames, IA (United States)

    2013-01-11

    We analyze the spatiotemporal behavior of species concentrations in a diffusion-mediated conversion reaction which occurs at catalytic sites within linear pores of nanometer diameter. A strict single-file (no passing) constraint occurs in the diffusion within such narrow pores. Both transient and steady-state behavior is precisely characterized by kinetic Monte Carlo simulations of a spatially discrete lattice–gas model for this reaction–diffusion process considering various distributions of catalytic sites. Exact hierarchical master equations can also be developed for this model. Their analysis, after application of mean-field type truncation approximations, produces discrete reaction–diffusion type equations (mf-RDE). For slowly varying concentrations, we further develop coarse-grained continuum hydrodynamic reaction–diffusion equations (h-RDE) incorporating a precise treatment of single-file diffusion (SFD) in this multispecies system. Noting the shortcomings of mf-RDE and h-RDE, we then develop a generalized hydrodynamic (GH) formulation of appropriate gh-RDE which incorporates an unconventional description of chemical diffusion in mixed-component quasi-single-file systems based on a refined picture of tracer diffusion for finite-length pores. The gh-RDE elucidate the non-exponential decay of the steady-state reactant concentration into the pore and the non-mean-field scaling of the reactant penetration depth. Then an extended model of a catalytic conversion reaction within a functionalized nanoporous material is developed to assess the effect of varying the reaction product – pore interior interaction from attractive to repulsive. The analysis is performed utilizing the generalized hydrodynamic formulation of the reaction-diffusion equations which can reliably capture the complex interplay between reaction and restricted transport for both irreversible and reversible reactions.

  18. Modelling of a 5-kW wind energy conversion system with induction generator and comparison with experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Surgevil, T.; Akpinar, E. [Dokuz Surgevil University, Izmir (Turkey). Dept. of Electrical and Electronics Engineering

    2005-05-01

    A 5-kW wind energy conversion system (WECS) having induction generator is designed and implemented. The induction machine is connected to the power system through PWM inverter and PWM rectifier. Two digital PI controllers are used, one of them is for regulating dc link voltage and the other is for speed control of induction machine. The whole system is governed by a single fixed-point digital signal-processing unit (DSP). A detailed simulation program is prepared by using Matlab facilities in order to predict the performance of the controllers before implementation. (author)

  19. 5 CFR 9701.231 - Conversion of positions and employees to the DHS classification system.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of positions and employees to the DHS classification system. 9701.231 Section 9701.231 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMA...

  20. 5 CFR 9701.373 - Conversion of employees to the DHS pay system.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Conversion of employees to the DHS pay system. 9701.373 Section 9701.373 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT...

  1. Conversational Rate of a Non-Vocal Person with Motor Neurone Disease Using the 'TALK' System.

    Science.gov (United States)

    Todman, J.; Lewins, E.

    1996-01-01

    This study evaluated the use of TALK, a computer-based augmentative and alternative communication (AAC) system, in the social communications of a nonvocal woman with motor neurone disease. She was able to achieve an average conversational rate of 42 words per minute (wpm) using TALK, compared with 2 to 10 wpm with other AAC systems using…

  2. Characterization of solid waste conversion and cogeneration systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The primary objective of the TASE program is to determine the probable consequences to the environment and to public health and safety resulting from widespread implementation of major solar and renewable resource technologies. The specific principal Phase I objective is to determine the levels of residuals most likely to result throughout the complete energy cycle from the utilization of each of the solar and renewable resource technologies. Three basic technologies for recovering energy from M SW are considered in this study. These are: (1) direct combustion using a waterwall incinerator in which the heat from burning refuse is converted to steam by circulating water in steel tubes jacketing the interior of the incinerator; (2) manufacture of a relatively uniform shredded, pulverized or pelleted refuse-derived fuel (RDF) for supplemental firing in a utility boiler; and (3) pyrolysis or destructive distillation of MSW to extract a low-Btu fuel gas. While resource recovery and energy recovery systems can be installed independently, the processes described here include both energy and resource recovery systems as well as necessary pollution control equipment for gaseous emissions. To meet the Phase I objective, LBL staff have characterized the individual application associated with each general technology; calculated operational residuals generated by each application; determined the input capital requirements and, when possible, annual operating input requirements; and have identified the technical and institutional constraints for the widespread implementation of each application. A description is presented of the energy and material development cycle required for the implementation of each technology. The capital requirements are compiled and presented in a SEAS system format.

  3. HVDC transmission power conversion applications in power systems

    CERN Document Server

    Kim, Chan-Ki; Jang, Gil-Soo; Lim, Seong-Joo; Lee, Seok-Jin

    2009-01-01

    HVDC is a critical solution to several major problems encountered when trying to maintain systemic links and quality in large-scale renewable energy environments. HDVC can resolve a number of issues, including voltage stability of AC power networks, reducing fault current, and optimal management of electric power, ensuring the technology will play an increasingly important role in the electric power industry. To address the pressing need for an up-to-date and comprehensive treatment of the subject, Kim, Sood, Jang, Lim and Lee have collaborated to produce this key text and reference.  Combin

  4. Application of Circuit Model for Photovoltaic Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Natarajan Pandiarajan

    2012-01-01

    Full Text Available Circuit model of photovoltaic (PV module is presented in this paper that can be used as a common platform by material scientists and power electronic circuit designers to develop better PV power plant. Detailed modeling procedure for the circuit model with numerical dimensions is presented using power system blockset of MATLAB/Simulink. The developed model is integrated with DC-DC boost converter with closed-loop control of maximum power point tracking (MPPT algorithm. Simulation results are validated with the experimental setup.

  5. A comparison and conversion table of 'the House-Brackmann facial nerve grading system' and 'the Yanagihara grading system'.

    Science.gov (United States)

    Satoh, Y; Kanzaki, J; Yoshihara, S

    2000-07-01

    A comparison between the House-Brackmann facial nerve grading system (the HB-system) and the Yanagihara grading system (the Y-system) was studied with 199 evaluations of 62 cases of postoperative unilateral acoustic neuroma. In the beginning, an original draft of the conversion table was formulated according to the 199 evaluations, in which, 0-6, 8-14, 16-20, 22-28, 30-38, and 40 points in the Y-system were matched with grade VI, V, IV, III, II, and I in the HB-system respectively. The result of the present study for prediction of sequelae showed that it was not necessary to consider the sequelae in a conversion table. And more, the study of an inter-observer variation showed that the lower and upper limits of the scores in the Y-system may shift within about a 2-point range in the draft table. From these aspects, a newly revised conversion table was proposed as a revised conversion table, in which, 0-6, 8-14, 16-22, 24-30, 32-38, and 40 points in the Y-system were matched with grade VI, V, IV, III, II, and I in the HB-system. This revised conversion table is much easier to remember for clinical use, because the score of the lower limit of each grade is simply in multiples of 8, that is, 0, 8, 16, 24, 32 and 40.

  6. Feedstock and Conversion Supply System Design and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mohammad, R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cafferty, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kenney, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Searcy, E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hansen, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    The success of the earlier logistic pathway designs (Biochemical and Thermochemical) from a feedstock perspective was that it demonstrated that through proper equipment selection and best management practices, conventional supply systems (referred to in this report as “conventional designs,” or specifically the 2012 Conventional Design) can be successfully implemented to address dry matter loss, quality issues, and enable feedstock cost reductions that help to reduce feedstock risk of variable supply and quality and enable industry to commercialize biomass feedstock supply chains. The caveat of this success is that conventional designs depend on high density, low-cost biomass with no disruption from incremental weather. In this respect, the success of conventional designs is tied to specific, highly productive regions such as the southeastern U.S. which has traditionally supported numerous pulp and paper industries or the Midwest U.S for corn stover.

  7. MHD conversion of solar energy. [space electric power system

    Science.gov (United States)

    Lau, C. V.; Decher, R.

    1978-01-01

    Low temperature plasmas wherein an alkali metal vapor is a component are uniquely suited to simultaneously absorb solar radiation by coupling to the resonance lines and produce electrical power by the MHD interaction. This work is an examination of the possibility of developing space power systems which take advantage of concentrated solar power to produce electricity. It is shown that efficient cycles in which expansion work takes place at nearly constant top cycle temperature can be devised. The power density of the solar MHD generator is lower than that of conventional MHD generators because of the relatively high seed concentration required for radiation absorption and the lower flow velocity permitted to avoid total pressure losses due to heating.

  8. Hydrokinetic energy conversion systems: A technology status review

    Energy Technology Data Exchange (ETDEWEB)

    Gueney, M.S. [Machinery Programm of Machinery of Undergraduate School, Giresun University, 28100 Giresun (Turkey); Kaygusuz, K. [Department of Chemistry, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2010-12-15

    The growing demand for electrical energy is one of the most important subjects today. Decreasing amount and environmental effect of fossil fuels does not seem to surmount this challenge. Renewable energies give a good perspective to be an alternative to fossil and nuclear-fueled power plants, in order to meet growing demand for electrical energy. Hydropower is well known in this category. Hydrokinetic energy technologies are relatively new than other hydropower systems. In this work has been investigated these kinds of hydrokinetic energy, and given some detailed information about current base of hydrokinetic. It has tried to give some knowledge in order to familiarize with the hydrokinetic turbine and generator. The selection information of a suitable turbine has been mentioned. (author)

  9. Impact of thermal energy storage properties on solar dynamic space power conversion system mass

    Science.gov (United States)

    Juhasz, Albert J.; Coles-Hamilton, Carolyn E.; Lacy, Dovie E.

    1987-01-01

    A 16 parameter solar concentrator/heat receiver mass model is used in conjunction with Stirling and Brayton Power Conversion System (PCS) performance and mass computer codes to determine the effect of thermal energy storage (TES) material property changes on overall PCS mass as a function of steady state electrical power output. Included in the PCS mass model are component masses as a function of thermal power for: concentrator, heat receiver, heat exchangers (source unless integral with heat receiver, heat sink, regenerator), heat engine units with optional parallel redundancy, power conditioning and control (PC and C), PC and C radiator, main radiator, and structure. Critical TES properties are: melting temperature, heat of fusion, density of the liquid phase, and the ratio of solid-to-liquid density. Preliminary results indicate that even though overall system efficiency increases with TES melting temperature up to 1400 K for concentrator surface accuracies of 1 mrad or better, reductions in the overall system mass beyond that achievable with lithium fluoride (LiF) can be accomplished only if the heat of fusion is at least 800 kJ/kg and the liquid density is comparable to that of LiF (1800 kg/cu m).

  10. Corrosion Performance of Composite Galvanic Coatings with Variable Concentration of Polymeric Nanoaggregates and/or Cr(III) Conversion Layers

    NARCIS (Netherlands)

    Koleva, D.A.; Taheri, P.; Tsvetkova, N.; Boshkov, N.; Van Breugel, K.; De Wit, J.H.W.; Mol, J.M.C.

    2011-01-01

    This paper reports on the corrosion performance of composite zinc layers (~ 8µm) on a steel substrate, considering the influence of nano-aggregates and Cr(III) conversion layers, compared to control (only Zn layers) conditions. The main factors, influencing the corrosion performance of Zn in this

  11. Noise and conversion performance of a high-Tc superconducting Josephson junction mixer at 0.6 THz

    Science.gov (United States)

    Gao, Xiang; Du, Jia; Zhang, Ting; Guo, Yingjie Jay

    2017-11-01

    This letter presents both theoretical and experimental investigations on the noise and conversion performance of a high-Tc superconducting (HTS) step-edge Josephson-junction mixer at the frequency of 0.6 THz and operating temperatures of 20-40 K. Based on the Y-factor and U-factor methods, a double-sideband noise temperature of around 1000 K and a conversion gain of -3.5 dB were experimentally obtained at 20 K. At the temperature of 40 K, the measured mixer noise and conversion efficiency are around 2100 K and -10 dB, respectively. The experimental data are in good agreement with the numerical analysis results using the three-port model. A detailed performance comparison with other reported HTS terahertz mixers has confirmed the superior performance of our presented mixer device.

  12. Performance Comparison of Steam-Based and Chromate Conversion Coatings on Aluminum Alloy 6060

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    In this study, oxide layers generated on aluminum alloy 6060(UNS A96060) using a steam-based process were compared with conventional chromate and chromate-phosphate conversion coatings. Chemical composition and microstructure of the conversion coatings were investigated and their corrosion perfor...

  13. Loneliness and the social monitoring system: Emotion recognition and eye gaze in a real-life conversation.

    Science.gov (United States)

    Lodder, Gerine M A; Scholte, Ron H J; Goossens, Luc; Engels, Rutger C M E; Verhagen, Maaike

    2016-02-01

    Based on the belongingness regulation theory (Gardner et al., 2005, Pers. Soc. Psychol. Bull., 31, 1549), this study focuses on the relationship between loneliness and social monitoring. Specifically, we examined whether loneliness relates to performance on three emotion recognition tasks and whether lonely individuals show increased gazing towards their conversation partner's faces in a real-life conversation. Study 1 examined 170 college students (Mage = 19.26; SD = 1.21) who completed an emotion recognition task with dynamic stimuli (morph task) and a micro(-emotion) expression recognition task. Study 2 examined 130 college students (Mage = 19.33; SD = 2.00) who completed the Reading the Mind in the Eyes Test and who had a conversation with an unfamiliar peer while their gaze direction was videotaped. In both studies, loneliness was measured using the UCLA Loneliness Scale version 3 (Russell, 1996, J. Pers. Assess., 66, 20). The results showed that loneliness was unrelated to emotion recognition on all emotion recognition tasks, but that it was related to increased gaze towards their conversation partner's faces. Implications for the belongingness regulation system of lonely individuals are discussed. © 2015 The British Psychological Society.

  14. What are Middle School Students Talking About During Clicker Questions? Characterizing Small-Group Conversations Mediated by Classroom Response Systems

    Science.gov (United States)

    Barth-Cohen, Lauren A.; Smith, Michelle K.; Capps, Daniel K.; Lewin, Justin D.; Shemwell, Jonathan T.; Stetzer, MacKenzie R.

    2016-02-01

    There is a growing interest in using classroom response systems or clickers in science classrooms at both the university and K-12 levels. Typically, when instructors use this technology, students are asked to answer and discuss clicker questions with their peers. The existing literature on using clickers at the K-12 level has largely focused on the efficacy of clicker implementation, with few studies investigating collaboration and discourse among students. To expand on this work, we investigated the question: Does clicker use promote productive peer discussion among middle school science students? Specifically, we collected data from middle school students in a physical science course. Students were asked to answer a clicker question individually, discuss the question with their peers, answer the same question again, and then subsequently answer a new matched-pair question individually. We audio recorded the peer conversations to characterize the nature of the student discourse. To analyze these conversations, we used a grounded analysis approach and drew on literature about collaborative knowledge co-construction. The analysis of the conversations revealed that middle school students talked about science content and collaboratively discussed ideas. Furthermore, the majority of conversations, both ones that positively and negatively impacted student performance, contained evidence of collaborative knowledge co-construction.

  15. Control Systems for Logistics Performance

    OpenAIRE

    Virolainen, V.-M.

    1991-01-01

    This text is concerned with identifying and outlining the various aspects of logistics control and performance measurement process. The objective is to identify, based on available literature, methods and techniques which can be used to measure the performance of logistics. Logistics management is essentially a task of balancing between minimizing cost and ensuring availability objectives. Availability can be seen as the output of logistics system. On the input side, management is concer...

  16. A Concise Presentation of Doubly Fed Induction Generator Wind Energy Conversion Systems Challenges and Solutions

    Directory of Open Access Journals (Sweden)

    Julius Mwaniki

    2017-01-01

    Full Text Available There is increased worldwide wind power generation, a large percentage of which is grid connected. The doubly fed induction generator (DFIG wind energy conversion system (WECS has many merits and, as a result, large numbers have been installed to date. The DFIG WECS operation, under both steady state and fault conditions, is of great interest since it impacts on grid performance. This review paper presents a condensed look at the various applied solutions to the challenges of the DFIG WECS including maximum power point tracking, common mode voltages, subsynchronous resonance, losses, modulation, power quality, and faults both internal and from the grid. It also looks at approaches used to meet the increasingly stringent grid codes requirements for the DFIG WECS to not only ride through faults but also provide voltage support. These are aspects of the DFIG WECS that are critical for system operators and prospective investors and can also serve as an introduction for new entrants into this area of study.

  17. Performance of envelope: an innovative energy system

    Directory of Open Access Journals (Sweden)

    Rossella Franchino

    2014-05-01

    Full Text Available In the field of applied research in construction, the constant request from the production's sector and the persisting both European (Directive 2010/31/EU and 2012/27/UE and national (Legislative Decree 63/13, LD 115/ 09, LD 28/11 normative indications require testing of technology solutions for envelope ever more efficient in terms of energy and the environment. The conversion of locally generated energy from renewable sources assumes a particularly important role in the energy balance of the building-plant system. In this respect, the paper illustrates the results of technological experimentation conducted within the SEEM (Solar Eco - efficient Envelope Model Project, funded in 2011 by the Ministry of Environment. The project involved the study of a combined system of solar and wind chimney, architecturally integrated into an envelope systems of the tertiary sector, in order to produce electricity and heat from renewable sources. The study proposes the performance analysis of the SEEM system's components, with particular attention to the thermo-physical relationship between the building and the integrated plant system.

  18. Hydraulic Performance of an Innovative Breakwater for Overtopping Wave Energy Conversion

    Directory of Open Access Journals (Sweden)

    Claudio Iuppa

    2016-11-01

    Full Text Available The Overtopping BReakwaterfor Energy Conversion (OBREC is an overtopping wave energy converter, totally embedded in traditional rubble mound breakwaters. The device consists of a reinforced concrete front reservoir designed with the aim of capturing the wave overtopping in order to produce electricity. The energy is extracted through low head turbines, using the difference between the water levels in the reservoir and the sea water level. This paper analyzes the OBREC hydraulic performances based on physical 2D model tests carried out at Aalborg University (DK. The analysis of the results has led to an improvement in the overall knowledge of the device behavior, completing the main observations from the complementary tests campaign carried out in 2012 in the same wave flume. New prediction formula are presented for wave reflection, the overtopping rate inside the front reservoir and at the rear side of the structure. Such methods have been used to design the first OBREC prototype breakwater in operation since January 2016 at Naples Harbor (Italy.

  19. Enhancing the Photovoltaic Performance of Perovskite Solar Cells with a Down-Conversion Eu-Complex.

    Science.gov (United States)

    Jiang, Ling; Chen, Wangchao; Zheng, Jiawei; Zhu, Liangzheng; Mo, Li'e; Li, Zhaoqian; Hu, Linhua; Hayat, Tasawar; Alsaedi, Ahmed; Zhang, Changneng; Dai, Songyuan

    2017-08-16

    Organometal halide perovskite solar cells (PSCs) have shown high photovoltaic performance but poor utilization of ultraviolet (UV) irradiation. Lanthanide complexes have a wide absorption range in the UV region and they can down-convert the absorbed UV light into visible light, which provides a possibility for PSCs to utilize UV light for higher photocurrent, efficiency, and stability. In this study, we use a transparent luminescent down-converting layer (LDL) of Eu-4,7-diphenyl-1,10-phenanthroline (Eu-complex) to improve the light utilization efficiency of PSCs. Compared with the uncoated PSC, the PSC coated with Eu-complex LDL on the reverse of the fluorine-doped tin oxide glass displayed an enhancement of 11.8% in short-circuit current density (Jsc) and 15.3% in efficiency due to the Eu-complex LDL re-emitting UV light (300-380 nm) in the visible range. It is indicated that the Eu-complex LDL plays the role of enhancing the power conversion efficiency as well as reducing UV degradation for PSCs.

  20. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...

  1. Understanding Power Electronics and Electrical Machines in Multidisciplinary Wind Energy Conversion System Courses

    Science.gov (United States)

    Duran, M. J.; Barrero, F.; Pozo-Ruz, A.; Guzman, F.; Fernandez, J.; Guzman, H.

    2013-01-01

    Wind energy conversion systems (WECS) nowadays offer an extremely wide range of topologies, including various different types of electrical generators and power converters. Wind energy is also an application of great interest to students and with a huge potential for engineering employment. Making WECS the main center of interest when teaching…

  2. Dynamic modelling and robust control of a wind energy conversion system

    NARCIS (Netherlands)

    Steinbuch, M.

    1989-01-01

    The application of wind energy conversion systems for the production of electrical energy requires a cheap and reliable operation. Especially at high wind velocities fluctuations from the wind field result in large mechanical loads of the wind turbine. Also fluctuations in the grid voltage may yield

  3. Robust Sliding Mode Control of Permanent Magnet Synchronous Generator-Based Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Guangping Zhuo

    2016-12-01

    Full Text Available The subject of this paper pertains to sliding mode control and its application in nonlinear electrical power systems as seen in wind energy conversion systems. Due to the robustness in dealing with unmodeled system dynamics, sliding mode control has been widely used in electrical power system applications. This paper presents first and high order sliding mode control schemes for permanent magnet synchronous generator-based wind energy conversion systems. The application of these methods for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource. Computer simulation results have shown the efficacy of the proposed sliding mode control approaches.

  4. Collaborative role construction in a conversation with dementia: an application of systemic functional linguistics.

    Science.gov (United States)

    Müller, Nicole; Wilson, Brent T

    2008-01-01

    This study applies the tools provided by Systemic Functional Linguistics (SFL) to the description of patterns in a conversation between a person with dementia and a person without. It shows how, in the presence of, on the one hand, considerable communicative and cognitive deficits, and on the other, a collaborative interlocutor, a person with dementia succeeds in leading and sustaining a lengthy conversation, and of constructing for himself a positive role in the interaction, namely that of the elder advising a much younger man.

  5. Preservice Mathematics Teachers' Solutions to Problems: Conversions within the Metric System

    Directory of Open Access Journals (Sweden)

    Jean E. Hallagan

    2013-10-01

    Full Text Available This paper reports on the results of a preliminary investigation to determine if preservice mathematics teachers solve conversion problems within the metric system in multiple ways. Here, four metric conversion problems of escalating difficulty were administered within a mathematics methods course at a comprehensive state university in the Northeastern United States. Results show that preservice teachers solved the problems in the same way that they were taught in high school, and that in high school they were only taught one way.

  6. Experimental model for architectural systematization and its basic thermal performance. Part 1. Research on architectural systematization of energy conversion devices; Kenchiku system ka model no gaiyo to kihon seino ni tsuite. 1. Energy henkan no kenchiku system ka ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Sunaga, N.; Ito, N.; Kimura, G.; Fukao, S.; Shimizu, T.; Tsunoda, M.; Muro, K. [Tokyo Metropolitan University, Tokyo (Japan)

    1996-10-27

    The outline of a model for architectural systematization of natural energy conversion and the experiment result on the basic thermal performance in winter are described. The model is about 20 m{sup 2} in floor space. Foam polystyrene of 100 mm and 200 mm thick was used for the outer wall as heat insulating materials. The model has a solar battery and air conditioner and uses red brick as a heat reservoir. An experiment was made on seven modes obtained when three elements (heating, heat storage, and night insulated door) are combined. The information obtained by the experiment showed that a model for architectural systematization has high heat insulation and tightness and can be used as an energy element or an evaluation model for architectural systematization. In this model for architectural systematization, the power consumption of an air conditioner in winter can be fully supplied by only the power generation based on a solar battery. In an architectural element, the heating energy consumption can be remarkably reduced and the indoor thermal environment can be greatly improved, by the combination of a heat reservoir and night heat insulated door. 1 ref., 6 figs., 3 tabs.

  7. Greenhouse Gas Conversion by Homogeneous Salen Catalyst Systems under Very Mild Reaction Condition

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Hyungsock; Song, Sanghoon; Ahn, Sunghyun; Kim, Taesoon; Kim, Beomsik; Chang, Taesun [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2013-08-15

    Homogeneous salen catalyt systems were investigated for the conversion of greenhouse gas into cyclic carbonate under room temperature and atmospheric pressure. Salen complexes were more active than salophen complexes. Neither electron withdrawing nor donating group showed lower conversion efficiency. Co-catalysts such as moisture or ammonium salt increased the conversion efficiency dramatically. These results have potential to decrease carbon dioxide emitted from fossil fuel combustions under mild condition. One of the main scientific challenges in the 21st century is the global warming due to the increasing level of carbon dioxide. The consumption of fossil fuels is continue to increase with emitting substantial amount of green house gas. The solution currently considered is capturing and storing of carbon dioxide which compressing carbon dioxide and then storing it into oil wells or under the ocean. The other solution include converting the carbon dioxide into useful chemicals with significant commercial demand, but low chemical reactivity of carbon dioxide restricts the chemical reactions.

  8. Solar electric and thermal conversion system in close proximity to the consumer. [solar panels on house roofs

    Science.gov (United States)

    Boeer, K. W.

    1975-01-01

    Solar cells may be used to convert sunlight directly into electrical energy and into lowgrade heat to be used for large-scale terrestrial solar-energy conversion. Both forms of energy can be utilized if such cells are deployed in close proximity to the consumer (rooftop). Cadmium-sulfide/copper-sulfide (CdS/Cu2S) solar cells are an example of cells which may be produced inexpensively enough to become economically attractive. Cell parameters relevant for combined solar conversion are presented. Critical issues, such as production yield, life expectancy, and stability of performance, are discussed. Systems-design parameters related to operating temperatures are analyzed. First results obtained on Solar One, the experimental house of the University of Delaware, are given. Economic aspects are discussed. Different modes of operation are discussed in respect to the power utility and consumer incentives.

  9. Performance of conversion efficiency of a crystalline silicon solar cell with base doping density

    Directory of Open Access Journals (Sweden)

    Gokhan Sahin

    Full Text Available In this study, we investigate theoretically the electrical parameters of a crystalline silicon solar cell in steady state. Based on a one-dimensional modeling of the cell, the short circuit current density, the open circuit voltage, the shunt and series resistances and the conversion efficiency are calculated, taking into account the base doping density. Either the I-V characteristic, series resistance, shunt resistance and conversion efficiency are determined and studied versus base doping density. The effects applied of base doping density on these parameters have been studied. The aim of this work is to show how short circuit current density, open circuit voltage and parasitic resistances are related to the base doping density and to exhibit the role played by those parasitic resistances on the conversion efficiency of the crystalline silicon solar. Keywords: Crystalline silicon solar cell, Base doping density, Series resistance, Shunt resistance, Conversion efficiency

  10. Performance Confirmation Data Aquisition System

    Energy Technology Data Exchange (ETDEWEB)

    D.W. Markman

    2000-10-27

    The purpose of this analysis is to identify and analyze concepts for the acquisition of data in support of the Performance Confirmation (PC) program at the potential subsurface nuclear waste repository at Yucca Mountain. The scope and primary objectives of this analysis are to: (1) Review the criteria for design as presented in the Performance Confirmation Data Acquisition/Monitoring System Description Document, by way of the Input Transmittal, Performance Confirmation Input Criteria (CRWMS M&O 1999c). (2) Identify and describe existing and potential new trends in data acquisition system software and hardware that would support the PC plan. The data acquisition software and hardware will support the field instruments and equipment that will be installed for the observation and perimeter drift borehole monitoring, and in-situ monitoring within the emplacement drifts. The exhaust air monitoring requirements will be supported by a data communication network interface with the ventilation monitoring system database. (3) Identify the concepts and features that a data acquisition system should have in order to support the PC process and its activities. (4) Based on PC monitoring needs and available technologies, further develop concepts of a potential data acquisition system network in support of the PC program and the Site Recommendation and License Application.

  11. Experimental self-etching HEMA-free adhesive systems: cytotoxicity and degree of conversion.

    Science.gov (United States)

    Barbosa, Marília Oliveira; de Carvalho, Rodrigo Varella; Demarco, Flávio Fernando; Ogliari, Fabrício Aulo; Zanchi, Cesar Henrique; Piva, Evandro; da Silva, Adriana Fernandes

    2015-01-01

    The aim of this study was to evaluate the effect of replacing 2-hydroxyethyl methacrylate (HEMA) by methacrylate surfactant monomers on the cytotoxicity and degree of conversion of two-step self-etching dentin adhesive systems. Five HEMA-free adhesive systems were tested: Bis-EMA 10, Bis-EMA 30, PEG400, PEG400UDMA, PEG1000, and a HEMA group was used as positive control. The cytotoxicity of the experimental primers, with different monomer concentrations (2 or 20 wt%), and bond resins, containing 25 wt% surfactant, was assessed using murine fibroblast cell line 3T3 and the tetrazolium assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)). The degree of conversion of the bond resins was analyzed using Fourier transform infrared spectroscopy. The data were submitted to statistical analysis using level of significance set at P cytotoxic than HEMA. With regard to the eluate from bond resin, the data showed that the groups BIS-EMA 10, BIS-EMA 30 and PEG400UDMA were less cytotoxic than HEMA. No statistically significant difference was found among degrees of conversion of the experimental groups and HEMA. PEG 1000, BIS-EMA 10 and 30 monomers showed the biological potential for use in new adhesive system formulations since they showed lower cytotoxicity and similar degree of conversion when compared with the HEMA-containing group.

  12. Performance of Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Yingwei Zhang

    2013-01-01

    Full Text Available Data packet dropout is a special kind of time delay problem. In this paper, predictive controllers for networked control systems (NCSs with dual-network are designed by model predictive control method. The contributions are as follows. (1 The predictive control problem of the dual-network is considered. (2 The predictive performance of the dual-network is evaluated. (3 Compared to the popular networked control systems, the optimal controller of the new NCSs with data packets dropout is designed, which can minimize infinite performance index at each sampling time and guarantee the closed-loop system stability. Finally, the simulation results show the feasibility and effectiveness of the controllers designed.

  13. ANALOG-TO-DIGITAL CONVERSION OF SIGNALS WITH ANGULAR MANIPULATION FOR SOFTWARE DEFINED RADIO SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Y. Tsvetkov

    2016-05-01

    Full Text Available The paper deals with the search of ways for speeding up and accuracy increase of conversion of modern analog-to-digital converters. The main shortcomings interfering a solution of this task including the field of optoelectronic analog-to-digital converters are provided. The proposed solution gives the chance to increase high-speed performance of analog-to-digital converters on the basis of holographic interferometry principles without reducing their accuracy of conversion. The optical scheme of interferential and holographic method of analog-to-digital conversion and results of its mathematical modeling are provided. Some recommendations about hardware implementation of this analog data digitizer are formulated. The physical principles and approaches to a choice of the converter structural elements are explained. An example of forming the functional scheme of a decoder for a luminous flux intensity in terms of registration of analog-to-digital converter is reviewed. The practical importance of the provided method consists in possibility of creation of analog-to-digital converters with high-speed performance about 600 MHz and with an accuracy of conversion up to 12 bits.

  14. Applied research on energy storage and conversion for photovoltaic and wind energy systems. Volume II. Photovoltaic systems with energy storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This volume of the General Electric study was directed at an evaluation of those energy storage technologies deemed best suited for use in conjunction with a photovoltaic energy conversion system in utility, residential and intermediate applications. Break-even cost goals are developed for several storage technologies in each application. These break-even costs are then compared with cost projections presented in Volume I of this report to show technologies and time frames of potential economic viability. The form of the presentation allows the reader to use more accurate storage system cost data as they become available. The report summarizes the investigations performed and presents the results, conclusions and recommendations pertaining to use of energy storage with photovoltaic energy conversion systems. Candidate storage concepts studied include (1) above ground and underground pumped hydro, (2) underground compressed air, (3) electric batteries, (4) flywheels, and (5) hydrogen production and storage. (WHK)

  15. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Interim report, 1994 Summer

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-01-01

    The federal government is the largest single energy consumer in the United States cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This interim report provides the results of a field evaluation that PNL conducted for DOE/FEMP and the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology-a hot water heater conversion system to convert electrically heated hot water tanks to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  16. Performance and economic evaluation of the seahorse natural gas hot water heater conversion at Fort Stewart. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, D.W.

    1995-12-01

    The Federal government is the largest single energy consumer in the United States with consumption of nearly 1.5 quads/year of energy (10{sup 15} quad = 1015 Btu) and cost valued at nearly $10 billion annually. The US Department of Energy`s (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP) seeks to evaluate new energy -- saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL) is one of four DOE laboratories that participate in the New Technologies Demonstration Program, providing technical expertise and equipment to evaluate new, energy-saving technologies being studied under that program. This report provides the results of a field evaluation that PNL conducted for DOE/FEMP with funding support from the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of 4 candidate energy-saving technology-a water heater conversion system to convert electrically powered water heaters to natural gas fuel. The unit was installed at a single residence at Fort Stewart, a US Army base in Georgia, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were Gas Fired Products, developers of the technology; the Public Service Company of North Carolina; Atlanta Gas Light Company; the Army Corps of Engineers; Fort Stewart; and Pacific Northwest Laboratory.

  17. Microencapsulated Phase Change Materials in Solar-Thermal Conversion Systems: Understanding Geometry-Dependent Heating Efficiency and System Reliability.

    Science.gov (United States)

    Zheng, Zhaoliang; Chang, Zhuo; Xu, Guang-Kui; McBride, Fiona; Ho, Alexandra; Zhuola, Zhuola; Michailidis, Marios; Li, Wei; Raval, Rasmita; Akhtar, Riaz; Shchukin, Dmitry

    2017-01-24

    The performance of solar-thermal conversion systems can be improved by incorporation of nanocarbon-stabilized microencapsulated phase change materials (MPCMs). The geometry of MPCMs in the microcapsules plays an important role for improving their heating efficiency and reliability. Yet few efforts have been made to critically examine the formation mechanism of different geometries and their effect on MPCMs-shell interaction. Herein, through changing the cooling rate of original emulsions, we acquire MPCMs within the nanocarbon microcapsules with a hollow structure of MPCMs (h-MPCMs) or solid PCM core particles (s-MPCMs). X-ray photoelectron spectroscopy and atomic force microscopy reveals that the capsule shell of the h-MPCMs is enriched with nanocarbons and has a greater MPCMs-shell interaction compared to s-MPCMs. This results in the h-MPCMs being more stable and having greater heat diffusivity within and above the phase transition range than the s-MPCMs do. The geometry-dependent heating efficiency and system stability may have important and general implications for the fundamental understanding of microencapsulation and wider breadth of heating generating systems.

  18. Single conversion audio amplifier and DC-AC converters with high performance and low complexity control scheme

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    This paper proposes a novel control topology for a mains isolated single conversion audio amplifier and DC-AC converters. The topology is made for use in audio applications, and differs from prior art in terms of significantly reduced distortion as well as lower system complexity. The topology can...

  19. PVMaT - OMNION Series 3000: Photovoltaic Power Conversion System for Utility Interconnected Application; Annual Report, May 1997 - February 1999

    Energy Technology Data Exchange (ETDEWEB)

    Porter, D.

    2000-09-13

    This report details the work performed which was geared towards making advancements in three major areas (cost, reliability and performance) of three-phase, utility interconnected and photovoltaic power conversion.

  20. Determining PHEV Performance Potential – User and Environmental Influences on A123 Systems’ Hymotion™ Plug-In Conversion Module for the Toyota Prius

    Energy Technology Data Exchange (ETDEWEB)

    John G. Smart; Huang Iu

    2009-05-01

    A123Systems’s HymotionTM L5 Plug-in Conversion Module (PCM) is a supplemental battery system that converts the Toyota Prius hybrid electric vehicle (HEV) into a plug-in hybrid electric vehicle (PHEV). The Hymotion system uses a lithium ion battery pack with 4.5 kWh of useable energy capacity and recharges by plugging into a standard 110/120V outlet. The system is designed to more than double the Prius fuel efficiency for 30-50km of charge depleting range. This paper will cover efforts by A123 Systems and the Idaho National Laboratory in studying the on-road performance of this PHEV fleet. The performance potentials of various fleets will be compared in order to determine the major influences on overall performance.

  1. Autonomous wind energy conversion system with a simple controller for maximum-power transfer

    Energy Technology Data Exchange (ETDEWEB)

    Ermis, M.; Ertan, H.B. (Middle East Technical Univ., Ankara (Turkey). Dept. of Electrical and Electronic Engineering); Akpinar, E. (New Orleans Univ., LA (United States). Dept. of Electrical Engineering); Uelguet, F. (Aselsan Military Electronic Ind. Inc., Ankara (Turkey))

    1992-09-01

    The paper describes a small autonomous wind energy conversion system. A simple, closed-loop control system assures maximum-power transfer by the aid of a lookup table which relates the electrical power output of the system to the shaft speed. A directly-coupled, wound-rotating field synchronous generator is used for energy conversion. The generator speed in this system is variable while the terminal voltage is substantially constant. The terminal voltage is kept under control by varying the field current to meet various load and battery conditions. In the paper a new criterion for determining optimum dimensions of a generator for wind energy conversion system applications is introduced. This criterion envisages a maximisation of the energy output for the chosen wind regime while keeping the generator cost at a minimum. To obtain the optimum solution of the cost minimisation problem, the constrained optimisation problem is first converted to the unconstrained form by using the external penalty approach and then solved using the Devidon-Fletcher-Powel method. Results of the optimisation are presented and evaluated. (author)

  2. Research and Technology Activities Supporting Closed-Brayton-Cycle Power Conversion System Development

    Science.gov (United States)

    Barrett, Michael J.

    2004-01-01

    The elements of Brayton technology development emphasize power conversion system risk mitigation. Risk mitigation is achieved by demonstrating system integration feasibility, subsystem/component life capability (particularly in the context of material creep) and overall spacecraft mass reduction. Closed-Brayton-cycle (CBC) power conversion technology is viewed as relatively mature. At the 2-kWe power level, a CBC conversion system Technology Readiness Level (TRL) of six (6) was achieved during the Solar Dynamic Ground Test Demonstration (SD-GTD) in 1998. A TRL 5 was demonstrated for 10 kWe-class CBC components during the development of the Brayton Rotating Unit (BRU) from 1968 to 1976. Components currently in terrestrial (open cycle) Brayton machines represent TRL 4 for similar uses in 100 kWe-class CBC space systems. Because of the baseline component and subsystem technology maturity, much of the Brayton technology task is focused on issues related to systems integration. A brief description of ongoing technology activities is given.

  3. Subsonic Performance of Ejector Systems

    Science.gov (United States)

    Weil, Samuel

    Combined cycle engines combining scramjets with turbo jets or rockets can provide efficient hypersonic flight. Ejectors have the potential to increase the thrust and efficiency of combined cycle engines near static conditions. A computer code was developed to support the design of a small-scale, turbine-based combined cycle demonstrator with an ejector, built around a commercially available turbojet engine. This code was used to analyze the performance of an ejector system built around a micro-turbojet. With the use of a simple ejector, net thrust increases as large as 20% over the base engine were predicted. Additionally the specific fuel consumption was lowered by 10%. Increasing the secondary to primary area ratio of the ejector lead to significant improvements in static thrust, specific fuel consumption (SFC), and propulsive efficiency. Further ejector performance improvements can be achieved by using a diffuser. Ejector performance drops off rapidly with increasing Mach number. The ejector has lower thrust and higher SFC than the turbojet core at Mach numbers above 0.2. When the nozzle chokes a significant drop in ejector performance is seen. When a diffuser is used, higher Mach numbers lead to choking in the mixer and a shock in the nozzle causing a significant decrease in ejector performance. Evaluation of different turbo jets shows that ejector performance depends significantly on the properties of the turbojet. Static thrust and SFC improvements can be achieved with increasing ejector area for all engines, but size of increase and change in performance at higher Mach numbers depend heavily on the turbojet. The use of an ejector in a turbine based combined cycle configuration also increases performance at static conditions with a thrust increase of 5% and SFC decrease of 5% for the tested configuration.

  4. Unique Reversible Conversion-Type Mechanism Enhanced Cathode Performance in Amorphous Molybdenum Polysulfide.

    Science.gov (United States)

    Wang, Xusheng; Du, Kuangzhou; Wang, Chao; Ma, Luxiang; Zhao, Binglu; Yang, Junfeng; Li, Meixian; Zhang, Xin-Xiang; Xue, Mianqi; Chen, Jitao

    2017-11-08

    A unique reversible conversion-type mechanism is reported in the amorphous molybdenum polysulfide (a-MoS5.7) cathode material. The lithiation products of metallic Mo and Li2S2 rather than Mo and Li2S species have been detected. This process could yield a high discharge capacity of 746 mAh g-1. Characterizations of the recovered molybdenum polysulfide after the delithiaiton process manifests the high reversibility of the unique conversion reaction, in contrast with the general irreversibility of the conventional conversion-type mechanism. As a result, the a-MoS5.7 electrodes deliver high cycling stability with an energy-density retention of 1166 Wh kg-1 after 100 cycles. These results provide a novel model for the design of high-capacity and long-life electrode materials.

  5. Silicon Heterojunction System Field Performance

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Dirk C.; Deline, Chris; Johnston, Steve; Rummel, Steve R.; Sekulic, Bill; Hacke, Peter; Kurtz, Sarah R.; Davis, Kristopher O.; Schneller, Eric John; Sun, Xingshu; Alam, Muhammad A.; Sinton, Ronald A.

    2017-11-17

    A silicon heterostructure photovoltaic system fielded for 10 years has been investigated in detail. The system has shown degradation, but at a rate similar to an average Si system, and still within the module warranty level. The power decline is dominated by a nonlinear Voc loss rather than more typical changes in Isc or Fill Factor. Modules have been evaluated using multiple techniques including: dark and light I-V measurement, Suns-Voc, thermal imaging, and quantitative electroluminescence. All techniques indicate that recombination and series resistance in the cells have increased along with a decrease of factor 2 in minority carrier lifetime. Performance changes are fairly uniform across the module, indicating changes occur primarily within the cells.

  6. Suomi NPP Ground System Performance

    Science.gov (United States)

    Grant, K. D.; Bergeron, C.

    2013-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, was launched on 28 October 2011, and is currently undergoing product calibration and validation activities. As products reach a beta level of maturity, they are made available to the community through NOAA's Comprehensive Large Array-data Stewardship System (CLASS). CGS's data processing capability processes the satellite data from the Joint Polar Satellite System satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to NOAA and Department of Defense (DoD) processing centers operated by the United States government. CGS is currently processing and delivering SDRs and EDRs for Suomi NPP and will continue through the lifetime of the Joint Polar Satellite System programs. Following the launch and sensor activation phase of the Suomi NPP mission, full volume data traffic is now flowing from the satellite through CGS's C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Raytheon developed a tool to measure, categorize, and

  7. A Family Systems Nursing Approach for Families Following a Stroke: Family Health Conversations.

    Science.gov (United States)

    Östlund, Ulrika; Bäckström, Britt; Saveman, Britt-Inger; Lindh, Viveca; Sundin, Karin

    2016-05-01

    Stroke in midlife is a life altering, challenging experience for the whole family thereby necessitating a family approach to intervention. The aim of this study was to describe the experiences of 17 family members living in Sweden, including seven adult stroke patients (six males; one female) under the age of 65 who participated in a series of three nurse-led family conversations that were offered in each family's home. These Family Health Conversations (FamHC) were guided by the conceptual lens of Family System Nursing. Individual, semi-structured, evaluative interviews conducted with each participant one month after the FamHC were analyzed by qualitative content analysis. The FamHC were described by family members as a unique conversation that they had not previously experienced in health care contexts. Family members described possibilities for relational sharing and meaningful conversations as well as changes in family functioning that support the suitability of FamHC for family stroke care. © The Author(s) 2016.

  8. A space-based combined thermophotovoltaic electric generator and gas laser solar energy conversion system

    Science.gov (United States)

    Yesil, Oktay

    1989-01-01

    This paper describes a spaceborne energy conversion system consisting of a thermophotovoltaic electric generator and a gas laser. As a power source for the converson, the system utilizes an intermediate blackbody cavity heated to a temperature of 2000-2400 K by concentrated solar radiation. A double-layer solar cell of GaAs and Si forms a cylindrical surface concentric to this blackbody cavity, receiving the blackbody radiation and converting it into electricity with cell conversion efficiency of 50 percent or more. If the blackbody cavity encloses a laser medium, the blackbody radiation can also be used to simultaneously pump a lasing gas. The feasibility of blackbody optical pumping at 4.3 microns in a CO2-He gas mixture was experimentally demonstrated.

  9. An adaptive feedback linearization strategy for variable speed wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Valenciaga, F.; Puleston, P.F.; Battaiotto, P.E.; Mantz, R.J. [Universidad Nacional de La Plata, Depto. de Electrotecnia, La Plata (Argentina)

    2000-07-01

    This paper presents a control strategy based on adaptive feedback linearization intended for variable speed grid-connected wind energy conversion systems (WECS). The proposed adaptive control law accomplishes energy capture maximization by tracking the wind speed fluctuations. In addition, it linearizes the system even in the presence of turbine model uncertainties, allowing the closed-loop dynamic behaviour to be determined by a simple tuning of the controller parameters. Particularly, the attention is focused on WECS with slip power recovery, which use a power conversion stage as a rotor-controlled double-output induction generator. However, the concepts behind the proposed control strategy are general and can be easily extended to other WECS configurations. (Author)

  10. 5 case studies : boiler system increases availability of hot water in CAP REIT apartment buildings while saving energy : electric-to-gas retrofit drives down energy costs and improves building performance : Novitherm heat reflector panels saves 28 per cent in heating costs for apartment building : Novitherm heat reflector panel installation with system adjustment saves 33.2 per cent in energy costs : natural gas conversion saves over $315,000 a year for condominium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    These 5 case studies presented the details of new systems and retrofits conducted by Enbridge Gas Distribution and its partners to improve the energy efficiency of various public and residential buildings. System retrofits included the installation of boiler system installed to address tenant demands on the domestic hot water systems of properties purchased purchased by the CAP REIT organization. The comprehensive program used to address the problems included replacement of the systems with high efficiency heating boilers designed to integrate space, hot water, ramp, and pool heat. A centralized controller included setback control, trend-following processors, and the isolation of heating equipment. The second case study described an electric-to-gas conversion of a make-up air unit and boiler system at an all-electric apartment building. The system was designed to address excessive air handling and water heating costs. The gas conversion included new heating and hot water boilers, as well as a number of efficiency upgrades. The third and fourth case study described the installation of Novitherm heat reflector panels at apartment buildings in Toronto. The fifth case study described a natural gas conversion project conducted at a luxury condominium. Energy savings for all 5 projects were presented. 9 figs.

  11. Legal-institutional arrangements facilitating offshore wind energy conversion systems (WECS) utilization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, L.H.

    1977-09-01

    Concern for the continuing sufficiency of energy supplies in the U.S. has tended to direct increasing attention to unconventional sources of supply, including wind energy. Some of the more striking proposals for the utilization of wind energy relate to offshore configurations. The legal-institutional arrangements for facilitating the utilization of offshore wind energy conversion systems (WECS) are examined by positioning three program alternatives and analyzing the institutional support required for the implementation of each.

  12. Evaluation and Design Methodologies - Embodied Conversational Agents: Effects on Memory Performance and Anthropomorphisation

    NARCIS (Netherlands)

    Beun, R.J.; Vos, E. de; Witteman, C.L.M.

    2003-01-01

    It is often assumed that the use of Embodied Conversational Agents (ECAs) in human-computer interfaces improves human-computer interaction. Because of their appearance and because they show human-like communicative behaviour, users tend to ascribe human characteristics to ECAs or anthropomorphize

  13. Feed conversion, protein efficiency, digestibility and growth performance of Oreochromis niloticus fed Delonix regia seed meal

    OpenAIRE

    Balogun, J.K.; Abdullahi, S.A.; Auta, J.; Ogunlade, O.P.

    2005-01-01

    Oreochromis niloticus fingerlings (mean weight 5.27~c0.29g) were fed raw and boiled Delonix regia seed meals following standard procedures. The weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), net protein utilization (NPU) were determined as growth indices. Diet formulated with seed boiled for 80 minutes showed significantly (P

  14. Novel Control for Voltage Boosted Matrix Converter based Wind Energy Conversion System with Practicality

    Science.gov (United States)

    Kumar, Vinod; Joshi, Raghuveer Raj; Yadav, Dinesh Kumar; Garg, Rahul Kumar

    2017-04-01

    This paper presents the implementation and investigation of novel voltage boosted matrix converter (MC) based permanent magnet wind energy conversion system (WECS). In this paper, on-line tuned adaptive fuzzy control algorithm cooperated with reversed MC is proposed to yield maximum energy. The control system is implemented on a dSPACE DS1104 real time board. Feasibility of the proposed system has been experimentally verified using a laboratory 1.2 kW prototype of WECS under steady-state and dynamic conditions.

  15. Preliminary Results about Growth Performance and Food Conversion Ratio of Acipenser stellatus juvenils, Fed with Different Dietary Protein Levels

    Directory of Open Access Journals (Sweden)

    Maria Desimira Dicu

    2012-10-01

    Full Text Available The main purpose of this study is to evaluate the effects of different dietary protein levels on Acipenser stellatus growth performance. Researches were conducted between 4 th November-3rd December 2011, in the recirculating system of Aquaculture, Environmental Science and Cadastre Department, University of Galati. A number of 60 fish with an average weight of 11.5±0.58 g were randomly stocked into four rearing units, with same stocking densities. Two experimental variants with different dietary protein levels, 64% (V1 respectively 41% (V2, were applied in duplicate. At the end of the experiment, the specific growth rate (SGR, calculated as mean value of both repetitions for each variant, was 4,64%/day at V1 and 4,63%/day at V2. Protein efficiency ratio PER (g/g registered a better value at V2 (2.55 g/g, comparing to V1 (1.62 g/g. Regarding feed conversion ratio, almost identical values were observed in case of both experimental variants: 0,96 at V1 and 0.97 at V2. The final results of the experiment showed that while PER was significantly influenced by dietary protein levels, the rest of growing indicators had a very limited variation scale.

  16. Multivariable H{sub 2} and H{infinity} control for a wind energy conversion system - a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Ronilson; Coutinho, Gilmar Alves; Ferreira, Alexandre Jose; Torga, Flavio Allison [Universidade Federal de Ouro Preto (EM/DECAT/UFOP), MG (Brazil). Escola de Minas. Dept. de Engenharia de Controle e Automacao e de Tecnicas Fundamentais], Emails: rocha@em.ufop.br, gacoutinho@gmail.com, aleengaut@yahoo.com.br, torgautomacao@yahoo.com.br

    2010-10-15

    The Wind Energy Conversion System (WECS) is a nonlinear system, highly dependent on a stochastic variable characterized by sudden variations, and subjected to cyclical disturbances caused by operational phenomena. Thus, the quality of a WECS controller is measured by its capacity to deal with unmodeled dynamics, stochastic signals, and periodic, as well as non-periodic disturbances. Since the WECS' objectives can be easily specified in terms of maximum allowable gain in the disturbance-to-output transfer functions, H2 and H{infinity} methodologies can be good options for designing a WECS stabilizing controller, combining specifications such as: disturbance attenuation, asymptotic tracking, bandwidth limitation, robust stability, and trade-off between performance and control effort. Designs for WECS multivariable feedback controllers based on H2 and H{infinity} methodologies are presented in this paper. The performances of both controllers are computationally simulated, analyzed and compared in order to identify the advantages and drawbacks of each controller design. (author)

  17. Geo-spatial multi-criteria analysis for wave energy conversion system deployment

    Energy Technology Data Exchange (ETDEWEB)

    Nobre, Ana; Pacheco, Miguel [Data Centre, Instituto Hidrografico, Portuguese Navy, Rua das Trinas 49, 1249-093 Lisboa (Portugal); Jorge, Raquel; Lopes, M.F.P.; Gato, L.M.C. [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais 1, 1049-001, Lisboa (Portugal)

    2009-01-15

    The growing requirements for renewable energy production lead to the development of a new series of systems, including wave energy conversion systems. Due to their sensitivity and the impact of the aggressive marine environment, the selection of the most adequate location for these systems is a major and very important task. Several factors, such as technological limitations, environmental conditions, administrative and logistic conditions, have to be taken into account in order to support the decision for best location. This paper describes a geo-spatial multi-criteria analysis methodology, based on geographic information systems technology, for identification of the best location to deploy a wave energy farm. This methodology is not conversion system dependent and therefore can be easily customized for different systems and implementation conditions. Selection factors can include, for example, ocean depth, sea bottom type, existing underwater cables, marine protected areas, ports location, shoreline, power grid location, military exercise areas, climatology of wave significant height, period and power. A case study demonstrating this methodology is presented, for an area offshore the Portuguese southwest coast. The system output allows a clear differential identification of the best spots for implementing a wave energy farm. It is not just a simple Boolean result showing valid and invalid locations, but a layer with a valued suitability for farm deployment. (author)

  18. Solid Waste Information and Tracking System Client Server Conversion Project Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    GLASSCOCK, J.A.

    2000-02-10

    The Project Management Plan governing the conversion of SWITS to a client-server architecture. The PMP describes the background, planning and management of the SWITS conversion. Requirements and specification documentation needed for the SWITS conversion

  19. Ocean Current Energy Conversion System in Wallacea Region Using Variable Speed Control Approach

    Directory of Open Access Journals (Sweden)

    Aditya Sukma Nugraha

    2012-03-01

    Full Text Available Ocean Current Energy Conversion System (OCECS is a promising green energy resource in this globe. The Thermohaline circulation data indicates that the Wallacea region has the potential of ocean current energy resources. This paper is aimed to propose research and development of OCECSs to be implemented in the Wallacea region. Firstly, four types of green energy conversion systems extracted from ocean are reviewed. Their advantages and disadvantages are discussed. Secondly, the potential of OCECS in the Wallacea region is described. Third, many types of turbines used for OCECS are reviewed and the turbine type for OCECS is selected to be implemented in the Wallacea region. Fourth, control strategy is proposed.From the work reported in this paper it is concluded that it is appropriate to implement OCECSs using axial flow water turbines in the Wallacea region, and that to maximize energy conversion variable speed control approach is selected together with control of mechanism to move the turbine vertically as well as to rotate the turbine in yaw direction. 

  20. Rates of intraoperative complications and conversion to laparotomy during laparoscopic ovariectomy performed by veterinary students: 161 cases (2010-2014).

    Science.gov (United States)

    Nylund, Adam M; Drury, Adam; Weir, Heather; Monnet, Eric

    2017-07-01

    OBJECTIVE To assess rates of intraoperative complications and conversion to laparotomy associated with supervised veterinary students performing laparoscopic ovariectomy in dogs. DESIGN Retrospective case series. ANIMALS 161 female shelter dogs for which elective laparoscopic ovariectomy had been performed by supervised senior (fourth-year) veterinary students from 2010 through 2014. PROCEDURES Medical records of all dogs were reviewed and data collected regarding duration of surgery, surgical complications and other characteristics, and whether conversion to laparotomy was required. RESULTS Laparoscopic ovariectomy was performed with a 2-cannula technique and a 10-mm vessel-sealing device for hemostasis in all dogs. A Veress needle was used for initial insufflation in 144 (89.4%) dogs; method of insufflation was not reported for the remaining 17 (10.6%) dogs. Mean ± SD duration of surgery was 114.90 ± 33.40 minutes. Surgical complications, all classified as minor blood loss, occurred in 24 (14.9%) dogs. These included splenic puncture during insertion of the Veress needle (n = 20 [12.4%]) and minor bleeding from the ovarian pedicle (4 [2.5%]). Splenic puncture required no intervention, and ovarian pedicle bleeding required application of the vessel-sealing device an additional time to control the bleeding. Two ovaries were dropped in the abdominal cavity at the time of removal. Both were retrieved without complication. Conversion to laparotomy was not required for any dog. All dogs were discharged from the hospital within 24 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE Laparoscopic ovariectomy in dogs was performed safely by closely supervised novice surgeons, with only minor intraoperative complications encountered and no need for conversion to laparotomy.

  1. Smart Bioinspired Nanochannels and their Applications in Energy-Conversion Systems.

    Science.gov (United States)

    Li, Ruirui; Fan, Xia; Liu, Zhaoyue; Zhai, Jin

    2017-12-01

    Smart bioinspired nanochannels exhibiting ion-transport properties similar to biological ion channels have attracted extensive attention. Like ion channels in nature, smart bioinspired nanochannels can respond to various stimuli, which lays a solid foundation for mass transport and energy conversion. Fundamental research into smart bioinspired nanochannels not only furthers understanding of life processes in living bodies, but also inspires researchers to construct smart nanodevices to meet the increasing demand for the use of renewable resources. Here, a brief summary of recent research progress regarding the design and preparation of smart bioinspired nanochannels is presented. Moreover, representative applications of smart bioinspired nanochannels in energy-conversion systems are also summarized. Finally, an outlook for future challenges in this field is given. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Making sense of the emerging conversation in evaluation about systems thinking and complexity science.

    Science.gov (United States)

    Gates, Emily F

    2016-12-01

    In the last twenty years, a conversation has emerged in the evaluation field about the potential of systems thinking and complexity science (STCS) to transform the practice of evaluating social interventions. Documenting and interpreting this conversation are necessary to advance our understanding of the significance of using STCS in planning, implementing, and evaluating social interventions. Guided by a generic framework for evaluation practice, this paper reports on an inter-disciplinary literature review and argues that STCS raises some new ways of thinking about and carrying out the following six activities: 1) supporting social problem solving; 2) framing interventions and contexts; 3) selecting and using methods; 4) engaging in valuing; 5) producing and justifying knowledge; and 6) facilitating use. Following a discussion of these issues, future directions for research and practice are suggested. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Progress of conversion system from CAD data to MCNP geometry data in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S., E-mail: sato.satoshi92@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-Mura, Ibaraki-ken 319-1195 (Japan); Nashif, H.; Masuda, F.; Morota, H.; Iida, H. [MHI Nuclear Engineering Company Ltd., Minatoku, Tokyo 108-0075 (Japan); Konno, C. [Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-Mura, Ibaraki-ken 319-1195 (Japan)

    2010-12-15

    Automatic conversion systems from CAD data to MCNP geometry input data have been developed to convert the CAD data of the fusion reactor with very complicated structure. So far, two conversion systems (GEOMIT-1 and ARCMCP) have been developed and the third system (GEOMIT-2) is under developing. The void data can be created in these systems. GEOMIT-1 was developed in 2007, but a lot of manual shape splitting work for the CAD data was required to convert the complicated geometry. ARCMCP was developed in 2008. The algorithm has been drastically improved on automatic creation of ambiguous surface in ARCMCP, but it still required a little manual shape splitting work. The latest system, GEOMIT-2, does not require additional commercial software packages, though the previous systems require them. It also has functions of the CAD data healing and the automatic shape splitting. Geometrical errors of CAD data can be automatically revised by the healing function, and complicated geometries can be automatically split into simple geometries by the shape splitting function. Any manual works for CAD data are not required in GEOMIT-2. GEOMIT-2 is very useful for nuclear analyses of fusion reactors.

  4. Urban Waste Conversion Systems. IGT Project 61030 final report, October 1, 1978-March 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Cowen, D.S.; Daniels, E.J.; Novil, M.

    1980-02-01

    The purpose of this study was to assess the market potential of the various systems available, or under development, for converting urban wastes into synthetic gas or liquids. The primary data base for this assessment is a survey which IGT has sent out to experts in this field. The experts were asked to evaluate various conversion systems by assigning point totals to an evaluation matrix. They were also asked to summarize their work in urban waste conversion, to list critical paths which represent obstacles to be surmounted by R and D, and to assess the effect of those obstacles on the market potential of that process. Critical areas for R and D work focus on materials handling and separation techniques, and protection of equipment from abrasive, caustic, or corrosive chemicals in the wastes. Also, prohibitive capital and operating costs in some existing systems must be cited, since investor confidence is eroded by evidence of such experiences. Downtime has been excessive with many systems, stemming from feed problems brought on by the heterogeneous nature of the feedstock. Systems using homogeneous feeds have shown considerably less problems. Perhaps a critical area from a social impact point of view is, can garbage separation be instituted for the home, factory, etc. If so, the chances for waste converison systems to overcome technical problems on the front end are greatly improved, and so is the potential for market penetration.

  5. Luminescent Spectral Conversion to Improve the Performance of Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Hosseini, Zahra; Taghavinia, Nima; Wei-Guang Diau, Eric

    2017-12-06

    Relative to the broadband solar spectrum, a narrow range of spectral absorption of photovoltaic (PV) devices is considered an important determinant that the efficiency of light harvesting of these devices is less than unity. Having the narrowest spectral response to solar radiation among all PV devices, dye-sensitized solar cells (DSSCs) suffer severely from this loss. Luminescent spectral conversion provides a mechanism to manipulate and to adapt the incident solar spectrum by converting, through photoluminescence, the energies of solar photons into those that are more effectively captured by a PV device. This mechanism is particularly helpful for DSSCs because there is much flexibility in both the choice of the light-harvesting materials and the architecture of the DSSC. Here we review and discuss recent advances in the field of luminescent spectral conversion for DSSCs. The focus is on the architectural design of DSSCs, and the complications, advantages and new functionalities offered by each of their configurations are discussed. The loss mechanisms are examined and important parameters governing the spectral conversion mechanism of a DSSC are introduced. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. New Multiphase Hybrid Boost Converter with Wide Conversion Ratio for PV System

    Directory of Open Access Journals (Sweden)

    Ioana-Monica Pop-Calimanu

    2014-01-01

    Full Text Available A new multiphase hybrid boost converter, with wide conversion ratio as a solution for photovoltaic energy system, is presented in this paper. To ensure that all the phases of the converter operate at the same switching frequency we use interleaving topology. The proposed converter can be used as an interface between the PV system and the DC load/inverter. This multiphase converter has the advantage of reduced value and physical size of the input and output capacitor as well as the effort for the inductors. To validate the operation of the converter we provide the analyses and the simulation results of the converter.

  7. Electrical energy conversion system design with single-phase inverter and H5 transformerless topology

    OpenAIRE

    Colina Morles, Eliézer

    2014-01-01

    This paper presents the design of an electrical energy conversion system (EECS) for the use of solar energy and its conditioning for injection of energy to the commercial power grid. A single-phase full-bridge inverter with transformerless H5 topology coupled to a LCL filter is used. The system is identified using an averaged small-signal state space model; while the used cascade control scheme is tuned by pole placement and includes a maximum power disturb-observe tracking type algorithm of ...

  8. High-temperature nuclear closed Brayton cycle power conversion system for the space exploration initiative

    Energy Technology Data Exchange (ETDEWEB)

    Brandes, D.J. (Allied-Signal Aerospace Company, Garrett Fluid Systems Division, 1300 West Warner Road, Tempe, Arizona 85284-2896 (US))

    1991-01-05

    The Space Exploration Initiative (SEI) has stated goals of colonizing the moon and conducting manned exploration of the planet Mars. Unlike previous ventures into space, both manned and unmanned, large quantities of electrical power will be required to provide the energy for lunar base sustenance and for highly efficient propulsion systems for the long trip to mars and return. Further, the requirement for electrical power of several megawatts will necessitate the use of nuclear reactor driven power conversion systems. This paper discusses a particle bed reactor closed Brayton cycle space power system that uses advanced materials technology to achieve a high-temperature, low-specific-weight modular system capable of providing the requisite electrical power for both a lunar base and a Mars flight vehicle propulsion system.

  9. Relations among Social Anxiety, Eye Contact Avoidance, State Anxiety, and Perception of Interaction Performance during a Live Conversation.

    Science.gov (United States)

    Howell, Ashley N; Zibulsky, Devin A; Srivastav, Akanksha; Weeks, Justin W

    2016-01-01

    There is building evidence that highly socially anxious (HSA) individuals frequently avoid making eye contact, which may contribute to less meaningful social interactions and maintenance of social anxiety symptoms. However, research to date is lacking in ecological validity due to the usage of either static or pre-recorded facial stimuli or subjective coding of eye contact. The current study examined the relationships among trait social anxiety, eye contact avoidance, state anxiety, and participants' self-perceptions of interaction performance during a live, four-minute conversation with a confederate via webcam, and while being covertly eye-tracked. Participants included undergraduate women who conversed with same-sex confederates. Results indicated that trait social anxiety was inversely related to eye contact duration and frequency averaged across the four minutes, and positively related to state social anxiety and negative self-ratings. In addition, greater anticipatory state anxiety was associated with reduced eye contact throughout the first minute of the conversation. Eye contact was not related to post-task state anxiety or self-perception of poor performance; although, trends emerged in which these relations may be positive for HSA individuals. The current findings provide enhanced support for the notion that eye contact avoidance is an important feature of social anxiety.

  10. Medium Bandgap Conjugated Polymer for High Performance Polymer Solar Cells Exceeding 9% Power Conversion Efficiency.

    Science.gov (United States)

    Jung, Jae Woong; Liu, Feng; Russell, Thomas P; Jo, Won Ho

    2015-12-02

    Two medium-bandgap polymers composed of benzo[1,2-b:4,5-b']dithiohpene and 2,1,3-benzothiadiazole with 6-octyl-thieno[3,2-b]thiophene as a π-bridge unit are synthesized and their photovoltaic properties are analyzed. The two polymers have deep highest occupied molecular orbital energy levels, high crystallinity, optimal bulk-heterojunction morphology, and efficient charge transport, resulting in a power conversion efficiency of as high as 9.44% for a single-junction polymer solar-cell device. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. High-temperature corrosion and applications of nickel and iron aluminides in coal-conversion power systems

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K. [Argonne National Lab., IL (United States); Tortorelli, P.F. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Nickel and iron aluminide intermetallics are being developed for use as structural materials and/or as cladding for conventional engineering alloys. In addition to strength advantages, these materials exhibit excellent resistance to corrosion in single- and multioxidant environments at elevated temperatures by the formation of slow-growing, adherent alumina scales. Corrosion resistance in a given environment is strongly dependent on the composition of the alloy and on the nature of the corrosive species prevalent in the service environment. This paper presents a comprehensive review of the current status of the corrosion performance of these intermetallics in oxidizing, sulfidizing, and multicomponent gas environments of typical coal-conversion systems. Mechanisms of scale development/breakdown, performance envelopes for long-term usage of these materials, approaches to modifying the surfaces of engineering alloys by cladding or coating them with intermetallics, and in-service experience with these materials are emphasized.

  12. Speed-sensorless control strategy for multi-phase induction generator in wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Dumnić Boris P.

    2016-01-01

    Full Text Available Renewable energy sources, especially wind energy conversion systems (WECS, exhibit constant growth. Increase in power and installed capacity led to advances in WECS topologies. Multi-phase approach presents a new development direction, with several key advantages over three-phase systems. Paired with a sensorless control strategy, multi-phase machines are expected to take primacy over standard solutions. This paper presents speed sensorless vector control of an asymmetrical six-phase induction generator based on a model reference adaptive system (MRAS. Suggested topology and developed control algorithm show that sensorless control can yield appropriate dynamic characteristics for the use in WECS with increase in reliability and robustness. [Projekat Ministarstva nauke Republike Srbije, br. III 042004: Smart Electricity Distribution Grids Based on Distribution Management System and Distributed Generation

  13. Systems analysis research for energy conversion and utilization technologies (ECUT). FY 1985 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, J.J.; Gunn, M.E.; Levinson, T.M.

    1985-11-01

    This Annual Report highlights ECUT accomplishments in the Systems Analysis Project for FY 1985. The Systems Analysis Project was established in 1980 along with the ECUT Division. The Systems Analysis mission is to identify, analyze, and assess R and D needs and research program strategies for advanced conservation technologies. The PNL Systems Analysis staff conducts topical research, provides technical studies, and plans program activities in three areas related to energy conversion and utilization technologies: (1) technology assessment, (2) engineering analysis, and (3) project evaluation and review. This report summarizes the technical results and accomplishments of the FY 1985 projects. They relate mostly to tribology, improved ctalysts, regenerative heat exchangers, robotics and electronics industries, and bioprocessing.

  14. Evaluation of maximum power point tracking in hydrokinetic energy conversion systems

    Directory of Open Access Journals (Sweden)

    Jahangir Khan

    2015-11-01

    Full Text Available Maximum power point tracking is a mature control issue for wind, solar and other systems. On the other hand, being a relatively new technology, detailed discussion on power tracking of hydrokinetic energy conversion systems are generally not available. Prior to developing sophisticated control schemes for use in hydrokinetic systems, existing know-how in wind or solar technologies can be explored. In this study, a comparative evaluation of three generic classes of maximum power point scheme is carried out. These schemes are (a tip speed ratio control, (b power signal feedback control, and (c hill climbing search control. In addition, a novel concept for maximum power point tracking: namely, extremum seeking control is introduced. Detailed and validated system models are used in a simulation environment. Potential advantages and drawbacks of each of these schemes are summarised.

  15. Systemic Approach to Architectural Performance

    Directory of Open Access Journals (Sweden)

    Marie Davidova

    2017-04-01

    Full Text Available First-hand experiences in several design projects that were based on media richness and collaboration are described in this article. Although complex design processes are merely considered as socio-technical systems, they are deeply involved with natural systems. My collaborative research in the field of performance-oriented design combines digital and physical conceptual sketches, simulations and prototyping. GIGA-mapping - is applied to organise the data. The design process uses the most suitable tools, for the subtasks at hand, and the use of media is mixed according to particular requirements. These tools include digital and physical GIGA-mapping, parametric computer aided design (CAD, digital simulation of analyses, as well as sampling and 1:1 prototyping. Also discussed in this article are the methodologies used in several design projects to strategize these tools and the developments and trends in the tools employed.  The paper argues that the digital tools tend to produce similar results through given pre-sets that often do not correspond to real needs. Thus, there is a significant need for mixed methods including prototyping in the creative design process. Media mixing and cooperation across disciplines is unavoidable in the holistic approach to contemporary design. This includes the consideration of diverse biotic and abiotic agents. I argue that physical and digital GIGA-mapping is a crucial tool to use in coping with this complexity. Furthermore, I propose the integration of physical and digital outputs in one GIGA-map and the participation and co-design of biotic and abiotic agents into one rich design research space, which is resulting in an ever-evolving research-design process-result time-based design.

  16. Applying systemic functional linguistics to conversations with dementia: the linguistic construction of relationships between participants.

    Science.gov (United States)

    Müller, Nicole; Mok, Zaneta

    2012-02-01

    Social isolation in dementia is a growing concern as the incidence and prevalence of dementing conditions is on the rise in many societies. Positive social interactions, which foster the construction and enactment of positive interpersonal relationships and therefore positive discursive identities, make an important contribution to emotional well-being. In this article, we investigate how two women diagnosed with dementia of the Alzheimer's type use language to relate to each other and two visiting graduate students. We use Systemic Functional Linguistics as an analytical framework, specifically investigating the use of vocatives and naming, and conversational moves and exchanges. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  17. A statistical analysis of wind speed data used in installation of wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Kavak Akpinar, E. [Firat University, Elazig (Turkey). Mechanical Engineering Dept.; Akpinar, S. [Firat University, Elazig (Turkey). Physics Dept.

    2005-03-01

    Wind speed is the most important parameter in the design and study of wind energy conversion systems. In this study, statistical methods were used to analyze the wind speed data of Keban-Elazig in the east region of Turkey. Measured hourly time series of wind speed data were obtained from the State Meteorological Station in Keban-Elazig over a five-year period from 1998 to 2002. The probability density distributions are derived from the time series data and the distributional parameters are identified. Two probability density functions are fitted to the measured probability distributions on a yearly basis. (author)

  18. Glossary of terms and table of conversion factors used in design of chemical propulsion systems

    Science.gov (United States)

    Keller, R. B., Jr. (Compiler)

    1979-01-01

    The glossary presented is based entirely on terms used in the monographs on Chemical Propulsion. Significant terms relating to material properties and to material fabrication are presented. The terms are arranged in alphabetical order, with multiple word terms appearing in the normal sequence of usage; for example, ablative cooling appears as such, not as cooling, ablative, and lip seal appears as such, not as seal, lip. Conversion Factors for converting U.S. customary units to the International System of Units are presented in alphabetical order of the physical quantity (e.g., density, heat flux, specific impulse) involved.

  19. Bioenergy conversion and storage systems: from conventional electrochemical cells to hybrid bioelectronic devices

    DEFF Research Database (Denmark)

    Pankratov, Dmitrii; Chi, Qijin

    2017-01-01

    machinery for direct conversion of solar energy into electric power, is one of the most promising prospects for green and selfsustainablev energy harvesting. In addition, utilizing the inherent capacitance of electrodes as an activecharge-storing element enables to enhance the efficiency of electron...... transfer processes proceeding in the system and further miniaturization and simplification of a full-function device by elimination of internal capacitors in the electronic circuit. Remarkably, some pioneering attempts to design and create hybrid bioelectrochemical cells have already shown the positive...

  20. Feedstock Supply System Design and Economics for Conversion of Lignocellulosic Biomass to Hydrocarbon Fuels Conversion Pathway: Fast Pyrolysis and Hydrotreating Bio-Oil Pathway "The 2017 Design Case"

    Energy Technology Data Exchange (ETDEWEB)

    Kevin L. Kenney; Kara G. Cafferty; Jacob J. Jacobson; Ian J. Bonner; Garold L. Gresham; J. Richard Hess; William A. Smith; David N. Thompson; Vicki S. Thompson; Jaya Shankar Tumuluru; Neal Yancey

    2014-01-01

    The U.S. Department of Energy promotes the production of liquid fuels from lignocellulosic biomass feedstocks by funding fundamental and applied research that advances the state of technology in biomass sustainable supply, logistics, conversion, and overall system sustainability. As part of its involvement in this program, Idaho National Laboratory (INL) investigates the feedstock logistics economics and sustainability of these fuels. Between 2000 and 2012, INL quantified and the economics and sustainability of moving biomass from the field or stand to the throat of the conversion process using conventional equipment and processes. All previous work to 2012 was designed to improve the efficiency and decrease costs under conventional supply systems. The 2012 programmatic target was to demonstrate a biomass logistics cost of $55/dry Ton for woody biomass delivered to fast pyrolysis conversion facility. The goal was achieved by applying field and process demonstration unit-scale data from harvest, collection, storage, preprocessing, handling, and transportation operations into INL’s biomass logistics model.

  1. Stochastic Model Predictive Fault Tolerant Control Based on Conditional Value at Risk for Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Yun-Tao Shi

    2018-01-01

    Full Text Available Wind energy has been drawing considerable attention in recent years. However, due to the random nature of wind and high failure rate of wind energy conversion systems (WECSs, how to implement fault-tolerant WECS control is becoming a significant issue. This paper addresses the fault-tolerant control problem of a WECS with a probable actuator fault. A new stochastic model predictive control (SMPC fault-tolerant controller with the Conditional Value at Risk (CVaR objective function is proposed in this paper. First, the Markov jump linear model is used to describe the WECS dynamics, which are affected by many stochastic factors, like the wind. The Markov jump linear model can precisely model the random WECS properties. Second, the scenario-based SMPC is used as the controller to address the control problem of the WECS. With this controller, all the possible realizations of the disturbance in prediction horizon are enumerated by scenario trees so that an uncertain SMPC problem can be transformed into a deterministic model predictive control (MPC problem. Finally, the CVaR object function is adopted to improve the fault-tolerant control performance of the SMPC controller. CVaR can provide a balance between the performance and random failure risks of the system. The Min-Max performance index is introduced to compare the fault-tolerant control performance with the proposed controller. The comparison results show that the proposed method has better fault-tolerant control performance.

  2. Flexible Mode Control of Grid Connected Wind Energy Conversion System Using Wavelet

    Directory of Open Access Journals (Sweden)

    Bhavna Jain

    2015-01-01

    Full Text Available Small wind turbine systems offer services to critical loads during grid faults and also connected back to grid in normal condition. The connection of a wind energy conversion system to the grid requires a robust phase locked loop (PLL and continuous monitoring of the grid conditions such as overvoltage, undervoltage, overfrequency, underfrequency, and grid outages. This paper describes a flexible control operation to operate a small wind turbine in both stand-alone mode via planned islanding and grid connected mode as well. In particular, a proper monitoring and control algorithm is required for transition between the modes. A wavelet based energy function is used for detection of grid disturbances as well as recovery of grid so that transition between the modes is made. To obtain good power quality LCL filter is used to reduce ripples. PLL is used for synchronization whenever mode changes from stand-alone to grid connected. Simulation results from a 10 kW wind energy conversion system are included to show the usefulness of the proposed methods. The control method is tested by generated gate pulses for single phase bridge inverter using field programmable gate array (FPGA.

  3. Performance confirmation data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    McAffee, D.A.; Raczka, N.T. [Yucca Mountain Project, Las Vegas, NV (United States)

    1997-12-31

    As part of the Viability Assessment (VA) work, this QAP-3-9 document presents and evaluates a comprehensive set of viable concepts for collecting Performance Confirmation (PC) related data. The concepts include: monitoring subsurface repository air temperatures, humidity levels and gaseous emissions via the subsurface ventilation systems, and monitoring the repository geo-technical parameters and rock mass from bore-holes located along the perimeter main drifts and throughout a series of human-rated Observation Drifts to be located in a plane 25 meters above the plane of the emplacement drifts. A key element of this document is the development and analysis of a purposed multi-purpose Remote Inspection Gantry that would provide direct, real-time visual, thermal, and radiological monitoring of conditions inside operational emplacement drifts and close-up observations of in-situ Waste Packages. Preliminary finite-element analyses are presented that indicate the technological feasibility of operating an inspection gantry inside the operational emplacement drifts for short inspection missions lasting 2--3 hours. Overall reliability, availability, and maintainability of the PC data collection concepts are discussed. Preliminary concepts for PC data collection network are also provided.

  4. IT Performance Dashboard: Systems Dashboard

    Data.gov (United States)

    Department of Veterans Affairs — The IT Performance Dashboard a trusted source for IT performance information across VA. This is available only on the VA intranet. The dashboard is a collection of...

  5. Coordinated Operation of the Electricity and Natural Gas Systems with Bi-directional Energy Conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Zhang, Baohua; Fang, Jiakun

    2017-01-01

    A coordinated operation of the natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables. This work focuses on the unified optimal operation of the integrated natural gas and electricity system considering the network...... constraints in both systems. An iterative method is proposed to deal with the nonlinearity in the proposed model. The models of the natural gas and power system are linearized in every iterative step. Simulation results demonstrate the effectiveness of the approach. Applicability of the proposed method...... is tested in the sample case. Finally, the effect of Power to Gas (P2G) on the daily economic dispatch is also investigated....

  6. Transient Analysis of Manufacturing Systems Performance

    OpenAIRE

    Narahari, Y.; Viswanadham, N

    1994-01-01

    Studies in performance evaluation of automated manufacturing systems, using simulation or analytical models,have always emphasized steady-state or equilibrium performance in preference to transient performance. In this study, we present several situations in manufacturing systems where transient analysis is very important. Manufacturing systems and models in which such situations arise include: systems with failure states and deadlocks, unstable queueing systems, and systems with fluctuating ...

  7. Does laser diode irradiation improve the degree of conversion of simplified dentin bonding systems?

    Directory of Open Access Journals (Sweden)

    Leticia Ferreira de Freitas BRIANEZZI

    Full Text Available Abstract Simplified dentin-bonding systems are clinically employed for most adhesive procedures, and they are prone to hydrolytic degradation. Objective This study aimed to investigate the effect of laser diode irradiation on the degree of conversion (DC, water sorption (WS, and water solubility (WSB of these bonding systems in an attempt to improve their physico-mechanical resistance. Material and Methods Two bonding agents were tested: a two-step total-etch system [Adper™ Single Bond 2, 3M ESPE (SB] and a universal system [Adper™ Single Bond Universal, 3M ESPE (SU]. Square-shaped specimens were prepared and assigned into 4 groups (n=5: SB and SU (control groups – no laser irradiation and SB-L and SU-L [SB and SU laser (L – irradiated groups]. DC was assessed using Fourier transform infrared spectroscopy with attenuated total reflectance. Additional uncured resin samples (≈3.0 µL, n=5 of each adhesive were also scanned for final DC calculation. For WS/WSB tests, similar specimens (n=10 were prepared and measured by monitoring the mass changes after dehydration/water storage cycles. For both tests, adhesive fluids were dropped into standardized Teflon molds (6.0×6.0×1.0 mm, irradiated with a 970-nm laser diode, and then polymerized with an LED-curing unit (1 W/cm2. Results Laser irradiation immediately before photopolymerization increased the DC (% of the tested adhesives: SB-L>SB>SU-L>SU. For WS/WSB (μg/mm3, only the dentin bonding system (DBS was a significant factor (pSU. Conclusion Irradiation with a laser diode improved the degree of conversion of all tested simplified dentin bonding systems, with no impact on water sorption and solubility.

  8. Half-time Tc-99m sestamibi imaging with a direct conversion molecular breast imaging system.

    Science.gov (United States)

    Hruska, Carrie B; Conners, Amy Lynn; Jones, Katie N; Weinmann, Amanda L; Lingineni, Ravi K; Carter, Rickey E; Rhodes, Deborah J; O'Connor, Michael K

    2014-01-15

    In an effort to reduce necessary acquisition time to perform molecular breast imaging (MBI), we compared diagnostic performance of MBI performed with standard 10-min-per-view acquisitions and half-time 5-min-per-view acquisitions, with and without wide beam reconstruction (WBR) processing. Eighty-two bilateral, two-view MBI studies were reviewed. Studies were performed with 300 MBq Tc-99 m sestamibi and a direct conversion molecular breast imaging (DC-MBI) system. Acquisitions were 10 min-per-view; the first half of each was extracted to create 5-min-per-view datasets, and WBR processing was applied.The 10-min-, 5-min-, and 5-min-per-view WBR studies were independently interpreted in a randomized, blinded fashion by two radiologists. Assessments of 1 to 5 were assigned; 4 and 5 were considered test positive. Background parenchymal uptake, lesion type, distribution of non-mass lesions, lesion intensity, and image quality were described. Considering detection of all malignant and benign lesions, 5 min-per-view MBI had lower sensitivity (mean of 70% vs. 85% (p ≤ 0.04) for two readers) and lower area under curve (AUC) (mean of 92.7 vs. 99.6, p ≤ 0.01) but had similar specificity (p = 1.0). WBR processing did not alter sensitivity, specificity, or AUC obtained at 5 min-per-view.Overall agreement in final assessment between 5-min-per-view and 10-min-per-view acquisition types was near perfect (κ = 0.82 to 0.89); however, fair to moderate agreement was observed for assessment category 3 (probably benign) (κ = 0.24 to 0.48). Of 33 malignant lesions, 6 (18%) were changed from assessment of 4 or 5 with 10-min-per-view MBI to assessment of 3 with 5-min-per-view MBI. Image quality of 5-min-per-view studies was reduced compared to 10-min-per-view studies for both readers (3.24 vs. 3.98, p < 0.0001 and 3.60 vs. 3.91, p < 0.0001). WBR processing improved image quality for one reader (3.85 vs. 3.24, p < 0.0001). Although similar

  9. Assessment of materials technology of pressure vessels and piping for coal conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Canonico, D.A.; Cooper, R.H.; Foster, B.E.; McClung, R.W.; Nanstad, R.K.; Robinson, G.C.; Slaughter, G.M.

    1978-08-01

    The current technology of the materials, fabrication, and inspection of pressure vessels and piping for commercial coal conversion systems is reviewed. Comparison is made between the various codes applicable to these conversion systems. Areas of concern, such as material compatibility and fracture toughness, are cited. Recommendations are made that should increase the reliability of these components, the failure of which would result in a major outage of the plant. We believe that to date most of the current studies of various competing processes have emphasized the capital cost aspects to show potential competition with other energy sources but have not adequately examined the influence of design features on both potential maintenance and disruptive failure costs. It appears, for example, that the choice of vessel size (which is dictated by single vs multiple train process designs) has been examined primarily from the standpoint of capital costs. Maintenance, operation, relative part load capability, and relative probability of failure are unanswered questions. The materials having the most favorable mechanical properties and costs, unfortunately, are sensitive to various embrittling phenomena.

  10. Report on the Field Performance of A123Systems’s HymotionTM Plug-in Conversion Module for the Toyota Prius

    Energy Technology Data Exchange (ETDEWEB)

    Huang Iu; John Smart

    2009-04-01

    A123Systems’s HymotionTM L5 Plug-in Conversion Module (PCM) is a supplemental battery system that converts the Toyota Prius hybrid electric vehicle (HEV) into a plug-in hybrid electric vehicle (PHEV). The Hymotion system uses a lithium ion battery pack with 4.5 kWh of useable energy capacity. It recharges by plugging into a standard 110/120V outlet. The system is designed to more than double the Prius fuel efficiency for 30-40 miles of charge depleting range. If the Hymotion pack is fully depleted, the Prius operates as a normal HEV in charge sustaining mode. The Hymotion L5 PCM is the first commercially available aftermarket product complying with CARB emissions and NHTSA impact standards. Since 2006, over 50 initial production Hymotion Plug-in Conversion Modules have been installed in private fleet vehicles across the United States and Canada. With the help of the Idaho National Laboratory, which conducts the U.S. Department of Energy’s (DOE) Advanced Vehicle Testing Activity (AVTA), A123Systems collects real-time vehicle data from each fleet vehicle using on-board data loggers. These data are analyzed to determine vehicle performance. This paper presents the results of this field evaluation. Data to be presented includes the L5 Prius charge depleting range, gasoline fuel efficiency, and electrical energy efficiency. Effects of driving conditions, driving style, and charging patterns on fuel efficiency are also presented. Data show the Toyota Prius equipped with the Hymotion Plug-in Conversion Module is capable of achieving over 100 mpg in certain driving conditions when operating in charge depleting mode.

  11. Hybrid photovoltaic-thermoelectric system for concentrated solar energy conversion: Experimental realization and modeling

    Science.gov (United States)

    Beeri, Ofer; Rotem, Oded; Hazan, Eden; Katz, Eugene A.; Braun, Avi; Gelbstein, Yaniv

    2015-09-01

    An experimental demonstration of the combined photovoltaic (PV) and thermoelectric conversion of concentrated sunlight (with concentration factor, X, up to ˜300) into electricity is presented. The hybrid system is based on a multi-junction PV cell and a thermoelectric generator (TEG). The latter increases the electric power of the system and dissipates some of the excessive heat. For X ≤ 200, the system's maximal efficiency, ˜32%, was mostly due to the contribution from the PV cell. With increasing X and system temperature, the PV cell's efficiency decreased while that of the TEG increased. Accordingly, the direct electrical contribution of the TEG started to dominate in the total system power, reaching ˜20% at X ≈ 290. Using a simple steady state finite element modeling, the cooling effect of the TEG on the hybrid system's efficiency was proved to be even more significant than its direct electrical contribution for high solar concentrations. As a result, the total efficiency contribution of the TEG reached ˜40% at X ≈ 200. This suggests a new system optimization concept that takes into account the PV cell's temperature dependence and the trade-off between the direct electrical generation and cooling capabilities of the TEG. It is shown that the hybrid system has a real potential to exceed 50% total efficiency by using more advanced PV cells and TE materials.

  12. Probabilistic performance-based design for high performance control systems

    Science.gov (United States)

    Micheli, Laura; Cao, Liang; Gong, Yongqiang; Cancelli, Alessandro; Laflamme, Simon; Alipour, Alice

    2017-04-01

    High performance control systems (HPCS) are advanced damping systems capable of high damping performance over a wide frequency bandwidth, ideal for mitigation of multi-hazards. They include active, semi-active, and hybrid damping systems. However, HPCS are more expensive than typical passive mitigation systems, rely on power and hardware (e.g., sensors, actuators) to operate, and require maintenance. In this paper, a life cycle cost analysis (LCA) approach is proposed to estimate the economic benefit these systems over the entire life of the structure. The novelty resides in the life cycle cost analysis in the performance based design (PBD) tailored to multi-level wind hazards. This yields a probabilistic performance-based design approach for HPCS. Numerical simulations are conducted on a building located in Boston, MA. LCA are conducted for passive control systems and HPCS, and the concept of controller robustness is demonstrated. Results highlight the promise of the proposed performance-based design procedure.

  13. Ocean thermal energy conversion power system development-I. Phase I. Preliminary design report. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-18

    The results of a conceptual and preliminary design study of Ocean Thermal Energy Conversion (OTEC) closed loop ammonia power system modules performed by Lockheed Missiles and Space Company, Inc. (LMSC) are presented. This design study is the second of 3 tasks in Phase I of the Power System Development-I Project. The Task 2 objectives were to develop: 1) conceptual designs for a 40 to 50-MW(e) closed cycle ammonia commercial plant size power module whose heat exchangers are immersed in seawater and whose ancillary equipments are in a shirt sleeve environment; preliminary designs for a modular application power system sized at 10-MW(e) whose design, construction and material selection is analogous to the 50 MW(e) module, except that titanium tubes are to be used in the heat exchangers; and 3) preliminary designs for heat exchanger test articles (evaporator and condenser) representative of the 50-MW(e) heat exchangers using aluminum alloy, suitable for seawater service, for testing on OTEC-1. The reference ocean platform was specified by DOE as a surface vessel with the heat exchanger immersed in seawater to a design depth of 0 to 20 ft measured from the top of the heat exchanger. For the 50-MW(e) module, the OTEC 400-MW(e) Plant Ship, defined in the Platform Configuration and Integration study, was used as the reference platform. System design, performance, and cost are presented. (WHK)

  14. Prospects for the development of independent power supply systems on the basis of solid fuel thermal conversion technology

    Science.gov (United States)

    Sultanguzin, I. A.; Fedyukhin, A. V.; Kurzanov, S. Yu.; Gyulmaliev, A. M.; Stepanova, T. A.; Tumanovsky, V. A.; Titov, D. P.

    2015-05-01

    Theoretical principles of using solid fuel for organizing independent power supply to small settlements and industrial consumers are considered. Thermogravimetric experiments have been carried out for a few types of wood with determining the universal kinetic parameters characterizing the pyrolysis process. A procedure for describing the solid fuel thermal decomposition process has been proposed that is based on writing the equations of four independent parallel thermal decomposition reactions for each component of the initial raw material. A software package has been developed using which the calorific value, composition, and volume of the gas produced in the thermal conversion of solid fuels can be estimated. The impact of operating parameters on the synthesis gas composition has been evaluated. It has been found that increasing the thermal conversion temperature results in a higher calorific value of the obtained gas per unit weight of the feedstock. A qualitative and quantitative comparison of the computational model and the results obtained during experimental studies on the existing gasifier has been carried out. It is shown that the parameters of gas obtained on the test bench are consistent with the calculated ones in both the amount of gas and its chemical energy. The combined-cycle power plant flow chart involving the biomass gasification process has been numerically simulated in the Aspen Plus computer program, and calculations aimed at determining the optimal operating parameters of different thermal process circuit components and of the entire CCP system were performed.

  15. Conversion therapy of gastric cancer with massive malignant ascites and ovarian metastases by systemic and intraperitoneal chemotherapy.

    Science.gov (United States)

    Kondo, Tomohiro; Kitayama, Hiromitsu; Sugiyama, Junko; Hirayama, Michiaki; Suzuki, Yoshinori; Oyamada, Yumiko; Tsuji, Yasushi

    2016-12-01

    Intravenous and intraperitoneal paclitaxel with S-1 is showing promising results in gastric cancer with peritoneal metastases. We herein report a successful conversion of unresectable to resectable disease using combination chemotherapy with trastuzumab. The patient was a 39-year-old woman with human epidermal growth factor receptor 2-positive gastric cancer with peritoneal, pulmonary and bilateral ovarian metastases. After 6 cycles of S-1 plus cisplatin with trastuzumab, followed by 15 cycles of intravenous and intraperitoneal paclitaxel with S-1 and trastuzumab, the pulmonary and peritoneal metastases exhibited complete response and no evidence of malignancy was found on diagnostic laparoscopy. We performed metastasectomy of the bilateral sizeable ovaries, followed by total gastrectomy. The patient had no recurrence for 16 months after the gastrectomy. Therefore, satisfactory response to systemic and intraperitoneal chemotherapy may convert unresectable to resectable disease, and primary tumor resection with ovarian metastasectomy may prolong survival. This combination chemotherapy has the potential of becoming a conversion therapy for gastric cancer with peritoneal metastases, even if ascites and ovarian metastases are extensive.

  16. Experimental demonstration of information to energy conversion in a quantum system at the Landauer limit.

    Science.gov (United States)

    Peterson, J P S; Sarthour, R S; Souza, A M; Oliveira, I S; Goold, J; Modi, K; Soares-Pinto, D O; Céleri, L C

    2016-04-01

    Landauer's principle sets fundamental thermodynamical constraints for classical and quantum information processing, thus affecting not only various branches of physics, but also of computer science and engineering. Despite its importance, this principle was only recently experimentally considered for classical systems. Here we employ a nuclear magnetic resonance set-up to experimentally address the information to energy conversion in a quantum system. Specifically, we consider a three nuclear spins [Formula: see text] (qubits) molecule-the system, the reservoir and the ancilla-to measure the heat dissipated during the implementation of a global system-reservoir unitary interaction that changes the information content of the system. By employing an interferometric technique, we were able to reconstruct the heat distribution associated with the unitary interaction. Then, through quantum state tomography, we measured the relative change in the entropy of the system. In this way, we were able to verify that an operation that changes the information content of the system must necessarily generate heat in the reservoir, exactly as predicted by Landauer's principle. The scheme presented here allows for the detailed study of irreversible entropy production in quantum information processors.

  17. Robust Fault Detection of Wind Energy Conversion Systems Based on Dynamic Neural Networks

    Directory of Open Access Journals (Sweden)

    Nasser Talebi

    2014-01-01

    Full Text Available Occurrence of faults in wind energy conversion systems (WECSs is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS is required. Recurrent neural networks (RNNs have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate.

  18. Robust fault detection of wind energy conversion systems based on dynamic neural networks.

    Science.gov (United States)

    Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

    2014-01-01

    Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate.

  19. A current controlled matrix converter for wind energy conversion systems based on permanent magnet synchronous generator

    Directory of Open Access Journals (Sweden)

    Naggar H. Saad

    2016-05-01

    Full Text Available The main challenges of wind energy conversion systems (WECS are to maximize the energy capture from the wind and injecting reactive power during the fault. This paper presents a current controlled matrix converter to interface Permanent Magnet Synchronous Generators (PMSG based WECS with the grid. To achieve fast dynamic response with reduced current ripples, a hysteresis current control is utilized. The proposed control system decouples the active and reactive components of the PMSG current to extract the maximum power from the wind at a given wind velocity and to inject reactive power to the grid. Reactive power injection during the fault satisfying the grid-codes requirement. The proposed WECS has been modeled and simulated using PSCAD/EMTDC software package.

  20. Conversion and Validation of Distribution System Model from a QSTS-Based Tool to a Real-Time Dynamic Phasor Simulator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Chamana, Manohar; Prabakar, Kumaraguru; Palmintier, Bryan; Baggu, Murali M.

    2017-04-11

    A software process is developed to convert distribution network models from a quasi-static time-series tool (OpenDSS) to a real-time dynamic phasor simulator (ePHASORSIM). The description of this process in this paper would be helpful for researchers who intend to perform similar conversions. The converter could be utilized directly by users of real-time simulators who intend to perform software-in-the-loop or hardware-in-the-loop tests on large distribution test feeders for a range of use cases, including testing functions of advanced distribution management systems against a simulated distribution system. In the future, the developers intend to release the conversion tool as open source to enable use by others.

  1. Develop the dual fuel conversion system for high output, medium speed diesel engines. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-16

    The original plan for the project involved design modifications to an existing system to enhance its performance and increase the limit of power that was achieved by the original design and to apply the higher performance product to the full sized engine and test its performance. The new system would also be applied to a different engine model. The specific work would include the redesign of gas injectors, piston configurations and two types of igniters, engine instrumentation, monitoring and testing.

  2. Ocean Thermal Energy Conversion power system development. Phase I: preliminary design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    Westinghouse has completed the Preliminary Desigh Phase for the Power System Development of the Ocean Thermal Energy Conversion (OTEC) Demonstration Plant project. This study included the development of a preliminary design for a Modular Application scaled power system (10MWe) and Heat Exchanger Test Articles, both based on the concept developed in the Conceptual Design Phase. The results of this study were used to improve the baseline design of the 50MWe module for the Commercial Size Power System, which was recommended for the demonstration plant by the conceptual design study. The 50MWe module was selected since it has the lowest cost, and since its size convincingly demonstrates that future economically viable commercial plants, having reliable operation with credible anticipated costs, are possible. Additional optimization studies on the size of the power system plus hull continue to identify 50MWe as the preferred minimum cost configuration. This study was limited to a closed cycle ammonia power system module, using a seawater temperature difference of 40/sup 0/F, and a surface platform/ship reference hull. This volume presents the preliminary design configuration and system optimization. (WHK)

  3. A Fast linking approach for CMYK to CMYK conversion preserving black separation in ICC color management system

    Science.gov (United States)

    Zeng, Huanzhao

    2003-12-01

    In the linking step of the standard ICC color management workflow for CMYK to CMYK conversion, a CMM takes an AToBn tag (n = 0, 1, or 2) from a source ICC profile to convert a color from the source color space to PCS (profile connection space), and then takes a BToAn tag from the destination ICC profile to convert the color from PCS to the destination color space. This approach may give satisfactory result perceptually or colorimetrically. However, it does not preserve the K channel for CMYK to CMYK conversion, which is often required in graphic art"s market. The problem is that the structure of a BtoAn tag is designed to convert colors from PCS to a device color space ignoring the K values from the source color space. Different approaches have been developed to control K in CMYK to CMYK printing, yet none of them well fits into the "Profile - PCS - Profile" model in the ICC color management system. A traditional approach is to transform the source CMYK to the destination CMYK by 1-D TRC curves and GCR/UCR tables. This method is so simple that it cannot accurately transform colors perceptually or colorimetrically. Another method is to build a 4-D CMYK to CMYK closed-loop lookup table (LUT) (or a deviceLink ICC profile) for the color transformation. However, this approach does not fit into opened color management workflows for it ties the source and the destination color spaces in the color characterization step. A specialized CMM may preserve K for a limit number of colors by mapping those CMYK colors to some carefully chosen PCS colors in both the AToBi tag and the BToAi tag. A more complete solution is to move to smart linking in which gamut mapping is performed in the real-time linking at a CMM. This method seems to solve all problems existed in the CMYK to CMYK conversion. However, it introduces new problems: 1) gamut mapping at real-time linking is often unacceptable slow; 2) gamut mapping may not be optimized or may be unreliable; 3) manual adjustment for

  4. Quantitative performance assessments for neuromagnetic imaging systems.

    Science.gov (United States)

    Koga, Ryo; Hiyama, Ei; Matsumoto, Takuya; Sekihara, Kensuke

    2013-01-01

    We have developed a Monte-Carlo simulation method to assess the performance of neuromagnetic imaging systems using two kinds of performance metrics: A-prime metric and spatial resolution. We compute these performance metrics for virtual sensor systems having 80, 160, 320, and 640 sensors, and discuss how the system performance is improved, depending on the number of sensors. We also compute these metrics for existing whole-head MEG systems, MEGvision™ (Yokogawa Electric Corporation, Tokyo, Japan) that uses axial-gradiometer sensors, and TRIUX™ (Elekta Corporate, Stockholm, Sweden) that uses planar-gradiometer and magnetometer sensors. We discuss performance comparisons between these significantly different systems.

  5. Image quality evaluation of direct-conversion digital mammography system with new dual a-Se layer detector

    Science.gov (United States)

    Kuwabara, Takao; Iwasaki, Nobuyuki; Sendai, Tomonari; Furue, Ryosuke; Agano, Toshitaka

    2009-02-01

    To increase the detection performance of breast cancers in mammograms, we need to improve shape delineation of micro calcifications and tumors. We accomplished this by developing a direct-conversion mammography system with an optical reading method and a new dual a-Se layer detector. The system achieved both small pixel size (50 micrometer) and a high Detective Quantum Efficiency (DQE) realized by 100 % of fill factor and noise reduction. We evaluated image quality performance and determined the best exposure conditions. We measured DQE and Modulation Transfer Function(MTF) according to the IEC62220-1-2. High DQE was maintained at a low radiation dosage, indicating that the optical reading method accompanies low noises. Response of MTF was maintained at up to the Nyquist frequency of 10 cyc/mm, which corresponds to 50 micrometer pixel size. To determine the best exposure conditions, we measured Contrast to Noise Ratio (CNR) and visually evaluated images of a resected breast under conditions of MoMo, MoRh, and WRh. There were occasional disagreements between the exposure conditions for achieving the maximum CNR and those for the best image graded by the visual evaluation. This was probably because CNR measurement does not measure effects of scattered X-ray. The images verified the improvement in detection and delineation performance of micro calcifications and tumors.

  6. Improving Process Heating System Performance v3

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-04-11

    Improving Process Heating System Performance: A Sourcebook for Industry is a development of the U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) and the Industrial Heating Equipment Association (IHEA). The AMO and IHEA undertook this project as part of an series of sourcebook publications developed by AMO on energy-consuming industrial systems, and opportunities to improve performance. Other topics in this series include compressed air systems, pumping systems, fan systems, steam systems, and motors and drives

  7. Investigating conversational dynamics: Interactive alignment, Interpersonal synergy, and collective task performance

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between inte...

  8. Open-cycle OTEC system performance analysis. [Claude cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, A.A.; Olson, D.A.; Johnson, D.H.

    1980-10-01

    An algorithm developed to calculate the performance of Claude-Cycle ocean thermal energy conversion (OTEC) systems is described. The algorithm treats each component of the system separately and then interfaces them to form a complete system, allowing a component to be changed without changing the rest of the algorithm. Two components that are subject to change are the evaporator and condenser. For this study we developed mathematical models of a channel-flow evaporator and both a horizontal jet and spray director contact condenser. The algorithm was then programmed to run on SERI's CDC 7600 computer and used to calculate the effect on performance of deaerating the warm and cold water streams before entering the evaporator and condenser, respectively. This study indicates that there is no advantage to removing air from these streams compared with removing the air from the condenser.

  9. Standard Guide for Specifying Thermal Performance of Geothermal Power Systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide covers power plant performance terms and criteria for use in evaluation and comparison of geothermal energy conversion and power generation systems. The special nature of these geothermal systems makes performance criteria commonly used to evaluate conventional fossil fuel-fired systems of limited value. This guide identifies the limitations of the less useful criteria and defines an equitable basis for measuring the quality of differing thermal cycles and plant equipment for geothermal resources. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. On the rejection of internal and external disturbances in a wind energy conversion system with direct-driven PMSG.

    Science.gov (United States)

    Li, Shengquan; Zhang, Kezhao; Li, Juan; Liu, Chao

    2016-03-01

    This paper deals with the critical issue in a wind energy conversion system (WECS) based on a direct-driven permanent magnet synchronous generator (PMSG): the rejection of lumped disturbance, including the system uncertainties in the internal dynamics and unknown external forces. To simultaneously track the motor speed in real time and capture the maximum power, a maximum power point tracking strategy is proposed based on active disturbance rejection control (ADRC) theory. In real application, system inertia, drive torque and some other parameters change in a wide range with the variations of disturbances and wind speeds, which substantially degrade the performance of WECS. The ADRC design must incorporate the available model information into an extended state observer (ESO) to compensate the lumped disturbance efficiently. Based on this principle, a model-compensation ADRC is proposed in this paper. Simulation study is conducted to evaluate the performance of the proposed control strategy. It is shown that the effect of lumped disturbance is compensated in a more effective way compared with the traditional ADRC approach. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Cognitive performance modeling based on general systems performance theory.

    Science.gov (United States)

    Kondraske, George V

    2010-01-01

    General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

  12. Performance assurance for IT systems

    CERN Document Server

    King, Brian

    2004-01-01

    INDIVIDUAL AREAS OF INTERESTPreparing for the ChallengeAbstractIntroductionIn the BeginningThe Need to Address New ApplicationsDefinition of PerformanceThe Required SkillsPerformance Assurance Within a Project LifecycleSummaryCaveat Emptor (Let the Buyer Beware)AbstractSoftware Product LifecycleHardware Product LifecycleMarketingTechnical Reviews of ProductsLies, Damned Lies and BenchmarksAbstractIntroductionIndustry BenchmarksVendor BenchmarksIndependent BenchmarkingIn-House Benchmarking""Tricks of the Trade""Using Benchmarks Non-Functional Requirements and SolutionsAbstractIntroductionThe Pr

  13. Online Data Conversion for the LHCb Active Radiation Monitor System (ARMS)

    CERN Document Server

    Farrugia, Julia

    2015-01-01

    Active radiation monitors are distributed in and around the LHCb experiment in order to monitor the evolution of radiation dose and 1 MeV equivalent neutron fluence. The active monitors are connected to an online network and their raw voltage measurement can be read out via WinCC panels. However, the raw voltage measurements must be corrected before conversion into correct dose or fluence. Previous work by [1] included a signal correction algorithm that corrects the values offline. The aim of this work is to understand how the signal correction algorithm works, archive previously corrected values into a new database system that will be integrated to a WinCC graphical interface and modify the algorithm so that it may process new values online while using less time and computing resources.

  14. Ocean Thermal Energy Conversion program. EPFFEP program for OTEC structural systems

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, H.; Chen, W. F.

    1976-01-01

    A constitutive relation and failure criterion for concrete material under general three-dimensional stress states has been developed using the work-hardening theory of plasticity. The formulation has all the required properties of concrete and gives a close estimate to experimental stresses for complete general stress states. In order that the results of research be readily usable in the analysis of suboceanic structures such as the large shells proposed for adoption in the Ocean Thermal Energy Conversion program (OTEC), corresponding computer code called EPFFEP (Elastic Plastic Fracture Finite Element Program) is developed here to reflect this material response. This report describes the details of this program and its implementation on the computer system CDC 6400. It defines all the input and output of the program along with an example illustrating a typical application of EPFFEP modeling. Detail computer algorithm for the constitutive relations of concrete is also given in the form of flow charts.

  15. The direct conversion of sugars into 2,5-furandicarboxylic acid in a triphasic system.

    Science.gov (United States)

    Yi, Guangshun; Teong, Siew Ping; Zhang, Yugen

    2015-04-13

    A one-pot conversion of sugars into 2,5-furandicarboxylic acid (FDCA) is demonstrated in a triphasic system: tetraethylammonium bromide (TEAB) or water-methyl isobutyl ketone (MIBK)-water. In this reaction, sugars are first converted into 5-hydroxymethylfurfural (HMF) in TEAB or water (Phase I). The HMF in Phase I is then extracted to MIBK (Phase II) and transferred to water (Phase III), where HMF is converted into FDCA. Phase II plays multiple roles: as a bridge for HMF extraction, transportation and purification. Overall FDCA yields of 78 % and 50 % are achieved from fructose and glucose respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Exergy analysis for resource conversion of the Chinese Society 1993 under the material product system

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B.; Chen, G.Q. [National Laboratory for Complex Systems and Turbulence, Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)

    2006-07-15

    The resource exergy conversion in Chinese society in 1993 under the material product system (MPS) was investigated. Major resources that entered the society were divided into subgroups and analyzed in detail. The end use was broken down into ten end-use sectors: the forestry industry, food industry, iron and steel industry, nonferrous metal industry, chemical industry, textile industry, transportation, households, commerce, other industry. The total exergy input was 62.9EJ, which was 53.3GJ/cap. The total exergy output contained 11.66EJ or 9.88GJ/cap, which was 19% of the total exergy input. One RMB (Chinese Renminbi) yuan ($ 0.17) corresponded to 3.37MJ resource exergy output. (author)

  17. Financial problems facing the manufacturers of small wind energy conversion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bolle, T G

    1979-11-01

    The financial barriers faced by the manufacturers of small wind energy conversion systems (SWECS) are assessed and found to be similar to those faced by other start up businesses. However, these problems are found to be aggravated by the high expectations for accelerated SWECS industry growth in the face of moderate government support and lack of investment capital. The underlying conditions of limited SWECS entrepreneur business experience, the highly competitive venture capital market, the inability of existing financial institutions to aid infant busineses and public unawareness of SWECS are reviewed. Specific manufacturer-oriented recommendations and federal, state and regulatory policy-oriented recommendations are made. In addition, the dynamics of the SWECS commercialization process are assessed and the variety of financial institutions playing a role in this process is detailed. Issues related to inflation, tax policy, regulation and federal R and D procurement policies are analyzed.

  18. Clean energy systems in the subsurface. Production, storage and conversion. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Zhengmeng Michael; Were, Patrick (eds.) [Clausthal Univ. of Technology, Goslar (Germany). Energie-Forschungszentrum Niedersachsen (EFZN); Xie, Heping [Sichuan Univ., Chengdu (China)

    2013-04-01

    Recent research on Integrated Energy and Environmental Utilization of Deep Underground Space. Results of the 3{sup rd} Sino-German Conference ''Underground Storage of CO{sub 2} and Energy'', held at Goslar, Germany, 21-23 May 2013. Researchers and professionals from academia and industry discuss the future of deep underground space technologies for an integrated energy and environmental utilization. Anthropogenic greenhouse gas emissions, energy security and sustainability are three of the greatest contemporary global challenges today. This year the Sino-German Cooperation Group ''Underground Storage of CO{sub 2} and Energy'', is meeting on the 21-23 May 2013 for the second time in Goslar, Germany, to convene its 3{sup rd} Sino-German conference on the theme ''Clean Energy Systems in the Subsurface: Production, Storage and Conversion''.

  19. Investigating the Influence of Mesoporosity in Zeolite Beta on its Catalytic Performance for the Conversion of Methanol to Hydrocarbons

    KAUST Repository

    Liu, Zhaohui

    2015-08-26

    Hierarchically porous zeolite Beta (Beta-MS) synthesized by a soft-templating method contains remarkable intra-crystalline mesoporosity, which reduces the diffusion length in zeolite channels down to several nanometers and alters the distribution of Al among distinct crystallographic sites. When used as a catalyst for the conversion of methanol to hydrocarbons (MTH) at 330 oC, Beta-MS exhibited a 2.7-fold larger conversion capacity, a 2.0-fold faster reaction rate, and a remarkably longer lifetime than conventional zeolite Beta (Beta-C). The superior catalytic performance of Beta-MS is attributed to its hierarchical structure, which offers full accessibility to all catalytic active sites. In contrast, Beta-C was easily deactivated because a layer of coke quickly deposited on the outer surfaces of the catalyst crystals, impeding access to interior active sites. This difference is clearly demonstrated by using electron microscopy combined with electron energy loss spectroscopy to probe the distribution of coke in the deactivated catalysts. At both low and high conversions, ranging from 20% to 100%, Beta-MS gave higher selectivity towards higher aliphatics (C4-C7) but lower ethene selectivity compared to Beta-C. Therefore, we conclude that a hierarchical structure decreases the residence time of methylbenzenes in zeolite micropores, disfavoring the propagation of the aromatic-based catalytic cycle. This conclusion is consistent with a recent report on ZSM-5 and is also strongly supported by our analysis of soluble coke species residing in the catalysts. Moreover, we identified an oxygen-containing compound, 4-methyl-benzaldehyde, in the coke, which has not been observed in the MTH reaction before.  

  20. Mass, Energy, Space And Time Systemic Theory--MEST--photoelectric conversion equation

    Science.gov (United States)

    Cao, Dayong

    2010-03-01

    Things have their physical system of the mass, energy, space and time of themselves-MEST. The time is from the frequency of wave, the space is from the amplitude of wave. In the system, the mass-energy is center and the space-time is around. In the general relativity, there is the equation: ma=mg . So get the equation: mar=mv^2=mgr. We use the data of the planets into this equation, and find it is right. (see the figure 1 and table 2) But the kinetic energy's equation is: Ek=mv^2/2mgr. How do explain it? Because the other kinetic energy's equations: Ek=δmc^2 like the wave's energy equation: E'=m'c^2. And things have both of the matter and the wave. So the equation belong to the wave. So the δm can be see like the increased mass of wave of the things. The matter's kinetic energy equal the wave's energy: mv^2/2=δmc^2=δm'c^2. And them give the things the repulsion force together. So the repulsion energy equation is: Er=mv^2=mv^2/2+δm'c^2=mar. The repulsion energy of the planets equal it's potential energy: Er=Ep=GMm/r=mgr. In photoelectron conversion, Not only there is a relationship between the wave and the kinetic energy of the photoelectron, but also there is a relationship between the wave and the mass of the photoelectron. So get the photoelectric conversion equation: m ev^2/2=δm'c^2-E= hν-E, and δm e= h/c λ-m e. The mass of the photoelectron is bigger than the electron's mass.

  1. Investigation of MEBES 4500 system composite performance

    Science.gov (United States)

    DeWitt, Jim; Watson, Joe; Alexander, David W.; Cook, Allen; Gasiorek, Leonard; Mayse, Mark; Naber, Robert J.; Phillips, Wayne; Sauer, Charles A.

    1995-12-01

    MEBES systems are characterized by constituent error performance, whereas masks produced on pattern generators are characterized by composite error performance. System evaluation by constituent specification is notable for the ease with which system calibration can be obtained, monitored, and maintained. Constituent specifications need to be retained for these reasons. This work investigates the composite performance of a MEBES 4500 system when generating masks compared to system constituent performance. Masks with scan-centered and non-scan- centered patterns are characterized and compared with both MEBES-based MARKET metrology and independent tool-based metrology.

  2. Performance Modeling of Mimosa pudica Extract as a Sensitizer for Solar Energy Conversion

    Directory of Open Access Journals (Sweden)

    M. B. Shitta

    2016-01-01

    Full Text Available An organic material is proposed as a sustainable sensitizer and a replacement for the synthetic sensitizer in a dye-sensitized solar cell technology. Using the liquid extract from the leaf of a plant called Mimosa pudica (M. pudica as a sensitizer, the performance characteristics of the extract of M. pudica are investigated. The photo-anode of each of the solar cell sample is passivated with a self-assembly monolayer (SAM from a set of four materials, including alumina, formic acid, gelatine, and oxidized starch. Three sets of five samples of an M. pudica–based solar cell are produced, with the fifth sample used as the control experiment. Each of the solar cell samples has an active area of 0.3848cm2. A two-dimensional finite volume method (FVM is used to model the transport of ions within the monolayer of the solar cell. The performance of the experimentally fabricated solar cells compares qualitatively with the ones obtained from the literature and the simulated solar cells. The highest efficiency of 3% is obtained from the use of the extract as a sensitizer. It is anticipated that the comparison of the performance characteristics with further research on the concentration of M. pudica extract will enhance the development of a reliable and competitive organic solar cell. It is also recommended that further research should be carried out on the concentration of the extract and electrolyte used in this study for a possible improved performance of the cell.

  3. [Conversion of L-cystine and L-cysteine to taurin by the enzyme systems of liver cells].

    Science.gov (United States)

    Soboleva, A V; Krasnoshtanova, A A; Krylov, I A

    2004-01-01

    The kinetics of conversion of sulfur-containing amino acids L-cystine and L-cysteine to taurin by the enzyme system of cattle liver cells was studied, and a mathematical model was developed. It was shown that L-cystine and L-cysteine conversion obeyed the Michaelis-Menten equations of serial-sequential conversions with regard to inhibition by the final product and inactivation. The yield of taurin under the optimized conditions of L-cystine and L-cysteine conversion (temperature, 40 degrees C; pH 1.5 and 3.0, respectively; and addition of enzyme preparations in five equal portions at 2-h intervals) was in the range 80-85% of the substrate weight.

  4. Phase 1: conceptual design. Ocean thermal energy conversion power system development. Volume 2 of 3. Technical details. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-30

    Westinghouse has completed the conceptual design of the Power System for the Ocean Thermal Energy Conversion (OTEC) Demonstration Plant project. This study included the development of a conceptual design for the following three items: first, a full-size power system module for the 100 MWe Demonstration Plant; second, a scaled proof of concept power system; and third, a heat exchanger test article. The study was limited to a closed cycle ammonia power system module, using a water temperature difference of 40/sup 0/F., and a surface platform/ship reference hull. Two power module of 50 MWe each are recommended for the demonstration plant. The 50 MWe module was selected since it has the lowest cost, and since it is of a size which convincingly demonstrates that future economically viable commercial plants, having reliable operation with credible anticipated costs, are possible. A modular, tube bundle approach to heat exchanger design makes large heat exchangers practical and economical. Other power module elements are considered to be within state-of-practice. Technological assessments of all subsystems indicate requirements for verification only, rather than continued research. A complete test program, which will verify the mechanical reliability as well as thermal performance, is recommended.

  5. Investigation of performance and durability of polymer electrolytes for electrochemical energy storage and conversion technologies

    Science.gov (United States)

    Jung, Min-Suk

    Polymeric ion exchange membranes are integral components of electrochemical conversion/storage devices such as fuel cells, water electrolyzers, and redox flow batteries. There has been dramatic progress in the research and development of cation exchange membranes (CEM). NafionRTM (perfluorosulfonic acid membranes) is one example of a state-of-the-art CEM and has been successfully demonstrated in various electrochemical energy devices. Unlike CEMs, anion exchange membranes (AEMs) have been of limited utility to date due to their drawbacks, including poor chemical/mechanical stability and low ionic conductivity. However, alkaline environments result in better activity for electrochemical reactions and afford the possibility of using non-platinum group metal (PGM) electrocatalysts. AEMs, therefore, are still being studied in order to resolve existing challenges in terms of conductivity and stability in alkaline media and in strongly oxidizing solutions. In this work, AEMs derived from different types of polymer backbones were prepared, and their chemical stability and electrochemical property were investigated. Polysulfone (PSF) AEMs were prepared by first chloromethylating polysulfone, then by functionalizing chloromethylated polysulfone (CMPSF) with different base reagents. PSF-trimethylamine (TMA) AEMs showed a 40-fold reduction in vanadium (IV) ion (VO2+) permeability when compared to a NafionRTM membrane and exceptional oxidative stability after exposure to a 1.5 M vanadium (V) ion (VO2+) solution for 90 days. PSF-TMA AEMs were successfully demonstrated in the all-vanadium redox flow battery. Excellent energy efficiencies (>75 %) were attained and sustained over 75 charge-discharge cycles for a vanadium redox flow battery prepared using the PSF-TMA separator. Crosslinking of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) AEMs using diamine was tried with intentions to improve the mechanical stability and electrochemical property of PPO AEM. Crosslinked PPO AEMs (30

  6. Novel, Integrated Reactor/Power Conversion System. Quarterly Report, September 1 - November 30, 1999

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-12-06

    The desired design objectives and operation parameters were determined and system characteristics to be investigated were identified together with critical issues. Specific tasks were outlined and communicated to the performing personnel.

  7. Steam based conversion coating on AA6060 alloy: Effect of sodium silicate chemistry and corrosion performance

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Bordo, Kirill; Tabrizian, Naja

    2017-01-01

    Surface treatment of aluminium alloy AA6060 using an industrially applicable pilot steam jet system with and without silicate chemistry has been investigated. Treatment using steam alone and steam with silicate, resulted in an oxide layer formation with thickness ∼425 nm and ∼160 nm, respectively...

  8. Development of optimal enzymatic and microbial conversion systems for biofuel production

    Science.gov (United States)

    Aramrueang, Natthiporn

    The increase in demand for fuels, along with the concerns over the depletion of fossil fuels and the environmental problems associated with the use of the petroleum-based fuels, has driven the exploitation of clean and renewable energy. Through a collaboration project with Mendota Bioenergy LLC to produce advanced biofuel from sugar beet and other locally grown crops in the Central Valley of California through demonstration and commercial-scale biorefineries, the present study focused on the investigation of selected potential biomass as biofuel feedstock and development of bioconversion systems for sustainable biofuel production. For an efficient biomass-to-biofuel conversion process, three important steps, which are central to this research, must be considered: feedstock characterization, enzymatic hydrolysis of the feedstock, and the bioconversion process. The first part of the research focused on the characterization of various lignocellulosic biomass as feedstocks and investigated their potential ethanol yields. Physical characteristics and chemical composition were analyzed for four sugar beet varieties, three melon varieties, tomato, Jose tall wheatgrass, wheat hay, and wheat straw. Melons and tomato are those products discarded by the growers or processors due to poor quality. The mass-based ethanol potential of each feedstock was determined based on the composition. The high sugar-containing feedstocks are sugar beet roots, melons, and tomato, containing 72%, 63%, and 42% average soluble sugars on a dry basis, respectively. Thus, for these crops, the soluble sugars are the main substrate for ethanol production. The potential ethanol yields, on average, for sugar beet roots, melons, and tomato are 591, 526, and 448 L ethanol/metric ton dry basis (d.b.), respectively. Lignocellulosic biomass, including Jose Tall wheatgrass and wheat straw, are composed primarily of cellulose (27-39% d.b.) and hemicellulose (26-30% d.b.). The ethanol yields from these

  9. Comparison of Stirling engines for use with a 25-kW disk-electric conversion system

    Science.gov (United States)

    Shaltens, Richard K.

    1987-01-01

    Heat engines were evaluated for terrestrial solar heat receivers. The Stirling Engine was identified as one of the most promising engines for terrestrial applications. The potential to meet the Department of Energy (DOE) goals for performance and cost can be met by the free-piston Stirling engine. NASA Lewis is providing technical management for an Advanced Stirling Conversion System (ASCS) through a cooperative interagency agreement with DOE. Parallel contracts were awarded for conceptual designs of an ASCS. Each design will feature a free-piston Stirling engine, a liquid-metal heat pipe receiver, and a means to provide about 25 kW of electric power to a utility grid while meeting long-term performance and goals. The Mechanical Technology, Ins. (MTI) design incorporates a linear alternator to directly convert the solar energy to electricity while the Stirling Technology Company (STC) generates electrical power indirectly by using a hydraulic output to a ground-bases hydraulic pump/motor coupled to a rotating alternator. Both designs use technology which can reasonably be expected to be available in the 1980's. The ASCS designs using a free-piston Stirling engine, a heat transport system, a receiver, and the methods of providing electricity to the utility grid will be discussed.

  10. A Condensed Introduction to the Doubly Fed Induction Generator Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Julius Mwaniki

    2017-01-01

    Full Text Available The increase in wind power penetration, at 456 GW as of June 2016, has resulted in more stringent grid codes which specify that the wind energy conversion systems (WECS must remain connected to the system during and after a grid fault and, furthermore, must offer grid support by providing reactive currents. The doubly fed induction generator (DFIG WECS is a well-proven technology, having been in use in wind power generation for many years and having a large world market share due to its many merits. Newer technologies such as the direct drive gearless permanent magnet synchronous generator have come up to challenge its market share, but the large number of installed machines ensures that it remains of interest in the wind industry. This paper presents a concise introduction of the DFIG WECS covering its construction, operation, merits, demerits, modelling, control types, levels and strategies, faults and their proposed solutions, and, finally, simulation. Qualities for the optimal control strategy are then proposed. The paper is intended to cover major issues related to the DFIG WECS that are a must for an overview of the system and hence serve as an introduction especially for new entrants into this area of study.

  11. Hybrid Intelligent Control Method to Improve the Frequency Support Capability of Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Shin Young Heo

    2015-10-01

    Full Text Available This paper presents a hybrid intelligent control method that enables frequency support control for permanent magnet synchronous generators (PMSGs wind turbines. The proposed method for a wind energy conversion system (WECS is designed to have PMSG modeling and full-scale back-to-back insulated-gate bipolar transistor (IGBT converters comprising the machine and grid side. The controller of the machine side converter (MSC and the grid side converter (GSC are designed to achieve maximum power point tracking (MPPT based on an improved hill climb searching (IHCS control algorithm and de-loaded (DL operation to obtain a power margin. Along with this comprehensive control of maximum power tracking mode based on the IHCS, a method for kinetic energy (KE discharge control of the supporting primary frequency control scheme with DL operation is developed to regulate the short-term frequency response and maintain reliable operation of the power system. The effectiveness of the hybrid intelligent control method is verified by a numerical simulation in PSCAD/EMTDC. Simulation results show that the proposed approach can improve the frequency regulation capability in the power system.

  12. High Quality Factor 80 MHz Microelectromechanical Systems Resonator Utilizing Torsional-to-Transverse Vibration Conversion

    Science.gov (United States)

    Kiso, Masaya; Okada, Mitsuhiro; Fujiura, Hideaki; Miyauchi, Hideo; Niki, Kazuya; Tanigawa, Hiroshi; Suzuki, Kenichiro

    2012-06-01

    A silicon microelectromechanical systems (MEMS) resonator utilizing torsional-to-transverse vibration conversion with quarter-wavelength torsional support beams is designed, fabricated, and evaluated. The resonant frequency for torsional modes mostly depends only on beam length, providing a large tolerance in the fabrication process. However, the following have remained critical issues: the increase in the quality factor (Q-factor) and the reduction in the motional resistance. We propose a new beam structure, in which the MEMS resonator utilizing torsional-to-transverse vibration conversion is anchored by four quarter-wavelength torsional support beams. First, the fabricated resonators are measured with a laser-Doppler (LD) vibrometer. The measured resonant frequency of 78.224 MHz has been in good agreement with the simulated one. The Q-factor has also been measured to be as high as 3.0×104 in vacuum. Then, the electrical characteristic is evaluated with an impedance analyzer. The Q-factor has been electrically measured to be as high as 3.1×104 in vacuum, which agrees well with the mechanically measured one of 3.0×104. The Q-factor has also been electrically measured to be as high as 1.3×104 at atmospheric pressure. In the measurement, a spring softening effect has been clearly observed. By increasing the DC bias voltage from 20 to 40 V, the resonant frequency has decreased by 640 Hz. The extracted motional resistance for a 0.1-µm-gap resonator has been greatly reduced to 0.039 MΩ at 5 V DC, owing to the narrow-gap effect, from that of a 0.25-µm-gap resonator. The tolerance in the fabrication process has also been evaluated and successfully verified from the measurement of the fabricated MEMS resonators.

  13. Investigation of the Performance of D2O-Cooled High-Conversion Reactors for Fuel Cycle Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Hiruta, Hikaru [Idaho National Lab. (INL), Idaho Falls, ID (United States); Youinou, Gilles [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-09-01

    This report presents FY13 activities for the analysis of D2O cooled tight-pitch High-Conversion PWRs (HCPWRs) with U-Pu and Th-U fueled cores aiming at break-even or near breeder conditions while retaining the negative void reactivity. The analyses are carried out from several aspects which could not be covered in FY12 activities. SCALE 6.1 code system is utilized, and a series of simple 3D fuel pin-cell models are developed in order to perform Monte Carlo based criticality and burnup calculations. The performance of U-Pu fueled cores with axial and internal blankets is analyzed in terms of their impact on the relative fissile Pu mass balance, initial Pu enrichment, and void coefficient. In FY12, Pu conversion performances of D2O-cooled HCPWRs fueled with MOX were evaluated with small sized axial/internal DU blankets (approximately 4cm of axial length) in order to ensure the negative void reactivity, which evidently limits the conversion performance of HCPWRs. In this fiscal year report, the axial sizes of DU blankets are extended up to 30 cm in order to evaluate the amount of DU necessary to reach break-even and/or breeding conditions. Several attempts are made in order to attain the milestone of the HCPWR designs (i.e., break-even condition and negative void reactivity) by modeling of HCPWRs under different conditions such as boiling of D2O coolant, MOX with different 235U enrichment, and different target burnups. A similar set of analyses are performed for Th-U fueled cores. Several promising characteristics of 233U over other fissile like 239Pu and 235U, most notably its higher fission neutrons per absorption in thermal and epithermal ranges combined with lower ___ in the fast range than 239Pu allows Th-U cores to be taller than MOX ones. Such an advantage results in 4% higher relative fissile mass balance than that of U-Pu fueled cores while retaining the negative void

  14. Improve Compressed Air System Performance with AIRMaster+

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-05-01

    AIRMaster+ provides a systematic apporach for assessing the supply-side performance of compressed air systems. Using plant-specific data, the software effectively evaluates supply-side operational costs for various equipment configurations and system pro

  15. Steam based conversion coating on AA6060 alloy: Effect of sodium silicate chemistry and corrosion performance

    Science.gov (United States)

    Din, Rameez Ud; Bordo, Kirill; Tabrizian, Naja; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-11-01

    Surface treatment of aluminium alloy AA6060 using an industrially applicable pilot steam jet system with and without silicate chemistry has been investigated. Treatment using steam alone and steam with silicate, resulted in an oxide layer formation with thickness ∼425 nm and ∼160 nm, respectively. Moreover, the use of sodium silicate resulted in the formation of distinct microstructure and incorporation of silicate into the oxide film. These oxide films reduced the anodic activity 4 times, while the corrosion protection by silicate containing oxide was the function of its concentration. Further, in acid salt spray and filiform corrosion tests, oxide layer containing silicate exhibited two times higher corrosion resistance.

  16. Simulated performance of the in-beam conversion-electron spectrometer, SPICE

    Energy Technology Data Exchange (ETDEWEB)

    Ketelhut, S., E-mail: ketelhut@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Evitts, L.J.; Garnsworthy, A.B.; Bolton, C.; Ball, G.C.; Churchman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Dunlop, R. [Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Hackman, G.; Henderson, R.; Moukaddam, M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada); Rand, E.T.; Svensson, C.E. [Department of Physics, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Witmer, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (Canada)

    2014-07-01

    The SPICE spectrometer is a new in-beam electron spectrometer designed to operate in conjunction with the TIGRESS HPGe Clover array at TRIUMF-ISAC. The spectrometer consists of a large area, annular, segmented lithium-drifted silicon electron detector shielded from the target by a photon shield. A permanent magnetic lens directs electrons around the photon shield to the detector. Experiments will be performed utilising Coulomb excitation, inelastic-scattering, transfer and fusion–evaporation reactions using stable and radioactive ion beams with suitable heavy-ion detection. Good detection efficiency can be achieved in a large energy range up to 3500 keV electron energy using several magnetic lens designs which are quickly interchangeable. COMSOL and Geant4 simulations have been used to maximise the detection efficiency. In addition, the simulations have guided the design of components to minimise the contributions from various sources of backgrounds.

  17. Off-axis holographic lens spectrum-splitting photovoltaic system for direct and diffuse solar energy conversion.

    Science.gov (United States)

    Vorndran, Shelby D; Chrysler, Benjamin; Wheelwright, Brian; Angel, Roger; Holman, Zachary; Kostuk, Raymond

    2016-09-20

    This paper describes a high-efficiency, spectrum-splitting photovoltaic module that uses an off-axis volume holographic lens to focus and disperse incident solar illumination to a rectangular shaped high-bandgap indium gallium phosphide cell surrounded by strips of silicon cells. The holographic lens design allows efficient collection of both direct and diffuse illumination to maximize energy yield. We modeled the volume diffraction characteristics using rigorous coupled-wave analysis, and simulated system performance using nonsequential ray tracing and PV cell data from the literature. Under AM 1.5 illumination conditions the simulated module obtained a 30.6% conversion efficiency. This efficiency is a 19.7% relative improvement compared to the more efficient cell in the system (silicon). The module was also simulated under a typical meteorological year of direct and diffuse irradiance in Tucson, Arizona, and Seattle, Washington. Compared to a flat panel silicon module, the holographic spectrum splitting module obtained a relative improvement in energy yield of 17.1% in Tucson and 14.0% in Seattle. An experimental proof-of-concept volume holographic lens was also fabricated in dichromated gelatin to verify the main characteristics of the system. The lens obtained an average first-order diffraction efficiency of 85.4% across the aperture at 532 nm.

  18. Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

    Science.gov (United States)

    Huang, Shoudao; Wu, Xuan; Liu, Xiao; Gao, Jian; He, Yunze

    2017-09-01

    Electric power conversion system (EPCS), which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine (DD-WT). However, this component accounts for the most failures (approximately 60% of the total number) in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring (CM) and fault diagnostics (FD). Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.

  19. ICRF heated enhanced performance modes and mode conversion electron heating in alcator C-mod

    Energy Technology Data Exchange (ETDEWEB)

    Takase, Y.; Golovato, S.; Porkolab, M.; Boivin, R.; Bombarda, F.; Bonoli, P.; Fiore, C.; Garnier, D.; Goetz, J.; Graf, M.; Granetz, R.; Greenwald, M.; Horne, S.; Hubbard, A.; Hutchinson, I.; Irby, J.; LaBombard, B.; Lipschultz, B.; Majeski, R.; Marmar, E.; May, M.; Mazurenko, A.; McCracken, G.; OShea, P.; Pinsker, R.; Reardon, J.; Rice, J.; Rost, C.; Snipes, J.; Terry, J.; Watterson, R.; Welch, B.; Wolfe, S. [MIT Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)

    1996-02-01

    D(H) minority heating experiments were performed at {ital B}{sub {ital T}}=5.3 T with up to 3.5 MW of RF power. The highest stored energy of 130 kJ was achieved in an ELM-free H-mode plasma. The H-mode power threshold is roughly consistent with the ITER scaling, {ital P}/{ital S}=0.044{bar {ital n}}{sub {ital eB}}{sub {ital T}}, but H-modes have been obtained at power levels as much as a factor of two below this scaling. H-factors of up to 1.5 have been observed in ELM-free H-mode plasmas. The highest fusion reactivity of 9{times}10{sup 13} sec{sup {minus}1} was obtained in a PEP H-mode plasma with lithium pellet injection and on-axis ICRF heating. These discharges are characterized by highly peaked density and ion temperature profiles, with fusion reactivity enhanced by typically an order of magnitude above similar L-mode discharges. Effective localized direct electron heating by mode converted IBW was observed in H-{sup 3}He plasmas (analogous to D-T plasmas) at 6.5 T. {copyright} {ital 1996 American Institute of Physics.}

  20. High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

    Science.gov (United States)

    Liu, Wei; Mu, Wei; Deng, Yulin

    2014-12-01

    Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A multi-agent conversational system with heterogeneous data sources access

    KAUST Repository

    Eisman, Eduardo M.

    2016-01-28

    In many of the problems that can be found nowadays, information is scattered across different heterogeneous data sources. Most of the natural language interfaces just focus on a very specific part of the problem (e.g. an interface to a relational database, or an interface to an ontology). However, from the point of view of users, it does not matter where the information is stored, they just want to get the knowledge in an integrated, transparent, efficient, effective, and pleasant way. To solve this problem, this article proposes a generic multi-agent conversational architecture that follows the divide and conquer philosophy and considers two different types of agents. Expert agents are specialized in accessing different knowledge sources, and decision agents coordinate them to provide a coherent final answer to the user. This architecture has been used to design and implement SmartSeller, a specific system which includes a Virtual Assistant to answer general questions and a Bookseller to query a book database. A deep analysis regarding other relevant systems has demonstrated that our proposal provides several improvements at some key features presented along the paper.

  2. Maximum-power-point tracking with reduced mechanical stress applied to wind-energy-conversion-systems

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, L.G. [Departamento de Electronica y Comunicaciones, Universidad de los Andes, nucleo la Hechicera, 5101 Merida (Venezuela); Figueres, E.; Garcera, G. [Grupo de Sistemas Electronicos Industriales, Universidad Politecnica de Valencia, Camino de vera s/n, 46022 Valencia (Spain); Carranza, O. [Escuela Superior de Computo, Instituto Politecnico Nacional, Av. Juan de Dios Batiz s/n, 07738 DF (Mexico)

    2010-07-15

    This paper presents an improved maximum-power-point tracking algorithm for wind-energy-conversion-systems. The proposed method significantly reduces the turbine mechanical stress with regard to conventional techniques, so that both the maintenance needs and the medium time between failures are expected to be improved. To achieve these objectives, a sensorless speed control loop receives its reference signal from a modified Perturb and Observe algorithm, in which the typical steps on the reference speed have been substituted by a fixed and well-defined slope ramp signal. As a result, it is achieved a soft dynamic response of both the torque and the speed of the wind turbine, so that the whole system suffers from a lower mechanical stress than with conventional P and O techniques. The proposed method has been applied to a wind turbine based on a permanent magnet synchronous generator operating at variable speed, which is connected to the distribution grid by means of a back to back converter. (author)

  3. The preparation of high conversion polymeric systems containing eugenol residues and their rheological characterization.

    Science.gov (United States)

    Rojo, Luis; Borzacchiello, Assunta; Parra, Juan; Deb, Sanjukta; Vázquez, Blanca; San Román, Julio

    2008-04-01

    Copolymeric systems bearing eugenol covalently linked to the macromolecular chains have been prepared and characterised in terms of thermal, rheological and in vitro behaviour. Eugenyl methacrylate (EgMA) and ethoxyeugenyl methacrylate (EEgMA) were polymerized and copolymerized with ethyl methacrylate (EMA) in a wide range of feed composition by bulk at high conversion. Glass transition temperature (Tg) increased with the content of EgMA in the copolymer whereas Tg decreased with the content of EEgMA. The presence of any of the eugenyl monomers in the copolymer increased the thermal stability of the materials. Rheological analysis showed that EMA-co-EgMA copolymers present a higher density of crosslinking or entanglements among the chains compared with EMA-co-EEgMA materials, and copolymers containing more than 40% EgMA exhibited a pseudo-solid like behaviour with G' relatively independent of the frequency. The average molecular weight between cross-links (Mc) for the latter copolymers was in the order of 10(4) Da. For EEgMA copolymers, tan delta was lower than unity and G' showed a gradual and slight dependency with frequency over the whole range of composition. In vitro behaviour showed a higher hydrophilicity of the EEgMA containing copolymers manifested in higher water sorption values, lower water contact angle values and higher surface free energy due to an increase in polarity. All systems presented a good cytocompatibility with human fibroblasts assessed through direct and indirect assays.

  4. Ecological and socio-economic functions across tropical land use systems after rainforest conversion.

    Science.gov (United States)

    Drescher, Jochen; Rembold, Katja; Allen, Kara; Beckschäfer, Philip; Buchori, Damayanti; Clough, Yann; Faust, Heiko; Fauzi, Anas M; Gunawan, Dodo; Hertel, Dietrich; Irawan, Bambang; Jaya, I Nengah S; Klarner, Bernhard; Kleinn, Christoph; Knohl, Alexander; Kotowska, Martyna M; Krashevska, Valentyna; Krishna, Vijesh; Leuschner, Christoph; Lorenz, Wolfram; Meijide, Ana; Melati, Dian; Nomura, Miki; Pérez-Cruzado, César; Qaim, Matin; Siregar, Iskandar Z; Steinebach, Stefanie; Tjoa, Aiyen; Tscharntke, Teja; Wick, Barbara; Wiegand, Kerstin; Kreft, Holger; Scheu, Stefan

    2016-05-19

    Tropical lowland rainforests are increasingly threatened by the expansion of agriculture and the extraction of natural resources. In Jambi Province, Indonesia, the interdisciplinary EFForTS project focuses on the ecological and socio-economic dimensions of rainforest conversion to jungle rubber agroforests and monoculture plantations of rubber and oil palm. Our data confirm that rainforest transformation and land use intensification lead to substantial losses in biodiversity and related ecosystem functions, such as decreased above- and below-ground carbon stocks. Owing to rapid step-wise transformation from forests to agroforests to monoculture plantations and renewal of each plantation type every few decades, the converted land use systems are continuously dynamic, thus hampering the adaptation of animal and plant communities. On the other hand, agricultural rainforest transformation systems provide increased income and access to education, especially for migrant smallholders. Jungle rubber and rubber monocultures are associated with higher financial land productivity but lower financial labour productivity compared to oil palm, which influences crop choice: smallholders that are labour-scarce would prefer oil palm while land-scarce smallholders would prefer rubber. Collecting long-term data in an interdisciplinary context enables us to provide decision-makers and stakeholders with scientific insights to facilitate the reconciliation between economic interests and ecological sustainability in tropical agricultural landscapes. © 2016 The Authors.

  5. Speech-To-Text Conversion STT System Using Hidden Markov Model HMM

    Directory of Open Access Journals (Sweden)

    Su Myat Mon

    2015-06-01

    Full Text Available Abstract Speech is an easiest way to communicate with each other. Speech processing is widely used in many applications like security devices household appliances cellular phones ATM machines and computers. The human computer interface has been developed to communicate or interact conveniently for one who is suffering from some kind of disabilities. Speech-to-Text Conversion STT systems have a lot of benefits for the deaf or dumb people and find their applications in our daily lives. In the same way the aim of the system is to convert the input speech signals into the text output for the deaf or dumb students in the educational fields. This paper presents an approach to extract features by using Mel Frequency Cepstral Coefficients MFCC from the speech signals of isolated spoken words. And Hidden Markov Model HMM method is applied to train and test the audio files to get the recognized spoken word. The speech database is created by using MATLAB.Then the original speech signals are preprocessed and these speech samples are extracted to the feature vectors which are used as the observation sequences of the Hidden Markov Model HMM recognizer. The feature vectors are analyzed in the HMM depending on the number of states.

  6. Solar-energy conversion system provides electrical power and thermal control for life-support systems

    Science.gov (United States)

    Davis, B. K.

    1974-01-01

    System utilizes Freon cycle and includes boiler turbogenerator with heat exchanger, regenerator and thermal-control heat exchangers, low-pressure and boiler-feed pumps, and condenser. Exchanger may be of interest to engineers and scientists investigating new energy sources.

  7. Approaching Sentient Building Performance Simulation Systems

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer; Perkov, Thomas; Heller, Alfred

    2014-01-01

    Sentient BPS systems can combine one or more high precision BPS and provide near instantaneous performance feedback directly in the design tool, thus providing speed and precision of building performance in the early design stages. Sentient BPS systems are essentially combining: 1) design tools, 2...

  8. Performances of the HL (Hyperloop) transport system

    NARCIS (Netherlands)

    van Goeverden, C.D.; Milakis, D.; Janic, M.; Cools, M.; Limbourg, S.

    2017-01-01

    This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental.

  9. Performance Appraisals Systems in the Middle Eeast

    DEFF Research Database (Denmark)

    Giangreco, Antonio; Carugati, Andrea; Pilati, Massimo

    2010-01-01

    This paper critically examines the logics behind performance appraisal systems in Western contexts in an effort to better understand their applicability in the Middle East (ME). We present a literature review that investigates the major justifications and uses of Performance appraisal systems (PASs...

  10. Telerobotic system performance measurement: motivation and methods

    Science.gov (United States)

    Kondraske, George V.; Khoury, George J.

    1992-11-01

    Telerobotic systems (TRSs) and shared teleautonomous systems result from the integration of multiple sophisticated modules. Procedures used in systems integration design decision-making of such systems are frequently ad hoc compared to more quantitative and systematic methods employed elsewhere in engineering. Experimental findings associated with verification and validation (V&V) are often application-specific. Furthermore, models and measurement strategies do not exist which allow prediction of overall TRS performance in a given task based on knowledge of the performance characteristics of individual subsystems. This paper introduces the use of general systems performance theory (GSPT), developed by the senior author to help resolve similar problems in human performance, as a basis for: (1) measurement of overall TRS performance (viewing all system components, including the operator, as a single entity); (2) task decomposition; (3) development of a generic TRS model; and (4) the characterization of performance of subsystems comprising the generic model. GSPT uses a resource construct to model performance and resource economic principles to govern the interface of systems to tasks. It provides a comprehensive modeling/measurement strategy applicable to complex systems including both human and artificial components. Application is presented in the context of a distributed telerobotics network (Universities Space Automation and Robotics Consortium) as a testbed. Insight into the design of test protocols which elicit application-independent data (i.e., multi-purpose or reusable) is described. Although the work is motivated by space automation and robotics challenges, it is considered to be applicable to telerobotic systems in general.

  11. Comparative study of energy conversion system dedicated to a small wind turbine; Etude comparative de chaines de conversion d'energie dediees a une eolienne de petite puissance

    Energy Technology Data Exchange (ETDEWEB)

    Mirecki, A

    2005-07-01

    This study presents a comparison of architectures and strategies of energy management dedicated to VAWT turbines such as Savonius. A Maximum Power Point Tracking must be implemented in order to optimize the energetic behavior. A torque or a speed control, or an indirect control of the DC bus current is possible. In the fact that the wind turbine characteristic is unknown, an operational research based on fuzzy logic is proposed. Aiming to minimize the cost of the static conversion structure, simple structures (diode bridge inverter, associated with DC-DC chopper) are analyzed and compared with a system based on a PWM Voltage Source Inverter. A test bench has been realized in the meantime as a system simulation. Comparisons of the provided energy are made for different wind speeds allowing to evaluate the performance of each structure and of the control strategies. (author)

  12. Analytical performance modeling for computer systems

    CERN Document Server

    Tay, Y C

    2013-01-01

    This book is an introduction to analytical performance modeling for computer systems, i.e., writing equations to describe their performance behavior. It is accessible to readers who have taken college-level courses in calculus and probability, networking and operating systems. This is not a training manual for becoming an expert performance analyst. Rather, the objective is to help the reader construct simple models for analyzing and understanding the systems that they are interested in.Describing a complicated system abstractly with mathematical equations requires a careful choice of assumpti

  13. Business School's Performance Management System Standards Design

    Science.gov (United States)

    Azis, Anton Mulyono; Simatupang, Togar M.; Wibisono, Dermawan; Basri, Mursyid Hasan

    2014-01-01

    This paper aims to compare various Performance Management Systems (PMS) for business school in order to find the strengths of each standard as inputs to design new model of PMS. There are many critical aspects and gaps notified for new model to improve performance and even recognized that self evaluation performance management is not well…

  14. Performances of the HL (Hyperloop) transport system

    OpenAIRE

    Van Goeverden, C.D.; Milakis, D.; Janic, M.; Cools, M.; S Limbourg

    2017-01-01

    This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental. The operational performance include capacity and quality of service provided to the system’s users-passengers with attributes such as door-to-door travel time consisting of the access and egress ti...

  15. Performance of modified-release tacrolimus after conversion in liver transplant patients indicates potentially favorable outcomes in selected cohorts.

    Science.gov (United States)

    Considine, Aisling; Tredger, J Michael; Heneghan, Michael; Agarwal, Kosh; Samyn, Marianne; Heaton, Nigel D; O'Grady, John G; Aluvihare, Varuna R

    2015-01-01

    Clinical outcomes, dose changes, and dose-equalized tacrolimus concentrations were examined sequentially in 129 liver transplantation (LT) recipients after successful conversion to once daily modified-release tacrolimus either early (within 1 month) or late (>1 month) after LT. The data were compared with data for a group of 60 patients maintained on twice daily conventional-release tacrolimus. Formulation- and time-dependent changes in dose requirements for once and twice daily tacrolimus differed after transplantation. A 1.7-fold initial increase in the median daily dose was required to achieve target tacrolimus concentrations in the early-conversion cohort (P = 0.006), whereas a 1.25-fold increase was required for those converted later (P = 0.013 and P conversion cohort, remained stable for the late-conversion cohort, but rose by 33% with conventional therapy. Lower median dose-equalized concentrations persisted for up to 3 months after the conversion to modified-release therapy. Sex, ethnicity, and the underlying liver disease did not significantly affect these variables. The frequency of treated biopsy-proven acute rejection episodes fell approximately 4-fold after the conversion to modified-release tacrolimus, most notably in the late-conversion cohort, which experienced a high incidence of rejection before conversion. Posttransplant increases in serum creatinine concentrations were smaller after the introduction of modified-release tacrolimus in the late-conversion group (0.7 versus 4 mg/mL for twice daily tacrolimus over 6 months). Reduced interpatient variability in tacrolimus concentrations was evident in the early-conversion cohort versus the twice daily cohort. A decline in intrapatient variability accompanied the reduction in acute rejection in the late-conversion cohort. Our data highlight potential benefits for the rejection rate and renal function on conversion to once daily modified-release tacrolimus late after LT. © 2014 American Association for

  16. Strain selection, biomass to biofuel conversion, and resource colocation have strong impacts on the economic performance of algae cultivation sites

    Energy Technology Data Exchange (ETDEWEB)

    Venteris, Erik R.; Wigmosta, Mark S.; Coleman, Andre M.; Skaggs, Richard

    2014-09-16

    Decisions involving strain selection, biomass to biofuel technology, and the location of cultivation facilities can strongly influence the economic viability of an algae-based biofuel enterprise. In this contribution we summarize our past results in a new analysis to explore the relative economic impact of these design choices. We present strain-specific growth model results from two saline strains (Nannocloropsis salina, Arthrospira sp.), a fresh to brackish strain (Chlorella sp., DOE strain 1412), and a freshwater strain of the order Sphaeropleales. Biomass to biofuel conversion is compared between lipid extraction (LE) and hydrothermal liquefaction (HTL) technologies. National-scale models of water, CO2 (as flue gas), land acquisition, site leveling, construction of connecting roads, and transport of HTL oil to existing refineries are used in conjunction with estimates of fuel value (from HTL) to prioritize and select from 88,692 unit farms (UF, 405 ha in pond area), a number sufficient to produce 136E+9 L yr-1 of renewable diesel (36 billion gallons yr-1, BGY). Strain selection and choice of conversion technology have large economic impacts, with differences between combinations of strains and biomass to biofuel technologies being up to $10 million dollars yr-1 UF-1. Results based on the most productive species, HTL-based fuel conversion, and resource costs show that the economic potential between geographic locations within the selection can differ by up to $4 million yr-1 UF-1, with 2.0 BGY of production possible from the most cost-effective sites. The local spatial variability in site rank is extreme, with very high and low rank sites within 10s of km of each other. Colocation with flue gas sources has a strong influence on site rank, but the most costly resource component varies from site to site. The highest rank sites are located predominantly in Florida and Texas, but most states south of 37°N latitude contain promising locations. Keywords: algae

  17. Performance Analysis of Photovoltaic Water Heating System

    OpenAIRE

    Tomas Matuska; Borivoj Sourek

    2017-01-01

    Performance of solar photovoltaic water heating systems with direct coupling of PV array to DC resistive heating elements has been studied and compared with solar photothermal systems. An analysis of optimum fixed load resistance for different climate conditions has been performed for simple PV heating systems. The optimum value of the fixed load resistance depends on the climate, especially on annual solar irradiation level. Use of maximum power point tracking compared to fixed optimized loa...

  18. Management system, organizational climate and performance relationships

    Science.gov (United States)

    Davis, B. D.

    1979-01-01

    Seven aerospace firms were investigated to determine if a relationship existed among management systems, organizational climate, and organization performance. Positive relationships were found between each of these variables, but a statistically significant relationship existed only between the management system and organizational climate. The direction and amount of communication and the degree of decentralized decision-making, elements of the management system, also had a statistically significant realtionship with organization performance.

  19. Thermophotovoltaic energy conversion system having a heavily doped n-type region

    Science.gov (United States)

    DePoy, David M.; Charache, Greg W.; Baldasaro, Paul F.

    2000-01-01

    A thermophotovoltaic (TPV) energy conversion semiconductor device is provided which incorporates a heavily doped n-type region and which, as a consequence, has improved TPV conversion efficiency. The thermophotovoltaic energy conversion device includes an emitter layer having first and second opposed sides and a base layer in contact with the first side of the emitter layer. A highly doped n-type cap layer is formed on the second side of the emitter layer or, in another embodiment, a heavily doped n-type emitter layer takes the place of the cap layer.

  20. Conversion-Integration of MSFC Nonlinear Signal Diagnostic Analysis Algorithms for Realtime Execution of MSFC's MPP Prototype System

    Science.gov (United States)

    Jong, Jen-Yi

    1996-01-01

    NASA's advanced propulsion system Small Scale Magnetic Disturbances/Advanced Technology Development (SSME/ATD) has been undergoing extensive flight certification and developmental testing, which involves large numbers of health monitoring measurements. To enhance engine safety and reliability, detailed analysis and evaluation of the measurement signals are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce the risk of catastrophic system failures and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. During the development of SSME, ASRI participated in the research and development of several advanced non- linear signal diagnostic methods for health monitoring and failure prediction in turbomachinery components. However, due to the intensive computational requirement associated with such advanced analysis tasks, current SSME dynamic data analysis and diagnostic evaluation is performed off-line following flight or ground test with a typical diagnostic turnaround time of one to two days. The objective of MSFC's MPP Prototype System is to eliminate such 'diagnostic lag time' by achieving signal processing and analysis in real-time. Such an on-line diagnostic system can provide sufficient lead time to initiate corrective action and also to enable efficient scheduling of inspection, maintenance and repair activities. The major objective of this project was to convert and implement a number of advanced nonlinear diagnostic DSP algorithms in a format consistent with that required for integration into the Vanderbilt Multigraph Architecture (MGA) Model Based Programming environment. This effort will allow the real-time execution of these algorithms using the MSFC MPP Prototype System. ASRI has completed the software conversion and integration of a sequence of nonlinear signal analysis techniques specified in the SOW for real

  1. Toward High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  2. Towards High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  3. Maintenance for power conversion system of gas turbine high temperature reactor (GTHTR300). Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Kosugiyama, Shinichi; Takada, Shoji; Katanishi, Shoji; Yan, Xing; Takizuka, Takakazu; Kunitomi, Kazuhiko [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    2002-11-01

    In order to be a suitable next generation nuclear power plant from reliable and economical points of view, it is necessary for GTHTR300 to have good maintenability and inspectability. Appropriate maintenance concept for the power conversion system of GTHTR300 consisting of a gas turbine, a compressor, a generator, a recuperator, a precooler and so on was studied based on results of the basic design of GTHTR300 in fiscal 2001. Considering degradation phenomena which could occur on each objective equipment, it is technically possible to reduce several maintenance items and extend maintenance interval for some equipment compared to those for existing LWR power plants and combined cycle fossil power plants. But owing to structural feature and installed location of each equipment, and fission product plate-out on each equipment, it became clear that some problems must be solved for making the maintenance works realistic and efficient. Solving the problems and confirming appropriateness of the proposed maintenance concept and plans will be done in coming detailing work of GTHTR300 design. (author)

  4. Rapid cell-surface prion protein conversion revealed using a novel cell system

    Science.gov (United States)

    Goold, R.; Rabbanian, S.; Sutton, L.; Andre, R.; Arora, P.; Moonga, J.; Clarke, A.R.; Schiavo, G.; Jat, P.; Collinge, J.; Tabrizi, S.J.

    2011-01-01

    Prion diseases are fatal neurodegenerative disorders with unique transmissible properties. The infectious and pathological agent is thought to be a misfolded conformer of the prion protein. Little is known about the initial events in prion infection because the infecting prion source has been immunologically indistinguishable from normal cellular prion protein (PrPC). Here we develop a unique cell system in which epitope-tagged PrPC is expressed in a PrP knockdown (KD) neuroblastoma cell line. The tagged PrPC, when expressed in our PrP-KD cells, supports prion replication with the production of bona fide epitope-tagged infectious misfolded PrP (PrPSc). Using this epitope-tagged PrPSc, we study the earliest events in cellular prion infection and PrP misfolding. We show that prion infection of cells is extremely rapid occurring within 1 min of prion exposure, and we demonstrate that the plasma membrane is the primary site of prion conversion. PMID:21505437

  5. Analysis Of Functional Stability Of The Triphased Asynchronous Generator Used In Conversion Systems Of A Eolian Energy Into Electric Energy

    Directory of Open Access Journals (Sweden)

    Ion VONCILA

    2003-12-01

    Full Text Available This paper presents a study of the influence of the main perturbation agent over the functional stability of the triphased asynchronous generator (for the two alternative: with coiled and short circuit rotor, used for the conversion systems from a eolian energy into electric energy.

  6. L1 Adaptive Speed Control of a Small Wind Energy Conversion System for Maximum Power Point Tracking

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Rasmussen, Claus Nygaard

    2014-01-01

    This paper presents the design of an L1 adaptive controller for maximum power point tracking (MPPT) of a small variable speed Wind Energy Conversion System (WECS). The proposed controller generates the optimal torque command for the vector controlled generator side converter (GSC) based on the wind...

  7. Formation of the multidimensional performance measurement system

    OpenAIRE

    Sližytė, Asta

    2009-01-01

    The growing attention of scientists and practitioners towards the issues of performance measurement encourage to analyze actualities of performance measurement as individual object of management. It becomes relevant to analyze what performance measurement system must be in order to ensure for the organizations operating in the changing environment the multidimensional performance measurement and usage of measurement results for the management of organization. In dissertation concepts of pe...

  8. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton...... series of wind power and power load are used to investigate the mitigation effect of the integrated energy system. At last, the effect of wind power and power demand on the output of Power to Gas (P2G) and gas-fired power generation (GPG) has also been investigated....

  9. Converse Piezoelectricity

    Science.gov (United States)

    Springborg, Michael; Kirtman, Bernard

    2013-03-01

    Piezoelectricity results from a coupling between responses to mechanical and electric perturbations and leads to changes in the polarization due to strain or stress or, alternatively, the occurrence of strain as a function of an applied external, electrostatic field (i.e., converse piezoelectricity). Theoretical studies of those properties for extended systems require accordingly that their dipole moment or polarization can be calculated. However, whereas the definition of the operator for the dipole moment for any finite system is trivial, it is only within the last 2 decades that the expressions for the equivalent operator in the independent-particle approximation for the infinite and periodic system have been presented. Here, we demonstrate that the so called branch dependence of the polarization for the infinite, periodic system is related to physical observables in contrast to what often is assumed. This is related to the finding that converse piezoelectric properties depend both on the surfaces of the samples of interest even for samples with size well above the thermodynamic limit. However, we shall demonstrate that these properties can be calculated without explicitly taking the surfaces into account. Both the foundations and results for real system shall be presented.

  10. Study on Conversion of Municipal Plastic Wastes into Liquid Fuel Compounds, Analysis of Crdi Engine Performance and Emission Characteristics

    Science.gov (United States)

    Divakar Shetty, A. S.; Kumar, R. Ravi; Kumarappa, S.; Antony, A. J.

    2016-09-01

    The rate of economic evolution is untenable unless we save or stops misusing the fossil fuels like coal, crude oil or fossil fuels. So we are in need of start count on the alternate or renewable energy sources. In this experimental analysis an attempt has been made to investigate the conversion of municipal plastic wastes like milk covers and water bottles are selected as feed stocks to get oil using pyrolysis method, the performance analysis on CRDI diesel engine and to assess emission characteristics like HC, CO, NOX and smoke by using blends of Diesel-Plastic liquid fuels. The plastic fuel is done with the pH test using pH meter after the purification process and brought to the normal by adding KOH and NaOH. Blends of 0 to 100% plastic liquid fuel-diesel mixture have been tested for performance and emission aspect as well. The experimental results shows the efficiently convert weight of municipal waste plastics into 65% of useful liquid hydrocarbon fuels without emitting much pollutants.

  11. Cooperative Strategies for Enhancing Performance of Photothermal Therapy (PTT) Agent: Optimizing Its Photothermal Conversion and Cell Internalization Ability.

    Science.gov (United States)

    Du, Baoji; Ma, Chongbo; Ding, Guanyu; Han, Xu; Li, Dan; Wang, Erkang; Wang, Jin

    2017-04-01

    Photothermal conversion ability (PCA) and cell internalization ability (CIA) are two key factors for determining the performance of photothermal agents. The previous studies mostly focus on improving the PCA by exploring new photothermal nanomaterials. Herein, the authors take the hybrids of graphene and gold nanostar (GGN) as an example to investigate the gradually enhanced phototherapy effect by changing the PCA and CIA of photothermal therapy (PTT) agent simultaneously. Based on the GGN, the GGN and the reduced GGN protected by bovine serum albumin (BSA) or BSA-FA (folic acid) are prepared, which are named as GGNB, rGGNB, and rGGNB-FA, respectively. The rGGNB showed an enhanced PCA compared to GGNB, leading to strong cell ablation. On the other hand, the 1,2-dioleoyl-3-trimethylammoniumpropan (DOTAP) can activate the endocytosis and promote the CIA of rGGNB, further help rGGNB to be more internalized into the cells. Finally, rGGNB-FA with the target ability can make itself further internalized into the cells with the aid of DOTAP, which can significantly destroy the cancer cells even at the low laser density of 0.3 W cm-2 . Therefore, a new angle of view is brought out for researching the PTT agents of high performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Advanced Control of Permanent Magnet Synchronous Generators for Variable Speed Wind Energy Conversion Systems

    Science.gov (United States)

    Hostettler, Jacob

    Various environmental and economic factors have lead to increased global investment in alternative energy technologies such as solar and wind power. Although methodologies for synchronous generator control are well researched, wind turbines present control systems challenges not presented by traditional generation. The varying nature of wind makes achieving synchronism with the existing electrical power grid a greater challenge. Departing from early use of induction machines, permanent magnet synchronous generators have become the focus of power systems and control systems research into wind energy systems. This is due to their self excited nature, along with their high power density. The problem of grid synchronism is alleviated through the use of high performance power electronic converters. In achievement of the optimal levels of efficiency, advanced control systems techniques oer promise over more traditional approaches. Research into sliding mode control, and linear matrix inequalities with nite time boundedness and Hinfinity performance criteria, when applied to the dynamical models of the system, demonstrate the potential of these control methodologies as future avenues for achieving higher levels of performance and eciency in wind energy.

  13. Energy Conversion and Transmission Characteristics Analysis of Ice Storage Air Conditioning System Driven by Distributed Photovoltaic Energy System

    Directory of Open Access Journals (Sweden)

    Yongfeng Xu

    2016-01-01

    Full Text Available In order to reduce the investment and operation cost of distributed PV energy system, ice storage technology was introduced to substitute batteries for solar energy storage. Firstly, the ice storage air conditioning system (ISACS driven by distributed photovoltaic energy system (DPES was proposed and the feasibility studies have been investigated in this paper. And then, the theoretical model has been established and experimental work has been done to analyze the energy coupling and transferring characteristics in light-electricity-cold conversion process. In addition, the structure optimization analysis was investigated. Results revealed that energy losses were high in ice making process of ice slide maker with only 17.38% energy utilization efficiency and the energy efficiency and exergy efficiency of ISACS driven by DPES were 5.44% and 67.30%, respectively. So the immersed evaporator and cointegrated exchanger were adopted for higher energy utilization efficiency and better financial rewards in structure optimization. The COP and exergy efficiency of ice maker can be increased to 1.48 and 81.24%, respectively, after optimization and the energy utilization efficiency of ISACS driven by DPES could be improved 2.88 times. Moreover, ISACS has the out-of-the-box function of ordinary air conditioning system. In conclusion, ISACS driven by DPES will have good application prospects in tropical regions without power grid.

  14. The use of conversation mapping to frame key perceptual issues facing the general dental practice system in England.

    Science.gov (United States)

    Harris, R V; Dancer, J M; Smith, D; Campbell, S

    2009-06-01

    To demonstrate the use of a novel qualitative methodology namely conversation mapping, which can be used to capture differences in stakeholder perspectives and give a root definition of the problem in a complex policy area. The methodology is used in the context of the changes introduced in the English general dental practice system in April 2006, to investigate the key issues facing the system, as perceived by general dental practitioners (GDPs). From a broad trigger statement, three transformational statements were produced. Each participant recorded their contribution on a hard diagrammatic form as a 'map', with others responding with their own written comment, thus generating three conversation maps. Thematic analysis resulted in the generation of a preliminary model summarising key perceptual issues. The five emergent themes identified were: financing, dentists' wants/needs, the role of the public and patients, system goals and policy level decision making. Financing was identified as the core category to which all other categories were related. Conversation mapping, a methodology arising from a systems approach, can be used to develop a 'rich picture' of an oral health care system in order to define the core problem within this policy area. Findings suggest that GDPs identify the financing of the system as a fundamental source of problems within the general dental practice system. This appears to be at variance with the perception of policy makers, who report a more limited view, identifying the system of remuneration as the 'heart of the problem'.

  15. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Vitor S.C. de; Mattos, Marcio C.S. de, E-mail: mmattos@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2014-05-15

    An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

  16. Ocean thermal energy conversion (OTEC). Power system development. Preliminary design report, final

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The preliminary design of the 10 MWe OTEC power module and the 200 kWe test articles is given in detail. System operation and performance; power system cost estimates; 10 MWe heat exchangers; 200 kWe heat exchanger articles; biofouling control;ammonia leak detection, and leak repair; rotating machinery; support subsystem; instrumentation and control; electrical subsystem; installation approach; net energy and resource analysis; and operability, maintainability, and safety are discussed. The conceptual design of the 40 MWe electrical power system includes four or five 10 MWe modules as designed for the 10 MWe pilot plant. (WHK)

  17. Second order sliding power control for a variable speed-constant frequency energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Valenciaga, Fernando, E-mail: fval@ing.unlp.edu.a [CONICET, Laboratorio de Electronica Industrial Control e Instrumentacion (LEICI), Facultad de Ingenieria, Universidad Nacional de La Plata, CC.91, C.P. 1900 La Plata (Argentina)

    2010-12-15

    This paper presents a decoupled active and reactive power control for a variable speed-constant frequency generation system based on a brushless doubly fed reluctance machine. The control design is approached using multi-input second order sliding techniques which are specially appropriate to deal with nonlinear system models in presence of external disturbances and model inaccuracies. The controller synthesized through this theoretical framework presents very good robustness features, a finite reaching time and a chattering-free behavior. The performance of the closed loop system is assessed through representative computer simulations.

  18. Conversational sensemaking

    Science.gov (United States)

    Preece, Alun; Webberley, Will; Braines, Dave

    2015-05-01

    Recent advances in natural language question-answering systems and context-aware mobile apps create opportunities for improved sensemaking in a tactical setting. Users equipped with mobile devices act as both sensors (able to acquire information) and effectors (able to act in situ), operating alone or in collectives. The currently- dominant technical approaches follow either a pull model (e.g. Apple's Siri or IBM's Watson which respond to users' natural language queries) or a push model (e.g. Google's Now which sends notifications to a user based on their context). There is growing recognition that users need more flexible styles of conversational interaction, where they are able to freely ask or tell, be asked or told, seek explanations and clarifications. Ideally such conversations should involve a mix of human and machine agents, able to collaborate in collective sensemaking activities with as few barriers as possible. Desirable capabilities include adding new knowledge, collaboratively building models, invoking specific services, and drawing inferences. As a step towards this goal, we collect evidence from a number of recent pilot studies including natural experiments (e.g. situation awareness in the context of organised protests) and synthetic experiments (e.g. human and machine agents collaborating in information seeking and spot reporting). We identify some principles and areas of future research for "conversational sensemaking".

  19. Microbial community response to chlorine conversion in a chloraminated drinking water distribution system.

    Science.gov (United States)

    Wang, Hong; Proctor, Caitlin R; Edwards, Marc A; Pryor, Marsha; Santo Domingo, Jorge W; Ryu, Hodon; Camper, Anne K; Olson, Andrew; Pruden, Amy

    2014-09-16

    Temporary conversion to chlorine (i.e., "chlorine burn") is a common approach to controlling nitrification in chloraminated drinking water distribution systems, yet its effectiveness and mode(s) of action are not fully understood. This study characterized occurrence of nitrifying populations before, during and after a chlorine burn at 46 sites in a chloraminated distribution system with varying pipe materials and levels of observed nitrification. Quantitative polymerase chain reaction analysis of gene markers present in nitrifying populations indicated higher frequency of detection of ammonia oxidizing bacteria (AOB) (72% of samples) relative to ammonia oxidizing archaea (AOA) (28% of samples). Nitrospira nitrite oxidizing bacteria (NOB) were detected at 45% of samples, while presence of Nitrobacter NOB could not be confirmed at any of the samples. During the chlorine burn, the numbers of AOA, AOB, and Nitrospira greatly reduced (i.e., 0.8-2.4 log). However, rapid and continued regrowth of AOB and Nitrospira were observed along with nitrite production in the bulk water within four months after the chlorine burn, and nitrification outbreaks appeared to worsen 6-12 months later, even after adopting a twice annual burn program. Although high throughput sequencing of 16S rRNA genes revealed a distinct community shift and higher diversity index during the chlorine burn, it steadily returned towards a condition more similar to pre-burn than burn stage. Significant factors associated with nitrifier and microbial community composition included water age and sampling location type, but not pipe material. Overall, these results indicate that there is limited long-term effect of chlorine burns on nitrifying populations and the broader microbial community.

  20. Real time implementation and control validation of the wind energy conversion system

    Science.gov (United States)

    Sattar, Adnan

    The purpose of the thesis is to analyze dynamic and transient characteristics of wind energy conversion systems including the stability issues in real time environment using the Real Time Digital Simulator (RTDS). There are different power system simulation tools available in the market. Real time digital simulator (RTDS) is one of the powerful tools among those. RTDS simulator has a Graphical User Interface called RSCAD which contains detail component model library for both power system and control relevant analysis. The hardware is based upon the digital signal processors mounted in the racks. RTDS simulator has the advantage of interfacing the real world signals from the external devices, hence used to test the protection and control system equipments. Dynamic and transient characteristics of the fixed and variable speed wind turbine generating systems (WTGSs) are analyzed, in this thesis. Static Synchronous Compensator (STATCOM) as a flexible ac transmission system (FACTS) device is used to enhance the fault ride through (FRT) capability of the fixed speed wind farm. Two level voltage source converter based STATCOM is modeled in both VSC small time-step and VSC large time-step of RTDS. The simulation results of the RTDS model system are compared with the off-line EMTP software i.e. PSCAD/EMTDC. A new operational scheme for a MW class grid-connected variable speed wind turbine driven permanent magnet synchronous generator (VSWT-PMSG) is developed. VSWT-PMSG uses fully controlled frequency converters for the grid interfacing and thus have the ability to control the real and reactive powers simultaneously. Frequency converters are modeled in the VSC small time-step of the RTDS and three phase realistic grid is adopted with RSCAD simulation through the use of optical analogue digital converter (OADC) card of the RTDS. Steady state and LVRT characteristics are carried out to validate the proposed operational scheme. Simulation results show good agreement with real

  1. Conversational Dominance.

    Science.gov (United States)

    Esau, Helmut; Poth, Annette

    Details of conversational behavior can often not be interpreted until the social interaction, including the rights and obligations of the participants, their intent, the topic, etc., has been defined. This paper presents a model of conversation in which the conversational image a person presents in a given conversational situation is a function of…

  2. Ocean thermal energy conversion (OTEC) power system development. Preliminary design report, Appendices, Part 1 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the developed computer models, water system dynamic studies, miscellaneous performance analysis, materials and processes, detailed equipment lists, turbine design studies, tube cleaner design, ammonia leak detection, and heat exchanger design supporting data. (WHK)

  3. A Study of Mars Dust Environment Simulation at NASA Johnson Space Center Energy Systems Test Area Resource Conversion Test Facility

    Science.gov (United States)

    Chen, Yuan-Liang Albert

    1999-01-01

    The dust environment on Mars is planned to be simulated in a 20 foot thermal-vacuum chamber at the Johnson Space Center, Energy Systems Test Area Resource Conversion Test Facility in Houston, Texas. This vacuum chamber will be used to perform tests and study the interactions between the dust in Martian air and ISPP hardware. This project is to research, theorize, quantify, and document the Mars dust/wind environment needed for the 20 foot simulation chamber. This simulation work is to support the safety, endurance, and cost reduction of the hardware for the future missions. The Martian dust environment conditions is discussed. Two issues of Martian dust, (1) Dust Contamination related hazards, and (2) Dust Charging caused electrical hazards, are of our interest. The different methods of dust particles measurement are given. The design trade off and feasibility were studied. A glass bell jar system is used to evaluate various concepts for the Mars dust/wind environment simulation. It was observed that the external dust source injection is the best method to introduce the dust into the simulation system. The dust concentration of 30 Mg/M3 should be employed for preparing for the worst possible Martian atmosphere condition in the future. Two approaches thermal-panel shroud for the hardware conditioning are discussed. It is suggested the wind tunnel approach be used to study the dust charging characteristics then to be apply to the close-system cyclone approach. For the operation cost reduction purpose, a dehumidified ambient air could be used to replace the expensive CO2 mixture for some tests.

  4. Performance Monitoring Applied to System Supervision

    Directory of Open Access Journals (Sweden)

    Bertille Somon

    2017-07-01

    Full Text Available Nowadays, automation is present in every aspect of our daily life and has some benefits. Nonetheless, empirical data suggest that traditional automation has many negative performance and safety consequences as it changed task performers into task supervisors. In this context, we propose to use recent insights into the anatomical and neurophysiological substrates of action monitoring in humans, to help further characterize performance monitoring during system supervision. Error monitoring is critical for humans to learn from the consequences of their actions. A wide variety of studies have shown that the error monitoring system is involved not only in our own errors, but also in the errors of others. We hypothesize that the neurobiological correlates of the self-performance monitoring activity can be applied to system supervision. At a larger scale, a better understanding of system supervision may allow its negative effects to be anticipated or even countered. This review is divided into three main parts. First, we assess the neurophysiological correlates of self-performance monitoring and their characteristics during error execution. Then, we extend these results to include performance monitoring and error observation of others or of systems. Finally, we provide further directions in the study of system supervision and assess the limits preventing us from studying a well-known phenomenon: the Out-Of-the-Loop (OOL performance problem.

  5. Exploratory analysis of real personal emergency response call conversations: considerations for personal emergency response spoken dialogue systems.

    Science.gov (United States)

    Young, Victoria; Rochon, Elizabeth; Mihailidis, Alex

    2016-11-14

    The purpose of this study was to derive data from real, recorded, personal emergency response call conversations to help improve the artificial intelligence and decision making capability of a spoken dialogue system in a smart personal emergency response system. The main study objectives were to: develop a model of personal emergency response; determine categories for the model's features; identify and calculate measures from call conversations (verbal ability, conversational structure, timing); and examine conversational patterns and relationships between measures and model features applicable for improving the system's ability to automatically identify call model categories and predict a target response. This study was exploratory and used mixed methods. Personal emergency response calls were pre-classified according to call model categories identified qualitatively from response call transcripts. The relationships between six verbal ability measures, three conversational structure measures, two timing measures and three independent factors: caller type, risk level, and speaker type, were examined statistically. Emergency medical response services were the preferred response for the majority of medium and high risk calls for both caller types. Older adult callers mainly requested non-emergency medical service responders during medium risk situations. By measuring the number of spoken words-per-minute and turn-length-in-words for the first spoken utterance of a call, older adult and care provider callers could be identified with moderate accuracy. Average call taker response time was calculated using the number-of-speaker-turns and time-in-seconds measures. Care providers and older adults used different conversational strategies when responding to call takers. The words 'ambulance' and 'paramedic' may hold different latent connotations for different callers. The data derived from the real personal emergency response recordings may help a spoken dialogue system

  6. Forecasting the Performance of Agroforestry Systems

    Science.gov (United States)

    Luedeling, E.; Shepherd, K.

    2014-12-01

    Agroforestry has received considerable attention from scientists and development practitioners in recent years. It is recognized as a cornerstone of many traditional agricultural systems, as well as a new option for sustainable land management in currently treeless agricultural landscapes. Agroforestry systems are diverse, but most manifestations supply substantial ecosystem services, including marketable tree products, soil fertility, water cycle regulation, wildlife habitat and carbon sequestration. While these benefits have been well documented for many existing systems, projecting the outcomes of introducing new agroforestry systems, or forecasting system performance under changing environmental or climatic conditions, remains a substantial challenge. Due to the various interactions between system components, the multiple benefits produced by trees and crops, and the host of environmental, socioeconomic and cultural factors that shape agroforestry systems, mechanistic models of such systems quickly become very complex. They then require a lot of data for site-specific calibration, which presents a challenge for their use in new environmental and climatic domains, especially in data-scarce environments. For supporting decisions on the scaling up of agroforestry technologies, new projection methods are needed that can capture system complexity to an adequate degree, while taking full account of the fact that data on many system variables will virtually always be highly uncertain. This paper explores what projection methods are needed for supplying decision-makers with useful information on the performance of agroforestry in new places or new climates. Existing methods are discussed in light of these methodological needs. Finally, a participatory approach to performance projection is proposed that captures system dynamics in a holistic manner and makes probabilistic projections about expected system performance. This approach avoids the temptation to take

  7. Amtrak performance tracking (APT) system : methodology summary

    Science.gov (United States)

    2017-09-15

    The Volpe Center collaborated with Amtrak and the Federal Railroad Administration (FRA) to develop a cost accounting system named Amtrak Performance Tracking (APT) used by Amtrak to manage, allocate, and report its costs. APTs initial development ...

  8. Performance Evaluation for DFB and VCSEL-based 60 GHz Radio-over-Fiber System

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Lebedev, Alexander; Vegas Olmos, Juan José

    2013-01-01

    In this paper, we report on a detailed analysis and performance comparison work between 60 GHz radio-over-fiber systems based on a DFB laser and a C-band VCSEL. Coherent photonic up-conversion method is applied for the 60 GHz millimeter-wave signal generation. The generated signals are evaluated...

  9. Financial performance of a mobile pyrolysis system used to produce biochar from sawmill residues

    Science.gov (United States)

    Dongyeob Kim; Nathaniel McLean Anderson; Woodam Chung

    2015-01-01

    Primary wood products manufacturers generate significant amounts of woody biomass residues that can be used as feedstocks for distributed-scale thermochemical conversion systems that produce valuable bioenergy and bioproducts. However, private investment in these technologies is driven primarily by financial performance, which is often unknown for new technologies with...

  10. Performance Analysis of Photovoltaic Water Heating System

    Directory of Open Access Journals (Sweden)

    Tomas Matuska

    2017-01-01

    Full Text Available Performance of solar photovoltaic water heating systems with direct coupling of PV array to DC resistive heating elements has been studied and compared with solar photothermal systems. An analysis of optimum fixed load resistance for different climate conditions has been performed for simple PV heating systems. The optimum value of the fixed load resistance depends on the climate, especially on annual solar irradiation level. Use of maximum power point tracking compared to fixed optimized load resistance increases the annual yield by 20 to 35%. While total annual efficiency of the PV water heating systems in Europe ranges from 10% for PV systems without MPP tracking up to 15% for system with advanced MPP trackers, the efficiency of solar photothermal system for identical hot water load and climate conditions is more than 3 times higher.

  11. Performance of the Community Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Worley, Patrick H [ORNL; Craig, Anthony [National Center for Atmospheric Research (NCAR); Dennis, John [National Center for Atmospheric Research (NCAR); Mirin, Arthur A. [Lawrence Livermore National Laboratory (LLNL); Taylor, Mark [Sandia National Laboratories (SNL); Vertenstein, Mariana [National Center for Atmospheric Research (NCAR)

    2011-01-01

    The Community Earth System Model (CESM), released in June 2010, incorporates new physical process and new numerical algorithm options, significantly enhancing simulation capabilities over its predecessor, the June 2004 release of the Community Climate System Model. CESM also includes enhanced performance tuning options and performance portability capabilities. This paper describes the performance engineering aspects of the CESM and reports performance and performance scaling on both the Cray XT5 and the IBM BG/P for four representative production simulations, varying both problem size and enabled physical processes. The paper also describes preliminary performance results for high resolution simulations using over 200,000 processor cores, indicating the promise of ongoing work in numerical algorithms and where further work is required.

  12. PVFORM3.3. Photovoltaic System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, D.F.; Fernandez, J.P. [Sandia National Labs., Albuquerque, NM (United States)

    1989-09-25

    PVFORM3.3 is used to design a photovoltaic (PV) system using a set of design parameters which optimize the system`s economic potential for the proposed location and the expected operating conditions. PVFORM3.3 has been used to determine PV system size and optimum mounting configuration. The anticipated electrical load determines the system size and the weather and the mounting configuration affect the system output. PVFORM3.3 uses program-supplied default values or their user-supplied equivalents for each of a large number of parameters describing the system and time-series data describing the environment to perform a series of hourly calculations to simulate the physical (photovoltaic) performance of a PV system for a one-year period. These iterative calculations sample the performance of the PV system throughout a simulated 365-day year of system operation. Within any simulated day on which system performance is sampled, the calculations are done hourly. The number of days sampled and the interval between them is determined by an input parameter. The results of these calculations are summarized on a monthly basis in output tables and an optional plot file. The program is applicable to grid interactive or stand-alone flat-plate systems. The grid interactive system is assumed to use power purchased from a local utility to supply that portion of the load not met by the simulated PV array. If the array produces more energy than can be consumed by the load, the excess energy is assumed to be sold back to the utility at a constant energy sellback price. If a stand-alone system is being modeled, the program assumes that all energy produced by the simulated PV array is first applied to the external load, and any excess is then used to charge the battery bank. Energy not consumed by the load or the batteries is considered to be wasted.

  13. Verification of a 2 kWe Closed-Brayton-Cycle Power Conversion System Mechanical Dynamics Model

    Science.gov (United States)

    Ludwiczak, Damian R.; Le, Dzu K.; McNelis, Anne M.; Yu, Albert C.; Samorezov, Sergey; Hervol, Dave S.

    2005-01-01

    Vibration test data from an operating 2 kWe closed-Brayton-cycle (CBC) power conversion system (PCS) located at the NASA Glenn Research Center was used for a comparison with a dynamic disturbance model of the same unit. This effort was performed to show that a dynamic disturbance model of a CBC PCS can be developed that can accurately predict the torque and vibration disturbance fields of such class of rotating machinery. The ability to accurately predict these disturbance fields is required before such hardware can be confidently integrated onto a spacecraft mission. Accurate predictions of CBC disturbance fields will be used for spacecraft control/structure interaction analyses and for understanding the vibration disturbances affecting the scientific instrumentation onboard. This paper discusses how test cell data measurements for the 2 kWe CBC PCS were obtained, the development of a dynamic disturbance model used to predict the transient torque and steady state vibration fields of the same unit, and a comparison of the two sets of data.

  14. The adhesive system and root canal region do not influence the degree of conversion of dual resin cement

    Science.gov (United States)

    PEREIRA, Priscilla Cristoforides; de MELO, Renata Marques; CHAVES, Carolina; GALHANO, Graziela A. P.; BOTTINO, Marco Antonio; BALDUCCI, Ivan

    2010-01-01

    Objectives The aim of this study was to evaluate the influence of two adhesive systems and the post space region on the degree of conversion of dual resin cement and its bond strength to root dentin. Material and Methods One three-step etch-andrinse (All-bond 2, Bisco) and another one-step self-etch (Xeno III, Dentsply) adhesive systems were applied on 20 (n=10) crownless bovine incisors, at 12-mm-deep post space preparation, and a fiber post (DT Light Post, Bisco) was cemented using a dual cure resin cement (Duo-Link, Bisco). Three transverse sections (3 mm) were obtained, being one from each study region (cervical, middle and apical). The degree of conversion of the dual cure resin cement was determined by a micro-Raman spectrometer. The data (%) were submitted to repeated-measures analysis of variance and Tukey's test (p<0.05). Results For both groups, the degree of conversion means (%) (All bond 2cervical = 69.3; All bond 2middle = 55.1; All bond 2apical= 56; Xeno IIIcervical = 68.7; Xeno IIImiddle = 68.8; Xeno IIIapical = 54.3) were not significantly different along the post space regions (p<0.05). Conclusion Neither the adhesive nor the post space region influenced the degree of conversion of the cement layer. PMID:21085803

  15. The adhesive system and root canal region do not influence the degree of conversion of dual resin cement

    Directory of Open Access Journals (Sweden)

    Priscilla Cristoforides Pereira

    2010-10-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate the influence of two adhesive systems and the post space region on the degree of conversion of dual resin cement and its bond strength to root dentin. MATERIAL AND METHODS: One three-step etch-and-rinse (All-bond 2, Bisco and another one-step self-etch (Xeno III, Dentsply adhesive systems were applied on 20 (n=10 crownless bovine incisors, at 12-mm-deep post space preparation, and a fiber post (FRC Postec, Ivoclar was cemented using a dual cure resin cement (Duo-Link, Bisco. Three transverse sections (3 mm were obtained, being one from each study region (cervical, middle and apical. The degree of conversion of the dual cure resin cement was determined by a micro-Raman spectrometer. The data (% were submitted to repeated-measures analysis of variance and Tukey's test (p<0.05. RESULTS: For both groups, the degree of conversion means (% (All bond 2cervical = 69.3; All bond 2middle = 55.1; All bond 2apical= 56; Xeno III cervical = 68.7; Xeno IIImiddle = 68.8; Xeno III apical = 54.3 were not significantly different along the post space regions (p<0.05. CONCLUSION: Neither the adhesive nor the post space region influenced the degree of conversion of the cement layer.

  16. A novel solid state fermentation coupled with gas stripping enhancing the sweet sorghum stalk conversion performance for bioethanol

    Science.gov (United States)

    2014-01-01

    Background Bioethanol production from biomass is becoming a hot topic internationally. Traditional static solid state fermentation (TS-SSF) for bioethanol production is similar to the traditional method of intermittent operation. The main problems of its large-scale intensive production are the low efficiency of mass and heat transfer and the high ethanol inhibition effect. In order to achieve continuous production and high conversion efficiency, gas stripping solid state fermentation (GS-SSF) for bioethanol production from sweet sorghum stalk (SSS) was systematically investigated in the present study. Results TS-SSF and GS-SSF were conducted and evaluated based on different SSS particle thicknesses under identical conditions. The ethanol yield reached 22.7 g/100 g dry SSS during GS-SSF, which was obviously higher than that during TS-SSF. The optimal initial gas stripping time, gas stripping temperature, fermentation time, and particle thickness of GS-SSF were 10 h, 35°C, 28 h, and 0.15 cm, respectively, and the corresponding ethanol stripping efficiency was 77.5%. The ethanol yield apparently increased by 30% with the particle thickness decreasing from 0.4 cm to 0.05 cm during GS-SSF. Meanwhile, the ethanol yield increased by 6% to 10% during GS-SSF compared with that during TS-SSF under the same particle thickness. The results revealed that gas stripping removed the ethanol inhibition effect and improved the mass and heat transfer efficiency, and hence strongly enhanced the solid state fermentation (SSF) performance of SSS. GS-SSF also eliminated the need for separate reactors and further simplified the bioethanol production process from SSS. As a result, a continuous conversion process of SSS and online separation of bioethanol were achieved by GS-SSF. Conclusions SSF coupled with gas stripping meet the requirements of high yield and efficient industrial bioethanol production. It should be a novel bioconversion process for bioethanol production from SSS

  17. A novel solid state fermentation coupled with gas stripping enhancing the sweet sorghum stalk conversion performance for bioethanol.

    Science.gov (United States)

    Chen, Hong-Zhang; Liu, Zhi-Hua; Dai, Shu-Hua

    2014-01-01

    Bioethanol production from biomass is becoming a hot topic internationally. Traditional static solid state fermentation (TS-SSF) for bioethanol production is similar to the traditional method of intermittent operation. The main problems of its large-scale intensive production are the low efficiency of mass and heat transfer and the high ethanol inhibition effect. In order to achieve continuous production and high conversion efficiency, gas stripping solid state fermentation (GS-SSF) for bioethanol production from sweet sorghum stalk (SSS) was systematically investigated in the present study. TS-SSF and GS-SSF were conducted and evaluated based on different SSS particle thicknesses under identical conditions. The ethanol yield reached 22.7 g/100 g dry SSS during GS-SSF, which was obviously higher than that during TS-SSF. The optimal initial gas stripping time, gas stripping temperature, fermentation time, and particle thickness of GS-SSF were 10 h, 35°C, 28 h, and 0.15 cm, respectively, and the corresponding ethanol stripping efficiency was 77.5%. The ethanol yield apparently increased by 30% with the particle thickness decreasing from 0.4 cm to 0.05 cm during GS-SSF. Meanwhile, the ethanol yield increased by 6% to 10% during GS-SSF compared with that during TS-SSF under the same particle thickness. The results revealed that gas stripping removed the ethanol inhibition effect and improved the mass and heat transfer efficiency, and hence strongly enhanced the solid state fermentation (SSF) performance of SSS. GS-SSF also eliminated the need for separate reactors and further simplified the bioethanol production process from SSS. As a result, a continuous conversion process of SSS and online separation of bioethanol were achieved by GS-SSF. SSF coupled with gas stripping meet the requirements of high yield and efficient industrial bioethanol production. It should be a novel bioconversion process for bioethanol production from SSS biomass.

  18. Power system development: Ocean Thermal Energy Conversion (OTEC). Preliminary design report: appendices, Part 2 (Final)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-12-04

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC demonstration plant. In turn, this demonstration plant is to demonstrate, by 1984, the operation and performance of an Ocean Thermal Power Plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the demonstration plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibilty studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report contains appendices on the electrical system, instrumentation and control, ammonia pump evaluation study, ammonia and nitrogen support subsystems, piping and support design calculations, and plant availability. (WHK)

  19. Gas Turbine Energy Conversion Systems for Nuclear Power Plants Applicable to LiFTR Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.

    2014-01-01

    This panel plans to cover thermal energy and electric power production issues facing our nation and the world over the next decades, with relevant technologies ranging from near term to mid-and far term.Although the main focus will be on ground based plants to provide baseload electric power, energy conversion systems (ECS) for space are also included, with solar- or nuclear energy sources for output power levels ranging tens of Watts to kilo-Watts for unmanned spacecraft, and eventual mega-Watts for lunar outposts and planetary surface colonies. Implications of these technologies on future terrestrial energy systems, combined with advanced fracking, are touched upon.Thorium based reactors, and nuclear fusion along with suitable gas turbine energy conversion systems (ECS) will also be considered by the panelists. The characteristics of the above mentioned ECS will be described, both in terms of their overall energy utilization effectiveness and also with regard to climactic effects due to exhaust emissions.

  20. Performance of the Amoeba Distributed Operating System

    NARCIS (Netherlands)

    van Renesse, R.; van Staveren, H.; Tanenbaum, A.S.

    1989-01-01

    Amoeba is a capability‐based distributed operating system designed for high‐performance interactions between clients and servers using the well‐known RPC model. The paper starts out by describing the architecture of the Amoeba system, which is typified by specialized components such as workstations,

  1. Diversity in School Performance Feedback Systems

    Science.gov (United States)

    Verhaeghe, Goedele; Schildkamp, Kim; Luyten, Hans; Valcke, Martin

    2015-01-01

    As data-based decision making is receiving increased attention in education, more and more school performance feedback systems (SPFSs) are being developed and used worldwide. These systems provide schools with data on their functioning. However, little research is available on the characteristics of the different SPFSs. Therefore, this study…

  2. Optimizing Hydronic System Performance in Residential Applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-10-01

    Even though new homes constructed with hydronic heat comprise only 3% of the market (US Census Bureau 2009), of the 115 million existing homes in the United States, almost 14 million of those homes (11%) are heated with steam or hot water systems according to 2009 US Census data. Therefore, improvements in hydronic system performance could result in significant energy savings in the US.

  3. High Performance Commercial Fenestration Framing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli

    2010-01-31

    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial

  4. Computer performance optimization systems, applications, processes

    CERN Document Server

    Osterhage, Wolfgang W

    2013-01-01

    Computing power performance was important at times when hardware was still expensive, because hardware had to be put to the best use. Later on this criterion was no longer critical, since hardware had become inexpensive. Meanwhile, however, people have realized that performance again plays a significant role, because of the major drain on system resources involved in developing complex applications. This book distinguishes between three levels of performance optimization: the system level, application level and business processes level. On each, optimizations can be achieved and cost-cutting p

  5. Internal Performance Measurement Systems: Problems and Solutions

    DEFF Research Database (Denmark)

    Jakobsen, Morten; Mitchell, Falconer; Nørreklit, Hanne

    2010-01-01

    This article pursues two aims: to identify problems and dangers related to the operational use of internal performance measurement systems of the Balanced Scorecard (BSC) type and to provide some guidance on how performance measurement systems may be designed to overcome these problems....... The analysis uses and extends N rreklit's (2000) critique of the BSC by applying the concepts developed therein to contemporary research on the BSC and to the development of practice in performance measurement. The analysis is of relevance for many companies in the Asia-Pacific area as an increasing numbers...

  6. Influence of Information Systems on Business Performance

    Directory of Open Access Journals (Sweden)

    Dmitrij Lipaj

    2013-04-01

    Full Text Available Considering increased competition nowadays, businesses strive to gain competitive advantage, increase their economic indicators, work productivity and efficiency, reduce costs and get other benefits through implementation of integrated information systems. By improving internal processes and financial performance of the company, the general business performance could be influenced by the deployment of such information system (IS. In order to identify tangible and intangible benefits of IS implementation, influence on business performance, business processes and areas that are being affected, analysis of scientific literature, research synthesis and generalizations have been made.

  7. Conversation for Textual Case-Based Reasoning

    Science.gov (United States)

    2007-01-01

    structures (e.g., Gupta et al., 2002; Gu & Aamodt , 2005). These organized feature vocabularies make existing conversation approaches...e.g., Brüninghaus & Ashley, 2005; Gupta et al., 2002; Gu & Aamodt , 2005). Attribute organization has usually been performed...measured conversation performance, it has done so only as part of system evaluation within a limited framework (e.g., Gupta & Aha, 2003; Gu & Aamodt , 2006

  8. Assessing the Performance of Natural Resource Systems

    Directory of Open Access Journals (Sweden)

    Bruce Campbell

    2002-01-01

    Full Text Available Assessing the performance of management is central to natural resource management, in terms of improving the efficiency of interventions in an adaptive-learning cycle. This is not simple, given that such systems generally have multiple scales of interaction and response; high frequency of nonlinearity, uncertainty, and time lags; multiple stakeholders with contrasting objectives; and a high degree of context specificity. The importance of bounding the problem and preparing a conceptual model of the system is highlighted. We suggest that the capital assets approach to livelihoods may be an appropriate organizing principle for the selection of indicators of system performance. In this approach, five capital assets are recognized: physical, financial, social, natural, and human. A number of principles can be derived for each capital asset; indicators for assessing system performance should cover all of the principles. To cater for multiple stakeholders, participatory selection of indicators is appropriate, although when cross-site comparability is required, some generic indicators are suitable. Because of the high degree of context specificity of natural resource management systems, a typology of landscapes or resource management domains may be useful to allow extrapolation to broader systems. The problems of nonlinearities, uncertainty, and time lags in natural resource management systems suggest that systems modeling is crucial for performance assessment, in terms of deriving "what would have happened anyway" scenarios for comparison to the measured trajectory of systems. Given that a number of indicators are necessary for assessing performance, the question becomes whether these can be combined to give an integrative assessment. We explore five possible approaches: (1 simple additive index, as used for the Human Development Index; (2 derived variables (e.g., principal components as the indices of performance; (3 two-dimensional plots of

  9. Shared performance monitor in a multiprocessor system

    Science.gov (United States)

    Chiu, George; Gara, Alan G.; Salapura, Valentina

    2012-07-24

    A performance monitoring unit (PMU) and method for monitoring performance of events occurring in a multiprocessor system. The multiprocessor system comprises a plurality of processor devices units, each processor device for generating signals representing occurrences of events in the processor device, and, a single shared counter resource for performance monitoring. The performance monitor unit is shared by all processor cores in the multiprocessor system. The PMU comprises: a plurality of performance counters each for counting signals representing occurrences of events from one or more the plurality of processor units in the multiprocessor system; and, a plurality of input devices for receiving the event signals from one or more processor devices of the plurality of processor units, the plurality of input devices programmable to select event signals for receipt by one or more of the plurality of performance counters for counting, wherein the PMU is shared between multiple processing units, or within a group of processors in the multiprocessing system. The PMU is further programmed to monitor event signals issued from non-processor devices.

  10. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Science.gov (United States)

    Martin, Randal G.; Robinson, Elisa L.

    1988-01-01

    The Automated Laser Seeker Performance Evaluation System (ALSPES), which supports the Hellfire missile and Copperhead projectile laser seekers, is discussed. The ALSPES capabilities in manual and automatic operation are described, and the ALSPES test hardware is examined, including the computer system, the laser/attenuator, optics systems, seeker test fixture, and the measurement and test equipment. The calibration of laser energy and test signals in ALSPES is considered.

  11. Introduction to control system performance measurements

    CERN Document Server

    Garner, K C

    1968-01-01

    Introduction to Control System Performance Measurements presents the methods of dynamic measurements, specifically as they apply to control system and component testing. This book provides an introduction to the concepts of statistical measurement methods.Organized into nine chapters, this book begins with an overview of the applications of automatic control systems that pervade almost every area of activity ranging from servomechanisms to electrical power distribution networks. This text then discusses the common measurement transducer functions. Other chapters consider the basic wave

  12. Performance improvement clarification for refrigeration system using active system monitoring

    DEFF Research Database (Denmark)

    Green, Torben; Niemann, Hans Henrik; Izadi-Zamanabadi, Roozbeh

    2011-01-01

    This paper addresses the problem of determining whether a refrigeration plant has the possibility of delivering a better performance of the operation. The controllers are wellknown but detailed knowledge about the underlying dynamics of the refrigeration plant is not available. Thus, the question...... is if it is possible to achieve a better performance by changing the controller parameter. An approach to active system monitoring, based on active fault diagnosis techniques, is employed in order to evaluate changes in the system performance under operation....

  13. Development of a system for characterizing biomass quality of lignocellulosic feedstocks for biochemical conversion

    Science.gov (United States)

    Murphy, Patrick Thomas

    The purpose of this research was twofold: (i) to develop a system for screening lignocellulosic biomass feedstocks for biochemical conversion to biofuels and (ii) to evaluate brown midrib corn stover as feedstock for ethanol production. In the first study (Chapter 2), we investigated the potential of corn stover from bm1-4 hybrids for increased ethanol production and reduced pretreatment intensity compared to corn stover from the isogenic normal hybrid. Corn stover from hybrid W64A X A619 and respective isogenic bm hybrids was pretreated by aqueous ammonia steeping using ammonium hydroxide concentrations from 0 to 30%, by weight, and the resulting residues underwent simultaneous saccharification and cofermentation (SSCF) to ethanol. Dry matter (DM) digested by SSCF increased with increasing ammonium hydroxide concentration across all genotypes (P>0.0001) from 277 g kg-1 DM in the control to 439 g kg-1 DM in the 30% ammonium hydroxide pretreatment. The bm corn stover materials averaged 373 g kg-1 DM of DM digested by SSCF compared with 335 g kg-1 DM for the normal corn stover (Pcorn stover, (ii) the lowest initial cell-wall carbohydrate concentration, (iii) the lowest dry matter remaining after pretreatment, and (iv) the highest amount of monosaccharides released during enzymatic hydrolysis. However, bm corn stover did not reduce the severity of aqueous ammonia steeping pretreatment needed to maximize DM hydrolysis during SSCF compared with normal corn stover. In the remaining studies (Chapters 3 thru 5), a system for analyzing the quality of lignocellulosic biomass feedstocks for biochemical conversion to biofuels (i.e., pretreatment, enzymatic hydrolysis, and fermentation) was developed. To accomplish this, a carbohydrate availability model was developed to characterize feedstock quality. The model partitions carbohydrates within a feedstock material into fractions based on their availability to be converted to fermentable sugars, including non

  14. Characterisation of Systems for Raman-Assisted High-Speed Wavelength Conversion

    DEFF Research Database (Denmark)

    Galili, Michael; Oxenløwe, Leif Katsuo; Zibar, Darko

    2005-01-01

    Raman-assisted wavelength conversion for ultra-high speed data is characterised in approaches: a novel scheme based on cross-phase modulation using specially designed notch filters and a 160 Gb/s experiment based on self-phase modulation......Raman-assisted wavelength conversion for ultra-high speed data is characterised in approaches: a novel scheme based on cross-phase modulation using specially designed notch filters and a 160 Gb/s experiment based on self-phase modulation...

  15. Hydrothermal conversion of FAU zeolite into RUT zeolite in TMAOH system

    OpenAIRE

    Jon, Hery; Takahashi, Shoutarou; Sasaki, Hitoshi; Oumi, Yasunori; Sano, Tsuneji

    2008-01-01

    The highly crystalline and pure RUT (RUB-10) zeolite could be obtained from the hydrothermal conversion of FAU zeolite used as a crystalline Si/Al source in tetramethylammonium hydroxide (TMAOH) media. As compared to amorphous silica/Al(OH)3 and amorphous silica/γ-Al2O3 sources, the crystallization rate for the formation of RUT zeolite was clearly faster when FAU zeolite was employed as the Si/Al source. Moreover, it was found that the hydrothermal conversion of FAU zeolite into RUT zeolite d...

  16. Performance analysis of hybrid district heating system

    DEFF Research Database (Denmark)

    Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii

    2013-01-01

    could reach up to 20% with utilisation of solar energy as supplement energy source in traditional fossil fuel based district heating systems. In this work, the performance of hybrid district energy system for a particular location will be analysed. For performance analysis, mathematical model...... more extensively used in district heating systems either separately or as a supplement to traditional fossil fuels in order to achieve national energy policy objectives. However, they are still facing problems such as high intermittences, high energy production costs and low load factors as well...... sources that can complement each other on daily and yearly basis and reduce negative aspects of particular energy source utilisation. In district heating systems, hybridisation could be performed through utilisation of renewable and non-renewable energy sources. Potential of fuel and emission reduction...

  17. A Critique of Health System Performance Measurement.

    Science.gov (United States)

    Lynch, Thomas

    2015-01-01

    Health system performance measurement is a ubiquitous phenomenon. Many authors have identified multiple methodological and substantive problems with performance measurement practices. Despite the validity of these criticisms and their cross-national character, the practice of health system performance measurement persists. Theodore Marmor suggests that performance measurement invokes an "incantatory response" wrapped within "linguistic muddle." In this article, I expand upon Marmor's insights using Pierre Bourdieu's theoretical framework to suggest that, far from an aberration, the "linguistic muddle" identified by Marmor is an indicator of a broad struggle about the representation and classification of public health services as a public good. I present a case study of performance measurement from Alberta, Canada, examining how this representational struggle occurs and what the stakes are. © The Author(s) 2015.

  18. WFIRST: Coronagraph Systems Engineering and Performance Budgets

    Science.gov (United States)

    Poberezhskiy, Ilya; cady, eric; Frerking, Margaret A.; Kern, Brian; Nemati, Bijan; Noecker, Martin; Seo, Byoung-Joon; Zhao, Feng; Zhou, Hanying

    2018-01-01

    The WFIRST coronagraph instrument (CGI) will be the first in-space coronagraph using active wavefront control to directly image and characterize mature exoplanets and zodiacal disks in reflected starlight. For CGI systems engineering, including requirements development, CGI performance is predicted using a hierarchy of performance budgets to estimate various noise components — spatial and temporal flux variations — that obscure exoplanet signals in direct imaging and spectroscopy configurations. These performance budgets are validated through a robust integrated modeling and testbed model validation efforts.We present the performance budgeting framework used by WFIRST for the flow-down of coronagraph science requirements, mission constraints, and observatory interfaces to measurable instrument engineering parameters.

  19. 160 Gb/s Raman-assisted notch-filtered XPM wavelength conversion and transmission

    DEFF Research Database (Denmark)

    Galili, Michael; Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen

    2007-01-01

    In-line wavelength conversion of 160 Gb/s data by Raman-assisted notch-filtered XPM is demonstrated for 130 km total transmission. The improvement in system performance from applying Raman gain during conversion is shown.......In-line wavelength conversion of 160 Gb/s data by Raman-assisted notch-filtered XPM is demonstrated for 130 km total transmission. The improvement in system performance from applying Raman gain during conversion is shown....

  20. PVUSA experience with power conversion for grid-connected photovoltaic systems

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, W.

    1995-11-01

    The Photovoltaics for Utility Scale Application (PVUSA) project was established to demonstrate photovoltaic (PV) systems in grid-connected utility applications. One of PVUSA`s key objectives is to evaluate the performance, reliability, and cost of the PV balance of system (BOS). Power conditioning units (PCUs) are the interface between the dc PV arrays and the ac utility lines, and have proved to be the most critical element in grid-connected PV systems. There are five different models of PCUs at PVUSA`s Davis and Kerman sites. This report describes the design, testing, performance characteristics, and maintenance history of each of these PCUs. PVUSA required PCUs in the power range 25 kW to 500 kW which could operate automatically and reliably under changing conditions of sunlight and changing conditions on the utility grid. Although a number of manufacturers can provide PCUs in this power range, none of these PCUs have been produced in sufficient quantity to allow refinement of a particular model into the highly reliable unit needed for long-term, unattended operation. Factory tests were useful but limited by the inability to test under full power and changing power conditions. The inability to completely test PCUs at the factory resulted in difficulty during startup, field testing, and subsequent operation. PVUSA has made significant progress in understanding the requirements for PCUs in grid-connected PV applications and improving field performance. This record of PVUSA`s experience with a variety of PCUs is intended to help utilities and their suppliers identify and retain the good performance characteristics of PCUs, and to make improvements where necessary to meet the needs of utilities.

  1. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    Science.gov (United States)

    Charache, Greg W.; Baldasaro, Paul F.; Nichols, Greg J.

    1998-01-01

    A thermophotovoltaic energy conversion device and a method for making the device. The device includes a substrate formed from a bulk single crystal material having a bandgap (E.sub.g) of 0.4 eVternary or quaternary III-V semiconductor active layers.

  2. Identification of an Enzyme System for Daidzein-to-Equol Conversion in Slackia sp. Strain NATTS

    Science.gov (United States)

    Moriyama, Kaoru; Nomoto, Koji; Akaza, Hideyuki

    2012-01-01

    An Escherichia coli library comprising 8,424 strains incorporating gene fragments of the equol-producing bacterium Slackia sp. strain NATTS was constructed and screened for E. coli strains having daidzein- and dihydrodaidzein (DHD)- metabolizing activity. We obtained 3 clones that functioned to convert daidzein to DHD and 2 clones that converted DHD to equol. We then sequenced the gene fragments inserted into plasmids contained by these 5 clones. All of the gene fragments were contiguous, encoding three open reading frames (ORF-1, -2, and -3). Analysis of E. coli strains containing an expression vector incorporating one of the orf-1, -2, or -3 genes revealed that (i) the protein encoded by orf-1 was involved in the conversion of cis/trans-tetrahydrodaidzein (cis/trans-THD) to equol, (ii) the protein encoded by orf-2 was involved in the conversion of DHD to cis/trans-THD, and (iii) the protein encoded by orf-3 was involved in the conversion of daidzein to DHD. ORF-1 had a primary amino acid structure similar to that of succinate dehydrogenase. ORF-2 was presumed to be an enzyme belonging to the short-chain dehydrogenase/reductase superfamily. ORF-3 was predicted to have 42% identity to the daidzein reductase of Lactococcus strain 20-92 and belonged to the NADH:flavin oxidoreductase family. These findings showed that the daidzein-to-equol conversion reaction in the Slackia sp. NATTS strain proceeds by the action of these three enzymes. PMID:22179235

  3. Evaluation of Switch Currents in Nine-Switch Energy Conversion Systems

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Bahman, Amir Sajjad; Qin, Zian

    2013-01-01

    since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac-ac, ac-dc, dc-ac and dc-dc energy conversions. Relevant...

  4. Evaluation of current stresses in nine-switch energy conversion systems

    DEFF Research Database (Denmark)

    Qin, Zian; Loh, Poh Chiang; Bahman, Amir Sajjad

    2014-01-01

    since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac-ac, ac-dc, dc-ac and dc-dc energy conversions. Relevant...

  5. Manipulating Stress and Cognitive Load in Conversational Interactions with a Multimodal System for Crisis Management Support

    NARCIS (Netherlands)

    Niculescu, A.I.; Cao, Y.; Esposito, A.; Campbell, N.; Vogel, C.; Hussain, A.; Nijholt, Antinus

    2010-01-01

    The quality assessment of multimodal conversational interfaces is influenced by many factors. Stress and cognitive load are two of most important. In the literature, these two factors are considered as being related and accordingly summarized under the single concept of ‘cognitive demand’. However,

  6. Simulating the Conversion of Rural Settlements to Town Land Based on Multi-Agent Systems and Cellular Automata

    Science.gov (United States)

    Liu, Yaolin; Kong, Xuesong; Liu, Yanfang; Chen, Yiyun

    2013-01-01

    Rapid urbanization in China has triggered the conversion of land from rural to urban use, particularly the conversion of rural settlements to town land. This conversion is the result of the joint effects of the geographic environment and agents involving the government, investors, and farmers. To understand the dynamic interaction dominated by agents and to predict the future landscape of town expansion, a small town land-planning model is proposed based on the integration of multi-agent systems (MAS) and cellular automata (CA). The MAS-CA model links the decision-making behaviors of agents with the neighbor effect of CA. The interaction rules are projected by analyzing the preference conflicts among agents. To better illustrate the effects of the geographic environment, neighborhood, and agent behavior, a comparative analysis between the CA and MAS-CA models in three different towns is presented, revealing interesting patterns in terms of quantity, spatial characteristics, and the coordinating process. The simulation of rural settlements conversion to town land through modeling agent decision and human-environment interaction is very useful for understanding the mechanisms of rural-urban land-use change in developing countries. This process can assist town planners in formulating appropriate development plans. PMID:24244472

  7. Performance regression manager for large scale systems

    Science.gov (United States)

    Faraj, Daniel A.

    2017-08-01

    System and computer program product to perform an operation comprising generating, based on a first output generated by a first execution instance of a command, a first output file specifying a value of at least one performance metric, wherein the first output file is formatted according to a predefined format, comparing the value of the at least one performance metric in the first output file to a value of the performance metric in a second output file, the second output file having been generated based on a second output generated by a second execution instance of the command, and outputting for display an indication of a result of the comparison of the value of the at least one performance metric of the first output file to the value of the at least one performance metric of the second output file.

  8. Performance regression manager for large scale systems

    Energy Technology Data Exchange (ETDEWEB)

    Faraj, Daniel A.

    2017-10-17

    System and computer program product to perform an operation comprising generating, based on a first output generated by a first execution instance of a command, a first output file specifying a value of at least one performance metric, wherein the first output file is formatted according to a predefined format, comparing the value of the at least one performance metric in the first output file to a value of the performance metric in a second output file, the second output file having been generated based on a second output generated by a second execution instance of the command, and outputting for display an indication of a result of the comparison of the value of the at least one performance metric of the first output file to the value of the at least one performance metric of the second output file.

  9. Enhanced Capability of Photoelectrochemical CO2 Conversion System Using an AlGaN/GaN Photoelectrode

    Science.gov (United States)

    Deguchi, Masahiro; Yotsuhashi, Satoshi; Hashiba, Hiroshi; Yamada, Yuka; Ohkawa, Kazuhiro

    2013-08-01

    We report significantly improved photosynthesis system based on AlGaN/GaN photochemical process. The resultant energy conversion efficiency is 0.13% which is the same level as that of real plants. The capability of this system is enhanced by high cathode potential due to the reduction of energy loss while utilizing the piezoelectric effect in the AlGaN/GaN heterostructure. The Faradaic efficiency of the CO2 conversion to organic materials is enhanced, accompanied by an increment in photocurrent by modification of the AlGaN/GaN photoelectrode structure and electrolytes. Furthermore, reaction products such as C2H4 and C2H5OH are generated by light illumination alone.

  10. Photoactivation studies of zinc porphyrin-myoglobin system and its application for light-chemical energy conversion.

    Science.gov (United States)

    Chang, Chin-Hao; Hu, Yi-Ting; Lo, Chen-Fu; Luo, Liyang; Lin, Hung-Ming; Chang, Cheng-Hsiang; Lin, Ching-Yao; Diau, Eric Wei-Guang; Wu, Tung-Kung

    2011-01-01

    An artificial zinc porphyrin-myoglobin-based photo-chemical energy conversion system, consisting of ZnPP-Mb or ZnPE(1)-Mb as a photosensitizer, NADP(+) as an electron acceptor, and triethanolamine as an electron donor, has been constructed to mimic photosystem I. The photoirradiated product is able to reduce a single-electron acceptor protein cytochrome c, but cannot catalyze the two-electron reduction of acetaldehyde by alcohol dehydrogenase, thus demonstrating a single electron transfer mechanism. Furthermore, the artificial system can bifunctionally promote oxidoredox reactions, depending on the presence or absence of a sacrificial electron donor, thus suggesting its potential application in electrochemical regeneration steps involved in chemical transformation and/or energy conversion.

  11. 2D materials. Graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage.

    Science.gov (United States)

    Bonaccorso, Francesco; Colombo, Luigi; Yu, Guihua; Stoller, Meryl; Tozzini, Valentina; Ferrari, Andrea C; Ruoff, Rodney S; Pellegrini, Vittorio

    2015-01-02

    Graphene and related two-dimensional crystals and hybrid systems showcase several key properties that can address emerging energy needs, in particular for the ever growing market of portable and wearable energy conversion and storage devices. Graphene's flexibility, large surface area, and chemical stability, combined with its excellent electrical and thermal conductivity, make it promising as a catalyst in fuel and dye-sensitized solar cells. Chemically functionalized graphene can also improve storage and diffusion of ionic species and electric charge in batteries and supercapacitors. Two-dimensional crystals provide optoelectronic and photocatalytic properties complementing those of graphene, enabling the realization of ultrathin-film photovoltaic devices or systems for hydrogen production. Here, we review the use of graphene and related materials for energy conversion and storage, outlining the roadmap for future applications. Copyright © 2015, American Association for the Advancement of Science.

  12. Bayesian Zero-Failure (BAZE) reliability demonstration testing procedure and its application to a Rankine dynamic radioisotope power conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Martz, H.F. Jr.; Waller, R.A.

    1976-07-01

    A Bayesian Zero-Failure (BAZE) reliability demonstration testing procedure is developed. The procedure may be used to verify component failure rates associated with both real-time dependent and cycle-dependent chance failure mechanisms. A constant falure-rate model with a gamma prior distribution is assumed. The procedure is used to obtain sample test plans for components of a proposed Rankine power conversion system.

  13. Performance analysis of memory hierachies in high performance systems

    Energy Technology Data Exchange (ETDEWEB)

    Yogesh, Agrawel [Iowa State Univ., Ames, IA (United States)

    1993-07-01

    This thesis studies memory bandwidth as a performance predictor of programs. The focus of this work is on computationally intensive programs. These programs are the most likely to access large amounts of data, stressing the memory system. Computationally intensive programs are also likely to use highly optimizing compilers to produce the fastest executables possible. Methods to reduce the amount of data traffic by increasing the average number of references to each item while it resides in the cache are explored. Increasing the average number of references to each cache item reduces the number of memory requests. Chapter 2 describes the DLX architecture. This is the architecture on which all the experiments were performed. Chapter 3 studies memory moves as a performance predictor for a group of application programs. Chapter 4 introduces a model to study the performance of programs in the presence of memory hierarchies. Chapter 5 explores some compiler optimizations that can help increase the references to each item while it resides in the cache.

  14. Performance management system enhancement and maintenance

    Science.gov (United States)

    Cleaver, T. G.; Ahour, R.; Johnson, B. R.

    1984-01-01

    The research described in this report concludes a two-year effort to develop a Performance Management System (PMS) for the NCC computers. PMS provides semi-automated monthly reports to NASA and contractor management on the status and performance of the NCC computers in the TDRSS program. Throughout 1984, PMS was tested, debugged, extended, and enhanced. Regular PMS monthly reports were produced and distributed. PMS continues to operate at the NCC under control of Bendix Corp. personnel.

  15. Regional Innovation Systems: How to Assess Performance

    OpenAIRE

    Zabala Iturriagagoitia, Jon Mikel; Voigt, Peter; Gutiérrez Gracia, Antonio; Jiménez Sáez, Fernando

    2007-01-01

    Abstract This paper applies Data Envelopment Analysis [DEA] methodology to the evaluation of regional innovation system performance based on information provided by the European Innovation Scoreboard [EIS] for 2002 and 2003. We find that those European regions ranked in the EIS as showing better performance in high-technology areas, are ranked somewhat differently according to DEA. The results of our study show that the higher the technological level of a region, the greater is ...

  16. Traditional formwork system sustainability performance: experts’ opinion

    Science.gov (United States)

    Taher Al-ashwal, Mohammed; Abdullah, Redzuan; Zakaria, Rozana

    2017-11-01

    The traditional formwork system is one of the commonly used systems in concrete construction. It is considered as one of the least observed activities in term of sustainability performance. In this paper, the sustainability performance of the traditional formwork has been assessed by using a multi-criteria assessment tool to facilitate the decision on the sustainability performance measurement. A quantitative five Likert scale survey study using judgemental sampling is employed in this study. A sample of 93 of engineering construction experts, with different fields including contractors, developers, and consultants in the Malaysian context has made the body of the collected primary data. The results show variety in the distribution of the respondents’ working experience. The sustainability performance is considered moderately sustainable by the experts with only given 40.24 % of the overall total score for the three sustainable categories namely environmental, social and economic. Despite the finding that shows that the economic pillar was rated as the most sustainable aspect in comparison to the environmental and social pillars the traditional formwork system sustainability still needs enhancement. Further incorporation of the social and environmental pillars into the concrete construction the sustainability performance of traditional formwork system could be improved.

  17. Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration.

    Science.gov (United States)

    Guo, Gang; Wu, Di; Hao, Tianwei; Mackey, Hamish Robert; Wei, Li; Wang, Haiguang; Chen, Guanghao

    2016-05-15

    A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD

  18. Computers and conversation

    CERN Document Server

    Luff, Paul; Gilbert, Nigel G

    1986-01-01

    In the past few years a branch of sociology, conversation analysis, has begun to have a significant impact on the design of human*b1computer interaction (HCI). The investigation of human*b1human dialogue has emerged as a fruitful foundation for interactive system design.****This book includes eleven original chapters by leading researchers who are applying conversation analysis to HCI. The fundamentals of conversation analysis are outlined, a number of systems are described, and a critical view of their value for HCI is offered.****Computers and Conversation will be of interest to all concerne

  19. Management issues for high performance storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Louis, S. [Lawrence Livermore National Lab., CA (United States); Burris, R. [Oak Ridge National Lab., TN (United States)

    1995-03-01

    Managing distributed high-performance storage systems is complex and, although sharing common ground with traditional network and systems management, presents unique storage-related issues. Integration technologies and frameworks exist to help manage distributed network and system environments. Industry-driven consortia provide open forums where vendors and users cooperate to leverage solutions. But these new approaches to open management fall short addressing the needs of scalable, distributed storage. We discuss the motivation and requirements for storage system management (SSM) capabilities and describe how SSM manages distributed servers and storage resource objects in the High Performance Storage System (HPSS), a new storage facility for data-intensive applications and large-scale computing. Modem storage systems, such as HPSS, require many SSM capabilities, including server and resource configuration control, performance monitoring, quality of service, flexible policies, file migration, file repacking, accounting, and quotas. We present results of initial HPSS SSM development including design decisions and implementation trade-offs. We conclude with plans for follow-on work and provide storage-related recommendations for vendors and standards groups seeking enterprise-wide management solutions.

  20. High efficiency energy conversion from liquid jet flow

    NARCIS (Netherlands)

    Xie, Yanbo; de Vreede, Lennart; Nguyen, Trieu; de Boer, Hans L.; Sprenkels, A.J.; van den Berg, Albert; Eijkel, Jan C.T.; Fujii, T.; Hibara, A.; Takeuchi, S.; Fukuba, T.

    2012-01-01

    We investigate the performance of a microfluidic energy conversion system using jetting flow. Preliminary results indicate that a voltage can be generated of several kilo-Volts and energy efficiencies can reach 15%. Such values are by far the highest obtained for electrokinetic conversion systems

  1. Dentin bond strength and degree of conversion evaluation of experimental self-etch adhesive systems

    OpenAIRE

    Yazdi, Fatemeh Maleknejad; Moosavi, Horieh; Atai,Mohammad; Zeynali, Mahsa

    2015-01-01

    Background The aim of this study was to investigate the effect of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer in one-step self-etch experimental adhesives on dentinal microshear bond strength (?SBS), their degree of conversion and bonded micro structure. Material and Methods Composite resin cylinders (Clearfil AP-X) were bonded on human sound molar dentinal surfaces by using five experimental one-step self-etching adhesives (1-SEAs) containing 0% ...

  2. Impact of Managers' Coaching Conversations on Staff Knowledge Use and Performance in Long-Term Care Settings.

    Science.gov (United States)

    Cummings, Greta G; Hewko, Sarah J; Wang, Mengzhe; Wong, Carol A; Laschinger, Heather K Spence; Estabrooks, Carole A

    2017-07-29

    Extended lifespans and complex resident care needs have amplified resource demands on nursing homes. Nurse managers play an important role in staff job satisfaction, research use, and resident outcomes. Coaching skills, developed through leadership skill-building, have been shown to be of value in nursing. To test a theoretical model of nursing home staff perceptions of their work context, their managers' use of coaching conversations, and their use of instrumental, conceptual and persuasive research. Using a two-group crossover design, 33 managers employed in seven Canadian nursing homes were invited to attend a 2-day coaching development workshop. Survey data were collected from managers and staff at three time points; we analyzed staff data (n = 333), collected after managers had completed the workshop. We used structural equation modeling to test our theoretical model of contextual characteristics as causal variables, managers' characteristics, and coaching behaviors as mediating variables and staff use of research, job satisfaction, and burnout as outcome variables. The theoretical model fit the data well (χ2 = 58, df = 43, p = .06) indicating no significant differences between data and model-implied matrices. Resonant leadership (a relational approach to influencing change) had the strongest significant relationship with manager support, which in turn influenced frequency of coaching conversations. Coaching conversations had a positive, non-significant relationship with staff persuasive use of research, which in turn significantly increased instrumental research use. Importantly, coaching conversations were significantly, negatively related to job satisfaction. Our findings add to growing research exploring the role of context and leadership in influencing job satisfaction and use of research by healthcare practitioners. One-on-one coaching conversations may be difficult for staff not used to participating in such conversations. Resonant leadership, as

  3. Experimental study of the influence of different resonators on thermoacoustic conversion performance of a thermoacoustic-Stirling heat engine.

    Science.gov (United States)

    Luo, E C; Ling, H; Dai, W; Yu, G Y

    2006-12-22

    In this paper, an experimental study of the effect of the resonator shape on the performance of a traveling-wave thermoacoustic engine is presented. Two different resonators were tested in the thermoacoustic-Stirling heat. One resonator is an iso-diameter one, and the other is a tapered one. To have a reasonable comparison reference, we keep the same traveling-wave loop, the same resonant frequency and the same operating pressure. The experiment showed that the resonator shape has significant influence on the global performance of the thermoacoustic-Stirling heat engine. The tapered resonator gives much better performance than the iso-diameter resonator. The tapered resonator system achieved a maximum pressure ratio of about 1.3, a maximum net acoustical power output of about 450 W and a highest thermoacoustic efficiency of about 25%.

  4. Dentin bond strength and degree of conversion evaluation of experimental self-etch adhesive systems.

    Science.gov (United States)

    Yazdi, Fatemeh-Maleknejad; Moosavi, Horieh; Atai, Mohammad; Zeynali, Mahsa

    2015-04-01

    The aim of this study was to investigate the effect of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer in one-step self-etch experimental adhesives on dentinal microshear bond strength (µSBS), their degree of conversion and bonded micro structure. Composite resin cylinders (Clearfil AP-X) were bonded on human sound molar dentinal surfaces by using five experimental one-step self-etching adhesives (1-SEAs) containing 0% (E0), 5% (E5), 10% (E10), 15% (E15), 20% (E20) (by weight) 10-MDP monomer and Clearfil S3 Bond (CS3) as a control. After 24 hours, microshear bond strength was tested. The degree of conversion was also measured using Fourier transform infrared spectroscopy. Interfacial ultrastructure was observed under a scanning electron microscope in all the groups. A higher microshear bond strength was observed with adhesives containing 10% and 15% 10-MDP in comparison to study groups (PSelf-etch adhesives, 10-MDP, bond strength, degree of conversion.

  5. Dentin bond strength and degree of conversion evaluation of experimental self-etch adhesive systems

    Science.gov (United States)

    Yazdi, Fatemeh-Maleknejad; Atai, Mohammad; Zeynali, Mahsa

    2015-01-01

    Background The aim of this study was to investigate the effect of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer in one-step self-etch experimental adhesives on dentinal microshear bond strength (µSBS), their degree of conversion and bonded micro structure. Material and Methods Composite resin cylinders (Clearfil AP-X) were bonded on human sound molar dentinal surfaces by using five experimental one-step self-etching adhesives (1-SEAs) containing 0% (E0), 5% (E5), 10% (E10), 15% (E15), 20% (E20) (by weight) 10-MDP monomer and Clearfil S3 Bond (CS3) as a control. After 24 hours, microshear bond strength was tested. The degree of conversion was also measured using Fourier transform infrared spectroscopy. Interfacial ultrastructure was observed under a scanning electron microscope in all the groups. Results A higher microshear bond strength was observed with adhesives containing 10% and 15% 10-MDP in comparison to study groups (PSelf-etch adhesives, 10-MDP, bond strength, degree of conversion. PMID:26155340

  6. A Study of Vicon System Positioning Performance

    Directory of Open Access Journals (Sweden)

    Pierre Merriaux

    2017-07-01

    Full Text Available Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today’s life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  7. High Performance Work Systems for Online Education

    Science.gov (United States)

    Contacos-Sawyer, Jonna; Revels, Mark; Ciampa, Mark

    2010-01-01

    The purpose of this paper is to identify the key elements of a High Performance Work System (HPWS) and explore the possibility of implementation in an online institution of higher learning. With the projected rapid growth of the demand for online education and its importance in post-secondary education, providing high quality curriculum, excellent…

  8. High performance computing on vector systems

    CERN Document Server

    Roller, Sabine

    2008-01-01

    Presents the developments in high-performance computing and simulation on modern supercomputer architectures. This book covers trends in hardware and software development in general and specifically the vector-based systems and heterogeneous architectures. It presents innovative fields like coupled multi-physics or multi-scale simulations.

  9. Performance Aspects of Synthesizable Computing Systems

    DEFF Research Database (Denmark)

    Schleuniger, Pascal

    of interfaces can be integrated on a single device. This thesis consists of ve parts that address performance aspects of synthesizable computing systems on FPGAs. First, it is evaluated how synthesizable processor cores can exploit current state-of-the-art FPGA architectures. This evaluation results...

  10. South Africa's School Infrastructure Performance Indicator System

    Science.gov (United States)

    Gibberd, Jeremy

    2007-01-01

    While some South African schools have excellent infrastructure, others lack basic services such as water and sanitation. This article describes the school infrastructure performance indicator system (SIPIS) in South Africa. The project offers an approach that can address both the urgent provision of basic services as well as support the…

  11. Precast concrete pavement - systems and performance review

    Science.gov (United States)

    Novak, Josef; Kohoutková, Alena; Křístek, Vladimír; Vodička, Jan

    2017-09-01

    Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.

  12. Performance Analysis of a Photovoltaic-Thermal Integrated System

    Directory of Open Access Journals (Sweden)

    Ewa Radziemska

    2009-01-01

    Full Text Available The present commercial photovoltaic solar cells (PV converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is higly desirable to obtain efficiency increase. The total efficiency of 60–80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV. In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings—the destroyed exergy has been called anergy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiences in a system. This information, which cannot be provided by other means (e.g., an energy analysis, is very useful for the improvement and cost-effictiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solarwatt module.

  13. Solar thermal conversion

    Science.gov (United States)

    Selcuk, M. K.

    1978-01-01

    A brief review of the fundamentals of the conversion of solar energy into mechanical work (or electricity via generators) is given. Both past and present work on several conversion concepts are discussed. Solar collectors, storage systems, energy transport, and various types of engines are examined. Ongoing work on novel concepts of collectors, energy storage and thermal energy conversion are outlined and projections for the future are described. Energy costs for various options are predicted and margins and limitations are discussed.

  14. Performance evaluation of a computed radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Roussilhe, J.; Fallet, E. [Carestream Health France, 71 - Chalon/Saone (France); Mango, St.A. [Carestream Health, Inc. Rochester, New York (United States)

    2007-07-01

    Computed radiography (CR) standards have been formalized and published in Europe and in the US. The CR system classification is defined in those standards by - minimum normalized signal-to-noise ratio (SNRN), and - maximum basic spatial resolution (SRb). Both the signal-to-noise ratio (SNR) and the contrast sensitivity of a CR system depend on the dose (exposure time and conditions) at the detector. Because of their wide dynamic range, the same storage phosphor imaging plate can qualify for all six CR system classes. The exposure characteristics from 30 to 450 kV, the contrast sensitivity, and the spatial resolution of the KODAK INDUSTREX CR Digital System have been thoroughly evaluated. This paper will present some of the factors that determine the system's spatial resolution performance. (authors)

  15. Influence of the photoinitiator system and light photoactivation units on the degree of conversion of dental composites

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Celerino de Moraes Porto

    2010-12-01

    Full Text Available The aim of this study was to observe the influence of two light polymerization units (LED or halogen light on the degree of conversion (DC of three dental composites with lighter shades and a different photoinitiator system. The top (T and bottom (B surfaces of 60 discs of composite resin (Filtek™ Supreme, Filtek™ Z250, Tetric™ Ceram Bleach cured either by LED or by halogen lamp (HL were studied using an FT-Raman spectrometer. The degree of conversion (DC was evaluated by following the changes in the intensity of the methacrylate C=C stretching mode at 1640 cm-1. The calculated DC ranged from 54.2% (B to 73.4% (T and from 60.2% (B to 76.6% (T for the LED and HL, respectively. LED and halogen devices were able to produce an adequate DC for all the resins tested.

  16. Conversion of radioactive and hazardous chemical wastes into borosilicate glass using the glass material oxidation and dissolution system

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Elam, K.R. [Oak Ridge National Lab., TN (United States)

    1996-12-31

    A new vitrification process has been invented. The Glass Material Oxidation and Dissolution System (GMODS) allows direct conversion of radioactive and hazardous chemical wastes to borosilicate glass. GMODS directly converts metals, ceramics and amorphous solids to glass, oxidizes organics with the residue converted to glass, and converts halides (such as chlorides) to borosilicate glass and a secondary sodium halide stream. The glass is designed to meet EPA criteria for chemically non-hazardous waste forms. Laboratory work has demonstrated the conversion of stainless steel, aluminum, cerium (a plutonium surrogate), uranium, Zircaloy, multiple oxides and other materials to glass. Equipment options have been identified for processing rates between 1 and 100,000 t/y. Significant work, including a pilot plant, is required to develop GMODS for applications at an industrial scale.

  17. Performance of the new SPS beam position orbit system (MOPOS)

    CERN Document Server

    Boccard, C; Brazier, J C L; De Vries, J; Jackson, S; Jones, O R; Papis, J P; Rawnsley, W; Rybaltchenko, K; Schmickler, Hermann

    2000-01-01

    The orbit and trajectory measurement system COPOS of the CERN SPS accelerator has been in operation since the construction of the machine in 1976. Over the years the system has been slightly modified in order to follow the evolving demands of the machine, in particular for its operation as a p-pbar collider and, since 1991, for the acceleration of heavy ions. In 1995 the performance of the system was reviewed and the following shortcomings were identified: - lack of turn-by-turn position measurements due to the 1ms integration time of the voltage to frequency converters used for the analogue to digital conversion (to be compared with a revolution time of 23 ms), - ageing effects on the 200 MHz resonating input filters, which had over the years drifted out of tolerance. As a consequence the signal to noise ratio, the linearity and the absolute precision were affected, - the calibration system based on electromechanical relays had become very unreliable, such that frequent calibrations were no longer possible, ...

  18. Conversion of Hanford site well locations to Washington coordinate system of 1983, South Zone 1991 (WCS83S)

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, R.A.; Tzemos, S. [Pacific Northwest Lab., Richland, WA (United States); Dietz, L.A. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-12-01

    Past construction and survey practices have resulted in the use of multiple local coordinate systems for measuring and reporting the horizontal position of wells and other facilities and locations on the Hanford Site. This report describes the development of a coordinate transformation process and algorithm and its application to the conversion of the horizontal coordinates of Hanford site wells from the various local coordinate systems and datums to a single standard coordinate system, the Washington Coordinate system of 1983, South Zone 1991 (WCS83S). The coordinate transformation algorithm, implemented as a computer program called CTRANS, uses standard two-dimensional translation, rotation, and scaling transformation equations and can be applied to any set of horizontal point locations. For each point to be transformed, the coefficients of the transformation equations are calculated locally, using the coordinates of the three nearest registration points (points with known locations in both coordinate systems). The report contains a discussion of efforts to verify and validate both the software and the well location data, a description of the methods used to estimate transformation and registration point accuracy, instructions for using the computer program, and a summary of the Hanford well conversion results for each local coordinate system and datum. Also included are the results of using recent U.S. Army Corps of Engineers survey data to obtain estimated measures of location errors in wells for which the local coordinate data source is undocumented, unverified, and therefore of unknown accuracy.

  19. Comparison of simulations and offshore measurement data of a prototype of a floating combined wind and wave energy conversion system

    DEFF Research Database (Denmark)

    Yde, Anders; Larsen, Torben J.; Hansen, Anders Melchior

    2015-01-01

    In this paper, results from comparisons of simulations and measured offshore data from a floating combined wind and wave energy conversion system are presented. The device is a downscaled prototype that consists of a floating platform equipped with ten wave energy absorbers and three wind turbines....... The numerical model of the platform is based on the aeroelastic code, HAWC2, developed by DTU Wind Energy, which is coupled with a special external system that reads the output generated directly by the wave analysis software, WAMIT. The model also includes models for the dynamic mooring lines as well...

  20. Digital computer study of nuclear reactor thermal transients during startup of 60-kWe Brayton power conversion system

    Science.gov (United States)

    Jefferies, K. S.; Tew, R. C.

    1974-01-01

    A digital computer study was made of reactor thermal transients during startup of the Brayton power conversion loop of a 60-kWe reactor Brayton power system. A startup procedure requiring the least Brayton system complication was tried first; this procedure caused violations of design limits on key reactor variables. Several modifications of this procedure were then found which caused no design limit violations. These modifications involved: (1) using a slower rate of increase in gas flow; (2) increasing the initial reactor power level to make the reactor respond faster; and (3) appropriate reactor control drum manipulation during the startup transient.

  1. Engineered Barrier System performance requirements systems study report. Revision 02

    Energy Technology Data Exchange (ETDEWEB)

    Balady, M.A.

    1997-01-14

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

  2. Summary of photovoltaic system performance models

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J. H.; Reiter, L. J.

    1984-01-15

    The purpose of this study is to provide a detailed overview of photovoltaics (PV) performance modeling capabilities that have been developed during recent years for analyzing PV system and component design and policy issues. A set of 10 performance models have been selected which span a representative range of capabilities from generalized first-order calculations to highly specialized electrical network simulations. A set of performance modeling topics and characteristics is defined and used to examine some of the major issues associated with photovoltaic performance modeling. Next, each of the models is described in the context of these topics and characteristics to assess its purpose, approach, and level of detail. Then each of the issues is discussed in terms of the range of model capabilities available and summarized in tabular form for quick reference. Finally, the models are grouped into categories to illustrate their purposes and perspectives.

  3. Coal-fired high performance power generating system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-31

    As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.

  4. Hybrid ventilation systems and high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Utzinger, D.M. [Wisconsin Univ., Milwaukee, WI (United States). School of Architecture and Urban Planning

    2009-07-01

    This paper described hybrid ventilation design strategies and their impact on 3 high performance buildings located in southern Wisconsin. The Hybrid ventilation systems combined occupant controlled natural ventilation with mechanical ventilation systems. Natural ventilation was shown to provide adequate ventilation when appropriately designed. Proper control integration of natural ventilation into hybrid systems was shown to reduce energy consumption in high performance buildings. This paper also described the lessons learned from the 3 buildings. The author served as energy consultant on all three projects and had the responsibility of designing and integrating the natural ventilation systems into the HVAC control strategy. A post occupancy evaluation of building energy performance has provided learning material for architecture students. The 3 buildings included the Schlitz Audubon Nature Center completed in 2003; the Urban Ecology Center completed in 2004; and the Aldo Leopold Legacy Center completed in 2007. This paper included the size, measured energy utilization intensity and percentage of energy supplied by renewable solar power and bio-fuels on site for each building. 6 refs., 2 tabs., 6 figs.

  5. Motor starting a Brayton cycle power conversion system using a static inverter

    Science.gov (United States)

    Curreri, J. S.; Edkin, R. A.; Kruchowy, R.

    1973-01-01

    The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.

  6. Performance evaluation of the suggestion system.

    Science.gov (United States)

    Hadi, Mohammad; Sajjadi, Haniye Sadat; Baratpour, Sara; Toghiani, Ali

    2013-01-01

    This cross-sectional research evaluated the suggestion system of Isfahan University of Medical Sciences (IUMS) using CIPP model. The population consisted of all members of executive committee of suggestion system and the members of professional and general committee of IUMS; regarding to some limitations, sampling was not done. The tool of gathering data was a self-constructed questionnaire that its content validity approved by the professors' ideas, and calculating Cronbach's alpha confirmed its reliability. Collected data was analyzed using SPSS software. Analyzed data showed that the average score of the performance of the mentioned system was 50.47 +/- 14.8; based on this result it can be claimed that most of the participants (about 91%) evaluated the performance of the system moderate. The comparison of the average score of the four dimensions of CIPP model showed that the input dimension had the highest score and process, product and context dimensions were next on the hierarchy. Planning some programs for paying awards, facilitating and accelerating the personnel's and notifying the procedures of the suggestion system implementation are some useful strategy that could be used to increase the staff's participants.

  7. Optimizing Hydronic System Performance in Residential Applications

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Faakye, O.

    2013-10-01

    Even though new homes constructed with hydronic heat comprise only 3% of the market (US Census Bureau 2009), of the 115 million existing homes in the United States, almost 14 million of those homes (11%) are heated with steam or hot water systems according to 2009 US Census data. Therefore, improvements in hydronic system performance could result in significant energy savings in the US. When operating properly, the combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater is a viable option for high-efficiency residential space heating in cold climates. Based on previous research efforts, however, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency. Furthermore, guidance on proper design and commissioning for heating contractors and energy consultants is hard to find and is not comprehensive. Through modeling and monitoring, CARB sought to determine the optimal combination(s) of components - pumps, high efficiency heat sources, plumbing configurations and controls - that result in the highest overall efficiency for a hydronic system when baseboard convectors are used as the heat emitter. The impact of variable-speed pumps on energy use and system performance was also investigated along with the effects of various control strategies and the introduction of thermal mass.

  8. Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy Conversion Devices (a.k.a. Understanding Photosystem I as a Biomolecular Reactor for Energy Conversion)

    Science.gov (United States)

    2014-04-01

    Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy Conversion Devices (a.k.a. Understanding Photosystem I as...Laboratory Adelphi, MD 20783-1197 ARL-TR-6904 April 2014 Hydrogen Production from Water by Photosynthesis System I for Use as Fuel in Energy...Final 3. DATES COVERED (From - To) 10/1/2010–10/1/2013 4. TITLE AND SUBTITLE Hydrogen Production from Water by Photosynthesis System I for Use as Fuel

  9. High performance reversible electrochemical cell for H2O electrolysis or conversion of CO2 and H2O to fuel

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a reversible electrochemical cell, such as an electrolysis cell for water splitting or for conversion of carbon dioxide and water into fuel. The present invention relates also to an electrochemical cell that when operated in reverse performs as a fuel cell. The el....... The electrochemical cell comprises gas5 diffusion electrodes and a porous layer made of materials and having a structure adapted to allow for a temperature range of operation between 100-374 DEG C and in a pressure range between 3-200 bars.......The present invention relates to a reversible electrochemical cell, such as an electrolysis cell for water splitting or for conversion of carbon dioxide and water into fuel. The present invention relates also to an electrochemical cell that when operated in reverse performs as a fuel cell...

  10. Engineering performant, innovative and sustainable health systems

    OpenAIRE

    Wouters, Raphael

    2016-01-01

    Background: In a time of growing health expenditures and inefficiencies, ageing populations, rise of chronic diseases, co-morbity and technical evolutions, there is a worldwide quest for performant, innovative and sustainable health systems that are, a.o. effective and cost-efficient, patient-centric and co-creative and able to deal with the growing society dynamics.Problem statement: Effectively implementing strategic initiatives that tackle these challenges appears a frightening task since ...

  11. Financial systems, innovation and economic performance

    OpenAIRE

    Block, T.H.

    2002-01-01

    There is growing evidence of international divergence in the performance of newindustries. While the United States is at the forefront of the recent revolution ininformation technologies, European economists and policy makers are concerned thatEurope is falling behind with negative implications for long-term economicperformance. This paper investigates the role of financial systems as a crucialdeterminant of apparent differences in national abilities to promote innovativeactivities in specifi...

  12. Enhancing an enterprise's innovation performance measurement system

    OpenAIRE

    Stanković, Ljiljana; Novićević, Blagoje; Đukić, Suzana

    2011-01-01

    Business conditions under which modern enterprises operate are becoming more and more complex. The complexity of the business environment is caused not only by external but also by internal factors, which imposes the need for turnover in management focus. The turnover is reflected primarily in the change of business models. The changes are evident at all management stages. Development and enhancement of business performance measurement system is the area where the changes are most evident con...

  13. A Management System for Computer Performance Evaluation.

    Science.gov (United States)

    1981-12-01

    background nearly always exposes an individual to fundamientals of mathematics and statistics. These traits of systematic thinking and a kmowledge of math and...It may be derived rigorously through the use of measurement, simulation, or mathematics or it may be literally estimated based on observation and...systematic identification of a. comuter performance management system. 5. Administration of Group and Project 11anagement Depending on the size and

  14. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    Directory of Open Access Journals (Sweden)

    Narang Prineha

    2016-06-01

    Full Text Available Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic ‘hot’ carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem into three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions.We identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.

  15. Improvement an enterprises marketing performance measurement system

    Directory of Open Access Journals (Sweden)

    Stanković Ljiljana

    2013-01-01

    Full Text Available Business conditions in which modern enterprises do business are more and more complex. The complexity of the business environment is caused by activities of external and internal factors, which imposes the need for the turn in management focus. One of key turns is related to the need of adaptation and development of new business performance evaluation systems. The evaluation of marketing contribution to business performance is very important however a complex task as well. The marketing theory and practice indicates the need for developing adequate standards and systems for evaluating the efficiency of marketing decisions. The better understanding of marketing standards and ways that managers use is a very important factor that affects the efficiency of strategic decision-making. The paper presents the results of researching the way in which managers perceive and apply marketing performance measures. The data that were received through the field research sample enabled the consideration of the managers' attitudes on practical ways of implementing marketing performance measurement and identifying measures that managers imply as used mostly in business practice.

  16. Wind energy conversion systems with electric transmission to the water pumping with field control to constant flow; Sistema de conversao de energia eolica com transmissao eletrica para bombeamento de agua com controle de campo a fluxo constante

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Juraci Carlos de Castro

    1989-07-01

    The stead-state analysis of a Wind Energy Conversion Systems, consisting on a Windmill, Synchronous Generator, transmission Line and Induction Motor driving a Centrifugal Pump is developed. The performance of the system operating at variable Speed with a flux control is examined using mathematical and digital simulation. The control scheme is proposed and tested in laboratory and a tested in laboratory and a test centre to be compared with simulation results. (author)

  17. Comparative study between PI, RST and sliding mode controllers of a DFIG supplied by an AC-AC converter for wind energy conversion system

    Directory of Open Access Journals (Sweden)

    Ahmed Bourouina

    2015-12-01

    Full Text Available This paper deals with a variable speed device to produce electrical energy on a power network, based on a doubly-fed induction generator (DFIG supplied by a direct matrix converter used in wind energy conversion systems. In the first place, we carried out briefly a study of modelling on the whole system. In order to control the power flowing between the stator of the DFIG and the power network, a control law is synthesized using three types of controllers: PI, RST and sliding mode controllers. Their respective performances are compared in terms of power reference tracking, response to sudden speed variations, sensitivity to perturbations and robustness against machine parameters variations.

  18. Power quality control and design of power converter for variable-speed wind energy conversion system with permanent-magnet synchronous generator.

    Science.gov (United States)

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%.

  19. Power Quality Control and Design of Power Converter for Variable-Speed Wind Energy Conversion System with Permanent-Magnet Synchronous Generator

    Science.gov (United States)

    Oğuz, Yüksel; Güney, İrfan; Çalık, Hüseyin

    2013-01-01

    The control strategy and design of an AC/DC/AC IGBT-PMW power converter for PMSG-based variable-speed wind energy conversion systems (VSWECS) operation in grid/load-connected mode are presented. VSWECS consists of a PMSG connected to a AC-DC IGBT-based PWM rectifier and a DC/AC IGBT-based PWM inverter with LCL filter. In VSWECS, AC/DC/AC power converter is employed to convert the variable frequency variable speed generator output to the fixed frequency fixed voltage grid. The DC/AC power conversion has been managed out using adaptive neurofuzzy controlled inverter located at the output of controlled AC/DC IGBT-based PWM rectifier. In this study, the dynamic performance and power quality of the proposed power converter connected to the grid/load by output LCL filter is focused on. Dynamic modeling and control of the VSWECS with the proposed power converter is performed by using MATLAB/Simulink. Simulation results show that the output voltage, power, and frequency of VSWECS reach to desirable operation values in a very short time. In addition, when PMSG based VSWECS works continuously with the 4.5 kHz switching frequency, the THD rate of voltage in the load terminal is 0.00672%. PMID:24453905

  20. Highly Efficient Performance and Conversion Pathway of Photocatalytic NO Oxidation on SrO-Clusters@Amorphous Carbon Nitride.

    Science.gov (United States)

    Cui, Wen; Li, Jieyuan; Dong, Fan; Sun, Yanjuan; Jiang, Guangming; Cen, Wanglai; Lee, S C; Wu, Zhongbiao

    2017-09-19

    This work demonstrates the first molecular-level conversion pathway of NO oxidation over a novel SrO-clusters@amorphous carbon nitride (SCO-ACN) photocatalyst, which is synthesized via copyrolysis of urea and SrCO 3 . The inclusion of SrCO 3 is crucial in the formation of the amorphous carbon nitride (ACN) and SrO clusters by attacking the intralayer hydrogen bonds at the edge sites of graphitic carbon nitride (CN). The amorphous nature of ACN can promote the transportation, migration, and transformation of charge carriers on SCO-ACN. And the SrO clusters are identified as the newly formed active centers to facilitate the activation of NO via the formation of Sr-NO δ(+) , which essentially promotes the conversion of NO to the final products. The combined effects of the amorphous structure and SrO clusters impart outstanding photocatalytic NO removal efficiency to the SCO-ACN under visible-light irradiation. To reveal the photocatalytic mechanism, the adsorption and photocatalytic oxidation of NO over CN and SCO-ACN are analyzed by in situ DRIFTS, and the intermediates and conversion pathways are elucidated and compared. This work presents a novel in situ DRIFTS-based strategy to explore the photocatalytic reaction pathway of NO oxidation, which is quite beneficial to understand the mechanism underlying the photocatalytic reaction and advance the development of photocatalytic technology for environmental remediation.

  1. The LHCb trigger system: performance and outlook

    CERN Document Server

    Langenbruch, Christoph

    2014-01-01

    The LHCb experiment is dedicated to the study of heavy flavour at the LHC. The LHCb trigger system plays a key role in selecting signal events and rejecting background. The bulk of the LHCb trigger is implemented in software and deployed on a farm of 29,000 processor cores. This system, called the high level trigger, is responsible for reducing the event rate from 1 MHz, at which the LHCb detector can be read out, to 5 kHz, which can be written to disk. With its flexible design, the LHCb trigger can quickly adapt to changing running conditions and has performed far beyond its design in terms of signal efficiencies. The trigger system showcases a number of pioneering concepts, among them the use of multivariate classifiers to identify b -hadrons and the buffering of events to local disks and their processing at a later time, when the LHC is not producing collisions. The design of the trigger system, its performance during 2011 and 2012 and planned improvements for data taking in 2015 and beyond are discussed

  2. Benchmarking the performance of fixed-image receptor digital radiography systems. Part 2: system performance metric.

    Science.gov (United States)

    Lee, Kam L; Bernardo, Michael; Ireland, Timothy A

    2016-06-01

    This is part two of a two-part study in benchmarking system performance of fixed digital radiographic systems. The study compares the system performance of seven fixed digital radiography systems based on quantitative metrics like modulation transfer function (sMTF), normalised noise power spectrum (sNNPS), detective quantum efficiency (sDQE) and entrance surface air kerma (ESAK). It was found that the most efficient image receptors (greatest sDQE) were not necessarily operating at the lowest ESAK. In part one of this study, sMTF is shown to depend on system configuration while sNNPS is shown to be relatively consistent across systems. Systems are ranked on their signal-to-noise ratio efficiency (sDQE) and their ESAK. Systems using the same equipment configuration do not necessarily have the same system performance. This implies radiographic practice at the site will have an impact on the overall system performance. In general, systems are more dose efficient at low dose settings.

  3. Human performance modeling for system of systems analytics :soldier fatigue.

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

    2005-10-01

    The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

  4. Performance of the St. George Detector System

    Science.gov (United States)

    Morales, Luis; Kalkal, Sunil; Jung, Hyo Soon; Seymour, Chris; Gilardy, Gwenaelle; Moran, Mike; Meisel, Zachary; Hinnefeld, Jerry; Couder, Manoel

    2016-09-01

    The St. George recoil mass separator at the University of Notre Dame will be used to study (α , γ) reactions of astrophysical interest. A detection system was developed for the St. George recoil mass separator, in collaboration with Indiana University South Bend, that will utilize energy and time-of-flight to separate reaction products from residual unreacted beam particles. The detection system uses two microchannel plate (MCP) detectors, perpendicular electric and magnetic field are used to bend secondary electrons from the surface of a parylene backed carbon foil to register timing measurements, and a silicon strip detector is used to measure the ion's kinetic energy. The performance of the detection system will be presented. NSF Grant (PHY-0959816 & PHY-1062819).

  5. Integrating modular mechatronic systems for immersive performances

    DEFF Research Database (Denmark)

    Pagliarini, Luigi; Lund, Henrik Hautop

    2015-01-01

    As a branch of mechatronic research in interactivity, and in robot art, we describe the concept of implementing Playware based tools inspired by modern AI robotic systems for audio-video performances. We develop immersive and personalizable tools that can allow any user to manipulate both audio...... and video output in a very easy manner, thanks to mechatronical wearable interfaces. In this light, we describe two of our systems that explore the concept of run-time composition of a variety of input and output modalities, e.g. both music and graphical expression. Indeed, we developed both hardware....../software tools by which it is possible to allow any user to create new song versions of music (e.g. the MusicTiles app) and software that are able to translate the musical experience in to a visual one (e.g. the MAG software). By interfacing these technologies into mechatronic systems, it is now possible...

  6. Performance of the ALICE VZERO system

    CERN Document Server

    Abbas, E.; Adam, J.; Adamova, D.; Adare, A.M.; Aggarwal, M.M.; Aglieri Rinella, G.; Agnello, M.; Agocs, A.G.; Agostinelli, A.; Ahammed, Z.; Ahmad, N.; Masoodi, A.Ahmad; Ahmed, I.; Ahn, S.A.; Ahn, S.U.; Aimo, I.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Molina, R.Alfaro; Alici, A.; Alkin, A.; Almaraz Avina, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Anticic, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshauser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I.C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T.C.; Aysto, J.; Azmi, M.D.; Bach, M.; Badala, A.; Baek, Y.W.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baltasar Dos Santos Pedrosa, F.; Ban, J.; Baral, R.C.; Barbera, R.; Barile, F.; Barnafoldi, G.G.; Barnby, L.S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P.C.; Baumann, C.; Bearden, I.G.; Beck, H.; Behera, N.K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A.A.E.; Bertens, R.A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A.K.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielcik, J.; Bielcikova, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bottger, S.; Bogdanov, A.; Boggild, H.; Bogolyubsky, M.; Boldizsar, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bossu, F.; Botje, M.; Botta, E.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T.A.; Browning, T.A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G.E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, W.; Carena, F.; Carlin Filho, N.; Carminati, F.; Casanova Diaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J.F.; Casula, E.A.R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J.L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D.D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C.H.; Christiansen, P.; Chujo, T.; Chung, S.U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M.E.; Contin, G.; Contreras, J.G.; Cormier, T.M.; Corrales Morales, Y.; Cortese, P.; Cortes Maldonado, I.; Cosentino, M.R.; Costa, F.; Cotallo, M.E.; Crescio, E.; Crochet, P.; Alaniz, E.Cruz; Albino, R.Cruz; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, K.; Das, I.; Das, S.; Das, D.; Dash, S.; Dash, A.; De, S.; de Barros, G.O.V.; De Caro, A.; De Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; Delagrange, H.; Deloff, A.; De Marco, N.; Denes, E.; De Pasquale, S.; Deppman, A.; Erasmo, G.D.; de Rooij, R.; Diaz Corchero, M.A.; Di Bari, D.; Dietel, T.; Di Giglio, C.; Di Liberto, S.; Di Mauro, A.; Di Nezza, P.; Divia, R.; Djuvsland, O.; Dobrin, A.; Dobrowolski, T.; Donigus, B.; Dordic, O.; Dubey, A.K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A.K.; Elia, D.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H.A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Fenton-Olsen, B.; Feofilov, G.; Fernandez Tellez, A.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M.A.S.; Filchagin, S.; Finogeev, D.; Fionda, F.M.; Fiore, E.M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhoje, J.J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D.R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, M.; Gheata, A.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glassel, P.; Gomez, R.; Ferreiro, E.G.; Gonzalez-Trueba, L.H.; Gonzalez-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Grabski, V.; Graczykowski, L.K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J.F.; Grossiord, J.Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, O.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Han, B.H.; Hanratty, L.D.; Hansen, A.; Harmanova-Tothova, Z.; Harris, J.W.; Hartig, M.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Hayrapetyan, A.; Heckel, S.T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, N.; Hess, B.A.; Hetland, K.F.; Hicks, B.; Hippolyte, B.; Hori, Y.; Hristov, P.; Hrivnacova, I.; Huang, M.; Humanic, T.J.; Hwang, D.S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G.M.; Innocenti, P.G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, M.; Ivanov, A.; Ivanov, V.; Ivanytskyi, O.; Jacholkowski, A.; Jacobs, P.M.; Jahnke, C.; Jang, H.J.; Janik, M.A.; Jayarathna, P.H.S.Y.; Jena, S.; Jha, D.M.; Jimenez Bustamante, R.T.; Jones, P.G.; Jung, H.; Jusko, A.; Kaidalov, A.B.; Kalcher, S.; Kalinak, P.; Kalliokoski, T.; Kalweit, A.; Kang, J.H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Ketzer, B.; Khan, M.M.; Khan, P.; Khan, S.A.; Khan, K.H.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, M.; Kim, T.; Kim, B.; Kim, S.; Kim, M.; Kim, D.J.; Kim, J.S.; Kim, J.H.; Kim, D.W.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J.L.; Klein, J.; Klein-Bosing, C.; Kliemant, M.; Kluge, A.; Knichel, M.L.; Knospe, A.G.; Kohler, M.K.; Kollegger, T.; Kolojvari, A.; Kompaniets, M.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Kralik, I.; Kramer, F.; Kravcakova, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P.G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A.B.; Kuryakin, A.; Kushpil, V.; Kushpil, S.; Kvaerno, H.; Kweon, M.J.; Kwon, Y.; Ladron de Guevara, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; La Pointe, S.L.; Lara, C.; Lardeux, A.; La Rocca, P.; Lea, R.; Lechman, M.; Lee, S.C.; Lee, G.R.; Legrand, I.; Lehnert, J.; Lemmon, R.C.; Lenhardt, M.; Lenti, V.; Leon, H.; Leoncino, M.; Leon Monzon, I.; Levai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M.A.; Ljunggren, H.M.; Lodato, D.F.; Loenne, P.I.; Loggins, V.R.; Loginov, V.; Lohner, D.; Loizides, C.; Loo, K.K.; Lopez, X.; Lopez Torres, E.; Lovhoiden, G.; Lu, X.G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.; Luzzi, C.; Ma, R.; Ma, K.; Madagodahettige-Don, D.M.; Maevskaya, A.; Mager, M.; Mahapatra, D.P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mares, J.; Margagliotti, G.V.; Margotti, A.; Marin, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N.A.; Martinengo, P.; Martinez, M.I.; Martinez Garcia, G.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazumder, R.; Mazzoni, M.A.; Meddi, F.; Menchaca-Rocha, A.; Mercado Perez, J.; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A.N.; Miskowiec, D.; Mitu, C.; Mizuno, S.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Montano Zetina, L.; Monteno, M.; Montes, E.; Moon, T.; Morando, M.; Moreira De Godoy, D.A.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Muller, H.; Munhoz, M.G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B.K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T.K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B.S.; Niida, T.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B.S.; Nilsson, M.S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Nyanin, A.; Nyatha, A.; Nygaard, C.; Nystrand, J.; Ochirov, A.; Oeschler, H.; Oh, S.; Oh, S.K.; Oleniacz, J.; Da Silva, A.C. Oliveira; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Ostrowski, P.; Otwinowski, J.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paic, G.; Painke, F.; Pajares, C.; Pal, S.K.; Palaha, A.; Palmeri, A.; Papikyan, V.; Pappalardo, G.S.; Park, W.J.; Passfeld, A.; Patalakha, D.I.; Paticchio, V.; Paul, B.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Perez Lara, C.E.; Perrino, D.; Peryt, W.; Pesci, A.; Pestov, Y.; Petracek, V.; Petran, M.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piyarathna, D.B.; Planinic, M.; Ploskon, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta-Lerma, P.L.M.; Poghosyan, M.G.; Polak, K.; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Pospisil, V.; Potukuchi, B.; Prasad, S.K.; Preghenella, R.; Prino, F.; Pruneau, C.A.; Pshenichnov, I.; Puddu, G.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Raiha, T.S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, S.; Raniwala, R.; Rasanen, S.S.; Rascanu, B.T.; Rathee, D.; Rauch, W.; Rauf, A.W.; Razazi, V.; Read, K.F.; Real, J.S.; Redlich, K.; Reed, R.J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A.R.; Reshetin, A.; Rettig, F.; Revol, J.P.; Reygers, K.; Riccati, L.; Ricci, R.A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodriguez Cahuantzi, M.; Rodriguez Manso, A.; Roed, K.; Rogochaya, E.; Rohr, D.; Rohrich, D.; Romita, R.; Ronchetti, F.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roy, P.; Roy, C.; Rubio Montero, A.J.; Rui, R.; Russo, R.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Safarik, K.; Sahoo, R.; Sahu, P.K.; Saini, J.; Sakaguchi, H.; Sakai, S.; Sakata, D.; Salgado, C.A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Sandor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Santoro, R.; Sarkamo, J.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R.P.; Schiaua, C.; Schicker, R.; Schmidt, H.R.; Schmidt, C.; Schuchmann, S.; Schukraft, J.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Scott, P.A.; Segato, G.; Selyuzhenkov, I.; Senyukov, S.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Sharma, S.; Sharma, N.; Rohni, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Sicking, E.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, T.; Sinha, B.C.; Sitar, B.; Sitta, M.; Skaali, T.B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.J.M.; Sogaard, C.; Soltz, R.; Song, M.; Song, J.; Soos, C.; Soramel, F.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B.K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J.H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A.A.P.; Subieta Vasquez, M.A.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Sumbera, M.; Susa, T.; Symons, T.J.M.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M.A.; J.Tapia Takaki, D.; Peloni, A.Tarantola; Tarazona Martinez, A.; Tauro, A.; Tejeda Munoz, G.; Telesca, A.; Ter Minasyan, A.; Terrevoli, C.; Thader, J.; Thomas, D.; Tieulent, R.; Timmins, A.R.; Tlusty, D.; Toia, A.; Torii, H.; Toscano, L.; Trubnikov, V.; Truesdale, D.; Trzaska, W.H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T.S.; Ulery, J.; Ullaland, K.; Ulrich, J.; Uras, A.; Urciuoli, G.M.; Usai, G.L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Vande Vyvre, P.; Van Hoorne, J.W.; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, Y.; Vinogradov, L.; Vinogradov, A.; Virgili, T.; Viyogi, Y.P.; Vodopyanov, A.; Volkl, M.A.; Voloshin, S.; Voloshin, K.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrlakova, J.; Vulpescu, B.; Vyushin, A.; Wagner, V.; Wagner, B.; Wan, R.; Wang, Y.; Wang, Y.; Wang, M.; Watanabe, K.; Weber, M.; Wessels, J.P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Williams, M.C.S.; Windelband, B.; Winn, M.; Yaldo, C.G.; Yamaguchi, Y.; Yang, S.; Yang, P.; Yang, H.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.K.; Yoon, J.; Yuan, X.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Zavada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zelnicek, P.; Zgura, I.S.; Zhalov, M.; Zhang, Y.; Zhang, H.; Zhang, X.; Zhou, D.; Zhou, Y.; Zhou, F.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.

    2013-01-01

    ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton--proton, proton--nucleus and nucleus--nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE. In addition to its core function as a trigger, the VZERO system is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction in nucleus--nucleus collisions. After describing the VZERO system, this publication presents its performance over more than four years of operation at the LHC.

  7. Performance TTradeoffs in Distributed Control Systems

    Science.gov (United States)

    Borowski, Holly

    Large scale systems consisting of many interacting subsystems are often controlled in a distributed fashion due to inherent limitations in computation, communication, or sensing. Here, individual agents must make decisions based on local, often incomplete information. This dissertation focuses on understanding performance tradeoffs in distributed control systems, specifically focusing on using a game theoretic framework to assign agent control laws. Performance of a distributed control law is determined by (1) the degree with which it meets a stated objective, (2) the amount of time it takes to converge, (3) agents' informational requirements, and (4) vulnerability to adversarial manipulation. The three main research questions addressed in this work are: • When is fast convergence to near-optimal behavior possible in a distributed system? We design a distributed control law which converges to a near-optimal configuration in a time that is near-linear in the number of agents. This worst case convergence time is an improvement over existing algorithms whose worst-case convergence times are exponential in the number of agents. • Can agents in a distributed system learn near-optimal correlated behavior despite severely limited information about one another's behavior? We design a distributed control law that imposes limited informational requirements for individual agents and converges to near-optimal correlated behavior. • How does the structure of agent interaction impact a distributed control system's vulnerability to adversarial manipulation? We derive a graph theoretical condition that ensures resilience to adversarial manipulation, and we examine the conditions under which an adversary can manipulate collective behavior in a distributed control system, simply by influencing small subsets of agents.

  8. Human performance modeling for system of systems analytics.

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kevin R.; Lawton, Craig R.; Basilico, Justin Derrick; Longsine, Dennis E. (INTERA, Inc., Austin, TX); Forsythe, James Chris; Gauthier, John Henry; Le, Hai D.

    2008-10-01

    A Laboratory-Directed Research and Development project was initiated in 2005 to investigate Human Performance Modeling in a System of Systems analytic environment. SAND2006-6569 and SAND2006-7911 document interim results from this effort; this report documents the final results. The problem is difficult because of the number of humans involved in a System of Systems environment and the generally poorly defined nature of the tasks that each human must perform. A two-pronged strategy was followed: one prong was to develop human models using a probability-based method similar to that first developed for relatively well-understood probability based performance modeling; another prong was to investigate more state-of-art human cognition models. The probability-based modeling resulted in a comprehensive addition of human-modeling capability to the existing SoSAT computer program. The cognitive modeling resulted in an increased understanding of what is necessary to incorporate cognition-based models to a System of Systems analytic environment.

  9. Energy Conversion and Storage Program

    Science.gov (United States)

    Cairns, E. J.

    1993-06-01

    This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Chemical applications research includes topics such as separations, catalysis, fuels, and chemical analyses. Included in this program area are projects to develop improved, energy-efficient methods for processing product and waste streams from synfuel plants, coal gasifiers, and biomass conversion processes. Materials applications research includes evaluation of the properties of advanced materials, as well as development of novel preparation techniques. For example, techniques such as sputtering, laser ablation, and poised laser deposition are being used to produce high-temperature superconducting films.

  10. Design Concepts for RF-DC Conversion in Particle Accelerator Systems

    CERN Document Server

    Caspers, F; Grudiev, A; Sapotta, H

    2010-01-01

    In many particle accelerators considerable amounts of RF power reaching the megawatt level are converted into heat in dummy loads. After an overview of RF power in the range 200 MHz to 1 GHz dissipated at CERN we discuss several developments that have come up in the past using vacuum tube technology for RF-DC conversion. Amongst those the developments of the cyclotron wave converter CWC appears most suitable. With the availability of powerful Schottky diodes the solid state converter aspect has to be addressed as well. One of the biggest problems of Schottky diode based structures is the junction capacity. GaAs and GaN Schottky diodes show a significant reduction of this junction capacity as compared to silicon. Small rectenna type converter units which have been already developed for microwave powered helicopters can be used in waveguides or with coaxial power dividers.

  11. Thermophotovoltaic Energy Conversion for Personal Power Sources

    Science.gov (United States)

    2012-02-01

    TEC) system including the balance-of- plant and provides a review of the state of the art. Evaluation of each component’s performance determined that...7 2.5 Thermophotovoltaic and Thermoelectric Conversion Efficiency Comparison...Balance-of- plant Components .......................................................................................19 3.3 TEC System Power Density and

  12. System Level Modelling and Performance Estimation of Embedded Systems

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer

    does the design time and eort. This challenge is widely recognized throughout academia and the industry and in order to address this, novel frameworks and methods, which will automate design steps as well as raise the level of abstraction used to design systems, are being called upon. To support...... is performed by having the framework produce detailed quantitative information about the system model under investigation. The project is part of the national Danish research project, Danish Network of Embedded Systems (DaNES), which is funded by the Danish National Advanced Technology Foundation. The project...

  13. Part-load performance characteristics of a lean burn catalytic combustion gas turbine system

    Science.gov (United States)

    Yin, Juan; Li, Ming; Zhu, Jun-qiang

    2013-04-01

    The purpose of this study is to compare the part-load performance of a lean burn catalytic combustion gas turbine (LBCCGT) system in three different control modes: varying fuel, bleeding off the fuel mixture flow after the compressor and varying rotational speed. The conversions of methane species for chemical process are considered. A 1D heterogeneous plug flow model was utilized to analyze the system performance. The actual turbomachinery components were designed and predicted performance maps were applied to system performance research. The part-load characteristics under three control strategies were numerically investigated. The main results show that: the combustor inlet temperature is a significant factor that can significantly affect the part-load characteristics of the LBCCGT system; the rotational speed control mode can provide the best performance characteristics for part-load operations; the operation range of the bleed off mode is narrower than that of the speed control mode and wider than that of the fuel only mode; with reduced power, methane does not achieve full conversion over the reactor at the fuel only control mode, which will not warrant stable operation of the turbine system; the thermal efficiency of the LBCCGT system at fuel only control strategy is higher than that at bleed off control strategy within the operation range.

  14. Evaluation of the Measured Energy Performance of Four Solar Systems.

    Science.gov (United States)

    1984-09-01

    exception occurred because a building occupant manually operated the system. Although the manual operacion of this one system prevented damage to the solar...Specification 13985, Solar Equipment and the Army Technical Manual 5-804-2, Solar Energy Systems. -....... .. . .. . 2 DESCRIPTION OF THE SOLAR...standard built-up roof. *Metric Conversion Table is on p 81. 3C. Knapp, T. Stoffel, and S. Whitaker, Insolation Data Manual , SERI/SP-755- 789 (Solar

  15. A comparison of Stirling engines for use with a 25 kW dish-electric conversion system

    Science.gov (United States)

    Shaltens, Richard K.

    1987-01-01

    Two designs for an advanced Stirling conversion system (ASCS) are described. The objective of the ASCS is to generate about 25 kW of electric power to an electric utility grid at an engine/alternator target cost of $300.00/kW at the manufacturing rate of 10,000 unit/yr. Both designs contain a free-piston Stirling engine (FPSE), a heat transport system, solar receiver, a means to generate electric power, the necessary auxiliaries, and a control system. The major differences between the two concepts are: one uses a 25 kWe single-piston FPSE which incorporates a linear alternator to directly convert the energy to electricity on the utility grid; and in the second design, electrical power is generated indirectly using a hydraulic output to a ground based hydraulic motor coupled to a rotating alternator. Diagrams of the two designs are presented.

  16. Demonstration of simultaneous mode conversion and demultiplexing for mode and wavelength division multiplexing systems based on tilted few-mode fiber Bragg gratings.

    Science.gov (United States)

    Gao, Ya; Sun, Junqiang; Chen, Guodong; Sima, Chaotan

    2015-04-20

    We experimentally demonstrate mode conversion by exploiting optical reflection of tilted few-mode fiber Bragg grating (FM-FBG). Mode conversions from LP(01) mode to higher symmetric and asymmetric modes are achieved, and more than 99.5% conversion efficiency from LP(01) to LP(11) mode is obtained using a 1.6°-tilted FM-FBG. Influences of the weakly tilted FM-FBG parameters on the property of mode conversion is analyzed and discussed. A simultaneous mode conversion and demultiplexing scheme for 4-mode × 3-wavelength multiplexing transmission is proposed and the modal crosstalk is analyzed based on the transmission spectra of the tilted FM-FBGs. The proposed approach shows potential applications in mode and wavelength division multiplexing communication systems.

  17. Performance Assessment and Active System Monitoring for Refrigeration Systems

    DEFF Research Database (Denmark)

    Green, Torben

    The refrigeration system in a supermarket is an important part of the business for the supermarkets, both in terms of the possibility it provides and because of the associated cost of operating the system. It provides the possibility of selling chilled and frozen food but on the other hand...... that quanties and measure the criteria has been developed in this project. The quality is measured by the control errors in the system because there is a connection between the quality of the stored goods and the ability of the refrigeration system to provide the required temperature. A deviation from...... the controller set-point corresponds to a temperature deviation,which will eventually harm the stored goods. The energy eciency is measured by the coecient of performance, COP, which basically is the delivered cooling power divided by the consumed electrical power of the system. The reliability criteria...

  18. Thermal Performance Testing of Cryogenic Insulation Systems

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stan D.; Scholtens, Brekke E.

    2007-01-01

    Efficient methods for characterizing thermal performance of materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and are complementary to established methods. The actual-use environment of full temperature difference in combination with vacuum-pressure is essential for understanding insulation system performance. Test articles include solids, foams, powders, layered blankets, composite panels, and other materials. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boil-off calorimetry. Heat flux capability ranges from approximately 0.5 to 500 watts per square meter; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m- K. Example data for different insulation materials are also presented. Upon further standardization work, these patented insulation test cryostats can be available to industry for a wide range of practical applications.

  19. Strain selection, biomass to biofuel conversion, and resource colocation have strong impacts on the economic performance of algae cultivation sites

    Directory of Open Access Journals (Sweden)

    Erik R. Venteris

    2014-09-01

    Full Text Available Decisions involving strain selection, biomass to biofuel technology, and the location of cultivation facilities can strongly influence the economic viability of an algae-based biofuel enterprise. We summarize our past results in a new analysis to explore the relative economic impact of these design choices. Our growth model is used to predict average biomass production for two saline strains (Nannocloropsis salina, Arthrospira sp., one fresh to brackish strain (Chlorella sp., DOE strain 1412, and one freshwater strain (order Sphaeropleales. Biomass to biofuel conversion is compared between lipid extraction (LE and hydrothermal liquefaction (HTL technologies. National-scale models of water, CO2 (as flue gas, land acquisition, site leveling, construction of connecting roads, and transport of HTL oil to existing refineries are used in conjunction with estimates of fuel value (from HTL to prioritize and select from 88,692 unit farms (UF, 405 ha in pond area, a number sufficient to produce 136E+9 L yr-1 of renewable diesel (36 billion gallons yr-1. Strain selection and choice of conversion technology have large economic impacts, with differences between combinations of strains and biomass to biofuel technologies being up to $10 million dollars yr-1 UF-1. Results based on the most productive strain, HTL-based fuel conversion, and resource costs show that the economic potential between geographic locations within the selection can differ by up to $4 million yr-1 UF-1, with 1.8 BGY of production possible from the most cost-effective sites. The local spatial variability in site rank is extreme, with very high and low sites within 10s of km of each other. Colocation with flue gas sources has a strong influence on rank, but the most costly resource component varies from site to site. The highest rank UFs are located predominantly in Florida and Texas, but most states south of 37°N latitude contain promising locations.

  20. Performance Criteria of Nuclear Space Propulsion Systems

    Science.gov (United States)

    Shepherd, L. R.

    Future exploration of the solar system on a major scale will require propulsion systems capable of performance far greater than is achievable with the present generation of rocket engines using chemical propellants. Viable missions going deeper into interstellar space will be even more demanding. Propulsion systems based on nuclear energy sources, fission or (eventually) fusion offer the best prospect for meeting the requirements. The most obvious gain coming from the application of nuclear reactions is the possibility, at least in principle, of obtaining specific impulses a thousandfold greater than can be achieved in chemically energised rockets. However, practical considerations preclude the possibility of exploiting the full potential of nuclear energy sources in any engines conceivable in terms of presently known technology. Achievable propulsive power is a particularly limiting factor, since this determines the acceleration that may be obtained. Conventional chemical rocket engines have specific propulsive powers (power per unit engine mass) in the order of gigawatts per tonne. One cannot envisage the possibility of approaching such a level of performance by orders of magnitude in presently conceivable nuclear propulsive systems. The time taken, under power, to reach a given terminal velocity is proportional to the square of the engine's exhaust velocity and the inverse of its specific power. An assessment of various nuclear propulsion concepts suggests that, even with the most optimistic assumptions, it could take many hundreds of years to attain the velocities necessary to reach the nearest stars. Exploration within a range of the order of a thousand AU, however, would appear to offer viable prospects, even with the low levels of specific power of presently conceivable nuclear engines.

  1. Effect of preparation conditions on the catalytic performance of cobalt manganese oxide catalysts for conversion of synthesis gas to light olefins

    Energy Technology Data Exchange (ETDEWEB)

    Mirzaei, Ali A.; Faizi, Mostafa; Habibpour, Razieh [Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan 98135-674 (Iran, Islamic Republic of)

    2006-06-07

    Cobalt manganese oxides are prepared using a co-precipitation procedure and studied for the conversion of synthesis gas to light olefins. In particular, the effect of a range of preparation variables is investigated in detail. The variables investigated include the precipitate ageing time, pH and temperature of precipitation, the [Co]/[Mn] ratio of the precipitation solution and also reactor conditions such as reaction temperature and H{sub 2}/CO molar feed ratio. The effect of different supports on the activity and selectivity of catalysts are also studied. The optimum preparation conditions are identified with respect to catalytic performance for the conversion of synthesis gas to ethylene and propylene. The results are interpreted in terms of the structure of the active catalyst. Generally it has been concluded that catalysts containing cobalt manganese mixed phases are found to be the most active. (author)

  2. Numerical Study on Self-Starting Performance of Darrieus Vertical Axis Turbine for Tidal Stream Energy Conversion

    Directory of Open Access Journals (Sweden)

    Zhen Liu

    2016-09-01

    Full Text Available Self-starting performance is a key factor in the evaluation of a Darrieus straight-bladed vertical axis turbine. Most traditional studies have analyzed the turbine’s self-starting capability using the experimental and numerical data of the forced rotation. A 2D numerical model based on the computational fluid dynamics (CFD software ANSYS-Fluent was developed to simulate the self-starting process of the rotor at constant incident water-flow velocities. The vertical-axis turbine (VAT rotor is driven directly by the resultant torque generated by the water flow and system loads, including the friction and reverse loads of the generator. It is found that the incident flow velocity and the moment of inertia of the rotor have little effect on the averaged values of tip-speed ratios in the equilibrium stage under no-load conditions. In the system load calculations, four modes of the self-starting were found: stable equilibrium mode, unstable equilibrium mode, switch mode and halt mode. The dimensionless power coefficient in the simulations of passive rotation conditions is found to be, on average, 38% higher than those achieved in the simulations of forced rotation conditions.

  3. Evaluation of the performance of high temperature conversion reactors for compound-specific oxygen stable isotope analysis.

    Science.gov (United States)

    Hitzfeld, Kristina L; Gehre, Matthias; Richnow, Hans-Hermann

    2017-05-01

    In this study conversion conditions for oxygen gas chromatography high temperature conversion (HTC) isotope ratio mass spectrometry (IRMS) are characterised using qualitative mass spectrometry (IonTrap). It is shown that physical and chemical properties of a given reactor design impact HTC and thus the ability to accurately measure oxygen isotope ratios. Commercially available and custom-built tube-in-tube reactors were used to elucidate (i) by-product formation (carbon dioxide, water, small organic molecules), (ii) 2nd sources of oxygen (leakage, metal oxides, ceramic material), and (iii) required reactor conditions (conditioning, reduction, stability). The suitability of the available HTC approach for compound-specific isotope analysis of oxygen in volatile organic molecules like methyl tert-butyl ether is assessed. Main problems impeding accurate analysis are non-quantitative HTC and significant carbon dioxide by-product formation. An evaluation strategy combining mass spectrometric analysis of HTC products and IRMS (18)O/(16)O monitoring for future method development is proposed.

  4. High Efficiency Three Phase Resonant Conversion for Standardized Architecture Power System Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A low-cost, standardized-architecture power system is proposed for NASA electric propulsion (EP) applications. Three approaches are combined to develop a system that...

  5. Experimental Performance Investigation of Photovoltaic/Thermal (PV–T System

    Directory of Open Access Journals (Sweden)

    Bakir C.

    2013-04-01

    Full Text Available Photovoltaic solar cells convert light energy from the sun into electricity. Photovoltaic cells are produced by semi-conducting materials to convert the energy into electricity and during this process heat is absorbed by the solar radiation. This heat causes a loss of electricity generation efficiencies.In this study, an experimental setup was designed and established to test two separate photovoltaic panel systems with alone PV and with water cooling system PV/T to examine the heat effect on PV systems. The absorbed heat energy behind the photovoltaic cell's surface in insulated ambient was removed by means of a water cooling system and the tests for both systems were simultaneously performed along the July 2011. It is found that without active water cooling, the temperature of the PV module was higher during day time and solar cells could only achieve around 8% conversion efficiency. On the other hand, when the PV module was operated with active water cooling condition, the temperature dropped significantly, leading to an increase in the efficiency of solarcells as much as 13.6%. Gained from absorbed solar heat and maximum thermal conversion efficiencies of the system are determined as 49% and 51% for two different mass flow rates. It is observed that water flow rate is effective on the increasing the conversion efficiency as well as absorption and transitionrates of cover glass in PV/T (PV–Thermal collector, the insulation material and cell efficiency. As a conclusion, the conversion efficiency of the PV system with water cooling might be improved on average about 10%. Therefore, it is recommended that PV system should be designed with most efficient type cooling system to enhance the efficiency and to decrease the payback period.

  6. The LHCb trigger system: performance and outlook

    CERN Document Server

    Stracka, Simone

    2014-01-01

    The LHCb experiment is a spectrometer dedicated to the study of heavy flavor at the LHC. The rate of proton-proton collisions at the LHC is 15 MHz, of which only 5 kHz can be written to storage for offline analysis. The trigger system plays a key role in selecting signal events and rejecting background, and is comprised of a hardware level (L0), reducing the rate to the maxi- mum at which the detector can be fully read out, and a High Level Trigger (HLT) -implemented in software and deployed on a farm of roughly 25000 parallel processing cores- responsible for reducing the rate to the 5 kHz which can be processed offline. The LHCb trigger system allowed LHCb to run at twice its design luminosity in 2012, and performed beyond the nominal design in terms of signal yields. The design and performance of the selection algorithms are discussed in the context of the 2012 data taking, and planned improvements for RunII are presented

  7. GEO-TEP. Development of thermoelectric materials for geothermal energy conversion systems. Final report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Bocher, L.; Weidenkaff, A.

    2008-07-01

    Geothermal heat can be directly converted into electricity by using thermoelectric converters. Thermoelectric conversion relies on intrinsic materials properties which have to be optimised. In this work novel environmentally friendly and stable oxide ceramics were developed to fulfil this task. Thus, manganate phases were studied regarding their potential thermoelectric properties for converting geothermal heat into electricity. Perovskite-type phases were synthesized by applying different methods: the ceramic route, and innovative synthesis routes such as the 'chimie douce' method by bulk thermal decomposition of the citrate precursor or using an USC process, and also the polyol-mediated synthesis route. The crystal structures of the manganate phases are evaluated by XRPD, NPD, and ED techniques while specific microstructures such as twinned domains are highlighted by HRTEM imaging. Besides, the thermal stability of the Mn-oxide phases in air atmosphere are controlled over a wide temperature range (T < 1300 K). The thermoelectric figure of merit ZT was enhanced from 0.021 to 0.3 in a broad temperature range for the studied phases which makes these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures. (author)

  8. Spin-symmetry conversion and internal rotation in high J molecular systems

    Science.gov (United States)

    Mitchell, Justin; Harter, William

    2006-05-01

    Dynamics and spectra of molecules with internal rotation or rovibrational coupling is approximately modeled by rigid or semi-rigid rotors with attached gyroscopes. Using Rotational Energy (RE)^1 surfaces, high resolution molecular spectra for high angular momentum show two distinct but related phenomena; spin-symmetry conversion and internal rotation. For both cases the high total angular momentum allows for transitions that would otherwise be forbidden. Molecular body-frame J-localization effects associated with tight energy level-clusters dominate the rovibronic spectra of high symmetry molecules, particularly spherical tops at J>10. ^2 The effects include large and widespread spin-symmetry mixing contrary to conventional wisdom^3 about weak nuclear moments. Such effects are discussed showing how RE surface plots may predict them even at low J. Classical dynamics of axially constrained rotors are approximated by intersecting rotational-energy-surfaces (RES) that have (J-S).B.(J-S) forms in the limit of constraints that do no work. Semi-classical eigensolutions are compared to those found by direct diagonalization. ^1 W.G Hater, in Handbook of Atomic, Molecular and Optical Physics, edited by G.W.F Drake (Springer, Germany 2006) ^2 W. G. Harter, Phys. Rev. A24,192-262(1981). ^3 G. Herzberg, Infrared and Raman Spectra (VanNostrand 1945) pp. 458,463.

  9. Design and Properties of an Immobilization Enzyme System for Inulin Conversion.

    Science.gov (United States)

    Hang, Hua; Wang, Changbao; Cheng, Yiqun; Li, Ning; Song, Liuli

    2018-02-01

    A commercial inulinase could convert inulin into fructose, which was optimized to be entrapped in the calcium alginate-gelatin beads with the immobilization yield of 86% for free inulinase activities. The optimum pH values and temperatures were 4.5 and 40 °C for the free enzyme and 5.0-5.5 and 45-50 °C for the immobilized enzyme. The kinetic parameters of V max and K m were 5.24 μmol/min and 57.6 mg/mL for the free inulinase and 4.32 μmol/min and 65.8 mg/mL for the immobilized inulinase, respectively. The immobilized enzyme retained 80% of its initial activities at 45 °C for 4 days, which could exhibit better thermal stability. The reuse of immobilized inulinase throughout the continuous batch operations was explored, which had better reusability of the immobilized biocatalyst. At the same time, the stability of immobilized enzyme in the continuous packed-bed bioreactor was estimated, which showed the better results and had its potential scale-up fructose production for inulin conversion.

  10. Environmental studies related to the operation of wind energy conversion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, S.E.; Cornaby, B.W.; Rodman, C.W.; Sticksel, P.R.; Tolle, D.A.

    1977-12-01

    This biophysical impact assessment explores the environmental consequences of the emerging wind energy conversion technology through field studies done at the DOE/NASA 100-kW Experimental Wind Turbine located at NASA Lewis Research Center's Plum Brook Station near Sandusky, Ohio. A micrometeorological field program monitored changes in the downwind wake of the wind turbine. Horizontal and/or vertical measurements of wind speed, temperature, carbon dioxide concentration, precipitation, and incident solar radiation showed measurable variation within the wake only for precipitation and wind speed. The changes were minor and not likely to result in any secondary effects to vegetation, including crops, because they are within the natural range of variability in the site environment. Effects are negligible beyond the physically altered area of the tower pad, access, and control structures. The wind turbine has not proved to be a high risk to airborne fauna, including the most vulnerable night-migrating songbirds. Behavioral studies indicate the birds will avoid the turbine if they can see it.

  11. Modelling Of Converter Characteristics of Wind Energy Conversion System during Voltage Sags

    OpenAIRE

    Pratyusha Dikkala,; B. Srinivasa Rao

    2014-01-01

    The proposed system presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. This hybrid system allows maximum utilization of freely available renewable energy sources like wind and photovoltaic energies. For this, an adaptive maximum power point tracking (MPPT) algorithm along with standard perturbs and observe method will be used for the system. The turbine rotor speed is the main determinant of mechanical output from wind energy and Sola...

  12. Proceedings of the fourth biennial conference and workshop on wind energy conversion systems

    Energy Technology Data Exchange (ETDEWEB)

    Kottler, Jr., R. J. [ed.

    1980-06-01

    Separate abstracts are included for papers presented concerning research and development requirements and utility interface and institutional issues for small-scale systems; design requirements and research and development requirements for large-scale systems; economic and operational requirements of large-scale wind systems; wind characteristics and wind energy siting; international activities; wind energy applications in agriculture; federal commercialization and decentralization plans; and wind energy innovative systems.

  13. An integrated, semi-automated approach to thermochemical conversion research for sustainable farming systems

    Science.gov (United States)

    An integrated, semi-automated system is presented for the rapid and efficient testing and production of research-scale quantities of biochar. This biochar, produced from agricultural waste materials, can easily be incorporated in future sustainable livestock farming systems. These farming systems wi...

  14. Human performance modeling for system of systems analytics: combat performance-shaping factors.

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R.; Miller, Dwight Peter

    2006-01-01

    The US military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives. To support this goal, Sandia National Laboratories (SNL) has undertaken a program of HPM as an integral augmentation to its system-of-system (SoS) analytics capabilities. The previous effort, reported in SAND2005-6569, evaluated the effects of soldier cognitive fatigue on SoS performance. The current effort began with a very broad survey of any performance-shaping factors (PSFs) that also might affect soldiers performance in combat situations. The work included consideration of three different approaches to cognition modeling and how appropriate they would be for application to SoS analytics. This bulk of this report categorizes 47 PSFs into three groups (internal, external, and task-related) and provides brief descriptions of how each affects combat performance, according to the literature. The PSFs were then assembled into a matrix with 22 representative military tasks and assigned one of four levels of estimated negative impact on task performance, based on the literature. Blank versions of the matrix were then sent to two ex-military subject-matter experts to be filled out based on their personal experiences. Data analysis was performed to identify the consensus most influential PSFs. Results indicate that combat-related injury, cognitive fatigue, inadequate training, physical fatigue, thirst, stress, poor perceptual processing, and presence of chemical agents are among the PSFs with the most negative impact on combat performance.

  15. TRMM On Orbit Attitude Control System Performance

    Science.gov (United States)

    Robertson, Brent; Placanica, Sam; Morgenstern, Wendy

    1999-01-01

    This paper presents an overview of the Tropical Rainfall Measuring Mission (TRMM) Attitude Control System (ACS) along with detailed in-flight performance results for each operational mode. The TRMM spacecraft is an Earth-pointed, zero momentum bias satellite launched on November 27, 1997 from Tanegashima Space Center, Japan. TRMM is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan designed to monitor and study tropical rainfall and the associated release of energy. Launched to provide a validation for poorly known rainfall data sets generated by global climate models, TRMM has demonstrated its utility by reducing uncertainties in global rainfall measurements by a factor of two. The ACS is comprised of Attitude Control Electronics (ACE), an Earth Sensor Assembly (ESA), Digital Sun Sensors (DSS), Inertial Reference Units (IRU), Three Axis Magnetometers (TAM), Coarse Sun Sensors (CSS), Magnetic Torquer Bars (MTB), Reaction Wheel Assemblies (RWA), Engine Valve Drivers (EVD) and thrusters. While in Mission Mode, the ESA provides roll and pitch axis attitude error measurements and the DSS provide yaw updates twice per orbit. In addition, the TAM in combination with the IRU and DSS can be used to provide pointing in a contingency attitude determination mode which does not rely on the ESA. Although the ACS performance to date has been highly successful, lessons were learned during checkout and initial on-orbit operation. This paper describes the design, on-orbit checkout, performance and lessons learned for the TRMM ACS.

  16. High conversion self-curing sealer based on a novel injectable polyurethane system for root canal filling

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bin [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Zuo, Yi, E-mail: zoae@scu.edu.cn [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Li, Jidong; Wang, Li [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China); Tang, Kuangyun [The State Key Laboratory of Oral Diseases and Orthognathic Surgery, Sichuan University West China College of Stomatology, Chengdu 610064 (China); Huang, Di; Du, Jingjing; Luo, Peipei; Li, Yubao [Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064 (China)

    2013-08-01

    Low monomer–polymer conversion is the key factor leading to cytotoxicity for resin-containing restorative materials. This paper provides a new root canal filling system based on self-curing injectable polyurethane which can achieve high conversion in a short time. Traced FTIR spectra show more than 90% NCO group participated in the curing reaction after 4 h, and only about 5% remained after 24 h. The calculated data also testified the curing process supports a third-order reaction, and this efficient and sufficient reaction is postulated to weaken the toxic stimulation. By culturing with L929 murine fibroblasts, the PU sealer is shown to be favorable for cell attachment and proliferation. Then physicochemical properties of the injectable PU-based sealer were evaluated according to the Standard [ISO 6876:2001 (E)] for clinical application. A series of physicochemical properties of PU sealer have been tested comparing with AH Plus and Apexit Plus. And the results present that the self-curing PU sealer could not only match the clinic requirements, but even has better properties than the other two commercial sealers. We expect the high conversion PU sealer has a tremendous potential in the field of root canal filling after further biological evaluation. - Highlights: • A new root canal sealer based on self-curing injectable polyurethane was provided. • More than 90% NCO group reacted after 4h, and only about 5% remained after 24 h. • By culturing with L929 murine fibroblasts, the PU sealer showed perfect cytocompatibility. • Volumetric dilatancy after curing will make the sealer achieve a tight seal.

  17. Computational modelling of Yorùbá numerals in a number-to-text conversion system

    Directory of Open Access Journals (Sweden)

    Olúgbénga O. Akinadé

    2014-08-01

    Full Text Available In this paper, we examine the processes underlying the Yorùbá numeral system and describe a computational system that is capable of converting cardinal numbers to their equivalent Standard Yorùbá number names. First, we studied the  mathematical and linguistic basis of the Yorùbá numeral system so as to formalise its arithmetic and syntactic procedures. Next, the process involved in formulating a Context-Free Grammar (CFG to capture the structure of the Yorùbá numeral system was highlighted.  Thereafter, the model was reduced into a set of computer programs to implement the numerical to lexical conversion process. System evaluation was done by ranking the output from the software and comparing the output with the representations given by a group of Yorùbá native speakers. The result showed that the system gave correct representation for numbers and produced a recall of 100% with respect to the collected corpus. Our future study is focused on developing a text normalisation system that will produce number names for other numerical expressions such as ordinal numbers, date, time, money, ratio, etc. in Yorùbá text.

  18. Advanced energy conversion and application - Decentralized energy systems. Papers; Fortschrittliche Energiewandlung und -anwendung - Schwerpunkt: Dezentrale Energiesysteme. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Decentralized energy systems is the major topic of this VDI report which contains the proceedings of the VDI conference on advanced energy conversion and application. The decentralized energy systems are in the focus because it is expected that they will gain in significance in the course of restructuring and liberalisation of the energy markets and growing commitment to greenhouse gas mitigation. The subjects of the papers are the cogeneration technology in general, and specific systems for combined generation of heat, power and cold,(CHPC systems), systems for renewable energy generation, industrial energy technology, and analysis and optimization of energy systems. The report is intended to serve as a source of guidance and reference for manufacturers and operators of decentralized energy systems, for decision-making on energy policy, and for the energy industry, counselling firms and regulatory/surveillance bodies, and members of universities involved in relevant research and development work. (orig./CB) [German] Themenschwerpunkt des VDI-Berichts sind die dezentralen Energiesysteme, die im Spannungsfeld von fortschreitender Liberalisierung der Energiemaerkte und der Bemuehungen um die Reduzierung von Emissionen an Bedeutung gewinnen. Dabei widmen sich die Beitraege den Systemen zur Kraft-Waerme-Kaelte-Kopplung und zur Nutzung erneuerbarer Energie sowie der industriellen Energietechnik und der Analyse und Optimierung von Energiesystemen. Der Bericht wendet sich an Hersteller und Betreiber dezentraler Energieanlagen, an Entscheidungstraeger aus Politik und Wirtschaft, an Berater und Ueberwachungsinstitutionen sowie an auf diesem Gebiet taetige Hochschullehrer und -mitarbeiter. (orig.)

  19. Mass-energy balance analysis for estimation of light energy conversion in an integrated system of biological H2 production

    Directory of Open Access Journals (Sweden)

    A.I. Gavrisheva

    2015-12-01

    Full Text Available The present study investigated an integrated system of biological H2 production, which includes the accumulation of biomass of autotrophic microalgae, dark fermentation of biomass, and photofermentation of the dark fermentation effluent. Particular emphasis was placed on the estimation of the conversion efficiency of light into hydrogen energy at each stage of this system. For this purpose, the mass and energy balance regularities were applied. The efficiency of the energy transformation from light into the microalgal biomass did not exceed 5%. The efficiency of the energy transformation from biomass to biological H2 during the dark fermentation stage stood at about 0.3%. The photofermentation stage using the model fermentation effluent could improve this estimation to 11%, resulting in an overall efficiency 0.55%. Evidently, this scheme is counterproductive for light energy bioconversion due to numerous intermediate steps even if the best published data would be taken into account.

  20. Conversation Analysis.

    Science.gov (United States)

    Schiffrin, Deborah

    1990-01-01

    Summarizes the current state of research in conversation analysis, referring primarily to six different perspectives that have developed from the philosophy, sociology, anthropology, and linguistics disciplines. These include pragmatics; speech act theory; interactional sociolinguistics; ethnomethodology; ethnography of communication; and…