WorldWideScience

Sample records for igcc performance comparison

  1. Comparison of Shell, Texaco, BGL and KRW gasifiers as part of IGCC plant computer simulations

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Furimsky, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2005-07-01

    The performances of four IGCC plants employing Shell, Texaco, BGL and KRW gasifiers were simulated using ASPEN Plus software for three different feeds. Performance analyses and comparisons of all four IGCC plants were performed based on the established data bank from the simulation. Discussions were focused on gas compositions, gasifier selection and overall performance.

  2. Exergetic comparison of two KRW-based IGCC power plants

    International Nuclear Information System (INIS)

    Tsatsaronis, G.; Tawfik, T.; Lin, L.; Gallaspy, D.T.

    1991-01-01

    In studies supported by the U.S. Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared in this paper, from the exergetic viewpoint. The exergetic comparison identifies the causes of performance differences between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using oxygen-blown versus air-blown KRW gasifiers, and hot gas versus cold gas cleanup processes is evaluated

  3. Technical comparison between Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Pablo Andres Silva; Venturini, Osvaldo Jose; Lora, Electo Eduardo Silva [Federal University of Itajuba - UNIFEI, MG (Brazil). Excellence Group in Thermal Power and Distributed Generation - NEST], e-mails: osvaldo@unifei.edu.br, electo@unifei.edu.br

    2010-07-01

    Among the emerging clean coal technologies for power generation, Integrated Gasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC) systems are receiving considerable attention as a potentially attractive option to reduce the emissions of greenhouse gases (GHG). The main reason is because these systems has high efficiency and low emissions in comparison with traditional power generation plants. Currently in IGCC and NGCC systems at demonstration stage is been considered to implement CCS technology. CO{sub 2} emissions can be avoided in a gasification-based power plant because by transferring almost all carbon compounds to CO{sub 2} through the water gas shift (WGS) reaction, then removing the CO{sub 2} before it is diluted in the combustion stage. The aim of this study is to compare the technical performance of an IGCC system that uses Brazilian coal and petroleum coke as fuel with a NGCC system, with the same fixed output power of 450 MW. The first section of this paper presents the plant configurations of IGCC systems. The following section presents an analysis of NGCC technology. (author)

  4. Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Yackly

    2005-12-01

    The ''Enabling & Information Technology To Increase RAM for Advanced Powerplants'' program, by DOE request, was re-directed, de-scoped to two tasks, shortened to a 2-year period of performance, and refocused to develop, validate and accelerate the commercial use of enabling materials technologies and sensors for coal/IGCC powerplants. The new program was re-titled ''Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants''. This final report summarizes the work accomplished from March 1, 2003 to March 31, 2004 on the four original tasks, and the work accomplished from April 1, 2004 to July 30, 2005 on the two re-directed tasks. The program Tasks are summarized below: Task 1--IGCC Environmental Impact on high Temperature Materials: The first task was refocused to address IGCC environmental impacts on high temperature materials used in gas turbines. This task screened material performance and quantified the effects of high temperature erosion and corrosion of hot gas path materials in coal/IGCC applications. The materials of interest included those in current service as well as advanced, high-performance alloys and coatings. Task 2--Material In-Service Health Monitoring: The second task was reduced in scope to demonstrate new technologies to determine the inservice health of advanced technology coal/IGCC powerplants. The task focused on two critical sensing needs for advanced coal/IGCC gas turbines: (1) Fuel Quality Sensor to rapidly determine the fuel heating value for more precise control of the gas turbine, and detection of fuel impurities that could lead to rapid component degradation. (2) Infra-Red Pyrometer to continuously measure the temperature of gas turbine buckets, nozzles, and combustor hardware. Task 3--Advanced Methods for Combustion Monitoring and Control: The third task was originally to develop and validate advanced monitoring and control methods for coal/IGCC gas

  5. A comparison of improved power plant technologies on lignite with (PFBC) and (IGCC) cycles

    International Nuclear Information System (INIS)

    Cherepnalkovski, Ilija

    1997-01-01

    Technologies and process diagrams descriptions for PFBC (Pressurised Fluidized Bed Combustion) and IGCC (Integrated Gasification Combined Cycle) are presented as for improved cycles with modern clean coal technologies, the most popular currently. A special attention is paid to the possibilities for Macedonian lignites use on the power plants with PFBC and IGCC cycles. The comparison of the above mention technologies has been done particularly on the desulfurization, NO x reduction, ash elimination and its use in the building and construction industries. A comparison between the power plants with PFBC and IGCC cycles is made by the following criteria: cycle efficiency, desulfurization and nitrogen oxides reduction, power plant complexity and their cost, as well as plant reliability. (Author)

  6. Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in COAL IGCC Powerplants

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth A. Yackly

    2004-09-30

    The ''Enabling & Information Technology To Increase RAM for Advanced Powerplants'' program, by DOE request, has been re-directed, de-scoped to two tasks, shortened to a 2-year period of performance, and refocused to develop, validate and accelerate the commercial use of enabling materials technologies and sensors for Coal IGCC powerplants. The new program has been re-titled as ''Enabling Technology for Monitoring & Predicting Gas Turbine Health & Performance in IGCC Powerplants'' to better match the new scope. This technical progress report summarizes the work accomplished in the reporting period April 1, 2004 to August 31, 2004 on the revised Re-Directed and De-Scoped program activity. The program Tasks are: Task 1--IGCC Environmental Impact on high Temperature Materials: This first materials task has been refocused to address Coal IGCC environmental impacts on high temperature materials use in gas turbines and remains in the program. This task will screen material performance and quantify the effects of high temperature erosion and corrosion of hot gas path materials in Coal IGCC applications. The materials of interest will include those in current service as well as advanced, high-performance alloys and coatings. Task 2--Material In-Service Health Monitoring: This second task develops and demonstrates new sensor technologies to determine the in-service health of advanced technology Coal IGCC powerplants, and remains in the program with a reduced scope. Its focus is now on only two critical sensor need areas for advanced Coal IGCC gas turbines: (1) Fuel Quality Sensor for detection of fuel impurities that could lead to rapid component degradation, and a Fuel Heating Value Sensor to rapidly determine the fuel heating value for more precise control of the gas turbine, and (2) Infra-Red Pyrometer to continuously measure the temperature of gas turbine buckets, nozzles, and combustor hardware.

  7. CO2 control technology effects on IGCC plant performance and cost

    International Nuclear Information System (INIS)

    Chen Chao; Rubin, Edward S.

    2009-01-01

    As part of the USDOE's Carbon Sequestration Program, an integrated modeling framework has been developed to evaluate the performance and cost of alternative carbon capture and storage (CCS) technologies for fossil-fueled power plants in the context of multi-pollutant control requirements. This paper uses the newly developed model of an integrated gasification combined cycle (IGCC) plant to analyze the effects of adding CCS to an IGCC system employing a GE quench gasifier with water gas shift reactors and a Selexol system for CO 2 capture. Parameters of interest include the effects on plant performance and cost of varying the CO 2 removal efficiency, the quality and cost of coal, and selected other factors affecting overall plant performance and cost. The stochastic simulation capability of the model is also used to illustrate the effect of uncertainties or variability in key process and cost parameters. The potential for advanced oxygen production and gas turbine technologies to reduce the cost and environmental impacts of IGCC with CCS is also analyzed

  8. Effective utilization of fossil fuels for low carbon world -- IGCC and high performance gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Hiromi; Hashimoto, Takao; Sakamoto, Koichi; Komori, Toyoaki; Kishine, Takashi; Shiozaki, Shigehiro

    2010-09-15

    The reduction of greenhouse-gas emissions is required to minimize the effect of hydrocarbon based power generation on global warming. In pursue of this objective, Mitsubishi Heavy Industries is dedicating considerable efforts on two different ways to reduce the environmental impact. The first one involves gas turbine performance improvement by raising firing temperature for Natural-gas and LNG applications. In this regard, the latest J class gas turbine was designed to operate at 1600 deg C and expected combined cycle efficiency in excess of 60%. The other approach involves the use of Integrated Gasification Combined Cycle (IGCC) plants to burn solid fuel like coal.

  9. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K; Keraenen, H [Enviropower Inc., Espoo (Finland)

    1997-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  10. Biomass IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Salo, K.; Keraenen, H. [Enviropower Inc., Espoo (Finland)

    1996-12-31

    Enviropower Inc. is developing a modern power plant concept based on pressurised fluidized-bed gasification and gas turbine combined cycle (IGCC). The process is capable of maximising the electricity production with a variety of solid fuels - different biomass and coal types - mixed or separately. The development work is conducted on many levels. These and demonstration efforts are highlighted in this article. The feasibility of a pressurised gasification based processes compared to competing technologies in different applications is discussed. The potential of power production from biomass is also reviewed. (orig.) 4 refs.

  11. Air permitting of IGCC plants

    Energy Technology Data Exchange (ETDEWEB)

    Chitikela, S.R.

    2007-07-01

    The IGCC process is, currently, the preferred choice over conventional thermal power production in regard to cleanup of fuel and significantly reduced contaminant emissions. The air permitting requirements include the review of: feed preparation and PM emissions; feed gasification and contaminant emissions; elemental sulfur recovery and SO{sub 2} emissions; options for carbon-dioxide recovery; syngas characteristics for combustion; CT design and combustion mechanisms; air contaminant emissions of CT; controlled CT emissions of nitrogen-oxides and carbon-monoxide gases using the SCR and oxidation catalysts, respectively; and, emission of volatile organic compounds (VOCs), and hazardous air pollutants (HAPs). However, the IGCC processes are being rigorously reviewed for the system integration and reliability, and significant reduction of air contaminant emissions (including the greenhouse gases). This paper included a review of IGCC air contaminant emission rates, and various applicable regulatory requirements, such as NSR (New Source Review), NSPS (New Source Performance Standards), and MACT (Maximum Achievable Control Technology). The IGCC facility's NOX, CO, SO{sub 2}, PM, VOCs, and HAPs emission rates would be significantly low. Thus, effective, construction and installation, and operation air permits would be necessary for IGCC facilities.

  12. IGCC crosses the threshold

    Energy Technology Data Exchange (ETDEWEB)

    Broderick, J E

    1986-07-01

    This paper describes the development of the Texaco Coal Gasification Process (TCGP), the first of the advanced gasification processes to become commercialized. The utilization of this process in various demonstration and commercial plants is described. The design of the Cool Water integrated gasification combined cycle (IGCC) plant in California is discussed in some detail. This plant has been operating successfully since June 1984, and has demonstrated that the Texaco gasification technology for electric power generation is commercially viable, can use many different feedstocks, has substantial efficiency growth potential, can provide competitively lower cost electric power, and offers vastly superior environmental performance.

  13. IGCC technology and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J [A. Ahlstrom Corporation, Karhula (Finland). Hans Ahlstrom Lab.; Lundqvist, R G [A. Ahlstrom Corporation, Helsinki (Finland); Staahl, K [Sydkraft AB, Malmoe (Sweden)

    1997-12-31

    Future energy production will be performed by advanced technologies that are more efficient, more environmentally friendly and less expensive than current technologies. Integrated gasification combined cycle (IGCC) power plants have been proposed as one of these systems. Utilising biofuels in future energy production will also be emphasised since this lowers substantially carbon dioxide emissions into the atmosphere due to the fact that biomass is a renewable form of energy. Combining advanced technology and biomass utilisation is for this reason something that should and will be encouraged. A. Ahlstrom Corporation of Finland and Sydkraft AB of Sweden have as one part of company strategies adopted this approach for the future. The companies have joined their resources in developing a biomass-based IGCC system with the gasification part based on pressurised circulating fluidized-bed technology. With this kind of technology electrical efficiency can be substantially increased compared to conventional power plants. As a first concrete step, a decision has been made to build a demonstration plant. This plant, located in Vaernamo, Sweden, has already been built and is now in commissioning and demonstration stage. The system comprises a fuel drying plant, a pressurised CFB gasifier with gas cooling and cleaning, a gas turbine, a waste heat recovery unit and a steam turbine. The plant is the first in the world where the integration of a pressurised gasifier with a gas turbine will be realised utilising a low calorific gas produced from biomass. The capacity of the Vaernamo plant is 6 MW of electricity and 9 MW of district heating. Technology development is in progress for design of plants of sizes from 20 to 120 MWe. The paper describes the Bioflow IGCC system, the Vaernamo demonstration plant and experiences from the commissioning and demonstration stages. (orig.)

  14. IGCC technology and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, J. [A. Ahlstrom Corporation, Karhula (Finland). Hans Ahlstrom Lab.; Lundqvist, R.G. [A. Ahlstrom Corporation, Helsinki (Finland); Staahl, K. [Sydkraft AB, Malmoe (Sweden)

    1996-12-31

    Future energy production will be performed by advanced technologies that are more efficient, more environmentally friendly and less expensive than current technologies. Integrated gasification combined cycle (IGCC) power plants have been proposed as one of these systems. Utilising biofuels in future energy production will also be emphasised since this lowers substantially carbon dioxide emissions into the atmosphere due to the fact that biomass is a renewable form of energy. Combining advanced technology and biomass utilisation is for this reason something that should and will be encouraged. A. Ahlstrom Corporation of Finland and Sydkraft AB of Sweden have as one part of company strategies adopted this approach for the future. The companies have joined their resources in developing a biomass-based IGCC system with the gasification part based on pressurised circulating fluidized-bed technology. With this kind of technology electrical efficiency can be substantially increased compared to conventional power plants. As a first concrete step, a decision has been made to build a demonstration plant. This plant, located in Vaernamo, Sweden, has already been built and is now in commissioning and demonstration stage. The system comprises a fuel drying plant, a pressurised CFB gasifier with gas cooling and cleaning, a gas turbine, a waste heat recovery unit and a steam turbine. The plant is the first in the world where the integration of a pressurised gasifier with a gas turbine will be realised utilising a low calorific gas produced from biomass. The capacity of the Vaernamo plant is 6 MW of electricity and 9 MW of district heating. Technology development is in progress for design of plants of sizes from 20 to 120 MWe. The paper describes the Bioflow IGCC system, the Vaernamo demonstration plant and experiences from the commissioning and demonstration stages. (orig.)

  15. Dynamic modeling of IGCC power plants

    International Nuclear Information System (INIS)

    Casella, F.; Colonna, P.

    2012-01-01

    Integrated Gasification Combined Cycle (IGCC) power plants are an effective option to reduce emissions and implement carbon-dioxide sequestration. The combination of a very complex fuel-processing plant and a combined cycle power station leads to challenging problems as far as dynamic operation is concerned. Dynamic performance is extremely relevant because recent developments in the electricity market push toward an ever more flexible and varying operation of power plants. A dynamic model of the entire system and models of its sub-systems are indispensable tools in order to perform computer simulations aimed at process and control design. This paper presents the development of the lumped-parameters dynamic model of an entrained-flow gasifier, with special emphasis on the modeling approach. The model is implemented into software by means of the Modelica language and validated by comparison with one set of data related to the steady operation of the gasifier of the Buggenum power station in the Netherlands. Furthermore, in order to demonstrate the potential of the proposed modeling approach and the use of simulation for control design purposes, a complete model of an exemplary IGCC power plant, including its control system, has been developed, by re-using existing models of combined cycle plant components; the results of a load dispatch ramp simulation are presented and shortly discussed. - Highlights: ► The acausal dynamic model of an entrained gasifier has been developed. ► The model can be used to perform system optimization and control studies. ► The model has been validated using field data. ► Model use is illustrated with an example showing the transient of an IGCC plant.

  16. Heat integration and analysis of decarbonised IGCC sites

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.S.; Lopez, Y.; Campbell, G.M.; Sadhukhan, J. [University of Manchester, Manchester (United Kingdom). School of Chemical Engineering & Analytical Science

    2010-02-15

    Integrated gasification combined cycle (IGCC) power generation systems have become of interest due to their high combined heat and power (CHP) generation efficiency and flexibility to include carbon capture and storage (CCS) in order to reduce CO{sub 2} emissions. However, IGCC's biggest challenge is its high cost of energy production. In this study, decarbonised coal IGCC sites integrated with CCS have been investigated for heat integration and economic value analyses. It is envisaged that the high energy production cost of an IGCC site can be offset by maximising site-wide heat recovery and thereby improving the cost of electricity (COE) of CHP generation. Strategies for designing high efficiency CHP networks have been proposed based on thermodynamic heuristics and pinch theory. Additionally, a comprehensive methodology to determine the COE from a process site has been developed. In this work, we have established thermodynamic and economic comparisons between IGCC sites with and without CCS and a trade-off between the degree of decarbonisation and the COE from the heat integrated IGCC sites. The results show that the COE from the heat integrated decarbonised IGCC sites is significantly lower compared to IGCC sites without heat integration making application of CCS in IGCC sites economically competitive.

  17. Advanced IGCC/Hydrogen Gas Turbine Development

    Energy Technology Data Exchange (ETDEWEB)

    York, William [General Electric Company, Schenectady, NY (United States); Hughes, Michael [General Electric Company, Schenectady, NY (United States); Berry, Jonathan [General Electric Company, Schenectady, NY (United States); Russell, Tamara [General Electric Company, Schenectady, NY (United States); Lau, Y. C. [General Electric Company, Schenectady, NY (United States); Liu, Shan [General Electric Company, Schenectady, NY (United States); Arnett, Michael [General Electric Company, Schenectady, NY (United States); Peck, Arthur [General Electric Company, Schenectady, NY (United States); Tralshawala, Nilesh [General Electric Company, Schenectady, NY (United States); Weber, Joseph [General Electric Company, Schenectady, NY (United States); Benjamin, Marc [General Electric Company, Schenectady, NY (United States); Iduate, Michelle [General Electric Company, Schenectady, NY (United States); Kittleson, Jacob [General Electric Company, Schenectady, NY (United States); Garcia-Crespo, Andres [General Electric Company, Schenectady, NY (United States); Delvaux, John [General Electric Company, Schenectady, NY (United States); Casanova, Fernando [General Electric Company, Schenectady, NY (United States); Lacy, Ben [General Electric Company, Schenectady, NY (United States); Brzek, Brian [General Electric Company, Schenectady, NY (United States); Wolfe, Chris [General Electric Company, Schenectady, NY (United States); Palafox, Pepe [General Electric Company, Schenectady, NY (United States); Ding, Ben [General Electric Company, Schenectady, NY (United States); Badding, Bruce [General Electric Company, Schenectady, NY (United States); McDuffie, Dwayne [General Electric Company, Schenectady, NY (United States); Zemsky, Christine [General Electric Company, Schenectady, NY (United States)

    2015-07-30

    The objective of this program was to develop the technologies required for a fuel flexible (coal derived hydrogen or syngas) gas turbine for IGCC that met DOE turbine performance goals. The overall DOE Advanced Power System goal was to conduct the research and development (R&D) necessary to produce coal-based IGCC power systems with high efficiency, near-zero emissions, and competitive capital cost. To meet this goal, the DOE Fossil Energy Turbine Program had as an interim objective of 2 to 3 percentage points improvement in combined cycle (CC) efficiency. The final goal is 3 to 5 percentage points improvement in CC efficiency above the state of the art for CC turbines in IGCC applications at the time the program started. The efficiency goals were for NOx emissions of less than 2 ppm NOx (@15 % O2). As a result of the technologies developed under this program, the DOE goals were exceeded with a projected 8 point efficiency improvement. In addition, a new combustion technology was conceived of and developed to overcome the challenges of burning hydrogen and achieving the DOE’s NOx goal. This report also covers the developments under the ARRA-funded portion of the program that include gas turbine technology advancements for improvement in the efficiency, emissions, and cost performance of gas turbines for industrial applications with carbon capture and sequestration. Example applications could be cement plants, chemical plants, refineries, steel and aluminum plants, manufacturing facilities, etc. The DOE’s goal for more than 5 percentage point improvement in efficiency was met with cycle analyses performed for representative IGCC Steel Mill and IGCC Refinery applications. Technologies were developed in this program under the following areas: combustion, larger latter stage buckets, CMC and EBC, advanced materials and coatings, advanced configurations to reduce cooling, sealing and rotor purge flows, turbine aerodynamics, advanced sensors, advancements in first

  18. Market potential of IGCC for domestic power production

    International Nuclear Information System (INIS)

    Gray, D.; Tomlinson, G.; Hawk, E.; Maskew, J.

    1999-01-01

    Mitretek Systems and CONSOL Inc. have completed the first phase of a market potential study for Integrated Coal Gasification Combined Cycle (IGCC) domestic power production. The U. S. Department of Energy (DOE) funded this study. The objective of this study is to provide DOE with data to estimate the future domestic market potential of IGCC for electricity generation. Major drivers in this study are the state of technology development, feedstock costs, environmental control costs, demand growth, and dispatchability. This study examines IGCC potential for baseload power production in the Northeast U. S., an important market area by virtue of existing coal infrastructure and proximity to coal producing regions. IGCC market potential was examined for two levels of technology development as a function of natural gas price and carbon tax. This paper discusses the results of this study, including the levels of performance and cost necessary to insure competitiveness with natural gas combined cycle plants

  19. Commercial gasifier for IGCC applications study report

    Energy Technology Data Exchange (ETDEWEB)

    Notestein, J.E.

    1990-06-01

    This was a scoping-level study to identify and characterize the design features of fixed-bed gasifiers appearing most important for a gasifier that was to be (1) potentially commercially attractive, and (2) specifically intended for us in integrated coal gasification/combined-cycle (IGCC) applications. It also performed comparative analyses on the impact or value of these design features and on performance characteristics options of the whole IGCC system since cost, efficiency, environmental traits, and operability -- on a system basis -- are what is really important. The study also reviewed and evaluated existing gasifier designs, produced a conceptual-level gasifier design, and generated a moderately advanced system configuration that was utilized as the reference framework for the comparative analyses. In addition, technical issues and knowledge gaps were defined. 70 figs., 31 tabs.

  20. Future technological and economic performance of IGCC and FT production facilities with and without CO2 capture: Combining component based learning curve and bottom-up analysis

    NARCIS (Netherlands)

    Knoope, M.M.J.; Meerman, J.C.; Ramirez, C.A.; Faaij, A.P.C.

    2013-01-01

    This study aims to investigate the technological and economic prospects of integrated gasification facilities for power (IGCC) and Fischer–Tropsch (FT) liquid production with and without CCS over time. For this purpose, a component based experience curve was constructed and applied to identify the

  1. Amine-based post-combustion CO2 capture in air-blown IGCC systems with cold and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, A.; Bonalumi, D.; Lozza, G.

    2013-01-01

    Highlights: • Hot fuel gas clean-up is a very favorable technology for IGCC concepts. • IGCC net efficiency reduces to 41.5% when realizing post-combustion CO 2 capture. • Complex IGCC layouts are necessary if exhaust gas recirculation is realized. • IGCC performance does not significantly vary with exhaust gas recirculation. - Abstract: This paper focuses on the thermodynamic performance of air-blown IGCC systems with post-combustion CO 2 capture by chemical absorption. Two IGCC technologies are investigated in order to evaluate two different strategies of coal-derived gas clean-up. After outlining the layouts of two power plants, the first with conventional cold gas clean-up and the second with hot gas clean-up, attention is paid to the CO 2 capture station and to issues related to exhaust gas recirculation in combined cycles. The results highlight that significant improvements in IGCC performance are possible if hot coal-derived gas clean-up is realized before the syngas fuels the combustion turbine, so the energy cost of CO 2 removal in an amine-based post-combustion mode is less strong. In particular, IGCC net efficiency as high as 41.5% is calculated, showing an interesting potential if compared to the one of IGCC systems with pre-combustion CO 2 capture. Thermodynamic effects of exhaust gas recirculation are investigated as well, even though IGCC performance does not significantly vary against a more complicated plant layout

  2. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    Energy Technology Data Exchange (ETDEWEB)

    Koljonen, T.; Solantausta, Y. [VTT Energy, Espoo (Finland). New Energy Technologies; Salo, K.; Horvath, A. [Carbona Inc. (Finland)

    1999-11-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  3. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    International Nuclear Information System (INIS)

    Koljonen, T.; Solantausta, Y.

    1999-01-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  4. Sulphur removal in IGCC projects

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F. (Parsons (United Kingdom))

    1998-01-01

    The technology for recovering elemental sulphur from H[sub 2]S bearing gases is well established. The modified Claus Process is the principal work-horse in sulphur recovery and can customarily achieve conversion efficiencies of 95% or better. Nowadays, such a level of recovery is no longer sufficient in most instances and sulphur recovery facility must then include some form of enhanced recovery, usually by treating the Claus tail gas. A number of processes have been introduced to enable the overall recovery to be increased. Recoveries in excess of 99% are both feasible and economic. Use of oxygen in place has become very popular in cases where oxygen is available cheaply or where capacity increases are designed. Most IGCC projects needing an air separation plant would automatically benefit from extending the use of oxygen to the sulphur recovery plant. The most popular route to minimising sulphur emissions in the context of IGCC projects has involved an oxygen based Claus plant followed by tail gas hydrogenation, hydrogen sulphide recovery and its recycle to the Claus section. The recovery of H[sub 2]S from the Claus tail gas can be integrated with the main gas treating system in the gasification plant. The cost advantage of doing so is significant. Parsons has been involved with the technology since 1949 and has been responsible for developments such as the ammonia burning Claus and jointly with Unocal, the BSRP tail gas process and Selectox processes. Recent innovations in response changing environmental and production requirements have included catalytic and tail gas processes which reduce sulphur emissions. 6 figs., 2 tabs.

  5. Sulphur removal in IGCC projects

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F. [Parsons (United Kingdom)

    1998-12-31

    The technology for recovering elemental sulphur from H{sub 2}S bearing gases is well established. The modified Claus Process is the principal work-horse in sulphur recovery and can customarily achieve conversion efficiencies of 95% or better. Nowadays, such a level of recovery is no longer sufficient in most instances and sulphur recovery facility must then include some form of enhanced recovery, usually by treating the Claus tail gas. A number of processes have been introduced to enable the overall recovery to be increased. Recoveries in excess of 99% are both feasible and economic. Use of oxygen in place has become very popular in cases where oxygen is available cheaply or where capacity increases are designed. Most IGCC projects needing an air separation plant would automatically benefit from extending the use of oxygen to the sulphur recovery plant. The most popular route to minimising sulphur emissions in the context of IGCC projects has involved an oxygen based Claus plant followed by tail gas hydrogenation, hydrogen sulphide recovery and its recycle to the Claus section. The recovery of H{sub 2}S from the Claus tail gas can be integrated with the main gas treating system in the gasification plant. The cost advantage of doing so is significant. Parsons has been involved with the technology since 1949 and has been responsible for developments such as the ammonia burning Claus and jointly with Unocal, the BSRP tail gas process and Selectox processes. Recent innovations in response changing environmental and production requirements have included catalytic and tail gas processes which reduce sulphur emissions. 6 figs., 2 tabs.

  6. Tampa Electric Company Polk Power Station IGCC project: Project status

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, J.E.; Carlson, M.R.; Hurd, R.; Pless, D.E.; Grant, M.D. [Tampa Electric Co., FL (United States)

    1997-12-31

    The Tampa Electric Company Polk Power Station is a nominal 250 MW (net) Integrated Gasification Combined Cycle (IGCC) power plant located to the southeast of Tampa, Florida in Polk County, Florida. This project is being partially funded under the Department of Energy`s Clean Coal Technology Program pursuant to a Round II award. The Polk Power Station uses oxygen-blown, entrained-flow IGCC technology licensed from Texaco Development Corporation to demonstrate significant reductions of SO{sub 2} and NO{sub x} emissions when compared to existing and future conventional coal-fired power plants. In addition, this project demonstrates the technical feasibility of commercial scale IGCC and Hot Gas Clean Up (HGCU) technology. The Polk Power Station achieved ``first fire`` of the gasification system on schedule in mid-July, 1996. Since that time, significant advances have occurred in the operation of the entire IGCC train. This paper addresses the operating experiences which occurred in the start-up and shakedown phase of the plant. Also, with the plant being declared in commercial operation as of September 30, 1996, the paper discusses the challenges encountered in the early phases of commercial operation. Finally, the future plans for improving the reliability and efficiency of the Unit in the first quarter of 1997 and beyond, as well as plans for future alternate fuel test burns, are detailed. The presentation features an up-to-the-minute update on actual performance parameters achieved by the Polk Power Station. These parameters include overall Unit capacity, heat rate, and availability. In addition, the current status of the start-up activities for the HGCU portion of the plant is discussed.

  7. IGCC demonstration project status combustion engineering IGCC repowering project

    International Nuclear Information System (INIS)

    Glamuzina, R.W.; Allen, R.J.; Peletz, L.J.

    1993-01-01

    This demonstration project was originally conceived as the repowering of an existing plant facility, the Lakeside Station in Springfield, Illinois. The Owner, City Water, Light and Power (CWL ampersand P), has removed five of the original boilers and three of the original turbines. The buildings have had asbestos insulation removed and the interiors have been prepared for the construction of a single Integrated Gasification Combined Cycle (IGCC) process train that will generate a net output of 60 megawatts. The plant consists of a combined cycle (gas turbine, heat recovery steam generator, steam turbine) power train located in the existing buildings and a coal gasification system in a new building. The gasification system contains ABB CE's air-blown, entrained flow, two stage gasifier, an advanced hot gas desulfurization system by General Electric Environmental Services, Inc. and the necessary auxiliary systems. The plant is designed to produce a nominal 60 MW net output with an ambient air temperature of 95 degrees F and a cooling water temperature of 89 degrees F on either Natural Gas or Illinois No. 5 coal

  8. Pinon Pine IGCC project status

    International Nuclear Information System (INIS)

    Higginbotham, E.B.; Lamarre, L.J.; Glazer, M.

    1993-01-01

    Sierra Pacific Power Company (SPPCo) intends to build the Pinon Pine Power Project, an integrated coal gasification combined cycle (IGCC) plant at its Tracy Power Station near Reno, Nevada. The plant will burn approximately 800 tons of coal per day to generate electricity in a base load application. The Pinon Project was selected by the U.S. Department of Energy (DOE) for funding under Round IV of the Clean Coal Technology Program. The project will demonstrate the use of the KRW agglomerating fluidized bed gasifer operating in the air blown mode. Hot gas cleanup consisting of particulate and sulfur removal will also be demonstrated. The Cooperative Agreement between SPPCo and the DOE was executed in August 1992. Foster Wheeler USA Corporation (FWUSA) will provide engineering and construction management services. The M.W. Kellogg Company (MWK) will provide engineering of the gasifer and hot gas cleanup systems. A discussion of project progress since the 1992 Clean Coal Technology Conference, design and economic considerations, and current project status is presented

  9. Strategic thinking on IGCC development in China

    International Nuclear Information System (INIS)

    Liu Hengwei; Ni Weidou; Li Zheng; Ma Linwei

    2008-01-01

    With electricity demand growing at a torrid pace-about 15% per year, faster than any other country in the world-China is fast-tracking the construction of new generation facilities, about 80% of which are coal-fired. China's total capacity in the reference scenario of World Energy Outlook 2006 (WEO2006) released by the International Energy Agency (IEA) is projected to practically 3.4 times, from 442 GW in 2004 to 1496 GW in 2030, growing at 4.8% per year on average. The vast majority of this huge generation requirement will still be met through the construction of coal power plants. Because new coal power plants built today have a long life cycle and are not easy to upgrade the technologies involved, decisions made now will have a major impact on the coal utilization mode in the coming years. Thus, the future 20 years is the strategic opportunity period of the transition of conventional coal utilization. Because the Integrated Gasification Combined Cycle (IGCC) can supply electricity, liquid fuels, hydrogen and other chemicals if needed at low pollution level, and has the potential to make carbon capture and sequestration much easier and cheaper than traditional pulverized coal boiler power plants, it should be the strategic direction for China to meet the requirements of the energy and environmental challenges. This paper makes an overview of China's energy and environmental challenges and opportunities, and describes the IGCC technology. It discusses why China should develop IGCC. What are the foundations for China to develop IGCC? What are the rational driving forces to develop IGCC in China? What is the reasonable developing path of IGCC in China?

  10. Efficiency enhancement in IGCC power plants with air-blown gasification and hot gas clean-up

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni

    2013-01-01

    Air-blown IGCC systems with hot fuel gas clean-up are investigated. In detail, the gas clean-up station consists of two reactors: in the first, the raw syngas exiting the gasifier and passed through high-temperature syngas coolers is desulfurized by means of a zinc oxide-based sorbent, whereas in the second the sulfided sorbent is duly regenerated. The hot fuel gas clean-up station releases H 2 S-free syngas, which is ready to fuel the combustion turbine after hot gas filtration, and a SO 2 -laden stream, which is successively treated in a wet scrubber. A thermodynamic analysis of two air-blown IGCC systems, the first with cold fuel gas clean-up and the second with hot fuel gas clean-up, both with a state-of-the-art combustion turbine as topping cycle, shows that it is possible to obtain a really attractive net efficiency (more than 51%) for the second system, with significant improvements in comparison with the first system. Nevertheless, higher efficiency is accomplished with a small reduction in the power output and no sensible efficiency improvements seem to be appreciated when the desulfurization temperature increases. Other IGCC systems, with an advanced 1500 °C-class combustion turbine as the result of technology improvements, are investigated as well, with efficiency as high as 53%. - Highlights: ► Hot fuel gas clean-up is a highly favorable technology for IGCC concepts. ► Significant IGCC efficiency improvements are possible with hot fuel gas clean-up. ► Size reductions of several IGCC components are possible. ► Higher desulfurization temperatures do not sensibly affect IGCC efficiency. ► IGCC efficiency as high as 53% is possible with a 1500°C-class combustion turbine

  11. Commercialization of IGCC technology looks promising

    International Nuclear Information System (INIS)

    Smith, D.J.

    1992-01-01

    This paper reports that a major focus of the latest round of the U.S. Department of Energy's Clean Coal Technology Program was three large-scale, high-efficiency electricity generating projects which will rely on coal gasification rather than burning the coal directly. The three projects are: Toms Creek integrated gasification combined-cycle (IGCC) demonstration project. The aim of the project is to demonstrate improved coal-to-power efficiencies in an integrated gasification combined-cycle process. According to the DOE, the Toms Creek project will show that significant reductions in SO 2 and NO x emissions can be accomplished through the use of IGCC technology. On completion of the project, 107 MW of electric capacity will be added to the grid. Pinon Pine IGCC power project. The project's aim is to demonstrate that IGCC plants can be constructed at significantly lower capital costs, and with higher thermal efficiencies, than conventional power generation technologies. It will also demonstrate the effectiveness of hot gas cleanup for low-sulfur western coals. Wasbash River coal gasification repowering project

  12. IGCC - fuel-flexible technology for the future

    Energy Technology Data Exchange (ETDEWEB)

    Karg, J.; Hannemann, F. [Siemens AG Power Generation, Erlangen (Germany)

    2004-07-01

    According to IEA's World Energy Investment Outlook 2003 the electricity sector will dominate with about 60% of the total investment requirements expected until 2030 for worldwide energy-supply infrastructure. Around 45% of the capital needed for the electricity sector will be for power generation. The investment will be needed for capacity additions and to replace existing older facilities. According to the estimates the global primary energy demand is projected to grow by two thirds over the next three decades and electricity demand is expected to double by 2030. The natural gas for power generation is projected to increase significantly, but coal will remain the largest source of electricity generation throughout the projection period. These trends must be seen against the background that environmental regulations, are becoming tighter, and that environmental legislation will increasingly address greenhouse gas emissions. The necessity for more efficient use of primary energies in combination with more stringent environmental regulations for fossil-fuelled power plants therefore pushes concepts with increased efficiencies and reduced CO{sub 2} emissions, respectively. Since significant reduction of CO{sub 2} emissions cannot only be achieved via increased efficiencies or application of fuels with low carbon content, CO{sub 2} removal options also need to be considered for future power plant configurations. Considering this, IGCC is again one of the most promising solutions which are of relevance in this context. However, these new IGCC applications require further overall a plant concept and component development efforts. One essential step for performance improvement of future IGCC applications is to further develop syngas capabilities of advanced gas turbines, thereby considering the experience and lessons learned from operational plants. 11 refs., 7 figs., 5 tabs.

  13. Thermodynamic assessment of IGCC power plants with hot fuel gas desulfurization

    International Nuclear Information System (INIS)

    Giuffrida, Antonio; Romano, Matteo C.; Lozza, Giovanni G.

    2010-01-01

    In IGCC power plants, hot gas desulfurization (HGD) represents an attractive solution to simplify syngas treatments and to improve the efficiency, potentially reducing the final cost of electricity. In the present study, the various consequences of the introduction of a HGD station in the power plant are discussed and evaluated, in comparison with conventional near-ambient temperature clean-up. Attention is paid to the potential improvements of the overall energy balance of the complete power station, along with the requirements of the sorbent regeneration process, to the influence of the desulfurization temperature and to the different solutions needed to control the NO x emissions (altered by the presence of HGD). The net performance of complete IGCC power plants (with HGD or with conventional desulfurization) were predicted, with reference to status-of-the-art solutions based on an entrained flow, dry-feed, oxygen-blown gasifier and on an advanced, FB-class combined cycle. The net efficiency experiences about 2.5% point improvement with HGD, even if a small reduction in the power output was predicted, when using the same combustion turbine. An exhaustive sensitivity analysis was carried out to evaluate the effects of different working conditions at the HGD station, e.g. desulfurization temperature and oxygen content in the gaseous stream for sorbent regeneration. According to the obtained results, these parameters have a weak influence on the efficiency. In particular, a very elevated desulfurization temperature (above 400-500 o C) does not provide decisive thermodynamic advantages. Therefore, the HGD unit optimization can be driven by technical and economical aspects and by emission abatement requirements. For instance, utilization of nitrogen for HGD sorbent regeneration (rather than for syngas dilution) and higher fuel temperature may improve the NO formation. Hence, different strategies to achieve acceptable NO x emissions (e.g. steam dilution) and their

  14. Thermal and sintering characterization of IGCC slag

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, A.; Iglesias, I.; Aineto, M.; Romero, M.; Rincon, J.M. [University of Castilla La Mancha, Ciudad Real (Spain)

    2002-07-01

    IGCC slag is a vitreous residual product from the new induction gasification combined cycle gasification thermal power plants. In order to characterize this waste as secondary raw material for the production of glasses and glass-ceramics as construction materials, slag from the Puertollano, Ciudad Real, Spain power plants was thermally investigated. After controlled heating this waste gives rise to hematite, anorthite, and cristobalite crystallized materials.

  15. Api Energia IGCC plant is fully integrated with refinery

    Energy Technology Data Exchange (ETDEWEB)

    Del Bravo, R. [api Energia, Rome (Italy); Trifilo, R. [ABB Sadelmi, Milan (Italy); Chiantore, P.V. [api anonima petroli Italiania Spa, Rome (Italy); Starace, F. [ABB Power Generation, Baden (Switzerland); O`Keefe, L.F. [Texico, White Plains (United States)

    1998-06-01

    The api Energia integrated gasification combined cycle (IGCC) plant being built at Falconara Marittima, on Italy`s Adriatic coast, is one of the three IGCC plants under construction in Italy following the liberalization of the electricity production sector. The plant will take 59.2 t/h of high sulphur heavy oil produced by the Falconara refinery, convert it to syngas and use the gas to generate 280 MW of electricity, plus steam and other gases for use in the refinery. The IGCC plant will be highly integrated into the refining process, with a large number of interchanges between the IGCC unit and the rest of the refinery. (author)

  16. CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY

    International Nuclear Information System (INIS)

    Ravi Prasad

    2000-01-01

    The objective of this program is to conduct a technology development program to advance the state-of-the-art in ceramic Oxygen Transport Membranes (OTM) to the level required to produce step change improvements in process economics, efficiency, and environmental benefits for commercial IGCC systems and other applications. The IGCC program is focused on addressing key issues in materials, processing, manufacturing, engineering and system development that will make the OTM a commercial reality. The objective of the OTM materials development task is to identify a suitable material that can be formed into a thin film to produce the target oxygen flux. This requires that the material have an adequate permeation rate, and thermo-mechanical and thermo-chemical properties such that the material is able to be supported on the desired substrate and sufficient mechanical strength to survive the stresses involved in operation. The objective of the composite OTM development task is to develop the architecture and fabrication techniques necessary to construct stable, high performance, thin film OTMs supported on suitable porous, load bearing substrates. The objective of the process development task of this program to demonstrate the program objectives on a single OTM tube under test conditions simulating those of the optimum process cycle for the power plant

  17. Techno-economic analysis of lignite fuelled IGCC with CO{sub 2} capture. Comparing fluidized bed and entrained flow gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guangjian; Wu, Zhen; Zhang, Haiying [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

    2013-07-01

    Integrated coal gasification combined cycle (IGCC) plants with pre-combustion capture of CO{sub 2} represent one of the most promising options for generating low-cost decarbonized power using bituminous coals. This work systematically quantify the effect of coal rank on the efficiency and economics of IGCC systems with CO2 capture and storage (CCS), with a special focus on comparison of systems using fluidized-bed gasifier (U-GAS) and entrained flow gasifier (Shell). It was found that the Shell IGCCs are little affect by low rank coal after pre-drying in terms of thermal efficiency and the levelized cost of electricity (LCOE) is only increase by 2-6% for lignite cases with and without CCS compared with bituminous coal cases. The specific CO{sub 2} emissions of U-GAS gasifier based lignite fuelled IGCC with CCS is 198 g/kWhe, almost two times of shell gasifier cases, mainly due to lower carbon conversion in the gasifier and the higher methane in the raw gas of gasifier. However, the total capital cost and COE of U-Gas IGCCs are 15-20% less than that of Shell IGCCs because of lower capital cost of gasifier, coal drying units and air separate units per kWe.

  18. The reliability of integrated gasification combined cycle (IGCC) power generation units

    Energy Technology Data Exchange (ETDEWEB)

    Higman, C.; DellaVilla, S.; Steele, B. [Syngas Consultants Ltd. (United Kingdom)

    2006-07-01

    This paper presents two interlinked projects aimed at supporting the improvement of integrated gasification combined cycle (IGCC) reliability. The one project comprises the extension of SPS's existing ORAP (Operational Reliability Analysis Program) reliability, availability and maintainability (RAM) tracking technology from its existing base in natural gas open and combined cycle operations into IGCC. The other project is using the extended ORAP database to evaluate performance data from existing plants. The initial work has concentrated on evaluating public domain data on the performance of gasification based power and chemical plants. This is being followed up by plant interviews in some 20 plants to verify and expand the database on current performance. 23 refs., 8 figs., 2 tabs.

  19. Air toxics emissions from an IGCC process

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Norrbacka, P. [Enviropower Inc., Espoo (Finland); Hinderson, A. [Vattenfall (Sweden); Rosenberg, R.; Zilliacus, R.; Kurkela, E.; Nieminen, M. [VTT Energy, Espoo (Finland); Hoffren, H. [IVO International Oy, Vantaa (Finland)

    1996-12-01

    The so-called simplified coal gasification combined cycle process, incorporating air gasification and hot gas cleanup, promises high power generation efficiency in an environmentally acceptable manner. Increasingly more stringent environmental regulations have focused attention on the emissions of not only SO{sub 2} and NO{sub x} but also on the so-called air toxics which include a number of toxic trace elements. As result of recent amendments to the United States Clean Air Act, IGCC emissions of eleven trace elements: antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium - as well as the radionuclides uranium and thorium may be regulated. Similarly, air missions standards in Europe include a limit of 0.05 mg Nm{sup 3} for mercury and cadmium and 1.0 3/Nm{sup 3} for other class I trace elements. A suitable sampling/measuring system has been developed in this project (in cooperation with Imatran Voima Oy, Electric Power Research Institute (EPRI) and Radian Cooperation) which will be used in the pressurized gasification tests. This will enable an accurate measurement of the volatilized trace element species, at high temperature and pressure, which may be found in the vapour phase. Models are being developed that can be used to determine not only the chemical equilibrium composition of gaseous, liquid and solid phases, but also possible interactions of the gaseous species with aerosol particles and surfaces, These should be used to more accurately assess the impact of the toxic trace metals emitted from the simplified IGCC system

  20. Puertollano IGCC plant. Present position and future competitiveness

    Energy Technology Data Exchange (ETDEWEB)

    Pedro Casero; Francisco Garcia-Pena

    2006-07-01

    This paper discusses the current status of the Puertollano 350 MW IGCC demonstration power plant in Spain. The experience provided by the operation of this plant during the last years is described, focussing on the core systems of the plant (gasifier, gas cleaning and gas turbines). Bottlenecks and weak points related to these systems are identified, along with the improvements. The production of hydrogen from coal at an IGCC plant is also discussed. 9 figs., 2 tabs.

  1. Demonstration of IGCC features - plant integration and syngas combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, F.; Huth, M.; Karg, J.; Schiffers, U. [Siemens AG Power Generation (KWU), Erlanger/Muelheim (Germany)

    2000-07-01

    Siemens is involved in three IGCC plants in Europe that are currently in operation. Against the background of the Puertollano and Buggenum plants, some of the specific new features of fully integrated IGCC power plants are discussed, including: requirements and design features of the gas turbine syngas supply system; gas turbine operating experience with air extraction for the air separation unit from the gas turbine air compressor; and design requirements and operational features of the combustion system. 7 refs., 17 figs., 1 tab.

  2. Computer models and simulations of IGCC power plants with Canadian coals

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Furimsky, E.

    1999-07-01

    In this paper, three steady state computer models for simulation of IGCC power plants with Shell, Texaco and BGL (British Gas Lurgi) gasifiers will be presented. All models were based on a study by Bechtel for Nova Scotia Power Corporation. They were built by using Advanced System for Process Engineering (ASPEN) steady state simulation software together with Fortran programs developed in house. Each model was integrated from several sections which can be simulated independently, such as coal preparation, gasification, gas cooling, acid gas removing, sulfur recovery, gas turbine, heat recovery steam generation, and steam cycle. A general description of each process, model's overall structure, capability, testing results, and background reference will be given. The performance of some Canadian coals on these models will be discussed as well. The authors also built a computer model of IGCC power plant with Kellogg-Rust-Westinghouse gasifier, however, due to limitation of paper length, it is not presented here.

  3. Development of advanced air-blown entrained-flow two-stage bituminous coal IGCC gasifier

    Directory of Open Access Journals (Sweden)

    Abaimov Nikolay A.

    2017-01-01

    Full Text Available Integrated gasification combined cycle (IGCC technology has two main advantages: high efficiency, and low levels of harmful emissions. Key element of IGCC is gasifier, which converts solid fuel into a combustible synthesis gas. One of the most promising gasifiers is air-blown entrained-flow two-stage bituminous coal gasifier developed by Mitsubishi Heavy Industries (MHI. The most obvious way to develop advanced gasifier is improvement of commercial-scale 1700 t/d MHI gasifier using the computational fluid dynamics (CFD method. Modernization of commercial-scale 1700 t/d MHI gasifier is made by changing the regime parameters in order to improve its cold gas efficiency (CGE and environmental performance, namely H2/CO ratio. The first change is supply of high temperature (900°C steam in gasifier second stage. And the second change is additional heating of blast air to 900°C.

  4. Water-gas shift (WGS) Operation of Pre-combustion CO2 Capture Pilot Plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Van Dijk, H.A.J.; Damen, K.; Makkee, M.; Trapp, C.

    2014-01-01

    In the Nuon/Vattenfall CO2 Catch-up project, a pre-combustion CO2 capture pilot plant was built and operated at the Buggenum IGCC power plant, the Netherlands. The pilot consist of sweet water-gas shift, physical CO2 absorption and CO2 compression. The technology performance was verified and

  5. Air toxics emission from an IGCC process

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W; Hovath, A [Carbona Inc, Helsinki (Finland); Hinderson, A [Vattenfall Utveckling (Sweden); Nykaenen, J; Hoffren, H [Imatran Voima Oy, Vantaa (Finland); Nieminen, M; Kurkela, E [VTT, Espoo (Finland)

    1997-10-01

    The emissions of 12 toxic trace element from a coal-fired IGCC plant were calculated based on thermodynamic equilibrium in the gas phase and some of the results published. The theoretical calculations were extended to include some other fuels as well as mixture of some of these fuels. The combustion of the product gas in the gas turbine is also considered. These simulations correspond to gasification of the fuel at 850-1050 deg C (depending on the fuel) and 1823 bar pressure. The gas composition was taken from the measured data as far as possible. In the absence of experimental data, a computer code developed for the U-Gas gasifier was used to determine the fuel gas composition. The gas was then cooled to 550 deg C in the gas cooler and filtered at this same temperature and burned in the gas turbine with an air ratio of 3.2. The results of these simulations are compared with the measured data of an experimental program designed to measure the emissions of a few selected trace elements from a 15 MW,h pressurized fluidized bed gasification pilot plant. The pilot plant was equipped with an advanced hot gas cleanup train which includes a two fluidized-bed reactor system for high-temperature, high-pressure external sulfur removal and a filtration unit housing porous, rigid ceramic candle filters. The trace element concentrations in the fuel, bottom ash, and filter ash are determined and the results compared with EPA regulatory levels

  6. Incorporating IGCC and CaO sorption-enhanced process for power generation with CO2 capture

    International Nuclear Information System (INIS)

    Chen, Shiyi; Xiang, Wenguo; Wang, Dong; Xue, Zhipeng

    2012-01-01

    Highlights: ► CaO sorption-enhanced process is incorporated with IGCC for CO 2 capture. ► IGCC–CCS is simplified using CaO sorption-enhanced process. ► The electricity efficiency is around 31–33% and CO 2 capture efficiency exceeds 95%. ► Parameters such as sorption pressure influence the system performance. -- Abstract: Integrated gasification combined cycle (IGCC) is a power generation technology to convert solid fuels into electricity. IGCC with CCS is regarded as a promising option to mitigate CO 2 emission. In this paper, the CaO sorption-enhanced process is incorporated downstream with coal gasification to produce a hydrogen-rich stream for electricity production and CO 2 separation. A WGS-absorber substitutes the high- and low-temperature water–gas shift reactors and desulfurization units in conventional IGCC–CCS to produce a hydrogen-rich stream, which is sent onto a gas turbine. CaO is used as the sorbent to enhance hydrogen production and for CO 2 capture. Regeneration of CaO is completed via calcination in a regenerator vessel. The IGCC with CaO sorption-enhanced process is modeled and simulated using Aspen Plus software. Two commercial available gasification technologies, Shell and Texaco, are integrated with the sorption-enhanced process. The results showed IGCC with CaO sorption-enhanced process has a satisfactory system performance. Even though the net electricity efficiency is not as high as expected, just around 30–33%, the system has a high CO 2 capture efficiency ∼97% and low pollutant emissions. Moreover, compared with conventional IGCC–CCS, the schematic diagram of the IGCC–CCS process is simplified. Parameters that affect the plant performance are analyzed in the sensitive analysis, including WGS-absorber temperature, H 2 O/CO ratio, pressure, etc. Some challenges to the system are also discussed.

  7. Recent operating experience and improvement of commercial IGCC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    IGCC has today reached a status where experience is available from first and second generation plants, built in the 1970s/1980s and in the 1990s respectively, as commercial-scale demonstration plants for coal-based applications. These plants feature variations on gasification technology and subsequent environmental controls and in operating them a number of technical and commercial lessons have been learned that will help to improve the next generation of IGCC projects. The report reviews and summarises the state-of-the-art and operating experience of several commercial IGCC plants worldwide, setting out the lessons learned and plans for future development embracing such issues as the changes or modifications to plant made to overcome the operational problems and to improve the reliability and availability of the plant. Since IGCC is considered a 'capture ready' technology for CO2 abatement, the current status with regard to the incorporation of carbon capture and storage systems (CCS) has been reviewed. Finally, the report outlines the issues associated with assessing the risks in commercialising IGCC plant.

  8. IGCC based on proven technology developing towards 50% efficiency mark

    Energy Technology Data Exchange (ETDEWEB)

    Goudappel, E.; Berkhout, M. [Jacobs Consultancy, Leiden (Netherlands)

    2006-07-01

    In this paper the achievements made over the last 10 years in terms of reliability, load following and efficiency improvement potential at the Buggenum IGCC plant, are presented. Also the air side heat integration and its pros and cons are discussed. Additionally future business opportunities adjacent to the power production itself and the view on coal gasification in the near future are provided. The results are discussed and it is shown that with 'proven' gasifier and gas treatment technology, overall efficiency exceeding 47% (LHV basis) can be reached. It puts this technical potential in perspective and describes the view on interesting business opportunities around IGCC projects. 5 figs., 3 tabs.

  9. Exergoeconomic evaluation of a KRW-based IGCC power plant

    International Nuclear Information System (INIS)

    Tsatsavonis, G.; Lin, L.; TawFik, T.; Gallaspy, D.T.

    1991-01-01

    This paper reports on a study supported by the US Department of Energy, in which several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. One of these configurations was analyzed from the exergoeconomic (thermoeconomic) viewpoint. The detailed exergoeconomic evaluation identified several changes for improving the cost effectiveness of this IGCC design configuration. Based on the cost information supplied by the M.W. Kellogg Company, an attempt was made to calculate the economically optimal exergetic efficiency for some of the most important plant components. This information is currently used in plant optimization studies

  10. Modeling and assessment of future IGCC plant concepts with CO{sub 2} capture; Simulation und Bewertung zukuenftiger IGCC-Kraftwerkskonzepte mit CO{sub 2}-Abtrennung

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, Christian A.

    2012-07-13

    The thesis focuses on the assessment of efficiency potential of future IGCC plants with CO{sub 2} capture. Starting point is a comprehensive analysis (thermodynamic, economic and exergy) of a state of the art IGCC. Additionally, five future IGCC concepts are proposed and evaluated for their efficiency potential in the mid- and long-term. The concepts showed significantly higher efficiencies up to approximately 60% and enable an almost CO{sub 2}-free operation.

  11. Advanced IGCC-Hypogen concepts for a developing hydrogen market

    Energy Technology Data Exchange (ETDEWEB)

    Starr, F.; Cormos, C.-C.; Tzimas, E.; Brown, A. [European Commission, Petten (Netherlands). DG Joint Research Centre, Institute for Energy

    2007-07-01

    With FP6 the EU is funding a project called 'Dynamis' which aims to design plants to generate electricity, plus a limited amount of hydrogen from fossil fuels, in which the CO{sub 2} is captured and stored underground. Such plants have been characterised as being of the 'HYPOGEN' type since they generate both hydrogen and electric power. As the hydrogen market develops IGCC-Hypogen based systems will need to produce much greater amounts of hydrogen. It is also desirable that such plants should be able to vary the proportion of hydrogen-to-electricity. This will enable IGCC-Hypogen plants to load follow and two-shift as electricity demand from the grid changes. Such variations in power output are not always practical with existing designs of electricity-only IGCCs. This paper reviews the technical issues involved in providing a high-flexibility IGCC-Hypogen plant. Three such concepts are discussed (1) very limited flexibility in which the changes from a fixed hydrogen-electricity ratio concept are minor, (2) moderate level of flexibility in which the limit is imposed by the CCGT gas turbine turndown (3) complete flexibility, the plant being able produce the energy as all-electricity or all-hydrogen. 9 refs., 2 figs., 1 tab.

  12. Shell coal IGCCS with carbon capture: Conventional gas quench vs. innovative configurations

    International Nuclear Information System (INIS)

    Martelli, Emanuele; Kreutz, Thomas; Carbo, Michiel; Consonni, Stefano; Jansen, Daniel

    2011-01-01

    Highlights: → We aim at defining the preferred IGCC design for dry feed gasifiers with CO 2 capture. → Multiple options of syngas cooling, humidification, and WGS are considered. → Plants are designed, modeled, numerically optimized and costs are carefully assessed. → Partial water quench has poor efficiency but low capital cost, then good performance. → Gas quench with the ECN staged WGS design has the best thermo-economic performance. -- Abstract: The Shell coal integrated gasification combined cycle (IGCC) based on the gas quench system is one of the most fuel flexible and energy efficient gasification processes because is dry feed and employs high temperature syngas coolers capable of rising high pressure steam. Indeed the efficiency of a Shell IGCC with the best available technologies is calculated to be 47-48%. However the system looses many percentage points of efficiency (up to 10) when introducing carbon capture. To overcome this penalty, two approaches have been proposed. In the first, the expensive syngas coolers are replaced by a 'partial water quench' where the raw syngas stream is cooled and humidified via direct injection of hot water. This design is less costly, but also less efficient. The second approach retains syngas coolers but instead employs novel water-gas shift (WGS) configurations that requires substantially less steam to obtain the same degree of CO conversion to CO 2 , and thus increases the overall plant efficiency. We simulate and optimize these novel configurations, provide a detailed thermodynamic and economic analysis and investigate how these innovations alter the plant's efficiency, cost and complexity.

  13. Integration optimisation of elevated pressure air separation unit with gas turbine in an IGCC power plant

    International Nuclear Information System (INIS)

    Han, Long; Deng, Guangyi; Li, Zheng; Wang, Qinhui; Ileleji, Klein E.

    2017-01-01

    Highlights: • IGCC thermodynamic model was setup carefully. • Simulations focus on integration between an elevated pressure ASU with gas turbine. • Different recommended solutions from those of low pressure ASUs are figured out. • Full N 2 injection and 80% air extraction was suggested as the optimum integration. - Abstract: The integration optimisation between an elevated pressure air separation unit (EP-ASU) and gas turbine is beneficial to promote net efficiency of an integrated gasification combined cycle (IGCC) power plant. This study sets up the thermodynamic model for a 400 MW plant specially coupled with an EP-ASU, aiming to examine system performances under different integrations and acquire the optimum solution. Influences of air extraction rate at conditions of without, partial and full N 2 injection, as well as the effects of N 2 injection rate when adopting separate ASU, partial and full integrated ASU were both analysed. Special attention has been paid to performance differences between utilising an EP-ASU and a low pressure unit. Results indicated that integration solution with a separate EP-ASU or without N 2 injection would not be reasonable. Among various recommended solutions for different integration conditions, N 2 injection rate increased with the growth of air extraction rate. The integration with an air extraction rate of 80% and full N 2 injection was suggested as the optimum solution. It is concluded that the optimum integration solution when adopting an EP-ASU is different from that using a low pressure one.

  14. THERMAL AND SINTERING CHARACTERIZATION OF A IGCC SLAG

    OpenAIRE

    Acosta, Anselmo; Iglesias, Isabel; Aineto, Mónica; Romero, Maximina; Rincón López, Jesús María

    2002-01-01

    IGCC slag is a vitreous residual product from the new induction gasification combined cycle gasification thermal power plants. In order to characterize this waste as secondary new material for the production of new glasses and glass-ceramics as construction materials; this slag from the Puertollano, Ciudad Real, Spain power plants has been fully thermally investigated. After controlled heating this waste gives rise to hematite, anorthite, and cristobalite crystallized materials.

  15. Kemper County IGCC (tm) Project Preliminary Public Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Matt; Rush, Randall; Madden, Diane; Pinkston, Tim; Lunsford, Landon

    2012-07-01

    The Kemper County IGCC Project is an advanced coal technology project that is being developed by Mississippi Power Company (MPC). The project is a lignite-fueled 2-on-1 Integrated Gasification Combined-Cycle (IGCC) facility incorporating the air-blown Transport Integrated Gasification (TRIG™) technology jointly developed by Southern Company; Kellogg, Brown, and Root (KBR); and the United States Department of Energy (DOE) at the Power Systems Development Facility (PSDF) in Wilsonville, Alabama. The estimated nameplate capacity of the plant will be 830 MW with a peak net output capability of 582 MW. As a result of advanced emissions control equipment, the facility will produce marketable byproducts of ammonia, sulfuric acid, and carbon dioxide. 65 percent of the carbon dioxide (CO{sub 2}) will be captured and used for enhanced oil recovery (EOR), making the Kemper County facility’s carbon emissions comparable to those of a natural-gas-fired combined cycle power plant. The commercial operation date (COD) of the Kemper County IGCC plant will be May 2014. This report describes the basic design and function of the plant as determined at the end of the Front End Engineering Design (FEED) phase of the project.

  16. A single IGCC design for variable CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, L.F.; Griffiths, J.; Wainwright, J.M. [Chevron Texaco Worldwide Power and Gasification, Houston, TX (United States)

    2002-07-01

    Global warming and the production of greenhouse gases (GHG) have become an important issue in many countries around the world. While there has been a heightened sense of awareness that the combustion of fossil fuels produces the majority of the controllable carbon dioxide released to the atmosphere, there have been few substantive solutions that produce economically realistic solutions. Moreover, some fossil fuels, like coal, are viewed negatively due to their relatively high carbon content per Btu. Integrated Gasification Combined Cycle (IGCC) offers the option of a realistic, economically viable solution for reducing, by pre-combustion capture, significant amounts of CO{sub 2} while using existing commercially proven technologies. The novel IGCC flowscheme is designed so that the power plant can be built and operated without CO{sub 2} removal and later upgraded to low CO{sub 2} emissions at minimal additional cost. The novel flowscheme is based on commercially proven technology using processes that are in operation today. Overall performance and capital cost estimates are presented and two other possible applications of the novel flowscheme are discussed in this paper. 17 refs., 3 figs., 2 tabs.

  17. Economic evaluation of pre-combustion CO2-capture in IGCC power plants by porous ceramic membranes

    International Nuclear Information System (INIS)

    Franz, Johannes; Maas, Pascal; Scherer, Viktor

    2014-01-01

    Highlights: • Process simulations of IGCC with pre-combustion capture via membranes were done. • Most promising technology is the water–gas-shift-membrane-reactor (WGSMR). • Energetic evaluations showed minimum efficiency loss of 5.8%-points for WGSMR. • Economic evaluations identified boundary limits of membrane technology. • Cost of electricity for optimum WGSMR-case is 57 €/MW h under made assumptions. - Abstract: Pre-combustion-carbon-capture is one of the three main routes for the mitigation of CO 2 -emissions by fossil fueled power plants. Based on the data of a detailed technical evaluation of CO 2 -capture by porous ceramic membranes (CM) and ceramic membrane reactors (WGSMR) in an Integrated-Gasification-Combined-Cycle (IGCC) power plant this paper focuses on the economic effects of CO 2 -abatement. First the results of the process simulations are presented briefly. The analysis is based on a comparison with a reference IGCC without CO 2 -capture (dry syngas cooling, bituminous coal, efficiency of 47.4%). In addition, as a second reference, an IGCC process with CO 2 removal based on standard Selexol-scrubbing is taken into account. The most promising technology for CO 2 -capture by membranes in IGCC applications is the combination of a water gas shift reactor and a H 2 -selective membrane into one water gas shift membrane reactor. For the WGSRM-case efficiency losses can be limited to about 6%-points (including losses for CO 2 compression) for a CO 2 separation degree of 90%. This is a severe reduction of the efficiency loss compared to Selexol (10.3% points) or IGCC–CM (8.6% points). The economic evaluation is based on a detailed analysis of investment and operational costs. Parameters like membrane costs and lifetime, costs of CO 2 -certificates and annual operating hours are taken into account. The purpose of these evaluations is to identify the minimum cost of electricity for the different capture cases for the variation of the boundary

  18. Technical and economic assessments commercial success for IGCC technology in China

    International Nuclear Information System (INIS)

    Xiong, T.

    1998-01-01

    The experiences gained from several Integrated Gasification Combined Cycle (IGCC) demonstration plants operating in the US and Europe facilitate commercial success of this advanced coal-based power generation technology. However, commercialization of coal-based IGCC technology in the West, particularly in the US, is restricted due to the low price of natural gas. On the contrary, in China--the largest coal producer and consumer in the world--a lack of natural gas supply, strong demand for air pollution control and relatively low costs of manufacturing and construction provide tremendous opportunities for IGCC applications. The first Chinese IGCC demonstration project was initiated in 1994, and other potential IGCC projects are in planning. IGCC applications in re-powering, fuel switching and multi-generation also show a great market potential in China. However, questions for IGCC development in China remain; where are realistic opportunities for IGCC projects and how can these opportunities be converted into commercial success? The answers to these questions should focus on the Chinese market needs and emphasize economic benefits, not just clean, or power. High price of imported equipment, high financing costs, and the technical risk of first-of-a-kind installation barricade IGCC development in China. This paper presents preliminary technical and economic assessments for four typical IGCC applications in the Chinese marketplace: central power station, fuel switching, re-powering, and multi-generation. The major factors affecting project economics--such as plant cost, financing, prices of fuel and electricity and operating capacity factor--are analyzed. The results indicate that well-proven technology for versatile applications, preferred financing, reduction of the plant cost, environmental superiority and appropriate project structure are the key for commercial success of IGCC in China

  19. RWE clean coal programme - IGCC power plant with CO{sub 2} capture & storage

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, K.-J.; Ewers, J.; Renzenbrink, W. [RWE Power AG, Essen (Germany)

    2007-07-01

    In early 2006, RWE Power announced it was building a 450 MW gross commercial IGCC power plant with carbon capture. This paper sums up the key results of the project development phase concerning the IGCC power plant and shows the basis for the feasibility phase of the project. 10 figs.

  20. Developments in the pre-combustion CO2 capture pilot plant at the Buggenum IGCC

    NARCIS (Netherlands)

    Damen, K.; Gnutek, R.; Kaptein, J.; Nannan, N.R.; Oyarzun, B.; Trapp, C.; Colonna, P.; Van Dijk, E.; Gross, J.; Bardow, A.

    2011-01-01

    N.V. Nuon (part of the Vattenfall Group) operates an IGCC in Buggenum and is developing a multi-fuel IGCC with CO2 capture and storage (Nuon Magnum) in Eemshaven, the Netherlands. In order to prepare for large-scale application of CO2 capture and storage, a CO2 capture pilot plant is constructed at

  1. Environmental Performance of Hypothetical Canadian Pre-Combustion Carbon Dioxide Capture Processes Using Life-Cycle Techniques

    Directory of Open Access Journals (Sweden)

    Lakkana Piewkhaow

    2016-03-01

    Full Text Available The methodology of life-cycle assessment was applied in order to evaluate the environmental performance of a hypothetical Saskatchewan lignite-fueled Integrated Gasification Combined Cycle (IGCC electricity generation, with and without pre-combustion carbon dioxide (CO2 capture from a full life-cycle perspective. The emphasis here is placed on environmental performance associated with air contaminants of the comparison between IGCC systems (with and without CO2 capture and a competing lignite pulverized coal-fired electricity generating station in order to reveal which technology offers the most positive environmental effects. Moreover, ambient air pollutant modeling was also conducted by using American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD air dispersion modeling to determine the ground-level concentration of pollutants emitted from four different electricity generating stations. This study assumes that all stations are located close to Estevan. The results showed a significant reduction in greenhouse gas (GHG emissions and acidification potential by applying both post-combustion and pre-combustion CO2 capture processes. The GHG emissions were found to have reduced by 27%–86%, and IGCC systems were found to compare favorably to pulverized coal systems. However, in other environmental impact categories, there are multiple environmental trade-offs depending on the capture technology used. In the case of post-combustion capture, it was observed that the environmental impact category of eutrophication potential, summer smog, and ozone depletion increased due to the application of the CO2 capture process and the surface mining coal operation. IGCC systems, on the other hand, showed the same tendency as the conventional coal-fired electricity generation systems, but to a lesser degree. This is because the IGCC system is a cleaner technology that produces lower pollutant emission levels than the electricity

  2. Pre-Combustion Capture of CO2 in IGCC Plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-12-15

    Pre-combustion capture involves reacting a fuel with oxygen or air and/or steam to give mainly a 'synthesis gas (syngas)' or 'fuel gas' composed of carbon monoxide and hydrogen. The carbon monoxide is reacted with steam in a catalytic reactor, called a shift converter, to produce CO2 and more hydrogen. CO2 is then separated, usually by a physical or chemical absorption process, resulting in a hydrogen-rich fuel which can be used in many applications, such as boilers, furnaces, gas turbines, engines and fuel cells. Pre-combustion capture is suitable for use in integrated gasification combined cycle (IGCC) plants especially since the CO2 partial pressures in the fuel gas are higher than in the flue gas. After the introduction there follows a short discussion of the water-gas shift (WGS) reaction. This is followed by chapters on the means of CO2 capture by physical and chemical solvents, solid sorbents, and membranes. The results and conclusions of techno-economic studies are introduced followed by a look at some of the pilot and demonstration plants relevant to pre-combustion capture in IGCC plants.

  3. ConocoPhillips Sweeny IGCC/CCS Project

    Energy Technology Data Exchange (ETDEWEB)

    Paul Talarico; Charles Sugg; Thomas Hren; Lauri Branch; Joseph Garcia; Alan Rezigh; Michelle Pittenger; Kathleen Bower; Jonathan Philley; Michael Culligan; Jeremy Maslen; Michele Woods; Kevin Elm

    2010-06-16

    Under its Industrial Carbon Capture and Sequestration (ICCS) Program, the United States (U.S.) Department of Energy (DOE) selected ConocoPhillips Company (ConocoPhillips) to receive funding through the American Recovery and Reinvestment Act (ARRA) of 2009 for the proposed Sweeny Integrated Gasification Combined Cycle (IGCC)/Carbon Capture and Storage (CCS) Project (Project) to be located in Brazoria County, Texas. Under the program, the DOE is partnering with industry to demonstrate the commercial viability and operational readiness of technologies that would capture carbon dioxide (CO{sub 2}) emissions from industrial sources and either sequester those emissions, or beneficially reuse them. The primary objective of the proposed Project was to demonstrate the efficacy of advanced technologies that capture CO{sub 2} from a large industrial source and store the CO{sub 2} in underground formations, while achieving a successful business venture for the entity (entities) involved. The Project would capture 85% of the CO{sub 2} produced from a petroleum coke (petcoke) fed, 703 MWnet (1,000 MWgross) IGCC power plant, using the ConocoPhillips (COP) proprietary and commercially proven E-Gas{trademark} gasification technology, at the existing 247,000 barrel per day COP Sweeny Refinery. In addition, a number of other commercially available technologies would be integrated into a conventional IGCC Plant in a unique, efficient, and reliable design that would capture CO{sub 2}. The primary destination for the CO{sub 2} would be a depleted natural gas field suitable for CO{sub 2} storage ('Storage Facility'). COP would also develop commercial options to sell a portion of the IGCC Plant's CO{sub 2} output to the growing Gulf Coast enhanced oil recovery (EOR) market. The IGCC Plant would produce electric power for sale in the Electric Reliability Council of Texas Houston Zone. The existing refinery effluent water would be treated and reused to fulfill all process

  4. Integrated assessment of IGCC power generation technology with carbon capture and storage (CCS)

    International Nuclear Information System (INIS)

    Cormos, Calin-Cristian

    2012-01-01

    IGCC (Integrated Gasification Combined Cycle) is a power generation technology in which the solid feedstock is partially oxidized with oxygen and steam to produce syngas. In a conventional IGCC design without carbon capture, the syngas is purified for dust and hydrogen sulphide removal and then it is sent to a CCGT (Combined Cycle Gas Turbine) for power generation. CCS (Carbon capture and storage) technologies are expected to play a significant role in the coming decades for reducing the greenhouse gas emissions. IGCC is one of the power generation technologies having the highest potential to capture CO 2 with low penalties in term of plant energy efficiency, capital and operational costs. This paper investigates the most important techno-economic and environmental indicators (e.g. power output, ancillary consumption, energy efficiency, CW consumption, normalised mass and energy balances and plant construction materials, capital and O and M (operational and maintenance) costs, specific CO 2 emissions, cost of electricity, CO 2 removal and avoidance costs etc.) for IGCC with CCS. Coal-based IGCC cases produce around 400–450 MW net electricity with 90% carbon capture rate. Similar IGCC plants without CCS were presented as references. Future IGCC developments for energy vectors poly-generation were also presented. -- Highlights: ► Techno-economical evaluations of coal-based IGCC power generation with CCS. ► Model development for capital, O and M, CO 2 capture costs and cash flow estimations. ► Technical and economic investigations of key plant design characteristics. ► Evaluations of carbon capture options for IGCC power generation technology.

  5. CO{sub 2}-capture in coal based IGCC power plants

    Energy Technology Data Exchange (ETDEWEB)

    Van Aart, F.; Fleuren, W.; Kamphuis, H.; Ploumen, P.; Jelles, S. [KEMA, Arnhem (Netherlands)

    2007-07-01

    The paper discusses IGCC with carbon capture and storage (CCS), both for retrofit and capture ready plants. The penalties for carbon dioxide capture are given, along with its effect on CAPEX and OPEC costs. 3 refs., 9 figs.

  6. Recycling of residual IGCC slags and their benefits as degreasers in ceramics.

    Science.gov (United States)

    Iglesias Martín, I; Acosta Echeverría, A; García-Romero, E

    2013-11-15

    This work studies the evolution of IGCC slag grains within a ceramic matrix fired at different temperatures to investigate the effect of using IGCC slag as a degreaser. Pressed ceramic specimens from two clay mixtures are used in this study. The M1 mixture is composed of standard clays, whereas the M2 mixture is composed of the same clay mixture as M1 mixture but contains 15% by weight IGCC slag. The amount of IGCC slag added coincides with the amount of slag typically used as a degreaser in the ceramic industry. Specimens are fired at 950 °C, 1000 °C, 1050 °C, 1100 °C and 1150 °C. The mineralogical composition and the IGCC slag grain shape within the ceramic matrix are determined by X-ray diffraction, polarized light microscopy and scanning electron microscopy. The results reveal that the surface of the slag grains is welded to the ceramic matrix while the quartz grains are separated, which causes increased water absorption and reduces the mechanical strength. IGCC slag, however, reduces water absorption. This behaviour is due to the softening temperature of the slag. This property is quite important from an industrial viewpoint because IGCC slag can serve as an alternative to traditional degreasing agents in the ceramic building industry. Additionally, using IGCC slag allows for the transformation of waste into a secondary raw material, thereby avoiding disposal at landfills; moreover, these industrial wastes are made inert and improve the properties of ceramics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Dynamic simulation of operating cases and malfunctions of an IGCC power plant system

    Energy Technology Data Exchange (ETDEWEB)

    Koch, I.; Hannemann, F. [Siemens AG, Power Generation (KWU), Erlangen (Germany); Hoffmann, U. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Chemische Verfahrenstechnik

    1999-07-01

    Fully integrated IGCC plants consist of several units. This novel integration of various plant systems places stiff new requirements on power plant design, as prediction of operating and faulted behavior is made more difficult by many different interactions. This is especially the case for the gas turbine fuel system in an IGCC power plant, as it affects and is affected by all of the other major plant systems. (orig.)

  8. Medicare Managed Care plan Performance, A Comparison...

    Data.gov (United States)

    U.S. Department of Health & Human Services — The study evaluates the performance of Medicare managed care, Medicare Advantage, Plans in comparison to Medicare fee-for-service Plans in three states with...

  9. Model Based Optimal Sensor Network Design for Condition Monitoring in an IGCC Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajeeva; Kumar, Aditya; Dai, Dan; Seenumani, Gayathri; Down, John; Lopez, Rodrigo

    2012-12-31

    This report summarizes the achievements and final results of this program. The objective of this program is to develop a general model-based sensor network design methodology and tools to address key issues in the design of an optimal sensor network configuration: the type, location and number of sensors used in a network, for online condition monitoring. In particular, the focus in this work is to develop software tools for optimal sensor placement (OSP) and use these tools to design optimal sensor network configuration for online condition monitoring of gasifier refractory wear and radiant syngas cooler (RSC) fouling. The methodology developed will be applicable to sensing system design for online condition monitoring for broad range of applications. The overall approach consists of (i) defining condition monitoring requirement in terms of OSP and mapping these requirements in mathematical terms for OSP algorithm, (ii) analyzing trade-off of alternate OSP algorithms, down selecting the most relevant ones and developing them for IGCC applications (iii) enhancing the gasifier and RSC models as required by OSP algorithms, (iv) applying the developed OSP algorithm to design the optimal sensor network required for the condition monitoring of an IGCC gasifier refractory and RSC fouling. Two key requirements for OSP for condition monitoring are desired precision for the monitoring variables (e.g. refractory wear) and reliability of the proposed sensor network in the presence of expected sensor failures. The OSP problem is naturally posed within a Kalman filtering approach as an integer programming problem where the key requirements of precision and reliability are imposed as constraints. The optimization is performed over the overall network cost. Based on extensive literature survey two formulations were identified as being relevant to OSP for condition monitoring; one based on LMI formulation and the other being standard INLP formulation. Various algorithms to solve

  10. Feasibility studies to improve plant availability and reduce total installed cost in IGCC plants

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Kevin [General Electric Company, Houston, TX (United States); Anasti, William [General Electric Company, Houston, TX (United States); Fang, Yichuan [General Electric Company, Houston, TX (United States); Subramanyan, Karthik [General Electric Company, Houston, TX (United States); Leininger, Tom [General Electric Company, Houston, TX (United States); Zemsky, Christine [General Electric Company, Houston, TX (United States)

    2015-03-30

    The main purpose of this project is to look at technologies and philosophies that would help reduce the costs of an Integrated Gasification Combined Cycle (IGCC) plant, increase its availability or do both. GE’s approach to this problem is to consider options in three different areas: 1) technology evaluations and development; 2) constructability approaches; and 3) design and operation methodologies. Five separate tasks were identified that fall under the three areas: Task 2 – Integrated Operations Philosophy; Task 3 – Slip Forming of IGCC Components; Task 4 – Modularization of IGCC Components; Task 5 – Fouling Removal; and Task 6 – Improved Slag Handling. Overall, this project produced results on many fronts. Some of the ideas could be utilized immediately by those seeking to build an IGCC plant in the near future. These include the considerations from the Integrated Operations Philosophy task and the different construction techniques of Slip Forming and Modularization (especially if the proposed site is in a remote location or has a lack of a skilled workforce). Other results include ideas for promising technologies that require further development and testing to realize their full potential and be available for commercial operation. In both areas GE considers this project to be a success in identifying areas outside the core IGCC plant systems that are ripe for cost reduction and ity improvement opportunities.

  11. [On comparison of hospital performance].

    Science.gov (United States)

    Kjekshus, L E

    2000-10-20

    The motivation to identify the causes of rising health care cost and variations across providers has intensified in all industrialized countries. These countries have an ongoing debate on efficiency and effectiveness in hospital production. In this debate, national and international comparative studies are important. There are very few international comparative studies that include Norwegian hospitals. Actually we know very little about how Norwegian hospitals are performing compared to others. This paper gives an introduction to comparative studies and to the DEA model which is often used in such studies and also a multilevel model which is not so common. A short review is given of a comparative study of Norwegian and North American hospitals. I also discuss the feasibility of comparative studies of hospitals from the Nordic countries, with references to several comparative studies performed in these countries. Comparative studies are often closely linked to national health politics, policy making and reforms; thus the outcome of such studies is important for the hospitals included. This makes such studies a sensitive field of research. It is important to be aware of the strength and weaknesses of comparative studies and acknowledge their importance beyond the development of new knowledge.

  12. Recovery of flue gas energy in heat-integrated gasification combined cycle (IGCC) power plants using the contact economizer system

    CSIR Research Space (South Africa)

    Madzivhandila, VA

    2011-03-01

    Full Text Available (flue gas) stream of a heat-integrated gasification combined cycle (IGCC) design of the Elcogas plant adopted from previous studies. The underlying support for this idea was the direct relationship between efficiency of the IGCC and the boiler feedwater...

  13. Briefing Book, Interagency Geothermal Coordinating Council (IGCC) Meeting of April 28, 1988

    Energy Technology Data Exchange (ETDEWEB)

    None

    1988-04-28

    The IGCC of the U.S. government was created under the intent of Public Law 93-410 (1974) to serve as a forum for the discussion of Federal plans, activities, and policies that are related to or impact on geothermal energy. Eight Federal Departments were represented on the IGCC at the time of this meeting. The main presentations in this report were on: Department of Energy Geothermal R&D Program, the Ormat binary power plant at East Mesa, CA, Potential for direct use of geothermal at Defense bases in U.S. and overseas, Department of Defense Geothermal Program at China Lake, and Status of the U.S. Geothermal Industry. The IGCC briefing books and minutes provide a historical snapshot of what development and impact issues were important at various time. (DJE 2005)

  14. Comprehensive report to Congress, Clean Coal Technology program: Pinon Pine IGCC Power Project

    International Nuclear Information System (INIS)

    1992-06-01

    The objective of the proposed project is to demonstrate an advanced IGCC system based upon the air-blown, fluidized-bed KRW gasifier with in-bed desulfurization using limestone sorbent and an external fixed- bed zinc ferrite sulfur removal system. Sierra Pacific Power Company (SPPC) requested financial assistance from DOE for the design, construction, and operation of a nominal 800 ton-per-day (86-Megawatt gross), air blown integrated gasification combined-cycle (IGCC) demonstration plant. The project, named the Pinon Pine IGCC Power Project, is to be located at SPPC's Tracy Station, a power generation facility located on a rural 400-acre plot about 17 miles east of Reno. The demonstration plant will produce electrical power for the utility grid. The project, including the demonstration phase, will last 96 months at a total cost of $269,993,100. DOE's share of the project cost will be 50 percent, or $134,996,550

  15. Assessment of oxy-fuel, pre- and post-combustion-based carbon capture for future IGCC plants

    International Nuclear Information System (INIS)

    Kunze, Christian; Spliethoff, Hartmut

    2012-01-01

    Highlights: ► Hot gas cleanup is a highly favorable technology for all selected IGCC concepts. ► Proposed high pressure IGCC with membrane reactor enables direct CO 2 condensation. ► IGCC with OTM and carbonate looping enable significant synergy effects. ► Combining IGCC and oxy-fuel is technically challenging but energetically favorable. ► All selected IGCC concepts are able to realize CO 2 capture rates up to 99%. -- Abstract: Environmental damage due to the emission of greenhouse gases from conventional coal-based power plants is a growing concern. Various carbon capture strategies to minimize CO 2 emissions are currently being investigated. Unfortunately, the efficiency drop due to de-carbonization is still significant and the capture rate is limited. Therefore three future hard coal IGCC concepts are assessed here, applying emerging technologies and various carbon capture approaches. The advanced pre-combustion capture concept is based on hot gas clean-up, membrane-enhanced CO conversion and direct CO 2 condensation. The concept reached a net efficiency of 45.1% (LHV), representing an improvement of 6.46% compared to the conventional IGCC base case. The second IGCC concept, based on post-combustion capture via calcination–carbonation loops, hot gas clean-up and oxygen membranes, showed a net efficiency of 45.87% (LHV). The third IGCC concept applies hot gas clean-up and combustion of the unconverted fuel gas using pure oxygen. The oxygen is supplied by an integrated oxygen membrane. The combination of IGCC and oxy-fuel process reached a net efficiency of 45.74% (LHV). In addition to their increased efficiency, all of the concepts showed significantly improved carbon capture rates up to 99%, resulting in virtually carbon-free fossil power plants.

  16. Recovery of flue gas energy in heat integrated IGCC power plants using the contact economizer system

    CSIR Research Space (South Africa)

    Madzivhandila, V

    2010-10-01

    Full Text Available Asia Pacific Confederation of APCChE 2010 Chemical Engineering Congress October 5-8, 2010, Taipei � �� Recovery of flue gas energy in heat integrated IGCC power plants using the contact economizer system Vhutshilo Madzivhandilaa, Thokozani... temperature and the thermal efficiency of the plant. The 13th Asia Pacific Confederation of APCChE 2010 Chemical Engineering Congress October 5-8, 2010, Taipei � �� 1. Introduction The IGCC (Integrated Gasification Combined Cycle) is one...

  17. Questionnaire regarding the international Freiberg conference on IGCC and XtL technologies. Analysis of 75 questionnaires

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The Puertollano IGCC Plant, owned by ELCOGAS, uses a mixture (50/50% weight) of local coal with high content of ash (approximately 45%) and pet-coke to be fed into its pressurised entrained flow gasifier. Ash is removed from the bottom of the gasifier as vitrified slag although a fraction is converted into fly ash (2.5-3 t/h) and entrained by the syngas. In order to remove this fly ash, it is filtered in two candle filter vessels with more than 1,000 candles each, using nitrogen for on-line cleaning. The filtering system suffers some malfunctions resulting in blinding of the internal candle surface and increasing of the candle DP. The model of candle filter was changed and modifications were performed without the desired results. Therefore, the identification of suitable hot gas filtration technologies capable of overcoming current and future severe operational constraints experienced is of the utmost importance for IGCC units. In this sense, a pilot plant which allows the performance of alternative filtering elements tests, pulse cleaning strategies, on-line particulate monitoring and off-cleaning procedures has come into operation at the ESI-University of Seville facilities. The design has been conceived as a versatile pilot unit, in order to hold both bags and ceramic candles which are to be tested in a wide range of operating conditions. The pilot is processing air laden with real fly ash provided by ELCOGAS, and high pressure nitrogen for the cleaning operation. This paper describes the design and operation of the pilot as well as the testing plan currently being carried out. (orig.)

  18. Multi-fuel multi-product operation of IGCC power plants with carbon capture and storage (CCS)

    International Nuclear Information System (INIS)

    Cormos, Ana-Maria; Dinca, Cristian; Cormos, Calin-Cristian

    2015-01-01

    This paper investigates multi-fuel multi-product operation of IGCC plants with carbon capture and storage (CCS). The investigated plant designs co-process coal with different sorts of biomass (e.g. sawdust) and solid wastes, through gasification, leading to different decarbonised energy vectors (power, hydrogen, heat, substitute natural gas etc.) simultaneous with carbon capture. Co-gasification of coal with different renewable energy sources coupled with carbon capture will pave the way towards zero emissions power plants. The energy conversions investigated in the paper were simulated using commercial process flow modelling package (ChemCAD) in order to produce mass and energy balances necessary for the proposed evaluation. As illustrative cases, hydrogen and power co-generation and Fischer–Tropsch fuel synthesis (both with carbon capture), were presented. The case studies investigated in the paper produce a flexible ratio between power and hydrogen (in the range of 400–600 MW net electricity and 0–200 MW th hydrogen considering the lower heating value) with at least 90% carbon capture rate. Special emphasis were given to fuel selection criteria for optimisation of gasification performances (fuel blending), to the selection criteria for gasification reactor in a multi-fuel multi-product operation scenario, modelling and simulation of whole process, to thermal and power integration of processes, flexibility analysis of the energy conversion processes, in-depth techno-economic and environmental assessment etc. - Highlights: • Assessment of IGCC-based energy vectors poly-generation systems with CCS. • Optimisation of gasification performances and CO 2 emissions by fuel blending. • Multi-fuel multi-product operation of gasification plants

  19. Tampa electric company - IGCC project. Quarterly report, January 1, 1996--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This quarterly report consists of materials presented at a recent review of the project. The project is an IGCC project being conducted by Tampa Electric Company. The report describes the status of the facility construction, components, operations staff training, and discusses aspects of the project which may impact the final scheduled completion.

  20. Puertollano IGCC Power Plant; Central de Gasificacion Integrada en Ciclo Combinado de Puertollano

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The Puertollano IGCC Power Plant, rated 335 MW and located in Puertollano, Ciudad Real, in the central area of Spain, is a project led by ELCOGAS, a company incorporated by the European utilities ENDESA, ELECTRICITE DE FRANCE, IBERDROLA HIDROCANTABRICO ELECTRICIDADE DE PURTUGAL, ENEL and NATIONAL POWER and the technology and equipment suppliers SIEMENS, KRUPP UHDE and BABCOCK WILCOX ESPANOLA. IGCC technology is based in a process of coal gasification to obtain a clean combustion synthetic gas, integrated with a combined cycle, agas and steam, electricity-generating unit. The energy efficiency which is aimed to achieve at the Plant is 46% in ISO conditions. The Gasification unit uses the process of pressurised entrained flow for coal gasification. The gas is produced by the reaction of coal with oxygen at high temperatures, of up to 1600 degree centigree. This process is capable of gasifying a wide variety of types and qualities of coal for the production of a synthetic fuel gas. In the case of Puertollano, the raw fuel is a 50% mixture by weight of local coal and petroleum coke. The oxygen needed in the process and the nitrogen used for covering the fuel is generated in the Air Separation. The Gas Cleaning and Sulphur Recovery Unit clean the gases from contaminants and solid particles before to send them to the Gas Turbine. The clean gas is burnt in gas turbine of the Combined Cycle Plant, producing electricity. The exhaust gases feed a heat recovery steam generator, which produces steam used to generate additional electricity in a conventional steam turbine. The gas turbine is capable of operating both with synthetic gas and with natural gas, allowing operation flexibility. The net output of the plant up to December 1999 was 3.061 GWh, from them 344 GWh were produced with synthetic gas. This project has an important technological value, being the first power plant which uses coal gasification to feed a combined cycle in Spain and being also the biggest power plant

  1. Unconventional Coal in Wyoming: IGCC and Gasification of Direct Coal Liquefaction Residue

    Science.gov (United States)

    Schaffers, William Clemens

    Two unconventional uses for Wyoming Powder River Basin coal were investigated in this study. The first was the use of coal fired integrated gasification combined cycle (IGCC) plants to generate electricity. Twenty-eight different scenarios were modeled using AspenPlusRTM software. These included slurry, mechanical and dried fed gasifiers; Wyodak and Green River coals, 0%, 70%, and 90% CO2 capture; and conventional evaporative vs air cooling. All of the models were constructed on a feed basis of 6,900 tons of coal per day on an "as received basis". The AspenPlus RTM results were then used to create economic models using Microsoft RTM Excel for each configuration. These models assumed a 3 year construction period and a 30 year plant life. Results for capital and operating costs, yearly income, and internal rates of return (IRR) were compared. In addition, the scenarios were evaluated to compare electricity sales prices required to obtain a 12% IRR and to determine the effects of a carbon emissions tax on the sales price. The second part of the study investigated the gasification potential of residue remaining from solvent extraction or liquefaction of Powder River Basin Coal. Coal samples from the Decker mine on the Wyoming-Montana border were extracted with tetralin at a temperature of 360°C and pressure of 250 psi. Residue from the extraction was gasified with CO2 or steam at 833°C, 900°C and 975°C at pressures of 0.1 and 0.4 MPa. Product gases were analyzed with a mass spectrometer. Results were used to determine activation energies, reaction order, reaction rates and diffusion effects. Surface area and electron microscopic analyses were also performed on char produced from the solvent extraction residue.

  2. Development of ITM oxygen technology for integration in IGCC and other advanced power generation

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Phillip A. [Air Products And Chemicals, Inc., Allentown, PA (United States)

    2015-03-31

    Ion Transport Membrane (ITM) technology is based on the oxygen-ion-conducting properties of certain mixed-metal oxide ceramic materials that can separate oxygen from an oxygen-containing gas, such as air, under a suitable driving force. The “ITM Oxygen” air separation system that results from the use of such ceramic membranes produces a hot, pure oxygen stream and a hot, pressurized, oxygen-depleted stream from which significant amounts of energy can be extracted. Accordingly, the technology integrates well with other high-temperature processes, including power generation. Air Products and Chemicals, Inc., the Recipient, in conjunction with a dozen subcontractors, developed ITM Oxygen technology under this five-phase Cooperative Agreement from the laboratory bench scale to implementation in a pilot plant capable of producing power and 100 tons per day (TPD) of purified oxygen. A commercial-scale membrane module manufacturing facility (the “CerFab”), sized to support a conceptual 2000 TPD ITM Oxygen Development Facility (ODF), was also established and operated under this Agreement. In the course of this work, the team developed prototype ceramic production processes and a robust planar ceramic membrane architecture based on a novel ceramic compound capable of high oxygen fluxes. The concept and feasibility of the technology was thoroughly established through laboratory pilot-scale operations testing commercial-scale membrane modules run under industrial operating conditions with compelling lifetime and reliability performance that supported further scale-up. Auxiliary systems, including contaminant mitigation, process controls, heat exchange, turbo-machinery, combustion, and membrane pressure vessels were extensively investigated and developed. The Recipient and subcontractors developed efficient process cycles that co-produce oxygen and power based on compact, low-cost ITMs. Process economics assessments show significant benefits relative to state

  3. Comparison of energy performance requirements levels

    DEFF Research Database (Denmark)

    Spiekman, Marleen; Thomsen, Kirsten Engelund; Rose, Jørgen

    This summary report provides a synthesis of the work within the EU SAVE project ASIEPI on developing a method to compare the energy performance (EP) requirement levels among the countries of Europe. Comparing EP requirement levels constitutes a major challenge. From the comparison of for instance...... the present Dutch requirement level (EPC) of 0,8 with the present Flemish level of E80, it can easily be seen that direct comparison is not possible. The conclusions and recommendations of the study are presented in part A. These constitute the most important result of the project. Part B gives an overview...... of all other project material related to that topic, which allows to easily identify the most pertinent information. Part C lists the project partners and sponsors....

  4. Aerodynamics and Heat Transfer Studies of Parameters Specific to the IGCC-Requirements: Endwall Contouring, Leading Edge and Blade Tip Ejection under Rotating Turbine Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schobeiri, Meinhard; Han, Je-Chin

    2014-09-30

    This report deals with the specific aerodynamics and heat transfer problematic inherent to high pressure (HP) turbine sections of IGCC-gas turbines. Issues of primary relevance to a turbine stage operating in an IGCC-environment are: (1) decreasing the strength of the secondary flow vortices at the hub and tip regions to reduce (a), the secondary flow losses and (b), the potential for end wall deposition, erosion and corrosion due to secondary flow driven migration of gas flow particles to the hub and tip regions, (2) providing a robust film cooling technology at the hub and that sustains high cooling effectiveness less sensitive to deposition, (3) investigating the impact of blade tip geometry on film cooling effectiveness. The document includes numerical and experimental investigations of above issues. The experimental investigations were performed in the three-stage multi-purpose turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A&M University. For the numerical investigations a commercial Navier-Stokes solver was utilized.

  5. IGCC and PFBC By-Products: Generation, Characteristics, and Management Practices

    Energy Technology Data Exchange (ETDEWEB)

    Pflughoeft-Hassett, D.F.

    1997-09-01

    The following report is a compilation of data on by-products/wastes from clean coal technologies, specifically integrated gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC). DOE had two objectives in providing this information to EPA: (1) to familiarize EPA with the DOE CCT program, CCT by-products, and the associated efforts by DOE contractors in the area of CCT by-product management and (2) to provide information that will facilitate EPA's effort by complementing similar reports from industry groups, including CIBO (Council of Industrial Boiler Owners) and EEI USWAG (Edison Electric Institute Utility Solid Waste Activities Group). The EERC cooperated and coordinated with DOE CCT contractors and industry groups to provide the most accurate and complete data on IGCC and PFBC by-products, although these technologies are only now being demonstrated on the commercial scale through the DOE CCT program.

  6. Dynamic simulation of a low-temperature rectification Column as part of an IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Hanke, R. [Leipzig University of Applied Sciences, Department of Mechanical and Energy Engineering, P.O. Box 300066, D-04251 Leipzig (Germany); Hannemann, F. [Siemens AG - Power Generation, PG CTET, P.O. Box 3220, D-91050 Erlangen (Germany); Sundmacher, K. [Max Planck Institute of Dynamics of Complex Technical Systems, Sandtorstrasse 1, D-39106 Magdeburg (Germany); Otto-von-Guericke University Magdeburg, Faculty of Process and Systems Engineering, P.O. Box 4120, D-39106 Magdeburg (Germany)

    2003-11-01

    IGCC plants offer the opportunity to utilize fossil energy sources, like coal or heavy refinery residues, to satisfy increasing energy demand while considering strict environmental constraints. Such a plant consists of a combined power cycle, a fuel gasifier with downstream fuel gas conditioning and an air separation unit (ASU), where the oxygen required for gasification is produced. The low-temperature rectification column as the core of the ASU strongly affects the transient behavior of the system. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  7. Novel findings about management of gastric cancer: A summary from 10th IGCC

    OpenAIRE

    Penon, Danila; Cito, Letizia; Giordano, Antonio

    2014-01-01

    The Tenth International Gastric Cancer Congress (IGCC) was held in Verona, Italy, from June 19 to 22, 2013. The meeting enclosed various aspects of stomach tumor management, including both tightly clinical approaches, and topics more related to basic research. Moreover, an overview on gastrointestinal stromal tumors was provided too, although here not discussed. Here we will discuss some topics related to molecular biology of gastric cancer (GC), inherent to prognostic, diagnostic and therape...

  8. The installation IGCC power plans in the petroleum refinement: international experiences and lessons for Mexico; La instalacion de plantas IGCC en la refinacion de petroleo: experiencias internacionales y lecciones para Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Joel [Ecole du Petrole et des Moteurs, Institut Franzais du Petrole, (France)

    2004-06-15

    In this work, are presented the technical and economic elements of the international experience for the installation of IGCC power plants in the petroleum refinement and the lessons for Mexico in the installation of this technology in PEMEX Refinacion are analyzed. The construction of IGCC power plants in the petroleum refinement has grown 14.3 % at worldwide level as of 1996, in which there was already an installed capacity of 160 MW. At the end of 2003 an installed capacity of 2,500 MW was reached. The growth in the installation of IGCC power plants fundamentally appears in Europe, being Italy and Spain leader countries in the construction of this technology in the petroleum refinement. However, countries like Holland, Japan, Singapore and the United States count on IGCC power plants for electricity and hydrogen generation, which take advantage of low value fuels such as vacuum tower residues, petroleum coke, asphalt, liquid fuels, among others. In Mexico, the installation IGCC power plants in the petroleum refinement is null, nevertheless Petroleos Mexicanos counts with the approval of the government for the installation of cogeneration power plants in its facilities. This approval would allow PEMEX to carry out projects for the installation IGCC power plants, specifically in PEMEX Refinacion, for the generation of electricity and hydrogen from the advantage of heavy residues of low economic value. The opportunity that the installation IGCC power plants in the petroleum refinement offers is directed towards the commercialization of the electricity and hydrogen, which would impel PEMEX Refinacion to enter the competition of the electrical market in Mexico. [Spanish] En este trabajo, se presentan los elementos tecnicos y economicos de la experiencia internacional para la instalacion de plantas IGCC en la refinacion de petroleo y se analizan las lecciones para Mexico en la instalacion de esta tecnologia en PEMEX Refinacion. La construccion de plantas IGCC en la

  9. Thermal expansion of slag and fly ash from coal gasification in IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    M. Aineto; A. Acosta; J.M.A. Rincon; M. Romero [University of Castilla La Mancha, Ciudad Real (Spain). Laboratory of Applied Mineralogy

    2006-11-15

    Integrated gasification in combined cycle (IGCC) is an electrical power generation system which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and pressure in reducing atmosphere. Under that conditions, gases such as H{sub 2}, N{sub 2} or CO, which are the main components of the gas mixture in the gasifier, show a high solubility in the melt and during the cooling remain enclosed in the vitreous slag. When these wastes are afterward thermal treated in oxidizing conditions, two phenomena occur. The development of a crystalline phase by devitrification of the glassy matrix and the releasing of the enclosed gas, which starts at temperatures nearly to the softening point. At higher temperatures the bubbles with increasing kinetic energy tend to ascend with difficulty through the viscous liquid phase and promotes an expansive reaction, giving rise to a foam glass-ceramic product. This paper has been focused on the study of thermal expansion in slag and fly ash samples from the ELCOGAS IGCC power plant located in Puertollano (Spain). 18 refs., 11 figs., 1 tab.

  10. Kotka ecopower IGCC-project, the attempt to transfer the biocycle project to Finland

    International Nuclear Information System (INIS)

    Salo, K.

    1998-01-01

    The Danish utilities Elsam and Elkraft planned to build a small (7 MW e ) IGCC-plant in Denmark, called Biocycle Project, based on the gasification and gas clean-up technology of Enviropower Inc. EU/THERMIE program committed to finance part of the investment. The project, however, was not feasible due to the difficulty of finding a suitable customer and sufficient amount of reasonably priced biomass. For this reason a new host and site was found for the Biocycle project. The new site was in Kotka, Finland, where Kotka Energy Ltd., the Energy Board of the City of Kotka acted as the main partner. The fuel of the IGCC project would have been sugar mill wood residue from Xyrofin Inc. During the feasibility investigation (project definition phase) Xyrofin Inc. made the decision to change the production process which eliminated the wood waste production. Without no-cost fuel and due to the low electricity price in Finland the small size IGCC power plant proved not to be feasible. (author)

  11. Design and evaluation of an IGCC power plant using iron-based syngas chemical-looping (SCL) combustion

    International Nuclear Information System (INIS)

    Sorgenfrei, Max; Tsatsaronis, George

    2014-01-01

    Highlights: • A new concept for power generation including carbon capture was found. • The air reactor temperature significantly influences the net efficiency. • The use of a CO 2 turbine decreases the net efficiency. • Compared to a conventional IGCC with 90% CO 2 capture the net efficiency increases. - Abstract: Chemical-looping combustion (CLC) is a novel and promising combustion technology with inherent separation of the greenhouse gas CO 2 . This paper focuses on the design and thermodynamic evaluation of an integrated gasification combined-cycle (IGCC) process using syngas chemical looping (SCL) combustion for generating electricity. The syngas is provided by coal gasification; the gas from the gasifier is cleaned using high-temperature gas desulfurization (HGD). In this study, the oxygen carrier iron oxide (Fe 2 O 3 ) is selected to oxidize the syngas in a multistage moving-bed reactor. The resulting reduced iron particles then consist of FeO and Fe 3 O 4 . To create a closed-cycle operation, these particles are partially re-oxidized with steam in a fluidized-bed regenerator to pure Fe 3 O 4 and then fully re-oxidized in a fluidized-bed air combustor to Fe 2 O 3 . One advantage of this process is the co-production of hydrogen diluted with water vapor within the steam regenerator. Both the HGD and CLC systems are not under commercial operation so far. This mixture is fed to a gas turbine for the purpose of generating electricity. The gas turbine is expected to exhibit low NO x emissions due to the high ratio of water in the combustion chamber. Cooling the flue gas in the HRSG condenses the water vapor to yield high-purity CO 2 for subsequent compression and disposal. To evaluate the net efficiency, two conventional syngas gasifiers are considered, namely the BGL slagging gasifier and the Shell entrained-flow gasifier. The option of using a CO 2 turbine after the SCL-fuel reactor is also investigated. A sensitivity analysis is performed on the SCL

  12. GASIFICATION PLANT COST AND PERFORMANCE OPTIMIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Samuel S. Tam

    2002-05-01

    The goal of this series of design and estimating efforts was to start from the as-built design and actual operating data from the DOE sponsored Wabash River Coal Gasification Repowering Project and to develop optimized designs for several coal and petroleum coke IGCC power and coproduction projects. First, the team developed a design for a grass-roots plant equivalent to the Wabash River Coal Gasification Repowering Project to provide a starting point and a detailed mid-year 2000 cost estimate based on the actual as-built plant design and subsequent modifications (Subtask 1.1). This unoptimized plant has a thermal efficiency of 38.3% (HHV) and a mid-year 2000 EPC cost of 1,681 $/kW. This design was enlarged and modified to become a Petroleum Coke IGCC Coproduction Plant (Subtask 1.2) that produces hydrogen, industrial grade steam, and fuel gas for an adjacent Gulf Coast petroleum refinery in addition to export power. A structured Value Improving Practices (VIP) approach was applied to reduce costs and improve performance. The base case (Subtask 1.3) Optimized Petroleum Coke IGCC Coproduction Plant increased the power output by 16% and reduced the plant cost by 23%. The study looked at several options for gasifier sparing to enhance availability. Subtask 1.9 produced a detailed report on this availability analyses study. The Subtask 1.3 Next Plant, which retains the preferred spare gasification train approach, only reduced the cost by about 21%, but it has the highest availability (94.6%) and produces power at 30 $/MW-hr (at a 12% ROI). Thus, such a coke-fueled IGCC coproduction plant could fill a near term niche market. In all cases, the emissions performance of these plants is superior to the Wabash River project. Subtasks 1.5A and B developed designs for single-train coal and coke-fueled power plants. This side-by-side comparison of these plants, which contain the Subtask 1.3 VIP enhancements, showed their similarity both in design and cost (1,318 $/kW for the

  13. The role of IGCC technology in power generation using low-rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Juangjandee, Pipat

    2010-09-15

    Based on basic test results on the gasification rate of Mae Moh lignite coal. It was found that an IDGCC power plant is the most suitable for Mae Moh lignite. In conclusion, the future of an IDGCC power plant using low-rank coal in Mae Moh mine would hinge on the strictness of future air pollution control regulations including green-house gas emission and the constraint of Thailand's foreign currency reserves needed to import fuels, in addition to economic consideration. If and when it is necessary to overcome these obstacles, IGCC is one variable alternative power generation must consider.

  14. Shell coal IGCCS with carbon capture. Conventional gas quench vs. innovative configurations

    Energy Technology Data Exchange (ETDEWEB)

    Martellia, E.; Consonni, S. [Politecnico di Milano, Via Scalabrini 76, Piacenza (Italy); Kreutz, T. [Princeton University, Guyot Hall, Room 129, Princeton, NJ (United States); Carbo, M.; Jansen, D. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG, Petten (Netherlands)

    2011-11-15

    The Shell coal integrated gasification combined cycle (IGCC) based on the gas quench system is one of the most fuel flexible and energy efficient gasification processes because is dry feed and employs high temperature syngas coolers capable of rising high pressure steam. Indeed the efficiency of a Shell IGCC with the best available technologies is calculated to be 47-48%. However the system looses many percentage points of efficiency (up to 10) when introducing carbon capture. To overcome this penalty, two approaches have been proposed. In the first, the expensive syngas coolers are replaced by a 'partial water quench' where the raw syngas stream is cooled and humidified via direct injection of hot water. This design is less costly, but also less efficient. The second approach retains syngas coolers but instead employs novel water-gas shift (WGS) configurations that requires substantially less steam to obtain the same degree of CO conversion to CO2, and thus increases the overall plant efficiency. We simulate and optimize these novel configurations, provide a detailed thermodynamic and economic analysis and investigate how these innovations alter the plant's efficiency, cost and complexity.

  15. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    International Nuclear Information System (INIS)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L.

    2009-01-01

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  16. More Energy-Efficient CO2 Capture from IGCC GE Flue Gases

    Directory of Open Access Journals (Sweden)

    Rakpong Peampermpool

    2017-03-01

    Full Text Available Carbon dioxide (CO2 emissions are one of the main reasons for the increase in greenhouse gasses in the earth’s atmosphere and carbon capture and sequestration (CCS is known as an effective method to reduce CO2 emissions on a larger scale, such as for fossil energy utilization systems. In this paper, the feasibility of capturing CO2 using cryogenic liquefaction and improving the capture rate by expansion will be discussed. The main aim was to design an energy-saving scheme for an IGCC (integrated gasification combined cycle power plant with CO2 cryogenic liquefaction capture. The experimental results provided by the authors, using the feed gas specification of a 740 MW IGCC General Electric (GE combustion power plant, demonstrated that using an orifice for further expanding the vent gas after cryogenic capture from 57 bar to 24 bar gave an experimentally observed capture rate up to 65%. The energy-saving scheme can improve the overall CO2 capture rate, and hence save energy. The capture process has also been simulated using Aspen HYSYS simulation software to evaluate its energy penalty. The results show that a 92% overall capture rate can be achieved by using an orifice.

  17. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A. D.; Velo, E.; Nougues, J. M. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain); Puigjaner, L., E-mail: luis.puigjaner@upc.edu [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data.

  18. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M; Bojarski, A D; Velo, E; Nougues, J M; Puigjaner, L [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  19. Conceptual model and evaluation of generated power and emissions in an IGCC plant

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Fortes, M.; Bojarski, A.D.; Velo, E.; Nougues, J.M.; Puigjaner, L. [Department of Chemical Engineering, Universitat Politecnica de Catalunya, ETSEIB, Avda. Diagonal, 647, E-08028 Barcelona (Spain)

    2009-10-15

    This work develops a design and operation support tool for an Integrated Gasification Combined Cycle (IGCC) power plant, which allows the efficiency and environmental issues of alternative process designs and feedstock to be assessed. The study is based on a conceptual model of an IGCC plant, validated with data from the ELCOGAS power plant in Spain. The layout of the model includes an Air Separation Unit (ASU), a Pressurized Entrained Flow (PRENFLO) gasifier, a series of purification gas units (venturi scrubber, sour water steam stripper, COS hydrolysis reactor, MDEA absorber columns and a sulphur recovery Claus plant), a Heat Recovery Steam Generator (HRSG) and a Combined Cycle (CC) system. It comprises steady state models. One of the purposes of this work is to analyze the feasibility of coal co-gasification using waste materials; specifically petcoke and olive pomace (orujillo) are considered here. The model has been developed in Aspen Hysys. It uses electrolyte models that have been implemented in Aspen Plus which are connected to Aspen Hysys by means of Artificial Neural Networks (ANNs) models. Results of the model's, gas composition and generated power, are in agreement with the industrial data. (author)

  20. Novel findings about management of gastric cancer: a summary from 10th IGCC.

    Science.gov (United States)

    Penon, Danila; Cito, Letizia; Giordano, Antonio

    2014-07-21

    The Tenth International Gastric Cancer Congress (IGCC) was held in Verona, Italy, from June 19 to 22, 2013. The meeting enclosed various aspects of stomach tumor management, including both tightly clinical approaches, and topics more related to basic research. Moreover, an overview on gastrointestinal stromal tumors was provided too, although here not discussed. Here we will discuss some topics related to molecular biology of gastric cancer (GC), inherent to prognostic, diagnostic and therapeutic tools shown at the conference. Results about well known subjects, such as E-cadherin loss of expression/function, were presented. They revealed that other mutations of the gene were identified, showing a continuous research to improve diagnosis and prognosis of stomach tumor. Simultaneously, new possible molecular markers with an established role for other neoplasms, were discussed, such as mesothelin, stomatin-like protein 2 and Notch-1. Hence, a wide overview including both old and new diagnostic/prognostic tools was offered. Great attention was also dedicated to possible drugs to be used against GC. They included monoclonal antibodies, such as MS57-2.1, drugs used in other pathologies, such as maraviroc, and natural extracts from plants such as biflorin. We would like to contribute to summarize the most impressive studies presented at the IGCC, concerning novel findings about molecular biology of gastric cancer. Although further investigations will be necessary, it can be inferred that more and more tools were developed, so as to better face stomach neoplasms.

  1. Towards retrofitting integrated gasification combined cycle (IGCC) power plants with solid oxide fuel cells (SOFC) and CO

    NARCIS (Netherlands)

    Thallam Thattai, A.; Oldenbroek, V.D.W.M.; Schoenmakers, L; Woudstra, T.; Purushothaman Vellayani, A.

    2017-01-01

    This article presents a detailed thermodynamic case study based on the Willem-Alexander Centrale (WAC) power plant in the Netherlands towards retrofitting SOFCs in existing IGCC power plants with a focus on near future implementation. Two systems with high percentage (up to 70%) biomass

  2. Comparison of selected variables of gaming performance in football

    OpenAIRE

    Parachin, Jiří

    2014-01-01

    Title: Comparison of selected variables of gaming performance in football Objectives: Analysis of selected variables of gaming performance in the matches of professional Czech football teams in the Champions League and UEFA Europa League in 2013. During the observation to register set variables, then evaluate obtained results and compare them. Methods: The use of observational analysis and comparison of selected variables of gaming performance in competitive matches of professional football. ...

  3. comparison of performance of public and private boreholes

    African Journals Online (AJOL)

    User

    comparison of the performance of three categories of boreholes namely: public operated boreholes ... Port Harcourt in River State of Nigeria is a fast developing state. ..... World. Bank. Dujam, Consultants (1988). Nation-wide water. Supply and.

  4. Comparison of broiler performance, carcass yields and intestinal ...

    African Journals Online (AJOL)

    Comparison of broiler performance, carcass yields and intestinal microflora when fed diets containing transgenic (Mon-40-3-2) and conventional soybean meal. Jianzhuang Tan, Shasha Liu, Zhe Sun, Hongfu Zhang, Yongwei wang, Dan Liu ...

  5. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  6. Speciation of major and selected trace elements in IGCC fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Oriol Font; Xavier Querol; Frank E. Huggins; Jose M. Chimenos; Ana I. Fernandez; Silvia Burgos; Francisco Garcia Pena [Institute of Earth Sciences ' Jaume Almera' , Barcelona (Spain)

    2005-08-01

    The speciation of Ga, Ge, Ni, V, S and Fe in fly ash from IGCC power plant were investigated for possible further extraction process by combining conventional mineral and chemical analysis, leaching tests, wet sequential extraction, Moessbauer and XAFS spectroscopies. The results shown that Ge occurs mainly as water-soluble species, GeS and/or GeS{sub 2} and hexagonal GeO{sub 2}. Ga is present as an oxide, Ni occurs mainly as nickeline (NiAs), with minor proportions of Ni arsenates and vanadium as V(III) with minor amounts of V(IV) in the aluminosilicate glass matrix. Pyrrhotite and wurtzite-sphalerite are sulfide species containing Fe and Zn, but an important fraction of iron is also present in the aluminosilicate glass. These clear differences between the speciation of the above elements in this material and those reported for fly ash from conventional PC combustion. 15 refs., 8 figs., 5 tabs.

  7. Pushing forward IGCC and CO{sub 2}-free power plant technology at Siemens

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, E.; Vortmeyer, N.; Zimmermann, G. [Siemens AG, Erlangen (Germany). Power Generation

    2004-07-01

    Siemens Power Generation has entered into several R & D projects within the European Commissions' 5th and 6th Framework Programs. One objective of those projects is to develop advanced modular IGCC concepts for in-refinery energy and hydrogen supply. Additional projects are dealing with pre- and post-combustion decarbonisation technologies, which should achieve high carbon dioxide capture at low costs. In parallel, the development of advanced combustion systems including enhanced fuel flexibility and application of low BTU gases in the highly efficient Siemens V94.3A gas turbine are in progress. In further step the technology for burning hydrogen enriched gases resulting from decarbonisation in CO{sub 2} free power plants will be provided. This report documents the current status of these activities. 9 refs., 12 figs.

  8. Siemens sees a future for IGCC - and now it has the technology

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, C.; Hannemann, F. [Siemens Fuel Gasification Technology, Freiberg (Germany)

    2007-10-15

    About 18 months ago Siemens became a key player in the gasification business through its acquisition of Freiberg based Future Energy and its GSP entrained flow technology, now called SFG (Siemens Fuel Gasification). Developed at Schwarze Pumpe in Eastern Germany over many years, a particular attraction of the process is its ability to use low rank fuels such as lignite, with a robust gasifier wall concept a 'cooling screen' that avoids the use of troublesome refractories. The article explains the SFG gasifier technology. It is ideally suited for coal-fueled IGCC power plants with integrated CO{sub 2} capture, especially for low-rank fuels. SFG has been ordered or pre-selected for a number of projects in China, North America and elsewhere. 5 figs.

  9. Performance comparison of various time variant filters

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, M [JEOL Engineering Co. Ltd., Akishima, Tokyo (Japan); Husimi, K

    1996-07-01

    This paper describes the advantage of the trapezoidal filter used in semiconductor detector system comparing with the other time variant filters. The trapezoidal filter is the compose of a rectangular pre-filter and a gated integrator. We indicate that the best performance is obtained by the differential-integral summing type rectangular pre-filter. This filter is not only superior in performance, but also has the useful feature that the rising edge of the output waveform is linear. We introduce an example of this feature used in a high-energy experiment. (author)

  10. A comparison of performance of lightweight mirrors

    Science.gov (United States)

    Cho, Myung K.; Richard, Ralph M.; Hileman, Edward A.

    1990-01-01

    Four lightweight solid contoured back mirror shapes (a double arch, a single arch, a modified single arch, and a double concave mirror) and a cellular sandwich lightweight meniscus mirror, have been considered for the primary mirror of the Space Infrared Telescope Facility (SIRTF). A parametric design study using these shapes for the SIRTF 40 inch primary mirror with a focal ratio f/2 is presented. Evaluations of the optical performance and fundamental frequency analyses are performed to compare relative merits of each mirror configuration. Included in these are structural, optical, and frequency analyses for (1) different back contour shapes, (2) different number and location of the support points, and (3) two gravity orientations (ZENITH and HORIZON positions). The finite element program NASTRAN is used to obtain the structural deflections of the optical surface. For wavefront error analysis, FRINGE and PCFRINGE programs are used to evaluate the optical performance. A scaling law relating the optical and structural performance for various mirror contoured back shapes is developed.

  11. Performance Comparison of Various Filters Media in

    Directory of Open Access Journals (Sweden)

    Lilyan Yaqup Matti

    2013-05-01

    Full Text Available   In this research, a bench-scale filter is designed and constructed in order to compare the performance of different media namely, sand, crushed marble stone and crushed red brick. The filters are operated under various operating conditions such as filter depth, raw water turbidity, pretreatment, effective size and uniformity coefficient.          These filters are operated under conventional and direct filtration modes with different doses of alum. Statistical methods had been used to determine the best media using  Duncan multiple range test.     The result showed the superiority of crushed red brick media in the  removal of turbidity and total bacteria. The results also indicated that filters operated under direct filtration mode show better performance than that operated under conventional filtration mode. The pH of treated water show slight increase for the two modes of filtration.

  12. Corrosion of ceramics for slag removal in IGCC-power plants; Korrosion von Keramiken fuer die Fluessigascheabscheidung in IGCC-Kraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Fuerst, Denny

    2012-06-12

    Coal gasification and the subsequent production of electricity from syngas in combined-cycle powerplants allows plant efficiencies of up to 43% (LHV). Existing technologies allow up to 50% in the short term. Efficiencies beyond 50% however, require concepts and technologies that still need a certain amount of research and development. One such method to raise plant efficiencies would be a high temperature (at temperatures above the melting point of the ash) syngas cleaning. To effectively utilize the heat from the syngas and enable high turbine inlet temperatures, it is necessary to remove slag particles from the hot gas. The feasibility of such a hot syngas cleaning has been successfully demonstrated for the Pressurized Pulverized Coal Combustion (PPCC) by passing the hot gas through a bed of ceramic balls for slag removal. In order to apply this concept to IGCC powerplants the slag resistance of various ceramic materials had to be investigated under gasifying conditions. Therefore, lab-made ceramics and commercially available refractory materials where treated with liquid slag at 1600 C in a number of reducing atmospheres. At first, three synthetic slags with different basicity were used and after evaluating the results, selected materials were treated with a gasifier slag under continuous conditions. It was shown that both slag and ceramic have to be adjusted to ensure a sufficient corrosion resistance of the ceramic bed for slag removal. Furthermore, the impact of the porosity of the utilized ceramic on the corrosion resistance was shown. The composition of the reducing atmosphere (mainly the partial pressure of Oxygen) affected both physical and chemical properties of the slag via slag components that could easily be reduced or oxidized. The materials most suitable for use in slag separation were found to be dense chromium oxide and other ceramics containing a high amount of chromium oxide. [German] Mit Kohlevergasung und der anschliessenden Stromerzeugung in

  13. The United States of America and the People`s Republic of China experts report on integrated gasification combined-cycle technology (IGCC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    A report written by the leading US and Chinese experts in Integrated Gasification Combined Cycle (IGCC) power plants, intended for high level decision makers, may greatly accelerate the development of an IGCC demonstration project in the People`s Republic of China (PRC). The potential market for IGCC systems in China and the competitiveness of IGCC technology with other clean coal options for China have been analyzed in the report. Such information will be useful not only to the Chinese government but also to US vendors and companies. The goal of this report is to analyze the energy supply structure of China, China`s energy and environmental protection demand, and the potential market in China in order to make a justified and reasonable assessment on feasibility of the transfer of US Clean Coal Technologies to China. The Expert Report was developed and written by the joint US/PRC IGCC experts and will be presented to the State Planning Commission (SPC) by the President of the CAS to ensure consideration of the importance of IGCC for future PRC power production.

  14. Performance comparison of wind park configurations

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, Stefan

    2003-07-01

    In this report, layouts of various large-scale wind parks, both AC as well as DC, are investigated. Loss modelling of the wind park components as well as calculations of the energy capture of the turbines using various electrical systems are performed, and the energy production cost of the various park configurations is determined. It was found that from an energy capture point of view, the difference in energy production between various wind turbine systems is very small. In addition, a study of the suitability of various DC/DC-converters is made. Three DC/DC-converters, Boost, Full Bridge and Full Bridge Isolated Boost, are found to be interesting candidates as the 'transformer' component in potential DC-based wind parks. Of all the investigated wind park configurations, the wind park with the series connected DC wind turbines seems to have the best potential to give the lowest energy production cost, if the transmission distance is longer then 10-20 km.

  15. Comparison between the Academic Performance of the National ...

    African Journals Online (AJOL)

    Comparison between the Academic Performance of the National and Regional Intake Medical Students at the University of Kordofan, Western Sudan. ... The dropout rate was 5.9% among the regional students compared to 8.9% among the national students. Conclusions: The academic performance of the national intake ...

  16. Comparison of the performances of male and female armed services ...

    African Journals Online (AJOL)

    Comparison of the performances of male and female armed services recruits undergoing sports vision testing. ... Previous research has shown that the difference in performance in both males and females is the result of brain lateralization, test familiarity and nerve conduction velocity in the brain. This was, however, not ...

  17. Proceedings of the coal-fired power systems 94: Advances in IGCC and PFBC review meeting. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    McDaniel, H.M.; Staubly, R.K.; Venkataraman, V.K. [eds.

    1994-06-01

    The Coal-Fired Power Systems 94 -- Advances in IGCC and PFBC Review Meeting was held June 21--23, 1994, at the Morgantown Energy Center (METC) in Morgantown, West Virginia. This Meeting was sponsored and hosted by METC, the Office of Fossil Energy, and the US Department of Energy (DOE). METC annually sponsors this conference for energy executives, engineers, scientists, and other interested parties to review the results of research and development projects; to discuss the status of advanced coal-fired power systems and future plans with the industrial contractors; and to discuss cooperative industrial-government research opportunities with METC`s in-house engineers and scientists. Presentations included industrial contractor and METC in-house technology developments related to the production of power via coal-fired Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) systems, the summary status of clean coal technologies, and developments and advancements in advanced technology subsystems, such as hot gas cleanup. A keynote speaker and other representatives from the electric power industry also gave their assessment of advanced power systems. This meeting contained 11 formal sessions and one poster session, and included 52 presentations and 24 poster presentations. Volume I contains papers presented at the following sessions: opening commentaries; changes in the market and technology drivers; advanced IGCC systems; advanced PFBC systems; advanced filter systems; desulfurization system; turbine systems; and poster session. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  18. Job Performance Effectiveness: A Comparison of Teachers in Public ...

    African Journals Online (AJOL)

    Job Performance Effectiveness: A Comparison of Teachers in Public and Private Schools ... Teachers in the two types of schools were about the same in classroom ... Also that public school teachers must be provided with conducive teaching/learning environment to enable them meet up the ... AJOL African Journals Online.

  19. Comparison of Outcome of Students' Performance Using the ...

    African Journals Online (AJOL)

    This study compared the outcome of students' performance using the standard setting method with the equivalent outcome they would have obtained using the absolute grading method. It involved the comparison of fail, pass, honors and distinction grades in Digestive System, Endocrine System, Cardiovascular System and ...

  20. Comparison of performance of simulation models for floor heating

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    This paper describes the comparison of performance of simulation models for floor heating with different level of detail in the modelling process. The models are compared in an otherwise identical simulation model containing room model, walls, windows, ceiling and ventilation system. By exchanging...

  1. Comparison of Performance of Public and Private Boreholes ...

    African Journals Online (AJOL)

    In the last fifteen years, a remarkable increase in the number of privately owned. There has been an increase in the individually owned and operated boreholes within the state because it is claimed that government owned boreholes breakdown too often. Hence, this study is aimed at comparison of the performance of three ...

  2. Performance comparison of optical interference cancellation system architectures.

    Science.gov (United States)

    Lu, Maddie; Chang, Matt; Deng, Yanhua; Prucnal, Paul R

    2013-04-10

    The performance of three optics-based interference cancellation systems are compared and contrasted with each other, and with traditional electronic techniques for interference cancellation. The comparison is based on a set of common performance metrics that we have developed for this purpose. It is shown that thorough evaluation of our optical approaches takes into account the traditional notions of depth of cancellation and dynamic range, along with notions of link loss and uniformity of cancellation. Our evaluation shows that our use of optical components affords performance that surpasses traditional electronic approaches, and that the optimal choice for an optical interference canceller requires taking into account the performance metrics discussed in this paper.

  3. Comparison of Cloud backup performance and costs in Oracle database

    OpenAIRE

    Aljaž Zrnec; Dejan Lavbič

    2011-01-01

    Current practice of backing up data is based on using backup tapes and remote locations for storing data. Nowadays, with the advent of cloud computing a new concept of database backup emerges. The paper presents the possibility of making backup copies of data in the cloud. We are mainly focused on performance and economic issues of making backups in the cloud in comparison to traditional backups. We tested the performance and overall costs of making backup copies of data in Oracle database u...

  4. [Tampa Electric Company IGCC project]. 1996 DOE annual technical report, January--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    Tampa Electric Company`s Polk Power Station Unit 1 (PPS-1) Integrated Gasification Combined Cycle (IGCC) demonstration project uses a Texaco pressurized, oxygen-blown, entrained-flow coal gasifier to convert approximately 2,000 tons per day of coal to syngas. The gasification plant is coupled with a combined cycle power block to produce a net 250 MW electrical power output. Coal is slurried in water, combined with 95% pure oxygen from an air separation unit, and sent to the gasifier to produce a high temperature, high pressure, medium-Btu syngas with a heat content of about 250 BTUs/cf (HHV). The syngas then flows through a high temperature heat recovery unit which cools the syngas prior to its entering the cleanup systems. Molten coal ash flows from the bottom of the high temperature heat recovery unit into a water-filled quench chamber where it solidifies into a marketable slag by-product. Approximately 10% of the raw, hot syngas at 900 F is designed to pass through an intermittently moving bed of metal-oxide sorbent which removes sulfur-bearing compounds from the syngas. PPS-1 will be the first unit in the world to demonstrate this advanced metal oxide hot gas desulfurization technology on a commercial unit. The emphasis during 1996 centered around start-up activities.

  5. A comparison of SAR ATR performance with information theoretic predictions

    Science.gov (United States)

    Blacknell, David

    2003-09-01

    Performance assessment of automatic target detection and recognition algorithms for SAR systems (or indeed any other sensors) is essential if the military utility of the system / algorithm mix is to be quantified. This is a relatively straightforward task if extensive trials data from an existing system is used. However, a crucial requirement is to assess the potential performance of novel systems as a guide to procurement decisions. This task is no longer straightforward since a hypothetical system cannot provide experimental trials data. QinetiQ has previously developed a theoretical technique for classification algorithm performance assessment based on information theory. The purpose of the study presented here has been to validate this approach. To this end, experimental SAR imagery of targets has been collected using the QinetiQ Enhanced Surveillance Radar to allow algorithm performance assessments as a number of parameters are varied. In particular, performance comparisons can be made for (i) resolutions up to 0.1m, (ii) single channel versus polarimetric (iii) targets in the open versus targets in scrubland and (iv) use versus non-use of camouflage. The change in performance as these parameters are varied has been quantified from the experimental imagery whilst the information theoretic approach has been used to predict the expected variation of performance with parameter value. A comparison of these measured and predicted assessments has revealed the strengths and weaknesses of the theoretical technique as will be discussed in the paper.

  6. International comparisons of public sector performance: how to move ahead?

    OpenAIRE

    Van de Walle, Steven

    2009-01-01

    textabstractMeasuring and comparing the overall performance of countries’ public sectors requires agreement on definitions and objectives of government. I argue that such an agreement is about finding a consensus rather about finding better definitions. Measuring government requires a number of leaps of faith, where certain definitions, assumptions and statistics are accepted as good enough for measurement and comparison. The political science and economic research community have a different ...

  7. Degradation of TBC Systems in Environments Relevant to Advanced Gas Turbines for IGCC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gleeson, Brian [Univ. of Pittsburgh, PA (United States)

    2014-09-30

    Air plasma sprayed (APS) thermal barrier coatings (TBCs) are used to provide thermal insulation for the hottest components in gas turbines. Zirconia stabilized with 7wt% yttria (7YSZ) is the most common ceramic top coat used for turbine blades. The 7YSZ coating can be degraded from the buildup of fly-ash deposits created in the power-generation process. Fly ash from an integrated gasification combined cycle (IGCC) system can result from coal-based syngas. TBCs are also exposed to harsh gas environments containing CO2, SO2, and steam. Degradation from the combined effects of fly ash and harsh gas atmospheres has the potential to severely limit TBC lifetimes. The main objective of this study was to use lab-scale testing to systematically elucidate the interplay between prototypical deposit chemistries (i.e., ash and its constituents, K2SO4, and FeS) and environmental oxidants (i.e., O2, H2O and CO2) on the degradation behavior of advanced TBC systems. Several mechanisms of early TBC failure were identified, as were the specific fly-ash constituents responsible for degradation. The reactivity of MCrAlY bondcoats used in TBC systems was also investigated. The specific roles of oxide and sulfate components were assessed, together with the complex interplay between gas composition, deposit chemistry and alloy reactivity. Bondcoat composition design strategies to mitigate corrosion were established, particularly with regard to controlling phase constitution and the amount of reactive elements the bondcoat contains in order to achieve optimal corrosion resistance.

  8. Process, background and design criteria of the gas cleaning at Puertollano IGCC

    Energy Technology Data Exchange (ETDEWEB)

    Pisa, J. [Elcogas, Madrid (Spain)

    1998-11-01

    The Puertollano IGCC plant selected cooling by a water-tube boiler with upstream quenching at high velocities that requires a dust-free cooling gas at not less than 250{degree}C in order not to penalise the heat recovery efficiency. A filtration system for gas dedusting in the 250{degree}C temperature range has been installed and will be commissioned at the end of 1997. The gas cleaning concept is completed with a Venturi Scrubber, a COS hydrolysis reactor and a MDEA column to strip the sulphuric acid to yield clean gas. The gasification island is based upon the PRENFLO system which is an entrained-flow system with dry feeding. The selection of the filter system arrangement considered the limited operational experience in comparable operating conditions and acknowledged the flexibility of the filter system versus the cyclone-scrubber as far as easier load variation operation, the reduction of residues needing deposition and increased slag flow, as well as easier maintenance. Additionally to the ceramic test filters in Furstenhausen (PRENFLO) and Deer Park near Houston (SHELL), ceramic candle-type filter were selected in Buggenum and at Wabash River, and for the KoBra plant. The main criteria for the selection of the filter system and the type of candle were: separation efficiency to match clean gas limits; uniform distribution of the dust-laden gas to the filters; wear-resistant routing of the dust-laden gas flow; need for a supporting structure which must cope with sudden pressure fluctuations; optimised pulse gas system; and maintenance and repair. Based upon the above criteria, the PRENFLO concept requirements and the gas turbine specification, an arrangement with two pressure filter vessels with LLB design and filter elements manufactured by Schumacher has been installed in Puertollano. 2 figs., 3 tabs.

  9. Modelling and dynamics of an air separation rectification column as part of an IGCC power plant

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, B.; Hanke-Rauschenbach, R.; Hannemann, F.; Sundmacher, K. [Otto Von Guericke University, Magdeburg (Germany)

    2006-04-15

    An Integrated Gasification Combined Cycle plant (IGCC) opens the well-proven and highly efficient combined cycle process to fossil fuels, like coal or heavy refinery residues. Such a plant thereby possesses a novel linkage of typical energy engineering related units, e.g. a gas turbine and typical process engineering parts, which in the present case is an air separation plant. Different responses from the connected components can cause undesired mass flow fluctuations within the system especially during changing load demands. The cryogenic rectification column, as the core of the air separation plant, strongly affects the system's transient behaviour. The upper part of such a heat-integrated double column, a packed column with structured packing, has therefore been more closely investigated in the present paper. For this purpose, a dynamic model of such a column has been developed which is also able to describe the pressure dynamics supposedly responsible for these mass flow fluctuations. The transient behaviour of the uncontrolled column is analysed and discussed with special regard to pressure dynamics. The column pressure responds to disturbances on two different time scales. The short-term response, which is in the range of 100-200 s, is governed by the transient behaviour of the fluid dynamics and is discussed in detail. The long-term response is dominated by the nonlinear dynamics of the concentration profiles. The time constant of this response depends strongly on the direction and intensity of the disturbance and takes from 10,000 up to several 100,000 s.

  10. Analysis of IGCC-based plants with carbon capture for an efficient and flexible electric power generation

    International Nuclear Information System (INIS)

    Sorgenfrei, Max

    2016-01-01

    In this work, systems based on the Integrated gasification combined cycle (IGCC) technology with carbon capture are analyzed regarding an efficient and flexible electric power generation. All analysis are related to a high-efficiency or low-cost IGCC base case with carbon capture which are both commercially available. In the high-efficiency base case, thermodynamic inefficiencies are determined based on a conventional exergy analysis. The gasifier followed by the combustion chamber of the gas turbine running on syngas are rated to the largest inefficiencies. Based on an advanced exergy analysis, the inefficiencies are split into an avoidable and unavoidable part as well as an endogenous and exogenous part. For example, it was found that about half of the inefficiencies within the gasifier are caused by other components of the overall system(exogenous part). Further investigations on the combination of both splitting types are presented. The gas turbine system is identified to be a major component and therefore a detailed model was developed using state-of-the-art technologies. Based on this model, 12 types of characteristic inefficiencies were determined and rated by their exergy destruction. Chemical-Looping Combustion (CLC) is one of the most promising technologies to enhance the available IGCC design. CLC uses composite metal particles acting as an oxygen carrier to transport oxygen from the air to the fuel gas through a redox-cycle. Thus, the inefficiencies associated with the combustion process decrease and the application of physical absorption for capturing CO 2 is replaced by an inherent CO 2 -capture. In this work, the most suitable oxygen carriers for CLC using syngas (nickel oxide and iron oxide) are analyzed at different temperatures. Moreover, different types of gasifier as well as CLC reactor designs are analyzed. Regenerating the oxygen carrier by steam and air, produces additional hydrogen from the reduction of steam which is further combusted

  11. Comparison of Cloud backup performance and costs in Oracle database

    Directory of Open Access Journals (Sweden)

    Aljaž Zrnec

    2011-06-01

    Full Text Available Normal 0 21 false false false SL X-NONE X-NONE Current practice of backing up data is based on using backup tapes and remote locations for storing data. Nowadays, with the advent of cloud computing a new concept of database backup emerges. The paper presents the possibility of making backup copies of data in the cloud. We are mainly focused on performance and economic issues of making backups in the cloud in comparison to traditional backups. We tested the performance and overall costs of making backup copies of data in Oracle database using Amazon S3 and EC2 cloud services. The costs estimation was performed on the basis of the prices published on Amazon S3 and Amazon EC2 sites.

  12. Performance comparison of Islamic and commercial banks in Malaysia

    Science.gov (United States)

    Azizud-din, Azimah; Hussin, Siti Aida Sheikh; Zahid, Zalina

    2016-10-01

    The steady growth in the size and increase in the number of Islamic banks show that the Islamic banking system is considered as an alternative to the conventional banking system. Due to this, comparisons in term of performance measurements and evaluation of the financial health for both type of banks are essential. The main purpose of this study is to analyse the differences between Islamic and commercial banks performance. Five years secondary data were collected from the annual report for each bank. Return on Asset ratio is chosen as the dependent variable, while capital adequacy, asset quality, management quality, earning, liquidity and sensitivity to market risk (CAMELS) are the independent variables. Descriptive analyses were done to understand the data. The independent t-test and Mann Whitney test show the differences of Islamic and commercial banks based on the financial variables. The stepwise and hierarchical multiple regressions were used to determine the factor that affects profitability performance of banks. Results show that Islamic banks are better in term of profitability performance, earning power performance, liquidity performance and sensitive to market risk. The factors that affect profitability performance are capital adequacy, earning power and liquidity variable.

  13. Thermodynamic simulation of CO{sub 2} capture for an IGCC power plant using the calcium looping cycle

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y. [National Engineering Laboratory for Coal-Burning Pollutant Emission Reduction, Shandong University, Jinan (China); Zhao, C.; Ren, Q. [School of Energy and Environment, Southeast University, Nanjing (China)

    2011-06-15

    A CO{sub 2} capture process for an integrated gasification combined cycle (IGCC) power plant using the calcium looping cycle was proposed. The CO{sub 2} capture process using natural and modified limestone was simulated and investigated with the software package Aspen Plus. It incorporated a fresh feed of sorbent to compensate for the decay in CO{sub 2} capture activity during long-term cycles. The sorbent flow ratios have significant effect on the CO{sub 2} capture efficiency and net efficiency of the CO{sub 2} capture system. The IGCC power plant, using the modified limestone, exhibits higher CO{sub 2} capture efficiency than that using the natural limestone at the same sorbent flow ratios. The system net efficiency using the natural and modified limestones achieves 41.7% and 43.1%, respectively, at the CO{sub 2} capture efficiency of 90% without the effect of sulfation. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Feasibility analysis of gas turbine inlet air cooling by means of liquid nitrogen evaporation for IGCC power augmentation

    International Nuclear Information System (INIS)

    Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Vaccari, Anna; Venturini, Mauro

    2015-01-01

    Integrated Gasification Combined Cycles (IGCC) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, an Air Separation Unit (ASU) is also part of the plant. In this paper, a system for power augmentation in IGCC is evaluated. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first liquefied to be used for inlet air cooling or stored for later use. This system is not characterized by the limits of water evaporative cooling systems (the lower temperature is limited by air saturation) and refrigeration cooling (the effectiveness is limited by the pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for energy conversion system simulation. A sensitivity analysis on the main parameters is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year and by comparing to traditional inlet air cooling strategies. - Highlights: • Gas turbine inlet air cooling by means of liquid nitrogen spray. • Humidity condensation may form a fog which provides further power augmentation. • High peak and off peak electric energy price ratios make the system profitable

  15. Performance Analysis Comparison Of Coca Cola And Pepsi

    OpenAIRE

    The, Glenny Marselia; Saerang, David Paul Elia; Tumewu, Ferdinand

    2014-01-01

    All companies fight to get as many consumers as they can and it makes, product, price, place and promotion become important factors to make a company has a successful marketing campaign. The companies spend much money for create an attractive product at an affordable price, a place that can be reached, and the promotion that can be well-received by the public. So, regarding that fact, the researcher writes a study about the performance analysis comparison of Coca Cola and Pepsi in Manado b...

  16. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Eric [Univ. of Connecticut, Storrs, CT (United States); Gell, Maurice [Univ. of Connecticut, Storrs, CT (United States)

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm⁻¹K⁻¹ in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al₂O₃ and TiO₂, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium

  17. Timing resolution performance comparison of different SiPM devices

    Energy Technology Data Exchange (ETDEWEB)

    Dolinsky, Sergei, E-mail: dolinsky@ge.com; Fu, Geng; Ivan, Adrian

    2015-11-21

    Silicon photomultiplier (SiPM) devices with improved parameters were recently introduced by several vendors. In addition to published manufacturer performance specifications, different research groups have reported on measurements of the available SiPMs in different operating conditions and using different test setups. In this work we performed a consistent set of test procedures for SiPM devices from various vendors, with focus on Time-of-Flight (TOF) PET detectors applications. SiPMs from Hamamatsu (HPK), SensL, Ketek, and Excelitas were tested. The same experimental setup and procedures were used for comparison of timing resolution for small (3×3 mm{sup 2}) and large (6×6 mm{sup 2} or 4×6 mm{sup 2}) devices coupled to short (3×3×10 mm{sup 3}) and long (4×4×25 mm{sup 3}) LYSO crystals. The potential opportunities for TOF PET detectors are also evaluated.

  18. Operator Performance Comparison of two VDT-based Alarm Systems

    International Nuclear Information System (INIS)

    Lee, Hyun-Chul; Oh, In-Suk; Sim, Bong-Shick; Koo, In-Soo; Kim, Jeong-Taek; Lee, Ki-Young; Park, Jong-Kyun

    1998-01-01

    This study is carried out to investigate performance differences between two alarm presentation methods from the viewpoint of human factors and to provide items to be improved. One of the alarm display methods considered in this study displays alarm lists on VDT combined with hardwired alarm panels. The other method displays alarms on plant mimic diagrams of VDT. This alarm display method has other features for operator aid with which operator can get detailed information on the activated alarm in the mimic diagrams, and the capability for alarm processing such as alarm reduction and prioritization. To compare the two display methods, a human factor experiment was performed with a plant simulator in the ITF (Integrated Test Facility) that plant operators run for 4 event scenarios. During the experiment, physiological measurements, system and operator action log, and audio/video recordings were collected. Operators subjective opinion was collected as well after the experiment. Time, error rate and situation awareness were major human factor criteria used for the comparison during the analysis stage of the experiment. No statistical significance was found in the results of our statistical comparison analysis. Several findings were identified, however, through the analysis of subjective opinions. (authors)

  19. The slag from ELCOGAS IGCC thermal power plant as raw material for the synthesis of glass-ceramic materials. Part I: Thermal behavior of the IGCC slag and synthesis of the parent glass.

    Energy Technology Data Exchange (ETDEWEB)

    Aineto, M.; Acosta, A. [University of Castilla La Mancha, Ciudad Real (Spain)

    2005-12-01

    We report here the results of the first phase of investigation on the melting behavior of the IGCC slag, and the use of this slag as raw component to produce glass ceramics. The vitrifying mixture named ECSCP, is composed of 40% slag, 30% glass cullet and 30% precipitated calcium carbonate obtained as a by-product in a sugar refining plant. This mixture was melted at 1450{sup o}C to obtain the ECSCP parent glass, that was then characterized and its crystallization kinetics studied by thermal analysis. The ECSCP glass exhibit a surface mechanism of crystallization, and will be used to produce anorthite/wollastonite glass ceramics in the second part of the investigation.

  20. Degradation of TBC Systems in Environments Relevant to Advanced Gas Turbines for IGCC Systems

    Science.gov (United States)

    Bohna, Nathaniel Allan

    Plasma sprayed (PS) thermal barrier coatings (TBCs) are used to provide thermal insulation for the hottest components in gas turbines. Zirconia stabilized with 7wt% yttria (7YSZ) is the most common ceramic top coat used for turbine blades. The 7YSZ coating can be degraded by the buildup of fly-ash deposits which can arise from the fuel source (coal/biomass) used in the combustion process in gas turbines. Fly-ash from the integrated gasification combined cycle (IGCC) process can result from coal-based syngas and also from ambient air which passes through the system. TBCs are also exposed to harsh gas environments containing CO2, SO2, and steam. As presented in this thesis, degradation from the combined effects of fly-ash and harsh gas atmosphere can severely limit TBC lifetimes. It is well established that degradation at very high temperatures (≥1250°C) from deposits consisting of the oxides CaO-MgO-Al2O3-SiO 2 results from extensive liquid silicate infiltration into the porous top coat of the YSZ. This infiltration causes early failure resulting from chemical and/or mechanical damage to the ceramic layer. Damage resulting from liquid infiltration, however, is not typically considered at relatively lower temperatures around 1100°C because liquid silicates would not be expected to form from the oxides in the deposit. A key focus of this study is to assess the mode and extent of TBC degradation at 1100°C in cases when some amount of liquid forms owing to the presence of K2SO4 as a minor ash constituent. Two types of liquid infiltrations are observed depending on the principal oxide (i.e., CaO or SiO2) in the deposit. The degradation is primarily the result of mechanical damage, which results from infiltration caused by the interaction of liquid K2SO4 with either the CaO or SiO2. The TBCs used in this work are representative of commonly used coatings used in the hottest sections of land-based gas turbines. The specimens consist of 7YSZ top coats deposited on

  1. Comparison of MODIS and VIIRS On-board Blackbody Performance

    Science.gov (United States)

    Xiong, Jack; Butler, Jim; Wu, Aisheng; Chiang, Vincent; McIntire, Jeff; Oudari, Hassan

    2012-01-01

    MODIS has 16 thermal emissive bands (TEBs), covering wavelengths from 3.7 to 14.4 microns. MODIS TEBs are calibrated on-orbit by a v-grooved blackbody (BB) on a scan-by-scan basis. The BB temperatures are measured by a set of 12 thennistors. As expected, the BB temperature uncertainty and stability have direct impact on the quality of TEB calibration and, therefore, the quality of the science products derived from TEB observations. Since launch, Terra and Aqua MODIS have successfully operated for more than 12 and 10 years, respectively. Their on-board BB performance has been satisfactory in meeting the TEB calibration requirements. The first VIIRS, launched on-board the Suomi NPP spacecraft on October 28, 2011, has successfully completed its initial Intensive Calibration and Validation (ICV) phase. VIIRS has 7 thermal emissive bands (TEBs), covering wavelengths from 3.7 to 12.4 microns. Designed with strong MODIS heritage, VIIRS uses a similar BB for its TEB calibration. Like MODIS, VIIRS BB is nominally controlled at a pre-determined temperature (set point). Periodically, a BB Warm-Up and Cool-Down (WUCD) operation is performed, during which the BB temperatures vary from instrument ambient (temperature) to 315K. This paper examines NPP VIIRS BB on-orbit performance. It focuses on its BB temperature scan-to-scan variations at nominally controlled temperature as well as during its WUCD operation and their impact on TEB calibration uncertainty. Comparisons of VIIRS (NPP) and MODIS (Terra and Aqua) BB on-orbit performance and lessons learned for future improvements are also presented in this paper.

  2. Sequential data access with Oracle and Hadoop: a performance comparison

    International Nuclear Information System (INIS)

    Baranowski, Zbigniew; Canali, Luca; Grancher, Eric

    2014-01-01

    The Hadoop framework has proven to be an effective and popular approach for dealing with 'Big Data' and, thanks to its scaling ability and optimised storage access, Hadoop Distributed File System-based projects such as MapReduce or HBase are seen as candidates to replace traditional relational database management systems whenever scalable speed of data processing is a priority. But do these projects deliver in practice? Does migrating to Hadoop's 'shared nothing' architecture really improve data access throughput? And, if so, at what cost? Authors answer these questions–addressing cost/performance as well as raw performance– based on a performance comparison between an Oracle-based relational database and Hadoop's distributed solutions like MapReduce or HBase for sequential data access. A key feature of our approach is the use of an unbiased data model as certain data models can significantly favour one of the technologies tested.

  3. Performances of different digital mammography imaging systems: Evaluation and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Bisogni, M.G. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)]. E-mail: giuseppina.bisogni@pi.infn.it; Bulajic, D. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); International Centre for Theoretical Physics, Trieste (Italy); Delogu, P. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Fantacci, M.E. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Novelli, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Quattrocchi, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Rosso, V. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Stefanini, A. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)

    2005-07-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems.

  4. Performances of different digital mammography imaging systems: Evaluation and comparison

    International Nuclear Information System (INIS)

    Bisogni, M.G.; Bulajic, D.; Delogu, P.; Fantacci, M.E.; Novelli, M.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2005-01-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems

  5. The Relationship Between Goal Orientation, Social Comparison Responses, Self-Efficacy, and Performance

    NARCIS (Netherlands)

    Carmona, Carmen; Buunk, Abraham P.; Dijkstra, Arie; Peiro, Jose M.

    2008-01-01

    The present study examined whether social comparison responses (identification and contrast in social comparison) mediated the relationship between goal orientation (promotion and prevention) and self-efficacy, and whether self-efficacy was subsequently related with a better performance. As

  6. Performance comparison of three trigeneration systems using organic rankine cycles

    International Nuclear Information System (INIS)

    Al-Sulaiman, Fahad A.; Hamdullahpur, Feridun; Dincer, Ibrahim

    2011-01-01

    In this paper, energetic performance comparison of three trigeneration systems is presented. The systems considered are SOFC-trigeneration, biomass-trigeneration, and solar-trigeneration systems. This study compares the performance of the systems considered when there is only electrical power and the efficiency improvement of these systems when there is trigeneration. Different key output parameters are examined: energy efficiency, net electrical power, electrical to heating and cooling ratios, and (GHG) GHG (greenhouse gas) emissions. This study shows that the SOFC-trigeneration system has the highest electrical efficiency among the three systems. Alternatively, when trigeneration is used, the efficiencies of all three systems considered increase considerably. The maximum trigeneration efficiency of the SOFC-trigeneration system is around 76% while it is around 90% for the biomass-trigeneration system. On the other hand, the maximum trigeneration efficiencies of the solar-trigeneration system is around 90% for the solar mode, 45% for storage and storage mode, and 41% for the storage mode. In addition, this study shows that the emissions of CO 2 in kg per MWh of electrical power are high for the biomass-trigeneration and SOFC-trigeneration systems. However, by considering the emissions per MWh of trigeneration, their values drop to less than one fourth. -- Highlights: → We have compared the energetic performance of three potential trigeneration systems. → These systems are SOFC, biomass, and solar-trigeneration systems. → The SOFC-trigeneration system has the highest electrical efficiency. → The trigeneration efficiencies of the biomass-trigeneration system and solar mode of the solar-trigeneration system are the highest. → The CO 2 emissions per MWh of combined cooling, heating, and power production drop significantly when trigeneration is used.

  7. Performance Comparison of Geobroadcast Strategies for Winding Roads

    Directory of Open Access Journals (Sweden)

    Edgar Talavera

    2018-03-01

    Full Text Available Vehicle-to-X (V2X communications allow real-time information sharing between vehicles and Roadside Units (RSUs. These kinds of technologies allow for the improvement of road safety and can be used in combination with other systems. Advanced Driver Assistance Systems (ADAS are an example and can be used along with V2X communications to improve performance and enable Cooperative Systems. A key element of vehicular communications is that the information transmitted through the network is always linked to a GPS position related to origin and destination (GeoNetworking protocol in order to adjust the data broadcast to the dynamic road environment needs. In this paper, we present the implementation and development of Institute for Automobile Research (INSIA V2X communication modules that follow the European vehicular networking standards in a close curve in a winding road where poor visibility causes a risk to the safety of road users. The technology chosen to support these communications is ETSI ITS-G5, which has the capability to enable specific services that support GeoNetworking protocols, specifically the Geobroadcast (GBC algorithm. These functionalities have been implemented and validated in a real environment in order to demonstrate the performance of the communication devices in real V2V (Vehicle-to-Vehicle and V2I (Vehicle-to-Infrastructure situations. GBC messages are also compared with two different configurations of emission area. A comparison with/without RSU modules in critical areas of the road with previous knowledge of the road cartography has also been made.

  8. Medicare managed care plan performance: a comparison across hospitalization types.

    Science.gov (United States)

    Basu, Jayasree; Mobley, Lee Rivers

    2012-01-01

    The study evaluates the performance of Medicare managed care (Medicare Advantage [MA]) Plans in comparison to Medicare fee-for-service (FFS) Plans in three states with historically high Medicare managed care penetration (New York, California, Florida), in terms of lowering the risks of preventable or ambulatory care sensitive conditions (ACSC) hospital admissions and providing increased referrals for admissions for specialty procedures. Using 2004 hospital discharge files from the Healthcare Cost and Utilization Project (HCUP-SID) of the Agency for Healthcare Research and Quality, ACSC admissions are compared with 'marker' admissions and 'referral-sensitive' admissions, using a multinomial logistic regression approach. The year 2004 represents a strategic time to test the impact of MA on preventable hospitalizations, because the HMOs dominated the market composition in that time period. MA enrollees in California experienced 22% lower relative risk (RRR= 0.78, p<0.01), those in Florida experienced 16% lower relative risk (RRR= 0.84, p<0.01), while those in New York experienced 9% lower relative risk (RRR=0.91, p<0.01) of preventable (versus marker) admissions compared to their FFS counterparts. MA enrollees in New York experienced 37% higher relative risk (RRR=1.37, p<0.01) and those in Florida had 41% higher relative risk (RRR=1.41, p<0.01)-while MA enrollees in California had 13% lower relative risk (RRR=0.87, p<0.01)-of referral-sensitive (versus marker) admissions compared to their FFS counterparts. While MA plans were associated with reductions in preventable hospitalizations in all three states, the effects on referral-sensitive admissions varied, with California experiencing lower relative risk of referral-sensitive admissions for MA plan enrollees. The lower relative risk of preventable admissions for MA plan enrollees in New York and Florida became more pronounced after accounting for selection bias.

  9. Performance Comparison of Big Data Analytics With NEXUS and Giovanni

    Science.gov (United States)

    Jacob, J. C.; Huang, T.; Lynnes, C.

    2016-12-01

    NEXUS is an emerging data-intensive analysis framework developed with a new approach for handling science data that enables large-scale data analysis. It is available through open source. We compare performance of NEXUS and Giovanni for 3 statistics algorithms applied to NASA datasets. Giovanni is a statistics web service at NASA Distributed Active Archive Centers (DAACs). NEXUS is a cloud-computing environment developed at JPL and built on Apache Solr, Cassandra, and Spark. We compute global time-averaged map, correlation map, and area-averaged time series. The first two algorithms average over time to produce a value for each pixel in a 2-D map. The third algorithm averages spatially to produce a single value for each time step. This talk is our report on benchmark comparison findings that indicate 15x speedup with NEXUS over Giovanni to compute area-averaged time series of daily precipitation rate for the Tropical Rainfall Measuring Mission (TRMM with 0.25 degree spatial resolution) for the Continental United States over 14 years (2000-2014) with 64-way parallelism and 545 tiles per granule. 16-way parallelism with 16 tiles per granule worked best with NEXUS for computing an 18-year (1998-2015) TRMM daily precipitation global time averaged map (2.5 times speedup) and 18-year global map of correlation between TRMM daily precipitation and TRMM real time daily precipitation (7x speedup). These and other benchmark results will be presented along with key lessons learned in applying the NEXUS tiling approach to big data analytics in the cloud.

  10. Performance comparison of renewable incentive schemes using optimal control

    International Nuclear Information System (INIS)

    Oak, Neeraj; Lawson, Daniel; Champneys, Alan

    2014-01-01

    Many governments worldwide have instituted incentive schemes for renewable electricity producers in order to meet carbon emissions targets. These schemes aim to boost investment and hence growth in renewable energy industries. This paper examines four such schemes: premium feed-in tariffs, fixed feed-in tariffs, feed-in tariffs with contract for difference and the renewable obligations scheme. A generalised mathematical model of industry growth is presented and fitted with data from the UK onshore wind industry. The model responds to subsidy from each of the four incentive schemes. A utility or ‘fitness’ function that maximises installed capacity at some fixed time in the future while minimising total cost of subsidy is postulated. Using this function, the optimal strategy for provision and timing of subsidy for each scheme is calculated. Finally, a comparison of the performance of each scheme, given that they use their optimal control strategy, is presented. This model indicates that the premium feed-in tariff and renewable obligation scheme produce the joint best results. - Highlights: • Stochastic differential equation model of renewable energy industry growth and prices, using UK onshore wind data 1992–2010. • Cost of production reduces as cumulative installed capacity of wind energy increases, consistent with the theory of learning. • Studies the effect of subsidy using feed-in tariff schemes, and the ‘renewable obligations’ scheme. • We determine the optimal timing and quantity of subsidy required to maximise industry growth and minimise costs. • The premium feed-in tariff scheme and the renewable obligations scheme produce the best results under optimal control

  11. Comparison of Small Unmanned Aerial Vehicles Performance Using Image Processing

    Directory of Open Access Journals (Sweden)

    Esteban Cano

    2017-01-01

    Full Text Available Precision agriculture is a farm management technology that involves sensing and then responding to the observed variability in the field. Remote sensing is one of the tools of precision agriculture. The emergence of small unmanned aerial vehicles (sUAV have paved the way to accessible remote sensing tools for farmers. This paper describes the development of an image processing approach to compare two popular off-the-shelf sUAVs: 3DR Iris+ and DJI Phantom 2. Both units are equipped with a camera gimbal attached with a GoPro camera. The comparison of the two sUAV involves a hovering test and a rectilinear motion test. In the hovering test, the sUAV was allowed to hover over a known object and images were taken every quarter of a second for two minutes. For the image processing evaluation, the position of the object in the images was measured and this was used to assess the stability of the sUAV while hovering. In the rectilinear test, the sUAV was allowed to follow a straight path and images of a lined track were acquired. The lines on the images were then measured on how accurate the sUAV followed the path. The hovering test results show that the 3DR Iris+ had a maximum position deviation of 0.64 m (0.126 m root mean square RMS displacement while the DJI Phantom 2 had a maximum deviation of 0.79 m (0.150 m RMS displacement. In the rectilinear motion test, the maximum displacement for the 3DR Iris+ and the DJI phantom 2 were 0.85 m (0.134 m RMS displacement and 0.73 m (0.372 m RMS displacement. These results demonstrated that the two sUAVs performed well in both the hovering test and the rectilinear motion test and thus demonstrated that both sUAVs can be used for civilian applications such as agricultural monitoring. The results also showed that the developed image processing approach can be used to evaluate performance of a sUAV and has the potential to be used as another feedback control parameter for autonomous navigation.

  12. Performance Comparison of Superresolution Array Processing Algorithms. Revised

    National Research Council Canada - National Science Library

    Barabell, A

    1998-01-01

    ... have been documented in the literature, no systematic comparison has heretofore been undertaken. The general approach of the current study is to simulate a sequence of increasingly more general...

  13. Does social comparison make a difference? Optimism as a moderator of the relation between comparison level and academic performance

    NARCIS (Netherlands)

    Gibbons, FX; Blanton, H; Gerrard, M; Buunk, B; Eggleston, T

    Previous research has demonstrated that poor academic performance is associated with a downward shift in preferred level of academic comparison level (ACL). The current study assessed the long-term impact of this downward shift on the academic performance of college students and also examined the

  14. Weigh-in-Motion Sensor and Controller Operation and Performance Comparison

    Science.gov (United States)

    2018-01-01

    This research project utilized statistical inference and comparison techniques to compare the performance of different Weigh-in-Motion (WIM) sensors. First, we analyzed test-vehicle data to perform an accuracy check of the results reported by the sen...

  15. 30 CFR 206.176 - How do I perform accounting for comparison?

    Science.gov (United States)

    2010-07-01

    ... paragraphs (b) and (c) of this section, the actual dual accounting value, for royalty purposes, is the... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I perform accounting for comparison? 206... REVENUE MANAGEMENT PRODUCT VALUATION Indian Gas § 206.176 How do I perform accounting for comparison? (a...

  16. An investigation and comparison on network performance analysis

    OpenAIRE

    Lanxiaopu, Mi

    2012-01-01

    This thesis is generally about network performance analysis. It contains two parts. The theory part summarizes what network performance is and inducts the methods of doing network performance analysis. To answer what network performance is, a study into what network services are is done. And based on the background research, there are two important network performance metrics: Network delay and Throughput should be included in network performance analysis. Among the methods of network a...

  17. Heat Integration of the Water-Gas Shift Reaction System for Carbon Sequestration Ready IGCC Process with Chemical Looping

    Energy Technology Data Exchange (ETDEWEB)

    Juan M. Salazara; Stephen E. Zitney; Urmila M. Diwekara

    2010-01-01

    Integrated gasification combined cycle (IGCC) technology has been considered as an important alternative for efficient power systems that can reduce fuel consumption and CO2 emissions. One of the technological schemes combines water-gas shift reaction and chemical-looping combustion as post gasification techniques in order to produce sequestration-ready CO2 and potentially reduce the size of the gas turbine. However, these schemes have not been energetically integrated and process synthesis techniques can be applied to obtain an optimal flowsheet. This work studies the heat exchange network synthesis (HENS) for the water-gas shift reaction train employing a set of alternative designs provided by Aspen energy analyzer (AEA) and combined in a process superstructure that was simulated in Aspen Plus (AP). This approach allows a rigorous evaluation of the alternative designs and their combinations avoiding all the AEA simplifications (linearized models of heat exchangers). A CAPE-OPEN compliant capability which makes use of a MINLP algorithm for sequential modular simulators was employed to obtain a heat exchange network that provided a cost of energy that was 27% lower than the base case. Highly influential parameters for the pos gasification technologies (i.e. CO/steam ratio, gasifier temperature and pressure) were calculated to obtain the minimum cost of energy while chemical looping parameters (oxidation and reduction temperature) were ensured to be satisfied.

  18. Power generation plants with carbon capture and storage: A techno-economic comparison between coal combustion and gasification technologies

    International Nuclear Information System (INIS)

    Tola, Vittorio; Pettinau, Alberto

    2014-01-01

    Highlights: • Techno-economic performance of coal-fired power plants (without and with CCS). • Without CCS system, USC is more efficient and cost-competitive than IGCC. • CCS energy penalties are more relevant for USC than IGCC. • Higher SNOX system costs are partially compensated by better USC performance. • CCS technologies cannot be profitable without adequate policies and incentives. - Abstract: Worldwide energy production requirements could not be fully satisfied by nuclear and renewables sources. Therefore a sustainable use of fossil fuels (coal in particular) will be required for several decades. In this scenario, carbon capture and storage (CCS) represents a key solution to control the global warming reducing carbon dioxide emissions. The integration between CCS technologies and power generation plants currently needs a demonstration at commercial scale to reduce both technological risks and high capital and operating cost. This paper compares, from the technical and economic points of view, the performance of three coal-fired power generation technologies: (i) ultra-supercritical (USC) plant equipped with a conventional flue gas treatment (CGT) process, (ii) USC plant equipped with SNOX technology for a combined removal of sulphur and nitrogen oxides and (iii) integrated gasification combined cycle (IGCC) plant based on a slurry-feed entrained-flow gasifier. Each technology was analysed in its configurations without and with CO 2 capture, referring to a commercial-scale of 1000 MW th . Technical assessment was carried out by using simulation models implemented through Aspen Plus and Gate-Cycle tools, whereas economic assessment was performed through a properly developed simulation model. USC equipped with CGT systems shows an overall efficiency (43.7%) comparable to IGCC (43.9%), whereas introduction of SNOX technology increases USC efficiency up to 44.8%. Being the CCS energy penalties significantly higher for USC (about 10.5% points vs. about 8

  19. On the comparison of group performance with categorical data.

    Directory of Open Access Journals (Sweden)

    Carmen Herrero

    Full Text Available There are many different evaluation problems that involve several groups (societies, firms or institutions whose members can be classified into ordered categories, pursuant to their characteristics or their achievements. This paper addresses these types of problems and provides an evaluation criterion based on the distribution of the agents across categories. The starting point is that of dominance relations in pair-wise comparisons. We say that group i dominates group j when the expected category of a member of i is higher than the expected category of a member of j. We introduce the notion of relative advantage of a group to extend this principle to multi-group comparisons and show that there is a unique evaluation function that ranks all groups consistently in terms of this criterion. This function associates to each evaluation problem the (unique dominant eigenvector of a matrix whose entries describe the dominance relations between groups in pair-wise comparisons. The working of the model is illustrated by means of three different applications.

  20. Using renewables and the co-production of hydrogen and electricity from CCS-equipped IGCC facilities, as a stepping stone towards the early development of a hydrogen economy

    International Nuclear Information System (INIS)

    Haeseldonckx, Dries; D'haeseleer, William

    2010-01-01

    In this paper, specific cases for the interaction between the future electricity-generation mix and a newly-developing hydrogen-production infrastructure is modelled with the model E-simulate. Namely, flexible integrated-gasification combined-cycle units (IGCC) are capable of producing both electricity and hydrogen in different ratios. When these units are part of the electricity-generation mix and when they are not operating at full load, they could be used to produce a certain amount of hydrogen, avoiding the costly installation of new IGCC units for hydrogen production. The same goes for the massive introduction of renewable energies (especially wind), possibly generating excess electricity from time to time, which could then perhaps be used to produce hydrogen electrolytically. However, although contra-intuitive, the interaction between both 'systems' turns out to be almost negligible. Firstly, it is shown that it is more beneficial to use IGCC facilities to produce hydrogen with, rather than (excess) wind-generated electricity due to the necessary electrolyser investment costs. But even flexible IGCC facilities do not seem to contribute substantially to the early development of a hydrogen economy. Namely, in most scenarios - which are combinations of a wide range of fuel prices and carbon taxes - one primary-energy carrier (natural gas or coal) seems to be dominant, pushing the other, and the corresponding technologies such as reformers or IGCCs, out of the market. (author)

  1. Peer influence on students' estimates of performance: social comparison in clinical rotations.

    Science.gov (United States)

    Raat, A N Janet; Kuks, Jan B M; van Hell, E Ally; Cohen-Schotanus, Janke

    2013-02-01

    During clinical rotations, students move from one clinical situation to another. Questions exist about students' strategies for coping with these transitions. These strategies may include a process of social comparison because in this context it offers the student an opportunity to estimate his or her abilities to master a novel rotation. These estimates are relevant for learning and performance because they are related to self-efficacy. We investigated whether student estimates of their own future performance are influenced by the performance level and gender of the peer with whom the student compares him- or herself. We designed an experimental study in which participating students (n = 321) were divided into groups assigned to 12 different conditions. Each condition entailed a written comparison situation in which a peer student had completed the rotation the participant was required to undertake next. Differences between conditions were determined by the performance level (worse, similar or better) and gender of the comparison peer. The overall grade achieved by the comparison peer remained the same in all conditions. We asked participants to estimate their own future performance in that novel rotation. Differences between their estimates were analysed using analysis of variance (ANOVA). Students' estimates of their future performance were highest when the comparison peer was presented as performing less well and lowest when the comparison peer was presented as performing better (p influences students' estimates of their future performance in a novel rotation. The effect depends on the performance level and gender of the comparison peer. This indicates that comparisons against particular peers may strengthen or diminish a student's self-efficacy, which, in turn, may ease or hamper the student's learning during clinical rotations. The study is limited by its experimental design. Future research should focus on students' comparison behaviour in real transitions

  2. The long-term effect of social comparison on academic performance

    NARCIS (Netherlands)

    Wehrens, Maike J. P. W.; Kuyper, Hans; Dijkstra, Pieternel; Buunk, Abraham P.; van der Werf, Margaretha P. C.

    2010-01-01

    The present study was part of a large-scale cohort study among several thousand students in the Netherlands. The purpose of the study was to investigate the long-term effects of comparison choice, i.e., comparison with a target performing better or worse than oneself, and academic comparative

  3. Comparison of wind mill cluster performance: A multicriteria approach

    Energy Technology Data Exchange (ETDEWEB)

    Rajakumar, D.G.; Nagesha, N. [Visvesvaraya Technological Univ., Karnataka (India)

    2012-07-01

    Energy is a crucial input for the economic and social development of any nation. Both renewable and non-renewable energy contribute in meeting the total requirement of the economy. As an affordable and clean energy source, wind energy is amongst the world's fastest growing renewable energy forms. Though there are several wind-mill clusters producing energy in different geographical locations, evaluating their performance is a complex task and not much of literature is available in this area. In this backdrop, an attempt is made in the current paper to estimate the performance of a wind-mill cluster through an index called Cluster Performance Index (CPI) adopting a multi-criteria approach. The proposed CPI comprises four criteria viz., Technical Performance Indicators (TePI), Economic Performance Indicators (EcPI), Environmental Performance Indicators (EnPI), and Sociological Performance Indicators (SoPI). Under each performance criterion a total of ten parameters are considered with five subjective and five objective oriented responses. The methodology is implemented by collecting empirical data from three wind-mill clusters located at Chitradurga, Davangere, and Gadag in the southern Indian State of Karnataka. Totally fifteen different stake holders are consulted through a set of structured researcher administered questionnaire to collect the relevant data in each wind farm. Stake holders involved engineers working in wind farms, wind farm developers, Government officials from energy department and a few selected residential people near the wind farms. The results of the study revealed that Chitradurga wind farm performed much better with a CPI of 45.267 as compared to Gadag (CPI of 28.362) and Davangere (CPI of 19.040) wind farms. (Author)

  4. Performance comparison of various seal coat grades used in Texas.

    Science.gov (United States)

    2012-07-01

    This report documents research efforts to provide comparative quantitative performance information for various grades of seal coat aggregate available in the Texas Department of Transportations standard specifications. Length of service before rep...

  5. Comparison and Prediction of Preclinical Students' Performance in ...

    African Journals Online (AJOL)

    olayemitoyin

    The data support the hypothesis that students who performed well in one discipline were likely to .... predict success in the clinical curriculum (Baciewicz,. 1990). Similarly ... the International Association of Medical Science. Educators. 17-20.

  6. A 2015 comparison of operational performance : Washington state ferries to ferry operators worldwide.

    Science.gov (United States)

    2015-03-01

    This report provides an update to the 2010 report A Comparison of Operational Performance: : Washington State Ferries to Ferry Operators Worldwide, observing changes in Washington State : Ferries, 23 other ferry systems, and the ferry industry ...

  7. Performance comparison analysis library communication cluster system using merge sort

    Science.gov (United States)

    Wulandari, D. A. R.; Ramadhan, M. E.

    2018-04-01

    Begins by using a single processor, to increase the speed of computing time, the use of multi-processor was introduced. The second paradigm is known as parallel computing, example cluster. The cluster must have the communication potocol for processing, one of it is message passing Interface (MPI). MPI have many library, both of them OPENMPI and MPICH2. Performance of the cluster machine depend on suitable between performance characters of library communication and characters of the problem so this study aims to analyze the comparative performances libraries in handling parallel computing process. The case study in this research are MPICH2 and OpenMPI. This case research execute sorting’s problem to know the performance of cluster system. The sorting problem use mergesort method. The research method is by implementing OpenMPI and MPICH2 on a Linux-based cluster by using five computer virtual then analyze the performance of the system by different scenario tests and three parameters for to know the performance of MPICH2 and OpenMPI. These performances are execution time, speedup and efficiency. The results of this study showed that the addition of each data size makes OpenMPI and MPICH2 have an average speed-up and efficiency tend to increase but at a large data size decreases. increased data size doesn’t necessarily increased speed up and efficiency but only execution time example in 100000 data size. OpenMPI has a execution time greater than MPICH2 example in 1000 data size average execution time with MPICH2 is 0,009721 and OpenMPI is 0,003895 OpenMPI can customize communication needs.

  8. Economic and environmental performance of future fusion plants in comparison

    International Nuclear Information System (INIS)

    Hamacher, T.; Saez, R.M.; Lako, P.

    2001-01-01

    If the good performance of fusion as technology with no CO 2 emission during normal operation and rather low external costs, reflecting the advantageous environmental and safety characteristics, are considered in future energy regulations, fusion can win considerable market shares in future electricity markets. The economic performance was elaborated for Western Europe for the time period till 2100. The software tool MARKAL widely used in energy research was used to simulate and optimise the development of the Western European energy system. Two different scenarios were considered, the main difference was the interest rate for investments. Stringent CO 2 -emission strategies lead to considerable market shares for fusion. As a comprehensive indicator of the environmental and safety performance of fusion plants the external costs following the ExternE method was used. External costs of fusion are rather low, much below the cost of electricity, and are in the same range as photovoltaics and wind energy. (author)

  9. A comparison of mental strategies during athletic skills performance.

    Science.gov (United States)

    Peluso, Eugenio A; Ross, Michael J; Gfeller, Jeffrey D; Lavoie, Donna J

    2005-12-01

    The current study examined the effects of performance enhancement techniques (PET's) on motor skill performance. Specifically, one hundred fifty college student volunteers (Men = 41; 27.3% and Women = 109; 72.6%) were randomly assigned to one of the nine conditions (Cond): Cond 1 and 2, simultaneous, externally verbalized self-talk or imagery (e.g., participants were instructed to say "aim, back, birdie "or engaged in imagery out loud while putting); Cond 3 and 4, delayed externally verbalized self-talk or imagery (e.g., participants were instructed to say "aim, back, birdie "or engaged in imagery out loud before putting); Cond 5 and 6, simultaneous, internally verbalized self-talk or imagery (e.g., participants were instructed to say "aim, back, birdie "or engaged in imagery silently to oneself while putting); Cond 7 and 8, delayed internally verbalized (e.g., participant were instructed to say "aim, back, birdie "or engaged in imagery silently to oneself before putting); and Cond 9, no instruction control group. All participants were asked to perform a golf-putting task. Results indicated that participants who implemented several (PET's) increased their putting accuracy across overall difference score evaluations F (8, 141) = 4.01, p focus.Results of the current study suggest that participants who engaged in several performance enhancement techniques exhibited enhanced performance on a golf putting task when compared to participants in a control condition.Participants who endorsed limited athletic familiarity and activity (e.g., ten hours or less) preferred self-talk practice whereas participants who endorsed higher ratings scores of athletic familiarity and activity (e.g., ten hours or more) preferred imagery strategies.The results of this study demonstrate the flexibility of Performance Enhancement Techniques (e.g., imagery v. self-talk, internal v. external, simultaneous v. delayed) and how they can be implemented to help an athlete reach his or her full

  10. SVD vs PCA: Comparison of Performance in an Imaging Spectrometer

    Directory of Open Access Journals (Sweden)

    Wilma Oblefias

    2004-12-01

    Full Text Available The calculation of basis spectra from a spectral library is an important prerequisite of any compact imaging spectrometer. In this paper, we compare the basis spectra computed by singular-value decomposition (SVD and principal component analysis (PCA in terms of estimation performance with respect to resolution, presence of noise, intensity variation, and quantization error. Results show that SVD is robust in intensity variation while PCA is not. However, PCA performs better with signals of low signal-to-noise ratio. No significant difference is seen between SVD and PCA in terms of resolution and quantization error.

  11. Highly scalable and robust rule learner: performance evaluation and comparison.

    Science.gov (United States)

    Kurgan, Lukasz A; Cios, Krzysztof J; Dick, Scott

    2006-02-01

    Business intelligence and bioinformatics applications increasingly require the mining of datasets consisting of millions of data points, or crafting real-time enterprise-level decision support systems for large corporations and drug companies. In all cases, there needs to be an underlying data mining system, and this mining system must be highly scalable. To this end, we describe a new rule learner called DataSqueezer. The learner belongs to the family of inductive supervised rule extraction algorithms. DataSqueezer is a simple, greedy, rule builder that generates a set of production rules from labeled input data. In spite of its relative simplicity, DataSqueezer is a very effective learner. The rules generated by the algorithm are compact, comprehensible, and have accuracy comparable to rules generated by other state-of-the-art rule extraction algorithms. The main advantages of DataSqueezer are very high efficiency, and missing data resistance. DataSqueezer exhibits log-linear asymptotic complexity with the number of training examples, and it is faster than other state-of-the-art rule learners. The learner is also robust to large quantities of missing data, as verified by extensive experimental comparison with the other learners. DataSqueezer is thus well suited to modern data mining and business intelligence tasks, which commonly involve huge datasets with a large fraction of missing data.

  12. Academic performance and pass rates: Comparison of three first ...

    African Journals Online (AJOL)

    First year students' academic performance in three Life Science courses (Botany, Zoology and Bioscience) was compared. Pass rates, as well as the means and distributions of final marks were analysed. Of the three components (coursework, practical and theory examinations) contributing to the final mark of each course, ...

  13. Comparison of Pickering NGS performance with world power reactors, 1977

    International Nuclear Information System (INIS)

    Buhay, S.

    Pickering NGS performance is compared, in highly graphic form, with the perfomance of other nuclear power plants around the world. The four Pickering reactors score in the top six, rated by gross capacity factor. Major system suppliers for world power reactors above 500 MW are cataloged. (E.C.B.)

  14. Comparisons of Faulting-Based Pavement Performance Prediction Models

    Directory of Open Access Journals (Sweden)

    Weina Wang

    2017-01-01

    Full Text Available Faulting prediction is the core of concrete pavement maintenance and design. Highway agencies are always faced with the problem of lower accuracy for the prediction which causes costly maintenance. Although many researchers have developed some performance prediction models, the accuracy of prediction has remained a challenge. This paper reviews performance prediction models and JPCP faulting models that have been used in past research. Then three models including multivariate nonlinear regression (MNLR model, artificial neural network (ANN model, and Markov Chain (MC model are tested and compared using a set of actual pavement survey data taken on interstate highway with varying design features, traffic, and climate data. It is found that MNLR model needs further recalibration, while the ANN model needs more data for training the network. MC model seems a good tool for pavement performance prediction when the data is limited, but it is based on visual inspections and not explicitly related to quantitative physical parameters. This paper then suggests that the further direction for developing the performance prediction model is incorporating the advantages and disadvantages of different models to obtain better accuracy.

  15. Prospects of performing multiple-country comparison of dairy sires ...

    African Journals Online (AJOL)

    International trade with genetic material has lead to the foundation of Interbull, an international organization that performs international evaluations of dairy bulls, enabling countries to obtain breeding values of foreign bulls on their on scale. Not all countries have the possibility to participate in the evaluations with their own ...

  16. Prospects of performing multiple-country comparison of dairy sires ...

    African Journals Online (AJOL)

    Anne Torsell

    Abstract. International trade with genetic material has lead to the foundation of Interbull, an international organization that performs international evaluations of dairy bulls, enabling countries to obtain breeding values of foreign bulls on their on scale. Not all countries have the possibility to participate in the evaluations.

  17. Performance comparison of plant root biofilm, gravel attached ...

    African Journals Online (AJOL)

    biofilm and planktonic microbial populations, in phenol removal within a ... This study was performed in order to understand the relative contribution of a constructed wetland (CW) system's various ... and natural physico-chemical processes are responsible for ..... rhizospheric bacterial activity: precluded by antibiotic supple-.

  18. Deep Energy Retrofit Performance Metric Comparison: Eight California Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fisher, Jeremy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-06-01

    In this paper we will present the results of monitored annual energy use data from eight residential Deep Energy Retrofit (DER) case studies using a variety of performance metrics. For each home, the details of the retrofits were analyzed, diagnostic tests to characterize the home were performed and the homes were monitored for total and individual end-use energy consumption for approximately one year. Annual performance in site and source energy, as well as carbon dioxide equivalent (CO2e) emissions were determined on a per house, per person and per square foot basis to examine the sensitivity to these different metrics. All eight DERs showed consistent success in achieving substantial site energy and CO2e reductions, but some projects achieved very little, if any source energy reduction. This problem emerged in those homes that switched from natural gas to electricity for heating and hot water, resulting in energy consumption dominated by electricity use. This demonstrates the crucial importance of selecting an appropriate metric to be used in guiding retrofit decisions. Also, due to the dynamic nature of DERs, with changes in occupancy, size, layout, and comfort, several performance metrics might be necessary to understand a project’s success.

  19. Electromagnetic Guns versus Conventional Guns - a performance comparison

    NARCIS (Netherlands)

    Reus, N.M. de; Weijden, J. van der

    1993-01-01

    Performance improvement is one of the key issues of Electromagnetic gun systems compared to conventional gun systems. Due to higher muzzle velocities, the gun's fire control computer will be able to predict the target's future position more accurately because prediction time will be smaller. In this

  20. Comparison of the Thermal Performance of Radiative and Convective Terminals

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per

    2012-01-01

    can provide a better indoor climate, and be more energy efficient because they can make use of low-grade sources. The output of this conceptual approach is a better understanding of the advantages and drawbacks of the two technologies under different conditions. The analysis has been performed...

  1. Procurement maturity, alignment and performance: a Dutch hospital case comparison.

    NARCIS (Netherlands)

    Plomp, M.; Batenburg, R.

    2009-01-01

    Procurement is an important supporting business function, with which competitive advantage can potentially be achieved. In this paper, the relation between maturity and alignment in procurement on the one hand, and procurement performance on the other, is investigated in the case study setting of

  2. Procurement Maturity, Alignment and Performance: a Dutch Hospital Case Comparison

    NARCIS (Netherlands)

    Plomp, M.G.A.; Batenburg, R.S.

    2009-01-01

    Procurement is an important supporting business function, with which competitive advantage can potentially be achieved. In this paper, the relation between maturity and alignment in procurement on the one hand, and procurement performance on the other, is investigated in the case study setting of

  3. International comparisons of public sector performance: how to move ahead?

    NARCIS (Netherlands)

    S.G.J. Van de Walle (Steven)

    2009-01-01

    textabstractMeasuring and comparing the overall performance of countries’ public sectors requires agreement on definitions and objectives of government. I argue that such an agreement is about finding a consensus rather about finding better definitions. Measuring government requires a number of

  4. PWR and WWER fuel performance. A comparison of major characteristics

    International Nuclear Information System (INIS)

    Weidinger, H.

    2006-01-01

    PWR and WWER fuel technologies have the same basic performance targets: most effective use of the energy stored in the fuel and highest possible reliability. Both fuel technologies use basically the same strategies to reach these targets: 1) Optimized reload strategies; 2) Maximal use of structural material with low neutron cross sections; 3) Decrease the fuel failure frequency towards a 'zero failure' performance by understanding and eliminating the root causes of those defects. The key driving force of the technology of both, PWR and WWER fuel is high burn-up. Presently a range of 45 - 50 MWD/kgU have been reached commercially for PWR and WWER fuel. The main technical limitations to reach high burn-up are typically different for PWR and WWER fuel: for PWR fuel it is the corrosion and hydrogen uptake of the Zr-based materials; for WWER fuel it is the mechanical and dimensional stability of the FA (and the whole core). Corrosion and hydrogen uptake of Zr-materials is a 'non-problem' for WWER fuel. Other performance criteria that are important for high burn-up are the creep and growth behaviour of the Zr materials and the fission gas release in the fuel rod. There exists a good and broad data base to model and design both fuel types. FA and fuel rod vibration appears to be a generic problem for both fuel types but with more evidence for PWR fuel performance reliability. Grid-to-rod fretting is still a major issue in the fuel failure statistics of PWR fuel. Fuel rod cladding defects by debris fretting is no longer a key problem for PWR fuel, while it still appears to be a significant root cause for WWER fuel failures. 'Zero defect' fuel performance is achievable with a high probability, as statistics for US PWR and WWER-1000 fuel has shown

  5. Comparison of performance of inclinometer casing and TDR technique

    Science.gov (United States)

    Aghda, S. M. Fatemi; Ganjalipour, K.; Nabiollahi, K.

    2018-03-01

    TDR (Time Domain Reflectometry) and GPR (Ground Penetrating Radar) are two of the electromagnetic methods in applied geophysics, which using them for various applications are developing. The Time Domain Reflectometry is a remote sensing method that has been used for years to determine the nature of the materials and spatial location. The use of TDR system has led to innovative applications of it and comparing it with previous measuring techniques, since it has developed. In this study, not only a summary of the basics of TDR application for monitoring of ground deformation is offered, but also a comparison of this technology with other measurement techniques (inclinometer casing) is provided. Actually, this paper presents a case study in which the opportunity arose to compare these two technologies in detecting subsurface deformation in slopes. A TDR system includes a radar wave receiver & generator, a transmission line and a waveguide. The generated electro-magnetic pulse moves toward the waveguide within the conductor cable and enters the test environment. For this study, slopes overlooking the Darian dam bottom outlet, power house and spillway were instrumented with RG59/U coaxial cables for TDR monitoring and slope inclinometer. Coaxial cables - as a TDR sensor - and inclinometer casings were installed in a same bore hole where coaxial cable was attached to the inclinometer casing. Shear and tensile deformations of the cable, which is caused by ground movements, significantly impacts on cable reflection coefficient. In Darian dam boreholes, the cable points subject to the shear and stretch were correlated with deformation points of the inclinometer casings in incremental displacement graphs. This study shows that TDR technique is more sensitive than inclinometer casing for small movement in the slide planes. Because manual processing of TDR data is hard and need experienced personnel, the authors have designed an algorithm to compare the shape of the new TDR

  6. Performance comparison of direct and indirect lighting systems

    International Nuclear Information System (INIS)

    Rubinstein, F.; Morse, O.; Clark, T.

    1993-01-01

    The performance of a retrofitted indirect lighting system was compared to the performance of a typical de-lamped direct lighting system in a partitioned office space. Power, illuminance and luminance measurements were made for the de-lamped direct lighting system and after installation of the indirect lighting system with various lamp and ballast combinations. Using the same lamps and ballasts, average workplace illuminance was slightly higher with indirect lighting than with direct lighting. With indirect lighting, workplace lumen efficacy was 4.5% lower due to the higher power draw of the lamps in the more open and cooler indirect fixtures. Indirect lighting with 36 watt T-8 lamps and electronic ballasts achieved an initial average workplace illuminance of 45 foot-candles in the partitioned office space at only 1.1 w/ft 2

  7. Blanket materials for fusion reactors: comparisons of thermochemical performance

    International Nuclear Information System (INIS)

    Johnson, C.E.; Fischer, A.K.; Tetenbaum, M.

    1984-01-01

    Thermodynamic calculations have been made to predict the thermochemical performance of the fusion reactor breeder materials, Li 2 O, LiAlO 2 , and Li 4 SiO 4 in the temperature range 900 to 1300 0 K and in the oxygen activity range 10 -25 to 10 -5 . Except for a portion of these ranges, the performance of LiAlO 2 is predicted to be better than that of Li 2 O and Li 4 SiO 4 . The protium purge technique for enhancing tritium release is explored for the Li 2 O system; it appears advantageous at higher temperatures but should be used cautiously at lower temperatures. Oxygen activity is an important variable in these systems and must be considered in executing and interpreting measurements on rates of tritium release, the form of released tritium, diffusion of tritiated species and their identities, retention of tritium in the condensed phase, and solubility of hydrogen isotope gases

  8. Comparison of academic performance of twins and singletons in adolescence

    DEFF Research Database (Denmark)

    Christensen, Kaare; Petersen, Inge; Skytthe, Axel

    2006-01-01

    deviations for twins and singletons (8.02 v 8.02 and 1.05 v 1.06) despite the twins weighing on average 908 g (95% confidence interval 886 to 930 g) less than the singletons at birth. Controlling for birth weight, gestational age at birth, age at test, and parents' age and education confirmed the similarity......OBJECTIVES: To determine whether twins in recent cohorts show similar academic performance in adolescence to singletons and to test the effect of birth weight on academic performance in twins and singletons. DESIGN: Follow-up study. SETTING: Denmark. PARTICIPANTS: All twins (n=3411) and a 5% random...... sample of singletons (n=7796) born in Denmark during 1986-8. MAIN OUTCOME MEASURES: Test scores in ninth grade (age 15 or 16), birth weight, gestational age at birth, parents' age, and parents' education. RESULTS: Ninth grade test scores were normally distributed, with almost identical mean and standard...

  9. Performance comparison between ISCSI and other hardware and software solutions

    CERN Document Server

    Gug, M

    2003-01-01

    We report on our investigations on some technologies that can be used to build disk servers and networks of disk servers using commodity hardware and software solutions. It focuses on the performance that can be achieved by these systems and gives measured figures for different configurations. It is divided into two parts : iSCSI and other technologies and hardware and software RAID solutions. The first part studies different technologies that can be used by clients to access disk servers using a gigabit ethernet network. It covers block access technologies (iSCSI, hyperSCSI, ENBD). Experimental figures are given for different numbers of clients and servers. The second part compares a system based on 3ware hardware RAID controllers, a system using linux software RAID and IDE cards and a system mixing both hardware RAID and software RAID. Performance measurements for reading and writing are given for different RAID levels.

  10. Cross-cultural comparison of neurobehavioral performance in Asian workers.

    Science.gov (United States)

    Chung, Jong-Hak; Sakong, Joon; Kang, Pock-Soo; Kim, Chang-Yoon; Lee, Kyeong-Soo; Jeon, Man-Joong; Sung, Nak-Jung; Ahn, Sang-Ho; Won, Kyu-Chang

    2003-08-01

    Widely-used neurobehavioral tests have been developed and standardized on Western populations, but studies on subject factors for Asian populations have been very limited. For the effective application and interpretation of neurobehavioral tests in Asian populations, an evaluation of the effects of subject factors, including cultural background, is necessary. A cross-cultural study was conducted to evaluate the effects of cultural background and the interaction between cultural background and education on neurobehavioral tests in Asian populations. The Korean version of the Swedish Performance Evaluation System (Simple Reaction Time, Symbol Digit, and Finger Tapping Speed) and a pegboard test were administered to 537 workers who were not exposed to chemicals at work from Fareast (Korea and Chinese), Central (Uzbekistan and Tajikistan), and South Asia (Sri Lanka and Indonesia). The Fareast Asian group exhibited better performance in adjusted test scores than other Asian groups, achieving significance for Symbol Digit and Finger Tapping Speed in both genders. The magnitude of the effect of cultural background on Symbol Digit was comparable to the effect of about 10 years of education. Cultural background did not modify the relation between years of education and Symbol Digit in either males or females. This study may provide the first evidence that cultural background has a large impact on neurobehavioral test performance, even within Asian populations, and suggests that cultural background is a critical confounding factor that must be controlled in epidemiologic studies which include Asian populations in the sample.

  11. Performance comparison of scintillators for alpha particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yuki [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Yamamoto, Seiichi [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Izaki, Kenji [Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Kaneko, Junichi H.; Toui, Kohei; Tsubota, Youichi; Higuchi, Mikio [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

    2014-11-11

    Scintillation detectors for alpha particles are often used in nuclear fuel facilities. Alpha particle detectors have also become important in the research field of radionuclide therapy using alpha emitters. ZnS(Ag) is the most often used scintillator for alpha particle detectors because its light output is high. However, the energy resolution of ZnS(Ag)-based scintillation detectors is poor because they are not transparent. A new ceramic sample, namely the cerium doped Gd{sub 2}Si{sub 2}O{sub 7} (GPS) scintillator, has been tested as alpha particle detector and its performances have been compared to that one of three different scintillating materials: ZnS(Ag), GAGG and a standard plastic scintillator. The different scintillating materials have been coupled to two different photodetectors, namely a photomultiplier tube (PMT) and a Silicon Photo-multiplier (Si-PM): the performances of each detection system have been compared. Promising results as far as the energy resolution performances (10% with PMT and 14% with Si-PM) have been obtained in the case of GPS and GAGG samples. Considering the quantum efficiencies of the photodetectors under test and their relation to the emission wavelength of the different scintillators, the best results were achieved coupling the GPS with the PMT and the GAGG with the Si-PM.

  12. Comparison of Simple Versus Performance-Based Fall Prediction Models

    Directory of Open Access Journals (Sweden)

    Shekhar K. Gadkaree BS

    2015-05-01

    Full Text Available Objective: To compare the predictive ability of standard falls prediction models based on physical performance assessments with more parsimonious prediction models based on self-reported data. Design: We developed a series of fall prediction models progressing in complexity and compared area under the receiver operating characteristic curve (AUC across models. Setting: National Health and Aging Trends Study (NHATS, which surveyed a nationally representative sample of Medicare enrollees (age ≥65 at baseline (Round 1: 2011-2012 and 1-year follow-up (Round 2: 2012-2013. Participants: In all, 6,056 community-dwelling individuals participated in Rounds 1 and 2 of NHATS. Measurements: Primary outcomes were 1-year incidence of “ any fall ” and “ recurrent falls .” Prediction models were compared and validated in development and validation sets, respectively. Results: A prediction model that included demographic information, self-reported problems with balance and coordination, and previous fall history was the most parsimonious model that optimized AUC for both any fall (AUC = 0.69, 95% confidence interval [CI] = [0.67, 0.71] and recurrent falls (AUC = 0.77, 95% CI = [0.74, 0.79] in the development set. Physical performance testing provided a marginal additional predictive value. Conclusion: A simple clinical prediction model that does not include physical performance testing could facilitate routine, widespread falls risk screening in the ambulatory care setting.

  13. Performance comparison of binary modulation schemes for visible light communication

    KAUST Repository

    Park, Kihong

    2015-09-11

    In this paper, we investigate the power spectral density of several binary modulation schemes including variable on-off keying, variable pulse position modulation, and pulse dual slope modulation which were previously proposed for visible light communication with dimming control. We also propose a novel slope-based modulation called differential chip slope modulation (DCSM) and develop a chip-based hard-decision receiver to demodulate the resulting signal, detect the chip sequence, and decode the input bit sequence. We show that the DCSM scheme can exploit spectrum density more efficiently than the reference schemes while providing an error rate performance comparable to them. © 2015 IEEE.

  14. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation...... with respect to a variety of SOFC inputs. SOFC stack operation on syn-gas is compared to operation on different coal properties and as expected there is a drop in performance, which is attributed to increased input fuel and air flow due to the lower quality of the fuel gas....

  15. A Performance Comparison of Nine Selected Liquid Scintillation Cocktails

    Energy Technology Data Exchange (ETDEWEB)

    Verrezen, F; Loots, H; Hurtgen, Ch

    2008-06-15

    In the selection of a suitable liquid scintillation (LSC) cocktail, the primary aspects taken into consideration are overall cocktail performance and specific laboratory needs. Overall performance of 9 selected, commercially available LSC cocktails was assessed by studying parameters of importance for the requirements of the Laboratory for Low Level Radioactivity Measurements of SCK-CEN: sample load capacity, sample compatibility, influence of sample load on counting efficiency, background count rate, figure of merit, quench resistance, sample stability and alpha/beta separation characteristics. The cocktails tested were EcoscintA, Insta Gel Plus, OptiPhase Hisafe3, OptiPhase Trisafe, Ready Gel, SafeScint 1:1, Ultima Gold, Ultima Gold LLT, and Ultima Gold XR. For the data acquisition a Packard TriCarb Model 1900CA and a Quantulus 1220 liquid scintillation counter is used. All samples were prepared in either 20 mL low potassium, borosilicate glass vials or 20 mL high density, polyethylene vials. The aim of this study was to determine a single cocktail that best suits all measurement requirements of the liquid scintillation laboratory at SCK-CEN for the determination of low levels of radioactivity in biological and environmental samples. As a conclusion, Optiphase HiSafe 3 was confirmed to be the optimal cocktail for the laboratory.

  16. A Performance Comparison of Nine Selected Liquid Scintillation Cocktails

    International Nuclear Information System (INIS)

    Verrezen, F.; Loots, H.; Hurtgen, Ch.

    2008-01-01

    In the selection of a suitable liquid scintillation (LSC) cocktail, the primary aspects taken into consideration are overall cocktail performance and specific laboratory needs. Overall performance of 9 selected, commercially available LSC cocktails was assessed by studying parameters of importance for the requirements of the Laboratory for Low Level Radioactivity Measurements of SCK-CEN: sample load capacity, sample compatibility, influence of sample load on counting efficiency, background count rate, figure of merit, quench resistance, sample stability and alpha/beta separation characteristics. The cocktails tested were EcoscintA, Insta Gel Plus, OptiPhase Hisafe3, OptiPhase Trisafe, Ready Gel, SafeScint 1:1, Ultima Gold, Ultima Gold LLT, and Ultima Gold XR. For the data acquisition a Packard TriCarb Model 1900CA and a Quantulus 1220 liquid scintillation counter is used. All samples were prepared in either 20 mL low potassium, borosilicate glass vials or 20 mL high density, polyethylene vials. The aim of this study was to determine a single cocktail that best suits all measurement requirements of the liquid scintillation laboratory at SCK-CEN for the determination of low levels of radioactivity in biological and environmental samples. As a conclusion, Optiphase HiSafe 3 was confirmed to be the optimal cocktail for the laboratory.

  17. Comparison of driving simulator performance and neuropsychological testing in narcolepsy.

    Science.gov (United States)

    Kotterba, Sylvia; Mueller, Nicole; Leidag, Markus; Widdig, Walter; Rasche, Kurt; Malin, Jean-Pierre; Schultze-Werninghaus, Gerhard; Orth, Maritta

    2004-09-01

    Daytime sleepiness and cataplexy can increase automobile accident rates in narcolepsy. Several countries have produced guidelines for issuing a driving license. The aim of the study was to compare driving simulator performance and neuropsychological test results in narcolepsy in order to evaluate their predictive value regarding driving ability. Thirteen patients with narcolepsy (age: 41.5+/-12.9 years) and 10 healthy control patients (age: 55.1+/-7.8 years) were investigated. By computer-assisted neuropsychological testing, vigilance, alertness and divided attention were assessed. In a driving simulator patients and controls had to drive on a highway for 60 min (mean speed of 100 km/h). Different weather and daytime conditions and obstacles were presented. Epworth Sleepiness Scale-Scores were significantly raised (narcolepsy patients: 16.7+/-5.1, controls: 6.6+/-3.6, P divided attention (56.9+/-25.4) and vigilance (58.7+/-26.8) were in a normal range. There was, however, a high inter-individual difference. There was no correlation between driving performance and neuropsychological test results or ESS Score. Neuropsychological test results did not significantly change in the follow-up. The difficulties encountered by the narcolepsy patient in remaining alert may account for sleep-related motor vehicle accidents. Driving simulator investigations are closely related to real traffic situations than isolated neuropsychological tests. At the present time the driving simulator seems to be a useful instrument judging driving ability especially in cases with ambiguous neuropsychological results.

  18. Performing bone marrow biopsies with or without sedation: a comparison.

    Science.gov (United States)

    Giannoutsos, I; Grech, H; Maboreke, T; Morgenstern, G

    2004-06-01

    Although intravenous sedation (ISED) in addition to a local anaesthetic (LA) is commonly used in the performance of a bone marrow aspirate and trephine (BMAT), it is not clear under what circumstances and in which way sedation may be most beneficial. In this study, information was gathered using a questionnaire, from 112 patients shortly after undergoing BMAT; the duration of the procedures and the length of the biopsy cores were measured and any complications noted. Most patients (68%) chose to receive LA only, and almost all (74/76) were happy with their decision. Patients who received sedation gave lower pain scores than patients receiving LA only (1 vs. 3) and were found to have lower levels of apprehension at the thought of having a repeat procedure. Patients having a repeat BMAT showed a slightly increased preference for having sedation compared with patients who were undergoing it for the first time. There is some concern that guidelines regarding the use of ISED for procedures other than BMAT are not always adhered to, and current practice may be best revealed by a large-scale audit of sedation practice for the performance of BMAT. Patients should be given the choice of having ISED if the appropriate resources are available, but in most cases the additional small risk of receiving sedation can be avoided.

  19. Cognitive performance of neuromyelitis optica patients: comparison with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Sandra Vanotti

    2013-06-01

    Full Text Available The aim of the present research was to investigate cognitive pattern of patients with neuromyelitis optica (NMO and to compare it with multiple sclerosis (MS patients' performance. Methods: Fourteen NMO, 14 relapsing remitting multiple sclerosis (RRMS, and 14 healthy control patients participated in the investigation. Neuropsychological functions were evaluated with the Brief Repeatable Neuropsychological Battery for MS; Symbol Digit Modalities Test; Digit Span; and Semantic Fluency. Results: Fifty-seven percent of NMO patients and 42.85% of the MS ones had abnormal performance in at least two cognitive tests. The NMO Group showed abnormal performance in verbal fluency, verbal and visual memories, with greater attention deficits. NMO patients outperformed healthy control in the paced auditory serial addition test (PASAT. However, no difference was found between NMO and RRMS patients. Conclusions: The NMO Group showed more dysfunction in attention and verbal fluencies than in verbal and visual memories. When compared with the MS patients, a similar dysfunction pattern was found. O objetivo da presente pesquisa foi investigar o padrão cognitivo de pacientes com neuromielite óptica (NMO e compará-lo com o desempenho de pacientes com esclerose múltipla (EM. Métodos: Quatorze pacientes com NMO, 14 com esclerose múltipla recorrente remitente (EMRR e 14 participantes do Controle saudáveis participaram da presente investigação. As funções neuropsicológicas foram avaliadas com a Bateria Breve de Testes Neuropsicológicos de Rao, Teste Símbolo Digit e a Fluência Semântica. Resultados: Cinquenta e sete por cento dos pacientes com NMO e 42,85% daqueles com EM apresentaram desempenho anormal em pelo menos dois testes cognitivos. O Grupo NMO apresentarou desempenho anormal na fluência verbal e nas memórias visual e verbal, com maiores déficits de atenção. Pacientes com NMO superaram os controles saudáveis em PASAT. No entanto, não foi

  20. Comparison of Ontario Hydro's performance with world power reactors - 1981

    International Nuclear Information System (INIS)

    Dumka, B.R.

    1982-04-01

    The performance of Ontario Hydro's CANDU reactors in 1981 is compared with that of 123 world nuclear power reactors rated at 500 MW(e) or greater. The report is based on data extracted from publications, as well as correspondence with a number of utilities. The basis used is the gross capacity factor, which is defined as gross unit generation divided by the perfect gross output for the period of interest. The lowest of the published turbine and generator design ratings is used to determine the perfect gross output, unless the unit has been proven capable of consistently exceeding this value. The first six reactors in the rankings were CANDU reactors operated by Ontario Hydro

  1. A performance comparison of single product kanban control systems

    Directory of Open Access Journals (Sweden)

    Alvin Ang

    2015-01-01

    Full Text Available This paper presents a simulation experiment comparing the Single Stage, Single Product Base Stock (BS, Traditional Kanban Control System (TKCS and Extended Kanban Control System (EKCS. The results showed that BS incurs the highest cost in all scenarios; while EKCS is found to be effective only in a very niche scenario. TKCS is still a very powerful factory management system to date; and EKCS did not perform exceptionally well. The only time EKCS did outperform TKCS was during low demand arrival rates and low Backorder (Cb and Shortage costs (Cs. That is because during then, it holds no stock. The most important discovery made here is that EKCS becomes TKCS once it has base stock (or dispatched kanbans. The results have also evinced the strength of the pure kanban system, the TKCS over BS. Hence managers using BS should consider upgrading to TKCS to save cost.

  2. Comparison of the performances of several modified bituminous mix formulas

    Science.gov (United States)

    Saoula, Samia; Haddadi, Smail; Mokhtar, Khedidja Ait

    2012-09-01

    The mechanical behaviour of several formulas of bituminous concrete containing polymer (HDPE), polymer-bitumens (EVA) and waste of sole of shoes (containing copolymer butadiene-styrene-SBR noted DSBR and ethylene and vinyl acetate-EVA noted DEVA) were studied. The aim of this work is to improvement of the poor mechanicals performances of a bituminous concrete formula (0/14) which isn't conforming to the Algerian standards. Also, the mechanical tests showed that the permanent deformations and the indirect tensile strength at the temperatures of service resistances are improved. At high-temperature service, formulas of asphalt bitumen-EVA most resistant against the average temperature in service, it mixes made with waste are best resistant. All the formulas have a good behaviour with water.

  3. A comparison of proxy performance in coral biodiversity monitoring

    Science.gov (United States)

    Richards, Zoe T.

    2013-03-01

    The productivity and health of coral reef habitat is diminishing worldwide; however, the effect that habitat declines have on coral reef biodiversity is not known. Logistical and financial constraints mean that surveys of hard coral communities rarely collect data at the species level; hence it is important to know if there are proxy metrics that can reliably predict biodiversity. Here, the performances of six proxy metrics are compared using regression analyses on survey data from a location in the northern Great Barrier Reef. Results suggest generic richness is a strong explanatory variable for spatial patterns in species richness (explaining 82 % of the variation when measured on a belt transect). The most commonly used metric of reef health, percentage live coral cover, is not positively or linearly related to hard coral species richness. This result raises doubt as to whether management actions based on such reefscape information will be effective for the conservation of coral biodiversity.

  4. Comparison of First Gear Performance for Manual and Automatic Transmissions

    Directory of Open Access Journals (Sweden)

    Kyle Stottlemyer

    2011-01-01

    Full Text Available The purpose of this project is to compare the first gear performance of an automobile for both its manual and automatic transmission options. Each transmission type has a different gear ratio, which yields a different acceleration curve for each transmission throughout the torque-rpm curve of the engine. The method of integral calculus was used to find an equation which could be used to solve for time at any point in the car's acceleration. The automobile velocity versus time was then graphed to compare each transmissions acceleration trend. This process is similar to that which automotive companies may use when determining what type of transmission to pair with a particular vehicle. By observing the trends in the acceleration graphs, it was determined that there are specific advantages and disadvantages to each type of transmission. Which transmission is the “better” choice is dependent on what application the automobile will be used for (e.g. racing, day-to-day driving, towing/hauling.

  5. Comparisons of processes and performance of SSC-VQP material

    International Nuclear Information System (INIS)

    Seuntjens, J.M.; Clark, F.Y.; Erdmann, M.J.; Coleman, E.S.; Jones, B.A.

    1994-01-01

    The Superconducting Super Collider's (SSC) cable Vendor Qualification Program (VQP) will end in FY 1993. At the time of this writing, all 8 vendors involved in this program have demonstrated capability to fabricate conductor which meets SSC specifications. The magnet vendors have hard choices to make in calendar year 1993 in deciding which cable vendors will make the production cable. It is well accepted that because of requirements of magnet uniformity, that only one vendor will be chosen for dipole Inner cable, one vendor for dipole Outer cable, and one vendor for quadrupole Outer cable. The production quantities are nominally 500, 500, and 200 metric tonnes, respectively. Among the many deciding factors are a technically sound production process, process control, and production quantity capability of each cable vendor. Qualified vendors will have proven their technical process and process control is adequate for production quantities. This paper is part of ongoing effort to provide technical information for the magnet vendor's decision making process. Some of the Phase IB process data is summarized as well as results of a portion of the materials characterization performed at the SSC Laboratory. Key process and final product parameters for each cable vendor are compared without identifying specific vendor's process detail

  6. Comparisons of processes and performance of SSC-VQP material

    International Nuclear Information System (INIS)

    Seuntjens, J.; Clark, F.; Erdmann, M.; Coleman, E.; Jones, B.

    1993-05-01

    The Superconducting Super Collider's (SSC) cable Vendor Qualification Program (VQP) will end in FY 1993. At the time of this writing, all 8 vendors involved in this program have demonstrated capability to fabricate conductor which meets SSC specifications. The magnet vendors have hard choices to make in calendar year 1993 in deciding which cable vendors will make the production cable. It is well accepted that because of requirements of magnet uniformity, that only one vendor will be chosen for dipole Inner cable, one vendor for dipole Outer cable, and one vendor for quadrupole Outer cable. The production quantities are nominally 500, 500, and 200 metric tonnes, respectively. Among the many deciding factors are a technically sound production process, process control, and production quantity capability of each cable vendor. Qualified vendors will have proven their technical process and process control is adequate for production quantities. This paper is part of ongoing effort to provide technical information for the magnet vendor's decision making process. Some of the Phase IB process data is summarized and well as results of a portion of the materials characterization performed at the SSC Laboratory. Key process and final product parameters for each cable vendor are compared without identifying specific vendor's process detail

  7. International Comparisons on Internal Labor Markets and Corporate Performance

    Directory of Open Access Journals (Sweden)

    Joonmo Cho

    2003-12-01

    Full Text Available This paper presents an analytical framework which demonstrates how the structures of corporate internal labor markets are formed within the broader labor and capital market context in the U.S. and Japan. This framework is then used to evaluate labor markets within Korean companies and to identify points of change which might promote greater efficiency. Prior to the Asian economic crisis, Korean conglomerates had large, closed internal labor markets. However, in the aftermath of the crisis, they have pursued structural downsizing and moved to open their labor markets. The empirical evidence introduced in this paper affirms the argument that the first step toward creating a flexible labor market in Korea should begin with establishing an efficient corporate governance structure. This implies that a simple switch from the Japanese paradigm for human resource management to an Anglo-American model or vice-versa may not improve internal labor market performance unless the change is accompanied by a solution to the problems posed by the minority controlling structure of Korean companies. The implications of this study for guiding policy in developing countries having labor market rigidities and underdeveloped corporate governance is clear. Capital market structure and corporate governance systems may provide an appropriate starting point for the development of any policies aimed at building an efficient human resource management system and a flexible labor market.

  8. Performance Comparison of Sweeping/Steady Jet Actuators

    Science.gov (United States)

    Hirsch, Damian; Mercier, Justin; Noca, Flavio; Gharib, Morteza

    2015-11-01

    Flow control through the use of steady jet actuators has been used on various aircraft models since the late 1950's. However, the focus of recent studies has shifted towards the use of sweeping jets (fluidic oscillators) rather than steady jet actuators. In this work, experiments using various jet actuator designs were conducted at GALCIT's Lucas Wind Tunnel on a NACA 0012 vertical tail model similar to that of the Boeing 767 vertical stabilizer at Reynolds numbers ranging from 0.5 to 1.2 million. The rudder angle was fixed at 20 degrees. A total of 32 jet actuators were installed along the wingspan perpendicular to the trailing edge and the rudder shoulder of the vertical stabilizer. It is known that these types of flow control prevent separation. However, the goal of this work is to compare different jet designs and evaluate their performance. Parameters such as the number of actuators, their volumetric flow, and the wind tunnel speed were varied. The lift generation capabilities of steady and sweeping jet actuators were then compared. Another set of experiments was conducted to compare a new sweeping jet actuator design with one of the standard versions. Supported by Boeing.

  9. Between-individual comparisons in performance evaluation: a perspective from prospect theory.

    Science.gov (United States)

    Wong, Kin Fai Ellick; Kwong, Jessica Y Y

    2005-03-01

    This article examines how between-individual comparisons influence performance evaluations in rating tasks. The authors demonstrated a systematic change in the perceived difference across ratees as a result of changing the way performance information is expressed. Study 1 found that perceived performance difference between 2 individuals was greater when their objective performance levels were presented with small numbers (e.g., absence rates of 2% vs. 5%) than when they were presented with large numbers (e.g., attendance rates of 98% vs. 95%). Extending this finding to situations involving trade-offs between multiple performance attributes across ratees, Study 2 showed that the relative preference for 1 ratee over another actually reversed when the presentation format of the performance information changed. The authors draw upon prospect theory to offer a theoretical framework describing the between-individual comparison aspect of performance evaluation.

  10. a Performance Comparison of Feature Detectors for Planetary Rover Mapping and Localization

    Science.gov (United States)

    Wan, W.; Peng, M.; Xing, Y.; Wang, Y.; Liu, Z.; Di, K.; Teng, B.; Mao, X.; Zhao, Q.; Xin, X.; Jia, M.

    2017-07-01

    Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.

  11. A PERFORMANCE COMPARISON OF FEATURE DETECTORS FOR PLANETARY ROVER MAPPING AND LOCALIZATION

    Directory of Open Access Journals (Sweden)

    W. Wan

    2017-07-01

    Full Text Available Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.

  12. Performance and operational economics estimates for a coal gasification combined-cycle cogeneration powerplant

    Science.gov (United States)

    Nainiger, J. J.; Burns, R. K.; Easley, A. J.

    1982-01-01

    A performance and operational economics analysis is presented for an integrated-gasifier, combined-cycle (IGCC) system to meet the steam and baseload electrical requirements. The effect of time variations in steam and electrial requirements is included. The amount and timing of electricity purchases from sales to the electric utility are determined. The resulting expenses for purchased electricity and revenues from electricity sales are estimated by using an assumed utility rate structure model. Cogeneration results for a range of potential IGCC cogeneration system sizes are compared with the fuel consumption and costs of natural gas and electricity to meet requirements without cogeneration. The results indicate that an IGCC cogeneration system could save about 10 percent of the total fuel energy presently required to supply steam and electrical requirements without cogeneration. Also for the assumed future fuel and electricity prices, an annual operating cost savings of 21 percent to 26 percent could be achieved with such a cogeneration system. An analysis of the effects of electricity price, fuel price, and system availability indicates that the IGCC cogeneration system has a good potential for economical operation over a wide range in these assumptions.

  13. Performance evaluation of 2D image registration algorithms with the numeric image registration and comparison platform

    International Nuclear Information System (INIS)

    Gerganov, G.; Kuvandjiev, V.; Dimitrova, I.; Mitev, K.; Kawrakow, I.

    2012-01-01

    The objective of this work is to present the capabilities of the NUMERICS web platform for evaluation of the performance of image registration algorithms. The NUMERICS platform is a web accessible tool which provides access to dedicated numerical algorithms for registration and comparison of medical images (http://numerics.phys.uni-sofia.bg). The platform allows comparison of noisy medical images by means of different types of image comparison algorithms, which are based on statistical tests for outliers. The platform also allows 2D image registration with different techniques like Elastic Thin-Plate Spline registration, registration based on rigid transformations, affine transformations, as well as non-rigid image registration based on Mobius transformations. In this work we demonstrate how the platform can be used as a tool for evaluation of the quality of the image registration process. We demonstrate performance evaluation of a deformable image registration technique based on Mobius transformations. The transformations are applied with appropriate cost functions like: Mutual information, Correlation coefficient, Sum of Squared Differences. The accent is on the results provided by the platform to the user and their interpretation in the context of the performance evaluation of 2D image registration. The NUMERICS image registration and image comparison platform provides detailed statistical information about submitted image registration jobs and can be used to perform quantitative evaluation of the performance of different image registration techniques. (authors)

  14. Performance comparison of OpenCL and CUDA by benchmarking an optimized perspective backprojection

    Energy Technology Data Exchange (ETDEWEB)

    Swall, Stefan; Ritschl, Ludwig; Knaup, Michael; Kachelriess, Marc [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. of Medical Physics (IMP)

    2011-07-01

    The increase in performance of Graphical Processing Units (GPUs) and the onward development of dedicated software tools within the last decade allows to transfer performance-demanding computations from the Central Processing Unit (CPU) to the GPU and to speed up certain tasks by utilizing the massiv parallel architecture of these devices. The Computate Unified Device Architecture (CUDA) developed by NVIDIA provides an easy hence effective way to develop application that target NVIDIA GPUs. It has become one of the cardinal software tools for this purpose. Recently the Open Computing Language (OpenCL) became available that is neither vendor-specific nor limited to GPUs only. As the benefits of CUDA-based image reconstruction are well known we aim at providing a comparison between the performance that can be achieved with CUDA in comparison to OpenCL by benchmarking the time required to perform a simple but computationally demanding task: the perspective backprojection. (orig.)

  15. Comparison of specific production performances by two crystalline silicon PV systems

    Directory of Open Access Journals (Sweden)

    Martin Fajman

    2013-01-01

    Full Text Available A comparison of two independent photovoltaic (PV systems located close to each other on the south of the Czech Moravian Highland was accomplished. Due to differences in installation parameters; reference quantities were used to calculate transformed data sets for specific production performances comparison. Differences in monthly and annually daily production were performed by t-test.According to obtained results, it was concluded that annually mean daily productions per 1 kWp of installed capacity and per 1 m2 of active area of the panels are significantly better by single crystal silicon installation in tracking system than by stable installation of a different technology of single crystal silicon. However, comparing this performance per 1 m2 of occupied land by studied power-plants the stable installation performed higher production rates on daily mean basis in majority of months of the year 2010 as well as by annually mean daily production.

  16. Comparison of reactivity estimation performance between two extended Kalman filtering schemes

    International Nuclear Information System (INIS)

    Peng, Xingjie; Cai, Yun; Li, Qing; Wang, Kan

    2016-01-01

    Highlights: • The performances of two EKF schemes using different Jacobian matrices are compared. • Numerical simulations are used for the validation and comparison of these two EKF schemes. • The simulation results show that the EKF scheme adopted by this paper performs better than the one adopted by previous literatures. - Abstract: The extended Kalman filtering (EKF) technique has been utilized in the estimation of reactivity which is a significantly important parameter to indicate the status of the nuclear reactor. In this paper, the performances of two EKF schemes using different Jacobian matrices are compared. Numerical simulations are used for the validation and comparison of these two EKF schemes, and the results show that the Jacobian matrix obtained directly from the discrete-time state model performs better than the one which is the discretization form of the Jacobian matrix obtained from the continuous-time state model.

  17. Comparison of the performance and security of free and open source smart card offcard APIs

    CSIR Research Space (South Africa)

    Chifura, A

    2008-09-01

    Full Text Available . Off card APIs provide a framework for this by providing interfaces that can be implemented to enhance the communication. This study looks at the performance and security comparisons of several free and open source smart card offcard APIs...

  18. Performance Comparison for Virtual Impedance Techniques Used in Droop Controlled Islanded Microgrids

    DEFF Research Database (Denmark)

    Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

    2016-01-01

    ). Virtual impedance loops were proposed in literature to improve the current sharing between the inverters by normalizing the output impedance of the inverters. However, virtual impedance loops have constraints in this respect since the improvement in the current sharing occurs through redistribution...... for a single phase microgrid setup to achieve a fair performance comparison of the different virtual impedance techniques....

  19. Bayesian Comparison of Alternative Graded Response Models for Performance Assessment Applications

    Science.gov (United States)

    Zhu, Xiaowen; Stone, Clement A.

    2012-01-01

    This study examined the relative effectiveness of Bayesian model comparison methods in selecting an appropriate graded response (GR) model for performance assessment applications. Three popular methods were considered: deviance information criterion (DIC), conditional predictive ordinate (CPO), and posterior predictive model checking (PPMC). Using…

  20. Bursty data traffic via satellite: performance comparison between two TDMA access schemes

    OpenAIRE

    Celandroni, Nedo; Ferro, Erina; Potort?, Francesco; Maral, Gerard

    1997-01-01

    This paper reports the simulation results of a performance comparison between two centralised thin route TDrvlA satellite access schemes, in terms of bursty data transmission delay in the context of LAN interconnection traffic. The schemes compared are CFRA' I, and FODA/IBEA'

  1. Comparison of Cloud vs. Tape Backup Performance and Costs with Oracle Database

    OpenAIRE

    Zrnec, Aljaž; Lavbič, Dejan

    2011-01-01

    Current practice of backing up data is based on using backup tapes and remote locations for storing data. Nowadays, with the advent of cloud computing a new concept of database backup emerges. The paper presents the possibility of making backup copies of data in the cloud. We are mainly focused on performance and economic issues of making backups in the cloud in comparison to traditional backups. We tested the performance and overall costs of making backup copies of data in Ora...

  2. Comparison Criteria and Performance Levels for Soundproofing Panels Made in Different Constructive Variants

    Directory of Open Access Journals (Sweden)

    Ana Gheorghe

    2013-09-01

    Full Text Available This paper presents an analysis of the performance lavels and comparison criteria for panels made from different soundproofing materials, in different constructive variants. Setting the performance level, on the basis of normative and regulatory documents, for soundproofing materials contained inside of noise reduction devices, is determined so that it can be defined, tested and established feasible technical solutions for sound absorbing protection, through a dissemination of obtained results as well for ensuring requirements for implementing the technology transfer for manufacturing.

  3. Green power production by co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGCC processes

    Energy Technology Data Exchange (ETDEWEB)

    Van Ree, R; Korbee, R; De Smidt, R P; Jansen, D [ECN Fuels Conversion and Environment, Petten (Netherlands); Baumann, H R; Ullrich, N [Krupp Uhde, Dortmund (Germany); Haupt, G; Zimmerman, [Siemens, Erlangen (Germany)

    1998-11-01

    The use of coal for large scale power production meets a growing environmental concern. In spite of the fact that clean coal conversion technologies integrated with high-efficiency power production facilities, such as IGCC, are developed, the aim for sustainable development strives for a power production system based on renewable energy sources. One of the most promising renewable energy sources that can be used in the Netherlands is biomass, i.e. organic waste materials and/or energy crops. To accelerate the introduction of this material, in a technical and economically acceptable way, co-gasification with fossil fuels, in particular coal, in large scale IGCC processes is considered. In this paper the technical feasibility, economic profitability, and environmental acceptability of co-gasification of biomass in coal-fired oxygen-blown entrained-flow based IGM is discussed. Both a base-case coal-fired oxygen-blown entrained-flow based IGCC process - showing strong resemblance to the Puertollano IGCC plant in Spain - and three co-gasification concepts, viz.: (1) a concept with separate dry coal and biomass feeding systems, (2) a concept with a combined dry coal/biomass-derived pyrolysis char feeding system, and (3) a concept with parallel biomass pre-treatment/gasification and combined fuel gas clean-up/power production, were defined for further consideration. The base-case system and the co-gasification concepts as well are modelled in the flowsheet simulation package ASPEN{sup +}. Steady-state integral system calculations resulted in an overall net electrical plant efficiency for the base-case system of 50. 1 %LHV (48.3 %HHV). Replacing about 10 % of the total thermal plant input (coal) by biomass (willow) resulted in a decrease of the overall net electrical plant efficiency of 1.4 to 2.1 %-points LHV, avoided specific CO2 emissions of 40-49 g/kWh{sub e}, and total avoided CO2 emissions of about 129 to 159 kt/a, all depending on the co-gasification concept

  4. Comparison of Core Performance with Various Oxide fuels on Sodium Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Ha; Kim, Myung Hyun [Kyung Hee University, Yongin (Korea, Republic of)

    2016-05-15

    The system is called Prototype GenIV Sodium-cooled Fast Reactor (PGSFR). Ultimate goal of PGSFR is test for capability of TRU transmutation. Purpose of this study is test for evaluation of in-core performance and TRU transmutation performance by applying various oxide fuel loaded TRU. Fuel type of reference core is changed to uranium-based oxide fuel. Oxide fuel has a lot of experience through fuel fabrication and reactor operation. This study performed by compared and analyzed a core performance of various oxide fuels. (U,Pu)O{sub 2} and (U,TRU)O{sub 2} which various oxide fuel types are selected as extreme case for comparison with core performance and transmutation capability of TRU isotopes. Thorium-based fuel is known that it has good performance for burner reactor due to low proliferation characteristic. To check the performance of TRU incineration for comparison with uranium-based fuel on prototype SFR, Thorium-based fuel, (Th,U)O{sub 2}, (Th,Pu)O{sub 2} and (Th,TRU)O{sub 2}, is selected. Calculations of core performance for various oxide fuel are performed using the fast calculation tool, TRANSX / DANTSTS / REBUS-3. In this study, comparison of core performance and transmutation performance is conducted with various fuel types in a sodium-cooled fast reactor. Mixed oxide fuel with TRU can produce the energy with small amount of fissile material. However, the TRU fuel is confirmed to bring a potential decline of the safety parameters. In case of (Th,U)O2 fuel, the flux level in thermal neutron region becomes lower because of higher capture cross-section of Th-232 than U-238. However, Th-232 has difficulty in converting to TRU isotopes. Therefore, the TRU consumption mass is relatively high in mixed oxide fuel with thorium and TRU.

  5. Comparison of Core Performance with Various Oxide fuels on Sodium Cooled Fast Reactor

    International Nuclear Information System (INIS)

    Choi, Jin Ha; Kim, Myung Hyun

    2016-01-01

    The system is called Prototype GenIV Sodium-cooled Fast Reactor (PGSFR). Ultimate goal of PGSFR is test for capability of TRU transmutation. Purpose of this study is test for evaluation of in-core performance and TRU transmutation performance by applying various oxide fuel loaded TRU. Fuel type of reference core is changed to uranium-based oxide fuel. Oxide fuel has a lot of experience through fuel fabrication and reactor operation. This study performed by compared and analyzed a core performance of various oxide fuels. (U,Pu)O_2 and (U,TRU)O_2 which various oxide fuel types are selected as extreme case for comparison with core performance and transmutation capability of TRU isotopes. Thorium-based fuel is known that it has good performance for burner reactor due to low proliferation characteristic. To check the performance of TRU incineration for comparison with uranium-based fuel on prototype SFR, Thorium-based fuel, (Th,U)O_2, (Th,Pu)O_2 and (Th,TRU)O_2, is selected. Calculations of core performance for various oxide fuel are performed using the fast calculation tool, TRANSX / DANTSTS / REBUS-3. In this study, comparison of core performance and transmutation performance is conducted with various fuel types in a sodium-cooled fast reactor. Mixed oxide fuel with TRU can produce the energy with small amount of fissile material. However, the TRU fuel is confirmed to bring a potential decline of the safety parameters. In case of (Th,U)O2 fuel, the flux level in thermal neutron region becomes lower because of higher capture cross-section of Th-232 than U-238. However, Th-232 has difficulty in converting to TRU isotopes. Therefore, the TRU consumption mass is relatively high in mixed oxide fuel with thorium and TRU.

  6. Comparison of High Performance Network Options: EDR InfiniBand vs.100Gb RDMA Capable Ethernet

    Energy Technology Data Exchange (ETDEWEB)

    Kachelmeier, Luke Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Van Wig, Faith Virginia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Missouri Univ. of Science and Technology, Rolla, MO (United States); Erickson, Kari Natania [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2016-08-08

    These are the slides for a presentation at the HPC Mini Showcase. This is a comparison of two different high performance network options: EDR InfiniBand and 100Gb RDMA capable ethernet. The conclusion of this comparison is the following: there is good potential, as shown with the direct results; 100Gb technology is too new and not standardized, thus deployment effort is complex for both options; different companies are not necessarily compatible; if you want 100Gb/s, you must get it all from one place.

  7. Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fei, E-mail: chenfei@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Zhang, Lishen, E-mail: lishenzhang@sina.com [Heating Technology Research and Development Center, Beijing District Heating Group, Beijing 100028 (China); Huai, Xiulan, E-mail: hxl@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Jufeng, E-mail: lijufeng.net@163.com [Nuclear and Radiation Safety Center, Ministry of Environmental Protection, Beijing 100082 (China); Zhang, Hang, E-mail: zhanghang@iet.cn [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Zhigang, E-mail: zgliu9322@163.com [Energy Research Institute of Shandong Academy of Sciences, Jinan, Shandong 250014 (China)

    2017-04-15

    Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

  8. Comprehensive performance comparison of airfoil fin PCHEs with NACA 00XX series airfoil

    International Nuclear Information System (INIS)

    Chen, Fei; Zhang, Lishen; Huai, Xiulan; Li, Jufeng; Zhang, Hang; Liu, Zhigang

    2017-01-01

    Highlights: • Pressure drop of NACA 0020 airfoil fin PCHE reduces strikingly in comparison with the zigzag PCHE. • Pressure drop of NACA 00XX airfoil fin PCHE decreases as airfoil thickness increases. • Heat transfer performance of NACA 00XX airfoil fin PCHE increases as airfoil thickness rises. • Comprehensive performance of NACA 00XX airfoil fin PCHE degrades as airfoil thickness increases. - Abstract: Printed circuit heat exchanger (PCHE) can be used in supercritical carbon dioxide (S-CO_2) Brayton cycle. The present study compares NACA 0020 airfoil fin PCHE with conventional zigzag PCHE by numerical analysis. Pressure drop of the former has a striking reduction while maintaining excellent heat transfer performance. Comparison on four NACA 00XX series airfoil fin PCHEs is performed to investigate the influence of airfoil profile on flow and heat transfer performance. With a fixed vertical pitch, heat transfer performance of NACA series airfoil fin PCHE increases as airfoil thickness increases. However, comprehensive performance, in which both flow and heat transfer are taken into account, degrades with increasing airfoil thickness. Among four NACA airfoil fin PCHEs presented in this paper, NACA 0010 airfoil fin PCHE demonstrates the best comprehensive performance.

  9. Comparison of power performance and noise between Aeolus 2 and Naesudden 2

    Energy Technology Data Exchange (ETDEWEB)

    Albers, C.; Hinsch, J.; Gabriel, J.; Klug, H. [Deutsches Windenergie-Institut gGmbH (DEWI), Wilhelmshaven (Germany); Ronsten, G. [Aeronautical Research Inst. of Sweden, Bromma (Sweden); Simonssen, B. [KM Akustikbyraan, Solna (Sweden)

    1996-12-01

    The German Wind Energy Institute DEWI and the Aeronautical Research Institute of Sweden FFA perform comparing measurements at the 3 MW sister turbines Aeolus II and Naesudden II in the framework of WEGA II (CAN-Project). Results exist concerning the comparison of power performance and noise emission. Load measurements have been carried out but no comparing results are available yet. In the case of Aeolus II interesting effects of different meteorological conditions on the power performance have been found. The project will continue till the end of 1996. 6 refs, 12 figs, 1 tab

  10. Comparison of Processor Performance of SPECint2006 Benchmarks of some Intel Xeon Processors

    OpenAIRE

    Abdul Kareem PARCHUR; Ram Asaray SINGH

    2012-01-01

    High performance is a critical requirement to all microprocessors manufacturers. The present paper describes the comparison of performance in two main Intel Xeon series processors (Type A: Intel Xeon X5260, X5460, E5450 and L5320 and Type B: Intel Xeon X5140, 5130, 5120 and E5310). The microarchitecture of these processors is implemented using the basis of a new family of processors from Intel starting with the Pentium 4 processor. These processors can provide a performance boost for many ke...

  11. A Note on Rocket Performance Comparison Through Impulse and Thrust Coefficients

    Science.gov (United States)

    Taylor, N. V.

    Comparison of rocket motor systems is important when generating data to be used in making design decisions. In order to present meaningful comparisons, non-dimensional numbers related to performance are beneficial, as they remove effects of scale. Traditionally thrust coefficients and C* have been used to quantify the aerodynamic and chemical performance of a system respectively. However, it is argued here that in fact the thrust coefficient does not fully account for aerodynamic performance, as the impact of non-uniform flow at the throat is not accounted for. This discharge coefficient is usually allocated to the chemical efficiency through a correction to C*. However, this causes a coupling between chemical and aerodynamic efficiencies which may lead to poor design decisions. Through the use of a specific impulse coefficient, this risk is avoided, and furthermore comparison of unconventional nozzles becomes more straightforward. It is admitted, however, that this has no actual impact on real motor performance, being more in the way of a tidier `accounting' system.

  12. Performance audits and laboratory comparisons for SCOS97-NARSTO measurements of speciated volatile organic compounds

    Science.gov (United States)

    Fujita, Eric M.; Harshfield, Gregory; Sheetz, Laurence

    Performance audits and laboratory comparisons were conducted as part of the quality assurance program for the 1997 Southern California Ozone Study (SCOS97-NARSTO) to document potential measurement biases among laboratories measuring speciated nonmethane hydrocarbons (NMHC), carbonyl compounds, halogenated compounds, and biogenic hydrocarbons. The results show that measurements of volatile organic compounds (VOC) made during SCOS97-NARSTO are generally consistent with specified data quality objectives. The hydrocarbon comparison involved nine laboratories and consisted of two sets of collocated ambient samples. The coefficients of variation among laboratories for the sum of the 55 PAM target compounds and total NMHC ranged from ±5 to 15 percent for ambient samples from Los Angeles and Azusa. Abundant hydrocarbons are consistently identified by all laboratories, but discrepancies occur for olefins greater than C 4 and for hydrocarbons greater than C 8. Laboratory comparisons for halogenated compounds and biogenic hydrocarbons consisted of both concurrent ambient sampling by different laboratories and round-robin analysis of ambient samples. The coefficients of variation among participating laboratories were about 10-20 percent. Performance audits were conducted for measurement of carbonyl compounds involving sampling from a standard mixture of carbonyl compounds. The values reported by most of the laboratories were within 10-20 percent of those of the reference laboratory. Results of field measurement comparisons showed larger variations among the laboratories ranging from 20 to 40 percent for C 1-C 3 carbonyl compounds. The greater variations observed in the field measurement comparison may reflect potential sampling artifacts, which the performance audits did not address.

  13. Pressurized planar electrochromatography, high-performance thin-layer chromatography and high-performance liquid chromatography--comparison of performance.

    Science.gov (United States)

    Płocharz, Paweł; Klimek-Turek, Anna; Dzido, Tadeusz H

    2010-07-16

    Kinetic performance, measured by plate height, of High-Performance Thin-Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Pressurized Planar Electrochromatography (PPEC) was compared for the systems with adsorbent of the HPTLC RP18W plate from Merck as the stationary phase and the mobile phase composed of acetonitrile and buffer solution. The HPLC column was packed with the adsorbent, which was scrapped from the chromatographic plate mentioned. An additional HPLC column was also packed with adsorbent of 5 microm particle diameter, C18 type silica based (LiChrosorb RP-18 from Merck). The dependence of plate height of both HPLC and PPEC separating systems on flow velocity of the mobile phase and on migration distance of the mobile phase in TLC system was presented applying test solute (prednisolone succinate). The highest performance, amongst systems investigated, was obtained for the PPEC system. The separation efficiency of the systems investigated in the paper was additionally confirmed by the separation of test component mixture composed of six hormones. 2010 Elsevier B.V. All rights reserved.

  14. Performance Comparison of Widely-Used Maximum Power Point Tracker Algorithms under Real Environmental Conditions

    Directory of Open Access Journals (Sweden)

    DURUSU, A.

    2014-08-01

    Full Text Available Maximum power point trackers (MPPTs play an essential role in extracting power from photovoltaic (PV panels as they make the solar panels to operate at the maximum power point (MPP whatever the changes of environmental conditions are. For this reason, they take an important place in the increase of PV system efficiency. MPPTs are driven by MPPT algorithms and a number of MPPT algorithms are proposed in the literature. The comparison of the MPPT algorithms in literature are made by a sun simulator based test system under laboratory conditions for short durations. However, in this study, the performances of four most commonly used MPPT algorithms are compared under real environmental conditions for longer periods. A dual identical experimental setup is designed to make a comparison between two the considered MPPT algorithms as synchronized. As a result of this study, the ranking among these algorithms are presented and the results show that Incremental Conductance (IC algorithm gives the best performance.

  15. Comparison of standard resampling methods for performance estimation of artificial neural network ensembles

    OpenAIRE

    Green, Michael; Ohlsson, Mattias

    2007-01-01

    Estimation of the generalization performance for classification within the medical applications domain is always an important task. In this study we focus on artificial neural network ensembles as the machine learning technique. We present a numerical comparison between five common resampling techniques: k-fold cross validation (CV), holdout, using three cutoffs, and bootstrap using five different data sets. The results show that CV together with holdout $0.25$ and $0.50$ are the best resampl...

  16. Profit, productivity, and price differential: an international performance comparison of the natural gas transportation industry

    International Nuclear Information System (INIS)

    Jeong-Dong Lee; Sung-Bae Park; Tai-Yoo Kim

    1999-01-01

    The objective of this paper is to evaluate the performance of natural gas transportation utilities, focusing on the three-key strategic performance measures of profit, productivity, and price differential. We propose a methodology that expresses the three performance measures in a unified single equation using the Edgeworth index. The proposed methodology is applied to an international comparison of the performance of 28 natural gas transportation utilities operating in eight countries in which the business environments differ greatly. The empirical results show the possible causes of performance differences and may shed some light on the direction of regulatory policy, especially for developing countries that have relatively short histories in the natural gas industry, such as Korea. (author)

  17. Performance comparisons of dish type solar concentrator with mirror arrangements and receiver shapes

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Joo Hyun; Kim, Yong; Ma, Dae Sung; Seo, Tae Beom [Graduate School, Dept. of Mechanical Engineering, Inha Univ., Inchon (Korea, Republic of); Kang, Yong Heack [Korea Inst. of Energy Research, Daejeon (Korea, Republic of)

    2008-07-01

    The performance comparisons of dish type solar concentrators are numerically investigated. The dish type solar concentrator considered in this paper consists of a receiver and multi-faceted mirrors. In order to investigate the performance comparisons of dish type solar concentrators, six different mirror arrangements and four different receivers are considered. A parabolic-shaped perfect mirror of which diameter is 1.40 m is considered as the reference for the mirror arrangements. The other mirror arrangements consist of twelve identical parabolic-shaped mirror facets of which diameter are 0.405 m. Their total collecting areas, which are 1.545 m{sup 2}, are the same. Four different solar receiver shapes are a conical, a dome, a cylindrical, and a unicorn type. In order to investigate the thermal performance of the dish type solar concentrator, the radiative heat loss in the receiver should be calculated. For calculation, the net radiation method and the Monte-Carlo method are used. Also, because the thermal performance of the dish type solar concentrator can vary as the receiver surface temperature, the various surface temperatures are considered. Based on the calculation, the unicorn type has the best performance in receiver shapes and the STAR has the best performance in mirror arrangements except the perfect mirror. (orig.)

  18. Comparison of precision and speed in laparoscopic and robot-assisted surgical task performance.

    Science.gov (United States)

    Zihni, Ahmed; Gerull, William D; Cavallo, Jaime A; Ge, Tianjia; Ray, Shuddhadeb; Chiu, Jason; Brunt, L Michael; Awad, Michael M

    2018-03-01

    Robotic platforms have the potential advantage of providing additional dexterity and precision to surgeons while performing complex laparoscopic tasks, especially for those in training. Few quantitative evaluations of surgical task performance comparing laparoscopic and robotic platforms among surgeons of varying experience levels have been done. We compared measures of quality and efficiency of Fundamentals of Laparoscopic Surgery task performance on these platforms in novices and experienced laparoscopic and robotic surgeons. Fourteen novices, 12 expert laparoscopic surgeons (>100 laparoscopic procedures performed, no robotics experience), and five expert robotic surgeons (>25 robotic procedures performed) performed three Fundamentals of Laparoscopic Surgery tasks on both laparoscopic and robotic platforms: peg transfer (PT), pattern cutting (PC), and intracorporeal suturing. All tasks were repeated three times by each subject on each platform in a randomized order. Mean completion times and mean errors per trial (EPT) were calculated for each task on both platforms. Results were compared using Student's t-test (P task performance was slower on the robotic platform compared with laparoscopy. In comparisons of expert laparoscopists performing tasks on the laparoscopic platform and expert robotic surgeons performing tasks on the robotic platform, expert robotic surgeons demonstrated fewer errors during the PC task (P = 0.009). Robotic assistance provided a reduction in errors at all experience levels for some laparoscopic tasks, but no benefit in the speed of task performance. Robotic assistance may provide some benefit in precision of surgical task performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A comparison of the screening performance of braided coaxial and triaxial cables

    International Nuclear Information System (INIS)

    Fowler, E.P.

    1975-03-01

    The screening performance of a coaxial screened circuit is derived from measurements of the surface transfer impedance, capacitive coupling and conductor eccentricity on short lengths of cable. This is then extended to a triaxial screen considering all the ways the two screens can be connected. Comparison of calculated performance and measured results on a 10m length show that the mechanisms of coupling interact to make triaxial cable screening worse than expected and, in fact, frequently no better than a coaxial cable. The use of superscreened cables is found to overcome all the problems known in triaxial cables. (author)

  20. Multi-country comparisons of energy performance: The index decomposition analysis approach

    International Nuclear Information System (INIS)

    Ang, B.W.; Xu, X.Y.; Su, Bin

    2015-01-01

    Index decomposition analysis (IDA) is a popular tool for studying changes in energy consumption over time in a country or region. This specific application of IDA, which may be called temporal decomposition analysis, has been extended by researchers and analysts to study variations in energy consumption or energy efficiency between countries or regions, i.e. spatial decomposition analysis. In spatial decomposition analysis, the main objective is often to understand the relative contributions of overall activity level, activity structure, and energy intensity in explaining differences in total energy consumption between two countries or regions. We review the literature of spatial decomposition analysis, investigate the methodological issues, and propose a spatial decomposition analysis framework for multi-region comparisons. A key feature of the proposed framework is that it passes the circularity test and provides consistent results for multi-region comparisons. A case study in which 30 regions in China are compared and ranked based on their performance in energy consumption is presented. - Highlights: • We conducted cross-regional comparisons of energy consumption using IDA. • We proposed two criteria for IDA method selection in spatial decomposition analysis. • We proposed a new model for regional comparison that passes the circularity test. • Features of the new model are illustrated using the data of 30 regions in China

  1. BER performance comparison of optical CDMA systems with/without turbo codes

    Science.gov (United States)

    Kulkarni, Muralidhar; Chauhan, Vijender S.; Dutta, Yashpal; Sinha, Ravindra K.

    2002-08-01

    In this paper, we have analyzed and simulated the BER performance of a turbo coded optical code-division multiple-access (TC-OCDMA) system. A performance comparison has been made between uncoded OCDMA and TC-OCDMA systems employing various OCDMA address codes (optical orthogonal codes (OOCs), Generalized Multiwavelength Prime codes (GMWPC's), and Generalized Multiwavelength Reed Solomon code (GMWRSC's)). The BER performance of TC-OCDMA systems has been analyzed and simulated by varying the code weight of address code employed by the system. From the simulation results, it is observed that lower weight address codes can be employed for TC-OCDMA systems that can have the equivalent BER performance of uncoded systems employing higher weight address codes for a fixed number of active users.

  2. Comparison of Processor Performance of SPECint2006 Benchmarks of some Intel Xeon Processors

    Directory of Open Access Journals (Sweden)

    Abdul Kareem PARCHUR

    2012-08-01

    Full Text Available High performance is a critical requirement to all microprocessors manufacturers. The present paper describes the comparison of performance in two main Intel Xeon series processors (Type A: Intel Xeon X5260, X5460, E5450 and L5320 and Type B: Intel Xeon X5140, 5130, 5120 and E5310. The microarchitecture of these processors is implemented using the basis of a new family of processors from Intel starting with the Pentium 4 processor. These processors can provide a performance boost for many key application areas in modern generation. The scaling of performance in two major series of Intel Xeon processors (Type A: Intel Xeon X5260, X5460, E5450 and L5320 and Type B: Intel Xeon X5140, 5130, 5120 and E5310 has been analyzed using the performance numbers of 12 CPU2006 integer benchmarks, performance numbers that exhibit significant differences in performance. The results and analysis can be used by performance engineers, scientists and developers to better understand the performance scaling in modern generation processors.

  3. Application of sonoelastography: Comparison of performance between mass and non-mass lesion

    International Nuclear Information System (INIS)

    Ko, Eun Sook; Choi, Hye Young; Kim, Rock Bum; Noh, Woo-Chul

    2012-01-01

    Objectives: The purpose of this study was to determine the performance of the conventional ultrasonography (US) and sonoelastography (SE) in three conditions of all lesions, confined to mass, and confined to non-mass lesion and to compare the performance of each modality between mass and non-mass lesion. Materials and methods: A total 364 patients with 375 lesions were evaluated with US and subsequently SE before performing US-guided biopsy. Two radiologists retrospectively analyzed conventional US and elasticity images by consensus. The US findings were classified as mass or non-mass lesion. With final pathology as reference, in each case of all lesions, masses, and non-mass lesions, areas under the ROC curves (Az) were calculated and compared for the two techniques. The comparison of Az values between the curves for US and SE, and between the curves for mass and non-mass lesion was performed. Results: Among 375 lesions, 104 (28%) lesions were malignant and 271 (72%) lesions were benign. 36 (9.6%) of 375 lesions were classified as non-mass lesion at US. There were statistically significant difference of performance between US and SE in cases of all lesion (p = 0.003) and mass (p = 0.023). However, there was no statistically significant difference of performance in case of non-mass lesion (p = 0.5). Comparisons of the Az values of US and SE between mass and non-mass lesions were not statistically significant (p = 0.745, p = 0.415, respectively). Conclusion: There was no statistically significant difference of performance of US and SE between mass and non-mass lesion.

  4. Performance comparisons of enhanced tubes with discrete and wavy disruption shapes

    Energy Technology Data Exchange (ETDEWEB)

    Arman, B.; Rabas, T.J.

    1993-08-01

    This paper presents comparisons of the friction factors and heat-transfer coefficients obtained with enhanced tubes with transverse discrete and almost transverse wavy two-dimensional disruptions. Both experimental data and numerical predictions were used for the comparisons. For the latter a two-layer turbulence model incorporated in a body-fitted, finite-volume method was used. The disruption shape, discrete or wavy, depends on the manufacturing process. If an extrusion process is used, discrete disruptions (ribs) of various profiles are obtained that are separated from each other by a flat or unaltered inside diameter. If a spirally indenting process is used, a wavy proflie is obtained with a continuously varying inside diameter between two adjacent disruption peaks. These disruptions are transverse or almost transverse to the tube axis and separated by a distance that exceeds the reattachment length. Based on these comparisons, the following conclusions are obtained: (1) the disruption shape is not an important correlating parameter for discrete disruptions, (2) only the friction factor is influenced by the shape for wavy disruptions, and (3) there are major differences between both the friction-factor and heat-transfer performance of discrete and wavy disruptions with the same maximum disruption height and spacing. However, the most important finding is that the groove radius of spirally indented tubes should be increased because of the substantial reduction of the friction factor but only a small decrease in the thermal performance. Additional comparisons of predicted results were made to obtain a fundamental understanding of the influence of these different shapes.

  5. Volumetric activity of SRS mixed waste and comparison with SRS performance and commercial facility limits

    International Nuclear Information System (INIS)

    Ades, M.J.; Daugherty, B.A.; Cook, J.R.

    1996-01-01

    This paper discusses the comparative analysis performed to estimate the after-treatment volumetric activity of the radionuclides included in the Savannah River site (SRS) mixed-waste streams and its comparison with the following: (1) The performance evaluation (PE) limits established for each radionuclide for on-site disposal: These limits correspond to the permissible waste disposal limits that are the lowest limits evaluated for the most restrictive release scenarios that include the groundwater pathway, the atmospheric pathway, and the intruder scenarios. (2) The radiological performance assessment (PA) limits established for each radionuclide for disposal in the SRS disposal vaults that meet the requirements of Chap. III of the U.S. Department of Energy Order 5820.2A: The vaults considered are the low-activity waste (LAW) vaults, the intermediate-level non-tritium (ILNT) vaults. and the intermediate-level tritium (ILT) vaults. (3) The radioactive limits of a commercial mixed waste disposal facility

  6. An open-source software program for performing Bonferroni and related corrections for multiple comparisons

    Directory of Open Access Journals (Sweden)

    Kyle Lesack

    2011-01-01

    Full Text Available Increased type I error resulting from multiple statistical comparisons remains a common problem in the scientific literature. This may result in the reporting and promulgation of spurious findings. One approach to this problem is to correct groups of P-values for "family-wide significance" using a Bonferroni correction or the less conservative Bonferroni-Holm correction or to correct for the "false discovery rate" with a Benjamini-Hochberg correction. Although several solutions are available for performing this correction through commercially available software there are no widely available easy to use open source programs to perform these calculations. In this paper we present an open source program written in Python 3.2 that performs calculations for standard Bonferroni, Bonferroni-Holm and Benjamini-Hochberg corrections.

  7. Performance analysis of a gas turbine for power generation using syngas as a fuel

    International Nuclear Information System (INIS)

    Lee, Jong Jun; Cha Kyu Sang; Kim, Tong Seop; Sohn, Jeong Lak; Joo, Yong Jin

    2008-01-01

    Integrated Gasification Combined Cycle (IGCC) power plant converts coal to syngas, which is mainly composed of hydrogen and carbon monoxide, by the gasification process and produces electric power by the gas and steam turbine combined cycle power plant. The purpose of this study is to investigate the influence of using syngas in a gas turbine, originally designed for natural gas fuel, on its performance. A commercial gas turbine is selected and variations of its performance characteristics due to adopting syngas is analyzed by simulating off-design gas turbine operation. Since the heating value of the syngas is lower, compared to natural gas, IGCC plants require much larger fuel flow rate. This increase the gas flow rate to the turbine and the pressure ratio, leading to far larger power output and higher thermal efficiency. Examination of using two different syngases reveals that the gas turbine performance varies much with the fuel composition

  8. Comparison of the performance of the next generation of optical interferometers

    Science.gov (United States)

    Pisani, Marco; Yacoot, Andrew; Balling, Petr; Bancone, Nicola; Birlikseven, Cengiz; Çelik, Mehmet; Flügge, Jens; Hamid, Ramiz; Köchert, Paul; Kren, Petr; Kuetgens, Ulrich; Lassila, Antti; Bartolo Picotto, Gian; Şahin, Ersoy; Seppä, Jeremias; Tedaldi, Matthew; Weichert, Christoph

    2012-08-01

    Six European National Measurement Institutes (NMIs) have joined forces within the European Metrology Research Programme funded project NANOTRACE to develop the next generation of optical interferometers having a target uncertainty of 10 pm. These are needed for NMIs to provide improved traceable dimensional metrology that can be disseminated to the wider nanotechnology community, thereby supporting the growth in nanotechnology. Several approaches were followed in order to develop the interferometers. This paper briefly describes the different interferometers developed by the various partners and presents the results of a comparison of performance of the optical interferometers using an x-ray interferometer to generate traceable reference displacements.

  9. French fission products experiments performed in Cadarache and Valduc. Results comparison

    International Nuclear Information System (INIS)

    Anno, Jacques; Barreau, Anne; Hudelot, Jean Pascal; Girault, Emmanuel; Fouillaud, Patrick; Toubon, Herve

    2003-01-01

    Cofunded by Cogema, two complementary experimental programmes on burn up credit (BUC) related to fission products (FPs) are performed by CEA and IRSN at Cadarache and Valduc. After shortly recalling the main characteristics of each experiment, a first comparison of some results is presented, especially the energy range in which most part of cross section absorption are qualified. Both experiments exhibit great quality and accurate results, giving a high degree of confidence to the whole experimental French process of qualification devoted to BUC. (author)

  10. Performance comparison of a novel configuration of beta-type Stirling engines with rhombic drive engine

    International Nuclear Information System (INIS)

    Solmaz, Hamit; Karabulut, Halit

    2014-01-01

    Highlights: • The paper describes a novel arrangement of a beta-type Stirling engine. • Its performance was compared with rhombic drive engine. • The power output of the engine was found to be greater than rhombic drive. • Efficiency was found to be higher than rhombic drive at the same working fluid mass. • Efficiency was found to be lower than rhombic drive at the same charge pressure. - Abstract: This study presents a beta type Stirling engine mechanism and its performance analysis. The displacer motion of the engine is performed by a lever mechanism. The performance of the engine was investigated via comparing with a rhombic-drive engine possessing an equal sided rhombic. Comparison was made for kinematic behaviors, power and thermal efficiency. For comparison; the piston swept volume, the inner heat transfer area, the hot and cold end temperatures, the inner heat transfer coefficient, charge pressure and dead volumes were kept equal for both engines. As working fluid the helium was used. Thermodynamic treatments of engines were performed via the nodal analysis. The power of the lever driven engine was found to be greater than the power of the rhombic drive engine. Under the equal charge pressure, the thermal efficiency of the lever driven engine was found to be lower than the efficiency of the rhombic drive engine however, under the equal working fluid mass the thermal efficiency of the lever driven engine was found to be greater than that of the rhombic drive engine. The external volume and mass of the lever driven engine is lower than the rhombic drive engine

  11. Systematic comparison of ORC configurations by means of comprehensive performance indexes

    International Nuclear Information System (INIS)

    Branchini, Lisa; De Pascale, Andrea; Peretto, Antonio

    2013-01-01

    The Organic Rankine Cycle (ORC) is considered as an emerging technology for power generation through heat recovering from different thermal sources, based on the use of organic fluids as working medium. This paper presents a numerical study to assess the relevance: i) of the thermodynamic cycle, ii) of the main design parameters and iii) of the working fluid, on the achievable performance. The ORC performance is here calculated in terms of six different thermodynamic indexes, offering comprehensive information, namely: cycle efficiency, specific work, recovery efficiency, turbine volumetric expansion ratio, ORC fluid-to-hot source mass flow ratio and heat exchangers size parameter. In the framework of a systematic investigation approach, various possible modifications to the simple ORC plant layout are here analyzed and compared, in order to improve the ORC recovery performance; arrangements such as recuperation, superheated cycle, supercritical conditions, regenerative cycle and their combinations are taken into account. The investigation is carried out by means of an in-house developed calculation tool, based on a thermodynamic property database of the considered fluids, including aromatics, siloxanes, refrigerants and hydrocarbons. A comprehensive parametric analysis of these cycles at different hot source temperature and different evaporation pressure values is carried out. The objectives of this investigation are to provide useful guidelines to select the ORC configuration, the most appropriate fluid and to define the operating parameters, depending on the specific application. Thermodynamic results are also related with sizing of ORC components and thus can be used for economic assessment of the different ORC design alternatives. -- Highlights: • Systematic comparison of ORC thermodynamic arrangements is performed. • Performance is calculated introducing six comprehensive energy and size/economic indexes. • An in-house-developed calculation tool is used

  12. Effect of noise on the performance of Digital Charge Comparison method for n-γ discrimination

    International Nuclear Information System (INIS)

    Singh, Harleen; Mehra, Rohit

    2017-01-01

    The neutron-gamma discrimination from a mixed radiation field is of prime importance in the field of nuclear safeguards, nuclear fission, radiation therapy etc. The liquid scintillators are widely used for n-γ discrimination as the relative decay rate of neutron pulse is less as compared to γ - ray in these detectors.The most popular and simple technique for pulse shape discrimination (PSD) is the charge comparison (CC). Due to the availability of fast ADCs and FPGAs, the traditional analogue techniques can be implemented in digital domain by sampling the PMT pulses. The performance of a PSD method depends on various parameters like sampling rate, noise distortion in the pulses the duration of processing gate etc. In this paper, the effect of noise levels on the performance of CC method is investigated at optimized processing gate

  13. Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment

    Science.gov (United States)

    Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Usman, Mohammed Joda

    2017-01-01

    Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing. PMID:28467505

  14. Visualizing request-flow comparison to aid performance diagnosis in distributed systems.

    Science.gov (United States)

    Sambasivan, Raja R; Shafer, Ilari; Mazurek, Michelle L; Ganger, Gregory R

    2013-12-01

    Distributed systems are complex to develop and administer, and performance problem diagnosis is particularly challenging. When performance degrades, the problem might be in any of the system's many components or could be a result of poor interactions among them. Recent research efforts have created tools that automatically localize the problem to a small number of potential culprits, but research is needed to understand what visualization techniques work best for helping distributed systems developers understand and explore their results. This paper compares the relative merits of three well-known visualization approaches (side-by-side, diff, and animation) in the context of presenting the results of one proven automated localization technique called request-flow comparison. Via a 26-person user study, which included real distributed systems developers, we identify the unique benefits that each approach provides for different problem types and usage modes.

  15. Comparison of ETF´s performance related to the tracking error

    Directory of Open Access Journals (Sweden)

    Michaela Dorocáková

    2017-12-01

    Full Text Available With the development of financial markets, there is also immediate expansion of fund industry, which is a representative issue of collective investment. The purpose of index funds is to replicate returns and risk of underling index to the largest possible extent, with tracking error being one of the most monitored performance indicator of these passively managed funds. The aim of this paper is to describe several perspectives concerning indexing, index funds and exchange-traded funds, to explain the issue of tracking error with its examination and subsequent comparison of such funds provided by leading investment management companies with regard to different methods used for its evaluation. Our research shows that the decisive factor for occurrence of copy deviation is fund size and fund´s stock consolidation. In addition, performance differences between exchange-traded fund and its benchmark tend to show the signs of seasonality in the sense of increasing in the last months of a year.

  16. Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment.

    Science.gov (United States)

    Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Abdulhamid, Shafi'i Muhammad; Usman, Mohammed Joda

    2017-01-01

    Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing.

  17. Dosimertry characteristics and performance comparisons: Environmental radiophotoluminescent glass dosemeters versus thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Lee, J.H.; Lin, M.S.; Hsu, S.M.; Chen, I.J.; Chen, W.L.; Wang, C.F.

    2009-01-01

    This paper describes the dosimetry characteristic comparison of environmental radiophotoluminescent glass dosemeter (RPLGD) and thermoluminescent dosemeter (TLD) systems employed at the Institute of Nuclear Energy Research (INER, Taiwan). The luminescence centers of TLD disappeared by reading process, and repetition of measurement is impossible. RPLGDs can be repeatedly read and keep the luminescence centers for a long time. The RPLGD fading is about 1% within 30 days after being exposed to ionizing radiation. Environmental cumulative doses measured by a RPLGD and a TLD were compared at the same monitoring points of INER during two years. The sensitivity of TLD decreased with gradual loss due to fading at higher temperatures. The difference between results obtained by RPLGD and TLD is discussed mainly with respect to the dependence on the ambient temperature. In addition, this research also refers to the American National Standard Institute (ANSI) Draft Standard N13.29 (1996) to organize the environmental dosimetry performance tests of the INER's RPLGDs and the TLDs. The results mean that both kinds of dosemeters can meet the performance test criteria. An accreditation procedure for the institutes which provide the environmental dosimetry services in Taiwan was suggested based on the comparison results of these two dosimetry systems

  18. Parameter Selection and Performance Comparison of Particle Swarm Optimization in Sensor Networks Localization

    Directory of Open Access Journals (Sweden)

    Huanqing Cui

    2017-03-01

    Full Text Available Localization is a key technology in wireless sensor networks. Faced with the challenges of the sensors’ memory, computational constraints, and limited energy, particle swarm optimization has been widely applied in the localization of wireless sensor networks, demonstrating better performance than other optimization methods. In particle swarm optimization-based localization algorithms, the variants and parameters should be chosen elaborately to achieve the best performance. However, there is a lack of guidance on how to choose these variants and parameters. Further, there is no comprehensive performance comparison among particle swarm optimization algorithms. The main contribution of this paper is three-fold. First, it surveys the popular particle swarm optimization variants and particle swarm optimization-based localization algorithms for wireless sensor networks. Secondly, it presents parameter selection of nine particle swarm optimization variants and six types of swarm topologies by extensive simulations. Thirdly, it comprehensively compares the performance of these algorithms. The results show that the particle swarm optimization with constriction coefficient using ring topology outperforms other variants and swarm topologies, and it performs better than the second-order cone programming algorithm.

  19. Parameter Selection and Performance Comparison of Particle Swarm Optimization in Sensor Networks Localization.

    Science.gov (United States)

    Cui, Huanqing; Shu, Minglei; Song, Min; Wang, Yinglong

    2017-03-01

    Localization is a key technology in wireless sensor networks. Faced with the challenges of the sensors' memory, computational constraints, and limited energy, particle swarm optimization has been widely applied in the localization of wireless sensor networks, demonstrating better performance than other optimization methods. In particle swarm optimization-based localization algorithms, the variants and parameters should be chosen elaborately to achieve the best performance. However, there is a lack of guidance on how to choose these variants and parameters. Further, there is no comprehensive performance comparison among particle swarm optimization algorithms. The main contribution of this paper is three-fold. First, it surveys the popular particle swarm optimization variants and particle swarm optimization-based localization algorithms for wireless sensor networks. Secondly, it presents parameter selection of nine particle swarm optimization variants and six types of swarm topologies by extensive simulations. Thirdly, it comprehensively compares the performance of these algorithms. The results show that the particle swarm optimization with constriction coefficient using ring topology outperforms other variants and swarm topologies, and it performs better than the second-order cone programming algorithm.

  20. Performance comparison between total variation (TV)-based compressed sensing and statistical iterative reconstruction algorithms

    International Nuclear Information System (INIS)

    Tang Jie; Nett, Brian E; Chen Guanghong

    2009-01-01

    Of all available reconstruction methods, statistical iterative reconstruction algorithms appear particularly promising since they enable accurate physical noise modeling. The newly developed compressive sampling/compressed sensing (CS) algorithm has shown the potential to accurately reconstruct images from highly undersampled data. The CS algorithm can be implemented in the statistical reconstruction framework as well. In this study, we compared the performance of two standard statistical reconstruction algorithms (penalized weighted least squares and q-GGMRF) to the CS algorithm. In assessing the image quality using these iterative reconstructions, it is critical to utilize realistic background anatomy as the reconstruction results are object dependent. A cadaver head was scanned on a Varian Trilogy system at different dose levels. Several figures of merit including the relative root mean square error and a quality factor which accounts for the noise performance and the spatial resolution were introduced to objectively evaluate reconstruction performance. A comparison is presented between the three algorithms for a constant undersampling factor comparing different algorithms at several dose levels. To facilitate this comparison, the original CS method was formulated in the framework of the statistical image reconstruction algorithms. Important conclusions of the measurements from our studies are that (1) for realistic neuro-anatomy, over 100 projections are required to avoid streak artifacts in the reconstructed images even with CS reconstruction, (2) regardless of the algorithm employed, it is beneficial to distribute the total dose to more views as long as each view remains quantum noise limited and (3) the total variation-based CS method is not appropriate for very low dose levels because while it can mitigate streaking artifacts, the images exhibit patchy behavior, which is potentially harmful for medical diagnosis.

  1. BER PERFORMANCE COMPARISON OF MIMO SYSTEMS USING OSTBC WITH ZF AND ML DECODING

    Directory of Open Access Journals (Sweden)

    Zenitha Rehman

    2014-12-01

    Full Text Available Multiple Input Multiple Output (MIMO systems with multiple antenna elements at both transmitter and receiver ends are an efficient solution for wireless communication systems. They provide high data rates by exploiting the spatial domain under the constraints of limited bandwidth and transmit power. Space-Time Block Coding (STBC is a MIMO transmit strategy which exploits transmit diversity and provides high reliability. Implementation of orthogonal space-time block codes (OSTBCs for a two transmitter–two receiver system under AWGN (Additive White Gaussian Noise channel and flat fading channel is performed. Alamouti code is employed for the STBC. The modulation techniques used are BPSK, QPSK and 16-QAM. Decoding is done using the Zero Forcing (ZF algorithm and Maximum Likelihood (ML algorithm. The BER Performance of each modulation scheme is compared with the un-coded version of the same. Performance comparison between the two decoding techniques is also done. It is found that ML detection offers a slightly better performance for BPSK and QPSK system than ZF detection.

  2. A forecasting performance comparison of dynamic factor models based on static and dynamic methods

    Directory of Open Access Journals (Sweden)

    Marra Fabio Della

    2017-03-01

    Full Text Available We present a comparison of the forecasting performances of three Dynamic Factor Models on a large monthly data panel of macroeconomic and financial time series for the UE economy. The first model relies on static principal-component and was introduced by Stock and Watson (2002a, b. The second is based on generalized principal components and it was introduced by Forni, Hallin, Lippi and Reichlin (2000, 2005. The last model has been recently proposed by Forni, Hallin, Lippi and Zaffaroni (2015, 2016. The data panel is split into two parts: the calibration sample, from February 1986 to December 2000, is used to select the most performing specification for each class of models in a in- sample environment, and the proper sample, from January 2001 to November 2015, is used to compare the performances of the selected models in an out-of-sample environment. The metholodogical approach is analogous to Forni, Giovannelli, Lippi and Soccorsi (2016, but also the size of the rolling window is empirically estimated in the calibration process to achieve more robustness. We find that, on the proper sample, the last model is the most performing for the Inflation. However, mixed evidencies appear over the proper sample for the Industrial Production.

  3. Performance comparison of AV1, HEVC, and JVET video codecs on 360 (spherical) video

    Science.gov (United States)

    Topiwala, Pankaj; Dai, Wei; Krishnan, Madhu; Abbas, Adeel; Doshi, Sandeep; Newman, David

    2017-09-01

    This paper compares the coding efficiency performance on 360 videos, of three software codecs: (a) AV1 video codec from the Alliance for Open Media (AOM); (b) the HEVC Reference Software HM; and (c) the JVET JEM Reference SW. Note that 360 video is especially challenging content, in that one codes full res globally, but typically looks locally (in a viewport), which magnifies errors. These are tested in two different projection formats ERP and RSP, to check consistency. Performance is tabulated for 1-pass encoding on two fronts: (1) objective performance based on end-to-end (E2E) metrics such as SPSNR-NN, and WS-PSNR, currently developed in the JVET committee; and (2) informal subjective assessment of static viewports. Constant quality encoding is performed with all the three codecs for an unbiased comparison of the core coding tools. Our general conclusion is that under constant quality coding, AV1 underperforms HEVC, which underperforms JVET. We also test with rate control, where AV1 currently underperforms the open source X265 HEVC codec. Objective and visual evidence is provided.

  4. SWIR, VIS and LWIR observer performance against handheld objects: a comparison

    Science.gov (United States)

    Adomeit, Uwe

    2016-10-01

    The short wave infrared spectral range caused interest to be used in day and night time military and security applications in the last years. This necessitates performance assessment of SWIR imaging equipment in comparison to the one operating in the visual (VIS) and thermal infrared (LWIR) spectral range. In the military context (nominal) range is the main performance criteria. Discriminating friend from foe is one of the main tasks in today's asymmetric scenarios and so personnel, human activities and handheld objects are used as targets to estimate ranges. The later was also used for an experiment at Fraunhofer IOSB to get a first impression how the SWIR performs compared to VIS and LWIR. A human consecutively carrying one of nine different civil or military objects was recorded from five different ranges in the three spectral ranges. For the visual spectral range a 3-chip color-camera was used, the SWIR range was covered by an InGaAs-camera and the LWIR by an uncooled bolometer. It was ascertained that the nominal spatial resolution of the three cameras was in the same magnitude in order to enable an unbiased assessment. Daytime conditions were selected for data acquisition to separate the observer performance from illumination conditions and to some extend also camera performance. From the recorded data, a perception experiment was prepared. It was conducted as a nine-alternative forced choice, unlimited observation time test with 15 observers participating. Before the experiment, the observers were trained on close range target data. Outcome of the experiment was the average probability of identification versus range between camera and target. The comparison of the range performance achieved in the three spectral bands gave a mixed result. On one hand a ranking VIS / SWIR / LWIR in decreasing order can be seen in the data, but on the other hand only the difference between VIS and the other bands is statistically significant. Additionally it was not possible

  5. Comparison of Aero-Propulsive Performance Predictions for Distributed Propulsion Configurations

    Science.gov (United States)

    Borer, Nicholas K.; Derlaga, Joseph M.; Deere, Karen A.; Carter, Melissa B.; Viken, Sally A.; Patterson, Michael D.; Litherland, Brandon L.; Stoll, Alex M.

    2017-01-01

    NASA's X-57 "Maxwell" flight demonstrator incorporates distributed electric propulsion technologies in a design that will achieve a significant reduction in energy used in cruise flight. A substantial portion of these energy savings come from beneficial aerodynamic-propulsion interaction. Previous research has shown the benefits of particular instantiations of distributed propulsion, such as the use of wingtip-mounted cruise propellers and leading edge high-lift propellers. However, these benefits have not been reduced to a generalized design or analysis approach suitable for large-scale design exploration. This paper discusses the rapid, "design-order" toolchains developed to investigate the large, complex tradespace of candidate geometries for the X-57. Due to the lack of an appropriate, rigorous set of validation data, the results of these tools were compared to three different computational flow solvers for selected wing and propulsion geometries. The comparisons were conducted using a common input geometry, but otherwise different input grids and, when appropriate, different flow assumptions to bound the comparisons. The results of these studies showed that the X-57 distributed propulsion wing should be able to meet the as-designed performance in cruise flight, while also meeting or exceeding targets for high-lift generation in low-speed flight.

  6. Generic Containment: Detailed comparison of containment simulations performed on plant scale

    International Nuclear Information System (INIS)

    Kelm, St.; Klauck, M.; Beck, S.; Allelein, H.-J.; Preusser, G.; Sangiorgi, M.; Klein-Hessling, W.; Bakalov, I.; Bleyer, A.; Bentaib, A.; Kljenak, I.; Stempniewicz, M.; Kostka, P.; Morandi, S.; Ada del Corno, B.; Bratfisch, C.; Risken, T.; Denk, L.; Parduba, Z.; Paci, S.

    2014-01-01

    Highlights: • Consequent implementation of the recommendations derived from the OECD/NEA ISP-47. • Phenomenological code-to-code comparison performed on plant scale. • Systematic identification and elimination of the user effect. • Identification of fundamental differences in the model basis. • Application to PAR system analysis. - Abstract: One outcome of the OECD/NEA ISP-47 activity was the recommendation to elaborate a ‘Generic Containment’ in order to allow comparing and rating the results obtained by different lumped-parameter models on plant scale. Within the European SARNET2 project ( (http://www.sar-net.eu)), such a Generic Containment nodalisation, based on a German PWR (1300 MW el ), was defined. This agreement on the nodalisation allows investigating the remaining differences among the results, especially the ‘user-effect’, related to the modelling choices, as well as fundamental differences in the underlying model basis in detail. The methodology applied in order to compare the different code predictions consisted of a series of three benchmark steps with increasing complexity as well as a systematic comparison of characteristic variables and observations. This paper summarises the benchmark series, the lessons learned during specifying the steps, comparing and discussing the results and finally gives an outlook on future steps

  7. Cogeneration based on gasified biomass - a comparison of concepts

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Fredrik

    1999-01-01

    In this report, integration of drying and gasification of biomass into cogeneration power plants, comprising gas turbines, is investigated. The thermodynamic cycles considered are the combined cycle and the humid air turbine cycle. These are combined with either pressurised or near atmospheric gasification, and steam or exhaust gas dryer, in a number of combinations. An effort is made to facilitate a comparison of the different concepts by using, and presenting, similar assumptions and input data for all studied systems. The resulting systems are modelled using the software package ASPEN PLUS{sup TM}, and for each system both the electrical efficiency and the fuel utilisation are calculated. The investigation of integrated gasification combined cycles (IGCC), reveals that systems with pressurised gasification have a potential for electrical efficiencies approaching 45% (LHV). That is 4 - 5 percentage points higher than the corresponding systems with near atmospheric gasification. The type of dryer in the system mainly influences the fuel utilisation, with an advantage of approximately 8 percentage points (LHV) for the steam dryer. The resulting values of fuel utilisation for the IGCC systems are in the range of 78 - 94% (LHV). The results for the integrated gasification humid air turbine systems (IGHAT) indicate that electrical efficiencies close to the IGCC are achievable, provided combustion of the fuel gas in highly humidified air is feasible. Reaching a high fuel utilisation is more difficult for this concept, unless the temperature levels in the district heating network are low. For comparison a conventional cogeneration plant, based on a CFB boiler and a steam turbine (Rankine cycle), is also modelled in ASPEN PLUS{sup TM}. The IGCC and IGHAT show electrical efficiencies in the range of 37 - 45% (LHV), compared with a calculated value of 31% (LHV) for the Rankine cycle cogeneration plant. Apart from the electrical efficiency, also a high value of fuel

  8. Performance comparison between crystalline and co-amorphous salts of indomethacin-lysine

    DEFF Research Database (Denmark)

    Kasten, Georgia; Nouri, Khatera; Grohganz, Holger

    2017-01-01

    The introduction of a highly water soluble amino acid as co-amorphous co-former has previously been shown to significantly improve the dissolution rate of poorly water soluble drugs. In this work, dry ball milling (DBM) and liquid assisted grinding (LAG) were used to prepare different physical...... forms of salts of indomethacin (IND) with the amino acid lysine (LYS), allowing the direct comparison of their solid-state properties to their in vitro performance. X-ray powder diffraction and Fourier-transformed infrared spectroscopy showed that DBM experiments led to the formation of a fully co......-amorphous salt, while LAG resulted in a crystalline salt. Differential scanning calorimetry showed that the samples prepared by DBM had a single glass transition temperature (Tg) of approx. 100°C for the co-amorphous salt, while a new melting point (223°C) was obtained for the crystalline salt prepared by LAG...

  9. The Impact of Governance on the Research Performance of European Universities in Cross-Country Comparisons

    Directory of Open Access Journals (Sweden)

    Sedláček Jan

    2017-12-01

    Full Text Available The article concentrates on the impact of selected aspects of governance - the level of autonomy and the involvement of stakeholders in the internal governance of a university - on the research performance of universities measured by indicators of international university rankings in cross-country comparisons. The analyses are geographically situated in Europe. They follow two paths which are from the theoretical point of view based on the concepts of the principal-agent problem and stakeholder theory. Using linear regression, the author identifies statistically significant aspects of governance and compares them with results of previous studies. The findings serve as a basis for a discussion regarding how to create appropriate conditions for universities in order to improve their prospects for international success in research. The limitations of the results relating to the data, methodology and their application in the European context are discussed and general recommendations are formulated.

  10. Comparison of RSYST and WIMSD-4 performance for gadolinium poisoned lattices

    Energy Technology Data Exchange (ETDEWEB)

    Kulikowska, T; Szczesna, B; Sadowska, B

    1992-06-01

    The participation in the Co-ordinated Research Programme on `Safe Core Management with Burnable Absorbers in VVERs` has created a possibility of validation of our basic calculational tools for advanced lattice calculations. A systematic analysis of the performance of WIMSD-4 and the recently adapted RSYST modular systems has been carried out on the basis of two benchmarks with gadolinium bearing pins. The report consists of a detailed comparison of methods and models available in RSYST and WIMSD-4 followed by calculational results and their discussion. Finally, the conclusions are drawn concerning the applicability of the two codes for clean fuel and gadolinium poisoned reactor lattices. (author). 26 refs, 19 figs, 19 tabs.

  11. Performance comparison of novel WNN approach with RBFNN in navigation of autonomous mobile robotic agent

    Directory of Open Access Journals (Sweden)

    Ghosh Saradindu

    2016-01-01

    Full Text Available This paper addresses the performance comparison of Radial Basis Function Neural Network (RBFNN with novel Wavelet Neural Network (WNN of designing intelligent controllers for path planning of mobile robot in an unknown environment. In the proposed WNN, different types of activation functions such as Mexican Hat, Gaussian and Morlet wavelet functions are used in the hidden nodes. The neural networks are trained by an intelligent supervised learning technique so that the robot makes a collision-free path in the unknown environment during navigation from different starting points to targets/goals. The efficiency of two algorithms is compared using some MATLAB simulations and experimental setup with Arduino Mega 2560 microcontroller in terms of path length and time taken to reach the target as an indicator for the accuracy of the network models.

  12. Comparison of Simulated PEC Probe Performance for Detecting Wall Thickness Reduction

    International Nuclear Information System (INIS)

    Shin, Young Kil; Choi, Dong Myung; Jung, Hee Sung

    2009-01-01

    In this paper, four different types of pulsed eddy current(PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction can be achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the thickness variation.

  13. A Diagnostic Comparison of Turkish and Korean Students’ Mathematics Performances on the TIMSS 2011 Assessment

    Directory of Open Access Journals (Sweden)

    Sedat Şen

    2015-11-01

    Full Text Available The purpose of the present study was to analyze an international large-scale data set using a cognitive assessment approach. Although some researchers question the usefulness of international large-scale assessments (e.g., TIMSS, participating countries have continued to use the results from these large-scale assessments to improve their curricula and teaching methods. Despite the common reporting practice—single-score—in these large scale assessments gives useful insights about students’ overall performances, they still lack diagnostic information. Cognitive diagnosis models (CDMs were developed to provide more feedback on students’ cognitive strengths and weaknesses. This study retrofitted the TIMSS 2011 eighth grade mathematics assessment by applying a specific CDM called the DINA (the deterministic, inputs, noisy, “and” gate model to data from South Korea and Turkey. Results of the DINA model were used to make a detailed comparison between students of these two countries.

  14. Comparison of Numerically Simulated and Experimentally Measured Performance of a Rotating Detonation Engine

    Science.gov (United States)

    Paxson, Daniel E.; Fotia, Matthew L.; Hoke, John; Schauer, Fred

    2015-01-01

    A quasi-two-dimensional, computational fluid dynamic (CFD) simulation of a rotating detonation engine (RDE) is described. The simulation operates in the detonation frame of reference and utilizes a relatively coarse grid such that only the essential primary flow field structure is captured. This construction and other simplifications yield rapidly converging, steady solutions. Viscous effects, and heat transfer effects are modeled using source terms. The effects of potential inlet flow reversals are modeled using boundary conditions. Results from the simulation are compared to measured data from an experimental RDE rig with a converging-diverging nozzle added. The comparison is favorable for the two operating points examined. The utility of the code as a performance optimization tool and a diagnostic tool are discussed.

  15. Finite-element analysis and comparison of the AC loss performance of BSCCO and YBCO conductors

    International Nuclear Information System (INIS)

    Stavrev, Svetlomir; Grilli, Francesco; Dutoit, Bertrand; Ashworth, Stephen

    2006-01-01

    The AC loss performance of two BSCCO and two YBCO conductors of different geometry, characterized by the same self-field critical current of 150 A, is analysed and compared quantitatively. The comparison is made using the finite-element method with a nonlinear B-dependent E-J relation. A new shell-region model is utilised for the simulations of thin YBCO strips. Different AC working conditions are simulated: self-field, applied external field, and combined transport current and external perpendicular field application. Magnetic field and current density profiles are investigated in order to illustrate the reasons for the loss difference in the conductors. Depending on the application, the advantages of using BSCCO or YBCO conductors with specific geometry are outlined

  16. Thermodynamic performance comparison between ORC and Kalina cycles for multi-stream waste heat recovery

    International Nuclear Information System (INIS)

    Wang, Yufei; Tang, Qikui; Wang, Mengying; Feng, Xiao

    2017-01-01

    Highlights: • Comparison between ORC and Kalina cycles (KC) for multi-stream waste heat recovery. • Divide waste heat into straight, convex and concave based on its composite curve. • Use heat ratio and temperature of the most point to show the feature of waste heat. • KC is suitable for straight and most concave heat, while ORC for convex one. - Abstract: Organic Rankine cycle (ORC) and Kalina cycle are the main technologies to recover waste heat for power generation. Up to now, many works dealing with the thermodynamic performance comparison between ORC and Kalina cycles are available, but these studies considered for heat recovery from a single heat source or stream. In the process industry, there are multiple waste heat streams, forming a complex heat source profile. In this paper, based on the simulation model developed in the Aspen Hysys software, the two cycles are calculated and compared. According to the waste heat composite curve, the multi-stream waste heat is divided into three kinds, straight, convex, and concave waste heat. Two parameters, the ratio of the heat above and below the most salient/concave point (R) and the temperature of the most point, are used to roughly express the feature of waste heat. With the efficiency from waste heat (exergy) to power as energy performance indicator, the calculation results for waste heat with maximum supply temperature 180 °C show that for straight and concave waste heat with R not less than 0.2, Kalina cycle is better than ORC, while for convex waste heat, ORC is preferable. The work can provide a reference to choose a suitable technology to recover low temperature waste heat for power generation in the process industry.

  17. Safety Performance Indicator for alcohol in road accidents--international comparison, validity and data quality.

    Science.gov (United States)

    Assum, Terje; Sørensen, Michael

    2010-03-01

    Safety Performance Indicators, SPIs, are developed for various areas within road safety such as speed, car occupant protection, alcohol and drugs, vehicle safety, etc. SPIs can be used to indicate the road safety situation and to compare road safety performance between countries and over time and to understand the process leading to accidents, helping to select the measures to reduce them. This article describes an alcohol SPI defined as the percentage of fatalities resulting from accidents involving at least one driver impaired by alcohol. The calculation of the alcohol SPI for 26 European countries shows that the SPI varies from 4.4% in Bulgaria to 72.2% in Italy. These results raise the question if the results reflect the real situation or if there is a methodological explanation. To answer this question three different studies were carried out: comparison with other alcohol SPIs, in-depth studies of data quality in seven selected countries, and a study of correlations between the SPI and influencing factors. These studies indicate clearly that there is a need to improve quality of the data used for the alcohol SPI. Most importantly, the total number of drivers involved in fatal accidents, the number tested for alcohol and the number not tested, should be reported, in addition to the number of alcohol positive and negative drivers among those tested. Until these improvements are made, the validity of this SPI seems poor and comparison of the alcohol SPI results across countries should be made with caution. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. Comparison study of different coatings on degradation performance and cell response of Mg-Sr alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shangguan, Yongming [Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Sun, Lina [Jinzhou Medical University, Jinzhou 121000 (China); Wan, Peng, E-mail: pwan@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Tan, Lili [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Wang, Chengyue [Jinzhou Medical University, Jinzhou 121000 (China); Fan, Xinmin [Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Qin, Ling [Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

    2016-12-01

    To solve the problem of rapid degradation for magnesium-based implants, surface modification especially coating method is widely studied and showed the great potential for clinical application. However, as concerned to the further application and medical translation for biodegradable magnesium alloys, there are still lack of data and comparisons among different coatings on their degradation and biological properties. This work studied three commonly used coatings on Mg-Sr alloy, including micro-arc oxidation coating, electrodeposition coating and chemical conversion coating, and compared these coatings for requirements of favorable degradation and biological performances, how each of these coating systems has performed. Finally the mechanism for the discrepancy between these coatings is proposed. The results indicate that the micro-arc oxidation coating on Mg-Sr alloy exhibited the best corrosion resistance and cell response among these coatings, and is proved to be more suitable for the orthopedic application. - Highlights: • The MAO, PED and Sr-P coating were fabricated on Mg-Sr alloy to evaluate the degradation. • The MAO coating showed the greatest degradation performance among these three coatings. • The PED coating exhibited worse corrosion resistance even than Mg-Sr substrate. • The value of cell proliferation and ALP activity were ranked in the following order: MAO > Sr-P > PED.

  19. Comparison study of different coatings on degradation performance and cell response of Mg-Sr alloy

    International Nuclear Information System (INIS)

    Shangguan, Yongming; Sun, Lina; Wan, Peng; Tan, Lili; Wang, Chengyue; Fan, Xinmin; Qin, Ling; Yang, Ke

    2016-01-01

    To solve the problem of rapid degradation for magnesium-based implants, surface modification especially coating method is widely studied and showed the great potential for clinical application. However, as concerned to the further application and medical translation for biodegradable magnesium alloys, there are still lack of data and comparisons among different coatings on their degradation and biological properties. This work studied three commonly used coatings on Mg-Sr alloy, including micro-arc oxidation coating, electrodeposition coating and chemical conversion coating, and compared these coatings for requirements of favorable degradation and biological performances, how each of these coating systems has performed. Finally the mechanism for the discrepancy between these coatings is proposed. The results indicate that the micro-arc oxidation coating on Mg-Sr alloy exhibited the best corrosion resistance and cell response among these coatings, and is proved to be more suitable for the orthopedic application. - Highlights: • The MAO, PED and Sr-P coating were fabricated on Mg-Sr alloy to evaluate the degradation. • The MAO coating showed the greatest degradation performance among these three coatings. • The PED coating exhibited worse corrosion resistance even than Mg-Sr substrate. • The value of cell proliferation and ALP activity were ranked in the following order: MAO > Sr-P > PED.

  20. Comparisons of Hydraulic Performance in Permanent Maglev Pump for Water-Jet Propulsion

    Directory of Open Access Journals (Sweden)

    Puyu Cao

    2014-08-01

    Full Text Available The operation of water-jet propulsion can generate nonuniform inflow that may be detrimental to the performance of the water-jets. To reduce disadvantages of the nonuniform inflow, a rim-driven water-jet propulsion was designed depending on the technology of passive magnetic levitation. Insufficient understanding of large performance deviations between the normal water-jets (shaft and permanent maglev water-jets (shaftless is a major problem in this paper. CFD was directly adopted in the feasibility and superiority of permanent maglev water-jets. Comparison and discussion of the hydraulic performance were carried out. The shaftless duct firstly has a drop in hydraulic losses (K1, since it effectively avoids the formation and evolution of the instability secondary vortex by the normalized helicity analysis. Then, the shaftless intake duct improves the inflow field of the water-jet pump, with consequencing the drop in the backflow and blocking on the blade shroud. So that the shaftless water-jet pump delivers higher flow rate and head to the propulsion than the shaft. Eventually, not only can the shaftless model increase the thrust and efficiency, but it has the ability to extend the working range and broaden the high efficiency region as well.

  1. Comparison of the performances of the CS model coil and the Good Joint SULTAN sample

    International Nuclear Information System (INIS)

    Wesche, Rainer; Herzog, Robert; Bruzzone, Pierluigi

    2008-01-01

    The relevance of short sample measurements in SULTAN for the prediction of the performance of the coils of the International Thermonuclear Experimental Reactor (ITER) is assessed using the case of the Nb 3 Sn high-field central solenoid model coil (CSMC) conductor, for which both coil performance and short sample SULTAN results (Good Joint (GJ) sample) are available. A least-squares fit procedure, based on a uniform current distribution among the strands and the Durham scaling relations for the field, temperature and strain dependences of the strand J c provides a thermal strain of -0.294% and a degradation factor of approximately 60% for the GJ sample. In the calculation of the voltage along Layer 1A of the CSMC the hoop stress and the variation of the magnetic field in the conductor cross-section were taken into account. The temperature profile, used in the calculations, is based on published temperature profiles and empirical relations between helium inlet and outlet temperatures. A comparison with the GJ results indicates that short sample measurements in SULTAN provide a conservative estimate of the coil performance

  2. Performance Comparison of Grid-Faulty Control Schemes for Inverter-Based Industrial Microgrids

    Directory of Open Access Journals (Sweden)

    Antonio Camacho

    2017-12-01

    Full Text Available Several control schemes specifically designed to operate inverter-based industrial microgrids during voltage sags have been recently proposed. This paper first classifies these control schemes in three categories and then performs a comparative analysis of them. Representative control schemes of each category are selected, described and used to identify the main features and performance of the considered category. The comparison is based on the evaluation of several indexes, which measure the power quality of the installation and utility grid during voltage sags, including voltage regulation, reactive current injection and transient response. The paper includes selected simulation results from a 500 kVA industrial microgrid to validate the expected features of the considered control schemes. Finally, in view of the obtained results, the paper proposes an alternative solution to cope with voltage sags, which includes the use of a static compensator in parallel with the microgrid. The novelty of this proposal is the suitable selection of the control schemes for both the microgrid and the static compensator. The superior performance of the proposal is confirmed by the analysis of the quality indexes. Its practical limitations are also revealed, showing that the topic studied in this paper is still open for further research.

  3. LCD displays performance comparison by MTF measurement using the white noise stimulus method

    Science.gov (United States)

    Mitjà, Carles; Escofet, Jaume

    2011-01-01

    The amount of images produced to be viewed as soft copies on output displays are significantly increasing. This growing occurs at the expense of the images targeted to hard copy versions on paper or any other physical support. Even in the case of high quality hard copy production, people working in professional imaging uses different displays in selecting, editing, processing and showing images, from laptop screen to specialized high end displays. Then, the quality performance of these devices is crucial in the chain of decisions to be taken in image production. Metrics of this quality performance can help in the equipment acquisition. Different metrics and methods have been described to determine the quality performance of CRT and LCD computer displays in clinical area. One of most important metrics in this field is the device spatial frequency response obtained measuring the modulation transfer function (MTF). This work presents a comparison between the MTF of three different LCD displays, Apple MacBook Pro 15", Apple LED Cinema Display 24" and Apple iPhone4, measured by the white noise stimulus method, over vertical and horizontal directions. Additionally, different displays show particular pixels structure pattern. In order to identify this pixel structure, a set of high magnification images is taken from each display to be related with the respective vertical and horizontal MTF.

  4. International comparisons of health system performance among OECD countries: opportunities and data privacy protection challenges.

    Science.gov (United States)

    Oderkirk, Jillian; Ronchi, Elettra; Klazinga, Niek

    2013-09-01

    Health data constitute a significant resource in most OECD countries that could be used to improve health system performance. Well-intended policies to allay concerns about breaches of confidentiality and to reduce potential misuse of personal health information may be limiting data use. A survey of 20 OECD countries explored the extent to which countries have developed and use personal health data and the reasons why data use may be problematic in some. Countries are divided, with one-half engaged regularly in national data linkage studies to monitor health care quality. Country variation is linked to risk management in granting an exemption to patient consent requirements; in sharing identifiable data among government authorities; and in project approvals and granting access to data. The resources required to comply with data protection requirements is a secondary problem. The sharing of person-level data across borders for international comparisons is rarely reported and there were few examples of studies of health system performance. Laws and policies enabling data sharing and data linkage are needed to strengthen national information infrastructure. To develop international studies comparing health care quality and health system performance, actions are needed to address heterogeneity in data protection practices. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  5. Comparison of two approaches for establishing performance criteria related to Maintenance Rule

    International Nuclear Information System (INIS)

    Jerng, Dong-Wook; Kim, Man Cheol

    2015-01-01

    Probabilistic safety assessment (PSA) serves as a tool for systemically analyzing the safety of nuclear power plants. This paper explains and compares two approaches for the establishment of performance criteria related to the Maintenance Rule: (1) the individual reliability-based approach, and (2) the PSA importance measure-based approach. Different characteristics of the two approaches were compared in a qualitative manner, while a quantitative comparison was performed through application of the two approaches to a nuclear power plant. It was observed that the individual reliability-based approach resulted in more conservative performance criteria, compared to the PSA importance measure-based approach. It is thus expected that the PSA importance measure-based approach will allow for more flexible maintenance policy under conditions of limited resources, while providing for a macroscopic view of overall plant safety. Based on insights derived through this analysis, we emphasize the importance of a balance between reliability and safety significance, and propose a balance measure accordingly. The conclusions of this analysis are likely to be applicable to other types of nuclear power plants. (author)

  6. Analysis of changes in environmental radiation, and three types of environmental radiation detector performance comparisons

    International Nuclear Information System (INIS)

    Park, J.H; Seo, J.H; Park, S.M; Yu, B.N; Park, J.H; Joo, K.S

    2013-06-01

    High-pressure ion chamber (GE Reuter-Stokes, HPIC), accuracy is high but the high price and do not have the ability nuclide analysis is a disadvantage. NaI(Tl) and PMT scintillation detector of radioactive materials can be divided. Environmental radiation measurements using a semiconductor with SiPM detector PMT to replace the value of the results were compared. SiPM detector using radiation environment were measured in the field to verify the accuracy and energy resolution. SiPMs performance as environmental radiation measurement equipment and radioactive material distinction as a personal dosimeter based technology, using the above results were prepared. The interest on the environmental radiation due to the Fukushima power plant crisis in Japan has been growing concern about the radiation environment of the relatively close proximity Korea is a very heightened state. Could be confirmed in the radiation environment of nuclear power plants around the analysis and performance of the next generation of environmental radiation meter. Fukushima power plants accident after 2 years, the equipment installed by this analysis meets the performance as a radiation detector could be confirmed as follows. CANA Inc. developed by radionuclides classification of using man-made and natural radionuclides and man-made radionuclides separated, ensure the value of the results were analyzed. Could be and alternative to the conventional detector energy resolution ( 137 CS<15%) and linearity (<15%) to satisfy the performance requirements of the measurement result of environmental radiation detector is considered. SiPM radiation environment changes and HPIC and NaI(TI) scintillation detector installed in Korea of the Fukushima power plant after the accident, radiation environment using a small alternative was to verify the accuracy of the measuring equipment. A big difference in performance as invisible by comparison with the large detector Assay miniaturization rough as a personal

  7. Performance comparison of two androgen receptor splice variant 7 (AR-V7) detection methods.

    Science.gov (United States)

    Bernemann, Christof; Steinestel, Julie; Humberg, Verena; Bögemann, Martin; Schrader, Andres Jan; Lennerz, Jochen K

    2018-01-23

    To compare the performance of two established androgen receptor splice variant 7 (AR-V7) mRNA detection systems, as paradoxical responses to next-generation androgen-deprivation therapy in AR-V7 mRNA-positive circulating tumour cells (CTC) of patients with castration-resistant prostate cancer (CRPC) could be related to false-positive classification using detection systems with different sensitivities. We compared the performance of two established mRNA-based AR-V7 detection technologies using either SYBR Green or TaqMan chemistries. We assessed in vitro performance using eight genitourinary cancer cell lines and serial dilutions in three AR-V7-positive prostate cancer cell lines, as well as in 32 blood samples from patients with CRPC. Both assays performed identically in the cell lines and serial dilutions showed identical diagnostic thresholds. Performance comparison in 32 clinical patient samples showed perfect concordance between the assays. In particular, both assays determined AR-V7 mRNA-positive CTCs in three patients with unexpected responses to next-generation anti-androgen therapy. Thus, technical differences between the assays can be excluded as the underlying reason for the unexpected responses to next-generation anti-androgen therapy in a subset of AR-V7 patients. Irrespective of the method used, patients with AR-V7 mRNA-positive CRPC should not be systematically precluded from an otherwise safe treatment option. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

  8. Comparison of test performance profile for blood tests of liver fibrosis in chronic hepatitis C.

    Science.gov (United States)

    Halfon, Philippe; Bacq, Yannick; De Muret, Anne; Penaranda, Guillaume; Bourliere, Marc; Ouzan, Denis; Tran, Albert; Botta, Danielle; Renou, Christophe; Bréchot, Marie-Claude; Degott, Claude; Paradis, Valérie

    2007-03-01

    We evaluated the test performance profile (TPP) of blood tests of liver fibrosis. Three hundred and fifty-six patients with C chronic hepatitis were included in two centers. Metavir staging of liver specimens by two independent pathologists and the following tests were evaluated: Fibrotest (FT), APRI, FibroMeter (FM), and Hepascore (HS). Metavir stages were: F0: 4%, F1: 55%, F2: 26%, F3: 11%, and F4: 4%. The AUROCs were not significantly different, respectively, FT, FM, APRI, HS: >or=F2: 0.79, 0.78, 0.76, >or=0.76; F3: 0.81, 0.85, 0.81, 0.81; and F4: 0.86, 0.94, 0.92, 0.89. The TPP relies on the paired comparison of blood-test misclassification based on liver specimen, e.g. FT vs FM, respectively: F0+1: 18 vs 28% (p=0.0003), >or=F2: 43 vs 31% (p=0.004). There was no center effect. In those populations, the four blood tests had a similar performance for significant fibrosis (F>or=2), lying in the lower range of published results which is attributable to a low >or=F2 prevalence, and for >or=F3 and F4. However, FM and FT had performance profiles significantly different as a function of fibrosis stages or diagnostic target (fibrosis cut-off). This has to be considered during the interpretation process. Moreover, the performance should be reported with different diagnostic targets.

  9. Comparison of Aerobic Performance Testing Protocols in Elite Male Wheelchair Basketball Players

    Directory of Open Access Journals (Sweden)

    Molik Bartosz

    2017-12-01

    Full Text Available In wheelchair sports, aerobic performance is commonly assessed with the use of an arm crank ergometer (ACE, a wheelchair ergometer (WCE or a wheelchair treadmill (WCT. There are different protocols to identify peak oxygen uptake in wheelchair sports; however, only a few protocols have been applied to evaluate these conditions in wheelchair basketball players. The purpose of this study was to compare physiological responses during maximal exercise testing with the use of ACE and WCT in wheelchair basketball players. Twelve elite male wheelchair basketball players participated in this study. The research was performed during a training camp of the Polish National Wheelchair Basketball Team. The study participants were divided into two functional categories: A (players with class 1.0 - 2.5 and B (players with class 3.0 - 4.5. Two main maximal exercise tests, i.e. wheelchair treadmill stress test (WCT test and arm crank ergometer stress test (ACE test were used to evaluate aerobic performance of the players. There were no statistically significant differences in aerobic tests between the players from both groups. The comparison of results achieved in two aerobic tests performed on WCT and ACE did not reveal any significant differences between the analyzed variables (peak heart rate (HRpeak, peak oxygen uptake (VO2peak, minute ventilation (VE, anaerobic threshold (AT, lactate concentration (LApeak, and a drop in lactate concentration (%LA. Strong correlations between results achieved in WCT and ACE tests were found for VO2peak, VE and LApeak. The main conclusion of the study is that both WCT and ACE tests may be useful when determining aerobic capacity of wheelchair basketball players. Moreover, both protocols can be used by athletes regardless of their functional capabilities and types of impairment.

  10. Recursive formulae and performance comparisons for first mode dynamics of periodic structures

    Science.gov (United States)

    Hobeck, Jared D.; Inman, Daniel J.

    2017-05-01

    Periodic structures are growing in popularity especially in the energy harvesting and metastructures communities. Common types of these unique structures are referred to in the literature as zigzag, orthogonal spiral, fan-folded, and longitudinal zigzag structures. Many of these studies on periodic structures have two competing goals in common: (a) minimizing natural frequency, and (b) minimizing mass or volume. These goals suggest that no single design is best for all applications; therefore, there is a need for design optimization and comparison tools which first require efficient easy-to-implement models. All available structural dynamics models for these types of structures do provide exact analytical solutions; however, they are complex requiring tedious implementation and providing more information than necessary for practical applications making them computationally inefficient. This paper presents experimentally validated recursive models that are able to very accurately and efficiently predict the dynamics of the four most common types of periodic structures. The proposed modeling technique employs a combination of static deflection formulae and Rayleigh’s Quotient to estimate the first mode shape and natural frequency of periodic structures having any number of beams. Also included in this paper are the results of an extensive experimental validation study which show excellent agreement between model prediction and measurement. Lastly, the proposed models are used to evaluate the performance of each type of structure. Results of this performance evaluation reveal key advantages and disadvantages associated with each type of structure.

  11. Comparison of multiphase mixing simulations performed on a staggered and a collocated grid

    International Nuclear Information System (INIS)

    Leskovar, M.

    2000-01-01

    During a severe reactor accident following core meltdown when the molten fuel comes into contact with the coolant water a steam explosion may occur. The premixing phase of a steam explosion covers the interaction of the melt jet or droplets with the water prior to any steam explosion occurrence. To get a better insight of the hydrodynamic processes during the premixing phase beside hot premixing experiments, where the water evaporation is significant, also cold isothermal premixing experiments are performed. To analyze the cold premixing experiments the computer code ESE has been developed. The specialty of ESE is that it uses a combined single-multiphase flow model. Because of problems with the convergence of the momentum equation written in conservative form on a staggered grid, the development of a collocated grid version of ESE was planed. But since we obtained the commercial code CFX-4.3, which uses a collocated variable arrangement, we decided first to test the capabilities of CFX-4.3. With ESE and CFX-4.3 the cold premixing experiment Q08 has been simulated. In the paper the simulation results performed with both codes are presented and commented in comparison to experimental data. (author)

  12. Artificial Knee Joints Actuators with Energy Recovery Capabilities: A Comparison of Performance

    Directory of Open Access Journals (Sweden)

    Roberta Alò

    2016-01-01

    Full Text Available The human knee absorbs more energy than it expends in level ground walking. For this reason it would be useful if the actuation system of a wearable robot for lower limbs was able to recover energy thus improving portability. Presently, we recognize three promising technologies with energy recovery capabilities already available in the literature: the Series Elastic Actuator (SEA, the Clutchable Series Elastic Actuator (C-SEA, and the flywheel Infinitely Variable Transmission (F-IVT actuator. In this paper, a simulation model based comparison of the performance of these actuators is presented. The focus is on two performance indexes: the energy consumed by the electric motor per gait and the peak torque/power requested to the electric motor. Both quantities are related to the portability of the device: the former affects the size of the batteries for a given desired range; the latter affects the size and the weight of the electric motor. The results show that, besides some well-explained limitations of the presented methodology, the C-SEA is the most energy efficient whereas the F-IVT allows cutting down the motor torque/peak power strongly. The analysis also leads to defining how it is possible to improve the F-IVT to achieve a reduction of the energy consumption.

  13. Mirror fusion propulsion system - A performance comparison with alternate propulsion systems for the manned Mars mission

    International Nuclear Information System (INIS)

    Deveny, M.; Carpenter, S.; O'connell, T.; Schulze, N.

    1993-06-01

    The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons. 50 refs

  14. Comparison of Student Performance, Student Perception, and Teacher Satisfaction with Traditional versus Flipped Classroom Models

    Directory of Open Access Journals (Sweden)

    Zafer Unal

    2017-11-01

    Full Text Available As new technologies become available, they are often embraced in educational innovation to enhance traditional instruction. The flipped teaching model is one of the most recent and popular technology-infused teaching models in which learning new concepts takes place at home while practice is conducted in the classroom. The purpose of this study was to investigate how using the flipped teaching model affects student performance, perceptions, and teacher satisfaction in comparison to the traditional model. Sixteen teachers implemented the flipped teaching model in their classrooms and reported the results of the flipped teaching model for the first time. Pretests and posttests were used to measure and compare student performance while student and teacher surveys facilitated data collection on student perception and teacher satisfaction. The results of the study showed that, in most cases, the flipped classroom model demonstrated higher student learning gains, more positive student perception, and higher teacher satisfaction compared to the traditional model. This study adds evidence to the current literature that, if the conditions are properly set, the flipped classroom should have the potential to be an extremely effective learning style.

  15. Comparison of Two Probabilistic Fatigue Damage Assessment Approaches Using Prognostic Performance Metrics

    Directory of Open Access Journals (Sweden)

    Xuefei Guan

    2011-01-01

    Full Text Available In this paper, two probabilistic prognosis updating schemes are compared. One is based on the classical Bayesian approach and the other is based on newly developed maximum relative entropy (MRE approach. The algorithm performance of the two models is evaluated using a set of recently developed prognostics-based metrics. Various uncertainties from measurements, modeling, and parameter estimations are integrated into the prognosis framework as random input variables for fatigue damage of materials. Measures of response variables are then used to update the statistical distributions of random variables and the prognosis results are updated using posterior distributions. Markov Chain Monte Carlo (MCMC technique is employed to provide the posterior samples for model updating in the framework. Experimental data are used to demonstrate the operation of the proposed probabilistic prognosis methodology. A set of prognostics-based metrics are employed to quantitatively evaluate the prognosis performance and compare the proposed entropy method with the classical Bayesian updating algorithm. In particular, model accuracy, precision, robustness and convergence are rigorously evaluated in addition to the qualitative visual comparison. Following this, potential development and improvement for the prognostics-based metrics are discussed in detail.

  16. Comparison of performance of three commercial platforms for warfarin sensitivity genotyping.

    Science.gov (United States)

    Babic, Nikolina; Haverfield, Eden V; Burrus, Julie A; Lozada, Anthony; Das, Soma; Yeo, Kiang-Teck J

    2009-08-01

    We performed a 3-way comparison on the Osmetech eSensor, AutoGenomics INFINITI, and a real-time PCR method (Paragonx reagents/Stratagene RT-PCR platform) for their FDA-cleared warfarin panels, and additional polymorphisms (CYP2C9*5, *6, and 11 and extended VKORC1 panels) where available. One hundred de-identified DNA samples were used in this IRB-approved study. Accuracy was determined by comparison of genotyping results across three platforms. Any discrepancy was resolved by bi-directional sequencing. The CYP4F2 on Osmetech was validated by bi-directional sequencing. Accuracies for CYP2C9*2 and *3 were 100% for all 3 platforms. VKORC1 3673 genotyping accuracies were 100% on eSensor and 97% on Infiniti. CYP2C9*5, *6 and *11 showed 100% concordance between eSensor and Infiniti. VKORC1 6484 and 9041 variants compared between ParagonDx and Infiniti analyzer were 100% (6484) and 99% (9041) concordant. CYP4F2 was 100% concordant with sequencing results. The time required to generate the results from automated DNA extraction-to-result was approximately 8h on Infiniti, and 4h on eSensor and ParagonDx, respectively. Overall, we observed excellent CYP2C9*2 and *3 genotyping accuracy for all three platforms. For VKORC1 3673 genotyping, eSensor demonstrated a slightly higher accuracy than the Infiniti, and CYP4F2 on Osmetech was 100% accurate.

  17. Comparison of Hemoglobin A1c assay performance on two different commercial systems

    Directory of Open Access Journals (Sweden)

    Jozo Ćorić

    2015-04-01

    Full Text Available Introduction: Glycated hemoglobin (HbA1c is formed by non-enzymatic binding of glucose to the free amino group of the N-terminal end of the ß-chain of hemoglobin A. HbA1c is representative of the mean blood glucose level over three months. The aim of the study was to evaluate the Hemoglobin A1c immunoturbidimetric assay performance on two different commercial systems.Methods: We evaluated the precision and trueness for determination of HbA1c in whole blood. Concentrations of total hemoglobin and HbA1c were evaluated on Dimension Xpand (Siemens and Cobas 501 (Roche analyzers. HbA1c was measured in a latex agglutination inhibition test. Commercial controls Liquichek Diabetes Control Level 1 and Liquichek Diabetes Control Level 2 (Bio Rad at two levels were used for quality control. Analytical validation of HbA1c included: within-run imprecision, between-day imprecision, inaccuracy and comparison determination on the human samples on 2 systems: Dimension Xpand and Cobas 501 analyzers. Results: Within-run imprecision on the commercially controls for Level 1 is 4.5% and Level 2 is 3.2% between-day imprecision on commercially controls is 6.1% Level 1 and 5.1% Level 2 for respectively inac- curacy on commercially controls for Level 1 is 1.8% and Level 2 is 4.8%. Method comparison on human samples shows the correlation coefficient of 0.99.Conclusion: The presented results of the analytical evaluation methods for the determination of HbA1c showed an acceptable accuracy and precision.

  18. Team performance in resuscitation teams: Comparison and critique of two recently developed scoring tools☆

    Science.gov (United States)

    McKay, Anthony; Walker, Susanna T.; Brett, Stephen J.; Vincent, Charles; Sevdalis, Nick

    2012-01-01

    Background and aim Following high profile errors resulting in patient harm and attracting negative publicity, the healthcare sector has begun to focus on training non-technical teamworking skills as one way of reducing the rate of adverse events. Within the area of resuscitation, two tools have been developed recently aiming to assess these skills – TEAM and OSCAR. The aims of the study reported here were:1.To determine the inter-rater reliability of the tools in assessing performance within the context of resuscitation.2.To correlate scores of the same resuscitation teams episodes using both tools, thereby determining their concurrent validity within the context of resuscitation.3.To carry out a critique of both tools and establish how best each one may be utilised. Methods The study consisted of two phases – reliability assessment; and content comparison, and correlation. Assessments were made by two resuscitation experts, who watched 24 pre-recorded resuscitation simulations, and independently rated team behaviours using both tools. The tools were critically appraised, and correlation between overall score surrogates was assessed. Results Both OSCAR and TEAM achieved high levels of inter-rater reliability (in the form of adequate intra-class coefficients) and minor significant differences between Wilcoxon tests. Comparison of the scores from both tools demonstrated a high degree of correlation (and hence concurrent validity). Finally, critique of each tool highlighted differences in length and complexity. Conclusion Both OSCAR and TEAM can be used to assess resuscitation teams in a simulated environment, with the tools correlating well with one another. We envisage a role for both tools – with TEAM giving a quick, global assessment of the team, but OSCAR enabling more detailed breakdown of the assessment, facilitating feedback, and identifying areas of weakness for future training. PMID:22561464

  19. Performance comparison of three-phase flux reversal permanent magnet motors in BLDC and BLAC operation mode

    International Nuclear Information System (INIS)

    Stumberger, B.; Stumberger, G.; Hadziselimovic, M.; Hamler, A.; Gorican, V.; Jesenik, M.; Trlep, M.

    2008-01-01

    The paper presents a comparison of torque capability and flux-weakening performance of three-phase flux reversal permanent magnet motors with surface and inset permanent magnets. Finite element analysis is employed to determine the performance of each motor in BLDC and BLAC operation mode. It is shown that the torque capability and flux-weakening performance of surface or inset permanent magnet configuration is strongly dependent on the stator teeth number/rotor pole number combination

  20. Comparison of Exercise Performance in Recreationally Active and Masters Athlete Women.

    Science.gov (United States)

    Stone, Matthew S; Glenn, Jordan M; Vincenzo, Jennifer L; Gray, Michelle

    2018-02-01

    Stone, MS, Glenn, JM, Vincenzo, JL, and Gray, M. Comparison of exercise performance in recreationally active and masters athlete women. J Strength Cond Res 32(2): 565-571, 2018-Master athletes (MA) are an understudied, ever-growing cohort. As such, it is important to examine how age affects muscular power and fatigability. Of particular interest is muscular power maintenance and fatigue mitigation of MA compared with young, healthy adults. The purpose of this investigation was to examine the differences in peak power, average power, total work (WRK), and fatigue index (FI) between recreationally active (RA) younger adults and female MA during anaerobic cycling exercise. Two groups, RA (n = 15; 20.6 ± 0.8 years) and MA (n = 17; 50.5 ± 8.6 years), participated in this study. Peak power, APWR, WRK, and FI were measured during a 30-second Wingate maximum anaerobic cycling protocol at a predetermined resistance of 7.5% body mass. Peak power (p = 0.92; RA: 654.1 ± 114.5 W; MA: 658.6 ± 147.6 W), APWR (p = 0.09; RA: 429.8 ± 73.3 W; MA: 384 ± 73.8 W), WRK (p = 0.09; RA: 12,894.3 ± 2,198.3 J; MA: 18,044.3 ± 27,184.9 J), and FI (p = 0.30; RA: 11.8 ± 4.1 W·s; MA: 14 ± 5.2 W·s) were not significantly different between groups. Master athletes produce power and WRK comparable to rates of fatigue among RA. This suggests that MA can maintain physical ability similar to RA in multiple parameters of high-intensity exercise while mitigating fatigue comparably. These data allow for advancements in exercise training and performance outcomes in MA populations. Further research within the MA population is warranted regarding other aspects of exercise and sport performance.

  1. Comparison of force, power, and striking efficiency for a Kung Fu strike performed by novice and experienced practitioners: preliminary analysis.

    Science.gov (United States)

    Neto, Osmar Pinto; Magini, Marcio; Saba, Marcelo M F; Pacheco, Marcos Tadeu Tavares

    2008-02-01

    This paper presents a comparison of force, power, and efficiency values calculated from Kung Fu Yau-Man palm strikes, when performed by 7 experienced and 6 novice men. They performed 5 palm strikes to a freestanding basketball, recorded by high-speed camera at 1000 Hz. Nonparametric comparisons and correlations showed experienced practitioners presented larger values of mean muscle force, mean impact force, mean muscle power, mean impact power, and mean striking efficiency, as is noted in evidence obtained for other martial arts. Also, an interesting result was that for experienced Kung Fu practitioners, muscle power was linearly correlated with impact power (p = .98) but not for the novice practitioners (p = .46).

  2. Performance Comparison of Containment PT analysis between CAP and CONTEMPT Code

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Yeon Jun; Hong, Soon Joon; Hwang, Su Hyun; Kim, Min Ki; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Ha, Sang Jun; Choi, Hoon [KHNP-CENTERAL RESEARCH INSTITUTE, Daejeon (Korea, Republic of)

    2013-10-15

    CAP, in the form that is linked with SPACE, computed the containment back-pressure during LOCA accident. In previous SAR (safety analysis report) report of Shin-Kori Units 3 and 4, the CONTEMPT series of codes(hereby referred to as just 'CONTEMPT') is used to evaluate the containment safety during the postulated loss-of-coolant accident (LOCA). In more detail, CONTEMPT-LT/028 was used to calculate the containment maximum PT, while CONTEMPT4/MOD5 to calculate the minimum PT. Actually, in minimum PT analysis, CONTEMPT4/MOD5, which provide back pressure condition of containment, was linked with RELAP5/MOD3.3 which calculate the amount of blowdown into containment. In this analysis, CONTEMPT4/MOD5 was modified based on KREM. CONTEMPT code was developed to predict the long term behavior of water-cooled nuclear reactor containment systems subjected to LOCA conditions. It calculates the time variation of compartment pressures, temperatures, mass and energy inventories, heat structure temperature distributions, and energy exchange with adjacent compartments, leakage on containment response. Models are provided for fan cooler and cooling spray as engineered safety systems. Any compartment may have both a liquid pool region and an air-vapor atmosphere region above the pool. Each region is assumed to have a uniform temperature, but the temperatures of the two regions may be different. As mentioned above, CONTEMP has the similar code features and it therefore is expected to show the similar analysis performance with CAP. In this study, the differences between CAP and two CONTEMPT code versions (CONTEMPT-LT/028 for maximum PT and CONTEMPT4/MOD5 for minimum PT) are, in detail, identified and the code performances were compared for the same problem. Code by code comparison was carried out to identify the difference of LOCA analysis between a series of COMTEMPT and CAP code. With regard to important factors that affect the transient behavior of compartment thermodynamic

  3. Performance Comparison of Containment PT analysis between CAP and CONTEMPT Code

    International Nuclear Information System (INIS)

    Choo, Yeon Jun; Hong, Soon Joon; Hwang, Su Hyun; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon

    2013-01-01

    CAP, in the form that is linked with SPACE, computed the containment back-pressure during LOCA accident. In previous SAR (safety analysis report) report of Shin-Kori Units 3 and 4, the CONTEMPT series of codes(hereby referred to as just 'CONTEMPT') is used to evaluate the containment safety during the postulated loss-of-coolant accident (LOCA). In more detail, CONTEMPT-LT/028 was used to calculate the containment maximum PT, while CONTEMPT4/MOD5 to calculate the minimum PT. Actually, in minimum PT analysis, CONTEMPT4/MOD5, which provide back pressure condition of containment, was linked with RELAP5/MOD3.3 which calculate the amount of blowdown into containment. In this analysis, CONTEMPT4/MOD5 was modified based on KREM. CONTEMPT code was developed to predict the long term behavior of water-cooled nuclear reactor containment systems subjected to LOCA conditions. It calculates the time variation of compartment pressures, temperatures, mass and energy inventories, heat structure temperature distributions, and energy exchange with adjacent compartments, leakage on containment response. Models are provided for fan cooler and cooling spray as engineered safety systems. Any compartment may have both a liquid pool region and an air-vapor atmosphere region above the pool. Each region is assumed to have a uniform temperature, but the temperatures of the two regions may be different. As mentioned above, CONTEMP has the similar code features and it therefore is expected to show the similar analysis performance with CAP. In this study, the differences between CAP and two CONTEMPT code versions (CONTEMPT-LT/028 for maximum PT and CONTEMPT4/MOD5 for minimum PT) are, in detail, identified and the code performances were compared for the same problem. Code by code comparison was carried out to identify the difference of LOCA analysis between a series of COMTEMPT and CAP code. With regard to important factors that affect the transient behavior of compartment thermodynamic state in

  4. Comparison of nuclear safety research reactor (TRIGA-ACPR) performance with analytical prediction

    International Nuclear Information System (INIS)

    West, G.B.; Whittemore, W.L.

    1976-01-01

    The NSRR was taken critical on June 30, 1975 at the Japan Atomic Energy Research Institute - Tokai-mura, Japan. Following initial core loading and control rod calibration, a series of pulsing tests was performed to characterize the performance of the reactor. A comparison has been made of performance parameters actually measured in the 157 element core versus predicted values based upon design analyses. The nuclear parameters measured were quite close to prediction. A $4.70 pulse produced a minimum period of 1.12 msec, a peak power of 20,500 MW and yielded a prompt energy release of 103 MW-sec. Pulse tests with experimental UO 2 fuel pins in the central irradiation cavity have produced 320 cal/gm, averaged at the axial center of 10% enriched UO 2 , for a 100 MW-sec pulse. The pulse rods for the NSRR contain B 4 C enriched to about 93 percent in Boron-10 in order to achieve maximum design performance with only three pulse rods. The total worth for the three transient rods was measured to be about $5.05 (vs $5.07 calculated for the 165 element core), thus verifying the effectiveness of the Boron-10 enrichment to achieve the desired result. Analysis of fuel temperature measurements made in the NSRR show that, for fuel temperatures produced during pulsing greater than 900 deg. C, heat transfer in the 0.010-inch gap between fuel and clad is enhanced by the minor outgassing of hydrogen which is characteristic of that temperature region. The hydrogen is normally all reabsorbed within about 100 sec of maximum temperature, at which time the heat transfer is characteristic of air (or argon) in the gap. In some of the temperature-instrumented elements, however, all of the hydrogen was not reabsorbed and as a result these elements gave significantly lower temperatures for high power steady state operation than were recorded prior to pulsing. In general, the NSRR parameters measured during startup were quite close to analytical prediction and the overall performance of the

  5. Design, implementation and performance comparison of multiplier topologies in power-delay space

    Directory of Open Access Journals (Sweden)

    Mansi Jhamb

    2016-03-01

    Full Text Available With the advancements in the semiconductor industry, designing a high performance processor is a prime concern. Multiplier is one of the most crucial parts in almost every digital signal processing applications. This paper addresses the implementation of an 8-bit multiplier design employing CMOS full adder, full adder using Double Pass Transistor (DPL and multioutput carry Lookahead logic (CLA. DPL adder avoids the noise margin problem and speed degradation at low value of supply voltages associated with complementary pass transistor (CPL logic circuits. Multioutput carry lookahead adder leads to significant improvement in the speed of the overall circuitry. The investigation is carried out with simulation runs on HSPICE environment using 90 nm process technology at 25 °C. Finally, the design guidelines are derived to select the most suitable topology for the desired applications. Investigation reveals that multiplier design using multioutput carry lookahead adder proves to be more speed efficient in comparison with the other two considered design strategies.

  6. Comparison of students from private and public schools on the spelling performance.

    Science.gov (United States)

    Silva, Nathane Sanches Marques; Crenitte, Patrícia Abreu Pinheiro

    2015-01-01

    To compare the spelling ability of schoolchildren from the fourth to sixth grades of the elementary schools in the private and public schools of Bauru, São Paulo, and to verify whether errors are overcome as studies progress and the hierarchy of errors as to how often they occur. A dictation was applied to 384 schoolchildren: 206 from the private schools: 74 were at the fourth grade, 65 at the fifth grade, and 67 at the sixth grade; and 178 from the public schools; 56 at the fourth grade, 63 at the fifth grade, and 59 at the sixth grade of elementary school. Student's t test was used. In comparison of total spelling errors score, difference was found among the fourth and sixth grades of the private and public schools. Spelling errors decreased as education progressed, and those related to language irregularities were more common. Spelling ability and performance of students from the private and public schools are not similar in the fourth and sixth grades, but it is in the fifth grade. Spelling errors are gradually overcome as education progresses; however, this overcome rate was considerable between the fourth and fifth grades in the public schools. Decrease in the types of spelling errors follows a hierarchy of categories: phoneme/grapheme conversion, simple contextual rules, complex contextual rules, and language irregularities. Finally, the most common type of spelling error found was that related to language irregularities.

  7. A performance comparison of direct- and indirect-detection flat-panel imagers

    CERN Document Server

    Partridge, M; Müller, L

    2002-01-01

    A comparison of the performance of a direct- and an indirect-detection amorphous silicon flat-panel X-ray imager is presented for a 6 MV beam. Experimental measurements of the noise characteristics, image lag, spectral response, spatial resolution and quantum efficiency are described, compared and discussed. The two systems are comprised of 512x512 pixel, 400 mu m pitch, arrays of a-Si:H p-i-n photodiodes and thin-film transistors. In the direct-detection system, X-rays interact to produce electron/hole pairs directly in the silicon photodiodes. For the indirect-detection system, a phosphor screen converts energy from the incident X-rays into visible light, which is then detected by the photodiodes. Both systems are shown to be quantum noise limited, with the total electronic noise in the detector 10-15 times smaller than the Poisson noise level in detected signal. The measured lag for both systems is 1.0+-0.1% or less in the first frame with subsequent signals decaying exponentially with frame read-out, with...

  8. Multidetector CT enteroclysis: comparison of the reading performance for axial and coronal views

    International Nuclear Information System (INIS)

    Schmidt, Sabine; Chalaron, Marc; Schnyder, Pierre; Denys, Alban; Chevallier, Patrick; Bessoud, Bertrand; Verdun, Francis R.; Frascarolo, Philippe

    2005-01-01

    The purpose of this study was to compare the diagnostic performance of axial and coronal views in multidetector CT enteroclysis (MDCTE). We retrospectively evaluated 48 patients with pathological correlation investigated by MDCTE for small bowel disorders. After nasojejunal administration of 2 l of 5% methylcellulose axial arterial and venous acquisition of MDCTE was followed by coronal reconstructions using equal slice thicknesses of 2.5 mm with 2 mm increments. Spatial resolution of both planes was evaluated by phantom. Three radiologists independently read axial and coronal images concerning 12 pathological features. The interobserver agreement and time of reading was calculated. Sensitivity and specificity resulted from comparison with histopathology (n=39) or follow-up (n=9). Phantom study revealed higher spatial resolution for axial than coronal views, whatever reconstruction interval was used. However, spatial frequency always remained high. Most pathological signs, such as bowel wall thickening (BWT), bowel wall enhancement (BWE) and intraperitoneal fluid (IPF), showed better interobserver agreement on axial than coronal views (BWT: 0.61 vs. 0.44; BWE: 0.56 vs. 0.5; IPF:0.53 vs. 0.43). The Wilcoxon signed-rank test revealed significantly higher sensitivity for axial than coronal views (P=0.0453); the time of reading was significantly shorter for the latter (P=0.0146). The diagnostic value of axial slices is superior to coronal reconstructions despite the reduced data volume and display of the physiological course of bowel loops on the coronal plane. (orig.)

  9. PERFORMANCE COMPARISON OF USART COMMUNICATION BETWEEN REAL TIME OPERATING SYSTEM (RTOS AND NATIVE INTERRUPT

    Directory of Open Access Journals (Sweden)

    Novian Habibie

    2016-02-01

    Full Text Available Comunication between microcontrollers is one of the crucial point in embedded sytems. On the other hand, embedded system must be able to run many parallel task simultaneously. To handle this, we need a reliabe system that can do a multitasking without decreasing every task’s performance. The most widely used methods for multitasking in embedded systems are using Interrupt Service Routine (ISR or using Real Time Operating System (RTOS. This research compared perfomance of USART communication on system with RTOS to a system that use interrupt. Experiments run on two identical development board XMega A3BU-Xplained which used intenal sensor (light and temperature and used servo as external component. Perfomance comparison done by counting ping time (elapsing time to transmit data and get a reply as a mark that data has been received and compare it. This experiments divided into two scenarios: (1 system loaded with many tasks, (2 system loaded with few tasks. Result of the experiments show that communication will be faster if system only loaded with few tasks. System with RTOS has won from interrupt in case (1, but lose to interrupt in case (2.

  10. Comparisons of uniform and discrete source distributions for use in bioassay laboratory performance testing

    International Nuclear Information System (INIS)

    Scherpelz, R.I.; MacLellan, J.A.

    1987-09-01

    The Pacific Northwest Laboratory (PNL) is sending a torso phantom with radioactive material uniformly distributed in the lungs to in vivo bioassay laboratories for analysis. Although the radionuclides ultimately chosen for the studies had relatively long half-lives, future accreditation testing will require repeated tests with short half-life test nuclides. Computer modeling was used to simulate the major components of the phantom. Radiation transport calculations were then performed using the computer models to calculate dose rates either 15 cm from the chest or at its surface. For 144 Ce and 60 Co, three configurations were used for the lung comparison tests. Calculations show that, for most detector positions, a single plug containing 40 K located in the back of the heart provides a good approximation to a uniform distribution of 40 K. The approximation would lead, however, to a positive bias for the detector reading if the detector were located at the chest surface near the center. Loading the 40 K in a uniform layer inside the chest wall is not a good approximation of the uniform distribution in the lungs, because most of the radionuclides would be situated close to the detector location and the only shielding would be the thickness of the chest wall. The calculated dose rates for 60 Co and 144 Ce were similar at all calculated reference points. 3 refs., 5 figs., 10 tabs

  11. LHCb: Statistical Comparison of CPU performance for LHCb applications on the Grid

    CERN Multimedia

    Graciani, R

    2009-01-01

    The usage of CPU resources by LHCb on the Grid id dominated by two different applications: Gauss and Brunel. Gauss the application doing the Monte Carlo simulation of proton-proton collisions. Brunel is the application responsible for the reconstruction of the signals recorded by the detector converting them into objects that can be used for later physics analysis of the data (tracks, clusters,…) Both applications are based on the Gaudi and LHCb software frameworks. Gauss uses Pythia and Geant as underlying libraries for the simulation of the collision and the later passage of the generated particles through the LHCb detector. While Brunel makes use of LHCb specific code to process the data from each sub-detector. Both applications are CPU bound. Large Monte Carlo productions or data reconstructions running on the Grid are an ideal benchmark to compare the performance of the different CPU models for each case. Since the processed events are only statistically comparable, only statistical comparison of the...

  12. Comparison of performance of some common Hartmann-Shack centroid estimation methods

    Science.gov (United States)

    Thatiparthi, C.; Ommani, A.; Burman, R.; Thapa, D.; Hutchings, N.; Lakshminarayanan, V.

    2016-03-01

    The accuracy of the estimation of optical aberrations by measuring the distorted wave front using a Hartmann-Shack wave front sensor (HSWS) is mainly dependent upon the measurement accuracy of the centroid of the focal spot. The most commonly used methods for centroid estimation such as the brightest spot centroid; first moment centroid; weighted center of gravity and intensity weighted center of gravity, are generally applied on the entire individual sub-apertures of the lens let array. However, these processes of centroid estimation are sensitive to the influence of reflections, scattered light, and noise; especially in the case where the signal spot area is smaller compared to the whole sub-aperture area. In this paper, we give a comparison of performance of the commonly used centroiding methods on estimation of optical aberrations, with and without the use of some pre-processing steps (thresholding, Gaussian smoothing and adaptive windowing). As an example we use the aberrations of the human eye model. This is done using the raw data collected from a custom made ophthalmic aberrometer and a model eye to emulate myopic and hyper-metropic defocus values up to 2 Diopters. We show that the use of any simple centroiding algorithm is sufficient in the case of ophthalmic applications for estimating aberrations within the typical clinically acceptable limits of a quarter Diopter margins, when certain pre-processing steps to reduce the impact of external factors are used.

  13. Medication reconciliation in pediatric cardiology performed by a pharmacy technician: a prospective cohort comparison study.

    Science.gov (United States)

    Chan, Carol; Woo, Renée; Seto, Winnie; Pong, Sandra; Gilhooly, Tessie; Russell, Jennifer

    2015-01-01

    Medication reconciliation reduces potential medication discrepancies and adverse drug events. The role of pharmacy technicians in obtaining best possible medication histories (BPMHs) and performing reconciliation at the admission and transfer interfaces of care for pediatric patients has not been described. To compare the completeness and accuracy of BPMHs and reconciliation conducted by a pharmacy technician (pilot study) and by nurses and/or pharmacists (baseline). The severity of identified unintentional discrepancies was rated to determine their clinical importance. This prospective cohort comparison study involved patients up to 18 years of age admitted to and/or transferred between the Cardiology ward and the Cardiac Critical Care Unit of a pediatric tertiary care teaching hospital. A pharmacy resident conducted two 3-week audits: the first to assess the completeness and accuracy of BPMHs and reconciliation performed by nurses and/or pharmacists and the second to assess the completeness and accuracy of BPMHs and reconciliation performed by a pharmacy technician. The total number of patients was 38 in the baseline phase and 46 in the pilot period. There were no statistically significant differences between the baseline and pilot audits in terms of completion of BPMH (82% [28/34] versus 78% [21/27], p = 0.75) or completion of reconciliation (70% [23/33] versus 75% [15/20], p = 0.76) within 24 h of admission. Completeness of transfer reconciliation was significantly higher during the pilot study than at baseline (91% [31/34] versus 61% [11/18], p = 0.022). No significant differences between the baseline and pilot audits were found in the proportions of patients with at least one BPMH discrepancy (38% [13/34] versus 22% [6/27], p = 0.27), at least one unintentional discrepancy upon admission (21% [7/33] versus 10% [2/20], p = 0.46), or at least one unintentional discrepancy at the transfer interface (6% [1/18] versus 3% [1/34], p = 0.58). None of the 16

  14. Comparison tests, in a pilot plant, of the performance of a coal-derived granular activated carbon: a comparison with coconut husk derived activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, S.; Kasahara, A.; Tsuruzono, Y.; Gotoh, M.

    1986-01-01

    A 160 m/sup 3//d pilot plant has been used in a series of comparison tests of the performance of coal-derived and coconut husk derived activated carbons. Activated carbons are used to remove trihalomethane precursors and malodorous substances from city water. A higher mean removal of coloration and COD/sub M//sub n/ was achieved with the coal-derived carbon (by factors of 1.5 and 1.8, respectively). The two activated carbons gave similar performances as regards turbidity, alkalinity, total iron and total manganese. 4 figures, 5 tables.

  15. Case-mix adjustment and the comparison of community health center performance on patient experience measures.

    Science.gov (United States)

    Johnson, M Laura; Rodriguez, Hector P; Solorio, M Rosa

    2010-06-01

    To assess the effect of case-mix adjustment on community health center (CHC) performance on patient experience measures. A Medicaid-managed care plan in Washington State collected patient survey data from 33 CHCs over three fiscal quarters during 2007-2008. The survey included three composite patient experience measures (6-month reports) and two overall ratings of care. The analytic sample includes 2,247 adult patients and 2,859 adults reporting for child patients. We compared the relative importance of patient case-mix adjusters by calculating each adjuster's predictive power and variability across CHCs. We then evaluated the impact of case-mix adjustment on the relative ranking of CHCs. Important case-mix adjusters included adult self-reported health status or parent-reported child health status, adult age, and educational attainment. The effects of case-mix adjustment on patient reports and ratings were different in the adult and child samples. Adjusting for race/ethnicity and language had a greater impact on parent reports than adult reports, but it impacted ratings similarly across the samples. The impact of adjustment on composites and ratings was modest, but it affected the relative ranking of CHCs. To ensure equitable comparison of CHC performance on patient experience measures, reports and ratings should be adjusted for adult self-reported health status or parent-reported child health status, adult age, education, race/ethnicity, and survey language. Because of the differential impact of case-mix adjusters for child and adult surveys, initiatives should consider measuring and reporting adult and child scores separately.

  16. Comparison of Different Approaches to Predict the Performance of Pumps As Turbines (PATs

    Directory of Open Access Journals (Sweden)

    Mauro Venturini

    2018-04-01

    Full Text Available This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs. The considered approaches are four, i.e., one physics-based simulation model (“white box” model, two “gray box” models, which integrate theory on turbomachines with specific data correlations, and one “black box” model. More in detail, the modeling approaches are: (1 a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2 a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3 the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4 an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53–5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed.

  17. The relationship between affective response to social comparison and academic performance in high school

    NARCIS (Netherlands)

    Wehrens, M.J.P.W.; Buunk, Abraham (Bram); Lubbers, M.J.; Dijkstra, Pieternel; Kuyper, H.; Van der Werf, M.P.C.

    The goal of the present study was to study the relationship between affective responses to social comparison and test scores among high school students Our analyses showed that three types of responses to social comparison could be distinguished: an empathic, constructive, and destructive response.

  18. Comparison of Static Picture and Video Prompting on the Performance of Cooking-Related Tasks by Students with Autism

    Science.gov (United States)

    Mechling, Linda C.; Gustafson, Melissa R.

    2009-01-01

    This study compared the effectiveness of static photographs and video prompts on the independent task performance of six young men with a diagnosis of autism. An adapted alternating-treatment design with baseline, comparison, withdrawal, and final treatment conditions was used to measure the percentage of cooking-related tasks completed…

  19. Identifying technology barriers in adapting a state-of-the-art gas turbine for IGCC applications and an experimental investigation of air extraction schemes for IGCC operations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tah-teh; Agrawal, A.K.; Kapat, J.S.

    1993-06-01

    Under contracted work with Morgantown Energy Technology Center, Clemson University, the prime contractor, and General Electric (GE) and CRSS, the subcontractors, made a comprehensive study in the first phase of research to investigate the technology barriers of integrating a coal gasification process with a hot gas cleanup scheme and the state-of-the-art industrial gas turbine, the GE MS-7001F. This effort focused on (1) establishing analytical tools necessary for modeling combustion phenomenon and emissions in gas turbine combustors operating on multiple species coal gas, (2) estimates the overall performance of the GE MS-7001F combined cycle plant, (3) evaluating material issues in the hot gas path, (4) examining the flow and temperature fields when air extraction takes place at both the compressor exit and at the manhole adjacent to the combustor, and (5) examining the combustion/cooling limitations of such a gas turbine by using 3-D numerical simulation of a MS-7001F combustor operated with gasified coal. In the second phase of this contract, a 35% cool flow model was built similar to GE`s MS-7001F gas turbine for mapping the flow region between the compressor exit and the expander inlet. The model included sufficient details, such as the combustor`s transition pieces, the fuel nozzles, and the supporting struts. Four cases were studied: the first with a base line flow field of a GE 7001F without air extraction; the second with a GE 7001F with air extraction; and the third and fourth with a GE 7001F using a Griffith diffuser to replace the straight wall diffuser and operating without air extraction and with extraction, respectively.

  20. Comparison of amount of physical load in the Czech and Austrian footballers at the same level of performance

    OpenAIRE

    Bujnovský, David

    2011-01-01

    Title: Comparison of the size of the motor load in the Czech and Austrian soccer players at the same performance level Objectives: The aim is to determine the size of the physical load of players during a football match. At the same time the next aim is to determinate the differences of physical load between Czech and Austrian soccer players at the same performance level. Methods: The indirect (mediated) observations was used in this bachelor thesis, because the data were recorded by computer...

  1. Comparison of the performance of three ion mobility spectrometers for measurement of biogenic amines

    International Nuclear Information System (INIS)

    Karpas, Zeev; Guamán, Ana V.; Pardo, Antonio; Marco, Santiago

    2013-01-01

    Graphical abstract: The response to different amounts of TMA (in μg) that were placed in a headspace vial as a function of time for the VG-Test (top) and the GDA (bottom). Note that the ratio [TMA/(TMA + TEP)] (top) and [TMA/(TMA + RIP)] (bottom) and the clearance time increase with the amount of TMA deposited in the vial. Highlights: ► First comparison of performance of IMS devices. ► Gas-phase ion chemistry affected by operational parameters. ► Limits of detection quite similar despite differences in devices. ► LODs determined in controlled continuous flow and in headspace vapor. ► Exponential dilution of headspace studies. - Abstract: The performance of three different types of ion mobility spectrometer (IMS) devices: GDA2 with a radioactive ion source (Airsense, Germany), UV-IMS with a photo-ionization source (G.A.S. Germany) and VG-Test with a corona discharge source (3QBD, Israel) was studied. The gas-phase ion chemistry in the IMS devices affected the species formed and their measured reduced mobility values. The sensitivity and limit of detection for trimethylamine (TMA), putrescine and cadaverine were compared by continuous monitoring of a stream of air with a given concentration of the analyte and by measurement of headspace vapors of TMA in a sealed vial. Preprocessing of the mobility spectra and the effectiveness of multivariate curve resolution techniques (MCR-LASSO) improved the accuracy of the measurements by correcting baseline effects and adjusting for variations in drift time as well as enhancing the signal to noise ratio and deconvolution of the complex data matrix to their pure components. The limit of detection for measurement of the biogenic amines by the three IMS devices was between 0.1 and 1.2 ppm (for TMA with the VG-Test and GDA, respectively) and between 0.2 and 0.7 ppm for putrescine and cadaverine with all three devices. Considering the uncertainty in the LOD determination there is almost no statistically significant

  2. Experimental and computational study and development of the bituminous coal entrained-flow air-blown gasifier for IGCC

    International Nuclear Information System (INIS)

    Abaimov, N A; Osipov, P V; Ryzhkov, A F

    2016-01-01

    In the paper the development of the advanced bituminous coal entrained-flow air- blown gasifier for the high power integrated gasification combined cycle is considered. The computational fluid dynamics technique is used as the basic development tool. The experiment on the pressurized entrained-flow gasifier was performed by “NPO CKTI” JSC for the thermochemical processes submodel verification. The kinetic constants for Kuznetsk bituminous coal (flame coal), obtained by thermal gravimetric analysis method, are used in the model. The calculation results obtained by the CFD model are in satisfactory agreements with experimental data. On the basis of the verified model the advanced gasifier structure was suggested which permits to increase the hydrogen content in the synthesis gas and consequently to improve the gas turbine efficiency. In order to meet the specified requirements vapor is added on the second stage of MHI type gasifier and heat necessary for air gasification is compensated by supplemental heating of the blasting air. (paper)

  3. Comparison of performance of analog-to-digital converters (ADC) for pulse height analyzers

    International Nuclear Information System (INIS)

    Suzuki, Shogo; Hirai, Shoji

    1981-01-01

    In the recent ADCs for pulse height analyzers (PHA), Wilkinson type is a leading one, and those with 50 to 200 MHz clock frequency and 8K channel are mostly on the market. The comparison of the performance of ADCs was conducted under the condition of using these multi-channel PHAs as γ-ray spectrometers. The following three ADCs were compared: ADC incorporated in CANBERRA 8100 MCA, and CANBERRA 8060 ADCs used as the ADCs for 1st and 2nd GAMA systems. In this case, the conversion gains of these ADCs were set at 4K because the memory of 8100 MCA was 4K, and the GAMA systems were also mostly operated at 4K. In this paper, report is made on the measurements of dead time, the change of γ peaks immediately after the power was turned on, the temperature dependence of ADCs the long term stability of ADCs, derivative non-linearity, and integration non-linearity. The dead time of the ADC of 8100 CMA was shorter in the range up to 1000 channels. The temperature dependence was -0.017%/deg C in 8100 MCA, and -0.061 and -0.072%/deg C in GAMA. The long term stability was -0.02%/14 hr in 8100 MCA, and -0.027%/14 hr in 8060 of 1st GAMA. The derivative non-linearity was 0.45% in 8100 MCA, 0.67% in 8060 of 1st GAMA, and the integration non-linearity was 0.075% for 8100 MCA, and 0.085 - 0.1% in 8060 ADCs. Also, the change of γ peaks immediately after the power was turned on for 8100 ADC was better than that of 8060 ADC. (Wakatsuki, Y.)

  4. Public Reporting of Primary Care Clinic Quality: Accounting for Sociodemographic Factors in Risk Adjustment and Performance Comparison.

    Science.gov (United States)

    Wholey, Douglas R; Finch, Michael; Kreiger, Rob; Reeves, David

    2018-01-03

    Performance measurement and public reporting are increasingly being used to compare clinic performance. Intended consequences include quality improvement, value-based payment, and consumer choice. Unintended consequences include reducing access for riskier patients and inappropriately labeling some clinics as poor performers, resulting in tampering with stable care processes. Two analytic steps are used to maximize intended and minimize unintended consequences. First, risk adjustment is used to reduce the impact of factors outside providers' control. Second, performance categorization is used to compare clinic performance using risk-adjusted measures. This paper examines the effects of methodological choices, such as risk adjusting for sociodemographic factors in risk adjustment and accounting for patients clustering by clinics in performance categorization, on clinic performance comparison for diabetes care, vascular care, asthma, and colorectal cancer screening. The population includes all patients with commercial and public insurance served by clinics in Minnesota. Although risk adjusting for sociodemographic factors has a significant effect on quality, it does not explain much of the variation in quality. In contrast, taking into account the nesting of patients within clinics in performance categorization has a substantial effect on performance comparison.

  5. Comparison of Powerlifting Performance in Trained Men Using Traditional and Flexible Daily Undulating Periodization.

    Science.gov (United States)

    Colquhoun, Ryan J; Gai, Christopher M; Walters, Jeoffrey; Brannon, Andrew R; Kilpatrick, Marcus W; DʼAgostino, Dominic P; Campbell, Bill I

    2017-02-01

    Colquhoun, RJ, Gai, CM, Walters, J, Brannon, AR, Kilpatrick, MW, D'Agostino, DP, and Campbell, WI. Comparison of powerlifting performance in trained men using traditional and flexible daily undulating periodization. J Strength Cond Res 31(2): 283-291, 2017-Daily undulating periodization (DUP) is a growing trend, both in practice and in the scientific literature. A new form of DUP, flexible daily undulating periodization (FDUP), allows for athletes to have some autonomy by choosing the order of their training. The purpose of this study was to compare an FDUP model to a traditional model of DUP on powerlifting performance in resistance-trained men. Twenty-five resistance-trained men were randomly assigned to one of 2 groups: FDUP (N = 14) or DUP (N = 11). All participants possessed a minimum of 6 months of resistance training experience and were required to squat, bench press, and deadlift 125, 100, and 150% of their body mass, respectively. Dependent variables assessed at baseline and after the 9-week training program included bench press 1 repetition maximum (1RM), squat 1RM, deadlift 1RM, powerlifting total, Wilks Coefficient, fat mass, and fat-free mass (FFM). Dependent variables assessed during each individual training session were motivation to train, Session Rating of Perceived Exertion (Session RPE), and satisfaction with training session. After the 9-week training program, no significant differences in intensity or volume were found between groups. Both groups significantly improved bench press 1RM (FDUP: +6.5 kg; DUP: +8.8 kg), squat 1RM (FDUP: +15.6 kg; DUP: +18.0 kg), deadlift 1RM (FDUP: +14.8 kg; DUP: +13.6 kg), powerlifting total (FDUP: +36.8 kg; DUP: +40.4 kg), and Wilks Coefficient (FDUP: +24.8; DUP: +26.0) over the course of study (p = <0.001 for each variable). There was also a significant increase in FFM (FDUP: +0.8 kg; DUP: +0.8 kg) for both groups (p = 0.003). There were no differences in motivation to train, session RPE, or satisfaction with

  6. Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

    Science.gov (United States)

    Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

    2017-09-01

    A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. WWF Climate Scorecards. Comparison of the climate performance of the G8 countries

    International Nuclear Information System (INIS)

    Hoehne, N.; Wartmann, S.; Graus, W.

    2005-07-01

    , Japan, Russia, United Kingdom and United States of America). They provide recent and expected emission developments of each country and various other indicators. The scorecards also provide an overview of the most important activities by the governments to respond to the threat of climate change. They finally provide an overall summary evaluation of the climate performance of the country based on all of the criteria covered in the scorecard. This is based on the core benchmark that countries implement enough measures to reduce emissions by the order of 80% by 2050 as to keep the global-average temperature increase below 2C in comparison with pre-industrial levels. The scoring, based on the ten indicators, demonstrates that none of the G8 countries are implementing enough measures in order to be considered for the upper range of the score (see summary table at the end of this document). Three countries are furthest along this track including France, Germany and the UK, but each is likely to see increases in emissions if further measures are not implemented soon. Italy, Japan, Russia and Canada rank much lower due to their low scoring on the range of indicators, thus quite far away from making a contribution to staying below 2C. The United States scores the worst of all G8 countries, not having ratified the Kyoto Protocol, nor having put any substantive measures in place to curb emissions in the short term. Information is also provided for major developing countries (Brazil, China, India, Mexico and South Africa), where a number of initiatives are already underway. These five countries are expecting large growth of emissions in the future and the question remains whether G8 countries will assist them in developing in a less carbon intensive manner. These countries have not been scored in the same manner as G8 due to their different national circumstances and level of development

  8. WWF Climate Scorecards. Comparison of the climate performance of the G8 countries

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, N.; Wartmann, S.; Graus, W. [Ecofys GmbH, Koeln (Germany)

    2005-07-01

    , Italy, Japan, Russia, United Kingdom and United States of America). They provide recent and expected emission developments of each country and various other indicators. The scorecards also provide an overview of the most important activities by the governments to respond to the threat of climate change. They finally provide an overall summary evaluation of the climate performance of the country based on all of the criteria covered in the scorecard. This is based on the core benchmark that countries implement enough measures to reduce emissions by the order of 80% by 2050 as to keep the global-average temperature increase below 2C in comparison with pre-industrial levels. The scoring, based on the ten indicators, demonstrates that none of the G8 countries are implementing enough measures in order to be considered for the upper range of the score (see summary table at the end of this document). Three countries are furthest along this track including France, Germany and the UK, but each is likely to see increases in emissions if further measures are not implemented soon. Italy, Japan, Russia and Canada rank much lower due to their low scoring on the range of indicators, thus quite far away from making a contribution to staying below 2C. The United States scores the worst of all G8 countries, not having ratified the Kyoto Protocol, nor having put any substantive measures in place to curb emissions in the short term. Information is also provided for major developing countries (Brazil, China, India, Mexico and South Africa), where a number of initiatives are already underway. These five countries are expecting large growth of emissions in the future and the question remains whether G8 countries will assist them in developing in a less carbon intensive manner. These countries have not been scored in the same manner as G8 due to their different national circumstances and level of development.

  9. Comparison of performance of three different types of respiratory protection devices.

    Science.gov (United States)

    Lawrence, Robert B; Duling, Matthew G; Calvert, Catherine A; Coffey, Christopher C

    2006-09-01

    Respiratory protection is offered to American workers in a variety of ways to guard against potential inhalation hazards. Two of the most common ways are elastomeric N95 respirators and N95 filtering-facepiece respirators. Some in the health care industry feel that surgical masks provide an acceptable level of protection in certain situations against particular hazards. This study compared the performance of these types of respiratory protection during a simulated workplace test that measured both filter penetration and face-seal leakage. A panel of 25 test subjects with varying face sizes tested 15 models of elastomeric N95 respirators, 15 models of N95 filtering-facepiece respirators, and 6 models of surgical masks. Simulated workplace testing was conducted using a TSI PORTACOUNT Plus model 8020, and consisted of a series of seven exercises. Six simulated workplace tests were performed with redonning of the respirator/mask occurring between each test. The results of these tests produced a simulated workplace protection factor (SWPF). The geometric mean (GM) and the 5th percentile values of the SWPFs were computed by category of respiratory protection using the six overall SWPF values. The level of protection provided by each of the three respiratory protection types was compared. The GM and 5th percentile SWPF values without fit testing were used for the comparison, as surgical masks were not intended to be fit tested. The GM values were 36 for elastomeric N95 respirators, 21 for N95 filtering-facepiece respirators, and 3 for surgical masks. An analysis of variance demonstrated a statistically significant difference between all three. Elastomeric N95 respirators had the highest 5th percentile SWPF of 7. N95 filtering-facepiece respirators and surgical masks had 5th percentile SWPFs of 3 and 1, respectively. A Fisher Exact Test revealed that the 5th percentile SWPFs for all three types of respiratory protection were statistically different. In addition, both

  10. A performance comparison of direct- and indirect-detection flat-panel imagers

    International Nuclear Information System (INIS)

    Partridge, M.; Hesse, B.-M.; Mueller, L.

    2002-01-01

    A comparison of the performance of a direct- and an indirect-detection amorphous silicon flat-panel X-ray imager is presented for a 6 MV beam. Experimental measurements of the noise characteristics, image lag, spectral response, spatial resolution and quantum efficiency are described, compared and discussed. The two systems are comprised of 512x512 pixel, 400 μm pitch, arrays of a-Si:H p-i-n photodiodes and thin-film transistors. In the direct-detection system, X-rays interact to produce electron/hole pairs directly in the silicon photodiodes. For the indirect-detection system, a phosphor screen converts energy from the incident X-rays into visible light, which is then detected by the photodiodes. Both systems are shown to be quantum noise limited, with the total electronic noise in the detector 10-15 times smaller than the Poisson noise level in detected signal. The measured lag for both systems is 1.0±0.1% or less in the first frame with subsequent signals decaying exponentially with frame read-out, with a half-life of between 3.3 and 3.8 frames. Both systems are demonstrated to have a pronounced sensitivity to low-energy multiply scattered photons, although this is shown to be effectively filtered out using a 2 mm copper build-up plate. The direct-detection system, with the 2 mm Cu build-up, shows greater sensitivity to scattered radiation than the indirect system. The spatial resolutions of both systems were effectively equal with an f 50 of 0.25 mm -1 when pixels are binned 2x2, although a slight contribution from optical scattering in the phosphor screen is seen for the indirect-detection system. The quantum efficiency of the direct-detection system is a factor of 0.45 lower than that of the indirect-detection system. The application of these detectors to megavoltage CT is discussed, with the conclusion that the indirect-detection system is to be preferred

  11. Performance Comparison between Neutralization Tailings and Flotation Tailings Used for Backfill Mix and Mechanism Analysis

    OpenAIRE

    Han, Bin; Sun, Wei; Yu, Shaofeng; Liu, Chao; Yao, Song; Wu, Jianxun

    2016-01-01

    A comparison test of different tailings used for underground backfill was conducted, using neutralized tailings from BIOX and flotation tailings of Jinfeng Mine. Laboratory comparison test results show that, with neutralized tailings, when the cement dosage is at 19%, backfill UCS after 7 days, 14 days, and 28 days are 105%–163%, 80%–102%, and 33%–43%, respectively, which are higher than those of flotation tailings. When the cement dosage is at 12%, backfill UCS after 7 days, 14 days, and 28 ...

  12. Predicting Performance: A Comparison of University Supervisors' Predictions and Teacher Candidates' Scores on a Teaching Performance Assessment

    Science.gov (United States)

    Sandholtz, Judith Haymore; Shea, Lauren M.

    2012-01-01

    The implementation of teaching performance assessments has prompted a range of concerns. Some educators question whether these assessments provide information beyond what university supervisors gain through their formative evaluations and classroom observations of candidates. This research examines the relationship between supervisors' predictions…

  13. Peer influence on students' estimates of performance : social comparison in clinical rotations

    NARCIS (Netherlands)

    Raat, A. N. (Janet); Kuks, Jan B. M.; van Hell, E. Ally; Cohen-Schotanus, Janke

    Context During clinical rotations, students move from one clinical situation to another. Questions exist about students strategies for coping with these transitions. These strategies may include a process of social comparison because in this context it offers the student an opportunity to estimate

  14. International comparison of systems to determine entitlements to medical specialist care: performance and organizational issues

    NARCIS (Netherlands)

    E.A. Stolk (Elly); A.A. de Bont (Antoinette); M.J. Poley (Marten); S. Jerak (Sonja); M. Stroet (Mary); F.F.H. Rutten (Frans)

    2008-01-01

    textabstractSummary Objective: CVZ has asked us to provide a comparison of criteria and procedures that different countries use to determine entitlements to medical specialist care. This question was asked within the context of the recent introduction of the DBC (diagnosis treatment combinations)

  15. Harming High Performers : A Social Comparison Perspective on Interpersonal Harming in Work Teams

    NARCIS (Netherlands)

    Lam, Catherine K.; Van der Vegt, Gerben S.; Walter, Frank; Huang, Xu; Huang, Xin

    This study developed a multilevel model of the interpersonal harming behavior associated with social comparison processes in work teams. We tested this model using temporally lagged data from a sample of student teams (Study 1) and cross-sectional data from a sample of work teams in a

  16. Performance comparison between a solar driven rotary desiccant cooling system and conventional vapor compression system (performance study of desiccant cooling)

    International Nuclear Information System (INIS)

    Ge, T.S.; Ziegler, F.; Wang, R.Z.; Wang, H.

    2010-01-01

    Solar driven rotary desiccant cooling systems have been widely recognized as alternatives to conventional vapor compression systems for their merits of energy-saving and being eco-friendly. In the previous paper, the basic performance features of desiccant wheel have been discussed. In this paper, a solar driven two-stage rotary desiccant cooling system and a vapor compression system are simulated to provide cooling for one floor in a commercial office building in two cities with different climates: Berlin and Shanghai. The model developed in the previous paper is adopted to predict the performance of the desiccant wheel. The objectives of this paper are to evaluate and compare the thermodynamic and economic performance of the two systems and to obtain useful data for practical application. Results show that the desiccant cooling system is able to meet the cooling demand and provide comfortable supply air in both of the two regions. The required regeneration temperatures are 55 deg. C in Berlin and 85 deg. C in Shanghai. As compared to the vapor compression system, the desiccant cooling system has better supply air quality and consumes less electricity. The results of the economic analysis demonstrate that the dynamic investment payback periods are 4.7 years in Berlin and 7.2 years in Shanghai.

  17. An evaluation of the performance of chemistry transport models by comparison with research aircraft observations. Part 1: Concepts and overall model performance

    Directory of Open Access Journals (Sweden)

    D. Brunner

    2003-01-01

    Full Text Available A rigorous evaluation of five global Chemistry-Transport and two Chemistry-Climate Models operated by several different groups in Europe, was performed. Comparisons were made of the models with trace gas observations from a number of research aircraft measurement campaigns during the four-year period 1995-1998. Whenever possible the models were run over the same four-year period and at each simulation time step the instantaneous tracer fields were interpolated to all coinciding observation points. This approach allows for a very close comparison with observations and fully accounts for the specific meteorological conditions during the measurement flights. This is important considering the often limited availability and representativity of such trace gas measurements. A new extensive database including all major research and commercial aircraft measurements between 1995 and 1998, as well as ozone soundings, was established specifically to support this type of direct comparison. Quantitative methods were applied to judge model performance including the calculation of average concentration biases and the visualization of correlations and RMS errors in the form of so-called Taylor diagrams. We present the general concepts applied, the structure and content of the database, and an overall analysis of model skills over four distinct regions. These regions were selected to represent various atmospheric conditions and to cover large geographical domains such that sufficient observations are available for comparison. The comparison of model results with the observations revealed specific problems for each individual model. This study suggests the further improvements needed and serves as a benchmark for re-evaluations of such improvements. In general all models show deficiencies with respect to both mean concentrations and vertical gradients of important trace gases. These include ozone, CO and NOx at the tropopause. Too strong two-way mixing across the

  18. Energy performance requirements for new buildings in 11 countries from Central Europe. Exemplary comparison of three buildings

    Energy Technology Data Exchange (ETDEWEB)

    Loga, Tobias; Knissel, Jens; Diefenbach, Nikolaus

    2008-12-05

    The objective of the present comparison study is to show which energy efficiency require-ments have to be complied in different European countries when a new building is going to be constructed. For this purpose three Model Buildings were defined: a single-family house, a multi-family house and a school building. For each involved country (or region) the energy quality of the thermal envelope was determined which is necessary in order to just comply with the building code. Due to requirements on the overall energy performance the requested envelope quality usually depends also on the type of heat supply system or energy carrier. Therefore the systems were varied in a parameter study. The main result for each of the three Model Buildings is a comparison table which shows the heat transfer coefficient by transmission (a sort of mean U-value) for the different countries differenti-ated by supply system types. In a final step the primary energy demand according to the German regulation (EnEV 2007) was calculated for every envelope/system combination of the different countries. This allows a comparison of buildings with different supply systems. The study was performed by experts from 11 European member states: Germany, Austria, Czech Republic, Poland, Sweden, Denmark, UK, The Netherlands, Belgium, Luxembourg and France. (orig.)

  19. Operation window and part-load performance study of a syngas fired gas turbine

    International Nuclear Information System (INIS)

    He, Fen; Li, Zheng; Liu, Pei; Ma, Linwei; Pistikopoulos, Efstratios N.

    2012-01-01

    Integrated coal gasification combined cycle (IGCC) provides a great opportunity for clean utilization of coal while maintaining the advantage of high energy efficiency brought by gas turbines. A challenging problem arising from the integration of an existing gas turbine to an IGCC system is the performance change of the gas turbine due to the shift of fuel from natural gas to synthesis gas, or syngas, mainly consisting of carbon monoxide and hydrogen. Besides the change of base-load performance, which has been extensively studied, the change of part-load performance is also of great significance for the operation of a gas turbine and an IGCC plant. In this paper, a detailed mathematical model of a syngas fired gas turbine is developed to study its part-load performance. A baseline is firstly established using the part-load performance of a natural gas fired gas turbine, then the part-load performance of the gas turbine running with different compositions of syngas is investigated and compared with the baseline. Particularly, the impacts of the variable inlet guide vane, the degree of fuel dilution, and the degree of air bleed are investigated. Results indicate that insufficient cooling of turbine blades and a reduced compressor surge margin are the major factors that constrain the part-load performance of a syngas fired gas turbine. Results also show that air bleed from the compressor can greatly improve the working condition of a syngas fired gas turbine, especially for those fired with low lower heating value syngas. The regulating strategy of a syngas fired gas turbine should also be adjusted in accordance to the changes of part-load performance, and a reduced scope of constant TAT (turbine exhaust temperature) control mode is required.

  20. Test Performance and Social Comparison Choices of High School Men and Women.

    Science.gov (United States)

    Golden, Gail Anna; Cherry, Frances

    1982-01-01

    Hypothesized that high school girls would perform better if they anticipated test results to be private, and that boys would perform better under conditions of anticipated public feedback. Found the hypothesis to be supported for girls in average ability classes; girls in advanced ability classes performed better with public feedback. (Author/GC)

  1. Can Performance Feedback during Instruction Boost Knowledge Acquisition? Contrasting Criterion-Based and Social Comparison Feedback

    Science.gov (United States)

    Kollöffel, Bas; de Jong, Ton

    2016-01-01

    Feedback indicating how well students are performing during a learning task can be very stimulating. In this study with a pre- and post-test design, the effects of two types of performance feedback on learning results were compared: feedback during a learning task was either stated in terms of how well the students were performing relative to…

  2. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    Science.gov (United States)

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration

  3. Antisaccade performance in schizophrenia patients, their first-degree biological relatives, and community comparison subjects: data from the COGS study.

    Science.gov (United States)

    Radant, Allen D; Dobie, Dorcas J; Calkins, Monica E; Olincy, Ann; Braff, David L; Cadenhead, Kristin S; Freedman, Robert; Green, Michael F; Greenwood, Tiffany A; Gur, Raquel E; Gur, Ruben C; Light, Gregory A; Meichle, Sean P; Millard, Steve P; Mintz, Jim; Nuechterlein, Keith H; Schork, Nicholas J; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Swerdlow, Neal R; Tsuang, Ming T; Turetsky, Bruce I; Tsuang, Debby W

    2010-09-01

    The antisaccade task is a widely used technique to measure failure of inhibition, an important cause of cognitive and clinical abnormalities found in schizophrenia. Although antisaccade performance, which reflects the ability to inhibit prepotent responses, is a putative schizophrenia endophenotype, researchers have not consistently reported the expected differences between first-degree relatives and comparison groups. Schizophrenia participants (n=219) from the large Consortium on the Genetics of Schizophrenia (COGS) sample (n=1078) demonstrated significant deficits on an overlap version of the antisaccade task compared to their first-degree relatives (n=443) and community comparison subjects (CCS; n=416). Although mean antisaccade performance of first-degree relatives was intermediate between schizophrenia participants and CCS, a linear mixed-effects model adjusting for group, site, age, and gender found no significant performance differences between the first-degree relatives and CCS. However, admixture analyses showed that two components best explained the distributions in all three groups, suggesting two distinct doses of an etiological factor. Given the significant heritability of antisaccade performance, the effects of a genetic polymorphism is one possible explanation of our results.

  4. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    INSPIRE-00207984

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region < 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  5. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    Shah, Mehar Ali

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region lt 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  6. Performance comparison of genetic algorithms and particle swarm optimization for model integer programming bus timetabling problem

    Science.gov (United States)

    Wihartiko, F. D.; Wijayanti, H.; Virgantari, F.

    2018-03-01

    Genetic Algorithm (GA) is a common algorithm used to solve optimization problems with artificial intelligence approach. Similarly, the Particle Swarm Optimization (PSO) algorithm. Both algorithms have different advantages and disadvantages when applied to the case of optimization of the Model Integer Programming for Bus Timetabling Problem (MIPBTP), where in the case of MIPBTP will be found the optimal number of trips confronted with various constraints. The comparison results show that the PSO algorithm is superior in terms of complexity, accuracy, iteration and program simplicity in finding the optimal solution.

  7. Elastomer damper performance - A comparison with a squeeze film for a supercritical power transmission shaft

    Science.gov (United States)

    Zorzi, E. S.; Burgess, G.; Cunningham, R.

    1980-01-01

    This paper describes the design and testing of an elastomer damper on a super-critical power transmission shaft. The elastomers were designed to provide acceptable operation through the fourth bending mode and to control synchronous as well as nonsynchronous vibration throughout the operating range. The design of the elastomer was such that it could be incorporated into the system as a replacement for a squeeze-film damper without a reassembly, which could have altered the imbalance of the shaft. This provided a direct comparison of the elastomer and squeeze-film dampers without having to assess the effect of shaft imbalance changes.

  8. Performance comparison of CO2 and diode lasers for deep-section concrete cutting

    International Nuclear Information System (INIS)

    Crouse, Philip L.; Li, Lin; Spencer, Julian T.

    2004-01-01

    Layer-by-layer laser machining with mechanical removal of vitrified dross between passes is a new technique with a demonstrated capability for deep-section cutting, not only of concrete, but of ceramic and refractory materials in general. For this application fairly low power densities are required. A comparison of experimental results using high-power CO 2 and diode lasers under roughly equivalent experimental conditions, cutting to depths of >100 mm, is presented. A marked improvement in cutting depth per pass is observed for the case of the diode laser. The increased cutting rate is rationalized in terms of the combined effects of coupling efficiency and beam shape

  9. Comparison of Performance Measurements of Photovoltaic Modules during Winter Months in Taxila, Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Anser Bashir

    2014-01-01

    Full Text Available This paper presents the comparative performance evaluation of three commercially available photovoltaic modules (monocrystalline, polycrystalline, and single junction amorphous silicon in Taxila, Pakistan. The experimentation was carried out at outdoor conditions for winter months. Power output, module efficiency, and performance ratio were calculated for each module and the effect of module temperature and solar irradiance on these parameters was investigated. Module parameters showed strong dependence on the solar irradiance and module temperature. Monocrystalline and polycrystalline modules showed better performance in high irradiance condition whereas it decreased suddenly with decrease in irradiance. Amorphous solar module also showed good performance in low irradiance due to its better light absorbing characteristics and thus showed higher average performance ratio. Monocrystalline photovoltaic module showed higher monthly average module efficiency and was found to be more efficient at this site. Module efficiency and performance ratio showed a decreasing trend with increase of irradiance and photovoltaic module back surface temperature.

  10. Asymptotic SER performance comparison of MPSK and MDPSK in wireless fading channels

    KAUST Repository

    Song, Xuegui

    2015-02-01

    We propose a general framework to investigate asymptotic relative performance between M-ary phase-shift keying (MPSK) and M-ary differential phase-shift keying (MDPSK) in wireless fading channels. Using this framework, we provide an alternative derivation for the closed-form expression of the asymptotic performance loss of MDPSK w.r.t. MPSK in an additive white Gaussian noise channel. The same performance loss is also shown to be true for the lognormal fading channels.

  11. Asymptotic SER performance comparison of MPSK and MDPSK in wireless fading channels

    KAUST Repository

    Song, Xuegui; Yang, Fan; Cheng, Julian; Alouini, Mohamed-Slim

    2015-01-01

    We propose a general framework to investigate asymptotic relative performance between M-ary phase-shift keying (MPSK) and M-ary differential phase-shift keying (MDPSK) in wireless fading channels. Using this framework, we provide an alternative derivation for the closed-form expression of the asymptotic performance loss of MDPSK w.r.t. MPSK in an additive white Gaussian noise channel. The same performance loss is also shown to be true for the lognormal fading channels.

  12. Performance comparison between Java and JNI for optimal implementation of computational micro-kernels

    OpenAIRE

    Halli , Nassim; Charles , Henri-Pierre; Méhaut , Jean-François

    2015-01-01

    International audience; General purpose CPUs used in high performance computing (HPC) support a vector instruction set and an out-of-order engine dedicated to increase the instruction level parallelism. Hence, related optimizations are currently critical to improve the performance of applications requiring numerical computation. Moreover, the use of a Java run-time environment such as the HotSpot Java Virtual Machine (JVM) in high performance computing is a promising alternative. It benefits ...

  13. Multiple Criteria and Multiple Periods Performance Analysis: The Comparison of North African Railways

    Science.gov (United States)

    Sabri, Karim; Colson, Gérard E.; Mbangala, Augustin M.

    2008-10-01

    Multi-period differences of technical and financial performances are analysed by comparing five North African railways over the period (1990-2004). A first approach is based on the Malmquist DEA TFP index for measuring the total factors productivity change, decomposed into technical efficiency change and technological changes. A multiple criteria analysis is also performed using the PROMETHEE II method and the software ARGOS. These methods provide complementary detailed information, especially by discriminating the technological and management progresses by Malmquist and the two dimensions of performance by Promethee: that are the service to the community and the enterprises performances, often in conflict.

  14. Comparison of two methods to determine fan performance curves using computational fluid dynamics

    Science.gov (United States)

    Onma, Patinya; Chantrasmi, Tonkid

    2018-01-01

    This work investigates a systematic numerical approach that employs Computational Fluid Dynamics (CFD) to obtain performance curves of a backward-curved centrifugal fan. Generating the performance curves requires a number of three-dimensional simulations with varying system loads at a fixed rotational speed. Two methods were used and their results compared to experimental data. The first method incrementally changes the mass flow late through the inlet boundary condition while the second method utilizes a series of meshes representing the physical damper blade at various angles. The generated performance curves from both methods are compared with an experiment setup in accordance with the AMCA fan performance testing standard.

  15. Performance Comparison between Neutralization Tailings and Flotation Tailings Used for Backfill Mix and Mechanism Analysis

    Directory of Open Access Journals (Sweden)

    Bin Han

    2016-01-01

    Full Text Available A comparison test of different tailings used for underground backfill was conducted, using neutralized tailings from BIOX and flotation tailings of Jinfeng Mine. Laboratory comparison test results show that, with neutralized tailings, when the cement dosage is at 19%, backfill UCS after 7 days, 14 days, and 28 days are 105%–163%, 80%–102%, and 33%–43%, respectively, which are higher than those of flotation tailings. When the cement dosage is at 12%, backfill UCS after 7 days, 14 days, and 28 days are 58%–77%, 50%–60%, and 28%–51%, respectively, which are higher than those of flotation tailings. Slurry fluidity of neutralized tailings is lower than that of flotation tailings, while, in these two tailings, the difference of slump and diffusivity values is less than 6%, which is not a significant difference in slurry fluidity. The reason for neutralized tailings showing higher UCS is as follows: during backfill curing, neutralization tailings produce abundant crystals of CaSO4·2H2O in interlaced structure which helps in combining aggregates closely; CaSO4·2H2O hydrates with C3A C4AF contained in the cement and forms clavate cement bacillus which works as a micro reinforcing steel bar. The test proved that neutralized tailings are more optimal for backfilling.

  16. DHS small-scale safety and thermal testing of improvised explosives-comparison of testing performance

    International Nuclear Information System (INIS)

    Reynolds, J G; Hsu, P C; Sandstrom, M M; Brown, G W; Warner, K F; Phillips, J J; Shelley, T J; Reyes, J A

    2014-01-01

    One of the first steps in establishing safe handling procedures for explosives is small-scale safety and thermal (SSST) testing. To better understand the response of improvised materials or homemade explosives (HMEs) to SSST testing, 16 HME materials were compared to three standard military explosives in a proficiency-type round robin study among five laboratories-two DoD and three DOE-sponsored by DHS. The testing matrix has been designed to address problems encountered with improvised materials-powder mixtures, liquid suspensions, partially wetted solids, immiscible liquids, and reactive materials. More than 30 issues have been identified that indicate standard test methods may require modification when applied to HMEs to derive accurate sensitivity assessments needed for developing safe handling and storage practices. This paper presents a generalized comparison of the results among the testing participants, comparison of friction results from BAM (German Bundesanstalt für Materi-alprüfung) and ABL (Allegany Ballistics Laboratory) designed testing equipment, and an overview of the statistical results from the RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) standard tested throughout the proficiency test.

  17. Critical thinking skills in nursing students: comparison of simulation-based performance with metrics

    Science.gov (United States)

    Fero, Laura J.; O’Donnell, John M.; Zullo, Thomas G.; Dabbs, Annette DeVito; Kitutu, Julius; Samosky, Joseph T.; Hoffman, Leslie A.

    2018-01-01

    Aim This paper is a report of an examination of the relationship between metrics of critical thinking skills and performance in simulated clinical scenarios. Background Paper and pencil assessments are commonly used to assess critical thinking but may not reflect simulated performance. Methods In 2007, a convenience sample of 36 nursing students participated in measurement of critical thinking skills and simulation-based performance using videotaped vignettes, high-fidelity human simulation, the California Critical Thinking Disposition Inventory and California Critical Thinking Skills Test. Simulation- based performance was rated as ‘meeting’ or ‘not meeting’ overall expectations. Test scores were categorized as strong, average, or weak. Results Most (75·0%) students did not meet overall performance expectations using videotaped vignettes or high-fidelity human simulation; most difficulty related to problem recognition and reporting findings to the physician. There was no difference between overall performance based on method of assessment (P = 0·277). More students met subcategory expectations for initiating nursing interventions (P ≤ 0·001) using high-fidelity human simulation. The relationship between video-taped vignette performance and critical thinking disposition or skills scores was not statistically significant, except for problem recognition and overall critical thinking skills scores (Cramer’s V = 0·444, P = 0·029). There was a statistically significant relationship between overall high-fidelity human simulation performance and overall critical thinking disposition scores (Cramer’s V = 0·413, P = 0·047). Conclusion Students’ performance reflected difficulty meeting expectations in simulated clinical scenarios. High-fidelity human simulation performance appeared to approximate scores on metrics of critical thinking best. Further research is needed to determine if simulation-based performance correlates with critical thinking skills

  18. Critical thinking skills in nursing students: comparison of simulation-based performance with metrics.

    Science.gov (United States)

    Fero, Laura J; O'Donnell, John M; Zullo, Thomas G; Dabbs, Annette DeVito; Kitutu, Julius; Samosky, Joseph T; Hoffman, Leslie A

    2010-10-01

    This paper is a report of an examination of the relationship between metrics of critical thinking skills and performance in simulated clinical scenarios. Paper and pencil assessments are commonly used to assess critical thinking but may not reflect simulated performance. In 2007, a convenience sample of 36 nursing students participated in measurement of critical thinking skills and simulation-based performance using videotaped vignettes, high-fidelity human simulation, the California Critical Thinking Disposition Inventory and California Critical Thinking Skills Test. Simulation-based performance was rated as 'meeting' or 'not meeting' overall expectations. Test scores were categorized as strong, average, or weak. Most (75.0%) students did not meet overall performance expectations using videotaped vignettes or high-fidelity human simulation; most difficulty related to problem recognition and reporting findings to the physician. There was no difference between overall performance based on method of assessment (P = 0.277). More students met subcategory expectations for initiating nursing interventions (P ≤ 0.001) using high-fidelity human simulation. The relationship between videotaped vignette performance and critical thinking disposition or skills scores was not statistically significant, except for problem recognition and overall critical thinking skills scores (Cramer's V = 0.444, P = 0.029). There was a statistically significant relationship between overall high-fidelity human simulation performance and overall critical thinking disposition scores (Cramer's V = 0.413, P = 0.047). Students' performance reflected difficulty meeting expectations in simulated clinical scenarios. High-fidelity human simulation performance appeared to approximate scores on metrics of critical thinking best. Further research is needed to determine if simulation-based performance correlates with critical thinking skills in the clinical setting. © 2010 The Authors. Journal of Advanced

  19. Enhancing Self-Efficacy and Performance: An Experimental Comparison of Psychological Techniques

    Science.gov (United States)

    Wright, Bradley James; O'Halloran, Paul Daniel; Stukas, Arthur Anthony

    2016-01-01

    Purpose: We assessed how 6 psychological performance enhancement techniques (PETs) differentially improved self-efficacy (SE) and skill performance. We also assessed whether vicarious experiences and verbal persuasion as posited sources of SE (Bandura, 1982) were supported and, further, if the effects of the 6 PETs remained after controlling for…

  20. Business Statistics: A Comparison of Student Performance in Three Learning Modes

    Science.gov (United States)

    Simmons, Gerald R.

    2014-01-01

    The purpose of this study was to compare the performance of three teaching modes and age groups of business statistics sections in terms of course exam scores. The research questions were formulated to determine the performance of the students within each teaching mode, to compare each mode in terms of exam scores, and to compare exam scores by…

  1. Academic Performance and Pass Rates: Comparison of Three First-Year Life Science Courses

    Science.gov (United States)

    Downs, C. T.

    2009-01-01

    First year students' academic performance in three Life Science courses (Botany, Zoology and Bioscience) was compared. Pass rates, as well as the means and distributions of final marks were analysed. Of the three components (coursework, practical and theory examinations) contributing to the final mark of each course, students performed best in the…

  2. A comparison of the performance of Holstein and Friesian bulls in ...

    African Journals Online (AJOL)

    The performance of 92 Holstein-Friesian bulls, which were accepted for progeny testing ander the South African National Dairy Animal Performance and Progeny Testing Scheme during 1982, 1983 and 1984, was compared. Bulls which were locally bred for more than one generation were not entered under the Scheme.

  3. Comparison of the noise performance of 10GHz QW and QD mode-locked laser diodes

    DEFF Research Database (Denmark)

    Carpintero, Guillermo; Thompson, Mark G.; Yvind, Kresten

    2010-01-01

    This paper reports the experimental characterization of the noise performance of a quantum dot and a quantum well 10GHz passive mode locked laser diodes.......This paper reports the experimental characterization of the noise performance of a quantum dot and a quantum well 10GHz passive mode locked laser diodes....

  4. Comparison study of thickness swell performance of commercial oriented strandboard flooring products

    Science.gov (United States)

    Hongmei Gu; Siqun Wang; Trairat Neimsuwan; Sunguo Wang

    2005-01-01

    The multiple layer structure of oriented strandboard (OSB) has a significant influence on its performance, including thickness swell (TS). TS is recognized as an important performance property for OSB products. Optimization of TS through layer property ma- nipulation to achieve the lowest total TS while maintaining acceptable mechanical properties is attainable if the...

  5. A Comparison of the School Performance of Sexually Abused, Neglected and Non-Maltreated Children.

    Science.gov (United States)

    Reyome, Nancy Dodge

    1993-01-01

    Compared the school performance of sexually abused children and neglected children with the performance of two matched groups of nonmaltreated children, those from lower middle class families and from families receiving public assistance. Analyses of children's behavior ratings and school achievement indicated marked cognitive and behavioral…

  6. A Comparison of Low Performing Students' Achievements in Factoring Cubic Polynomials Using Three Different Strategies

    Science.gov (United States)

    Ogbonnaya, Ugorji I.; Mogari, David L.; Machisi, Eric

    2013-01-01

    In this study, repeated measures design was employed to compare low performing students' achievements in factoring cubic polynomials using three strategies. Twenty-five low-performing Grade 12 students from a secondary school in Limpopo province took part in the study. Data was collected using achievement test and was analysed using repeated…

  7. Comparison of Turkey and United States in terms of teacher performance indicators

    Directory of Open Access Journals (Sweden)

    Zühal Çubukçu

    2017-12-01

    Full Text Available Developing objective standards and indicators, and establishing the transparency of the evaluation process have significant importance in reducing negative teacher opinions and ensuring healthy functioning of the performance evaluation system. The purpose of this study is to compare teacher performance indicators in Turkey and United States. This study was conducted using document review, which is one of the qualitative research methods. In the study, document review was used as the data collection method. In the first stage, the official documents of the two countries were accessed via websites. The authenticity of the obtained documents was checked. Finally, the analysis was done with the classification form developed by the researchers. In the study, the analysis of the documents was done by descriptive analysis technique. General Proficiencies of Teaching Profession consist of 233 performance indicator and Core Teaching Standards consist of 74 performance indicators. The findings of the study were examined under five themes determined by considering the General Proficiencies of Teaching Profession and Core Teaching Standards: Student and learning, content knowledge, instructional practice, assessment and professional development. General Proficiencies of Teaching Profession lists the knowledge, skills, and behaviors expected from teachers as performance indicators. In Core Teaching Standards, the performance indicators provide suggestions and explanations for the development of teaching in accordance with the requirements of today's world. the preparation of performance indicators to provide teachers' development and the realistic use of these indicators in evaluating will help improve the quality of teacher performance evaluation.

  8. Can performance feedback during instruction boost knowledge acquisition? Contrasting criterion-based and social comparison feedback

    NARCIS (Netherlands)

    Kolloffel, Bas Jan; de Jong, Anthonius J.M.

    2016-01-01

    Feedback indicating how well students are performing during a learning task can be very stimulating. In this study with a pre- and post-test design, the effects of two types of performance feedback on learning results were compared: feedback during a learning task was either stated in terms of how

  9. Locating the difference: A comparison of pedagogic strategies in high and low performing schools

    Directory of Open Access Journals (Sweden)

    Kaylianne Rialda Aploon-Zokufa

    2013-12-01

    Full Text Available A number of research studies have suggested that specific pedagogic strategies can have a positive impact on learning, and in turn, have a positive impact on school performance, in particular for children being schooled in disadvantaged contexts. This analysis describes and measures how four of these pedagogic strategies identified in research – the pacing of a lesson, the sequence and coherence of a lesson, cognitive demand and the nature of feedback within a lesson – are displayed in higher and lower performing schools located in lower-income communities in the Western Cape. The analysis forms part of a broader research project, SPADE (Schools Performing Above Demographic Expectation, and is based on fifteen video-recorded Grade 3 numeracy lessons. The analysis suggests a relationship between specific pedagogic strategies and higher performance for individual learners and for schools. The analysis also identifies further effective pedagogic strategies in higher performing schools in lower-income communities.

  10. A comparison of thermal algorithms of fuel rod performance code systems

    International Nuclear Information System (INIS)

    Park, C. J.; Park, J. H.; Kang, K. H.; Ryu, H. J.; Moon, J. S.; Jeong, I. H.; Lee, C. Y.; Song, K. C.

    2003-11-01

    The goal of the fuel rod performance is to identify the robustness of a fuel rod with cladding material. Computer simulation of the fuel rod performance becomes one of important parts to designed and evaluate new nuclear fuels and claddings. To construct a computing code system for the fuel rod performance, several algorithms of the existing fuel rod performance code systems are compared and are summarized as a preliminary work. Among several code systems, FRAPCON, and FEMAXI for LWR, ELESTRES for CANDU reactor, and LIFE for fast reactor are reviewed. Thermal algorithms of the above codes are investigated including methodologies and subroutines. This work will be utilized to construct a computing code system for dry process fuel rod performance

  11. Web-based application on employee performance assessment using exponential comparison method

    Science.gov (United States)

    Maryana, S.; Kurnia, E.; Ruyani, A.

    2017-02-01

    Employee performance assessment is also called a performance review, performance evaluation, or assessment of employees, is an effort to assess the achievements of staffing performance with the aim to increase productivity of employees and companies. This application helps in the assessment of employee performance using five criteria: Presence, Quality of Work, Quantity of Work, Discipline, and Teamwork. The system uses the Exponential Comparative Method and Weighting Eckenrode. Calculation results using graphs were provided to see the assessment of each employee. Programming language used in this system is written in Notepad++ and MySQL database. The testing result on the system can be concluded that this application is correspond with the design and running properly. The test conducted is structural test, functional test, and validation, sensitivity analysis, and SUMI testing.

  12. A comparison of thermal algorithms of fuel rod performance code systems

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. J.; Park, J. H.; Kang, K. H.; Ryu, H. J.; Moon, J. S.; Jeong, I. H.; Lee, C. Y.; Song, K. C

    2003-11-01

    The goal of the fuel rod performance is to identify the robustness of a fuel rod with cladding material. Computer simulation of the fuel rod performance becomes one of important parts to designed and evaluate new nuclear fuels and claddings. To construct a computing code system for the fuel rod performance, several algorithms of the existing fuel rod performance code systems are compared and are summarized as a preliminary work. Among several code systems, FRAPCON, and FEMAXI for LWR, ELESTRES for CANDU reactor, and LIFE for fast reactor are reviewed. Thermal algorithms of the above codes are investigated including methodologies and subroutines. This work will be utilized to construct a computing code system for dry process fuel rod performance.

  13. Performance Comparison of Two Topologies Double-Fed Brushless Machine with 36 Slots for Low-Speed Applications

    Directory of Open Access Journals (Sweden)

    Yue Hao

    2014-12-01

    Full Text Available The performances of two topologies of low-speed double-fed brushless machine (DFBM with fractional slot windings are quantitatively compared and analyzed using two-dimensional (2-D finite element method (FEM. To fairly compare the torque capability and power efficiency of different DFBMs, the investigated DFBMs have the same outer diameter, the same axial stack length and the same iron core materials, and some comparison rules are presented. In order to maximize the torque density, several important structure parameters are optimized. The results of this paper reveal the torque density levels and power density levels of two kinds of DFBMs.

  14. Construction Professionals Job Performance and Characteristics: A Comparison of Indigenous and Expatriate Construction Companies in Nigeria

    Directory of Open Access Journals (Sweden)

    Henry Ndubuisi Onukwube

    2011-06-01

    Job performance is considered one of the most important constructs in human resources management because it helps to explain the value and utility that each employee adds to the organisation. The professionals in the Nigerian construction companies are not exception to the perceived low job performance rate within the industry. Extant literature points to the fact that job characteristics of employees can account for variance in their job performance rate.This study compares the job performance rate and job characteristics of construction professionals in indigenous and expatriate construction companies with a view to establish a relationship between job performance and job characteristics of construction professionals. A total of 762 questionnaires were collected and used for the study.  Eighty one (81 construction companies, 50 (62% indigenous and 31 (38% expatriate were selected using stratified random sampling technique. Data collected were analysed using mean item score, spearman rank correlation, linear regression analysis where appropriate. Findings of the study revealed that the relationship between job characteristics and job performance of construction professionals in construction companies in Nigeria is positive but low and the correlation coefficient is higher in expatriate construction companies. Based on the above finding, the study recommends that construction companies in Nigeria should endeavour and improve on their current core job dimensions (task significance, skill variety, task identity, autonomy and feedback inherent in various jobs designed within their respective organizations as this will constitute as one of the variants that will improve the job performance rate of construction professionals.

  15. Humidification performance of 48 passive airway humidifiers: comparison with manufacturer data.

    Science.gov (United States)

    Lellouche, François; Taillé, Solenne; Lefrançois, Frédéric; Deye, Nicolas; Maggiore, Salvatore Maurizio; Jouvet, Philippe; Ricard, Jean-Damien; Fumagalli, Bruno; Brochard, Laurent

    2009-02-01

    Heat and moisture exchangers (HMEs) are increasingly used in the ICU for gas conditioning during mechanical ventilation. Independent assessments of the humidification performance of HMEs are scarce. The aim of the present study was thus to assess the humidification performance of a large number of adult HMEs. We assessed 48 devices using a bench test apparatus that simulated real-life physiologic ventilation conditions. Thirty-two devices were described by the manufacturers as HMEs, and 16 were described as antibacterial filters. The test apparatus provided expiratory gases with an absolute humidity (AH) of 35 mg H(2)O/L. The AH of inspired gases was measured after steady state using the psychrometric method. We performed three hygrometric measurements for each device, measured their resistance, and compared our results with the manufacturer data. Of the 32 HMEs tested, only 37.5% performed well (>or= 30 mg H(2)O/L), while 25% performed poorly ( 4 mg H(2)O/L. The mean difference for the antibacterial filters was 0.2 +/- 1.4 mg H(2)O/L. The mean resistance of all the tested devices was 2.17 +/- 0.70 cm H(2)O/L/s. Several HMEs performed poorly and should not be used as HMEs. The values determined by independent assessments may be lower than the manufacturer data. Describing a device as an HME does not guarantee that it provides adequate humidification. The performance of HMEs must be verified by independent assessment.

  16. Comparison of Colonoscopy Quality Measures Across Various Practice Settings and the Impact of Performance Scorecards.

    Science.gov (United States)

    Inra, Jennifer A; Nayor, Jennifer; Rosenblatt, Margery; Mutinga, Muthoka; Reddy, Sarathchandra I; Syngal, Sapna; Kastrinos, Fay

    2017-04-01

    Quality performance measures for screening colonoscopy vary among endoscopists. The impact of practice setting is unknown. We aimed to (1) compare screening colonoscopy performance measures among three different US practice settings; (2) evaluate factors associated with adenoma detection; and (3) assess a scorecard intervention on performance metrics. This multi-center prospective study compared patient, endoscopist, and colonoscopy characteristics performed at a tertiary care hospital (TCH), community-based hospital (CBH), and private practice group (PPG). Withdrawal times (WT), cecal intubation, and adenoma detection rates (ADR) were compared by site at baseline and 12 weeks following scorecard distribution. Generalized linear mixed models identified factors associated with adenoma detection. Twenty-eight endoscopists performed colonoscopies on 1987 asymptomatic, average-risk individuals ≥50 years. Endoscopist and patient characteristics were similar across sites. The PPG screened more men (TCH: 42.8%, CBH: 45.0%, PPG: 54.2%; p scorecard distribution. Adenoma detection was associated with increasing patient age, male gender, WT, adequate preparation, but not practice setting. Each practice performed high-quality screening colonoscopy. Scorecards did not improve performance metrics. Preparation quality varies among practice settings and can be modified to improve adenoma detection.

  17. Investigation of Industrialised Building System Performance in Comparison to Conventional Construction Method

    Directory of Open Access Journals (Sweden)

    Othuman Mydin M.A.

    2014-03-01

    Full Text Available Conventional construction methods are still widely practised, although many researches have indicated that this method is less effective compared to the IBS construction method. The existence of the IBS has added to the many techniques within the construction industry. This study is aimed at making comparisons between the two construction approaches. Case studies were conducted at four sites in the state of Penang, Malaysia. Two projects were IBS-based while the remaining two deployed the conventional method of construction. Based on an analysis of the results, it can be concluded that the IBS approach has more to offer compared to the conventional method. Among these advantages are shorter construction periods, reduced overall costs, less labour needs, better site conditions and the production of higher quality components.

  18. Economic Comparison of Electric Vehicles Performing Unidirectional and Bidirectional Frequency Control in Denmark with Practical Validation

    DEFF Research Database (Denmark)

    Thingvad, Andreas; Martinenas, Sergejus; Andersen, Peter Bach

    2016-01-01

    the EV is plugged into the network ready to support the system frequency. Performing unidirectional frequency control with Electric Vehicles (EVs) requires little hardware implementation in the household but has the limit that the service only can be performed until the battery is fully charged....... Bidirectional V2G frequency control requires an external charger but also enables the EV to perform services at higher powers, during the entire period the EV is parked. The yearly revenue is in both cases calculated using some assumptions that are then verified in 2 experiments. Both EVs are discharged...

  19. Research on the comparison of performance-based concept and force-based concept

    Science.gov (United States)

    Wu, Zeyu; Wang, Dongwei

    2011-03-01

    There are two ideologies about structure design: force-based concept and performance-based concept. Generally, if the structure operates during elastic stage, the two philosophies usually attain the same results. But beyond that stage, the shortage of force-based method is exposed, and the merit of performance-based is displayed. Pros and cons of each strategy are listed herein, and then which structure is best suitable to each method analyzed. At last, a real structure is evaluated by adaptive pushover method to verify that performance-based method is better than force-based method.

  20. Comparison of two different high performance mixed signal controllers for DC/DC converters

    DEFF Research Database (Denmark)

    Jakobsen, Lars Tønnes; Andersen, Michael Andreas E.

    2006-01-01

    This paper describes how mixed signal controllers combining a cheap microcontroller with a simple analogue circuit can offer high performance digital control for DC/DC converters. Mixed signal controllers have the same versatility and performance as DSP based controllers. It is important to have...... an engineer experienced in microcontroller programming write the software algorithms to achieve optimal performance. Two mixed signal controller designs based on the same 8-bit microcontroller are compared both theoretically and experimentally. A 16-bit PID compensator with a sampling frequency of 200 k......Hz implemented in the 16 MIPS, 8-bit ATTiny26 microcontroller is demonstrated....

  1. A Comparison of the Bariatric Procedures that Are Performed in the Treatment of Super Morbid Obesity.

    Science.gov (United States)

    Uno, Kohei; Seki, Yosuke; Kasama, Kazunori; Wakamatsu, Kotaro; Umezawa, Akiko; Yanaga, Katsuhiko; Kurokawa, Yoshimochi

    2017-10-01

    We have experienced numerous cases of super morbid obesity (SMO), defined by a BMI of ≥50 kg/m 2 , in which laparoscopic sleeve gastrectomy (LSG) was not able to achieve a sufficient weight loss effect. However, the most appropriate procedure for the treatment of SMO has not yet been established. The subjects included 248 successive patients who underwent surgery at our hospital from June 2006 to December 2012. We divided the subjects into an SMO group (BMI, 50 to <70 kg/m 2 ) and a morbid obesity (MO) group (BMI, 35 to <50 kg/m 2 ). The subjects underwent LSG, LSG with duodenojejunal bypass (LSG/DJB), or laparoscopic Roux-en-Y gastric bypass (LRYGB). The weight loss effects, safety of surgery, and metabolic profile changes were compared. Sixty-two subjects were classified into the SMO group (25%). The percent excess weight loss (%EWL) after LSG among the patients in the SMO group was not significantly different from that of patients who underwent other procedures. LSG was associated with a significantly lower success rate in terms of weight loss (%EWL ≥ 50%), in comparison to the weight loss at 1 year after LRYGB and at 2 years after LSG/DJB and LRYGB. Among the patients in the MO group, the %EWL and the rate of successful weight loss did not differ to a statistically significant extent. This study demonstrated that in patients with SMO, LSG/DJB and LRYGB can achieve superior weight loss effects in comparison to LSG.

  2. Methods to stimulate national and sub-national benchmarking through international health system performance comparisons: a Canadian approach.

    Science.gov (United States)

    Veillard, Jeremy; Moses McKeag, Alexandra; Tipper, Brenda; Krylova, Olga; Reason, Ben

    2013-09-01

    This paper presents, discusses and evaluates methods used by the Canadian Institute for Health Information to present health system performance international comparisons in ways that facilitate their understanding by the public and health system policy-makers and can stimulate performance benchmarking. We used statistical techniques to normalize the results and present them on a standardized scale facilitating understanding of results. We compared results to the OECD average, and to benchmarks. We also applied various data quality rules to ensure the validity of results. In order to evaluate the impact of the public release of these results, we used quantitative and qualitative methods and documented other types of impact. We were able to present results for performance indicators and dimensions at national and sub-national levels; develop performance profiles for each Canadian province; and show pan-Canadian performance patterns for specific performance indicators. The results attracted significant media attention at national level and reactions from various stakeholders. Other impacts such as requests for additional analysis and improvement in data timeliness were observed. The methods used seemed attractive to various audiences in the Canadian context and achieved the objectives originally defined. These methods could be refined and applied in different contexts. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  3. Comparison of accelerated pavement test results with long term pavement behaviour and performance

    CSIR Research Space (South Africa)

    Jooste, FJ

    1997-08-01

    Full Text Available The aim of this study was to investigate the following:how accelerated pavement testing predictions compare with actual road behaviour and performance the relative influences of load and environmental factors on pavement deterioration and how well...

  4. COMPARISON OF PERFORMANCES OF DIFFERENT SVM IMPLEMENTATIONS WHEN USED FOR AUTOMATED EVALUATION OF DESCRIPTIVE ANSWERS

    Directory of Open Access Journals (Sweden)

    C. Sunil Kumar

    2015-04-01

    Full Text Available In this paper, we studied the performances of models built using various SVM implementations during the multiclass classification task of automated evaluation of descriptive answers. The performances were evaluated on five datasets each with 900 samples and with each of the datasets treated using symmetric uncertainty feature selection filter. We quantitatively analyzed the best SVM implementation technique from amongst the 17 different SVM implementation combinations derived by using various SVM classifier libraries, SVM types and Kernel methods. Accuracy, F Score, Kappa and Area under ROC curve are used as model evaluation metrics in order to evaluate the models and rank them according to their performances. Based on the results, we derived the conclusion that SMO classifier when used with Polynomial kernel is the overall best performing classifier applicable for auto evaluation of descriptive answers.

  5. Proposal of an innovative benchmark for comparison of the performance of contactless digitizers

    Science.gov (United States)

    Iuliano, Luca; Minetola, Paolo; Salmi, Alessandro

    2010-10-01

    Thanks to the improving performances of 3D optical scanners, in terms of accuracy and repeatability, reverse engineering applications have extended from CAD model design or reconstruction to quality control. Today, contactless digitizing devices constitute a good alternative to coordinate measuring machines (CMMs) for the inspection of certain parts. The German guideline VDI/VDE 2634 is the only reference to evaluate whether 3D optical measuring systems comply with the declared or required performance specifications. Nevertheless it is difficult to compare the performance of different scanners referring to such a guideline. An adequate novel benchmark is proposed in this paper: focusing on the inspection of production tools (moulds), the innovative test piece was designed using common geometries and free-form surfaces. The reference part is intended to be employed for the evaluation of the performance of several contactless digitizing devices in computer-aided inspection, considering dimensional and geometrical tolerances as well as other quantitative and qualitative criteria.

  6. Proposal of an innovative benchmark for comparison of the performance of contactless digitizers

    International Nuclear Information System (INIS)

    Iuliano, Luca; Minetola, Paolo; Salmi, Alessandro

    2010-01-01

    Thanks to the improving performances of 3D optical scanners, in terms of accuracy and repeatability, reverse engineering applications have extended from CAD model design or reconstruction to quality control. Today, contactless digitizing devices constitute a good alternative to coordinate measuring machines (CMMs) for the inspection of certain parts. The German guideline VDI/VDE 2634 is the only reference to evaluate whether 3D optical measuring systems comply with the declared or required performance specifications. Nevertheless it is difficult to compare the performance of different scanners referring to such a guideline. An adequate novel benchmark is proposed in this paper: focusing on the inspection of production tools (moulds), the innovative test piece was designed using common geometries and free-form surfaces. The reference part is intended to be employed for the evaluation of the performance of several contactless digitizing devices in computer-aided inspection, considering dimensional and geometrical tolerances as well as other quantitative and qualitative criteria

  7. A FINANCIAL PERFORMANCE COMPARISON OF GROUP AND NON-GROUP FIRMS IN TEXTILE SECTOR OF PAKISTAN

    Directory of Open Access Journals (Sweden)

    Ishtiaq AHMAD

    2016-12-01

    Full Text Available Pakistan is a developing economy and business groups are key players of the Pakistan’s economy. Previous research evidence shows that in the emerging economies group affiliation creates value for the firms. This study is intended to empirically investigate to know that whether group affiliated (GA firms perform financially better than non-group affiliated firms or not? GA firms in emerging economies can have better financial performance by sharing tangible and intangible resources at group level. The financial ratio is used to compare performance of affiliated and non-group affiliated firms by using the data of 70 textile firms listed at Karachi Stock Exchange(now Pakistan Stock Exchange covering a period from 2008 to 2012. Based on mean values of return on assets (ROA, results of the study show that GA firms have higher financial performance than non-group affiliated firms in each year and over all five years.

  8. Comparison of Portfolio Selection and Performance: Shari’ah-Compliant and Socially Responsible Investment Portfolios

    Directory of Open Access Journals (Sweden)

    Mehmet Asutay

    2015-04-01

    Full Text Available This study examines the effect of Islamic screening criteria on Shari’ah-compliant portfolio selection and performance compared to Socially Responsible Investment (SRI portfolio. Each portfolio constructed from 15 stocks based on FTSE 100 using data from year 1997. Mean-variance portfolio optimization is employed with some financial ratios added as constraints for the Shari’ah portfolio. Annual expected return of each portfolio from 2008 to 2013 is used to calculate Sharpe’s ratio, Treynor ratio and Jensen’s alpha as the performance measurement tools. Macroeconomic variables are assessed using ordinary least square to examine whether they influence the portfolios’ expected returns or not. The result finds that Shari’ah portfolio has a better performance than SRI from year 2008 to 2010 shown by higher value of the measurement tools. However, from 2011 to 2013, SRI portfolio has better performance than Shari’ah portfolio. 

  9. Trends in Motor Performance of First Graders: A Comparison of Cohorts from 2006 to 2015

    Directory of Open Access Journals (Sweden)

    Sarah Spengler

    2017-09-01

    Full Text Available BackgroundMotor performance is an important factor for health. Already in childhood, motor performance is associated with, e.g., obesity and risk factors for cardiovascular diseases. It is widely believed that the motor performance of children has declined over recent years. However, this belief is lacking clear evidence. The objective of this study was to examine trends in motor performance of first grade students during a period of 10 years (2006–2015. We examined trends in (a aerobic fitness, (b strength, (c speed, and (d balance for boys and girls separately and considered body mass index (BMI as a potential confounder.MethodsFrom 2006 to 2015, we tested 5,001 first graders [50.8% boys; mean age 6.76 (0.56 years] of 18 primary schools in Germany. Each year between 441 and 552 students of the same schools were surveyed. Performance tests were taken from the Motorik-Module Study and the “German Motor Ability Test”: “6-min run,” “push-ups,” “20-m sprint,” and “static stand.” Linear regression models were conducted for statistical analysis.ResultsA slightly negative trend in aerobic fitness performance was revealed in boys (β = −0.050; p = 0.012 but not in girls. In the strength performance test no trend over time was detected. Performance in speed (boys: β = −0.094; girls: β = −0.143; p ≤ 0.001 and balance tests (boys: β = −0.142; girls: β = −0.232; p ≤ 0.001 increased over time for both boys and girls. These findings held true when BMI was considered.ConclusionThis study only partly supported the assumption that motor performance of children has declined: in our study, aerobic fitness declined (only in boys, while strength remained stable and speed and balance even increased in both sexes. Moreover, it seems as if BMI can explain changes in performance only to a small extent. Changed lifestyles might be a substantial cause. Further research on recent trends of motor

  10. Trends in Motor Performance of First Graders: A Comparison of Cohorts from 2006 to 2015.

    Science.gov (United States)

    Spengler, Sarah; Rabel, Matthias; Kuritz, Arvid Marius; Mess, Filip

    2017-01-01

    Motor performance is an important factor for health. Already in childhood, motor performance is associated with, e.g., obesity and risk factors for cardiovascular diseases. It is widely believed that the motor performance of children has declined over recent years. However, this belief is lacking clear evidence. The objective of this study was to examine trends in motor performance of first grade students during a period of 10 years (2006-2015). We examined trends in (a) aerobic fitness, (b) strength, (c) speed, and (d) balance for boys and girls separately and considered body mass index (BMI) as a potential confounder. From 2006 to 2015, we tested 5,001 first graders [50.8% boys; mean age 6.76 (0.56) years] of 18 primary schools in Germany. Each year between 441 and 552 students of the same schools were surveyed. Performance tests were taken from the Motorik-Module Study and the "German Motor Ability Test": "6-min run," "push-ups," "20-m sprint," and "static stand." Linear regression models were conducted for statistical analysis. A slightly negative trend in aerobic fitness performance was revealed in boys (β = -0.050; p  = 0.012) but not in girls. In the strength performance test no trend over time was detected. Performance in speed (boys: β = -0.094; girls: β = -0.143; p  ≤ 0.001) and balance tests (boys: β = -0.142; girls: β = -0.232; p  ≤ 0.001) increased over time for both boys and girls. These findings held true when BMI was considered. This study only partly supported the assumption that motor performance of children has declined: in our study, aerobic fitness declined (only in boys), while strength remained stable and speed and balance even increased in both sexes. Moreover, it seems as if BMI can explain changes in performance only to a small extent. Changed lifestyles might be a substantial cause. Further research on recent trends of motor performance and interacting variables is needed to support the results

  11. A PERFORMANCE COMPARISON OF HEDGE FUNDS, HEDGED MUTUAL FUNDS AND HEDGE FUND ETFS

    OpenAIRE

    Shenyan Gu; Tina Zhang

    2015-01-01

    Hedged mutual funds and hedge fund ETFs are new entrants to the market thatallow individual investors to invest in funds using hedge fund strategies.   In this paper, we study the performance of these two funds relative to the traditional hedge funds to see if the three asset classes are comparable investments. We use four performance measurement models, including CAPM, Fama French three factor model, Carhart four factor model and Fung and Hsieh eight factor model, to test the fund...

  12. Binary and multi-category ratings in a laboratory observer performance study: A comparison

    OpenAIRE

    Gur, David; Bandos, Andriy I.; King, Jill L.; Klym, Amy H.; Cohen, Cathy S.; Hakim, Christiane M.; Hardesty, Lara A.; Ganott, Marie A.; Perrin, Ronald L.; Poller, William R.; Shah, Ratan; Sumkin, Jules H.; Wallace, Luisa P.; Rockette, Howard E.

    2008-01-01

    The authors investigated radiologists, performances during retrospective interpretation of screening mammograms when using a binary decision whether to recall a woman for additional procedures or not and compared it with their receiver operating characteristic (ROC) type performance curves using a semi-continuous rating scale. Under an Institutional Review Board approved protocol nine experienced radiologists independently rated an enriched set of 155 examinations that they had not personally...

  13. Comparison of the performance of Islamic, Sri and green mutual funds

    OpenAIRE

    Paradinovic, Ivana

    2017-01-01

    This paper measures and compares performance of Islamic, SRI and Green mutual equity funds worldwide in the period from 1 January 2001 to 31 December 2015. The sample consists of 611 mutual equity funds and their performance was assessed by using traditional risk-adjusted measures, namely Sharpe ratio, Modified Sharpe Ratio, Adjusted Sharpe Ratio, Treynor measure, Information ratio and Jensen’s alpha. The main findings show that Green mutual equity funds, on average, outperform both SRI and I...

  14. Performance comparison of plastic shopping bags in modern and traditional retail

    Science.gov (United States)

    Radini, F. A.; Wulandari, R.; Nasiri, S. J. A.; Winarto, D. A.

    2017-07-01

    Followed by implementation of paid plastic bag policy in Indonesia’s modern and traditional retail, community question related to plastic shopping bag performance arise. But, there is limited information about it. Therefore, the assessment of the performance to compare between plastic shopping bags in modern retail and traditional retail should be interesting. The observation performance of plastic shopping bag were weight holding capacity, tear resistant and elongation. This performance were tested using Universal Testing Machine. Physical and physico-chemical properties also identified to determine factor affecting the performance of plastic shopping bag. The physical properties were analysed using visual and thickness gauge to see the colour and measure the thickness. The analysis of physico-chemical properties were carried out using DSC (Differential Scanning Calorimetry), TGA (Thermal Gravimetry Analysis), Furnace and FTIR (Fourier Transform Infra Red Spectroscopy) to identify the materials, also its melting and decomposition temperature. The result showed that the performance difference between modern retail plastic bag with traditional retail plastic bag appears only in the performance of elongation. The elongation of modern retail plastic bag is 121 - 413%, while traditional has 170 - 609%. According to physico-chemical test result, modern retail and traditional retail plastic bag contain polyethylene as main material and has melting temperature in the range of High Density Polyethylene (HDPE) melting temperature. However, modern retail plastic bag has 18.31 - 33.87% of inorganic filler percentage, whereas the traditional retail plastic bag has 0.35 - 9.85%. This inorganic filler percentage probably a contributing factor in the elongation performance difference between modern retail plastic bag with traditional retail plastic bag.

  15. Comparison of motor and cognitive performance of children attending public and private day care centers

    Directory of Open Access Journals (Sweden)

    Mariana M. Santos

    2013-12-01

    Full Text Available BACKGROUND: Given that environmental factors, such as the school environment, can influence child development, more attention should be paid to the development of children attending day care centers. OBJECTIVE: Todetermine whether there are differences in the gross motor, fine motor, or cognitive performances of children between 1 and3 years-old of similar socioeconomic status attending public and private day care centers full time. METHOD: Participants were divided into 2 groups, 1 of children attending public day care centers (69 children and another of children attending private day care centers (47 children. All children were healthy and regularly attended day care full time for over 4 months. To assess cognitive, gross and fine motor performance, the Bayley Scales of Infant and Toddler Development III was used. The Mann-Whitney test was used for comparative analyses between groups of children between 13 and 24 months, 25 and 41 months, and 13 and 41 months. RESULTS: Children in public day care centers exhibited lower scores on the cognitive development scale beginning at 13 months old. The fine and gross motor performance scores were lower in children over the age of 25 months attending public centers. Maternal education was not related to the performance of children in either group. CONCLUSION: The scores of cognitive performance as well as fine and gross motor performance of children of similar socioeconomic status who attend public day care centers are lower than children attending private daycare centers.

  16. Comparison between Unilateral and Bilateral Plyometric Training on Single and Double Leg Jumping Performance and Strength.

    Science.gov (United States)

    Bogdanis, Gregory C; Tsoukos, Athanasios; Kaloheri, Olga; Terzis, Gerasimos; Veligekas, Panagiotis; Brown, Lee E

    2017-04-18

    This study compared the effects of unilateral and bilateral plyometric training on single and double-leg jumping performance, maximal strength and rate of force development (RFD). Fifteen moderately trained subjects were randomly assigned to either a unilateral (U, n=7) or bilateral group (B, n=8). Both groups performed maximal effort plyometric leg exercises two times per week for 6 weeks. The B group performed all exercises with both legs, while the U group performed half the repetitions with each leg, so that total exercise volume was the same. Jumping performance was assessed by countermovement jumps (CMJ) and drop jumps (DJ), while maximal isometric leg press strength and RFD were measured before and after training for each leg separately and both legs together. CMJ improvement with both legs was not significantly different between U (12.1±7.2%) and B (11.0±5.5%) groups. However, the sum of right and left leg CMJ only improved in the U group (19.0±7.1%, pplyometric training was more effective at increasing both single and double-leg jumping performance, isometric leg press maximal force and RFD when compared to bilateral training.

  17. Quantitative comparison of performance analysis techniques for modular and generic network-on-chip

    Directory of Open Access Journals (Sweden)

    M. C. Neuenhahn

    2009-05-01

    Full Text Available NoC-specific parameters feature a huge impact on performance and implementation costs of NoC. Hence, performance and cost evaluation of these parameter-dependent NoC is crucial in different design-stages but the requirements on performance analysis differ from stage to stage. In an early design-stage an analysis technique featuring reduced complexity and limited accuracy can be applied, whereas in subsequent design-stages more accurate techniques are required.

    In this work several performance analysis techniques at different levels of abstraction are presented and quantitatively compared. These techniques include a static performance analysis using timing-models, a Colored Petri Net-based approach, VHDL- and SystemC-based simulators and an FPGA-based emulator. Conducting NoC-experiments with NoC-sizes from 9 to 36 functional units and various traffic patterns, characteristics of these experiments concerning accuracy, complexity and effort are derived.

    The performance analysis techniques discussed here are quantitatively evaluated and finally assigned to the appropriate design-stages in an automated NoC-design-flow.

  18. A comparison of cognitive performance decreases during acute, progressive fatigue arising from different concurrent stressors.

    Science.gov (United States)

    Fogt, Donovan L; Kalns, John E; Michael, Darren J

    2010-12-01

    Fatigue is known to impair cognitive performance, but it remains unclear whether concurrent common stressors affect cognitive performance similarly. We used the Stroop Color-Word Conflict Test to assess cognitive performance over 24 hours for four groups: control, sleep-deprived (SD), SD + energy deficit, and SD + energy deficit + fluid restricted. Fatigue levels were quantified using the Profile of Mood States (POMS) survey. Linear mixed-effects (LME) models allowed for testing of group-specific differences in cognitive performance while accounting for subject-level variation. Starting fatigue levels were similar among all groups, while 24-hour fatigue levels differed significantly. For each cognitive performance test, results were modeled separately. The simplest LME model contained a significant fixed-effects term for slope and intercept. Moreover, the simplest LME model used a single slope coefficient to fit data from all four groups, suggesting that loss in cognitive performance over a 24-hour duty cycle with respect to fatigue level is similar regardless of the cause.

  19. Sex and age differences in physical performance: A comparison of Army basic training and operational populations.

    Science.gov (United States)

    Dada, Esther O; Anderson, Morgan K; Grier, Tyson; Alemany, Joseph A; Jones, Bruce H

    2017-11-01

    To determine the age- and sex-specific differences of physical fitness performances and Body Mass Index (BMI) in basic training and the operational Army. Cross-sectional Study. This secondary analysis utilizes retrospective surveys of U.S. Army Soldiers in Basic Combat Training (BCT) and operational units to compare physical performances between men and women as measured by the Army Physical Readiness Test (APFT). An ANOVA was used to compare mean differences in APFT results and BMI within sex-specific populations. A post hoc Tukey test identified specific mean differences. Adjusting for age, an ANCOVA was used to compare sex and occupation (infantry and non-infantry) differences in APFT results. Surveyed populations consisted of 2216 BCT Soldiers (1573 men and 643 women) and 5515 Operational Soldiers (4987 men and 528 women). Male and female operational Soldiers had greater muscular performance (79%-125% higher APFT push-ups, 66%-85% higher APFT sit-ups) and cardiorespiratory performance (22%-24% faster APFT 2-mile run times) than BCT Soldiers. Male BCT and operational Soldiers outperform their female counterparts on tests of muscular and cardiorespiratory endurance. Sex differences in physical performances attenuated among female Soldiers in operational units compared to BCT. Among male operational Soldiers, infantry Soldiers exhibited greater cardiorespiratory and muscular performance than non-infantry Soldiers. Higher BMI was associated with higher age groups, except for female BCT Soldiers. Gaps in cardiorespiratory and muscular performances between men and women should be addressed through targeted physical training programs that aim to minimize physiological differences. Published by Elsevier Ltd.

  20. Comparison of exertion required to perform standard and active compression-decompression cardiopulmonary resuscitation.

    Science.gov (United States)

    Shultz, J J; Mianulli, M J; Gisch, T M; Coffeen, P R; Haidet, G C; Lurie, K G

    1995-02-01

    Active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) utilizes a hand-held suction device with a pressure gauge that enables the operator to compress as well as actively decompress the chest. This new CPR method improves hemodynamic and ventilatory parameters when compared with standard CPR. ACD-CPR is easy to perform but may be more labor intensive. The purpose of this study was to quantify and compare the work required to perform ACD and standard CPR. Cardiopulmonary testing was performed on six basic cardiac life support- and ACD-trained St. Paul, MN fire-fighter personnel during performance of 10 min each of ACD and standard CPR on a mannequin equipped with a compression gauge. The order of CPR techniques was determined randomly with > 1 h between each study. Each CPR method was performed at 80 compressions/min (timed with a metronome), to a depth of 1.5-2 inches, and with a 50% duty cycle. Baseline cardiopulmonary measurements were similar at rest prior to performance of both CPR methods. During standard and ACD-CPR, respectively, rate-pressure product was 18.2 +/- 3.0 vs. 23.8 +/- 1.7 (x 1000, P CPR compared with standard CPR. Both methods require subanaerobic energy expenditure and can therefore be sustained for a sufficient length of time by most individuals to optimize resuscitation efforts. Due to the slightly higher work requirement, ACD-CPR may be more difficult to perform compared with standard CPR for long periods of time, particularly by individuals unaccustomed to the workload requirement of CPR, in general.

  1. Comparison of the Prevalence of Psychiatric Disorders in Performance-Enhancing Drug Users and Nonuser Bodybuilders

    Directory of Open Access Journals (Sweden)

    Afshin Ostovar

    2017-10-01

    Full Text Available Objective: The present study aimed at comparing the prevalence of major psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, and generalized anxiety disorder between performance-enhancing drug users and nonuser bodybuilders. Moreover, the prevalence of major psychiatric disorders in bodybuilders was also reported.Method: In this study, 453 athletes were recruited from Bushehr bodybuilding gyms from February to May 2015. A structured questionnaire was used to collect the participants’ information, including demographic characteristics, sports’ status and performance-enhancing drug use. According to the condition of performance-enhancing drug use, the participants were divided into current users, non-current users, and nonusers. The psychiatric status of the participants was evaluated using DSM-IV diagnostic criteria for major depressive disorder, bipolar disorder, generalized anxiety disorder, and schizophrenia. We also asked about the acute psychotic disturbances after using performance-enhancing drugs, alcohol use, and history of aggressive behavior in bodybuilders. Data were analyzed using one-way analysis of variance and chi-square tests.Results: Prevalence of major depressive disorder, bipolar disorder, schizophrenia, generalized anxiety disorder, and the overall prevalence of psychiatric disorders in the bodybuilders was 19.7%, 3.8%, 1.5%, 16.6%, and 26.7%, respectively. After using performance-enhancing drugs, 33% of the bodybuilders had experienced acute psychological disturbances. There were no significant differences between current, non-current, and nonuser bodybuilding athletes in the measured psychiatric disorders.Conclusion: Prevalence of psychiatric disorders was not significantly different in performance-enhancing drug users and nonusers. Thus, it can be concluded that performance-enhancing drugs do not increase the risk of psychiatric disorders in bodybuilders.

  2. Performance comparisons of selected personnel-dosimetry systems in use at Department of Energy facilities

    International Nuclear Information System (INIS)

    Roberson, P.L; Holbrook, K.L.; Yoder, R.C.; Fox, R.A.; Hadley, R.T.; Hogan, B.T.; Hooker, C.D.

    1983-10-01

    Dosimeter performance data were collected to help develop a uniform approach to the calibration and use of personnel dosimetry systems for Department of Energy (DOE) laboratories. Eleven DOE laboratories participated in six months of testing using the American National Draft Standard, Criteria for Testing Personnel Dosimetry Performance, ANSI N13.11, and additional testing categories. The tests described in ANSI N13.11 used a pass/fail system to determine compliance with the draft standard. Recalculation to PNL irradiations showed that the 137 Cs, 90 Sr/ 90 Y, and 252 Cf categories can be recalibrated to have acceptable performance for nearly all participant systems. Deficient dosimeter design or handling techniques caused poor performance in the x-ray category for nearly half of the participants. Too little filtration for the deep-dose element caused poor performance in the beta/photon mixture category for one participant. Two participants had excessively high standard deviations in the neutron category due to dosimeter design or handling deficiencies. The participating dosimetry systems were separated into three categories on their dose evaluation procedure for low-energy photons. These were film dosimeters, fixed-calibration thermoluminescent (TL) dosimeters, and variable-calibration TL dosimeters. The performance of the variable-calibration design was best while the film dosimeters performed considerably worse than either TL dosimeter design. Beta energy dependence studies confirmed a strong correlation between sensitive element thickness, shallow element filtration and low-energy beta response. Studies of neutron calibration conditions for each participant suggested a relationship between response and calibration facility design

  3. Comparison of the Prevalence of Psychiatric Disorders in Performance-Enhancing Drug Users and Nonuser Bodybuilders.

    Science.gov (United States)

    Ostovar, Afshin; Haerinejad, Mohammad Javad; Akbarzadeh, Samad; Keshavarz, Mojtaba

    2017-10-01

    Objective: The present study aimed at comparing the prevalence of major psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, and generalized anxiety disorder between performance-enhancing drug users and nonuser bodybuilders. Moreover, the prevalence of major psychiatric disorders in bodybuilders was also reported. Method: In this study, 453 athletes were recruited from Bushehr bodybuilding gyms from February to May 2015. A structured questionnaire was used to collect the participants' information, including demographic characteristics, sports' status and performance-enhancing drug use. According to the condition of performance-enhancing drug use, the participants were divided into current users, non-current users, and nonusers. The psychiatric status of the participants was evaluated using DSM-IV diagnostic criteria for major depressive disorder, bipolar disorder, generalized anxiety disorder, and schizophrenia. We also asked about the acute psychotic disturbances after using performance-enhancing drugs, alcohol use, and history of aggressive behavior in bodybuilders. Data were analyzed using one-way analysis of variance and chi-square tests. Results: Prevalence of major depressive disorder, bipolar disorder, schizophrenia, generalized anxiety disorder, and the overall prevalence of psychiatric disorders in the bodybuilders was 19.7%, 3.8%, 1.5%, 16.6%, and 26.7%, respectively. After using performance-enhancing drugs, 33% of the bodybuilders had experienced acute psychological disturbances. There were no significant differences between current, non-current, and nonuser bodybuilding athletes in the measured psychiatric disorders. Conclusion: Prevalence of psychiatric disorders was not significantly different in performance-enhancing drug users and nonusers. Thus, it can be concluded that performance-enhancing drugs do not increase the risk of psychiatric disorders in bodybuilders.

  4. Binary and multi-category ratings in a laboratory observer performance study: a comparison.

    Science.gov (United States)

    Gur, David; Bandos, Andriy I; King, Jill L; Klym, Amy H; Cohen, Cathy S; Hakim, Christiane M; Hardesty, Lara A; Ganott, Marie A; Perrin, Ronald L; Poller, William R; Shah, Ratan; Sumkin, Jules H; Wallace, Luisa P; Rockette, Howard E

    2008-10-01

    The authors investigated radiologists, performances during retrospective interpretation of screening mammograms when using a binary decision whether to recall a woman for additional procedures or not and compared it with their receiver operating characteristic (ROC) type performance curves using a semi-continuous rating scale. Under an Institutional Review Board approved protocol nine experienced radiologists independently rated an enriched set of 155 examinations that they had not personally read in the clinic, mixed with other enriched sets of examinations that they had individually read in the clinic, using both a screening BI-RADS rating scale (recall/not recall) and a semi-continuous ROC type rating scale (0 to 100). The vertical distance, namely the difference in sensitivity levels at the same specificity levels, between the empirical ROC curve and the binary operating point were computed for each reader. The vertical distance averaged over all readers was used to assess the proximity of the performance levels under the binary and ROC-type rating scale. There does not appear to be any systematic tendency of the readers towards a better performance when using either of the two rating approaches, namely four readers performed better using the semi-continuous rating scale, four readers performed better with the binary scale, and one reader had the point exactly on the empirical ROC curve. Only one of the nine readers had a binary "operating point" that was statistically distant from the same reader's empirical ROC curve. Reader-specific differences ranged from -0.046 to 0.128 with an average width of the corresponding 95% confidence intervals of 0.2 and p-values ranging for individual readers from 0.050 to 0.966. On average, radiologists performed similarly when using the two rating scales in that the average distance between the run in individual reader's binary operating point and their ROC curve was close to zero. The 95% confidence interval for the fixed

  5. First-principles simulation and comparison with beam tests for transverse instabilities and damper performance in the Fermilab Main Injector

    International Nuclear Information System (INIS)

    Nicklaus, Dennis; Foster, G.William; Kashikhin, Vladimir

    2005-01-01

    An end-to-end performance calculation and comparison with beam tests was performed for the bunch-by-bunch digital transverse damper in the Fermilab Main Injector. Time dependent magnetic wakefields responsible for ''Resistive Wall'' transverse instabilities in the Main Injector were calculated with OPERA-2D using the actual beam pipe and dipole magnet lamination geometry. The leading order dipole component was parameterized and used as input to a bunch-by-bunch simulation which included the filling pattern and injection errors experienced in high-intensity operation of the Main Injector. The instability growth times, and the spreading of the disturbance due to newly misinjected batches was compared between simulations and beam data collected by the damper system. Further simulation models the effects of the damper system on the beam

  6. Fractal Loop Heat Pipe Performance Comparisons of a Soda Lime Glass and Compressed Carbon Foam Wick

    Science.gov (United States)

    Myre, David; Silk, Eric A.

    2014-01-01

    This study compares heat flux performance of a Loop Heat Pipe (LHP) wick structure fabricated from compressed carbon foam with that of a wick structure fabricated from sintered soda lime glass. Each wick was used in an LHP containing a fractal based evaporator. The Fractal Loop Heat Pipe (FLHP) was designed and manufactured by Mikros Manufacturing Inc. The compressed carbon foam wick structure was manufactured by ERG Aerospace Inc., and machined to specifications comparable to that of the initial soda lime glass wick structure. Machining of the compressed foam as well as performance testing was conducted at the United States Naval Academy. Performance testing with the sintered soda lime glass wick structures was conducted at NASA Goddard Space Flight Center. Heat input for both wick structures was supplied via cartridge heaters mounted in a copper block. The copper heater block was placed in contact with the FLHP evaporator which had a circular cross-sectional area of 0.88 cm(sup 2). Twice distilled, deionized water was used as the working fluid in both sets of experiments. Thermal performance data was obtained for three different Condenser/Subcooler temperatures under degassed conditions. Both wicks demonstrated comparable heat flux performance with a maximum of 75 W/cm observed for the soda lime glass wick and 70 W /cm(sup 2) for the compressed carbon foam wick.

  7. Developing measures of fatigue using an alcohol comparison to validate the effects of fatigue on performance.

    Science.gov (United States)

    Williamson, A M; Feyer, A M; Mattick, R P; Friswell, R; Finlay-Brown, S

    2001-05-01

    The effects of 28 h of sleep deprivation were compared with varying doses of alcohol up to 0.1% blood alcohol concentration (BAC) in the same subjects. The study was conducted in the laboratory. Twenty long-haul truck drivers and 19 people not employed as professional drivers acted as subjects. Tests were selected that were likely to be affected by fatigue, including simple reaction time, unstable tracking, dual task, Mackworth clock vigilance test, symbol digit coding, visual search, sequential spatial memory and logical reasoning. While performance effects were seen due to alcohol for all tests, sleep deprivation affected performance on most tests, but had no effect on performance on the visual search and logical reasoning tests. Some tests showed evidence of a circadian rhythm effect on performance, in particular, simple reaction time, dual task, Mackworth clock vigilance, and symbol digit coding, but only for response speed and not response accuracy. Drivers were slower but more accurate than controls on the symbol digit test, suggesting that they took a more conservative approach to performance of this test. This study demonstrated which tests are most sensitive to sleep deprivation and fatigue. The study therefore has established a set of tests that can be used in evaluations of fatigue and fatigue countermeasures.

  8. Enhancing Application Performance Using Mini-Apps: Comparison of Hybrid Parallel Programming Paradigms

    Science.gov (United States)

    Lawson, Gary; Sosonkina, Masha; Baurle, Robert; Hammond, Dana

    2017-01-01

    In many fields, real-world applications for High Performance Computing have already been developed. For these applications to stay up-to-date, new parallel strategies must be explored to yield the best performance; however, restructuring or modifying a real-world application may be daunting depending on the size of the code. In this case, a mini-app may be employed to quickly explore such options without modifying the entire code. In this work, several mini-apps have been created to enhance a real-world application performance, namely the VULCAN code for complex flow analysis developed at the NASA Langley Research Center. These mini-apps explore hybrid parallel programming paradigms with Message Passing Interface (MPI) for distributed memory access and either Shared MPI (SMPI) or OpenMP for shared memory accesses. Performance testing shows that MPI+SMPI yields the best execution performance, while requiring the largest number of code changes. A maximum speedup of 23 was measured for MPI+SMPI, but only 11 was measured for MPI+OpenMP.

  9. Performance and strategy comparisons of human listeners and logistic regression in discriminating underwater targets.

    Science.gov (United States)

    Yang, Lixue; Chen, Kean

    2015-11-01

    To improve the design of underwater target recognition systems based on auditory perception, this study compared human listeners with automatic classifiers. Performances measures and strategies in three discrimination experiments, including discriminations between man-made and natural targets, between ships and submarines, and among three types of ships, were used. In the experiments, the subjects were asked to assign a score to each sound based on how confident they were about the category to which it belonged, and logistic regression, which represents linear discriminative models, also completed three similar tasks by utilizing many auditory features. The results indicated that the performances of logistic regression improved as the ratio between inter- and intra-class differences became larger, whereas the performances of the human subjects were limited by their unfamiliarity with the targets. Logistic regression performed better than the human subjects in all tasks but the discrimination between man-made and natural targets, and the strategies employed by excellent human subjects were similar to that of logistic regression. Logistic regression and several human subjects demonstrated similar performances when discriminating man-made and natural targets, but in this case, their strategies were not similar. An appropriate fusion of their strategies led to further improvement in recognition accuracy.

  10. Measuring the effects of visual demand on lateral deviation: a comparison among driver's performance indicators.

    Science.gov (United States)

    Minin, Luca; Benedetto, Simone; Pedrotti, Marco; Re, Alessandra; Tesauri, Francesco

    2012-05-01

    In this study we compare the efficacy of three driver's performance indicators based on lateral deviation in detecting significant on-road performance degradations while interacting with a secondary task: the High Frequency Component of steering wheel (HFC), and two indicators described in ISO/DIS 26022 (2007): the Normative and the Adapted Lane Change Test (LCT). Sixteen participants were asked to perform a simulated lane-change task while interacting, when required, with a visual search task with two levels of difficulty. According to predictions, results showed that the Adapted LCT indicator, taking into consideration individual practices in performing the LCT, succeeded in discriminating between single and dual task conditions. Furthermore, this indicator was also able to detect whether the driver was interacting with an easy or a difficult secondary task. Despite predictions, results did not confirm Normative LCT and HFC to be reliable indicators of performance degradation within the simulated LCT. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. The comparison of the energy performance of hotel buildings using PROMETHEE decision-making method

    Directory of Open Access Journals (Sweden)

    Vujosevic Milica L.

    2016-01-01

    Full Text Available Annual energy performance of the atrium type hotel buildings in Belgrade climate conditions are analysed in this paper. The objective is to examine the impact of the atrium on the hotel building’s energy needs for space heating and cooling, thus establishing the best design among four proposed alternatives of the hotels with atrium. The energy performance results are obtained using EnergyPlus simulation engine, taking into account Belgrade climate data and thermal comfort parameters. The selected results are compared and the hotels are ranked according to certain criteria. Decision-making process that resulted in the ranking of the proposed alternatives is conducted using PROMETHEE method and Borda model. The methodological approach in this research includes the creation of a hypothetical model of an atrium type hotel building, numerical simulation of energy performances of four design alternatives of the hotel building with an atrium, comparative analysis of the obtained results and ranking of the proposed alternatives from the building’s energy performance perspective. The main task of the analysis is to examine the influence of the atrium, with both its shape and position, on the energy performance of the hotel building. Based on the results of the research it can be to determine the most energy efficient model of the hotel building with atrium for Belgrade climate condition areas. [Projekat Ministarstva nauke Republike Srbije: Spatial, Environmental, Energy and Social aspects of the Developing Settlements and Climate Change - Mutual Impacts

  12. A comparison of the effects of a secondary task and lorazepam on cognitive performance.

    Science.gov (United States)

    File, S E

    1992-01-01

    In order to test whether the lorazepam-induced impairments in a variety of cognitive tasks were similar to those of divided attention, the effects of lorazepam (2.5 mg) in healthy volunteers were compared with those requiring subjects to perform an additional task (detecting silences superimposed onto classical music). Neither treatment impaired implicit memory or judgements of frequency. Both treatments impaired performance in tests of speed, lorazepam having the greatest effect on number cancellation and the additional task having the greatest effect on simple reaction time. Both treatments impaired performance in a coding task, in a test of explicit episodic memory and in judgements of recency (indicating impaired coding of contextual information). Lorazepam significantly reduced performance in a word completion task, but this was unimpaired in the group performing the additional task. In general, the pattern of results suggests that there are similarities between the effects of divided attention and lorazepam treatment, and that lorazepam-induced cognitive impairments are not restricted to explicit tests of episodic memory.

  13. Conventional and Islamic indices in Indonesia: A Comparison on Performance, Volatility, and the Determinants

    Directory of Open Access Journals (Sweden)

    Nika Pranata

    2015-10-01

    Full Text Available The purpose of this study is to evaluate performance and volatility of Islamic andconventional stock indices along with their determinant factor variables in Indonesia. The study adopts: (1 Capital Asset Pricing Model (CAPM to compare the performance of the Jakarta Islamic Index (JII to represent Islamic indexandLQ45 to represent the conventional, (2 beta calculation to measure volatility, and (3 Autoregressive Distributed Lag (ARDL to capture the determinants and the reason behind the outperformance. The data coverage is from January 2006 to November 2015. The study finds that: (1 There is no significant differenceon performance between JII and LQ45, (2 JII is less volatile than LQ45, except in 2010, and (3JII performance is less affected by external factorsexcept for crude oil price. Moreover, the result implies challenge for the authorities to educate society, particularly whom concern to shari’ah principles, with information that Islamic index performance is not much difference from conventional index and less volatile.

  14. A comparison of resampling schemes for estimating model observer performance with small ensembles

    Science.gov (United States)

    Elshahaby, Fatma E. A.; Jha, Abhinav K.; Ghaly, Michael; Frey, Eric C.

    2017-09-01

    In objective assessment of image quality, an ensemble of images is used to compute the 1st and 2nd order statistics of the data. Often, only a finite number of images is available, leading to the issue of statistical variability in numerical observer performance. Resampling-based strategies can help overcome this issue. In this paper, we compared different combinations of resampling schemes (the leave-one-out (LOO) and the half-train/half-test (HT/HT)) and model observers (the conventional channelized Hotelling observer (CHO), channelized linear discriminant (CLD) and channelized quadratic discriminant). Observer performance was quantified by the area under the ROC curve (AUC). For a binary classification task and for each observer, the AUC value for an ensemble size of 2000 samples per class served as a gold standard for that observer. Results indicated that each observer yielded a different performance depending on the ensemble size and the resampling scheme. For a small ensemble size, the combination [CHO, HT/HT] had more accurate rankings than the combination [CHO, LOO]. Using the LOO scheme, the CLD and CHO had similar performance for large ensembles. However, the CLD outperformed the CHO and gave more accurate rankings for smaller ensembles. As the ensemble size decreased, the performance of the [CHO, LOO] combination seriously deteriorated as opposed to the [CLD, LOO] combination. Thus, it might be desirable to use the CLD with the LOO scheme when smaller ensemble size is available.

  15. Comparison between disign criteria and observed structural performance of underground openings at WIPP

    International Nuclear Information System (INIS)

    Cook, R.F.; Francke, C.

    1989-01-01

    This paper discusses the observed structural performance of the underground excavations at the Waste Isolation Pilot Plant (WIPP) in relation to design criteria. The criteria were established at an early stage of the project to define the functional and structural requirements that were to be addressed in the design of the facility. For the underground structural response, the criteria defined the requirements for the shaft and shaft liner design, mine design, waste emplacement, retrievability and instrumentation. The observed structural performance of the underground is determined by the field data that have been collected since excavations were started at the WIPP site. The observations include field measurements of rock and water conditions, as well as maintenance records. The data provide input to design confirmation, performance assessment and form the basis for the design of new underground structures. For this paper, the field data have been compared with the design criteria applicable to ground control to demonstrate that the requirements of the design are met

  16. Comparison of overhead line lightning performance based on two different tower geometries

    DEFF Research Database (Denmark)

    Ebdrup, Thomas; Olason, Daniel; Bak, Claus Leth

    2014-01-01

    of the substation and transmission line is of great importance as it is a part of the 400 kV backbone between Sweden, Norway, Germany and the offshore wind farms in Horns Rev, Denmark. The new Eagle pylon has been designed with the focus of minimizing the visual impacted of overhead lines. A detailed lightning...... performance analysis of the existing Donau and the new Eagle pylon is therefore important in order to assess the risk of failure. The lightning strike analysis is based on the number of strikes expected to terminate on the line and an investigation of how many of these there may be expected to cause...... better protected from direct stroke than the phase conductors on the Donau pylon. Furthermore with respect to a backflash, the Eagle has a better performance than the Donau pylon. It is therefore concluded that the Eagle has a better lightning performance than the Donau....

  17. PERFORMANCE COMPARISON FOR INTRUSION DETECTION SYSTEM USING NEURAL NETWORK WITH KDD DATASET

    Directory of Open Access Journals (Sweden)

    S. Devaraju

    2014-04-01

    Full Text Available Intrusion Detection Systems are challenging task for finding the user as normal user or attack user in any organizational information systems or IT Industry. The Intrusion Detection System is an effective method to deal with the kinds of problem in networks. Different classifiers are used to detect the different kinds of attacks in networks. In this paper, the performance of intrusion detection is compared with various neural network classifiers. In the proposed research the four types of classifiers used are Feed Forward Neural Network (FFNN, Generalized Regression Neural Network (GRNN, Probabilistic Neural Network (PNN and Radial Basis Neural Network (RBNN. The performance of the full featured KDD Cup 1999 dataset is compared with that of the reduced featured KDD Cup 1999 dataset. The MATLAB software is used to train and test the dataset and the efficiency and False Alarm Rate is measured. It is proved that the reduced dataset is performing better than the full featured dataset.

  18. Analysis and comparison of the breakdown performance of semi- insulator and dielectric passivated Si strip detectors

    CERN Document Server

    Ranjan, Kirti; Chatterji, S; Srivastava-Ajay, K; Shivpuri, R K

    2002-01-01

    The harsh radiation environment in future high-energy physics (HEP) experiments like LHC provides a challenging task to the performance of Si microstrip detectors. Normal operating condition for silicon detectors in HEP experiments are in most cases not as favourable as for experiments in nuclear physics. In HEP experiments the detector may be exposed to moisture and other adverse atmospheric environment. It is therefore utmost important to protect the sensitive surfaces against such poisonous effects. These instabilities can be nearly eliminated and the performance of Si detectors can be improved by implementing suitably passivated metal-overhang structures. This paper presents the influence of the relative permittivity of the passivant on the breakdown performance of the Si detectors using computer simulations. The semi-insulator and the dielectric passivated metal-overhang structures are compared under optimal conditions. The influence of various parameters such as passivation layer thickness, junction dep...

  19. Loose and Tight GNSS/INS Integrations: Comparison of Performance Assessed in Real Urban Scenarios.

    Science.gov (United States)

    Falco, Gianluca; Pini, Marco; Marucco, Gianluca

    2017-01-29

    Global Navigation Satellite Systems (GNSSs) remain the principal mean of positioning in many applications and systems, but in several types of environment, the performance of standalone receivers is degraded. Although many works show the benefits of the integration between GNSS and Inertial Navigation Systems (INSs), tightly-coupled architectures are mainly implemented in professional devices and are based on high-grade Inertial Measurement Units (IMUs). This paper investigates the performance improvements enabled by the tight integration, using low-cost sensors and a mass-market GNSS receiver. Performance is assessed through a series of tests carried out in real urban scenarios and is compared against commercial modules, operating in standalone mode or featuring loosely-coupled integrations. The paper describes the developed tight-integration algorithms with a terse mathematical model and assesses their efficacy from a practical perspective.

  20. Enhancing Self-Efficacy and Performance: An Experimental Comparison of Psychological Techniques.

    Science.gov (United States)

    Wright, Bradley James; O'Halloran, Paul Daniel; Stukas, Arthur Anthony

    2016-01-01

    We assessed how 6 psychological performance enhancement techniques (PETs) differentially improved self-efficacy (SE) and skill performance. We also assessed whether vicarious experiences and verbal persuasion as posited sources of SE (Bandura, 1982 ) were supported and, further, if the effects of the 6 PETs remained after controlling for achievement motivation traits and self-esteem. A within-subject design assessed each individual across 2 trials for 3 disparate PETs. A between-groups design assessed differences between PETs paired against each other for 3 similar novel tasks. Participants (N = 96) performed 2 trials of 10 attempts at each of the tasks (kick, throw, golf putt) in a counterbalanced sequence using their nondominant limb. Participants completed the Sport Orientation Questionnaire, Rosenberg Self-Esteem Scale, and General Self-Efficacy Scale and were randomly allocated to either the modeling or imagery, goal-setting or instructional self-statement, or knowledge-of-results or motivational feedback conditions aligned with each task. An instructional self-statement improved performance better than imagery, modeling, goal setting, and motivational and knowledge-of-results augmented feedback. Motivational auditory feedback most improved SE. Increased SE change scores were related to increased performance difference scores on all tasks after controlling for age, sex, achievement motivation, and self-esteem. Some sources of SE may be more influential than others on both SE and performance improvements. We provide partial support for the sources of SE proposed by Bandura's social-cognitive theory with verbal persuasion but not vicarious experiences improving SE.

  1. Comparison of measured and predicted long term performance of grid a connected photovoltaic system

    International Nuclear Information System (INIS)

    Mondol, Jayanta Deb; Yohanis, Yigzaw G.; Norton, Brian

    2007-01-01

    Predicted performance of a grid connected photovoltaic (PV) system using TRNSYS was compared with measured data. A site specific global-diffuse correlation model was developed and used to calculate the beam and diffuse components of global horizontal insolation. A PV module temperature equation and a correlation relating input and output power of an inverter were developed using measured data and used in TRNSYS to perform PV array and inverter outputs simulation. Different combinations of the tilted surface radiation model, global-diffuse correlation model and PV module temperature equation were used in the simulations. Statistical error analysis was performed to compare the results for each combination. The simulation accuracy was improved by using the new global-diffuse correlation and module temperature equation in the TRNSYS simulation. For an isotropic sky tilted surface radiation model, the average monthly difference between measured and predicted PV output before and after modification of the TRNSYS component were 10.2% and 3.3%, respectively, and, for an anisotropic sky model, 15.4% and 10.7%, respectively. For inverter output, the corresponding errors were 10.4% and 3.3% and 15.8% and 8.6%, respectively. Measured PV efficiency, overall system efficiency, inverter efficiency and performance ratio of the system were compared with the predicted results. The predicted PV performance parameters agreed more closely with the measured parameters in summer than in winter. The difference between predicted performances using an isotropic and an anisotropic sky tilted surface models is between 1% and 2%

  2. Comparison of heat pump performance using fin-and-tube and microchannel heat exchangers under frost conditions

    International Nuclear Information System (INIS)

    Shao, Liang-Liang; Yang, Liang; Zhang, Chun-Lu

    2010-01-01

    Vapor compression heat pumps are drawing more attention in energy saving applications. Microchannel heat exchangers can provide higher performance via less core volume and reduce system refrigerant charge, but little is known about their performance in heat pump systems under frosting conditions. In this study, the system performance of a commercial heat pump using microchannel heat exchangers as evaporator is compared with that using conventional finned-tube heat exchangers numerically and experimentally. The microchannel and finned-tube heat pump system models used for comparison of the microchannel and finned-tube evaporator performance under frosting conditions were developed, considering the effect of maldistribution on both refrigerant and air sides. The quasi-steady-state modeling results are in reasonable agreement with the test data under frost conditions. The refrigerant-side maldistribution is found remarkable impact on the microchannel heat pump system performance under the frost conditions. Parametric study on the fan speed and the fin density under frost conditions are conducted as well to figure out the best trade-off in the design of frost tolerant evaporators. (author)

  3. Medicare Advantage and Fee-for-Service Performance on Clinical Quality and Patient Experience Measures: Comparisons from Three Large States.

    Science.gov (United States)

    Timbie, Justin W; Bogart, Andy; Damberg, Cheryl L; Elliott, Marc N; Haas, Ann; Gaillot, Sarah J; Goldstein, Elizabeth H; Paddock, Susan M

    2017-12-01

    To compare performance between Medicare Advantage (MA) and Fee-for-Service (FFS) Medicare during a time of policy changes affecting both programs. Performance data for 16 clinical quality measures and 6 patient experience measures for 9.9 million beneficiaries living in California, New York, and Florida. We compared MA and FFS performance overall, by plan type, and within service areas associated with contracts between CMS and MA organizations. Case mix-adjusted analyses (for measures not typically adjusted) were used to explore the effect of case mix on MA/FFS differences. Performance measures were submitted by MA organizations, obtained from the nationwide fielding of the Medicare Consumer Assessment of Healthcare Providers and Systems (MCAHPS) Survey, or derived from claims. Overall, MA outperformed FFS on all 16 clinical quality measures. Differences were large for HEDIS measures and small for Part D measures and remained after case mix adjustment. MA enrollees reported better experiences overall, but FFS beneficiaries reported better access to care. Relative to FFS, performance gaps were much wider for HMOs than PPOs. Excluding HEDIS measures, MA/FFS differences were much smaller in contract-level comparisons. Medicare Advantage/Fee-for-Service differences are often large but vary in important ways across types of measures and contracts. © Health Research and Educational Trust.

  4. Number comparison and number ordering as predictors of arithmetic performance in adults: Exploring the link between the two skills, and investigating the question of domain-specificity.

    Science.gov (United States)

    Morsanyi, Kinga; O'Mahony, Eileen; McCormack, Teresa

    2017-12-01

    Recent evidence has highlighted the important role that number-ordering skills play in arithmetic abilities, both in children and adults. In the current study, we demonstrated that number comparison and ordering skills were both significantly related to arithmetic performance in adults, and the effect size was greater in the case of ordering skills. Additionally, we found that the effect of number comparison skills on arithmetic performance was mediated by number-ordering skills. Moreover, performance on comparison and ordering tasks involving the months of the year was also strongly correlated with arithmetic skills, and participants displayed similar (canonical or reverse) distance effects on the comparison and ordering tasks involving months as when the tasks included numbers. This suggests that the processes responsible for the link between comparison and ordering skills and arithmetic performance are not specific to the domain of numbers. Finally, a factor analysis indicated that performance on comparison and ordering tasks loaded on a factor that included performance on a number line task and self-reported spatial thinking styles. These results substantially extend previous research on the role of order processing abilities in mental arithmetic.

  5. A clinical comparison of cordless and conventional displacement systems regarding clinical performance and impression quality.

    Science.gov (United States)

    Acar, Özlem; Erkut, Selim; Özçelik, Tuncer Burak; Ozdemır, Erdem; Akçil, Mehtap

    2014-05-01

    It is not clear whether newly introduced cordless displacement systems are better able to manage gingiva than conventional systems. The purpose of this in vivo study was to evaluate the gingival management ability of 4 different displacement methods with a standardized subgingival preparation finish line. The effects of 4 displacement techniques on gingival management and impression quality were evaluated by means of 6 evaluation criteria. A subgingival preparation finish line of between 1 and 2 mm was ensured, and the buccal aspects of 252 (n=63) teeth were clinically assessed for ease of application, time spent, bleeding, remnants, and dilatation. The complete reproduction of the preparation finish line and the bubble and void formations on polyether impressions were also evaluated. The data were statistically analyzed with the χ(2) test (α=.05). The Bonferroni correction was used to control Type I error for the pairwise comparison groups (α=.008). Statistically significant differences were found for all criteria among the groups (Pimpression quality (Pimpression quality (P>.008). The retraction cap with paste group showed better results for ease of application, time spent, and bleeding than the aluminum chloride impregnated cord group (Pimpression qualities. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. Comparison performance of split plug-in hybrid electric vehicle and hybrid electric vehicle using ADVISOR

    Directory of Open Access Journals (Sweden)

    Mohd Rashid Muhammad Ikram

    2017-01-01

    Full Text Available Electric vehicle suffers from relatively short range and long charging times and consequently has not become an acceptable solution to the automotive consumer. The addition of an internal combustion engine to extend the range of the electric vehicle is one method of exploiting the high efficiency and lack of emissions of the electric vehicle while retaining the range and convenient refuelling times of a conventional gasoline powered vehicle. The term that describes this type of vehicle is a hybrid electric vehicle. Many configurations of hybrid electric vehicles have been designed and implemented, namely the series, parallel and power-split configurations. This paper discusses the comparison between Split Plug-in Hybrid Electric Vehicle(SPHEV and Hybrid Electric Vehicle(HEV. Modelling methods such as physics-based Resistive Companion Form technique and Bond Graph method are presented with powertrain component and system modelling examples. The modelling and simulation capability of existing tools such as ADvanced VehIcle SimulatOR (ADVISOR is demonstrated through application examples. Since power electronics is indispensable in hybrid vehicles, the issue of numerical oscillations in dynamic simulations involving power electronics is briefly addressed.

  7. Comparison of neuropsychological performance between students from public and private Brazilian schools.

    Science.gov (United States)

    Casarin, Fabíola Schwengber; Wong, Cristina Elizabeth Izábal; Parente, Maria Alice de Mattos Pimenta; de Salles, Jerusa Fumagalli; Fonseca, Rochele Paz

    2012-11-01

    Neuropsychological assessment reveals that certain cognitive changes that take place during the neural development process may be associated with biopsychosocial issues. A substantial body of research has focused on cognitive development in children and adults, but few such studies have been carried out on adolescents. Therefore, research into the processing of neuropsychological functions in adolescents, taking into account the role of major socio-cultural factors such as school type (public vs. private), is highly relevant. The present study sought to assess whether differences in neuropsychological development exist between adolescent students of public (government-funded) and private schools. A total of 373 grade-matched students between the ages of 12 and 18, 190 from public schools and 183 from private schools, took part in the study. All subjects had no self-reported neurologic or psychiatric conditions and sensory disorders. The NEUPSILIN Brazilian Brief Neuropsychological Assessment Battery was administered to this sample. Comparison of mean scores (one-way ANCOVA with socioeconomic score and age as covariates) showed that adolescents attending private schools generally outperformed their public-school peers in tasks involving sustained attention, memory (working and visual), dictated writing, and constructional and reflective abilities. We conclude that school type should be taken into account during standardization of neuropsychological assessment instruments for adolescent and, probably, child populations.

  8. Morphology, production, and chemical content performance of black rice Matesih accession with several comparisons

    Science.gov (United States)

    Nandariyah; Purwanto, E.; Meidini, A. N.

    2018-03-01

    Rice (Oryza sativa L.) is an important food crop in Indonesia. In Matesih area, Karanganyar, recently found new varieties of black rice cultured by local farmers which morphology and chemical content have not yet identified. The purpose of this research was to obtain information of morphology, production, and chemical content of black rice matesih accession and to compare the appearance in order to detect the superiority of black rice matesih accession with the comparison of other accession of black rice. There were four accessions of black rice tested, namely Matesih Accession, Klaten Accession, Toraja, and Cempo. Research data were divided into qualitative data which processed by scoring, and quantitative data are processed with simple descriptive statistic. The kinship test was done by using NTSYSpc program with SIMQual and SIMInt function. The observation of qualitative properties indicates that accession matesih has a form that is relatively similar to other accessions. Qualitatively, accession matesih superior at leaf length, leaf width, plant height and culm diameter. Klaten accession has higher production than accession matesih. Matesih accession has the advantage of having shorter period on heading time and harvest time than other accessions. Matesih accession has the highest amylose content, lower protein content than klaten accession and lower content of anthocyanin than toraja accession. The kinship analysis showed that matesih accession and klaten accession has close kinship.

  9. Performance comparison of four lithium–ion battery technologies under calendar aging

    International Nuclear Information System (INIS)

    Eddahech, Akram; Briat, Olivier; Vinassa, Jean-Michel

    2015-01-01

    This work depicts the calendar aging results of four Li-ion battery technologies. The differences in the chemistry of Li-ion batteries was studied and revealed that cathodes containing manganese are more sensitive to state-of-charge and temperature increase than lithium–iron-phosphate or lithium–nickel–cobalt–aluminum batteries. The first step in presenting the differences in technology of the Li-ion battery is through the study of the battery voltage evolution versus the amount of charge at various states of health. This study revealed a significant increase in resistance on lithium–nickel–manganese–cobalt and lithium–manganese-oxide cells; a result which was confirmed through impedance spectroscopy measurements. Finally, a study of the comparison of the different types of Li-ion batteries was undertaken, based on the analysis of the evolution of energy efficiency with respect to aging. - Highlights: • Calendar aging results of four Li-ion battery technologies are presented. • High temperature and/or the increased state-of-charge accelerated battery aging. • We analyzed the evolution of energy efficiency with respect to aging. • Cathodes with manganese are more sensitive to SOC and temperature increase

  10. Performance of Dutch children on the Bayley III: a comparison study of US and Dutch norms.

    Science.gov (United States)

    Steenis, Leonie J P; Verhoeven, Marjolein; Hessen, Dave J; van Baar, Anneloes L

    2015-01-01

    The Bayley Scales of Infant and Toddler Development-third edition (Bayley-III) are frequently used to assess early child development worldwide. However, the original standardization only included US children, and it is still unclear whether or not these norms are adequate for use in other populations. Recently, norms for the Dutch version of the Bayley-III (The Bayley-III-NL) were made. Scores based on Dutch and US norms were compared to study the need for population-specific norms. Scaled scores based on Dutch and US norms were compared for 1912 children between 14 days and 42 months 14 days. Next, the proportions of children scoring Dutch norms fluctuated around values based on US norms on all subtests. The extent of the deviations differed across ages and subtests. Differences in means were significant across all five subtests (p Dutch norms resulted in over-referral regarding gross motor skills, and under-referral regarding cognitive, receptive communication, expressive communication, and fine motor skills. The Dutch norms differ from the US norms for all subtests and these differences are clinically relevant. Population specific norms are needed to identify children with low scores for referral and intervention, and to facilitate international comparisons of population data.

  11. Experimental comparison between R409A and R437A performance in a heat pump unit

    Directory of Open Access Journals (Sweden)

    Duarte M. V.

    2017-04-01

    Full Text Available This paper reports an experimental comparison between the use of the refrigerants R409A and R437A in a heat pump unit designed and developed to work with R12. Although the use of both refrigerants in new equipments were abolished in EU and US according the new F-Gas Regulation of EU and SNAP, they still being used as options for R12 in old equipments, especially in developing countries. Both refrigerants were studied for the same test conditions, according to two groups of tests: group A (variation of the heat source temperature and group B (variation of refrigerant flow rate. The results obtained showed that the R437A presents a higher discharge pressure and a lower discharge temperature. The heating and cooling capacities of both refrigerants were similar, as well as the exergetic efficiency. For the group A of tests the COP of both refrigerants was similar and for the group B of tests the R409A presented an average COP 15% higher. According to the results obtained it is recommended the use of R409A in old equipments (as transition refrigerant until the acquisition of equipments operating with refrigerants with low-GWP becomes technically and economic feasible.

  12. Comparison of higher irradiance and black panel temperature UV backsheet exposures to field performance

    Science.gov (United States)

    Felder, Thomas C.; Gambogi, William J.; Phillips, Nancy; MacMaster, Steven W.; Yu, Bao-Ling; Trout, T. John

    2017-08-01

    The need for faster PV qualification tests that more accurately match field observations is leading to tests with higher acceleration levels, and validating the new tests through comparison to field data is an important step. We have tested and compared a wide panel of backsheets according to a proposed new backsheet UV exposure qualification standard from the International Electrotechnical Commission (IEC). Weathering Technical Standard IEC 62788-7-2 specifies higher irradiance and higher black panel temperature UV Xenon exposures. We tested PVF, PVDF, PET, PA and FEVEbased backsheets in glass laminates and simple backsheet coupons in UV exposure condition A3 (0.8W/sqmnm@340nm and 90° C BPT) We find mild yellowing with no mechanical loss in the original lower intensity ASTM G155 0.55 W/sqm-nm 70C BPT exposure condition. The new A3 exposures creates mechanical loss in sensitive backsheets, with no effect on known durable backsheets. Results from the new exposure are closer to field mechanical loss data.

  13. Performance Comparison of Reconstruction Algorithms in Discrete Blind Multi-Coset Sampling

    DEFF Research Database (Denmark)

    Grigoryan, Ruben; Arildsen, Thomas; Tandur, Deepaknath

    2012-01-01

    This paper investigates the performance of different reconstruction algorithms in discrete blind multi-coset sampling. Multi-coset scheme is a promising compressed sensing architecture that can replace traditional Nyquist-rate sampling in the applications with multi-band frequency sparse signals...

  14. Performance in College Chemistry: a Statistical Comparison Using Gender and Jungian Personality Type

    Science.gov (United States)

    Greene, Susan V.; Wheeler, Henry R.; Riley, Wayne D.

    This study sorted college introductory chemistry students by gender and Jungian personality type. It recognized differences from the general population distribution and statistically compared the students' grades with their Jungian personality types. Data from 577 female students indicated that ESFP (extroverted, sensory, feeling, perceiving) and ENFP (extroverted, intuitive, feeling, perceiving) profiles performed poorly at statistically significant levels when compared with the distribution of females enrolled in introductory chemistry. The comparable analysis using data from 422 male students indicated that the poorly performing male profiles were ISTP (introverted, sensory, thinking, perceiving) and ESTP (extroverted, sensory, thinking, perceiving). ESTJ (extroverted, sensory, thinking, judging) female students withdrew from the course at a statistically significant level. For both genders, INTJ (introverted, intuitive, thinking, judging) students were the best performers. By examining the documented characteristics of Jungian profiles that correspond with poorly performing students in chemistry, one may more effectively assist the learning process and the retention of these individuals in the fields of natural science, engineering, and technology.

  15. A comparison of operational performance : Washington state ferries to ferry operators worldwide.

    Science.gov (United States)

    2010-06-01

    This project compares eight measures of performance related to transit service quality (e.g. trip reliability, on-time departures) and cost-efficiency (e.g. farebox recovery, subsidy per passenger) between Washington State Ferries (WSF) and 23 ferry ...

  16. Motor Performance of Primary Age Handicapped and Nonhandicapped Children in the Mainstream: A Comparison.

    Science.gov (United States)

    Sherrill, Claudine; Kelly, Luke

    A comparative study was made of mentally retarded and nonhandicapped children in the first through third grades on motor performance as measured by running (50-yard dash), jumping (standing broad jump), and throwing (softball throw for distance). The subjects had received all of their physical education instruction in a mainstream setting since…

  17. Squat Jump Performance during Growth in Both Sexes: Comparison with Cycling Power

    Science.gov (United States)

    Dore, Eric; Bedu, Mario; Van Praagh, Emmanuel

    2008-01-01

    The purpose of this cross-sectional study was to investigate leg muscle power and compare two activities (jumping and cycling) in 383 girls and 407 boys ages 9-19 years. Results in anthropometric characteristics and jumping performance were comparable until midadolescence, and sex differences were observed. Lean leg volume (LLV) was the reason for…

  18. Comparisons of Performance and Job Insecurity in Union and Nonunion Sites of a Manufacturing Company

    Science.gov (United States)

    Filipkowski, Monica; Johnson, C. Merle

    2008-01-01

    Layoffs and employment changes caused by current economic conditions have significant effects on employee work behavior and emotions as well as organizational outcomes. We examined the relationships between measures of job insecurity, organizational commitment, turnover, absenteeism, and worker performance within a manufacturer in Chapter 11…

  19. System thermodynamic performance comparison of CO2-EGS and water-EGS systems

    International Nuclear Information System (INIS)

    Zhang, Fu-Zhen; Jiang, Pei-Xue; Xu, Rui-Na

    2013-01-01

    CO 2 may be a better heat transmission fluid than water for Enhanced Geothermal Systems (EGS). The advantages and disadvantages of these two kinds of EGS are the focus of this study. The water and CO 2 -EGS system models including simple subsurface heat transfer and flow models and a surface energy conversion system model were designed based on the reservoir grade and the ambient temperatures. The results indicate that the operating parameters including the injection pressure, turbine outlet pressure and reservoir stimulated area should be optimized to match the actual CO 2 -EGS conditions. CO 2 -EGS produce more power than water-EGS for reservoirs with low recoverable thermal energies due to less irreversible losses compared to ORC or flash cycles for water-EGS. However, high resistance losses caused by high mass flow rates degrade the CO 2 -EGS performance; thus, the water-EGS has better performance than CO 2 -EGS for larger energy content reservoirs. -- Highlights: • Comparing the performance of CO 2 -EGS and water-EGS for various conditions. • Presenting the scope of applications for these two kinds of EGS systems. • Cooling after compression before the CO 2 is injected improves CO 2 -EGS performance. • There is an optimum recoverable thermal energy content for CO 2 -EGS

  20. A comparison of performance of several artificial intelligence methods for forecasting monthly discharge time series

    Science.gov (United States)

    Wang, Wen-Chuan; Chau, Kwok-Wing; Cheng, Chun-Tian; Qiu, Lin

    2009-08-01

    SummaryDeveloping a hydrological forecasting model based on past records is crucial to effective hydropower reservoir management and scheduling. Traditionally, time series analysis and modeling is used for building mathematical models to generate hydrologic records in hydrology and water resources. Artificial intelligence (AI), as a branch of computer science, is capable of analyzing long-series and large-scale hydrological data. In recent years, it is one of front issues to apply AI technology to the hydrological forecasting modeling. In this paper, autoregressive moving-average (ARMA) models, artificial neural networks (ANNs) approaches, adaptive neural-based fuzzy inference system (ANFIS) techniques, genetic programming (GP) models and support vector machine (SVM) method are examined using the long-term observations of monthly river flow discharges. The four quantitative standard statistical performance evaluation measures, the coefficient of correlation ( R), Nash-Sutcliffe efficiency coefficient ( E), root mean squared error (RMSE), mean absolute percentage error (MAPE), are employed to evaluate the performances of various models developed. Two case study river sites are also provided to illustrate their respective performances. The results indicate that the best performance can be obtained by ANFIS, GP and SVM, in terms of different evaluation criteria during the training and validation phases.

  1. Performance comparison of two types of technologies associated with a positive energy building

    DEFF Research Database (Denmark)

    Dumont, Olivier; Carmo, Carolina; Randaxhe, François

    2015-01-01

    the annual performance of two competing systems. First, a conventional solution, consisting of a passive house coupled with a water to water heat pump and photovoltaic panels (HP/PV). On the other hand, a passive house with a solar thermal roof combined with a reversible heat pump unit / organic Rankine...

  2. Fundamental and empirical rheological behaviour of wheat flour doughs and comparison with bread making performance

    NARCIS (Netherlands)

    Janssen, A. M.; vanVliet, T; Vereijken, JM

    The rheological characteristics of wheat flour doughs from the cultivars Obelisk and Katepwa and of biscuit flour doughs, and also of biscuit flour doughs containing glutens isolated from cv. Obelisk and cv. Katepwa flour, were compared and discussed in relation to bread making performance. Four

  3. Financial Indicators of Reduced Impact Logging Performance in Brazil: Case Study Comparisons

    Science.gov (United States)

    Thomas P. Holmes; Frederick Boltz; Douglas R. Carter

    2001-01-01

    Indicators of financial performance are compared for three case studies in the Brazilian Amazon. Each case study presents parameters obtained from monitoring initial harvest entries into primary forests for reduced impact logging (RIL) and conventional logging (CL) operations. Differences in cost definitions and data collection protocols complicate the analysis, and...

  4. Comparison of physical therapy anatomy performance and anxiety scores in timed and untimed practical tests.

    Science.gov (United States)

    Schwartz, Sarah M; Evans, Cathy; Agur, Anne M R

    2015-01-01

    Students in health care professional programs face many stressful tests that determine successful completion of their program. Test anxiety during these high stakes examinations can affect working memory and lead to poor outcomes. Methods of decreasing test anxiety include lengthening the time available to complete examinations or evaluating students using untimed examinations. There is currently no consensus in the literature regarding whether untimed examinations provide a benefit to test performance in clinical anatomy. This study aimed to determine the impact of timed versus untimed practical tests on Master of Physical Therapy student anatomy performance and test anxiety. Test anxiety was measured using the State-Trait Anxiety Inventory (STAI). Differences in performance, anxiety scores, and time taken were compared using paired sample Student's t-tests. Eighty-one of the 84 students completed the study and provided feedback. Students performed significantly higher on the untimed test (P = 0.005), with a significant reduction in test anxiety (P anxiety. If the intended goal of evaluating health care professional students is to determine fundamental competencies, these factors should be considered when designing future curricula. © 2014 American Association of Anatomists.

  5. Performance comparison of different graylevel image fusion schemes through a universal image quality index

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2003-01-01

    We applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the

  6. Post-Graduate Performance, an Academic Comparison Evaluating Situating Learning and Law School Acceptance Scores

    Science.gov (United States)

    Traverse, Maria A.

    2012-01-01

    Research on post-graduate performance, pertaining to law school graduates, indicates that success in the legal profession is attributable to more than the theoretical content or cognitive knowledge obtained through educational curricula. Research suggests that the combination of creative and analytic thinking skills contributes to a higher rate of…

  7. Learner Performance in Mandarin Immersion and High School World Language Programs: A Comparison

    Science.gov (United States)

    Xu, Xiaoqiu; Padilla, Amado M.; Silva, Duarte M.

    2015-01-01

    This study compared the Mandarin performance of elementary immersion program students and high school world language program students in the same school district. A cross-sectional design was employed to gather information on Mandarin proficiency of fourth and fifth graders and Level 4 and Level 5 (AP Chinese) high school students who took the…

  8. A Cross-National Comparison of Reported Effort and Mathematics Performance in TIMSS Advanced

    Science.gov (United States)

    Eklöf, Hanna; Pavešic, Barbara Japelj; Grønmo, Liv Sissel

    2014-01-01

    The purpose of the study was to measure students' reported test-taking effort and the relationship between reported effort and performance on the Trends in International Mathematics and Science Study (TIMSS) Advanced mathematics test. This was done in three countries participating in TIMSS Advanced 2008 (Sweden, Norway, and Slovenia), and the…

  9. Comparison between conventional heat exchanger performance and an heat pipes exchanger

    International Nuclear Information System (INIS)

    Souza, J.R.G. de; Rocha, N.R.

    1989-01-01

    The thermal performance of conventional compact heat exchanger and of exchanger with heat pipes are simulated using a digital computer, for equal volumes and the same process conditions. The comparative analysis is depicted in graphs that indicate which of the situations each equipment is more efficient. (author)

  10. Spunlaced and chemically bonded nonwovens for filtration applications: Performance evaluation and comparison

    CSIR Research Space (South Africa)

    Boguslavsky, L

    2008-11-01

    Full Text Available . The physical, mechanical and performance properties were measured and compared. It was concluded that chemical bonding had a higher effect on the fabric structural changes, such as pore size and its distribution. The results showed an improvement in dust...

  11. Comparison of reading performance tests concerning difficulty of sentences and paragraphs and their reliability

    NARCIS (Netherlands)

    Brussee, T.; van Nispen, R.M.A.; Klerkx, E.M.F.J.; Knol, D.L.; van Rens, G.H.M.B.

    2015-01-01

    In research and practice, sentences or paragraphs of reading tests may be randomly chosen to assess reading performance. This means that in addition to test reliability, all sentences or paragraphs should be reliable and equally difficult to read. The sentences and paragraphs of five (un-)

  12. A comparison between prescriptive- and performance-based approaches in fire safety design of structures

    DEFF Research Database (Denmark)

    Budny, Iwona; Giuliani, Luisa

    2010-01-01

    methodology of the performance-based fire design approach is considered, with the avail of computer-aided simulations of the main frame of the car-park. Nonlinear analyses, with respect to thermally induced effects and emphasis laid to the collapse modality, are carried out on a frame of the considered...

  13. Comparison of blind imaging performance of Fizeau and Michelson type arrays for a partially resolved object

    NARCIS (Netherlands)

    Van der Avoort, C.; Den Herder, J.W.; Braat, J.

    2005-01-01

    This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or

  14. Academic performance of male in comparison with female undergraduate medical students in Pharmacology examinations.

    Science.gov (United States)

    Faisal, Rizwan; Shinwari, Laiyla; Hussain, Shahzadi Saima

    2017-02-01

    To compare the academic performance of male and female medical students in Pharmacology examinations. The comparative study was conducted at Rehman Medical College, Peshawar, Pakistan, from March to August 2015. For evaluating the students' academic performance, male and female students of academic sessions 2013-14 and 2014-15 were divided into 4 groups. Group 1: 80% marks. SPSS 20 was used for data analysis. Of the 200 medical students enrolled, 102(51%) were male and 98(41%) were female. There was no significant difference in the academic performance in terms of gender in multiple choice questions (p=0.811) and short essay questions (p=0.515). The effect of attendance was also insignificant (p=0.130). Significant difference was found between the academic records of urban male and female students compared to rural students (p=0.038). Boarder students' results were insignificantly different from those of day scholars (p=0.887). There was no significant difference between the academic performance of male and female students.

  15. An empirical comparison of voluntary and mandatory building energy performance disclosure outcomes

    International Nuclear Information System (INIS)

    Gabe, Jeremy

    2016-01-01

    In 2010, the federal Australian government mandated the disclosure of energy performance ratings in advertisements for sale or lease of large commercial office properties. Prior to 2010, participation in the rating scheme was voluntary. This study first develops a theoretical model of mandatory disclosure policy effectiveness. Then, with a dataset of all ratings since inception of the voluntary regime in 1999, it tests the expectation that initial voluntary adopters have a greater tendency towards environmental stewardship and are more likely to manage and invest in environmental performance improvements, potentially dampening the effectiveness of mandatory disclosure policy. However, multiple statistical models of certification are unable to reject the null hypothesis that there is no difference in energy efficiency outcomes between the mandatory and voluntary adopters at equivalent stages. For urban policymakers, the extrapolation of voluntary adopter performance appears to be a good – perhaps even conservative – estimation of mandatory energy performance disclosure outcomes. - Highlights: •A theoretical model of building energy disclosure policy effectiveness is proposed. •Mandatory disclosure adopters reduce consumption similar to voluntary adopters. •Mandatory building energy disclosure in Australia has been effective. •Early adopters creating a market for energy retrofits is a likely reason for success.

  16. A comparison of performance of flat and bent photovoltaic luminescent solar concentrators

    NARCIS (Netherlands)

    Vishwanathan, B.; Reinders, A. H.M.E.; de Boer, D.K.G.; Desmet, L.; Ras, A. J.M.; Zahn, F. H.; Debije, M.G.

    2015-01-01

    To employ new solar photovoltaic technologies in products and buildings, many systems need to be adapted. Inspired by the cylindrical shape, in this work we have evaluated the performance of luminescent solar concentrator photovoltaic (LSC-PV) elements with narrow PV cell strips that could be

  17. The comparison of the performance of two screening strategies identifying newly-diagnosed HIV during pregnancy

    NARCIS (Netherlands)

    Boer, K.; Smit, C.; Flier, M. van der; Wolf, F. de; Koopmans †, P.P.; Crevel, R. van; Eggink, A.J.; Groot, R. de; Keuter, M.; Post, F.; Ven, A.J.A.M. van der; Warris, A.; et al.,

    2011-01-01

    BACKGROUND: In the Netherlands, a non-selective opt-out instead of a selective opt-in antenatal HIV screening strategy was implemented in 2004. In case of infection, screening was followed by prevention of mother-to-child-transmission (PMTCT). We compared the performance of the two strategies in

  18. The comparison of the performance of two screening strategies identifying newly-diagnosed HIV during pregnancy

    NARCIS (Netherlands)

    Boer, Kees; Smit, Colette; van der Flier, Michiel; de Wolf, Frank; Bezemer, D. O.; Gras, L. A. J.; Kesselring, A. M.; van Sighem, A. I.; Smit, C.; Zhang, S.; Zaheri, S.; Bronsveld, W.; Hillebrand-Haverkort, M. E.; Prins, J. M.; Branger, J.; Eeftinck Schattenkerk, J. K. M.; Gisolf, J.; Godfried, M. H.; Lange, J. M. A.; Lettinga, K. D.; van der Meer, J. T. M.; Nellen, F. J. B.; van der Poll, T.; Reiss, P.; Ruys, Th A.; Steingrover, R.; van Twillert, G.; Vermeulen, J. N.; Vrouenraets, S. M. E.; van Vugt, M.; Wit, F. W. M. N.; Kuijpers, T. W.; Pajkrt, D.; Scherpbier, H. J.; van Eeden, A.; Brinkman, K.; van den Berk, G. E. L.; Blok, W. L.; Frissen, P. H. J.; Roos, J. C.; Schouten, W. E. M.; Bekendam, D. J.; Weigel, H. M.; Mulder, J. W.; van Gorp, E. C. M.; Wagenaar, J.; Veenstra, J.; Danner, S. A.; van Agtmael, M. A.; Claessen, F. A. P.

    2011-01-01

    In the Netherlands, a non-selective opt-out instead of a selective opt-in antenatal HIV screening strategy was implemented in 2004. In case of infection, screening was followed by prevention of mother-to-child-transmission (PMTCT). We compared the performance of the two strategies in terms of

  19. A Cross-National Comparison of School Students' Perceptions Regarding High Performing Peers

    Directory of Open Access Journals (Sweden)

    Hyerim Oh

    2014-06-01

    Full Text Available This cross-national scenario based study exam-ined fourth-grade students’ perceptions of high-performing classmates in terms of their ex-pected intellectual abilities, positive social qual-ities and popularity among their peers across seven countries. The overall results show that high academic achievements predominantly lead to positive expectations within the peer group. However, pronounced differences were found between the countries. The results indi-cated that students from Spanish-speaking countries viewed their potential high-perform-ing peers most favorably, followed by students from Australia, the United Kingdom and Ger-many. The least favorable expectations, but by no means negative attitude, were exhibited by students from the two East-Asian countries Ko-rea and Vietnam. In contrast, the respondents’ gender and the gender of the hypothetical suc-cessful classmates had less influence on student perceptions of high-performers. These findings have implications for the educational provision of high performing students in different cross-national contexts.

  20. Comparison of the effect of semi-rigid ankle bracing on performance ...

    African Journals Online (AJOL)

    Objective. To determine the comparative proprioceptive performance of injured v. non-injured adolescent female hockey players wearing an ankle brace. Methods. Data were collected from 100 high school players who belonged to the Highway Secondary School Hockey League, KwaZulu- Natal, via voluntary parental ...

  1. International comparisons of health system performance among OECD countries: opportunities and data privacy protection challenges

    NARCIS (Netherlands)

    Oderkirk, Jillian; Ronchi, Elettra; Klazinga, Niek

    2013-01-01

    Health data constitute a significant resource in most OECD countries that could be used to improve health system performance. Well-intended policies to allay concerns about breaches of confidentiality and to reduce potential misuse of personal health information may be limiting data use. A survey of

  2. Comparison of the effects of active, passive and mixed warm ups on swimming performance.

    Science.gov (United States)

    Adams, S; Psycharakis, S G

    2014-10-01

    The aim of this paper was to compare the effects of an active (AWU), passive (PWU) and mixed warm up (MWU) on swimming performance. Eight male competitive swimmers completed each type of WU and, following a 20-minute rest, performed a maximum 100m test on their specialised stroke. The order of WUs was randomized and there was a 7-day period between subsequent testing sessions. The time taken to complete the 100m trial was the performance measure. The rating of perceived exertion (RPE) was measured immediately post WU, while heart rate (HR) was measured pre and post WU and pre and post the maximum swim. During the 20-minute rest, the swimmers' psychological state was assessed with the CSAI-2 questionnaire. Post WU HR and RPE had the lowest values following the AWU and the highest values following the PWU (Pperformance HR increased significantly relative to pre WU HR for all conditions (P≤0.01). Swimmers had relatively low levels of anxiety and modest to high levels of self confidence for all conditions. No WU appeared to be superior to the others with respect to swimming performance. The MWU produced nearly identical values to the AWU for most variables, and was therefore found to be an appropriate alternative WU type that swimmers may use before competition. The PWU also seemed to be appropriate, but the somewhat worse performance and lower cognitive anxiety and self confidence scores recorded, albeit non-significant, suggested that more swimmers and distances are tested before any firm conclusions regarding its effectiveness can be drawn.

  3. Work Functioning Among Firefighters: A Comparison Between Self-Reported Limitations and Functional Task Performance.

    Science.gov (United States)

    MacDermid, Joy C; Tang, Kenneth; Sinden, Kathryn E; D'Amico, Robert

    2018-05-25

    Purpose Performance-based and disease indicators have been widely studied in firefighters; self-reported work role limitations have not. The aim of this study was to describe the distributions and correlations of a generic self-reported Work Limitations Questionnaire (WLQ-26) and firefighting-specific task performance-based tests. Methods Active firefighters from the City of Hamilton Fire Services (n = 293) were recruited. Participants completed the WLQ-26 to quantify on-the-job difficulties over five work domains: work scheduling (4 items), output demands (7 items), physical demands (8 items), mental demands (4 items), and social demands (3 items). A subset of participants (n = 149) were also assessed on hose drag and stair climb with a high-rise pack performance-based tests. Descriptive statistics and correlations were used to compare item/subscale performance; and to describe the inter-relationships between tests. Results The mean WLQ-26 item scores (/5) ranged from 4.1 to 4.4 (median = 5 for all items); most firefighters (54.5-80.5%) selected "difficult none of the time" response option on all items. A substantial ceiling effect was observed across all five WLQ-26 subscales as 44.0-55.6% were in the highest category. Subscale means ranged from 61.8 (social demands) to 78.7 (output demands and physical demands). Internal consistency exceeded 0.90 on all subscales. For the hose drag task, the mean time-to-completion was 48.0 s (SD = 14.5; range 20.4-95.0). For the stair climb task, the mean time-to-completion was 76.7 s (SD = 37.2; range 21.0-218.0). There were no significant correlations between self-report work limitations and performance of firefighting tasks. Conclusions The WLQ-26 measured five domains, but had ceiling effects in firefighters. Performance-based testing showed wider score range, lacked ceiling effects and did not correlate to the WLQ-26. A firefighter-specific, self-report role functioning scale may be needed to identify

  4. Comparison of Performance of the VIP and WMT in a Criminal Forensic Sample.

    Science.gov (United States)

    Fazio, Rachel L; Denney, Robert L

    2018-01-24

    To compare the efficacy of the Validity Indicator Profile (VIP) and Word Memory Test (WMT) in a criminal forensic population. Potential participants included 225 male evaluees from a maximum-security Federal prison referred for neuropsychological evaluation for either forensic purposes or for suspected neurocognitive dysfunction as part of a medical evaluation. Examinees were included in the analysis if administered the VIP (Verbal, Nonverbal, or both tests) and WMT along with at least two other freestanding PVTs; 74 satisfied these criteria. Participants were then categorized as having probable Malingered Neurocognitive Dysfunction (+MND) if they failed at least two freestanding validity indicators, negative for MND (-MND) if they passed all indicators, and Possible MND (pMND) if they failed one indicator. Groups were very demographically similar. There were significant differences in WMT scores and distribution of VIP profiles across groups. Whether using traditional or investigative cut scores, and whether using the WMT with or without consideration of a GMIP profile, the WMT demonstrated superior sensitivity and specificity on nearly every comparison. The VIP, when interpreted in the traditional fashion, and the WMT with GMIP, both had more than adequate psychometric properties when used with criminal forensic evaluees, strengthening the body of literature supporting their use for these types of evaluations. Counting a positive on either of the VIP subtests as an indication of +MND improves the psychometric properties of the VIP slightly, although the WMT had the better overall classification accuracy. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Comparison of Multi-Tensor Diffusion Models' Performance for White Matter Integrity Estimation in Chronic Stroke

    Directory of Open Access Journals (Sweden)

    Olena G. Filatova

    2018-04-01

    Full Text Available Better insight into white matter (WM alterations after stroke onset could help to understand the underlying recovery mechanisms and improve future interventions. MR diffusion imaging enables to assess such changes. Our goal was to investigate the relation of WM diffusion characteristics derived from diffusion models of increasing complexity with the motor function of the upper limb. Moreover, we aimed to evaluate the variation of such characteristics across different WM structures of chronic stroke patients in comparison to healthy subjects. Subjects were scanned with a two b-value diffusion-weighted MRI protocol to exploit multiple diffusion models: single tensor, single tensor with isotropic compartment, bi-tensor model, bi-tensor with isotropic compartment. From each model we derived the mean tract fractional anisotropy (FA, mean (MD, radial (RD and axial (AD diffusivities outside the lesion site based on a WM tracts atlas. Asymmetry of these measures was correlated with the Fugl-Meyer upper extremity assessment (FMA score and compared between patient and control groups. Eighteen chronic stroke patients and eight age-matched healthy individuals participated in the study. Significant correlation of the outcome measures with the clinical scores of stroke recovery was found. The lowest correlation of the corticospinal tract FAasymmetry and FMA was with the single tensor model (r = −0.3, p = 0.2 whereas the other models reported results in the range of r = −0.79 ÷ −0.81 and p = 4E-5 ÷ 8E-5. The corticospinal tract and superior longitudinal fasciculus showed most alterations in our patient group relative to controls. Multiple compartment models yielded superior correlation of the diffusion measures and FMA compared to the single tensor model.

  6. Comparison the performance of different catalysts in chemical modification of Poplar wood with Glutaraldehyde

    Directory of Open Access Journals (Sweden)

    ندا اسماعیلی

    2016-12-01

    Full Text Available In this study, the effect of different catalysts on chemical modification of poplar wood and physical properties of the resulting product was evaluated. 12.5% HCl and water soluble salts containing ZnCl2, CaCl2, AlCl3, MgCl2 (based on the weight of glutaraldehyde and 1% Al2O3, SiO2 and ZnO nano particles (based on the weight of glutaraldehyde were used. After heating in oven for 48 hour, modification with glutaraldehyde and MgCl2, ZnO nano particles, SiO2, Al2O3, ZnCl2, AlCl3, CaCl2 and HCl as catalysts were resulted to 14.5, 12.57, 10.62, 8.69, 8.51, 7.19, 5.97 and 5.41 % weight gain respectively. After 24h soaking in water, the physical properties of modified specimens, such as water absorption, volume swelling and ASE were measured. The highest and lowest bulking were calculated for Mgcl2 and Hcl catalysts with 6.98 and 2.37% respectively. The modification in presence of Mgcl2 catalyst was shown highest increase of density with average of 0.55 g/cm3. The highest and lowest water absorption was measured 79.61 and 45.32% in the modification with HCl and MgCl catalysts. Hcl with acidic quality, can break ether bonds in hemiacetal and even acetal structure. Modification with MgCl2 was shown best result in comparison with other catalysts. It is likely that the formation a complex of magnesium with oxygen, could resulted to activate carbonyl groups in glutaraldehyde and created the crosslink.

  7. Performance of Dutch children on the Bayley III: a comparison study of US and Dutch norms.

    Directory of Open Access Journals (Sweden)

    Leonie J P Steenis

    Full Text Available The Bayley Scales of Infant and Toddler Development-third edition (Bayley-III are frequently used to assess early child development worldwide. However, the original standardization only included US children, and it is still unclear whether or not these norms are adequate for use in other populations. Recently, norms for the Dutch version of the Bayley-III (The Bayley-III-NL were made. Scores based on Dutch and US norms were compared to study the need for population-specific norms.Scaled scores based on Dutch and US norms were compared for 1912 children between 14 days and 42 months 14 days. Next, the proportions of children scoring < 1-SD and < -2 SD based on the two norms were compared, to identify over- or under-referral for developmental delay resulting from non-population-based norms.Scaled scores based on Dutch norms fluctuated around values based on US norms on all subtests. The extent of the deviations differed across ages and subtests. Differences in means were significant across all five subtests (p < .01 with small to large effect sizes (ηp2 ranging from .03 to .26. Using the US instead of Dutch norms resulted in over-referral regarding gross motor skills, and under-referral regarding cognitive, receptive communication, expressive communication, and fine motor skills.The Dutch norms differ from the US norms for all subtests and these differences are clinically relevant. Population specific norms are needed to identify children with low scores for referral and intervention, and to facilitate international comparisons of population data.

  8. Comparison Between Different Teaching Methods to Increase Performance of Students in Biochemistry

    Directory of Open Access Journals (Sweden)

    Mrinal Pal

    2014-08-01

    RESULTS: The results of the study showed that as per the subjective assessment of the lectures concern, students preferred PPT teaching the most. As far as the students and #8217; performance was concerned the impact of traditional Chalk and Talk teaching was more than the lectures using transparency and overhead projector (TOHP and PowerPoint presentations (PPT. But when supplementing chalkboard with PPT or TOHP, the enhancement of the student and #8217;s preference and performance was much better. This fact was true about teacher and #8217;s preference also. CONCLUSION: This observation may probably be due to the fact that, inherent deficiency of each teaching aid was compensated by the other. With regard to teaching method, the combination of teaching methods was more effective when compared to didactic lectures. [TAF Prev Med Bull 2014; 13(4.000: 281-288

  9. Experimental comparison of MCFC performance using three different biogas types and methane

    Science.gov (United States)

    Bove, Roberto; Lunghi, Piero

    Biogas recovery is an environmentally friendly and cost-effective practice that is getting consensus in both the scientific and industrial community, as the growing number of projects demonstrate. The use of fuel cells as energy conversion systems increases the conversion efficiency, as well as the environmental benefits. Molten carbonate fuel cells (MCFC) operate at a temperature of about 650 °C, thus presenting a high fuel flexibility, compared to low temperature fuel cells. Aim of the present study is to compare the performance of an MCFC single cell, fuelled with different biogas types as well as methane. The biogases considered are derived from the following processes: (1) steam gasification in an entrained flow gasifier; (2) steam gasification in a duel interconnect fluidized bed gasifier; (3) biogas from an anaerobic digestion process. The performances are evaluated for different fuel utilization and current densities. The results are an essential starting point for a complete system design and demonstration.

  10. Comparison of observer performance reading from a video CRT vs. reading from film

    International Nuclear Information System (INIS)

    Keyes, J.W. Jr.; Kline, R.C.; Resinger, W.W.; Rose, E.A.; Koral, K.F.; Rogers, W.L.

    1983-01-01

    The developing trend for all medical images to be in digital form raises an important question: should diagnostic interpretations be made directly from a CRT or from some form of hard copy recording of the CRT. This question was studied by having two observers read a series of digital images of the thyroid including both conventional scintigrams and computer-generated tomograms. The CRT images were photographed in a carefully controlled fashion. Images were read once from film and a second time directly from the CRT. No significant difference in performance could be found for either display modality based on an ROC analysis. Although based on uncomplicated images and analysis, this result suggests that the decision to read from film or from the CRT can be made on other grounds than observer performance. This important result needs confirmation with more complex images such as ultrasound or CT

  11. Acute comparison of clovoxamine and mianserin, alone and in combination with ethanol, on human psychomotor performance.

    Science.gov (United States)

    Strömberg, C; Mattila, M J

    1987-05-01

    Objective and subjective effects on human performance of clovoxamine and mianserin were measured in 12 student volunteers who participated in 12 test sessions and received single doses of clovoxamine 50 mg, 100 mg and 150 mg, mianserin 20 mg, and placebo in a double-blind and cross-over manner. Each test drug was given twice, both in combination with alcohol 0.8 g/kg and with a non-alcoholic drink. The tests included tracking, body balance, flicker fusion, horizontal nystagmus, digit symbol substitution, recall memory, and subjective assessments on visual analogue scales. Mianserin and alcohol impaired objective performance in most tests, and their combination showed at least an additive effect. Alcohol counteracted rather than increased mianserin-induced subjective sedation. Clovoxamine neither differed significantly from placebo nor increased alcohol effects. On the contrary, clovoxamine 150 mg reduced significantly alcohol-induced body sway. No evidence of pharmacokinetic interactions were found between the study drugs and alcohol.

  12. A comparison of performances of consultant surgeons, NCHDs and medical students in a modified HPAT examination.

    LENUS (Irish Health Repository)

    Quinn, A

    2010-06-01

    Following the implementation of the Fottrell report, entry to medical school in Ireland has undergone significant change. Medical school studentship is now awarded based on a combination of points obtained from the final examination of Irish secondary schools (the leaving certificate) combined with HPAT scores (Health Professions Admissions Test). The HPAT is designed to test a candidate\\'s knowledge in several different fields including problem solving skills, logical and non verbal reasoning. A sample HPAT was administered to a test group composed of consultant surgeons, non consultant hospital doctors, and medical students. Statistical analysis was performed and no significant difference was found between the performances of the groups. This is surprising as it was expected that groups with greater experience at medical problem solving would have translated to higher scores. This exposes a flaw within the HPAT system and a potential weakness in the process of doctor selection.

  13. Comparison of Performance, Meat Lipids and Oxidative Status of Pigs from Commercial Breed and Organic Crossbreed

    Directory of Open Access Journals (Sweden)

    Giuseppe Martino

    2014-06-01

    Full Text Available The aim of this research was to determine the effect of rearing systems for pig production, as concerns performance, meat lipid content, the fatty acid profile, histidinic antioxidants, coenzyme Q10, and TBARs. One hundred pigs were assigned to one of three treatments: intensively reared commercial hybrid pig (I, free range commercial hybrid pig (FR or organically reared crossbred pig (O, according to organic EU Regulations. I pigs showed the best productive performance, but FR and O increased: C20:1n9, Δ9-desaturase (C18 and thioesterase indices in meat. Lipid, dipeptides and CoQ10 appeared correlated to glycolytic and oxidative metabolic pathways. We can conclude that all studied parameters were influenced by the rearing system used, and that differences were particularly evident in the O system, which produced leaner meat with higher oxidative stability. In this respect, the organic pig rearing system promotes and enhances biodiversity, environmental sustainability and food quality.

  14. Comparison of performance coatings thermally sprayed subject to testing adhesive wear

    International Nuclear Information System (INIS)

    Marangoni, G.F.; Arnt, A.B.C.; Rocha, M.R. da

    2014-01-01

    In this work, the microstructural changes and wear resistance adhesive coatings obtained from powders thermally sprayed by high velocity oxy-fuel (HVOF) were evaluated. Based coatings chrome-nickel and tungsten-cobalt are applied in conditions subject to intense wear especially abrasive. With the aim of evaluate the performance of these coatings under conditions of adhesive wear, these coatings samples were tested by the standard ASTM G99. As test parameters were used: Tungsten carbide pin (SAE 52100) with 6 mm diameter, normal load of 50N and a tangential velocity of 0.5 m / s. The worn surfaces of the coatings were characterized by optical and scanning electron microscopy and X-ray diffraction. Results indicate that the performance front wear is related to the conditions of adhesion and uniformity of the coating applied. (author)

  15. Comparison of Refractory Performance in Black Liquor Gasifiers and a Smelt Test System

    International Nuclear Information System (INIS)

    Peascoe, RA

    2001-01-01

    Prior laboratory corrosion studies along with experience at the black liquor gasifier in New Bern, North Carolina, clearly demonstrate that serious material problems exist with the gasifier's refractory lining. Mullite-based and alumina-based refractories used at the New Bern facility suffered significant degradation even though they reportedly performed adequately in smaller scale systems. Oak Ridge National Laboratory's involvement in the failure analysis, and the initial exploration of suitable replacement materials, led to the realization that a simple and reliable, complementary method for refractory screening was needed. The development of a laboratory test system and its suitability for simulating the environment of black liquor gasifiers was undertaken. Identification and characterization of corrosion products were used to evaluate the test system as a rapid screening tool for refractory performance and as a predictor of refractory lifetime. Results from the test systems and pl ants were qualitatively similar

  16. Performance comparison of a wdm pon with tdm pon at 10 gbps

    International Nuclear Information System (INIS)

    Usman, M.

    2014-01-01

    Recent developments in optical technologies have realized wavelength division multiplexed passive optical network (WDM PON) as a promising and a cost-effective solution for the next generation networks. Due to the intrinsic optical transparency and extremely high transmission capacity, WDM PON is considered more future oriented than conventional TDM PON. In this paper we compare an eight channel WDM PON with an eight channel TDM PON, both operating at 10 Gbps data rate. Network parameters like input laser power, optical fiber length and optical amplifier gain are varied and their impact on performance parameters i.e. Q-factor, BER, OSNR, Eye opening and Extinction ratio penalty is recorded. Results reveal that WDM PON exhibits superior performance than TDM PON in each case. (author)

  17. Performance Comparison Of Triangle Antenna of 60 GHz for 5G Wireless Communication Network

    Directory of Open Access Journals (Sweden)

    Aishah A.S.

    2017-01-01

    Full Text Available In this paper microstrip triangle with slot antenna for 5G wireless communication network are proposed. The microstip triangle antenna is design and operating 60 GHz milimeter-wave frequency band and it's suitable for 5G wireless communication. The substrates are chosen in the design, which are RogerRT5880 with copper thickness 0.035 mm to analyze their effect toward milimeter-wave performance on the designed. The designed and analysis is performed by using CST Microwave Studio. The lowest return loss of the antenna is -24.75dB which is triangle with slot and the maximum gain obtained is 6.82 db at the 59.68GHz for this antenna. The antenna is considering the gain, return loss and size, the microstrip antenna can be a suitable candidate for the 5G wireless application for short range high speed communication.

  18. Comparison of Taxi Time Prediction Performance Using Different Taxi Speed Decision Trees

    Science.gov (United States)

    Lee, Hanbong

    2017-01-01

    In the STBO modeler and tactical surface scheduler for ATD-2 project, taxi speed decision trees are used to calculate the unimpeded taxi times of flights taxiing on the airport surface. The initial taxi speed values in these decision trees did not show good prediction accuracy of taxi times. Using the more recent, reliable surveillance data, new taxi speed values in ramp area and movement area were computed. Before integrating these values into the STBO system, we performed test runs using live data from Charlotte airport, with different taxi speed settings: 1) initial taxi speed values and 2) new ones. Taxi time prediction performance was evaluated by comparing various metrics. The results show that the new taxi speed decision trees can calculate the unimpeded taxi-out times more accurately.

  19. Performance comparison for modes of operation and suppression cases of the clover detector

    International Nuclear Information System (INIS)

    Kshetri, R

    2014-01-01

    Peak-to-total ratios have been extracted for a segmented clover detector for various modes of operation and suppression cases. Based on absorption and scattering of gamma-rays, a formalism has been presented for quantifying the advantages of using addback mode and active suppression. Further investigations have been performed to find if the reduction of background counts is caused more by active suppression or by addback process

  20. A comparison of the effect of mobile phone use and alcohol consumption on driving simulation performance.

    Science.gov (United States)

    Leung, Sumie; Croft, Rodney J; Jackson, Melinda L; Howard, Mark E; McKenzie, Raymond J

    2012-01-01

    The present study compared the effects of a variety of mobile phone usage conditions to different levels of alcohol intoxication on simulated driving performance and psychomotor vigilance. Twelve healthy volunteers participated in a crossover design in which each participant completed a simulated driving task on 2 days, separated by a 1-week washout period. On the mobile phone day, participants performed the simulated driving task under each of 4 conditions: no phone usage, a hands-free naturalistic conversation, a hands-free cognitively demanding conversation, and texting. On the alcohol day, participants performed the simulated driving task at four different blood alcohol concentration (BAC) levels: 0.00, 0.04, 0.07, and 0.10. Driving performance was assessed by variables including time within target speed range, time spent speeding, braking reaction time, speed deviation, and lateral lane position deviation. In the BAC 0.07 and 0.10 alcohol conditions, participants spent less time in the target speed range and more time speeding and took longer to brake in the BAC 0.04, 0.07, and 0.10 than in the BAC 0.00 condition. In the mobile phone condition, participants took longer to brake in the natural hands-free conversation, cognitively demanding hands-free conversation and texting conditions and spent less time in the target speed range and more time speeding in the cognitively demanding, hands-free conversation, and texting conditions. When comparing the 2 conditions, the naturalistic conversation was comparable to the legally permissible BAC level (0.04), and the cognitively demanding and texting conversations were similar to the BAC 0.07 to 0.10 results. The findings of the current laboratory study suggest that very simple conversations on a mobile phone may not represent a significant driving risk (compared to legally permissible BAC levels), whereas cognitively demanding, hands-free conversation, and particularly texting represent significant risks to driving.

  1. Comparison of differences in performance evaluation of faculty by students with faculty's self-assessment.

    Science.gov (United States)

    Azizi, Kourosh; Aghamolaei, Teamur; Parsa, Nader; Dabbaghmanesh, Tahereh

    2014-07-01

    The present study aimed to compare self-assessment forms of coursework taught in the school of public health at undergraduate, graduate, and postgraduate levels and students' evaluation of the performance of the faculty members at these levels. The subjects in this cross-sectional study were the faculty members and students of the School of Public Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran. The data were collected using a socio-demographic information form and evaluation forms of professors prepared by the Educational Development Center (EDC). The faculty members were assessed by the students in undergraduate and graduate classes. Among the study subjects, 23 faculty members filled out the self-assessment forms which were then evaluated by 23 students. Then, the data were analyzed using the SPSS statistical 14. Paired t-test was used to compare the students' evaluation of the faculty members' performance and the professors' self-assessment. The mean score of self-assessment of the faculty members who taught undergraduate courses was 289.7±8.3, while that of the students' evaluation was 281.3±16.1; the difference was statistically significant (t=3.56, p=0.001). Besides, the mean score of the self-assessment of the faculty members who taught graduate courses was 269.0±9.7, while that of the students' evaluation was 265.7±14.6 but the difference was not statistically significant (t=1.09, p=0.28). Teaching performance perceptions of the faculty were similar to those of the graduate students as compared to the undergraduate ones. This may reflect better understanding of coursework at this level compared to the undergraduate students. Faculty members may need to adjust teaching methods to improve students' performance and understanding especially in the undergraduate level.

  2. Loose and Tight GNSS/INS Integrations: Comparison of Performance Assessed in Real Urban Scenarios

    OpenAIRE

    Falco, Gianluca; Pini, Marco; Marucco, Gianluca

    2017-01-01

    Global Navigation Satellite Systems (GNSSs) remain the principal mean of positioning in many applications and systems, but in several types of environment, the performance of standalone receivers is degraded. Although many works show the benefits of the integration between GNSS and Inertial Navigation Systems (INSs), tightly-coupled architectures are mainly implemented in professional devices and are based on high-grade Inertial Measurement Units (IMUs). This paper investigates the performanc...

  3. Performance Comparison of the Optimized Inverted Joined Wing Airplane Concept and Classical Configuration Airplanes

    OpenAIRE

    Sieradzki Adam; Dziubiński Adam; Galiński Cezary

    2016-01-01

    The joined wing concept is an unconventional airplane configuration, known since the mid-twenties of the last century. It has several possible advantages, like reduction of the induced drag and weight due to the closed wing concept. The inverted joined wing variant is its rarely considered version, with the front wing being situated above the aft wing. The following paper presents a performance prediction of the recently optimized configuration of this airplane. Flight characteristics obtaine...

  4. MHD stability of JET high performance discharges. Comparison of MHD calculations with experimental observations

    International Nuclear Information System (INIS)

    Huysmans, G.

    1998-03-01

    One of the aims of the JET, the Joint European Torus, project is to optimise the maximum fusion performance as measured by the neutron rate. At present, two different scenarios are developed at JET to achieve the high performance the so-called Hot-Ion H-mode scenario and the more recent development of the Optimised Shear scenario. Both scenarios have reached similar values of the neutron rate in Deuterium plasmas, up to 5 10 17 neutrons/second. Both scenarios are characterised by a transport barrier, i.e., a region in the plasma where the confinement is improved. The Hot-Ion H-mode has a transport barrier at the plasma boundary just inside the separatrix, an Optimised Shear plasma exhibits a transport barrier at about mid radius. Associated with the improved confinement of the transport barriers are locally large pressure gradients. It is these pressure gradients which, either directly or indirectly, can drive MHD instabilities. The instabilities limit the maximum performance. In the optimised shear scenario a global MHD instability leads to a disruptive end of the discharge. In the Hot-Ion H-mode plasmas, so-called Outer Modes can occur which are localised at the plasma boundary and lead to a saturation of the plasma performance. In this paper, two examples of the MHD instabilities are discussed and identified by comparing the experimentally observed modes with theoretical calculations from the ideal MHD code MISHKA-1. Also, the MHD stability boundaries of the two scenarios are presented. Section 3 contains a discussion of the mode observed just before the disruption

  5. Comparison of Individual Performance in Intelligence Tests WAIS III and RPM (Raven's Progressive Matrices)

    OpenAIRE

    Petrů, Vít

    2017-01-01

    This thesis deals with replacement of performative scale of Wechsler Adult Intelligence Scale (3rd revision) through Raven's Standard Progressive Matrices and Advanced Progressive Matrices. In the theoretical part introduces the concepts of intelligence, approaches to its exploration and intelligence tests. The theoretical part is also devoted to the description of the used methods and presents an overview of the research on a similar theme as this work. In the empirical part of the thesis is...

  6. Performance Comparison of Assorted Color Spaces for Multilevel Block Truncation Coding based Face Recognition

    OpenAIRE

    H.B. Kekre; Sudeep Thepade; Karan Dhamejani; Sanchit Khandelwal; Adnan Azmi

    2012-01-01

    The paper presents a performance analysis of Multilevel Block Truncation Coding based Face Recognition among widely used color spaces. In [1], Multilevel Block Truncation Coding was applied on the RGB color space up to four levels for face recognition. Better results were obtained when the proposed technique was implemented using Kekre’s LUV (K’LUV) color space [25]. This was the motivation to test the proposed technique using assorted color spaces. For experimental analysis, two face databas...

  7. Comparison of performance between Raw SQL and Eloquent ORM in Laravel

    OpenAIRE

    Jound, Ishaq; Halimi, Hamed

    2016-01-01

    Context. PHP framework Laravel offers three techniques to interact with databases, Eloquent ORM, Query builder and Raw SQL. It is important to select the right database technique when developing a web application because there are pros and cons with each approach.  Objectives. In this thesis we will measure the performance of Raw SQL and Eloquent ORM, there is little research on which technique is faster. Intuitively, Raw SQL should be faster than Eloquent ORM, but exactly how much faster nee...

  8. Performance of sustainable investments : a comparison of sustainable and conventional mutual funds in emerging markets

    OpenAIRE

    Christensson, Lars Stefan Bjerke; Skagestad, Ole Jakob

    2017-01-01

    This thesis compares the performance and risk factor exposure of sustainable and conventional mutual funds in emerging markets from January 2012 to July 2017. We use the latest sustainability ratings provided by Morningstar to define sustainable funds, and apply CAPM, Fama-French and Carhart models to control for the market, size, book-to-market and momentum factors. Additionally, we add a dummy to compare the risk-adjusted returns of the funds, and examine if the difference is...

  9. Seismic Performance Comparison of a High-Content SDA Frame and Standard RC Frame

    OpenAIRE

    van de Lindt, John W.; Rechan, R. Karthik

    2011-01-01

    This study presents the method and results of an experiment to study the seismic behavior of a concrete portal frame with fifty percent of its cement content replaced with a spray dryer ash (SDA). Based on multiple-shake-table tests, the high content SDA frame was found to perform as well as the standard concrete frame for two earthquakes exceeding design-level intensity earthquakes. Hence, from a purely seismic/structural standpoint, it may be possible to replace approximately fifty percen...

  10. A comparison of three interventions for increasing oral reading performance: Application of the instructional hierarchy

    OpenAIRE

    Daly, Edward J.; Martens, Brian K.

    1994-01-01

    The instructional hierarchy is a behavior-analytic model that links level of academic skill development (i.e., acquisition, fluency, generalization, adaptation) with appropriate instructional techniques. The present study used the instructional hierarchy to compare the effects of three instructional interventions (listening passage preview, subject passage preview, and taped words) on subjects' oral reading performance on word lists and passages. Subjects were 4 male students with learning di...

  11. Performance comparison of air-source heat pump water heater with different expansion devices

    International Nuclear Information System (INIS)

    Peng, Jing-Wei; Li, Hui; Zhang, Chun-Lu

    2016-01-01

    Highlights: • An air-source heat pump water heater model was developed and validated. • System performance with EEV, capillary tube or short tube orifice were compared. • Short tube orifice is more suitable for heat pump water heater than capillary tube. - Abstract: Air source heat pump water heater (ASHPWH) is designed to work under wide operating conditions. Therefore, both the system and components require higher reliability and stability than ordinary heat pump air-conditioning systems. In this paper, a quasi-steady-state system model of ASHPWH using electronic expansion valve (EEV), capillary tube or short tube orifice as expansion device is developed and validated by a prototype using R134a and scroll compressor, by which the system performance is evaluated and compared at varying water temperature and different ambient temperature. Flow characteristics of those three expansion devices in ASHPWH are comparatively analyzed. Results show that the EEV throttling system performs best. Compared with capillary tube, flow characteristics of short tube orifice are closer to that of EEV and therefore more suitable for ASHPWH. Reliability concern of liquid carryover to the compressor in the system using short tube orifice is investigated as well. Higher superheat or less system refrigerant charge could help mitigate the risk.

  12. Comparison of patient doses in interventional radiology procedures performed in two large hospitals in Greece

    International Nuclear Information System (INIS)

    Papageorgiou, E.; Tsapaki, V.; Tsalafoutas, I. A.; Maurikou, E.; Kottou, S.; Orfanos, A.; Karidas, G.; Fidanis, T.; Zafiriadou, E.; Neofotistou, V.

    2007-01-01

    Purpose of the study was to determine patient doses in the most common interventional radiology (IR) procedures performed in two large Greek hospitals. A total of 164 patients who underwent 4 types of IR procedures were studied. Fluoroscopy time, total exposure time, number of frames, number of runs, radiation field size, and cumulative dose-area product (DAP) were recorded. The median DAP values for carotid arteriography and lower limb arteriography were 66 and 123 Gy cm 2 for hospital 'A' and 21 and 49 Gy cm 2 for hospital 'B'. For the cerebral arteriographies performed in hospital 'A', the median DAP was 116 Gy cm 2 while for the hepatic embolizations performed in hospital 'B', it was 104 Gy cm 2 . The DAP values observed in hospital 'A' for carotid arteriography and lower limb arteriography were almost three times than those of hospital 'B'. From the data analysis, it is evident that dose optimization in hospital 'A' should be pursued through revision of the techniques used. (authors)

  13. Comparison between the performance of some KEK-klystrons and simulation results

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Shigeki [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1997-04-01

    Recent developments of various klystron simulation codes have enabled us to realistically design klystrons. This paper presents various simulation results using the FCI code and the performances of tubes manufactured based on this code. Upgrading a 30-MW S-band klystron and developing a 50-MW S-band klystron for the KEKB projects are successful examples based on FCI-code predictions. Mass-productions of these tubes have already started. On the other hand, a discrepancy has been found between the FCI simulation results and the performance of real tubes. In some cases, the simulation results lead to high-efficiency results, while manufactured tubes show the usual value, or a lower value, of the efficiency. One possible cause may come from a data mismatch between the electron-gun simulation and the input data set of the FCI code for the gun region. This kind of discrepancy has been observed in 30-MW S-band pulsed tubes, sub-booster pulsed tubes and L-band high-duty pulsed klystrons. Sometimes, JPNDSK (one-dimensional disk-model code) gives similar results. Some examples using the FCI code are given in this article. An Arsenal-MSU code could be applied to the 50-MW klystron under collaboration with Moscow State University; a good agreement has been found between the prediction of the code and performance. (author)

  14. A comparison of back propagation and Generalized Regression Neural Networks performance in neutron spectrometry.

    Science.gov (United States)

    Martínez-Blanco, Ma Del Rosario; Ornelas-Vargas, Gerardo; Solís-Sánchez, Luis Octavio; Castañeda-Miranada, Rodrigo; Vega-Carrillo, Héctor René; Celaya-Padilla, José M; Garza-Veloz, Idalia; Martínez-Fierro, Margarita; Ortiz-Rodríguez, José Manuel

    2016-11-01

    The process of unfolding the neutron energy spectrum has been subject of research for many years. Monte Carlo, iterative methods, the bayesian theory, the principle of maximum entropy are some of the methods used. The drawbacks associated with traditional unfolding procedures have motivated the research of complementary approaches. Back Propagation Neural Networks (BPNN), have been applied with success in neutron spectrometry and dosimetry domains, however, the structure and learning parameters are factors that highly impact in the networks performance. In ANN domain, Generalized Regression Neural Network (GRNN) is one of the simplest neural networks in term of network architecture and learning algorithm. The learning is instantaneous, requiring no time for training. Opposite to BPNN, a GRNN would be formed instantly with just a 1-pass training on the development data. In the network development phase, the only hurdle is to optimize the hyper-parameter, which is known as sigma, governing the smoothness of the network. The aim of this work was to compare the performance of BPNN and GRNN in the solution of the neutron spectrometry problem. From results obtained it can be observed that despite the very similar results, GRNN performs better than BPNN. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Performance comparison between silicon solar panel and dye-sensitized solar panel in Malaysia

    Science.gov (United States)

    Hamed, N. K. A.; Ahmad, M. K.; Urus, N. S. T.; Mohamad, F.; Nafarizal, N.; Ahmad, N.; Soon, C. F.; Ameruddin, A. S.; Faridah, A. B.; Shimomura, M.; Murakami, K.

    2017-09-01

    In carrying out experimental research in performance between silicon solar panel and dye-sensitive solar panel, we have been developing a device and a system. This system has been developed consisting of controllers, hardware and software. This system is capable to get most of the input sources. If only need to change the main circuit and coding for a different source input value. This device is able to get the ambient temperature, surface temperature, surrounding humidity, voltage with load, current with load, voltage without load and current without load and save the data into external memory. This device is able to withstand the heat and rain as it was fabricated in a waterproof box. This experiment was conducted to examine the performance of both the solar panels which are capable to maintain their stability and performance. A conclusion based on data populated, the distribution of data for dye-sensitized solar panel is much better than silicon solar panel as dye-sensitized solar panel is very sensitive to heat and not depend only on midday where is that is the maximum ambient temperature for both solar panel as silicon solar panel only can give maximum and high output only when midday.

  16. PERFORMANCE COMPARISON OF INTRUSION DETECTION SYSTEM USING VARIOUS TECHNIQUES – A REVIEW

    Directory of Open Access Journals (Sweden)

    S. Devaraju

    2013-09-01

    Full Text Available Nowadays, the security has become a critical part of any organization or industry information systems. The Intrusion Detection System is an effective method to deal with the new kind of threats such as DoS, Porbe, R2L and U2R. In this paper, we analyze the various approaches such as Hidden Semi Markov Model, Conditional Random Fields and Layered Approach, Bayesian classification, Data Mining techniques, Clustering Algorithms such as K-Means and Fuzzy c-Means, Back Propagation Neural Network, SOM Neural Network, Rough Set Neural Network Algorithm, Genetic Algorithm, Pattern Matching, Principle Component Analysis, Linear Discriminant Analysis, Independent Component Analysis, Multivariate Statistical Analysis, SOM/PSO algorithm etc. The performance is measured for two different datasets using various approaches. The datasets are trained and tested for identifying the new attacks that will affect the hosts or networks. The well known KDD Cup 1999 or DARPA 1999 dataset has been used to improve the accuracy and performance. The four groups of attacks are identified as Probe, DoS, U2R and R2L. The dataset used for training set is 494,021 and testing set is 311,028. The aim is to improve the detection rate and performance of the proposed system.

  17. Performance comparison of extracellular spike sorting algorithms for single-channel recordings.

    Science.gov (United States)

    Wild, Jiri; Prekopcsak, Zoltan; Sieger, Tomas; Novak, Daniel; Jech, Robert

    2012-01-30

    Proper classification of action potentials from extracellular recordings is essential for making an accurate study of neuronal behavior. Many spike sorting algorithms have been presented in the technical literature. However, no comparative analysis has hitherto been performed. In our study, three widely-used publicly-available spike sorting algorithms (WaveClus, KlustaKwik, OSort) were compared with regard to their parameter settings. The algorithms were evaluated using 112 artificial signals (publicly available online) with 2-9 different neurons and varying noise levels between 0.00 and 0.60. An optimization technique based on Adjusted Mutual Information was employed to find near-optimal parameter settings for a given artificial signal and algorithm. All three algorithms performed significantly better (psorting algorithm, receiving the best evaluation score for 60% of all signals. OSort operated at almost five times the speed of the other algorithms. In terms of accuracy, OSort performed significantly less well (palgorithms was optimal in general. The accuracy of the algorithms depended on proper choice of the algorithm parameters and also on specific properties of the examined signal. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Performance Comparison of the Optimized Inverted Joined Wing Airplane Concept and Classical Configuration Airplanes

    Directory of Open Access Journals (Sweden)

    Sieradzki Adam

    2016-09-01

    Full Text Available The joined wing concept is an unconventional airplane configuration, known since the mid-twenties of the last century. It has several possible advantages, like reduction of the induced drag and weight due to the closed wing concept. The inverted joined wing variant is its rarely considered version, with the front wing being situated above the aft wing. The following paper presents a performance prediction of the recently optimized configuration of this airplane. Flight characteristics obtained numerically were compared with the performance of two classical configuration airplanes of similar category. Their computational fluid dynamics (CFD models were created basing on available documentation, photographs and some inverse engineering methods. The analysis included simulations performed for a scale of 3-meter wingspan inverted joined wing demonstrator and also for real-scale manned airplanes. Therefore, the results of CFD calculations allowed us to assess the competitiveness of the presented concept, as compared to the most technologically advanced airplanes designed and manufactured to date. At the end of the paper, the areas where the inverted joined wing is better than conventional airplane were predicted and new research possibilities were described.

  19. Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

    Science.gov (United States)

    Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

    2018-04-01

    Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

  20. Performance comparison of low-temperature direct alcohol fuel cells with different anode catalysts

    Science.gov (United States)

    Zhou, W. J.; Zhou, B.; Li, W. Z.; Zhou, Z. H.; Song, S. Q.; Sun, G. Q.; Xin, Q.; Douvartzides, S.; Goula, M.; Tsiakaras, P.

    Low-temperature polymer electrolyte membrane fuel cells directly fed by methanol and ethanol were investigated employing carbon supported Pt, PtSn and PtRu as anode catalysts, respectively. Employing Pt/C as anode catalyst, both direct methanol fuel cell (DMFC) and direct ethanol fuel cell (DEFC) showed poor performances even in presence of high Pt loading on anode. It was found that the addition of Ru or Sn to the Pt dramatically enhances the electro-oxidation of both methanol and ethanol. It was also found that the single cell adopting PtRu/C as anode shows better DMFC performance, while PtSn/C catalyst shows better DEFC performance. The single fuel cell using PtSn/C as anode catalyst at 90 °C shows similar power densities whenever fueled by methanol or ethanol. The cyclic voltammetry (CV) and single fuel cell tests indicated that PtRu is more suitable for DMFC while PtSn is more suitable for DEFC.