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Sample records for pre ivc hydrogen-fueled

  1. Pre-operative renal artery embolization and suprarenal IVC filter placement for prevention of fat embolization in renal angiomyolipoma with venous extension.

    Science.gov (United States)

    Cornman-Homonoff, Joshua; Li, David; Schiffman, Marc

    2017-01-26

    Though generally considered benign, angiomyolipomas can invade through the renal vein into the inferior vena cava, putting patients at risk of catastrophic pulmonary fat embolization. Venous invasion is thus an indication for surgical resection but is thought to increase the risk of adverse operative outcomes including intraoperative hemorrhage and embolization of fat and/or tumor thrombus. We report a novel approach to mitigating these complications illustrated in the case of a 43-year-old woman with IVC-invasive renal AML who underwent successful radical nephrectomy after concurrent pre-operative renal artery embolization and placement of a retrievable suprarenal IVC filter.

  2. Hydrogen Fuel Quality

    Energy Technology Data Exchange (ETDEWEB)

    Rockward, Tommy [Los Alamos National Laboratory

    2012-07-16

    For the past 6 years, open discussions and/or meetings have been held and are still on-going with OEM, Hydrogen Suppliers, other test facilities from the North America Team and International collaborators regarding experimental results, fuel clean-up cost, modeling, and analytical techniques to help determine levels of constituents for the development of an international standard for hydrogen fuel quality (ISO TC197 WG-12). Significant progress has been made. The process for the fuel standard is entering final stages as a result of the technical accomplishments. The objectives are to: (1) Determine the allowable levels of hydrogen fuel contaminants in support of the development of science-based international standards for hydrogen fuel quality (ISO TC197 WG-12); and (2) Validate the ASTM test method for determining low levels of non-hydrogen constituents.

  3. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-01-21

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into a fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  4. DLA’s Hydrogen Fuel Cell Pilots

    Science.gov (United States)

    2009-05-07

    DLA’s Hydrogen Fuel Cell Pilots E2S2 Conference May 7, 2009 Rob Hardison LMI rhardison@lmi.org Report Documentation Page Form ApprovedOMB No. 0704...2009 to 00-00-2009 4. TITLE AND SUBTITLE DLA’s Hydrogen Fuel Cell Pilots 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...and fuel cells offer potential „green‟ solutions •DLA‟s efforts to measure and improve viability of fuel cells DoD is supporting long term solutions

  5. Water reactive hydrogen fuel cell power system

    Science.gov (United States)

    Wallace, Andrew P; Melack, John M; Lefenfeld, Michael

    2014-11-25

    A water reactive hydrogen fueled power system includes devices and methods to combine reactant fuel materials and aqueous solutions to generate hydrogen. The generated hydrogen is converted in a fuel cell to provide electricity. The water reactive hydrogen fueled power system includes a fuel cell, a water feed tray, and a fuel cartridge to generate power for portable power electronics. The removable fuel cartridge is encompassed by the water feed tray and fuel cell. The water feed tray is refillable with water by a user. The water is then transferred from the water feed tray into the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

  6. The DDO IVC Distance Project

    CERN Document Server

    Gladders, M D; Burns, C R; Attard, A; Casey, M P; Hamilton, D; Mallén-Ornelas, G; Karr, J L; Poirier, S M; Sawicki, M; Barrientos, F; Barkhouse, W A; Brodwin, M; Clark, J; McNaughton, R; Ruetalo-Pacheco, M; Mochnacki, S W; Gladders, Michael D.; Clarke, Tracy E.; Burns, Christopher R.; Attard, Allen; Casey, Michael P.; Hamilton, Devon; Mallen-Ornelas, Gabriela; Karr, Jennifer L.; Poirier, Sara M.; Sawicki, Marcin; Barrientos, Felipe; Barkhouse, Wayne; Brodwin, Mark; Clark, Jason; Naughton, Rosemary Mc; Ruetalo-Pacheco, Marcelo; Mochnacki, Stefan W.

    1998-01-01

    We present the first set of distance limits from the David Dunlap Observatory Intermediate Velocity Cloud (DDO IVC) distance project. Such distance measures are crucial to understanding the origins and dynamics of IVCs, as the distances set most of the basic physical parameters for the clouds. Currently there are very few IVCs with reliably known distances. This paper describes in some detail the basic techniques used to measure distances, with particular emphasis on the the analysis of interstellar absorption line data, which forms the basis of our distance determinations. As an example, we provide a detailed description of our distance determination for the Draco Cloud. Preliminary distance limits for a total of eleven clouds are provided.

  7. National FCEV and Hydrogen Fueling Station Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian; Melaina, Marc

    2016-06-09

    This presentation provides a summary of the FY16 activities and accomplishments for NREL's national fuel cell electric vehicle (FCEV) and hydrogen fueling station scenarios project. It was presented at the U.S. Department of Energy Hydrogen and Fuel Cells Program 2016 Annual Merit Review and Peer Evaluation Meeting on June 9, 2016, in Washington, D.C.

  8. Hydrogen Fuel Cells: Part of the Solution

    Science.gov (United States)

    Busby, Joe R.; Altork, Linh Nguyen

    2010-01-01

    With the decreasing availability of oil and the perpetual dependence on foreign-controlled resources, many people around the world are beginning to insist on alternative fuel sources. Hydrogen fuel cell technology is one answer to this demand. Although modern fuel cell technology has existed for over a century, the technology is only now becoming…

  9. Hydrogen Fuel Cells: Part of the Solution

    Science.gov (United States)

    Busby, Joe R.; Altork, Linh Nguyen

    2010-01-01

    With the decreasing availability of oil and the perpetual dependence on foreign-controlled resources, many people around the world are beginning to insist on alternative fuel sources. Hydrogen fuel cell technology is one answer to this demand. Although modern fuel cell technology has existed for over a century, the technology is only now becoming…

  10. Fundamentals: IVC and Computer Science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Gerhard J.; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    The working group on “Fundamentals: IVC and Computer Science‿ discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  11. Fundamentals: IVC and Computer Science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Gerhard J.; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    2013-01-01

    The working group on “Fundamentals: IVC and Computer Science‿ discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  12. Fundamentals: IVC and computer science

    NARCIS (Netherlands)

    Gozalvez, Javier; Haerri, Jerome; Hartenstein, Hannes; Heijenk, Geert; Kargl, Frank; Petit, Jonathan; Scheuermann, Björn; Tieler, Tessa; Altintas, O.; Dressler, F.; Hartenstein, H.; Tonguz, O.K.

    2013-01-01

    The working group on “Fundamentals: IVC and Computer Science” discussed the lasting value of achieved research results as well as potential future directions in the field of inter- vehicular communication. Two major themes ‘with variations’ were the dependence on a specific technology (particularly

  13. Hydrogen: ``Fuel for the 21st century``

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1996-11-01

    This article briefly discusses the impact of the Hindenburg airship disaster on the reputation of hydrogen. The global production of hydrogen, growing interest in the use of hydrogen as a fuel, the desire to reduce emissions, and the status of hydrogen fuels in Japan, Germany, USA and Canada are explored. The possible mixing of hydrogen with natural gas, and the use of fuel cells are considered. (UK)

  14. Installation of Ohio's First Electrolysis-Based Hydrogen Fueling Station

    Science.gov (United States)

    Scheidegger, Brianne T.; Lively, Michael L.

    2012-01-01

    This paper describes progress made towards the installation of a hydrogen fueling station in Northeast Ohio. In collaboration with several entities in the Northeast Ohio area, the NASA Glenn Research Center is installing a hydrogen fueling station that uses electrolysis to generate hydrogen on-site. The installation of this station is scheduled for the spring of 2012 at the Greater Cleveland Regional Transit Authority s Hayden bus garage in East Cleveland. This will be the first electrolysis-based hydrogen fueling station in Ohio.

  15. Hydrogen Fuel Cell development in Columbia (SC)

    Energy Technology Data Exchange (ETDEWEB)

    Reifsnider, Kenneth [Univ. of South Carolina, Columbia, SC (United States); Chen, Fanglin [Univ. of South Carolina, Columbia, SC (United States); Popov, Branko [Univ. of South Carolina, Columbia, SC (United States); Chao, Yuh [Univ. of South Carolina, Columbia, SC (United States); Xue, Xingjian [Univ. of South Carolina, Columbia, SC (United States)

    2012-09-15

    This is an update to the final report filed after the extension of this program to May of 2011. The activities of the present program contributed to the goals and objectives of the Fuel Cell element of the Hydrogen, Fuel Cells and Infrastructure Technologies Program of the Department of Energy through five sub-projects. Three of these projects have focused on PEM cells, addressing the creation of carbon-based metal-free catalysts, the development of durable seals, and an effort to understand contaminant adsorption/reaction/transport/performance relationships at low contaminant levels in PEM cells. Two programs addressed barriers in SOFCs; an effort to create a new symmetrical and direct hydrocarbon fuel SOFC designs with greatly increased durability, efficiency, and ease of manufacturing, and an effort to create a multiphysics engineering durability model based on electrochemical impedance spectroscopy interpretations that associate the micro-details of how a fuel cell is made and their history of (individual) use with specific prognosis for long term performance, resulting in attendant reductions in design, manufacturing, and maintenance costs and increases in reliability and durability.

  16. Coupling hydrogen fuel and carbonless utilities

    Energy Technology Data Exchange (ETDEWEB)

    Berry, G.D. [Lawrence Livermore National Lab., CA (United States)

    1998-08-01

    A number of previous analyses have focused on comparisons of single hydrogen vehicles to petroleum and alternative fuel vehicles or of stationary hydrogen storage for utility or local power applications. LLNL`s approach is to compare combined transportation/utility storage systems using hydrogen and fossil fuels. Computer models have been constructed to test the hypothesis that combining carbonless electricity sources and vehicles fueled by electrolytic hydrogen can reduce carbon emissions more cost effectively than either approach alone. Three scenarios have been developed and compared using computer simulations, hourly utility demand data, representative data for solar and wind energy sites, and the latest available EIA projections for transportation and energy demand in the US in 2020. Cost projections were based on estimates from GRI, EIA, and a recent DOE/EPRI report on renewable energy technologies. The key question guiding this analysis was: what can be gained by combining hydrogen fuel production and renewable electricity? Bounding scenarios were chosen to analyze three carbon conscious options for the US transportation fuel and electricity supply system beyond 2020: Reference Case -- petroleum transportation and natural gas electric sector; Benchmark Case -- petroleum transportation and carbonless electric sector; and Target Case -- hydrogen transportation and carbonless electric sector.

  17. Hydrogen Fuel Cell Development in Columbia (SC)

    Energy Technology Data Exchange (ETDEWEB)

    Reifsnider, Kenneth

    2011-07-31

    This is an update to the final report filed after the extension of this program to May of 2011. The activities of the present program contributed to the goals and objectives of the Fuel Cell element of the Hydrogen, Fuel Cells and Infrastructure Technologies Program of the Department of Energy through five sub-projects. Three of these projects have focused on PEM cells, addressing the creation of carbon-based metal-free catalysts, the development of durable seals, and an effort to understand contaminant adsorption/reaction/transport/performance relationships at low contaminant levels in PEM cells. Two programs addressed barriers in SOFCs; an effort to create a new symmetrical and direct hydrocarbon fuel SOFC designs with greatly increased durability, efficiency, and ease of manufacturing, and an effort to create a multiphysics engineering durability model based on electrochemical impedance spectroscopy interpretations that associate the micro-details of how a fuel cell is made and their history of (individual) use with specific prognosis for long term performance, resulting in attendant reductions in design, manufacturing, and maintenance costs and increases in reliability and durability.

  18. Ohio's First Electrolysis-Based Hydrogen Fueling Station

    Science.gov (United States)

    Demattia, Brianne

    2014-01-01

    Presentation to the earth day coalition describing efforts with NASA GRC and Cleveland RTA on Ohio's hydrogen fueling station and bus demonstration. Project background and goals, challenges and successes, and current status.

  19. Management of traumatic blunt IVC injury

    Directory of Open Access Journals (Sweden)

    Ali Cheaito, MD

    2016-01-01

    Conclusion: Of all incoming patients, IVC injuries are highly fatal with mortality rates between 70 and 90%. Management of these injuries should be tailored based on hemodynamic stability of such patients.

  20. Evaluation of the Crux IVC Filter in an animal model.

    Science.gov (United States)

    Murphy, Erin H; White, Rodney A; Rosenthal, David; Johnson, Eric D; Zarins, Christopher K; Fogarty, Thomas J; Arko, Frank R

    2008-06-01

    To determine the safety and performance of a new inferior vena cava (IVC) filter in an ovine model and evaluate the retrievability at 5 weeks. The Crux Vena Cava Filter (VCF) is composed of 2 nitinol spiral supports with a polymeric filter suspended between them. Retrieval tails on each end facilitate retrieval. Twelve filters were placed in the infrarenal IVCs of 12 sheep. The vessels were imaged pre and post deployment to assess acute device performance. At 5 weeks, the vessels were re-imaged to evaluate continued device performance and vessel integrity. Nine of 12 filters were retrieved, and the animals were returned to their housing. The other 3 animals were sacrificed, and the filters and vessels were processed for gross and histological examination. At 9 weeks, 4 weeks after filter retrieval, vessel integrity of the remaining 9 animals was again assessed under fluoroscopy. The animals were sacrificed, and the IVCs were explanted for study. All 12 filters were implanted without complications at the intended deployment site and remained fixed over the implantation period. At 5 weeks, the filters intended for recovery were successfully retrieved, with a mean capture time of 9.6+/-13.7 minutes. There were no complications during the 4-week follow-up after filter retrieval. Post-retrieval imaging at 5 and 9 weeks showed no visible signs of vessel wall damage. Histological study of 3 explanted vessels and filters revealed slight neointima encapsulation of the filter elements and minimal incorporation. Gross examination of the post-retrieval vessel walls after the 4-week healing period showed minimal superficial vessel damage; histology showed minimal residual signs of hemorrhage, with little to no inflammatory reaction. The Crux VCF was deployed and safely retrieved without incident at 5 weeks in an animal model. There was no significant damage seen to the IVCs 1 month after filter retrieval.

  1. Solar Hydrogen Fuel Cell Projects at Brooklyn Tech

    Science.gov (United States)

    Fedotov, Alex; Farah, Shadia; Farley, Daithi; Ghani, Naureen; Kuo, Emmy; Aponte, Cecielo; Abrescia, Leo; Kwan, Laiyee; Khan, Ussamah; Khizner, Felix; Yam, Anthony; Sakeeb, Khan; Grey, Daniel; Anika, Zarin; Issa, Fouad; Boussayoud, Chayama; Abdeldayem, Mahmoud; Zhang, Alvin; Chen, Kelin; Chan, Kameron Chuen; Roytman, Viktor; Yee, Michael

    2010-01-01

    This article describes the projects on solar hydrogen powered vehicles using water as fuel conducted by teams at Brooklyn Technical High School. Their investigations into the pure and applied chemical thermodynamics of hydrogen fuel cells and bio-inspired devices have been consolidated in a new and emerging sub-discipline that they define as solar…

  2. Liquid Hydrogen Fuel System for Small Unmanned Air Vehicles

    Science.gov (United States)

    2013-01-07

    propulsion plant comprised a hydrogen fuel cell system, built by Protonex Technology Corporation, which weighed 2.5 lbs and produced a maximum of 550... NASA for flight on long-endurance UAVs. 9 Aluminum was selected for both the inner and outer walls of the LH2 dewar because of its low H2...impact of cooling from air flow would ordinarily be tested in a wind tunnel, LH2 safety complicates indoor testing in a wind tunnel, as

  3. Respiratory-Induced Haemodynamic Changes: A Contributing Factor to IVC Filter Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Laborda, Alicia, E-mail: alaborda@unizar.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); Kuo, William T., E-mail: wkuo@stanford.edu [Stanford University Medical Center, Division of Vascular and Interventional Radiology (United States); Ioakeim, Ignatios, E-mail: ignacio.ioakim@hotmail.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain); De Blas, Ignacio, E-mail: deblas@unizar.es [Universidad de Zaragoza, Unit of Infectious Diseases and Epidemiology, Department of Animal Pathology (Spain); Malvè, Mauro, E-mail: mauro.malve@unavarra.es [Universidad Pública de Navarra, Department of Mechanical, Energy and Materials Engineering (Spain); Lahuerta, Celia, E-mail: celialahuerta@gmail.com; De Gregorio, Miguel A., E-mail: mgregori@unizar.es [Universidad de Zaragoza, Minimally Invasive Techniques Research Group (GITMI) (Spain)

    2015-10-15

    PurposeThe purpose of the study is to evaluate the influence of respiratory-induced vena caval hemodynamic changes on filter migration/penetration.Materials and MethodsAfter placement of either a Gunther Tulip or Celect IVC filter, 101 consecutive patients scheduled for filter retrieval were prospectively enrolled in this study. Pre-retrieval CT scans were used to assess filter complications and to calculate cross-sectional area in three locations: at level of filter strut fixation, 3 cm above and 3 cm below. A 3D finite element simulation was constructed on these data and direct IVC pressure was recorded during filter retrieval. Cross-sectional areas and pressures of the vena cava were measured during neutral breathing and in Valsalva maneuver and identified filter complications were recorded. A statistical analysis of these variables was then performed.ResultsDuring Valsalva maneuvers, a 60 % decrease of the IVC cross-sectional area and a fivefold increase in the IVC pressure were identified (p < 0.001). There was a statistically significant difference in the reduction of the cross-sectional area at the filter strut level (p < 0.001) in patient with filter penetration. Difficulty in filter retrieval was higher in penetrated or tilted filters (p < 0.001; p = 0.005). 3D computational models showed significant IVC deformation around the filter during Valsalva maneuver.ConclusionCaval morphology and hemodynamics are clearly affected by Valsalva maneuvers. A physiological reduction of IVC cross-sectional area is associated with higher risk of filter penetration, despite short dwell times. Physiologic data should be used to improve future filter designs to remain safely implanted over longer dwell times.

  4. Premixer Design for High Hydrogen Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin P. Lacy; Keith R. McManus; Balachandar Varatharajan; Biswadip Shome

    2005-12-16

    This 21-month project translated DLN technology to the unique properties of high hydrogen content IGCC fuels, and yielded designs in preparation for a future testing and validation phase. Fundamental flame characterization, mixing, and flame property measurement experiments were conducted to tailor computational design tools and criteria to create a framework for predicting nozzle operability (e.g., flame stabilization, emissions, resistance to flashback/flame-holding and auto-ignition). This framework was then used to establish, rank, and evaluate potential solutions to the operability challenges of IGCC combustion. The leading contenders were studied and developed with the most promising concepts evaluated via computational fluid dynamics (CFD) modeling and using the design rules generated by the fundamental experiments, as well as using GE's combustion design tools and practices. Finally, the project scoped the necessary steps required to carry the design through mechanical and durability review, testing, and validation, towards full demonstration of this revolutionary technology. This project was carried out in three linked tasks with the following results. (1) Develop conceptual designs of premixer and down-select the promising options. This task defined the ''gap'' between existing design capabilities and the targeted range of IGCC fuel compositions and evaluated the current capability of DLN pre-mixer designs when operated at similar conditions. Two concepts (1) swirl based and (2) multiple point lean direct injection based premixers were selected via a QFD from 13 potential design concepts. (2) Carry out CFD on chosen options (1 or 2) to evaluate operability risks. This task developed the leading options down-selected in Task 1. Both a GE15 swozzle based premixer and a lean direct injection concept were examined by performing a detailed CFD study wherein the aerodynamics of the design, together with the chemical kinetics of the

  5. Hydrogen Fueling Station in Honolulu, Hawaii Feasibility Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Porter Hill; Michael Penev

    2014-08-01

    The Department of Energy Hydrogen & Fuel Cells Program Plan (September 2011) identifies the use of hydrogen for government and fleet electric vehicles as a key step for achieving “reduced greenhouse gas emissions; reduced oil consumption; expanded use of renewable power …; highly efficient energy conversion; fuel flexibility …; reduced air pollution; and highly reliable grid-support.” This report synthesizes several pieces of existing information that can inform a decision regarding the viability of deploying a hydrogen (H2) fueling station at the Fort Armstrong site in Honolulu, Hawaii.

  6. Creation of Favourable Conditions for Introducing Hydrogen Fuel in Russia

    Science.gov (United States)

    Boretsky, E.; Egorova, M.

    2016-06-01

    The paper presents the key problems that hinder the introduction of new fuel for Russian automobile manufacturers. By analyzing the energy market, as well as trends and forecasts of crude oil and petroleum product prices, it proposes the necessary steps for the Government, along with oil producers and automakers, to gradually convert motor vehicles to hydrogen fuel and, therefore, to occupy a high-potential niche in the energy market. The recommended steps are assumed to be applicable not only to this specific case - introduction of hydrogen to the Russian market - but also to any other alternative fuel in a country with the similar or superior national economy.

  7. Elimination of abnormal combustion in a hydrogen-fueled engine

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.R.; Swain, M.N. [Analytical Technologies, Inc., Miami, FL (United States)

    1995-11-01

    This report covers the design, construction, and testing of a dedicated hydrogen-fueled engine. Both part-load and full-load data were taken under laboratory conditions. The engine design included a billet aluminum single combustion chamber cylinder-head with one intake valve, two sodium coiled exhaust valves, and two spark plugs. The cylinder-head design also included drilled cooling passages. The fuel-delivery system employed two modified Siemens electrically actuated fuel injectors, The exhaust system included two separate headers, one for each exhaust port. The piston/ring combination was designed specifically for hydrogen operation.

  8. Development of a Turnkey Hydrogen Fueling Station Final Report

    Energy Technology Data Exchange (ETDEWEB)

    David E. Guro; Edward Kiczek; Kendral Gill; Othniel Brown

    2010-07-29

    The transition to hydrogen as a fuel source presents several challenges. One of the major hurdles is the cost-effective production of hydrogen in small quantities (less than 1MMscf/month). In the early demonstration phase, hydrogen can be provided by bulk distribution of liquid or compressed gas from central production plants; however, the next phase to fostering the hydrogen economy will likely include onsite generation and extensive pipeline networks to help effect a pervasive infrastructure. Providing inexpensive hydrogen at a fleet operator’s garage or local fueling station is a key enabling technology for direct hydrogen Fuel Cell Vehicles (FCVs). The objective of this project was to develop a comprehensive, turnkey, stand-alone, commercial hydrogen fueling station for FCVs with state-of-the-art technology that is cost-competitive with current hydrocarbon fuels. Such a station would promote the advent of the hydrogen fuel economy for buses, fleet vehicles, and ultimately personal vehicles. Air Products, partnering with the U.S. Department of Energy (DOE), The Pennsylvania State University, Harvest Energy Technology, and QuestAir, developed a turnkey hydrogen fueling station on the Penn State campus. Air Products aimed at designing a station that would have 65% overall station efficiency, 82% PSA (pressure swing adsorption) efficiency, and the capability of producing hydrogen at $3.00/kg (gge) H2 at mass production rates. Air Products designed a fueling station at Penn State from the ground up. This project was implemented in three phases. The first phase evaluated the various technologies available in hydrogen generation, compression, storage, and gas dispensing. In the second phase, Air Products designed the components chosen from the technologies examined. Finally, phase three entailed a several-month period of data collection, full-scale operation, maintenance of the station, and optimization of system reliability and performance. Based on field data

  9. Options for refuelling hydrogen fuel cell vehicles in Italy

    Science.gov (United States)

    Mercuri, R.; Bauen, A.; Hart, D.

    Hydrogen fuel cell vehicle (H 2 FCV) trials are taking place in a number of cities around the world. In Italy, Milan and Turin are the first to have demonstration projects involving hydrogen-fuelled vehicles, in part to satisfy increasing consumer demand for improved environmental performance. The Italian transport plan specifically highlights the potential for FCVs to enter into the marketplace from around 2005. A scenario for FCV penetration into Italy, developed using projected costs for FCV and hydrogen fuel, suggests that by 2015, 2 million Italian cars could be powered by fuel cells. By 2030, 60% of the parc could be FCVs. To develop an infrastructure to supply these vehicles, a variety of options is considered. Large-scale steam reforming, on-site reforming and electrolysis options are analysed, with hydrogen delivered both in liquid and gaseous form. Assuming mature technologies, with over 10,000 units produced, on-site steam reforming provides the most economic hydrogen supply to the consumer, at US 2.6/kg. However, in the early stages of the infrastructure development there is a clear opportunity for on-site electrolysis and for production of hydrogen at centralised facilities, with delivery in the form of liquid hydrogen. This enables additional flexibility, as the hydrogen may also be used for fuel refining or for local power generation. In the current Italian context, energy companies could have a significant role to play in developing a hydrogen infrastructure. The use of hydrogen FCVs can substantially reduce emissions of regulated pollutants and greenhouse gases. Using externality costs for regulated pollutants, it is estimated that the use of hydrogen fuel cell buses in place of 5% of diesel buses in Milan could avoid US 2 million per year in health costs. The addition of even very low externality costs to fuel prices makes the use of untaxed hydrogen in buses and cars, which is slightly more expensive for the motorist than untaxed gasoline or

  10. UN Global Technical Regulation for Hydrogen Fuel Cell Vehicles

    Institute of Scientific and Technical Information of China (English)

    He Yuntang; Zheng Jinyang; Ou Kesheng

    2012-01-01

    1.Background Along with the gradual depletion of fossil energy such as petrol,coal and natural gas and the increasing attention paid to the environment problems,hydrogen energy as the important secondary energy source is developing at amazing pace.Since 1990s,the research on the application of hydrogen energy in transport has been increasingly vigorous,which is now one of the most active research areas for hydrogen energy.With the advantages of high energy conversion rate,good economical efficiency of the fuel,zero emission,etc.,hydrogen fuel cell vehicles have attracted the close concern and support from many countries,enterprises and academies.In recent years,our HFCV technologies have experienced rapid development,with joint efforts of production,teaching and research and continuous enhancement of international cooperation.

  11. Rational Design of Competitive Electrocatalysts for Hydrogen Fuel Cells.

    Science.gov (United States)

    Stolbov, Sergey; Alcántara Ortigoza, Marisol

    2012-02-16

    The large-scale application of one of the most promising clean and renewable sources of energy, hydrogen fuel cells, still awaits efficient and cost-effective electrocatalysts for the oxygen reduction reaction (ORR) occurring on the cathode. We demonstrate that truly rational design renders electrocatalysts possessing both qualities. By unifying the knowledge on surface morphology, composition, electronic structure, and reactivity, we solve that trimetallic sandwich-like structures are an excellent choice for optimization. Their constituting species are expected to couple synergistically yielding reaction-environment stability, cost-effectiveness, and tunable reactivity. This cooperative-action concept enabled us to predict two advantageous ORR electrocatalysts: Pd/Fe/W(110) and Au/Ru/W(110). Density functional theory calculations of the reaction free-energy diagrams suggest that these materials are more active toward ORR than the so-far best Pt-based catalysts. Our designing concept advances also a general approach for engineering advanced materials.

  12. ISOLATED IVC THROMBUS: A RARE COMPLICATION OF PANCREATITIS

    Directory of Open Access Journals (Sweden)

    Senthil Kumaran

    2014-06-01

    Full Text Available Venous thrombosis and hypercoagulable state has been described in patients with acute and chronic pancreatitis. Though this is commonly observed in splanchnic vessels, thrombosis of IVC is not frequently encountered. 1

  13. Project Profile: Hydrogen Fuel Cell Mobile Lighting Tower (HFCML)

    Science.gov (United States)

    McLaughlin, Russell

    2013-01-01

    NASA is committed to finding innovative solutions that improve the operational performance of ground support equipment while providing environment and cost benefits, as well. Through the Hydrogen Fuel Cell Mobile Lighting Tower (HFCML) project, NASA gained operational exposure to a novel application of high efficiency technologies. Traditionally, outdoor lighting and auxiliary power at security gates, launch viewing sites, fallback areas, outage support, and special events is provided by diesel generators with metal halide lights. Diesel generators inherently contribute to C02, NOx, particulate emissions, and are very noisy. In 2010, engineers from NASA's Technology Evaluation for Environmental Risk Mitigation Principal Center (TEERM) introduced KSC operations to a novel technology for outdoor lighting needs. Developed by a team led by Sandia National Laboratory (SNL), the technology pairs a 5kW hydrogen fuel cell with robust high efficiency plasma lights in a towable trailer. Increased efficiency, in both the fuel cell power source and lighting load, yields longer run times between fueling operations while providing greater auxiliary power. Because of the unit's quiet operation and no exhaust fumes, it is capable of being used indoors and in emergency situations, and meets the needs of all other operational roles for metal halide/diesel generators. The only discharge is some water and warm air. Environmental benefits include elimination of diesel particulate emissions and estimated 73% greenhouse gas emissions savings when the hydrogen source is natural gas (per GREET model). As the technology matures the costs could become competitive for the fuel cell units which are approximately 5 times diesel units. Initial operational . concerns included the hydrogen storage tanks and valves, lightning safety/grounding, and required operating and refueling procedures. TEERM facilitated technical information exchange (design drawings, technical standards, and operations

  14. Safety evaluation of a hydrogen fueled transit bus

    Energy Technology Data Exchange (ETDEWEB)

    Coutts, D.A.; Thomas, J.K.; Hovis, G.L.; Wu, T.T. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-12-31

    Hydrogen fueled vehicle demonstration projects must satisfy management and regulator safety expectations. This is often accomplished using hazard and safety analyses. Such an analysis has been completed to evaluate the safety of the H2Fuel bus to be operated in Augusta, Georgia. The evaluation methods and criteria used reflect the Department of Energy`s graded approach for qualifying and documenting nuclear and chemical facility safety. The work focused on the storage and distribution of hydrogen as the bus motor fuel with emphases on the technical and operational aspects of using metal hydride beds to store hydrogen. The safety evaluation demonstrated that the operation of the H2Fuel bus represents a moderate risk. This is the same risk level determined for operation of conventionally powered transit buses in the United States. By the same criteria, private passenger automobile travel in the United States is considered a high risk. The evaluation also identified several design and operational modifications that resulted in improved safety, operability, and reliability. The hazard assessment methodology used in this project has widespread applicability to other innovative operations and systems, and the techniques can serve as a template for other similar projects.

  15. Hydrogen-fueled Wankel engines for small integrated power systems

    Energy Technology Data Exchange (ETDEWEB)

    Salanki, P. A.; Wallace, J. S. [Toronto Univ., ON (Canada)

    1997-05-01

    An experimental investigation into hydrogen fueling of Wankel engines, currently underway at the University of Toronto, was described. The objective of the experiment was to generate an emissions and efficiency database. In the first phase of the work, external mixture formation was used. Results confirmed Mazda`s own unpublished results. Using a small air-cooled Wankel engine, the authors investigated simpler means of injecting hydrogen through a row of four symmetric and equally separated orifices drilled through the epitrochoid wall. Hydrogen was supplied continuously to the orifices through the distribution manifold on the outside of the housing, with the flow controlled by a needle valve at the inlet of the distribution manifold. Although this system of continuous injection did not provide the complete separation of inlet air and injected hydrogen achieved by the Mazda timed hydrogen injection system, it was considered to be far simpler and achieved the critical goal of isolating open air intake from the hot combustion chamber surfaces. It was concluded that the epitrochoid wall injection offers some advantages over simple external mixture formation. It also has the added advantage of avoiding the complexity of a timed injection system with a valve. 9 refs., 4 figs..

  16. Computational Simulations of Inferior Vena Cava (IVC) Filter Placement and Hemodynamics in Patient-Specific Geometries

    Science.gov (United States)

    Aycock, Kenneth; Sastry, Shankar; Kim, Jibum; Shontz, Suzanne; Campbell, Robert; Manning, Keefe; Lynch, Frank; Craven, Brent

    2013-11-01

    A computational methodology for simulating inferior vena cava (IVC) filter placement and IVC hemodynamics was developed and tested on two patient-specific IVC geometries: a left-sided IVC, and an IVC with a retroaortic left renal vein. Virtual IVC filter placement was performed with finite element analysis (FEA) using non-linear material models and contact modeling, yielding maximum vein displacements of approximately 10% of the IVC diameters. Blood flow was then simulated using computational fluid dynamics (CFD) with four cases for each patient IVC: 1) an IVC only, 2) an IVC with a placed filter, 3) an IVC with a placed filter and a model embolus, all at resting flow conditions, and 4) an IVC with a placed filter and a model embolus at exercise flow conditions. Significant hemodynamic differences were observed between the two patient IVCs, with the development of a right-sided jet (all cases) and a larger stagnation region (cases 3-4) in the left-sided IVC. These results support further investigation of the effects of IVC filter placement on a patient-specific basis.

  17. Influence of the Ambient Temperature, to the Hydrogen Fuel Cell Functioning

    Directory of Open Access Journals (Sweden)

    POPOVICI Ovidiu

    2012-10-01

    Full Text Available The reversible fuel cell can be used to produce hydrogen. The hydrogen is further the chemical energy source to produce electrical energy using the fuel cell. The ambient temperature will influence theparameters of the hydrogen fuel cell.

  18. Fiber Optic Sensors for Leak Detection and Condition Monitoring in Hydrogen Fuel Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal addresses the need for explosion proof, sensitive and reliable hydrogen sensors for NASA and commercial hydrogen fuel systems. It also...

  19. Behavioral response to hydrogen fuel cell vehicles and refueling: Results of California drive clinics

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Elliot; Lidicker, Jeffrey R. [Transportation Sustainability Research Center (TSRC), University of California, Berkeley, 1301 S. 46th Street. Bldg 190, Richmond, CA 94804-4648 (United States); Shaheen, Susan A. [Transportation Sustainability Research Center (TSRC), University of California, Berkeley, 1301 S. 46th Street. Bldg 190, Richmond, CA 94804-4648 (United States); Institute of Transportation Studies, University of California, Davis (United States); Lipman, Timothy E. [Transportation Sustainability Research Center (TSRC), University of California, Berkeley, 2614 Dwight Way, MC 1782, Berkeley, CA 94720-1782 (United States)

    2009-10-15

    Over the last several decades, hydrogen fuel cell vehicles (FCVs) have emerged as a zero tailpipe-emission alternative to the battery electric vehicle (EV). To address questions about consumer reaction to FCVs, this report presents the results of a ''ride-and-drive'' clinic series (N = 182) held in 2007 with a Mercedes-Benz A-Class ''F-Cell'' hydrogen FCV. The clinic evaluated participant reactions to driving and riding in an FCV, as well as vehicle refueling. Pre-and post-clinic surveys assessed consumer response. More than 80% left with a positive overall impression of hydrogen. The majority expressed a willingness to travel 5-10 min to find a hydrogen station. More than 90% of participants would consider an FCV driving range of 300 miles (480 km) to be acceptable. Stated willingness-to-pay preferences were explored. The results show that short-term exposure can improve consumer perceptions of hydrogen performance and safety among people who are the more likely early adopters. (author)

  20. City of Chula Vista hydrogen fuel cell bus demonstration project

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, B.; Bamberger, B.

    1996-10-01

    Hydrogen as an energy carrier and fuel has potential for various uses including electricity, commercial, residential, transportation, and industrial. It is an energy carrier that can be produced from a variety of primary sources and potentially can accomplish these various uses while significantly reducing pollution by substituting for or reducing the use of fossil fuels. One of the most immediate and potentially viable roles for hydrogen as an energy carrier will be its use as a transportation fuel, especially in densely populated urban areas where automotive emissions contribute significantly to air pollution. The Department of Energy`s commitment to research and development of hydrogen as an alternative fuel, and California`s Zero Emission Vehicle (ZEV) requirements, both provide the impetus and favorable circumstance for demonstrating hydrogen as a transportation fuel on an urban bus system. The purpose of this project is to demonstrate the feasibility of using solid polymer fuel cells in a hydrogen-powered electric drive system for an urban transit bus application. Fuel cell buses use hydrogen fuel and oxygen from the air to produce electrical power with the only byproduct being pure water. Proton Exchange Membrane (PEM) fuel cells are proposed for this project. Current evidence suggests that fuel cells, which rely on hydrogen and a process known as proton exchange to generate their power, appear to have an infinite life span. All exhaust pollution is completely eliminated, resulting in a Zero Emission Vehicle (ZEV). An urban bus system offers the potential for developing a market for the production of hydrogen propulsion technology due to extensive vehicular use in densely populated areas experiencing pollution from numerous sources, and because the central garaging facilities or the bus system facilitates fueling and maintenance functions.

  1. Successful catheter directed thrombolysis of IVC and renal vein occlusive thrombus.

    LENUS (Irish Health Repository)

    McCarthy, E

    2011-11-01

    Thrombus formation is a recognised complication of IVC filter placement, however IVC and bilateral renal vein occlusion secondary to thrombus is much less common. We present a case of infrahepatic caval and bilateral renal vein occlusion secondary to thrombosis of a suprarenal IVC filter. With progressive clinical deterioration and failure of conservative medical management the patient underwent successful mechanical disruption and catheter directed thrombolysis.

  2. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    Energy Technology Data Exchange (ETDEWEB)

    BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-06-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from

  3. Numerical study of test gas vitiation effects on hydrogen-fueled scramjet combustion%Numerical study of test gas vitiation effects on hydrogen-fueled scramjet combustion

    Institute of Scientific and Technical Information of China (English)

    CHEN Chao-qun; TIAN Liang; XU Xu

    2012-01-01

    The effects of major vitiated species (H2O and CO2) and minor vitiated species (H,OH and O radicals) produced by combustion air preheater on ignition and combustion of hydrogen-fueled seramjet were numerically investigated. Firstly, kinetic analyses with CHEMKIN SENKIN code were conducted to evaluate the effects of contamination on the ignition delay times of hydrogen fuel over a range of temperature and pressure variations. Then numerical simulation of a three-dimensional reacting flow in hydrogen-fueled seramjet combustor was performed. The two-equation shear stress transport k-ω turbulence model was used for modeling turbulence and 33 reactions finite-rate chemistry was used for modeling the H2/air kinetics. The results show that: free radical species such as H,O,and OH may significantly promote the ignition process of hydrogen-air at relatively low initial temperature and pressure. However, H2O and CO2 have inhibition effects on the ignition process. Under the same conditions, H2O has more effective inhibition effects than CO2. The temperature and pressure rise due to combustion are lower in the air vitiated with H2O and CO2 because of their higher heat capacities and more dissociation. Combustion efficiency and thrust calculated for vitiated air case are lower than clean air case. These results indicate the importance of accounting for vitiation effects when extrapolating performance data from ground test to flight demonstration.

  4. Experimental hydrogen-fueled automotive engine design data-base project. Volume 2. Main technical report

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.R.; Adt, R.R. Jr.; Pappas, J.M.

    1983-05-01

    Operational performance and emissions characteristics of hydrogen-fueled engines are reviewed. The project activities are reviewed including descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained. Analyses of other hydrogen engine project data are also presented and compared with the results of the present effort.

  5. A Barrier Options Approach to Modeling Project Failure : The Case of Hydrogen Fuel Infrastructure

    NARCIS (Netherlands)

    Engelen, P.J.; Kool, C.J.M.; Li, Y.

    2016-01-01

    Hydrogen fuel cell vehicles have the potential to contribute to a sustainable transport system with zero tailpipe emissions. This requires the construction of a network of fuel stations, a long-term, expensive and highly uncertain investment. We contribute to the literature by including a knock-out

  6. Biomass & Natural Gas Based Hydrogen Fuel For Gas Turbine (Power Generation)

    Science.gov (United States)

    Significant progress has been made by major power generation equipment manufacturers in the development of market applications for hydrogen fuel use in gas turbines in recent years. Development of a new application using gas turbines for significant reduction of power plant CO2 e...

  7. Evaluation of the hydrogen-fueled rotary engine for hybrid vehicle applications

    Energy Technology Data Exchange (ETDEWEB)

    Salanki, P.A.; Wallace, J.S. [Univ. of Toronto, Ontario (Canada)

    1996-09-01

    The hydrogen-fueled engine has been identified as a viable power unit for ultra-low emission series-hybrid vehicles. The Wankel engine is particularly well suited to the use of hydrogen fuel, since its design minimizes most of the combustion difficulties. In order to evaluate the possibilities offered by the hydrogen fueled rotary engine, dynamometer tests were conducted with a small (2.2 kW) Wankel engine fueled with hydrogen. Preliminary results show an absence of the combustion difficulties present with hydrogen-fueled homogeneous charge piston engines. The engine was operated unthrottled and power output was controlled by quality governing, i.e. by varying the fuel-air equivalence ratio on the lean side of stoichiometric. The ability to operate with quality governing is made possible by the wide flammability limits of hydrogen-air mixtures. NO{sub x} emissions are on the order of 5 ppm for power outputs up to 70% of the maximum attainable on hydrogen fuel. Thus, by operating with very lean mixtures, which effectively derates the engine, very low NO{sub x} emissions can be achieved. Since the rotary engine has a characteristically high power to weight ratio and a small volume per unit power compared to the piston engine, operating a rotary engine on hydrogen and derating the power output could yield an engine with extremely low emissions which still has weight and volume characteristics comparable to a gasoline-fueled piston engine. Finally, since engine weight and volume affect vehicle design, and consequently in-use vehicle power requirements, those factors, as well as engine efficiency, must be taken into account in evaluating overall hybrid vehicle efficiency.

  8. H2FIRST: A partnership to advance hydrogen fueling station technology driving an optimal consumer experience.

    Energy Technology Data Exchange (ETDEWEB)

    Moen, Christopher D.; Dedrick, Daniel E.; Pratt, Joseph William; Balfour, Bruce; Noma, Edwin Yoichi; Somerday, Brian P.; San Marchi, Christopher W.; K. Wipke; J. Kurtz; D. Terlip; K. Harrison; S. Sprik

    2014-03-01

    The US Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) Office of Fuel Cell Technologies Office (FCTO) is establishing the Hydrogen Fueling Infrastructure Research and Station Technology (H2FIRST) partnership, led by the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL). FCTO is establishing this partnership and the associated capabilities in support of H2USA, the public/private partnership launched in 2013. The H2FIRST partnership provides the research and technology acceleration support to enable the widespread deployment of hydrogen infrastructure for the robust fueling of light-duty fuel cell electric vehicles (FCEV). H2FIRST will focus on improving private-sector economics, safety, availability and reliability, and consumer confidence for hydrogen fueling. This whitepaper outlines the goals, scope, activities associated with the H2FIRST partnership.

  9. Impact of experience on government policy toward acceptance of hydrogen fuel cell vehicles in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Min Jung [Department of Information and Industrial Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul 120-749 (Korea, Republic of); Park, Heejun, E-mail: h.park@yonsei.ac.kr [Department of Information and Industrial Engineering, Yonsei University, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul 120-749 (Korea, Republic of)

    2011-06-15

    As the 'low carbon, green growth' agenda, which emphasized sustainable development through equilibrium between economic growth and environmental preservation, is propagated rapidly in Korea. Despite this progress, it is not uncommon for new products made through advanced technologies, such as hydrogen fuel cell vehicles, to face public skepticism preventing market penetration. Therefore, the factors impacting customer acceptance of hydrogen fuel cell vehicles have to be estimated. Furthermore, it is necessary to examine whether or not the policies related to these products can prevent public skepticism regarding them. This empirical study examining the relationship between personal experiences related to the policy and acceptance of the innovative products of hydrogen fuel cell vehicles shows that government involvement in technology targeting and promotions administered by the 'low carbon, green growth' agenda rarely stimulate potential customers' purchase intentions. Thus, technology targeting administered by the 'low carbon, green growth' agenda needs to be reconciled with customer responses to the future market. - Highlights: > Experience of the 'low carbon, green growth' policy affects perception of it. > Positive perception on the policy seldom arouses positive perception on HFCV performance. > Technology targeting by the policy rarely stimulates purchase intention of HFCV. > Desire to be regarded as a person with environment concern impacts purchase intentions.> Technology targeting by the policy needs to be reconciled with customer responses to it.

  10. Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) Filters: A Powerful Tool to Optimize Care of Patients with IVC Filters.

    Science.gov (United States)

    Deso, Steven E; Idakoji, Ibrahim A; Muelly, Michael C; Kuo, William T

    2016-06-01

    Owing to a myriad of inferior vena cava (IVC) filter types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC filters and related complications, to optimize the care of patients with indwelling IVC filters. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC filter types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each filter type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC filter registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC filter types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each filter type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC filter types and related complications. This application may be used to optimize the care of patients with IVC filters.

  11. Prophylactic IVC Filter Placement during Endovascular Treatment of Deep Venous Thrombosis of the Lower Extremities

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Byung Suk; Cho, Han Il; Lee, Yeum Sik; Bang, Dong Ho; Park, Seong Hoon; Lee, Young Hwan [Wonkwang University Hospital, Iksan (Korea, Republic of)

    2009-09-15

    To evaluate the efficacy of an IVC filter implantation in the prevent of a pulmonary embolism (PE) during endovascular treatment for a deep venous thrombosis (DVT) of the lower extremities. We implanted IVC filters in 43 patients (22 females, 21 males, average age: 63 years) with DVT and who had undergone treatments including thrombolysis, aspiration and mechanical thrombectomy, as well as stent placement. We evaluated the incidence of PE by capturing the thrombus within the IVC filters, as well as the amount of captured thrombus. New developing PE or aggravating of PE in patients with existing PE was avoided in all patients. No thrombus was evident in the IVC filter of 19 (44%) of the patients, whereas any thrombus was captured in 24 (56%) of the patients. Small amounts of thrombus were captured in 10 patients, whereas large amounts of thrombus were captured in 14 patents within the IVC filter. We performed a retrieval of the IVC filters in 17 patients within an average period of 15.3 days (range 6-45 days). The captured incidence of migrated thrombus in the IVC filters was high in 56% of cases. As a result, PE was effectively prevented by IVC filters during the interventional treatment of DVT in the lower extremities.

  12. Numerical Study on the Performance Characteristics of Hydrogen Fueled Port Injection Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Rosli A. Bakar

    2009-01-01

    Full Text Available This study was focused on the engine performance of single cylinder hydrogen fueled port injection internal combustion engine. GT-Power was utilized to develop the model for port injection engine. One dimensional gas dynamics was represented the flow and heat transfer in the components of the engine model. The governing equations were introduced first, followed by the performance parameters and model description. Air-fuel ratio was varied from stoichiometric limit to a lean limit and the rotational speed varied from 2500 to 4500 rpm while the injector location was considered fixed in the midway of the intake port. The effects of air fuel ratio, crank angle and engine speed are presented in this study. From the acquired results show that the air-fuel ratio and engine speed were greatly influence on the performance of hydrogen fueled engine. It was shown that decreases the Brake Mean Effective Pressure (BMEP and brake thermal efficiency with increases of the engine speed and air-fuel ratio however the increase the Brake Specific Fuel Consumption (BSFC with increases the speed and air-fuel ratio. The cylinder temperature increases with increases of engine speed however temperature decreases with increases of air-fuel ratio. The pressure fluctuations increased substantially with increases of speed at intake port however rise of pressure at the end of the exhaust stroke lead to reverse flow into the cylinder past exhaust valve. The fluctuation amplitude responded to the engine speed in case of exhaust pressure were given less than the intake pressure. The volumetric efficiency increased with increases of engine speed and equivalent ratio. The volumetric efficiency of the hydrogen engines with port injection is a serious problem and reduces the overall performance of the engine. This emphasized the ability of retrofitting the traditional engines with hydrogen fuel with minor modifications.

  13. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1995-09-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. The low temperature, polymer electrolyte membrane fuel cell (PEMFC) has recently been identified as an attractive option for stationary power generation, based on the relatively simple and benign materials employed, the zero-emission character of the device, and the expected high power density, high reliability and low cost. However, a PEMFC stack fueled by hydrogen with the combined properties of low cost, high performance and high reliability has not yet been demonstrated. Demonstration of such a stack will remove a significant barrier to implementation of this advanced technology for electric power generation from hydrogen. Work done in the past at LANL on the development of components and materials, particularly on advanced membrane/electrode assemblies (MEAs), has contributed significantly to the capability to demonstrate in the foreseeable future a PEMFC stack with the combined characteristics described above. A joint effort between LANL and an industrial stack manufacturer will result in the demonstration of such a fuel cell stack for stationary power generation. The stack could operate on hydrogen fuel derived from either natural gas or from renewable sources. The technical plan includes collaboration with a stack manufacturer (CRADA). It stresses the special requirements from a PEMFC in stationary power generation, particularly maximization of the energy conversion efficiency, extension of useful life to the 10 hours time scale and tolerance to impurities from the reforming of natural gas.

  14. Development and validation of purged thermal protection systems for liquid hydrogen fuel tanks of hypersonic vehicles

    Science.gov (United States)

    Helenbrook, R. D.; Colt, J. Z.

    1977-01-01

    An economical, lightweight, safe, efficient, reliable, and reusable insulation system was developed for hypersonic cruise vehicle hydrogen fuel tanks. Results indicate that, a nitrogen purged, layered insulation system with nonpermeable closed-cell insulation next to the cryogenic tank and a high service temperature fibrous insulation surrounding it, is potentially an attractive solution to the insulation problem. For the postulated hypersonic flight the average unit weight of the purged insulation system (including insulation, condensate and fuel boil off) is 6.31 kg/sq m (1.29 psf). Limited cyclic tests of large specimens of closed cell polymethacrylimide foam indicate it will withstand the expected thermal cycle.

  15. Hybrid electric system for an Hydrogen Fuel Cell Vehicle and its energy management

    OpenAIRE

    DA FONSECA, Ramon Naiff; BIDEAUX, Eric; Gerard, Mathias; DESBOIS-RENAUDIN, Matthieu; JEANNERET, Bruno

    2012-01-01

    Fuel cell vehicles, (FCV) are characterized by the utilization on the same electric bus of an hydrogen fuel cell (FC) as a primary energy source and of storage elements like batterie s as a secondary source. In our project, the fuel c ell is a Polymer Electrolyte Membrane (PEM), which is well adapted for transport field applications. A Lithium rechargeable battery , more specifically a LiFePO4, is used to supplement the FC over the driv ing cycle. According to the requirements of the dri ...

  16. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    Science.gov (United States)

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-01

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  17. British Society of Interventional Radiology (BSIR) Inferior Vena Cava (IVC) Filter Registry

    Energy Technology Data Exchange (ETDEWEB)

    Uberoi, Raman, E-mail: raman.Uberoi@orh.nhs.uk; Tapping, Charles Ross [Oxford University Hospitals, John Radcliffe Hospital, Department of Radiology (United Kingdom); Chalmers, Nicholas [Manchester Royal Infirmary, Department of Radiology (United Kingdom); Allgar, Victoria [University of York, Hull and York Medical School (United Kingdom)

    2013-12-15

    Purpose: The British Society of Interventional Radiology (BSIR) Inferior Vena Cava (IVC) Filter Registry was produced to provide an audit of current United Kingdom (UK) practice regarding placement and retrieval of IVC filters to address concerns regarding their safety. Methods: The IVC filter registry is a web-based registry, launched by the BSIR on behalf of its membership in October 2007. This report is based on prospectively collected data from October 2007 to March 2011. This report contains analysis of data on 1,434 IVC filter placements and 400 attempted retrievals performed at 68 UK centers. Data collected included patient demographics, insertion and retrieval data, and patient follow-up. Results: IVC filter use in the majority of patients in the UK follows accepted CIRSE guidelines. Filter placement is usually a low-risk procedure, with a low major complication rate (<0.5 %). Cook Gunther Tulip (560 filters: 39 %) and Celect (359 filters: 25 %) filters constituted the majority of IVC filters inserted, with Bard G2, Recovery filters, Cordis Trapease, and OptEase constituting most of the remainder (445 filters: 31 %). More than 96 % of IVC filters deployed as intended. Operator inexperience (<25 procedure) was significantly associated with complications (p < 0.001). Of the IVC filters initially intended for temporary placement, retrieval was attempted in 78 %. Of these retrieval was technically successful in 83 %. Successful retrieval was significantly reduced for implants left in situ for >9 weeks versus those with a shorter dwell time. New lower limb deep vein thrombosis (DVT) and/or IVC thrombosis was reported in 88 patients following filter placement, there was no significant difference of incidence between filter types. Conclusions: This registry report provides interventional radiologists and clinicians with an improved understanding of the technical aspects of IVC filter placement to help improve practice, and the potential consequences of IVC filter

  18. Design, fabrication and testing of a liquid hydrogen fuel tank for a long duration aircraft

    Science.gov (United States)

    Mills, Gary L.; Buchholtz, Brian; Olsen, Al

    2012-06-01

    Liquid hydrogen has distinct advantages as an aircraft fuel. These include a specific heat of combustion 2.8 times greater than gasoline or jet fuel and zero carbon emissions. It can be utilized by fuel cells, turbine engines and internal combustion engines. The high heat of combustion is particularly important in the design of long endurance aircraft with liquid hydrogen enabling cruise endurance of several days. However, the mass advantage of the liquid hydrogen fuel will result in a mass advantage for the fuel system only if the liquid hydrogen tank and insulation mass is a small fraction of the hydrogen mass. The challenge is producing a tank that meets the mass requirement while insulating the cryogenic liquid hydrogen well enough to prevent excessive heat leak and boil off. In this paper, we report on the design, fabrication and testing of a liquid hydrogen fuel tank for a prototype high altitude long endurance (HALE) demonstration aircraft. Design options on tank geometry, tank wall material and insulation systems are discussed. The final design is an aluminum sphere insulated with spray on foam insulation (SOFI). Several steps and organizations were involved in the tank fabrication and test. The tank was cold shocked, helium leak checked and proof pressure tested. The overall thermal performance was verified with a boil off test using liquid hydrogen.

  19. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Zawodzinski, C.; Wilson, M.; Gottesfeld, S. [Los Alamos National Lab., NM (United States)

    1996-10-01

    The fuel cell is the most efficient device for the conversion of hydrogen fuel to electric power. As such, the fuel cell represents a key element in efforts to demonstrate and implement hydrogen fuel utilization for electric power generation. A central objective of a LANL/Industry collaborative effort supported by the Hydrogen Program is to integrate PEM fuel cell and novel stack designs at LANL with stack technology of H-Power Corporation (H-Power) in order to develop a manufacturable, low-cost/high-performance hydrogen/air fuel cell stack for stationary generation of electric power. A LANL/H-Power CRADA includes Tasks ranging from exchange, testing and optimization of membrane-electrode assemblies of large areas, development and demonstration of manufacturable flow field, backing and bipolar plate components, and testing of stacks at the 3-5 cell level and, finally, at the 4-5 kW level. The stack should demonstrate the basic features of manufacturability, overall low cost and high energy conversion efficiency. Plans for future work are to continue the CRADA work along the time line defined in a two-year program, to continue the LANL activities of developing and testing stainless steel hardware for longer term stability including testing in a stack, and to further enhance air cathode performance to achieve higher energy conversion efficiencies as required for stationary power application.

  20. Nitrogen-doped fullerene as a potential catalyst for hydrogen fuel cells.

    Science.gov (United States)

    Gao, Feng; Zhao, Guang-Lin; Yang, Shizhong; Spivey, James J

    2013-03-06

    We examine the possibility of nitrogen-doped C60 fullerene (N-C60) as a cathode catalyst for hydrogen fuel cells. We use first-principles spin-polarized density functional theory calculations to simulate the electrocatalytic reactions on N-C60. The first-principles results show that an O2 molecule can be adsorbed and partially reduced on the N-C complex sites (Pauling sites) of N-C60 without any activation barrier. Through a direct pathway, the partially reduced O2 can further react with H(+) and additional electrons and complete the water formation reaction (WFR) with no activation energy barrier. In the indirect pathway, reduced O2 reacts with H(+) and additional electrons to form H2O molecules through a transition state (TS) with a small activation barrier (0.22-0.37 eV). From an intermediate state to a TS, H(+) can obtain a kinetic energy of ∼0.95-3.68 eV, due to the Coulomb electric interaction, and easily overcome the activation energy barrier during the WFR. The full catalytic reaction cycles can be completed energetically, and N-C60 fullerene recovers to its original structure for the next catalytic reaction cycle. N-C60 fullerene is a potential cathode catalyst for hydrogen fuel cells.

  1. Selection of Trusted Service Providers by Enforcing Bayesian Analysis in iVCE

    Institute of Scientific and Technical Information of China (English)

    GU Bao-jun; LI Xiao-yong; WANG Wei-nong

    2008-01-01

    The initiative of internet-based virtual computing environment (iVCE) aims to provide the end users and applications With a harmonious, trustworthy and transparent integrated computing environment which will facilitate sharing and collaborating of network resources between applications. Trust management is an elementary component for iVCE. The uncertain and dynamic characteristics of iVCE necessitate the requirement for the trust management to be subjective, historical evidence based and context dependent. This paper presents a Bayesian analysis-based trust model, which aims to secure the active agents for selecting appropriate trustod services in iVCE. Simulations are made to analyze the properties of the trust model which show that the subjective prior information influences trust evaluation a lot and the model stimulates positive interactions.

  2. Internet-based virtual computing environment (iVCE): Concepts and architecture

    Institute of Scientific and Technical Information of China (English)

    LU Xicheng; WANG Huaimin; WANG Ji

    2006-01-01

    Resources over Internet have such intrinsic characteristics as growth, autonomy and diversity, which have brought many challenges to the efficient sharing and comprehensive utilization of these resources. This paper presents a novel approach for the construction of the Internet-based Virtual Computing Environment (iVCE), whose significant mechanisms are on-demand aggregation and autonomic collaboration. The iVCE is built on the open infrastructure of the Internet and provides harmonious, transparent and integrated services for end-users and applications. The concept of iVCE is presented and its architectural framework is described by introducing three core concepts, i.e., autonomic element, virtual commonwealth and virtual executor. Then the connotations, functions and related key technologies of each components of the architecture are deeply analyzed with a case study, iVCE for Memory.

  3. IVC filter limb penetration of the caval wall during retroperitoneal surgery/lymph node dissection.

    LENUS (Irish Health Repository)

    Goh, Gerard S

    2012-12-01

    Optional inferior vena cava (IVC) filters are being increasingly used for protection against pulmonary embolism in patients with deep vein thrombosis where anticoagulation is contraindicated. We describe two cases during retroperitoneal surgery where the IVC filters were found to have perforated the cava wall and were subsequently removed intra-operatively. Cava wall penetration by filter limbs poses a significant danger during retroperitoneal lymph node dissection and filters should be removed preoperatively.

  4. Project Termination Report. Title IV-C Classroom Management Project. ESEA Title IV-C, August 29, 1981 - September 30, 1982.

    Science.gov (United States)

    Halasa, Ofelia; Theus, Frank

    This report provides a summary description of the Title IV-C Classroom Management Project conducted in the Cleveland (Ohio) Public Schools. The purpose of this project was to develop and pilot test a resource handbook designed to improve elementary and secondary school teachers' ability to organize and manage their classrooms. The development of…

  5. A polymer electrolyte fuel cell stack for stationary power generation from hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Moeller-Holst, S.; Webb, D.M.; Zawodzinski, C.; Gottesfeld, S. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1998-08-01

    The objective is to develop and demonstrate a 4 kW, hydrogen-fueled polymer electrolyte fuel cell (PEFC) stack, based on non-machined stainless steel hardware and on membrane/electrode assemblies (MEAs) of low catalyst loadings. The stack is designed to operate at ambient pressure on the air-side and can accommodate operation at higher fuel pressures, if so required. This is to be accomplished by working jointly with a fuel cell stack manufacturer, based on a CRADA. The performance goals are 57% energy conversion efficiency hydrogen-to-electricity (DC) at a power density of 0.9 kW/liter for a stack operating at ambient inlet pressures. The cost goal is $600/kW, based on present materials costs.

  6. Simulation of a solar-hydrogen-fuel cell system: results for different locations in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Torres, L.A.; Rodriguez, F.J.; Sebastian, P.J. [CIE-UNAM, Morelos (Mexico). Centro de Computo

    1998-12-31

    The authors report the results obtained from the simulation of a PV-hydrogen-fuel-cell (PVHFC) hybrid system for different locations in Mexico. The hybrid system consists of photovoltaic arrays coupled with an electrolyzer to produce hydrogen, a fuel cell which converts chemical energy (H{sub 2}) to electricity, a hydrogen storage, a battery storage system, and the load. In this kind of system, all components can be connected electrically in parallel. The voltage of the PV arrays the fuel cell must be high enough to charge the battery, and the voltage of the electrolyzer must be low enough for the battery to power it during periods of low insolation. The simulation is based on the electrical component models and variable insolation data depending on the location. (author)

  7. Industry requirements for introduction of alternative energies with emphasis on hydrogen fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Delabbio, F. [Rio Tinto, Canadian Exploration Ltd., Toronto, ON (Canada); Starbuck, D. [Newmont Mining Corp., Denver, CO (United States); Akerman, A. [CVRD-Inco, Toronto, ON (Canada); Betournay, M.C. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Mining and Mineral Sciences Laboratories

    2007-07-01

    This paper discussed issues related to the use of alternate sources of energy in underground mining applications. Hydrogen power systems were examined in relation to operational drivers, available commercial supplies, site supplies, health and safety issues, capital and operating costs, mine production, and the role of government. Hydrogen power systems are being considered for mining applications in an effort to reduce greenhouse gas (GHG) emissions and reduce cooling and ventilation requirements. This article examined a range of issues that must be addressed before alternate energy systems such as hydrogen fuel cell technology can be used in larger-scale underground mining applications. The mining industry supports the development of new technologies. However, the introduction of alternate energy technologies must proceed in steps which include proof of concept testing, the development of generic infrastructure, power systems and regulations, and whole operating system studies. 13 refs., 1 fig.

  8. Hydrogen Fueling Station Using Thermal Compression: a techno-economic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kriha, Kenneth [Gas Technology Inst., Des Plaines, IL (United States); Petitpas, Guillaume [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Melchionda, Michael [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Soto, Herie [Shell, Houston TX (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Yanli [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-11

    The goal of this project was to demonstrate the technical and economic feasibility of using thermal compression to create the hydrogen pressure necessary to operate vehicle hydrogen fueling stations. The concept of utilizing the exergy within liquid hydrogen to build pressure rather than mechanical components such as compressors or cryogenic liquid pumps has several advantages. In theory, the compressor-less hydrogen station will have lower operating and maintenance costs because the compressors found in conventional stations require large amounts of electricity to run and are prone to mechanical breakdowns. The thermal compression station also utilizes some of the energy used to liquefy the hydrogen as work to build pressure, this is energy that in conventional stations is lost as heat to the environment.

  9. Influence of contaminations on combustion kinetics in hydrogen-fueled engine

    Institute of Scientific and Technical Information of China (English)

    LIU WeiXiong; HE Wei; LI HongBin; LI XiangYuan; LE JiaLing

    2009-01-01

    In this work,we investigate the combustion of hydrogen fuel through the wind tunnel tests.Two kinds of fuel,the pure hydrogen and the hydrogen-ethene mixture,have been chosen to heat the oxy-gen-enriched air.It is found that the stable pressure in the engine combustor and the thrusts is almost the same in two cases.A valuable feature we revealed is that the heating pattern of hydrogen and ethene mixture leads to a considerable delay of the establishment of the wall pressure in the combustor,compared with the pure hydrogen case.This phenomenon implies a longer ignition delay time for the mixture case.The shorter ignition delay resulting from the hydrogen heater is attributed to the conti-nuity of chain propagation and the exclusion of the less active C-containing radicals.

  10. Method of Hydrogenous Fuel Usage to Increase the Efficiency in Tandem Diverse Temperature Oxidation System

    Directory of Open Access Journals (Sweden)

    Zubkova Marina

    2016-01-01

    Full Text Available This paper presents the results of estimation energy efficiency, the collation data of thermodynamic calculations and data on material balance for an assessment of electric and thermal components in considered ways to use convention products, performance enhancement in the tandem system containing the high-temperature fuel cell and the low-temperature fuel cell with full heat regeneration for hydrogenous fuel (CH4. The overall effective efficiency (ηΣef. making full use of the recovered heat considered tandem system depends on the efficiency of its constituent fuel cells. The overall effective efficiency of the tandem installation including the fuel converter, separating system, high-temperature oxidation system, and hydrogen disposal system in case of fuel use in the low-temperature fuel cell, is higher than for each of the fuel cell elements separately.

  11. Pathways to Commercial Success: Technologies and Products Supported by the Hydrogen, Fuel Cells and Infrastructure Technologies Program

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2009-08-01

    This report documents the results of an effort to identify and characterize commercial and near-commercial (emerging) technologies and products that benefited from the support of the Hydrogen, Fuel Cells and Infrastructure Technologies Program and its predecessor programs within DOE's Office of Energy Efficiency and Renewable Energy.

  12. The Value of Rotational Venography Versus Anterior–Posterior Venography in 100 Consecutive IVC Filter Retrievals

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Ryan M., E-mail: rkiefer11@gmail.com; Pandey, Nirnimesh; Trerotola, Scott O.; Nadolski, Gregory J.; Stavropoulos, S. William, E-mail: stav@uphs.upenn.edu [Hospital of University of Pennsylvania Medical Center, Division of Interventional Radiology, Department of Radiology (United States)

    2016-03-15

    PurposeAccurately detecting inferior vena cava (IVC) filter complications is important for safe and successful retrieval as tip-embedded filters require removal with non-standard techniques. Venography prior to IVC filter retrieval has traditionally used a single anterior–posterior (AP) projection. This study compares the utility of rotational venography to AP venography prior to IVC filter removal.Materials and MethodsThe rotational venograms from 100 consecutive IVC filter retrievals over a 35-month period were evaluated retrospectively. The AP view of the rotational venogram was examined separately from the full series by a radiologist blinded to alternative imaging and operative findings. The venograms were evaluated for tip embedding, filter fracture, filter thrombus, and IVC thrombus. Statistical analysis was performed.ResultsUsing operative findings and peri-procedural imaging as the reference standard, tip embedding occurred in 59 of the 100 filters (59 %). AP venography was used to correctly identify 31 tip-embedded filters (53 % sensitivity) with two false positives (95 % specificity) for an accuracy of 70 %. Rotational venography was used to correctly identify 58 tip-embedded filters (98 % sensitivity) with one false positive (98 % specificity) for an accuracy of 98 %. A significant difference was found in the sensitivities of the two diagnostic approaches (P < .01). Other findings of thrombus and filter fracture were not significantly different between the two groups.ConclusionRotational venograms allow for more accurate detection of tip-embedded IVC filters compared to AP views alone. As this determines the approach taken, rotational venograms are helpful if obtained prior to IVC filter retrieval.

  13. Toward an Optimal Position for IVC Filters: Computational Modeling of the Impact of Renal Vein Inflow

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S L; Singer, M A

    2009-07-13

    The purpose of this report is to evaluate the hemodynamic effects of renal vein inflow and filter position on unoccluded and partially occluded IVC filters using three-dimensional computational fluid dynamics. Three-dimensional models of the TrapEase and Gunther Celect IVC filters, spherical thrombi, and an IVC with renal veins were constructed. Hemodynamics of steady-state flow was examined for unoccluded and partially occluded TrapEase and Gunther Celect IVC filters in varying proximity to the renal veins. Flow past the unoccluded filters demonstrated minimal disruption. Natural regions of stagnant/recirculating flow in the IVC are observed superior to the bilateral renal vein inflows, and high flow velocities and elevated shear stresses are observed in the vicinity of renal inflow. Spherical thrombi induce stagnant and/or recirculating flow downstream of the thrombus. Placement of the TrapEase filter in the suprarenal vein position resulted in a large area of low shear stress/stagnant flow within the filter just downstream of thrombus trapped in the upstream trapping position. Filter position with respect to renal vein inflow influences the hemodynamics of filter trapping. Placement of the TrapEase filter in a suprarenal location may be thrombogenic with redundant areas of stagnant/recirculating flow and low shear stress along the caval wall due to the upstream trapping position and the naturally occurring region of stagnant flow from the renal veins. Infrarenal vein placement of IVC filters in a near juxtarenal position with the downstream cone near the renal vein inflow likely confers increased levels of mechanical lysis of trapped thrombi due to increased shear stress from renal vein inflow.

  14. Cryogenic hydrogen fuel for controlled inertial confinement fusion (formation of reactor-scale cryogenic targets)

    Science.gov (United States)

    Aleksandrova, I. V.; Koresheva, E. R.; Krokhin, O. N.; Osipov, I. E.

    2016-12-01

    In inertial fusion energy research, considerable attention has recently been focused on low-cost fabrication of a large number of targets by developing a specialized layering module of repeatable operation. The targets must be free-standing, or unmounted. Therefore, the development of a target factory for inertial confinement fusion (ICF) is based on methods that can ensure a cost-effective target production with high repeatability. Minimization of the amount of tritium (i.e., minimization of time and space at all production stages) is a necessary condition as well. Additionally, the cryogenic hydrogen fuel inside the targets must have a structure (ultrafine layers—the grain size should be scaled back to the nanometer range) that supports the fuel layer survivability under target injection and transport through the reactor chamber. To meet the above requirements, significant progress has been made at the Lebedev Physical Institute (LPI) in the technology developed on the basis of rapid fuel layering inside moving free-standing targets (FST), also referred to as the FST layering method. Owing to the research carried out at LPI, unique experience has been gained in the development of the FST-layering module for target fabrication with an ultrafine fuel layer, including a reactor- scale target design. This experience can be used for the development of the next-generation FST-layering module for construction of a prototype of a target factory for power laser facilities and inertial fusion power plants.

  15. A proposed model of factors influencing hydrogen fuel cell vehicle acceptance

    Science.gov (United States)

    Imanina, N. H. Noor; Kwe Lu, Tan; Fadhilah, A. R.

    2016-03-01

    Issues such as environmental problem and energy insecurity keep worsening as a result of energy use from household to huge industries including automotive industry. Recently, a new type of zero emission vehicle, hydrogen fuel cell vehicle (HFCV) has received attention. Although there are argues on the feasibility of hydrogen as the future fuel, there is another important issue, which is the acceptance of HFCV. The study of technology acceptance in the early stage is a vital key for a successful introduction and penetration of a technology. This paper proposes a model of factors influencing green vehicle acceptance, specifically HFCV. This model is built base on two technology acceptance theories and other empirical studies of vehicle acceptance. It aims to provide a base for finding the key factors influencing new sustainable energy fuelled vehicle, HFCV acceptance which is achieved by explaining intention to accept HFCV. Intention is influenced by attitude, subjective norm and perceived behavioural control from Theory of Planned Behaviour and personal norm from Norm Activation Theory. In the framework, attitude is influenced by perceptions of benefits and risks, and social trust. Perceived behavioural control is influenced by government interventions. Personal norm is influenced by outcome efficacy and problem awareness.

  16. Economic and environmental comparison of conventional, hybrid, electric and hydrogen fuel cell vehicles

    Science.gov (United States)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

    Published data from various sources are used to perform economic and environmental comparisons of four types of vehicles: conventional, hybrid, electric and hydrogen fuel cell. The production and utilization stages of the vehicles are taken into consideration. The comparison is based on a mathematical procedure, which includes normalization of economic indicators (prices of vehicles and fuels during the vehicle life and driving range) and environmental indicators (greenhouse gas and air pollution emissions), and evaluation of an optimal relationship between the types of vehicles in the fleet. According to the comparison, hybrid and electric cars exhibit advantages over the other types. The economic efficiency and environmental impact of electric car use depends substantially on the source of the electricity. If the electricity comes from renewable energy sources, the electric car is advantageous compared to the hybrid. If electricity comes from fossil fuels, the electric car remains competitive only if the electricity is generated on board. It is shown that, if electricity is generated with an efficiency of about 50-60% by a gas turbine engine connected to a high-capacity battery and an electric motor, the electric car becomes advantageous. Implementation of fuel cells stacks and ion conductive membranes into gas turbine cycles permits electricity generation to increase to the above-mentioned level and air pollution emissions to decrease. It is concluded that the electric car with on-board electricity generation represents a significant and flexible advance in the development of efficient and ecologically benign vehicles.

  17. Single-use paper-based hydrogen fuel cells for point-of-care diagnostic applications

    Science.gov (United States)

    Esquivel, J. P.; Buser, J. R.; Lim, C. W.; Domínguez, C.; Rojas, S.; Yager, P.; Sabaté, N.

    2017-02-01

    This work demonstrates a stand-alone power source that integrates a paper-based hydrogen fuel cell with a customized chemical heater that produces hydrogen in-situ upon the addition of a liquid. The presented approach operates by capillary action and takes advantage of the hydrogen released as a by-product of an exothermic reaction used in point-of-care diagnostics. The paper-based fuel cell produces a maximum power of 25.8 mW (103.2 mW cm-2), which is suitable for powering a diversity of electrical devices such as commercially available digital pregnancy tests and glucometers. While device shape and dimensions can be customized, here it is shown that the fuel cell can be designed in a compact form factor and footprint comparable to a lateral flow test while providing a remarkable power output. This approach holds great promise for powering portable diagnostics, as the generated electric power could enable device functionalities required for advanced assays, such as device timing, actuation, and signal quantification. Part of the same liquid sample that is to be analyzed (urine, saliva, water, etc) could be used to trigger the hydrogen generation and start the fuel cell operation.

  18. Cryogenic hydrogen fuel for controlled inertial confinement fusion (formation of reactor-scale cryogenic targets)

    Energy Technology Data Exchange (ETDEWEB)

    Aleksandrova, I. V.; Koresheva, E. R., E-mail: elena.koresheva@gmail.com; Krokhin, O. N. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Osipov, I. E. [Power Efficiency Centre, Inter RAO UES (Russian Federation)

    2016-12-15

    In inertial fusion energy research, considerable attention has recently been focused on low-cost fabrication of a large number of targets by developing a specialized layering module of repeatable operation. The targets must be free-standing, or unmounted. Therefore, the development of a target factory for inertial confinement fusion (ICF) is based on methods that can ensure a cost-effective target production with high repeatability. Minimization of the amount of tritium (i.e., minimization of time and space at all production stages) is a necessary condition as well. Additionally, the cryogenic hydrogen fuel inside the targets must have a structure (ultrafine layers—the grain size should be scaled back to the nanometer range) that supports the fuel layer survivability under target injection and transport through the reactor chamber. To meet the above requirements, significant progress has been made at the Lebedev Physical Institute (LPI) in the technology developed on the basis of rapid fuel layering inside moving free-standing targets (FST), also referred to as the FST layering method. Owing to the research carried out at LPI, unique experience has been gained in the development of the FST-layering module for target fabrication with an ultrafine fuel layer, including a reactor- scale target design. This experience can be used for the development of the next-generation FST-layering module for construction of a prototype of a target factory for power laser facilities and inertial fusion power plants.

  19. Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

    Science.gov (United States)

    Ally, Jamie; Pryor, Trevor

    The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.

  20. A storage module evaluation for the hydrogen fuel cell on toy design

    Energy Technology Data Exchange (ETDEWEB)

    Pa, P.S.; Lin, S.H.

    2011-01-15

    One aim of modern science is the search for non-polluting methods of energy production. The fuel cell is one of the most important power sources devised in the 21st century and has all the characteristics for environmental protection. It is pollution-free and highly efficient, converting the chemical energy of hydrogen gas directly into electricity. This study concerns the development of the 'hydrogen fuel cell generates electricity module' and demonstrates this in the design and use of a toy. A systematized analysis of power operation using existing fuel cell products and a setup of the module was carried out. The Taguchi method was used to arrive at the best parameter combination between fuel cell and toy. An assessment was made of the arrangement of a non-pressurized single fuel cell that best suit the requirement for use in the toy. It is hoped this can be applied on a larger scale to provide non-polluting power for many applications.

  1. Integration of direct carbon and hydrogen fuel cells for highly efficient power generation from hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Choi, Pyoungho; Smith, Franklyn; Bokerman, Gary [Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Road, Cocoa, FL 32922-5703 (United States)

    2010-02-15

    In view of impending depletion of hydrocarbon fuel resources and their negative environmental impact, it is imperative to significantly increase the energy conversion efficiency of hydrocarbon-based power generation systems. The combination of a hydrocarbon decomposition reactor with a direct carbon and hydrogen fuel cells (FC) as a means for a significant increase in chemical-to-electrical energy conversion efficiency is discussed in this paper. The data on development and operation of a thermocatalytic hydrocarbon decomposition reactor and its coupling with a proton exchange membrane FC are presented. The analysis of the integrated power generating system including a hydrocarbon decomposition reactor, direct carbon and hydrogen FC using natural gas and propane as fuels is conducted. It was estimated that overall chemical-to-electrical energy conversion efficiency of the integrated system varied in the range of 49.4-82.5%, depending on the type of fuel and FC used, and CO{sub 2} emission per kW{sub el}h produced is less than half of that from conventional power generation sources. (author)

  2. Mechanism and kinetics of the electrocatalytic reaction responsible for the high cost of hydrogen fuel cells.

    Science.gov (United States)

    Cheng, Tao; Goddard, William A; An, Qi; Xiao, Hai; Merinov, Boris; Morozov, Sergey

    2017-01-25

    The sluggish oxygen reduction reaction (ORR) is a major impediment to the economic use of hydrogen fuel cells in transportation. In this work, we report the full ORR reaction mechanism for Pt(111) based on Quantum Mechanics (QM) based Reactive metadynamics (RμD) simulations including explicit water to obtain free energy reaction barriers at 298 K. The lowest energy pathway for 4 e(-) water formation is: first, *OOH formation; second, *OOH reduction to H2O and O*; third, O* hydrolysis using surface water to produce two *OH and finally *OH hydration to water. Water formation is the rate-determining step (RDS) for potentials above 0.87 Volt, the normal operating range. Considering the Eley-Rideal (ER) mechanism involving protons from the solvent, we predict the free energy reaction barrier at 298 K for water formation to be 0.25 eV for an external potential below U = 0.87 V and 0.41 eV at U = 1.23 V, in good agreement with experimental values of 0.22 eV and 0.44 eV, respectively. With the mechanism now fully understood, we can use this now validated methodology to examine the changes upon alloying and surface modifications to increase the rate by reducing the barrier for water formation.

  3. Single-wall carbon nanotube-based proton exchange membrane assembly for hydrogen fuel cells.

    Science.gov (United States)

    Girishkumar, G; Rettker, Matthew; Underhile, Robert; Binz, David; Vinodgopal, K; McGinn, Paul; Kamat, Prashant

    2005-08-30

    A membrane electrode assembly (MEA) for hydrogen fuel cells has been fabricated using single-walled carbon nanotubes (SWCNTs) support and platinum catalyst. Films of SWCNTs and commercial platinum (Pt) black were sequentially cast on a carbon fiber electrode (CFE) using a simple electrophoretic deposition procedure. Scanning electron microscopy and Raman spectroscopy showed that the nanotubes and the platinum retained their nanostructure morphology on the carbon fiber surface. Electrochemical impedance spectroscopy (EIS) revealed that the carbon nanotube-based electrodes exhibited an order of magnitude lower charge-transfer reaction resistance (R(ct)) for the hydrogen evolution reaction (HER) than did the commercial carbon black (CB)-based electrodes. The proton exchange membrane (PEM) assembly fabricated using the CFE/SWCNT/Pt electrodes was evaluated using a fuel cell testing unit operating with H(2) and O(2) as input fuels at 25 and 60 degrees C. The maximum power density obtained using CFE/SWCNT/Pt electrodes as both the anode and the cathode was approximately 20% better than that using the CFE/CB/Pt electrodes.

  4. Effects of wind-powered hydrogen fuel cell vehicles on stratospheric ozone and global climate

    Science.gov (United States)

    Jacobson, Mark Z.

    2008-10-01

    Converting the world's fossil-fuel onroad vehicles (FFOV) to hydrogen fuel cell vehicles (HFCV), where the H2 is produced by wind-powered electrolysis, is estimated to reduce global fossil, biofuel, and biomass-burning emissions of CO2 by ~13.4%, NOx ~23.0%, nonmethane organic gases ~18.9%, black carbon ~8% H2 ~3.2% (at 3% leakage), and H2O ~0.2%. Over 10 years, such reductions were calculated to reduce tropospheric CO ~5%, NOx ~5-13%, most organic gases ~3-15%, OH ~4%, ozone ~6%, and PAN ~13%, but to increase tropospheric CH4 ~0.25% due to the lower OH. Lower OH also increased upper tropospheric/lower stratospheric ozone, increasing its global column by ~0.41%. WHFCV cooled the troposphere and warmed the stratosphere, reduced aerosol and cloud surface areas, and increased precipitation. Other renewable-powered HFCV or battery electric vehicles should have similar impacts.

  5. Hydrogen Fuel Cell Analysis: Lessons Learned from Stationary Power Generation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Scott E. Grasman; John W. Sheffield; Fatih Dogan; Sunggyu Lee; Umit O. Koylu; Angie Rolufs

    2010-04-30

    This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and a combination of distributed power generating stations, and provides an overview of stationary power markets, benefits of hydrogen-based stationary power systems, and competitive and technological challenges. The motivation for this project was to identify the lessons learned from prior stationary power programs, including the most significant obstacles, how these obstacles have been approached, outcomes of the programs, and how this information can be used by the Hydrogen, Fuel Cells & Infrastructure Technologies Program to meet program objectives primarily related to hydrogen pathway technologies (production, storage, and delivery) and implementation of fuel cell technologies for distributed stationary power. In addition, the lessons learned address environmental and safety concerns, including codes and standards, and education of key stakeholders.

  6. High Efficiency Generation of Hydrogen Fuels Using Nuclear Power - for the period August 1, 1999 through October 31, 1999

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Brown

    2000-01-01

    OAK B188 High Efficiency Generation of Hydrogen Fuels Using Nuclear Power - for the period August 1, 1999 through October 31, 1999. The highlights for this period are: (1) The methodologies for searching the literature for potentially attractive thermochemical water-splitting cycles, storing cycle and reference data, and screening the cycles have been established; and (2) The water-splitting cycle screening criteria were established on schedule.

  7. Estimating the early household market for light-duty hydrogen-fuel-cell vehicles and other "Mobile Energy" innovations in California: A constraints analysis

    Science.gov (United States)

    Williams, Brett D.; Kurani, Kenneth S.

    Facing stiff competition from conventional and gasoline-hybrid vehicles, the commercialization prospects for hydrogen-fuel-cell vehicles (H 2FCVs) are uncertain. Starting from the premise that new consumer value must drive their adoption, early markets for H 2FCVs are explored in the context of a group of promising opportunities collectively called mobile energy (ME) innovation. An estimate of the initial market potential for ME-enabled vehicles is produced by applying various constraints that eliminate unlikely households from consideration for early adoption of H 2FCVs and other ME technologies (such as plug-in hybrids). Currently 5.2 million of 33.9 million Californians live in households pre-adapted to ME-enabled vehicles, 3.9 million if natural gas is required for home refueling. Several differences in demographic and other characteristics between the target market and the population as a whole are highlighted, and two issues related to the design of H 2FCVs and their supporting infrastructure are discussed: vehicle range and home hydrogen refueling. These findings argue for continued investigation of this and similar target segments-which represent more efficient research populations for subsequent study by product designers and other decision-makers wishing to understand the early market dynamics facing H 2FCVs and related ME innovations.

  8. Hydrogen Fuel Cells and Storage Technology: Fundamental Research for Optimization of Hydrogen Storage and Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Perret, Bob; Heske, Clemens; Nadavalath, Balakrishnan; Cornelius, Andrew; Hatchett, David; Bae, Chusung; Pang, Tao; Kim, Eunja; Hemmers, Oliver

    2011-03-28

    Design and development of improved low-cost hydrogen fuel cell catalytic materials and high-capacity hydrogenn storage media are paramount to enabling the hydrogen economy. Presently, effective and durable catalysts are mostly precious metals in pure or alloyed form and their high cost inhibits fuel cell applications. Similarly, materials that meet on-board hydrogen storage targets within total mass and volumetric constraints are yet to be found. Both hydrogen storage performance and cost-effective fuel cell designs are intimately linked to the electronic structure, morphology and cost of the chosen materials. The FCAST Project combined theoretical and experimental studies of electronic structure, chemical bonding, and hydrogen adsorption/desorption characteristics of a number of different nanomaterials and metal clusters to develop better fundamental understanding of hydrogen storage in solid state matrices. Additional experimental studies quantified the hydrogen storage properties of synthesized polyaniline(PANI)/Pd composites. Such conducting polymers are especially interesting because of their high intrinsic electron density and the ability to dope the materials with protons, anions, and metal species. Earlier work produced contradictory results: one study reported 7% to 8% hydrogen uptake while a second study reported zero hydrogen uptake. Cost and durability of fuel cell systems are crucial factors in their affordability. Limits on operating temperature, loss of catalytic reactivity and degradation of proton exchange membranes are factors that affect system durability and contribute to operational costs. More cost effective fuel cell components were sought through studies of the physical and chemical nature of catalyst performance, characterization of oxidation and reduction processes on system surfaces. Additional development effort resulted in a new hydrocarbon-based high-performance sulfonated proton exchange membrane (PEM) that can be manufactured at low

  9. Literature Review for the Baseline Knowledge Assessment of the Hydrogen, Fuel Cells, and Infrastructure Technologies Program

    Energy Technology Data Exchange (ETDEWEB)

    Truett, L.F.

    2003-12-10

    The purpose of the Hydrogen, Fuel Cells, and Infrastructure Technologies (HFCIT) Program Baseline Knowledge Assessment is to measure the current level of awareness and understanding of hydrogen and fuel cell technologies and the hydrogen economy. This information will be an asset to the HFCIT program in formulating an overall education plan. It will also provide a baseline for comparison with future knowledge and opinion surveys. To assess the current understanding and establish the baseline, the HFCIT program plans to conduct scientific surveys of four target audience groups--the general public, the educational community, governmental agencies, and potential large users. The purpose of the literature review is to examine the literature and summarize the results of surveys that have been conducted in the recent past concerning the existing knowledge and attitudes toward hydrogen. This literature review covers both scientific and, to a lesser extent, non-scientific polls. Seven primary data sources were reviewed, two of which were studies based in Europe. Studies involved both closed-end and open-end questions; surveys varied in length from three questions to multi-page interviews. Populations involved in the studies were primarily adults, although one study involved students. The number of participants ranged from 13 to over 16,000 per study. In addition to the primary surveys, additional related studies were mined for pertinent information. The primary conclusions of the surveys reviewed are that the public knows very little about hydrogen and fuel cell technologies but is generally accepting of the potential for hydrogen use. In general, respondents consider themselves as environmentally conscious. The public considers safety as the primary issue surrounding hydrogen as a fuel. Price, performance, and convenience are also considerations that will have major impacts on purchase decisions.

  10. CC8 MRSA Strains Harboring SCCmec Type IVc are Predominant in Colombian Hospitals

    Science.gov (United States)

    Jiménez, J. Natalia; Ocampo, Ana M.; Vanegas, Johanna M.; Rodriguez, Erika A.; Mediavilla, José R.; Chen, Liang; Muskus, Carlos E.; A. Vélez, Lázaro; Rojas, Carlos; Restrepo, Andrea V.; Ospina, Sigifredo; Garcés, Carlos; Franco, Liliana; Bifani, Pablo; Kreiswirth, Barry N.; Correa, Margarita M.

    2012-01-01

    Background Recent reports highlight the incursion of community-associated MRSA within healthcare settings. However, knowledge of this phenomenon remains limited in Latin America. The aim of this study was to evaluate the molecular epidemiology of MRSA in three tertiary-care hospitals in Medellín, Colombia. Methods An observational cross-sectional study was conducted from 2008–2010. MRSA infections were classified as either community-associated (CA-MRSA) or healthcare-associated (HA-MRSA), with HA-MRSA further classified as hospital-onset (HAHO-MRSA) or community-onset (HACO-MRSA) according to standard epidemiological definitions established by the U.S. Centers for Disease Control and Prevention (CDC). Genotypic analysis included SCCmec typing, spa typing, PFGE and MLST. Results Out of 538 total MRSA isolates, 68 (12.6%) were defined as CA-MRSA, 243 (45.2%) as HACO-MRSA and 227 (42.2%) as HAHO-MRSA. The majority harbored SCCmec type IVc (306, 58.7%), followed by SCCmec type I (174, 33.4%). The prevalence of type IVc among CA-, HACO- and HAHO-MRSA isolates was 92.4%, 65.1% and 43.6%, respectively. From 2008 to 2010, the prevalence of type IVc-bearing strains increased significantly, from 50.0% to 68.2% (p = 0.004). Strains harboring SCCmec IVc were mainly associated with spa types t1610, t008 and t024 (MLST clonal complex 8), while PFGE confirmed that the t008 and t1610 strains were closely related to the USA300-0114 CA-MRSA clone. Notably, strains belonging to these three spa types exhibited high levels of tetracycline resistance (45.9%). Conclusion CC8 MRSA strains harboring SCCmec type IVc are becoming predominant in Medellín hospitals, displacing previously reported CC5 HA-MRSA clones. Based on shared characteristics including SCCmec IVc, absence of the ACME element and tetracycline resistance, the USA300-related isolates in this study are most likely related to USA300-LV, the recently-described ‘Latin American variant’ of USA300. PMID:22745670

  11. Experimental and Numerical Studies of Vitiated Air Effects on Hydrogen-fueled Supersonic Combustor Performance

    Institute of Scientific and Technical Information of China (English)

    LUO Feiteng; SONG Wenyan; ZHANG Zhiqiang; LI Weiqiang; LI Jianping

    2012-01-01

    This paper deals with the vitiation effects of test air on the scramjet performance in the ground combustion heated facilities.The primary goal is to evaluate the effects of H2O and CO2,the two major vitiated species generated by combustion heater,on hydrogen-fueled supersonic combustor performance with experimental and numerical approaches.The comparative experiments in the clean air and vitiated air are conducted by using the resistance heated direct-connected facility,with the typical Mach 4 flight conditions simulated.The H2O and CO2 species with accurately controlled contents are added to the high enthalpy clean air from resistance heater,to synthesize the vitiated air of a combustion-type heater.Typically,the contents of H2O species can be varied within the range of 3.5%-30o% by mole,and 3.0%-10% for CO2 species.The total temperature,total pressure,Mach number and O2 mole fraction at the combustor entrance are well-matched between the clean air and vitiated air.The combustion experiments are completed at the fuel equivalence ratios of 0.53 and 0.42 respectively.Furthermore,three-dimensional (3D) reacting flow simulations of combustor towpath are performed to provide insight into flow field structures and combustion chemistry details that cannot resolved by experimental instruments available.Finally,the experimental data,combined with computational results,are employed to analyze the effects of H2O and CO2 vitiated air on supersonic combustion characteristics and performance.It is concluded that H2O and CO2 contaminants can significantly inhibit the combustion induced pressure rise measured from combustor wall,and the pressure profile decreases with the increasing H2O and CO2 contents in nonlinear trend;simulation results agree well with experimental data and the overall vitiation effects are captured; direct extrapolation of the results from vitiated air to predict the performance of actual flight conditions could result in over-fueling the combustor

  12. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Oei, D.; Adams, J.A.; Kinnelly, A.A. [and others

    1997-07-01

    In partial fulfillment of the U.S. Department of Energy Contract No. DE-ACO2-94CE50389, {open_quotes}Direct Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell System for Transportation Applications{close_quotes}, this conceptual vehicle design report addresses the design and packaging of battery augmented fuel cell powertrain vehicles. This report supplements the {open_quotes}Conceptual Vehicle Design Report - Pure Fuel Cell Powertrain Vehicle{close_quotes} and includes a cost study of the fuel cell power system. The three classes of vehicles considered in this design and packaging exercise are the same vehicle classes that were studied in the previous report: the Aspire, representing the small vehicle class; the AIV (Aluminum Intensive Vehicle) Sable, representing the mid-size vehicle; and the E-150 Econoline, representing the van-size class. A preliminary PEM fuel cell power system manufacturing cost study is also presented. As in the case of the previous report concerning the {open_quotes}Pure Fuel Cell Powertrain Vehicle{close_quotes}, the same assumptions are made for the fuel cell power system. These assumptions are fuel cell system power densities of 0.33 kW/ka and 0.33 kW/l, platinum catalyst loading of less than or equal to 0.25 mg/cm{sup 2} total, and hydrogen tanks containing compressed gaseous hydrogen under 340 atm (5000 psia) pressure. The batteries considered for power augmentation of the fuel cell vehicle are based on the Ford Hybrid Electric Vehicle (HEV) program. These are state-of-the-art high power lead acid batteries with power densities ranging from 0.8 kW/kg to 2 kW/kg. The results reported here show that battery augmentation provides the fuel cell vehicle with a power source to meet instant high power demand for acceleration and start-up. Based on the assumptions made in this report, the packaging of the battery augmented fuel cell vehicle appears to be as feasible as the packaging of the pure fuel cell powered vehicle.

  13. High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water

    Energy Technology Data Exchange (ETDEWEB)

    Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

    2011-09-29

    The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector

  14. High Efficiency Generation of Hydrogen Fuels using Nuclear Power Annual Report August, 2000 - July 2001

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.C.

    2002-11-01

    OAK B188 High Efficiency Generation of Hydrogen Fuels using Nuclear Power Annual Report August 2000 - July 2001. Currently no large scale, cost-effective, environmentally attractive hydrogen production process is available for commercialization nor has such a process been identified. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Carbon dioxide emissions from fossil fuel combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. The benefits of this work will include the generation of a low-polluting transportable energy feedstock in an efficient method that has little or no implication for greenhouse gas emissions from a primary energy source whose availability and sources are domestically controlled. This will help to ensure energy for a future transportation/energy infrastructure that is not influenced/controlled by foreign governments. This report describes work accomplished during the second year (Phase 2) of a three year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first year (Phase 1) was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water, in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most, three) for further detailed consideration. Phase 1 met its goals and did select one process, the sulfur-iodine process, for investigation in Phases 2 and 3. The combined goals of Phases 2 and 3 were to select the advanced nuclear reactor best

  15. Preliminary performance appraisal of Navy V/STOL transport and search-type airplanes using hydrogen fuel

    Science.gov (United States)

    Strack, W. C.

    1974-01-01

    First-cut estimates are given of the performance advantages of liquid-hydrogen-fueled, ejector wing, V/STOL aircraft designed for shipboard delivery and search-type missions. Results indicate that the use of LH2 could reduce gross weights 30 percent, empty weights 15 percent, and energy consumption 10 percent for a fixed payload and mission. If gross weight is fixed, the delivery range could be increased about 60 percent or the hover time during a search mission doubled. No analysis or discussion of the economic and operational disadvantages is presented.

  16. The Günther-Tulip retrievable IVC filter: clinical experience in 118 consecutive patients.

    Science.gov (United States)

    Ota, Satoshi; Yamada, Norikazu; Tsuji, Akihiro; Ishikura, Ken; Nakamura, Mashio; Isaka, Naoki; Ito, Masaaki

    2008-02-01

    The purpose of this study was to assess the use of the Günther Tulip Filter (GTF) for the management of venous thromboembolism (VTE). Between December 2000 and April 2005, 118 patients (42 males, 76 females; mean age 60.5 years) diagnosed with VTE, underwent treatment with a GTF. The filter was left permanently in 52 patients. In the other 66 patients, attempts were made to retrieve it, with success in 60 cases (90.9%). No major complication was found throughout the filter's use. Of the 58 patients with the permanent filters, 41 underwent enhanced computed tomography at follow-up in the chronic phase. Thirty-eight filters (92.7%) remained patent, and under low-intensity anticoagulation therapy (international normalized ratio 1.8+/-0.4), the patency rate was 97.1%. Penetration of the inferior vena cava (IVC) wall by the filter's struts beyond a distance of 3 mm occurred in 23 patients (56.1%), but there was no observable leakage from the IVC or injury to adjacent organs. The GTF is feasible and safe for treating VTE. When used permanently, GTFs have a high patency rate, and there is neither leakage from the IVC nor injury to adjacent organs in the event of penetration by the struts.

  17. CECT EVALUATION OF AN ISOLATED LONG SEGMENT IVC THROMBUS IN A PATIENT WITH ACUTE ON CHRONIC PANCREATITIS: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Pronami

    2015-10-01

    Full Text Available Isolated Inferior vena cava (IVC thrombosis is a rare vascular complication of Pancreatitis. Vascular complications associated with Pancreatitis are more commonly seen in peripancreatic vessels like Splenic, portal or mesenteric veins. We report a case of isolated IVC thrombosis in a patient with chronic pancreatitis on acute exacerbation. Awareness of this rare complication will help in early diagnosis & treatment as well as prevent further dreaded complication like pulmonary embolism.

  18. Analytical and experimental investigation of rubbing interaction in labyrinth seals for a liquid hydrogen fuel pump. [space shuttle main engine

    Science.gov (United States)

    Dolan, F. X.; Kennedy, F. E.; Schulson, E. M.

    1984-01-01

    Cracking of the titanium knife edges on the labyrinth seals of the liquid hydrogen fuel pump in the Space Shuttle main engine is considered. Finite element analysis of the thermal response of the knife edge in sliding contact with the wear ring surface shows that interfacial temperatures can be quite high and they are significantly influenced by the thermal conductivity of the surfaces in rubbing contact. Thermal shock experiments on a test specimen similar to the knife edge geometry demonstrate that cracking of the titanium alloy is possible in a situation involving repeated thermal cycles over a wide temperature range, as might be realized during a rub in the liquid hydrogen fuel pump. High-speed rub interaction tests were conducted using a representative knife edge and seal geometry over a broad range of interaction rates and alternate materials were experimentally evaluated. Plasma-sprayed aluminum-graphite was found to be significantly better than presently used aluminum alloy seals from the standpoint of rub performance. Ion nitriding the titanium alloy knife-edges also improved rub performance compared to the untreated baseline.

  19. 3D Computation of Hydrogen-Fueled Combustion around Turbine Blade-Effect of Arrangement of Injector Holes -

    Institute of Scientific and Technical Information of China (English)

    Makoto YAMAMOTO; Junichi IKEDA; Kazuaki INABA

    2006-01-01

    Recently, a number of environmental problems caused from fossil fuel combustion have been focused on. In addition, with the eventual depletion of fossil energy resources, hydrogen gas is expected to be an alternative energy resource in the near future. It is characterized by high energy per unit weight, high reaction rate, wide range of flammability and the low emission property. On the other hand, many researches have been underway in several countries to improve a propulsion system for an advanced aircraft. The system is required to have higher power, lighter weight and lower emissions than existing ones. In such a future propulsion system, hydrogen gas would be one of the promising fuels for realizing the requirements. Considering these backgrounds, our group has proposed a new cycle concept for hydrogen-fueled aircraft propulsion system. In the present study, we perform 3dimensional computations of turbulent flow fields with hydrogen-fueled combustion around a turbine blade. The main objective is to clarify the influence of arrangement of hydrogen injector holes. Changing the chordwise and spanwise spacings of the holes, the 3 dimensional nature of the flow and thermal fields is numerically studied.

  20. Robot-arm-based NDE of hydrogen fuel tank using a 3D-movable HTS-SQUID gradiometer

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukade, Y; Hayashi, K; Tanaka, S [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Tanabe, K, E-mail: hatukade@eco.tut.ac.j [Superconductivity Research Laboratory, ISTEC, Shinonome 1-chome, Koto-ku, Tokyo 135-0062 (Japan)

    2010-06-01

    In this study, we constructed a robot-arm-based SQUID-NDE system utilizing a novel HTS-SQUID gradiometer with ramp-edge Josephson junctions for hydrogen fuel tank inspection, and developed an automatic 3D-scanning program. A cylindrical hydrogen fuel tank with a double-layer structure, in which a 3mm-thick Al liner was reinforced by a 3mm-thick carbon-fibre reinforced plastic (CFRP) cover, was prepared. The tank had a 10-mm-long through crack in the Al liner made by pressure cycle test. To inspect the tank using the SQUID-NDE system, we adopted a low-frequency eddy current technique that enables to excite deep part in the Al liner. By applying an excitation field of 7.5 {mu}T at 0.4 to 10 kHz to the tank from a double-D coil, the tank was scanned by the system while moving the HTS-SQUID gradiometer along curved surface of the tank in magnetically unshielded environment. Magnetic responses from the deep-lying crack in the tank were successfully detected by the system.

  1. The effect of IVM and IVC media on in vitro development of bovine embryos

    Directory of Open Access Journals (Sweden)

    E.T Mergawati

    2000-12-01

    Full Text Available The purpose of this study was to examine the effect of medium combination of IVM and IVC on the in vitro development of bovine embryos. The study involved 4 groups in a 2 (IVM medium x 2 (IVC medium factorial in a randomized block design. Each group was replicated for 5 times. The treatments were as follows: TCM-199/CR1aa (T1; TCM-199/SOF (T2; B- 199/CR1aa (T3 and B-199/SOF (T4. Oocytes were aspirated from ovaries collected at local abattoirs using aspiration medium of PBS supplemented with 3% FCS and 0.1% Penicillin and Streptomycin. The oocytes were matured in medium of TCM-199 or B-199 supplemented with 10% FCS, hormones: 10μg/ml FSH+ 10μg/ml hCG+ 1μg/ml Estradiol. Maturation was maintained at 37oC for 22 hours in 5% CO2 incubator with high humidity. A method of BRACKETT & Oliphant (BO was used to fertilize the matured oocytes. The fertilization was incubated for 7 hours in the 5% CO2 incubator. Two culture media of CR1aa or SOF/AA/BSA were used to develop the fertilized oocytes undergo to morula and blastocyst embryos. The findings showed that the proportion of oocytes cleaved and formation of blastocysts were affected significantly by a combination of IVM and IVC media (P<0.05. A combination of B-199/SOF (T4 resulted in a higher blastocyst rate (32% than others (T3= 29%; T2=T1= 23%. This study suggests that either SOF/AA/BSA or CR1aa has similar competence in development of bovine embryos in vitro.

  2. Subclassification of stage IV gastric cancer (IVa, IVb, and IVc) and prognostic significance of substages.

    Science.gov (United States)

    Ma, Yan; Xue, Yingwei; Li, Yanfeng; Lan, Xiuwen; Zhang, Yongle; Zhang, Ming

    2010-03-01

    Although the prognosis of stage IV gastric cancer is poor, some patients with stage IV gastric cancer had a long-term survival after gastrectomy. The objective of this study was to subclassify stage IV gastric cancer according to survival differences, evaluate the prognosis by substage, and identify the factors associated with patient survival in each substage. The data from 1,176 patients who underwent gastric resection for stage IV gastric cancer between 1988 and 2007 at Tumor Hospital of Harbin Medical University were reviewed retrospectively. The patients were divided into three substages according to the survival differences: stage IVa (T1-2N3M0), stage IVb (T3N3M0 and T4N1-2M0), and stage IVc (T4N3M0 and TanyNanyM1). The clinicopathological characteristics as well as survival of the patients were evaluated retrospectively by substage. There were no significant differences in survival among T3N3M0, T4N1M0, and T4N2M0 groups (p = 0.884) and between T4N3M0 and TanyNanyM1 groups (p = 0.192). The 5-year survival rates in stage IVa (T1-2N3M0), stage IVb (T3N3M0 and T4N1-2M0), and stage IVc (T4N3M0 and TanyNanyM1) were 22.7%, 9.9%, and 2.2%, respectively (p IVa and IVb; chemotherapy and operation type for stage IVc. For 406 patients with curative resection in stage IVa and IVb, hematogenous recurrence (35.9%) was the dominant recurrence pattern in stage IVa, whereas the most common patterns of recurrence were peritoneal (40.8%) and locoregional recurrence (31.8%) in stage IVb. Subclassification of stage IV gastric cancer into IVa (T1-2N3M0), IVb (T3N3M0 and T4N1-2M0), and IVc (T4N3M0, TanyNanyM1) may be helpful to predict the outcome and determine the therapeutic strategies for patients with stage IV gastric cancer.

  3. Final Project Closeout Report for Sprint Hydrogen Fuel Cell (HFC) Deployment Project in California, Gulf Coast and Eastern Seaboard Markets

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Kevin [Sprint, Reston, VA (United States); Bradley, Dwayne [Burns & McDonnell, Kansas City, MO (United States)

    2015-09-01

    Sprint is one of the telecommunications industry leaders in the deployment of hydrogen fuel cell (HFC) systems to provide backup power for their mission critical wireless network facilities. With several hundred fuel cells commissioned in California, states in the gulf coast region, and along the upper eastern seaboard. A strong incentive for advancing the integration of fuel cells into the Sprint network came through the award of a Department of Energy (DOE) grant focused on Market Transformation activities for project (EE0000486). This grant was funded by the 2009 American Recovery and Reinvestment Act (ARRA). The funding provided by DOE ($7.295M) was allocated to support the installation of 260 new HFC systems, equipped with an on-site refillable Medium Pressure Hydrogen Storage Solution (MPHSS), as well as for the conversion of 21 low pressure hydrogen systems to the MPHSS, in hopes of reducing barriers to market acceptance.

  4. Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.C.; Funk, J.F.; Showalter, S.K.

    1999-12-15

    OAK B188 Initial Screening of Thermochemical Water-Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using Nuclear Power There is currently no large scale, cost-effective, environmentally attractive hydrogen production process, nor is such a process available for commercialization. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Fossil fuels are polluting and carbon dioxide emissions from their combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. Almost 800 literature references were located which pertain to thermochemical production of hydrogen from water and over 100 thermochemical watersplitting cycles were examined. Using defined criteria and quantifiable metrics, 25 cycles have been selected for more detailed study.

  5. Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

    Science.gov (United States)

    Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

    2004-01-01

    This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

  6. Balancing low cost with reliable operation in the rotordynamic design of the ALS Liquid Hydrogen Fuel Turbopump

    Science.gov (United States)

    Greenhill, L. M.

    1990-01-01

    The Air Force/NASA Advanced Launch System (ALS) Liquid Hydrogen Fuel Turbopump (FTP) has primary design goals of low cost and high reliability, with performance and weight having less importance. This approach is atypical compared with other rocket engine turbopump design efforts, such as on the Space Shuttle Main Engine (SSME), which emphasized high performance and low weight. Similar to the SSME turbopumps, the ALS FTP operates supercritically, which implies that stability and bearing loads strongly influence the design. In addition, the use of low cost/high reliability features in the ALS FTP such as hydrostatic bearings, relaxed seal clearances, and unshrouded turbine blades also have a negative influence on rotordynamics. This paper discusses the analysis conducted to achieve a balance between low cost and acceptable rotordynamic behavior, to ensure that the ALS FTP will operate reliably without subsynchronous instabilities or excessive bearing loads.

  7. A study on the ultrasonic application for the efficiency elevation of the hydrogen fuel production: by the pressure sensor gage

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Eun Sun; Song, Min Guen; Son, Seung Woo [Gyeongsang National Univ., Jinju (Korea, Republic of)

    2003-09-01

    The production of hydrogen fuel depends basically on the water electrolysis. The ultrasonic effects the decrease of the overpotential in a water electrolysis. A study on the overpotential which activates the hydrogen production is the core to elevate the hydrogen production efficiency on the principle. A pressure sensor system by a new idea is developed and applied. Solutions are 4 kinds of KOH concentration such as 0%, 10%, 20%, and 30%. Two frequency bands of the ultrasonic transducer are 28kHz and 2MHz. The directions of ultrasonic forcing are the vertical direction and the horizontal direction. The temperatures are two states, i.e., no constant and constant. Experiments are carried out sequentially in order in three cases of no ultrasonic forcing, ultrasonic forcing, and ultrasonic discontinuation. In results, it is clarified that the ultrasonic effects the decrease of overpotential to elevate the efficiency of hydrogen production.

  8. Hydrogen Fuel Cell Vehicle Fuel Economy Testing at the U.S. EPA National Vehicle and Fuel Emissions Laboratory (SAE Paper 2004-01-2900)

    Science.gov (United States)

    The introduction of hydrogen fuel cell vehicles and their new technology has created the need for development of new fuel economy test procedures and safety procedures during testing. The United States Environmental Protection Agency-National Vehicle Fuels and Emissions Laborato...

  9. Sonographic evaluation of intravascular volume status: Can internal jugular or femoral vein collapsibility be used in the absence of IVC visualization?

    Directory of Open Access Journals (Sweden)

    Alistair Kent

    2015-01-01

    Full Text Available Introduction: Inferior vena cava collapsibility index (IVC-CI has been shown to correlate with both clinical and invasive assessment of intravascular volume status, but has important limitations such as the requirement for advanced sonographic skills, the degree of difficulty in obtaining those skills, and often challenging visualization of the IVC in the postoperative patient. The current study aims to explore the potential for using femoral (FV or internal jugular (IJV vein collapsibility as alternative sonographic options in the absence of adequate IVC visualization. Methods: A prospective, observational study comparing IVC-CI and Fem- and/or IJV-CI was performed in two intensive care units (ICU between January 2012 and April 2014. Concurrent M-mode measurements of IVC-CI and FV- and/or IJV-CI were collected during each sonographic session. Measurements of IVC were obtained using standard technique. IJV-CI and FV-CI were measured using high-frequency, linear array ultrasound probe placed in the corresponding anatomic areas. Paired data were analyzed using coefficient of correlation/determination and Bland-Altman determination of measurement bias. Results: We performed paired ultrasound examination of IVC-IJV (n = 39 and IVC-FV (n = 22, in 40 patients (mean age 54.1; 40% women. Both FV-CI and IJV-CI scans took less time to complete than IVC-CI scans (both, P < 0.02. Correlations between IVC-CI/FV-CI (R 2 = 0.41 and IVC-CI/IJV-CI (R 2 = 0.38 were weak. There was a mean -3.5% measurement bias between IVC-CI and IJV-CI, with trend toward overestimation for IJV-CI with increasing collapsibility. In contrast, FV-CI underestimated collapsibility by approximately 3.8% across the measured collapsibility range. Conclusion: Despite small measurement biases, correlations between IVC-CI and FV-/IJV-CI are weak. These results indicate that IJ-CI and FV-CI should not be used as a primary intravascular volume assessment tool for clinical decision support in

  10. IVC CLAMP: infrahepatic inferior vena cava clamping during hepatectomy - a randomised controlled trial in an interdisciplinary setting

    Directory of Open Access Journals (Sweden)

    Reissfelder Christoph

    2009-10-01

    Full Text Available Abstract Background Intraoperative haemorrhage is a known predictor for perioperative outcome of patients undergoing hepatic resection. While anaesthesiological lowering of central venous pressure (CVP by fluid restriction is known to reduce bleeding during transection of the hepatic parenchyma its potential side effects remain poorly investigated. In theory it may have negative effects on kidney function and tissue perfusion and bears the risk to result in severe haemodynamic instability in case of profound intraoperative blood loss. The present randomised controlled trial evaluates efficacy and safety of infrahepatic inferior vena cava (IVC clamping as an alternative surgical technique to reduce CVP during hepatic resection. Methods/Design The proposed IVC CLAMP trial is a single-centre randomised controlled trial with a two-group parallel design. Patients and outcome-assessors are blinded for the treatment intervention. Patients undergoing elective hepatic resection due to any reason are enrolled in IVC CLAMP. All patients admitted to the Department of General-, Visceral-, and Transplant Surgery, University of Heidelberg for elective hepatic resection are consecutively screened for eligibility and written informed consent is obtained on the day before surgery. The primary objective of this trial is to assess and compare the amount of blood loss during hepatic resection in patients receiving surgical CVP reduction by clamping of the IVC as compared to anaesthesiological CVP without infrahepatic IVC clamping reduction. In addition to blood loss a set of general as well as surgical variables are analysed. Discussion This is a randomised controlled patient and observer blinded two-group parallel trial designed to assess efficacy and safety of infrahepatic IVC clamping during elective hepatectomy. Trial registration ClinicalTrials NCT00732979

  11. Commercializing light-duty plug-in/plug-out hydrogen-fuel-cell vehicles: "Mobile electricity" technologies, early California household markets, and innovation management

    Science.gov (United States)

    Williams, Brett David

    Starting from the premise that new consumer value must drive hydrogen-fuel-cell-vehicle (H2FCV) commercialization, a group of opportunities collectively called "Mobile Electricity" (Me-) is characterized. Me- redefines H2 FCVs as innovative products able to provide home recharging and mobile power, for example for tools, mobile activities, emergencies, and electric-grid-support services. To characterize such opportunities, this study first integrates and extends previous analyses of H2FCVs, plug-in hybrids, and vehicle-to-grid (V2G) power. It uses a new model to estimate zero-emission-power vs. zero-emission-driving tradeoffs, costs, and grid-support revenues for various electric-drive vehicle types and levels of infrastructure service. Next, the initial market potential for Me- enabled vehicles, such as H2FCVs and plug-in hybrids, is estimated by eliminating unlikely households from consideration for early adoption. 5.2 million of 33.9 million Californians in the 2000 Census live in households pre-adapted to Me-, 3.9 million if natural gas is required for home refueling. The possible sales base represented by this population is discussed. Several differences in demographic and other characteristics between the target market and the population as a whole are highlighted, and two issues related to the design of H2FCVs and their supporting infrastructure are discussed: vehicle range and home hydrogen refueling. These findings argue for continued investigation of this and similar target segments-which represent more efficient research populations for subsequent study by product designers and other decision-makers wishing to understand the early market dynamics facing Me- innovations. Next, Me-H2FCV commercialization issues are raised from the perspectives of innovation, product development, and strategic marketing. Starting with today's internalcombustion hybrids, this discussion suggests a way to move beyond the battery vs. fuel-cell zero-sum game and towards the

  12. Activation of group IVC phospholipase A2 by polycyclic aromatic hydrocarbons induces apoptosis of human coronary artery endothelial cells

    Science.gov (United States)

    Richards, Sean M.; Elgayyar, Mona A.; Menn, Fu-Minn; Vulava, Vijay M.; McKay, Larry; Sanseverino, John; Sayler, Gary; Tucker, Dawn E.; Leslie, Christina C.; Lu, Kim P.; Ramos, Kenneth S.

    2016-01-01

    Exposure to environmental pollutants, such as polycyclic aromatic hydrocarbons (PAHs) found in coal tar mixtures and tobacco sources, is considered a significant risk factor for the development of heart disease in humans. The goal of this study was to determine the influence of PAHs present at a Superfund site on human coronary artery endothelial cell (HCAEC) phospholipase A2 (PLA2) activity and apoptosis. Extremely high levels of 12 out of 15 EPA high-priority PAHs were present in both the streambed and floodplain sediments at a site where an urban creek and its adjacent floodplain were extensively contaminated by PAHs and other coal tar compounds. Nine of the 12 compounds and a coal tar mixture (SRM 1597A) activated group IVC PLA2 in HCAECs, and activation of this enzyme was associated with histone fragmentation and poly (ADP) ribose polymerase (PARP) cleavage. Genetic silencing of group IVC PLA2 inhibited both 3H-fatty acid release and histone fragmentation by PAHs and SRM 1597A, indicating that individual PAHs and a coal tar mixture induce apoptosis of HCAECs via a mechanism that involves group IVC PLA2. Western blot analysis of aortas isolated from feral mice (Peromyscus leucopus) inhabiting the Superfund site showed increased PARP and caspase-3 cleavage when compared to reference mice. These data suggest that PAHs induce apoptosis of HCAECs via activation of group IVC PLA2. PMID:21132278

  13. An Application of the PMI Model at the Project Level Evaluation of ESEA Title IV-C Projects.

    Science.gov (United States)

    McBeath, Marcia

    All of the papers presented as part of a symposium concerned the application of the Planning, Monitoring, and Implementation Model (PMI) to the evaluation of the District of Columbia Public Schools' programs supported by the Elementary Secondary Education Act (ESEA) Title IV-C. PMI was developed to provide a model for systematic evaluation of…

  14. Commercializing light-duty plug-in/plug-out hydrogen-fuel-cell vehicles: "Mobile Electricity" technologies and opportunities

    Science.gov (United States)

    Williams, Brett D.; Kurani, Kenneth S.

    Starting from the premise that new consumer value must drive hydrogen-fuel-cell-vehicle (H 2FCV) commercialization, a group of opportunities collectively called "Mobile Electricity" is characterized. Mobile Electricity (Me-) redefines H 2FCVs as innovative products able to import and export electricity across the traditional vehicle boundary. Such vehicles could provide home recharging and mobile power, for example for tools, mobile activities, emergencies, and electric-grid-support services. This study integrates and extends previous analyses of H 2FCVs, plug-in hybrids, and vehicle-to-grid (V2G) power. Further, it uses a new electric-drive-vehicle and vehicular-distributed-generation model to estimate zero-emission-power versus zero-emission-driving tradeoffs, costs, and grid-support revenues for various electric-drive vehicle types and levels of infrastructure service. By framing market development in terms of new consumer value flowing from Me-, this study suggests a way to move beyond the battery versus fuel-cell zero-sum game and towards the development of integrated plug-in/plug-out hybrid platforms. As one possible extension of this Me- product platform, H 2FCVs might supply clean, high-power, and profitable Me- services as the technologies and markets mature.

  15. Overcoming the Range Limitation of Medium-Duty Battery Electric Vehicles through the use of Hydrogen Fuel-Cells

    Energy Technology Data Exchange (ETDEWEB)

    Wood, E.; Wang, L.; Gonder, J.; Ulsh, M.

    2013-10-01

    Battery electric vehicles possess great potential for decreasing lifecycle costs in medium-duty applications, a market segment currently dominated by internal combustion technology. Characterized by frequent repetition of similar routes and daily return to a central depot, medium-duty vocations are well positioned to leverage the low operating costs of battery electric vehicles. Unfortunately, the range limitation of commercially available battery electric vehicles acts as a barrier to widespread adoption. This paper describes the National Renewable Energy Laboratory's collaboration with the U.S. Department of Energy and industry partners to analyze the use of small hydrogen fuel-cell stacks to extend the range of battery electric vehicles as a means of improving utility, and presumably, increasing market adoption. This analysis employs real-world vocational data and near-term economic assumptions to (1) identify optimal component configurations for minimizing lifecycle costs, (2) benchmark economic performance relative to both battery electric and conventional powertrains, and (3) understand how the optimal design and its competitiveness change with respect to duty cycle and economic climate. It is found that small fuel-cell power units provide extended range at significantly lower capital and lifecycle costs than additional battery capacity alone. And while fuel-cell range-extended vehicles are not deemed economically competitive with conventional vehicles given present-day economic conditions, this paper identifies potential future scenarios where cost equivalency is achieved.

  16. Efficiency analysis of a hydrogen-fueled solid oxide fuel cell system with anode off-gas recirculation

    Science.gov (United States)

    Peters, Roland; Deja, Robert; Engelbracht, Maximilian; Frank, Matthias; Nguyen, Van Nhu; Blum, Ludger; Stolten, Detlef

    2016-10-01

    This study analyzes different hydrogen-fueled solid oxide fuel cell (SOFC) system layouts. It begins with a simple system layout without any anode off-gas recirculation, continues with a configuration equipped with off-gas recirculation, including steam condensation and then considers a layout with a dead-end anode off-gas loop. Operational parameters such as stack fuel utilization, as well as the recirculation rate, are modified, with the aim of achieving the highest efficiency values. Drawing on experiments and the accumulated experience of the SOFC group at the Forschungszentrum Jülich, a set of operational parameters were defined and applied to the simulations. It was found that anode off-gas recirculation, including steam condensation, improves electrical efficiency by up to 11.9 percentage-points compared to a layout without recirculation of the same stack fuel utilization. A system layout with a dead-end anode off-gas loop was also found to be capable of reaching electrical efficiencies of more than 61%.

  17. An experimental investigation on hydrogen fuel injection in intake port and manifold with different EGR rates

    Directory of Open Access Journals (Sweden)

    N.Saravanan, G.Nagarajan

    2010-03-01

    Full Text Available In the present investigation hydrogen was used in a diesel engine in the dual fuel mode using diesel as an ignition source. In order to have a precise control of hydrogen flow and to avoid the backfire and pre-ignition problems hydrogen was injected into the intake system. Experiments were conducted to determine the optimized injection timing, injection duration and injection quantity of the fuel in manifold and port injected hydrogen-operated engine using diesel as ignition source for hydrogen operation. From the results it was observed that in manifold injection technique the optimized condition was start of injection at gas exchange top dead centre (GTDC with injection duration of 30o crank angle (CA with hydrogen flow rate of 7.5 litres/min. In port injection technique, the optimized condition was start of injection at 5o before gas exchange top dead centre (5o BGTDC with injection duration of 30o CA with hydrogen flow rate of 7.5 litres/min. With the above optimized timings of port and manifold injection it was observed that brake thermal efficiency in port injection increases by 13 % and 16 % in manifold injection at 75 % load. However at full load the brake thermal efficiency decreases by 1 % in port injection and 8 % in manifold injection. A reduction in NOX emission by 4 times is observed in port injection and 7 times in manifold injection at full load. At 75 % load the NOX emission reduces by 3 times in both port injection and manifold injection. Smoke emission increases with increase in EGR percentage. The smoke increases by 36 % at full load in port injection and by 44 % in manifold injection. At 75 % load the smoke emission reduces by 13 % in port injection and 9 % in manifold injection. In both the port injection and manifold injection ignition delay was 12o or 1.33 ms while for diesel it was 11o or 1.22 ms. Port injection system with diesel as ignition source operates smoothly and shows improved performance and emit lesser

  18. The Effect of Converting to a U.S. Hydrogen Fuel Cell Vehicle Fleet on Emissions and Energy Use

    Science.gov (United States)

    Colella, W. G.; Jacobson, M. Z.; Golden, D. M.

    2004-12-01

    This study analyzes the potential change in emissions and energy use from replacing fossil-fuel based vehicles with hydrogen fuel cell vehicles. This study examines three different hydrogen production scenarios to determine their resultant emissions and energy usage: hydrogen produced via 1) steam reforming of methane, 2) coal gasification, or 3) wind electrolysis. The atmospheric model simulations require two primary sets of data: the actual emissions associated with hydrogen fuel production and use, and the corresponding reduction in emissions associated with reducing fossil fuel use. The net change in emissions is derived using 1) the U.S. EPA's National Emission Inventory (NEI) that incorporates several hundred categories of on-road vehicles and 2) a Process Chain Analysis (PCA) for the different hydrogen production scenarios. NEI: The quantity of hydrogen-related emission is ultimately a function of the projected hydrogen consumption in on-road vehicles. Data for hydrogen consumption from on-road vehicles was derived from the number of miles driven in each U.S. county based on 1999 NEI data, the average fleet mileage of all on-road vehicles, the average gasoline vehicle efficiency, and the efficiency of advanced 2004 fuel cell vehicles. PCA: PCA involves energy and mass balance calculations around the fuel extraction, production, transport, storage, and delivery processes. PCA was used to examine three different hydrogen production scenarios: In the first scenario, hydrogen is derived from natural gas, which is extracted from gas fields, stored, chemically processed, and transmitted through pipelines to distributed fuel processing units. The fuel processing units, situated in similar locations as gasoline refueling stations, convert natural gas to hydrogen via a combination of steam reforming and fuel oxidation. Purified hydrogen is compressed for use onboard fuel cell vehicles. In the second scenario, hydrogen is derived from coal, which is extracted from

  19. Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) System for Long-Haul Rail Application

    Science.gov (United States)

    Chow, Justin Jeff

    Freight movement of goods is the artery for America's economic health. Long-haul rail is the premier mode of transport on a ton-mile basis. Concerns regarding greenhouse gas and criteria pollutant emissions, however, have motivated the creation of annually increasing locomotive emissions standards. Health issues from diesel particulate matter, especially near rail yards, have also been on the rise. These factors and the potential to raise conventional diesel-electric locomotive performance warrants the investigation of using future fuels in a more efficient system for locomotive application. This research evaluates the dynamic performance of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) Hybrid system operating on hydrogen fuel to power a locomotive over a rail path starting from the Port of Los Angeles and ending in the City of Barstow. Physical constraints, representative locomotive operation logic, and basic design are used from a previous feasibility study and simulations are performed in the MATLAB Simulink environment. In-house controls are adapted to and expanded upon. Results indicate high fuel-to-electricity efficiencies of at least 54% compared to a conventional diesel-electric locomotive efficiency of 35%. Incorporation of properly calibrated feedback and feed-forward controls enables substantial load following of difficult transients that result from train kinematics while maintaining turbomachinery operating requirements and suppressing thermal stresses in the fuel cell stack. The power split between the SOFC and gas turbine is deduced to be a deterministic factor in the balance between capital and operational costs. Using hydrogen results in no emissions if renewable and offers a potential of 24.2% fuel energy savings for the rail industry.

  20. Platinum supported on titanium-ruthenium oxide is a remarkably stable electrocatayst for hydrogen fuel cell vehicles.

    Science.gov (United States)

    Parrondo, Javier; Han, Taehee; Niangar, Ellazar; Wang, Chunmei; Dale, Nilesh; Adjemian, Kev; Ramani, Vijay

    2014-01-07

    We report a unique and highly stable electrocatalyst-platinum (Pt) supported on titanium-ruthenium oxide (TRO)-for hydrogen fuel cell vehicles. The Pt/TRO electrocatalyst was exposed to stringent accelerated test protocols designed to induce degradation and failure mechanisms identical to those seen during extended normal operation of a fuel cell automobile-namely, support corrosion during vehicle startup and shutdown, and platinum dissolution during vehicle acceleration and deceleration. These experiments were performed both ex situ (on supports and catalysts deposited onto a glassy carbon rotating disk electrode) and in situ (in a membrane electrode assembly). The Pt/TRO was compared against a state-of-the-art benchmark catalyst-Pt supported on high surface-area carbon (Pt/HSAC). In ex situ tests, Pt/TRO lost only 18% of its initial oxygen reduction reaction mass activity and 3% of its oxygen reduction reaction-specific activity, whereas the corresponding losses for Pt/HSAC were 52% and 22%. In in situ-accelerated degradation tests performed on membrane electrode assemblies, the loss in cell voltage at 1 A · cm(-2) at 100% RH was a negligible 15 mV for Pt/TRO, whereas the loss was too high to permit operation at 1 A · cm(-2) for Pt/HSAC. We clearly show that electrocatalyst support corrosion induced during fuel cell startup and shutdown is a far more potent failure mode than platinum dissolution during fuel cell operation. Hence, we posit that the need for a highly stable support (such as TRO) is paramount. Finally, we demonstrate that the corrosion of carbon present in the gas diffusion layer of the fuel cell is only of minor concern.

  1. Platinum supported on titanium–ruthenium oxide is a remarkably stable electrocatayst for hydrogen fuel cell vehicles

    Science.gov (United States)

    Parrondo, Javier; Han, Taehee; Niangar, Ellazar; Wang, Chunmei; Dale, Nilesh; Adjemian, Kev; Ramani, Vijay

    2014-01-01

    We report a unique and highly stable electrocatalyst—platinum (Pt) supported on titanium–ruthenium oxide (TRO)—for hydrogen fuel cell vehicles. The Pt/TRO electrocatalyst was exposed to stringent accelerated test protocols designed to induce degradation and failure mechanisms identical to those seen during extended normal operation of a fuel cell automobile—namely, support corrosion during vehicle startup and shutdown, and platinum dissolution during vehicle acceleration and deceleration. These experiments were performed both ex situ (on supports and catalysts deposited onto a glassy carbon rotating disk electrode) and in situ (in a membrane electrode assembly). The Pt/TRO was compared against a state-of-the-art benchmark catalyst—Pt supported on high surface-area carbon (Pt/HSAC). In ex situ tests, Pt/TRO lost only 18% of its initial oxygen reduction reaction mass activity and 3% of its oxygen reduction reaction-specific activity, whereas the corresponding losses for Pt/HSAC were 52% and 22%. In in situ-accelerated degradation tests performed on membrane electrode assemblies, the loss in cell voltage at 1 A · cm−2 at 100% RH was a negligible 15 mV for Pt/TRO, whereas the loss was too high to permit operation at 1 A · cm−2 for Pt/HSAC. We clearly show that electrocatalyst support corrosion induced during fuel cell startup and shutdown is a far more potent failure mode than platinum dissolution during fuel cell operation. Hence, we posit that the need for a highly stable support (such as TRO) is paramount. Finally, we demonstrate that the corrosion of carbon present in the gas diffusion layer of the fuel cell is only of minor concern. PMID:24367118

  2. Green tea polyphenols added to IVM and IVC media affect transcript abundance, apoptosis, and pregnancy rates in bovine embryos.

    Science.gov (United States)

    Wang, Zhengguang; Fu, Chunquan; Yu, Songdong

    2013-01-01

    Three experiments were conducted to examine the effects of green tea polyphenols (GTP) during IVM and IVC on apoptosis and relative transcript abundance (RA) of three genes controlling antioxidant enzymes, as well as subsequent pregnancy rates. In experiment 1, oocytes were matured in the presence of 0, 10, 15, or 25 μM GTP for 24 hours. The GTP dose applied to IVM medium was followed by the same dose supplemented to IVC medium, so oocytes and embryos of a given group were cultured in similar conditions. This resulted in a total of four groups (three experimental groups and the control). After IVF, presumptive zygotes were cultured in medium containing 0 to 25 μM GTP for 8 days. The addition of 15 μM GTP during IVM and IVC increased RA of SOD1, CAT, and GPX genes in blastocysts compared with the control (P decreased the apoptotic index (AI) in blastocysts (7.4% and 6.2% respectively) compared with the control (9.3%; P pregnancy rate was evaluated after embryo transfer in experiment 3. Cows receiving embryos treated with 15 μM GTP had higher pregnancy rates on Day 30 (34.8% vs. 28.6%) and Day 60 (34.8% vs. 23.9%) than those receiving control embryos (P pregnancy rates; this improvement seemed to be associated with the increase of RA of antioxidant enzyme genes and the decrease in AI in bovine blastocysts.

  3. Iatrogenic migration of VenaTech LP IVC filter to superior vena cava secondary to guidewire entrapment: case report and review of literature.

    Science.gov (United States)

    Almestady, Rajaa; Spain, James; Bayona-Molano, Maria Del Pilar; Wang, Weiping

    2013-01-01

    Modern inferior vena cava (IVC) filters are generally safe devices for preventing pulmonary embolus, with fewer complications compared to earlier techniques of caval interruption. Despite continuing improvement in filter designs and insertion methods, complications still occur. The IVC filter complications resulting from iatrogenic causes are rare and include but are not limited to misplacement, filter tilting, incomplete deployment, and filter migration. We recently experienced a problem in which the Vena Tech LP filter (B. Braun, Bethlehem, Pennsylvania) migrated to the superior vena cava (SVC) immediately after successful deployment of the filter in the infrarenal venacava. The root cause analysis of this case revealed that the complication was related to blind pullout of the J-tipped guidewire following deployment of the filter in the IVC. This report highlights the potential risks of using a wire while an IVC filter is in place.

  4. Perforation of the IVC: rule rather than exception after longer indwelling times for the Günther Tulip and Celect retrievable filters.

    Science.gov (United States)

    Durack, Jeremy C; Westphalen, Antonio C; Kekulawela, Stephanie; Bhanu, Shiv B; Avrin, David E; Gordon, Roy L; Kerlan, Robert K

    2012-04-01

    This study was designed to assess the incidence, magnitude, and impact upon retrievability of vena caval perforation by Günther Tulip and Celect conical inferior vena cava (IVC) filters on computed tomographic (CT) imaging. Günther Tulip and Celect IVC filters placed between July 2007 and May 2009 were identified from medical records. Of 272 IVC filters placed, 50 (23 Günther Tulip, 46%; 27 Celect, 54%) were retrospectively assessed on follow-up abdominal CT scans performed for reasons unrelated to the filter. Computed tomography scans were examined for evidence of filter perforation through the vena caval wall, tilt, or pericaval tissue injury. Procedure records were reviewed to determine whether IVC filter retrieval was attempted and successful. Perforation of at least one filter component through the IVC was observed in 43 of 50 (86%) filters on CT scans obtained between 1 and 880 days after filter placement. All filters imaged after 71 days showed some degree of vena caval perforation, often as a progressive process. Filter tilt was seen in 20 of 50 (40%) filters, and all tilted filters also demonstrated vena caval perforation. Transjugular removal was attempted in 12 of 50 (24%) filters and was successful in 11 of 12 (92%). Longer indwelling times usually result in vena caval perforation by retrievable Günther Tulip and Celect IVC filters. Although infrequently reported in the literature, clinical sequelae from IVC filter components breaching the vena cava can be significant. We advocate filter retrieval as early as clinically indicated and increased attention to the appearance of IVC filters on all follow-up imaging studies.

  5. Hydrogen fuel - Universal energy

    Science.gov (United States)

    Prince, A. G.; Burg, J. A.

    The technology for the production, storage, transmission, and consumption of hydrogen as a fuel is surveyed, with the physical and chemical properties of hydrogen examined as they affect its use as a fuel. Sources of hydrogen production are described including synthesis from coal or natural gas, biomass conversion, thermochemical decomposition of water, and electrolysis of water, of these only electrolysis is considered economicially and technologically feasible in the near future. Methods of production of the large quantities of electricity required for the electrolysis of sea water are explored: fossil fuels, hydroelectric plants, nuclear fission, solar energy, wind power, geothermal energy, tidal power, wave motion, electrochemical concentration cells, and finally ocean thermal energy conversion (OTEC). The wind power and OTEC are considered in detail as the most feasible approaches. Techniques for transmission (by railcar or pipeline), storage (as liquid in underwater or underground tanks, as granular metal hydride, or as cryogenic liquid), and consumption (in fuel cells in conventional power plants, for home usage, for industrial furnaces, and for cars and aircraft) are analyzed. The safety problems of hydrogen as a universal fuel are discussed, noting that they are no greater than those for conventional fuels.

  6. Günther Tulip and Celect IVC filters in multiple-trauma patients.

    Science.gov (United States)

    Rosenthal, David; Kochupura, Paul V; Wellons, Eric D; Burkett, Allison B; Methodius-Rayford, Walaya C

    2009-08-01

    To evaluate results with the retrievable Günther Tulip (GT) and Celect inferior vena cava filters (IVCFs) placed at the intensive care unit (ICU) bedside under "real-time" intravascular ultrasound (IVUS) guidance in multiple-trauma patients. Between December 2004 and December 2008, 187 multiple-trauma patients (109 men; mean age 44+/-2 years, range 17-71) with contraindications to low-dose anticoagulation therapy or sequential compression devices had Günther Tulip (n = 97) or Celect (n = 90) retrievable IVCFs placed under real-time IVUS guidance. Günther Tulip filters were inserted using a "double-puncture" technique. The Celect IVCFs were placed with a simplified single-puncture technique in which the filter introducer sheath was advanced until the radiopaque tip "covered" the IVUS image of the renal vein, indicating that the filter sheath was in position for filter deployment. The 2 filter groups were compared on the endpoints of technical implantation success, retrievability, prevention of PE, and procedure-related deep vein thrombosis (DVT). As verified by abdominal radiography, 93.1% (174/187) of IVCFs were placed without complications; 6 IVCFs (all GT; p = 0.03 versus Celect) were misplaced in the iliac vein but uneventfully retrieved and replaced in the IVC within 24 hours. Two insertion site femoral vein DVTs (both in the dual puncture group; p>0.2) and 5 groin hematomas occurred during follow-up. GT filters were in place a mean of 107 days and Celect 97 days. In this time, 2 pulmonary embolisms occurred (1 in each group; p>0.2). Of the 115 filters scheduled for retrieval (50 Günther Tulip, 65 Celect), 33 (23 Günther Tulip, 10 Celect) could not be retrieved (p = 0.0004). Vena cavography identified filter tilting (>20 degrees ) in 21 cases (15 GT, 6 Celect), while 12 filters (8 GT, 4 Celect) had extended indwell times (mean 187 days) and excessive tissue ingrowth covering the retrieval hook. Subjectively, the Celect filters were clinically "easier" to

  7. Rise and subsequent decline of community-associated methicillin resistant Staphylococcus aureus ST30-IVc in Copenhagen, Denmark through an effective search and destroy policy

    DEFF Research Database (Denmark)

    Bartels, M D; Kristoffersen, K; Boye, K;

    2010-01-01

    , evaluating the effect of MRSA eradication therapy (ET), and finding links among patients. Twenty-three index patients infected with the ST30-IVc clone from November 2003 to September 2005 were contacted and transmission chains were studied. The majority of ST30-IVc patients had a connection......The number of patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased rapidly in Copenhagen, Denmark since 2003. Patients with the typical Panton-Valentine leukocidin-positive CA-MRSA clone ST30-IVc were contacted with the aim of treating MRSA carriers...... to the Philippines. Household members were screened for MRSA and all members of families with MRSA carriers were offered treatment of the carrier state and were followed for 1 year. MRSA carriers were found in seven of 16 households and transmission occurred among close contacts and in kindergartens. Five days of ET...

  8. U.S. Department of Energy FreedomCar & Vehicle Technologies Program CARB Executive Order Exemption Process for a Hydrogen-fueled Internal Combustion engine Vehicle -- Status Report

    Energy Technology Data Exchange (ETDEWEB)

    2008-04-01

    The CARB Executive Order Exemption Process for a Hydrogen-fueled Internal Combustion Engine Vehicle was undertaken to define the requirements to achieve a California Air Resource Board Executive Order for a hydrogenfueled vehicle retrofit kit. A 2005 to 2006 General Motors Company Sierra/Chevrolet Silverado 1500HD pickup was assumed to be the build-from vehicle for the retrofit kit. The emissions demonstration was determined not to pose a significant hurdle due to the non-hydrocarbon-based fuel and lean-burn operation. However, significant work was determined to be necessary for Onboard Diagnostics Level II compliance. Therefore, it is recommended that an Experimental Permit be obtained from the California Air Resource Board to license and operate the vehicles for the durability of the demonstration in support of preparing a fully compliant and certifiable package that can be submitted.

  9. An In-situ materials analysis particle probe (MAPP) diagnostic to study particle density control and hydrogenic fuel retention in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Allain, Jean-Paul [Purdue Univ., West Lafayette, IN (United States)

    2014-09-05

    A new materials analysis particle probe (MAPP) was designed, constructed and tested to develop understanding of particle control and hydrogenic fuel retention in lithium-based plasma-facing surfaces in NSTX. The novel feature of MAPP is an in-situ tool to probe the divertor NSTX floor during LLD and lithium-coating shots with subsequent transport to a post-exposure in-vacuo surface analysis chamber to measure D retention. In addition, the implications of a lithiated graphite-dominated plasma-surface environment in NSTX on LLD performance, operation and ultimately hydrogenic pumping and particle control capability are investigated in this proposal. MAPP will be an invaluable tool for erosion/redeposition simulation code validation.

  10. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications: Conceptual vehicle design report pure fuel cell powertrain vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Oei, D.; Kinnelly, A.; Sims, R.; Sulek, M.; Wernette, D.

    1997-02-01

    In partial fulfillment of the Department of Energy (DOE) Contract No. DE-AC02-94CE50389, {open_quotes}Direct-Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell for Transportation Applications{close_quotes}, this preliminary report addresses the conceptual design and packaging of a fuel cell-only powered vehicle. Three classes of vehicles are considered in this design and packaging exercise, the Aspire representing the small vehicle class, the Taurus or Aluminum Intensive Vehicle (AIV) Sable representing the mid-size vehicle and the E-150 Econoline representing the van-size class. A fuel cell system spreadsheet model and Ford`s Corporate Vehicle Simulation Program (CVSP) were utilized to determine the size and the weight of the fuel cell required to power a particular size vehicle. The fuel cell power system must meet the required performance criteria for each vehicle. In this vehicle design and packaging exercise, the following assumptions were made: fuel cell power system density of 0.33 kW/kg and 0.33 kg/liter, platinum catalyst loading less than or equal to 0.25 mg/cm{sup 2} total and hydrogen tanks containing gaseous hydrogen under 340 atm (5000 psia) pressure. The fuel cell power system includes gas conditioning, thermal management, humidity control, and blowers or compressors, where appropriate. This conceptual design of a fuel cell-only powered vehicle will help in the determination of the propulsion system requirements for a vehicle powered by a PEMFC engine in lieu of the internal combustion (IC) engine. Only basic performance level requirements are considered for the three classes of vehicles in this report. Each vehicle will contain one or more hydrogen storage tanks and hydrogen fuel for 560 km (350 mi) driving range. Under these circumstances, the packaging of a fuel cell-only powered vehicle is increasingly difficult as the vehicle size diminishes.

  11. 太阳能-氢燃料电池系统性能研究%A Study on the Performance of Solar Hydrogen Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    孙建起; 耿亮; 郭晓飞; 杨郝楠; 李嘉欣

    2016-01-01

    氢燃料电池因其来源广泛、无污染、转换率高而成为能源领域关注的焦点.以质子交换膜氢燃料电池作为研究对象,通过对其发电过程原理分析及理论计算,阐明了太阳能-氢燃料电池在太阳能发电(光能原电能转换),电解水制取氢气(电能原氢能转换),燃料电池发电(氢能原电能转换)的整个能量转换过程.结果显示:质子交换膜氢燃料电池的转换率可达36.42%,实际制氢量与理论计算值误差小于5豫.%Hydrogen fuel cell has become the focus of attention in the field of energy because of its wide source, no pollution and high conversion rate. This paper, taking the proton exchange membrane fuel cell hydrogen as the object of study, expounds the energy conversion process of the solar hydrogen fuel cell in the solar electrical energy generation (solar energy to electric energy conversion), brine electrolysis to produce hydrogen (energy hydrogen energy conversion), fuel cell power generation (hydrogen electric en-ergy conversion) by the power generation process principle analysis and theoretical calculation. Then, through the experimental analysis of output characteristics and characteristics of proton exchange membrane, the result of the conversion rate of 36.42% and the actual production of hydrogen, with the theoretical cal-culated values with an error less than 5% are obtained by using HLD-QDC-1 type analyzer.

  12. Rise and subsequent decline of community-associated methicillin resistant Staphylococcus aureus ST30-IVc in Copenhagen, Denmark through an effective search and destroy policy

    DEFF Research Database (Denmark)

    Bartels, M D; Kristoffersen, K; Boye, K

    2010-01-01

    The number of patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased rapidly in Copenhagen, Denmark since 2003. Patients with the typical Panton-Valentine leukocidin-positive CA-MRSA clone ST30-IVc were contacted with the aim of treating MRSA carrie....... Treatment of MRSA carriers was difficult and required many resources, but the clone was eventually successfully eliminated. The import of ST30-IVc to Denmark will continue, but the spread of the clone in Denmark can be kept to a minimum by direct intervention in the affected families....

  13. Virulence of viral hemorrhagic septicemia virus (VHSV) genotypes Ia, IVa, IVb, and IVc in five fish species.

    Science.gov (United States)

    Emmenegger, Eveline J; Moon, Chang Hoon; Hershberger, Paul K; Kurath, Gael

    2013-12-12

    The susceptibility of yellow perch Perca flavescens, rainbow trout Oncorhynchus mykiss, Chinook salmon O. tshawytscha, koi Cyprinus carpio koi, and Pacific herring Clupea pallasii to 4 strains of viral hemorrhagic septicemia virus (VHSV) was assessed. Fish were challenged via intraperitoneal injection with high (1 × 106 plaque-forming units, PFU) and low (1 × 103 PFU) doses of a European strain (genotype Ia), and North American strains from the West coast (genotype IVa), Great Lakes (genotype IVb), and the East coast (genotype IVc). Pacific herring were exposed to the same VHSV strains, but at a single dose of 5 × 103 PFU ml-1 by immersion in static seawater. Overall, yellow perch were the most susceptible, with cumulative percent mortality (CPM) ranging from 84 to 100%, and 30 to 93% in fish injected with high or low doses of virus, respectively. Rainbow trout and Chinook salmon experienced higher mortalities (47 to 98% CPM) after exposure to strain Ia than to the other virus genotypes. Pacific herring were most susceptible to strain IVa with an average CPM of 80% and moderately susceptible (42 to 52% CPM) to the other genotypes. Koi had very low susceptibility (≤5.0% CPM) to all 4 VHSV strains. Fish tested at 7 d post challenge were positive for all virus strains, with yellow perch having the highest prevalence and concentrations of virus, and koi the lowest. While genotype Ia had higher virulence in salmonid species, there was little difference in virulence or host-specificity between isolates from subtypes IVa, IVb, and IVc.

  14. Virulence of viral hemorrhagic septicemia virus (VHSV) genotypes Ia, IVa, IVb, and IVc in five fish species.

    Science.gov (United States)

    Emmenegger, Eveline J.; Moon, Chang Hoon; Hershberger, Paul K.; Kurath, Gael

    2013-01-01

    The susceptibility of yellow perch Perca flavescens, rainbow trout Oncorhynchus mykiss, Chinook salmon O. tshawytscha, koi Cyprinus carpio koi, and Pacific herring Clupea pallasii to 4 strains of viral hemorrhagic septicemia virus (VHSV) was assessed. Fish were challenged via intraperitoneal injection with high (1 × 106 plaque-forming units, PFU) and low (1 × 103 PFU) doses of a European strain (genotype Ia), and North American strains from the West coast (genotype IVa), Great Lakes (genotype IVb), and the East coast (genotype IVc). Pacific herring were exposed to the same VHSV strains, but at a single dose of 5 × 103 PFU ml-1 by immersion in static seawater. Overall, yellow perch were the most susceptible, with cumulative percent mortality (CPM) ranging from 84 to 100%, and 30 to 93% in fish injected with high or low doses of virus, respectively. Rainbow trout and Chinook salmon experienced higher mortalities (47 to 98% CPM) after exposure to strain Ia than to the other virus genotypes. Pacific herring were most susceptible to strain IVa with an average CPM of 80% and moderately susceptible (42 to 52% CPM) to the other genotypes. Koi had very low susceptibility (≤5.0% CPM) to all 4 VHSV strains. Fish tested at 7 d post challenge were positive for all virus strains, with yellow perch having the highest prevalence and concentrations of virus, and koi the lowest. While genotype Ia had higher virulence in salmonid species, there was little difference in virulence or host-specificity between isolates from subtypes IVa, IVb, and IVc.  

  15. Activation of group IVC phospholipase A{sub 2} by polycyclic aromatic hydrocarbons induces apoptosis of human coronary artery endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tithof, Patricia K. [University of Tennessee, Department of Pathobiology, College of Veterinary Medicine, Knoxville, TN (United States); University of Tennessee, Center for Environmental Biotechnology, Knoxville, TN (United States); Richards, Sean M. [University of Tennessee, Department of Biological and Environmental Sciences, Chattanooga, TN (United States); Elgayyar, Mona A. [University of Tennessee, Department of Pathobiology, College of Veterinary Medicine, Knoxville, TN (United States); Menn, Fu-Minn; Vulava, Vijay M.; McKay, Larry; Sanseverino, John; Sayler, Gary [University of Tennessee, Center for Environmental Biotechnology, Knoxville, TN (United States); Tucker, Dawn E.; Leslie, Christina C. [National Jewish Medical and Research Center, Department of Pediatrics, Denver, CO (United States); Lu, Kim P. [Texas A and M University, Department of Biology, College Station, TX (United States); Ramos, Kenneth S. [University of Louisville, Department of Biochemistry and Molecular Biology, Louisville, KY (United States)

    2011-06-15

    Exposure to environmental pollutants, such as polycyclic aromatic hydrocarbons (PAHs) found in coal tar mixtures and tobacco sources, is considered a significant risk factor for the development of heart disease in humans. The goal of this study was to determine the influence of PAHs present at a Superfund site on human coronary artery endothelial cell (HCAEC) phospholipase A{sub 2} (PLA{sub 2}) activity and apoptosis. Extremely high levels of 12 out of 15 EPA high-priority PAHs were present in both the streambed and floodplain sediments at a site where an urban creek and its adjacent floodplain were extensively contaminated by PAHs and other coal tar compounds. Nine of the 12 compounds and a coal tar mixture (SRM 1597A) activated group IVC PLA{sub 2} in HCAECs, and activation of this enzyme was associated with histone fragmentation and poly (ADP) ribose polymerase (PARP) cleavage. Genetic silencing of group IVC PLA{sub 2} inhibited both {sup 3}H-fatty acid release and histone fragmentation by PAHs and SRM 1597A, indicating that individual PAHs and a coal tar mixture induce apoptosis of HCAECs via a mechanism that involves group IVC PLA{sub 2}. Western blot analysis of aortas isolated from feral mice (Peromyscus leucopus) inhabiting the Superfund site showed increased PARP and caspase-3 cleavage when compared to reference mice. These data suggest that PAHs induce apoptosis of HCAECs via activation of group IVC PLA{sub 2}. (orig.)

  16. Hydrogen Scenario Analysis Summary Report: Analysis of the Transition to Hydrogen Fuel Cell Vehicles and the Potential Hydrogen Energy Infrastructure Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Greene, David L [ORNL; Leiby, Paul Newsome [ORNL; James, Brian [Directed Technologies, Inc.; Perez, Julie [Directed Technologies, Inc.; Melendez, Margo [National Renewable Energy Laboratory (NREL); Milbrandt, Anelia [National Renewable Energy Laboratory (NREL); Unnasch, Stefan [Life Cycle Associates; Rutherford, Daniel [TIAX, LLC; Hooks, Matthew [TIAX, LLC

    2008-03-01

    Achieving a successful transition to hydrogen-powered vehicles in the U.S. automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction of these agents in the marketplace will determine the real costs and benefits of early market transformation policies, and ultimately the success of the transition itself. The transition to hydrogen-powered transportation faces imposing economic barriers. The challenges include developing and refining a new and different power-train technology, building a supporting fuel infrastructure, creating a market for new and unfamiliar vehicles, and achieving economies of scale in vehicle production while providing an attractive selection of vehicle makes and models for car-buyers. The upfront costs will be high and could persist for a decade or more, delaying profitability until an adequate number of vehicles can be produced and moved into consumer markets. However, the potential rewards to the economy, environment, and national security are immense. Such a profound market transformation will require careful planning and strong, consistent policy incentives. Section 811 of the Energy Policy Act (EPACT) of 2005, Public Law 109-59 (U.S. House, 2005), calls for a report from the Secretary of Energy on measures to support the transition to a hydrogen economy. The report was to specifically address production and deployment of hydrogen-fueled vehicles and the hydrogen production and delivery infrastructure needed to support those vehicles. In addition, the 2004 report of the National Academy of Sciences (NAS, 2004), The Hydrogen Economy, contained two recommendations for analyses to be conducted by the U.S. Department of Energy (DOE) to strengthen hydrogen energy transition and infrastructure planning for the hydrogen economy. In response to the EPACT requirement and NAS recommendations, DOE's Hydrogen, Fuel Cells and

  17. Role of IVC Filters in Endovenous Therapy for Deep Venous Thrombosis: The FILTER-PEVI (Filter Implantation to Lower Thromboembolic Risk in Percutaneous Endovenous Intervention) Trial

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi, Mohsen, E-mail: seyedmohsensharifi@yahoo.com [Arizona Cardiovascular Consultants (United States); Bay, Curt [A.T. Still University, Arizona School of Health Sciences (United States); Skrocki, Laura; Lawson, David; Mazdeh, Shahnaz [Arizona Cardiovascular Consultants (United States)

    2012-12-15

    Objectives: The purpose of this study was to evaluate the necessity of and recommend indications for inferior vena cava (IVC) filter implantation during percutaneous endovenous intervention (PEVI) for deep venous thrombosis (DVT).BackgroundPEVI has emerged as a powerful tool in the management of acute proximal DVT. Instrumentation of extensive fresh thrombus is potentially associated with iatrogenic pulmonary embolism (PE). The true frequency of this complication has not been studied in a randomized fashion. We evaluated IVC filter implantation during PEVI for DVT. Methods: A total of 141 patients with symptomatic proximal DVT undergoing PEVI for symptomatic DVT were randomized to receive an IVC filter (70 patients) or no filter (71 patients; control group). The anticoagulation and PEVI regimen were similar between the two groups. Patients with development of symptoms suggestive of PE underwent objective testing for PE. Results: PE developed in 1 of the 14 symptomatic patients in the filter group and 8 of the 22 patients in the control group (P = 0.048). There was no mortality in any group. Three patients (4.2%) in the control group had transient hemodynamic instability necessitating resuscitory efforts. Predictors of iatrogenic PE were found to be PE at admission; involvement of two or more adjacent venous segments with acute thrombus; inflammatory form of DVT (severe erythema, edema, pain, and induration); and vein diameter of {>=}7 mm with preserved architecture. Conclusions: IVC filter implantation during PEVI reduces the risk of iatrogenic PE by eightfold without a mortality benefit. A selective approach may be exercised in filter implantation during PEVI.

  18. Out with The Old-in with New -- Have Flexible Film Isolators Been Superceded by Individual Ventilated Cages(IVCs)?%以新换旧--用独立通风笼盒(IVC)取代弹性薄膜隔离器

    Institute of Scientific and Technical Information of China (English)

    格里·C·班廷

    2003-01-01

    In response to the needs for improved standards of bio-containment, individual ventilated cages (IVCs) have been developed. These cages provide a protected environment for animals and are of great assistance in containing airborne contaminants. As the number of transgenic animals has increased, IVCs have become more popular because of the possibilities they offer in the prevention of cross-contamination and their capability to house small groups of animals of differing sources in close proximity without compromising their health status.This paper will compare IVCs with flexible film isolators. Historically flexible film isolators have been the method of choice for housing animals of a defined health status such as gnotobiotic and germ free animals. The isolator was devel oped by Trexler and Reyniers during World War Ⅱ for the study of scrub typhus. Today the perception of using isolators for animal housing is still often met with the assumption that isolators are difficult to use and expensive to operate.At B&K Universal Limited we use both isolators and IVCs depending on the particular need. This paper will present a practical comparison of the two methods of containment.

  19. An Analysis of Environmental Dimensions Affected in Adoption of Hydrogen Fuel Cell Vehicles: A Study in Shah ALAM Industrial AREA, Selangor

    Directory of Open Access Journals (Sweden)

    Siron Rusinah

    2016-01-01

    Full Text Available The aim of the study is to identify the perceptions of respondents on environmental dimensions hat affected in adoption of hydrogen fuel cell vehicles. The study was conducted at Shah Alam industrial areas of Selangor, Malaysia, with the number of respondents are 120 respondents with various job positions that related with engineering and automobiles industry. The findings of the research shows that the dimensions of HFCV Internal Environmental total score of the items statement is 3.40 with the percentage of agreement in implementation is 3.72 percent, HFCV Environmental Information Systems shows that the total score of the items statement is 3.63 with the percentage of agreement on use to great extend is 42.5 percent, HFCV Cooperation with Customers shows that the total score of the items statement is 3.81 with the percentage of agreement on implementation is 44.2 percent. The findings on HFCV Eco Design shows that the total score of items statement is 4.02 with the percentage of agreement on implementation is 42.3 percent, HFCV Environmental Organizational Culture shows that the total score of the items statement is 3.37 with the percentage of agreement is 34.2 percent, HFCV Environmental Leadership shows that the total score of the items statement is 3.34 with the percentage of agreement is 48.2 percent. HFCV Proactive Green Innovation shows that the total score of items statement is 4.10 ahead of automobile got the highest mean score of 4.32 with the percentage of agreement is 41 percent. HFCV Environmental performance shows that the total score of the items statement is 3.87 with the percentage of agreement is 39 percent and the last environmental dimensions was HFCV Environmental Risks shows that the total score of the item statement is 4.00 with the percentage of agreement is 40 percent

  20. Hydrogen Scenario Analysis Summary Report: Analysis of the Transition to Hydrogen Fuel Cell Vehicles and the Potential Hydrogen Energy Infrastructure Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Greene, David L [ORNL; Leiby, Paul Newsome [ORNL; James, Brian [Directed Technologies, Inc.; Perez, Julie [Directed Technologies, Inc.; Melendez, Margo [National Renewable Energy Laboratory (NREL); Milbrandt, Anelia [National Renewable Energy Laboratory (NREL); Unnasch, Stefan [Life Cycle Associates; Rutherford, Daniel [TIAX, LLC; Hooks, Matthew [TIAX, LLC

    2008-03-01

    Achieving a successful transition to hydrogen-powered vehicles in the U.S. automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction of these agents in the marketplace will determine the real costs and benefits of early market transformation policies, and ultimately the success of the transition itself. The transition to hydrogen-powered transportation faces imposing economic barriers. The challenges include developing and refining a new and different power-train technology, building a supporting fuel infrastructure, creating a market for new and unfamiliar vehicles, and achieving economies of scale in vehicle production while providing an attractive selection of vehicle makes and models for car-buyers. The upfront costs will be high and could persist for a decade or more, delaying profitability until an adequate number of vehicles can be produced and moved into consumer markets. However, the potential rewards to the economy, environment, and national security are immense. Such a profound market transformation will require careful planning and strong, consistent policy incentives. Section 811 of the Energy Policy Act (EPACT) of 2005, Public Law 109-59 (U.S. House, 2005), calls for a report from the Secretary of Energy on measures to support the transition to a hydrogen economy. The report was to specifically address production and deployment of hydrogen-fueled vehicles and the hydrogen production and delivery infrastructure needed to support those vehicles. In addition, the 2004 report of the National Academy of Sciences (NAS, 2004), The Hydrogen Economy, contained two recommendations for analyses to be conducted by the U.S. Department of Energy (DOE) to strengthen hydrogen energy transition and infrastructure planning for the hydrogen economy. In response to the EPACT requirement and NAS recommendations, DOE's Hydrogen, Fuel Cells and

  1. Exploring Hydrogen Fuel Cell Technology

    Science.gov (United States)

    Brus, David; Hotek, Doug

    2010-01-01

    One of the most significant technological issues of the 21st Century is finding a way to fulfill the energy demands without destroying the environment through global warming and climate change. Worldwide human population is on the rise, and with it, the demand for more energy in pursuit of a higher quality of life. In the meantime, as people use…

  2. Exploring Hydrogen Fuel Cell Technology

    Science.gov (United States)

    Brus, David; Hotek, Doug

    2010-01-01

    One of the most significant technological issues of the 21st Century is finding a way to fulfill the energy demands without destroying the environment through global warming and climate change. Worldwide human population is on the rise, and with it, the demand for more energy in pursuit of a higher quality of life. In the meantime, as people use…

  3. DOE Hydrogen & Fuel Cell Overview

    Science.gov (United States)

    2011-01-13

    Technologies Program eere.energy.gov BMW Manufacturing site. Courtesy of Waste Management World ona power supp y 9 Additional vehicle fuel source...commercial demand • HEB, Whole Foods, Coca Cola, Sysco Nestle FedEx BMW etc , , , , ¾DLA Demonstrations helped enable Codes and Standard approval of

  4. WVU Hydrogen Fuel Dispensing Station

    Energy Technology Data Exchange (ETDEWEB)

    Davis, William [West Virginia University Research Corporation, Morgantown, WV (United States)

    2015-09-01

    The scope of this project was changed during the course of the project. Phase I of the project was to construct a site similar to the site at Central West Virginia Regional Airport in Charleston, WV to show that duplication of the site was a feasible method of conducting hydrogen stations. Phase II of the project was necessitated due to a lack of funding that was planned for the development of the station in Morgantown. The US Department of Energy determined that the station in Charleston would be dismantled and moved to Morgantown and reassembled at the Morgantown site. This necessitated storage of the components of the station for almost a year at the NAFTC Headquarters which caused a number of issues with the equipment that will be discussed in later portions of this report. This report will consist of PHASE I and PHASE II with discussions on each of the tasks scheduled for each phase of the project.

  5. Multi-unit inertial fusion plants based on HYLIFE-II, with shared heavy-ion RIA driver and target factory, producing electricity and hydrogen fuel

    Energy Technology Data Exchange (ETDEWEB)

    Logan, G.; Moir, R. [Lawrence Livermore National Lab., CA (United States); Hoffman, M. [Univ. of California, Davis, CA (United States)

    1994-05-05

    Following is a modification of the IFEFUEL systems code, called IFEFUEL2, to treat specifically the HYLIFE-II target chamber concept. The same improved Recirculating Induction Accelerator (RIA) energy scaling model developed recently by Bieri is used in this survey of the economics of multi-unit IFE plants producing both electricity and hydrogen fuel. Reference cases will assume conventional HI-indirect target gains for a 2 mm spot, and improved HYLIFE-II BoP models as per Hoffman. Credits for improved plant availability and lower operating costs due to HYLIFE-II`s 30-yr target chamber lifetime are included, as well as unit cost reductions suggested by Delene to credit greater {open_quotes}learning curve{close_quotes} benefits for the duplicated portions of a multi-unit plant. To illustrate the potential impact of more advanced assumptions, additional {open_quotes}advanced{close_quotes} cases will consider the possible benefits of an MHD + Steam BoP, where direct MHD conversion of plasma from baseball-size LiH target blanket shells is assumed to be possible in a new (as yet undesigned) liquid Flibe-walled target chamber, together and separately, with advanced, higher-gain heavy-ion targets with Fast Ignitors. These runs may help decide the course of a possible future {open_quotes}HYLIFE-III{close_quotes} IFE study. Beam switchyard and final focusing system costs per target chamber are assumed to be consistent with single-sided illumination, for either {open_quotes}conventional{close_quotes} or {open_quotes}advanced{close_quotes} indirect target gain assumptions. Target costs are scaled according to the model by Woodworth. In all cases, the driver energy and rep rate for each chosen number of target chambers and total plant output will be optimized to minimize the cost of electricity (CoE) and the associated cost of hydrogen (CoH), using a relationship between CoE and CoH to be presented in the next section.

  6. Caprine ovarian follicle requirements differ between preantral and early antral stages after IVC in medium supplemented with GH and VEGF alone or in combination.

    Science.gov (United States)

    Cadenas, J; Leiva-Revilla, J; Vieira, L A; Apolloni, L B; Aguiar, F L N; Alves, B G; Lobo, C H; Rodrigues, A P R; Apgar, G A; Smitz, J; Figueiredo, J R; Maside, C

    2017-01-01

    The aim of the present study was to evaluate the effect of growth hormone (GH) and vascular endothelial growth factor (VEGF) added alone, sequentially or in combination, in the presence of insulin at physiological concentration (10 ng/mL) on the IVC of two different follicular categories: preantral (experiment 1; Exp.1) and early antral (experiment 2; Exp.2). Isolated follicles were individually cultured for 24 (Exp.1) and 18 days (Exp.2) in the following treatments: αMEM(+) (Control), or Control medium supplemented with 50 ng/mL GH (GH), 100 ng/mL VEGF (VEGF), the combination of both (GH + VEGF), GH during the first 12 days and VEGF from Day 12 until the end of the culture (GH/VEGF) and vice versa (VEGF/GH). At the end of the culture, cumulus-oocyte complexes from in vitro-grown follicles were recovered and subjected to IVM. The following end points were evaluated: Follicle morphology, growth rates and antrum formation, production of estradiol, progesterone and testosterone, oocyte viability and meiotic stage, as well as relative expression of LHR, Amh, HAS2, PTGS2, CYP17, CYP19A1, and 3βHSD. A considerable amount of viable fully grown oocytes were recovered after the IVC of early antral follicles in all treatments. Nevertheless, the GH treatment presented the highest percentage of fully grown oocytes (60%), mean oocyte diameter (117.74 ± 2.61 μm), and meiotic resumption (50%). Furthermore, GH treatment produced higher (P GH to a culture medium containing physiological concentrations of insulin improves oocyte growth and maturation after the IVC of goat early antral follicles.

  7. Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina.

    Science.gov (United States)

    Fernandez, Silvina; Murzicato, Sofía; Sandoval, Orlando; Fernández-Canigia, Liliana; Mollerach, Marta

    2015-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. Community-acquired necrotizing pneumonia caused by methicillin-resistant Staphylococcus aureus ST30-SCCmecIVc-spat019-PVL positive in San Antonio de Areco, Argentina

    Directory of Open Access Journals (Sweden)

    Silvina Fernández

    2015-03-01

    Full Text Available Community-acquired methicillin-resistant Staphylococcus aureus is the first cause of skin and soft tissue infections, but can also produce severe diseases such as bacteremia, osteomyelitis and necrotizing pneumonia. Some S. aureus lineages have been described in cases of necrotizing pneumonia worldwide, usually in young, previously healthy patients. In this work, we describe a fatal case of necrotizing pneumonia due to community-acquired methicillin-resistant S. aureus clone ST30-SCCmecIVc-spat019-PVL positive in an immunocompetent adult patient.

  9. KILT (Kidney and IVC Abnormalities with Leg Thrombosis) Syndrome in a 41-Years-Old Man with Loin Pain and Fever.

    Science.gov (United States)

    Fung, James Kiujing; Yeung, Victor Hip Wo; Chu, Sau Kwan; Man, Chi Wan

    2017-05-01

    KILT syndrome is a rare condition composing the triad of kidney and inferior vena cava anomaly and extensive venous thrombosis. We present a case of newly diagnosed KILT syndrome in a 41-years-old gentleman presenting with loin pain and fever. Reviewing previous case reports, KILT syndrome is usually an incidental finding on imaging studies and there is a wide scope of initial clinical presentations. However, recent evidence suggests IVC anomaly may have caused subsequent renal hypoplasia. Identification of the underlying etiology may be helpful in planning early vascular intervention to treat the condition.

  10. Experiment on Synchronous Timing Signal Detection from ISDB-T Terrestrial Digital TV Signal with Application to Autonomous Distributed ITS-IVC Network

    Science.gov (United States)

    Karasawa, Yoshio; Kumagai, Taichi; Takemoto, Atsushi; Fujii, Takeo; Ito, Kenji; Suzuki, Noriyoshi

    A novel timing synchronizing scheme is proposed for use in inter-vehicle communication (IVC) with an autonomous distributed intelligent transport system (ITS). The scheme determines the timing of packet signal transmission in the IVC network and employs the guard interval (GI) timing in the orthogonal frequency divisional multiplexing (OFDM) signal currently used for terrestrial broadcasts in the Japanese digital television system (ISDB-T). This signal is used because it is expected that the automotive market will demand the capability for cars to receive terrestrial digital TV broadcasts in the near future. The use of broadcasts by automobiles presupposes that the on-board receivers are capable of accurately detecting the GI timing data in an extremely low carrier-to-noise ratio (CNR) condition regardless of a severe multipath environment which will introduce broad scatter in signal arrival times. Therefore, we analyzed actual broadcast signals received in a moving vehicle in a field experiment and showed that the GI timing signal is detected with the desired accuracy even in the case of extremely low-CNR environments. Some considerations were also given about how to use these findings.

  11. Evaluación del efecto de diferentes cepas de levadura (montrachet, k1-v1116, ec-1118, 71b-1122 y ivc-gre ®) y clarificantes sobre los atributos sensoriales del vino de naranja criolla (citrus sinensis)

    OpenAIRE

    Olivero, Rafael E; Aguas M, Yelitza; Cury R., Katia

    2011-01-01

    Evaluation of effect of various strains of yeast (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ®) and clearer on the sensory attributes orange wine (Citrus sinensis) RESUMEN En este trabajo se evaluó el efecto de diferentes cepas de levadura (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ®) sobre los atributos sensoriales del vino de naranja. Estos atributos fueron medidos utilizando la escala modificada de UC Davis. En una prueba de ordenamiento para determinar el mejor tratamiento ...

  12. Reassessment of IVC-CI in fluid resuscitation for hypovolemic shock%下腔静脉塌陷指数在低血容量性休克患者液体复苏疗效中的再评估

    Institute of Scientific and Technical Information of China (English)

    史迪; 郭树彬; 于学忠

    2015-01-01

    目的 明确下腔静脉塌陷指数能否作为低血容量性休克患者液体复苏疗效评估指标,寻找超声检查指标用于反映指导早期低血容量性休克诊断治疗.方法 对急诊低血容量性休克患者进行500 mL生理盐水液体复苏治疗,在治疗前及治疗后分别记录一般生命体征同时测量床旁心脏超声参数,进行一般生命体征参数与超声参数的前后比较.结果 本研究共入组40例低血容量性休克患者,其中男性23例、女性17例,年龄为(50.00±17.71)岁,超声检查时间为(8.68±5.73) min,中心静脉导管置管时间为(29.32±8.06) min,下腔静脉塌陷指数IVC-CI治疗前和治疗后分别为(0.43±0.16)、(0.38±0.13).左室流出道的峰流速Vpeak在液体复苏治疗前后的相关性为Vpeak补液前与补液后r值0.755、P为0.001.左室流出道峰流速Vpeak与左室舒张末容积LEDV在液体复苏治疗前后相关性P为0.03及0.05.结论 (1) IVC-CI并未表现出与液体复苏疗效间的相关性,本次实验认为不能作为其评估指标.(2)在本实验中,Vpeak在补液前后发生明显变化,整体为上升趋势.(3)Vpeak在本次实验中表现出与LEDV相关性,支持Vpeak是左室收缩功能指标的结论.(4)心脏超声检查耗时明显低于中心静脉导管置管时间.%Objective To study the utility of inferior vena cava-collapse index (IVC-CI) for assessing fluid resuscitation for hypovolemic shock in order to look for better echocardiographic markers to assess patients' condition with hypovolemic shock,also to look for optimal guidance for the adjustment of the treatment for these patients.Methods A total of 40 patients with hypovolemic shock admitted to Emergency Department were enrolled for study.All patients were treated with 500 mL normal saline iutravenously as fluid resuscitation.The vital signs and echocardiographic findings before and after the treatment were documented.Comparison of data between pre-treatment and post

  13. Hydrogen engine performance analysis project. Second annual report

    Energy Technology Data Exchange (ETDEWEB)

    Adt, Jr., R. R.; Swain, M. R.; Pappas, J. M.

    1980-01-01

    Progress in a 3 year research program to evaluate the performance and emission characteristics of hydrogen-fueled internal combustion engines is reported. Fifteen hydrogen engine configurations will be subjected to performance and emissions characterization tests. During the first two years, baseline data for throttled and unthrottled, carburetted and timed hydrogen induction, Pre IVC hydrogen-fueled engine configurations, with and without exhaust gas recirculation (EGR) and water injection, were obtained. These data, along with descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained, are given. Analyses of other hydrogen-engine project data are also presented and compared with the results of the present effort. The unthrottled engine vis-a-vis the throttled engine is found, in general, to exhibit higher brake thermal efficiency. The unthrottled engine also yields lower NO/sub x/ emissions, which were found to be a strong function of fuel-air equivalence ratio. (LCL)

  14. Biorefinery and Hydrogen Fuel Cell Research

    Energy Technology Data Exchange (ETDEWEB)

    K.C. Das; Thomas T. Adams; Mark A. Eiteman; John Stickney; Joy Doran Peterson; James R. Kastner; Sudhagar Mani; Ryan Adolphson

    2012-06-12

    In this project we focused on several aspects of technology development that advances the formation of an integrated biorefinery. These focus areas include: [1] establishment of pyrolysis processing systems and characterization of the product oils for fuel applications, including engine testing of a preferred product and its pro forma economic analysis; [2] extraction of sugars through a novel hotwater extaction process, and the development of levoglucosan (a pyrolysis BioOil intermediate); [3] identification and testing of the use of biochar, the coproduct from pyrolysis, for soil applications; [4] developments in methods of atomic layer epitaxy (for efficient development of coatings as in fuel cells); [5] advancement in fermentation of lignocellulosics, [6] development of algal biomass as a potential substrate for the biorefinery, and [7] development of catalysts from coproducts. These advancements are intended to provide a diverse set of product choices within the biorefinery, thus improving the cost effectiveness of the system. Technical effectiveness was demonstrated in the pyrolysis biooil based diesel fuel supplement, sugar extraction from lignocelluose, use of biochar, production of algal biomass in wastewaters, and the development of catalysts. Economic feasibility of algal biomass production systems seems attractive, relative to the other options. However, further optimization in all paths, and testing/demonstration at larger scales are required to fully understand the economic viabilities. The various coproducts provide a clear picture that multiple streams of value can be generated within an integrated biorefinery, and these include fuels and products.

  15. Microcontroller-driven hydrogen fuel cell car

    OpenAIRE

    Queirós, Hugo; Lafuente, António; Sepúlveda, João; Esteves, João Sena

    2010-01-01

    This paper presents a fuel cell car with 8 minutes autonomy, capable of following a white line on a black track, using infrared sensors that detect white and black colors. A servomotor controls its direction. Guidelines to the servomotor are given by a system based on an 8051 microcontroller, according to the information it receives from the infrared sensors. The hydrogen needed by the fuel cell is produced by electrolysis, which requires an external power supply. The gas is retained on an is...

  16. Hydrogen fuel for space conditioning of buildings

    Science.gov (United States)

    Bonne, U.

    A comparative study is presented concerning the unique characteristics and relative advantages of hydrogen-air flames employed in boilers for building space heating. From the standpoint of safety, it is noted that the flammability limits of H2, at 4-75 percent in air, are far wider than the 5-15 percent of CH4. In addition to ignition characteristics, pipe sizing and storage tanks, stoichiometric fuel/air ratios, influence of fuel consumption on heating values, UV spectra, and the influence of fuel composition on fuel gas composition, are considered for a variety of hydrocarbon gas, heating oil, alcohols, and carbonaceous solid fuel alternatives to hydrogen.

  17. Evaluación del efecto de diferentes cepas de levadura (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® y clarificantes sobre los atributos sensoriales del vino de naranja criolla (Citrus sinensis

    Directory of Open Access Journals (Sweden)

    Rafael E Olivero

    2011-04-01

    Full Text Available Evaluation of effect of various strains of yeast (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® and clearer on the sensory attributes orange wine (Citrus sinensis RESUMEN En este trabajo se evaluó el efecto de diferentes cepas de levadura (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® sobre los atributos sensoriales del vino de naranja. Estos atributos fueron medidos utilizando la escala modificada de UC Davis. En una prueba de ordenamiento para determinar el mejor tratamiento de clarificación se determinó que la gelatina por sí sola no causa efecto sobre el atributo apariencia general, la combinación de la gelatina y la microfiltración tienen un efecto positivo sobre la apariencia del vino de naranja. Los cinco vinos tratados con diferentes levaduras presentaron diferencias significativas sobre la puntuación total, acidez total, sabor y calidad en general. En términos del efecto de las levaduras, la evaluación sensorial realizada a los vinos mostró que el de naranja con la levadura K1-V1116 fue el que sobresalió en términos de puntuación en los promedios de casi todos los atributos analizados por el panel sensorial.  Palabras clave: vino de naranja criolla, levaduras, clarificantes, atributos sensoriales.  ABSTRACT In this Wort was evaluated the effect of different types of strains of yeast (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE over the sensorial attributes of orange wines were also studied. These attributes were measured in a modified scale of UC Davis. By using an order test in order to know the best cleared treatment, it was determined that gelatin by itself does not cause any effect over the general quality attribute, but the combination of gelatin and microfiltration, cause a positive effect over the orange wine appearance. The five wines treated with different yeasts presented significant differences on individual scores, total acidy, flavor and general quality of the UC Davis scale. The

  18. Carcinoma de células renais com invasão da veia cava inferior: a propósito de um caso clínico Renal cell carcinoma with IVC invasion: clinical report

    Directory of Open Access Journals (Sweden)

    Rita Sousa

    2011-09-01

    Full Text Available O carcinoma de células renais (CCR é uma neoplasia com propensão à extensão ao sistema venoso sob a forma de trombo tumoral, sendo o tumor maligno mais frequentemente associado a trombose da veia cava inferior (VCI. A clínica é muitas vezes inespecífica até um estadio avançado da doença, com a tríade clássica de dor no flanco, hematúria e massa abdominal palpável a surgir como forma de apresentação em apenas 6-10% dos casos. Os métodos imagiológicos não invasivos têm, por isso, assumido um papel cada vez mais importante no diagnóstico e estadiamento desta neoplasia. Quando existe trombo tumoral associado, a terapêutica curativa passa pela intervenção cirúrgica que consiste na remoção do rim e do trombo tumoral, técnica que se reveste de algumas particularidades consoante o nível cefálico atingido pelo trombo venoso na VCI.Renal cell carcinoma (RCC is a tumor with propensity for extending into the venous system as tumor thrombus. It is the malignant tumor most frequently associated with inferior vena cava (IVC thrombosis. The symptoms are often nonspecific until an advanced stage of the disease, with the classic triad of flank pain, haematuria and palpable abdominal mass found at presentation in only 6-10% of all cases, thus the increasing role of noninvasive imaging in the diagnostic and staging of this tumor. In the presence of a tumor thrombus, the curative treatment relies on surgery, which consists of the ressection of the kidney and the thrombus. This technique has its particularities according to the cephalic level achieved by the thrombus in the IVC.

  19. Pre-Test Assessment

    Science.gov (United States)

    Berry, Thomas

    2008-01-01

    Pre-tests are a non-graded assessment tool used to determine pre-existing subject knowledge. Typically pre-tests are administered prior to a course to determine knowledge baseline, but here they are used to test students prior to topical material coverage throughout the course. While counterintuitive, the pre-tests cover material the student is…

  20. Pre-Hausdorff Spaces

    CERN Document Server

    Stine, Jay

    2008-01-01

    This paper introduces three separation conditions for topological spaces, called T_{0,1}, T_{0,2} ("pre-Hausdorff"), and T_{1,2}. These conditions generalize the classical T_(1) and T_(2) separation axioms, and they have advantages over them topologically which we discuss. We establish several different characterizations of pre-Hausdorff spaces, and a characterization of Hausdorff spaces in terms of pre-Hausdorff. We also discuss some classical Theorems of general topology which can or cannot be generalized by replacing the Hausdorff condition by pre-Hausdorff.

  1. Near-surface alloys for hydrogen fuel cell applications

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Mavrikakis, Manos

    2006-01-01

    Near-surface alloys (NSAs) possess a variety of unusual catalytic properties that could make them useful candidates for improved catalysts in a variety of chemical processes. It is known from previous work, for example, that some NSAs bind hydrogen very weakly while, at the same time, permitting ...

  2. Hydrogen-fuel-powered bell segments of biomimetic jellyfish

    Science.gov (United States)

    Tadesse, Yonas; Villanueva, Alex; Haines, Carter; Novitski, David; Baughman, Ray; Priya, Shashank

    2012-04-01

    Artificial muscles powered by a renewable energy source are desired for joint articulation in bio-inspired autonomous systems. In this study, a robotic underwater vehicle, inspired by jellyfish, was designed to be actuated by a chemical fuel source. The fuel-powered muscles presented in this work comprise nano-platinum catalyst-coated multi-wall carbon nanotube (MWCNT) sheets, wrapped on the surface of nickel-titanium (NiTi) shape memory alloy (SMA). As a mixture of oxygen and hydrogen gases makes contact with the platinum, the resulting exothermic reaction activates the nickel-titanium (NiTi)-based SMA. The MWCNT sheets serve as a support for the platinum particles and enhance the heat transfer due to the high thermal conductivity between the composite and the SMA. A hydrogen and oxygen fuel source could potentially provide higher power density than electrical sources. Several vehicle designs were considered and a peripheral SMA configuration under the robotic bell was chosen as the best arrangement. Constitutive equations combined with thermodynamic modeling were developed to understand the influence of system parameters that affect the overall actuation behavior of the fuel-powered SMA. The model is based on the changes in entropy of the hydrogen and oxygen fuel on the composite actuator within a channel. The specific heat capacity is the dominant factor controlling the width of the strain for various pulse widths of fuel delivery. Both theoretical and experimental strains for different diameter (100 and 150 µm) SMA/MWCNT/Pt fuel-powered muscles with dead weight attached at the end exhibited the highest magnitude under 450 ms of fuel delivery within 1.6 mm diameter conduit size. Fuel-powered bell deformation of 13.5% was found to be comparable to that of electrically powered (29%) and natural jellyfish (42%).

  3. Modular Energy Storage System for Hydrogen Fuel Cell Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Janice [Magna International, Rochester Mills, MI (United States)

    2010-08-27

    The objective of the project is to develop technologies, specifically power electronics, energy storage electronics and controls that provide efficient and effective energy management between electrically powered devices in alternative energy vehicles plug-in electric vehicles, hybrid vehicles, range extended vehicles, and hydrogen-based fuel cell vehicles. The in-depth research into the complex interactions between the lower and higher voltage systems from data obtained via modeling, bench testing and instrumented vehicle data will allow an optimum system to be developed from a performance, cost, weight and size perspective. The subsystems are designed for modularity so that they may be used with different propulsion and energy delivery systems. This approach will allow expansion into new alternative energy vehicle markets.

  4. Direct hydrogen fuel cell systems for hybrid vehicles

    Science.gov (United States)

    Ahluwalia, Rajesh K.; Wang, X.

    Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

  5. Energizing Engineering Students with Hydrogen Fuel Cell Project

    Science.gov (United States)

    Cannell, Nori; Zavaleta, Dan

    2010-01-01

    At Desert Vista High School, near Phoenix, Arizona, Perkins Innovation Grant funding is being used to fund a program that is helping to prepare students for careers in engineering by giving them hands-on experience in areas like hydrogen generation and fuel cell utilization. As one enters Dan Zavaleta's automotive and engineering classroom and lab…

  6. Hydrogen-fueled polymer electrolyte fuel cell systems for transportation.

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R.; Doss, E.D.; Kumar, R.

    1998-10-19

    The performance of a polymer electrolyte fuel cell (PEFC) system that is fueled directly by hydrogen has been evaluated for transportation vehicles. The performance was simulated using a systems analysis code and a vehicle analysis code. The results indicate that, at the design point for a 50-kW PEFC system, the system efficiency is above 50%. The efficiency improves at partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the voltage-current characteristic curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and, eventually, the fuel cell. The results also indicate that the PEFC system can start rapidly from ambient temperatures. Depending on the specific weight of the fuel cell (1.6 kg/kW in this case), the system takes up to 180s to reach its design operating conditions. The PEFC system has been evaluated for three mid-size vehicles: the 1995 Chrysler Sedan, the near-term Ford AIV (Aluminum Intensive Vehicle) Sable, and the future P2000 vehicle. The results show that the PEFC system can meet the demands of the Federal Urban Driving Schedule and the Highway driving cycles, for both warm and cold start-up conditions. The results also indicate that the P2000 vehicle can meet the fuel economy goal of 80 miles per gallon of gasoline (equivalent).

  7. Onboard Catalysis of Formic Acid for Hydrogen Fueled Vehicles

    Science.gov (United States)

    Karim, Altaf; Mamoor, Muhammad

    2015-03-01

    Metal hydrides are used as a medium of hydrogen storage in hydrogen powered vehicles. Such hydride materials cannot store hydrogen more than 10 wt%. The bottleneck in this issue is the reversible storage of hydrogen at ambient temperature and pressure. Alternatively formic acid is becoming more popular medium for the onboard hydrogen production for these vehicles. Its decomposition on metal surfaces and nanostructures is considered to be a potential method to produce CO-free hydrogen at near ambient temperatures. We applied Density Functional Theory (DFT) based Kinetic Monte Carlo (KMC) simulations as our tool to study the reaction kinetics of hydrogen production from formic acid on different catalytic surfaces and nano structures (Au, Pd, Rh, Pt). Our results show that nanostructures and artificially engineered bimetallic catalysts give higher rate of hydrogen production then their monometallic counter parts under various temperature and pressure conditions.

  8. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Science.gov (United States)

    Titterington, W. A.; Fickett, A. P.

    1973-01-01

    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.

  9. Fabrication and characterisation of hydrogen fuel cell membrane electrode assemblies

    CSIR Research Space (South Africa)

    Mathe

    2006-09-01

    Full Text Available stream_source_info Mathe_2006.pdf.txt stream_content_type text/plain stream_size 1 Content-Encoding ISO-8859-1 stream_name Mathe_2006.pdf.txt Content-Type text/plain; charset=ISO-8859-1 ...

  10. PreCam

    Energy Technology Data Exchange (ETDEWEB)

    Allam, Sahar S. [Fermilab; Tucker, Douglas L. [Fermilab

    2015-01-01

    The Dark Energy Survey (DES) will be taking the next step in probing the properties of Dark Energy and in understanding the physics of cosmic acceleration. A step towards the photometric calibration of DES is to have a quick, bright survey in the DES footprint (PreCam), using a pre-production set of the Dark Energy Camera (DECam) CCDs and a set of 100 mm×100 mm DES filters. The objective of the PreCam Survey is to create a network of calibrated DES grizY standard stars that will be used for DES nightly calibrations and to improve the DES global relative calibrations. Here, we describe the first year of PreCam observation, results, and photometric calibrations.

  11. Pre-eclampsia.

    Science.gov (United States)

    Mol, Ben W J; Roberts, Claire T; Thangaratinam, Shakila; Magee, Laura A; de Groot, Christianne J M; Hofmeyr, G Justus

    2016-03-05

    Pre-eclampsia affects 3-5% of pregnancies and is traditionally diagnosed by the combined presentation of high blood pressure and proteinuria. New definitions also include maternal organ dysfunction, such as renal insufficiency, liver involvement, neurological or haematological complications, uteroplacental dysfunction, or fetal growth restriction. When left untreated, pre-eclampsia can be lethal, and in low-resource settings, this disorder is one of the main causes of maternal and child mortality. In the absence of curative treatment, the management of pre-eclampsia involves stabilisation of the mother and fetus, followed by delivery at an optimal time. Although algorithms to predict pre-eclampsia are promising, they have yet to become validated. Simple preventive measures, such as low-dose aspirin, calcium, and diet and lifestyle interventions, show potential but small benefit. Because pre-eclampsia predisposes mothers to cardiovascular disease later in life, pregnancy is also a window for future health. A collaborative approach to discovery and assessment of the available treatments will hasten our understanding of pre-eclampsia and is an effort much needed by the women and babies affected by its complications.

  12. Caspase-9 inhibitor Z-LEHD-FMK enhances the yield of in vitro produced buffalo (Bubalus bubalis) pre-implantation embryos and alters cellular stress response.

    Science.gov (United States)

    Mullani, N; Singh, M K; Sharma, A; Rameshbabu, K; Manik, R S; Palta, P; Singla, S K; Chauhan, M S

    2016-02-01

    The present investigation was done to study the effect of caspase-9 inhibitor Z-LEHD-FMK, on in vitro produced buffalo embryos. Z-LEHD-FMK is a cell-permeable, competitive and irreversible inhibitor of enzyme caspase-9, which helps in cell survival. Buffalo ovaries were collected from slaughterhouse and the oocytes were subjected to in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC). The culture medium was supplemented with Z-LEHD-FMK at different concentrations i.e. 0 μM (control), 10 μM, 20 μM, 30 μM and 50 μM during IVM and IVC respectively. After day-2 post-insemination, the cleavage rate was significantly higher (74.20 ± 5.87% at PZ-LEHD-FMK than at any other concentration. Same trend was observed in the blastocyst production rate which was higher at 20 μM (27.42 ± 2.94% at PZ-LEHD-FMK which showed apoptotic index significantly lower (1.88 ± 0.87 at PZ-LEHD-FMK treated blastocysts. The quantitative gene expression of CHOP and HSP10 genes showed significant increase (PZ-LEHD-FMK, while, HSP40 showed significant increase (PZ-LEHD-FMK concentrations. From the afore mentioned results we conclude that, Z-LEHD-FMK at 20 μM increased the cleavage and blastocyst rate of buffalo pre-implantation embryos also affecting the rate of apoptosis and cellular stress at various concentrations.

  13. Linac pre-injector

    CERN Multimedia

    1965-01-01

    New accelerating column of the linac pre-injector, supporting frame and pumping system. This new system uses two mercury diffusion pumps (in the centre) and forms part of the modifications intended to increase the intensity of the linac. View taken during assembly in the workshop.

  14. Blind Pre-School.

    Science.gov (United States)

    Taylor, Billie, Comp.

    Articles pertinent to aiding the pre-school blind child are collected in this publication. Topics include discussion of attitudes and emotional reactions important for parents and teachers of blind children, and optimal development in regard to early motor behavior and emotional and social needs. Common areas of parental concern such as discipline…

  15. Pre-Osteoarthritis

    Science.gov (United States)

    Brittberg, Mats; Eriksson, Karl; Jurvelin, Jukka S.; Lindahl, Anders; Marlovits, Stefan; Möller, Per; Richardson, James B.; Steinwachs, Matthias; Zenobi-Wong, Marcy

    2015-01-01

    Objective An attempt to define pre-osteoarthritis (OA) versus early OA and definitive osteoarthritis. Methods A group of specialists in the field of cartilage science and treatment was formed to consider the nature of OA onset and its possible diagnosis. Results Late-stage OA, necessitating total joint replacement, is the end stage of a biological process, with many previous earlier stages. Early-stage OA has been defined and involves structural changes identified by arthroscopy or radiography. The group argued that before the “early-stage OA” there must exist a stage where cellular processes, due to the presence of risk factors, have kicked into action but have not yet resulted in structural changes. The group suggested that this stage could be called “pre-osteoarthritis” (pre-OA). Conclusions The group suggests that defining points of initiation for OA in the knee could be defined, for example, by traumatic episodes or surgical meniscectomy. Such events may set in motion metabolic processes that could be diagnosed by modern MRI protocols or arthroscopy including probing techniques before structural changes of early OA have developed. Preventive measures should preferably be applied at this pre-OA stage in order to stop the projected OA “epidemic.” PMID:26175861

  16. Morphological characterization of pre- and peri-implantation in vitro cultured, somatic cell nuclear transfer and in vivo derived ovine embryos

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille Yde; Peura, T.T.; Hartwich, K.M.

    2005-01-01

    The processes of cellular differentiation were studied in somatic cell nuvlear transfer (SCNT), in vitro cultured (IVC) and in vivo developed (in vivo) ovine embryos on days 7, 9, 11, 13, 17 and 19. SCNT embryos were constructed from in vitro matured oocytes and granulosa cells, and IVC embryos w...

  17. Pre-emptive perception.

    Science.gov (United States)

    Bodis-Wollner, Ivan

    2008-01-01

    How can an action to a target be selected without yet knowing what it is? Pre-emptive perception (PEP) is a framework which orders neuronal mechanisms in association with voluntary actions before an action is started and until it is completed. It is assumed that PEP serves the purpose of perception, but a conscious, perceptual identification of the goal is not obligatorily completed during the time period of PEP itself. The concept of PEP is that the brain pre-emptively optimizes an action plan to maximize eventual perception, even before being sure what the goal is. Experimental studies of voluntary saccadic eye movements are considered as prototypic activity within the framework of PEP. The core concept of pre-emption is that a particular saccade is selected while a large number of other possible actions are deselected. Pre-emptive computations include mechanisms associated with internal context and reward. Neurophysiological studies which show anatomically and functionally separate cortical and some subcortical neuronal groups in computing saccades are summarized. There is a potential relationship of PEP as a neurobiological framework and some philosophical concepts. Terms for processes between planning and action, such as intention, anticipation, and attention, are often incongruent in everyday language and in epistemology. It is proposed here that a scrutiny of these terms can be rigorously approached by temporal subdivision of PEP and conversely, clear definitions of these terms can lead to organized experimental designs of cognitive neurobiology. The temporal subdivision of PEP allows a critique of The Will in the definition of Schopenhauer and distinguishes it from the 'free will'.

  18. Pre-calculus essentials

    CERN Document Server

    Woodward, Ernest

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Pre-Calculus reviews sets, numbers, operations and properties, coordinate geometry, fundamental algebraic topics, solving equations and inequalities, functions, trigonometry, exponents

  19. Morphological characterization of pre- and peri-implantation in vitro cultured, somatic cell nuclear transfer and in vivo derived ovine embryos

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille Yde; Peura, T.T.; Hartwich, K.M.;

    2005-01-01

    The processes of cellular differentiation were studied in somatic cell nuvlear transfer (SCNT), in vitro cultured (IVC) and in vivo developed (in vivo) ovine embryos on days 7, 9, 11, 13, 17 and 19. SCNT embryos were constructed from in vitro matured oocytes and granulosa cells, and IVC embryos...... were produced by in vitro culture of in vivo fertilized zygotes. Most SCNT and IVC embryos were transferred to recipients on day 6 while some remained in culture for day 7 processing. In vivo embryos were collected as zygotes, transferred to intermediate recipients and retransferred to final recipients...... embryos had impaired hypoblast development, some lacking identifiable inner cell masses. On day 11, only in vivo and IVC embryos had developed an embryonic disc, and gastrulation was evident in half of in vivo embryos and one IVC embryo. By day 13, all in vivo embryos had completed gastrulation whereas...

  20. Pre-operative anaemia.

    Science.gov (United States)

    Clevenger, B; Richards, T

    2015-01-01

    Pre-operative anaemia is a relatively common finding, affecting a third of patients undergoing elective surgery. Traditionally associated with chronic disease, management has historically focused on the use of blood transfusion as a solution for anaemia in the peri-operative period. Data from large series now suggest that anaemia is an independent risk associated with poor outcome in both cardiac and non-cardiac surgery. Furthermore, blood transfusion does not appear to ameliorate this risk, and in fact may increase the risk of postoperative complications and hospital length of stay. Consequently, there is a need to identify, diagnose and manage pre-operative anaemia to reduce surgical risk. Discoveries in the pathways of iron metabolism have found that chronic disease can cause a state of functional iron deficiency leading to anaemia. The key iron regulatory protein hepcidin, activated in response to inflammation, inhibits absorption of iron from the gastrointestinal tract and further reduces bioavailability of iron stores for red cell production. Consequently, although iron stores (predominantly ferritin) may be normal, the transport of iron either from the gastrointestinal tract or iron stores to the bone marrow is inhibited, leading to a state of 'functional' iron deficiency and subsequent anaemia. Since absorption from the gastrointestinal tract is blocked, increasing oral iron intake is ineffective, and studies are now looking at the role of intravenous iron to treat anaemia in the surgical setting. In this article, we review the incidence and impact of anaemia on the pre-operative patient. We explain how anaemia may be caused by functional iron deficiency, and how iron deficiency anaemia may be diagnosed and treated.

  1. The multi-faceted Type II-L supernova 2014G from pre-maximum to nebular phase

    CERN Document Server

    Terreran, G; Benetti, S; Smartt, S J; Ochner, P; Tomasella, L; Howell, D A; Morales-Garoffolo, A; Harutyunyan, A; Kankare, E; Arcavi, I; Cappellaro, E; Elias-Rosa, N; Hosseinzadeh, G; Kangas, T; Pastorello, A; Tartaglia, L; Turatto, M; Valenti, S; Wiggins, P; Yuan, F

    2016-01-01

    We present multi-band ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (SN) 2014G in the nearby galaxy NGC 3448 (25 Mpc). The early-phase spectra show strong emission lines of the high ionisation species He II/N IV/C IV during the first 2-3 d after explosion, traces of a metal-rich CSM probably due to pre-explosion mass loss events. These disappear by day 9 and the spectral evolution then continues matching that of normal Type II SNe. The post-maximum light curve declines at a rate typical of Type II-L class. The extensive photometric coverage tracks the drop from the photospheric stage and constrains the radioactive tail, with a steeper decline rate than that expected from the $^{56}$Co decay if $\\gamma$-rays are fully trapped by the ejecta. We report the appearance of an unusual feature on the blue-side of H$\\alpha$ after 100 d, which evolves to appear as a flat spectral feature linking H$\\alpha$ and the O I doublet. This may be due to interaction o...

  2. Enhancing pre-service elementary

    Directory of Open Access Journals (Sweden)

    Mehmet AYDENİZ

    2010-03-01

    Full Text Available This study explored the impact of a reflective teaching method on pre-service elementary teachers’ conceptual understanding of the lunar phases, reasons for seasons, and simple electric circuits. Data were collected from 40 pre-service elementary teachers about their conceptual understanding of the lunar phases, reasons for seasons and day and night, and simple electric circuits pre and post instruction. Findings show that the instructional approach adopted by a science teacher educator had a significant impact on pre-serviceelementary school teachers’ conceptual understanding of lunar phases, seasonal changes and simple electric circuits. The discussion focuses on pre-service elementary school teachers’ misconceptions about the lunar phases, seasonal changes and simple electric circuits as revealed through their answers to the pre-test questions. Further discussion focuses on the implications of the findings for pre-service elementary school science teacher education.

  3. Implantation of radioactive ~(125)Ⅰ seed strand and metallic stent combined with TACE for the treatment of HCC with IVC obstruction: initial results in 8 patients%植入~(125)Ⅰ籽源条及金属支架联合经动脉化疗栓塞治疗肝癌合并下腔静脉梗阻的初步经验

    Institute of Scientific and Technical Information of China (English)

    罗剑钧; 颜志平; 王建华; 刘清欣; 瞿旭东

    2009-01-01

    Objective To report the preliminary results of placing metallic stent and ~(125)Ⅰ seed strand combined with transcatheter arterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC) with inferior vena cava (IVC) obstruction. Methods From March 2009 to June 2009, implantation of radioactive ~(125)Ⅰ seed strand and metallic stent combined with TACE treatment was performed in 8 cases of HCC with malignant IVC obstruction. All patients were males with a mean age of (60.6 ± 9.6) years, ~(125)Ⅰ seed strand and Z-type soft-expandable metallic stent were placed in the obstructive segment of IVC, which was followed by TACE. Before and after the treatment, the diameter of the obstructive segment of IVC, the pressure gradient between right atrium and distal end of obstructive segment of IVC, and the symptoms related to the obstruction were estimated and recorded, the results were compared individually. Clinical follow-up was conducted in all patients. Results A total of 8 stents and 10 ~(125)Ⅰ seed strands were placed in the obstructive segment of IVC. Altogether 138 ~(125)Ⅰ seeds were implanted in 8 patients. Obvious clinical improvements were obtained after therapy. No complications occurred in all patients except one patient who experienced acute renal dysfunction at the second day after therapy. During a mean of (2.1 ± 0.6) months follow-up, occlusion of IVC stent was detected in 1 patient. The remaining stents remained patent. Conclusion Our initial results indicate that placement of ~(125)Ⅰ seed strand and metallic stent combined with TACE is a safe and feasible therapeutic option for advanced HCC with malignant IVC obstruction.%目的 报道植入~(125)Ⅰ籽源条及金属支架联合经动脉化疗栓寒治疗肝癌合并下腔静脉梗阻的初步结果.方法 自2009年3-6月,8例肝癌合并下腔静脉梗阻的患者入选本组研究,所有患者均为男性,平均年龄(61±10)岁.在患

  4. [Pre- and probiotic cosmetics].

    Science.gov (United States)

    Simmering, R; Breves, R

    2009-10-01

    The human skin provides a habitat for a variety of microorganisms, the skin microflora. There is a complex network of interactions between the microbes and cells of the epidermis. Modern analytical methods in molecular biology have revealed new insights into this complex diversity of partially unculturable microbial organisms. Most of the resident microbes on healthy skin can be regarded as being harmless or even beneficial to skin. In the case of diseases with some imbalance in microorganisms, such as impure skin/mild acne or dry skin/mild atopic dermatitis, pre- and probiotic concepts represent an effective alternative to strictly antibacterial products. Prebiotic actives rebalance the skin microflora while probiotic approaches predominantly consist of applying an inactivated microbial biomass of beneficial bacteria. Several examples of successful in vivo studies illustrate this new principle for gentle cosmetics derived from the food sector.

  5. The multifaceted Type II-L supernova 2014G from pre-maximum to nebular phase

    Science.gov (United States)

    Terreran, G.; Jerkstrand, A.; Benetti, S.; Smartt, S. J.; Ochner, P.; Tomasella, L.; Howell, D. A.; Morales-Garoffolo, A.; Harutyunyan, A.; Kankare, E.; Arcavi, I.; Cappellaro, E.; Elias-Rosa, N.; Hosseinzadeh, G.; Kangas, T.; Pastorello, A.; Tartaglia, L.; Turatto, M.; Valenti, S.; Wiggins, P.; Yuan, F.

    2016-10-01

    We present multiband ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (SN) 2014G in the nearby galaxy NGC 3448 (25 Mpc). The early-phase spectra show strong emission lines of the high ionization species He II/N IV/C IV during the first 2-3 d after explosion, traces of a metal-rich circumstellar material (CSM) probably due to pre-explosion mass-loss events. These disappear by day 9 and the spectral evolution then continues matching that of normal Type II SNe. The post-maximum light curve declines at a rate typical of Type II-L class. The extensive photometric coverage tracks the drop from the photospheric stage and constrains the radioactive tail, with a steeper decline rate than that expected from the 56Co decay if γ-rays are fully trapped by the ejecta. We report the appearance of an unusual feature on the blue side of H α after 100 d, which evolves to appear as a flat spectral feature linking H α and the [O I] doublet. This may be due to interaction of the ejecta with a strongly asymmetric, and possibly bipolar CSM. Finally, we report two deep spectra at ˜190 and 340 d after explosion, the latter being arguably one of the latest spectra for a Type II-L SN. By modelling the spectral region around the [Ca II], we find a supersolar Ni/Fe production. The strength of the [O I] λλ6300,6363 doublet, compared with synthetic nebular spectra, suggests a progenitor with a zero-age main-sequence mass between 15 and 19 M⊙.

  6. PRE-RETIREMENT PROGRAMME

    CERN Multimedia

    2001-01-01

    Special Meeting concerning the TAXATION OF PENSIONS IN FRANCE Following the pre-retirement seminar held at CERN in March 2001, the Human Resources Division and the CERN Pensioners Association (GAC) are organising a special information session on the Taxation of CERN pensions in France The speaker will be S. Agarrat, a barrister specialising in tax law (practising in Lyon) and the meeting will take the form of a general presentation of the subject, followed by a question-and-answer session. This meeting is intended for CERN pensioners residing in France, as well as for staff due to retire from the Organization in 2001/2002. Registration is not necessary. The meeting will take place on Wednesday, 28 November 2001, from 4.30 p.m. to 6.30 p.m., in the Main Auditorium N.B.: Questions concerning the taxation rules applicable to salaries paid by CERN, in particular questions relating to the CRDS tax, will not be dealt with during this meeting.

  7. Pre-ExCom 2003

    Directory of Open Access Journals (Sweden)

    Norweigan Refugee Council/Global IDP Project

    2004-01-01

    Full Text Available The consultations which precede the annual meetingof UNHCR’s Executive Committee (‘Pre-ExCom’,in UN jargon are an important forum for NGOs toraise concerns with UNHCR about the protection ofrefugees and IDPs. The report of Pre-ExCom ispresented to the Executive Committee.

  8. Pre-Lie Deformation Theory

    NARCIS (Netherlands)

    Dotsenko, V.; Shadrin, S.; Vallette, B.

    2016-01-01

    In this paper, we develop the deformation theory controlled by pre-Lie algebras; the main tool is a new integration theory for preLie algebras. The main field of application lies in homotopy algebra structures over a Koszul operad; in this case, we provide a homotopical description of the associated

  9. Pre-hospital emergency medicine.

    Science.gov (United States)

    Wilson, Mark H; Habig, Karel; Wright, Christopher; Hughes, Amy; Davies, Gareth; Imray, Chirstopher H E

    2015-12-19

    Pre-hospital care is emergency medical care given to patients before arrival in hospital after activation of emergency medical services. It traditionally incorporated a breadth of care from bystander resuscitation to statutory emergency medical services treatment and transfer. New concepts of care including community paramedicine, novel roles such as emergency care practitioners, and physician delivered pre-hospital emergency medicine are re-defining the scope of pre-hospital care. For severely ill or injured patients, acting quickly in the pre-hospital period is crucial with decisions and interventions greatly affecting outcomes. The transfer of skills and procedures from hospital care to pre-hospital medicine enables early advanced care across a range of disciplines. The variety of possible pathologies, challenges of environmental factors, and hazardous situations requires management that is tailored to the patient's clinical need and setting. Pre-hospital clinicians should be generalists with a broad understanding of medical, surgical, and trauma pathologies, who will often work from locally developed standard operating procedures, but who are able to revert to core principles. Pre-hospital emergency medicine consists of not only clinical care, but also logistics, rescue competencies, and scene management skills (especially in major incidents, which have their own set of management principles). Traditionally, research into the hyper-acute phase (the first hour) of disease has been difficult, largely because physicians are rarely present and issues of consent, transport expediency, and resourcing of research. However, the pre-hospital phase is acknowledged as a crucial period, when irreversible pathology and secondary injury to neuronal and cardiac tissue can be prevented. The development of pre-hospital emergency medicine into a sub-specialty in its own right should bring focus to this period of care.

  10. Pre-Calculus For Dummies

    CERN Document Server

    Kuang, Yang

    2012-01-01

    The fun and easy way to learn pre-calculus Getting ready for calculus but still feel a bit confused? Have no fear. Pre-Calculus For Dummies is an un-intimidating, hands-on guide that walks you through all the essential topics, from absolute value and quadratic equations to logarithms and exponential functions to trig identities and matrix operations. With this guide's help you'll quickly and painlessly get a handle on all of the concepts - not just the number crunching - and understand how to perform all pre-calc tasks, from graphing to tackling proofs. You'll also get a new appreciation for

  11. Pre-prosthetic surgery: Mandible

    Science.gov (United States)

    Devaki, Veeramalai Nadu; Balu, Kandasamy; Ramesh, Sadashiva Balakrishnapillai; Arvind, Ramraj Jayabalan; Venkatesan

    2012-01-01

    Pre-prosthetic surgery is that part of oral and maxillofacial surgery which restores oral function and facial form. This is concerned with surgical modification of the alveolar process and its surrounding structures to enable the fabrication of a well-fitting, comfortable, and esthetic dental prosthesis. The ultimate goal of pre-prosthetic surgery is to prepare a mouth to receive a dental prosthesis by redesigning and smoothening bony edges. PMID:23066301

  12. Pre-prosthetic surgery: Mandible

    Directory of Open Access Journals (Sweden)

    Veeramalai Naidu Devaki

    2012-01-01

    Full Text Available Pre-prosthetic surgery is that part of oral and maxillofacial surgery which restores oral function and facial form. This is concerned with surgical modification of the alveolar process and its surrounding structures to enable the fabrication of a well-fitting, comfortable, and esthetic dental prosthesis. The ultimate goal of pre-prosthetic surgery is to prepare a mouth to receive a dental prosthesis by redesigning and smoothening bony edges.

  13. Update in pre-eclampsia.

    Science.gov (United States)

    Chanprapaph, Pharuhas

    2004-10-01

    Pre-eclampsia, formerly called pregnancy-induced hypertension, refers to the new onset of hypertension (SBP > or = 140 mmHg or DBP > or = 90 mmHg) and proteinuria (> or = 0.3 g protein in a 24-hour urine specimen or 1+ on dipstick) after 20 weeks of gestation in a previously normotensive women. It is a life-threatening, multi-organ involvement disease and remains the leading cause of maternal death. Its clinical manifestations are the result of generalized vasospasm, activation of the coagulation system, and changes in several humoral and autoregulatory systems related to volume and blood pressure control. Pre-eclampsia is responsible for high perinatal mortality and morbidity rates, primarily due to early termination of pregnancy. Fetus growth restriction, oligohyrdramnios and non-reassuring fetal status are the consequences of chronic placental hypoperfusion. Pre-eclampsia does not appear to accelerate fetal maturation, as once believed. Delivery remains the definitive treatment of choice for pre-eclampsia and should be timely. Cesarean section is not necessary and reserved for the obstetrical indications only. The expectant management may be considered for women remote from term (< 32 to 34 weeks of gestation) with stable and uncomplicated severe disease. The supportive management such as blood pressure control, seizure prevention, and fetal well-being assessment are also important to ensure the satisfactory outcome. To date, no screening test has been proved to be reliable and cost-effective. The prevention of pre-eclampsia with antioxidant therapy (vitamin C, E) has shown promise, but large, randomized trials are needed. Although controversy exists, calcium supplementation has shown no benefit in large trials, and most evidence suggests little or no benefit for low-dose aspirin as prevention in women in the low-risk category.

  14. Cluster pre-existence probability

    Energy Technology Data Exchange (ETDEWEB)

    Rajeswari, N.S.; Vijayaraghavan, K.R.; Balasubramaniam, M. [Bharathiar University, Department of Physics, Coimbatore (India)

    2011-10-15

    Pre-existence probability of the fragments for the complete binary spectrum of different systems such as {sup 56}Ni, {sup 116}Ba, {sup 226}Ra and {sup 256}Fm are calculated, from the overlapping part of the interaction potential using the WKB approximation. The role of reduced mass as well as the classical hydrodynamical mass in the WKB method is analysed. Within WKB, even for negative Q -value systems, the pre-existence probability is calculated. The calculations reveal rich structural information. The calculated results are compared with the values of preformed cluster model of Gupta and collaborators. The mass asymmetry motion is shown here for the first time as a part of relative separation motion. (orig.)

  15. Pre-Service Teachers Institute

    Science.gov (United States)

    2008-01-01

    The Pre-Service Teachers Institute sponsored by Jackson (Miss.) State University participated in an agencywide Hubble Space Telescope workshop at Stennis Space Center on July 18. Twenty-five JSU junior education majors participated in the workshop, a site tour and educational presentations by Karma Snyder of the NASA SSC Engineering & Safety Center and Anne Peek of the NASA SSC Deputy Science & Technology Division.

  16. Medication or Lifestyle for Pre-Diabetes

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Medication or Lifestyle Changes for Pre-diabetes Updated:Aug 30,2016 What’s best? Medication or lifestyle changes? Most people at the pre- ...

  17. Cytomegalovirus Infection and Pre-Eclampsia

    Directory of Open Access Journals (Sweden)

    Rădulescu Carmen

    2016-06-01

    Full Text Available Introduction: Pre-eclampsia is a pregnancy-specific disease characterized by hypertension after 20 weeks of gestation and proteinuria. It is a major cause of maternal and perinatal morbidity and mortality. The pathogenesis of pre-eclampsia is not completely understood. In our study we investigated if there is a potential link between cytomegalovirus infection and pre-eclampsia and if cytomegalovirus infection is the triggering factor of pre-eclampsia.

  18. Cytomegalovirus Infection and Pre-Eclampsia

    OpenAIRE

    Rădulescu Carmen; Huţanu Adina; Gabor Rozalia; Şincu Nina

    2016-01-01

    Introduction: Pre-eclampsia is a pregnancy-specific disease characterized by hypertension after 20 weeks of gestation and proteinuria. It is a major cause of maternal and perinatal morbidity and mortality. The pathogenesis of pre-eclampsia is not completely understood. In our study we investigated if there is a potential link between cytomegalovirus infection and pre-eclampsia and if cytomegalovirus infection is the triggering factor of pre-eclampsia.

  19. Pre-Seismic Electromagnetic Effects

    Institute of Scientific and Technical Information of China (English)

    Guo Yahong

    2007-01-01

    Along with intense rock strain and rock bursting processes at the late stage of earthquake preparation, mechanical-electrical energy conversion appears in the seismogenic region and its nearby rock formations, which correspondingly stimulate certain electromagnetic effects. The paper mainly analyzes the pre-seismic electromagnetic effect of the ionosphere and proposes a method of monitoring VLF radio waves over the additional ionized region and so on. It is deemed that the method is of significance for short and imminent term prediction of strong earthquakes.

  20. (Pre)kernel catchers for cooperative games

    NARCIS (Netherlands)

    Chang, Chih; Driessen, Theo

    1995-01-01

    The paper provides a new (pre)kernel catcher in that the relevant set always contains the (pre)kernel. This new (pre)kernel catcher gives rise to a better lower bound ɛ*** such that the kernel is included in strong ɛ-cores for all real numbers ɛ not smaller than the relevant bound ɛ***.

  1. Pre-flare coronal dimmings

    CERN Document Server

    Zhang, Q M; Ji, H S

    2016-01-01

    In this paper, we focus on the pre-flare coronal dimmings. We report our multiwavelength observations of the GOES X1.6 solar flare and the accompanying halo CME produced by the eruption of a sigmoidal magnetic flux rope (MFR) in NOAA active region (AR) 12158 on 2014 September 10. The eruption was observed by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamic Observatory (SDO). The photospheric line-of-sight magnetograms were observed by the Helioseismic and Magnetic Imager (HMI) aboard SDO. The soft X-ray (SXR) fluxes were recorded by the GOES spacecraft. The halo CME was observed by the white light coronagraphs of the Large Angle Spectroscopic Coronagraph (LASCO) aboard SOHO.} {About 96 minutes before the onset of flare/CME, narrow pre-flare coronal dimmings appeared at the two ends of the twisted MFR. They extended very slowly with their intensities decreasing with time, while their apparent widths (8$-$9 Mm) nearly kept constant. During the impulsive and decay phases of flare, typical fanlike ...

  2. A pre-Hispanic head.

    Directory of Open Access Journals (Sweden)

    Raffaella Bianucci

    Full Text Available This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS compatible with the last pre-Hispanic period (1418-1491 AD, 95.4% probability. Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic and mercury incompatible with life. There was no evidence for lead deposition in bone consistent with post-mortem accumulation of this toxic element in the hair. We propose that the high content of metals in hair was the result of metabolic activity of bacteria leading to metal complexation in extra cellular polymeric substances (EPS. This is a recognized protective mechanism for bacteria that thrive in toxic environments. This mechanism may account for the tissues preservation and gives a hint at soil composition where the head was presumably buried. Our results have implications for forensic toxicology which has, hitherto, relied on hair analyses as one means to reconstruct pre-mortem metabolism and for detecting toxic elements accumulated during life. Our finding also has implications for other archaeological specimens where similar circumstances may distort the results of toxicological studies.

  3. Pre-Algebra Essentials For Dummies

    CERN Document Server

    Zegarelli, Mark

    2010-01-01

    Many students worry about starting algebra. Pre-Algebra Essentials For Dummies provides an overview of critical pre-algebra concepts to help new algebra students (and their parents) take the next step without fear. Free of ramp-up material, Pre-Algebra Essentials For Dummies contains content focused on key topics only. It provides discrete explanations of critical concepts taught in a typical pre-algebra course, from fractions, decimals, and percents to scientific notation and simple variable equations. This guide is also a perfect reference for parents who need to review critical pre-algebra

  4. 40 CFR 1065.520 - Pre-test verification procedures and pre-test data collection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Pre-test verification procedures and pre-test data collection. 1065.520 Section 1065.520 Protection of Environment ENVIRONMENTAL PROTECTION... Specified Duty Cycles § 1065.520 Pre-test verification procedures and pre-test data collection. (a) If...

  5. Hemostasis in pre-eclampsia.

    LENUS (Irish Health Repository)

    Ismail, Siti Khadijah

    2012-01-31

    Pre-eclampsia (P-EC) is a multisystem disorder exclusive to pregnancy. It complicates ~2 to 8% of all pregnancies and remains a major cause of maternal mortality. P-EC is characterized by a profound hypercoagulable state. The delicate hemostatic balance that must be maintained in the uteroplacental circulation during pregnancy makes this system vulnerable to perturbation. An abnormal hemostatic pattern occurs within the uteroplacental circulation in P-EC compared with normal pregnancy. Much recent research has focused on the epidemiological link between inherited thrombophilia and P-EC. The data suggest a weak statistical association, indicating an improbable primary role in the pathogenesis. Without clear evidence, low molecular weight heparins have been widely used to reduce recurrence of P-EC in thrombophilia-positive women. This practice now should be reviewed. Future research needs to focus on improving our basic scientific understanding of the role of the hemostatic system in human placentation.

  6. Hemostasis in pre-eclampsia.

    LENUS (Irish Health Repository)

    Ismail, Siti Khadijah

    2011-03-01

    Pre-eclampsia (P-EC) is a multisystem disorder exclusive to pregnancy. It complicates ~2 to 8% of all pregnancies and remains a major cause of maternal mortality. P-EC is characterized by a profound hypercoagulable state. The delicate hemostatic balance that must be maintained in the uteroplacental circulation during pregnancy makes this system vulnerable to perturbation. An abnormal hemostatic pattern occurs within the uteroplacental circulation in P-EC compared with normal pregnancy. Much recent research has focused on the epidemiological link between inherited thrombophilia and P-EC. The data suggest a weak statistical association, indicating an improbable primary role in the pathogenesis. Without clear evidence, low molecular weight heparins have been widely used to reduce recurrence of P-EC in thrombophilia-positive women. This practice now should be reviewed. Future research needs to focus on improving our basic scientific understanding of the role of the hemostatic system in human placentation.

  7. Pre-combustion CO{sub 2} capture: Analysis of integrated reforming combined cycle

    Energy Technology Data Exchange (ETDEWEB)

    Nord, Lars Olof

    2010-06-15

    NGCC plant. For an IRCC with a lot of high-pressure saturated steam generated in the process, a single-pressure steam cycle can actually perform in parity with a dual- or triple-pressure system (with or without reheat). Preheating of process streams further add to the complexity. The complexity of selecting an HRSG design increased when also considering that steam could be superheated and low-pressure and intermediate-pressure steam could be generated in the reforming process heat exchangers. For the concept studied it was also of importance to maintain a high net plant efficiency when operating on NG. Therefore the selection of HRSG design had to be a compromise between NGCC and IRCC operating modes. Duct burning proved positive for plant flexibility and the option to switch between a hydrogen-rich fuel and NG for the GT. Functional analysis and FMECA are important steps in a system reliability analysis, as they can serve as a platform and basis for further analysis. Also, the results from the FMECA can be interesting for determining how the failures propagate through the system and their failure effects on the operation of the process. From the FMECA performed in this work, it is clear that the gas turbine is the most critical equipment in an IRCC plant. One of the reasons for this is the process integration between the power island and the pre-combustion process. For example, the gas turbine feeds air to the ATR and receives fuel from the pre-combustion process. This integration has an effect on the overall reliability of the system. In addition to the integration issues, the gas turbine technology is less mature for hydrogen fuels than for natural gas fuels. It should also be mentioned that even in an NG-fired combined cycle plant the gas turbine is the most critical equipment. The need for part load analysis and consideration to dual fuel capability were important conclusions from the reliability analysis since many of the failures resulted in IRCC plant shutdown

  8. Pre-Dawn Martian Sky

    Science.gov (United States)

    1997-01-01

    On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  9. Pre-equilibrium plasma dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heinz, U.

    1986-01-01

    Approaches towards understanding and describing the pre-equilibrium stage of quark-gluon plasma formation in heavy-ion collisions are reviewed. Focus is on a kinetic theory approach to non-equilibrium dynamics, its extension to include the dynamics of color degrees of freedom when applied to the quark-gluon plasma, its quantum field theoretical foundations, and its relationship to both the particle formation stage at the very beginning of the nuclear collision and the hydrodynamic stage at late collision times. The usefulness of this approach to obtain the transport coefficients in the quark-gluon plasma and to derive the collective mode spectrum and damping rates in this phase are discussed. Comments are made on the general difficulty to find appropriated initial conditions to get the kinetic theory started, and a specific model is given that demonstrates that, once given such initial conditions, the system can be followed all the way through into the hydrodynamical regime. 39 refs., 7 figs. (LEW)

  10. Design of a reconfigurable liquid hydrogen fuel tank for use in the Genii unmanned aerial vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Patrick; Leachman, Jacob [HYdrogen Properties for Energy Research (HYPER) Laboratory, Washington State University, Pullman, WA 99164-2920 (United States)

    2014-01-29

    Long endurance flight, on the order of days, is a leading flight performance characteristic for Unmanned Aerial Vehicles (UAVs). Liquid hydrogen (LH2) is well suited to providing multi-day flight times with a specific energy 2.8 times that of conventional kerosene based fuels. However, no such system of LH2 storage, delivery, and use is currently available for commercial UAVs. In this paper, we develop a light weight LH2 dewar for integration and testing in the proton exchange membrane (PEM) fuel cell powered, student designed and constructed, Genii UAV. The fuel tank design is general for scaling to suit various UAV platforms. A cylindrical vacuum-jacketed design with removable end caps was chosen to incorporate various fuel level gauging, pressurizing, and slosh mitigation systems. Heat and mechanical loadings were modeled to compare with experimental results. Mass performance of the fuel tank is characterized by the fraction of liquid hydrogen to full tank mass, and the insulation performance was characterized by effective thermal conductivity and boil-off rate.

  11. Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-03-01

    Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

  12. Performance assessment of a spiral methanol to hydrogen fuel processor for fuel cell applications

    Institute of Scientific and Technical Information of China (English)

    Foad Mehri; Majid Taghizadeh

    2012-01-01

    A novel design of plate-type microchannel reactor has been developed for fuel cell-grade hydrogen production.Commercial Cu/Zn/Al2O3 was used as catalyst for the reforming reaction,and its effectiveness was evaluated on the mole fraction of products,methanol conversion,hydrogen yield and the amount of carbon monoxide under various operating conditions.Subsequently,0.5 wt% Ru/Al2O3 as methanation catalyst was prepared by impregnation method and coupled with MSR step to evaluate the capability of methanol processor for CO reduction.Based on the experimental results,the optimum conditions were obtained as feed flow rate of 5 mL/h and temperature of 250℃,leading to a low CO selectivity and high H2 yield.The designed reformer with catalyst coated layer was compared with the conventional packed bed reformer at the same operating conditions.The constructed fuel processor had a good performance and excellent capability for on-board hydrogen production.

  13. Hydrogen-Fuel Infrastructure Investment with Endogenous Demand : A Real Options Approach

    NARCIS (Netherlands)

    Li, Y.; Kool, C.J.M.; Engelen, P.J.

    2016-01-01

    In this paper, we explicitly incorporate the impact that realized investment in new infrastructure has on adoption speed in a real options framework for investment decisions and analyze the consequences of this dependence for optimal investment. For the adoption diffusion process, we use a modified

  14. Novel catalysts for hydrogen fuel cell applications:Final report (FY03-FY05).

    Energy Technology Data Exchange (ETDEWEB)

    Thornberg, Steven Michael; Coker, Eric Nicholas; Jarek, Russell L.; Steen, William Arthur

    2005-12-01

    The goal of this project was to develop novel hydrogen-oxidation electrocatalyst materials that contain reduced platinum content compared to traditional catalysts by developing flexible synthesis techniques to fabricate supported catalyst structures, and by verifying electrochemical performance in half cells and ultimately laboratory fuel cells. Synthesis methods were developed for making small, well-defined platinum clusters using zeolite hosts, ion exchange, and controlled calcination/reduction processes. Several factors influence cluster size, and clusters below 1 nm with narrow size distribution have been prepared. To enable electrochemical application, the zeolite pores were filled with electrically-conductive carbon via infiltration with carbon precursors, polymerization/cross-linking, and pyrolysis under inert conditions. The zeolite host was then removed by acid washing, to leave a Pt/C electrocatalyst possessing quasi-zeolitic porosity and Pt clusters of well-controlled size. Plotting electrochemical activity versus pyrolysis temperature typically produces a Gaussian curve, with a peak at ca. 800 C. The poorer relative performances at low and high temperature are due to low electrical conductivity of the carbon matrix, and loss of zeolitic structure combined with Pt sintering, respectively. Cluster sizes measured via adsorption-based methods were consistently larger than those observed by TEM and EXAFS, suggesting , that a fraction of the clusters were inaccessible to the fluid phase. Detailed EXAFS analysis has been performed on selected catalysts and catalyst precursors to monitor trends in cluster size evolution, as well as oxidation states of Pt. Experiments were conducted to probe the electroactive surface area of the Pt clusters. These Pt/C materials had as much as 110 m{sup 2}/g{sub pt} electroactive surface area, an almost 30% improvement over what is commercially (mfg. by ETEK) available (86 m{sup 2}/g{sub pt}). These Pt/C materials also perform qualitatively as well as the ETEK material for the ORR, a non-trivial achievement. A fuel cell test showed that Pt/C outperformed the ETEK material by an average of 50% for a 300 hour test. Increasing surface area decreases the amount of Pt needed in a fuel cell, which translates into cost savings. Furthermore, the increased performance realized in the fuel cell test might ultimately mean less Pt is needed in a fuel cell; this again translates into cost savings. Finally, enhanced long-term stability is a key driver within the fuel cell community as improvements in this area must be realized before fuel cells find their way into the marketplace; these Pt/C materials hold great promise of enhanced stability over time. An external laser desorption ion source was successfully installed on the existing Fourier transform ion-cyclotron resonance (FT-ICR) mass spectrometer. However, operation of this laser ablation source has only generated metal atom ions, no clusters have been found to date. It is believed that this is due to the design of the pulsed-nozzle/laser vaporization chamber. The final experimental configuration and design of the two source housings are described.

  15. Advanced DC-DC converter for power conditioning in hydrogen fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Kovacevic, G.; Tenconi, A.; Bojoi, R. [Department of Electrical Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2008-06-15

    The fuel cell (FC) generators can produce electric energy directly from hydrogen and oxygen. The DC voltage generated by FC is generally low amplitude and it is not constant, depending on the operating conditions. Furthermore, FC systems have dynamic response that is slower than the transient responses typically requested by the load. For this reason, in many applications the FC generators must be interfaced with other energy/power sources by means of an electronic power converter. An advanced full-bridge (FB) DC-DC converter, which effectively achieves zero-voltage switching and zero-current switching (ZVS-ZCS), is proposed for power-conditioning (PC) in hydrogen FC applications. The operation and features of the converter are analyzed and verified by simulations results. The ZVS-ZCS operation is obtained by means of a simple auxiliary circuit. Introduction of the soft-switching operation in PC unit brings improvements not only from the converter efficiency point of view, but also in terms of increased converter power density. Quantitative analysis of hard and soft-switching operating of the proposed converter is also made, bringing in evidence the benefits of soft-switching operation mode. The proposed converter can be a suitable solution for PC in hydrogen FC systems, especially for the medium to high-power applications. (author)

  16. Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

    Science.gov (United States)

    Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

    2015-01-01

    Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

  17. Waste biomass toward hydrogen fuel supply chain management for electricity: Malaysia perspective

    Science.gov (United States)

    Zakaria, Izatul Husna; Ibrahim, Jafni Azhan; Othman, Abdul Aziz

    2016-08-01

    Green energy is becoming an important aspect of every country in the world toward energy security by reducing dependence on fossil fuel import and enhancing better life quality by living in the healthy environment. This conceptual paper is an approach toward determining physical flow's characteristic of waste wood biomass in high scale plantation toward producing gas fuel for electricity using gasification technique. The scope of this study is supply chain management of syngas fuel from wood waste biomass using direct gasification conversion technology. Literature review on energy security, Malaysia's energy mix, Biomass SCM and technology. This paper uses the theoretical framework of a model of transportation (Lumsden, 2006) and the function of the terminal (Hulten, 1997) for research purpose. To incorporate biomass unique properties, Biomass Element Life Cycle Analysis (BELCA) which is a novel technique develop to understand the behaviour of biomass supply. Theoretical framework used to answer the research questions are Supply Chain Operations Reference (SCOR) framework and Sustainable strategy development in supply chain management framework

  18. Combustion Dynamics in Multi-Nozzle Combustors Operating on High-Hydrogen Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Santavicca, Dom; Lieuwen, Tim

    2013-09-30

    Actual gas turbine combustors for power generation applications employ multi-nozzle combustor configurations. Researchers at Penn State and Georgia Tech have extended previous work on the flame response in single-nozzle combustors to the more realistic case of multi-nozzle combustors. Research at Georgia Tech has shown that asymmetry of both the flow field and the acoustic forcing can have a significant effect on flame response and that such behavior is important in multi-flame configurations. As a result, the structure of the flame and its response to forcing is three-dimensional. Research at Penn State has led to the development of a three-dimensional chemiluminescence flame imaging technique that can be used to characterize the unforced (steady) and forced (unsteady) flame structure of multi-nozzle combustors. Important aspects of the flame response in multi-nozzle combustors which are being studied include flame-flame and flame-wall interactions. Research at Penn State using the recently developed three-dimensional flame imaging technique has shown that spatial variations in local flame confinement must be accounted for to accurately predict global flame response in a multi-nozzle can combustor.

  19. Numerical Simulation of Supersonic Combustion with Parallel Injection of Hydrogen Fuel

    Directory of Open Access Journals (Sweden)

    M.S.R. Chandra Murty

    2010-08-01

    Full Text Available Thermochemical exploration of mixing and combustion of parallel hydrogen injection into supersonic vitiated air stream in a divergent duct is presented. Three-dimensional Navier Stokes equations along with twoequation turbulence models and Eddy dissipation concept (EDC-based combustion models are solved using commercial CFD software. Chemical reaction for H2-air system is modelled by two different simple chemical kinetic schemes namely; infinitely fast rate kinetics as well as the single-step finite rate kinetics. Grid convergence of the solution is demonstrated and a grid convergence index-based error estimate has been provided. Insight into the mixing and combustion of high-speed turbulent reacting flow is obtained through the analysis of various thermochemical variables. Very good comparisons are obtained for the exit profiles for various fluid dynamical and chemical variables for the mixing case. For reacting case, the comparison between the experimental and the numerical values are reasonable. Parametric studies were carried out to study the effect of different turbulence models and turbulent Schmidt numbers. It is seen that Wilcox k-w turbulence model performed better than the other two-equation turbulence models in its class. Strong dependence of flow behaviour on turbulent Schmidt number was observed. The results indicate that simple chemical kinetics is adequate to describe the H2-air reaction in the scramjet combustor.Defence Science Journal, 2010, 60(5, pp.465-475, DOI:http://dx.doi.org/10.14429/dsj.60.57

  20. Appendix B: Hydrogen, Fuel Cells, and Infrastructure Technologies Program inputs for FY 2008 benefits estimates

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    Document summarizes the results of the benefits analysis of EERE’s programs, as described in the FY 2008 Budget Request. EERE estimates benefits for its overall portfolio and nine Research, Development, Demonstration, and Deployment (RD3) programs.

  1. Mesoporous silicon synthesis and applications in Li-ion batteries and solar hydrogen fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Donghai; Dai, Fang; Yi, Ran; Zai, Jianto

    2017-05-23

    We provide a mesoporous silicon material (PSi) prepared via a template-free and HF-free process. The production process is facile and scalable, and it may be conducted under mild reaction conditions. The silicon may be produced directly by the reduction of a silicon-halogenide precursor (for example, SiCl.sub.4) with an alkaline alloy (for example, NaK alloy). The resulting Si-salt matrix is then annealed for the pore formation and crystallite growth. Final product is obtained by removal of the salt by-products with water.

  2. High-performance hydrogen fuel cell using nitrate reduction reaction on a non-precious catalyst.

    Science.gov (United States)

    Han, Sang-Beom; Song, You-Jung; Lee, Young-Woo; Ko, A-Ra; Oh, Jae-Kyung; Park, Kyung-Won

    2011-03-28

    The H(2)-NO(3)(-) electrochemical cell using nitrate reduction on a non-precious cathode catalyst shows much improved efficiency despite ∼75% reduction of Pt metal loading as compared to typical PEMFCs using typical ORR on precious catalysts.

  3. DOE Hydrogen, Fuel Cells and Infrastructure Technologies Program Integrated Hydrogen Production, Purification and Compression System

    Energy Technology Data Exchange (ETDEWEB)

    Tamhankar, Satish; Gulamhusein, Ali; Boyd, Tony; DaCosta, David; Golben, Mark

    2011-06-30

    The project was started in April 2005 with the objective to meet the DOE target of delivered hydrogen of <$1.50/gge, which was later revised by DOE to $2-$3/gge range for hydrogen to be competitive with gasoline as a fuel for vehicles. For small, on-site hydrogen plants being evaluated at the time for refueling stations (the 'forecourt'), it was determined that capital cost is the main contributor to the high cost of delivered hydrogen. The concept of this project was to reduce the cost by combining unit operations for the entire generation, purification, and compression system (refer to Figure 1). To accomplish this, the Fluid Bed Membrane Reactor (FBMR) developed by MRT was used. The FBMR has hydrogen selective, palladium-alloy membrane modules immersed in the reformer vessel, thereby directly producing high purity hydrogen in a single step. The continuous removal of pure hydrogen from the reformer pushes the equilibrium 'forward', thereby maximizing the productivity with an associated reduction in the cost of product hydrogen. Additional gains were envisaged by the integration of the novel Metal Hydride Hydrogen Compressor (MHC) developed by Ergenics, which compresses hydrogen from 0.5 bar (7 psia) to 350 bar (5,076 psia) or higher in a single unit using thermal energy. Excess energy from the reformer provides up to 25% of the power used for driving the hydride compressor so that system integration improved efficiency. Hydrogen from the membrane reformer is of very high, fuel cell vehicle (FCV) quality (purity over 99.99%), eliminating the need for a separate purification step. The hydride compressor maintains hydrogen purity because it does not have dynamic seals or lubricating oil. The project team set out to integrate the membrane reformer developed by MRT and the hydride compression system developed by Ergenics in a single package. This was expected to result in lower cost and higher efficiency compared to conventional hydrogen production technologies. The overall objective was to develop an integrated system to directly produce high pressure, high-purity hydrogen from a single unit, which can meet the DOE cost H2 cost target of $2 - $3/gge when mass produced. The project was divided into two phases with the following tasks and corresponding milestones, targets and decision points. Phase 1 - Task 1 - Verify feasibility of the concept, perform a detailed techno-economic analysis, and develop a test plan; and Task 2: Build and experimentally test a Proof of Concept (POC) integrated membrane reformer/metal hydride compressor system. Phase 2 - Task 3: Build an Advanced Prototype (AP) system with modifications based on POC learning and demonstrate at a commercial site; and Task 4: Complete final product design for mass manufacturing units capable of achieving DOE 2010 H2 cost and performance targets.

  4. Prediction of Combustion Stability and Flashback in Turbines with High-Hydrogen Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lieuwen, Tim; Santavicca, Dom; Yang, Vigor

    2012-03-31

    During the duration of this sponsorship, we broadened our understanding of combustion instabilities through both analytical and experimental work. Predictive models were developed for flame response to transverse acoustic instabilities and for quantifying how a turbulent flame responds to velocity and fuel/air ratio forcing. Analysis was performed on the key instability mechanisms controlling heat release response for flames over a wide range of instability frequencies. Importantly, work was done closely with industrial partners to transition existing models into internal instability prediction codes. Experimentally, the forced response of hydrogen-enriched natural gas/air premixed and partially premixed flames were measured. The response of a lean premixed flame was investigated, subjected to velocity, equivalence ratio, and both forcing mechanisms simultaneously. In addition, important physical mechanisms controlling the response of partially premixed flames to inlet velocity and equivalence ratio oscillations were analyzed. This final technical report summarizes our findings and major publications stemming from this program.

  5. Selection and Evaluation of Carbon-Resin Composites for Bipolar Plates for Hydrogen Fuel Cells

    Science.gov (United States)

    1978-01-01

    890L.F 0 es - 9S O Arofene 2869 Polyvinyl Butyral 93 - 104 low Arofene 860 Epoxy 96 - 102 Low to Medium In addition to the above standard resins, the...diphenyloxide Modified 890) EP-032217-A-35 (High Aniline 875) EP-032217-A-36 (875 with polyvinyl butvral) DISCUSSION The composites for this project must be

  6. Numerical Simulation of Vitiation Effects on a Hydrogen-Fueled Dual-Mode Scramjet

    Science.gov (United States)

    Vyas, Manan A.; Engblom, William A.; Georgiadis, Nicholas J.; Trefny, Charles J.; Bhagwandin, Vishal A.

    2010-01-01

    The Wind-US computational fluid dynamics (CFD) flow solver was used to simulate dual-mode direct-connect ramjet/scramjet engine flowpath tests conducted in the University of Virginia (UVa) Supersonic Combustion Facility (SCF). The objective was to develop a computational capability within Wind-US to aid current hypersonic research and provide insight to flow as well as chemistry details that are not resolved by instruments available. Computational results are compared with experimental data to validate the accuracy of the numerical modeling. These results include two fuel-off non-reacting and eight fuel-on reacting cases with different equivalence ratios, split between one set with a clean (non-vitiated) air supply and the other set with a vitiated air supply (12 percent H2O vapor). The Peters and Rogg hydrogen-air chemical kinetics model was selected for the scramjet simulations. A limited sensitivity study was done to investigate the choice of turbulence model and inviscid flux scheme and led to the selection of the k-epsilon model and Harten, Lax and van Leer (for contact waves) (HLLC) scheme for general use. Simulation results show reasonably good agreement with experimental data and the overall vitiation effects were captured.

  7. Hydrogen Storage Experiments for an Undergraduate Laboratory Course--Clean Energy: Hydrogen/Fuel Cells

    Science.gov (United States)

    Bailey, Alla; Andrews, Lisa; Khot, Ameya; Rubin, Lea; Young, Jun; Allston, Thomas D.; Takacs, Gerald A.

    2015-01-01

    Global interest in both renewable energies and reduction in emission levels has placed increasing attention on hydrogen-based fuel cells that avoid harm to the environment by releasing only water as a byproduct. Therefore, there is a critical need for education and workforce development in clean energy technologies. A new undergraduate laboratory…

  8. Developing and Implementing a Simple, Affordable Hydrogen Fuel Cell Laboratory in Introductory Chemistry

    Science.gov (United States)

    Klara, Kristina; Hou, Ning; Lawman, Allison; Wu, Liheng; Morrill, Drew; Tente, Alfred; Wang, Li-Qiong

    2014-01-01

    A simple, affordable hydrogen proton exchange membrane (PEM) fuel cell laboratory was developed through a collaborative effort between faculty and undergraduate students at Brown University. It has been incorporated into the introductory chemistry curriculum and successfully implemented in a class of over 500 students per academic year for over 3…

  9. The choice of low-temperature hydrogen fuel cells: Acidic - or alkaline

    Science.gov (United States)

    Kordesch, K.

    A comparison of the major types of hydrogen-oxygen (air) fuel cells is given. The criteria for the selection is the fuel availability, system performance, optimal cost and life expectancy in most suitable application areas. Special recommendations are given for designs of bipolar alkaline batteries for intermittent use in electric vehicles on the road, combining high conversion efficiency with long stand-by periods. Such batteries with liquid alkaline electrolytes will have to compete with matrix-type cells using improved acidic- or membrane-type cells. Hybrid systems will be discussed and their advantages from the economic point of view will be considered. In electric vehicles the combination with an advanced rechargeable battery system, like zinc-bromine, could be decisive for success. Unfortunately, there are not enough cost data available to compare the systems now.

  10. Developing and Implementing a Simple, Affordable Hydrogen Fuel Cell Laboratory in Introductory Chemistry

    Science.gov (United States)

    Klara, Kristina; Hou, Ning; Lawman, Allison; Wu, Liheng; Morrill, Drew; Tente, Alfred; Wang, Li-Qiong

    2014-01-01

    A simple, affordable hydrogen proton exchange membrane (PEM) fuel cell laboratory was developed through a collaborative effort between faculty and undergraduate students at Brown University. It has been incorporated into the introductory chemistry curriculum and successfully implemented in a class of over 500 students per academic year for over 3…

  11. Oxygen-hydrogen fuel cell with an iodine-iodide cathode - A concept

    Science.gov (United States)

    Javet, P.

    1970-01-01

    Fuel cell uses a porous cathode through which is fed a solution of iodine in aqueous iodide solution, the anode is a hydrogen electrode. No activation polarization appears on the cathode because of the high exchange-current density of the iodine-iodide electrode.

  12. Extension Sliding Mode Controller for Maximum Power Point Tracking of Hydrogen Fuel Cells

    Directory of Open Access Journals (Sweden)

    Meng-Hui Wang

    2013-01-01

    Full Text Available Fuel cells (FCs are characterized by low pollution, low noise, and high efficiency. However, the voltage-current response of an FC is nonlinear, with the result that there exists just one operating point which maximizes the output power given a particular set of operating conditions. Accordingly, the present study proposes a maximum power point tracking (MPPT control scheme based on extension theory to stabilize the output of an FC at the point of maximum power. The simulation results confirm the ability of the controller to stabilize the output power at the maximum power point despite sudden changes in the temperature, hydrogen pressure, and membrane water content. Moreover, the transient response time of the proposed controller is shown to be faster than that of existing sliding mode (SM and extremum seeking (ES controllers.

  13. Ionic Solid Hydrogen Fuel: Production and Properties of Hydrogen ion and Energetic Neutral Clusters

    Science.gov (United States)

    1990-09-01

    LORENTS ,olecular Ph vsics Laboratory. SRI International. Menlo Park, 1-i V4025. tUSA Received 22 March 1989: in final form I Ma, 1989 We have observed...at n= 18, not n= 12 as observed. From the corn - It 6 puter simulation of the growth kinetics which will be presented in section 4, we tentatively

  14. The production of hydrogen fuel from renewable sources and its role in grid operations

    Science.gov (United States)

    Barton, John; Gammon, Rupert

    Understanding the scale and nature of hydrogen's potential role in the development of low carbon energy systems requires an examination of the operation of the whole energy system, including heat, power, industrial and transport sectors, on an hour-by-hour basis. The Future Energy Scenario Assessment (FESA) software model used for this study is unique in providing a holistic, high resolution, functional analysis, which incorporates variations in supply resulting from weather-dependent renewable energy generators. The outputs of this model, arising from any given user-definable scenario, are year round supply and demand profiles that can be used to assess the market size and operational regime of energy technologies. FESA was used in this case to assess what - if anything - might be the role for hydrogen in a low carbon economy future for the UK. In this study, three UK energy supply pathways were considered, all of which reduce greenhouse gas emissions by 80% by 2050, and substantially reduce reliance on oil and gas while maintaining a stable electricity grid and meeting the energy needs of a modern economy. All use more nuclear power and renewable energy of all kinds than today's system. The first of these scenarios relies on substantial amounts of 'clean coal' in combination with intermittent renewable energy sources by year the 2050. The second uses twice as much intermittent renewable energy as the first and virtually no coal. The third uses 2.5 times as much nuclear power as the first and virtually no coal. All scenarios clearly indicate that the use of hydrogen in the transport sector is important in reducing distributed carbon emissions that cannot easily be mitigated by Carbon Capture and Storage (CCS). In the first scenario, this hydrogen derives mainly from steam reformation of fossil fuels (principally coal), whereas in the second and third scenarios, hydrogen is made mainly by electrolysis using variable surpluses of low-carbon electricity. Hydrogen thereby fulfils a double facetted role of Demand Side Management (DSM) for the electricity grid and the provision of a 'clean' fuel, predominantly for the transport sector. When each of the scenarios was examined without the use of hydrogen as a transport fuel, substantially larger amounts of primary energy were required in the form of imported coal. The FESA model also indicates that the challenge of grid balancing is not a valid reason for limiting the amount of intermittent renewable energy generated. Engineering limitations, economic viability, local environmental considerations and conflicting uses of land and sea may limit the amount of renewable energy available, but there is no practical limit to the conversion of this energy into whatever is required, be it electricity, heat, motive power or chemical feedstocks.

  15. A review of PEM hydrogen fuel cell contamination: Impacts, mechanisms, and mitigation

    Science.gov (United States)

    Cheng, Xuan; Shi, Zheng; Glass, Nancy; Zhang, Lu; Zhang, Jiujun; Song, Datong; Liu, Zhong-Sheng; Wang, Haijiang; Shen, Jun

    This paper reviewed over 150 articles on the subject of the effect of contamination on PEM fuel cell. The contaminants included were fuel impurities (CO, CO 2, H 2S, and NH 3); air pollutants (NO x, SO x, CO, and CO 2); and cationic ions Fe 3+ and Cu 2+ resulting from the corrosion of fuel cell stack system components. It was found that even trace amounts of impurities present in either fuel or air streams or fuel cell system components could severely poison the anode, membrane, and cathode, particularly at low-temperature operation, which resulted in dramatic performance drop. Significant progress has been made in identifying fuel cell contamination sources and understanding the effect of contaminants on performance through experimental, theoretical/modeling, and methodological approaches. Contamination affects three major elements of fuel cell performance: electrode kinetics, conductivity, and mass transfer. This review was focused on three areas: (1) contamination impacts on the fuel cell performance, (2) mechanism approaches dominated by modeling studies, and (3) mitigation development. Some future work on fuel cell contamination research is suggested in order to facilitate the move toward commercialization.

  16. Thermodynamic Analysis of Three Compressed Air Energy Storage Systems: Conventional, Adiabatic, and Hydrogen-Fueled

    Directory of Open Access Journals (Sweden)

    Hossein Safaei

    2017-07-01

    Full Text Available We present analyses of three families of compressed air energy storage (CAES systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latter two methods involve no fossil fuel combustion. We modeled both a low-temperature and a high-temperature electrolysis process for hydrogen production. Adiabatic CAES (A-CAES with physical storage of heat is the most efficient option with an exergy efficiency of 69.5% for energy storage. The exergy efficiency of the conventional CAES system is estimated to be 54.3%. Both high-temperature and low-temperature electrolysis CAES systems result in similar exergy efficiencies (35.6% and 34.2%, partly due to low efficiency of the electrolyzer cell. CAES with high-temperature electrolysis has the highest energy storage density (7.9 kWh per m3 of air storage volume, followed by A-CAES (5.2 kWh/m3. Conventional CAES and CAES with low-temperature electrolysis have similar energy densities of 3.1 kWh/m3.

  17. Slovenian Pre-Service Teachers' Prototype Biography

    Science.gov (United States)

    Lipovec, Alenka; Antolin, Darja

    2014-01-01

    In this article we apply narrative methodology to the study of pre-service elementary teachers' school-time memories connected to mathematics education. In the first phase of our empirical study we asked 214 Slovenian pre-service teachers to write their mathematical autobiographies. On the basis of the mathematical autobiographies we constructed a…

  18. Action plan pre-crash evaluation

    NARCIS (Netherlands)

    Bartels, O.; Langner, T.; Aparicio, A.; Lemmen, P.; Rodarius, C.

    2010-01-01

    This deliverable “Action plan pre-crash evaluation” forms the starting point of WP4 pre-crash evaluation. This document mainly is the outcome of a two days workshop held at BASt. It is strongly linked to the WP1.1 results that came up with data concerning the accident situation on European roads. WP

  19. Visual Disturbances in (Pre)eclampsia

    NARCIS (Netherlands)

    Roos, Nina M.; Wiegman, Marjon J.; Jansonius, Nomdo M.; Zeeman, Gerda G.

    2012-01-01

    This review aims to summarize existing information concerning visual disturbances in (pre) eclampsia that have been described in the literature. Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortality worldwide. Visual disturbances in (pre) eclampsia seem to be freque

  20. Pre-Service Teachers' Conceptions of Probability

    Science.gov (United States)

    Odafe, Victor U.

    2011-01-01

    Probability knowledge and skills are needed in science and in making daily decisions that are sometimes made under uncertain conditions. Hence, there is the need to ensure that the pre-service teachers of our children are well prepared to teach probability. Pre-service teachers' conceptions of probability are identified, and ways of helping them…

  1. Pre-eclampsia, eclampsia, and hypertension

    OpenAIRE

    Duley, Lelia

    2011-01-01

    Pre-eclampsia (raised blood pressure and proteinuria) complicates 2% to 8% of pregnancies, and increases morbidity and mortality in the mother and child. Pre-eclampsia is more common in women with multiple pregnancy and in those with conditions associated with microvascular disease.

  2. The Pre-IPO Dividend Puzzle

    NARCIS (Netherlands)

    Martin, J.; Zeckhauser, R.

    2011-01-01

    We investigate dividend payments of companies prior to their IPOs. U.S. companies conducting an IPO between 1990 through 2006 comprise our sample. Pre-IPO dividend payments are significant both in number and size in the quarter leading up to the IPO. We find support for the hypothesis that pre-IPO

  3. Pre-Service Teachers' Conceptions of Probability

    Science.gov (United States)

    Odafe, Victor U.

    2011-01-01

    Probability knowledge and skills are needed in science and in making daily decisions that are sometimes made under uncertain conditions. Hence, there is the need to ensure that the pre-service teachers of our children are well prepared to teach probability. Pre-service teachers' conceptions of probability are identified, and ways of helping them…

  4. Visual Disturbances in (Pre)eclampsia

    NARCIS (Netherlands)

    Roos, Nina M.; Wiegman, Marjon J.; Jansonius, Nomdo M.; Zeeman, Gerda G.

    This review aims to summarize existing information concerning visual disturbances in (pre) eclampsia that have been described in the literature. Preeclampsia is one of the leading causes of maternal and fetal morbidity and mortality worldwide. Visual disturbances in (pre) eclampsia seem to be

  5. PRE: A framework for enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    Whiteside, R.A.; Friedman-Hill, E.J. [Sandia National Labs., Livermore, CA (United States); Detry, R.J. [Sandia National Labs., Albuquerque, NM (United States)

    1998-03-01

    Sandia National Laboratories` Product Realization Environment (PRE) is a lightweight, CORBA based framework for the integration of a broad variety of applications. These applications are wrapped for use in the PRE framework as reusable components. For example, some of the PRE components currently available include: (1) product data management (PDM) system, (2) human resources database, several finite element analysis programs, and (3) a variety of image and document format converters. PRE enables the development of end user applications (as Java applets, for example) that use these components as building blocks. To aid such development, the PreLib library (available in both C++ and Java) permits both wrapping and using these components without knowledge of either CORBA or the security mechanisms used.

  6. Pre-task music improves swimming performance.

    Science.gov (United States)

    Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

    2015-12-01

    The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

  7. Roseires Dam Heightening Project in Sudan Works of Pre-tensioned Pre-stressed Concrete Beams

    Institute of Scientific and Technical Information of China (English)

    黄志敏

    2014-01-01

    Works of pre-tensioned and pre-stressed concrete beams at dam crest of Roseires Dam Heightening Project located on Nile Riv-er in the Country of Sudan was in a big quantity, complexity and tight completion time. For pre-tensioning operation, frame type pedestal was built. Strict work method statement and applicable work procedure were also developed to assure high work quality and timely completion. All these have become precious experience in the field of pre-tensioning and pre-stressing beams.

  8. Pre-symptomatic increase in urine-orosomucoid excretion in pre-eclamptic women

    DEFF Research Database (Denmark)

    Kronborg, Camilla Skovhus; Allen, Jim; Vittinghus, Erik;

    2007-01-01

    , 32 women developed pre-eclampsia, and 5 controls for every case of pre-eclampsia were found. Blood samples were collected 4 times and urine samples 6 times from the 18/19th week and throughout pregnancy. Orosomucoid and albumin in plasma were analysed by standard methods, and in urine by sandwich...... in orosomucoid. In the plasma samples, orosomucoid was significantly higher late in pre-eclamptic pregnancies (>or=36th week, p=0.0275). CONCLUSIONS: Pre-eclampsia is associated with a pre-symptomatic increase in the urine excretion of orosomucoid, and orosomucoid excretion precedes that of albumin. Orosomucoid...... excretion can probably be used as a prognostic tool in combination with other screening methods, and seems to be a more sensitive marker for evolving pre-eclampsia than albumin. Plasma orosomucoid is significantly increased late in pre-eclampsia. Thus, the increased excretion of orosomucoid must primarily...

  9. Understanding Pre-Quantitative Risk in Projects

    Science.gov (United States)

    Cooper, Lynne P.

    2011-01-01

    Standard approaches to risk management in projects depend on the ability of teams to identify risks and quantify the probabilities and consequences of these risks (e.g., the 5 x 5 risk matrix). However, long before quantification does - or even can - occur, and long after, teams make decisions based on their pre-quantitative understanding of risk. These decisions can have long-lasting impacts on the project. While significant research has looked at the process of how to quantify risk, our understanding of how teams conceive of and manage pre-quantitative risk is lacking. This paper introduces the concept of pre-quantitative risk and discusses the implications of addressing pre-quantitative risk in projects.

  10. Pre-Existing Condition Insurance Plan Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Affordable Care Act created the new Pre-Existing Condition Insurance Plan (PCIP) program to make health insurance available to Americans denied coverage by...

  11. Pre-Congestion Notification (PCN) Architecture

    NARCIS (Netherlands)

    Eardley, P; Chan, K.; Charny, A.; Geib, R.; Karagiannis, Georgios; Menth, M.; Tsou, T.; Eardley, P

    2009-01-01

    This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain.

  12. Pre-Trip Notification Database (PTNS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The PTNS contains pre-trip notification data from vessels participating in the Northeast Multispecies groundfish fishery from 2010 to present and the Longfin squid...

  13. Coverage for SCS Pre-1941 Aerial Photography

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This shapefile was generated by the U.S. Bureau of Land Management (BLM) at the New Mexico State Office to show the coverage for the Pre-1941 aerial photography...

  14. Pre-heating mitigates composite degradation

    Directory of Open Access Journals (Sweden)

    Jessika Calixto da SILVA

    2015-12-01

    Full Text Available ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS. Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm and the composites Durafill VS (Heraeus Kulzer, Z-250 (3M/ESPE, and Z-350 (3M/ESPE, cured at 25°C (no pre-heating or 60°C (pre-heating. Specimens were stored sequentially in the following solutions: 1 water for 7 days (60°C, plus 0.1 N sodium hydroxide (NaOH for 14 days (60°C; 2 50% silver nitrate (AgNO3 for 10 days (60°C. Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%. Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (p<0.05. After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05. There was a lower penetration of silver in pre-heated specimens (p<0.05. Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

  15. Pre-Flare Flows in the Corona

    Science.gov (United States)

    Wallace, A. J.; Harra, L. K.; van Driel-Gesztelyi, L.; Green, L. M.; Matthews, S. A.

    2010-12-01

    Solar flares take place in regions of strong magnetic fields and are generally accepted to be the result of a resistive instability leading to magnetic reconnection. When new flux emerges into a pre-existing active region it can act as a flare and coronal mass ejection trigger. In this study we observed active region 10955 after the emergence of small-scale additional flux at the magnetic inversion line. We found that flaring began when additional positive flux levels exceeded 1.38×1020 Mx (maxwell), approximately 7 h after the initial flux emergence. We focussed on the pre-flare activity of one B-class flare that occurred on the following day. The earliest indication of activity was a rise in the non-thermal velocity one hour before the flare. 40 min before flaring began, brightenings and pre-flare flows were observed along two loop systems in the corona, involving the new flux and the pre-existing active region loops. We discuss the possibility that reconnection between the new flux and pre-existing loops before the flare drives the flows by either generating slow mode magnetoacoustic waves or a pressure gradient between the newly reconnected loops. The subsequent B-class flare originated from fast reconnection of the same loop systems as the pre-flare flows.

  16. Pre: Surgical orthopedic pre-maxillary alignment in bilateral cleft lip and palate patient

    OpenAIRE

    Vijaya Prasad Kamavaram Ellore; Naveen Kumar Ramagoni; Mahantesha Taranatha; Asha Nara; Gururaj Gunjalli; Ashwin Devasya Bhat

    2012-01-01

    Pre-surgical orthopedic appliances are mainly used to retract and align the protruded and deviated pre-maxilla and to facilitate initial lip repair. This article presents a case report of a five year old male child patient with bilateral cleft lip and palate in whom a special custom made pre-surgical orthopedic appliance was delivered. Use of a special custom made presurgical orthopedic appliance for repositioning pre-maxilla in bilateral cleft lip and palate patient is discussed in this arti...

  17. Examining the Association Between the NAPLEX, Pre-NAPLEX, and Pre- and Post-admission Factors.

    Science.gov (United States)

    Chisholm-Burns, Marie A; Spivey, Christina A; Byrd, Debbie C; McDonough, Sharon L K; Phelps, Stephanie J

    2017-06-01

    Objective. To examine the relationship between the NAPLEX and Pre-NAPLEX among pharmacy graduates, as well as determine effects of pre-pharmacy, pharmacy school, and demographic variables on NAPLEX performance. Methods. A retrospective review of pharmacy graduates' NAPLEX scores, Pre-NAPLEX scores, demographics, pre-pharmacy academic performance factors, and pharmacy school academic performance factors was performed. Bivariate (eg, ANOVA, independent samples t-test) and correlational analyses were conducted, as was stepwise linear regression to examine the significance of Pre-NAPLEX score and other factors as related to NAPLEX score. Results. One hundred fifty graduates were included, with the majority being female (60.7%) and white (72%). Mean NAPLEX score was 104.7. Mean Pre-NAPLEX score was 68.6. White students had significantly higher NAPLEX scores compared to Black/African American students. NAPLEX score was correlated to Pre-NAPLEX score, race/ethnicity, PCAT composite and section scores, undergraduate overall and science GPAs, pharmacy GPA, and on-time graduation. The regression model included pharmacy GPA and Pre-NAPLEX score. Conclusion. The findings provide evidence that, although pharmacy GPA is the most critical determinant, the Pre-NAPLEX score is also a significant predictor of NAPLEX score.

  18. Pre: Surgical orthopedic pre-maxillary alignment in bilateral cleft lip and palate patient

    Directory of Open Access Journals (Sweden)

    Vijaya Prasad Kamavaram Ellore

    2012-01-01

    Full Text Available Pre-surgical orthopedic appliances are mainly used to retract and align the protruded and deviated pre-maxilla and to facilitate initial lip repair. This article presents a case report of a five year old male child patient with bilateral cleft lip and palate in whom a special custom made pre-surgical orthopedic appliance was delivered. Use of a special custom made presurgical orthopedic appliance for repositioning pre-maxilla in bilateral cleft lip and palate patient is discussed in this article.

  19. Severe hyponatraemia associated with pre-eclampsia.

    Science.gov (United States)

    Anglim, Breffini; Levins, Kirk; Bussmann, Neidin; Imcha, Mendinaro

    2016-08-24

    Pre-eclampsia is a multisystem disorder with incidence rates ranging from 2% to 5%. Hyponatraemia is a rare complication of pre-eclampsia. A 41-year-old, para 0+1 in vitro fertilisation monochorionic diamniotic triplet pregnancy woman presented at 25 weeks with dyspnoea and general malaise. Her antenatal course was complicated by the diagnosis of intrauterine growth restriction in triplet one at 27 weeks of gestation. At 27+3 weeks gestation, she was diagnosed as having pre-eclampsia. Subsequent biochemical analysis demonstrated hyponatraemia with serum sodium falling steadily to 117 mmol/L over the next 19 days. She was admitted to intensive care unit for stabilisation of fulminant pre-eclampsia and severe hyponatraemia at 30+5 weeks of gestation. Hypertonic saline and intravenous labetolol were administered prior to delivery by caesarean section. She recovered well postdelivery with stabilisation of her blood pressure and normalisation of her sodium level to 135 mmol/L. Awareness and frequent monitoring of hyponatraemia should become an integral part of monitoring women with pre-eclampsia.

  20. Inclusive Education in Pre-Schools: Predictors of Pre-Service Teacher Attitudes in Australia

    Science.gov (United States)

    Hoskin, Jake; Boyle, Christopher; Anderson, Joanna

    2015-01-01

    Teachers' attitudes have been identified as being vital to the success of inclusive education (IE). With pre-school student populations becoming increasingly diverse, and many children experiencing this as their first involvement in formal education, the attitudes towards IE of pre-school teachers are more important than ever. This study…

  1. Pre-eclampsia and childhood asthma.

    Science.gov (United States)

    Magnus, Maria C; Håberg, Siri E; Magnus, Per; Engeland, Anders; Nafstad, Per; Karlstad, Øystein; Nystad, Wenche

    2016-12-01

    Studies of pre-eclampsia and childhood asthma are conflicting, and none have performed a formal mediation analysis of preterm birth.We examined the association between pre-eclampsia and asthma at 7 years using national registries, including all births in Norway from 1999 to 2006 (n=406 907), and a subsample of children in the Norwegian Mother and Child Cohort Study (MoBa) (n=45 028) using log-linear regression. We performed a mediation analysis of preterm birth, and a sibling comparison to evaluate unobserved confounding.There was a positive association between pre-eclampsia and asthma in the registry study, with an adjusted relative risk of 1.31 (95% CI 1.22-1.41), but not in MoBa, which had an adjusted relative risk of 1.19 (95% CI 0.99-1.44). The odds ratios for the direct effect not mediated through preterm birth and the indirect effect in the registry linkage were 1.19 (95% CI 1.10-1.29) and 1.12 (95% CI 1.11-1.14), respectively. The sibling comparison indicated no association between pre-eclampsia and asthma (adjusted OR 1.07, 95% CI 0.87-1.33).In this large study, which used different datasets and analytic approaches, there was little evidence for an association between pre-eclampsia and childhood asthma. The association was weak and largely explained by pre-term birth and confounders shared by siblings.

  2. Determining Views of Pre-School Teachers, Working at Pre-School Education Institutions on Pre-School Music Education

    Directory of Open Access Journals (Sweden)

    Aylin MENTİŞ KÖKSOY

    2005-06-01

    Full Text Available The main purpose of this study was to determine the opinions in about music education during the preschool period of kindergarten teachers working in state and private pre-schools of Ministry of Education in Çamardı, Bor, Altunhisar (Niğde and in Niğde.58 pre-scholl teachers were included in the study group. A questionnaire designed by researchers was given to the teachers. The questionnaire had two parts. In the first one there were personal questions about the teachers and in the second part their opinions about music education and some questions about the opportunitiesprovided by their instititutions about music education were asked. There were 10 questions in total. One of them was open-ended. In the study of data frequency, percent and one Way Anova analysis was used. According to the results, there were spinificant differences between the opinions of the teachers about music education depending on the institutions from which they graduated. In the study it was observed that musical instruments and music rooms at pre-school were insufficient. It was also seen by statement that some of the pre-schools teachers were not efficient in music.

  3. Pre-aggregation for Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

  4. Pre-eclampsia: pathophysiology, diagnosis, and management

    OpenAIRE

    Ayoubi JM

    2011-01-01

    Jennifer Uzan1, Marie Carbonnel1, Olivier Piconne1,3, Roland Asmar2, Jean-Marc Ayoubi11Department of Gynecology and Obstetrics, Hôpital Foch, Suresnes, France; 2Foundation Medical Research Institutes, Geneva, Switzerland; 3Department of Gynecology and Obstetrics, Hôpital Antoine Béclère, Clamart, FranceAbstract: The incidence of pre-eclampsia ranges from 3% to 7% for nulliparas and 1% to 3% for multiparas. Pre-eclampsia is a major cause of maternal mo...

  5. Pre-operative fasting guidelines: an update

    DEFF Research Database (Denmark)

    Søreide, E; Eriksson, L I; Hirlekar, G

    2005-01-01

    Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children......Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children...

  6. Extending maps between pre-uniform spaces

    OpenAIRE

    Adalberto García-Máynez; Rubén Mancio-Toledo

    2012-01-01

    [EN] We give sufficient conditions on a uniformly continuous map f: (X,U) → (Y, V ) between completable T1-pre-uniform spaces (X,U), (Y, V ) to have a continuous or a uniformly continuous extension f:X → Y between the corresponding completions. García-Máynez, A.; Mancio-Toledo, R. (2012). Extending maps between pre-uniform spaces. Applied General Topology. 13(1):21-25. doi:10.4995/agt.2012.1634. 21 25 13 1

  7. Pre-calculus workbook for dummies

    CERN Document Server

    Kuang, Yang

    2011-01-01

    Get the confidence and math skills you need to get started with calculus Are you preparing for calculus? This hands-on workbook helps you master basic pre-calculus concepts and practice the types of problems you'll encounter in the course. You'll get hundreds of valuable exercises, problem-solving shortcuts, plenty of workspace, and step-by-step solutions to every problem. You'll also memorize the most frequently used equations, see how to avoid common mistakes, understand tricky trig proofs, and much more. Pre-Calculus Workbook For Dummies is the perfect tool for anyone who wa

  8. Pre-aggregation for Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....

  9. Pre-K Benefits: The Facts on Fade-Out

    Science.gov (United States)

    Southern Regional Education Board (SREB), 2015

    2015-01-01

    As policymakers adopt policies for pre-K programs, they want to know that the programs are effective. Do the gains last? This brief report presents information that pre-k yields short-term academic gains; pre-k yields long-term academic gains; and pre-k yields substantial nonacademic benefits.

  10. Pre-K Benefits: The Facts on Fade-Out

    Science.gov (United States)

    Southern Regional Education Board (SREB), 2015

    2015-01-01

    As policymakers adopt policies for pre-K programs, they want to know that the programs are effective. Do the gains last? This brief report presents information that pre-k yields short-term academic gains; pre-k yields long-term academic gains; and pre-k yields substantial nonacademic benefits.

  11. Extending maps between pre-uniform spaces

    OpenAIRE

    Adalberto García-Máynez; Rubén Mancio-Toledo

    2012-01-01

    We give sufficient conditions on a uniformly continuous map f: (X,U) → (Y, V ) between completable T1-pre-uniform spaces (X,U), (Y, V ) to have a continuous or a uniformly continuous extension f:X → Y between the corresponding completions.

  12. Telomerase in (pre)neoplastic cervical disease

    NARCIS (Netherlands)

    Wisman, GBA; De Jong, S; Meersma, GJ; Helder, MN; Hollema, H; de Vries, EGE; Keith, WN; van der Zee, AGJ

    2000-01-01

    This study was performed to determine upregulation of the human telomerase RNA component (hTR) and mRNA of the catalytic subunit of telomerase (hTERT) in (pre)malignant cervical lesions, to analyze possible intralesional heterogeneity of hTR expression, and to relate hTR and hTERT mRNA levels to tel

  13. Rational Suggestions for Pre-Marital Counseling.

    Science.gov (United States)

    Ball, J.D.; Henning, Lawrence H.

    1981-01-01

    To demonstrate the utility of Rational Emotive Therapy in pre-marital counseling, examples of specific irrational beliefs which clinicians can use to help couples are presented. Mental health practitioners are encouraged to apply these principles to other specific irrationalities they may discover in their own work experience. (Author)

  14. Pre-operative fasting guidelines: an update

    DEFF Research Database (Denmark)

    Søreide, E; Eriksson, L I; Hirlekar, G

    2005-01-01

    Liberal pre-operative fasting routines have been implemented in most countries. In general, clear fluids are allowed up to 2 h before anaesthesia, and light meals up to 6 h. The same recommendations apply for children and pregnant women not in labour. In children...

  15. Neurologic Complications of Pre-eclampsia

    NARCIS (Netherlands)

    Zeeman, Gerda G.

    2009-01-01

    Pre-eclampsia is mainly responsible for the world's large maternal mortality rates, mostly due to acute cerebral complications. This review provides insight into the pathogenesis of the neurologic complications of hypertensive disease in pregnancy. In addition, practical relevance for clinical care

  16. Developing Pre-service Teachers' Technology Integration ...

    African Journals Online (AJOL)

    Developing Pre-service Teachers' Technology Integration Competencies in Science and Mathematics Teaching: Experiences from Tanzania and Uganda. ... Makerere Journal of Higher Education ... Thus, it emerged that there is a need to explore models situated in a more encompassing theoretical framework like ...

  17. Overview of Pre-Congestion Notification Encoding

    NARCIS (Netherlands)

    Karagiannis, G.; Chan, K.; Moncaster, T.; Menth, M.; Eardley, P.; Briscoe, B.

    2012-01-01

    The objective of Pre-Congestion Notification (PCN) is to protect the quality of service (QoS) of inelastic flows within a Diffserv domain. On every link in the PCN-domain, the overall rate of PCN-traffic is metered, and PCN-packets are appropriately marked when certain configured rates are exceeded.

  18. Pre-registration education: learning communities.

    Science.gov (United States)

    Thomas, Gail; Crooke, Lois; Curtis, Peter

    Changes in nurse education in the UK and the introduction of a new pre-registration nursing programme have led to developments in education methods. This article describes the creation of learning communities at Thames Valley University as a means of adapting to the new curriculum.

  19. Het pre-insolventieakkoord : grondslagen en raamwerk

    NARCIS (Netherlands)

    Tollenaar, Nicolaes

    2016-01-01

    Background and topicality Legislation is currently being prepared, at both the European and the national levels, to introduce proceedings that aim to rescue ailing businesses before formal insolvency proceedings are begun. Such proceedings are commonly referred to as “pre-insolvency” proceedings. Th

  20. Children's collaborative encounters in pre-school

    DEFF Research Database (Denmark)

    Svinth, Lone

    2013-01-01

    ’s collaboration and how the institutional demands influence children’s collaborative encounters. The study is based on video recordings of paedagogical activities (workshops and circle times) in two Danish pre-schools over a period of 11 months. Although institutional demands challenge children’s initiatives...

  1. Het pre-insolventieakkoord : grondslagen en raamwerk

    NARCIS (Netherlands)

    Tollenaar, Nicolaes

    2016-01-01

    Background and topicality Legislation is currently being prepared, at both the European and the national levels, to introduce proceedings that aim to rescue ailing businesses before formal insolvency proceedings are begun. Such proceedings are commonly referred to as “pre-insolvency” proceedings.

  2. Telomerase in (pre)neoplastic cervical disease

    NARCIS (Netherlands)

    Wisman, GBA; De Jong, S; Meersma, GJ; Helder, MN; Hollema, H; de Vries, EGE; Keith, WN; van der Zee, AGJ

    2000-01-01

    This study was performed to determine upregulation of the human telomerase RNA component (hTR) and mRNA of the catalytic subunit of telomerase (hTERT) in (pre)malignant cervical lesions, to analyze possible intralesional heterogeneity of hTR expression, and to relate hTR and hTERT mRNA levels to tel

  3. Dissection in Pre-college Education

    OpenAIRE

    Buyukmihci, NC

    2016-01-01

    This paper discusses the educational and ethical issues surrounding dissection of non-human animals in pre-college education. It argues that this exercise has no benefits to students that could possibly be outweighed by the death of healthy animals killed for this purpose.

  4. The effect of supine versus upright patient positioning on inferior vena cava metrics.

    Science.gov (United States)

    Panebianco, Nova L; Shofer, Frances; Cheng, Alfred; Fischer, Jonathan; Cody, Kenneth; Dean, Anthony J

    2014-11-01

    Ultrasound of the inferior vena cava (IVC) is a noninvasive and rapidly obtainable method of intravascular volume assessment; however not all patients can lie supine for this procedure. In this study we assess whether patient positioning affects IVC diameter metrics. This was a prospective convenience sample of patients in an in-patient dialysis unit at an urban tertiary care center. IVC metrics taken in the supine patient, and then at 45o semi-upright position, pre and post dialysis. Measurements were taken in M-mode in longitudinal plane roughly 2 cm below the level of the diaphragm. IVC-maximum and IVC-minimum diameter measurements were used to determine the IVC collapse index (IVC Max - IVC Min)/IVC Max). Statistics such as means, frequencies and percentages, intraclass correlation coefficient and Bland Altman summary statistics were calculated. Forty-five patients were enrolled. Average age was 57 years, 69% were male, 73% were African American, 82% had hypertension, 42% had diabetes. There was good to excellent agreement between supine and upright IVC measurements. Both the IVC minimum and maximum measurements had similar coefficient correlation (ri) measurements (0.917 and 0.890 respectively), whereas agreement in the collapse index was lower (ri = 0.813). Bland Altman analysis demonstrated excellent agreement and small 95% limits of agreement (±6 mm) with minimal mean bias for both the minimum and maximum measurements. IVC metrics do not change significantly based on patient position. For those patients who are unable to lay completely supine, a semi-upright measurement of the IVC for volume status may be an accurate alternative. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Pre-anaesthetic screening of geriatric dogs

    Directory of Open Access Journals (Sweden)

    K.E. Joubert

    2007-05-01

    Full Text Available Pre-anaesthetic screening has been advocated as a valuable tool for improving anaesthetic safety and determining anaesthetic risk. This study was done determine whether pre-anaesthetic screening result in cancellation of anaesthesia and the diagnosis of new clinical conditions in geriatric dogs. One hundred and one dogs older than 7 years of age provided informed owner consent were included in the study. Each dog was weighed, and its temperature, pulse and respiration recorded. An abdominal palpation, examination of the mouth, including capillary refill time and mucous membranes, auscultation, body condition and habitus was performed and assessed. A cephalic catheter was placed and blood drawn for pre-anaesthetic testing. A micro-haematocrit tube was filled and the packed cell volume determined. The blood placed was in a test tube, centrifuged and then analysed on an in-house blood analyser. Alkaline phosphatase, alanine transferase, urea, creatinine, glucose and total protein were determined. A urine sample was then obtained by cystocentesis, catheterisation or free-flow for analysis. The urine specific gravity was determined with a refractometer. A small quantity of urine was then placed on a dip stick. Any new diagnoses made during the pre-anaesthetic screening were recorded. The average age of the dogs was 10.99+2.44 years and the weight was 19.64+15.78 kg. There were 13 dogs with pre-existing medical conditions. A total of 30 new diagnoses were made on the basis of the pre-anaesthetic screening. The most common conditions were neoplasia, chronic kidney disease and Cushing's disease. Of the 30 patients with a new diagnosis, 13 did not undergo anaesthesia as result of the new diagnosis. From this study it can be concluded that screening of geriatric patients is important and that sub-clinical disease could be present in nearly 30 % of these patients. The value of screening before anaesthesia is perhaps more questionable in terms of

  6. Advanced CANDU reactor pre-licensing progress

    Energy Technology Data Exchange (ETDEWEB)

    Popov, N.K.; West, J.; Snell, V.G.; Ion, R.; Archinoff, G.; Xu, C. [Atomic Energy of Canada Limited., Mississauga, Ontario (Canada)]. E-mail: popovn@aecl.ca

    2005-07-01

    The Advanced CANDU Reactor (ACR) is an evolutionary advancement of the current CANDU 6 reactor, aimed at producing electrical power for a capital cost and at a unit-energy cost significantly less than that of the current reactor designs. The Canadian Nuclear Safety Commission (CNSC) staff are currently reviewing the ACR design to determine whether, in their opinion, there are any fundamental barriers that would prevent the licensing of the design in Canada. This CNSC licensability review will not constitute a licence, but is expected to reduce regulatory risk. The CNSC pre-licensing review started in September 2003, and was focused on identifying topics and issues for ACR-700 that will require a more detailed review. CNSC staff reviewed about 120 reports, and issued to AECL 65 packages of questions and comments. Currently CNSC staff is reviewing AECL responses to all packages of comments. AECL has recently refocused the design efforts to the ACR-1000, which is a larger version of the ACR design. During the remainder of the pre-licensing review, the CNSC review will be focused on the ACR-1000. AECL Technologies Inc. (AECLT), a wholly-owned US subsidiary of AECL, is engaged in a pre-application process for the ACR-700 with the US Nuclear Regulatory Commission (USNRC) to identify and resolve major issues prior to entering a formal process to obtain standard design certification. To date, the USNRC has produced a Pre-Application Safety Assessment Report (PASAR), which contains their reviews of key focus topics. During the remainder of the pre-application phase, AECLT will address the issues identified in the PASAR. Pursuant to the bilateral agreement between AECL and the Chinese nuclear regulator, the National Nuclear Safety Administration (NNSA) and its Nuclear Safety Center (NSC), NNSA/NSC are reviewing the ACR in seven focus areas. The review started in September 2004, and will take three years. The main objective of the review is to determine how the ACR complies

  7. Activin signalling and pre-eclampsia: from genetic risk to pre-symptomatic biomarker.

    Science.gov (United States)

    Williamson, Rachel D; O'Keeffe, Gerard W; Kenny, Louise C

    2015-02-01

    Pre-eclampsia is a multi-system condition in pregnancy that is characterised by the onset of hypertension and proteinuria in women after the 20th week and it remains a leading cause of maternal and fetal mortality. Despite this the causative molecular basis of pre-eclampsia remains poorly understood. As a result, an intensive research effort has focused on understanding the molecular mechanisms involved in pre-eclampsia and using this information to identify new pre-symptomatic bio-markers of the condition. Activin A and its receptor, ACVR2A, have been extensively studied in this regard. Activin A is a member of the transforming growth factor (TGF)-β superfamily that has a wide range of biological functions depending on the cellular context. Recent work has shown that polymorphisms in ACVR2A may be a genetic risk factor for pre-eclampsia. Furthermore, both placenta and serum levels of Activin A are significantly increased in pre-eclampsia suggesting that Activin A may be a possible biomarker for the condition. Here we review the latest advances in this field and link these with new molecular data that suggest that the oxidative stress and pro-inflammatory cytokine production seen in pre-eclampsia may result in increased placental Activin A secretion in an attempt to maintain placental function.

  8. Pre-heating mitigates composite degradation.

    Science.gov (United States)

    Silva, Jessika Calixto da; Rogério Vieira, Reges; Rege, Inara Carneiro Costa; Cruz, Carlos Alberto dos Santos; Vaz, Luís Geraldo; Estrela, Carlos; Castro, Fabrício Luscino Alves de

    2015-01-01

    Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (pheated specimens presented higher radiopacity values than non-pre-heated specimens (pheated specimens (pheating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

  9. Stress responses and pre-eclampsia.

    Science.gov (United States)

    Redman, C W G

    2013-04-01

    Biological stress may affect individual cells, tissues or whole organisms, arising from disturbed homoeostasis of any cause. Stress is rarely localised. Because biological systems are closely integrated, it spreads to involve other systems. Stress responses are highly integrated and work to restore homoeostasis. Different response pathways overlap and interlink. If the responses fail or decompensate, distress ensues, of which the end-stage is death. Pre-eclampsia results from a series of biological stresses, possibly from conception, which become established by abnormal placentation and affect the mother, her foetus and her placenta. The stresses involve dialogue between mother and placenta. Even a normal placenta imposes substantial stress on maternal systems. When placental growth and perfusion is abnormal (poor placentation) then the placenta, particularly its outer trophoblast layer, becomes stressed - loosely denoted hypoxic damage or oxidative stress. Signals from the placenta spread the stress to the mother, who develops signs of pre-eclampsia. Cellular stress sensors initiate stress responses. Different stresses may trigger similar responses in specific cell types. The first cell response is reduced protein synthesis. However some synthetic pathways are spared or activated to produce stress signals. In relation to pre-eclampsia and the placenta, an excessive release of sFlt-1 a soluble decoy receptor for vascular endothelial growth factor (VEGF) is a trophoblast related stress signal. SFlt1 perturbs the angiogenic balance in the maternal circulation and is considered to cause many of the specific features of the maternal syndrome in pre-eclampsia. Three key points will be emphasised. First, multiple stressors, not simply hypoxia, stimulate the release of sFlt-1 from trophoblast. Second, sFlt-1 is only one of the group of stress signals delivered by trophoblast to the mother. Third, sFlt-1 is not the only trophoblast derived factor to perturb the maternal

  10. Nutritional practices in full-day-care pre-schools.

    LENUS (Irish Health Repository)

    Jennings, A

    2011-06-01

    Full-day-care pre-schools contribute significantly to the nutritional intake and acquisition of dietary habits of the pre-school child. The present study investigated nutritional practices in full-day-care pre-schools in Dublin, Ireland, aiming to determine the nutritional support that pre-school managers deem necessary, thereby facilitating the amelioration of existing pre-school nutritional training and practices.

  11. Planetary Protection Concerns During Pre-Launch Radioisotope Power System Final Integration Activities

    Science.gov (United States)

    Chen, Fei; McKay, Terri; Spry, James A.; Colozza, Anthony J.; DiStefano, Salvador

    2012-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a next-generation radioisotope-based power system that is currently being developed as an alternative to the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Power sources such as these may be needed for proposed missions to solar system planets and bodies that have challenging Planetary Protection (PP) requirements (e.g. Mars, Europa, Enceladus) that may support NASA s search for life, remnants of past life, and the precursors of life. One concern is that the heat from the ASRG could potentially create a region in which liquid water may occur. As advised by the NASA Planetary Protection Officer, when deploying an ASRG to Mars, the current COSPAR/NASA PP policy should be followed for Category IVc mission. Thus, sterilization processing of the ASRG to achieve bioburden reduction would be essential to meet the Planetary Protection requirements. Due to thermal constraints and associated low temperature limits of elements of the ASRG, vapor hydrogen peroxide (VHP) was suggested as a candidate alternative sterilization process to complement dry heat microbial reduction (DHMR) for the assembled ASRG. The following proposed sterilization plan for the ASRG anticipates a mission Category IVc level of cleanliness. This plan provides a scenario in which VHP is used as the final sterilization process. Keywords: Advanced Stirling Radioisotope Generator (ASRG), Planetary Protection (PP), Vapor hydrogen peroxide (VHP) sterilization.

  12. Iron therapy for pre-operative anaemia.

    Science.gov (United States)

    Ng, Oliver; Keeler, Barrie D; Mishra, Amitabh; Simpson, Alastair; Neal, Keith; Brookes, Matthew J; Acheson, Austin G

    2015-12-22

    Pre-operative anaemia is common and occurs in up to 76% of patients. It is associated with increased peri-operative allogeneic blood transfusions, longer hospital lengths of stay and increased morbidity and mortality. Iron deficiency is one of the most common causes of this anaemia. Oral iron therapy has traditionally been used to treat anaemia but newer, safer parenteral iron preparations have been shown to be more effective in other conditions such as inflammatory bowel disease, chronic heart failure and post-partum haemorrhage. A limited number of studies look at iron therapy for the treatment of pre-operative anaemia. The aim of this Cochrane review is to summarise the evidence for use of iron supplementation, both enteral and parenteral, for the management of pre-operative anaemia. The objective of this review is to evaluate the effects of pre-operative iron therapy (enteral or parenteral) in reducing the need for allogeneic blood transfusions in anaemic patients undergoing surgery. We ran the search on 25 March 2015. We searched the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), EMBASE Classic and EMBASE (Ovid), CINAHL Plus (EBSCO), PubMed, clinical trials registries, conference abstracts, and we screened reference lists. We included all randomised controlled trials (RCTs) which compared pre-operative iron monotherapy to placebo, no treatment, standard of care or another form of iron therapy for anaemic adults undergoing surgery. Anaemia was defined by haemoglobin values less than 13 g/dL for males and 12 g/dL for non-pregnant females. Data were collected by two authors on the proportion of patients who receive a blood transfusion, amount of blood transfused per patient (units) and haemoglobin measured as continuous variables at pre-determined time-points: pre

  13. Extension of the pre-retirement programmes

    CERN Document Server

    2015-01-01

    Following a recommendation by the Standing Concertation Commitee at its meeting on 9 November 2015 and approval by the Director-General, please note that:   the Progressive Retirement Programme has been extended by one year, from 1 April 2016 until 31 March 2017;   the Scheme of Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2016 until 31 December 2016. Further information is available from the following sites: - https://admin-eguide.web.cern.ch/en/procedure/progressive-retirement-programme-prp - https://admin-eguide.web.cern.ch/en/procedure/part-time-work-pre-retirement-measure-ptp Human Resources Department Tel.: 79257 / 73903

  14. Pre-eclampsia, diagnosis and treatment.

    Science.gov (United States)

    Sunanda, G V; Johanson, R

    2001-11-01

    Pre-eclampsia is a multisystem disorder of pregnancy usually associated with raised blood pressure (BP) and proteinuria. The pathogenesis is not understood despite decades of research. Abnormal placentation related to immune mechanisms and maladaptation of the placenta may be the first step in the development of the disease. Although there are a number of risk factors and new innovatory tests (e.g., uterine artery Doppler) which can be used to predict pre-eclampsia, none fulfils standard diagnostic criteria. Of possible prophylactic value are antiplatelet agents, calcium supplementation and vitamins C and E. Prevention of eclampsia with magnesium sulfate is the subject of a current international randomised controlled trial (RCT), known as MAGPIE. Therapeutic strategies include avoidance of hypertensive injury and delivery of the baby and placenta. Further research into specific antihypertensive agents and conservative management strategies is required.

  15. An overview of pre-surgical evaluation

    Directory of Open Access Journals (Sweden)

    Kurupath Radhakrishnan

    2014-01-01

    Full Text Available The success of an epilepsy surgery program depends upon the early identification of potential surgical candidates and selecting from them, ideal candidates for surgery, who are destined to have a post-operative seizure-free outcome without any unacceptable neurological deficits. Since epilepsy surgery centers in resource-poor countries will lack the full range of state-of-the-art technologies usually available in resource-rich countries to perform pre-surgical evaluation, cost-effectively utilization of the locally available investigative facilities to select the surgical candidates becomes challenging. In the present era of rapid electronic communications and telemedicine, it has become possible for epilepsy surgery centers to pool their technological and human resources and to partner with centers nationally and internationally in implementing pre-surgical evaluation strategies.

  16. Imaging the Pre-PN/PN Transition

    Science.gov (United States)

    Gledhill, T.

    2014-04-01

    "We present 2 - 2.4 micron integral-field spectroscopy, using Gemini NIFS, of a sample of hot post-AGB stars with early B spectral types. These stars are just starting to ionize their environments and turn into planetary nebulae (PN). Unlike in the earlier dusty pre-PN phase, where outflow morphology is often visible in dust-scattered light, these hot post-AGB stars do not generally reveal their envelope structure in near-IR continuum emission, which is dominated by the bright central star. Instead we use molecular hydrogen emission lines to study the asymmetrical envelopes of these objects and atomic hydrogen and helium recombination lines to probe the extent and shape of the developing ionized region. This combination provides a unique snapshot as the ionization front propagates into the already-shaped pre-PN molecular material, just at the transition point where the new PN is emerging."

  17. INCLUSIVE CULTURE IN PRE-SCHOOL INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Irena NOVACHEVSKA

    2011-04-01

    Full Text Available Inclusive education is a rational concept that refers to the overall and long-term transformation of institutional systems in society, especially in education. Along with the transformation, a number of important and unresolved issues still appear in both theory and practice, as the duty of pre-school institutions and schools is to educate every student in the mainstream education system. One of the most important aspects of inclusion is the inclusive culture. Regardless of the good inclusive policy and practice, one cannot talk about successful inclusion without a properly developed inclusive institutional culture.This paper is a contribution to the research considering the development of inclusive culture in three preschool institutions. It is based on the thinking and attitudes of the pre­school staff toward the necessity of developing and nurturing an inclusive culture. Successful inclusion of pupils with special needs in the mainstream school system cannot be conceived without an inclusive culture.

  18. Pre-Columbian Earthworks in Coastal Amazonia

    Directory of Open Access Journals (Sweden)

    Stéphen Rostain

    2010-03-01

    Full Text Available As in other parts of Amazonia, pre-Columbian Indians have profoundly modified the coast of the Guianas. Between 650 and 1650 AD, Arauquinoid people occupied a territory that was approximately 600 km long and used the raised field technique intensively before the European conquest. They erected thousands of raised fields of various shapes, dug canals, ditches, and pathways, and built artificial mounds to establish their villages. All these earthworks changed forever the face of the coastal flooded savannas and their ecology. Such labor was probably organized under the leadership of a central authority: it seems that Arauquinoid societies were organized in a chiefdom system. Statistical calculations, based on the known surface area of raised fields and on their estimated productivity, suggest a population density of 50 to 100 inhabitants per km2. Pre-Columbian inhabitants of the Guianas coast carefully organized, managed and “anthropisized” their territory following a specific pattern.

  19. DebriSat Pre Preshot Laboratory Analyses

    Science.gov (United States)

    2015-03-27

    to be line of sight since witness plates protected by Whipple shield showed little change. LWIR spectral features from the deposited material are...Radhakrishnan Charles Griffice C. C. Wan UV -VIS-NIR Spectroscopy Dianna Alaan FIB/TEM Sample Preparation Miles Brodie © The Aerospace Corporation 2015 DebriSat...conditions responsible for the darkening. – UV -VIS-NIR-LWIR reflectance spectra were measured of post test debris for comparison with pre test

  20. International express student's book : pre-intermediate

    CERN Document Server

    Taylor, Liz

    1996-01-01

    The New Edition of International Express Pre-Intermediate retains all the keys features of this popular and successel four-level course. It combines engaging, up-to-date topics with a time-efficient and student-centred approach to language work, and clearly focused activities that reflect learner's real communicative needs - the ideal course for professional adults who use English for work, travel, and socializing.

  1. Pre- and postoperative MR imaging of craniopharyngiomas

    Energy Technology Data Exchange (ETDEWEB)

    Hald, J.K. [Rijkshospitalet, Oslo (Norway). Dept. of Radiology; Eldevik, O.P. [Rijkshospitalet, Oslo (Norway). Dept. of Neurosurgery; Quint, D.J. [Rijkshospitalet, Oslo (Norway). Dept. of Neurosurgery; Chandler, W.F. [Univ. of Michigan Hospital, Ann Arbor, MI (United States). Dept. of Radiology; Kollevold, T. [Univ. of Michigan Hospital, Ann Arbor, MI (United States). Dept. of Neurosurgery

    1996-09-01

    Purpose: To compare the pre- and postoperative MR appearance of craniopharyngiomas with respect to lesion size, tumour morphology and identification of surrounding normal structures. Material and Methods: MR images obtained prior to and following craniopharyngioma resection were evaluated retrospectively in 10 patients. Tumour signal charcteristics, size and extension with particular reference to the optic chiasm, the pituitary gland, the pituitary stalk and the third ventricle were evaluated. Results: Following surgery, tumour volume was reduced in all patients. In 6 patients there was further tumour volume reduction between the first and second postoperative images. Two of these patients received radiation therapy between the 2 postoperative studies, while 4 had no adjuvant treatment to the surgical intervention. There was improved visualization of the optic chiasm, in 3, the pituitary stalk in one, and the third ventricle in 9 of the 10 patients. The pituitary gland was identified preoperatively only in one patient, postoperatively only in another, pre- and postoperatively in 5, and neither pre- nor postoperatively in 3 patients. In 3 patients MR imaging 0-7 days postoperatively identified tumour remnants not seen at the end of the surgical procedure. The signal intensities of solid and cystic tumour components were stable from pre- to the first postoperative MR images. Optic tract increased signal prior to surgery was gone 28 days postoperatively in one patient, but persisted on the left side for 197 days after surgery in another. Conclusion: Postoperative MR imaging of craniopharyngiomas demonstrated tumour volume reduction and tumour remnants not seen at surgery. Early postoperative MR imaging of craniopharyngiomas may overestimate the size of residual tumour. Improved visualization of peritumoral structures may be achieved. (orig.).

  2. Speciation without Pre-Defined Fitness Functions.

    Science.gov (United States)

    Gras, Robin; Golestani, Abbas; Hendry, Andrew P; Cristescu, Melania E

    2015-01-01

    The forces promoting and constraining speciation are often studied in theoretical models because the process is hard to observe, replicate, and manipulate in real organisms. Most models analyzed to date include pre-defined functions influencing fitness, leaving open the question of how speciation might proceed without these built-in determinants. To consider the process of speciation without pre-defined functions, we employ the individual-based ecosystem simulation platform EcoSim. The environment is initially uniform across space, and an evolving behavioural model then determines how prey consume resources and how predators consume prey. Simulations including natural selection (i.e., an evolving behavioural model that influences survival and reproduction) frequently led to strong and distinct phenotypic/genotypic clusters between which hybridization was low. This speciation was the result of divergence between spatially-localized clusters in the behavioural model, an emergent property of evolving ecological interactions. By contrast, simulations without natural selection (i.e., behavioural model turned off) but with spatial isolation (i.e., limited dispersal) produced weaker and overlapping clusters. Simulations without natural selection or spatial isolation (i.e., behaviour model turned off and high dispersal) did not generate clusters. These results confirm the role of natural selection in speciation by showing its importance even in the absence of pre-defined fitness functions.

  3. Rotational inhomogeneities from pre-big bang?

    CERN Document Server

    Giovannini, Massimo

    2005-01-01

    The evolution of the rotational inhomogeneities is investigated in the specific framework of four-dimensional pre-big bang models. While minimal (dilaton-driven) scenarios do not lead to rotational fluctuations, in the case of non-minimal (string-driven) models, fluid sources are present in the pre-big bang phase. The rotational modes of the geometry, coupled to the divergenceless part of the velocity field, can then be amplified depending upon the value of the barotropic index of the perfect fluids. In the light of a possible production of rotational inhomogeneities, solutions describing the coupled evolution of the dilaton field and of the fluid sources are scrutinized in both the string and Einstein frames. In semi-realistic scenarios, where the curvature divergences are regularized by means of a non-local dilaton potential, the rotational inhomogeneities are amplified during the pre-big bang phase but they decay later on. Similar analyses can also be performed when a contraction occurs directly in the str...

  4. The Lost Foam method – pre-expansion process

    Directory of Open Access Journals (Sweden)

    T. Pacyniak

    2010-04-01

    Full Text Available In the study, a pre-expansion station, designed by authors, was presented. It consists of a batch pre-expander with a 90 liters capacity foaming chamber, equipped with fluidized-solid dryer of pre-expanded beads and a pneumatic transport system of granules to the silo. Steam is delivered to the pre-expander from the electric vapor generator type LW 40.1. In the study, work principle of the pre-expansion station and pre-expansion tests carried out on this position were presented.

  5. Pre-reforming of Liquefied Petroleum Gas over Magnesium Aluminum Mixed Oxide Supported Nickel Catalysts%镁铝混合氧化物负载镍催化剂上液化石油气的预重整

    Institute of Scientific and Technical Information of China (English)

    王新星; 汪学广; 尚兴付; 聂望欣; 邹秀晶; 鲁雄钢; 丁伟中

    2012-01-01

    catalysts showed easier coke deposition and a slight decrease in catalytic activity and stability. However, it may be more promising candidate for LPG pre-reforming for the use of hydrogen fuel cells in transportation and small stationary application due to lower reduction temperature.

  6. Elementary Pre-Service Teacher Perceptions of the Greenhouse Effect.

    Science.gov (United States)

    Groves, Fred H.; Pugh, Ava F.

    1999-01-01

    Expands on earlier work to examine pre-service teachers' views on environmental issues, especially global warming and the related term "greenhouse effect." Suggests that pre-service elementary teachers hold many misconceptions about environmental issues. (DDR)

  7. Serum homocysteine in pre-eclampsia and eclampsia.

    Science.gov (United States)

    Hoque, Md Mozammel; Bulbul, Tania; Mahal, Monzarin; Islam, Nur-A-Farzana; Ferdausi, Munira

    2008-04-01

    Pre-eclampsia and eclampsia are common obstetrical problem causing adverse effects on pregnancy outcome. Large bodies of evidences suggest that hyperhomocysteinemia is a causal factor of pre-eclampsia/eclampsia. This study designed to explore the association between hyperhomocysteinemia and pre-eclampsia/eclampsia, the knowledge of which expected to be used for prevention of pre-eclampsia and eclampsia. In a case-control study serum homocysteine was measured in 136 controls (healthy pregnant), 84 pre-eclamptic and 120 eclamptic pregnant women. Serum homocysteine in patients with pre-eclampsia (9.54 +/- 3.21 micromol/L) and eclampsia (10.57 +/- 3.39 micromol/L) found to be significantly increased compared to controls (6.86 +/- 2.47 micromol/L) (p homocysteine found to be raised more in eclampsia compared to pre-eclampsia (p homocysteine elevation is more compared to that in pre-eclampsia.

  8. Study of wafer pre-aligning approaches

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wafer pre-aligning system is an important component in IC manufacturing industry. A wafer prealigning platform with a CCD sensor is presented in this paper. The centering and notch detecting approaches are extended based on this platform. Least square circle fitting approach is adopted to calculate the center and radius of the wafer, and a formula for calculating the fitting error is derived. An approach called edge variation rate is also proposed to detect the range of wafer notch, and the fiducial is calculated by curve fitting approach. These approaches can improve the accuracy effectively as indicated by experiments.

  9. THE PRE-TRIAL CHAMBER JUDGE

    Directory of Open Access Journals (Sweden)

    Edgar Laurentiu DUMBRAVA

    2014-12-01

    Full Text Available The importance of this work lies in important changes in the new Code of Criminal Procedure, amendments justified by the new realities of a democratic society in which criminal procedural rules must be adapted according to the daily realities in the achievement of justice. The purpose of the paper is given by the need of approaching at a theoretically level the institution of The Pre-Trial Chamber Judge, given that so far there have not been developed any works on the subject. This paper addresses both practitioners and litigants.

  10. THE PRE-TRIAL CHAMBER JUDGE

    Directory of Open Access Journals (Sweden)

    Edgar Laurenţiu DUMBRAVĂ

    2014-05-01

    Full Text Available The importance of this work lies in important changes in the new Code of Criminal Procedure, amendments justified by the new realities of a democratic society in which criminal procedural rules must be adapted according to the daily realities in the achievement of justice. The purpose of the paper is given by the need of approaching at a theoretically level the institution of The Pre-Trial Chamber Judge, given that so far there have not been developed any works on the subject. This paper addresses both practitioners and litigants.

  11. Extension of the pre-retirement programmes

    CERN Multimedia

    2014-01-01

    Following a recommendation by the Standing Concertation Committee at its meeting on 27 November 2014 and approval by the Director-General, please note that: the Progressive Retirement Programme has been extended by one year, from 1 April 2015 until 31 March 2016; the Scheme of Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2015 until 31 December 2015. Further information is available at the following sites: https://admin-eguide.web.cern.ch/node/447 https://admin-eguide.web.cern.ch/node/484 Human Resources Department Tel. 79257 / 73903

  12. Pre-calculus workbook for dummies

    CERN Document Server

    Gilman, Michelle Rose; Neal, Karina

    2009-01-01

    Get the confidence and the math skills you need to get started with calculus! Are you preparing for calculus? This easy-to-follow, hands-on workbook helps you master basic pre-calculus concepts and practice the types of problems you'll encounter in your cour sework. You get valuable exercises, problem-solving shortcuts, plenty of workspace, and step-by-step solutions to every problem. You'll also memorize the most frequently used equations, see how to avoid common mistakes, understand tricky trig proofs, and much more. 100s of Problems! Detailed, fully worked-out solutions to problem

  13. Pre-sezary To Sezary Erythroderma Syndrome

    Directory of Open Access Journals (Sweden)

    Mittal R

    1998-01-01

    Full Text Available A 50-year old woman was admitted with pre-Se′zary syndrome in May, 97 as she had intractable progressive erythroderma with intense pruritus since 15 months. She also had axillary, inguinal, hilar and para-aortic lymphadenopathy, hepatomegaly, alopecia, hypersensitivity to cefadroxyl, and abnormal Sezary cells in peripheral blood film. Histopathology confirmed the diagnosis. Initially she was given 20 mg of prednisolone which was later increased to 40 mg daily but she did not respond. She responded favourably to combination of 20 mg prednisolone and chlorambucil 2.5 mg daily.

  14. Extension of the pre-retirement programmes

    CERN Document Server

    2012-01-01

    Following recommendation by the Standing Concertation Committee at its meeting on 2 December 2011 and approval by the Director-General, please note that: the Progressive Retirement Programme has been extended by one year, from 1 April 2012 until 31 March 2013; and the Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2012 until 31 December 2012. Further information is available from the following sites: https://cern.ch/admin-eguide/retraite/proc_prp.asp https://cern.ch/admin-eguide/retraite/proc_pTp.asp Tel.  73903 Human Resources Department

  15. Extension of the pre-retirement programmes

    CERN Document Server

    Human Resources Department

    2011-01-01

    Following recommendation by the Standing Concertation Committee and approval by the Director-General, please note that: the Progressive Retirement Programme has been extended by one year, from 1 April 2011 until 31 March 2012; and the Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2011 until 31 December 2011. Further information is available from the following sites: https://cern.ch/admin-eguide/retraite/proc_prp.asp https://cern.ch/admin-eguide/retraite/proc_pTp.asp Tel. 73903

  16. Extension of the pre-retirement programmes

    CERN Multimedia

    2013-01-01

    Following a recommendation by the Standing Concertation Commitee at its meeting on 4 December 2012 and approval by the Director-General, please note that: the Progressive Retirement Programme has been extended by one year, from 1 April 2013 until 31 March 2014; and the Scheme of Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2013 until 31 December 2013.   Further information is available from the following sites: https://cern.ch/admin-eguide/retraite/proc_prp_fr.asp https://cern.ch/admin-eguide/retraite/proc_pTp_fr.asp   Human Resources Department Tel. 73903

  17. Extension of the pre-retirement programmes

    CERN Multimedia

    2014-01-01

    Following a recommendation by the Standing Concertation Commitee at its meeting on 5 December 2013 and approval by the Director-General, please note that:   the Progressive Retirement Programme has been extended by one year, from 1 April 2014 until 31 March 2015; the Scheme of Part-Time Work as a Pre-retirement Measure has also been extended by one year, from 1 January 2014 until 31 December 2014. Further information is available from the following sites: https://cern.ch/admin-eguide/retraite/proc_prp_fr.asp https://cern.ch/admin-eguide/retraite/proc_pTp_fr.asp Human Resources Department Tel. 79257/ 73903

  18. Web-based pre-Analysis Tools

    CERN Document Server

    Moskalets, Tetiana

    2014-01-01

    The project consists in the initial development of a web based and cloud computing services to allow students and researches to perform fast and very useful cut-based pre-analysis on a browser, using real data and official Monte-Carlo simulations (MC). Several tools are considered: ROOT files filter, JavaScript Multivariable Cross-Filter, JavaScript ROOT browser and JavaScript Scatter-Matrix Libraries. Preliminary but satisfactory results have been deployed online for test and future upgrades.

  19. Pre - big bang inflation requires fine tuning

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Michael S. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Weinberg, Erick J. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    1997-10-01

    The pre-big-bang cosmology inspired by superstring theories has been suggested as an alternative to slow-roll inflation. We analyze, in both the Jordan and Einstein frames, the effect of spatial curvature on this scenario and show that too much curvature --- of either sign --- reduces the duration of the inflationary era to such an extent that the flatness and horizon problems are not solved. Hence, a fine-tuning of initial conditions is required to obtain enough inflation to solve the cosmological problems.

  20. 28 CFR 345.81 - Pre-industrial training.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Pre-industrial training. 345.81 Section... INDUSTRIES (FPI) INMATE WORK PROGRAMS FPI Inmate Training and Scholarship Programs § 345.81 Pre-industrial training. FPI encourages the development and use of pre-industrial training programs. Such...

  1. Drawing Identity: Beginning Pre-Service Teachers' Professional Identities

    Science.gov (United States)

    Beltman, Susan; Glass, Christine; Dinham, Judith; Chalk, Beryl; Nguyen, Bich

    2015-01-01

    Developing a professional teacher identity can be complex as pre-service teachers engage with a process informed by their previous experiences of teachers and teaching, by learning in their pre-service course, by field placements, and by societal expectations. Using drawing as the method for gathering data, pre-service teachers in an Australian…

  2. CONSTRUCTION ENVIRONMENT EDUCATION DEVELOPMENT ACTIVITY FOR CHILDREN PRE-SCHOOL

    OpenAIRE

    MA. TRAN THI THUY NGA; MA. PHAM THI YEN

    2015-01-01

    Education motor development contribute to the comprehensive development of pre-school children. Building educational environment for young athletes develop in pre-school is one of many issues of concern in the current stage of pre-school education in Vietnam.

  3. Pre-Service Teachers' Opinions on Teaching Thinking Skills

    Science.gov (United States)

    Akinoglu, Orhan; Karsantik, Yasemin

    2016-01-01

    The purpose of the present study is to determine pre-service teachers' opinions on teaching thinking skills. 134 senior pre-service pre-school, English and mathematics teachers studying at a state university in Istanbul participated in the study which is designed based on survey model. A questionnaire which was developed by the researchers was…

  4. Btk at the Pre-B Cell Receptor Checkpoint

    NARCIS (Netherlands)

    S. Middendorp

    2004-01-01

    textabstractSignalling from the BCR or its immature form, the pre-BCR, was shown to be crucial for B cell development. Gene-targeted mice have defined differential roles of components of the (pre-) BCR complex or its downstream signalling pathways. One of the proteins involved in (pre-) BCR signa

  5. Pre-Diabetes Non-Modifiable Risk Factors

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Pre-diabetes Non-modifiable Risk Factors Updated:Nov 9,2015 ... This content was last reviewed August 2015. Pre-diabetes • Introduction • About Pre-diabetes • What's the Problem? Intro ...

  6. Pre-Service Primary Teachers' Attitudes towards Energy Conservation

    Science.gov (United States)

    Tekbiyik, Ahmet; Ipek, Cemalettin

    2008-01-01

    This study aims to examine the pre-service primary teachers' attitudes towards energy conservation. In order to reach this main aim following research questions are formulated: (1) What are the attitude levels of pre-service primary teachers in terms of energy conservation? (2) Do pre-service primary teachers' attitudes towards energy conservation…

  7. 10 CFR 603.500 - Pre-award business evaluation.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Pre-award business evaluation. 603.500 Section 603.500 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Pre-Award Business Evaluation § 603.500 Pre-award business evaluation. (a) The contracting officer must determine...

  8. 17 CFR 204.38 - Pre-offset hearing.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Pre-offset hearing. 204.38... DEBT COLLECTION Salary Offset § 204.38 Pre-offset hearing. (a) The hearing official shall determine the... of the hearing official. (f) Pre-offset “paper” hearing. If a hearing is to be held only upon...

  9. An Investigation of School Violence and Pre-Service Teachers

    Science.gov (United States)

    McCaleb, Karen Nykorchuk; Andersen, Amy; Hueston, Harry

    2008-01-01

    All educators need to be aware of issues regarding school violence. Recent years have shown that violence can happen in a variety of school settings. This study conducted a one-group, pretest-posttest, pre-experimental design to explore pre-service teachers' perceptions regarding school violence. First, pre-service educators were asked to complete…

  10. Pre-Service Science and Mathematics Teachers' Thoughts about Technology

    Science.gov (United States)

    Aran, Özge Can; Derman, Ipek; Yagci, Esed

    2016-01-01

    This study aims to investigate pre-service teachers' opinions about the technology. In this respect, the opinions of pre-service science and mathematics teachers were taken. The study was carried out at a university, located in the capital of Turkey. The data were collected from 20 pre-service teachers in the department of secondary school science…

  11. Pre-energy reasoning in preschool children

    Directory of Open Access Journals (Sweden)

    DIMITRIS KOLIOPOULOS

    2009-01-01

    Full Text Available The research presented in this paper explores the degree to which preschool children have the ability to use mental representations which constitute precursor energy models. Twenty-five children (10 boys and 15 girls participated in the study. They were presented with two different phenomenological situations considered as important for the establishment of pre-energy reasoning: the movement of a toy car with the use of batteries and the movement of an identical car with the use of a spring. The children were involved in personal, semi-structured interviews, which aimed at eliciting their explanations about the movement of the two cars. The analysis of children’s explanations reveals that they tend to explain the movement of cars in both phenomenological situations in naturalistic terms. These naturalistic explanations were mainly agentive, that is they regard the batteries and the spring correspondingly as external agents causing the cars’ movement. The major percentage of agentive naturalistic explanations was given in terms of the function of the objects under discussion, while a number of them were formulated in terms of distribution. These findings designate a developing understanding of physical causality and a pre-energy character in children’s reasoning, since they are capable of accounting for the two phenomenological situations in terms of object chains. Therefore, an attempt to introduce the aspect of energy transfer in preschool education could be considered.

  12. Neuroimaging in pre-motor Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Thomas R. Barber

    2017-01-01

    Full Text Available The process of neurodegeneration in Parkinson's disease begins long before the onset of clinical motor symptoms, resulting in substantial cell loss by the time a diagnosis can be made. The period between the onset of neurodegeneration and the development of motoric disease would be the ideal time to intervene with disease modifying therapies. This pre-motor phase can last many years, but the lack of a specific clinical phenotype means that objective biomarkers are needed to reliably detect prodromal disease. In recent years, recognition that patients with REM sleep behaviour disorder (RBD are at particularly high risk of future parkinsonism has enabled the development of large prodromal cohorts in which to investigate novel biomarkers, and neuroimaging has generated some of the most promising results to date. Here we review investigations undertaken in RBD and other pre-clinical cohorts, including modalities that are well established in clinical Parkinson's as well as novel imaging methods. Techniques such as high resolution MRI of the substantia nigra and functional imaging of Parkinsonian brain networks have great potential to facilitate early diagnosis. Further longitudinal studies will establish their true value in quantifying prodromal neurodegeneration and predicting future Parkinson's.

  13. Pulling PreK into a K-12 Orbit: The Evolution of PreK in the Age of Standards

    Science.gov (United States)

    Graue, M. Elizabeth; Ryan, Sharon; Nocera, Amato; Northey, Kaitlin; Wilinski, Bethany

    2017-01-01

    We might call this decade the era of early childhood. In the US, federal and state governments invest in the creation of public pre-kindergarten (preK) programs and create standards that articulate goals for practice and benchmarks that can be used to evaluate success. How have these trends provided a context for the evolution of preK curriculum?…

  14. Pulling PreK into a K-12 Orbit: The Evolution of PreK in the Age of Standards

    Science.gov (United States)

    Graue, M. Elizabeth; Ryan, Sharon; Nocera, Amato; Northey, Kaitlin; Wilinski, Bethany

    2017-01-01

    We might call this decade the era of early childhood. In the US, federal and state governments invest in the creation of public pre-kindergarten (preK) programs and create standards that articulate goals for practice and benchmarks that can be used to evaluate success. How have these trends provided a context for the evolution of preK curriculum?…

  15. Pre-processing Tasks in Indonesian Twitter Messages

    Science.gov (United States)

    Hidayatullah, A. F.; Ma’arif, M. R.

    2017-01-01

    Twitter text messages are very noisy. Moreover, tweet data are unstructured and complicated enough. The focus of this work is to investigate pre-processing technique for Twitter messages in Bahasa Indonesia. The main goal of this experiment is to clean the tweet data for further analysis. Thus, the objectives of this pre-processing task is simply removing all meaningless character and left valuable words. In this research, we divide our proposed pre-processing experiments into two parts. The first part is common pre-processing task. The second part is a specific pre-processing task for tweet data. From the experimental result we can conclude that by employing a specific pre-processing task related to tweet data characteristic we obtained more valuable result. The result obtained is better in terms of less meaningful word occurrence which is not significant in number comparing to the result obtained by just running common pre-processing tasks.

  16. Flexible Pre-Majors: Final Report of the Flexible Pre-Majors Working Group

    Science.gov (United States)

    FitzGibbon, John; Orum, Jennifer

    2011-01-01

    This report provides advice for program areas contemplating the development of a Flexible Pre-Major (FPM) in their discipline. The FPM is another means of aiding student transfer in a system that expects and encourages significant student mobility. The FPM addresses a problematic area for academic students: that of completing the lower level major…

  17. Risk of early or severe pre-eclampsia related to pre-existing conditions

    DEFF Research Database (Denmark)

    Catov, Janet M; Ness, Roberta B; Kip, Kevin E;

    2007-01-01

    BACKGROUND: Preeclampsia (PE), especially severe or early PE, is a leading cause of morbidity and mortality among mothers and infants. We estimated the population attributable fractions of severe or early PE associated with pre-existing conditions among nulliparous and multiparous women. METHODS...

  18. evaluation and retiming of a pre evaluation and retiming of a pre ...

    African Journals Online (AJOL)

    eobe

    This study evaluates and retimes a pre-timed traffic signal using the current volume of traffic and saturation flow traffic signal ... made up of yield signs, stop signs, multi-way signs, intersection ..... expected to go through the intersection without.

  19. Improving the Leadership Skills of Pre-Service School Librarians through Leadership Pre-Assessment

    Science.gov (United States)

    Smith, Daniella

    2014-01-01

    School librarian guidelines encourage active leadership in schools. Two ways school librarian educators can encourage school librarians to be leaders are to embed the standards into the certification curriculum and to assess the leadership potential of pre-service school librarians in order to adapt the curriculum to their needs. This mixed-method…

  20. Classification of Hom-preLie Algebras in Dimension Two%二维Hom-preLie代数的分类

    Institute of Scientific and Technical Information of China (English)

    安慧辉; 康健; 王治淳

    2014-01-01

    In this paper, we mainly discuss the basic properties and the classification of Hom-Novikov algebras and Hom-preLie algebras in dimension two in the complex field. At first, we give the definition of the Hom-Novikov algebras, Hom-preLie algebras and some related defi-nitions. Then we discuss regular Hom-preLie algebras and give the necessary conditions for an Hom-preLie algebras to be pre-Lie type. We also give the direct sum of Hom-preLie alge-bras and get the necessary and sufficient condition for the existence of homomorphism between two Hom-preLie algebras. At last, with these definitions and their basic properties, we obtain the classification of the Hom-Novikov algebras and Hom-preLie algebras in two dimensions.%讨论了复数域上的二维Hom-Novikov 代数与Hom-preLie代数的基本性质以及分类。给出了Hom-Novikov 代数与Hom-preLie代数相关的一些基本定义和Hom-preLie是Pre-Lie型的必要条件;讨论Hom-preLie代数的直和,给出了两个Hom-preLie代数之间存在代数同态的充分必要条件。利用这些定义及其简单的性质,完成二维Hom-Novikov 代数与Hom-preLie代数的分类

  1. [Societal cost of pre-lingual deafness].

    Science.gov (United States)

    Bubbico, L; Bartolucci, M A; Broglio, D; Boner, A

    2007-01-01

    Congenital hearing loss still remain an important medical and social problem for the delayed language development. Object of this study is to provide an updated and close estimate of the economic burden involved in pre-lingual hearing loss. Data were provided by the Ministry of Health data bank, the Ministry of Education national data bank, the National Institute of Social Insurance national data bank and the Italian Central Statistics Institute. The information was collected by means of a specially provided Societal Cost Questionnaire (SCQ). Direct medical costs, direct non-medical costs and indirect welfare costs involved in deafness were included in the cost estimate. Was enrolled in the study a sample of subjects with pre-lingual deafness, with a mean bilateral neuro-sensorial hearing impairment equal to 60 dB or more for 500, 1,000 and 2,000 Hz frequency tones in the better ear detected in neonatal age, had prevented speech from developing. The statistical assessment was performed according to an actuarial approach, considering the estimated life expectancy at birth, based on updated population data from census 2001. Based on life expectancy, the lifetime mean cost assessed for a subject affected by profound pre-lingual deafness turned out to be equal to Euro 737,994.76 for a male and Euro 755,404.02 for a female. Unlike other disabling affections, deafness weighs significantly more on the social system than on the health system. As a matter of fact, the direct medical costs, such as audiological diagnosis, hearing aids, etc., only account for 3.8% of the societal cost, whereas education, rehabilitation and welfare costs reach 96.2% of the total. Finally, our results suggest that societal costs can only be reduced by zeroing in on promotion and broadening of effective prevention strategies. The appropriate public health measures (such as the universal newborn hearing screening) set up and implemented in several European and non-European countries proved

  2. Pre-Aggregation with Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    2006-01-01

    Motivated by the increasing need to analyze complex, uncertain multidimensional data this paper proposes probabilistic OLAP queries that are computed using probability distributions rather than atomic values. The paper describes how to create probability distributions from base data, and how...... the distributions can be subsequently used in pre-aggregation. Since the probability distributions can become large, we show how to achieve good time and space efficiency by approximating the distributions. We present the results of several experiments that demonstrate the effectiveness of our methods. The work...... is motivated with a real-world case study, based on our collaboration with a leading Danish vendor of location-based services. This paper is the first to consider the approximate processing of probabilistic OLAP queries over probability distributions....

  3. Pre-operative antiseptic skin preparation.

    Science.gov (United States)

    Murkin, Claire Elizabeth

    Theatre nurses use antiseptic skin preparation products every day, but little thought seems to be given as to why a surgeon has a particular preference for one antiseptic skin preparation over another - whether it is for its efficacy, safety or application properties. Woodhead et al (2004) states that nurses still work in a ritualistic environment. Rituals are 'any action performed according to custom, without understanding the reasons why it is being practised'. Nursing practice should be evidence-based; nurses should understand the rationale behind the choice of a particular antiseptic, and be knowledgable about the clinical effectiveness of antiseptic's use pre-operatively, to achieve optimum results. This article focuses on the main types of antiseptic skin preparation while highlighting each product's activity and the relevant considerations for choosing the appropriate product for each patient. Theatre staff need to emphasize the importance of skin preparation and the correct application techniques, while educating the scrub team and surgeons with respect to skin preparation.

  4. Pre-Starbursts in Luminous IR Galaxies?

    CERN Document Server

    Gao, Y; Hwang, C Y; Lo, K Y; Veilleux, S; Gao, Yu; Gruendl, Robert A.

    1997-01-01

    We present first results of our on-going BIMA Key Project: imaging the CO(1-0) emission from a sample of 10 luminous IR galaxies (LIRGs) that are at various merging stages, with special emphasis on systems apparently in the early/intermediate stages of merging. We present here CO images with $\\sim 5''$ resolution. An important result is the recognition of a plausible pre-starburst phase in some early LIRG mergers (e.g., Arp 302 and NGC 6670). Our initial analysis suggests that a merger-induced starburst phase may not begin before the nuclear separation between the merging galaxies reaches roughly 10 kpc. The surface gas density seems to increase from a few times $10^2 \\Msun pc^{-2} to >10^3 \\Msun pc^{-2}$ while the prominent CO extent systematically decreases as merging progresses.

  5. Psychoanalytic multifamily groups with pre-adolescents

    Directory of Open Access Journals (Sweden)

    Simone Bruschetta

    2014-09-01

    Full Text Available This paper presents two variations of the classic group device (GPMF developed by García Badaracco (1989, 2000, in order to adapt to the prevention and early care. In particular, the two variations of multi- family setting, which will be described below, are addressed to children aged 9-10 and 13-14 years, attending junior-high schools, and belonging to those types of families mentioned in the scientific literature as families with multiple-problems or those social groups marginalized and at risk such as children with severe distress at school.Keywords: Multifamiliar psychoanalysis, Serious mental illness, Pre-adolescently age, Therapeutic community, Junior-high school, Severe socio-familiar distress.

  6. Perinatal mortality at pre-Columbian Teotihuacan.

    Science.gov (United States)

    Storey, R

    1986-04-01

    The skeletal population of 166 individuals from a low-status apartment compound of the pre-Columbian city of Teotihuacan contained 52 perinatal individuals. The most perilous time of the lifespan was around birth, as revealed by life table analysis. Femur length was not increasing during the last month of gestation, and individuals were probably shorter somatically at birth than modern standards or historic-period Arikara skeletal controls. The possibility of intrauterine growth retardation is investigated through paleo-pathological indicators of prenatal growth arrest. The evidence of prenatal stress and the high rate of mortality at birth seem to indicate that this New World preindustrial urban population faced similar health and nutritional stresses as Old World preindustrial cities.

  7. Pre-Flare Dynamics of Sunspot Groups

    CERN Document Server

    Korsos, M B; Ludmany, A

    2014-01-01

    Several papers provide evidences that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare producing areas the present work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms, it follows the behaviour of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalogue. The most promising pre-flare signatures are the following properties of the gradient variation: i) steep increase, ii) high maximum, iii) significant fluctuation and iv) a gradual decrease between the maximum and the flare onset which can be related to the "pull mode" of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the next 8-10 hours.

  8. Pre-flare dynamics of sunspot groups

    Energy Technology Data Exchange (ETDEWEB)

    Korsós, M. B.; Baranyi, T.; Ludmány, A., E-mail: korsos.marianna@csfk.mta.hu, E-mail: baranyi.tunde@csfk.mta.hu, E-mail: ludmany.andras@csfk.mta.hu [Heliophysical Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, 4010 Debrecen, P.O. Box 30 (Hungary)

    2014-07-10

    Several papers provide evidence that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare-producing areas, this work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms and follows the behavior of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalog. The most promising pre-flare signatures are the following properties of gradient variation: (1) steep increase, (2) high maximum, (3) significant fluctuation, and (4) a gradual decrease between the maximum and the flare onset that can be related to the 'pull mode' of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the following 8-10 hr.

  9. Pre-hospital care--current concepts.

    Science.gov (United States)

    Boyington, T; Williams, D

    1995-01-01

    After a brief outline of past developments in the training of ambulance personnel, this paper traces the adoption in the UK of Pre-Hospital Trauma Life Support (PHTLS) courses from the US. The 1991 World Student Games in Sheffield, UK led to liaison between training staff from South Yorkshire Metropolitan Ambulance and Paramedic Service (SYMAPS) and from Western New York Medical Training Institute. As a result, the trauma care policy of SYMAPS was altered from aiming to stabilise the patient at the scene of the accident to emphasising rapid and thorough assessment, packaging and transport. This is a resume of the scope of the PHTLS provider course. The course concentrates on the principles of PHTLS for the multisystems trauma victim.

  10. Pre-Aggregation with Probability Distributions

    DEFF Research Database (Denmark)

    Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach

    2006-01-01

    Motivated by the increasing need to analyze complex, uncertain multidimensional data this paper proposes probabilistic OLAP queries that are computed using probability distributions rather than atomic values. The paper describes how to create probability distributions from base data, and how...... the distributions can be subsequently used in pre-aggregation. Since the probability distributions can become large, we show how to achieve good time and space efficiency by approximating the distributions. We present the results of several experiments that demonstrate the effectiveness of our methods. The work...... is motivated with a real-world case study, based on our collaboration with a leading Danish vendor of location-based services. This paper is the first to consider the approximate processing of probabilistic OLAP queries over probability distributions....

  11. Pre-School Attendance and Child Development

    DEFF Research Database (Denmark)

    Bauchmüller, Robert; Gørtz, Mette; Rasmussen, Astrid Würtz

    , of total work experiences, ages and hourly wages of staff members. Those indicators show the expected correlations with children's development outcomes, better day-care quality being linked to better child outcomes ten years later. We use rich administrative information about the children's background......Earlier research suggests that children's development is shaped in their early years of life. This paper examines whether differences in day-care experiences during pre-school age are important for children's cognitive and language development at the age of 15. The analysis is based on class...... performance at the end of elementary schooling. We assess the effects of attended types and qualities of day-care institutions on various child outcomes as measured by school grades in mathematics, science, English and Danish for the whole Danish population as well as outcomes from the 2006 PISA Denmark...

  12. Do pre-drinkers consume more alcohol than non-pre-drinkers on an event-specific night out?

    DEFF Research Database (Denmark)

    Østergaard, Jeanette; Skov, Peter Rohde

    2014-01-01

    Introduction and Aims Young people drinking heavily before going out to bars and clubs is associated with alcohol-related harm and therefore of great public concern. This study examines whether pre-drinkers consume more alcohol than non-pre-drinkers on an event-specific night out in England...... demographics, socioeconomic status, frequency of intoxication and alcohol unit intake before and during the young people's night out. Results A mixed linear model performed on the panel mobile survey shows that pre-drinkers in England and Denmark consume 9.185 (P ..., respectively, more than the non-pre-drinkers. However, in both countries pre-drinkers consume 3.430 (P alcohol on-premises than the non-pre-drinkers. Discussion and Conclusion Pre-drinking is a widespread phenomenon in England and Denmark, with more than half of young...

  13. Maternal lipids in pre-eclampsia: innocent bystander or culprit?

    Science.gov (United States)

    Barrett, Helen L; Dekker Nitert, Marloes; McIntyre, H David; Callaway, Leonie K

    2014-11-01

    Pre-eclampsia continues to be a challenge--to understand the underlying pathogenesis and to prevent or treat in the clinical setting. One area of potential therapies opening up is treatment of maternal lipids and clinical trials are underway using statins in early pre-eclampsia. At present, most potential therapies to treat lipids cannot be recommended for general use in pregnancy and if we were to target maternal lipids to reduce rates of pre-eclampsia, very large numbers of women may need to be treated. Prior to reaching that point, we first need to understand whether maternal lipids are pathogenic in the processes underlying pre-eclampsia. The aim of this review is to examine the role of lipids in the pathogenesis and outcomes of pre-eclampsia, how abnormal lipid genes may be implicated and consider whether treatment of hyperlipidemia has a more general place in the prevention or treatment of pre-eclampsia.

  14. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications. Hydrogen vehicle safety report

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.E. [Directed Technologies, Inc., Arlington, VA (United States)

    1997-05-01

    This report reviews the safety characteristics of hydrogen as an energy carrier for a fuel cell vehicle (FCV), with emphasis on high pressure gaseous hydrogen onboard storage. The authors consider normal operation of the vehicle in addition to refueling, collisions, operation in tunnels, and storage in garages. They identify the most likely risks and failure modes leading to hazardous conditions, and provide potential countermeasures in the vehicle design to prevent or substantially reduce the consequences of each plausible failure mode. They then compare the risks of hydrogen with those of more common motor vehicle fuels including gasoline, propane, and natural gas.

  15. Numerical Investigation on Hydrogen-Fueled Scramjet Combustor with Parallel Strut Fuel Injector at a Flight Mach Number of 6

    Directory of Open Access Journals (Sweden)

    Krishna Pandey

    2016-01-01

    Full Text Available A numerical analysis of the inlet-combustor interaction and flow structure through a scramjet engine at a flight Mach number M = 6 with parallel injection (Strut with circular inlet is presented in the present research article. Three different angles of attack (α=-4°, α=0°, α=4° have been studied for parallel injection. The scramjet configuration used here is a modified version of DLR scramjet model. Fuel is injected at supersonic speed (M=2 through a parallel strut injector. For parallel injection, the shape of the strut is chosen in a way to produce strong stream wise vorticity and thus to enhance the hydrogen/air mixing inside the combustor. These numerical simulations are aimed to study the flow structure, supersonic mixing, and combustion phenomena for the three different types of geometries along with circular shaped strut configuration.

  16. Coherent Anti-Stokes Raman Scattering (CARS) as a Probe for Supersonic Hydrogen-Fuel/Air Mixing

    Science.gov (United States)

    Danehy, P. M.; O'Byrne, S.; Cutler, A. D.; Rodriguez, C. G.

    2003-01-01

    The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) method was used to measure temperature and the absolute mole fractions of N2, O2 and H2 in a supersonic non-reacting fuel-air mixing experiment. Experiments were conducted in NASA Langley Research Center s Direct Connect Supersonic Combustion Test Facility. Under normal operation of this facility, hydrogen and air burn to increase the enthalpy of the test gas and O2 is added to simulate air. This gas is expanded through a Mach 2 nozzle and into a combustor model where fuel is then injected, mixes and burns. In the present experiment the O2 of the test gas is replaced by N2. The lack of oxidizer inhibited combustion of the injected H2 fuel jet allowing the fuel/air mixing process to be studied. CARS measurements were performed 427 mm downstream of the nozzle exit and 260 mm downstream of the fuel injector. Maps were obtained of the mean temperature, as well as the N2, O2 and H2 mean mole fraction fields. A map of mean H2O vapor mole fraction was also inferred from these measurements. Correlations between different measured parameters and their fluctuations are presented. The CARS measurements are compared with a preliminary computational prediction of the flow.

  17. Analysis of the Transition to Hydrogen Fuel Cell Vehicles and the Potential Hydrogen Energy Infrastructure Requirements, March 2008

    Energy Technology Data Exchange (ETDEWEB)

    Greene, David L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Leiby, Paul N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); James, Brian [Directed Technologies, Inc., Youngstown, OH (United States); Perez, Julie [Directed Technologies, Inc., Youngstown, OH (United States); Melendez, Margo [National Renewable Energy Lab. (NREL), Golden, CO (United States); Milbrandt, Anelia [National Renewable Energy Lab. (NREL), Golden, CO (United States); Unnash, Stefan [Life Cycle Associates, Portola Valley, CA (United States); Rutherford, Daniel [Life Cycle Associates, Portola Valley, CA (United States); Hooks, Matthew [TIAX, LLC, Lexingtion, MA (United States)

    2008-03-14

    Achieving a successful transition to hydrogen-powered vehicles in the U.S. automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction of these agents in the marketplace will determine the real costs and benefits of early market transformation policies, and ultimately the success of the transition itself.

  18. Modeling, Control, and Simulation of a Solar Hydrogen/Fuel Cell Hybrid Energy System for Grid-Connected Applications

    Directory of Open Access Journals (Sweden)

    Tourkia Lajnef

    2013-01-01

    Full Text Available Different energy sources and converters need to be integrated with each other for extended usage of alternative energy, in order to meet sustained load demands during various weather conditions. The objective of this paper is to associate photovoltaic generators, fuel cells, and electrolysers. Here, to sustain the power demand and solve the energy storage problem, electrical energy can be stored in the form of hydrogen. By using an electrolyser, hydrogen can be generated and stored for future use. The hydrogen produced by the electrolyser using PV power is used in the FC system and acts as an energy buffer. Thus, the effects of reduction and even the absence of the available power from the PV system can be easily tackled. Modeling and simulations are performed using MATLAB/Simulink and SimPowerSystems packages and results are presented to verify the effectiveness of the proposed system.

  19. Wavelet analysis of cyclic variability in a spark ignition engine powered by gasoline-hydrogen fuel blends

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Asok K. [Richard G. Lugar Centre for Renewable Energy, and Department of Mathematical Sciences, Indiana University, (United States)], email: asen@iupui.edu; Akif Ceviz, M.; Volkan Oner, I. [Department of Mechanical Engineering, University of Ataturk (Turkey)], email: aceviz@atauni.edu.tr

    2011-07-01

    The cycle-to-cycle variations (CCV) of the indicated mean effective pressure (IMEP) in a spark ignition engine fuelled by gasoline and gasoline-hydrogen blends is investigated. CCVs are estimated by using the coefficient of variation (COV) and the overall spectral power given by the global wavelet spectrum (GWS). It was found that the addition of hydrogen reduces the CCV of the IMEP. Analysis of the wavelet can also identify the dominant modes of variability and delineate the engine cycles over which these modes can persist. Air-fuel ratio was varied from 1.0 to 1.3, and hydrogen was added up to 7.74% by volume. The engine was operated at 2000 rpm. Results demonstrate that subject to air-fuel ratio and % of hydrogen added, IMEP time series can exhibit multiscale dynamics consisting of persistent oscillations and intermittent fluctuations. These results can help develop effective control strategies to reduce cyclic variability in a spark ignition engine fuelled by gasoline-hydrogen mixtures.

  20. Location models applied to the design of a distribution network for hydrogen fuel produced from renewable energy sources

    OpenAIRE

    Barnett Lawton, Jorge Enrique; Gonsalvez, David; Menezes, Mozart Batista de Castro

    2013-01-01

    El agotamiento de las reservas de combustibles fósiles, la creciente preocupación sobre el posible impacto a corto y mediano plazo de las emisiones de gases invernadero en la sociedad y el medio ambiente, y las resultantes políticas orientadas hacia energías más limpias y menor dependencia de combustibles fósiles, han todos puesto mayor presión en incrementar la capacidad de generar energía a partir de fuentes renovables, de las cuales la energía eólica ha sido uno de los segmentos de más ráp...

  1. Development and integration of a scalable low NOx combustion chamber for a hydrogen-fueled aerogas turbine

    Science.gov (United States)

    Boerner, S.; Funke, H. H.-W.; Hendrick, P.; Recker, E.; Elsing, R.

    2013-03-01

    The usage of alternative fuels in aircraft industry plays an important role of current aero engine research and development processes. The micromix burning principle allows a secure and low NOx combustion of gaseous hydrogen. The combustion principle is based on the fluid phenomenon of jet in cross flow and achieves a significant lowering in NOx formation by using multiple miniaturized flames. The paper highlights the development and the integration of a combustion chamber, based on the micromix combustion principle, into an Auxiliary Power Unit (APU) GTCP 36-300 with regard to the necessary modifications on the gas turbine and on the engine controller.

  2. Cryoplane, a European project of hydrogen-fueled aircraft; Cryoplane, un projet europeen d'avion a hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2002-10-01

    The use of liquid hydrogen for the propulsion of aircraft offers an interesting alternative to fossil fuels, on the ecological point of view. The European research project 'Cryoplane' shows that the use of liquid hydrogen is feasible and that it should greatly reduce the environmental impact of air transport without any loss in security. This project, financed by the European Commission for a duration of 26 months and managed by Airbus Industries, groups together 35 partners from the industry, research centers and universities, and 11 member states. (J.S.)

  3. Hydrogen fuel: Japan tries to pull away; Carburant hydrogene: le Japon tente de prendre de l'avance

    Energy Technology Data Exchange (ETDEWEB)

    Henry, P.

    2003-04-01

    The energy production of Japan is highly dependent from its oil and gas imports. Thus, Japan tries to diversify its energy sources in order to find alternate solutions to this dependence. Hydrogen should be one of these solutions providing that some economically and environmentally viable hydrogen production techniques are implemented with reliable and competitive distribution networks. The 'world energy network' (WE-NET) program, started thanks to Japan's impetus, aims at establishing a large scale international network for the development of hydrogen as energy source. (J.S.)

  4. ORFEUS echelle spectra Molecular hydrogen in disk, IVC, and HVC gas in front of the LMC

    CERN Document Server

    Bluhm, H J; Marggraf, O; Richter, P; Bluhm, Hartmut; Boer, Klaas. S. de; Marggraf, Ole; Richter, Philipp

    2001-01-01

    In front of the LMC molecular hydrogen is found in absorption near 0 km/s, being local disk gas, near +60 km/s in an intermediate velocity cloud, and near +120 km/s, in a high velocity halo cloud. The nature of the gas is discussed based on four ORFEUS far UV spectra of LMC stars and including data from the ground and from the IUE satellite. The local gas is cool and, given a span of sight lines of only 2.5 deg, rather fluffy. The fractional abundance of H_2 varies from log(f)=-5.4 to -3.3. Metal depletions (up to -1.7 dex for Fe) are typical for galactic disk gas. In the IV and HV gas an apparent underabundance of neutral oxygen points to an ionization level of the gas of about 90%. H_2 is detected in IV and HV gas toward HD 269546. In the IV gas we find an H_2 column density of log(N)\\simeq15.6. The H_2 excitation indicates that the line of sight samples a cloud at a temperature below 150 K. Column densities are too small to detect the higher UV pumped excitation levels. The high velocity H_2 (log(N)\\simeq1...

  5. Introducer curving technique to reduce tilting of transfemoral Gunther Tulip IVC filter: in vitro study.

    Science.gov (United States)

    Xiao, Liang; Wang, Man; Huang, De-Sheng; Shen, Jing; Tong, Jia-Jie

    2012-09-01

    Severe tilting of Günther Tulip filter (GTF) may be associated with difficulty in retrieval. To determine if an introducer curving technique of GTF can decrease the tilting degree of GTF in a caval model. The model was constructed by placing Dacron grafts in bifurcated glass tubes. The study included three groups: Right Straight Group (G(1)), Left Straight Group (G(2)), and Left Curved Group (G(3)). In G(3), a 10-20° angle was curved on the metal introducer before insertion to decrease the angle between inferior vena cava axes and metal introducer (A(CM)). Before GTF was released, the distance between the caval right wall and the apical hook (D(CH1)), and A(CM) were measured. The tilt angle of GTF (A(CF)) was also measured. In G(1), GTF apex tended to center compared to G(2) (59% vs. 36%, P < 0.01). In G(3), GTF apex tended to center compared to G(2) (71% vs. 36%, P < 0.01). The differences of A(CF) between G(1) and G(2) (2.66 ± 1.80 vs. 4.13 ± 2.07, P < 0.01) and between G(2) and G(3) (4.13 ± 2.07 vs. 2.39 ± 1.79, P < 0.01) were statistically significant. There were significant positive correlations between A(CM) and A(CF), whereas significant negative correlations were detected between D(CH1) and A(CF) in each group. The oblique course of GTF delivery system relative to the axis of the cava causes filter tilt, and thus, curving the introducer prior to its introduction helps to reduce the filter tilt. We recommend a clinical study to determine whether the introducer curving technique improves filter centering and its retrievability.

  6. Formation of a Tunnel under the Major Hepatic Vein Mouths during Removal of IVC Tumor Thrombus

    Directory of Open Access Journals (Sweden)

    Dmytro Shchukin

    2013-01-01

    Full Text Available This study describes a clinical observation of successful implementation of a new surgical maneuver: formation of a cross tunnel under the mouths of the major hepatic veins during removal of a tumor thrombus of the inferior vena cava. This surgical technique helps avoid the usage of   “piggyback” mobilization of the liver and the complications associated with it. However, for objective evaluation of this approach, a further clinical study is required.

  7. Exciton-Dependent Pre-formation Probability of Composite Particles

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Shang; WANG Ji-Min; DUAN Jun-Feng

    2007-01-01

    In Iwamoto-Harada model the whole phase space is full of fermions. When the momentum distributions of the exciton states are taken into account, the pre-formation probability of light composite particles could be improved,and the exciton state-dependent pre-formation probability has been proposed. The calculated results indicate that the consideration of the momentum distribution enhances the pre-formation probability of [1,m] configuration, and suppresses that of [l > 1, m] configurations seriously.

  8. Semantics-based pre-fetching for reducing WWW latency

    Institute of Scientific and Technical Information of China (English)

    赵晨; 施鹏飞; 许欢庆

    2004-01-01

    A semantics-based pre-fetching model is presented. This model predicts future requests based on latent intention that the user's current access path implies in semantics, rather than on temporal relationships, which oversomes the limitation of previous pre-fetching approaches. The hidden Markov model (HMM) was employed for mining actual intention from access patterns. Experimental results show that the proposed pre-fetching model has better general performance.

  9. ICT in pre-service teacher training: an exploratory study

    OpenAIRE

    Silva, Fátima Vicente; Miranda, Guilhermina Lobato

    2003-01-01

    Pre-service teacher training (PTT) is one of the points where questions about school life inevitable converge. Teacher profile required by each educational system, according to the context and specific characteristics os each society, should be based on pre-service teacher training. This is the way pre-service teacher training is approached here. On the one hand, this works attempts to reflect on the importance of PTT in the construction of teacher profession integrated in what is known as th...

  10. Early pre-eclampsia unmasks underlying IgA nephropathy

    OpenAIRE

    Mona Singh; Akhenaton Pappoe; Don, Burl R.

    2010-01-01

    Mona Singh, Akhenaton Pappoe, Burl R DonDivision of Nephrology, University of California Davis Medical Center, Sacramento, CA, USAAbstract: Pre-eclampsia is the most ominous complication of pregnancy, and primary glomerular diseases can mimic pre-eclampsia in presentation. A patient presented at 21 weeks gestation with signs and symptoms of both pre-eclampsia and primary glomerular nephropathy. A critical clinical decision whether to continue or terminate the pregnancy was dependent on result...

  11. Moving From Theory to Practice: ELT Pre-service Teachers

    OpenAIRE

    Şaziye Yaman; Meryem Özdemir

    2012-01-01

    This study was conducted to investigate the perceptual change in pre-service teachers’ effective teacher beliefs throughout their education in English Language Teaching (ELT) Department of which programme is constructed spirally from theoretical knowledge to the practical one. Throughout a data collection procedure lasted 5 academic terms, 80 pre-service teachers were asked to write their ideas about “the characteristics of an effective teacher”. In each time, as the pre-service teachers move...

  12. Fixation of compressive deformation in wood by pre-steaming

    Science.gov (United States)

    M. Inoue; N. Sekino; T. Morooka; R.M. Rowell; M. Norimoto

    2008-01-01

    Wood block specimens pre-steamed at 120-220 °C for 5-20 min were compressed in the radial direction. The recovery of set decreased with increasing pre-steaming temperature and time. The reduction of set recovery correlated with the amount of weight loss in steaming irrespective of pre-steaming temperature and time. The weight loss for the highest level of...

  13. The Pontryagin class for pre-Courant algebroids

    Science.gov (United States)

    Liu, Zhangju; Sheng, Yunhe; Xu, Xiaomeng

    2016-06-01

    In this paper, we show that the Jacobiator J of a pre-Courant algebroid is closed naturally. The corresponding equivalence class [J♭ ] is defined as the Pontryagin class, which is the obstruction of a pre-Courant algebroid to be deformed into a Courant algebroid. We construct a Leibniz 2-algebra and a Lie 2-algebra associated to a pre-Courant algebroid and prove that these algebraic structures are isomorphic under deformations. Finally, we introduce the twisted action of a Lie algebra on a manifold to give more examples of pre-Courant algebroids, which include the Cartan geometry.

  14. CULTURAL INFLUENCES ON PRE-PAY MOBILE TELECOMMUNICATIONS SERVICES USERS

    Directory of Open Access Journals (Sweden)

    Georgeta-Madalina MEGHISAN

    2015-06-01

    Full Text Available Purpose: The purpose of this research paper is to identify the preferences of the pre-pay mobile telecommunications services young users from Romania. Approach/ methodology: The analysis of the pre-pay mobile telecommunications services was made using statistical functions: descriptive statistics, t test, correlation and factor analysis. Results: According to the analysis made, we could underline the habits of usage from the part of pre-pay mobile telecommunications services consumers. Originality: The paper drew an objective analysis on the pre-pay mobile telecommunications services from the perspective of young consumers.

  15. Basic math and pre-algebra practice problems for dummies

    CERN Document Server

    Zegarelli, Mark

    2013-01-01

    1001 Basic Math & Pre- Algebra Practice Problems For  Dummies   Practice makes perfect-and helps deepen your understanding of basic math and pre-algebra 1001 Basic Math & Pre-Algebra Practice Problems For Dummies, with free access to online practice problems, takes you beyond the instruction and guidance offered in Basic Math & Pre-Algebra For Dummies, giving you 1,001 opportunities to practice solving problems from the major topics in your math course. You begin with some basic arithmetic practice, move on to fractions, decimals, and per

  16. Pre-service English teachers’ intercultural sensitivity

    Directory of Open Access Journals (Sweden)

    Feryal Cubukcu

    2013-04-01

    Full Text Available Globalisation has helped the number of people to be cognizant of the importance of foreign language teaching and learning. As  it is almost impossible to separate culture from language and the familiarization of  diverse cultures from language do not help students for the real life because people from diverse cultural backgrounds use language differently, Kramsch (1993:258 holds that the aim of language learning is “cultivating international understanding, responsibility, and effective participation in a global age”. The purpose of  this  article is to explore the intercultural sensitivity among teacher trainees. For this purpose two scales were administered to  the pre- service teachers to see to what extent they have intercultural sensitivity and how they see culture teaching in the curriculum. The results yield that Turkish teacher  trainees  integrate language teaching objectives  with culture teaching and they prioritize the attitudinal knowledge, showing tolerance and sympathy for the others.  

  17. Pre-Inca Astronomy in Peru

    Science.gov (United States)

    McKim Malville, J.

    Huacas (shrines) and ushnus (ceremonial platforms) are ever-present elements of millennia-old Andean cosmology extending backward to 3100 BCE. Major themes of Pan-Andean cosmology include sacred mountains, the power of water, the solstice sun, as well as shamanic-like movement across the three worlds of the cosmos. Common features of many pre-Inca sites are monumental platforms and sunken circular plazas, and stairways with axes established by bi-lateral symmetries oriented along solstice lines. This style of ritual architecture first appeared in Chupacigarro/Caral, other sites in the Norte Chico area, and Sechin Bajo in the Casma Valley. Ceremonial plazas provided opportunities for public viewing of ritual ceremonies on the tops of platforms, which may have been understood as sacred mountains. Mounds and temples of the Casma Valley, such as Sechin Alto, Sechin Bajo, and Chankillo, developed an explicit astronomy associated with June and December solstices. The ritualistic use of water, which is typically associated with visual astronomy at Inca sites, appeared at Chavin de Huantar and later in Tiwanaku.

  18. The pre-history of urban scaling.

    Science.gov (United States)

    Ortman, Scott G; Cabaniss, Andrew H F; Sturm, Jennie O; Bettencourt, Luís M A

    2014-01-01

    Cities are increasingly the fundamental socio-economic units of human societies worldwide, but we still lack a unified characterization of urbanization that captures the social processes realized by cities across time and space. This is especially important for understanding the role of cities in the history of human civilization and for determining whether studies of ancient cities are relevant for contemporary science and policy. As a step in this direction, we develop a theory of settlement scaling in archaeology, deriving the relationship between population and settled area from a consideration of the interplay between social and infrastructural networks. We then test these models on settlement data from the Pre-Hispanic Basin of Mexico to show that this ancient settlement system displays spatial scaling properties analogous to those observed in modern cities. Our data derive from over 1,500 settlements occupied over two millennia and spanning four major cultural periods characterized by different levels of agricultural productivity, political centralization and market development. We show that, in agreement with theory, total settlement area increases with population size, on average, according to a scale invariant relation with an exponent in the range [Formula: see text]. As a consequence, we are able to infer aggregate socio-economic properties of ancient societies from archaeological measures of settlement organization. Our findings, from an urban settlement system that evolved independently from its old-world counterparts, suggest that principles of settlement organization are very general and may apply to the entire range of human history.

  19. Pre-Inflationary Relics in the CMB?

    CERN Document Server

    Gruppuso, A; Mandolesi, N; Natoli, P; Sagnotti, A

    2015-01-01

    String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an imprint in the CMB anisotropy, if it occurred at accessible wavelengths. We model the effect extending $\\Lambda$CDM with a scale $\\Delta$ related to the infrared depression and explore the constraints allowed by {\\sc Planck} data, employing also more conservative, wider Galactic masks in the low resolution CMB likelihood. In an extended mask with $f_{sky}=39\\%$, we thus find $\\Delta = (0.351 \\pm 0.114) \\times 10^{-3} \\, \\mbox{Mpc}^{-1}$, at $99.4\\%$ confidence level, to be compared with a nearby value at $88.5\\%$ with the standard $f_{sky}=94\\%$ mask. With about 64 $e$--folds of inflation, these values for $\\Delta$ would translate into primordial energy scales ${\\cal O}(10^{14})$ GeV.

  20. Comparing Binaural Pre-processing Strategies II

    Directory of Open Access Journals (Sweden)

    Regina M. Baumgärtel

    2015-12-01

    Full Text Available Several binaural audio signal enhancement algorithms were evaluated with respect to their potential to improve speech intelligibility in noise for users of bilateral cochlear implants (CIs. 50% speech reception thresholds (SRT50 were assessed using an adaptive procedure in three distinct, realistic noise scenarios. All scenarios were highly nonstationary, complex, and included a significant amount of reverberation. Other aspects, such as the perfectly frontal target position, were idealized laboratory settings, allowing the algorithms to perform better than in corresponding real-world conditions. Eight bilaterally implanted CI users, wearing devices from three manufacturers, participated in the study. In all noise conditions, a substantial improvement in SRT50 compared to the unprocessed signal was observed for most of the algorithms tested, with the largest improvements generally provided by binaural minimum variance distortionless response (MVDR beamforming algorithms. The largest overall improvement in speech intelligibility was achieved by an adaptive binaural MVDR in a spatially separated, single competing talker noise scenario. A no-pre-processing condition and adaptive differential microphones without a binaural link served as the two baseline conditions. SRT50 improvements provided by the binaural MVDR beamformers surpassed the performance of the adaptive differential microphones in most cases. Speech intelligibility improvements predicted by instrumental measures were shown to account for some but not all aspects of the perceptually obtained SRT50 improvements measured in bilaterally implanted CI users.

  1. Pre-, Pro-, Synbiotics and Human Health

    Directory of Open Access Journals (Sweden)

    Stig Bengmark

    2010-01-01

    Full Text Available Western lifestyle is associated with a sustained low grade increase in inflammation leading to an impaired innate immunity and reduced resistance to disease, changes which might explain the epidemic of chronic diseases spreading around the globe. The immune system cannot function properly without access to bacteria and plants, which when raw, are rich not only in bacteria but also in plant fibres, antioxidants, healthy fats and numerous other nutrients. Modern food technology with plant breeding, separation, condensation of food ingredients, heating, freezing, drying, irradiation, microwaving, an effective tool for destroying foods and hereby counteracting optimal immune function, is suspected to be a leading cause of so-called Western diseases. The supply of pre-, pro-, and synbiotics has sometimes proved to be effective tool to counteract, especially acute diseases, but has often failed, especially in chronic diseases. Thousands of factors contribute to unhealthy living. Numerous alterations in lifestyle and food habits are needed, if to prevent and cure 'treatment-resistant' chronic diseases. Among these are avoiding such processed foods that are known to be rich in pro-inflammatory molecules, and also eating substantial amounts of foods with documented anti-inflammatory effects such as turmeric/curcumin, molecules which might be included in future synbiotic compositions.

  2. Microbial communities in pre-columbian coprolites.

    Directory of Open Access Journals (Sweden)

    Tasha M Santiago-Rodriguez

    Full Text Available The study of coprolites from earlier cultures represents a great opportunity to study an "unaltered" composition of the intestinal microbiota. To test this, pre-Columbian coprolites from two cultures, the Huecoid and Saladoid, were evaluated for the presence of DNA, proteins and lipids by cytochemical staining, human and/or dog-specific Bacteroides spp. by PCR, as well as bacteria, fungi and archaea using Terminal Restriction Fragment analyses. DNA, proteins and lipids, and human-specific Bacteroides DNA were detected in all coprolites. Multidimensional scaling analyses resulted in spatial arrangements of microbial profiles by culture, further supported by cluster analysis and ANOSIM. Differences between the microbial communities were positively correlated with culture, and SIMPER analysis indicated 68.8% dissimilarity between the Huecoid and Saladoid. Proteobacteria, Bacteroidetes and methanogens were found in all coprolite samples. Propionebacteria, Shewanella and lactic acid bacteria dominated in the Huecoid samples, while Acidobacteria, and peptococci were dominant in Saladoid samples. Yeasts, including Candida albicans and Crypotococcus spp. were found in all samples. Basidiomycetes were the most notable fungi in Huecoid samples while Ascomycetes predominated in Saladoid samples, suggesting differences in dietary habits. Our study provides an approach for the study of the microbial communities of coprolite samples from various cultures.

  3. Capturing a flavivirus pre-fusion intermediate.

    Directory of Open Access Journals (Sweden)

    Bärbel Kaufmann

    2009-11-01

    Full Text Available During cell entry of flaviviruses, low endosomal pH triggers the rearrangement of the viral surface glycoproteins to a fusion-active state that allows the release of the infectious RNA into the cytoplasm. In this work, West Nile virus was complexed with Fab fragments of the neutralizing mAb E16 and was subsequently exposed to low pH, trapping the virions in a pre-fusion intermediate state. The structure of the complex was studied by cryo-electron microscopy and provides the first structural glimpse of a flavivirus fusion intermediate near physiological conditions. A radial expansion of the outer protein layer of the virion was observed compared to the structure at pH 8. The resulting approximately 60 A-wide shell of low density between lipid bilayer and outer protein layer is likely traversed by the stem region of the E glycoprotein. By using antibody fragments, we have captured a structural intermediate of a virus that likely occurs during cell entry. The trapping of structural transition states by antibody fragments will be applicable for other processes in the flavivirus life cycle and delineating other cellular events that involve conformational rearrangements.

  4. Pre-inflationary clues from String Theory?

    Energy Technology Data Exchange (ETDEWEB)

    Kitazawa, N. [Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo, 192-0397 JAPAN (Japan); Sagnotti, A., E-mail: kitazawa@phys.se.tmu.ac.jp, E-mail: sagnotti@sns.it [Scuola Normale Superiore and INFN, Piazza dei Cavalieri, 7, Pisa, 56126 (Italy)

    2014-04-01

    ''Brane supersymmetry breaking'' occurs in String Theory when the only available combinations of D-branes and orientifolds are not mutually BPS and yet do not introduce tree-level tachyon instabilities. It is characterized by the emergence of a steep exponential potential, and thus by the absence of maximally symmetric vacua. The corresponding low-energy supergravity admits intriguing spatially-flat cosmological solutions where a scalar field is forced to climb up toward the steep potential after an initial singularity, and additional milder terms can inject an inflationary phase during the ensuing descent. We show that, in the resulting power spectra of scalar perturbations, an infrared suppression is typically followed by a pre-inflationary peak that reflects the end of the climbing phase and can lie well apart from the approximately scale invariant profile. A first look at WMAP9 raw data shows that, while the χ{sup 2} fits for the low-ℓ CMB angular power spectrum are clearly compatible with an almost scale invariant behavior, they display nonetheless an eye-catching preference for this type of setting within a perturbative string regime.

  5. Pre - Inflationary Clues from String Theory ?

    CERN Document Server

    Kitazawa, N

    2014-01-01

    "Brane supersymmetry breaking" occurs in String Theory when the only available combinations of D-branes and orientifolds are not mutually BPS and yet do not introduce tree-level tachyon instabilities. It is characterized by the emergence of a steep exponential potential, and thus by the absence of maximally symmetric vacua. The corresponding low-energy supergravity admits intriguing spatially-flat cosmological solutions where a scalar field is forced to climb up toward the steep potential after an initial singularity, and additional milder terms can inject an inflationary phase during the ensuing descent. We show that, in the resulting power spectra of scalar perturbations, an infrared suppression is typically followed by a pre-inflationary peak that reflects the end of the climbing phase and can lie well apart from the approximately scale invariant profile. A first look at WMAP9 raw data shows that, while the chi^2 fits for the low-l CMB angular power spectrum are clearly compatible with an almost scale inva...

  6. Pre-Schoolers, Pre-School Teachers, and Interpersonal Problem-Solving Skills: A Comparative Study in Turkey and Belgium

    Science.gov (United States)

    Sahin, Derya

    2011-01-01

    Interpersonal cognitive problem solving, one of the most crucial social skills, is a life-long competency that must be supported from the early years of life. In this study, the opinions of 55 Turkish pre-school teachers and 53 Flemish pre-school teachers who work with 3-6-year-old children in private and public pre-schools in metropolitan cities…

  7. Rethinking Privacy Decisions: Pre-Existing Attitudes, Pre-Existing Emotional States, and a Situational Privacy Calculus

    OpenAIRE

    Kehr, Flavius; Wentzel, Daniel; Kowatsch, Tobias; Fleisch, Elgar

    2015-01-01

    As a potential explanation to measured inconsistencies between stated privacy concerns and actual disclosing behavior, denoted as the "privacy paradox", scholars have proposed a systematic distinction between situational privacy considerations and pre-existing, superordinate factors that shape the decisive situation without being directly connected to the situation itself. Deploying an experimental approach, we explored the dynamics of two types of such pre-existing factors, namely (1) pre-ex...

  8. Teaching about 21st Century Energy Sources to Pre-college Students and Teachers

    Science.gov (United States)

    Zwicker, Andrew P.; Morgan, J.; Ritter, C.; DeLooper, J.; Guilbert, N.

    2006-12-01

    For several years, the Princeton Plasma Physics Laboratory has led a weeklong summer workshop on alternative energy sources for high school students. We have several versions of the workshop, depending upon the students participating. Recently, we offered the workshop to students attending a science magnet school, students from a large, urban school, and “learning different” students. Students perform a variety of “design and build” projects, one for each of the major energy sources. Energy sources typically explored include solar, hydrogen fuel cells, and fusion. Along with the laboratory exercises, students work on virtual experiments, computer simulations and some lecture. This summer, we will begin a four-week professional development program centered on the same topic. Participants will use their work in the laboratory and classroom to develop inquiry-based curricula, aligned with State and National standards that use energy as a theme for exploring various topics in physics and physical science. A description of each workshop will be given along with results from various exit surveys that probe the impact of the workshop on student attitudes towards energy.

  9. The pre-Caledonian margin of Baltica

    Science.gov (United States)

    Andersen, Torgeir B.; Jørgen Kjøll, Hans; Jakob, Johannes; Corfu, Fernando; Tegner, Christian

    2017-04-01

    It is well-documented that the pre-Caledonian margin of Baltica constituted a several hundred-km wide and more than 2000 km long passive margin. Its vestiges occur at low- to intermediate structural levels in the mountain belt, and are variably overprinted by the early- to end-Caledonian orogenic deformation and extension. Attempts to reconstruct the Caledonian margin of Baltica must be based on detailed maps integrated with studies of the rock-complexes that originally constituted the passive margin. The proximal parts of pre-Caledonian margin of Baltica are dominated by continental rift basins with coarse to fine-grained sediments deposited in the late Proterozoic through the Ediacaran and into the Lower Palaeozoic. The youngest dated clastic zircons probably record magmatism associated with initial contraction near or in the distal margin. The 'margin nappes' also comprise Baltican basement slivers and coarse to fine-grained sedimentary units as well as deep-marine basin deposits. A major change in the architecture of the passive margin units takes place across a transvers zone, which is sub-parallel to the present-day Gudbrandsdalen of South Norway. The transition is roughly parallel to the major basement lineament of the Sveconorwegian orogenic front in south Norway. The most important change across this transverse lineament is that the NE segment is magma-rich, characterized by abundant basaltic magmatism. The SW segment is magma-poor, and characterised by numerous (>100) solitary meta-peridotites, mostly meta-dunites and meta-harzburgites as well as a number of detrital serpentinites and soapstones. These are interpreted as fragments of exhumed mantle and their erosion products, respectively. The meta-peridotites emplaced structurally, and covered by dominantly deep-basin sediments, but also by coarser sedimentary breccias and conglomerates, as part of the rifted margin development. This mixed unit (mélange) was locally intruded by Late Cambrian to Early

  10. niños pre-escolares

    Directory of Open Access Journals (Sweden)

    Sandra León Muñoz

    2006-01-01

    Full Text Available Este estudio tuvo como objetivo caracterizar las producciones narrativas orales de niños de pre-escolar y relacionar estos desempeños con la lectura de imágenes. Se conformó una muestra de 9 niños entre 4 y 6 años que pertenecían a instituciones de educación formal. Se realizó un análisis de tarea de la historieta presentada y la aplicación de ésta fue de manera individual en el contexto familiar del niño. Los resultados mostraron que los niños identificaban la situación inicial de la narración, en la cual relacionaban personajes principales, actividades propias de ellos y del espacio donde sucedían sin embargo, a medida que se avanzaban en el procedimiento, se observó cómo se dificultaba para los niños la elaboración de las otras categorías que estructuran la narración como la complicación, la reacción, la resolución y la situación final. En relación con las estrategias cognitivas se observó que cuatro niños se encuentra en un nivel cognitivo bajo, cuatro se encuentra en un nivel cognitivo medio y un niño, en un nivel cognitivo alto. En cuanto a los procesos de lectura de imágenes se encontró que sólo dos niños utilizaron la referencia y dos niños usaron conectores temporales

  11. 20 CFR 655.15 - Required pre-filing recruitment.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Required pre-filing recruitment. 655.15... States (H-2B Workers) § 655.15 Required pre-filing recruitment. (a) Time of filing of application. An... recruitment steps set forth in this section have been fully satisfied, except where specifically exempted from...

  12. Linking pre-meeting communication to meeting effectiveness

    NARCIS (Netherlands)

    Allen, J.A.; Lehmann-Willenbrock, N.K.; Landowski, N.

    2014-01-01

    Purpose – The present study investigates the importance of communication that occurs just before workplace meetings (i.e., pre-meeting talk). We explore how pre-meeting talk impacts meeting effectiveness through the” ripple effect”, allowing before meeting communication/behaviors to ripple into and

  13. Resisting Vocationalism in the Pre-Professional Writing Course.

    Science.gov (United States)

    Griffin, Susan

    This paper discusses vocationalism versus a utilitarian view of the university in the context of funding and inclusion of pre-professional writing courses in a liberal arts education. It begins by describing a situation in which pre-professional writing courses for medicine, law, and business might be eliminated, based on their vocational…

  14. Algebraic Generalization Strategies Used by Kuwaiti Pre-Service Teachers

    Science.gov (United States)

    Alajmi, Amal Hussain

    2016-01-01

    This study reports on the algebraic generalization strategies used by elementary and middle/high school pre-service mathematics teachers in Kuwait. They were presented with 9 tasks that involved linear, exponential, and quadratic situations. The results showed that these pre-service teachers had difficulty in generalizing algebraic rules in all 3…

  15. ELL School Readiness and Pre-Kindergarten Care

    Science.gov (United States)

    Gottfried, Michael A.

    2017-01-01

    The increased utilization of non-parental pre-kindergarten care has spurred interest by both researchers and policy makers as to what types of care might be effective at boosting school readiness. Under-developed in the research has been an assessment of the influence of pre-kindergarten care on school readiness for English Language Learners…

  16. Pre-Service Teachers' Beliefs and Knowledge about Multiculturalism

    Science.gov (United States)

    Acquah, Emmanuel O.; Commins, Nancy L.

    2013-01-01

    The present study examined pre-service teachers' knowledge of issues related to multiculturalism and diversity before and after taking a multicultural education course. Data from 38 degree students in an urban university in the southwest of Finland were analysed using a mixed method approach. The results indicate that pre-service teachers'…

  17. Investigating Classroom Teaching Competencies of Pre Service Elementary Mathematics Teachers

    Science.gov (United States)

    Gokalp, Murat

    2016-01-01

    The study has sought answers to two major questions: What is the current situation in Elementary Mathematics Education programs at Faculty of Education in terms of classroom teaching competencies? To what extent do pre service teachers acquire these competencies? The research was conducted on 202 senior pre service teachers studying at the…

  18. Pre-1970 transuranic solid waste at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Greenhalgh, W.O.

    1995-05-23

    The document is based on a search of pre-1970 Hanford Solid Waste Records. The available data indicates seven out of thirty-one solid waste burial sites used for pre-1970 waste appear to be Transuranic (TRU). A burial site defined to be TRU contains >100 nCi/gm Transuranic nuclides.

  19. Examination of Pre-Service Teacher's Training through Tutoring Approach

    Science.gov (United States)

    Wu, Hsiao-ping; Guerra, Myriam Jimena

    2017-01-01

    Pre-service teacher preparation in the United States is becoming progressively more challenging with respect to the demands on teachers. This study examined the impact of tutoring approach on pre-service teachers? skills to work with English language learners through a qualitative research design. Content analysis was used at the thematic level on…

  20. Pre-Service Mathematics Teachers' Concept Images of Radian

    Science.gov (United States)

    Akkoc, Hatice

    2008-01-01

    This study investigates pre-service mathematics teachers' concept images of radian and possible sources of such images. A multiple-case study was conducted for this study. Forty-two pre-service mathematics teachers completed a questionnaire, which aims to assess their understanding of radian. Six of them were selected for individual interviews on…

  1. Periodontal disease and pre-eclampsia : a systematic review

    NARCIS (Netherlands)

    Kunnen, Alina; van Doormaal, Jasper J.; Abbas, Frank; Aarnoudse, Jan G.; van Pampus, Maria; Faas, Marijke M.

    2010-01-01

    P>Aim This review evaluates the possible relationship between periodontal disease and pre-eclampsia, a major pregnancy complication. A generalized inflammatory response plays an important role in the pathogenesis of pre-eclampsia. Because periodontal disease is a low-grade inflammatory state, period

  2. Query processing of pre-partitioned data using Sandwich Operators

    NARCIS (Netherlands)

    Baumann, S.; Boncz, P.A.; Sattler, K.-U.

    2012-01-01

    In this paper we present the Sandwich Operators, an elegant approach to exploit pre-sorting or pre-grouping from clustered storage schemes in operators such as Aggregation/Grouping, HashJoin, and Sort of a database management system. Thereby, each of these operator types is "sandwiched" by two new o

  3. 26 CFR 1.679-5 - Pre-immigration trusts.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Pre-immigration trusts. 1.679-5 Section 1.679-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Grantors and Others Treated As Substantial Owners § 1.679-5 Pre-immigration trusts. (a)...

  4. Periodontal disease and pre-eclampsia : a systematic review

    NARCIS (Netherlands)

    Kunnen, Alina; van Doormaal, Jasper J.; Abbas, Frank; Aarnoudse, Jan G.; van Pampus, Maria; Faas, Marijke M.

    2010-01-01

    P>Aim This review evaluates the possible relationship between periodontal disease and pre-eclampsia, a major pregnancy complication. A generalized inflammatory response plays an important role in the pathogenesis of pre-eclampsia. Because periodontal disease is a low-grade inflammatory state,

  5. Moving House for Education in the Pre-School Years

    Science.gov (United States)

    Hansen, Kirstine

    2014-01-01

    This paper uses data from the Millennium Cohort Study (MCS) to examine house moves that take place in the pre-school years, focusing on families who move for the education of their children. We present results showing that education- related house moves do indeed occur in the pre-school years with particular types of parents making these…

  6. Pre-Service Teachers Designing and Constructing "Good Digital Games"

    Science.gov (United States)

    Artym, Corbett; Carbonaro, Mike; Boechler, Patricia

    2016-01-01

    There is a growing interest in the application of digital games to enhance learning across many educational levels. This paper investigates pre-service teachers' ability to operationalize the learning principles that are considered part of a good digital game (Gee, 2007) by designing digital games in Scratch. Forty pre-service teachers, enrolled…

  7. Depression, Fatigue, and Pre-Sleep Arousal: A Mediation Model

    Science.gov (United States)

    Karlson, Cynthia W.; Stevens, Natalie R.; Olson, Christy A.; Hamilton, Nancy A.

    2010-01-01

    Fatigue is a common and debilitating symptom of clinical depression; however, the causes are not well understood. The present study was designed to test the hypotheses that subjective sleep, objective sleep, and arousal in the pre-sleep state would mediate the relationship between depression status and fatigue. Sleep, pre-sleep arousal, and…

  8. Pre-Service Teachers' Episodic Memories of Classroom Management

    Science.gov (United States)

    Balli, Sandra J.

    2011-01-01

    This study focused on past excellent teachers' classroom management strategies from the perspective of 148 pre-service teachers. The purpose of the study was to examine how pre-service teachers' memories reflect classroom management models that are typically taught in teacher education coursework prior to their study of those models, as well as to…

  9. Minimum fatigue pre-crack extension for fracture testing

    NARCIS (Netherlands)

    Walters, C.L.; Voormeeren, L.O.

    2013-01-01

    The minimum pre-crack necessary to achieve an accurate measurement of the J-integral is examined with the use of elastic-plastic finite element analysis. This minimum pre-crack is shorter than what is specified in fracture codes ASTM E1820 and BS 7448. A variety of steel properties are considered, b

  10. Pre-School Education in Morocco and Algeria

    Science.gov (United States)

    Bouzoubaa, Khadija; Benghabrit-Remaoun, Nouria

    2004-01-01

    This article is an analysis of the current state of early childhood care in the Maghreb, in particular in Morocco and Algeria, where the pre-schooling rate for 5-year-olds is on the increase. Extending pre-school infrastructures and the need to create unified curricula have been among the most urgent questions to be tackled over the last decade in…

  11. Pre-Service Teachers' Efficacy Beliefs and Emotional States

    Science.gov (United States)

    DeMauro, Anthony A.; Jennings, Patricia A.

    2016-01-01

    Teachers' efficacy beliefs play an important role in how they create quality learning environments. When pre-service teachers (also known as initial teacher trainees) develop strong efficacy beliefs, they can be confident in their abilities to be successful teachers once they enter the field. One way pre-service teachers obtain efficacy…

  12. Variable volume combustor with pre-nozzle fuel injection system

    Energy Technology Data Exchange (ETDEWEB)

    Keener, Christopher Paul; Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Ostebee, Heath Michael

    2016-09-06

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of fuel nozzles, a pre-nozzle fuel injection system supporting the fuel nozzles, and a linear actuator to maneuver the fuel nozzles and the pre-nozzle fuel injection system.

  13. Pre-Service Teachers' Concept Images on Fractal Dimension

    Science.gov (United States)

    Karakus, Fatih

    2016-01-01

    The analysis of pre-service teachers' concept images can provide information about their mental schema of fractal dimension. There is limited research on students' understanding of fractal and fractal dimension. Therefore, this study aimed to investigate the pre-service teachers' understandings of fractal dimension based on concept image. The…

  14. Pre-Service Teachers and Climate Change: A Stalemate?

    Science.gov (United States)

    Boon, Helen J.

    2016-01-01

    Findings from the second phase of a study of pre-service teachers' attitudes to environmental education and knowledge of climate change are reported in this paper. A sample of 87 pre-service teachers participated in a survey study in the last year of their Bachelor of Education degree to examine developments to their attitudes to environmental…

  15. Association between Asymptomatic Bacteriuria and Pre-Eclampsia.

    Science.gov (United States)

    Rezavand, Negin; Veisi, Firooze; Zangane, Mrayam; Amini, Roghaye; Almasi, Afshin

    2015-12-18

    Asymptomatic bacteriuria is one of the most common and important bacterial infections during pregnancy and can result in progressive infections and endanger maternal as well as fetal health. In this study, we assessed the relationship between asymptomatic bacteriuria and pre-eclampsia. In this case-control study, pregnant women who presented to Imam Reza Hospital in Kermanshah in 2013-14 were studied. The minimum sample size was calculated as 125 pregnant women in each group with a total of 250 subjects. There were 125 women with pre-eclampsia and 125 women without pre-eclampsia (control group). Matching was done for age, gestational age, and parity between case and control groups. Matching was verified by a P value of 0.061 for maternal age and gestational age and 0.77 for parity. The statistical analyses were done by applying the chi-squared test and determining odds ratio (OR) for having bacteriuria in univariate logistic regression as well as multivariate regression with adjusting the effect of maternal age, gestational age, and parity. Pyuria and bacteriuria were significantly more common in pre-eclampsia group than in control group. The results showed that a significant association existed between asymptomatic bacteriuria and pre-eclampsia. The rate of asymptomatic bacteriuria was 6.8 times higher in women with pre-eclampsia compared to those without pre-eclampsia. Further studies are required for better clarification of association between asymptomatic bacteriuria and pre-eclampsia.

  16. Turkish Pre-Service Physics Teachers' Preferred Learning Styles

    Science.gov (United States)

    Kandil Ingec, Sebnem

    2015-01-01

    This study aims to determine the dominant learning styles of pre-service physics teachers and to examine them in terms of variables such as gender, information and communication technologies skills, academic achievement and type of motivation. Survey model was used. The sample composed of 50 pre-service physics teachers. The data were collected…

  17. PRE-IMAGE ENTROPY OF NONAUTONOMOUS DYNAMICAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Xianjiu HUANG; Xi WEN; Fanping ZENG

    2008-01-01

    The authors define and study topological pre-image entropy for the non-autonomous discrete dynamical systems given by a sequence {fi}∞/i=1 of continuous self-maps of a compact topological space.The basic properties and the invariant with respect to equiconjugacy of pre-image entropy for the non-autonomous discrete dynamical systems are obtained.

  18. Pre-Employment Course: A Partnership for Success?

    Science.gov (United States)

    Pepper, Ian K.; McGrath, Ruth

    2010-01-01

    Purpose: The purpose of this paper is to examine the benefits of pre-employment education and training and its impact on the students' choice of career paths. It focuses on a programme delivered in partnership between Teesside University and a North East Police Force, and provides a model for future pre-employment education and training.…

  19. 22 CFR 229.545 - Pre-employment inquiries.

    Science.gov (United States)

    2010-04-01

    ... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 229.545 Pre-employment inquiries. (a... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Pre-employment inquiries. 229.545 Section...

  20. 28 CFR 54.545 - Pre-employment inquiries.

    Science.gov (United States)

    2010-07-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 54.545 Pre-employment... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Pre-employment inquiries. 54.545...

  1. 40 CFR 5.545 - Pre-employment inquiries.

    Science.gov (United States)

    2010-07-01

    ... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 5.545 Pre... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Pre-employment inquiries. 5.545...

  2. 22 CFR 146.545 - Pre-employment inquiries.

    Science.gov (United States)

    2010-04-01

    ... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Employment in Education Programs or Activities Prohibited § 146.545 Pre-employment inquiries. (a... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Pre-employment inquiries. 146.545 Section...

  3. Pre-Service Teachers' Mental Models of Basic Astronomy Concepts

    Science.gov (United States)

    Arslan, A. Saglam; Durikan, U.

    2016-01-01

    The aim of the present study is to determine pre-service teachers' mental models related to basic astronomy concepts. The study was conducted using a survey method with 293 pre-service teachers from 4 different departments; physics education, science education, primary teacher education and early childhood education. An achievement test with…

  4. Preparing Pre-Service English Teachers for Reflective Practice

    Science.gov (United States)

    Lee, Icy

    2007-01-01

    This article explores how dialogue journals and response journals can be used to encourage reflection among pre-service teachers. Thirty-one pre-service English teachers from two Hong Kong universities participated in the study. One group wrote dialogue journals and the other group wrote response journals throughout two semesters on two separate…

  5. Promoting Experiential Learning in Pre-Service Teacher Education

    Science.gov (United States)

    Gao, Xuesong

    2015-01-01

    This report introduces the experiential learning initiative at a major university in Hong Kong that prepares pre-service teachers with experience of engaging with social and cultural issues in teaching. It calls on teacher educators in different contexts to work together on similar initiatives that help pre-service teachers grow professionally…

  6. Periodontal disease and pre-eclampsia : a systematic review

    NARCIS (Netherlands)

    Kunnen, Alina; van Doormaal, Jasper J.; Abbas, Frank; Aarnoudse, Jan G.; van Pampus, Maria; Faas, Marijke M.

    2010-01-01

    P>Aim This review evaluates the possible relationship between periodontal disease and pre-eclampsia, a major pregnancy complication. A generalized inflammatory response plays an important role in the pathogenesis of pre-eclampsia. Because periodontal disease is a low-grade inflammatory state, period

  7. Pre-Service Teachers' Episodic Memories of Classroom Management

    Science.gov (United States)

    Balli, Sandra J.

    2011-01-01

    This study focused on past excellent teachers' classroom management strategies from the perspective of 148 pre-service teachers. The purpose of the study was to examine how pre-service teachers' memories reflect classroom management models that are typically taught in teacher education coursework prior to their study of those models, as well as to…

  8. 8 CFR 287.11 - Pre-enrolled Access Lane.

    Science.gov (United States)

    2010-01-01

    ... 287.11 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS FIELD OFFICERS... checkpoint. (b) General requirements for Pre-enrolled Access Lane Program. (1) Participation in the Pre... States citizens and members of the classes of aliens which the Commissioner of the Service or...

  9. 40 CFR 304.31 - Pre-hearing conference.

    Science.gov (United States)

    2010-07-01

    ... CLAIMS Hearings Before the Arbitrator § 304.31 Pre-hearing conference. (a) The Arbitrator and the parties... 110 days after the appointment of the Arbitrator (see § 304.22 of this part) or within 10 days prior to the pre-hearing conference, whichever is earlier. (b) The Arbitrator shall select the...

  10. 41 CFR 105-56.004 - Pre-offset notice.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Pre-offset notice. 105... Administration 56-SALARY OFFSET FOR INDEBTEDNESS OF FEDERAL EMPLOYEES TO THE UNITED STATES Salary Offset of General Services Administration Employees § 105-56.004 Pre-offset notice. An employee must be...

  11. 17 CFR 204.33 - Pre-offset notice.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Pre-offset notice. 204.33... DEBT COLLECTION Salary Offset § 204.33 Pre-offset notice. A program official must provide an employee... of offset. The agreement must be in writing, signed by both the employee and the Commission,...

  12. 40 CFR 761.369 - Pre-cleaning the surface.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Pre-cleaning the surface. 761.369... PROHIBITIONS Double Wash/Rinse Method for Decontaminating Non-Porous Surfaces § 761.369 Pre-cleaning the surface. If visible PCB-containing liquid is present on the surface to be cleaned, thoroughly wipe or...

  13. Australian Primary Pre-Service Teachers' Conceptions of Geography

    Science.gov (United States)

    Preston, Lou

    2014-01-01

    This article reports on the results of a survey of Australian primary pre-service teachers' experiences, conceptions and perceptions of geography. Research was conducted with two cohorts of undergraduate primary pre-service teachers; one group in second year and another in the final year of a four-year teacher education course. The findings show…

  14. 14 CFR 16.21 - Pre-complaint resolution.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pre-complaint resolution. 16.21 Section 16... to Complaints § 16.21 Pre-complaint resolution. (a) Prior to filing a complaint under this part, a... responsible for the noncompliance. These efforts at informal resolution may include, without limitation,...

  15. 31 CFR 547.702 - Pre-Penalty Notice; settlement.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Pre-Penalty Notice; settlement. 547.702 Section 547.702 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... REGULATIONS Penalties § 547.702 Pre-Penalty Notice; settlement. (a) When required. If the Office of Foreign...

  16. Investigation of Pre-Service Teachers' Communication Skills

    Science.gov (United States)

    Kana, Fatih

    2015-01-01

    The purpose of this study is to determine the levels of Turkish language pre-service teachers' communication skills. Descriptive survey model was used in this study. 218 pre-service Turkish language teachers, who are studying at Department of Turkish Language Teaching at a university in the west of Turkey, participated in the study. Criterion…

  17. 36 CFR 1210.11 - Pre-award policies.

    Science.gov (United States)

    2010-07-01

    ..., “substantial involvement is expected between the executive agency and the State, local government, or other... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Pre-Award Requirements § 1210.11 Pre-award policies... Government. (b) Public notice and priority setting. The NHPRC shall notify the public of its intended funding...

  18. 41 CFR 105-72.201 - Pre-award policies.

    Science.gov (United States)

    2010-07-01

    ... latter, “substantial involvement is expected between the executive agency and the State, local government... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS 72.2-Pre-Award Requirements § 105-72.201 Pre-award... the Federal Government. (b) Public notice and priority setting. Federal awarding agencies shall notify...

  19. 22 CFR 145.11 - Pre-award policies.

    Science.gov (United States)

    2010-04-01

    ..., “substantial involvement is expected between the executive agency and the State, local government, or other... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Pre-Award Requirements § 145.11 Pre-award policies... Government. The Department may not award grants or cooperative agreements unless specific statutory authority...

  20. 24 CFR 84.11 - Pre-award policies.

    Science.gov (United States)

    2010-04-01

    ..., “substantial involvement is expected between the executive agency and the State, local government, or other... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Pre-Award Requirements § 84.11 Pre-award policies... Government. (b) Public Notice and Priority Setting. HUD shall notify the public of its intended funding...

  1. 14 CFR 1260.111 - Pre-award policies.

    Science.gov (United States)

    2010-01-01

    ..., “substantial involvement is expected between the executive agency and the State, local government, or other... Higher Education, Hospitals, and Other Non-Profit Organizations Pre-Award Requirements § 1260.111 Pre... Government. (b) Public notice and priority setting. NASA notifies the public of its intended funding...

  2. LIF supports primitive endoderm expansion during pre-implantation development

    DEFF Research Database (Denmark)

    Morgani, Sophie M; Brickman, Joshua M

    2015-01-01

    report that LIF has two distinct roles: it blocks early epiblast (Epi) differentiation, and it supports the expansion of primitive endoderm (PrE)-primed ESCs and PrE in vivo. We find that activation of JAK/STAT signalling downstream of LIF occurs initially throughout the pre-implantation embryo......, but later marks the PrE. Moreover, the addition of LIF to cultured embryos increases the GATA6(+) PrE population, whereas inhibition of JAK/STAT signalling reduces both NANOG(+) epiblast and GATA6(+) PrE. The reduction of the NANOG(+) Epi might be explained by its precocious differentiation to later Epi...... derivatives, whereas the increase in PrE is mediated both by an increase in proliferation and inhibition of PrE apoptosis that is normally triggered in embryos with an excess of GATA6(+) cells. Thus, it appears that the relative size of the PrE is determined by the number of LIF-producing cells in the embryo...

  3. AHA Moments of Science and Mathematics Pre-Service Teachers

    Science.gov (United States)

    Caniglia, Joanne C.; Borgerding, Lisa; Courtney, Scott

    2017-01-01

    This research study explored pre-service teachers' (PST) reflections of their student teaching experiences through AHA moments. Participants included 37 pre-service teachers enrolled in mathematics and science student teaching seminars. Qualitative methods were used to analyze PSTs' written and verbal responses to questions regarding AHA…

  4. Making IBSE durable through pre-service teacher education

    NARCIS (Netherlands)

    Berg, van den Ed; Damsma, Welmoet; Herik, van den Maaike; Mulken, van Frans; Ruis, Paul; Blagotinsek, Ana; Cronin, Sue; Holub, Sigrid; Holub, Peter; Sokolowska, Dagmara; Sporea, Dan; Sporea, Adelina

    2013-01-01

    How can we make Inquiry-Based Science and Mathematics Education (IBSME) durable? …. by incorporating it in the pre-service programs for elementary teachers! With pre-service students the training can be much more intensive than with inservice teachers. To have an impact in the classroom the minimum

  5. 40 CFR 791.27 - Pre-hearing preparation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Pre-hearing preparation. 791.27 Section 791.27 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) DATA REIMBURSEMENT Hearing Procedures § 791.27 Pre-hearing preparation. (a) Responses...

  6. Pre-Service Physics Teachers' Conceptions of Nature of Science

    Science.gov (United States)

    Buaraphan, Khajornsak

    2011-01-01

    Understanding of NOS (nature of science) appears as a prerequisite of a scientifically literate person. Promoting adequate understanding of NOS in pre-service physics teachers is, therefore, an important task of science educators. Before doing that, science educators must have information concerning their pre-service teachers' conceptions of NOS.…

  7. Measuring the Economic Value of Pre-MBA Work Experience

    Science.gov (United States)

    Yeaple, Ronald N.; Johnston, Mark W.; Whittingham, Keith L.

    2010-01-01

    Pre-MBA work experience is required for admission to many graduate schools of business. In the present study, MBA graduates with a wide range of pre-MBA work experience were surveyed to assess the economic value of such work experience. No evidence was found of a systematic financial advantage to students from working for several years before…

  8. Technology Acceptance among Pre-Service Teachers: Does Gender Matter?

    Science.gov (United States)

    Teo, Timothy; Fan, Xitao; Du, Jianxia

    2015-01-01

    This study examined possible gender differences in pre-service teachers' perceived acceptance of technology in their professional work under the framework of the technology acceptance model (TAM). Based on a sample of pre-service teachers, a series of progressively more stringent measurement invariance tests (configural, metric, and scalar…

  9. Turkish Pre-Service Physics Teachers' Preferred Learning Styles

    Science.gov (United States)

    Kandil Ingec, Sebnem

    2015-01-01

    This study aims to determine the dominant learning styles of pre-service physics teachers and to examine them in terms of variables such as gender, information and communication technologies skills, academic achievement and type of motivation. Survey model was used. The sample composed of 50 pre-service physics teachers. The data were collected…

  10. Organ donation and pre-emptive kidney transplantation: ethical issues.

    Science.gov (United States)

    Petrini, C

    2013-01-01

    There is considerable evidence that pre-emptive transplants have several clinical advantages. However, pre-emptive transplants raise a number of ethical issues. Pre-emptive transplants from living donors offer distinctly greater benefits than those from deceased donors and some pre-emptive transplantation programmes actively encourage living organ donations. Moreover, the offer of a pre-emptive transplant to a patient who is not yet on dialysis unquestionably penalises patients already on dialysis who may have been on the waiting list for a long time. Therefore preemptive transplants give rise to conflicts between justice and utility. Several factors should be considered: health conditions, clinical urgency, probability of imminent worsening of a patient's clinical condition, the future chances of finding a matching organ, and others. From the various values at stake, ethical issues are analysed in search of an acceptable synthesis.

  11. Combined Screening for Early Detection of Pre-Eclampsia

    Directory of Open Access Journals (Sweden)

    Hee Jin Park

    2015-08-01

    Full Text Available Although the precise pathophysiology of pre-eclampsia remains unknown, this condition continues to be a major cause of maternal and fetal mortality. Early prediction of pre-eclampsia would allow for timely initiation of preventive therapy. A combination of biophysical and biochemical markers are superior to other tests for early prediction of the development of pre-eclampsia. Apart from the use of parameters in first-trimester aneuploidy screening, cell-free fetal DNA quantification is emerging as a promising marker for prediction of pre-eclampsia. This article reviews the current research of the most important strategies for prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters, and biomarkers.

  12. Web Pre-fetching Model Based on Concept Association Network

    Institute of Scientific and Technical Information of China (English)

    XUHuanqing; WANGYongcheng

    2004-01-01

    With the enormous growth of information on the web, Internet has become one of the most important information sources. However, limited by the network bandwidth, users always suffer from long time waiting. Web pre-fetching is one of the most popular strategies,which are proposed for reducing the perceived access delay and improving the service quality of web server. This paper presents a pre-fetching model based on concept as sociation network, which mines concept association relationships that are implied in user access patterns and employs online learning and oitiine mining algorithm to construct the user-oriented concept association network. Using concept association network, pre-fetching model makes semantics-based pre-fetching decisions in the client side.This model implements the concept-based analysis on user access patterns and improves the prediction accuracy. Experimental results show that the proposed pre-fetching model has better general performance.

  13. Gene expression profiling of placentas affected by pre-eclampsia

    DEFF Research Database (Denmark)

    Hoegh, Anne Mette; Borup, Rehannah; Nielsen, Finn Cilius;

    2010-01-01

    Several studies point to the placenta as the primary cause of pre-eclampsia. Our objective was to identify placental genes that may contribute to the development of pre-eclampsia. RNA was purified from tissue biopsies from eleven pre-eclamptic placentas and eighteen normal controls. Messenger RNA...... expression from pooled samples was analysed by microarrays. Verification of the expression of selected genes was performed using real-time PCR. A surprisingly low number of genes (21 out of 15,000) were identified as differentially expressed. Among these were genes not previously associated with pre-eclampsia...... as bradykinin B1 receptor and a 14-3-3 protein, but also genes that have already been connected with pre-eclampsia, for example, inhibin beta A subunit and leptin. A low number of genes were repeatedly identified as differentially expressed, because they may represent the endpoint of a cascade of events...

  14. Gene expression profiling of placentas affected by pre-eclampsia

    DEFF Research Database (Denmark)

    Hoegh, Anne Mette; Borup, Rehannah; Nielsen, Finn Cilius

    2010-01-01

    Several studies point to the placenta as the primary cause of pre-eclampsia. Our objective was to identify placental genes that may contribute to the development of pre-eclampsia. RNA was purified from tissue biopsies from eleven pre-eclamptic placentas and eighteen normal controls. Messenger RNA...... expression from pooled samples was analysed by microarrays. Verification of the expression of selected genes was performed using real-time PCR. A surprisingly low number of genes (21 out of 15,000) were identified as differentially expressed. Among these were genes not previously associated with pre-eclampsia...... as bradykinin B1 receptor and a 14-3-3 protein, but also genes that have already been connected with pre-eclampsia, for example, inhibin beta A subunit and leptin. A low number of genes were repeatedly identified as differentially expressed, because they may represent the endpoint of a cascade of events...

  15. Combined Screening for Early Detection of Pre-Eclampsia.

    Science.gov (United States)

    Park, Hee Jin; Shim, Sung Shin; Cha, Dong Hyun

    2015-08-04

    Although the precise pathophysiology of pre-eclampsia remains unknown, this condition continues to be a major cause of maternal and fetal mortality. Early prediction of pre-eclampsia would allow for timely initiation of preventive therapy. A combination of biophysical and biochemical markers are superior to other tests for early prediction of the development of pre-eclampsia. Apart from the use of parameters in first-trimester aneuploidy screening, cell-free fetal DNA quantification is emerging as a promising marker for prediction of pre-eclampsia. This article reviews the current research of the most important strategies for prediction of pre-eclampsia, including the use of maternal risk factors, mean maternal arterial pressure, ultrasound parameters, and biomarkers.

  16. Pre-Forming Effects on AHSS Edge Cracking

    Science.gov (United States)

    Chen, Xiaoming; Chen, Ke; Smith, Lorenzo

    2011-08-01

    Edge cracking in advanced high strength steels (AHSS) is a significant failure mode in many sheet metal stamping processes. Edge pre-forming into a wave (or scallop) shape is a common technique used in conventional steels to gather material in high edge stretch regions in preparation for the subsequent edge stretch process. The pre-forms designed for mild steels do not always apply to AHSS because the properties of AHSS can differ greatly from those of conventional steels. This work has studied the effects of pre-forming on AHSS edge cracking. Experiments have been conducted to stretch pre-formed steel strips to failure. Strain distributions of pre-forms with various levels of stretch have been measured using digital image correlation (DIC) technology. Finite element analyses have been performed and compared with the experimental results. Different failure criteria have also been evaluated for use in this type of application.

  17. Serum 8-isoprostane increased in pre-eclampsia

    Directory of Open Access Journals (Sweden)

    Besari Adi Pramono

    2012-04-01

    Full Text Available Background The main causes of maternal mortality in Indonesia are pre-eclampsia, hemorrhage, and infection. Oxidative stress has a primary role in pre-eclampsia and one of its parameters is 8-isoprostane serum level. The objective of this study is to measure 8-isoprostane and to analyze the relationship between 8-isoprostane level and birth weight in pre-eclampsia. Methods A cross-sectional study involving 23 pre-eclampsia and 29 normotensive pregnant women with normal or cesarean delivery at Dr. Kariadi Hospital Semarang from January to May 2011. Collected maternal blood samples were assessed for 8-Isoprostane levels by means of a specific ELISA kit. Neonatal birth weight was measured immediately after delivery by means of calibrated baby scales. Differences in 8-isoprostane levels between pre-eclampsia and normotensive women were assessed using independent t-test for normal distributed data, and the Mann-Whitney test for non-normally distributed data. Results Mean 8-isoprostane level was significantly higher in women with pre-eclampsia than in normotensive women (62.52 ± 12.19 pg/mL vs 28.64 ± 8.81 pg/mL (p<0.05. Low birth weight was twice as frequent in pre-eclampsia than in normotensives. There was no correlation between 8-isoprostane serum level and neonatal birth weight in pre-eclampsia. Conclusion The level of 8-isoprostane was higher in pre-eclampsia than in normotensives. It is recommended to conduct further studies to determine whether 8-isoprostane may be used as a predictive marker of pre-eclampsia.

  18. Comparing blastocyst quality and live birth rates of intravaginal culture using INVOcell™ to traditional in vitro incubation in a randomized open-label prospective controlled trial.

    Science.gov (United States)

    Doody, Kevin J; Broome, E Jason; Doody, Kathleen M

    2016-04-01

    The purpose of this study is to to compare the efficacy of intravaginal culture (IVC) of embryos in INVOcell™ (INVO Bioscience, MA, USA) to traditional in vitro fertilization (IVF) incubators in a laboratory setting using a mild pre-determined stimulation regimen based solely on anti-mullerian hormone (AMH) and body weight with minimal ultrasound monitoring. The primary endpoint examined was total quality blastocysts expressed as a percentage of total oocytes placed in incubation. Secondary endpoints included percentage of quality blastocysts transferred, pregnancy, and live birth rates. In this prospective randomized open-label controlled single-center study, 40 women aged culture. IVF produced a greater percentage of total quality embryos as compared to IVC (50.6 vs. 30.7 %, p = 0.0007, respectively). There was no significant difference between in IVF and IVC in the percentage of quality blastocysts transferred (97.5 vs. 84.9 %, p = 0.09) or live birth rate (60 % IVF, 55 % IVC). IVF was shown to be superior to IVC in creating quality blastocysts. However, both IVF and IVC produced identical blastocysts for transfer resulting in similar live birth rates. IVC using INVOcell™ is effective and may broaden access to fertility care in selected patient populations by ameliorating the need for a traditional IVF laboratory setting. Further studies will help elucidate the potential physiological, psychological, geographic, and financial impact of IVC on the delivery of fertility care.

  19. Pre-Dawn Temperatures on Ganymede

    Science.gov (United States)

    1997-01-01

    This infrared image of Jupiter's moon Ganymede, showing heat radiation from its surface at a wavelength of 27 microns (millionths of a meter), provides the best view yet of pre-dawn temperatures on Ganymede. Temperatures, derived from the brightness of the infrared radiation, can be determined from the colors by reference to the scale at the bottom of the image.The image, taken by NASA's Galileo spacecraft, shows half of Ganymede's disk as seen by the approaching spacecraft. Longitudes covered range from 340 on the right of the image, through longitude zero (the direction facing Jupiter) to longitude 60 near Ganymede's limb on the left. The morning terminator, near longitude 15, curves through the middle of the image, separating areas experiencing the last hours of the long (3.5 Earth day) Ganymede night, on the left, from areas that are warming up in the morning sunshine, on the right. Ganymede's north pole is in the upper right corner of the image, and the south pole is in the lower right. Ganymede rotates from left to right.Nighttime temperatures, shown in blue and purple colors, are in the range 85 - 100 Kelvin (-306 to -279 F). The surface cools steadily during the night, so the warmest nighttime temperatures are on the left side of the disk, and temperatures drop towards the dawn terminator on the right, before warming rapidly once the sun rises (the red, yellow and white areas on the far right). Study of the rate of nighttime cooling and the rate of post-sunrise warming, will provide information about Ganymede's surface properties.The image was taken with Galileo's PPR (Photopolarimeter-Radiometer) instrument on the spacecraft's seventh orbit around Jupiter, from a range of about 190,000 kilometers (118,060 miles). Surface temperatures derived from the strength of infrared radiation, as was done here, are called 'brightness temperatures', and may be slightly in error.The PPR instrument builds up an image by slowly scanning across the target over a period of

  20. Day care for pre-school children.

    Science.gov (United States)

    Zoritch, B; Roberts, I; Oakley, A

    2000-01-01

    The debate about how, where and by whom young children should be looked after is one which has occupied much social policy and media attention in recent years. Mothers undertake most of the care of young children. Internationally, out-of-home day-care provision ranges widely. These different levels of provision are not simply a response to different levels of demand for day-care, but reflect cultural and economic interests concerning the welfare of children, the need to promote mothers' participation in paid work, and the importance of socialising children into society's values. At a time when a decline in family values is held responsible for a range of social problems, the day-care debate has a special prominence. To quantify the effects of out-of-home day-care for preschool children on educational, health and welfare outcomes for children and their families. Randomised controlled trials of day-care for pre-school children were identified using electronic databases, hand searches of relevant literature, and contact with authors. Studies were included in the review if the intervention involved the provision of non-parental day care for children under 5 years of age, and the evaluation design was that of a randomised or quasi-randomised controlled trial. A total of eight trials were identified after examining 920 abstracts and 19 books. The trials were assessed for methodological quality. Day-care increases children's IQ, and has beneficial effects on behavioural development and school achievement. Long-term follow up demonstrates increased employment, lower teenage pregnancy rates, higher socio-economic status and decreased criminal behaviour. There are positive effects on mothers' education, employment and interaction with children. Effects on fathers have not been examined. Few studies look at a range of outcomes spanning the health, education and welfare domains. Most of the trials combined non-parental day-care with some element of parent training or education

  1. Pre-exposure prophylaxis of HIV

    Directory of Open Access Journals (Sweden)

    Smriti Naswa

    2011-01-01

    Full Text Available Pre-exposure prophylaxis (PrEP is an experimental approach to HIV prevention and consists of antiretroviral drugs to be taken before potential HIV exposure in order to reduce the risk of HIV infection and continued during periods of risk. An effective PrEP could provide an additional safety net to sexually active persons at risk, when combined with other prevention strategies. Women represent nearly 60% of adults infected with HIV and PrEP can be a female-controlled prevention method for women who are unable to negotiate condom use. Two antiretroviral nucleoside analog HIV-1 reverse transcriptase inhibitor drugs are currently under trial as PrEP drugs, namely tenofovirdisoproxilfumarate (TDF alone and TDF in combination with emricitabine (FTC, to be taken as daily single dose oral drugs. There are 11 ongoing trials of ARV-based prevention in different at risk populations across the world. The iPrex trial showed that daily use of oral TDF/FTC by MSM resulted in 44% reduction in the incidence of HIV. This led to publication of interim guidance by CDC to use of PrEP by health providers for MSM. Few other trials are Bangkok Tenofovir Study, Partners PrEP Study, FEM-PrEP study, and VOICE (MTN-003 study. Future trials are being formulated for intermittent PrEP (iPrEP where drugs are taken before and after sex, "stand-in dose" iPrEP, vaginal or rectal PrEP, etc. There are various issues/concerns with PrEP such as ADRs and resistance to TDF/FTC, adherence to drugs, acceptability, sexual disinhibition, use of PrEP as first line of defense for HIV without other prevention strategies, and cost. The PrEP has a potential to address unmet need in public health if delivered as a part of comprehensive toolkit of prevention services, including risk-reduction, correct and consistent use of condoms, and diagnosis and treatment of sexually transmitted infections.

  2. Pre-admission criteria and pre-clinical achievement: Can they predict medical students performance in the clinical phase?

    Science.gov (United States)

    Salem, Raneem O; Al-Mously, Najwa; AlFadil, Sara; Baalash, Amal

    2016-01-01

    Various factors affect medical students' performance during clinical phase. Identifying these factors would help in mentoring weak students and help in selection process for residency programmes. Our study objective is to evaluate the impact of pre-admission criteria, and pre-clinical grade point average (GPA) on undergraduate medical students' performance during clinical phase. This study has a cross-sectional design that includes fifth- and sixth-year female medical students (71). Data of clinical and pre-clinical GPA in medical school and pre-admission to medical school tests scores were collected. A significant correlation between clinical GPA with the pre-clinical GPA was observed (p performed, and the only significant predictor of students clinical performance was the pre-clinical GPA (p GPA for both cohorts was observed (p > 0.05). Pre-clinical GPA is strongly correlated with and can predict medical students' performance during clinical years. Our study highlighted the importance of evaluating the academic performances of students in pre-clinical years before they move into clinical years in order to identify weak students to mentor them and monitor their progress.

  3. Who are the young adult Danish pre-drinkers, and why do they pre-drink before a night out?

    Science.gov (United States)

    Østergaard, Jeanette; Andrade, Stefan Bastholm

    2014-06-01

    To reveal young Danes' main motive for pre-drinking and whether their motives and socio economic status can explain how much they pre-drink on an event-specific night out. A binary logistic and negative binomial regression models were used on a survey of 670 Danes (aged 18-35 years) conducted on-site in 24 bars, clubs and pubs in four cities and towns in Denmark. Young males drink on average 12.3 and females 9.3 standard units (defined as 8 g of pure ethanol) of alcohol before a night out. Pre-drinking to be social is the most prevalent motive. Although lower income levels cannot explain whether a young person will pre-drink on an event-specific night out, young people's income level and their motives explain the quantities they consume. Lower-earning males who pre-drank to save money consumed larger quantities of alcohol at home, but lower-earning females pre-drank larger quantities because they wanted to be out of control. Not only young people's motives for pre-drinking but also the price of off- and on-premises alcohol should be considered for outlining prevention strategies seeking to reduce the alcohol quantities that young people pre-drink before a night out. © 2014 the Nordic Societies of Public Health.

  4. Prevalence of pre-diabetes, diabetes, pre-hypertension, and hypertension in children weighing more than normal

    Directory of Open Access Journals (Sweden)

    Priti Phatale

    2012-01-01

    Full Text Available Aim: Prevalence of pre-diabetes, diabetes, pre-hypertension (pre-HT, and hypertension (HT in children weighing more than normal. Materials and Methods: Three- to eighteen-year old children weighing more than normal were included. Pathological short children were excluded. According to Centre for Disease Control (CDC, children are grouped into overweight (OW and obese (OB. Indian B.P. reference tables are used for defining HT and pre-HT. [2] HbA1c by HPLC (BIO RAD method was used to define pre-diabetes and diabetes. [3] Children with HbA1c ≥6.5 were subjected for Glucose Tolerance Test (GTT. C-peptide assay was done to rule out (r/o IDDM. Observations: When we compare this with our earlier presentation at PEDICON 2011, we found that hypertension (HTN (22.9% vs. 23.07% is not significantly different but pre-HTN (28.09% vs. 33.9%, pre-diabetes mellitus (pre-DM (3.7% vs. 64.3%, and diabetes mellitus (DM (0.35% vs. 3.8% are significantly high in this study. Conclusion: (1 Prevalence of HT (22.90% vs. 23.07% is similar in both groups but pre-HT (33.9% vs. 28.09% is high in this study. (2 Significant rise in prevalence of diabetes (3.84% vs. 0.35% and pre-diabetes (64.33% vs. 3.7% is seen in this study. (3 This change is because of using HbA1c as screening tool in children weighing more than normal.

  5. Pre-analytical workstations: a tool for reducing laboratory errors.

    Science.gov (United States)

    Da Rin, Giorgio

    2009-06-01

    Laboratory testing, a highly complex process commonly called the total testing process (TTP), is usually subdivided into three traditional (pre-, intra-, and post-) analytical phases. The majority of errors in TTP originate in the pre-analytical phase, being due to individual or system design defects. In order to reduce errors in TTP, the pre-analytical phase should therefore be prioritized. In addition to developing procedures, providing training, improving interdepartmental cooperation, information technology and robotics may be a tool to reduce errors in specimen collection and pre-analytical sample handling. It has been estimated that >2000 clinical laboratories worldwide use total or subtotal automation supporting pre-analytic activities, with a high rate of increase compared to 2007; the need to reduce errors seems to be the catalyst for increasing the use of robotics. Automated systems to prevent medical personnel from drawing blood from the wrong patient were introduced commercially in the early 1990s. Correct patient identification and test tube labelling before phlebotomy are of extreme importance for patient safety in TTP, but currently few laboratories are interested in such products. At San Bassiano hospital, the implementation of advanced information technology and robotics in the pre-analytical phase (specimen collection and pre-analytical sample handling) have improved accuracy, and clinical efficiency of the laboratory process and created a TTP that minimizes errors.

  6. Potential role of folate in pre-eclampsia.

    Science.gov (United States)

    Singh, Mansi Dass; Thomas, Philip; Owens, Julie; Hague, William; Fenech, Michael

    2015-10-01

    Dietary deficiencies of folate and other B vitamin cofactors involved in one-carbon metabolism, together with genetic polymorphisms in key folate-methionine metabolic pathway enzymes, are associated with increases in circulating plasma homocysteine, reduction in DNA methylation patterns, and genome instability events. All of these biomarkers have also been associated with pre-eclampsia. The aim of this review was to explore the literature and identify potential knowledge gaps in relation to the role of folate at the genomic level in either the etiology or the prevention of pre-eclampsia. A systematic search strategy was designed to identify citations in electronic databases for the following terms: folic acid supplementation AND pre-eclampsia, folic acid supplementation AND genome stability, folate AND genome stability AND pre-eclampsia, folic acid supplementation AND DNA methylation, and folate AND DNA methylation AND pre-eclampsia. Forty-three articles were selected according to predefined selection criteria. The studies included in the present review were not homogeneous, which made pooled analysis of the data very difficult. The present review highlights associations between folate deficiency and certain biomarkers observed in various tissues of women at risk of pre-eclampsia. Further investigation is required to understand the role of folate in either the etiology or the prevention of pre-eclampsia.

  7. Early Grade Teacher Effectiveness and Pre-K Effect Persistence

    Directory of Open Access Journals (Sweden)

    Walker A. Swain

    2015-11-01

    Full Text Available In recent years, states have significantly expanded access to prekindergarten (pre-K, and federal policy makers have proposed funding near-universal access across the country. However, researchers know relatively little about the role of subsequent experiences in prolonging or truncating the persistence of benefits for participants. This study examines the interaction between pre-K participation and one of our most important educational interventions—teaching quality. We pair student-level data from a statewide pre-K experiment with records of teacher observation scores from Tennessee’s new formal evaluation program to assess whether a student’s access to high-quality early grade teachers moderates the persistence of pre-K effects. Our analyses indicate a small positive interaction between teaching quality and state pre-K exposure on some but not all early elementary cognitive measures, such that better teaching quality in years subsequent to pre-K is associated with more persistent positive pre-K effects.

  8. Monitoring Pre-Stressed Composites Using Optical Fibre Sensors

    Directory of Open Access Journals (Sweden)

    Sriram Krishnamurthy

    2016-05-01

    Full Text Available Residual stresses in fibre reinforced composites can give rise to a number of undesired effects such as loss of dimensional stability and premature fracture. Hence, there is significant merit in developing processing techniques to mitigate the development of residual stresses. However, tracking and quantifying the development of these fabrication-induced stresses in real-time using conventional non-destructive techniques is not straightforward. This article reports on the design and evaluation of a technique for manufacturing pre-stressed composite panels from unidirectional E-glass/epoxy prepregs. Here, the magnitude of the applied pre-stress was monitored using an integrated load-cell. The pre-stressing rig was based on a flat-bed design which enabled autoclave-based processing. A method was developed to end-tab the laminated prepregs prior to pre-stressing. The development of process-induced residual strain was monitored in-situ using embedded optical fibre sensors. Surface-mounted electrical resistance strain gauges were used to measure the strain when the composite was unloaded from the pre-stressing rig at room temperature. Four pre-stress levels were applied prior to processing the laminated preforms in an autoclave. The results showed that the application of a pre-stress of 108 MPa to a unidirectional [0]16 E-glass/913 epoxy preform, reduced the residual strain in the composite from −600 µε (conventional processing without pre-stress to approximately zero. A good correlation was observed between the data obtained from the surface-mounted electrical resistance strain gauge and the embedded optical fibre sensors. In addition to “neutralising” the residual stresses, superior axial orientation of the reinforcement can be obtained from pre-stressed composites. A subsequent publication will highlight the consequences of pres-stressing on fibre alignment, the tensile, flexural, compressive and fatigue performance of unidirectional E

  9. Serum inhibin and leptin: Risk factors for pre-eclampsia?

    Science.gov (United States)

    Chrelias, Georgios; Makris, Georgios-Marios; Papanota, Aristea-Maria; Spathis, Aris; Salamalekis, Georgios; Sergentanis, Theodoros N; Rizos, Demetrios; Karakitsos, Petros; Chrelias, Charalampos

    2016-12-01

    Pre-eclampsia and eclampsia are parts of the broader spectrum of hypertensive disorders complicating pregnancy. This study aims to examine the association between serum inhibin and leptin levels and pre-eclampsia. This study included 98 consecutive cases of pregnant women with pre-eclampsia, together with their 98 pregnant controls, matched for age, gestational week and time period of delivery. Maternal venous blood samples were obtained within 24h before delivery. In addition to serum inhibin and leptin, birth order, multiple pregnancy, maternal age, maternal overweight/obesity, maternal education, maternal smoking and family history of diabetes/hypertension, were examined as risk factors. Multivariate logistic regression analysis was performed. At the univariate analysis, serum inhibin and leptin levels were significantly higher in cases vs. Pre-eclampsia occurred more frequently in primiparous women, whereas overweight and obesity were also associated with pre-eclampsia. At the multivariate analysis, higher serum inhibin levels were associated with pre-eclampsia (multivariate OR=1.09, 95%CI: 1.03-1.17, p=0.004, increase per 0.1ng/mL). On the other hand, leptin was not independently associated with the occurrence of pre-eclampsia (multivariate OR=1.02, 95%CI: 0.95-1.09, p=0.631, increase per 10ng/mL). Elevated serum inhibin levels seem to be associated with pre-eclampsia, reflecting placental dysfunction. Increased serum leptin levels may merely reflect an elevated maternal body mass index, which is a well-known risk factor for pre-eclampsia. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Pre-calculus 1,001 practice problems for dummies

    CERN Document Server

    Sterling, Mary Jane; Sterling

    2014-01-01

    Prepare for calculus the smart way, with customizable pre-calculus practice 1,001 Pre-Calculus Practice Problems For Dummies offers 1,001 opportunities to gain confidence in your math skills. Much more than a workbook, this study aid provides pre-calculus problems ranked from easy to advanced, with detailed explanations and step-by-step solutions for each one. The companion website gives you free online access to all 1,001 practice problems and solutions, and you can track your progress and ID where you should focus your study time. Accessible on the go by smart phone, tablet, o

  11. LONGITUDINAL DISCH. CO2 LASER WITH PULSED PRE-IONIZATION

    Institute of Scientific and Technical Information of China (English)

    Yu Yanning; Wan Chongyi

    2002-01-01

    A novel pre-ionization scheme of helical transverse-pulsed pre-ionization in a longitudinal discharge CO2 laser is presented. The laser tube is made of glass with inner diameter of 7.5mm and discharge length of 50cm. The laser performance characteristics as functions of parameters, such as pressure, charging capacitance and applied voltage, are investigated. Compared with the same laser structure without pre-ionization, the maximum pulse energy improves by 23%, the optimum electro-optical efficiency increases by 31%, and the specific output energy reaches 26 J/(L·atm).

  12. Pre-operative investigations: yield and conformity to national guidelines.

    Science.gov (United States)

    Juliana, H; Lim, T A; Inbasegaran, K

    2003-03-01

    Routine ordering of pre-operative investigations yields a low true positive rate and is not cost effective. In this study, case notes of 251 adults who underwent elective surgery were reviewed. Pre-operative investigations were classified as 'indicated' or 'not indicated', based on the national guidelines. Only 56% of all tests done were indicated. The overall rates of expected and unexpected abnormal values from pre-operative blood investigations were 51.1% and 34.4% respectively. This study found that selective testing based on guidelines was beneficial. However, the results also suggest that the local guidelines need to be reviewed.

  13. Pre-expanded Deep Inferior Epigastric Perforator Flap.

    Science.gov (United States)

    Monsivais, Sharon E; Webster, Nicholas D; Wong, Stacy; Saint-Cyr, Michel H

    2017-01-01

    The deep inferior epigastric perforator (DIEP) flap can be used to cover large defects of the proximal lower extremity, abdominal wall, perineum, vulva, and buttock. Pre-expanding DIEP flaps cause a possible delay phenomenon improving vascularity, decrease donor site morbidity, and increase the area that can be covered. Pre-expansion requires staged procedures, has risk of extrusion and infection, causes temporary contour deformity during the expansion process, and requires a longer course. Pre-expanded DIEP flaps can be a useful flap with proper patient selection and planning. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Isotope heterogeneity of Pre-Holocene groundwater in Iceland

    DEFF Research Database (Denmark)

    Sveinbjörnsdóttir, Á.E.; Arnorsson, S.; Heinemeier, Jan

    2007-01-01

    In recent years, it has been shown that groundwater with a Pre-Holocene component is more common in the Icelandic bedrock than previously thought. Some of the Pre-Holocene water samples are more depleted in delta H-2 and delta O-18 than any mean annual precipitation in Iceland today due to the cold......-Holocene component in the groundwater. The deuterium excess value may also help to identify water from a different climate regime, if no oxygen shift has occurred. The relative abundance of a Pre-Holocene water component of the Icelandic groundwater has led to the understanding that combined interpretation of water...

  15. Hybrid pre training algorithm of Deep Neural Networks

    Directory of Open Access Journals (Sweden)

    Drokin I. S.

    2016-01-01

    Full Text Available This paper proposes a hybrid algorithm of pre training deep networks, using both marked and unmarked data. The algorithm combines and extends the ideas of Self-Taught learning and pre training of neural networks approaches on the one hand, as well as supervised learning and transfer learning on the other. Thus, the algorithm tries to integrate in itself the advantages of each approach. The article gives some examples of applying of the algorithm, as well as its comparison with the classical approach to pre training of neural networks. These examples show the effectiveness of the proposed algorithm.

  16. Pre-migration Trauma Exposure and Psychological Distress for Asian American Immigrants: Linking the Pre- and Post-migration Contexts.

    Science.gov (United States)

    Li, Miao; Anderson, James G

    2016-08-01

    Drawing on the life course perspective and the assumptive world theory, this paper examines whether pre-migration trauma exposure is associated with psychological distress through post-migration perceived discrimination for Asian American immigrants. The study is based on cross-sectional data from the National Latino and Asian American Study (N = 1639). Structural equation model is used to estimate the relationship between pre-migration trauma, post-migration perceived discrimination, and psychological distress. Additional models are estimated to explore possible variations across ethnic groups as well as across different types of pre-migration trauma experience. Pre-migration trauma exposure is associated with higher levels of psychological distress, both directly and indirectly through higher level of perceived discrimination, even after controlling for demographic/acculturative factors and post-migration trauma exposure. This pattern holds for the following sub-types of pre-migration trauma: political trauma, crime victimization, physical violence, accidental trauma, and relational trauma. Multi-group analyses show that this pattern holds for all Asian immigrant subgroups except the Vietnamese. Studies of immigrant mental health primarily focus on post-migration stressors. Few studies have considered the link between pre- and post-migration contexts in assessing mental health outcomes. The study illustrates the usefulness of bridging the pre- and post-migration context in identifying the mental health risks along the immigrant life course.

  17. Different pre-term formulas for different pre-term infants.

    Science.gov (United States)

    Fanaro, Silvia; Ballardini, Elisa; Vigi, Vittorio

    2010-07-01

    Optimal nutrition is one of the most important aspects in the care of pre-term infants, especially for the gestationally youngest ones. These infants should receive a supply of nutrients that can sustain growth similar to that of a third trimester normal foetus. Traditional pre-term formulas do not ensure an optimal protein supply except when fed at high volumes, with an excess of fat and carbohydrates. Formulas with a protein content of 2-2.5 g 100ml(-1) and a protein/energy (P:E) ratio of less than 3g 100 kcal(-1) are not the best choice for the very low birth weight (VLBW) infants. We have tested a new formulation designed for the nutrition of the VLBW infants that is characterised by a protein content of 2.9 g 100ml(-1) and a P:E ratio of 3.5 g 100 kcal(-1). The milk formula was well tolerated and associated with better weight gain compared with fortified breast milk (18.1 vs. 15.2 g kg(-1)day(-1); p=0.0015). These results were obtained with a noticeably lower fluid supply (157 vs. 177 ml kg day(-1); pday(-1); p<0.0001). Infant length and head circumference did not differ significantly between groups. Currently, the use of a formula with a P:E ratio of 3.5 g 100 kcal(-1) appears to be safe and to represent the best choice available for the gestationally youngest infants.

  18. Boston University Pre-Majors Program (BU Pre-Map): Promoting Diversity through First-Year Undergraduate Research

    Science.gov (United States)

    West, Andrew A.

    2015-01-01

    One of largest points of attrition for underrepresented minorities in STEM fields is the transition from high school to college. A report from Building Engineering and Science Talent (BEST) demonstrates that underrepresented minorities begin college interested in STEM fields at rates equal to (if nor slightly above) their representation in both college and the population (25%). However, by the time they graduate, underrepresented minorities make up only 15% of STEM majors and only 9% of the STEM advanced degrees. Most of the attrition occurs during the first year of college, when large classes, a lack of mentors and challenging courses lead many students (from all backgrounds) to consider other majors.In 2012 I started the Boston University Pre-Majors Program (or BU Pre-MaP), which is modeled after the University of Washington Pre-Majors in Astronomy Program (UW Pre-MAP), a program for recruiting, mentoring and training underrepresented, first-year introductory astronomy students (and of which I was an architect). As a significant part of the Pre-MAP (or Pre-MaP) model, first-year students are engaged in a research project with a faculty or grad-student mentor and learn many of the skills needed to be successful in science.The BU Pre-MaP uses weekly seminars to introduce students to BU and the college environment, discuss ways to be successful in and out of the classroom, highlights the importance of peer mentoring and cohort building and serves as a mechanism to introduce first-year students to research skills. In teams of two, the Pre-MaP students select (with assistance) a research mentor and work with him/her on a original research project.In addition, Pre-MaP students attend several field trips including (but not limited to) viewing original science documents at the Boston Public Library (including a first edition Copernicus) and an observing run at Lowell Observatory in Arizona.

  19. Report on the Pre-existing Condition Insurance Plan Program

    Data.gov (United States)

    U.S. Department of Health & Human Services — Before the Affordable Care Act, Americans with pre-existing conditions who did not receive health coverage through their employers had few affordable options to get...

  20. Regulation of mammalian pre-mRNA splicing

    Institute of Scientific and Technical Information of China (English)

    HUI JingYi

    2009-01-01

    In eukaryotes, most protein-coding genes contain introns which are removed by precursor messenger RNA (pre-mRNA) splicing. Alternative splicing is a process by which multiple messenger RNAs (mRNAs) are generated from a single pre-mRNA, resulting in functionally distinct proteins. Recent genome-wide analyses of alternative splicing indicated that in higher eukaryotes alternative splicing is an important mechanism that generates proteomic complexity and regulates gene expression. Mis-regulation of splicing causes a wide range of human diseases. This review describes the current understanding of pre-mRNA splicing and the mechanisms that regulate mammalian pre-mRNA splicing. It also discusses emerging directions in the field of alternative splicing.

  1. Regulation of mammalian pre-mRNA splicing

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In eukaryotes,most protein-coding genes contain introns which are removed by precursor messenger RNA(pre-mRNA) splicing.Alternative splicing is a process by which multiple messenger RNAs(mRNAs) are generated from a single pre-mRNA,resulting in functionally distinct proteins.Recent genome-wide analyses of alternative splicing indicated that in higher eukaryotes alternative splicing is an important mechanism that generates proteomic complexity and regulates gene expression.Mis-regulation of splicing causes a wide range of human diseases.This review describes the current understanding of pre-mRNA splicing and the mechanisms that regulate mammalian pre-mRNA splicing.It also discusses emerging directions in the field of alternative splicing.

  2. Monthly Pre-Existing Condition Insurance Plan Enrollment

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Affordable Care Act created the new Pre-Existing Condition Insurance Plan (PCIP) program to make health insurance available to Americans denied coverage by...

  3. Engaging Youth and Pre-Service Teachers in Immigration Deliberations

    Science.gov (United States)

    Daniel, Shannon M.

    2015-01-01

    In this report of innovative teacher practice, the author describes an arts-based event which brought together adolescent refugee and immigrant students and pre-service teachers to deliberate about immigration policies and attitudes in the United States.

  4. Storing, Transporting and Pre-treating of Contaminated Biomass

    OpenAIRE

    Tlustoš, P.

    2014-01-01

    The proposed technology is a unique method evaluating decrease of risk element release into environment while the contaminated biomass is transported, stored and pre-treated. This biomass was produced on phytoextraction plantations for further energetic purposes.

  5. Pre-Stressed Rope Reinforced Anti-Sliding Pile

    Institute of Scientific and Technical Information of China (English)

    XU Jun; WANG Chenghua

    2006-01-01

    Pre-stressed rope reinforced anti-sliding pile is a composite anti-sliding structure. It is made up of pre-stressed rope and general anti-sliding pile. It can bring traditional anti-sliding pile's retaining performance into full play, and to treat with landslide fast and economically. The difference between them is that the pre-stressed rope will transfix the whole anti-sliding pile through a prearranged pipe in this structure. The working mechanics, the design method and economic benefit are studied. The results show that the pre-stressed rope reinforced anti-sliding pile can treat with the small and middle landslides or high slopes well and possess the notable advantage of technology and economic.

  6. Dynamics of pre-ionized fast capillary discharge

    Science.gov (United States)

    Hübner, J.; Vrba, P.; Straus, J.; Jancarek, A.; Nevrkla, M.

    2014-05-01

    The goal of this work is to determine the best conditions for pre-ionization of the nitrogen filled capillary plasma column applying an external exponentially damped or high-frequency alternating current. As we supposed, optimal pre-ionization conditions are achieved when the plasma is quiescent, motionless and isothermal, near the local thermodynamical equilibrium. At the time of optimal conditions for the pre-ionization plasma column, the main pulse is applied. This approach enables us to estimate the influence of such prepared plasma on the value of emitted energy during the main current pulse. For modeling of plasma during the pre-pulse and main pulse, the magneto-hydro-dynamics (MHD) NPINCH code [1] and the radiative-MHD Z* code [2] were used. The computer results are used for further improvement of x-ray-ultraviolet-capillary sources designed in IPP ASCR and CTU FNSPE laboratories in Prague.

  7. Moving From Theory to Practice: ELT Pre-service Teachers

    Directory of Open Access Journals (Sweden)

    Meryem Özdemir

    2012-05-01

    Full Text Available This study was conducted to investigate the perceptual change in pre-service teachers’ effective teacher beliefs throughout their education in English Language Teaching (ELT Department of which programme is constructed spirally from theoretical knowledge to the practical one. Throughout a data collection procedure lasted 5 academic terms, 80 pre-service teachers were asked to write their ideas about “the characteristics of an effective teacher”. In each time, as the pre-service teachers moved from theoretical courses to practical ones, the data obtained at each time was analyzed through content analysis and classified under 3 semantic groups; “content knowledge, classroom behaviours, academic qualities”. Results showed that pre-service teachers’ beliefs of effective teacher changed throughout their teacher education programme as theymoved from theory to practice.

  8. ORIGINAL ARTICLE CASE REPORT Functional MRI in pre-surgical ...

    African Journals Online (AJOL)

    CASE REPORT. Functional magnetic resonance imaging (fMRI) is an MRI technique ... most promising direct clinical application is in pre-surgical planning, where fMRI is ... robust and established, although it is interesting to note that recent.

  9. Pre-cataract surgery test using speckle pattern

    Science.gov (United States)

    Jutamulia, Suganda; Wihardjo, Erning; Widjaja, Joewono

    2016-11-01

    A laser diode device for pre cataract surgery test is proposed. The operation is based on the speckle generated on the retina by the cataract lens, when the cataract lens is illuminated with a coherent laser light.

  10. Southern Great Plains rapid ecoregional assessment : Pre-assessment report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of the Pre-Assessment Report for the Southern Great Plains Rapid Ecoregional Assessment (REA) is to document the selection process for and final list of...

  11. Transcription factors and target genes of pre-TCR signaling.

    Science.gov (United States)

    López-Rodríguez, Cristina; Aramburu, Jose; Berga-Bolaños, Rosa

    2015-06-01

    Almost 30 years ago pioneering work by the laboratories of Harald von Boehmer and Susumo Tonegawa provided the first indications that developing thymocytes could assemble a functional TCRβ chain-containing receptor complex, the pre-TCR, before TCRα expression. The discovery and study of the pre-TCR complex revealed paradigms of signaling pathways in control of cell survival and proliferation, and culminated in the recognition of the multifunctional nature of this receptor. As a receptor integrated in a dynamic developmental process, the pre-TCR must be viewed not only in the light of the biological outcomes it promotes, but also in context with those molecular processes that drive its expression in thymocytes. This review article focuses on transcription factors and target genes activated by the pre-TCR to drive its different outcomes.

  12. Lithium Depletion in Fully Convective Pre-Main Sequence Stars

    CERN Document Server

    Bildsten, L; Matzner, C D; Ushomirsky, G; Bildsten, Lars; Brown, Edward F.; Matzner, Christopher D.; Ushomirsky, Greg

    1996-01-01

    We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully convective, pre-main sequence stars of mass M 0.08 M_sun) and for constraining the masses of lithium depleted stars.

  13. ORIGINAL ARTICLE EVALUATION OF PRE-SERVICE TRAINING ...

    African Journals Online (AJOL)

    user

    Background: The Integrated Management of Newborn and Childhood Illness ... als prepared for pre-service training like handbook and model chapter was limited. ... Exploring for an alternative/innovative and sustainable training approach.

  14. Preparing pre-service teachers as emancipatory and participatory ...

    African Journals Online (AJOL)

    Keywords: critical reflection; emancipatory action research; participatory action research; pre-service ... tion and the integration of theory and practice among postgraduate candidate teachers, by exposing them ..... Germany: Frankfurt am Main.

  15. 46 CFR 115.640 - Pre-Survey meeting.

    Science.gov (United States)

    2010-10-01

    ... operated vehicle (ROV) as the predominate means to examine the vessel's hull plating, then a representative of the ROV operating company must attend the pre-survey meeting and address the underwater ROV's...

  16. Assessment of pre and postoperative psychiatric comorbidity among ...

    African Journals Online (AJOL)

    Research Journal of Health Sciences ... Studies on pre and postoperative comorbid psychiatric disorders among ophthalmological patients ... twentieth version of the Self-rating Questionnaire and the Hospital Anxiety and Depression Scale.

  17. relationship of some variables in predicting pre service teachers ...

    African Journals Online (AJOL)

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    ABSTRACT. The study examines the extent to which the relationship between pre-service .... the statistical tests were done at 0.05α-level. Participants ... solving test, chemistry achievement test, and mathematics skill test, were developed by.

  18. Immune Evasion Strategies of Pre-Erythrocytic Malaria Parasites

    Directory of Open Access Journals (Sweden)

    Hong Zheng

    2014-01-01

    Full Text Available Malaria is a mosquito-borne infectious disease of humans. It begins with a bite from an infected female Anopheles mosquito and leads to the development of the pre-erythrocytic and blood stages. Blood-stage infection is the exclusive cause of clinical symptoms of malaria. In contrast, the pre-erythrocytic stage is clinically asymptomatic and could be an excellent target for preventive therapies. Although the robust host immune responses limit the development of the liver stage, malaria parasites have also evolved strategies to suppress host defenses at the pre-erythrocytic stage. This paper reviews the immune evasion strategies of malaria parasites at the pre-erythrocytic stage, which could provide us with potential targets to design prophylactic strategies against malaria.

  19. Fire-free land use in pre-1492 Amazonian savannas.

    Science.gov (United States)

    Iriarte, José; Power, Mitchell J; Rostain, Stéphen; Mayle, Francis E; Jones, Huw; Watling, Jennifer; Whitney, Bronwen S; McKey, Doyle B

    2012-04-24

    The nature and scale of pre-Columbian land use and the consequences of the 1492 "Columbian Encounter" (CE) on Amazonia are among the more debated topics in New World archaeology and paleoecology. However, pre-Columbian human impact in Amazonian savannas remains poorly understood. Most paleoecological studies have been conducted in neotropical forest contexts. Of studies done in Amazonian savannas, none has the temporal resolution needed to detect changes induced by either climate or humans before and after A.D. 1492, and only a few closely integrate paleoecological and archaeological data. We report a high-resolution 2,150-y paleoecological record from a French Guianan coastal savanna that forces reconsideration of how pre-Columbian savanna peoples practiced raised-field agriculture and how the CE impacted these societies and environments. Our combined pollen, phytolith, and charcoal analyses reveal unexpectedly low levels of biomass burning associated with pre-A.D. 1492 savanna raised-field agriculture and a sharp increase in fires following the arrival of Europeans. We show that pre-Columbian raised-field farmers limited burning to improve agricultural production, contrasting with extensive use of fire in pre-Columbian tropical forest and Central American savanna environments, as well as in present-day savannas. The charcoal record indicates that extensive fires in the seasonally flooded savannas of French Guiana are a post-Columbian phenomenon, postdating the collapse of indigenous populations. The discovery that pre-Columbian farmers practiced fire-free savanna management calls into question the widely held assumption that pre-Columbian Amazonian farmers pervasively used fire to manage and alter ecosystems and offers fresh perspectives on an emerging alternative approach to savanna land use and conservation that can help reduce carbon emissions.

  20. Pre-operative pain and sensory function in groin hernia

    DEFF Research Database (Denmark)

    Aasvang, Eske K; Hansen, Jeanette B; Kehlet, Henrik

    2009-01-01

    mechanism. AIMS: To investigate the correlation between pre-operative pain intensity and sensory functions in the groin hernia area. METHODS: Patients with unilateral groin hernia were examined preoperatively by quantitative sensory testing (thermal, mechanical, and pressure [detection and pain thresholds...... pain is not related to findings of hyperalgesia or other changes in sensory function that may support pain-induced pre-operative neuroplasticity as a pathogenic mechanism for the development of persistent postherniotomy pain....