WorldWideScience

Sample records for line valve accident

  1. 49 CFR 192.181 - Distribution line valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Distribution line valves. 192.181 Section 192.181... line valves. (a) Each high-pressure distribution system must have valves spaced so as to reduce the time to shut down a section of main in an emergency. The valve spacing is determined by the...

  2. 49 CFR 192.365 - Service lines: Location of valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Location of valves. 192.365 Section..., and Service Lines § 192.365 Service lines: Location of valves. (a) Relation to regulator or meter. Each service-line valve must be installed upstream of the regulator or, if there is no...

  3. 49 CFR 192.745 - Valve maintenance: Transmission lines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valve maintenance: Transmission lines. 192.745... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.745 Valve maintenance: Transmission lines. (a) Each transmission line valve that might be required during any...

  4. 49 CFR 192.179 - Transmission line valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission line valves. 192.179 Section 192.179... line valves. (a) Each transmission line, other than offshore segments, must have sectionalizing block valves spaced as follows, unless in a particular case the Administrator finds that alternative...

  5. Assessment of Severe Accident Depressurization Valve Activation Strategy for Chinese Improved 1000 MWe PWR

    Directory of Open Access Journals (Sweden)

    Ge Shao

    2013-01-01

    Full Text Available To prevent HPME and DCH, SADV is proposed to be added to the pressurizer for Chinese improved 1000 MWe PWR NPP with the reference of EPR design. Rapid depressurization capability is assessed using the mechanical analytical code. Three typical severe accident sequences of TMLB’, SBLOCA, and LOFW are selected. It shows that with activation of the SADV the RCS pressure is low enough to prevent HPME and DCH. Natural circulation at upper RPV and hot leg is considered for the rapid depressurization capacity analysis. The result shows that natural circulation phenomenon results in heat transfer from the core to the pipes in RCS which may cause the creep rupture of pipes in RCS and delays the severe accident progression. Different SADV valve areas are investigated to the influence of depressurization of RCS. Analysis shows that the introduction of SADV with right valve area will delay progression of core degradation to RPV failure. Valve area is to be optimized since smaller SADV area will reduce its effect and too large valve area will lead to excessive loss of water inventory in RCS and makes core degradation progression to RPV failure faster without additional core cooling water sources.

  6. The analysis of pressurizer safety valve stuck open accident for low power and shutdown PSA

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ho Gon; Park, Jin Hee; Jang, Seong Chul; Kim, Tae Woon

    2005-01-01

    The PSV (Pressurizer Safety Valve) popping test carried out practically in the early phase of a refueling outage has a little possibility of triggering a test-induced LOCA due to a PSV not fully closed or stuck open. According to a KSNP (Korea Standard Nuclear Power Plant) low power and shutdown PSA (Probabilistic Safety Assessment), the failure of a HPSI (High Pressure Safety Injection) following a PSV stuck open was identified as a dominant accident sequence with a significant contribution to low power and shutdown risks. In this study, we aim to investigate the consequences of the NPP for the various accident sequences following the PSV stuck open as an initiating event through the thermal-hydraulic system code calculations. Also, we search the accident mitigation method for the sequence of HPSI failure, then, the applicability of the method is verified by the simulations using T/H system code.

  7. Optimization and Improvisation of Production Assembly Line of Two Valve Engine of Light Commercial Vehicle

    Directory of Open Access Journals (Sweden)

    Sumit Bhadouriya

    2014-07-01

    Full Text Available In automobile engineering terminology a multi-valve engine is one where each cylinder has more than two valves. A multivalve engine has better breathing and can operate at higher revolutions per minute (rpm than a two valve engine, delivering more power. Nowadays Eicher Motor is generating only two valve engines. But the need of the hour is to develop more efficient, four valve engines, which provide better fuel efficiency. Eicher Motor has started working on four valve engines because two valve engines apart from delivering inferior fuel efficiency compared to four valve engines also fall short on the front of emission norms compliance. To keep the transition two valve to four valve economical, it was proposed that instead of having an entirely new set up for assembling the four valve engines, two valve engine assembly line be use after required modification. For this change were made to engine assembly common line (Block, and cylinder head assembly line conveyors, location of cylinder head assembly line, manpower, machine and tools etc. of Eicher Motor as per the requirement of four valve and two valve assembly line and also engine assembly process was changed.

  8. Analysis of main steam isolation valve leakage in design basis accidents using MELCOR 1.8.6 and RADTRAD.

    Energy Technology Data Exchange (ETDEWEB)

    Salay, Michael (United States Nuclear Regulatory Commission, Washington, D.C.); Kalinich, Donald A.; Gauntt, Randall O.; Radel, Tracy E.

    2008-10-01

    Analyses were performed using MELCOR and RADTRAD to investigate main steam isolation valve (MSIV) leakage behavior under design basis accident (DBA) loss-of-coolant (LOCA) conditions that are presumed to have led to a significant core melt accident. Dose to the control room, site boundary and LPZ are examined using both approaches described in current regulatory guidelines as well as analyses based on best estimate source term and system response. At issue is the current practice of using containment airborne aerosol concentrations as a surrogate for the in-vessel aerosol concentration that exists in the near vicinity of the MSIVs. This study finds current practice using the AST-based containment aerosol concentrations for assessing MSIV leakage is non-conservative and conceptually in error. A methodology is proposed that scales the containment aerosol concentration to the expected vessel concentration in order to preserve the simplified use of the AST in assessing containment performance under assumed DBA conditions. This correction is required during the first two hours of the accident while the gap and early in-vessel source terms are present. It is general practice to assume that at {approx}2hrs, recovery actions to reflood the core will have been successful and that further core damage can be avoided. The analyses performed in this study determine that, after two hours, assuming vessel reflooding has taken place, the containment aerosol concentration can then conservatively be used as the effective source to the leaking MSIV's. Recommendations are provided concerning typical aerosol removal coefficients that can be used in the RADTRAD code to predict source attenuation in the steam lines, and on robust methods of predicting MSIV leakage flows based on measured MSIV leakage performance.

  9. Valve Disease

    Science.gov (United States)

    ... heart valves, valve insufficiency, valve regurgitation, valve stenosis, valvular heart disease Every time your heart beats, blood flows into, ... removed from the market after being linked to heart valve disease. An infection in the lining of the heart's ...

  10. Calculation of Departure from Nucleate Boiling Ratio (DNBR) minimum for accident analysis of main steam line break at Angra-1; Calculo do minimo DNBR para analise do acidente de ruptura da linha principal de vapor em Angra-1

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Marcio Dornellas [ELETROBRAS Termonuclear S.A. (ELETRONUCLEAR), Rio de Janeiro, RJ (Brazil). E-mail: mdorne@eletronuclear.gov.br

    2000-07-01

    The maintenance costs, the operational problems and the failures possibilities of the boron injection system, composed by pumps, valves, heated lines and the boron injection tank, make this tank removal or the boron concentration reduction advisable for Angra 1 Power Plant. The main accident from chapter XV of the final safety analysis report affected by this modification is the main steam line break. It is necessary the interaction of the areas of Accidents and Transients Analysis (RETRAN 02/Mod 5.1 code), Neutronics (APA System) and Thermohydraulics (COBRA IIIC/MIT) to analyse this accident. The present Angra 1 boron concentration is 20000 ppm and it could be reduced to 2000 ppm as a result of the present study. The Departure from Nucleate Boiling Ratio (DNBR) is the restrictive parameter of this accident, which is calculated from the initials and boundary conditions obtained from the Transients and Accidents Analysis and Neutronics areas. (author)

  11. 49 CFR 192.381 - Service lines: Excess flow valve performance standards.

    Science.gov (United States)

    2010-10-01

    ... SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer... excess flow valve as near as practical to the fitting connecting the service line to its source of gas...

  12. Former of Turn Trajectory of Sliding Valve Shaft of Gas Line

    Directory of Open Access Journals (Sweden)

    Dementyev Vladislav. Yu.

    2017-01-01

    Full Text Available Former of turn trajectory of sliding valve shaft of gas line, that allows to provide desired motion trajectory of sliding valve and its full closing, is considered in that paper. Imitation model of that former, research results, which allow to detect influence of gain factor and time constant of position controller on value of speed error, that has impact on delay of output coordinate from setting, and that results to delay of sliding valve motion process to setting position point, are shown.

  13. Coupled simulation of steam line break accident; Simulation couplee d'un accident de rupture de tuyauterie vapeur

    Energy Technology Data Exchange (ETDEWEB)

    Royer, E.; Raimond, E.; Caruge, D

    2000-07-01

    The steam line break is a PWR type reactor design accident, which concerns coupled physical phenomena. To control these problems simulation are needed to define and validate the operating procedures. The benchmark OECD PWR MSLB (Main Steam Line Break) has been proposed by the OECD to validate the feasibility and the contribution of the multi-dimensional tools in the simulation of the core transients. First the benchmark OECD PWR MSLB is presented. Then the analysis of the three exercises (system with pinpoint kinetic, three-dimensional core and whole system with three-dimensional core) are discussed. (A.L.B.)

  14. Whitey Swagelok SCHe Ball Valves Provide Isolation between SCHe Purge Lines C and D and the Process Vent

    Energy Technology Data Exchange (ETDEWEB)

    MISKA, C.R.

    2000-09-15

    These valves are 1/4 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They provide an isolation function betwen SCHe Purge Line C, (PV-V-*079), and Purge Line D, (PV-V-*080), and the Process Vent.

  15. Assessment of SWBR safety-relief valve discharge line dynamic loads due to steam blowdown

    Energy Technology Data Exchange (ETDEWEB)

    Spoelstra, S.; Stoop, P.M. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Dijk, A.B. van [Stork Nucon BV (Netherlands)

    1997-06-01

    The Safety/Relief Valve Discharge Lines of the SBWR nuclear power plant are subject to dynamic loads due to steam blowdown after rapid opening of the Safety/Relief Valves. This paper describes the calculation of the thermal-hydraulic loads exerted on the piping system and the calculation of the resulting pipe stresses. These calculations have been performed using the CHARME and PS+CAEPIPE computer programs respectively. The calculated pipe stresses have been combined with the ones resulting from dead weight and thermal expansion and compared with ASME III criteria. (orig.).

  16. On-line measurement of gaseous iodine species during a PWR severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Haykal, I.; Doizi, D. [CEA, DEN, Departement de Physico-chimie, 91191 Gif sur Yvette Cedex, (France); Perrin, A. [CNRS-University of Paris Est and Paris 7, Laboratoire Inter-Universitaire des Systemes Atmospheriques, 94010 Creteil, (France); Vincent, B. [University of Burgundy, Laboratoire de physique, CNRS UMR 5027, 9, Avenue Alain Savary, BP 47870, F-21078 Dijon Cedex, (France); Manceron, L. [Synchrotron SOLEIL, L' Orme des Merisiers, St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, (France); Mejean, G. [University of Joseph Fourier in Grenoble, Laboratoire de Spectrometrie Physique-CNRS UMR 5588, 38402 Saint Martin d' Heres, (France); Ducros, G. [CEA Cadarache, CEA, DEN, Departement d' Etudes des Combustibles, 13108 Saint-Paul-lez-Durance cedex, (France)

    2015-07-01

    A long-range remote sensing of severe accidents in nuclear power plants can be obtained by monitoring the online emission of volatile fission products such as xenon, krypton, caesium and iodine. The nuclear accident in Fukushima was ranked at level 7 of the International Nuclear Event Scale by the NISA (Nuclear and Industrial Safety Agency) according to the importance of the radionuclide release and the off-site impact. Among volatile fission products, iodine species are of high concern, since they can be released under aerosols as well as gaseous forms. Four years after the Fukushima accident, the aerosol/gaseous partition is still not clear. Since the iodine gaseous forms are less efficiently trapped by the Filtered Containment Venting Systems than aerosol forms, it is of crucial importance to monitor them on-line during a nuclear accident, in order to improve the source term assessment in such a situation. Therefore, we propose to detect and quantify these iodine gaseous forms by the use of highly sensitive optical methods. (authors)

  17. On-line measurements of RuO{sub 4} during a PWR severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Reymond-Laruinaz, S.; Doizi, D. [CEA, DEN, Departement de Physico-chimie, CEA/Saclay, 91191 Gif sur Yvette Cedex, (France); Manceron, L. [Societe Civile Synchrotron SOLEIL, L' Orme des Merisiers, St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, (France); MONARIS, UMR 8233, Universite Pierre et Marie Curie, 4 Place Jussieu, case 49, F-75252 Paris Cedex 05, (France); Boudon, V. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, F-21078 Dijon Cedex, (France); Ducros, G. [CEA, DEN, Departement d' Etudes des Combustibles, CEA/Cadarache, 13108 Saint-Paul-lez-Durance cedex, (France)

    2015-07-01

    After the Fukushima accident, it became essential to have a way to monitor in real time the evolution of a nuclear reactor during a severe accident, in order to react efficiently and minimize the industrial, ecological and health consequences of the accident. Among gaseous fission products, the tetroxide of ruthenium RuO{sub 4} is of prime importance since it has a significant radiological impact. Ruthenium is a low volatile fission product but in case of the rupture of the vessel lower head by the molten corium, the air entering into the vessel oxidizes Ru into gaseous RuO{sub 4}, which is not trapped by the Filtered Containment Venting Systems. To monitor the presence of RuO{sub 4} allows making a diagnosis of the core degradation and quantifying the release into the atmosphere. To determine the presence of RuO{sub 4}, FTIR spectrometry was selected. To study the feasibility of the monitoring, high-resolution IR measurements were realized at the French synchrotron facility SOLEIL on the infrared beam line AILES. Thereafter, theoretical calculations were done to simulate the FTIR spectrum to describe the specific IR fingerprint of the molecule for each isotope and based on its partial pressure in the air. (authors)

  18. Accidents by electrical contact of heavy vehicles with the power distribution network overhead lines

    Energy Technology Data Exchange (ETDEWEB)

    Bourkas, P.D.; Tsarabaris, P.T.; Katsanis, J.S.; Polykrati, A.D. [National Technical Univ. of Athens (Greece). School of Electrical and Computer Engineering; Koufakis, E.I. [Public Power Corp., Crete (Greece)

    2009-07-01

    This paper examined an electrical accident that occurred when a heavy vehicle came into contact with a distribution overhead primary circuit transmission line protected by an oil circuit breaker. The back part of a concrete pump truck made contact with a bare conductor on the medium voltage line located in a city. The driver sustained an electrical shock when he tried to descend from his truck and touched the metallic part of the driver's cabin at the same time his feet touched the ground. The accident occurred as a result of the conductive path created between the conductor and the earth through the body of the driver. The thermal, electromechanical, thermochemical and partial discharge breakdowns of the truck's solid insulation tires were studied. The oil circuit breaker was also investigated. Experiments demonstrated that reductions in the dielectric strength of the tires were caused by the wire mesh materials used to reinforce mechanical strength. The old tires avoided static electricity as a result of their increased friction and ohmic resistance value. Thermal breakdown of the wheel rubber occurred when the vehicle came into contact with the medium voltage conductor. It was concluded that drivers must jump away from vehicles that come into contact with transmission lines. 12 refs., 5 figs.

  19. Effect of Check Valve on Consequences of Coolant Pump Rotor Seizure Accident for EPR Reactor%止回阀对EPR反应堆主泵卡轴事故后果的影响

    Institute of Scientific and Technical Information of China (English)

    陈秋炀; 周拥辉

    2012-01-01

    分析计算欧洲先进压水堆(EPR)反应堆主泵卡轴事故,并对比在主泵出口安装止回阀和没有安装止回阀模型的卡轴事故安全分析.结果表明,在EPR主泵卡轴事故中,止回阀可增加模型堆芯进口流量约4%,有利于堆芯的冷却.止回阀可显著地提高堆芯最小偏离泡核沸腾比(DNBR),降低堆芯偏离泡核沸腾(DNB)份额,降低包壳温度约14℃.模型分析结果表明,在主泵卡轴事故工况下,主泵出口安装止回阀可更好地维持堆芯的完整性.%Counter current flow phenomenon would appear during reactor coolant pump rotor seizure accident. Present work analyzes the coolant pump rotor seizure accident for European Pressurized Reactor (EPR). The accident safety analysis results of model with check valve and without check valve are compared. It can be found that the check valve can increase the core inlet flow rate of model about 4%. The increasing of coolant flow rate is beneficial to the reactor core cooling. Check valve can increase the minimum departure from nucleate boiling ratio (DNBR), reduce the departure from nucleate boiling (DNB) fraction and the fuel rod cladding temperature about 14℃ during coolant pump rotor seizure accident. The analyses results show that the model with check valve can maintain the integrity of nuclear fuel rod effectively during reactor coolant pump rotor seizure accident.

  20. Predictive modelization of actuators tires in related valves with safety Cofrentes NPP; Modelizacion predictiva de actuadores neumaticos en valvulas relacionadas con la seguridad de C.N.Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Calduch Cervera, F.; Verdu Rios, M. F.; Villena Rivera, M.; Munoz Guijosa, J. M.

    2011-07-01

    The main function of these valves is isolation, and in some cases this function is especially critical because they must isolate Elementary and Secondary Containment. Particularly valves must be able to ensure a perfect sealing of the lines which are installed under any conditions, whether in normal operation or in a design basis accident scenario.

  1. Design of Pressure Relief Valves for Protection of Steel-Lined Pressure Shafts and Tunnels Against Buckling During Emptying

    OpenAIRE

    Schleiss, Anton; Manso, Pedro

    2012-01-01

    Using high-strength steels for pressure shafts and tunnel liners and taking into account significant rock mass participation allows the design of comparatively thin steel liners in hydropower projects. Nevertheless, during emptying of waterways, these steel linings may be endangered by buckling. Compared with traditional measures such as increased steel liner thickness and stiffeners, pressure relief valves are a very economical solution for protection of steel liners against critical extern...

  2. 全船断电叠加安全阀失效事故放射性释放分析%Analysis of accident due to interruption of power supply and safety valve failure

    Institute of Scientific and Technical Information of China (English)

    展锋; 张帆; 王伟; 于雷

    2014-01-01

    针对全船断电叠加安全阀失效事故,以严重事故分析程序 MELCOR 为研究工具,建立了某型船用堆的分析模型,分析了稳压器安全阀在断电事故后开启1次、开启5次、开启13次后卡开失效及正常启闭4种工况。结果表明:安全阀开启1次后卡开失效事故进程最快,后果最严重;不卡开的情况,事故进程最慢;在安全阀开启13次以内的卡开失效时,各工况放射性物质释放至各部位的份额均比较接近,放射性后果的影响差别不大。%Aiming at the blackout accident,this paper presents a ship reactor model by use of the inte-gration code of MELCOR.The model is used to analyze severe accidents.The analysis refers to four operating conditions:the pressurizer safe valve opening 1 time,5 times,13 times,and reiterative times.The result shows that the accident happens fastest and the aftereffect is the most serious after safe valve opens 1 time,and the accident happens slowest after the opening in reiterative times.When the safe valve opening is less than 13 times,the radioactive fraction is nearly the same in every situa-tion and the radioactive aftereffect is not sensitive.

  3. Recommendations for main line block valves installation in gas pipelines; Recomendacoes para instalacao de valvulas de bloqueio de linha tronco em gasodutos

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Oliveira, Valeriano Duque de [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Cases of gas pipelines block valves and its pneumatic actuators presenting problems during the final pipeline commissioning and pre-operation phases, like internal leaks, leaking to the atmosphere, pneumatic circuit defects caused by water and debris, are nearly common. The majority can be avoided if a series of measuring are to be planned and implemented, as well as if an adequate planning of commissioning operations and line gasification, valves and actuators, are to be applied. This paper shows the practical experience in the construction and commissioning of valves and its actuators in the Bolivia-Brazil gas pipeline, which, in the first construction phase had a series of problems. After the diagnosis a set of procedures was implemented in the secondary construction phase, resulting in insignificant problems detected. All measures and procedures taken in the planning process, as well as additional aspects related to the main line valve design, its by-passes and supports, are demonstrated. (author)

  4. Analysis of hexavalent chromium in Colla corii asini with on-line sample pretreatment valve-switching ion chromatography.

    Science.gov (United States)

    Yang, Yuling; He, Jie; Huang, Zhongping; Zhong, Naifei; Zhu, Zuoyi; Jiang, Renyu; You, Jinghua; Lu, Xiuyang; Zhu, Yan; He, Shiwei

    2013-08-30

    An ion chromatography (IC) system with on-line sample pretreatment using valve-switching technique was developed for the determination of hexavalent chromium (Cr(VI)) in Colla corii asini. Colla corii asini is a complicated sample with organics as main matrix. In this work, a polymer-based reversed-phase column was used as a pretreatment column. Via valve-switching technique, sample solution with target ions were eluted from a collection loop to analytical columns, with matrix eliminated on-line. Under the optimized separation conditions, the method showed good linearity (r=0.9998) in the range of 0.004-1.0mg/L and satisfactory repeatability (RSD<3%, n=6). The limit of detection (LOD) was 1.4μg/L (S/N=3). The average spiked recoveries of Cr(VI) were 93.4-102.0%. The result showed that the on-line sample pretreatment IC system was convenient and practical for the determination of trace Cr(VI) in Colla corii asini samples.

  5. Analytical model for computing transient pressures and forces in the safety/relief valve discharge line. Mark I Containment Program, task number 7. 1. 2

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, A.J.

    1978-02-01

    An analytical model is described that computes the transient pressures, velocities and forces in the safety/relief valve discharge line immediately after safety/relief valve opening. Equations of motion are defined for the gas-flow and water-flow models. Results are not only verified by comparing them with an earlier version of the model, but also with Quad Cities and Monticello plant data. The model shows reasonable agreement with the earlier model and the plant data.

  6. Accidents - Chernobyl accident; Accidents - accident de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This file is devoted to the Chernobyl accident. It is divided in four parts. The first part concerns the accident itself and its technical management. The second part is relative to the radiation doses and the different contaminations. The third part reports the sanitary effects, the determinists ones and the stochastic ones. The fourth and last part relates the consequences for the other European countries with the case of France. Through the different parts a point is tackled with the measures taken after the accident by the other countries to manage an accident, the cooperation between the different countries and the groups of research and studies about the reactors safety, and also with the international medical cooperation, specially for the children, everything in relation with the Chernobyl accident. (N.C.)

  7. Generation and Characterization of Vascular Smooth Muscle Cell Lines Derived from a Patient with a Bicuspid Aortic Valve

    Directory of Open Access Journals (Sweden)

    Pamela Lazar-Karsten

    2016-04-01

    Full Text Available Thoracic aortic dilation is the most common malformation of the proximal aorta and is responsible for 1%–2% of all deaths in industrialized countries. In approximately 50% of patients with a bicuspid aortic valve (BAV, dilation of any or all segments of the aorta occurs. BAV patients with aortic dilation show an increased incidence of cultured vascular smooth muscle cell (VSMC loss. In this study, VSMC, isolated from the ascending aorta of BAV, was treated with Simian virus 40 to generate a BAV-originated VSMC cell line. To exclude any genomic DNA or cross-contamination, highly polymorphic short tandem repeats of the cells were profiled. The cells were then characterized using flow cytometry and karyotyping. The WG-59 cell line created is the first reported VSMC cell line isolated from a BAV patient. Using an RT2 Profiler PCR Array, genes within the TGFβ/BMP family that are dependent on losartan treatment were identified. Endoglin was found to be among the regulated genes and was downregulated in WG-59 cells following treatment with different losartan concentrations, when compared to untreated WG-59 cells.

  8. Safety valve for offshore borehole

    Energy Technology Data Exchange (ETDEWEB)

    McGill, H.L.; Randermann, E. Jr.; Musik, O.J.

    1977-10-06

    The invention concerns a new and improved submarine safety valve with a valve element which rotate, which can be used, in emergencies, to separate the wound-up piping which extends into the borehole and to close the production line.

  9. Analysis and prevention of accident-caused faults in power cable lines

    Directory of Open Access Journals (Sweden)

    Susakova Tatyana V.

    2017-01-01

    Full Text Available To ensure fault-free operation of power cable lines it is essential to make a thorough analysis of the type of faults and their location. The paper considers the most common type of faults and main reasons for cable damage. The case study of cable faults at an urban network (Zabaikalsky Krai shows that the root cause is insulation deterioration, especially with the cables reaching the end of their 35 year lifetime. Therefore, to prevent faults and mitigate the threats it is necessary to increase surveillance of cable systems and use cables with higher reliability and functionality, e.g., XLPE cables.

  10. Determinants of image quality of rotational angiography for on-line assessment of frame geometry after transcatheter aortic valve implantation.

    Science.gov (United States)

    Rodríguez-Olivares, Ramón; El Faquir, Nahid; Rahhab, Zouhair; Maugenest, Anne-Marie; Van Mieghem, Nicolas M; Schultz, Carl; Lauritsch, Guenter; de Jaegere, Peter P T

    2016-07-01

    To study the determinants of image quality of rotational angiography using dedicated research prototype software for motion compensation without rapid ventricular pacing after the implantation of four commercially available catheter-based valves. Prospective observational study including 179 consecutive patients who underwent transcatheter aortic valve implantation (TAVI) with either the Medtronic CoreValve (MCS), Edward-SAPIEN Valve (ESV), Boston Sadra Lotus (BSL) or Saint-Jude Portico Valve (SJP) in whom rotational angiography (R-angio) with motion compensation 3D image reconstruction was performed. Image quality was evaluated from grade 1 (excellent image quality) to grade 5 (strongly degraded). Distinction was made between good (grades 1, 2) and poor image quality (grades 3-5). Clinical (gender, body mass index, Agatston score, heart rate and rhythm, artifacts), procedural (valve type) and technical variables (isocentricity) were related with the image quality assessment. Image quality was good in 128 (72 %) and poor in 51 (28 %) patients. By univariable analysis only valve type (BSL) and the presence of an artefact negatively affected image quality. By multivariate analysis (in which BMI was forced into the model) BSL valve (Odds 3.5, 95 % CI [1.3-9.6], p = 0.02), presence of an artifact (Odds 2.5, 95 % CI [1.2-5.4], p = 0.02) and BMI (Odds 1.1, 95 % CI [1.0-1.2], p = 0.04) were independent predictors of poor image quality. Rotational angiography with motion compensation 3D image reconstruction using a dedicated research prototype software offers good image quality for the evaluation of frame geometry after TAVI in the majority of patients. Valve type, presence of artifacts and higher BMI negatively affect image quality.

  11. Determinants of image quality of rotational angiography for on-line assessment of frame geometry after transcatheter aortic valve implantation

    NARCIS (Netherlands)

    R. Rodríguez-Olivares (Ramón); N. El Faquir (Nahid); Z. Rahhab (Zouhair); A.M. Maugenest; N.M. van Mieghem (Nicolas); C. Schultz (Carl); G. Lauritsch (Guenter); P.P.T. de Jaegere (Peter)

    2016-01-01

    textabstractTo study the determinants of image quality of rotational angiography using dedicated research prototype software for motion compensation without rapid ventricular pacing after the implantation of four commercially available catheter-based valves. Prospective observational study including

  12. Phenomena identification and ranking tables for Westinghouse AP600 small break loss-of-coolant accident, main steam line break, and steam generator tube rupture scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.E.; Fletcher, C.D.; Davis, C.B. [and others

    1997-06-01

    This report revision incorporates new experimental evidence regarding AP600 behavior during small break loss-of-coolant accidents. This report documents the results of Phenomena Identification and Ranking Table (PIRT) efforts for the Westinghouse AP600 reactor. The purpose of this PIRT is to identify important phenomena so that they may be addressed in both the experimental programs and the RELAP5/MOD3 systems analysis computer code. In Revision of this report, the responses of AP600 during small break loss-of-coolant accident, main steam line break, and steam generator tube rupture accident scenarios were evaluated by a committee of thermal-hydraulic experts. Committee membership included Idaho National Engineering and Environmental Laboratory staff and recognized thermal-hydraulic experts from outside of the laboratory. Each of the accident scenarios was subdivided into separate, sequential periods or phases. Within each phase, the plant behavior is controlled by, at most, a few thermal-hydraulic processes. The committee identified the phenomena influencing those processes, and ranked & influences as being of high, medium, low, or insignificant importance. The primary product of this effort is a series of tables, one for each phase of each accident scenario, describing the thermal-hydraulic phenomena judged by the committee to be important, and the relative ranking of that importance. The rationales for the phenomena selected and their rankings are provided. This document issue incorporates an update of the small break loss-of-coolant accident portion of the report. This revision is the result of the release of experimental evidence from AP600-related integral test facilities (ROSA/AP600, OSU, and SPES) and thermal-hydraulic expert review. The activities associated with this update were performed during the period from June 1995 through November 1996. 8 refs., 26 figs., 42 tabs.

  13. 14 CFR 125.133 - Fuel valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fuel valves. 125.133 Section 125.133....133 Fuel valves. Each fuel valve must— (a) Comply with § 125.155; (b) Have positive stops or suitable... operation or from accelerated flight conditions are not transmitted to the lines connected to the valve....

  14. On-line liquid phase micro-extraction based on drop-in-plug sequential injection lab-at-valve platform for metal determination

    Energy Technology Data Exchange (ETDEWEB)

    Mitani, Constantina [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece); Anthemidis, Aristidis N., E-mail: anthemid@chem.auth.gr [Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University, Thessaloniki 54124 (Greece)

    2013-04-10

    Highlights: ► Drop-in-plug micro-extraction based on SI-LAV platform for metal preconcentration. ► Automatic liquid phase micro-extraction coupled with FAAS. ► Organic solvents with density higher than water are used. ► Lead determination in environmental water and urine samples. -- Abstract: A novel automatic on-line liquid phase micro-extraction method based on drop-in-plug sequential injection lab-at-valve (LAV) platform was proposed for metal preconcentration and determination. A flow-through micro-extraction chamber mounted at the selection valve was adopted without the need of sophisticated lab-on-valve components. Coupled to flame atomic absorption spectrometry (FAAS), the potential of this lab-at-valve scheme is demonstrated for trace lead determination in environmental and biological water samples. A hydrophobic complex of lead with ammonium pyrrolidine dithiocarbamate (APDC) was formed on-line and subsequently extracted into an 80 μL plug of chloroform. The extraction procedure was performed by forming micro-droplets of aqueous phase into the plug of the extractant. All critical parameters that affect the efficiency of the system were studied and optimized. The proposed method offered good performance characteristics and high preconcentration ratios. For 10 mL sample consumption an enhancement factor of 125 was obtained. The detection limit was 1.8 μg L{sup −1} and the precision expressed as relative standard deviation (RSD) at 50.0 μg L{sup −1} of lead was 2.9%. The proposed method was evaluated by analyzing certified reference materials and applied for lead determination in natural waters and urine samples.

  15. Experimental and Analytical Study on the Lift Check Valve

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Song, C. S.; Kim, H. S.; Hong, S. C. [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Lee, W. H. [Samshin Limited Co., Chonan (Korea, Republic of)

    2009-10-15

    In general, the check valve mounted on the flow line is used for the purpose of protecting the pump and the related facility, making the flow path, and maintaining the pressure boundary during the operation mode change in steam power plant and nuclear power plant. Fig. 1 shows the example of check valve in nuclear power plant. Especially, the check valve mounted on safety feed system and nuclear safety system is operated to open state and has a role of acquiring enough fluid such as safety feed and auxiliary feed water in the Design Basis Accident. And the check valve is operated with enough sealing and with protecting steam hammer in normal operational mode. For this purpose, the check valve can be open easily and be maintained in the open state in case of small flow velocity. In this research, the experimental and analytical study on the check vale was performed. The flow coefficient and closure time were compared between the experimental and the analytical result by numerical simulation. The validation of the analytical method was performed.

  16. On-line two-dimensional capillary electrophoresis with mass spectrometric detection using a fully electric isolated mechanical valve.

    Science.gov (United States)

    Kohl, Felix J; Montealegre, Cristina; Neusüß, Christian

    2016-04-01

    CE is becoming more and more important in many fields of bioanalytical chemistry. Besides optical detection, hyphenation to ESI-MS detection is increasingly applied for sensitive identification purposes. Unfortunately, many CE techniques and methods established in research and industry are not compatible to ESI-MS since essential components of the background electrolyte interfere in ES ionization. In order to identify unknown peaks in established CE methods, here, a heart-cut 2D-CE separation system is introduced using a fully isolated mechanical valve with an internal loop of only 20 nL. In this system, the sample is separated using potentially any non-ESI compatible method in the first separation dimension. Subsequently, the portion of interest is cut by the internal sample loop of the valve and reintroduced to the second dimension where the interfering compounds are removed, followed by ESI-MS detection. When comparing the separation efficiency of the system with the valve to a system using a continuous capillary only a slight increase in peak width is observed. Ultraviolet/visible detection is integrated in the first dimension for switching time determination, enabling reproducible cutting of peaks of interest. The feasibility of the system is successfully demonstrated by a 2D analysis of a BSA tryptic digest sample using a nonvolatile (phosphate based) background electrolyte in the first dimension.

  17. Assessing the efficiency of automatically controlled valves (ACV) for pipeline sectioning

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, Leandro S. da; Silva, Marcos J.M. da; Leite, Joao Paulo de B.; Santos, Renata N.R. dos; Jardim, Rodrigo B.O.; Quinto, Thiago C. do [Petrobras Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In order to mitigate the effects caused by the rupture of a gas pipeline and following ASME B 31.8 recommendations, block valves are installed in these structures. However, many transportation companies also install devices capable of infer the occurrence of an accident in a gas pipeline. The most common devices are the ones that actuate when pressure in gas pipeline reaches a low value early established (PSL) and those which close valves due to high rate of pressure drop (line-break). Line-break has the function of identifying as fast as possible the occurrence of a rupture in a gas pipeline by high rate of pressure drop in that line. Although PSL presents a later actuation when compared to the line break, it represents redundancy to the line-break system, since it is able to isolate the segment where the accident happened even if other devices or the operator had not done it before. The growing of gas pipelines transport capacity has been generated transients capable of causing an erroneous shut down of the shut down valves (SDV). The aim of this paper, therefore, is to present how the operational limits of SDV can be overcome with remote operation using SCADA System. (author)

  18. Preliminary Analysis of a Steam Line Break Accident with the MARS-KS code for the SMART Design with Passive Safety Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Doohyuk; Ko, Yungjoo; Suh, Jaeseung [Hannam Univ., Daejeon (Korea, Republic of); Bae, Hwang; Ryu, Sunguk; Yi, Sungjae; Park, Hyunsik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    SMART has been developed by KAERI, and SMART-Standard Design Approval (SDA) was recently granted in 2012. A SMART design with Passive Safety System (PSS) features (called SMART-PSS) is being developed and added to the standard design of SMART by KAERI to improve its safety system. Active safety systems such as safety injection pumps will be replaced by a passive safety system, which is actuated only by the gravity force caused by the height difference. All tanks for the passive safety systems are higher than the injection nozzle, which is located around the reactor coolant pumps (RCPs). In this study, a preliminary analysis of the main steam line break accident (MSLB) was performed using the MARS-KS code to understand the general behavior of the SMART-PSS design and to prepare its validation test with the SMART-ITL (FESTA) facility. An anticipated accident for the main steam line break (MSLB) was performed using the MARS-KS code to understand the thermal-hydraulic behaviors of the SMART-PSS design. The preliminary analysis provides good insight into the passive safety system design features of the SMART-PSS and the thermal-hydraulic characteristics of the SMART design. The analysis results of the MSLB showed that the core water collapsed level inside the core support barrel was maintained high over the active core top level during the transient period. Therefore, the SMART-PSS design has satisfied the requirements to maintain the plant at a safe shutdown condition during 72 hours without AC power or operator action after an anticipated accident.

  19. Experimental Investigation on Small Break Loss of Coolant Accident for Direct Vessel Injection Line%DVI管小破口失水事故实验研究

    Institute of Scientific and Technical Information of China (English)

    彭传新; 张妍; 黄志刚; 昝元锋; 卓文彬; 闫晓

    2016-01-01

    在模块化小型反应堆非能动安全系统综合模拟实验装置上进行了压力容器直接注入(DVI)管小破口失水事故实验,研究了DVI管小破口失水事故过程中的热工水力现象和非能动安全系统运行特性。研究结果表明:模块化小型反应堆DVI管小破口失水事故中,非能动安全系统可对堆芯进行注水,有效导出堆芯衰变热量,保护堆芯安全。%T he small break loss of coolant accident (SBLOCA ) experiment for direct vessel injection (DVI ) line , w hich investigated the thermal‐hydraulic phenomena and the performances of passive safety system during the accident ,was performed on the passive safety system test facility for small modular reactor .The experimental results show that the passive safety system of small modular reactor can provide effective cool‐ant injection ,successful removal of core residual heat under the DVI line SBLOCA and protection to reactor core safety .

  20. Thermal-Hydraulic Integral Effect Test with ATLAS for an Intermediate Break Loss of Coolant Accident at a Pressurizer Surge Line

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyoung Ho; Seok Cho; Park, Hyun Sik; Choi, Nam Hyun; Park, Yu Sun; Kim, Jong Rok; Bae, Byoung Uhn; Kim, Yeon Sik; Kim, Kyung Doo; Choi, Ki Yong; Song, Chul Hwa [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The main objectives of this test were not only to provide physical insight into the system response of the APR1400 during the pressurizer surge line break accident but also to produce an integral effect test data to validate the SPACE code. In order to simulate a double-ended guillotine break of a pressurizer surge line in the APR1400, the IB-SUR-01R test was performed with ATLAS. The major thermal-hydraulic phenomena such as the system pressures, the collapsed water levels, and the break flow rate were presented and discussed. Despite the core was uncovered, no excursion in the cladding temperature was observed. The pressurizer surge line break can be classified as a hot leg break from a break location point of view. Compared with a cold leg break, coolability in the core may be better in case of a hot leg break due to the enhanced flow in the core region. This integral effect test data will be used to evaluate the prediction capability of existing safety analysis codes of the MARS and the RELAP5 as well as the SPACE code. Furthermore, this data can be utilized to identify any code deficiency for an IBLOCA simulation, especially for DVI-adapted plants. Redefinition of break size for design basis accident (DBA) based on risk information is being extensively investigated due to the potential for safety benefits and unnecessary burden reduction from current LBLOCA (large break loss of coolant accident)-based ECC (Emergency Core Cooling) Acceptance Criteria. As a transition break size (TBS), the rupture of medium-size pipe is considered to be more important than ever in risk-informed regulation (RIR)-relevant safety analysis. As plants age, are up-rated, and continue to seek improved operating efficiencies, the small break and intermediate break LOCA (IBLOCA) can become a concern. In particular, IBLOCA with DVI (Direct Vessel Injection) features will be addressed to support redefinition of a design-basis LOCA. With an aim of expanding code validation to address small

  1. Whitey SCHE Gauge and Root Valves

    Energy Technology Data Exchange (ETDEWEB)

    MISKA, C.R.

    2000-09-11

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHa System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHa supply line.

  2. Whitey SCHE Gauge and Root Valves

    Energy Technology Data Exchange (ETDEWEB)

    MISKA, C.R.

    2000-09-03

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHe System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHe supply line.

  3. 49 CFR 229.109 - Safety valves.

    Science.gov (United States)

    2010-10-01

    ....109 Safety valves. Every steam generator shall be equipped with at least two safety valves that have a combined capacity to prevent an accumulation of pressure of more than five pounds per square inch above the... ends of the safety valve discharge lines shall be located or protected so that discharged steam...

  4. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    DEFF Research Database (Denmark)

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    The analytical performance of an on-line sequential injection lab-on-valve (SI-LOV) system using chelating Sepharose beads as sorbent material for the determination of ultra trace levels of Cd(II), Pb(II) and Ni(II) by electrothermal atomic absorption spectrometry (ETAAS) is described and discussed...

  5. Bicycle accidents.

    Science.gov (United States)

    Lind, M G; Wollin, S

    1986-01-01

    Information concerning 520 bicycle accidents and their victims was obtained from medical records and the victims' replies to questionnaires. The analyzed aspects included risk of injury, completeness of accident registrations by police and in hospitals, types of injuries and influence of the cyclists' age and sex, alcohol, fatigue, hunger, haste, physical disability, purpose of cycling, wearing of protective helmet and other clothing, type and quality of road surface, site of accident (road junctions, separate cycle paths, etc.) and turning manoeuvres.

  6. Performance and scenario evaluation of PAFS through the LOFW accident in APR1400 by using MARS code

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sung Won; Bae, Byoung Uhn; Yun, Byong Jo [Korea Atomic Energy Institute, Daejeon (Korea, Republic of)

    2009-07-01

    In order to enhance the safety feature of the APR1400 through the passive ways, the passive auxiliary feedwater system(PAFS) is under preliminary consideration by KAERI. For the successful adaptation of PAFS, accident scenario evaluation of PWR plant that is assumed to have the PAFS system should be performed. Condensing heat exchanger assemblies are installed at the exterior boundary of the containment building per one steam generator. The performance of the heat exchanger is designed to remove the decay heat of the fuel completely. In normal operation condition, PAFS system is not connected with the steam and feed lines. A Total Loss of Feed Water(TLOFW) accident is selected for the performance and scenario evaluation after the severity check. The PAFS connection valves are open at the signal of 25% level trip of steam generator. With the single failure assumption of PAFS open valve, the scenario propagations are calculated by using MARS code.

  7. Characterization and Analyses of Valves, Feed Lines and Tanks used in Propellant Delivery Systems at NASA SSC

    Science.gov (United States)

    Ryan, Harry M.; Coote, David J.; Ahuja, Vineet; Hosangadi, Ashvin

    2006-01-01

    Accurate modeling of liquid rocket engine test processes involves assessing critical fluid mechanic and heat and mass transfer mechanisms within a cryogenic environment, and accurately modeling fluid properties such as vapor pressure and liquid and gas densities as a function of pressure and temperature. The Engineering and Science Directorate at the NASA John C. Stennis Space Center has developed and implemented such analytic models and analysis processes that have been used over a broad range of thermodynamic systems and resulted in substantial improvements in rocket propulsion testing services. In this paper, we offer an overview of the analyses techniques used to simulate pressurization and propellant fluid systems associated with the test stands at the NASA John C. Stennis Space Center. More specifically, examples of the global performance (one-dimensional) of a propellant system are provided as predicted using the Rocket Propulsion Test Analysis (RPTA) model. Computational fluid dynamic (CFD) analyses utilizing multi-element, unstructured, moving grid capability of complex cryogenic feed ducts, transient valve operation, and pressurization and mixing in propellant tanks are provided as well.

  8. 46 CFR 105.25-20 - Shutoff valves required.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Shutoff valves required. 105.25-20 Section 105.25-20... Installed Below Decks § 105.25-20 Shutoff valves required. (a) Shutoff valves shall be provided in the suction lines as close to the tanks as possible. The valves shall be installed so as to shut off...

  9. Avoidance of transmission line pressure oscillations in discrete hydraulic systems – by shaping of valve opening characteristics

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Pedersen, Henrik C.; Bech, Michael Møller

    2015-01-01

    The architecture of multi pressure line discrete fluid power force systems imposes rapid pressure shifts in the actuator volumes. These fast shifts between pressure levels often introduce pressure oscillations in the actuator chamber and connecting pipes. The topic of this paper is to perform...... pressure shifts by changing the connection between various fixed pressure lines without introducing significant pressure oscillation. As a case study a discrete force system is utilised is a Power Take Off(PTO) system of a wave energy converter. Four pressure shifting algorithms are proposed...

  10. CPR1000全厂断电叠加蒸汽发生器安全阀误开启事故引起的严重事故分析%Analysis of CPR1000 Severe Accident Induced by SBO With SG Safety Valve Stuck Open

    Institute of Scientific and Technical Information of China (English)

    李龙泽; 王明军; 田文喜; 苏光辉; 秋穗正

    2014-01-01

    The CPR1000 severe accident caused by station blackout (SBO) with the SG safety valve stuck open was modeled and analyzed using MELCOR code ,and the simula-tion of CPR1000 severe accident process was preliminarily achieved . Three assump-tions ,namely without shaft sealing leakage and auxiliary feed water ,with shaft sealing leakage and auxiliary feed water ,and with shaft sealing leakage but without auxiliary feed water ,were analyzed .The results imply that SG safety valve stuck open has great influence on the accident sequences .According to the calculation results ,without shaft sealing leakage and auxiliary feed water ,pressure vessel will fail at 9 576 s .When auxil-iary feed water supplies ,pressure vessel failure delays nearly 30 000 s .When the leak-age of the shaft sealing system exists ,pressure vessel failure will delay about 50 s .The results show that the auxiliary feed water and the leakage of the shaft sealing system have great mitigation effect on the severe accident induced by SBO with SG safety valve stuck open .%利用MELCOR程序对CPR1000全厂断电叠加蒸汽发生器(SG)安全阀误开启事故引发的严重事故进行建模与分析,初步实现了对CPR1000严重事故进程的仿真计算与模拟。文中重点分析了无轴封泄漏和辅助给水、有轴封泄漏和辅助给水、有轴封泄漏但无辅助给水3种不同假设条件下CPR1000全厂断电严重事故的响应进程和结果。计算结果显示,SG安全阀误开启对事故进程有重要影响。在无轴封泄漏和辅助给水的情况下,压力容器在9576 s失效;当存在辅助给水时,压力容器失效延后近30000 s;而当存在轴封泄漏时,压力容器失效延后50 s左右。结果证明了发生全场断电叠加SG安全阀误开启事故情况下辅助给水和轴封泄漏对事故起到有效缓解作用。

  11. EVALUATION OF A MULTIFUNCTIONAL VALVE ASSEMBLY IN A DIRECT EXPANSION REFRIGERATION SYSTEM REPORT

    Science.gov (United States)

    The report describes the performance, including energy consumption, of a refrigeration system incorporating a multifunctional valve (MXV assembly). The MXV assembly (consisting of additional liquid line, an XTC valve, and a larger thermostatic expansion valve) was installed on al...

  12. Valve's Way

    Directory of Open Access Journals (Sweden)

    Phanish Puranam

    2015-06-01

    Full Text Available What can we learn from outliers? While statisticians rightly warn us against their non-representativeness, we believe it is also true that thinking carefully about what makes them atypical may improve our understanding of the typical case. This is the premise behind the Organization Zoo series. Valve Corporation (Valve is an unusual firm. It is a rare example of a firm that appears to operate without any formal hierarchy in its organization. What can we learn about the viability of authority hierarchies from Valve’s way of organizing? We wrote a brief account of Valve based on public information sources and asked several renowned organizational experts to comment on this unusual firm. We asked them to write a short commentary on what the Valve example means for organizational theorists and practitioners. Thankfully, they all accepted, and we are excited to present the results of their thinking in this first “exhibit” in the Organization Zoo.

  13. Safety/relief-valve test program

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, J.A.

    1982-01-01

    In response to the NRC's Task 2.1.2 following the TMI-2 accident, government and industry programs were formulated to address the performance of safety and relief valve systems for pressurized and boiling water reactors. Objective is to demonstrate by testing and analysis that safety and relief valve systems in the reactor coolant system are qualified for the anticipated full range of reactor operating and accident conditions. The EPRI PWR program tested PWR safety valves and power operated relief valves (PORVs) under steam, liquid, and steam/liquid transition conditions. The program also tested PWR PORV block valves under steam conditions. The GE BWR program tested BWR relief and safety/relief valves under high pressure steam and low pressure liquid conditions. EG and G Idaho recent activities have focused on the evaluation of the industry test data, evaluation and modification of analytical codes for safety/relief valve system analysis, and initial evaluation of utility responses to US NRC program requirements.

  14. Accident Statistics

    Data.gov (United States)

    Department of Homeland Security — Accident statistics available on the Coast Guard’s website by state, year, and one variable to obtain tables and/or graphs. Data from reports has been loaded for...

  15. Sports Accidents

    CERN Multimedia

    Kiebel

    1972-01-01

    Le Docteur Kiebel, chirurgien à Genève, est aussi un grand ami de sport et de temps en temps médecin des classes genevoises de ski et également médecin de l'équipe de hockey sur glace de Genève Servette. Il est bien qualifié pour nous parler d'accidents de sport et surtout d'accidents de ski.

  16. 49 CFR 236.383 - Valve locks, valves, and valve magnets.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Valve locks, valves, and valve magnets. 236.383... Inspection and Tests § 236.383 Valve locks, valves, and valve magnets. Valve locks on valves of the non-cut-off type shall be tested at least once every three months, and valves and valve magnets shall...

  17. Piezoelectric valve

    Science.gov (United States)

    Petrenko, Serhiy Fedorovich

    2013-01-15

    A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

  18. ENERGY EFFICIENT AND SAFE VALVE TESTING UNIT USING WIRELESS TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    V. Dhivya

    2013-04-01

    Full Text Available The valve testing unit is a high pressure test equipment to test the valve manufactured in industries. Valves are tested to ensure that they sustain high pressure in the range of 10000 to 15000 PSI for the required amount of time without any leakage. It has few drawbacks such as inefficient usage of power, fatal accidents due to the proximity of the users with the testing unit to note the valve pressure during operation. It is much dangerous for the industry personnel to note the valve pressure for every minute during operation. There are chances of bolts fitted in the valve thrown away due to the issues in the bolt fittings and the immense pressure inside the valve. Therefore in order to avoid fatal accidents andto improve the industrial safety an efficient valve testing unit is designed and developed using ZigBee wireless transmission technology. The proposed efficient pressure monitoring unit uses emerging technologies like ZigBee, RFID along with ARM 7 processor. The proposed system uses LabVIEW software to develop the monitoring unit in PC. ZigBee wireless transmission technology is used for remote monitoring of valve pressure for every minute. RFID module is used for uniquely identifying the valve and to track the test results. The proposed unit saves energy by sending a signal to turn off the air driven booster pump once the prescribed pressure level is reached. Theproposed unit also indicates the oil level of the test unit which avoids the manual intervention to verify the oil level and also detects issues in the bolts fitted in the valve by using a distance sensor which is to avoid fatal accidents by stopping the valve testing unit.

  19. APT Blanket System Loss-of-Coolant Accident (LOCA) Based on Initial Conceptual Design - Case 4: External Pressurizer Surge Line Break Near Inlet Header

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L.L.

    1998-10-07

    This report is one of a series of reports documenting accident scenario simulations for the Accelerator Production of Tritium (APT) blanket heat removal systems. The simulations were performed in support of the Preliminary Safety Analysis Report (PSAR) for the APT.

  20. Excess flow shutoff valve

    Energy Technology Data Exchange (ETDEWEB)

    Kiffer, Micah S.; Tentarelli, Stephen Clyde

    2016-02-09

    Excess flow shutoff valve comprising a valve body, a valve plug, a partition, and an activation component where the valve plug, the partition, and activation component are disposed within the valve body. A suitable flow restriction is provided to create a pressure difference between the upstream end of the valve plug and the downstream end of the valve plug when fluid flows through the valve body. The pressure difference exceeds a target pressure difference needed to activate the activation component when fluid flow through the valve body is higher than a desired rate, and thereby closes the valve.

  1. Vacuum Valve

    CERN Multimedia

    1974-01-01

    This valve was used in the Intersecting Storage Rings (ISR) to protect against the shock waves that would be caused if air were to enter the vacuum tube. Some of the ISR chambers were very fragile, with very thin walls - a design required by physicists on the lookout for new particles.

  2. Valve's Way

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Dobrajska, Magdalena

    2015-01-01

    to what extent it represents a new blueprint for organization design, despite it being consistent with an “egalitarian Zeitgeist” (Puranam, 2014). In fact, managerial authority may be of increasing importance rather than the opposite (Guadalupe, Li, & Wulf, 2015). Thus, Valve is, and will remain...

  3. Valve's Way

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Dobrajska, Magdalena

    2015-01-01

    Puranam and Håkonsson (2015) challenge us to ponder what we as organization design theorists make of Valve’s way (see also Jeppesen, 2008). We believe that Valve, in spite of its radical vision, does not represent a challenge to fundamental organization design theory and that it is questionable...

  4. Recurrent stuck mitral valve: eosinophilia an unusual pathology.

    Science.gov (United States)

    Awasthy, Neeraj; Bhat, Yasser; Radhakrishnan, S; Sharma, Rajesh

    2015-03-01

    Eosinophilia is a very unusual and rare cause of thrombosis of prosthetic mitral valve. We report a 10-year-old male child of recurrent stuck prosthetic mitral valve. The child underwent mitral valve replacement for severe mitral regurgitation secondary to Rheumatic heart disease. He had recurrent prosthetic mitral valve thrombosis, despite desired INR levels. There was associated eosinophilia. The child was treated on the lines of tropical eosinophilia with oral prednisolone and diethylcarbamazine, the eosinophil count dropped significantly with no subsequent episode of stuck mitral valve. We discuss the management of recurrent stuck mitral valve and also eosinophilia as a causative factor for the same.

  5. Aortic valve bypass

    DEFF Research Database (Denmark)

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI...

  6. Robotic mitral valve replacement.

    Science.gov (United States)

    Senay, Sahin; Gullu, Ahmet Umit; Kocyigit, Muharrem; Degirmencioglu, Aleks; Karabulut, Hasan; Alhan, Cem

    2014-01-01

    Robotic surgical techniques allow surgeons to perform mitral valve surgery. This procedure has gained acceptance, particularly for mitral valve repair in degenerative mitral disease. However, mitral repair may not always be possible, especially in severely calcified mitral valve of rheumatic origin. This study demonstrates the basic concepts and technique of robotic mitral valve replacement for valve pathologies that are not suitable for repair.

  7. 46 CFR 45.155 - Inlets and discharge piping: Valves.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Inlets and discharge piping: Valves. 45.155 Section 45... LINES Conditions of Assignment § 45.155 Inlets and discharge piping: Valves. (a) Except as provided in... visited by the crew. (e) Through-hull piping systems in machinery spaces may have valves with...

  8. 33 CFR 183.528 - Fuel stop valves.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel stop valves. 183.528 Section...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.528 Fuel stop valves. (a) Each electrically operated fuel stop valve in a fuel line between the fuel tank and the...

  9. Accident: Reminder

    CERN Document Server

    2003-01-01

    There is no left turn to Point 1 from the customs, direction CERN. A terrible accident happened last week on the Route de Meyrin just outside Entrance B because traffic regulations were not respected. You are reminded that when travelling from the customs, direction CERN, turning left to Point 1 is forbidden. Access to Point 1 from the customs is only via entering CERN, going down to the roundabout and coming back up to the traffic lights at Entrance B

  10. Automatic shutoff valve

    Science.gov (United States)

    Hawkins, S. F.; Overbey, C. W.

    1980-01-01

    Cellulose-sponge disk absorbs incoming water and expands with enough force to shut valve. When water recedes, valve opens by squeezing sponge dry to its original size. This direct mechanical action is considered more reliable than solenoid valve.

  11. Hydrodynamic Performance of the Medtronic CoreValve and the Edwards SAPIEN XT Transcatheter Heart Valve in Surgical Bioprostheses: An In Vitro Valve-in-Valve Model.

    Science.gov (United States)

    Sedaghat, Alexander; Sinning, Jan-Malte; Utzenrath, Marc; Ghalati, Pejman Farhadi; Schmitz, Christoph; Werner, Nikos; Nickenig, Georg; Grube, Eberhard; Ensminger, Stephan; Steinseifer, Ulrich; Kuetting, Maximilian

    2016-01-01

    Valve-in-valve transcatheter aortic valve replacement (TAVR) is becoming a valuable option with promising clinical results in failed bioprosthetic heart valves. Sizing recommendations are based on size compatibility rather than on broad clinical data, in vitro measurements, or biomechanical evidence. The hemodynamic performance of transcatheter heart valves within degenerated surgical heart valves is unknown. We evaluated the in vitro hydrodynamic performance of two commercially available transcatheter heart valves (Medtronic CoreValve [Medtronic, Minneapolis, MN] and Edwards SAPIEN XT [Edwards Lifesciences, Irvine, CA]) in two different bioprosthetic aortic valves (Edwards Perimount [Edwards Lifesciences] and St. Jude Trifecta [St. Jude Medical, St. Paul, MN]). Within the Edwards Perimount (23 mm) prosthesis, pressure gradients were higher for the SAPIEN XT compared with the CoreValve (11.2 ± 0.1 mm Hg versus 10.1 ± 0.1 mm Hg, p < 0.01), whereas effective orifice area (1.99 ± 0.01 cm(2) versus 1.80 ± 0.01 cm(2), p < 0.01) and total paravalvular leakage (9.0% ± 1.0% versus 5.4% ± 1.3%, p < 0.01) were increased when using the CoreValve. Similarly, measurements in the St. Jude Trifecta revealed higher transvalvular pressure gradients (13.0 ± 0.2 mm Hg versus 10.9 ± 0.3 mm Hg, p < 0.01) and lower effective orifice area for the SAPIEN XT compared with the CoreValve. However, total relative regurgitation was higher with SAPIEN XT as compared with the CoreValve in St. Jude Trifecta prostheses (11.2% ± 1.4% versus 8.3% ± 0.9%, p < 0.01). Both transcatheter heart valve prostheses performed well in the described valve-in-valve settings. Hydrodynamic results were in line with the International Organization for Standardization standards for all configurations. The observed differences indicate a necessity for preclinical valve-in-valve tests in addition to clinical long-term data about longevity. Copyright © 2016 The Society of Thoracic Surgeons. Published by

  12. Adjustable safety relief valve

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W.L.

    1990-06-12

    This patent describes a pressure relief valve having a relief set pressure. It comprises: a valve body having a fluid inlet and outlet, a spherical, metal valve seat associated with the inlet and a valve member comprising at least a portion of a spherical,metal ball attached to a ball holding element, the valve member being biased against the valve seat and thus providing a metal-to-metal seal preventing the passage of fluids past the valve seat when the fluid pressure in the inlet is below the relief pressure setting of the valve.

  13. Improvements to the RELAP/SCDAPSIM of Laguna Verde model for the analysis of transients and accidents; Mejoras al modelo de Laguna Verde de RELAP/SCDAPSIM para el analisis de transitorios y accidentes

    Energy Technology Data Exchange (ETDEWEB)

    Amador G, R.; Castillo D, R.; Ortiz V, J.; Araiza M, E.; Martinez C, E., E-mail: rogelio.castillo@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2016-09-15

    This work presents the improvements to the integral model of the nuclear power plant of Laguna Verde for the RELAP/SCDAPSIM code, for the simulation of transients and severe accidents. The model includes a new detailed geometry of the steam lines, as well as improvements in the performance of the emergency systems. A primary containment model has also been created, which will be used to analyze the effect of safety valve and relief valve discharges to the wet well suppression pool and the effect of the rupture of a recirculation loop on the dry well. The simulations performed with the new model show that the changes made improve the prediction of the phenomenology involved during transients and accidents. (Author)

  14. On-line dynamic extraction and automated determination of readily bioavailable hexavalent chromium in solid substrates using micro-sequential injection bead-injection lab-on-valve hyphenated with electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald

    2006-01-01

    A novel and miniaturized micro-sequential injection bead injection lab-on-valve (μSI-BI-LOV) fractionation system was developed for in-line microcolumn soil extraction under simulated environmental scenarios and accurate monitoring of the content of easily mobilisable hexavalent chromium in soil...... environments at the sub-low parts-per-million level. The flow system integrates dynamic leaching of hexavalent chromium using deionized water as recommended by the German Standard DIN 38414-S4 method; on-line pH adjustment of the extract by a 0.01 mol L-1 Tris-HNO3 buffer solution; isolation of the chromate......). The effect of simulated acidic rain on the accessibility of chromate forms for plant uptake was also investigated. The proposed approach offers several advantages over conventional speciation/fractionation protocols in the batch mode, including immediate separation with concomitant preconcentration...

  15. Self-reported accidents

    DEFF Research Database (Denmark)

    Møller, Katrine Meltofte; Andersen, Camilla Sloth

    2016-01-01

    The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals.......The main idea behind the self-reporting of accidents is to ask people about their traffic accidents and gain knowledge on these accidents without relying on the official records kept by police and/or hospitals....

  16. Valve-in-valve-in-valve: Treating endocarditis of a transcatheter heart valve.

    Science.gov (United States)

    Nguyen, Caroline; Cheong, Adrian P; Himbert, Dominique

    2015-10-01

    Transcatheter heart valve endocarditis is a rare, but life threatening complication. We describe the case of a patient who was successfully treated by transcatheter aortic valve-in-valve-in-valve replacement with a favorable 1-year outcome, despite severe early complications.

  17. Microfluidic sieve valves

    Science.gov (United States)

    Quake, Stephen R; Marcus, Joshua S; Hansen, Carl L

    2015-01-13

    Sieve valves for use in microfluidic device are provided. The valves are useful for impeding the flow of particles, such as chromatography beads or cells, in a microfluidic channel while allowing liquid solution to pass through the valve. The valves find particular use in making microfluidic chromatography modules.

  18. Remote actuated valve implant

    Energy Technology Data Exchange (ETDEWEB)

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  19. Thermal-hydraulic analysis for changing feedwater check valve leakage rate testing methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.; Harrell, J.

    1996-12-01

    The current design and testing requirements for the feedwater check valves (FWCVs) at the Grand Gulf Nuclear Station are established from original licensing requirements that necessitate extremely restrictive air testing with tight allowable leakage limits. As a direct result of these requirements, the original high endurance hard seats in the FWCVs were modified with elastomeric seals to provide a sealing surface capable of meeting the stringent air leakage limits. However, due to the relatively short functional life of the elastomeric seals compared to the hard seats, the overall reliability of the sealing function actually decreased. This degraded performance was exhibited by frequent seal failures and subsequent valve repairs. The original requirements were based on limited analysis and the belief that all of the high energy feedwater vaporized during the LOCA blowdown. These phenomena would have resulted in completely voided feedwater lines and thus a steam environment within the feedwater leak pathway. To challenge these criteria, a comprehensive design basis accident analysis was developed using the RELAP5/MOD3.1 thermal-hydraulic code. Realistic assumptions were used to more accurately model the post-accident fluid conditions within the feedwater system. The results of this analysis demonstrated that no leak path exists through the feedwater lines during the reactor blowdown phase and that sufficient subcooled water remains in various portions of the feedwater piping to form liquid water loop seals that effectively isolate this leak path. These results provided the bases for changing the leak testing requirements of the FWCVs from air to water. The analysis results also established more accurate allowable leakage limits, determined the real effective margins associated with the FWCV safety functions, and led to design changes that improved the overall functional performance of the valves.

  20. Scissor thrust valve actuator

    Science.gov (United States)

    DeWall, Kevin G.; Watkins, John C; Nitzel, Michael E.

    2006-08-29

    Apparatus for actuating a valve includes a support frame and at least one valve driving linkage arm, one end of which is rotatably connected to a valve stem of the valve and the other end of which is rotatably connected to a screw block. A motor connected to the frame is operatively connected to a motor driven shaft which is in threaded screw driving relationship with the screw block. The motor rotates the motor driven shaft which drives translational movement of the screw block which drives rotatable movement of the valve driving linkage arm which drives translational movement of the valve stem. The valve actuator may further include a sensory control element disposed in operative relationship with the valve stem, the sensory control element being adapted to provide control over the position of the valve stem by at least sensing the travel and/or position of the valve stem.

  1. Valve-in-Valve Replacement Using a Sutureless Aortic Valve

    Science.gov (United States)

    Dohmen, Pascal M.; Lehmkuhl, Lukas; Borger, Michael A.; Misfeld, Martin; Mohr, Friedrich W.

    2016-01-01

    Patient: Female, 61 Final Diagnosis: Tissue degeneration Symptoms: Dyspnea Medication: — Clinical Procedure: Redo valve replacement Specialty: Surgery Objective: Rare disease Background: We present a unique case of a 61-year-old female patient with homograft deterioration after redo surgery for prosthetic valve endocarditis with root abscess. Case Report: The first operation was performed for type A dissection with root, arch, and elephant trunk replacement of the thoracic aorta. The present re-redo surgery was performed as valve-in-valve with a sutureless aortic biopros-thesis. The postoperative course was uneventful and the patient was discharged on day 6. Conclusions: The current case report demonstrates that sutureless bioprostheses are an attractive option for surgical valve-in-valve procedures, which can reduce morbidity and mortality. PMID:27694795

  2. Large Scale Magnetostrictive Valve Actuator

    Science.gov (United States)

    Richard, James A.; Holleman, Elizabeth; Eddleman, David

    2008-01-01

    Marshall Space Flight Center's Valves, Actuators and Ducts Design and Development Branch developed a large scale magnetostrictive valve actuator. The potential advantages of this technology are faster, more efficient valve actuators that consume less power and provide precise position control and deliver higher flow rates than conventional solenoid valves. Magnetostrictive materials change dimensions when a magnetic field is applied; this property is referred to as magnetostriction. Magnetostriction is caused by the alignment of the magnetic domains in the material s crystalline structure and the applied magnetic field lines. Typically, the material changes shape by elongating in the axial direction and constricting in the radial direction, resulting in no net change in volume. All hardware and testing is complete. This paper will discuss: the potential applications of the technology; overview of the as built actuator design; discuss problems that were uncovered during the development testing; review test data and evaluate weaknesses of the design; and discuss areas for improvement for future work. This actuator holds promises of a low power, high load, proportionally controlled actuator for valves requiring 440 to 1500 newtons load.

  3. Oil pipeline valve automation for spill reduction

    Energy Technology Data Exchange (ETDEWEB)

    Mohitpour, Mo; Trefanenko, Bill [Enbridge Technology Inc, Calgary (Canada); Tolmasquim, Sueli Tiomno; Kossatz, Helmut [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    Liquid pipeline codes generally stipulate placement of block valves along liquid transmission pipelines such as on each side of major river crossings where environmental hazards could cause or are foreseen to potentially cause serious consequences. Codes, however, do not stipulate any requirement for block valve spacing for low vapour pressure petroleum transportation, nor for remote pipeline valve operations to reduce spills. A review of pipeline codes for valve requirement and spill limitation in high consequence areas is thus presented along with a criteria for an acceptable spill volume that could be caused by pipeline leak/full rupture. A technique for deciding economically and technically effective pipeline block valve automation for remote operation to reduce oil spilled and control of hazards is also provided. In this review, industry practice is highlighted and application of the criteria for maximum permissible oil spill and the technique for deciding valve automation thus developed, as applied to ORSUB pipeline is presented. ORSUB is one of the three initially selected pipelines that have been studied. These pipelines represent about 14% of the total length of petroleum transmission lines operated by PETROBRAS Transporte S.A. (TRANSPETRO) in Brazil. Based on the implementation of valve motorization on these three pipeline, motorization of block valves for remote operation on the remaining pipelines is intended, depending on the success of these implementations, on historical records of failure and appropriate ranking. (author)

  4. Transient Characteristics of Main Feedwater Line Rupture Accident for AP1000 Nuclear Power Plant%AP1000核电厂主给水管道断裂事故瞬态特性分析

    Institute of Scientific and Technical Information of China (English)

    贾祥; 安婕铷; 靖剑平

    2016-01-01

    AP1000是目前国际上典型的“三代”非能动核电厂,基于最佳估算程序 RELAP5/MOD3.3,对AP1000核电厂系统进行了详细的建模分析,获得了主给水管道断裂事故下 AP1000核电厂关键参数的瞬态特性和非能动系统响应特性。结果表明,事故过程中一、二回路的压力和温度呈现波动变化,一回路压力最大值为17.13 MPa,低于设计压力的91%,主蒸汽系统的压力也低于设计值的91%,满足验收准则的要求。%The AP1000 is the typical “third generation”passive nuclear power plant in the world at present.The primary system of AP1000 nuclear power plant was modeled using RELAP5/MOD3.3 code,and the transient thermal-hydraulic characteristics and the response characteristics of passive system were analyzed under the accident sequence of main feedwater line rupture accident.The results show that during the accident,the primary loop pressure,secondary loop pressure and primary loop temperature are fluc-tuant.The RCS pressure maximum value is 17.13 MPa,less than 91% of the design pressure.The pressure of the main steam system is also less than 91% of the designed value,which satisfies acceptance criteria.

  5. Water Distribution Lines, City of Emporia Water distribution. The point feature identifies valves, reducers, tees, etc. The line feature indicates the size of the line. We have water meters identified. Valves and meters are in process of being GPSed., Published in 2010, 1:1200 (1in=100ft) scale, City of Emporia/Lyon County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Water Distribution Lines dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Hardcopy Maps information as of 2010. It is described...

  6. Which valve is which?

    Directory of Open Access Journals (Sweden)

    Pravin Saxena

    2015-01-01

    Full Text Available A 25-year-old man presented with a history of breathlessness for the past 2 years. He had a history of operation for Tetralogy of Fallot at the age of 5 years and history suggestive of Rheumatic fever at the age of 7 years. On echocardiographic examination, all his heart valves were severely regurgitating. Morphologically, all the valves were irreparable. The ejection fraction was 35%. He underwent quadruple valve replacement. The aortic and mitral valves were replaced by metallic valve and the tricuspid and pulmonary by tissue valve.

  7. Explore Off Valve Water Hammer Problem with Long-distance Lines Filling Water Supply Project%长距离供水工程的关阀水锤与线路充填问题探讨

    Institute of Scientific and Technical Information of China (English)

    姚财鸿

    2015-01-01

    主要分析了长距离供水工程中关阀水锤特性和出现的线路填充现象,在无摩阻输水系统水锤公式的基础上,分别探讨了长距离供水系统的直接水锤和间接水锤,以期能为相关管道设计和运行调度提供理论参考。%The analysis of the long-distance water supply project hammer feature off valve and the emergence of the phenomenon of filling lines, water supply systems on the basis of non-friction formula on water hammer, water hammer, respectively, discussed the direct and indirect long-distance water supply system hammer, with a view to provide theoretical reference for the associated piping design and operation scheduling.

  8. Sequential injection/bead injection lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by ETAAS and ICPMS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald; Miró, Manuel

    2003-01-01

    This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions......, that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C18-PS/DVB). Using ETAAS as detection device, the easy......-to-handle hydrophilic renewable reactors hold the features of improved R.S.D.s and LODs as compared to those operated in the conventional, permanent mode, in addition to the elimination of flow resistance. The hydrophobic columns fall into two categories, that is, the renewable one packed with C18-PS/DVB beads entails...

  9. Project installation the large equipment in line system in Brazil. Gas export line valve P-40 FPSO-MLS. Field Marlim Sul, Campos Basin, Brazil; Operacao de instalacao do maior equipamento no sistema in line ja realizado no Brasil. Valvula do gasoduto P-40 X FPSO-MLS. Campo de Marlim Sul, Bacia de Campos, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Marcos Antonio Rodrigues; Fernandes, Paulo Tavares [PETROBRAS, Campos dos Goytacases, RJ (Brazil). Exploracao e Producao

    2005-07-01

    This work will approach the current level of development of the installation of connected underwater equipment to flexible lines in the underwater engineering operations in Campos' Basin. The project will show studies, analysis and simulations (through software developed by PETROBRAS) about the installation of the largest equipment laid in the 'in-line' system (connected to flexible lines) in Brazil - and one of the largest of the world: the ESDV (Emergency Shut Down Valve) of the gas pipeline P-40 x FPSO-MLS, in the South Marlim field, in Campos' Basin. This ESDV, of about 18.000 kg, 4 m height and 6,5 m length, has the purpose of assuring the safety conditions on the facilities, interrupting the gas flow exported for P-40 in case of emergency situations. Its installation opened a new alternative in releasing underwater equipment, using the ships that install the flexible lines. This operation occurred in June, 2004, and required the use of a second vessel for support and monitoring of the ESDV laying. The ESDV was installed at 400 m from FPSO-MLS, in a water depth of 1.137 m. This method shall be used broadly by the company in the implantation of the new units of Campos' Basin, and the upcoming studies must consider the gradual increase of the water depth in the new projects. This work will focus the technological development in this area, and one of its purposes is to foresee the future difficulties that can appear in the implantation of the production systems in deep and ultra-deep waters. (author)

  10. Aortic Valve Regurgitation

    Science.gov (United States)

    ... inside your heart that involves heart valves. Rheumatic fever. Rheumatic fever — a complication of strep throat and once a ... the United States — can damage the aortic valve. Rheumatic fever is still prevalent in developing countries but rare ...

  11. Pulmonary Valve Stenosis

    Science.gov (United States)

    ... growths called carcinoid tumors in the digestive system. Rheumatic fever. This complication of an infection caused by streptococcus ... valve stenosis later in life, including: Carcinoid syndrome Rheumatic fever Noonan's syndrome Mild to moderate pulmonary valve stenosis ...

  12. Aortic Valve Disease

    Science.gov (United States)

    ... Tricuspid Valve Disease Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Pediatric and Congenital Heart Disease Heart abnormalities that are ... Transplantation End-stage Lung Disease Adult Lung Transplantation Pediatric Lung ... Aortic Aneurysm Aortic Valve Disease Overview The human heart has ...

  13. Mitral Valve Stenosis

    Science.gov (United States)

    ... up around the ring around the mitral valve (annulus), which can occasionally cause mitral valve stenosis. Other ... the condition of your lungs. Transesophageal echocardiogram. A small transducer attached to the end of a tube ...

  14. Heart valve surgery

    Science.gov (United States)

    ... Tricuspid valve stenosis Risks The risks of having cardiac surgery include: Death Heart attack Heart failure Bleeding requiring ... and the A.D.A.M. Editorial team. Heart Surgery Read more Heart Valve Diseases Read more Latest ...

  15. Posttraumatic tricuspid valve injury and severe tricuspid valve regurgitation.

    Science.gov (United States)

    Gucuk Ipek, Esra

    2013-09-01

    A 66-year-old male was brought to our hospital following a car accident. He had subarachnoid hemorrhage, multiple rib fractures, and left hemopneumothorax. He was referred to the Cardiology Department for elevated troponin levels (42 ng/ml, reference 0-1 ng/ml). The electrocardiogram was free of ischemia, whereas the transthoracic echocardiography revealed dilated right heart chambers, enlarged tricuspid annulus and coaptation failure of the tricuspid valvular leaflets. There was rupture on the subvalvular apparatus of the anterior leaflet of the tricuspid valve with accompanying prolapse, causing severe tricuspid valvular regurgitation. The patient did not present right ventricular failure signs and symptoms; he was referred to surgery after the resolution of associated thoracic and cranial injuries.

  16. Isolated Pulmonary Valve Endocarditis

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hatamizadeh

    2009-06-01

    Full Text Available Infective endocarditis is one of the most severe complications of parenteral drug abuse. The outstanding clinical feature of infective endocarditis in intravenous drug abusers is the high incidence of right-sided valve infection, and the tricuspid valve is involved in 60% to 70% of the cases. We herein report a case of isolated pulmonic valve infective endocarditis with a native pulmonary valve.

  17. Aerodynamic Shutoff Valve

    Science.gov (United States)

    Horstman, Raymond H.

    1992-01-01

    Aerodynamic flow achieved by adding fixed fairings to butterfly valve. When valve fully open, fairings align with butterfly and reduce wake. Butterfly free to turn, so valve can be closed, while fairings remain fixed. Design reduces turbulence in flow of air in internal suction system. Valve aids in development of improved porous-surface boundary-layer control system to reduce aerodynamic drag. Applications primarily aerospace. System adapted to boundary-layer control on high-speed land vehicles.

  18. Heart Valve Diseases

    Science.gov (United States)

    Your heart has four valves. Normally, these valves open to let blood flow through or out of your heart, and then shut to keep it from flowing ... close tightly. It's one of the most common heart valve conditions. Sometimes it causes regurgitation. Stenosis - when ...

  19. Dump valve assembly

    Science.gov (United States)

    Owen, T.J.

    1984-01-01

    A dump valve assembly comprising a body having a bore defined by a tapered wall and a truncated spherical valve member adapted to seat along a spherical surface portion thereof against said tapered wall. Means are provided for pivoting said valve member between a closed position engagable with said tapered wall and an open position disengaged therefrom.

  20. Quadricuspid Aortic Valve

    Directory of Open Access Journals (Sweden)

    Mehmet Taşar

    2013-03-01

    Full Text Available Quadricuspid aortic valve is an extremely rare congenital defect. Isolated form appears frequently. It is seen with aortic valve regurgitation in adulthood. This case report presents a rare clinical finding of an isolated quadricuspid aortic valve with aortic regurgitation in an 64-year-old female who was referred for cardiac evaluation due to newly identified murmur.

  1. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  2. [Surgical treatment of traumatic rupture of the bicuspid aortic valve; report of a case].

    Science.gov (United States)

    Fujimoto, K; Okamoto, H; Tamenishi, A; Niimi, T

    2002-07-01

    A 27-year-old man was injured during a motocross game. He was suffered from dyspnea, orthopnea, and hemoptysis. The to-and-fro murmur was noticed 3 days after the accident and then the patient was admitted to our hospital. Echocardiography revealed severe aortic regurgitation. Computerized tomography also showed severe pulmonary contusions. Seventeen days after the accident the aortic valve replacement was performed. The aortic valve was anterior-posterior type bicuspid valve (fusion of right coronary cusp and light coronary cusp) and the tear was detected in the anterior cusp. The postoperative course was uneventful. Rupture of the aortic valve due to a blunt chest trauma is rare and reported in 20 cases previously in Japan. This case is the second report of traumatic rupture of the bicuspid aortic valve.

  3. [Surgical treatment of traumatic rupture of the aortic valve with dove-coo murmur--case report].

    Science.gov (United States)

    Shigemitsu, O; Hadama, T; Mori, Y; Miyamoto, S; Sako, H; Uchida, Y

    1995-03-01

    Aortic regurgitation due to traumatic rupture of the aortic valve with dove-coo murmur is rare. A 71-year-old man was admitted for cardiac failure due to aortic regurgitation with dove-coo murmur, 4 years after the traffic accident. The aortic valve replacement was performed and his postoperative course was good. The aortic valve was tricuspid valve with the tear in the left side of right coronary cusp, and the size of the tear was 7 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic change in the pathological study.

  4. Motor operated valves problems tests and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pinier, D.; Haas, J.L.

    1996-12-01

    An analysis of the two refusals of operation of the EAS recirculation shutoff valves enabled two distinct problems to be identified on the motorized valves: the calculation methods for the operating torques of valves in use in the power plants are not conservative enough, which results in the misadjustement of the torque limiters installed on their motorizations, the second problem concerns the pressure locking phenomenon: a number of valves may entrap a pressure exceeding the in-line pressure between the disks, which may cause a jamming of the valve. EDF has made the following approach to settle the first problem: determination of the friction coefficients and the efficiency of the valve and its actuator through general and specific tests and models, definition of a new calculation method. In order to solve the second problem, EDF has made the following operations: identification of the valves whose technology enables the pressure to be entrapped: the tests and numerical simulations carried out in the Research and Development Division confirm the possibility of a {open_quotes}boiler{close_quotes} effect: determination of the necessary modifications: development and testing of anti-boiler effect systems.

  5. Main Oxidizer Valve Design

    Science.gov (United States)

    Addona, Brad; Eddleman, David

    2015-01-01

    A developmental Main Oxidizer Valve (MOV) was designed by NASA-MSFC using additive manufacturing processes. The MOV is a pneumatically actuated poppet valve to control the flow of liquid oxygen to an engine's injector. A compression spring is used to return the valve to the closed state when pneumatic pressure is removed from the valve. The valve internal parts are cylindrical in shape, which lends itself to traditional lathe and milling operations. However, the valve body represents a complicated shape and contains the majority of the mass of the valve. Additive manufacturing techniques were used to produce a part that optimized mass and allowed for design features not practical with traditional machining processes.

  6. Glovebox pressure relief and check valve

    Energy Technology Data Exchange (ETDEWEB)

    Blaedel, K.L.

    1986-03-17

    This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury.

  7. Completion of Flow Interruption Capability Test Stand for Functional Qualification Test of Valves Used in Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    CHENG; Dao-xi; QI; Xiao-guang; ZHAI; Wei-ming; YANG; Bing; ZHOU; Ping

    2013-01-01

    The flow interruption capability test of valve is used for researching the capability of the valves used in nuclear power plants emergently shut off the flow,when the reactor loop is in emergency situations,especially in the design basis accident conditions.This test is one of the most difficult tests in the functional

  8. New technology for accident prevention

    Energy Technology Data Exchange (ETDEWEB)

    Byne, P. [Shiftwork Solutions, Vancouver, BC (Canada)

    2006-07-01

    This power point presentation examined the effects of fatigue in the workplace and presented 3 technologies designed to prevent or monitor fatigue. The relationship between mental fatigue, circadian rhythms and cognitive performance was explored. Details of vigilance related degradations in the workplace were presented, as well as data on fatigue-related accidents and a time-line of meter-reading errors. It was noted that the direct cause of the Exxon Valdez disaster was sleep deprivation. Fatigue related accidents during the Gulf War were reviewed. The effects of fatigue on workplace performance include impaired logical reasoning and decision-making; impaired vigilance and attention; slowed mental operations; loss of situational awareness; slowed reaction time; and short cuts and lapses in optional or self-paced behaviours. New technologies to prevent fatigue-related accidents include (1) the driver fatigue monitor, an infra-red camera and computer that tracks a driver's slow eye-lid closures to prevent fatigue related accidents; (2) a fatigue avoidance scheduling tool (FAST) which collects actigraphs of sleep activity; and (3) SAFTE, a sleep, activity, fatigue and effectiveness model. refs., tabs., figs.

  9. Experimental apparatus to test air trap valves

    Science.gov (United States)

    Lemos De Lucca, Y. de F.; de Aquino, G. A.; Filho, J. G. D.

    2010-08-01

    It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the water hammer phenomenon, the instability and the loss of pressure in the water distribution networks. As a result, it can overload the pumps, increase the consumption of electricity, and damage the pumping system. In order to avoid its formation, all of the trapped air should be removed through "air trap valves". In Brazil, manufacturers frequently have unreliable sizing charts, which cause malfunctioning of the "air trap valves". The result of these malfunctions causes accidents of substantial damage. The construction of a test facility will provide a foundation of technical information that will be used to help make decisions when designing a system of pipelines where "air trap valves" are used. To achieve this, all of the valve characteristics (geometric, mechanic, hydraulic and dynamic) should be determined. This paper aims to describe and analyze the experimental apparatus and test procedure to be used to test "air trap valves". The experimental apparatus and test facility will be located at the University of Campinas, Brazil at the College of Civil Engineering, Architecture, and Urbanism in the Hydraulics and Fluid Mechanics laboratory. The experimental apparatus will be comprised of various components (pumps, steel pipes, butterfly valves to control the discharge, flow meter and reservoirs) and instrumentation (pressure transducers, anemometer and proximity sensor). It should be emphasized that all theoretical and experimental procedures should be defined while taking into consideration flow parameters and fluid properties that influence the tests.

  10. Experimental apparatus to test air trap valves

    Energy Technology Data Exchange (ETDEWEB)

    Lemos De Lucca, Y de F [CTH-DAEE-USP/FAAP/UNICAMP (Brazil); Aquino, G A de [SABESP/UNICAMP (Brazil); Filho, J G D, E-mail: yvone.lucca@gmail.co [Water Resources Department, University of Campinas-UNICAMP, Av. Albert Einstein, 951, Cidade Universitaria-Barao Geraldo-Campinas, S.P., 13083-852 (Brazil)

    2010-08-15

    It is known that the presence of trapped air within water distribution pipes can lead to irregular operation or even damage to the distribution systems and their components. The presence of trapped air may occur while the pipes are being filled with water, or while the pumping systems are in operation. The formation of large air pockets can produce the water hammer phenomenon, the instability and the loss of pressure in the water distribution networks. As a result, it can overload the pumps, increase the consumption of electricity, and damage the pumping system. In order to avoid its formation, all of the trapped air should be removed through 'air trap valves'. In Brazil, manufacturers frequently have unreliable sizing charts, which cause malfunctioning of the 'air trap valves'. The result of these malfunctions causes accidents of substantial damage. The construction of a test facility will provide a foundation of technical information that will be used to help make decisions when designing a system of pipelines where 'air trap valves' are used. To achieve this, all of the valve characteristics (geometric, mechanic, hydraulic and dynamic) should be determined. This paper aims to describe and analyze the experimental apparatus and test procedure to be used to test 'air trap valves'. The experimental apparatus and test facility will be located at the University of Campinas, Brazil at the College of Civil Engineering, Architecture, and Urbanism in the Hydraulics and Fluid Mechanics laboratory. The experimental apparatus will be comprised of various components (pumps, steel pipes, butterfly valves to control the discharge, flow meter and reservoirs) and instrumentation (pressure transducers, anemometer and proximity sensor). It should be emphasized that all theoretical and experimental procedures should be defined while taking into consideration flow parameters and fluid properties that influence the tests.

  11. Valve selection in aortic valve endocarditis

    Science.gov (United States)

    Zubrytska, Yana

    2016-01-01

    Aortic prosthetic valve endocarditis (PVE) is a potentially life-threatening disease. Mortality and incidence of infective endocarditis have been reduced in the past 30 years. Medical treatment of aortic PVE may be successful in patients who have a prompt response after antibiotic treatment and who do not have prosthetic dysfunction. In advanced stages, antibiotic therapy alone is insufficient to control the disease, and surgical intervention is necessary. Surgical treatment may be lifesaving, but it is still associated with considerable morbidity and mortality. The aim of surgery is to perform a radical excision of all infected and necrotic tissue, reconstruction of the left ventricle outflow tract, and replacement of the aortic valve. There is no unanimous consensus on which is the optimal prosthesis to implant in this context, and several surgical techniques have been suggested. We aim to analyze the efficacy of the surgical treatment and discuss the issue of valve selection in patients with aortic valve endocarditis.

  12. Analysis of Fukushima Daiichi Accident Using HFACS

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Saeed Almheiri [Korea Advanced Institue of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    The shadow of Fukushima Daiichi nuclear power plant (NPP) accident is still too big and will last long. On the other hand, it could still teach us lots of lessons to better design and operate nuclear power plants. In this paper, we will be focusing on the Fukushima Daiichi accident, especially on human organizational factors. We will analyze the accident using Human Factors Analysis and Classification System (HFACS) in order to better understand the organizational climate of TEPCO{sup 1} and NISA{sup 2} that led to Fukushima Daiichi Accident. HFACS was developed for the U. S. aviation industry and has been used at many industries like the rail and mining industries. We found that the HFACS to be greatly beneficial in investigating the latent and organizational causes for the accident. The application results show that the causes of Fukushima Daiichi accident were spread out from sharp end (i.e. Unsafe Act) to blunt end (i. e. Organizational Influences). This means that the corresponding countermeasures should cover from front line staff to management. Thus, we managed to develop a better understanding on how to prevent similar errors or violations. The incident and near-miss have a lot of helpful information because it may show the actual and latent deficiencies of complex systems. We applied the HFACS into Fukushima Daiichi accident to better locate the causes related to both sharp and blunt ends of operation of NPP. In order to derive useful lessons from the accident analysis, the analyst should try to find the similarities not differences from the incident. It is imperative that whatever accident/incident analysis systems we use, we should fully utilize the disastrous Fukushima accident.

  13. Aortic or Mitral Valve Replacement With the Biocor and Biocor Supra

    Science.gov (United States)

    2016-03-09

    Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence

  14. Recently patented transcatheter aortic valves in clinical trials.

    Science.gov (United States)

    Neragi-Miandoab, Siyamek; Skripochnik, Edvard; Salemi, Arash; Girardi, Leonard

    2013-12-01

    The most widely used heart valve worldwide is the Edwards Sapien, which currently has 60% of the worldwide transcatheter aortic valve implantation (TAVI) market. The CoreValve is next in line in popularity, encompassing 35% of the worldwide TAVI market. Although these two valves dominate the TAVI market, a number of newer transcatheter valves have been introduced and others are in early clinical evaluation. The new valves are designed to reduce catheter delivery diameter, improve ease of positioning and sealing, and facilitate repositioning or removal. The most recent transcatheter valves for transapical use include Acurate TA (Symetis), Engager (Medtronic), and JenaValve the Portico (St Jude), Sadra Lotus Medical (Boston Scientific), and the Direct Flow Medical. These new inventions may introduce more effective treatment options for high-risk patients with severe aortic stenosis. Improvements in transcatheter valves and the developing variability among them may allow for more tailored approaches with respect to patient's anatomy, while giving operators the opportunity to choose devices they feel more comfortable with. Moreover, introducing new devices to the market will create a competitive environment among producers that will reduce high prices and expand availability. The present review article includes a discussion of recent patents related to Transcatheter Aortic Valves.

  15. JenaValve.

    Science.gov (United States)

    Treede, Hendrik; Rastan, Ardawan; Ferrari, Markus; Ensminger, Stephan; Figulla, Hans-Reiner; Mohr, Friedrich-Wilhelm

    2012-09-01

    The JenaValve is a next-generation TAVI device which consists of a well-proven porcine root valve mounted on a low-profile nitinol stent. Feeler guided positioning and clip fixation on the diseased leaflets allow for anatomically correct implantation of the device without rapid pacing. Safety and efficacy of transapical aortic valve implantation using the JenaValve were evaluated in a multicentre prospective study that showed good short and midterm results. The valve was CE-mark released in Europe in September 2011. A post-market registry ensures on-going and prospective data collection in "real-world" patients. The transfemoral JenaValve delivery system will be evaluated in a first-in-man study in the near future.

  16. Cryogenic Cam Butterfly Valve

    Science.gov (United States)

    McCormack, Kenneth J. (Inventor)

    2016-01-01

    A cryogenic cam butterfly valve has a body that includes an axially extending fluid conduit formed there through. A disc lug is connected to a back side of a valve disc and has a circular bore that receives and is larger than a cam of a cam shaft. The valve disc is rotatable for a quarter turn within the body about a lug axis that is offset from the shaft axis. Actuating the cam shaft in the closing rotational direction first causes the camming side of the cam of the cam shaft to rotate the disc lug and the valve disc a quarter turn from the open position to the closed position. Further actuating causes the camming side of the cam shaft to translate the valve disc into sealed contact with the valve seat. Opening rotational direction of the cam shaft reverses these motions.

  17. Fracturing mechanics before valve-in-valve therapy of small aortic bioprosthetic heart valves

    DEFF Research Database (Denmark)

    Johansen, Peter; Engholt, Henrik; Tang, Mariann

    2017-01-01

    AIMS: Patients with degraded bioprosthetic heart valves (BHV) who are not candidates for valve replacement may benefit from transcatheter valve-in-valve (VIV) therapy. However, at smaller sized surgical BHV the resultant orifice may become too narrow. To overcome this, the valve frame can be frac...

  18. An analysis of aircraft accidents involving fires

    Science.gov (United States)

    Lucha, G. V.; Robertson, M. A.; Schooley, F. A.

    1975-01-01

    All U. S. Air Carrier accidents between 1963 and 1974 were studied to assess the extent of total personnel and aircraft damage which occurred in accidents and in accidents involving fire. Published accident reports and NTSB investigators' factual backup files were the primary sources of data. Although it was frequently not possible to assess the relative extent of fire-caused damage versus impact damage using the available data, the study established upper and lower bounds for deaths and damage due specifically to fire. In 12 years there were 122 accidents which involved airframe fires. Eighty-seven percent of the fires occurred after impact, and fuel leakage from ruptured tanks or severed lines was the most frequently cited cause. A cost analysis was performed for 300 serious accidents, including 92 serious accidents which involved fire. Personal injury costs were outside the scope of the cost analysis, but data on personnel injury judgements as well as settlements received from the CAB are included for reference.

  19. Visualization of Traffic Accidents

    Science.gov (United States)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  20. Modeling the Mitral Valve

    Science.gov (United States)

    Kaiser, Alexander

    2016-11-01

    The mitral valve is one of four valves in the human heart. The valve opens to allow oxygenated blood from the lungs to fill the left ventricle, and closes when the ventricle contracts to prevent backflow. The valve is composed of two fibrous leaflets which hang from a ring. These leaflets are supported like a parachute by a system of strings called chordae tendineae. In this talk, I will describe a new computational model of the mitral valve. To generate geometry, general information comes from classical anatomy texts and the author's dissection of porcine hearts. An MRI image of a human heart is used to locate the tips of the papillary muscles, which anchor the chordae tendineae, in relation to the mitral ring. The initial configurations of the valve leaflets and chordae tendineae are found by solving solving an equilibrium elasticity problem. The valve is then simulated in fluid (blood) using the immersed boundary method over multiple heart cycles in a model valve tester. We aim to identify features and mechanisms that influence or control valve function. Support from National Science Foundation, Graduate Research Fellowship Program, Grant DGE 1342536.

  1. Mitral valve prolapse.

    Science.gov (United States)

    Gould, L; Gopalaswamy, C

    1984-05-01

    Mitral valve prolapse is a very common condition. It occurs in 4-5% of the population. It may be idiopathic or associated with a number of other conditions. Myxomatous degeneration is the underlying mechanism of mitral valve prolapse. Most patients with mitral valve prolapse have no symptoms. When symptoms do occur, palpitations, chest pain and dyspnea are the major complaints. The midsystolic click occasionally followed by the late systolic murmur are the typical physical findings. The echocardiogram plays a big role in the diagnosis of mitral valve prolapse. The beta blockers are used in the treatment of the symptomatic patient.

  2. Biological heart valves.

    Science.gov (United States)

    Ciubotaru, Anatol; Cebotari, Serghei; Tudorache, Igor; Beckmann, Erik; Hilfiker, Andres; Haverich, Axel

    2013-10-01

    Cardiac valvular pathologies are often caused by rheumatic fever in young adults, atherosclerosis in elderly patients, or by congenital malformation of the heart in children, in effect affecting almost all population ages. Almost 300,000 heart valve operations are performed worldwide annually. Tissue valve prostheses have certain advantages over mechanical valves such as biocompatibility, more physiological hemodynamics, and no need for life-long systemic anticoagulation. However, the major disadvantage of biological valves is related to their durability. Nevertheless, during the last decade, the number of patients undergoing biological, rather than mechanical, valve replacement has increased from half to more than three-quarters for biological implants. Continuous improvement in valve fabrication includes development of new models and shapes, novel methods of tissue treatment, and preservation and implantation techniques. These efforts are focused not only on the improvement of morbidity and mortality of the patients but also on the improvement of their quality of life. Heart valve tissue engineering aims to provide durable, "autologous" valve prostheses. These valves demonstrate adaptive growth, which may avoid the need of repeated operations in growing patients.

  3. A piezoelectrically actuated ball valve

    Science.gov (United States)

    Erwin, L. R.; Schwartz, H. W.; Teitelbaum, B. R.

    1972-01-01

    Bimorph strip composed of two layers of poled piezoelectric ceramic material closes and opens valve. Strip performs like capacitator, allowing initial inrush of current when valve is energized and then only small leakage current flows as valve remains energized.

  4. Simulation of a postulated loss of coolant accident due to a break in the pressurizer surge line of Angra 2 Nuclear Power Plan; Calculo do acidente postulado de perda de refrigerante por uma ruptura na linha de surto do pressurizador da central nuclear Angra 2

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Carlos V. Goulart de; Palmieri, Elcio T.; Aronne, Ivan D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: cvga@cdtn.br; etp@cdtn.br; aroneid@cdtn.br

    2005-07-01

    This work presents the simulation of a postulated loss of coolant accident due to a 437 cm{sup 2} break in the pressurizer surge line of Angra 2 Nuclear Power Plant, as described in its Final Safety Analysis Report, section 15.6.4.1.3.11. This accident is characterized by a fast depressurization of the reactor coolant system followed by the actuation of the safety injection system. This work, which aims to develop and qualify a basic Angra 2 nodalization for RELAP5, was done in the framework of a CNEN internal technical cooperation involving three of its research centers (CDTN, IPEN and IEN) and its Reactors Division. This simulation is part of a comprehensive number of accidents and transients necessary to verify the adequacy of the modeled logic of the control and protection systems as well as the performance of the modeled thermal-hydraulic systems. Therefore this work contributes to the qualification process of the developed nodalization. (author)

  5. Laser accidents: Being Prepared

    Energy Technology Data Exchange (ETDEWEB)

    Barat, K

    2003-01-24

    The goal of the Laser Safety Officer and any laser safety program is to prevent a laser accident from occurring, in particular an injury to a person's eyes. Most laser safety courses talk about laser accidents, causes, and types of injury. The purpose of this presentation is to present a plan for safety offices and users to follow in case of accident or injury from laser radiation.

  6. Simulation of A Main Steam Line Break Accident Using the Coupled 'System Thermal-Hydraulics, 3D reactor Kinetics, and Hot Channel' Analysis Capability of MARS 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Jun; Chung, Bub Dong

    2005-09-15

    For realistic analysis of thermal-hydraulics (T-H) transients in light water reactors, KAERI has developed the best-estimate T-H system code, MARS. The code has been improved from the consolidated version of the RELAP5/MOD3 and COBRA-TF codes. Then, the MARS code was coupled with a three-dimensional (3-D) reactor kinetics code, MASTER. This coupled calculation feature, in conjunction with the existing hot channel analysis capabilities of the MARS and MASTER codes, allows for more realistic simulations of nuclear system transients. In this work, a main steam line break (MSLB) accident is simulated using the coupled 'system T-H, 3-D reactor kinetics, and hot channel analysis' feature of the MARS code. Two coupled calculations are performed for demonstration. First, a coupled calculation of the 'system T-H and 3-D reactor kinetics' with a refined core T-H nodalization is carried out to obtain global core power and local departure from nucleate boiling (DNB) ratio (DNBR) behaviors. Next, for a more accurate DNBR prediction, another coupled calculation with subchannel meshes for the hot channels is performed. The results of the coupled calculations are very reasonable and consistent so that these can be used to remove the excessive conservatism in the conventional safety analysis.

  7. Evaluation of Flood Level under Main Feedwater Line Break Accident using GOTHIC Computer Code and Analytical Calculation by ANSI 56.11

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keon Yeop; Park, Jae Won; Jeon, Woo Jae [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    The design basis internal flooding is caused by postulated pipe ruptures or component failures. The flooding can cause failure of safety-related equipment and affect the integrity of the structure. Though large diameter pipe rupture is significant in flooding analysis, split breaks should also be considered with consideration of a spectrum of pipe break size and power level. The pipe rupture analysis should be based on the most severe single active failure. For enveloping spectrum of pipe break condition, flood relief paths are necessary and passive flood protection without operating action, basically, shall be applied. In this study, the evaluation of flood level in case of Main Feedwater Line Break (MFLB) was performed by using GOTHIC computer program and hand calculation. The flooding analyses were performed by hand calculation and GOTHIC analysis for an assumed MFLB condition. The calculated flood levels were 0.823m and 0.691m for hand calculation and GOTHIC analysis, respectively. In comparison to the GOTHIC analysis, hand calculation showed conservative results. However, in actual flood protection design, margin for uncertainty shall be considered, in order to reflect the outflow reducing effect due to vortex and intake of air.

  8. [Accidents with the "paraglider"].

    Science.gov (United States)

    Lang, T H; Dengg, C; Gabl, M

    1988-09-01

    With a collective of 46 patients we show the details and kinds of accidents caused by paragliding. The base for the casuistry of the accidents was a questionnaire which was answered by most of the injured persons. These were questions about the theoretical and practical training, the course of the flight during the different phases, and the subjective point of view of the course of the accident. The patterns of the injuries showed a high incidence of injuries of the spinal column and high risks for the ankles. At the end, we give some advice how to prevent these accidents.

  9. Accidents (FARS) (National)

    Data.gov (United States)

    Department of Transportation — Accident - (1975-current): This data file (NTAD) contains information about crash characteristics and environmental conditions at the time of the crash. There is one...

  10. Mitral valve surgery - open

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Mitral Valve Prolapse Browse the Encyclopedia A.D. ...

  11. Blocked Urethral Valves

    Science.gov (United States)

    ... Blocked Urethral Valves Health Issues Listen Español Text Size Email Print Share Blocked Urethral Valves Page Content Article Body Urine leaves the bladder through a tube called the urethra, which in boys passes through the penis. Rarely, small membranes form across the urethra in ...

  12. Shutoff and throttling valve

    Science.gov (United States)

    Hays, L. G.

    1974-01-01

    Leaktight shutoff, precise flow control, and very low pressure drop are incorporated in all-metal valve designed for operation under extreme temperatures. Valve constructed with refractory metal is intended for control of high-temperature liquid cesium, but has applications related to control of high- and low-temperature liquids and gases.

  13. Bioprinting a cardiac valve.

    Science.gov (United States)

    Jana, Soumen; Lerman, Amir

    2015-12-01

    Heart valve tissue engineering could be a possible solution for the limitations of mechanical and biological prostheses, which are commonly used for heart valve replacement. In tissue engineering, cells are seeded into a 3-dimensional platform, termed the scaffold, to make the engineered tissue construct. However, mimicking the mechanical and spatial heterogeneity of a heart valve structure in a fabricated scaffold with uniform cell distribution is daunting when approached conventionally. Bioprinting is an emerging technique that can produce biological products containing matrix and cells, together or separately with morphological, structural and mechanical diversity. This advance increases the possibility of fabricating the structure of a heart valve in vitro and using it as a functional tissue construct for implantation. This review describes the use of bioprinting technology in heart valve tissue engineering.

  14. Anticoagulation for Prosthetic Valves

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kaneko

    2013-01-01

    Full Text Available Implantation of prosthetic valve requires consideration for anticoagulation. The current guideline recommends warfarin on all mechanical valves. Dabigatran is the new generation anticoagulation medication which is taken orally and does not require frequent monitoring. This drug is approved for treatment for atrial fibrillation and venous thromboembolism, but the latest large trial showed that this drug increases adverse events when used for mechanical valve anticoagulation. On-X valve is the new generation mechanical valve which is considered to require less anticoagulation due to its flow dynamics. The latest study showed that lower anticoagulation level lowers the incidence of bleeding, while the risk of thromboembolism and thrombosis remained the same. Anticoagulation poses dilemma in cases such as pregnancy and major bleeding event. During pregnancy, warfarin can be continued throughout pregnancy and switched to heparin derivative during 6–12 weeks and >36 weeks of gestation. Warfarin can be safely started after 1-2 weeks of discontinuation following major bleeding episode.

  15. Communication and industrial accidents

    NARCIS (Netherlands)

    As, Sicco van

    2001-01-01

    This paper deals with the influence of organizational communication on safety. Accidents are actually caused by individual mistakes. However the underlying causes of accidents are often organizational. As a link between these two levels - the organizational failures and mistakes - I suggest the conc

  16. Accidents - personal factors

    Energy Technology Data Exchange (ETDEWEB)

    Zaitsev, S.L.; Tsygankov, A.V.

    1982-03-01

    This paper evaluates influence of selected personal factors on accident rate in underground coal mines in the USSR. Investigations show that so-called organizational factors cause from 80 to 85% of all accidents. About 70% of the organizational factors is associated with social, personal and economic features of personnel. Selected results of the investigations carried out in Donbass mines are discussed. Causes of miner dissatisfaction are reviewed: 14% is caused by unsatisfactory working conditions, 21% by repeated machine failures, 16% by forced labor during days off, 14% by unsatisfactory material supply, 16% by hard physical labor, 19% by other reasons. About 25% of miners injured during work accidents are characterized as highly professionally qualified with automatic reactions, and about 41% by medium qualifications. About 60% of accidents is caused by miners with less than a 3 year period of service. About 15% of accidents occurs during the first month after a miner has returned from a leave. More than 30% of accidents occurs on the first work day after a day or days off. Distribution of accidents is also presented: 19% of accidents occurs during the first 2 hours of a shift, 36% from the second to the fourth hour, and 45% occurs after the fourth hour and before the shift ends.

  17. Accident investigation and analysis

    NARCIS (Netherlands)

    Kampen, J. van; Drupsteen, L.

    2013-01-01

    Many organisations and companies take extensive proactive measures to identify, evaluate and reduce occupational risks. However, despite these efforts things still go wrong and unintended events occur. After a major incident or accident, conducting an accident investigation is generally the next ste

  18. Design of a High Power Robotic Manipulator for Emergency Response to the Nuclear Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jongwon; Bae, Yeong-Geol; Kim, Myoung Ho; Choi, Young Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    An accident in a nuclear facility causes a great social cost. To prevent an unexpected nuclear accident from spreading to the catastrophic disaster, emergency response action in early stage is required. However, high radiation environment has been proved as a challenging obstacle for human workers to access to the accident site and take an action in previous accident cases. Therefore, emergency response robotic technology to be used in a nuclear accident site instead of human workers are actively conducted in domestically and internationally. Robots in an accident situation are required to carry out a variety of tasks depend on the types and patterns of accidents. An emergency response usually includes removing of debris, make an access road to a certain place and handling valves. These tasks normally involve high payload handling. A small sized high power robotic manipulator can be an appropriate candidate to deal with a wide spectrum of tasks in an emergency situation. In this paper, we discuss about the design of a high power robotic manipulator, which is capable of handling high payloads for an initial response action to the nuclear facility accident. In this paper, we presented a small sized high power robotic manipulator design. Actuator types of manipulator was selected and mechanical structure was discussed. In the future, the servo valve and hydraulic pump systems will be determined. Furthermore, control algorithms and test bed experiments will be also conducted.

  19. Face-Sealing Butterfly Valve

    Science.gov (United States)

    Tervo, John N.

    1992-01-01

    Valve plate made to translate as well as rotate. Valve opened and closed by turning shaft and lever. Interactions among lever, spring, valve plate, and face seal cause plate to undergo combination of translation and rotation so valve plate clears seal during parts of opening and closing motions.

  20. CURRENT FACTORS OF ROAD ACCIDENTS IN ISFAHAN

    Directory of Open Access Journals (Sweden)

    B AMINMAN SOUR

    2000-06-01

    Full Text Available

    line-height: normal" class="MsoNormal">Introduction. Car accident mortality is the third order causes of death in the USA, following cardiovascular diseases and cancers. Given present survival and outcome Iranian data, more than 14,000 patients die annually in road accidents. Having a valid and reliable data could be useful in reduce mortality and morbidity reduction.
    Methods. Twenty five percent of total traumatic patients in Isfahan were selected (N=2809 at the time of study (1997-1998. Forty five percent of them with car accident were asked about causes of accidents and risk factors for the severity and type of injuries were recorded based on International Classification of Disease 10.
    Results. Most of the victims were young (10-20 years old, students and industrial workers. Statistically unreasonable numbers of cars without extension of roads and high ways, using old and unsafe cars will affects on accidents.
    Discussion. In comparison with European and some Asian countries, Iran has unacceptable road accidents and it seems necessary to pay more attention to stop the current increasing data.

     

  1. Chemical Accident Prevention Publications

    Science.gov (United States)

    These include chemical safety alerts, emergency preparedness and prevention advisories, and topical backgrounders. Excess flow valves, protecting workers in ethylene oxide sterilization facilities, reactivity hazards, and delayed coker units are covered.

  2. Mesofluidic two stage digital valve

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, John F; Love, Lonnie J; Lind, Randall F; Richardson, Bradley S

    2013-12-31

    A mesofluidic scale digital valve system includes a first mesofluidic scale valve having a valve body including a bore, wherein the valve body is configured to cooperate with a solenoid disposed substantially adjacent to the valve body to translate a poppet carried within the bore. The mesofluidic scale digital valve system also includes a second mesofluidic scale valve disposed substantially perpendicular to the first mesofluidic scale valve. The mesofluidic scale digital valve system further includes a control element in communication with the solenoid, wherein the control element is configured to maintain the solenoid in an energized state for a fixed period of time to provide a desired flow rate through an orifice of the second mesofluidic valve.

  3. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European...... countries. METHODS: A multi-institutional, non-randomized, retrospective analysis was conducted among 2,932 patients who underwent AVR surgery at seven tertiary cardiac surgery centers throughout Europe. Demographic and perioperative variables including valve size and type, body surface area (BSA) and early...

  4. GIANT PROSTHETIC VALVE THROMBUS

    Directory of Open Access Journals (Sweden)

    Prashanth Kumar

    2015-04-01

    Full Text Available Mechanical prosthetic valves are predisposed to bleeding, thrombosis & thromboembolic complications. Overall incidence of thromboembolic complications is 1% per year who are on oral anticoagulants, whereas bleeding complications incidence is 0.5% to 6.6% per year. 1, 2 Minimization of Scylla of thromboembolic & Charybdis of bleeding complication needs a balancing act of optimal antithrombotic therapy. We are reporting a case of middle aged male patient with prosthetic mitral valve presenting in heart failure. Patient had discontinued anticoagulants, as he had subdural hematoma in the past. He presented to our institute with a giant prosthetic valve thrombus.

  5. Danfos: Thermostatic Radiator Valves

    DEFF Research Database (Denmark)

    Gregersen, Niels; Oliver, James; Hjorth, Poul G.

    2000-01-01

    This problem deals with modelling the flow through a typical Danfoss thermostatic radiator valve.Danfoss is able to employ Computational Fluid Dynamics (CFD) in calculations of the capacity of valves, but an experienced engineer can often by rules of thumb "guess" the capacity, with a precision...... similar to the one achieved by the expensive and time-consuming CFD calculations. So CFD is only used in case of entirely new designs or where a very detailed knowledge of the flow is required. Even though rules of thumb are useful for those, who have developed them, Danfoss needs an objective and general...... method that can be used to predict the performance of valves....

  6. A valve disk

    Energy Technology Data Exchange (ETDEWEB)

    Khayrullin, N.A.; Isayev, B.N.; Kruglov, S.A.; Molokanov, Yu.K.; Shchelkunov, V.A.; Shegay, V.R.; Vizhgorodskiy, B.N.

    1982-01-01

    A valve disk is proposed which includes a horizontal bed, on which there are laminar valves arranged in staggered order. To ensure the stable and effective operation of the disk in a broad range of loads by compensating for the direct flow and the partial sectioning of the disk bed, it is equipped with compensating elements installed in openings in the bed and hinged with it. They are made in the form of straight, triangular prisms with ports in the bases. The prisms are installed with the capability of movement relative to the disk bed. The valves are positioned on the upper lateral facets of the compensating elements.

  7. Persistence of airline accidents.

    Science.gov (United States)

    Barros, Carlos Pestana; Faria, Joao Ricardo; Gil-Alana, Luis Alberiko

    2010-10-01

    This paper expands on air travel accident research by examining the relationship between air travel accidents and airline traffic or volume in the period from 1927-2006. The theoretical model is based on a representative airline company that aims to maximise its profits, and it utilises a fractional integration approach in order to determine whether there is a persistent pattern over time with respect to air accidents and air traffic. Furthermore, the paper analyses how airline accidents are related to traffic using a fractional cointegration approach. It finds that airline accidents are persistent and that a (non-stationary) fractional cointegration relationship exists between total airline accidents and airline passengers, airline miles and airline revenues, with shocks that affect the long-run equilibrium disappearing in the very long term. Moreover, this relation is negative, which might be due to the fact that air travel is becoming safer and there is greater competition in the airline industry. Policy implications are derived for countering accident events, based on competition and regulation. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.

  8. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  9. Surgical double valve replacement after transcatheter aortic valve implantation and interventional mitral valve repair.

    Science.gov (United States)

    Wendeborn, Jens; Donndorf, Peter; Westphal, Bernd; Steinhoff, Gustav

    2013-11-01

    Transcatheter aortic valve implantation, as well as interventional mitral valve repair, offer reasonable therapeutic options for high-risk surgical patients. We report a rare case of early post-interventional aortic valve prosthesis migration to the left ventricular outflow tract, with paravalvular leakage and causing severe mitral valve regurgitation. Initial successful interventional mitral valve repair using a clipped edge-to-edge technique revealed, in a subsequent procedure, the recurrence of mitral valve regurgitation leading to progressive heart failure and necessitating subsequent surgical aortic and mitral valve replacement.

  10. Risk factors for rejection for morphological reasons of heart valves for transplantation.

    Science.gov (United States)

    van Wijk, Marja J; van den Bogaerdt, Antoon; Bokhorst, Arlinke G

    2013-03-01

    The study aim was to identify risk factors for morphological rejection of aortic and pulmonary valves for transplantation that could be used to optimize donor selection. The files of all Dutch heart valve donors, donating in a 2.5 years period, whose hearts were processed at Heart Valve Bank Rotterdam, were reviewed for all factors that could be relevant for valve rejection and related to outcome of morphological assessment of the valves. Valves were retrieved from 813 deceased Dutch donors, 24.1% also donating organs. For 797 aortic and 767 pulmonary valves, who met retrieval criteria, morphological assessment was done. 69.5% of aortic and 37.5% of pulmonary valves were considered unsuitable for transplantation at morphological assessment. Backward stepwise multivariate logistic regression analysis, showed age, cardiac cause of death, cerebrovascular accident as cause of death or in medical history, and number of cardiovascular risk factors in a donor to be independent risk factors for morphological rejection of aortic valves. Age, sex, weight >100 kg and ruptured aortic aneurysm as cause of death were independent risk factors for morphological rejection of pulmonary valves. Being an organ donor was an independent predictor of morphological approval of aortic and pulmonary valves, while hypertension was an independent predictor for morphological approval of aortic valves. Thus, independent factors were identified that are associated with morphological rejection of aortic and pulmonary valves for transplantation, and that could be used to optimize donor selection by preventing unnecessary retrievals, limiting costs, while improving yield per donor with minimal compromise for availability.

  11. Mitral Valve Disease

    Science.gov (United States)

    ... for more information on procedures, news, and pre- & post-operative care. Section Navigation Select Topic Aortic Valve Disease ... is most commonly caused by inflammation from rheumatic fever, a disease that is related to strep infections; ...

  12. Valve Repair or Replacement

    Science.gov (United States)

    ... valve surgery can be done using a robot. Robotic surgery does not require a large incision in the ... The Texas Heart Institute has a robot. With robotic surgery, the surgeon has a control console, a side ...

  13. Pulmonary valve stenosis

    Science.gov (United States)

    ... valvuloplasty - pulmonary Images Heart valves References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil ... Saunders; 2016:chap 69. Otto CM, Bownow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ...

  14. Mitral valve regurgitation

    Science.gov (United States)

    ... and dentist if you have a history of heart valve disease or congenital heart disease before treatment. Some people ... the middle Heart, front view References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  15. Mitral Valve Prolapse

    Science.gov (United States)

    ... Kawasaki Disease Long Q-T Syndrome Marfan Syndrome Metabolic Syndrome Mitral Valve Prolapse Myocardial Bridge Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden ...

  16. Neural Networks Based Modelling of Traffic Accidents in Interurban Rural Highways, Duzce Sampling

    Science.gov (United States)

    Ozgan, Ercan; Demirci, Recep

    this study, alternatively, Artificial Neural Network (ANN) based modelling of traffic accidents on two line interurban rural highways in terms of number of accidents; injuries and dead have been presented. This study was conducted for D100/11 state highway section in Duzce. In this section of the highway, totally 783 traffic accidents occurred and 1396 vehicles involved in these accidents between 2002 and 2006 years. Using traffic accident reports data, ANN was applied for modelling of traffic accidents with respect to distance and months. As a result, it was observed that there was a perfect fit between the simulation results and actual data of accidents and the created neural network model of accidents resembles the actual data. Therefore, the developed model could be an alternative method for predictions of traffic accidents on interurban rural highways.

  17. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, David J., E-mail: david.murphy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); McEvoy, Sinead H., E-mail: s.mcevoy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Iyengar, Sri, E-mail: sri.iyengar@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Feuchtner, Gudrun, E-mail: Gudrun.Feuchtner@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck (Austria); Cury, Ricardo C., E-mail: r.cury@baptisthealth.net [Department of Radiology, Baptist Cardiac and Vascular Institute, 8900 North Kendall Drive, Miami, FL 33176 (United States); Roobottom, Carl, E-mail: carl.roobottom@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Plymouth University Peninsula Schools of Medicine and Dentistry (United Kingdom); Baumueller, Stephan, E-mail: Hatem.Alkadhi@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Alkadhi, Hatem, E-mail: stephan.baumueller@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Dodd, Jonathan D., E-mail: jonniedodd@gmail.com [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2014-08-15

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm{sup 2}, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  18. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...

  19. Boating Accident Statistics

    Data.gov (United States)

    Department of Homeland Security — Accident statistics available on the Coast Guard’s website by state, year, and one variable to obtain tables and/or graphs. Data from reports has been loaded for...

  20. Accident resistant transport container

    Science.gov (United States)

    Andersen, John A.; Cole, James K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  1. Electromagnetically driven, fast opening and closing gas jet valve

    Science.gov (United States)

    Krishnan, Mahadevan; Elliott, Kristi Wilson; Geddes, C. G. R.; van Mourik, R. A.; Leemans, W. P.; Murphy, H.; Clover, M.

    2011-03-01

    The design and performance are presented of an electromagnetically driven gas valve [M. Krishnan, J. Wright, and T. Ma, Proceedings of the 13th Advanced Accelerator Concepts Workshop, Santa Cruz, CA, AIP Conf. Proc. No. 1086 (AIP, New York, 2008)] that opens in <100μs, closes in <500μs, and can operate at pressures of ˜1000psia to drive supersonic nozzles. Such a valve has applications to laser-plasma accelerators, where the fast opening and closing would allow sharper edges to the flow and also allow higher rep-rate operation without loading the vacuum chamber. The valve action is effected by a flyer plate accelerated by the electromagnetic impulse of a low inductance, spiral wound, strip-line coil driven by a capacitor. Gas flows out of the valve when the seal between this flyer plate and the valve seat is broken. The electromagnetic force greatly exceeds the restoring forces provided by a spring and the gas pressure against the valve seat. Piezoresistive sensor and laser interferometer measurements of flow show that the valve opens in ˜100μs for all pressures up to 800 psia. The closing time is 500μs, set by the spring constant and mass. The prototype valve has been operated with helium at 0.5 Hz and at 500 psia for ˜1 hour at a time with no cooling.

  2. The Fukushima accident; Accident nucleaire a Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Delbecq, D.

    2012-02-15

    The Fukushima accident is characterized by a sequence of natural disasters: earthquake and tsunamis that deprived simultaneously 3 reactors from cooling and electrical power for quite a long time. A series of hydrogen explosion has added to the mess. Experts agree to say that certainly nuclear fuel has melt to form corium in all 3 reactors. The accident has contaminated tens of thousand acres of land around the plant and has jeopardized local coastal fishery. The human toll is unexpectedly low: no direct casualty in the population but several suicides among the people that was forced to leave their home. 5 people from the plant staff died certainly from the consequences of the tsunami. (A.C.)

  3. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  4. Comparison of three small-break loss-of-coolant accident tests with different break locations using the system-integrated modular advanced reactor-integral test loop facility to estimate the safety of the smart design

    Directory of Open Access Journals (Sweden)

    Hwang Bae

    2017-08-01

    Full Text Available Three small-break loss-of-coolant accident (SBLOCA tests with safety injection pumps were carried out using the integral-effect test loop for SMART (System-integrated Modular Advanced ReacTor, i.e., the SMART-ITL facility. The types of break are a safety injection system line break, shutdown cooling system line break, and pressurizer safety valve line break. The thermal–hydraulic phenomena show a traditional behavior to decrease the temperature and pressure whereas the local phenomena are slightly different during the early stage of the transient after a break simulation. A safety injection using a high-pressure pump effectively cools down and recovers the inventory of a reactor coolant system. The global trends show reproducible results for an SBLOCA scenario with three different break locations. It was confirmed that the safety injection system is robustly safe enough to protect from a core uncovery.

  5. Cyclical Fluctuations in Workplace Accidents

    OpenAIRE

    Boone, J.; J. C. VAN OURS

    2002-01-01

    This Paper presents a theory and an empirical investigation on cyclical fluctuations in workplace accidents. The theory is based on the idea that reporting an accident dents the reputation of a worker and raises the probability that he is fired. Therefore a country with a high or an increasing unemployment rate has a low (reported) workplace accident rate. The empirical investigation concerns workplace accidents in OECD countries. The analysis confirms that workplace accident rates are invers...

  6. Implantation of the CoreValve percutaneous aortic valve.

    Science.gov (United States)

    Lamarche, Yoan; Cartier, Raymond; Denault, André Y; Basmadjian, Arsène; Berry, Colin; Laborde, Jean-Claude; Bonan, Raoul

    2007-01-01

    Surgical aortic valve replacement is the only recommended treatment for significant aortic valve stenosis. Percutaneous aortic valve replacement appears to be a novel option for high-risk patients. We report the implantation of the ReValving system (CoreValve, Paris, France) in a 64-year-old woman who was refused aortic valve replacement surgery for critical aortic stenosis and left ventricular dysfunction because of severe pulmonary fibrosis. After anesthesia, the patient was put on femorofemoral cardiopulmonary bypass, and underwent a balloon valvuloplasty with subsequent retrograde aortic valve replacement by the ReValving system. Transesophageal echocardiographic monitoring of the patient's hemodynamics showed immediate improvements of the valvular area and left ventricular ejection fraction and only traces of paravalvular leaks. The patient was easily weaned from ventilation and resumed activity soon after the surgery. A multidisciplinary approach is presently necessary to offer a reliable and safe procedure.

  7. [Technologies for cardiac valve prostheses].

    Science.gov (United States)

    Nakano, Kiyoharu

    2009-07-01

    To show the technological development of cardiac valve prostheses, a historical review of both mechanical and biological valve prostheses and a current overview of modern cardiac valve devices are provided. Scince the 1st implantation of Starr-Edwards ball valve in 1960, both mechanical and biological valve prostheses have advanced. The valve design, the material of the leaflet and the hausing of mechanical prostheses have improved. Currently, the majority of the mechanical prostheses are bileaflet tilting disc valves made of pyrolytic carbon, which is antithromboembolic. However, anticoagulation therapy with warfarin is still required. As for the bioprostheses, although the fixation and anti-mineralization methods of the tissues improved, the durability of these valves is still limited. For the material of the current biological valves, the porcine aortic valve or bovine pericardium are used. The tissues are fixed by non-pressure or low-pressure method in glutaraldehyde solution. A stented and non-stented valves are available. Epoch-making events in this field are the implantation of new bioprosthetic valves using tissue engineering methods and the development of the transcatheter valve replacement therapies.

  8. Transcatheter Aortic Valve Replacement for Degenerative Bioprosthetic Surgical Valves

    DEFF Research Database (Denmark)

    Dvir, Danny; Webb, John; Brecker, Stephen;

    2012-01-01

    Transcatheter aortic valve-in-valve implantation is an emerging therapeutic alternative for patients with a failed surgical bioprosthesis and may obviate the need for reoperation. We evaluated the clinical results of this technique using a large, worldwide registry.......Transcatheter aortic valve-in-valve implantation is an emerging therapeutic alternative for patients with a failed surgical bioprosthesis and may obviate the need for reoperation. We evaluated the clinical results of this technique using a large, worldwide registry....

  9. Accidents in nuclear ships

    Energy Technology Data Exchange (ETDEWEB)

    Oelgaard, P.L. [Risoe National Lab., Roskilde (Denmark)]|[Technical Univ. of Denmark, Lyngby (Denmark)

    1996-12-01

    This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10{sup -3} per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au).

  10. Mitral Valve Aneurysm: A Rare Complication of Aortic Valve Endocarditis

    Directory of Open Access Journals (Sweden)

    A Moaref

    2008-11-01

    Full Text Available A 20-year-old intravenous drug abuser man, refered to our hospital with dyspnea and orthopnea. Tranesophagealechocardiography revealed severe aortic regurgitation, healed vegetation of aortic valve and an aneurysm of theanterior leaflet of the mitral valve. The patient was discharged after aortic valve replacement and mitral valverepair.

  11. Research on Valve Body Design of Large Bore Sodium Valve

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Large bore sodium valve is one kind of key equipments of China Demonstration Fast Reactor (CDFR). It is installed in the pipeline before and behind SG units as a locking mechanism. Valve body which is used to bear pressure is the core of sodium valve design.

  12. Transcatheter Aortic Heart Valve Thrombosis

    DEFF Research Database (Denmark)

    Hansson, Nicolaj C; Grove, Erik L; Andersen, Henning R;

    2016-01-01

    BACKGROUND: There is increasing focus on transcatheter heart valve (THV) thrombosis. However, there are limited data on incidence, clinical implications and predisposing factors of THV thrombosis following transcatheter aortic valve replacement (TAVR). OBJECTIVES: We assessed the incidence...

  13. Heart valve disease: investigation by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Myerson Saul G

    2012-01-01

    Full Text Available Abstract Cardiovascular magnetic resonance (CMR has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves, and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease. A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries. Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion.

  14. Nasal valve surgery.

    Science.gov (United States)

    Apaydin, Fazil

    2011-04-01

    Nasal obstruction can be due to internal and external valve problems that can be seen before and after rhinoplasty. The main scope of this article is to concentrate on surgical solutions to these problems. To overcome nasal obstruction at the internal valve, spreader grafts, spreader flaps, upper lateral splay graft, butterfly graft, flaring suture, M-plasty, Z-plasty, and suspension sutures have been described. The management of the external valve problems is possible by using lateral crural dissection and repositioning, lateral crural strut grafts, alar battens, lateral crural turn-in flap, alar rim grafts, and various other methods. It is not easy to decide which techniques would work best in every case. After a thorough examination and analysis, the underlying cause of the nasal obstruction can be understood, and one or multiple procedures can be chosen according to each individual problem.

  15. Percutaneous mitral valve repair.

    Science.gov (United States)

    Gillinov, A Marc; Liddicoat, John R

    2006-01-01

    Surgical mitral valve repair is the procedure of choice to treat mitral regurgitation of all etiologies. Whereas annuloplasty is the cornerstone of mitral valve repair, a variety of other surgical techniques are utilized to correct dysfunction of the leaflets and subvalvular apparatus; in most cases, surgical repair entails application of multiple repair techniques in each patient. Preclinical studies and early human experience have demonstrated that some of these surgical repair techniques can be performed using percutaneous approaches. Specifically, there has been great progress in the development of novel technology to facilitate percutaneous annuloplasty and percutaneous edge-to-edge repair. The objectives of this report were to (1) discuss the surgical foundations for these percutaneous approaches; (2) review device design and experimental and clinical results of percutaneous valve repair; and (3) address future directions, including the key challenges of patient selection and clinical trial design.

  16. Future lines of research in the field of toxic and psychological factors in road accidents : a study made on request of the Ad Hoc Working Group on Toxic and Psychological Factors in Road Traffic Accidents of the Committee of Medical Research and Public Health of the Commission of European Communities, Directorate General for Research Science and Education.

    NARCIS (Netherlands)

    1976-01-01

    The scope of this report is to state, discuss and forecast the various aspects related to toxic and psychological factors in road traffic accidents. The more specific aim is to prepare a basis on which future action (and more particularly the different priorities for these actions), can be defined.

  17. Building valve amplifiers

    CERN Document Server

    Jones, Morgan

    2013-01-01

    Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment--as an electronics hobbyist, audiophile or audio engineer. This 2nd Edition builds on the success of the first with technology and technique revisions throughout and, significantly, a major new self-build project, worked through step-by-step, which puts into practice the principles and techniques introduced throughout the book. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the valve, whether audio enthusiasts tackling their first build or

  18. SAFETY SHUTOFF VALVE

    DEFF Research Database (Denmark)

    2010-01-01

    It is disclosed a shut-off valve which acts automatically and has a fully mechanical performance with respect to the loosing of the tower-shape part balance under the effect of the special acceleration Which is arisen from the quakes waves or serious vibrations, while such vibrations are mainly...... resulted from collision or effusion. A static tower has been applied for the main core of this part of the valve which loses balance state under the effect of collision and bounces to the neighboring part, which results in release of the catch and blockage of the gas passing channel....

  19. Pulsatile prosthetic valve flows.

    Science.gov (United States)

    Phillips, W M; Snyder, A; Alchas, P; Rosenberg, G; Pierce, W S

    1980-01-01

    The laser Doppler system has been established as a useful tool for eliciting the properties of simulated cardiovascular flows, and thus for comparative studies of flow properties of prosthetic valves. Significant differences among valve types and between models of one type have been documented. The complex variations of velocity profiles with time show that comparisons must be made for unsteady pulsatile rather than steady flow, despite the volume and complexity of the data required. Future studies will include methods of compacting the data presentation and improving the details of the experimental stimulation.

  20. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-12-31

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele`s pivot. The Schiele`s pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele`s pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele`s pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  1. Transcatheter Valve-in-Valve: A Cautionary Tale.

    Science.gov (United States)

    Luc, Jessica G Y; Shanks, Miriam; Tyrrell, Benjamin D; Welsh, Robert C; Butler, Craig R; Meyer, Steven R

    2016-09-01

    Transcatheter aortic valve replacement (TAVR) by valve-in-valve (VIV) implantation is an alternative treatment for high-risk patients with a degenerating aortic bioprosthesis. We present a case of transapical TAVR VIV with a 29-mm Edwards SAPIEN XT (ESV) (Edwards Lifesciences, Irvine, CA) into a 29-mm Medtronic Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, MN) in which unanticipated dilatation of the Freestyle bioprosthesis resulted in intraprocedural embolization of the TAVR valve, necessitating urgent conversion to a conventional surgical aortic valve replacement (AVR). Our experience suggests that TAVR VIV with the 29-mm ESV in the setting of a degenerated 29-mm Freestyle stentless bioprosthesis must be undertaken with caution.

  2. Valve Concepts for Microfluidic Cell Handling

    Directory of Open Access Journals (Sweden)

    M. Grabowski

    2010-01-01

    Full Text Available In this paper we present various pneumatically actuated microfluidic valves to enable user-defined fluid management within a microfluidic chip. To identify a feasible valve design, certain valve concepts are simulated in ANSYS to investigate the pressure dependent opening and closing characteristics of each design. The results are verified in a series of tests. Both the microfluidic layer and the pneumatic layer are realized by means of soft-lithographic techniques. In this way, a network of channels is fabricated in photoresist as a molding master. By casting these masters with PDMS (polydimethylsiloxane we get polymeric replicas containing the channel network. After a plasma-enhanced bonding process, the two layers are irreversibly bonded to each other. The bonding is tight for pressures up to 2 bar. The valves are integrated into a microfluidic cell handling system that is designed to manipulate cells in the presence of a liquid reagent (e.g. PEG – polyethylene glycol, for cell fusion. For this purpose a user-defined fluid management system is developed. The first test series with human cell lines show that the microfluidic chip is suitable for accumulating cells within a reaction chamber, where they can be flushed by a liquid medium.

  3. Who by accident? The social morphology of car accidents.

    Science.gov (United States)

    Factor, Roni; Yair, Gad; Mahalel, David

    2010-09-01

    Prior studies in the sociology of accidents have shown that different social groups have different rates of accident involvement. This study extends those studies by implementing Bourdieu's relational perspective of social space to systematically explore the homology between drivers' social characteristics and their involvement in specific types of motor vehicle accident. Using a large database that merges official Israeli road-accident records with socioeconomic data from two censuses, this research maps the social order of road accidents through multiple correspondence analysis. Extending prior studies, the results show that different social groups indeed tend to be involved in motor vehicle accidents of different types and severity. For example, we find that drivers from low socioeconomic backgrounds are overinvolved in severe accidents with fatal outcomes. The new findings reported here shed light on the social regularity of road accidents and expose new facets in the social organization of death. © 2010 Society for Risk Analysis.

  4. Effect of Cone Angle on the Hydraulic Characteristics of Globe Control Valve

    Institute of Scientific and Technical Information of China (English)

    LIN Zhe; WANG Huijie; SHANG Zhaohui; CUI Baoling; ZHU Chongxi; ZHU Zuchao

    2015-01-01

    Globe control valve is widely used in chemical, petroleum and hydraulic industries, and its throttling feature is achieved by the adopting of valve plug. However, very limited information is avallable in literature regarding the influence of valve plug on the internal and external features in globe control valves. Thus the effect of valve plug is studied by CFD and experiment in this paper. It is obtalned from external features that the pressure drop between upstream and downstream pressure-sampling position increases exponentially with flow rate. And for small valve opening, the increment of pressure drop decreases with the increase of cone angle (β). However, with the increase of valve opening, the effect of cone angle diminishes significantly. It is also found that the cone angle has little effect on flow coefficient (Cv) when the valve opening is larger than 70%. But for the cases less than 70%, Cv curve varies from an arc to a stralght line. The variation of valve performance is caused by the change of internal flow. The results of internal flow show that cone angle has negligible effect on flow properties for the cases of valve opening larger than 70%. However, when valve opening is smaller than 70%, the pressure drop of orifice decreases with the increase ofβ, making the reduction in value and scope of the high speed zone around the conical surface of valve plug, and then results in a decreasing intensity of adjacent downstream vortex. Meanwhile, it is concluded from the results that the increase of cone angle will be beneficial for the anti-cavitation and anti-erosion of globe control valve. This paper focuses on the internal and external features of globe control valve that caused by the variation of cone angle, arriving at some results beneficial for the design and usage of globe control valve.

  5. ALICE Injected Beam Accidents

    CERN Document Server

    Appleby, R B

    2009-01-01

    The ALICE (point 2) interaction region is sensitive to beam orbit errors arising from magnet setting errors on injection. In this report, beam accident scenarios under injection for ALICE are described, focusing on ultra- fast error injection scenarios for the interaction straight correctors and dipoles. Beam 1 and beam 2 accident scenarios are considered, where the errors can lead to beam orbits striking the ALICE vacuum chamber or elements of the machine. The required thresholds for magnet current interlocks are calculated to avoid machine and detector risk.

  6. LHCb Injected Beam Accidents

    CERN Document Server

    Appleby, R B

    2009-01-01

    The LHCb (point 8) interaction region is sensitive to beam orbit errors arising from magnet setting errors on injection. In this report, beam accident scenarios under injection for LHCb are described, focusing on ultra- fast error injection scenarios for the interaction straight correctors and dipoles. Beam 1 and beam 2 accident scenarios are considered, where the errors can lead to beam orbits striking the LHCb vacuum chamber or elements of the machine. The required thresholds for magnet current interlocks are calculated to avoid machine and detector risk.

  7. Prosthetic valve thrombosis in a patient with mitral valve replacement.

    Science.gov (United States)

    Bilal, Muhammad; Khan, Muhammad Shahzeb; Haseeb, Abdul; Khan, Abdul Bari

    2015-07-01

    Prosthetic valve thrombosis within one year after mitral valve replacement is rarely seen in patients on warfarin therapy and without any risk factor. Here, we describe a case of a 39-year- old female, who presented with dyspnoea and shortness of breath 11 months after mitral valve replacement. The echocardiogram revealed severe valvular stenosis due to presence of clots on the mitral valve and restricted motion of the mitral leaflets. As a result of deterioration of general condition and haemodynamic un-stability, plan was made to re-operate for her valve replacement surgery. This case report highlights the diagnosis, prevention and management of patients with prosthetic valve thrombosis following mitral valve replacement.

  8. Effects of the Beijing Subway Accident on Engineering Monitoring and Auditing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Ⅰ. Beijing Subway Line 10 Accident On March 28, 2007, six people were buried by a cave-in at Suzhoujie Station on Line 10 of the Beijing Subway. The fatalities were caused when the unit in charge of construction failed to implement a timely evacuation after a construction accident took place. (See Beijing Youth, April 1, 2007)

  9. Distortion of the CoreValve during transcatheter aortic valve-in-valve implantation due to valve dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Souteyrand, Geraud, E-mail: gsouteyrand@chu-clermontferrand.fr [Department of Cardiology, Gabriel Montpied Hospital, CHU Clermont-Ferrand, Clermont-Ferrand (France); ERIM-EA3295, University of Auvergne, Clermont-Ferrand (France); Wilczek, Krzysztof [Department of Cardiology, Medical University of Silesia, Silesian Centre for Herat Diseases, Zabrze (Poland); Innorta, Andrea; Camilleri, Lionel [Department of Cardiology, Gabriel Montpied Hospital, CHU Clermont-Ferrand, Clermont-Ferrand (France); ERIM-EA3295, University of Auvergne, Clermont-Ferrand (France); Chodor, Piotr [Department of Cardiology, Medical University of Silesia, Silesian Centre for Herat Diseases, Zabrze (Poland); Lusson, Jean-René; Motreff, Pascal [Department of Cardiology, Gabriel Montpied Hospital, CHU Clermont-Ferrand, Clermont-Ferrand (France); ERIM-EA3295, University of Auvergne, Clermont-Ferrand (France); Laborde, Jean-Claude [St. George' s Hospital, London (United Kingdom); Chabrot, Pascal; Durel, Nicolas [Department of Cardiology, Gabriel Montpied Hospital, CHU Clermont-Ferrand, Clermont-Ferrand (France); ERIM-EA3295, University of Auvergne, Clermont-Ferrand (France)

    2013-09-15

    Nowadays transcatheter aortic valve implantation (TAVI) is an accepted alternative to surgical aortic valve replacement for high-risk patients (pts). Successful TAVI procedures for failed aortic surgical bioprosthesis (TAV-in-SAV) have already been reported. In the presented two cases of TAV-in-SAV implantation a strut distortion of the stent was revealed on angiographic imaging and confirmed on control CT scan. In both procedures, a dislocation of the medtronic core valve (MCV) prosthesis during implantation led to valve retrieval, with a necessity of reloading it in the 18F introducer before subsequent implantation of the same valve in correct position.

  10. An electrochemical active valve

    NARCIS (Netherlands)

    Neagu, C.R.; Gardeniers, J.G.E.; Elwenspoek, M.; Kelly, J.J.

    1997-01-01

    A novel electrochemical microactuator was developed, which operates as an active valve. The microactuator consists of an electrochemical cell and a membrane that deflects because of the pressure of oxygen gas generated by electrolysis. Relatively large pressures (up to tens of bars) can be reached w

  11. Thermostatic Radiator Valve Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Ansanelli, E.

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

  12. Heart valve surgery - discharge

    Science.gov (United States)

    ... ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  13. Aortic valve surgery - open

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otton CM, Bowow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  14. Vent Relief Valve Test

    Science.gov (United States)

    2008-01-01

    Shown is the disassembly, examination, refurbishment and testing of the LH2 ( liquid hydrogen) and LOX (liquid oxygen) vent and relief valves for the S-IVB-211 engine stage in support of the Constellation/Ares project. This image is extracted from high definition video and is the highest resolution available.

  15. The survey of occupational accidents in Yazd gas agency (2013

    Directory of Open Access Journals (Sweden)

    Amir Hossein Khoshakhlagh

    2016-10-01

    Full Text Available Background: Existence of coordinated and professional safety system to prevent occurrence of accidents and potential hazards seem to be essential in installing networks of gas distribution projects. Objective: To survey work-related accidents and safety performance indices in project implementation unit of Yazd gas agency. Methods: This analytical study was conducted on 197 of workforce in Yazd gas agency in 2013 that were selected by census and they were male. Demographic and accident information were gathered using a self-made questionnaire and face- to- face interview, and required information obtained from dossier to determine the safety performance indicators. Safety performance indicators were calculated in separately of 13 types occupations in project implementation unit of gas agency and data were analyzed using T-test. Findings: The highest accident frequency and severity rate were related to digging occupation and then metal line welding. Consequences of accidents were cuts (%56.7 and soreness (%14.9. The causes of accidents were related to uselessness of personal protective equipment (%25.2 and lack of precision in the task (%19.3. The highest rate of accident was observed among the age group 20-29 years with work experience of 4-6 years. Conclusion: According to the findings of this study and the risk of gas processes, it seems to be necessary the implementation of integrated management systems and training of workers about safety rules to improve the safety culture and prevent accidents.

  16. Analysis of hot leg natural circulation under station blackout severe accident

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Under severe accidents, natural circulation flows are important to influence the accident progression and result in a pressurized water reactor (PWR). In a station blackout accident with no recovery of steam generator (SG) auxiliary feedwater (TMLB' severe accident scenario), the hot leg countercurrent natural circulation flow is analyzed by using a severe-accident code, to better understand its potential impacts on the creep-rupture timing among the surge line, the hot leg, and SG tubes. The results show that the natural circulation may delay the failure time of the hot leg.The recirculation ratio and the hot mixing factor are also calculated and discussed.

  17. Measurement of reed valve kinematics

    Directory of Open Access Journals (Sweden)

    Fenkl Michael

    2016-01-01

    Full Text Available The measurement of key kinematic parameters of a reed valve movement is necessary for the further development of the reed valve system. These parameters are dependent on the geometry and material properties of the valve. As they directly affect the quantity of air flowing around the valve, a simple and easy to implement measurement of various valve configuration based on the air flow has been devised and is described in this paper, along with its technical parameters and drawbacks when evaluating reed valves used in reciprocating air compressors. Results are presented for a specimen of a compressor under examination. All kinematic parameters, and timing of the opening and closing of the valve, obtained from the measurement are presented and discussed.

  18. Measurement of reed valve kinematics

    Science.gov (United States)

    Fenkl, Michael; Dvořák, Václav; Vít, Tomáš

    2016-03-01

    The measurement of key kinematic parameters of a reed valve movement is necessary for the further development of the reed valve system. These parameters are dependent on the geometry and material properties of the valve. As they directly affect the quantity of air flowing around the valve, a simple and easy to implement measurement of various valve configuration based on the air flow has been devised and is described in this paper, along with its technical parameters and drawbacks when evaluating reed valves used in reciprocating air compressors. Results are presented for a specimen of a compressor under examination. All kinematic parameters, and timing of the opening and closing of the valve, obtained from the measurement are presented and discussed.

  19. Lessons learned from accidents investigations

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Bello, P. [Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico City (Mexico); Croft, J. [National Radiological Protection Board (United Kingdom); Glenn, J

    1997-12-31

    Accidents from three main practices: medical applications, industrial radiography and industrial irradiators are used to illustrate some common causes of accidents and the main lessons to be learned. A brief description of some of these accidents is given. Lessons learned from the described accidents are approached by subjects covering: safety culture, quality assurance, human factors, good engineering practice, defence in depth, security of sources, safety assessment and monitoring and verification compliance. (author)

  20. Developments in mechanical heart valve prosthesis

    Indian Academy of Sciences (India)

    Kalyani Nair; C V Muraleedharan; G S Bhuvaneshwar

    2003-06-01

    Artificial heart valves are engineered devices used for replacing diseased or damaged natural valves of the heart. Most commonly used for replacement are mechanical heart valves and biological valves. This paper briefly outlines the evolution, designs employed, materials being used,. and important factors that affect the performance of mechanical heart valves. The clinical performance of mechanical heart valves is also addressed. Efforts made in India in the development of mechanical heart valves are also discussed.

  1. Authority structure and industrial accidents

    NARCIS (Netherlands)

    As, Sicco van

    2001-01-01

    This paper deals with the influence of organizational characteristics on safety. Accidents are actually caused by individual mistakes. However the underlying causes of accidents are often organizational. The general hypothesis is that the authority structure is a main cause of accident-proneness

  2. [Three-dimensional reconstruction of heart valves].

    Science.gov (United States)

    Flachskampf, F A; Kühl, H; Franke, A; Frielingsdorf, J; Klues, H; Krebs, W; Hanrath, P

    1995-08-01

    The reconstruction of three-dimensional data sets from two-dimensional echocardiographic images offers several fundamental advantages: 1. more complete data than present in the few standard 2D-view; 2. off-line generation of any desired plane, cut, or perspective after the data set has been acquired; 3. access to quantitative parameters like surface areas (e.g., of valve leaflets or portions of leaflets), volumes, and others, without geometric assumptions. The mitral valve has been the focus of several studies using various techniques of reconstruction of transthoracic or transesophageal images. These studies have shown the mitral annulus to be a non-planar, "saddle-shaped" structure, with an average distance of highest to lowest points of 14 mm in normals. This recognition of mitral annular non-planarity has led to a more stringent echocardiographic definition of mitral valve prolapse. Further studies have shown systolic shrinkage of mitral annular area by about 30% and systolic apico-basal translation of the annulus by approximately 1 cm in normals. In patients with dilated cardiomyopathy, the annulus is flattened, and both cyclic change in annular area and apico-basal translation are significantly reduced. 3D-studies of the left ventricular outflow tract in hypertrophic obstructive cardiomyopathy allow measurement of outflow tract and leaflet surface areas and dynamic spatial visualization of systolic anterior motion of the anterior mitral leaflet. Automated techniques to reconstruct the full grey value data set from a high number of parallel or rotational transesophageal planes allow impressive visualization of normal and diseased mitral and aortic valves or valve prostheses, with special emphasis on generating "surgical" views and perspectives, which cannot be obtained by conventional tomographic imaging.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Chernobyl accident and its consequences

    Energy Technology Data Exchange (ETDEWEB)

    Gittus, J.H.

    1987-06-01

    The paper concerns the Chernobyl reactor accident, with emphasis on the design of the RBMK reactor and nuclear safety. A description is given of the Chernobyl nuclear power plant, including details of the RMBK reactor and safety systems. Comments on the design of the RBMK by UK experts prior to the accident are summarized, along with post-accident design changes to improve RBMK safety. Events of the Chernobyl accident are described, as well as design deficiencies highlighted by the accident. Differences between the USSR and UK approaches to nuclear safety are commented on. Finally source terms, release periods and environmental consequences are briefly discussed.

  4. Percutaneous tricuspid valve replacement in childhood

    Directory of Open Access Journals (Sweden)

    Mathias Emmel

    2015-01-01

    Full Text Available Percutaneous replacement of the tricuspid valve with a bovine jugular venous valve (melody valve was successfully undertaken in a 9-year-old boy. The patient had a previous history of bacterial endocarditis of the native tricuspid valve in infancy. Initially, a pericardial patch valve was created, followed by surgical replacement of the valve using a biological tissue valve at 4 years of age. Progressive stenosis and regurgitation of the biological valve, with severe venous congestion and resulting hepatic dysfunction prompted percutaneous valve replacement.

  5. Pressure model of a four-way spool valve for simulating electrohydraulic control systems

    Science.gov (United States)

    Gebben, V. D.

    1976-01-01

    An equation that relates the pressure flow characteristics of hydraulic spool valves was developed. The dependent variable is valve output pressure, and the independent variables are spool position and flow. This causal form of equation is preferred in applications that simulate the effects of hydraulic line dynamics. Results from this equation are compared with those from the conventional valve equation, whose dependent variable is flow. A computer program of the valve equations includes spool stops, leakage spool clearances, and dead-zone characteristics of overlap spools.

  6. Tricuspid Valve Replacement, Mechnical vs. Biological Valve, Which Is Better?

    Directory of Open Access Journals (Sweden)

    Haitham Akram Altaani

    2013-06-01

    Full Text Available Background: The initial trial in tricuspid surgery is repair; however, replacement is done whenever the valve is badly diseased. Tricuspid valve replacement comprises 1.7% of all tricuspid valve surgeries. Materials and Methods: The present retrospective study was performed using the medical records of 21 cases who underwent tricuspid valve replacement from January 2002 until the end of December 2010. The mean age of the participants was 52.3±8.8 years and 66.7% were females. In addition, tricuspid valve replacement was associated with mitral valve surgery, aortic valve surgery, and both in 14.3%, 4.8%, and 33.3% of the cases, respectively. Yet, isolated tricuspid valve replacement and redo surgery were performed in 10 cases (47.6% and 8 cases (38.1%, respectively. Besides, trial of repair was done in 14 cases (66.7%. Moreover, biological and mechanical valves were used in 76.2% and 23.8% of the patients, respectively. Results: According to the results, early mortality was 23.8% and one year survival was 66.7%. Moreover, early mortality was caused by right ventricular failure, multiorgan failure, medistinitis, and intracerbral bleeding in 42%, 28.6%, 14.3%, and 14.3% of the cases, respectively. In addition, 57.1% of the deaths had occurred in the cases where the biological valve was used, while 42.9% of the deaths had taken place where the mechanical one was utilized. Conclusions: The patients who require tricuspid valve replacement are usually high risk surgical candidates with early and long term mortality. The findings of the current study showed no significant hemodynamic difference between mechanical and biological valves.

  7. Transcatheter Replacement of Failed Bioprosthetic Valves

    DEFF Research Database (Denmark)

    Simonato, Matheus; Webb, John; Kornowski, Ran

    2016-01-01

    Background-Transcatheter valve implantation inside failed bioprosthetic surgical valves (valve-in-valve [ViV]) may offer an advantage over reoperation. Supra-annular transcatheter valve position may be advantageous in achieving better hemodynamics after ViV. Our objective was to define targets fo...

  8. Performance Characteristics of an Isothermal Freeze Valve

    Energy Technology Data Exchange (ETDEWEB)

    Hailey, A.E.

    2001-08-22

    This document discusses performance characteristics of an isothermal freeze valve. A freeze valve has been specified for draining the DWPF melter at the end of its lifetime. Two freeze valve designs have been evaluated on the Small Cylindrical Melter-2 (SCM-2). In order to size the DWPF freeze valve, the basic principles governing freeze valve behavior need to be identified and understood.

  9. Occupational accidents aboard merchant ships

    DEFF Research Database (Denmark)

    Hansen, H.L.; Nielsen, D.; Frydenberg, Morten

    2002-01-01

    Objectives: To investigate the frequency, circumstances, and causes of occupational accidents aboard merchant ships in international trade, and to identify risk factors for the occurrence of occupational accidents as well as dangerous working situations where possible preventive measures may...... be initiated. Methods: The study is a historical follow up on occupational accidents among crew aboard Danish merchant ships in the period 1993–7. Data were extracted from the Danish Maritime Authority and insurance data. Exact data on time at risk were available. Results: A total of 1993 accidents were...... rate of accidents than Danish citizens. Age was a major risk factor for accidents causing permanent disability. Change of ship and the first period aboard a particular ship were identified as risk factors. Walking from one place to another aboard the ship caused serious accidents. The most serious...

  10. "Vanishing" pulmonary valve stenosis

    Directory of Open Access Journals (Sweden)

    Nofil I Arain

    2012-01-01

    Full Text Available Objective: Both spontaneous resolution and progression of mild pulmonary valve stenosis (PS have been reported. We reviewed characteristics of the pulmonary valve (PV to determine factors that could influence resolution of mild PS. Methods: Fifteen asymptomatic pediatric patients with spontaneous resolution of isolated mild PS were retrospectively reviewed. Results: There was no correlation between the PV gradient, clinical presentation, age at diagnosis, or PV morphology. The PV annulus was small at initial presentation, which normalized at follow up. When corrected for the body surface area (z-score, the PV annulus was normal in all patients, including at initial evaluation. Conclusions: Based on our observation, neither age at diagnosis, nor PV-morphology-influenced resolution of mild PS. The variable clinical presentation makes it difficult to categorize and observe mild PS by auscultation alone. The PV annulus z-score could be a useful adjunct to determine the course and serial observation of mild PS.

  11. Scram discharge volume break studies accident sequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, R.M.; Hodge, S.A.

    1982-01-01

    This paper is a summary of a report describing the predicted response of Unit 1 at the Tennessee Valley Authority (TVA) Browns Ferry Nuclear Plant to a hypothetical small break loss of coolant accident (SBLOCA) outside of containment. The accident studied would be initiated by a break in the scram discharge volume (SDV) piping when it is pressurized to full reactor vessel pressure as a normal consequence of a reactor scram. If the scram could be reset, the scram outlet valves would close to isolate the SDV and the piping break from the reactor vessel. However, reset is possible only if the conditions that caused the scram have cleared; it has been assumed in this study that the scram signal remains in effect over a long period of time.

  12. Transcatheter aortic valve implantation in failed bioprosthetic surgical valves

    DEFF Research Database (Denmark)

    Dvir, Danny; Webb, John G; Bleiziffer, Sabine

    2014-01-01

    IMPORTANCE: Owing to a considerable shift toward bioprosthesis implantation rather than mechanical valves, it is expected that patients will increasingly present with degenerated bioprostheses in the next few years. Transcatheter aortic valve-in-valve implantation is a less invasive approach......, stroke, and New York Heart Association functional class. RESULTS: Modes of bioprosthesis failure were stenosis (n = 181 [39.4%]), regurgitation (n = 139 [30.3%]), and combined (n = 139 [30.3%]). The stenosis group had a higher percentage of small valves (37% vs 20.9% and 26.6% in the regurgitation...

  13. Minimally Invasive Mitral Valve Replacement and Transfemoral Aortic Valve Implantation.

    Science.gov (United States)

    Rustenbach, Christian; Baumbach, Hardy; Hill, Stephan; Franke, Ulrich F W

    2015-01-01

    The case is reported of a symptomatic elderly patient with severe mitral regurgitation, severe aortic valve stenosis, and coronary heart disease. The coronary artery disease had been interventionally treated four years previously with stent implantation into the right coronary artery. Published studies have shown that a combination of mitral and aortic valve surgery is associated with a significantly increased risk of mortality and morbidity, particularly in elderly patients. In the present patient, both valvular malformations were successfully treated with a single-step interdisciplinary approach, namely an initial surgical mitral valve replacement followed by transfemoral transcatheter aortic valve replacement.

  14. Accident Analysis and Research of the Tower Collapse by Ice Coating of the Transmission Line in Longnan Area, Gansu Province in 2014%2014年甘肃陇南地区耐张塔覆冰倒塔事故分析及研究

    Institute of Scientific and Technical Information of China (English)

    孔晨华

    2015-01-01

    An accident happened to the No. 2 strain tower of the 330kV transmission line in Longnan Area, Gansu in February, 2014. It’s a rare example of the strain tower’s collapse by ice coating. While checking the design parameters, systematically analyzed and researched the climate and terrain of the accident scene, and the real reasons of the tower collapse were found out. In the end it will offer several suggestions which should be got and would give reference to the subsequent design, operation and maintenance of the transmission lines.%2014年2月,甘肃陇南地区一条330kV输电线路发生了2基耐张塔倒塔的电网事故。耐张塔覆冰倒塔的案例非常少见,文章通过对设计相关参数的校核,对倒塔区域气象、地形等方面的系统分析研究,查找出了倒塔的真正原因,提出了事故应吸取的教训及建议,可为后续输电线路设计和运维提供参考依据。

  15. [Drowning accidents in childhood].

    Science.gov (United States)

    Krandick, G; Mantel, K

    1990-09-30

    This is a report on five boys aged between 1 and 5 years who, after prolonged submersion in cold water, were treated at our department. On being taken out of the water, all the patients were clinically dead. After 1- to 3-hour successful cardiopulmonary resuscitation, with a rectal temperature of about 27 degrees C, they were rewarmed at a rate of 1 degree/hour. Two patients died within a few hours after the accident. One patient survived with an apallic syndrome, 2 children survived with no sequelae. In the event of a water-related accident associated with hypothermia, we consider suitable resuscitation to have preference over rewarming measures. The most important treatment guidelines and prognostic factors are discussed.

  16. Anterior Urethral Valves

    Directory of Open Access Journals (Sweden)

    Vidyadhar P. Mali

    2006-07-01

    Full Text Available We studied the clinical presentation and management of four patients with anterior urethral valves; a rare cause of urethral obstruction in male children. One patient presented antenatally with oligohydramnios, bilateral hydronephrosis and bladder thickening suggestive of an infravesical obstruction. Two other patients presented postnatally at 1 and 2 years of age, respectively, with poor stream of urine since birth. The fourth patient presented at 9 years with frequency and dysuria. Diagnosis was established on either micturating cystourethrogram (MCU (in 2 or on cystoscopy (in 2. All patients had cystoscopic ablation of the valves. One patient developed a postablation stricture that was resected with an end-to-end urethroplasty. He had an associated bilateral vesicoureteric junction (VUJ obstruction for which a bilateral ureteric reimplantation was done at the same time. On long-term follow-up, all patients demonstrated a good stream of urine. The renal function is normal. Patients are continent and free of urinary infections. Anterior urethral valves are rare obstructive lesions in male children. The degree of obstruction is variable, and so they may present with mild micturition difficulty or severe obstruction with hydroureteronephrosis and renal impairment. Hence, it is important to evaluate the anterior urethra in any male child with suspected infravesical obstruction. The diagnosis is established by MCU or cystoscopy and the treatment is always surgical, either a transurethral ablation or an open resection. The long-term prognosis is good.

  17. Posterior Urethral Valves

    Directory of Open Access Journals (Sweden)

    Steve J. Hodges

    2009-01-01

    Full Text Available The most common cause of lower urinary tract obstruction in male infants is posterior urethral valves. Although the incidence has remained stable, the neonatal mortality for this disorder has improved due to early diagnosis and intensive neonatal care, thanks in part to the widespread use of prenatal ultrasound evaluations. In fact, the most common reason for the diagnosis of posterior urethral valves presently is the evaluation of infants for prenatal hydronephrosis. Since these children are often diagnosed early, the urethral obstruction can be alleviated rapidly through catheter insertion and eventual surgery, and their metabolic derangements can be normalized without delay, avoiding preventable infant mortality. Of the children that survive, however, early diagnosis has not had much effect on their long-term prognosis, as 30% still develop renal insufficiency before adolescence. A better understanding of the exact cause of the congenital obstruction of the male posterior urethra, prevention of postnatal bladder and renal injury, and the development of safe methods to treat urethral obstruction prenatally (and thereby avoiding the bladder and renal damage due to obstructive uropathy are the goals for the care of children with posterior urethral valves[1].

  18. Supramolecular spin valves

    Science.gov (United States)

    Urdampilleta, M.; Klyatskaya, S.; Cleuziou, J.-P.; Ruben, M.; Wernsdorfer, W.

    2011-07-01

    Magnetic molecules are potential building blocks for the design of spintronic devices. Moreover, molecular materials enable the combination of bottom-up processing techniques, for example with conventional top-down nanofabrication. The development of solid-state spintronic devices based on the giant magnetoresistance, tunnel magnetoresistance and spin-valve effects has revolutionized magnetic memory applications. Recently, a significant improvement of the spin-relaxation time has been observed in organic semiconductor tunnel junctions, single non-magnetic molecules coupled to magnetic electrodes have shown giant magnetoresistance and hybrid devices exploiting the quantum tunnelling properties of single-molecule magnets have been proposed. Herein, we present an original spin-valve device in which a non-magnetic molecular quantum dot, made of a single-walled carbon nanotube contacted with non-magnetic electrodes, is laterally coupled through supramolecular interactions to TbPc2 single-molecule magnets (Pc=phthalocyanine). Their localized magnetic moments lead to a magnetic field dependence of the electrical transport through the single-walled carbon nanotube, resulting in magnetoresistance ratios up to 300% at temperatures less than 1 K. We thus demonstrate the functionality of a supramolecular spin valve without magnetic leads. Our results open up prospects of new spintronic devices with quantum properties.

  19. RENEB accident simulation exercise

    OpenAIRE

    Brzozowska, Beata; Ainsbury, Elizabeth; Baert, Annelot; Beaton-Green, Lindsay; Barrios, Leonardo; Barquinero, Joan Francesc; Bassinet, Celine; Beinke, Christina; Benedek, Anett; Beukes, Philip; Bortolin, Emanuela; Buraczewska, Iwona; Burbidge, Christopher; De Amicis, Andrea; De Angelis, Cinzia

    2017-01-01

    Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results ob...

  20. A Study of the Gas Flow through a LNG Safety Valve

    Institute of Scientific and Technical Information of China (English)

    Heuy-Dong Kim; Jun-Hee Lee; Kyung-Am Park; Toshiaki Setoguchi; Shigeru Matsuo

    2006-01-01

    A safety valve functions to control an upper limit of pressure inside the LNG line of transportation.If the pressure inside the safety valve nozzle exceeds a pre-determined value on the valve sheet which plugs the nozzle,an excess of LNG discharges through the gap between the nozzle exit and valve sheet.In this situation,the forces acting on the valve sheet are gasdynamic forces generated by the discharge of LNG and mechanical forces supported by the spring behind the valve sheet.The flow through the gap is very complicated,involving vortices,flow separation,and shock waves.These affect adversely on the system accompanying with noise and vibration.The present study aims at understanding the flow physics of safety valve.A computational work using the twodimensional,axisymmetric,compressible Navier-Stokes equations is carried out to simulate the gas flow between the nozzle exit and valve sheet,and compared with the theoretical results.It has been found that there exists a distance between nozzle exit and valve sheet in which the thrust coefficient at the valve sheet increases abruptly.

  1. Performance Characterization of a Solenoid-type Gas Valve for the H- Magnetron Source at FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Sosa, A. [Fermilab; Bollinger, D. S. [Fermilab; Karns, P. R. [Fermilab

    2016-09-06

    The magnetron-style H- ion sources currently in operation at Fermilab use piezoelectric gas valves to function. This kind of gas valve is sensitive to small changes in ambient temperature, which affect the stability and performance of the ion source. This motivates the need to find an alternative way of feeding H2 gas into the source. A solenoid-type gas valve has been characterized in a dedicated off-line test stand to assess the feasibility of its use in the operational ion sources. H- ion beams have been extracted at 35 keV using this valve. In this study, the performance of the solenoid gas valve has been characterized measuring the beam current output of the magnetron source with respect to the voltage and pulse width of the signal applied to the gas valve.

  2. PREVENTION OF OCCUPATIONAL ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Jovica Jovanovic

    2004-01-01

    Full Text Available Medical services, physicians and nurses play an essential role in the plant safety program through primary treatment of injured workers and by helping to identify workplace hazards. The physician and nurse should participate in the worksite investigations to identify specific hazard or stresses potentially causing the occupational accidents and injuries and in planning the subsequent hazard control program. Physicians and nurses must work closely and cooperatively with supervisors to ensure the prompt reporting and treatment of all work related health and safety problems. Occupational accidents, work related injuries and fatalities result from multiple causes, affect different segments of the working population, and occur in a myriad of occupations and industrial settings. Multiple factors and risks contribute to traumatic injuries, such as hazardous exposures, workplace and process design, work organization and environment, economics, and other social factors. With such a diversity of theories, it will not be difficult to understand that there does not exist one single theory that is considered right or correct and is universally accepted. These theories are nonetheless necessary, but not sufficient, for developing a frame of reference for understanding accident occurrences. Prevention strategies are also varied, and multiple strategies may be applicable to many settings, including engineering controls, protective equipment and technologies, management commitment to and investment in safety, regulatory controls, and education and training. Research needs are thus broad, and the development and application of interventions involve many disciplines and organizations.

  3. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  4. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, John J. (Bingham County, ID)

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  5. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  6. Robot dispatching Scenario for Accident Condition Monitoring of NPP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongseog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-05-15

    In March of 2011, unanticipated big size of tsunami attacks Fukushima NPP, this accident results in explosion of containment building. Tokyo electric power of Japan couldn't dispatch a robot for monitoring of containment inside. USA Packbot robot used for desert war in Iraq was supplied to Fukushima NPP for monitoring of high radiation area. Packbot also couldn't reach deep inside of Fukushima NPP due to short length of power cable. Japanese robot 'Queens' also failed to complete a mission due to communication problem between robot and operator. I think major reason of these robot failures is absence of robot dispatching scenario. If there was a scenario and a rehearsal for monitoring during or after accident, these unanticipated obstacles could be overcome. Robot dispatching scenario studied for accident of nuclear power plant was described herein. Study on scenario of robot dispatching is performed. Flying robot is regarded as good choice for accident monitoring. Walking robot with arm equipped is good for emergency valve close. Short time work and shift work by several robots can be a solution for high radiation area. Thin and soft cable with rolling reel can be a good solution for long time work and good communication.

  7. Accident Analysis for the NIST Research Reactor Before and After Fuel Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Baek J.; Diamond D.; Cuadra, A.; Hanson, A.L.; Cheng, L-Y.; Brown, N.R.

    2012-09-30

    Postulated accidents have been analyzed for the 20 MW D2O-moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analysis has been carried out for the present core, which contains high enriched uranium (HEU) fuel and for a proposed equilibrium core with low enriched uranium (LEU) fuel. The analyses employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron transport calculations were performed with the MCNPX code to determine homogenized fuel compositions in the lower and upper halves of each fuel element and to determine the resulting neutronic properties of the core. The accident analysis employed a model of the primary loop with the RELAP5 code. The model includes the primary pumps, shutdown pumps outlet valves, heat exchanger, fuel elements, and flow channels for both the six inner and twenty-four outer fuel elements. Evaluations were performed for the following accidents: (1) control rod withdrawal startup accident, (2) maximum reactivity insertion accident, (3) loss-of-flow accident resulting from loss of electrical power with an assumption of failure of shutdown cooling pumps, (4) loss-of-flow accident resulting from a primary pump seizure, and (5) loss-of-flow accident resulting from inadvertent throttling of a flow control valve. In addition, natural circulation cooling at low power operation was analyzed. The analysis shows that the conversion will not lead to significant changes in the safety analysis and the calculated minimum critical heat flux ratio and maximum clad temperature assure that there is adequate margin to fuel failure.

  8. Latest design of gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Kurzhofer, U.; Stolte, J.; Weyand, M.

    1996-12-01

    Babcock Sempell, one of the most important valve manufacturers in Europe, has delivered valves for the nuclear power industry since the beginning of the peaceful application of nuclear power in the 1960s. The latest innovation by Babcock Sempell is a gate valve that meets all recent technical requirements of the nuclear power technology. At the moment in the United States, Germany, Sweden, and many other countries, motor-operated gate and globe valves are judged very critically. Besides the absolute control of the so-called {open_quotes}trip failure,{close_quotes} the integrity of all valve parts submitted to operational forces must be maintained. In case of failure of the limit and torque switches, all valve designs have been tested with respect to the quality of guidance of the gate. The guidances (i.e., guides) shall avoid a tilting of the gate during the closing procedure. The gate valve newly designed by Babcock Sempell fulfills all these characteristic criteria. In addition, the valve has cobalt-free seat hardfacing, the suitability of which has been proven by friction tests as well as full-scale blowdown tests at the GAP of Siemens in Karlstein, West Germany. Babcock Sempell was to deliver more than 30 gate valves of this type for 5 Swedish nuclear power stations by autumn 1995. In the presentation, the author will report on the testing performed, qualifications, and sizing criteria which led to the new technical design.

  9. Mitral Valve Prolapse in Pregnancy

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    Full Text Available Abstract Mitral valve prolapse is a benign condition. Mitral regurgitation is only complicated in patients with severe mitral valve prolapse. Women with mitral valve prolapse in the absence of other cardiovascular disorders tolerate pregnancy well and do not develop remarkable cardiac complications. Nevertheless, serious complications of mitral valve prolapse, including arrhythmia, infective endocarditis and cerebral ischemic events, can be present in pregnancy. Debates remain with regard to the use of prophylactic antibiotics and β-blockers in the pregnant women with mitral valve prolapse. The prognosis of the pregnant patients might be closely related to the pathological and (or functional changes of the mitral valve. Non-myxomatous mitral valve prolapse poses no or little obstetric risks in terms of pregnancy, labor and neonatal complications; whereas myxomatous mitral valve prolapse is a major etiology of valvular heart disease in women of childbearing age. In the pregnant patients with mitral valve prolapse progressing into major complications, surgical interventions are considered. Medicinal treatment of such patients with β-blockers should be a concern for the fetal safety.

  10. Innovative Stemless Valve Eliminates Emissions

    Science.gov (United States)

    2008-01-01

    Big Horn Valve Inc. (BHVI), of Sheridan, Wyoming, won a series of SBIR and Small Business Technology Transfer (STTR) contracts with Kennedy Space Center and Marshall Space Flight Center to explore and develop a revolutionary valve technology. BHVI developed a low-mass, high-efficiency, leak-proof cryogenic valve using composites and exotic metals, and had no stem-actuator, few moving parts, with an overall cylindrical shape. The valve has been installed at a methane coal gas field, and future applications are expected to include in-flight refueling of military aircraft, high-volume gas delivery systems, petroleum refining, and in the nuclear industry.

  11. A computerized system for video analysis of the aortic valve.

    Science.gov (United States)

    Vesely, I; Menkis, A; Campbell, G

    1990-10-01

    A novel technique was developed to study the dynamic behavior of the porcine aortic valve in an isolated heart preparation. Under the control of a personal computer, a video frame grabber board continuously acquired and digitized images of the aortic valve, and an analog-to-digital (A/D) converter read four channels of physiological data (flow rate, aortic and ventricular pressure, and aortic root diameter). The valve was illuminated with a strobe light synchronized to fire at the field acquisition rate of the CCD video camera. Using the overlay bits in the video board, the measured parameters were super-imposed over the live video as graphical tracing, and the resultant composite images were recorded on-line to video tape. The overlaying of the valve images with the graphical tracings of acquired data enabled the data tracings to be precisely synchronized with the video images of the aortic valve. This technique enabled us to observe the relationship between aortic root expansion and valve function.

  12. Whitey Gauge and Root Valves (VPS)

    Energy Technology Data Exchange (ETDEWEB)

    MISKA, C.

    2000-09-03

    These valves are 1/2 inch ball valves fabricated of 316 stainless steel: Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the Vacuum Pumping and Helium System.

  13. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    Science.gov (United States)

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power.

  14. Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve Disease

    DEFF Research Database (Denmark)

    Mylotte, Darren; Lefevre, Thierry; Søndergaard, Lars

    2014-01-01

    BACKGROUND: Limited information exists describing the results of transcatheter aortic valve (TAV) replacement in patients with bicuspid aortic valve (BAV) disease (TAV-in-BAV). OBJECTIVES: This study sought to evaluate clinical outcomes of a large cohort of patients undergoing TAV-in-BAV. METHODS...

  15. Prosthetic valve endocarditis after transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Olsen, Niels Thue; De Backer, Ole; Thyregod, Hans G H

    2015-01-01

    risk factors. METHODS AND RESULTS: Observational single-center study of 509 consecutive patients treated with a transcatheter implanted self-expandable aortic valve prosthesis (Medtronic CoreValve). We identified 18 patients diagnosed with TAVI-PVE during a median follow-up period of 1.4 years...

  16. High Reliability Cryogenic Piezoelectric Valve Actuator Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cryogenic fluid valves are subject to harsh exposure and actuators to drive these valves require robust performance and high reliability. DSM's piezoelectric...

  17. Percutaneous and minimally invasive approaches to mitral valve repair for severe mitral regurgitation-new devices and emerging outcomes

    Directory of Open Access Journals (Sweden)

    Fadi E Shamoun

    2015-01-01

    Full Text Available Mitral valve disease is common in the United States and around the world, and if left untreated, increases cardiovascular morbidity and mortality. Mitral valve repair is technically more demanding than mitral valve replacement. Mitral valve repair should be considered the first line of treatment for mitral regurgitation in younger patients, mitral valve prolapse, annular dilatation, and with structural damage to the valve. Several minimally invasive percutaneous treatment options for mitral valve repair are available that are not restricted to conventional surgical approaches, and may be better received by patients. A useful classification system of these approaches proposed by Chiam and Ruiz is based on anatomic targets and device action upon the leaflets, annulus, chordae, and left ventricle. Future directions of minimally invasive techniques will include improving the safety profile through patient selection and risk stratification, improvement of current imaging and techniques, and multidisciplinary education.

  18. Pattern extraction for high-risk accidents in the construction industry: a data-mining approach.

    Science.gov (United States)

    Amiri, Mehran; Ardeshir, Abdollah; Fazel Zarandi, Mohammad Hossein; Soltanaghaei, Elahe

    2016-09-01

    Accidents involving falls and falling objects (group I) are highly frequent accidents in the construction industry. While being hit by a vehicle, electric shock, collapse in the excavation and fire or explosion accidents (group II) are much less frequent, they make up a considerable proportion of severe accidents. In this study, multiple-correspondence analysis, decision tree, ensembles of decision tree and association rules methods are employed to analyse a database of construction accidents throughout Iran between 2007 and 2011. The findings indicate that in group I, there is a significant correspondence among these variables: time of accident, place of accident, body part affected, final consequence of accident and lost workdays. Moreover, the frequency of accidents in the night shift is less than others, and the frequency of injury to the head, back, spine and limbs are more. In group II, the variables time of accident and body part affected are mostly related and the frequency of accidents among married and older workers is more than single and young workers. There was a higher frequency in the evening, night shifts and weekends. The results of this study are totally in line with the previous research.

  19. [A case of death due to mitral regurgitation caused by traumatic mitral valve injury].

    Science.gov (United States)

    Iwasaki, Y; Kojima, T; Yasui, W; Nagasawa, N; Yashiki, M

    1996-06-01

    A 51-year-old male, who had been driving a motor bicycle, was involved in a traffic accident with a trailer, and he died immediately after the accident. According to the external examination of the victim, no fatal injuries were found. The medico-legal autopsy revealed a rupture of the left side of the pericardium, and a tear of the posterior leaflet of the mitral valve. There were no injuries of the papillary muscles and chordae. The cause of death was due to traumatic mitral regurgitation.

  20. Surge-damping vacuum valve

    Science.gov (United States)

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  1. Mitral valve surgery - minimally invasive

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... Editorial team. Related MedlinePlus Health Topics Heart Surgery Heart Valve Diseases Mitral Valve Prolapse Browse the Encyclopedia A.D. ...

  2. Valve-"Health"-Monitoring System

    Science.gov (United States)

    Jensen, Scott L.; Drouant, George J.

    2009-01-01

    A system that includes sensors and data acquisition, wireless data-communication, and data-processing subsystems has been developed as a means of both real-time and historical tracking of information indicative of deterioration in the mechanical integrity and performance of a highgeared ball valve or a linearly actuated valve that operates at a temperature between cryogenic and ambient.

  3. Combination throttle and shutoff valve

    Science.gov (United States)

    Carriker, J. W.

    1972-01-01

    Combination of translating sleeve throttle valve and conventional poppet valve provides capability of shutting off flow completely by poppet and sleeve control of the rate of flow. Integration of the two concepts can be accomplished without difficulty and in a manner that requires a minimum of development.

  4. Variable gas leak rate valve

    Energy Technology Data Exchange (ETDEWEB)

    Eernisse, Errol P. (Albuquerque, NM); Peterson, Gary D. (Albuquerque, NM)

    1976-01-01

    A variable gas leak rate valve which utilizes a poled piezoelectric element to control opening and closing of the valve. The gas flow may be around a cylindrical rod with a tubular piezoelectric member encircling the rod for seating thereagainst to block passage of gas and for reopening thereof upon application of suitable electrical fields.

  5. Severe Tricuspid Regurgitation Diagnosed 13 Years after a Car Accident: A Case Report

    Directory of Open Access Journals (Sweden)

    Burak Acar

    2015-10-01

    Full Text Available Blunt chest traumas mostly occur due to car accidents and can cause many cardiac complications such as septal rupture, free-wall rupture, coronary artery dissection or thrombosis, heart failure, arrhythmias, and chordae and papillary muscle rupture. One of the most serious complication is tricuspid regurgitation (TR, which can be simply diagnosed by physical examination and confirmed by echocardiography. We describe a 48-year-old female patient, diagnosed with severe TR 13 years after a blunt chest trauma due to a car accident. TR was diagnosed with transthoracic echocardiography and three dimensional transthoracic echocardiography had defined the exact pathology of the tricuspid valve. The patient underwent successful surgery with bioprosthetic valve implantation and was discharged at 6th postoperative day without any complication. The patient had no problem according to the follow-up one month and six months after operation

  6. Fluid mechanics of artificial heart valves.

    Science.gov (United States)

    Dasi, Lakshmi P; Simon, Helene A; Sucosky, Philippe; Yoganathan, Ajit P

    2009-02-01

    1. Artificial heart valves have been in use for over five decades to replace diseased heart valves. Since the first heart valve replacement performed with a caged-ball valve, more than 50 valve designs have been developed, differing principally in valve geometry, number of leaflets and material. To date, all artificial heart valves are plagued with complications associated with haemolysis, coagulation for mechanical heart valves and leaflet tearing for tissue-based valve prosthesis. For mechanical heart valves, these complications are believed to be associated with non-physiological blood flow patterns. 2. In the present review, we provide a bird's-eye view of fluid mechanics for the major artificial heart valve types and highlight how the engineering approach has shaped this rapidly diversifying area of research. 3. Mechanical heart valve designs have evolved significantly, with the most recent designs providing relatively superior haemodynamics with very low aerodynamic resistance. However, high shearing of blood cells and platelets still pose significant design challenges and patients must undergo life-long anticoagulation therapy. Bioprosthetic or tissue valves do not require anticoagulants due to their distinct similarity to the native valve geometry and haemodynamics, but many of these valves fail structurally within the first 10-15 years of implantation. 4. These shortcomings have directed present and future research in three main directions in attempts to design superior artificial valves: (i) engineering living tissue heart valves; (ii) development of advanced computational tools; and (iii) blood experiments to establish the link between flow and blood damage.

  7. Flow analysis by using solenoid valves for As(III determination in natural waters by an on-line separation and pre-concentration system coupled to a tungsten coil atomizer

    Directory of Open Access Journals (Sweden)

    José Y. Neira

    2005-03-01

    Full Text Available A flow system coupled to a tungsten coil atomizer in an atomic absorption spectrometer (TCA-AAS was developed for As(III determination in waters, by extraction with sodium diethyldithiocarbamate (NaDDTC as complexing agent, and by sorption of the As(III-DDTC complex in a micro-column filled with 5 mg C18 reversed phase (10 µL dry sorbent, followed by elution with ethanol. A complete pre-concentration/elution cycle took 208 s, with 30 s sample load time (1.7 mL and 4 s elution time (71 µL. The interface and software for the synchronous control of two peristaltic pumps (RUN/ STOP, an autosampler arm, seven solenoid valves, one injection valve, the electrothermal atomizer and the spectrometer Read function were constructed. The system was characterized and validated by analytical recovery studies performed both in synthetic solutions and in natural waters. Using a 30 s pre-concentration period, the working curve was linear between 0.25 and 6.0 µg L-1 (r = 0.9976, the retention efficiency was 94±1% (6.0 µg L-1, and the pre-concentration coefficient was 28.9. The characteristic mass was 58 pg, the mean repeatability (expressed as the variation coefficient was 3.4% (n=5, the detection limit was 0.058 µg L-1 (4.1 pg in 71 µL of eluate injected into the coil, and the mean analytical recovery in natural waters was 92.6 ± 9.5 % (n=15. The procedure is simple, economic, less prone to sample loss and contamination and the useful lifetime of the micro-column was between 200-300 pre-concentration cycles.

  8. Risk assessment of K basin twelve-inch drain valve failure from a postulated seismic initiating event

    Energy Technology Data Exchange (ETDEWEB)

    MORGAN, R.G.

    1999-04-06

    The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rates which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations suggest that only the valve's bonnet and stem are exposed above the basin concrete floor. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this activity are to: (1) evaluate the risk of damaging the three twelve-inch drain valves located along the north wall of the main basin from a seismic initiating event, and (2) determine the associated potential leak rate from a damaged valve.

  9. Risk assessment of K basin twelve-inch drain valve failure from a postulated seismic initiating event

    Energy Technology Data Exchange (ETDEWEB)

    MORGAN, R.G.

    1999-04-06

    The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rates which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations suggest that only the valve's bonnet and stem are exposed above the basin concrete floor. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this activity are to: (1) evaluate the risk of damaging the three twelve-inch drain valves located along the north wall of the main basin from a seismic initiating event, and (2) determine the associated potential leak rate from a damaged valve.

  10. Radiation accident grips Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, L.

    1987-11-20

    On 13 September two young scavengers in Goiania, Brazil, removed a stainless steel cylinder from a cancer therapy machine in an abandoned clinic, touching off a radiation accident second only to Chernobyl in its severity. On 18 September they sold the cylinder, the size of a 1-gallon paint can, to a scrap dealer for $25. At the junk yard an employee dismantled the cylinder and pried open the platinum capsule inside to reveal a glowing blue salt-like substance - 1400 curies of cesium-137. Fascinated by the luminescent powder, several people took it home with them. Some children reportedly rubbed in on their bodies like carnival glitter - an eerie image of how wrong things can go when vigilance over radioactive materials lapses. In all, 244 people in Goiania, a city of 1 million in central Brazil, were contaminated. The eventual toll, in terms of cancer or genetic defects, cannot yet be estimated. Parts of the city are cordoned off as radiation teams continue washing down buildings and scooping up radioactive soil. The government is also grappling with the political fallout from the accident.

  11. Investigation of relationship between mental workload and information flow rate of accident diagnosis tasks in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Chang Hoon

    2005-02-15

    The objective of this study is to investigate experimentally the relationship between an operator's mental workload and the information flow rate of accident diagnosis tasks and further to propose the information flow rate as an analytic method for measuring the mental workload. There are two types of mental workload in the advanced MCR of NPPs: the information processing workload, which is the processing that the human operator must actually perform in order to complete the diagnosis task, and emotional stress workload experienced by the operator. In this study, the focus is on the former. Three kinds of methods are used to measure the operator's workload: information flow rate, subjective methods, and physiological measures. Information flows for eight accident diagnosis tasks are modeled qualitatively using a stage model and are quantified using Conant's model. The eight accident cases are considered here are: Loss Of Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Steam Line Break (SLB), Feedwater Line Break (FLB), Pressurizer (PZR) spray and heater failure, Reactor Coolant Pump (RCP) trip, Main Steam Isolation Valve (MSIV) failure, and PZR spray failure. The information flow rate is obtained for each diagnosis task by imposing time limit restrictions for the tasks. Subjective methods require the operators to respond to questionnaires to rate their level of mental effort. NASA-TLX and MCH scale are selected as subjective methods. NASA-TLX is a subjective method used in the various fields including the aviation, automobile, and nuclear industries. It has a multi-dimensional rating technique and provides an overall workload score based on a weighted average on six subscales using pair-wise comparison tests. MCH, on the other hand, is one-dimensional and uses a 10- point rating technique. As with NASA-TLX, the higher the score is, the higher the subjective workload is. For the physiological measurements, an eye tracking system analyzes

  12. Robotic mitral valve surgery.

    Science.gov (United States)

    Kypson, Alan P; Nifong, L Wiley; Chitwood, W Randolph

    2003-12-01

    A renaissance in cardiac surgery has begun. The early clinical experience with computer-enhanced telemanipulation systems outlines the limitations of this approach despite some procedural success. Technologic advancements, such as the use of nitinol U-clips (Coalescent Surgical Inc., Sunnyvale, CA) instead of sutures requiring manual knot tying, have been shown to decrease operative times significantly. It is expected that with further refinements and development of adjunct technologies, the technique of computer-enhanced endoscopic cardiac surgery will evolve and may prove to be beneficial for many patients. Robotic technology has provided benefits to cardiac surgery. With improved optics and instrumentation, incisions are smaller. The ergometric movements and simulated three-dimensional optics project hand-eye coordination for the surgeon. The placement of the wristlike articulations at the end of the instruments moves the pivoting action to the plane of the mitral annulus. This improves dexterity in tight spaces and allows for ambidextrous suture placement. Sutures can be placed more accurately because of tremor filtration and high-resolution video magnification. Furthermore, the robotic system may have potential as an educational tool. In the near future, surgical vision and training systems might be able to model most surgical procedures through immersive technology. Thus, a "flight simulator" concept emerges where surgeons may be able to practice and perform the operation without a patient. Already, effective curricula for training teams in robotic surgery exist. Nevertheless, certain constraints continue to limit the advancement to a totally endoscopic computer-enhanced mitral valve operation. The current size of the instruments, intrathoracic instrument collisions, and extrathoracic "elbow" conflicts still can limit dexterity. When smaller instruments are developed, these restraints may be resolved. Furthermore, a working port incision is still required for

  13. Valve-related complications after mechanical heart valve implantation.

    Science.gov (United States)

    Misawa, Yoshio

    2015-10-01

    The number of heart valve surgeries is increasing, and 19,164 patients underwent heart valve surgery in Japan in 2011. The early mortality rate has remained stable for more than 10 years. Many patients now survive for many years, with a reported 10-year survival rate of at least 60 %. However, unfavorable complications can occur after valve surgery. Valve-related complications include thromboembolisms, bleeding complications and prosthetic valve endocarditis, followed by structural and nonstructural prosthetic valve dysfunctions. Our review of studies published after 2000 revealed that the rate of all valve-related complications was 0.7-3.5 % per patient-year. Thromboembolisms occur at a rate of approximately 1 % per patient-year, and bleeding complications occur at almost 0.5 % per patient-year. Thromboembolic and hemorrhagic events related to anticoagulant therapy should be considered during life-long follow-up. The occurrence rate of endocarditis reaches 0.5 % per patient-year, with a poor postoperative survival. Structural dysfunctions have been largely overcome, and the nonstructural dysfunction rate is 0.4-1.2 % per patient-year. The nonstructural dysfunctions induced by paravalvular leaks and pannus ingrowth are also issues that need to be resolved.

  14. Patents and heart valve surgery - II: tissue valves.

    Science.gov (United States)

    Cheema, Faisal H; Kossar, Alexander P; Rehman, Atiq; Younas, Fahad; Polvani, Gianluca

    2013-08-01

    Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace the defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart valves. Although various methods have made fantastic strides in producing durable prostheses, the therapeutic efficacy of prosthetic valves is inherently limited by a dependency upon lifelong anticoagulant regimens for recipients - a difficult challenge for many in clinical setting. Thus, biological tissue valves have been developed to circumvent vascular and immunemediated complications by incorporating biological materials to mimic native valves while still maintaining a necessary level of structural integrity. Over the past decade, a multitude of patents pertaining to the refinement of designs as well as the advancement in methodologies and technologies associated with biological tissue valves have been issued. This review seeks to chronicle and characterize such patents in an effort to track the past, present, and future progress as well as project the trajectory of tissue valves in the years to come.

  15. Eustachian valve endocarditis: a rare localization of right side endocarditis. A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Terranova Antonio

    2005-09-01

    Full Text Available Abstract Background Right-sided endocarditis occurs predominantly in intravenous drug users, in patients with pacemaker or central venous lines and in patients with congenital heart disease. The vast majority of cases involve the tricuspid valve. Eustachian valve endocarditis is an uncommon disease with similar signs and symptoms of the tricuspid valve endocarditis. A series of only 16 cases of eustachian valve endocarditis are reported in the literature. Case Presentation We present a case of a 25-year old woman with intravenous drug abuse who had a staphylococcus aureus tricuspid valve endocarditis associated to eustachian valve endocarditis. Transthoracic echocardiography, as first line examination, showed the vegetations on tricuspid and eustachian valve. Conclusion Our case describe an unusual location of right side endocarditis in a intravenous drug abuser. In our case, in accord with other cases described in the literature, transthoracic echocardiography disclosed eustachian valve endocarditis. Antimicrobial management is not altered by the recognition of eustachian valve endocarditis. Antibiotic treatment and duration of eustachian endocarditis depends on the isolated organism and is similar to antibiotic therapy used in native valve endocarditis.

  16. Accident Analysis and Countermeasures of the Enterprises Involved in Ammonia%涉氨企业事故分析与对策

    Institute of Scientific and Technical Information of China (English)

    卢均臣; 王延平

    2015-01-01

    从事故发生环节、事故类型、事故设备、事故原因等几个方面分析了2005年-2014年全国涉氨企业发生的事故。分析表明:储存和使用环节事故最多;事故主要类型事故泄漏和中毒;主要发生在食品厂、肉类加工厂、冷饮厂、水产公司、果蔬公司、制药厂的制冷车间;主要发生在管道、储罐、阀门、法兰等部位;材料失效事故占比最高。最后,提出了预防此类事故的建议措施。%Accidents occurred in 2005-2014 in our country were analyzed from the aspects of the accident link, accident type, accident equipment, accident cause. Analysis showed that accidents in links of the storage and use were the most, the main types of accidents were leakage and poisoning, accidents mainly occured in food factory, meat processing factory, beverage factory, etc, accidents mainly occured in pipeline, storage tanks, valves, flanges, etc, the amount of accidents caused by material failure was the largest. Suggestions for preventing such accidents were put forward.

  17. Self-Rupturing Hermetic Valve

    Science.gov (United States)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self

  18. PWR safety and relief valve test program. Valve selection/juftification report. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-12-01

    NUREG 0578 required that full-scale testing be performed on pressurizer safety valves and relief valves representative of those in use or planned for use in PWR plants. To obtain valve performance data for the entire population of PWR plant valves, nine safety valves and ten relief valves were selected as a fully representative set of test valves. Justification that the selected valves represent all PWR plant valves was provided by each safety and relief valve manufacturer. Both the valve selection and justification work was performed as part of the PWR Safety and Relief Valve Test Program conducted by EPRI on behalf of the PWR utilities in response to the recommendations of NUREG 0578 and the requirements of the NRC. Results of the Safety and Relief Valve Selection and Justification effort is documented in this report.

  19. Fatal motorcycle accidents and alcohol

    DEFF Research Database (Denmark)

    Larsen, C F; Hardt-Madsen, M

    1987-01-01

    A series of fatal motorcycle accidents from a 7-year period (1977-1983) has been analyzed. Of the fatalities 30 were operators of the motorcycle, 11 pillion passengers and 8 counterparts. Of 41 operators 37% were sober at the time of accident, 66% had measurable blood alcohol concentration (BAC...

  20. Learning from incidents and accidents

    NARCIS (Netherlands)

    Drupsteen, L.; Kampen, J. van

    2014-01-01

    There are many different definitions for what constitutes an incident or an accident, however the focus is always on unintended and often unforeseen events that cause unintended consequences. This article is focused on the process of learning from incidents and accidents. The focus is on making sure

  1. [Practical management of CPB accident].

    Science.gov (United States)

    Depoix, J-P; Fenet, L; Provenchere, S

    2012-05-01

    Accident of CPB is a reality. It is important to be prepared for discussion with the family, with the hospital administration, eventually with the justice. But we have also to support perfusionnist and anesthetic team in charge of the patient during accident.

  2. Learning from incidents and accidents

    NARCIS (Netherlands)

    Drupsteen, L.; Kampen, J. van

    2014-01-01

    There are many different definitions for what constitutes an incident or an accident, however the focus is always on unintended and often unforeseen events that cause unintended consequences. This article is focused on the process of learning from incidents and accidents. The focus is on making sure

  3. Malfunction of a Heimlich flutter valve causing tension pneumothorax: case report of a rare complication

    Directory of Open Access Journals (Sweden)

    Braunstein Volker A

    2010-06-01

    Full Text Available Abstract Background Thoracic injuries play an important role in major trauma patients due to their high incidence and critical relevance. A serious consequence of thoracic trauma is pneumothorax, a condition that quickly can become life-threatening and requires immediate treatment. Decompression is the state of the art for treating tension pneumothorax. There are many different methods of decompression using different techniques, devices, valves and drainage systems. Referring to our case report we would like to discuss the utilization of these devices. Case presentation We report of a patient suffering from tension pneumothorax despite insertion of a chest drain at the accident scene. The decompression was by tube thoracostomy which was connected to a Heimlich flutter valve. During air transportation the patient suffered from cardiorespiratory arrest with asystole and was admitted to the trauma room undergoing manual chest compressions. The initial chest film showed a persisting tension pneumothorax, despite the chest tube that had been correctly placed and connected properly to the Heimlich valve. We assume that the Heimlich valve leaves did not open up and thus tension pneumothorax was not released. Conclusion We would like to raise awareness to the fact that if a Heimlich flutter valve is applied in the pre-hospital setting it should be used with caution. Failure in this type of valve may lead to recurrent tension pneumothorax.

  4. 42 CFR 84.137 - Inhalation and exhalation valves; check valves; minimum requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Inhalation and exhalation valves; check valves... PROTECTIVE DEVICES Supplied-Air Respirators § 84.137 Inhalation and exhalation valves; check valves; minimum requirements. (a) Inhalation and exhalation valves shall be provided where necessary and protected...

  5. Traffic Accidents on Slippery Roads

    DEFF Research Database (Denmark)

    Fonnesbech, J. K.; Bolet, Lars

    2014-01-01

    Police registrations from 65 accidents on slippery roads in normally Danish winters have been studied. The study showed: • 1 accident per 100 km when using brine spread with nozzles • 2 accidents per 100 km when using pre wetted salt • 3 accidents per 100 km when using kombi spreaders The results...... of accidents in normally Danish winter seasons are remarkable alike the amount of salt used in praxis in the winter 2011/2012. • 2.7 ton NaCl/km when using brine spread with nozzles • 5 ton NaCl/km when using pre wetted salt. • 5.7 ton NaCl/km when using kombi spreaders The explanation is that spreading...

  6. Corporate Cost of Occupational Accidents

    DEFF Research Database (Denmark)

    Rikhardsson, Pall M.; Impgaard, M.

    2004-01-01

    method could be used in all of the companies without revisions. The evaluation of accident cost showed that 2/3 of the costs of occupational accidents are visible in the Danish corporate accounting systems reviewed while 1/3 is hidden from management view. The highest cost of occupational accidents......The systematic accident cost analysis (SACA) project was carried out during 2001 by The Aarhus School of Business and PricewaterhouseCoopers Denmark with financial support from The Danish National Working Environment Authority. Its focused on developing and testing a method for evaluating...... occupational costs of companies for use by occupational health and safety professionals. The method was tested in nine Danish companies within three different industry sectors and the costs of 27 selected occupational accidents in these companies were calculated. One of the main conclusions is that the SACA...

  7. Industrial accidents triggered by lightning.

    Science.gov (United States)

    Renni, Elisabetta; Krausmann, Elisabeth; Cozzani, Valerio

    2010-12-15

    Natural disasters can cause major accidents in chemical facilities where they can lead to the release of hazardous materials which in turn can result in fires, explosions or toxic dispersion. Lightning strikes are the most frequent cause of major accidents triggered by natural events. In order to contribute towards the development of a quantitative approach for assessing lightning risk at industrial facilities, lightning-triggered accident case histories were retrieved from the major industrial accident databases and analysed to extract information on types of vulnerable equipment, failure dynamics and damage states, as well as on the final consequences of the event. The most vulnerable category of equipment is storage tanks. Lightning damage is incurred by immediate ignition, electrical and electronic systems failure or structural damage with subsequent release. Toxic releases and tank fires tend to be the most common scenarios associated with lightning strikes. Oil, diesel and gasoline are the substances most frequently released during lightning-triggered Natech accidents.

  8. 49 CFR 195.116 - Valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valves. 195.116 Section 195.116 Transportation... PIPELINE Design Requirements § 195.116 Valves. Each valve installed in a pipeline system must comply with the following: (a) The valve must be of a sound engineering design. (b) Materials subject to...

  9. 49 CFR 192.145 - Valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valves. 192.145 Section 192.145 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.145 Valves. (a) Except for cast iron and plastic valves, each valve must meet the minimum requirements of API...

  10. 14 CFR 125.137 - Oil valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil valves. 125.137 Section 125.137....137 Oil valves. (a) Each oil valve must— (1) Comply with § 125.155; (2) Have positive stops or... the valve. (b) The closing of an oil shutoff means must not prevent feathering the propeller,...

  11. Experimental Investigation of Cavitation in a Safety Relief Valve using water. Extension to Cryogenic fluids.

    OpenAIRE

    Pinho, Jorge

    2015-01-01

    This thesis addresses the experimental investigation of the cavitation phenomenon and its main consequences on the normal operation of a safety relief valve (SRV). More particularly, limitation of the mass flux discharged and alteration of the hydraulic fluid forces behavior is of main interest for the proper design and sizing of such devices. In nuclear or thermal engineering systems, the use of SRVs is mandatory since it represents the ultimate protection device before an accident occurs, c...

  12. Cavitation guide for control valves

    Energy Technology Data Exchange (ETDEWEB)

    Tullis, J.P. [Tullis Engineering Consultants, Logan, UT (United States)

    1993-04-01

    This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation.

  13. Proportional valve with a piezoelectric actuator

    Science.gov (United States)

    Laski, Pawel Andrzej

    2016-11-01

    The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  14. Proportional valve with a piezoelectric actuator

    Directory of Open Access Journals (Sweden)

    Laski Pawel Andrzej

    2017-01-01

    Full Text Available The article concerns a slotted proportional valve for use in pneumatic and hydraulic systems. There is a growing demand for both hydraulic and pneumatic ultrafast proportional valves. The conducted analysis of literature confirms the lack of such solutions for proportional valves. The currently used pneumatic systems for selection and segregation of parts and objects require ultrafast valves. The presented solution for the proportional valve can significantly improve and accelerate this type of technological processes. Furthermore, fast proportional valves can be successfully used for positional control of pneumatic and hydraulic drives. The article presents the design of a slotted divide valve and sets the maximum mass flow rate for service roads.

  15. Double prosthetic aortic valve. Case report.

    Science.gov (United States)

    Liddicoat, J E; Bekassy, S M; De Bakey, M E

    1975-05-01

    A 55-year-old man underwent insection of a Hufnagel valve into his descending thoracic aorta for aortic valve insufficiency 18 years ago. He remained asymptomatic for 16 years. Because of progressive left ventricular failure his incompetent aortic valve was replaced with a De Bakey carbon ball aortic valve prosthesis 2 years later. Currently, 21 months after the operation, he is doing well with two aortic valves. Review of the literature suggests that he is the first patient reported with two aortic valves functioning concomitantly and one of the longest surviving patients with a Hufnagel valve.

  16. Typologie des Accidents Cyclistes

    OpenAIRE

    Amoros, Emmanuelle; BILLOT-GRASSET, Alice; Hours, Martine

    2015-01-01

    L'usage du vélo est en hausse en ville ; cette pratique est encouragée dans le cadre du développement durable et de la lutte contre la sédentarité. Pour accompagner cela, il faut réduire les risques d'accident, et pour ce faire, mieux les connaître. Nous utilisons le Registre des victimes de la circulation routière du Rhône, basé sur les services hospitaliers (dont les urgences) ; il est quasi-exhaustif : env. 1100 blessés à vélo/an versus 120 dans les données officielles. L'ensemble des cycl...

  17. Transcatheter, valve-in-valve transapical aortic and mitral valve implantation, in a high risk patient with aortic and mitral prosthetic valve stenoses

    Directory of Open Access Journals (Sweden)

    Harish Ramakrishna

    2015-01-01

    Full Text Available Transcatheter valve implantation continues to grow worldwide and has been used principally for the nonsurgical management of native aortic valvular disease-as a potentially less invasive method of valve replacement in high-risk and inoperable patients with severe aortic valve stenosis. Given the burden of valvular heart disease in the general population and the increasing numbers of patients who have had previous valve operations, we are now seeing a growing number of high-risk patients presenting with prosthetic valve stenosis, who are not potential surgical candidates. For this high-risk subset transcatheter valve delivery may be the only option. Here, we present an inoperable patient with severe, prosthetic valve aortic and mitral stenosis who was successfully treated with a trans catheter based approach, with a valve-in-valve implantation procedure of both aortic and mitral valves.

  18. Anatomic, histopathologic, and echocardiographic features in a dog with an atypical pulmonary valve stenosis with a fibrous band of tissue and a patent ductus arteriosus.

    Science.gov (United States)

    Yoon, Hakyoung; Kim, Jaehwan; Nahm, Sang-Soep; Eom, Kidong

    2017-07-11

    Congenital pulmonary valve stenosis and patent ductus arteriosus are common congenital heart defects in dogs. However, concurrence of atypical pulmonary valve stenosis and patent ductus arteriosus is uncommon. This report describes the anatomic, histopathologic, and echocardiographic features in a dog with concomitant pulmonary valve stenosis and patent ductus arteriosus with atypical pulmonary valve dysplasia that included a fibrous band of tissue. A 1.5-year-old intact female Chihuahua dog weighing 3.3 kg presented with a continuous grade VI cardiac murmur, poor exercise tolerance, and an intermittent cough. Echocardiography indicated pulmonary valve stenosis, a thickened dysplastic valve without annular hypoplasia, and a type IIA patent ductus arteriosus. The pulmonary valve was thick line-shaped in systole and dome-shaped towards the right ventricular outflow tract in diastole. The dog suffered a fatal cardiac arrest during an attempted balloon pulmonary valvuloplasty. Necropsy revealed pulmonary valve dysplasia, commissural fusion, and incomplete opening and closing of the pulmonary valve because of a fibrous band of tissue causing adhesion between the right ventricular outflow tract and the dysplastic intermediate cusp of the valve. A fibrous band of tissue between the right ventricular outflow track and the pulmonary valve should be considered as a cause of pulmonary valve stenosis. Pulmonary valve stenosis and patent ductus arteriosus can have conflicting effects on diastolic and systolic dysfunction, respectively. Therefore, beta-blockers should always be used carefully, particularly in patients with a heart defect where there is concern about left ventricular systolic function.

  19. Thermostatic Radiator Valve Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J. [Advanced Residential Integrated Energy Solutions Collaborative (ARIES), New York, NY (United States); Ansanelli, E. [Advanced Residential Integrated Energy Solutions Collaborative (ARIES), New York, NY (United States)

    2015-01-01

    A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market. In this project, the ARIES team sought to better understand the current usage of TRVs by key market players in steam and hot water heating and to conduct limited experiments on the effectiveness of new and old TRVs as a means of controlling space temperatures and reducing heating fuel consumption. The project included a survey of industry professionals, a field experiment comparing old and new TRVs, and cost-benefit modeling analysis using BEopt™ (Building Energy Optimization software).

  20. Workers’ health surveillance: a study of major accidents at work

    Directory of Open Access Journals (Sweden)

    Karini da Rosa

    2016-10-01

    Full Text Available Background and objectives: Work accidents are the biggest health problem of Brazilian workers, thus, the objective of the study is to characterize sociodemographic and occupational data affected by serious accidents workers work in the municipality of Santa Cruz do Sul/RS. Method: this is a field study, documental, retrospective, with data collection in epidemiological report forms of the Municipal Unit Worker Health Reference (UMREST in the period of 2008 to 2010. Results: We conducted data collection in 1263 patient notification forms of the UMREST, and found 986 cases of serious work accident, and 78.59% of cases with male workers aged 20 to 29 years. In 2008 there were more cases reported in the information systems of Occupational Health. The occupations with the highest occurrence were the production line feeders (13,48%, tobacco processing assistant (8.0%, workers in the maintenance and conservation of buildings and public parks (7.0%. Among the types of accidents, 66.63% were typical accidents and 31.23% of commuting accidents. It identified the central area of the city as the most frequent cases with 47.2%, followed by the Industrial District neighborhood with 27.1% of cases. Final Thoughts: it was found that the accidents occurred more often on male workers, young, from labor institutions located in the central area of the city. Thus, we emphasize the need for prevention and care actions that meet the profile of the workers studied. KEYWORDS: Accidents at work. Occupational health surveillance. Occupational health

  1. Fatal train accidents on Europe's railways: 1980-2009.

    Science.gov (United States)

    Evans, Andrew W

    2011-01-01

    This paper presents an analysis of fatal train accident rates and trends on Europe's main line railways from 1980 to 2009. The paper uses a new set of data for the European Union together with Norway and Switzerland, assembled partly under the auspices of the European Railway Agency and partly on the author's own account. The estimated overall trend in the number of fatal train collisions and derailments per train-kilometre is -6.3% per year from 1990 to 2009, with a 95% confidence interval of -8.7% to -3.9%. The estimated accident rate in 2009 is 1.35 fatal collisions or derailments per billion train-kilometres, giving an estimated mean number of fatal accidents in 2009 of 6.0. The overall number of fatalities per fatal accident in 1990-2009 is 4.10, with no apparent long term change over time, giving an estimated mean of 24.6 fatalities per year in train collisions and derailments in 2009. There are statistically significant differences in the fatal train accident rates and trends between the different European countries, although the estimates of the rates and trends for many individual countries have wide confidence limits. The distribution of broad causes of accidents appears to have remained unchanged over the long term, so that safety improvements appear to have been across the board, and not focused on any specific cause. The most frequent cause of fatal train collisions and derailments is signals passed at danger. In contrast to fatal train collisions and derailments, the rate per train-kilometre of serious accidents at level crossings remained unchanged in 1990-2009. The immediate causes of most of the serious level crossing accidents are errors or violations by road users. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Anesthetic management for combined mitral valve replacement and aortic valve repair in a patient with osteogenesis imperfecta

    Directory of Open Access Journals (Sweden)

    Huang Jiapeng

    2011-01-01

    Full Text Available Osteogenesis imperfecta is a rare disorder of connective tissues and presents multiple challenges, including difficult airway, hyperthermia, coagulopathy and respiratory dysfunction, for anesthesiologists, especially during cardiac surgery. We present anesthetic management of a patient with osteogenesis impertecta during double valve surgery. Dexmedetomidine infusion minimized the risks of malignant hyperthermia. Glidescope and in-line stabilization facilitated endotracheal intubation and protected his oral structures and cervical spine. Transesophageal echocardiography (TEE diagnosed a flail A3 segment and redundant left coronary cusp causing mitral and aortic regurgitation. The mitral valve was replaced and the aortic valve repaired. Coagulopathy was corrected according to comprehensive coagulation analysis. Glidescope, dexmedetomidine, coagulation analysis and TEE could facilitate anesthetic management in these patients.

  3. Space shuttle main engine definition (phase B). Volume 5: Valves and interconnects. [for space shuttle

    Science.gov (United States)

    Schultz, D. F.

    1971-01-01

    The steady state thermodynamic cycle balance of the single preburner staged combustion engine, coupled with dynamic transient analyses, dictated in detail the location and requirements for each valve defined in this volume. Valve configuration selections were influenced by overall engine and vehicle system weight and failure mode determinations. Modulating valve actuators are external to the valve and are line replaceable. Development and satisfactory demonstration of a high pressure dynamic shaft seal has made this configuration practical. Pneumatic motor driven actuators that use engine pumped hydrogen gas as the working fluid are used. The helium control system is proposed as a module containing a cluster of solenoid actuated valves. The separable couplings and flanges are designed to assure minimum leakage with minimum coupling weight. The deflection of the seal surface in the flange is defined by finite element analysis that has been confirmed with test data. The seal design proposed has passed preliminary pressure cycling and thermal cycling tests.

  4. Design of Bidirectional Check Valve for Discrete Fluid Power Force System for Wave Energy Converters

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Pedersen, Henrik C.; Andersen, Torben Ole

    2014-01-01

    Discrete fluid power force systems consisting of a multichamber cylinder, a witching manifold and common pressure lines have been proposed as a technology for increasing the efficiency of the power take off system in ocean wave energy converters. However the force shifting of these discrete systems...... enables passive force switching under minimal pressure difference, hence minimal energy loss. The bidirectional check valve is designed with a rated flow in the range of 1000L/min@5bar. The flow direction of the bidirectional check valve is set by the setting the pilot pressure. This paper presents...... a functionality test of a 125 L/min@5bar bidirectional check, leading to the design and modelling of a bidirectional check valve for ocean wave energy. It shows that a feasible bidirectional check valve may be configured by employing a multi-poppet topology for the main stage and utilising a 3/2 switching valve...

  5. Human tissue valves in aortic position: determinants of reoperation and valve regurgitation

    NARCIS (Netherlands)

    T.P. Willems (Tineke); E.W. Steyerberg (Ewout); V.E. Kleyburg-Linkers; E. Bos (Egbert); L.A. van Herwerden (Lex); J.R.T.C. Roelandt (Jos); J.J.M. Takkenberg (Hanneke)

    2001-01-01

    textabstractBACKGROUND: Human tissue valves for aortic valve replacement have a limited durability that is influenced by interrelated determinants. Hierarchical linear modeling was used to analyze the relation between these determinants of durability and valve

  6. Comparison of outcomes after aortic valve replacement with a mechanical valve or a bioprosthesis using microsimulation

    NARCIS (Netherlands)

    J.P.A. Puvimanasinghe (John); M.B. Edwards; M.J.C. Eijkemans (René); E.W. Steyerberg (Ewout); L.A. van Herwerden (Lex); K.M. Taylor; G.L. Grunkemeier (Gary); J.D.F. Habbema (Dik); A.J.J.C. Bogers (Ad); J.J.M. Takkenberg (Hanneke)

    2004-01-01

    textabstractBACKGROUND: Mechanical valves and bioprostheses are widely used for aortic valve replacement. Though previous randomised studies indicate that there is no important difference in outcome after implantation with either type of valve, knowledge of outcomes after aortic va

  7. Water Distribution Lines, Water distribution system details Including pumps, storage tanks, valves, and mains, Published in Not Provided, 1:600 (1in=50ft) scale, Town of Franklin.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Water Distribution Lines dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Field Survey/GPS information as of Not Provided. It is...

  8. Simpler valve for reciprocating engines

    Science.gov (United States)

    Akkerman, J. W.

    1978-01-01

    Simpler design eliminating camshafts, cams, and mechanical springs should improve reliability of hydrazine powered reciprocating engines. Valve is expected to improve efficiency, and reduce weight of engines in range up to 50 horsepower.

  9. Titanium in engine valve systems

    Energy Technology Data Exchange (ETDEWEB)

    Allison, J.E.; Sherman, A.M.; Bapna, M.R.

    1987-03-01

    Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. Still, their relatively high cost has discouraged consideration for widespread use in automotive components. Recent demands for increased fuel economy have led to the consideration of these alloys for use as valve train materials where higher costs might be offset by improvements in performance and fuel economy. Lighter weight valve train components permit the use of lower spring loads, thus reducing friction and increasing fuel economy. Camshaft friction measurements made on a typical small displacement engine indicate that a two-to-four percent increase in fuel economy can be achieved. Valve train components are, however, subject to a severe operating environment, including elevated temperatures, sliding wear and high mechanical loads. This paper discusses the details of alloy and heat treatment selection for optimizing valve performance.

  10. Diseases of the Tricuspid Valve

    Science.gov (United States)

    ... Kawasaki Disease Long Q-T Syndrome Marfan Syndrome Metabolic Syndrome Mitral Valve Prolapse Myocardial Bridge Myocarditis Obstructive Sleep Apnea Pericarditis Peripheral Vascular Disease Rheumatic Fever Sick Sinus Syndrome Silent Ischemia Stroke Sudden ...

  11. What Causes Heart Valve Disease?

    Science.gov (United States)

    ... a heart attack or injury to the heart. Rheumatic Fever Untreated strep throat or other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease. When the body ...

  12. CONGENITAL QUADRICUSPID AORTIC-VALVE

    NARCIS (Netherlands)

    BROUWER, MHJ; DEGRAAF, JJ; EBELS, T

    1993-01-01

    Two patients with a quadricuspid aortic valve are described, one of them with concomitant juxtaposed coronary orifices facing the right hand facing sinus. The etiology and incidence of this congenital anomaly will be discussed.

  13. Minimally invasive aortic valve replacement

    DEFF Research Database (Denmark)

    Foghsgaard, Signe; Schmidt, Thomas Andersen; Kjaergard, Henrik K

    2009-01-01

    In this descriptive prospective study, we evaluate the outcomes of surgery in 98 patients who were scheduled to undergo minimally invasive aortic valve replacement. These patients were compared with a group of 50 patients who underwent scheduled aortic valve replacement through a full sternotomy....... The 30-day mortality rate for the 98 patients was zero, although 14 of the 98 mini-sternotomies had to be converted to complete sternotomies intraoperatively due to technical problems. Such conversion doubled the operative time over that of the planned full sternotomies. In the group of patients whose...... is an excellent operation in selected patients, but its true advantages over conventional aortic valve replacement (other than a smaller scar) await evaluation by means of randomized clinical trial. The "extended mini-aortic valve replacement" operation, on the other hand, is a risky procedure that should...

  14. The spin-valve transistor

    NARCIS (Netherlands)

    Monsma, Douwe Johannes

    1998-01-01

    High density magnetic recording, magnetic random access memories, displacement and current detection, contactless switching and electronic compass applications all require magnetic field sensors with unprecedented sensitivity. The spin-valve effect (giant magnetoresistance) found in 1988 in magnetic

  15. Embryological origin of the endocardium and derived valve progenitor cells: from developmental biology to stem cell-based valve repair.

    Science.gov (United States)

    Pucéat, Michel

    2013-04-01

    The cardiac valves are targets of both congenital and acquired diseases. The formation of valves during embryogenesis (i.e., valvulogenesis) originates from endocardial cells lining the myocardium. These cells undergo an endothelial-mesenchymal transition, proliferate and migrate within an extracellular matrix. This leads to the formation of bilateral cardiac cushions in both the atrioventricular canal and the outflow tract. The embryonic origin of both the endocardium and prospective valve cells is still elusive. Endocardial and myocardial lineages are segregated early during embryogenesis and such a cell fate decision can be recapitulated in vitro by embryonic stem cells (ESC). Besides genetically modified mice and ex vivo heart explants, ESCs provide a cellular model to study the early steps of valve development and might constitute a human therapeutic cell source for decellularized tissue-engineered valves. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. 57. Aortic valve replacement with sutureless valve and mitral valve repair in patient with infected aortic homograft

    Directory of Open Access Journals (Sweden)

    A. attia

    2016-07-01

    Full Text Available The approach of implanting aortic sutureless valve inside the calcific homograft is suitable in redo surgery especially if associated with mitral valve surgery. Aortic valve replacement in patients who have undergone previous aortic root replacement with an aortic homograft remains a technical challenge because of homograft degeneration and the need for a redo Bentall operation. We report a case of redo aortic valve replacement (valve in valve with a sutureless valve and mitral valve repair by miniband annuloplasty in a female patient aged 64 years old who underwent aortic valve replacement with homograft 14 years ago and presented by sever aortic valve regurge and sever mitral valve regurge because of infective endocarditis. This technique allows rapid aortic valve replacement in a heavily calcified aortic root. It also avoids aortic valve size affection after mitral valve repair by ordinary methods especially in patients with small aortic annulus. This technique is particularly suitable in redo procedures for homograft degeneration, it avoids performing a redo Bentall operation with its known problems as well as to avoid patient prosthesis mismatch.

  17. Chernobyl accident and its consequences

    Energy Technology Data Exchange (ETDEWEB)

    Gittus, J.H.; Bonell, P.G.; Hicks, D.

    1987-01-01

    The USSR power reactor programme is first described. The reasons for the accident at the Chernobyl-4 RBMK nuclear reactor on 26 April 1986, the sequence of events that took place, and the immediate and long-term consequences are considered. A description of the RBMK-type reactors is given and the design changes resulting from the experience of the accident are explained. The source terms describing the details of the radioactivity release associated with the accident and the environmental consequences are covered in the last two sections of the report. Throughout the text comments referring to the UK Nuclear Installations Inspectorate Safety assessment principles have been inserted. (U.K.).

  18. An improved gate valve for critical applications in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kalsi, M.S.; Alvarez, P.D.; Wang, J.K.; Somagyi, D. [Kalsi Engineering, Inc., Sugar Land, TX (United States)] [and others

    1996-12-01

    U.S. Nuclear Regulatory Commission Generic Letters 89-10 for motor-operated valves (MOVs) and 95-07 for all power-operated valves document in detail the problems related to the performance of the safety-related valves in nuclear power plants. The problems relate to lack of reliable operation under design basis conditions including higher than anticipated stem thrust, unpredictable valve behavior, damage to the valve internals under blowdown/high flow conditions, significant degradation of performance when cycled under AP and flow, thermal binding, and pressure locking. This paper describes an improved motor-operated flexible wedge gate valve design, the GE Sentinel Valve, which is the outcome of a comprehensive and systematic development effort undertaken to resolve the issues identified in the NRC Generic Letters 89-10 and 95-07. The new design provides a reliable, long-term, low maintenance cost solution to the nuclear power industry. One of the key features incorporated in the disc permits the disc flexibility to be varied independently of the disc thickness (pressure boundary) dictated by the ASME Section III Pressure Vessel & Piping Code stress criteria. This feature allows the desired flexibility to be incorporated in the disc, thus eliminating thermal binding problems. A matrix of analyses was performed using finite element and computational fluid dynamics approaches to optimize design for stresses, flexibility, leak-tightness, fluid flow, and thermal effects. The design of the entire product line was based upon a consistent set of analyses and design rules which permit scaling to different valve sizes and pressure classes within the product line. The valve meets all of the ASME Section III Code design criteria and the N-Stamp requirements. The performance of the valve was validated by performing extensive separate effects and plant in-situ tests. This paper summarizes the key design features, analyses, and test results.

  19. An under-operation diagnostic apparatus for motor-operated valve. Technical trends on motor-operated valve conservation for nuclear power stations and condition based maintenance using the new diagnostic apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Itou, Haruo [Japan Atomic Power Co., Tokyo (Japan)

    2002-08-01

    A new motor-operated valve diagnostic analysis system (MOVDAS) can be, in short time, simply and with high precision, carried out diagnosis on deterioration and accident of motor-operated valves with many numbers used for separated and feeding valves important for safety of a nuclear reactor, not only at cease but also under operation of a power plant, and is technology capable of upgrading reliability on a motor-operated valve for a condition based maintenance tool and reducing conservation cost. MOVDAS is composed of a built-in torque sensor directly measurable transit torque behaviors with high precision by upgrading a torque sensing technology using strain gauges and a diagnostic apparatus to analyze their signals, which can be used even under operation of the valves. And, this technology can be adapted for under-operation integrity recognition of the valve recommended by NRC in U.S.A. and for operation and maintenance indication, JEAG-4803 in Japan. Here were introduced its contents and also a motor-operated valve remote diagnostic system recently developed in parallel. (G.K.)

  20. [Prevention of bicycle accidents].

    Science.gov (United States)

    Zwipp, H; Barthel, P; Bönninger, J; Bürkle, H; Hagemeister, C; Hannawald, L; Huhn, R; Kühn, M; Liers, H; Maier, R; Otte, D; Prokop, G; Seeck, A; Sturm, J; Unger, T

    2015-04-01

    For a very precise analysis of all injured bicyclists in Germany it would be important to have definitions for "severely injured", "seriously injured" and "critically injured". By this, e.g., two-thirds of surgically treated bicyclists who are not registered by the police could become available for a general analysis. Elderly bicyclists (> 60 years) are a minority (10 %) but represent a majority (50 %) of all fatalities. They profit most by wearing a helmet and would be less injured by using special bicycle bags, switching on their hearing aids and following all traffic rules. E-bikes are used more and more (145 % more in 2012 vs. 2011) with 600,000 at the end of 2011 and are increasingly involved in accidents but still have a lack of legislation. So even for pedelecs 45 with 500 W and a possible speed of 45 km/h there is still no legislative demand for the use of a protecting helmet. 96 % of all injured cyclists in Germany had more than 0.5 ‰ alcohol in their blood, 86 % more than 1.1 ‰ and 59 % more than 1.7 ‰. Fatalities are seen in 24.2 % of cases without any collision partner. Therefore the ADFC calls for a limit of 1.1 ‰. Some virtual studies conclude that integrated sensors in bicycle helmets which would interact with sensors in cars could prevent collisions or reduce the severity of injury by stopping the cars automatically. Integrated sensors in cars with opening angles of 180° enable about 93 % of all bicyclists to be detected leading to a high rate of injury avoidance and/or mitigation. Hanging lamps reduce with 35 % significantly bicycle accidents for children, traffic education for children and special trainings for elderly bicyclists are also recommended as prevention tools. As long as helmet use for bicyclists in Germany rates only 9 % on average and legislative orders for using a helmet will not be in force in the near future, coming up campaigns seem to be necessary to be promoted by the Deutscher

  1. Model for the calculation of transient hydraulics caused by the valve motion in water supply pipe line%泵阀动作给水管线水力瞬变计算模型研究

    Institute of Scientific and Technical Information of China (English)

    廖宗蓉

    2016-01-01

    Hydraulic transient (water hammer)refers to the dynamic change of flow and pres-sure in hydraulic system,which comes from the fact that transient increase of water pressure in the pipes would cause pressure waves and transmit it in sound velocity.In this paper,hydraulic transi-ent was analyzed through rigid water hammer model and flexible water hammer model.Simplified finite difference equation was adopted to build a characteristics-method mathematical model for hy-draulic transient and set up boundary conditions for pump motions and valve motions.Characteris-tic method equation and boundary conditions equation were used to get the transient of water hammer waves in pipelines so as to solve the problems of water hammer in complicated pipeline sys-tem and boundary conditions.%由于管道内压力瞬间升高,压力波在管道内以声速传递,导致水力系统流量和压力动态变化,即产生水力瞬变(水锤),通过刚性水锤模型和弹性水锤模型分析给水管线水力瞬变,采用简化的有限差分方程,建立特征线法水力瞬变数学模型,并建立了泵、阀动作的边界条件,可借助于特征线方程和边界条件方程,求解管线内水锤波的暂态,以解决复杂的管路系统和边界条件的水锤问题。

  2. Design of the Modular Pneumatic Valve Terminal

    Directory of Open Access Journals (Sweden)

    Jakub E. TAKOSOGLU

    2015-11-01

    Full Text Available The paper presents design of the modular pneumatic valve terminal, which was made on the basis of the patent application No A1 402905 „A valve for controlling fluid power drives, specially for pneumatic actuators, and the control system for fluid power drives valves”. The authors describe a method of operation of the system with double-acting valve and 5/2 (five ways and two position valve. Functions of the valve, and an example of application of the valve terminal in the production process were presented. 3D solid models of all the components of the valve were made. The paper presents a complete 3D model of the valve in various configurations. Using CAD-embedded SOLIDWORKS Flow Simulation computational fluid dynamics CFD analysis was also carried out of compressed air flow in the ways of the valve elements

  3. TCT-670 Optimal Transcatheter Heart Valve Sizing in Aortic Valve in Valve Implantation: Insights from the Valve in Valve International Data (VIVID) Registry

    DEFF Research Database (Denmark)

    Alnasser, Sami; Cheema, Asim N; Horlick, Eric

    2016-01-01

    Background: Optimal transcatheter heart valve (THV) sizing is crucial to optimize procedural outcomes. Larger THV oversizing is shown to decrease paravalvular leakage post transcatheter aortic valve replacement but its role in Valve in Valve implantation (ViV) is not well established. Methods...... group received a larger THV (25.5± 1.4 mm vs. 23.3 ± 1.0 mm, pimplantation, the oversized group achieved a larger EOA (1.54±0.4cm2 vs. 1.37± 0.5cm2, p...V implantation was associated with favorable post-implant EOA and gradient but a higher risk of aortic insufficiency and THV re-intervention. Further exploration within various THV and surgical valve types at different degree of THV oversizing is planned....

  4. Multimodal imaging of the tricuspid valve: normal appearance and pathological entities

    Directory of Open Access Journals (Sweden)

    Soham Shah

    2016-06-01

    Full Text Available Abstract The tricuspid valve, which is the atrioventricular valve attached to the morphological right ventricle, is affected by a wide range of pathological processes. Tricuspid valve diseases are now increasingly recognized as a significant cause of morbidity and mortality. Echocardiography is the most widely available and, hence, the first-line imaging modality used in the evaluation of tricuspid valve disorders; however, CT and MRI are also increasingly used for further evaluation and characterization of these entities. In this article, we first review the normal anatomy and embryology of the tricuspid valve, followed by a discussion of the role of multiple imaging modalities in the evaluation of tricuspid valve abnormalities. We then review and illustrate the imaging appearance of several congenital and acquired tricuspid valve abnormalities. Main Messages • Tricuspid valve diseases have a significant impact on morbidity and mortality. • CT and MRI are increasingly used in the evaluation of tricuspid disorders. • CT and MRI help in diagnosis, functional evaluation, pre-surgical planning and post-surgical follow-up. • The most common cause of tricuspid regurgitation is functional.

  5. Development of an effective valve packing program

    Energy Technology Data Exchange (ETDEWEB)

    Hart, K.A.

    1996-12-01

    Current data now shows that graphite valve packing installed within the guidance of a controlled program produces not only reliable stem sealing but predictable running loads. By utilizing recent technological developments in valve performance monitoring for both MOV`s and AOV`s, valve packing performance can be enhanced while reducing maintenance costs. Once known, values are established for acceptable valve packing loads, the measurement of actual valve running loads via the current MOV/AOV diagnostic techniques can provide indication of future valve stem sealing problems, improper valve packing installation or identify the opportunity for valve packing program improvements. At times the full benefit of these advances in material and predictive technology remain under utilized due to simple past misconceptions associated with valve packing. This paper will explore the basis for these misconceptions, provide general insight into the current understanding of valve packing and demonstrate how with this new understanding and current valve diagnostic equipment the key aspects required to develop an effective, quality valve packing program fit together. The cost and operational benefits provided by this approach can be significant impact by the: elimination of periodic valve repacking, reduction of maintenance costs, benefits of leak-free valve operation, justification for reduced Post Maintenance Test Requirements, reduced radiation exposure, improved plant appearance.

  6. Research on Converter Valve Overvoltage Mechanism and Calculation Conditions of ± 800 kV Converter Station

    Institute of Scientific and Technical Information of China (English)

    WANG Dongju; DENG Xu; ZHOU Hao; CHEN Xilei; XU Anwen; SHEN Yang

    2012-01-01

    The thyristor converter valve is the key equipment of commutation in ultra high voltage direct current (UHVDC) transmission systems. Owing to the limited voltage and current overload capacity, any transient overvoltage may cause permanent damage to the thyristor converter valve. In order to specify the converter valves' overvoltage levels of the ±800 kV UHVDC transmission system, the mechanisms of its generation and development are discussed in detail, from which the calculation conditions for the highest stresses of the converter valves are given. Finally, the converter valve's overvoltage of Xiluodu UHV converter station is simulated. The research results show that the overvoltages of the converter valves in the upper 3-pulse group of the high voltage(HV) and low voltage(LV) 12-pulse converter are generated jointly by the DC line voltage and the converter transformer's voltage at its valve side. Calculation conditions for this overvoltage are: DC system in bipolar operation mode, converter station operating as rectifier, maximum DC system operating voltage, minimum DC current, minimum AC system voltage of the converter station. Furthermore, the other converter valves' overvoltage is caused by the phase-to-phase switching surge generated at the converter station's AC side, penetrating into the valve hall. Overall, the maximum overvoltages of Xiluodu converter station in the upper 3-pulse group of the HV and LV 12-pulse converter are 379.1 kV and 384.9 kV, for other converter valves the maximum overvoltage is 375.3 kV.

  7. Three Mile Island Accident Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Three Mile Island Accident Data consists of mostly upper air and wind observations immediately following the nuclear meltdown occurring on March 28, 1979, near...

  8. Nuclear fuel cycle facility accident analysis handbook

    Energy Technology Data Exchange (ETDEWEB)

    Ayer, J E; Clark, A T; Loysen, P; Ballinger, M Y; Mishima, J; Owczarski, P C; Gregory, W S; Nichols, B D

    1988-05-01

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH.

  9. Paragliding accidents in remote areas.

    Science.gov (United States)

    Fasching, G; Schippinger, G; Pretscher, R

    1997-08-01

    Paragliding is an increasingly popular hobby, as people try to find new and more adventurous activities. However, there is an increased and inherent danger with this sport. For this reason, as well as the inexperience of many operators, injuries occur frequently. This retrospective study centers on the helicopter rescue of 70 individuals in paragliding accidents. All histories were examined, and 43 patients answered a questionnaire. Nineteen (42%) pilots were injured when taking off, 20 (44%) during the flight, and six (13%) when landing. Routine and experience did not affect the prevalence of accident. Analysis of the causes of accident revealed pilot errors in all but three cases. In 34 rescue operations a landing of the helicopter near the site of the accident was possible. Half of the patients had to be rescued by a cable winch or a long rope fixed to the helicopter. Seven (10%) of the pilots suffered multiple trauma, 38 (54%) had injuries of the lower extremities, and 32 (84%) of them sustained fractures. Injuries to the spine were diagnosed in 34 cases with a fracture rate of 85%. One patient had an incomplete paraplegia. Injuries to the head occurred in 17 patients. No paraglider pilot died. The average hospitalization was 22 days, and average time of working inability was 14 weeks. Fourteen (34%) patients suffered from a permanent damage to their nerves or joints. Forty-three percent of the paragliders continued their sport despite the accident; two of them had another accident. An improved training program is necessary to lower the incidence of paragliding accidents. Optimal equipment to reduce injuries in case of accidents is mandatory. The helicopter emergency physician must perform a careful examination, provide stabilization of airways and circulation, give analgesics, splint fractured extremities, and transport the victim on a vacuum mattress to the appropriate hospital.

  10. Multiplexed hydraulic valve actuation using ionic liquid filled soft channels and Braille displays

    Science.gov (United States)

    Gu, Wei; Chen, Hao; Tung, Yi-Chung; Meiners, Jens-Christian; Takayama, Shuichi

    2007-01-01

    Pneumatic actuation with multilayer soft lithography enables operation of up to thousands of valves in parallel using far fewer control lines. However, it is dependent on macroscopic switches and external pressure sources that require interconnects and limit portability. The authors present a more portable and multiplexed valve actuation strategy that uses a grid of mechanically actuated Braille pins to hydraulically, rather than pneumatically, deform elastic actuation channels that act as valves. Experimental and theoretical analyses show that the key to reliable operation of the hydraulic system is the use of nonvolatile ionic liquids as the hydraulic fluid.

  11. LOFT pressurizer safety: relief valve reliability

    Energy Technology Data Exchange (ETDEWEB)

    Brown, E.S.

    1978-01-18

    The LOFT pressurizer self-actuating safety-relief valves are constructed to the present state-of-the-art and should have reliability equivalent to the valves in use on PWR plants in the U.S. There have been no NRC incident reports on valve failures to lift that would challenge the Technical Specification Safety Limit. Fourteen valves have been reported as lifting a few percentage points outside the +-1% Tech. Spec. surveillance tolerance (9 valves tested over and 5 valves tested under specification). There have been no incident reports on failures to reseat. The LOFT surveillance program for assuring reliability is equivalent to nuclear industry practice.

  12. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    DEFF Research Database (Denmark)

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    . The samples are adjusted to pH 5.0 on-line in the system for optimum operation. The target ions are adsorbed by chelation on the surface of the beads, contained in a 20 mul microcolumn within the LOV, and following elution by 50 mul 2M nitric acid, the eluate is, as sandwiched by air segments, introduced...

  13. Severe accident analysis using dynamic accident progression event trees

    Science.gov (United States)

    Hakobyan, Aram P.

    In present, the development and analysis of Accident Progression Event Trees (APETs) are performed in a manner that is computationally time consuming, difficult to reproduce and also can be phenomenologically inconsistent. One of the principal deficiencies lies in the static nature of conventional APETs. In the conventional event tree techniques, the sequence of events is pre-determined in a fixed order based on the expert judgments. The main objective of this PhD dissertation was to develop a software tool (ADAPT) for automated APET generation using the concept of dynamic event trees. As implied by the name, in dynamic event trees the order and timing of events are determined by the progression of the accident. The tool determines the branching times from a severe accident analysis code based on user specified criteria for branching. It assigns user specified probabilities to every branch, tracks the total branch probability, and truncates branches based on the given pruning/truncation rules to avoid an unmanageable number of scenarios. The function of a dynamic APET developed includes prediction of the conditions, timing, and location of containment failure or bypass leading to the release of radioactive material, and calculation of probabilities of those failures. Thus, scenarios that can potentially lead to early containment failure or bypass, such as through accident induced failure of steam generator tubes, are of particular interest. Also, the work is focused on treatment of uncertainties in severe accident phenomena such as creep rupture of major RCS components, hydrogen burn, containment failure, timing of power recovery, etc. Although the ADAPT methodology (Analysis of Dynamic Accident Progression Trees) could be applied to any severe accident analysis code, in this dissertation the approach is demonstrated by applying it to the MELCOR code [1]. A case study is presented involving station blackout with the loss of auxiliary feedwater system for a

  14. Accident tolerant fuel analysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Curtis [Idaho National Laboratory; Chichester, Heather [Idaho National Laboratory; Johns, Jesse [Texas A& M University; Teague, Melissa [Idaho National Laboratory; Tonks, Michael Idaho National Laboratory; Youngblood, Robert [Idaho National Laboratory

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced ''RISMC toolkit'' that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional ''accident-tolerant'' (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant

  15. [Accidents of fulguration].

    Science.gov (United States)

    Virenque, C; Laguerre, J

    1976-01-01

    Fulguration, first electric accident in which the man was a victim, is to day better known. A clap of thunder is decomposed in two elements: lightning, and thunder. Lightning is caused by an electrical discharge, either within a cloud, or between two clouds, or, above all, between a cloud and the surface of the ground. Experimental equipments owned by the French Electricity Company and by the Atomic Energy Commission, have allowed to photograph lightnings and to measure certain physical characteristics (Intensity variable between 25 to 100 kA, voltage variable between 20 to 1 000 kV). The frequency of storms was learned: the isokeraunic level, in France, is about 20, meaning that thunder is heard twenty days during one year. Man may be stricken by thunder by direct hit, by sudden bursting, by earth current, or through various conductors. The electric charge which reached him may go to the earth directly by contact with the ground or may dissipate in the air through a bony promontory (elbow). The total number of victims, "wounded" or deceased, is not now known by statistics. Death comes by insulation breakdown of one of several anatomic cephalic formations: skull, meninx, brain. Many various lesions may happen in survivors: loss of consciousness, more or less long, sensorial or motion deficiencies. All these signs are momentary and generally reversible. Besides one may observe much more intense lesions on the skin: burns and, over all, characteristic aborescence (skin effect by high frequency current). The heart is protected, contrarily to what happens with industrial electrocution. The curative treatment is merely symptomatic : reanimation, surgery for burns or associated traumatic lesions. A prevention is researched to help the lonely man, in the country or in the mountains in the houses (lightning conductor, Faraday cage), in vehicles (aircraft, cars, ships). The mysterious and unforseeable character of lightning still stays, leaving a door opened for numerous

  16. Accident Tolerant Fuel Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Curtis Smith; Heather Chichester; Jesse Johns; Melissa Teague; Michael Tonks; Robert Youngblood

    2014-09-01

    Safety is central to the design, licensing, operation, and economics of Nuclear Power Plants (NPPs). Consequently, the ability to better characterize and quantify safety margin holds the key to improved decision making about light water reactor design, operation, and plant life extension. A systematic approach to characterization of safety margins and the subsequent margins management options represents a vital input to the licensee and regulatory analysis and decision making that will be involved. The purpose of the Risk Informed Safety Margin Characterization (RISMC) Pathway research and development (R&D) is to support plant decisions for risk-informed margins management by improving economics and reliability, and sustaining safety, of current NPPs. Goals of the RISMC Pathway are twofold: (1) Develop and demonstrate a risk-assessment method coupled to safety margin quantification that can be used by NPP decision makers as part of their margin recovery strategies. (2) Create an advanced “RISMC toolkit” that enables more accurate representation of NPP safety margin. In order to carry out the R&D needed for the Pathway, the Idaho National Laboratory is performing a series of case studies that will explore methods- and tools-development issues, in addition to being of current interest in their own right. One such study is a comparative analysis of safety margins of plants using different fuel cladding types: specifically, a comparison between current-technology Zircaloy cladding and a notional “accident-tolerant” (e.g., SiC-based) cladding. The present report begins the process of applying capabilities that are still under development to the problem of assessing new fuel designs. The approach and lessons learned from this case study will be included in future Technical Basis Guides produced by the RISMC Pathway. These guides will be the mechanism for developing the specifications for RISMC tools and for defining how plant decision makers should propose and

  17. Experiments and Valve Modelling in Thermoacoustic Device

    Science.gov (United States)

    Duthil, P.; Baltean Carlès, D.; Bétrancourt, A.; François, M. X.; Yu, Z. B.; Thermeau, J. P.

    2006-04-01

    In a so called heat driven thermoacoustic refrigerator, using either a pulse tube or a lumped boost configuration, heat pumping is induced by Stirling type thermodynamic cycles within the regenerator. The time phase between acoustic pressure and flow rate throughout must then be close to that met for a purely progressive wave. The study presented here relates the experimental characterization of passive elements such as valves, tubes and tanks which are likely to act on this phase relationship when included in the propagation line of the wave resonator. In order to carry out a characterization — from the acoustic point of view — of these elements, systematic measurements of the acoustic field are performed varying various parameters: mean pressure, oscillations frequency, supplied heat power. Acoustic waves are indeed generated by use of a thermoacoustic prime mover driving a pulse tube refrigerator. The experimental results are then compared with the solutions obtained with various one-dimensional linear models including non linear correction factors. It turns out that when using a non symmetrical valve, and for large dissipative effects, the measurements disagree with the linear modelling and non linear behaviour of this particular element is shown.

  18. Analysis of Complex Valve and Feed Systems

    Science.gov (United States)

    Ahuja, Vineet; Hosangadi, Ashvin; Shipman, Jeremy; Cavallo, Peter; Dash, Sanford

    2007-01-01

    A numerical framework for analysis of complex valve systems supports testing of propulsive systems by simulating key valve and control system components in the test loop. In particular, it is designed to enhance the analysis capability in terms of identifying system transients and quantifying the valve response to these transients. This system has analysis capability for simulating valve motion in complex systems operating in diverse flow regimes ranging from compressible gases to cryogenic liquids. A key feature is the hybrid, unstructured framework with sub-models for grid movement and phase change including cryogenic cavitations. The multi-element unstructured framework offers improved predictions of valve performance characteristics under steady conditions for structurally complex valves such as pressure regulator valve. Unsteady simulations of valve motion using this computational approach have been carried out for various valves in operation at Stennis Space Center such as the split-body valve and the 10-in. (approx.25.4-cm) LOX (liquid oxygen) valve and the 4-in. (approx.10 cm) Y-pattern valve (liquid nitrogen). Such simulations make use of variable grid topologies, thereby permitting solution accuracy and resolving important flow physics in the seat region of the moving valve. An advantage to this software includes possible reduction in testing costs incurred due to disruptions relating to unexpected flow transients or functioning of valve/flow control systems. Prediction of the flow anomalies leading to system vibrations, flow resonance, and valve stall can help in valve scheduling and significantly reduce the need for activation tests. This framework has been evaluated for its ability to predict performance metrics like flow coefficient for cavitating venturis and valve coefficient curves, and could be a valuable tool in predicting and understanding anomalous behavior of system components at rocket propulsion testing and design sites.

  19. Analytical model for estimating drag forces on rigid submerged structures caused by LOCA and safety relief valve ramshead air discharges. [BWR

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Basic information is presented for estimating drag forces on rigid structural members submerged in a pressure suppression pool, caused by either the air discharge from a loss-of-coolant accident (LOCA), or the air bubble oscillation following safey relief valve ramshead discharge. Methods are described for estimating acceleration (unsteady) and standard (velocity-squared) drag force components for a variety of structural geometries.

  20. [Paragliding accidents--a prospective analysis in Swiss mountain regions].

    Science.gov (United States)

    Lautenschlager, S; Karli, U; Matter, P

    1993-01-01

    During the period from 1.1 to 31.12.90, 86 injuries associated with paragliding were analysed in a prospective study in 12 different Swiss hospitals with reference to causes, patterns, and frequencies. Spine injuries (36%) and lesions of the lower extremities (35%) were diagnosed most frequently. Surprisingly no neurological complications occurred, which is possibly explained by the solitary axial trauma. In 15 cases very severe malleolar fractures required surgical intervention. One accident was fatal due to a lung rupture. 60% of all accidents happened during the landing phase, 26% at launching and 14% at flight. Half of the pilots were affected in their primary training course. Most accidents were due to an in-flight error of judgement, such as incorrect estimation of wind conditions and a choice of unfavourable landing sites. In contrast to early reports of hang-gliding injuries, only one accident was due to an equipment failure, namely a ruptured steering line. In more than a third of all accidents, the used paraglider was not in correct correlation with the pilot's weight and experience. Inspired by the desire for a long flight, gliders of too large surface-areas were often used, leading to a more unstable flight. To reduce the frequency of paragliding injuries, an accurate choice of equipment and increased attention to environmental factors is mandatory. Furthermore education-programs should focus more on intensifying the pilot's mental and practical skills.

  1. Study on operation of a research reactor during one PCS pump failure accident

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kyoung Woo; Yoon, Hyu Ngi; Kim, Seong Hoon; Chi, Dae Young; Yoon, Juh Yeon [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The Primary cooling system (PCS) of a research reactor is designed to provide adequate cooling to the reactor core with a reasonable margin during all operation modes. The PCS consists of pumps, heat exchangers, and all necessary interconnecting pipes, valves, and instruments. The number of pumps is determined from a safety and economic point of view. As the number of pump trains increase, the cost increases according to the increase in safety class equipment. However, it is impossible to install one pump for a PCS because a zero flow can instantaneously occur during a pump failure such as a pump seizure. Thus, a PCS frequently consists of two parallel 50% capacity pumps and heat exchangers. In addition, check valves are generally installed to prevent a reversal flow when multiple pumps are designed to operate. However, if a swing type check valve is used, it should be estimated whether the slam due to instantaneous closing of the valve affects the system vibration. To reduce the vibration by a slam phenomenon, additional equipment such as a damper will be installed in the valve. The purpose of the check valve in PCS is to prevent the flow path when a reverse flow occurs. The installation of additional equipment will make it difficult to perform this function. In this study, it is estimated whether the PCS can operate without check valves. First, a flow analysis using Flowmaster was compared and verified by the calculation employing a empirical correlation. Second, the simulation for a one pump failure accident was performed and analyzed.

  2. Titanium in Engine Valve Systems

    Science.gov (United States)

    Allison, J. E.; Sherman, A. M.; Bapna, M. R.

    1987-03-01

    Titanium alloys offer a unique combination of high strength-to-weight ratio, good corrosion resistance and favorable high temperature mechanical properties. Still, their relatively high cost has discouraged consideration for widespread use in automotive components. Recent demands for increased fuel economy have led to the consideration of these alloys for use as valve train materials where higher costs might be offset by improvements in performance and fuel economy. Lighter weight valve train components permit the use of lower spring loads, thus reducing friction and increasing fuel economy. Camshaft friction measurements made on a typical small displacement engine indicate that a twoto-four percent increase in fuel economy can be achieved. Valve train components are, however, subject to a severe operating environment, including elevated temperatures, sliding wear and high mechanical loads. This paper discusses the details of alloy and heat treatment selection for optimizing valve performance. When properly manufactured, titanium valves have been shown to withstand very stringent durability testing, indicating the technical feasibility of this approach to fuel economy improvement.

  3. Traffic Accidents Involving Cyclists Identifying Causal Factors Using Questionnaire Survey, Traffic Accident Data, and Real-World Observation.

    Science.gov (United States)

    Oikawa, Shoko; Hirose, Toshiya; Aomura, Shigeru; Matsui, Yasuhiro

    2016-11-01

    The purpose of this study is to clarify the mechanism of traffic accidents involving cyclists. The focus is on the characteristics of cyclist accidents and scenarios, because the number of traffic accidents involving cyclists in Tokyo is the highest in Japan. First, dangerous situations in traffic incidents were investigated by collecting data from 304 cyclists in one city in Tokyo using a questionnaire survey. The survey indicated that cyclists used their bicycles generally while commuting to work or school in the morning. Second, the study investigated the characteristics of 250 accident situations involving cyclists that happened in the city using real-world bicycle accident data. The results revealed that the traffic accidents occurred at intersections of local streets, where cyclists collided most often with vehicles during commute time in the morning. Third, cyclists' behavior was observed at a local street intersection in the morning in the city using video pictures. In one hour during the morning commute period, 250 bicycles passed through the intersection. The results indicated that one of the reasons for traffic accidents involving cyclists might be the combined effect of low visibility, caused by the presence of box-like building structures close to the intersections, and the cyclists' behavior in terms of their velocity and no confirming safety. It was observed that, on average, bicycle velocity was 3.1 m/s at the initial line of an intersection. The findings from this study could be useful in developing new technologies to improve cyclist safety, such as alert devices for cyclists and vehicle drivers, wireless communication systems between cyclists and vehicle drivers, or advanced vehicles with bicycle detection and collision mitigation systems.

  4. Aspects Concerning The Rules And The Investigation Of Traffic Accidents As Work Accidents

    Science.gov (United States)

    Tarnu, Lucian Ioan

    2015-07-01

    When Romania joined the European Union, it was imposed that the Romanian legislation in the field of the security and health at work be in line with the European one. The concept of health as it is defined by the International Body of Health, refers to a good physical, mental and social condition. The improvement of the activity of preventing the traffic accidents as work accidents must have as basis the correct and accurate evaluation of risks of getting injured. The goal of the activity of prevention and protection is to ensure the best working conditions, the prevention of accidents and occupational diseases and the adjustment to the scientific and technological progress. In the road transport sector, as in any other sector, it is very important to pay attention to working conditions to ensure a workforce motivated and well qualified. Some features make it a more difficult sector risk management than other sectors. However, if one takes into account how it works in practice this sector and the characteristics of drivers and how they work routinely, risks, dangers and threats can be managed efficiently and with great success.

  5. 49 CFR 179.400-19 - Valves and gages.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Valves and gages. 179.400-19 Section 179.400-19...-19 Valves and gages. (a) Valves. Manually operated shut-off valves and control valves must be... liquid flow rates. All valves must be made from approved materials compatible with the lading and...

  6. The nordic aortic valve intervention (NOTION) trial comparing transcatheter versus surgical valve implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Søndergaard, Lars; Ihlemann, Nikolaj;

    2013-01-01

    Degenerative aortic valve (AV) stenosis is the most prevalent heart valve disease in the western world. Surgical aortic valve replacement (SAVR) has until recently been the standard of treatment for patients with severe AV stenosis. Whether transcatheter aortic valve implantation (TAVI) can...

  7. Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement.

    Science.gov (United States)

    Kazama, S; Kurata, A; Yamashita, Y

    1999-10-01

    An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

  8. Transapical transcatheter valve-in-valve replacement for deteriorated mitral valve bioprosthesis without radio-opaque indicators: the "invisible" mitral valve bioprosthesis.

    Science.gov (United States)

    Rossi, Marco Luciano; Barbaro, Cristina; Pagnotta, Paolo; Cappai, Antioco; Ornaghi, Diego; Belli, Guido; Presbitero, Patrizia

    2015-02-01

    In view of the high number of bioprosthetic valves implanted during the past 30 years, an increasing number of patients are coming to medical attention because of degenerated bioprostheses. Transcatheter aortic valve-in-valve implantation has been described as a less invasive alternative to re-operation to treat severe structural valve deterioration. As far as degenerated mitral valve bioprostheses are concerned, transcatheter transapical mitral valve-in-valve replacement (TMVR) has been less commonly performed, but may also become a viable alternative to re-do replacement surgery. We describe treatment of a degenerated bioprosthetic mitral valve, characterised by complete absence of any radio-opaque landmarks making the TMVR procedure very challenging.

  9. Percutaneous heart valves; past, present and future.

    Science.gov (United States)

    Rozeik, M M; Wheatley, D J; Gourlay, T

    2014-09-01

    Percutaneous heart valves provide a promising future for patients refused surgery on the grounds of significant technical challenges or high risk for complications. Since the first human intervention more than 10 years ago, over 50 different types of valves have been developed. The CoreValve and Edwards SAPIEN valves have both experienced clinical trials and the latter has gained FDA approval for implantation in patients considered inoperable. Current complications, such as major vascular bleeding and stroke, prevent these valves from being commonly deployed in patients considered operable in conventional surgery. This review focuses on the past and present achievements of these valves and highlights the design considerations required to progress development further. It is envisaged that, with continued improvement in valve design and with increased clinical and engineering experience, percutaneous heart valve replacement may one day be a viable option for lower-risk operable patients.

  10. Three-Dimensional Echocardiography of the Aortic Valve: Feasibility, Clinical Potential, and Limitations.

    Science.gov (United States)

    Kasprzak, Jaroslaw D.; Salustri, Alessandro; Roelandt, Jos R.T.C.; Ten Cate, Folkert J.

    1998-02-01

    OBJECTIVES: The purpose of our study was to assess the feasibility and potential clinical utility of three-dimensional echocardiography for evaluation of the aortic valve. BACKGROUND: The value of three-dimensional echocardiographic assessment of the aortic valve has not been established yet. METHODS: The study group comprised 32 patients (11 women, 21 men), mean age 56.1 (range 20-82). Seven morphologically normal valves, 5 homografts, 6 mechanical prostheses, and 14 valves of abnormal morphology were evaluated. Images were acquired during a routine multiplane transesophageal echocardiographic examination (rotational scan with 2 degrees interval, respiration, and electrocardiogram [ECG] gating) and postprocessed off-line. A selection of reconstructed cutplanes (anyplane mode) and volume-rendered three-dimensional views of aortic valve anatomy were analyzed by two observers and compared with two-dimensional echocardiography findings. RESULTS: The quality of reconstructions was scored excellent when permitting unrestricted assessment of aortic valve anatomy with optimized planimetric measurements (19 patients, 59%), adequate when aortic valve was partially visualized (7 patients, 22%), or inadequate when no assessment was possible (6 patients, 19%, including 5 with prosthetic valves). Three-dimensional echocardiography provided additional information in ten (31%) patients as compared with the two-dimensional echocardiographic findings. CONCLUSIONS: It can be concluded that three-dimensional echocardiographic reconstruction of the aortic valve is feasible, with excellent or adequate quality in 81% of patients, more frequently in native than in prosthetic valves, P < 0.05. Morphologic information additional to that provided by two-dimensional echocardiography is obtained in a significant proportion of patients.

  11. Acoustic Resonance Frequency Elimination Device for Safety Relief Valves

    Energy Technology Data Exchange (ETDEWEB)

    Redmond, J.

    2014-07-01

    Industry experience has shown that Safety Relief Valves (SRVs) and Steam Dryers installed in Boiling Water Reactors (BWRs) experience vibration induced degradation and failures caused by acoustic resonance vibration of the main steam lines, resulting in decreased reliability and potential safety issues. The resonance is caused by vortex shedding from the standpipe inlet and acoustic standing waves in the standpipe, occurring when the two frequencies match. (Author)

  12. Statins for aortic valve stenosis

    Directory of Open Access Journals (Sweden)

    Luciana Thiago

    Full Text Available ABSTRACT BACKGROUND: Aortic valve stenosis is the most common type of valvular heart disease in the USA and Europe. Aortic valve stenosis is considered similar to atherosclerotic disease. Some studies have evaluated statins for aortic valve stenosis. OBJECTIVES: To evaluate the effectiveness and safety of statins in aortic valve stenosis. METHODS: Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, MEDLINE, Embase, LILACS - IBECS, Web of Science and CINAHL Plus. These databases were searched from their inception to 24 November 2015. We also searched trials in registers for ongoing trials. We used no language restrictions. Selection criteria: Randomized controlled clinical trials (RCTs comparing statins alone or in association with other systemic drugs to reduce cholesterol levels versus placebo or usual care. Data collection and analysis: Primary outcomes were severity of aortic valve stenosis (evaluated by echocardiographic criteria: mean pressure gradient, valve area and aortic jet velocity, freedom from valve replacement and death from cardiovascular cause. Secondary outcomes were hospitalization for any reason, overall mortality, adverse events and patient quality of life. Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias. The GRADE methodology was employed to assess the quality of result findings and the GRADE profiler (GRADEPRO was used to import data from Review Manager 5.3 to create a 'Summary of findings' table. MAIN RESULTS: We included four RCTs with 2360 participants comparing statins (1185 participants with placebo (1175 participants. We found low-quality evidence for our primary outcome of severity of aortic valve stenosis, evaluated by mean pressure gradient (mean difference (MD -0.54, 95% confidence interval (CI -1.88 to 0.80; participants = 1935; studies = 2, valve area (MD -0.07, 95% CI -0.28 to 0.14; participants = 127; studies = 2

  13. Propellant isolation shutoff valve program

    Science.gov (United States)

    Merritt, F. L.

    1973-01-01

    An analysis and design effort directed to advancing the state-of-the-art of space storable isolation valves for control of flow of the propellants liquid fluorine/hydrazine and Flox/monomethylhydrazine is discussed. Emphasis is on achieving zero liquid leakage and capability of withstanding missions up to 10 years in interplanetary space. Included is a study of all-metal poppet sealing theory, an evaluation of candidate seal configurations, a valve actuator trade-off study and design description of a pneumo-thermally actuated soft metal poppet seal valve. The concepts and analysis leading to the soft seal approach are documented. A theoretical evaluation of seal leakage versus seal loading, related finishes and yield strengths of various materials is provided. Application of a confined soft aluminum seal loaded to 2 to 3 times yield strength is recommended. Use of either an electro-mechanical or pneumatic actuator appears to be feasible for the application.

  14. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  15. 2D SIMPLIFIED SERVO VALVE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel pilot stage valve called simplified 2D valve, which utilizes both rotary and linear motions of a single spool, is presented.The rotary motion of the spool incorporating hydraulic resistance bridge, formed by a damper groove and a crescent overlap opening, is utilized as pilot to actuate linear motion of the spool.A criterion for stability is derived from the linear analysis of the valve.Special experiments are designed to acquire the mechanical stiffness, the pilot leakage and the step response.It is shown that the sectional size of the spiral groove affects the dynamic response and the stiffness contradictorily and is also very sensitive to the pilot leakage.Therefore, it is necessary to establish a balance between the static and dynamic characteristics in deciding the structural parameters.Nevertheless, it is possible to sustain the dynamic response at a fairly high level, while keeping the leakage of the pilot stage at an acceptable level.

  16. Condensation within small compartments during design basis accidents

    Energy Technology Data Exchange (ETDEWEB)

    Grgic, D.; Cavlina, N. [Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, 10000 Zagreb (Croatia); ANTOLOVIc, A. [NPP Krsko, Engineering Department, Vrbina 12, 8270 Krsko (Slovenia)

    2010-07-01

    During design basis events (LOCA, MSLB) in containment exists possibility for additional condensation within compartments and enclosures with different electrical equipment that can result in submergence of its parts and possible malfunction. The condensation within limit switch compartments (valve actuators) and attached electrical conduits during limiting LOCA and MSLB accidents in containment was analyzed using Gothic computer code with the assumptions corresponding to the ones used to generate containment EQ profiles for thermalhydraulic EQ parameters. The outcome of the analysis is volume of the liquid within the compartment and corresponding liquid level before and after additions of bottom openings (T-drains) required to drain condensed liquid. Different compartment sizes were analyzed during different LOCA and MSLB scenarios. After addition of bottom openings maximum possible condensed liquid level can not cause actuator malfunction. (authors)

  17. Transapical Mitral Valve-in-Valve Replacement in Patient With Previous Complex Sternal Reconstruction.

    Science.gov (United States)

    Hynes, Conor F; Fatemi, Omid; Sharma, Aditya C; Nagy, Christian D; Trachiotis, Gregory D

    2016-01-01

    We present a complex case of a transapical redo mitral valve-in-valve replacement. Repeat mitral valve replacement was indicated for severe symptomatic bioprosthetic stenosis. In addition to the patient's numerous comorbidities that included diabetes, hepatic cirrhosis, ischemic cardiomyopathy, and atrial flutter, he had undergone a previous open mitral valve replacement that was complicated by sternal dehiscence requiring extensive chest wall reconstruction. Transapical approach was performed through left minithoracotomy incision with balloon-expandable valve. Transapical valve-in-valve replacement of a stenotic mitral bioprosthesis is a viable solution in a patient with previous complex chest wall reconstruction and multiple comorbidities.

  18. Pregnancy-induced remodeling of heart valves.

    Science.gov (United States)

    Pierlot, Caitlin M; Moeller, Andrew D; Lee, J Michael; Wells, Sarah M

    2015-11-01

    Recent studies have demonstrated remodeling of aortic and mitral valves leaflets under the volume loading and cardiac expansion of pregnancy. Those valves' leaflets enlarge with altered collagen fiber architecture, content, and cross-linking and biphasic changes (decreases, then increases) in extensibility during gestation. This study extends our analyses to right-sided valves, with additional compositional measurements for all valves. Valve leaflets were harvested from nonpregnant heifers and pregnant cows. Leaflet structure was characterized by leaflet dimensions, and ECM composition was determined using standard biochemical assays. Histological studies assessed changes in cellular and ECM components. Leaflet mechanical properties were assessed using equibiaxial mechanical testing. Collagen thermal stability and cross-linking were assessed using denaturation and hydrothermal isometric tension tests. Pulmonary and tricuspid leaflet areas increased during pregnancy by 35 and 55%, respectively. Leaflet thickness increased by 20% only in the pulmonary valve and largely in the fibrosa (30% thickening). Collagen crimp length was reduced in both the tricuspid (61%) and pulmonary (42%) valves, with loss of crimped area in the pulmonary valve. Thermomechanics showed decreased collagen thermal stability with surprisingly maintained cross-link maturity. The pulmonary leaflet exhibited the biphasic change in extensibility seen in left side valves, whereas the tricuspid leaflet mechanics remained largely unchanged throughout pregnancy. The tricuspid valve exhibits a remodeling response during pregnancy that is significantly diminished from the other three valves. All valves of the heart remodel in pregnancy in a manner distinct from cardiac pathology, with much similarity valve to valve, but with interesting valve-specific responses in the aortic and tricuspid valves.

  19. Promising results after percutaneous mitral valve repair

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Franzen, Olaf; Jørgensen, Erik;

    2011-01-01

    Mitral valve regurgitation (MR) is the secondmost frequent valve disease in Europe. Untreated MR causes considerable morbidity and mortality. In the elderly, as many as half of these patients are denied surgery because of an estimated high surgical risk. Percutaneous mitral valve repair with the ...... with the MitraClip system resembles the Alfieristitch where a clip is used to connect the tip of the mitral valve leaflets....

  20. Infective endocarditis following percutaneous pulmonary valve replacement

    DEFF Research Database (Denmark)

    Cheung, Gary; Vejlstrup, Niels; Ihlemann, Nikolaj;

    2013-01-01

    Infective endocarditis (IE) following percutaneous pulmonary valve replacement (PPVR) with the Melody valve is rarely reported. Furthermore, there are challenges in this diagnosis; especially echocardiographic evidence of vegetation within the prosthesis may be difficult.......Infective endocarditis (IE) following percutaneous pulmonary valve replacement (PPVR) with the Melody valve is rarely reported. Furthermore, there are challenges in this diagnosis; especially echocardiographic evidence of vegetation within the prosthesis may be difficult....

  1. Promising results after percutaneous mitral valve repair

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Franzen, Olaf; Jørgensen, Erik;

    2011-01-01

    Mitral valve regurgitation (MR) is the secondmost frequent valve disease in Europe. Untreated MR causes considerable morbidity and mortality. In the elderly, as many as half of these patients are denied surgery because of an estimated high surgical risk. Percutaneous mitral valve repair...... with the MitraClip system resembles the Alfieristitch where a clip is used to connect the tip of the mitral valve leaflets....

  2. Accident knowledge and emergency management

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, B.; Groenberg, C.D.

    1997-03-01

    The report contains an overall frame for transformation of knowledge and experience from risk analysis to emergency education. An accident model has been developed to describe the emergency situation. A key concept of this model is uncontrolled flow of energy (UFOE), essential elements are the state, location and movement of the energy (and mass). A UFOE can be considered as the driving force of an accident, e.g., an explosion, a fire, a release of heavy gases. As long as the energy is confined, i.e. the location and movement of the energy are under control, the situation is safe, but loss of confinement will create a hazardous situation that may develop into an accident. A domain model has been developed for representing accident and emergency scenarios occurring in society. The domain model uses three main categories: status, context and objectives. A domain is a group of activities with allied goals and elements and ten specific domains have been investigated: process plant, storage, nuclear power plant, energy distribution, marine transport of goods, marine transport of people, aviation, transport by road, transport by rail and natural disasters. Totally 25 accident cases were consulted and information was extracted for filling into the schematic representations with two to four cases pr. specific domain. (au) 41 tabs., 8 ills.; 79 refs.

  3. Radioactive materials transport accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    McSweeney, T.I.; Maheras, S.J.; Ross, S.B. [Battelle Memorial Inst. (United States)

    2004-07-01

    Over the last 25 years, one of the major issues raised regarding radioactive material transportation has been the risk of severe accidents. While numerous studies have shown that traffic fatalities dominate the risk, modeling the risk of severe accidents has remained one of the most difficult analysis problems. This paper will show how models that were developed for nuclear spent fuel transport accident analysis can be adopted to obtain estimates of release fractions for other types of radioactive material such as vitrified highlevel radioactive waste. The paper will also show how some experimental results from fire experiments involving low level waste packaging can be used in modeling transport accident analysis with this waste form. The results of the analysis enable an analyst to clearly show the differences in the release fractions as a function of accident severity. The paper will also show that by placing the data in a database such as ACCESS trademark, it is possible to obtain risk measures for transporting the waste forms along proposed routes from the generator site to potential final disposal sites.

  4. Nuclear accident dosimetry intercomparison studies.

    Science.gov (United States)

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry.

  5. Advantages with small control valves

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Gunnar

    2008-09-15

    Between 1995 and 2005, the Swedish District Heating Association carried out several research projects concerning small dimensions on control valves. This lecture aims at giving a summary of these findings which, if they are carried out, have a great impact on the district heating system. The outcome is advantages on both the production side and the customer side. Some of the project's conclusions are as follows: 1. The simulations show that the consequences of temperature disturbances can be reduced when applying smaller control valves, especially at low outdoor temperatures (-5 deg C). 2. The consequences of flow disturbances (pump stop) are not depending on the outdoor temperature (heat demand), but results over the whole year in reduced maximum flow during the process of operation recovery. With adequately reduced valve size, the resulting maximum flow at restart can be approximately reduced to the half, leading in reduced need of pumping peak power. 3. Similarly, the maximum peak power taken from the net at net recovery will be reduced, however, this effect is not as strong as that for flow. 4. Generally, we have found clear indications for that the adjustment of the K{sub vs}-values of control valves in substations should follow a certain logical order of priority. An important factor is the location of substations in respect to the production plant and to the pressure control points in the network. Another important factor is the absolute K{sub vs}-value of the over sizing, i.e. the difference of the actual installed valve and the targeted valve size. 5. Smaller size of control valves means also an improvement of the everyday operation of the district heating net, especially in the case when flow and power peaks are expected to occur. Examples for that could be the morning peaks with increase heat and hot water demands, or such events when the air temperature is decreasing very fast because of weather phenomena. Smaller control valves will smear out the

  6. Fast-acting valve actuator

    Science.gov (United States)

    Cho, Nakwon

    1980-01-01

    A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

  7. Surface spin-valve effect.

    Science.gov (United States)

    Yanson, I K; Naidyuk, Yu G; Fisun, V V; Konovalenko, A; Balkashin, O P; Triputen, L Yu; Korenivski, V

    2007-04-01

    We report an observation of spin-valve-like hysteresis within a few atomic layers at a ferromagnetic interface. We use phonon spectroscopy of nanometer-sized point contacts as an in situ probe to study the mechanism of the effect. Distinctive energy phonon peaks for contacts with dissimilar nonmagnetic outer electrodes allow localizing the observed spin switching to the top or bottom interfaces for nanometer thin ferromagnetic layers. The mechanism consistent with our data is energetically distinct atomically thin surface spin layers that can form current- or field-driven surface spin-valves within a single ferromagnetic film.

  8. On-line ion exchange preconcentration in a sequential injection lab-on-valve microsystem incorporating a renewable column with ETAAS for the trace-level determination of bismuth in urine and river sediment

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2001-01-01

    A sequential injection system for on-line ion-exchange separation and preconcentration of trace-level amounts of metal ions with ensuing detection by electrothermal atomic absorption spectrometry (ETAAS) is described. Based on the use of a renewable microcolumn incorporated within an integrated l.......3% for the determination of 2.0 mug/l Bi (n = 7). The procedure was validated by determination of bismuth in a certified reference material CRM 320 (river sediment), and by bismuth spike recoveries in two human urine samples....

  9. Hyphenating multisyringe flow injection lab-on-valve analysis with atomic fluorescence spectrometry for on-line bead-injection preconcentration and determination of trace levels of hydride-forming elements in environmental samples

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald;

    2006-01-01

    of the functional moieties, so that maximum benefit can be taken from the application of the bead renewal strategy. The proposed procedure is characterized by a high tolerance to metal species and interfering hydride forming elements. In fact, ratios of Se(IV) to As ≤ 5000 and Sb(V) to As ≤ 500 are tolerated...... feasible by interfacing the micromachined LOV-module with AFS by a multisyringe flowing stream network for on-line post column derivatization of the eluate aimed at the generation of hydride species. The potential of this new hyphenated technique for environmental assays was ascertained via...

  10. Pregnancy in women with prosthetic heart valves

    NARCIS (Netherlands)

    Pieper, P. G.; Balci, A.; Van Dijk, A. P.

    2008-01-01

    Pregnancy in women with mechanical valve prostheses has a high maternal complication rate including valve thrombosis mid death. Coumarin derivatives are relatively safe for the mother with a lower incidence of valve thrombosis than unfractionated and low-molecular-weight heparin, but carry the risk

  11. Porcine Tricuspid Valve Anatomy and Human Compatibility

    DEFF Research Database (Denmark)

    Waziri, Farhad; Lyager Nielsen, Sten; Hasenkam, J. Michael

    2016-01-01

    before clinical use. The study aim was to evaluate and compare the tricuspid valve anatomy of porcine and human hearts. METHODS: The anatomy of the tricuspid valve and the surrounding structures that affect the valve during a cardiac cycle were examined in detail in 100 fresh and 19 formalin...

  12. Aerodynamic Characteristics of Tracheostomy Speaking Valves.

    Science.gov (United States)

    Fornataro-Clerici, Lisa; Zajac, David J.

    1993-01-01

    Pressure-flow characteristics were determined for four different one-way valves (Kisner, Montgomery, Olympic, and Passy-Muir) used for speech production in tracheotomy patients. Results indicated significant differences in resistance among the valves, with the resistance of one valve substantially greater than that of the normal upper airways.…

  13. 14 CFR 27.995 - Fuel valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 27.995 Section 27.995... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.995 Fuel valves. (a) There must be a positive, quick-acting valve to shut off fuel to each engine individually. (b) The control...

  14. 14 CFR 29.995 - Fuel valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 29.995 Section 29.995... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.995 Fuel valves. In addition to meeting the requirements of § 29.1189, each fuel valve must— (a) (b) Be supported so that no...

  15. 14 CFR 25.995 - Fuel valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel valves. 25.995 Section 25.995... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.995 Fuel valves. In addition to the requirements of § 25.1189 for shutoff means, each fuel valve must— (a) (b) Be supported...

  16. 14 CFR 29.1025 - Oil valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil valves. 29.1025 Section 29.1025... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1025 Oil valves. (a) Each oil shutoff.... (c) Each oil valve must have positive stops or suitable index provisions in the “on” and...

  17. 14 CFR 25.1025 - Oil valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil valves. 25.1025 Section 25.1025... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1025 Oil valves. (a) Each oil shutoff... feathering. (c) Each oil valve must have positive stops or suitable index provisions in the “on” and...

  18. 49 CFR 195.258 - Valves: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valves: General. 195.258 Section 195.258... PIPELINE Construction § 195.258 Valves: General. (a) Each valve must be installed in a location that is accessible to authorized employees and that is protected from damage or tampering. (b) Each submerged...

  19. 14 CFR 121.239 - Oil valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil valves. 121.239 Section 121.239..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.239 Oil valves. (a) Each oil valve must— (1) Comply with § 121.257; (2) Have positive stops or suitable index provisions in the...

  20. 14 CFR 121.235 - Fuel valves.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fuel valves. 121.235 Section 121.235..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.235 Fuel valves. Each fuel valve must— (a) Comply with § 121.257; (b) Have positive stops or suitable index provisions in the...

  1. Aerodynamic Characteristics of Tracheostomy Speaking Valves.

    Science.gov (United States)

    Fornataro-Clerici, Lisa; Zajac, David J.

    1993-01-01

    Pressure-flow characteristics were determined for four different one-way valves (Kisner, Montgomery, Olympic, and Passy-Muir) used for speech production in tracheotomy patients. Results indicated significant differences in resistance among the valves, with the resistance of one valve substantially greater than that of the normal upper airways.…

  2. Flow and plate motion in compressor valves

    NARCIS (Netherlands)

    Habing, Reinder André

    2005-01-01

    The Basic Valve Theory is based on steady ow characteristics. Therefore unsteady ow conditions in the model valve have been considered in order to assess effects of unsteadiness on the performance of the Basic Valve Theory. The instantaneous gas force was predicted rather accurately by the theory. H

  3. Staphylococcus saprophyticus causing native valve endocarditis.

    Science.gov (United States)

    Garduño, Eugenio; Márquez, Irene; Beteta, Alicia; Said, Ibrahim; Blanco, Javier; Pineda, Tomás

    2005-01-01

    Coagulase negative staphylococci are a rare cause of native valve endocarditis. Staphylococcus saprophyticus is a coagulase-negative Staphylococcus infrequently reported as a human pathogen, and most of the cases reported are urinary tract infections. We describe a case of native valve endocarditis attributed to this organism. The patient needed valve replacement due to heart failure.

  4. Miniature piezo electric vacuum inlet valve

    Science.gov (United States)

    Keville, Robert F.; Dietrich, Daniel D.

    1998-03-24

    A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

  5. The presence of fructosamine in human aortic valves is associated with valve stiffness.

    Science.gov (United States)

    Kishabongo, Antoine S; Katchunga, Philippe; Cikomola, Justin C; De Somer, Filip M; De Buyzere, Marc L; Speeckaert, Marijn M; Delanghe, Joris R

    2016-09-01

    Human heart valves are prone to glycation, a fundamental process of ageing. The aim of this study was to establish the relationship between fructosamine formation and the mechanical properties of human aortic valves. 67 patients (age: 76±8 years) diagnosed with an aortic valve stenosis, who underwent an aortic valve replacement were enrolled. Fructosamine and calcium concentrations in aortic valves were determined. Using a transthoracic Doppler echocardiography, aortic valve orifice area and transvalvular pressure gradients were measured. In a subgroup of 32 patients, the aortic valve orifice area was sufficient to carry out mechanical testing on a LFPlus Universal material tester. An in vitro removal of fructosamine of the valve was initiated using ATP-dependent fructosamine 3-kinase (FN3K). A significant correlation was found between the aortic valve fructosamine concentration and the calculated aortic valve orifice area: Y (aortic valve orifice area, mm(2))=1.050-0.228X (aortic valve fructosamine concentration, µmol/g valve) (r=-0.38). A significantly higher calcium concentration was measured in the aortic valves of diabetics in comparison with those of non-diabetics. A multiple regression analysis revealed that the presence of diabetes mellitus and aortic valve fructosamine concentration were the main predictors of the extensibility of the aortic valves. In the in vitro deglycation study, a significant lower aortic valve fructosamine concentration was detected after treatment with FN3K. This resulted in an increased flexibility of the aortic valves. Although no direct causativeness is proven with the presented results, which just show an association between fructosamine, the effect of FN3K and aortic valve stiffness, the present study points for the first time towards a possible additional role of the Amadori products in the biomechanical properties of ageing aortic valves. Published by the BMJ Publishing Group Limited. For permission to use (where not

  6. Pressure relief valve/safety relief valve testing

    Energy Technology Data Exchange (ETDEWEB)

    Murray, W.A.; Hamm, E.R.; Barber, J.R.

    1994-02-01

    Pressure vessels and piping systems are protected form overpressurization by pressure relief valves. These safety features are required to be tested-inspected on some periodic basis and, in most cases witnessed by a third party inspector. As a result nonconformances found by third parties Westinghouse Hanford Company initiated a task team to develop a pressure safety program. This paper reveals their findings.

  7. The child accident repeater: a review.

    Science.gov (United States)

    Jones, J G

    1980-04-01

    The child accident repeater is defined as one who has at least three accidents that come to medical attention within a year. The accident situation has features in common with those of the child who has a single accident through simple "bad luck", but other factors predispose him to repeated injury. In the child who has a susceptible personality, a tendency for accident repetition may be due to a breakdown in adjustment to a stressful environment. Prevention of repeat accidents should involve the usual measures considered appropriate for all children as well as an attempt to provide treatment of significant maladjustment and modification of a stressful environment.

  8. Hindsight Bias in Cause Analysis of Accident

    Institute of Scientific and Technical Information of China (English)

    Atsuo Murata; Yasunari Matsushita

    2014-01-01

    It is suggested that hindsight becomes an obstacle to the objective investigation of an accident, and that the proper countermeasures for the prevention of such an accident is impossible if we view the accident with hindsight. Therefore, it is important for organizational managers to prevent hindsight from occurring so that hindsight does not hinder objective and proper measures to be taken and this does not lead to a serious accident. In this study, a basic phenomenon potentially related to accidents, that is, hindsight was taken up, and an attempt was made to explore the phenomenon in order to get basically insights into the prevention of accidents caused by such a cognitive bias.

  9. Severe accident simulation at Olkiuoto

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkonen, H.; Saarenpaeae, T. [Teollisuuden Voima Oy (TVO), Olkiluoto (Finland); Cliff Po, L.C. [Micro-Simulation Technology, Montville, NJ (United States)

    1995-09-01

    A personal computer-based simulator was developed for the Olkiluoto nuclear plant in Finland for training in severe accident management. The generic software PCTRAN was expanded to model the plant-specific features of the ABB Atom designed BWR including its containment over-pressure protection and filtered vent systems. Scenarios including core heat-up, hydrogen generation, core melt and vessel penetration were developed in this work. Radiation leakage paths and dose rate distribution are presented graphically for operator use in diagnosis and mitigation of accidents. Operating on an graphically for operator use in diagnosis and mitigation of accidents. Operating on an 486 DX2-66, PCTRAN-TVO achieves a speed about 15 times faster than real-time. A convenient and user-friendly graphic interface allows full interactive control. In this paper a review of the component models and verification runs are presented.

  10. Road characteristics and bicycle accidents.

    Science.gov (United States)

    Nyberg, P; Björnstig, U; Bygren, L O

    1996-12-01

    In Umeå, Sweden, defects in the physical road surface contributed to nearly half of the single bicycle accidents. The total social cost of these injuries to people amount to at least SEK 20 million (SEK 60,000 or about USD 8,500 per accident), which corresponds to the estimated loss of "eight life equivalents a year". Improved winter maintenance seems to have the greatest injury prevention potential and would probably reduce the number of injuries considerably, whereas improved road quality and modification of kerbs would reduce the most severe injuries. A local traffic safety program should try to prevent road accidents instead of handling the consequences of them. In accordance with Parliament decisions on traffic we would like to see increased investment in measures favoring bicycle traffic, where cycling is seen as a solution, not as a problem.

  11. Bathtub immersion accidents involving children.

    Science.gov (United States)

    Pearn, J; Nixon, J

    1977-02-12

    A review of 19 consecutive serious bathtub immersion accidents (11 survivals, 8 fatalities) is presented. In all instances, consciousness was lost in the water. Unlike other childhood accidents which usually show a male predominance, the sexes are equally affected. The modal age is 11 months. Six separate causes of bath drownings and near-drownings have been identified, and in 14 of the 19 accidents, two or more causes were operating concurrently. Median estimated immersion time for survivals was four minutes, and five minutes for fatalities. The median depth of water was eight inches. An 'at risk' profile for home bathtub drownings is presented; this includes the youngest or second youngest child of a large family, a family of grade 4 to 7 sociooccupational status (congalton) and a family in which routine is temporarily broken.

  12. Internal Accident Report on EDH

    CERN Multimedia

    SC Department

    2006-01-01

    The A2 Safety Code requires that, the Internal Accident Report form must be filled in by the person concerned or any witness to ensure that all the relevant services are informed. Please note that an electronic version of this form has been elaborated in collaboration with SC-IE, HR-OPS-OP and IT-AIS. Whenever possible, the electronic form shall be used. The relative icon is available on the EDH Desktop, Other tasks page, under the Safety heading, or directly here: https://edh.cern.ch/Document/Accident/. If you have any questions, please contact the SC Secretariat, tel. 75097 Please notice that the Internal Accident Report is an integral part of the Safety Code A2 and does not replace the HS50.

  13. Fukushima accident study using MELCOR

    Institute of Scientific and Technical Information of China (English)

    Randall O Gauntt

    2013-01-01

    The accidents at the Fukushima Daiichi nuclear power station stunned the world as the sequences played out over severals days and videos of hydrogen explosions were televised as they took place.The accidents all resulted in severe damage to the reactor cores and releases of radioactivity to the environment despite heroic measures had taken by the operating personnel.The following paper provides some background into the development of these accidents and their root causes,chief among them,the prolonged station blackout conditions that isolated the reactors from their ultimate heat sink — the ocean.The interpretations given in this paper are summarized from a recently completed report funded by the United States Department of Energy (USDOE).

  14. Aortic valve stenosis after previous coronary bypass: Transcatheter valve implantation or aortic valve replacement?

    Directory of Open Access Journals (Sweden)

    Jegaden Olivier

    2012-05-01

    Full Text Available Abstract We report a prospective comparison between transcatheter valve implantation (TAVI, n = 13 and surgical aortic valve replacement (AVR, n = 10 in patients with severe aortic valve stenosis and previous coronary bypass surgery (CABG. All patients had at least bilateral patent internal thoracic arteries bypass without indication of repeat revascularization. After a similar post-procedure outcome, despite one early death in TAVI group, the 1-year survival was 100% in surgical group and in transfemoral TAVI group, and 73% in transapical TAVI group. When previous CABG is the lone surgical risk factor, indications for a TAVI procedure have to be cautious, specially if transfemoral approach is not possible.

  15. Accident of heavy oil spilling into rivers; Juyu kasen ryushutsu jiko

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, H.

    1995-07-15

    A case of accident of heavy oil spill was described for the safety control of a thermal power station of N plant. One unit of 2000kl receiving tank and a pump have been installed in the heavy oil base, and the oil has been transferred to the service tank of the plant a few hundred meters away. The heavy oil was found leaking and gushing out from the outlet piping of the pump. The pump was stopped and the outlet valve was closed, but the gushing did not stop. The reason was that, a pipe being plunged into the oil from above the service tank, a back flow of the oil occurred through the siphon action. The spill was finally stopped by opening an air vent valve of the piping. Upon removing an insulating material and checking the leakage part, it was found that a pipe with a drain valve attached was broken, making a hole. The outward appearance had seemed normal when inspection was made from the drainage channel to the river. However, the leaked oil had already flown to the mouth of the river at low tide and drifted into the sea. The spill was estimated to be 9kl. The cause of the accident was due to the lack of reinforcement such as bosses and metal patches on the pipe installation at the time of welding. 8 figs.

  16. Conceptual design of a compact absolute valve for the ITER neutral beam injectors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Chris [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)], E-mail: chris.m.jones@jet.uk; Waldon, Chris; Martin, David; Watson, Mike [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Sonderegger, Kurt; Lenherr, Bruno [VAT Vakuumventile AG, CH-9469 Haag (Switzerland); Andrews, Ian; Mansbridge, Simon [VAT Vacuum Products Ltd., Edmund House, Rugby Road, Leamington Spa, Warwickshire CV32 6EL (United Kingdom)

    2009-06-15

    The reference design for the ITER neutral beam injectors incorporated a fast shutter to limit tritium migration to the injector vacuum enclosures. In 2005, a need for an 'absolute' isolation valve was identified to facilitate injector maintenance procedures and protect the system from an in-vessel ingress of coolant event (ICE). An outline concept for an all-metal seal valve was developed during 2006, in close cooperation with the Swiss valve manufacturer VAT. During the following year, it became apparent that the length of beamline available for the valve was significantly less than originally envisaged, resulting in a radical revision of the design concept. A casing length of 760 mm has been achieved by means of major changes to the casing structure, plate dimensions, pendulum mechanism and seal actuators. A concept for a seal protection system has been developed to prevent beam line contamination reaching the valve components and to protect the valve plate from surface heating by plasma radiation. The new design concept has been extensively validated by analysis, including a whole-system FE model of the valve.

  17. Real-time 3D visualization of cellular rearrangements during cardiac valve formation.

    Science.gov (United States)

    Pestel, Jenny; Ramadass, Radhan; Gauvrit, Sebastien; Helker, Christian; Herzog, Wiebke; Stainier, Didier Y R

    2016-06-15

    During cardiac valve development, the single-layered endocardial sheet at the atrioventricular canal (AVC) is remodeled into multilayered immature valve leaflets. Most of our knowledge about this process comes from examining fixed samples that do not allow a real-time appreciation of the intricacies of valve formation. Here, we exploit non-invasive in vivo imaging techniques to identify the dynamic cell behaviors that lead to the formation of the immature valve leaflets. We find that in zebrafish, the valve leaflets consist of two sets of endocardial cells at the luminal and abluminal side, which we refer to as luminal cells (LCs) and abluminal cells (ALCs), respectively. By analyzing cellular rearrangements during valve formation, we observed that the LCs and ALCs originate from the atrium and ventricle, respectively. Furthermore, we utilized Wnt/β-catenin and Notch signaling reporter lines to distinguish between the LCs and ALCs, and also found that cardiac contractility and/or blood flow is necessary for the endocardial expression of these signaling reporters. Thus, our 3D analyses of cardiac valve formation in zebrafish provide fundamental insights into the cellular rearrangements underlying this process.

  18. Wireless. Automation of accident mountings. Development of a new solution of drive; Kabellos. Automatisierung von Havariearmaturen. Entwicklung einer neuen Antriebsloesung

    Energy Technology Data Exchange (ETDEWEB)

    Sacharowitz, Axel [3S Antriebe GmbH, Berlin (Germany)

    2013-01-15

    The Industrielle Werke Basel IWB (Basel, Switzerland) evaluate the automation of dividing an accident of its district heating grid. However, only a few of the relevant shafts have a grid connection. Furthermore, the mountings have no drive units. Due to the costs IWB dispensed with the exchange of the mountings and effort of underground engineering. The solution consists of wireless valve actuators of the 3 S actuators. The first 3 S actuators are put into operation in November 2012.

  19. Quantitative histologic analysis of the mitral valve anterior leaflet: ischemic alterations and implications for valve replacement design

    Science.gov (United States)

    Quick, David W.; Kunzelman, Karyn S.; Cochran, Richard P.

    1999-06-01

    There is a current trend to design innovative mitral valve replacements that mimic the native mitral valve (MV). A prerequisite for these new designs is the characterization of MV structure. This study was conducted to determine the distribution of MV collagen and glycosaminoglycan (GAGs) in MV anterior leaflets. Methods: Specimens from the mid-line of eight sheep MV anterior leaflets were stained with aniline blue (collagen) and alcian blue (GAGs). These specimens were analyzed using an image analysis system running Optimas software. Based on the luminance of stains within individual valve layers, the distribution of valvular collagen and GAGs from leaflet annulus to free-edge were determined. Results: Near the annulus, 100% of MV thickness is fibrosa (collagen dominated layer). Moving towards the free-edge, fibrosa prominence decreases and there is a transition to spongiosa (GAG dominated layer). Near the free-edge 100% of MV thickness is dominated by the spongiosa. Conclusions: Valvular collagen dominates MV structure near the annulus to support the stresses of bending and pressurization. Valvular GAGs dominate the MV near the free-edge to absorb the impact of leaflet coaptation. Image analysis has proven to be an effective tool to evaluate MV structure and facilitate the design of valve replacements.

  20. Field Experience with Lock Culvert Valves

    Science.gov (United States)

    2013-12-01

    interesting accounts regarding their lock culvert valves. ST. LAWRENCE SEAWAY Eisenhower and Snell Locks. The valves on the Eisenhower and Snell Locks...Tainter Valve Design Lift, ft Eisenhower St. Lawrence Seaway 80 x 860 12 x 14 21.0 DSP 43 Snell St. Lawrence Seaway 80 x 860 12 x 14 21.0 3 DSP, 1 VF 49...vertical-frame valves were furnished to the SLSDC in January 2011, and one was installed in the south filling-valve location at Snell Lock. An option

  1. Aortic valve surgery - minimally invasive

    Science.gov (United States)

    ... Saunders; 2012:chap 61. Otto CM, Bonow RO. Valvular heart disease. In: Mann DL, Zipes DP, Libby P, Bonow ... A.M. Editorial team. Related MedlinePlus Health Topics Heart Valve Diseases Browse the Encyclopedia A.D.A.M., Inc. ...

  2. Microprocessor-Based Valved Controller

    Science.gov (United States)

    Norman, Arnold M., Jr.

    1987-01-01

    New controller simpler, more precise, and lighter than predecessors. Mass-flow controller compensates for changing supply pressure and temperature such as occurs when gas-supply tank becomes depleted. By periodically updating calculation of mass-flow rate, controller determines correct new position for valve and keeps mass-flow rate nearly constant.

  3. Rotary actuators for plastic valves

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, M. [Georg Fischer Piping Systems Ltd, Schaffhausen (Switzerland)

    2004-07-01

    Flexibility and modularity plus a high level of quality are the defining characteristics of this new generation of actuators from Georg Fischer. In conjunction with the new 546 ball valve, the PA 11/PA 21 pneumatic actuators and the EA 11/EA 21 electric actuators form an optimally co-ordinated system. (orig.)

  4. Recommendation for environmental management and safety systems in high risk industrial accidents; Linee guida per l'integrazione dei sistemi di gestione ambiente e sicurezza nelle aziende a rischio di incidente rilevante

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, R.; Andriola, L.; Caropresso, G.; Paci, S.; Vignati, S.; Vignoni, P.C. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    2000-07-01

    This document presents the IMPREMAS Project from Italian ENEA (National Agency for New Technology, Energy and the Environment) for the eco-management of small and medium enterprises at risk for se and manipulation of hazardous substances. [Italian] Il presente documento e' stato elaborato nell'ambito del progetto IMPREMAS condotto dall'ENEA, in collaborazione con il Ministero dell'Ambiente, Regione Lombardia, Federchimica e Finlombarda, per la realizzazione di un progetto pilota per l'eco-gestione delle piccole e medie imprese classificate a rischio per l'uso e lo stoccaggio di sostanze pericolose previste dal DPR. n. 175 del 17-5-1988. L'azione ha riguardato l'applicazione del regolamento EMAS 1836/93 congiuntamente alla implementazione di un sistema di sicurezza per piccole e medie imprese a rischio di incidente rilevante del settore chimico-farmaceutico con l'obiettivo di mettere a punto le linee guida di riferimento per l'integrazione dei sistemi ambiente e sicurezza.

  5. Analysis on Cause of An Accident in AC/DC Hybrid System and Rectification Measures%一起交直流混联系统事故原因分析及整改措施

    Institute of Scientific and Technical Information of China (English)

    陈灿旭

    2014-01-01

    The cascading failure in China South Power Grid caused by an explosion accident of 500 kV circuit breaker is analyzed, and it is pointed out that the explosion accident of 500 kV circuit breaker occurred in Yandu substation simultaneously led to the commutation failures of three EHV/UHV DC transmission lines, i.e., the ±500 kV DC transmission line from Gaopo to Zhaoqing, the ±500 kV HVDC transmission line from Tianshengqiao to Guangzhou and the ±800 kV DC transmission line from Chuxiong to Suidong, and further the accident led to the forced outage of valve cooling system for Pole II of Guangzhou converter station. Because Zhaoqing converter station is electrically close to 500 kV Yandu substation, thus Zhaoqing converter station is subjected to the most severe affection, and the DC voltage of ±500 kV DC transmission line from Gaopo to Zhaoqing drastically fluctuated and a lot of harmonic components appeared and directly made the bipolar DC line under-voltage protection (27du/dt) acted. After the success bipolar re-starting of ±500 kV DC transmission line from Gaopo to Zhaoqing, the still existed forced outage of valve cooling system for pole II led to the pole II re-blocked. The author analyzes the spread of the accident as well as the related hidden danger, and proposes effective rectification measures to prevent the reoccurrence of similar cascading failures.%对南方电网系统一起500 kV断路器爆炸引起电网系统连锁反应的事故进行分析,指出500 kV 砚都站发生的断路器爆炸造成高肇、天广、楚穗3回直流换相失败,并造成广州换流站极2阀冷系统停运,肇庆换流站与500 kV砚都站电气距离非常近,受到故障的影响最大,高肇直流电压发生剧烈波动,出现大量谐波分量,直接导致双极直流线路低电压保护27 du/dt动作,高肇直流双极再启动成功后,由于肇庆换流站阀冷系统问题导致极2闭锁,同时对其存在的风险进行深入剖析

  6. Accident Precursor Analysis and Management: Reducing Technological Risk Through Diligence

    Science.gov (United States)

    Phimister, James R. (Editor); Bier, Vicki M. (Editor); Kunreuther, Howard C. (Editor)

    2004-01-01

    Almost every year there is at least one technological disaster that highlights the challenge of managing technological risk. On February 1, 2003, the space shuttle Columbia and her crew were lost during reentry into the atmosphere. In the summer of 2003, there was a blackout that left millions of people in the northeast United States without electricity. Forensic analyses, congressional hearings, investigations by scientific boards and panels, and journalistic and academic research have yielded a wealth of information about the events that led up to each disaster, and questions have arisen. Why were the events that led to the accident not recognized as harbingers? Why were risk-reducing steps not taken? This line of questioning is based on the assumption that signals before an accident can and should be recognized. To examine the validity of this assumption, the National Academy of Engineering (NAE) undertook the Accident Precursors Project in February 2003. The project was overseen by a committee of experts from the safety and risk-sciences communities. Rather than examining a single accident or incident, the committee decided to investigate how different organizations anticipate and assess the likelihood of accidents from accident precursors. The project culminated in a workshop held in Washington, D.C., in July 2003. This report includes the papers presented at the workshop, as well as findings and recommendations based on the workshop results and committee discussions. The papers describe precursor strategies in aviation, the chemical industry, health care, nuclear power and security operations. In addition to current practices, they also address some areas for future research.

  7. How to reduce the number of accidents

    CERN Multimedia

    2012-01-01

    Among the safety objectives that the Director-General has established for CERN in 2012 is a reduction in the number of workplace accidents.   The best way to prevent workplace accidents is to learn from experience. This is why any accident, fire, instance of pollution, or even a near-miss, should be reported using the EDH form that can be found here. All accident reports are followed up. The departments investigate all accidents that result in sick leave, as well as all the more common categories of accidents at CERN, essentially falls (slipping, falling on stairs, etc.), regardless of whether or not they lead to sick leave. By studying the accident causes that come to light in this way, it is possible to take preventive action to avoid such accidents in the future. If you have any questions, the HSE Unit will be happy to answer them. Contact us at safety-general@cern.ch. HSE Unit

  8. Mitral Valve Repair: The Chordae Tendineae

    Directory of Open Access Journals (Sweden)

    Carlos-A Mestres

    2015-10-01

    Full Text Available Repair of the mitral valve is the treatment of choice for mitral valve regurgitation when the anatomy is favorable. It is well known that mitral valve repair enjoys better clinical and functional results than any other type of valve substitute. This fact is beyond doubt regardless of the etiology of the valve lesion and is of particular importance in degenerative diseases.This review analyzes the most important advances in the knowledge of the anatomy, pathophysiology, and chordal function of the mitral valve as well as the different alternatives in the surgical repair and clinical results of the most prevalent diseases of the mitral valve. An attempt has been made to organize the acquired information available in a practical way.

  9. Development of the large main steam safety relief valve

    Energy Technology Data Exchange (ETDEWEB)

    Takeshima, Kikuo [Hitachi Ltd., Tokyo (Japan); Takasaki, Kiyoshi; Hamada, Nobuyoshi

    2000-02-01

    In order to control rise of reactor pressure at formation of over-pressure transition accident in a boiling water (BWR) type nuclear power plant, the numbers of the main steam safety relief valve (MSSRV) installed in a storage vessel increases with out-put in the plant, and for 1.35 MkW class improved BWR (ABWR) 18 sets of MSSRV are installed. And, in an ABWR preparing of construction at Ohma-cho, Aomori prefecture by the Electric Power Development Co., Ltd., uranium-plutonium mixed oxides (MOX) fuel is planned to load, to tend to further increase required numbers of MSSRV. In order to control arrangement in a storage vessel and increase of conservative inspection work together with increase the required numbers of MSSRV, it was planned to develop a large volume of MSSRV (16% increase in volume on comparison with that of conventional one), to confirm its function and feature by its testing and to apply to an actual machine. Here was introduced on its developmental contents and testing results. As a result, it could be estimated that required numbers of MSSRV would be sixteen, and was confirmed that features such as correlation on flowing-out pressure between nitrogen and steam, durability, work stability, valve seat leakage resistance, and so forth were similar to those of present MSSRV. (G.K.)

  10. Trismus: An unusual presentation following road accident

    Directory of Open Access Journals (Sweden)

    Thakur Jagdeep

    2007-01-01

    Full Text Available Trismus due to trauma usually follows road accidents leading to massive faciomaxillary injury. In the literature there is no report of a foreign body causing trismus following a road accident, this rare case is an exception. We present a case of isolated presentation of trismus following a road accident. This case report stresses on the thorough evaluation of patients presenting with trismus following a road accident.

  11. Replacement screws valve operating under Trunnion; Substituicao de parafusos de valvulas Trunnion em regime de operacao

    Energy Technology Data Exchange (ETDEWEB)

    Souza Netto, Charles de; Santos, Rogerio Andre Zolin dos; Arnhold, Diego [Companhia de Gas do Estado do Rio Grande do Sul (SULGAS), Porto Alegre, RS (Brazil); Jacques, Rodrigo das Neves [Guidotti e Vieira Manutencao Industrial Ltda., Canoas, RS (Brazil)

    2012-07-01

    The report shows the process created for the substitution and extraction of bearing screws of the Trunnion valves, in operation. The methodology was developed at the 'Companhia de Gas do Estado do Rio Grande do Sul - SULGAS', with the objective of avoiding failure emergency situations, and or sudden breaking of the screws of fixation of the lid of the inferior bearing of the Trunnion valves. it is a preventive process of substitution of these screws, that after a great period of use in atmospheres with high potential of oxidation present structural failure. The breaking of these components creates a leaking process by the inferior lid of the valves, fact that is intended to be avoided with the application of the technical procedure of this report, guaranteeing the integrity of the valves that are vital components for the continuous operation of the gas pipe line. (author)

  12. Transvalvular mitral regurgitation following mitral valve replacement a diagnostic dilemma

    OpenAIRE

    U S Dinesh Kumar; Umesh Nareppa; Shyam Prasad Shetty; Murugesh Wali

    2015-01-01

    After mitral valve replacement with a prosthetic valve, the valve should be competent and there should not be any residual prosthetic valve regurgitation. Transvalvular residual prosthetic valve regurgitation are difficult to diagnose and quantify. we are reporting interesting TEE images as a diagnostic dilemma in a case of transvalvular mitral regurgitation following mitral valve replacement secondary to entrapment of sub-valvular apparatus in a Chitra mechanical heart valve.

  13. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas;

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacement....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  14. The Physics of Traffic Accidents

    Science.gov (United States)

    Knight, Peter

    1975-01-01

    Shows how physics can be used to analyze and prevent traffic accidents by determining critical speeds on curves, the behavior of motor cycles and stability of articulated vehicles, and the visibility that is needed to make a minor road junction safe. (MLH)

  15. Work Accidents and Professional Diseases

    Directory of Open Access Journals (Sweden)

    Doru Hauptmann

    2009-10-01

    Full Text Available The major accident is defined as “any event occurred, like an emission of dangerous materials or agents, which emerges from uncontrolled evolutions along the exploitation of any objective that leads to the immediate or delayed occurrence of serious dangers with impact over human health or over the environment, inside or outside the objective in which are involved one or more than one dangerous materials”.The dangerous phenomenon is a potential source of harms. In the ambit of industrial risks of accidental origins, this expression more frequently refers to physical phenomena like conflagrations, explosions, toxic gases dispersion, etc.Any accident scenario relates itself to the potential effects at the level of environmental “targets”. In the case of major accidents, we can distinguish the following categories of “targets”: human (employees of the objective, working or resident people in the nearby of the emplacement; the installation or equipments that may stay at the origin of the accidents (dangerous equipments; certain all-important equipments to ensure the safety level of the installation (critical security equipments: control rooms, civil fire brigade headquarters, etc; goods and structures situated in the installation’ environment (ground water, rivers, soil, flora, fauna.

  16. Corporate Cost of Occupational Accidents

    DEFF Research Database (Denmark)

    Rikhardsson, Pall M.; Impgaard, M.

    2004-01-01

    The systematic accident cost analysis (SACA) project was carried out during 2001 by The Aarhus School of Business and PricewaterhouseCoopers Denmark with financial support from The Danish National Working Environment Authority. Its focused on developing and testing a method for evaluating...

  17. Crime, accidents and social control

    NARCIS (Netherlands)

    Junger, Marianne; Terlouw, Gert-Jan; van der Heijden, Peter G.M.

    1995-01-01

    This paper addresses to questions. (1) Is there a demonstrable relation between accidents and crime, does this relation hold for each type of crime and each means of transport, and does it subsist after controlling for age and gender? (2) Can social control theory explain involvements in both

  18. Detection and analysis of accident black spots with even small accident figures.

    NARCIS (Netherlands)

    Oppe, S.

    1982-01-01

    Accident black spots are usually defined as road locations with high accident potentials. In order to detect such hazardous locations we have to know the probability of an accident for a traffic situation of some kind, or the mean number of accidents for some unit of time. In almost all procedures

  19. Detection and analysis of accident black spots with even small accident figures.

    NARCIS (Netherlands)

    Oppe, S.

    1982-01-01

    Accident black spots are usually defined as road locations with high accident potentials. In order to detect such hazardous locations we have to know the probability of an accident for a traffic situation of some kind, or the mean number of accidents for some unit of time. In almost all procedures

  20. Radio and line transmission 2

    CERN Document Server

    Roddy, Dermot

    2013-01-01

    Radio and Line Transmission, Volume 2 gives a detailed treatment of the subject as well as an introduction to additional advanced subject matter. Organized into 14 chapters, this book begins by explaining the radio wave propagation, signal frequencies, and bandwidth. Subsequent chapters describe the transmission lines and cables; the aerials; tuned and coupled circuits; bipolar transistor amplifiers; field-effect transistors and circuits; thermionic valve amplifiers; LC oscillators; the diode detectors and modulators; and the superheterodyne receiver. Other chapters explore noise and interfere

  1. Development of Long-Lifetime Pulsed Gas Valves for Pulsed Electric Thrusters

    Science.gov (United States)

    Burkhardt, Wendel M.; Crapuchettes, John M.; Addona, Brad M.; Polzin, Kurt A.

    2015-01-01

    It is advantageous for gas-fed pulsed electric thrusters to employ pulsed valves so propellant is only flowing to the device during operation. The propellant utilization of the thruster will be maximized when all the gas injected into the thruster is acted upon by the fields produced by the electrical pulse. Gas that is injected too early will diffuse away from the thruster before the electrical pulse can act to accelerate the propellant. Gas that is injected too late will miss being accelerated by the already-completed electrical pulse. As a consequence, the valve must open quickly and close equally quickly, only remaining open for a short duration. In addition, the valve must have only a small amount of volume between the sealing body and the thruster so the front and back ends of the pulse are as coincident as possible with the valve cycling, with very little latent propellant remaining in the feed lines after the valve is closed. For a real mission of interest, a pulsed thruster can be expected to pulse at least 10(exp 10) - 10(exp 11) times, setting the range for the number of times a valve must open and close. The valves described in this paper have been fabricated and tested for operation in an inductive pulsed plasma thruster (IPPT) for in-space propulsion. In general, an IPPT is an electrodeless space propulsion device where a capacitor is charged to an initial voltage and then discharged, producing a high-current pulse through a coil. The field produced by this pulse ionizes propellant, inductively driving current in a plasma located near the face of the coil. Once the plasma is formed, it can be accelerated and expelled at a high exhaust velocity by the electromagnetic Lorentz body force arising from the interaction of the induced plasma current and the magnetic field produced by the current in the coil. The valve characteristics needed for the IPPT application require a fast-acting valve capable of a minimum of 10(exp 10) valve actuation cycles. Since

  2. Fault diagnosis of reciprocating compressor valve with the method integrating acoustic emission signal and simulated valve motion

    Science.gov (United States)

    Wang, Yuefei; Xue, Chuang; Jia, Xiaohan; Peng, Xueyuan

    2015-05-01

    This paper proposes a method of diagnosing faults in reciprocating compressor valves using the acoustic emission signal coupled with the simulated valve motion. The actual working condition of a valve can be obtained by analyzing the acoustic emission signal in the crank angle domain and the valve movement can be predicted by simulating the valve motion. The exact opening and closing locations of a normal valve, provided by the simulated valve motion, can be used as references for the valve fault diagnosis. The typical valve faults are diagnosed to validate the feasibility and accuracy of the proposed method. The experimental results indicate that this method can easily distinguish the normal valve, valve flutter and valve delayed closing conditions. The characteristic locations of the opening and closing of the suction and discharge valves can be clearly identified in the waveform of the acoustic emission signal and the simulated valve motion.

  3. Intersection layout, traffic volumes and accidents.

    NARCIS (Netherlands)

    Poppe, F.

    1988-01-01

    This paper reports on the accident research carried out as a part of a large project started in 1983. For this accident research an inventory was made of a large number of intersections.Recorded were layout features, accident data and estimates of traffic volumes. Attention will be given to the

  4. 48 CFR 836.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Accident prevention. 836... prevention. The contracting officer must insert the clause at 852.236-87, Accident Prevention, in solicitations and contracts for construction that contain the clause at FAR 52.236-13, Accident Prevention....

  5. 48 CFR 1836.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Accident prevention. 1836... 1836.513 Accident prevention. The contracting officer must insert the clause at 1852.223-70, Safety and Health, in lieu of FAR clause 52.236-13, Accident Prevention, and its Alternate I....

  6. 48 CFR 636.513 - Accident prevention.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Accident prevention. 636... CONTRACTING CONSTRUCTION AND ARCHITECT-ENGINEER CONTRACTS Contract Clauses 636.513 Accident prevention. (a) In... contracting activities shall insert DOSAR 652.236-70, Accident Prevention, in lieu of FAR clause...

  7. Barriers to learning from incidents and accidents

    NARCIS (Netherlands)

    Dechy, N.; Dien, Y.; Drupsteen, L.; Felicio, A.; Cunha, C.; Roed-Larsen, S.; Marsden, E.; Tulonen, T.; Stoop, J.; Strucic, M.; Vetere Arellano, A.L.; Vorm, J.K.J. van der; Benner, L.

    2015-01-01

    This document provides an overview of knowledge concerning barriers to learning from incidents and accidents. It focuses on learning from accident investigations, public inquiries and operational experience feedback, in industrial sectors that are exposed to major accident hazards. The document disc

  8. Early Clinical Outcome of Mitral Valve Replacement Using a Newly Designed Stentless Mitral Valve for Failure of Initial Mitral Valve Repair.

    Science.gov (United States)

    Nishida, Hidefumi; Kasegawa, Hitoshi; Kin, Hajime; Takanashi, Shuichiro

    2016-12-21

    Here we report the early outcome of mitral valve replacement using a newly designed stentless mitral valve for failure of initial mitral valve repair. Mitral valve plasty (MVP) for mitral regurgitation is currently a standard technique performed worldwide. However, whether mitral valve repair should be performed for patients with advanced leaflet damage or complicated pathology remains controversial. Mitral valve replacement might be feasible for patients who have undergone failed initial MVP; however, it is not an optimal treatment because of poor valve durability and the need for anticoagulative therapy. We report two cases of successful mitral valve replacement using a newly designed stentless mitral valve made of fresh autologous pericardium, which may have a potential benefit over mitral valve repair or mitral valve replacement with a mechanical or bioprosthetic valve.

  9. Analysing truck position data to study roundabout accident risk

    OpenAIRE

    Kamla, Jwan Jameel Shekh Mohammed

    2016-01-01

    In order to reduce accident risk, highway authorities prioritise maintenance budgets partly based upon previous accident history. However, as accident rates have continued to fall in most contexts, this approach has become problematic as accident ‘black spots’ have been treated and the number of accidents at any individual site has fallen. Another way of identifying sites of higher accident risk might be to identify near-miss accidents (where an accident nearly happened, but was avoided), whi...

  10. A Kinematic Analysis of the Variable Valve Timing Mechanism with Three Elements and Continuous Valve Lift

    Directory of Open Access Journals (Sweden)

    Stelian Mihalcea

    2010-01-01

    Full Text Available An innovating solution for throttle-free load control for spark-ignition engines is Variable Valve Timing system (VVT System, or VVA - Variable Valve Actuation System. In this paper is presented an analytic method for kinematic analysis of the valve timing mechanism with three elements, which mainly includes the camshaft, the roller rocker finger and an intermediate rocker arm. This type of mechanism ensures a continuous valve lift (VVL System between two extreme valve heights. It is also presented the numerical example for the variable valve lift mechanism’s motion.

  11. Redoing a bioprosthetic tricuspid valve replacement with pacemaker wire through the ruined bioprosthetic valve orifice

    Institute of Scientific and Technical Information of China (English)

    GUO Hong-wei; PAN Shi-wei; SONG Yun-hu; HU Sheng-shou

    2011-01-01

    Severe tricuspid regurgitation with permanent pacemaker wire passing through the orifice of bioprosthetic tricuspid valve is extremely rare. We present a case of such kind of patient and redid bioprosthetic tricuspid valve replacement. A hawk mouth forceps for bone surgery was used to cut off the mental ring of ruined bioprosthetic tricuspid valve and the ruined valve was removed. A new bioprosthetic tricuspid valve was implanted and the wire of permanent pacemaker was left outside the ring of bioprosthetic tricuspid valve. This method may be helpful for such kind of patient.

  12. Handwheel valve operation: assessment of four opening methods in terms of muscle loading, perceived comfort, and efficiency.

    Science.gov (United States)

    Aghazadeh, Fereydoun; Al Qaisi, Saif; Hutchinson, Francis; Ikuma, Laura

    2012-01-01

    Injuries due to manual valve handwheel operations are a major concern in the chemical process industry. Manual valves are used to start, stop, and control flow in process lines. The torque required to operate handwheels after the initial "breaking" can vary due to the size, design, and condition of the valve. This study tested four methods of turning the handwheel on a medium-sized gate valve at two different torque requirements (25 Nm and 50 Nm). The methods were compared to each other, in terms of efficiency, subjective ratings of perceived exertion, and electromyography activity of the upper extremity and trunk muscles. The results indicate that different methods and torque requirements are compensated for by the use of different muscles. Also, this use of different muscles, along with the increased mechanical advantage of the wrench, can affect the operator's actual and perceived comfort and efficiency while operating a valve handwheel.

  13. Predictive Modelling of Pneumatic Actuators in valves Related with security CN Cofrentes; Modelizacion Predictiva de Actuadores Neumaticos en Valvulas Relacionadas con la Seguridad de C. N. Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Calduch Cervera, F.; Verdu Rios, M. F.; Villena Rivera, M.; Munoz Guijosa, J. M.

    2012-07-01

    Once completed the static modeling; pneumatic actuators under analysis, consisting in the development of balance equations Kinematic compatibility forces and each of the internal components of the actuator, regardless of the valve to which it is attached and the effect dynamic conditions of the line has continued to develop the dynamic model of the valve - actuator.

  14. Candidate gene resequencing in a large bicuspid aortic valve-associated thoracic aortic aneurysm cohort: SMAD6 as an important contributor

    NARCIS (Netherlands)

    E. Gillis (Elisabeth); Kumar, A.A. (Ajay A.); Luyckx, I. (Ilse); Preuss, C. (Christoph); Cannaerts, E. (Elyssa); Beek, G. (Gerarda van de); Wieschendorf, B. (Björn); Alaerts, M. (Maaike); Bolar, N. (Nikhita); G. Vandeweyer (Geert); Meester, J. (Josephina); Wünnemann, F. (Florian); Gould, R.A. (Russell A.); Zhurayev, R. (Rustam); Zerbino, D. (Dmytro); Mohamed, S.A. (Salah A.); Mital, S. (Seema); L. Mertens (Luc); Björck, H.M. (Hanna M.); A. Franco-Cereceda (Anders); A.S. McCallion (Andrew); L. van Laer (Lut); J.M.A. Verhagen (Judith ); I.M.B.H. van de Laar (Ingrid); M.W. Wessels (Marja); Messas, E. (Emmanuel); Goudot, G. (Guillaume); Nemcikova, M. (Michaela); Krebsova, A. (Alice); M.J.E. Kempers (Marlies); Salemink, S. (Simone); Duijnhouwer, T. (Toon); X. Jeunemaître (Xavier); Albuisson, J. (Juliette); P. Eriksson (Per); Andelfinger, G. (Gregor); H.C. Dietz (Harry ); Verstraeten, A. (Aline); B.L. Loeys (Bart)

    2017-01-01

    textabstractBicuspid aortic valve (BAV) is the most common congenital heart defect. Although many BAV patients remain asymptomatic, at least 20% develop thoracic aortic aneurysm (TAA). Historically, BAV-related TAA was considered as a hemodynamic consequence of the valve defect. Multiple lines of

  15. Traumatic Mitral Valve and Pericardial Injury

    Directory of Open Access Journals (Sweden)

    Nissar Shaikh

    2013-01-01

    Full Text Available Cardiac injury after blunt trauma is common but underreported. Common cardiac trauma after the blunt chest injury (BCI is cardiac contusion; it is very rare to have cardiac valve injury. The mitral valve injury during chest trauma occurs when extreme pressure is applied at early systole during the isovolumic contraction between the closure of the mitral valve and the opening of the aortic valve. Traumatic mitral valve injury can involve valve leaflet, chordae tendineae, or papillary muscles. For the diagnosis of mitral valve injury, a high index of suspicion is required, as in polytrauma patients, other obvious severe injuries will divert the attention of the treating physician. Clinical picture of patients with mitral valve injury may vary from none to cardiogenic shock. The echocardiogram is the main diagnostic modality of mitral valve injuries. Patient’s clinical condition will dictate the timing and type of surgery or medical therapy. We report a case of mitral valve and pericardial injury in a polytrauma patient, successfully treated in our intensive care unit.

  16. [Hanggliding accidents. Distribution of injuries and accident analysis].

    Science.gov (United States)

    Ballmer, F T; Jakob, R P

    1989-12-01

    Paragliding--a relatively new sport to Switzerland--brought 23 patients with 48 injuries (38% lower limb and 29% spinal) within a period of 8 months to the Inselspital University hospital in Berne. The aim of the study in characterizing these injuries is to formulate some guidelines towards prevention. With over 90% of accidents occurring at either take off or landing, emphasis on better training for the beginner is proposed with strict guidelines for the more experienced pilot flying in unfavourable conditions.

  17. Preliminary Modeling of Accident Tolerant Fuel Concepts under Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, Kyle A.; Hales, Jason D.

    2016-12-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. Thus, the United States Department of Energy through its NEAMS (Nuclear Energy Advanced Modeling and Simulation) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is funded for a three-year period. The purpose of the HIP is to perform research into two potential accident tolerant concepts and provide an in-depth report to the Advanced Fuels Campaign (AFC) describing the behavior of the concepts, both of which are being considered for inclusion in a lead test assembly scheduled for placement into a commercial reactor in 2022. The initial focus of the HIP is on uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (INL, LANL, and ANL) a comprehensive mulitscale approach to modeling is being used including atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. In this paper, we present simulations of two proposed accident tolerant fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. The simulations investigate the fuel performance response of the proposed ATF systems under Loss of Coolant and Station Blackout conditions using the BISON code. Sensitivity analyses are completed using Sandia National Laboratories’ DAKOTA software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). Early results indicate that each concept has significant advantages as well as areas of concern. Further work is required prior to formulating the proposition report for the Advanced Fuels Campaign.

  18. Flow Characteristics of Butterfly Valve by PIV and CFD

    Science.gov (United States)

    Kim, S. W.; Kim, J. H.; Choi, Y. D.; Lee, Y. H.

    Butterfly valves are widely used as on-off and control valves for industrial process. The importance of butterfly valves as control valves has been increasing because the pressure loss is smaller than other types of valves and compactness is very desirable for installation. These features are desirable for saving energy and high efficiency of instruments.

  19. 49 CFR 179.500-11 - Loading and unloading valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Loading and unloading valves. 179.500-11 Section...-113 and 107A) § 179.500-11 Loading and unloading valves. (a) Loading and unloading valve or valves shall be mounted on the cover or threaded into the marked end of tank. These valves shall be of...

  20. Segmented ball valve is easy to open and close

    Science.gov (United States)

    Prono, E.; Shinault, L. H.; Speisman, C.

    1966-01-01

    Segmented ball valve and flowmeter in the same spherical housing provide a valve that will handle large fluid volume without bulkiness and weight of blade valves or conventional ball valves. The valve is easily opened or closed and the flowmeter remains stationary, so errors are eliminated.

  1. Transesophageal echocardiography evaluation of tricuspid and pulmonic valves

    Directory of Open Access Journals (Sweden)

    Aneeta Bhatia

    2016-01-01

    Full Text Available The tricuspid is the lost valve and the pulmonary being the most anterior, is not visualized well on TEE; The Pulmonary valve is a semilunar valve that separates the right ventricle from the pulmonary artery. It is situated anterior and superior to the aortic valve, almost at right angle to the aortic valve and parallel to the beam of the ultrasound.

  2. Aerococcus viridans Native Valve Endocarditis

    Directory of Open Access Journals (Sweden)

    Wenwan Zhou

    2013-01-01

    Full Text Available Aerococcus viridans is an infrequent human pathogen and few cases of infective endocarditis have been reported. A case involving a 69-year-old man with colon cancer and hemicolectomy 14 years previously, without recurrence, is reported. A diagnosis of native mitral valve endocarditis was established on the basis of clinical presentation, characteristic echocardiographic findings and pathological specimen examination after urgent valve replacement. A viridans endocarditis appears to be particularly virulent, requiring a surgical approach in four of 10 cases reported and death in one of nine. Given the aggressive nature of A viridans endocarditis and the variable time to diagnosis (a few days to seven months, prompt recognition of symptoms and echocardiography, in addition to blood cultures, should be performed when symptoms persist.

  3. [MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT].

    Science.gov (United States)

    Tabata, Minoru

    2016-03-01

    Minimally invasive aortic valve replacement (MIAVR) is defined as aortic valve replacement avoiding full sternotomy. Common approaches include a partial sternotomy right thoracotomy, and a parasternal approach. MIAVR has been shown to have advantages over conventional AVR such as shorter length of stay and smaller amount of blood transfusion and better cosmesis. However, it is also known to have disadvantages such as longer cardiopulmonary bypass and aortic cross-clamp times and potential complications related to peripheral cannulation. Appropriate patient selection is very important. Since the procedure is more complex than conventional AVR, more intensive teamwork in the operating room is essential. Additionally, a team approach during postoperative management is critical to maximize the benefits of MIAVR.

  4. Exploratory analysis of Spanish energetic mining accidents.

    Science.gov (United States)

    Sanmiquel, Lluís; Freijo, Modesto; Rossell, Josep M

    2012-01-01

    Using data on work accidents and annual mining statistics, the paper studies work-related accidents in the Spanish energetic mining sector in 1999-2008. The following 3 parameters are considered: age, experience and size of the mine (in number of workers) where the accident took place. The main objective of this paper is to show the relationship between different accident indicators: risk index (as an expression of the incidence), average duration index for the age and size of the mine variables (as a measure of the seriousness of an accident), and the gravity index for the various sizes of mines (which measures the seriousness of an accident, too). The conclusions of this study could be useful to develop suitable prevention policies that would contribute towards a decrease in work-related accidents in the Spanish energetic mining industry.

  5. The dominance of accidents caused by banalities

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten

    . Nevertheless, the fact is that the simpler accidents normally caused by what might be regarded as banalities occur at a much higher frequencies and with many more fatalities and invalidities than any of what are usually regarded as the most dangerous kinds of accidents. In depth analysis of national statistics...... on accidents could reveal the kind of accidents we are talking about, where they happen, to whom, how, and what can be done about them. This would require a special registration system of the events leading up to the accident. The main results for the four most frequent types of accident will be described...... as an example of how much information such systems can offer in general for the work of accident prevention in more traditional and common enterprises....

  6. [Redo Aortic and Mitral Valve Replacement by Manouguian's Procedure for Active Prosthetic Valve Infection].

    Science.gov (United States)

    Kunitomo, Ryuji; Okamoto, Ken; Moriyama, Shuji; Sakaguchi, Hisashi; Tazume, Hirokazu; Yoshinaga, Takashi; Kawasuji, Michio

    2016-03-01

    The damage to the intervalvular fibrous trigone (IVFT) by infective endocarditis makes combined aortic and mitral valve replacement difficult. We performed Manouguian's double valve replacement for such a case and obtained a good result. A 81-year-old male underwent emergency operation due to active prosthetic valve endocarditis. He had a history of receiving combined aortic and mitral valve replacement because of active infective endocarditis at the age of 74 and redo aortic valve replacement 3 years after that. The infectious lesion extended from the mitral annulus to the IVFT and the aortic annulus, and it caused the prosthetic valve detachment from the aortic annulus. Manouguian's double valve replacement was required for radical resection and reconstruction of the IVFT. No recurrent infection or paravalvular leakage was observed during 49months follow up period. Manouguian's procedure is useful for complete resection of the infected IVFT and makes combined aortic and mitral valve replacement safer.

  7. Design and performance characteristic analysis of servo valve-type water hydraulic poppet valve

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Hwan [Pusan National University, Busan (Korea, Republic of)

    2009-09-15

    For water hydraulic system control, the flow or pressure control using high-speed solenoid valve controlled by PWM control method could be a good solution for prevention of internal leakage. However, since the PWM control of on-off valves cause extensive flow and pressure fluctuation, it is difficult to control the water hydraulic actuators precisely. In this study, the servo valve-type water hydraulic valve using proportional poppet as the main valve is designed and the performance characteristics of the servo valve-type water hydraulic valve are analyzed. Furthermore, it is demonstrated through experiments that a decline in control chamber pressure that follows the change of pilot flow is caused by the occurrence of cavitation around the proportional poppet, and that fundamental characteristics of the developed valve remain unaffected by the occurrence of cavitation

  8. Percutaneous implantation of CoreValve aortic prostheses in patients with a mechanical mitral valve.

    Science.gov (United States)

    Bruschi, Giuseppe; De Marco, Federico; Oreglia, Jacopo; Colombo, Paola; Fratto, Pasquale; Lullo, Francesca; Paino, Roberto; Frigerio, Maria; Martinelli, Luigi; Klugmann, Silvio

    2009-11-01

    Concerns exist in the field of transcatheter aortic valve implantation regarding the treatment of patients with mechanical mitral valve for possible interference between the percutaneous aortic valve and the mechanical mitral prosthesis. We report our experience with percutaneous aortic valve implantation in 4 patients with severe aortic stenosis, previously operated on for mitral valve replacement with a mechanical prosthesis. All patients underwent uneventful percutaneous retrograde CoreValve implantation (CoreValve Inc, Irvine, CA). No deformation of the nitinol tubing of the prostheses (ie, neither distortion nor malfunction of the mechanical valve in the mitral position) occurred in any of the patients. All patients are alive and asymptomatic at a mean follow-up of 171 days.

  9. Imaging of Cardiac Valves by Computed Tomography

    Directory of Open Access Journals (Sweden)

    Gudrun Feuchtner

    2013-01-01

    Full Text Available This paper describes “how to” examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, “how to” perform and optimize a multislice CT scan and “how to” interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide “how to” use CT for planning of transcatheter aortic valve implantation (TAVI, an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

  10. 3D Printed Multimaterial Microfluidic Valve

    Science.gov (United States)

    Patrick, William G.; Sharma, Sunanda; Kong, David S.; Oxman, Neri

    2016-01-01

    We present a novel 3D printed multimaterial microfluidic proportional valve. The microfluidic valve is a fundamental primitive that enables the development of programmable, automated devices for controlling fluids in a precise manner. We discuss valve characterization results, as well as exploratory design variations in channel width, membrane thickness, and membrane stiffness. Compared to previous single material 3D printed valves that are stiff, these printed valves constrain fluidic deformation spatially, through combinations of stiff and flexible materials, to enable intricate geometries in an actuated, functionally graded device. Research presented marks a shift towards 3D printing multi-property programmable fluidic devices in a single step, in which integrated multimaterial valves can be used to control complex fluidic reactions for a variety of applications, including DNA assembly and analysis, continuous sampling and sensing, and soft robotics. PMID:27525809

  11. Two-Year Outcomes in Patients With Severe Aortic Valve Stenosis Randomized to Transcatheter Versus Surgical Aortic Valve Replacement

    DEFF Research Database (Denmark)

    Søndergaard, Lars; Steinbrüchel, Daniel Andreas; Ihlemann, Nikolaj

    2016-01-01

    BACKGROUND: The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize all-comers with severe native aortic valve stenosis to either transcatheter aortic valve replacement (TAVR) with the CoreValve self-expanding bioprosthesis or surgical aortic valve replacement (SAVR), inclu...... population. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01057173....

  12. Practical approaches in accident analysis

    Science.gov (United States)

    Stock, M.

    An accident analysis technique based on successive application of structural response, explosion dynamics, gas cloud formation, and plant operation failure mode models is proposed. The method takes into account the nonideal explosion characteristic of a deflagration in the unconfined cloud. The resulting pressure wave differs significantly from a shock wave and the response of structures like lamp posts and walls can differ correspondingly. This gives a more realistic insight into explosion courses than a simple TNT-equivalent approach.

  13. Safety Analyses on a Safety Valve Stuck-Open for the HANARO fuel test loop

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. K.; Sim, B. S.; Chi, D. Y.; Lee, J. M.; Lee, C. Y.; Ahn, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-05-15

    A fuel test loop (FTL) for irradiation tests is under development at the HANARO. The construction of the FTL was completed at the beginning of 2007 and integral performance tests have been carried out. The safety of the FTL including the PWR test fuels which will be installed should be verified for design basis accidents and anticipated operational occurrences (AOOs). This paper deals with the thermal-hydraulic transient analyses and the prediction for a departure from a nucleate boiling ratio (DNBR) during a safety valve stuck-open for the HANARO fuel test loop, which is one of the AOOs.

  14. STUDY ON FLUID THICKNESS BETWEEN POPPET AND VALVE GUIDE IN CONTROL VALVE OF INJECTOR

    Institute of Scientific and Technical Information of China (English)

    Zhang Jianming; Zhang Weigang; Wang Yawei

    2004-01-01

    The physical model of -20 diesel oil and force model of injector control valve of common rail system is built. The changes of the fluid thickness are investigated on the base of the results of CFD and experiments for control valve of injector. The results indicate that a fluid thickness of 0.02~0.03 mm between the poppet and valve guide is sufficient to dampen any excessive control valve poppet bouncing.

  15. An analysis of check valve performance characteristics based on valve design

    Energy Technology Data Exchange (ETDEWEB)

    McElhaney, K.L. [Oak Ridge National Lab., TN (United States). Engineering Technology Div.

    2000-04-01

    Although it had been theorized by nuclear industry valve experts that the two most significant factors in assessing check valve performance were valve type (or design) and operating conditions, until recently, no data was available to support their assumptions. In co-operation with the Nuclear Industry Check Valve Group (NIC), Oak Ridge National Laboratory (ORNL) undertook a review and analysis of check valve failures recorded in the Institute of Nuclear Power Operations' (INPO) Nuclear Plant Reliability Data System (NPRDS). This study involved the characterization of failures according to several parameters, including valve design (e.g. swing check, lift check). Since the valve design is not inherently included within the NPRDS engineering record for each component in the database, ORNL relied on input from NIC, valve manufacturers and catalogs to supply the missing information. As a result, nearly 60% of the 21000 check valves listed in the NPRDS component database and 85% of the 838 failures occurring during 1991-1992 were identified according to valve design. This data provided the basis to perform previously unavailable cross-correlations between parameters such as valve design versus failure mode, valve design versus failure discovery method, population/failure distributions by valve design, etc. Performance assessments and predictions based on more specific sets of parameters (as opposed to generic check valve failure rates obtained from standard reference sources that generally ignore the valve design) should result in a significant impact on future nuclear plant operations, including inservice testing (IST) practices, maintenance, and probabilistic risk assessments (PRAs) by providing a means to calculate more appropriate relative (and ultimately absolute) failure rates for check valves. (orig.)

  16. The consequences of Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Ion Chioșilă

    2016-12-01

    Full Text Available These days marks 30 years since the Chernobyl nuclear accident, followed by massive radioactive contamination of the environment and human in Belarus, Ukraine and Russia, and resulted in many deaths among people who intervened to decrease the effects of the nuclear disaster. The 26 April 1986 nuclear accident contaminated all European countries, but at a much lower level, without highlighted consequences on human health. In special laboratories, the main radionuclides (I-131, Cs-137, Cs-134 and Sr-90 were also analyzed in Romania from environmental samples, food, even human subjects. These radionuclides caused the population to receive a low dose of about 1 mSv in 1986 that is half of the dose of the natural background radiation (2.4 mSv per year. As in all European countries (excluding Ukraine, Belarus and Russia this dose of about 1 mSv fell rapidly by 1990, reaching levels close to ones before the accident at the nuclear tests.

  17. [Multicenter paragliding accident study 1990].

    Science.gov (United States)

    Lautenschlager, S; Karli, U; Matter, P

    1992-01-01

    During the period from 1.1.90 until 31.12.90, 86 injuries associated with paragliding were analyzed in a prospective study in 12 different Swiss hospitals with reference to causes, patterns, and frequencies. The injuries showed a mean score of over 2 and were classified as severe. Most frequent spine injuries (36%) and lesions of the lower extremity (35%) with a high risk of the ankles were diagnosed. One accident was fatal. 60% of the accidents happened during landing, 26% during launching and 14% during flight. Half of the pilots were affected during their primary training course. Most accidents were caused by inflight error of judgement--especially incorrect estimation of wind conditions--and further the choice of unfavourable landing sites. In contrast to previous injury-reports, only one equipment failure could be noted, but often the equipment was not corresponding with the experience and the weight of the pilot. To reduce the frequency of paragliding-injuries an accurate choice of equipment and an increased attention to environmental factors is mandatory. Furthermore an education-program regarding the attitude and intelligence of the pilot should be included in training courses.

  18. Medical consequences of Chernobyl accident

    Directory of Open Access Journals (Sweden)

    Galstyan I.A.

    2015-12-01

    Full Text Available Aim: to study the long-term effects of acute radiation syndrome (ARS, developed at the victims of the Chernobyl accident. Material and Methods. 237 people were exposed during the accident, 134 of them were diagnosed with ARS. Dynamic observation implies a thorough annual examination in a hospital. Results. In the first 1.5-2 years after the ARS mean group indices of peripheral blood have returned to normal. However, many patients had transient expressed moderate cytopenias. Granulocytopenia, thrombocytopenia, lymphopenia and erythropenia were the most frequently observed things during the first 5 years after the accident. After 5 years their occurences lowered. In 11 patients the radiation cataract was detected. A threshold dose for its development is a dose of 3.2 Gy Long-term effects of local radiation lesions (LRL range from mild skin figure smoothing to a distinct fibrous scarring, contractures, persistently recurrent late radiation ulcers. During all years of observation we found 8 solid tumors, including 2 thyroid cancers. 5 hematologic diseases were found. During 29 years 26 ARS survivors died of various causes. Conclusion. The health of ones with long-term ARS effects is determined by the evolution of the LRL effects on skin, radiation cataracts, hema-tological diseases and the accession of of various somatic diseases, not caused by radiation.

  19. Improved valve and dash-pot assembly

    Science.gov (United States)

    Chang, S.C.

    1985-04-23

    A dash-pot valve comprises a cylinder submerged in the fluid of a housing and have a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with targentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

  20. Valve and dash-pot assembly

    Science.gov (United States)

    Chang, Shih-Chih

    1986-01-01

    A dash-pot valve comprising a cylinder submerged in the fluid of a housing and having a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with tangentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

  1. Check valve slam analysis in pumping station

    Science.gov (United States)

    Himr, D.; Habán, V.; Dokoupil, P.

    2016-03-01

    Pumping station supplies water for technological process. The check valve in the station was replaced with a new one. The regular test of black out discovered the high pressure pulsations accompanied with noticeable pipeline movement of discharge pipe. It was caused by late check valve closing, probably, when the back flow reached the highest possible velocity. This statement was supported with analysis of results of pressure measurement near the check valve and with a numerical simulation of the flow in the pipeline system.

  2. Low-Pressure-Drop Shutoff Valve

    Science.gov (United States)

    Thornborrow, John

    1994-01-01

    Flapper valve remains open under normal flow conditions but closes upon sudden increases to high rate of flow and remains closed until reset. Valve is fluid/mechanical analog of electrical fuse or circuit breaker. Low-pressure-drop shutoff valve contains flapper machined from cylindrical surface. During normal flow conditions, flapper presents small cross section to flow. (Useful in stopping loss of fluid through leaks in cooling systems.)

  3. AN ACTIVE VALVE WITH A CLAMPED MEMBRANE

    DEFF Research Database (Denmark)

    2009-01-01

    An active valve for use e.g. in fluidic microsystems is provided, wherein the active valve comprises a membrane having at least one flow gate, arranged between a first and a second substantially rigid element. Adjusting means provides an adjustment of the clamping force on membrane arranged between...... the first and second substantially rigid element. Hereby the flow rate through the active valve can be continuously and precisely controlled....

  4. Bistable (latching) solenoid actuated propellant isolation valve

    Science.gov (United States)

    Wichmann, H.; Deboi, H. H.

    1979-01-01

    The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

  5. Implante de bioprótese aórtica "stentless" em pacientes com alterações do anel aórtico Aortic valve replacement with a stentless bioprosthesis in patients with weakened aortic annulus

    Directory of Open Access Journals (Sweden)

    Bayard Gontijo Filho

    1993-06-01

    ascending aorta was enlarged with a patch of bovine pericardium in 11 ocasions; mitral valve replacement was concomitantly performed in 3 patients. There was one hospital death secondary to multiple organ failure in a patient with acute endocarditis and a preoperative cerebro-vascular accident. One patient who was pacemaker dependant had a sudden death in the 6 th postoperative month. All other 15 patients are in regular follow-up with periodic ecocardiographic analysis. One patient had partial deiscense of the lower suture line which generated a gradient in the left ventricular outflow tract; he was reoperated upon and the valve was refixed with flow normalization. In all patients the valve has shown an excellent performance with very small gradients (mean = 10.6 mmHg and abscence of significant aortic regurgitation. No case of reinfection was observed in the patients with endocarditis. The stentless aortic bioprosthesis proved to be an excellent heart valve substitute in this difficult group of patients.

  6. Outcome of pregnancy in women after pulmonary autograft valve replacement for congenital aortic valve disease

    NARCIS (Netherlands)

    Yap, Sing-Chien; Drenthen, Willem; Pieper, Petronella G.; Moons, Philip; Mulder, Barbara J. M.; Klieverik, Loes M.; Vliegen, Hubert W.; van Dijk, Arie P. J.; Meijboom, Folkert J.; Roos-Hesselink, Jolien W.

    Background and aim of the study: The pulmonary autograft has been recommended as the valve of choice for aortic valve replacement (AVR) in young women contemplating pregnancy. However, current information on maternal and perinatal outcome of pregnancy in women with pulmonary autograft valve

  7. Outcome of pregnancy in women after pulmonary autograft valve replacement for congenital aortic valve disease.

    NARCIS (Netherlands)

    Yap, S.C.; Drenthen, W.; Pieper, P.G.; Moons, P.; Mulder, B.J.M.; Klieverik, L.M.; Vliegen, H.W.; Dijk, A.P.J. van; Meijboom, F.J.; Roos-Hesselink, J.W.

    2007-01-01

    BACKGROUND AND AIM OF THE STUDY: The pulmonary autograft has been recommended as the valve of choice for aortic valve replacement (AVR) in young women contemplating pregnancy. However, current information on maternal and perinatal outcome of pregnancy in women with pulmonary autograft valve

  8. Outcome of pregnancy in women after pulmonary autograft valve replacement for congenital aortic valve disease

    NARCIS (Netherlands)

    Yap, Sing-Chien; Drenthen, Willem; Pieper, Petronella G.; Moons, Philip; Mulder, Barbara J. M.; Klieverik, Loes M.; Vliegen, Hubert W.; van Dijk, Arie P. J.; Meijboom, Folkert J.; Roos-Hesselink, Jolien W.

    2007-01-01

    Background and aim of the study: The pulmonary autograft has been recommended as the valve of choice for aortic valve replacement (AVR) in young women contemplating pregnancy. However, current information on maternal and perinatal outcome of pregnancy in women with pulmonary autograft valve replacem

  9. Outcome of pregnancy in women after pulmonary autograft valve replacement for congenital aortic valve disease.

    NARCIS (Netherlands)

    Yap, S.C.; Drenthen, W.; Pieper, P.G.; Moons, P.; Mulder, B.J.M.; Klieverik, L.M.; Vliegen, H.W.; Dijk, A.P.J. van; Meijboom, F.J.; Roos-Hesselink, J.W.

    2007-01-01

    BACKGROUND AND AIM OF THE STUDY: The pulmonary autograft has been recommended as the valve of choice for aortic valve replacement (AVR) in young women contemplating pregnancy. However, current information on maternal and perinatal outcome of pregnancy in women with pulmonary autograft valve replacem

  10. Transapical JenaValve in a patient with mechanical mitral valve prosthesis.

    LENUS (Irish Health Repository)

    O' Sullivan, Katie E

    2014-01-29

    We report the first case of transcatheter aortic valve replacement implantation using JenaValve™ in a patient with mechanical mitral valve prosthesis. We believe that the design features of this valve may be particularly suited for use in this setting. © 2014 Wiley Periodicals, Inc.

  11. Maximizing prosthetic valve size with the Top Hat supra-annular aortic valve

    DEFF Research Database (Denmark)

    Aagaard, Jan; Geha, Alexander S.

    2007-01-01

    BACKGROUND AND AIM OF THE STUDY: The CarboMedics Top Hat supra-annular aortic valve allows a one-size (and often two-size) increase over the standard intra-annular valve. This advantage should minimize the risk of patient-prosthesis mismatch, where the effective prosthetic valve orifice area...

  12. Matching flow characteristics of standard shutoff valves eliminates need for custom fabricated valves

    Science.gov (United States)

    Bevan, A. F.

    1966-01-01

    Standard high pressure valves are used in low pressure fluid system testing when a substantial system pressure increase is required. The flow-vs-valve stroke is matched with that of the valves being replaced. Some correction to the plug contour may be necessary.

  13. New-onset atrial fibrillation after surgical aortic valve replacement and transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav;

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  14. New-Onset Atrial Fibrillation After Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav;

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  15. Repositioning of an Intraventricular Dislocated Aortic Valve during Transcatheter Aortic Valve Implantation

    NARCIS (Netherlands)

    Natour, Ehsan; Douglas, Yvonne L.; Jainandunsing, Jayant S.; Schurer, Remco A. J.; van der Werf, Hendrik W.; van den Heuvel, Ad F. M.

    2014-01-01

    The case is presented of a 75-year-old man referred for transcatheter aortic valve implantation. During the procedure the prosthetic aortic valve became dislocated into the left ventricle shortly after expansion. The subsequent steps taken to reposition the valve using only materials at hand are des

  16. New-Onset Atrial Fibrillation After Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...

  17. Hydraulic engine valve actuation system including independent feedback control

    Science.gov (United States)

    Marriott, Craig D

    2013-06-04

    A hydraulic valve actuation assembly may include a housing, a piston, a supply control valve, a closing control valve, and an opening control valve. The housing may define a first fluid chamber, a second fluid chamber, and a third fluid chamber. The piston may be axially secured to an engine valve and located within the first, second and third fluid chambers. The supply control valve may control a hydraulic fluid supply to the piston. The closing control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the second fluid chamber to the supply control valve. The opening control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the supply control valve to the second fluid chamber.

  18. Temporal Statistic of Traffic Accidents in Turkey

    Science.gov (United States)

    Erdogan, S.; Yalcin, M.; Yilmaz, M.; Korkmaz Takim, A.

    2015-10-01

    Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  19. [Accidents in travellers - the hidden epidemic].

    Science.gov (United States)

    Walz, Alexander; Hatz, Christoph

    2013-06-01

    The risk of malaria and other communicable diseases is well addressed in pre-travel advice. Accidents are usually less discussed. Thus, we aimed at assessing accident figures for the Swiss population, based on data of the register from 2004 to 2008 of the largest Swiss accident insurance organization (SUVA). More than 139'000 accidents over 5 years showed that 65 % of the accidents overseas are injuries, and 24 % are caused by poisoning or harm by cold, heat or air pressure. Most accidents happened during leisure activities or sports. More than one third of the non-lethal and more than 50 % of the fatal accidents happened in Asia. More than three-quarters of non-lethal accidents take place in people between 25 and 54 years. One out of 74 insured persons has an accident abroad per year. Despite of many analysis short-comings of the data set with regard to overseas travel, the figures document the underestimated burden of disease caused by accidents abroad and should affect the given pre-health advice.

  20. TEMPORAL STATISTIC OF TRAFFIC ACCIDENTS IN TURKEY

    Directory of Open Access Journals (Sweden)

    S. Erdogan

    2015-10-01

    Full Text Available Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  1. Severe Accident Recriticality Analyses (SARA)

    Energy Technology Data Exchange (ETDEWEB)

    Frid, W. [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Hoejerup, F. [Risoe National Lab. (Denmark); Lindholm, I.; Miettinen, J.; Puska, E.K. [VTT Energy, Helsinki (Finland); Nilsson, Lars [Studsvik Eco and Safety AB, Nykoeping (Sweden); Sjoevall, H. [Teoliisuuden Voima Oy (Finland)

    1999-11-01

    Recriticality in a BWR has been studied for a total loss of electric power accident scenario. In a BWR, the B{sub 4}C control rods would melt and relocate from the core before the fuel during core uncovery and heat-up. If electric power returns during this time-window unborated water from ECCS systems will start to reflood the partly control rod free core. Recriticality might take place for which the only mitigating mechanisms are the Doppler effect and void formation. In order to assess the impact of recriticality on reactor safety, including accident management measures, the following issues have been investigated in the SARA project: 1. the energy deposition in the fuel during super-prompt power burst, 2. the quasi steady-state reactor power following the initial power burst and 3. containment response to elevated quasi steady-state reactor power. The approach was to use three computer codes and to further develop and adapt them for the task. The codes were SIMULATE-3K, APROS and RECRIT. Recriticality analyses were carried out for a number of selected reflooding transients for the Oskarshamn 3 plant in Sweden with SIMULATE-3K and for the Olkiluoto 1 plant in Finland with all three codes. The core state initial and boundary conditions prior to recriticality have been studied with the severe accident codes SCDAP/RELAP5, MELCOR and MAAP4. The results of the analyses show that all three codes predict recriticality - both superprompt power bursts and quasi steady-state power generation - for the studied range of parameters, i. e. with core uncovery and heat-up to maximum core temperatures around 1800 K and water flow rates of 45 kg/s to 2000 kg/s injected into the downcomer. Since the recriticality takes place in a small fraction of the core the power densities are high which results in large energy deposition in the fuel during power burst in some accident scenarios. The highest value, 418 cal/g, was obtained with SIMULATE-3K for an Oskarshamn 3 case with reflooding

  2. Improving the pneumatic control valve performance using a PID controller

    OpenAIRE

    Heidari, Mohammad; Homaei, Hadi

    2014-01-01

    Pneumatic control valves are still the most used in process industries due to their low cost and simplicity. This paper presents a design procedure of a PID controller for a pneumatic control valve. For comparison, P and PI controllers are also utilized for the control valve. The bond graph method is used to model the control valve, in order to compare the response characteristics of the valve. Simulation results are found for three controllers of the valve. The integral time absolute error c...

  3. Globe stability during simulated vitrectomy with valved and non-valved trocar cannulas

    Directory of Open Access Journals (Sweden)

    Abulon DJ

    2015-09-01

    Full Text Available Dina Joy Abulon,1 Martin Charles,2 Daniel E Charles21Global Medical Affairs, Alcon Laboratories, Inc., Lake Forest, CA, USA; 2Centro Oftalmológico Dr Charles, Buenos Aires, ArgentinaPurpose: To compare the effects of valved and non-valved cannulas on intraocular pressure (IOP, fluid leakage, and vitreous incarceration during simulated vitrectomy.Methods: Three-port pars plana incisions were generated in six rubber eyes using 23-, 25-, and 27-gauge valved and non-valved trocar cannulas. The models were filled with air and IOP was measured. Similar procedures were followed for 36 acrylic eyes filled with saline solution. Vitreous incarceration was analyzed in eleven rabbit and twelve porcine cadaver eyes.Results: In the air-filled model, IOP loss was 89%–94% when two non-valved cannulas were unoccupied versus 1%–5% when two valved cannulas were unoccupied. In the fluid-filled model, with non-valved cannulas, IOP dropped while fluid leaked from the open ports. With two open ports, the IOP dropped to 20%–30% of set infusion pressure, regardless of infusion pressure and IOP compensation. The IOP was maintained in valved cannulas when one or two ports were left open, regardless of IOP compensation settings. There was no or minimal fluid leakage through open ports at any infusion pressure. Direct microscopic analysis of rabbit eyes showed that vitreous incarceration was significantly greater with 23-gauge non-valved than valved cannulas (P<0.005, and endoscopy of porcine eyes showed that vitreous incarceration was significantly greater with 23-gauge (P<0.05 and 27-gauge (P<0.05 non-valved cannulas. External observation of rabbit eyes showed vitreous prolapse through non-valved, but not valved, cannulas.Conclusion: Valved cannulas surpassed non-valved cannulas in maintaining IOP, preventing fluid leakage, and reducing vitreous incarceration during simulated vitrectomy.Keywords: IOP, fluid leakage, vitreous incarceration

  4. Transaortic aortic valve replacement using the Edwards Sapien-XT Valve and the Medtronic CoreValve: initial experience.

    Science.gov (United States)

    Spargias, Konstantinos; Bouboulis, Nikolaos; Halapas, Antonios; Chrissoheris, Michael; Skardoutsos, Spyridon; Nikolaou, Joulia; Tsolakis, Apostolos; Mourmouris, Christos; Pattakos, Stratis

    2014-01-01

    Transcatheter aortic valve replacement (TAVR) is now an established treatment for certain patients with severe aortic valve stenosis (AS). However, as the number of patients screened for TAVR increases, many are found to have absolutely no option for peripheral artery access. Transaortic valve replacement (TAoVR) has been proposed as a new alternative route in patients deemed unsuitable for conventional approaches. We present our first series of TAoVR cases using the Edwards Sapien-XT and the Medtronic CoreValve prostheses. Twenty-five (25) symptomatic patients (mean age 78 ± 8 years, mean logistic EuroSCORE I 25 ± 11%) with severe AS underwent TAoVR using the Sapien-XT valve (10 patients) or the CoreValve (15 patients). The mean fluoroscopy time was 15.6 ± 4.2 minutes, the mean time in the intensive care unit was 1.9 ± 1.0 days, and the mean hospital stay was 6.4 ± 1.6 days. The mean effective aortic valve area increased (from 0.68 ± 0.15 cm(2) to 1.82 ± 0.34 cm(2), pMedtronic CoreValve prosthesis demonstrated that it could be performed safely, resulting in substantial acute echocardiographic and early clinical improvement.

  5. PWR safety/relief valve blowdown analysis experience

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.Z.; Chou, L.Y.; Yang, S.H. (Gilbert/Commonwealth Engineers and Consultants, Reading, PA (USA). Speciality Engineering Dept.)

    1982-10-01

    The paper describes the difficulties encountered in analyzing a PWR primary loop pressurizer safety relief valve and power operated relief valve discharge system, as well as their resolution. The experience is based on the use of RELAP5/MOD1 and TPIPE computer programs as the tools for fluid transient analysis and piping dynamic analysis, respectively. General approaches for generating forcing functions from thermal fluid analysis solution to be used in the dynamic analysis of piping are reviewed. The paper demonstrates that the 'acceleration or wave force' method may have numerical difficulties leading to unrealistic, large amplitude, highly oscillatory forcing functions in the vicinity of severe flow area discontinuities or choking junctions when low temperature loop seal water is discharged. To avoid this problem, an alternate computational method based on the direct force method may be used. The simplicity and superiority in numerical stability of the forcing function computation method as well as its drawbacks are discussed. Additionally, RELAP modeling for piping, valve, reducer, and sparger is discussed. The effects of loop seal temperature on SRV and PORV discharge line blowdown forces, pressure and temperature distributions are examined. Finally, the effects of including support stiffness and support eccentricity in piping analysis models, method and modeling relief tank connections, minimization of tank nozzle loads, use of damping factors, and selection of solution time steps are discussed.

  6. Outline of the Desktop Severe Accident Graphic Simulator Module for OPR-1000

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. Y.; Ahn, K. I. [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    This paper introduce the desktop severe accident graphic simulator module (VMAAP) which is a window-based severe accident simulator using MAAP as its engine. The VMAAP is one of the submodules in SAMEX system (Severe Accident Management Support Expert System) which is a decision support system for use in a severe accident management following an incident at a nuclear power plant. The SAMEX system consists of four major modules as sub-systems: (a) Severe accident risk data base module (SARDB): stores the data of integrated severe accident analysis code results like MAAP and MELCOR for hundreds of high frequency scenarios for the reference plant; (b) Risk-informed severe accident risk data base management module (RI-SARD): provides a platform to identify the initiating event, determine plant status and equipment availability, diagnoses the status of the reactor core, reactor vessel and containment building, and predicts the plant behaviors; (c) Severe accident management simulator module (VMAAP): runs the MAAP4 code with user friendly graphic interface for input deck and output display; (d) On-line severe accident management guidance module (On-line SAMG); provides available accident management strategies with an electronic format. The role of VMAAP in SAMEX can be described as followings. SARDB contains the most of high frequency scenarios based on a level 2 probabilistic safety analysis. Therefore, there is good chance that a real accident sequence is similar to one of the data base cases. In such a case, RI-SARD can predict an accident progression by a scenario-base or symptom-base search depends on the available plant parameter information. Nevertheless, there still may be deviations or variations between the actual scenario and the data base scenario. The deviations can be decreased by using a real-time graphic accident simulator, VMAAP.. VMAAP is a MAAP4-based severe accident simulation model for OPR-1000 plant. It can simulate spectrum of physical processes

  7. Transcatheter valve-in-valve implantation due to severe aortic regurgitation in a degenerated aortic homograft

    DEFF Research Database (Denmark)

    Olsen, Lene Kjaer; Engstrøm, Thomas; Søndergaard, Lars

    2009-01-01

    Transcatheter aortic valve implantation (TAVI) in severe aortic stenosis has proven to be a feasible and effective treatment modality for inoperable patients. Until now, neither aortic regurgitation nor degenerated bioprostheses has been an indication for TAVI. However, this article reports...... a successful valve-in-valve implantation of a CoreValve aortic valve prosthesis through the right subclavian artery in a case of severe aortic regurgitation within a degenerated aortic homograft. The case exemplifies the possibilities of expanding the indications for TAVI, as well as other vascular access...

  8. Infective Endocarditis of the Aortic Valve with Anterior Mitral Valve Leaflet Aneurysm.

    Science.gov (United States)

    Tomsic, Anton; Li, Wilson W L; van Paridon, Marieke; Bindraban, Navin R; de Mol, Bas A J M

    2016-08-01

    Mitral valve leaflet aneurysm is a rare and potentially devastating complication of aortic valve endocarditis. We report the case of a 48-year-old man who had endocarditis of the native aortic valve and a concomitant aneurysm of the anterior mitral valve leaflet. Severe mitral regurgitation occurred after the aneurysm perforated. The patient showed no signs of heart failure and completed a 6-week regimen of antibiotic therapy before undergoing successful aortic and mitral valve replacement. In addition to the patient's case, we review the relevant medical literature.

  9. Gasoline New Timing and Flux Adjustable Rotary Valve Design (Hereinafter: Rotary Valve

    Directory of Open Access Journals (Sweden)

    Du huiqi

    2016-01-01

    Full Text Available Conventional gasoline engine with an umbrella valve control cylinder intake and exhaust, in order to achieve sealing effect, the valve is driven by the spring force; at the same time, when the cam opens the valve to overcome the spring force acting. Sealing the better, the more power consumed in the engine mechanical losses, the valve mechanism consumes about 30%, which is not a small loss! This article describes a new type of rotary valve is to significantly reduce mechanical losses, so as to achieve energy saving purposes.

  10. Quantifying the risk of extreme aviation accidents

    Science.gov (United States)

    Das, Kumer Pial; Dey, Asim Kumer

    2016-12-01

    Air travel is considered a safe means of transportation. But when aviation accidents do occur they often result in fatalities. Fortunately, the most extreme accidents occur rarely. However, 2014 was the deadliest year in the past decade causing 111 plane crashes, and among them worst four crashes cause 298, 239, 162 and 116 deaths. In this study, we want to assess the risk of the catastrophic aviation accidents by studying historical aviation accidents. Applying a generalized Pareto model we predict the maximum fatalities from an aviation accident in future. The fitted model is compared with some of its competitive models. The uncertainty in the inferences are quantified using simulated aviation accident series, generated by bootstrap resampling and Monte Carlo simulations.

  11. Aortic and Mitral Valve Replacement Through a Single Transverse Aortotomy: A Useful Approach in Difficult Mitral Valve Exposure

    OpenAIRE

    Carmichael, Michael J.; Cooley, Denton A.; Favor, Arsenio S.

    1983-01-01

    Replacement of the mitral valve through a standard vertical left atriotomy in patients requiring both aortic and mitral valve replacement can be very difficult. This is especially true in patients who have undergone previous median sternotomy. Replacement of the mitral valve through the aortic root after excision of the aortic valve is described in two case reports. This is a convenient approach when traditional exposure of the mitral valve is impractical in patients requiring double valve re...

  12. A Generic Model Based Tracking Controller for Hydraulic Valve-Cylinder Drives

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Schmidt, Lasse; Pedersen, Henrik Clemmensen

    2016-01-01

    , and are therefore constrained to utilize only measurements of the piston position, the valve spool position, the transmission line pressures and the supply pressure, as feedbacks. The control structures are generally targeting a high bandwidth of the controlled cylinder drive and accurate tracking ability...

  13. Injuries to pedestrians in road traffic accidents.

    OpenAIRE

    Atkins, R. M.; Turner, W H; Duthie, R. B.; Wilde, B. R.

    1988-01-01

    Although there have been many reports on injuries to occupants of cars in road traffic accidents, there have been few prospective studies of injuries to pedestrians in such accidents. For this reason a two year prospective study of pedestrians in road traffic accidents in the Oxford region was carried out. The incidence of death in pedestrians was significantly higher than in car occupants or motorcyclists. The principal determinant of death was the weight of the vehicle concerned. The most c...

  14. Why Airplanes Crash: Causes of Accidents Worldwide

    OpenAIRE

    Oster, Clinton V.; John S. Strong; Zorn, Kurt

    2010-01-01

    In this paper, we report the results of a detailed examination of the causes of 700 fatal aviation accidents that occurred worldwide between 1990 and 2006 in commercial passenger service. We look at both scheduled and nonscheduled and both domestic and international service. We also categorize the accident aircraft as large jets, regional and medium jets, small jets, turboprops, and piston powered aircraft. We find that the mix of causes of those accidents vary substantially across regions of...

  15. Disruption of silicone valve housing in a Codman Hakim Precision valve with integrated Siphonguard.

    Science.gov (United States)

    Woerdeman, Peter A; Cochrane, David D

    2014-05-01

    Authors of this report describe 2 patients who had undergone shunt insertion for hydrocephalus and who, at 6 weeks or 9 months after their last revision, presented with symptoms of shunt dysfunction and CSF collections at the valve site. At the ensuing shunt revision in both patients, the silicone housing was fractured and the Siphonguard was disconnected from the Codman Hakim Precision flat-bottom valve. The cause of these failures was not clear since manipulation, bending, and twisting of the valves were not thought to have occurred during implantation. A review of the FDA's Manufacturer and User Facility Device Experience (MAUDE) database revealed 58 cases of silicone housing failure in the Codman Hakim Precision valve with integrated Siphonguard since the year 2000. A single report was found in the databases administered by the Canadian Medical Devices Sentinel Network (CMDSNet). The Codman Hakim Precision valves with integrated Siphonguard are delicate devices that do not withstand the intraoperative handling tolerated by other valves. When these valves are implanted, gentle handling and wide exposures are needed to minimize the risk of valve damage. Valves should be handled according to the manufacturer's instructions. However, in light of this particular pattern of failure, it is recommended that the manufacturer redesign this valve to provide handling tolerance that is characteristic of other valves on the market. The featured cases illustrate the importance of the surgeon's role in postmarket surveillance of medical devices and reporting device failures to the responsible agencies and manufacturers.

  16. 7 CFR 58.219 - High pressure pumps and lines.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false High pressure pumps and lines. 58.219 Section 58.219....219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and shall be of such construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The...

  17. Cylinder valve packing nut studies

    Energy Technology Data Exchange (ETDEWEB)

    Blue, S.C. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

  18. Left atrial ball valve thrombus

    Directory of Open Access Journals (Sweden)

    R. Balaji

    2013-10-01

    Full Text Available "Ball valve thrombus" which is a spherical free floating clot in left atrium is an often quoted, but uncommonly encountered complication in patients with severe mitral stenosis of rheumatic origin, who are in atrial fibrillation. We describe the case of a 31-year-old lady with rheumatic heart disease, severe mitral stenosis and moderately severe aortic stenosis who had undergone closed mitral valvotomy 13 years ago. The patient presented with an episode of non-exertional syncope and breathlessness on exertion of 6 months duration and was in normal sinus rhythm. Echocardiography facilitated ante-mortem diagnosis and prompt institution of surgery was life saving.

  19. On-pump fibrillating heart mitral valve replacement with the SAPIEN™ XT transcatheter heart valve.

    Science.gov (United States)

    Ferrari, Enrico; Niclauss, Lars; Locca, Didier; Marcucci, Carlo

    2014-04-01

    In some high-risk patients, standard mitral valve replacement can represent a challenging procedure, requiring a risky extensive decalcification of the annulus. In particular, high-risk redo patients and patients with a previously implanted transcatheter aortic valve, who develop calcific mitral disease, would benefit from the development of new, minimally invasive, transcatheter or hybrid techniques for mitral valve replacement. In particular, mixing transcatheter valve therapies and well-established minimally invasive techniques for mitral replacement or repair can help in decreasing the surgical risk and the technical complexity. Thus, placing transcatheter, balloon-expandable Sapien™ XT stent-valves in calcified, degenerated mitral valves through a right thoracotomy, a left atriotomy and on an on-pump fibrillating heart, represents an attractive alternative to standard surgery in redo patients, in patients with concomitant transcatheter aortic stent-valves in place and in patients with a high-risk profile. We describe this hybrid technique in detail.

  20. COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    S.O. Bader

    1999-10-18

    The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be

  1. Predictors of mortality after aortic valve replacement

    NARCIS (Netherlands)

    Tjang, Yanto Sandy; van Hees, Yvonne; Koerfer, Reiner; Grobbee, Diederick E.; van der Heijden, Geert J. M. G.

    Aortic valve replacement (AVR) is recommended as a standard surgical procedure for aortic valve disease. Still the evidence for commonly claimed predictors of post-AVR prognosis, in particular mortality, appears scant. This systematic review reports on the evidence for predictors of post-AVR

  2. Numerical Analysis of Large Diameter Butterfly Valve

    Science.gov (United States)

    Youngchul, Park; Xueguan, Song

    In this paper, a butterfly valve with the diameter of 1,800 mm was studied. Three-dimensional numerical technique by using commercial code CFX were conducted to observe the flow patterns and to measure flow coefficient, hydrodynamic torque coefficient and so on, when the large butterfly valve operated with various angles and uniform incoming velocity.

  3. 49 CFR 195.420 - Valve maintenance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Valve maintenance. 195.420 Section 195.420 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Operation and Maintenance § 195.420 Valve maintenance. (a) Each operator shall maintain each...

  4. A highly sensitive spin-valve transistor

    NARCIS (Netherlands)

    Erve, van 't O.M.J.; Vlutters, R.; Anil Kumar, P.S.; Kim, S.D.; Jansen, R.; Lodder, J.C.; Hadjipanayis, G.C.

    2001-01-01

    In this paper we present a spin-valve transistor made with a silicon on insulator wafer as emitter and a double sided polished Si wafer as collector. Using vacuum metal bonding we obtain a three terminal device in which a spin-valve layer is sandwiched between two Si wafers. We measure a 217% change

  5. Mitral valve repair in acquired dextrocardia.

    Science.gov (United States)

    Elmistekawy, Elsayed; Chan, Vincent; Hynes, Mark; Mesana, Thierry

    2015-10-01

    Surgical correction of valvular heart disease in patients with dextrocardia is extremely rare. We report a surgical case of mitral valve repair in a patient with acquired dextrocardia. Successful mitral valve repair was performed through a right lateral thoracotomy. We describe our surgical strategy and summarize the literature.

  6. Whole Teflon valves for handling droplets.

    Science.gov (United States)

    Cybulski, Olgierd; Jakiela, Slawomir; Garstecki, Piotr

    2016-06-21

    We propose and test a new whole-Teflon gate valve for handling droplets. The valve allows droplet plugs to pass through without disturbing them. This is possible due to the geometric design, the choice of material and lack of any pulses of flow generated by closing or opening the valve. The duct through the valve resembles a simple segment of tubing, without constrictions, change in lumen or side pockets. There are no extra sealing materials with different wettability or chemical resistance. The only material exposed to liquids is FEP Teflon, which is resistant to aggressive chemicals and fully biocompatible. The valve can be integrated into microfluidic systems: we demonstrate a complex system for culturing bacteria in hundreds of microliter droplet chemostats. The valve effectively isolates modules of the system to increase precision of operations on droplets. We verified that the valve allowed millions of droplet plugs to safely pass through, without any cross-contamination with bacteria between the droplets. The valve can be used in automating complex microfluidic systems for experiments in biochemistry, biology and organic chemistry.

  7. 46 CFR 64.67 - Shutoff valve.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Shutoff valve. 64.67 Section 64.67 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.67 Shutoff valve. A shutoff...

  8. Digital hydraulic valving system. [design and development

    Science.gov (United States)

    1973-01-01

    The design and development are reported of a digital hydraulic valving system that would accept direct digital inputs. Topics include: summary of contractual accomplishments, design and function description, valve parameters and calculations, conclusions, and recommendations. The electrical control circuit operating procedure is outlined in an appendix.

  9. Inexpensive tamper proof safety relief valve

    Science.gov (United States)

    Frankewich, P. A.

    1970-01-01

    Basic relief valve has added safety relief valve capability that relieves overpressure before failure can occur. It may be installed in inaccesible areas with a high degree of reliability, constructed from a variety of materials, and adapted to the user's specific application.

  10. Heart Valve Disease among Patients with Hyperprolactinaemia

    DEFF Research Database (Denmark)

    Steffensen, Charlotte; Maegbaek, Merete Lund; Laurberg, Peter;

    2012-01-01

    Increased risk of heart valve disease during treatment with certain dopamine agonists, such as cabergoline, has been observed in patients with Parkinson's disease. The same compound is used to treat hyperprolactinemia, but it is unknown whether this also associates with heart valve disease....

  11. Mitral valve disease—morphology and mechanisms

    Science.gov (United States)

    Levine, Robert A.; Hagége, Albert A.; Judge, Daniel P.; Padala, Muralidhar; Dal-Bianco, Jacob P.; Aikawa, Elena; Beaudoin, Jonathan; Bischoff, Joyce; Bouatia-Naji, Nabila; Bruneval, Patrick; Butcher, Jonathan T.; Carpentier, Alain; Chaput, Miguel; Chester, Adrian H.; Clusel, Catherine; Delling, Francesca N.; Dietz, Harry C.; Dina, Christian; Durst, Ronen; Fernandez-Friera, Leticia; Handschumacher, Mark D.; Jensen, Morten O.; Jeunemaitre, Xavier P.; Le Marec, Hervé; Le Tourneau, Thierry; Markwald, Roger R.; Mérot, Jean; Messas, Emmanuel; Milan, David P.; Neri, Tui; Norris, Russell A.; Peal, David; Perrocheau, Maelle; Probst, Vincent; Pucéat, Michael; Rosenthal, Nadia; Solis, Jorge; Schott, Jean-Jacques; Schwammenthal, Ehud; Slaugenhaupt, Susan A.; Song, Jae-Kwan; Yacoub, Magdi H.

    2016-01-01

    Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but—even in adult life—remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular–ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease. PMID:26483167

  12. Mitral valve disease--morphology and mechanisms.

    Science.gov (United States)

    Levine, Robert A; Hagége, Albert A; Judge, Daniel P; Padala, Muralidhar; Dal-Bianco, Jacob P; Aikawa, Elena; Beaudoin, Jonathan; Bischoff, Joyce; Bouatia-Naji, Nabila; Bruneval, Patrick; Butcher, Jonathan T; Carpentier, Alain; Chaput, Miguel; Chester, Adrian H; Clusel, Catherine; Delling, Francesca N; Dietz, Harry C; Dina, Christian; Durst, Ronen; Fernandez-Friera, Leticia; Handschumacher, Mark D; Jensen, Morten O; Jeunemaitre, Xavier P; Le Marec, Hervé; Le Tourneau, Thierry; Markwald, Roger R; Mérot, Jean; Messas, Emmanuel; Milan, David P; Neri, Tui; Norris, Russell A; Peal, David; Perrocheau, Maelle; Probst, Vincent; Pucéat, Michael; Rosenthal, Nadia; Solis, Jorge; Schott, Jean-Jacques; Schwammenthal, Ehud; Slaugenhaupt, Susan A; Song, Jae-Kwan; Yacoub, Magdi H

    2015-12-01

    Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but--even in adult life--remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular-ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease.

  13. Transcatheter Aortic Valve Replacement in Europe

    DEFF Research Database (Denmark)

    Mylotte, Darren; Osnabrugge, Ruben L J; Windecker, Stephan;

    2013-01-01

    The authors sought to examine the adoption of transcatheter aortic valve replacement (TAVR) in Western Europe and investigate factors that may influence the heterogeneous use of this therapy.......The authors sought to examine the adoption of transcatheter aortic valve replacement (TAVR) in Western Europe and investigate factors that may influence the heterogeneous use of this therapy....

  14. Repair for acquired aortic valve disease.

    Science.gov (United States)

    Antunes, M J

    1996-10-01

    The favorable results of mitral valvuloplasty when compared with valve replacement have renewed the interest of many surgeons in aortic valve repair. However, these efforts have, for the most part, been unsuccessful. Also, the results of aortic valve replacement are usually better than those of mitral valve replacement. Yet, some patients appear to derive benefit from a conservative aortic valve procedure. The best examples are mild or moderate aortic valve disease associated with mitral valve or coronary artery disease, which constitute the primary indication for operation, where "prophylactic" aortic valve replacement does not appear justifiable. Other possible indications for aortic valvuloplasty includes patient's lack of compliance or contraindication to anticoagulation in young patients. Senile aortic stenosis, in very old patients with a small annulus, preserved leaflet morphology and nonsignificant commissural fusion should be considered for repair. However, since the procedure is not easily reproducible and the results not uniformly predictable, it cannot be recommended for generalized use. Nonetheless, experienced surgeons should be encouraged to continue these efforts.

  15. [Surgical Treatment of Prosthetic Valve Endocarditis].

    Science.gov (United States)

    Kaminishi, Yuichiro; Akutsu, Hirohiko; Sugaya, Akira; Kurumisawa, Soki; Takazawa, Ippei; Sato, Hirotaka; Muraoka, Arata; Aizawa, Kei; Ohki, Shinichi; Saito, Tsutomu; Kawahito, Koji; Misawa, Yoshio

    2015-11-01

    Between 2003 and 2014, at Jichi Medical University Hospital, 11 patients with prosthetic valve endocarditis (PVE) underwent re-operation. There was 1 in-hospital death and 2 late deaths. The cause of death was cirrhosis, heart failure and sepsis, respectively. Emergency surgery, previous double valve replacement (DVR) and Staphylococcus infection were common risk factors for all 3 cases. Two cases of patients that survived who underwent mitral valve replacement (MVR) and DVR for PVE after DVR were treated with multiple antibiotic courses for bacteremia associated with hemodialysis and colon cancer. One patient who underwent DVR after mitral valve plasty which was complicated with cerebral hemorrhage, had survived and was discharged. Of the aortic PVE patients, 2 cases of aortic valve replacement (AVR) using a mechanical valve, 1 case of aortic root replacement (ARR) using a mechanical valve, and 1 ARR using the homograft, were considered cured and never relapsed. A patient with aortic PVE, who underwent AVR after cesarean section for heart failure in birth period, has received ARR twice with the mechanical valve for recurrent pseudo-aneurysm of the left ventricular outflow tract. Since hemodialysis and colon cancer is a risk factor for recurrent PVE, it is necessary to consider the long-term administration of antibiotics after surgery.

  16. Relationship between childhood hyperactivity and accident proneness.

    Science.gov (United States)

    Gayton, W F; Bailey, C; Wagner, A; Hardesty, V A

    1986-10-01

    Previous research suggested that hyperactive children are especially susceptible to accidents. Two questions remain: is the relationship peculiar to hyperactivity in childhood or for behaviorally disturbed children in general and does the relationship hold for females as well as for males? To answer these questions 189 patients at a child psychiatric clinic were rated on a scale which included measures of hyperactivity and accident proneness. The hyperactive patients were more likely to be described as accident prone than nonhyperactive patients. The relationship between childhood hyperactivity and accident proneness is confirmed and is specific. The relationship holds for both boys and girls.

  17. Systematics of Reconstructed Process Facility Criticality Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.L.; McLaughlin, T.P.; Monahan, S.P.

    1999-09-19

    The systematics of the characteristics of twenty-one criticality accidents occurring in nuclear processing facilities of the Russian Federation, the United States, and the United Kingdom are examined. By systematics the authors mean the degree of consistency or agreement between the factual parameters reported for the accidents and the experimentally known conditions for criticality. The twenty-one reported process criticality accidents are not sufficiently well described to justify attempting detailed neutronic modeling. However, results of classic hand calculations confirm the credibility of the reported accident conditions.

  18. Methodological guidelines for developing accident modification functions

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use...... limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. © 2015 Elsevier Ltd. All rights...

  19. Occupational Accidents with Agricultural Machinery in Austria.

    Science.gov (United States)

    Kogler, Robert; Quendler, Elisabeth; Boxberger, Josef

    2016-01-01

    The number of recognized accidents with fatalities during agricultural and forestry work, despite better technology and coordinated prevention and trainings, is still very high in Austria. The accident scenarios in which people are injured are very different on farms. The common causes of accidents in agriculture and forestry are the loss of control of machine, means of transport or handling equipment, hand-held tool, and object or animal, followed by slipping, stumbling and falling, breakage, bursting, splitting, slipping, fall, and collapse of material agent. In the literature, a number of studies of general (machine- and animal-related accidents) and specific (machine-related accidents) agricultural and forestry accident situations can be found that refer to different databases. From the database Data of the Austrian Workers Compensation Board (AUVA) about occupational accidents with different agricultural machinery over the period 2008-2010 in Austria, main characteristics of the accident, the victim, and the employer as well as variables on causes and circumstances by frequency and contexts of parameters were statistically analyzed by employing the chi-square test and odds ratio. The aim of the study was to determine the information content and quality of the European Statistics on Accidents at Work (ESAW) variables to evaluate safety gaps and risks as well as the accidental man-machine interaction.

  20. Aerospace Accident - Injury Autopsy Data System -

    Data.gov (United States)

    Department of Transportation — The Aerospace Accident Injury Autopsy Database System will provide the Civil Aerospace Medical Institute (CAMI) Aerospace Medical Research Team (AMRT) the ability to...