National Library of Energy BETA

Sample records for variable valve timing

  1. Impact of Variable Valve Timing on Low Temperature Combustion

    Broader source: Energy.gov [DOE]

    Documents effects of variable valve actuation in implementing low temperature combustion in production engine platform.

  2. Abstract--A cam-based, shear force actuated electromechanical valve drive system offering variable valve timing in internal

    E-Print Network [OSTI]

    Perreault, Dave

    1 Abstract--A cam-based, shear force actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform, optimal cam design, nonlinear friction model, variable valve timing. I. INTRODUCTION espite their simple

  3. ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING in turbocharged gasoline engines with variable valve timing requires knowledge of exhaust mani- fold pressure, Pe strict emissions regulations. For turbocharged applica- tions, it has been shown [1] that knowledge

  4. Variable valve timing in a homogenous charge compression ignition engine

    DOE Patents [OSTI]

    Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

    2004-08-03

    The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

  5. Variable Valve Actuation

    SciTech Connect (OSTI)

    Jeffrey Gutterman; A. J. Lasley

    2008-08-31

    Many approaches exist to enable advanced mode, low temperature combustion systems for diesel engines - such as premixed charge compression ignition (PCCI), Homogeneous Charge Compression Ignition (HCCI) or other HCCI-like combustion modes. The fuel properties and the quantity, distribution and temperature profile of air, fuel and residual fraction in the cylinder can have a marked effect on the heat release rate and combustion phasing. Figure 1 shows that a systems approach is required for HCCI-like combustion. While the exact requirements remain unclear (and will vary depending on fuel, engine size and application), some form of substantially variable valve actuation is a likely element in such a system. Variable valve actuation, for both intake and exhaust valve events, is a potent tool for controlling the parameters that are critical to HCCI-like combustion and expanding its operational range. Additionally, VVA can be used to optimize the combustion process as well as exhaust temperatures and impact the after treatment system requirements and its associated cost. Delphi Corporation has major manufacturing and product development and applied R&D expertise in the valve train area. Historical R&D experience includes the development of fully variable electro-hydraulic valve train on research engines as well as several generations of mechanical VVA for gasoline systems. This experience has enabled us to evaluate various implementations and determine the strengths and weaknesses of each. While a fully variable electro-hydraulic valve train system might be the 'ideal' solution technically for maximum flexibility in the timing and control of the valve events, its complexity, associated costs, and high power consumption make its implementation on low cost high volume applications unlikely. Conversely, a simple mechanical system might be a low cost solution but not deliver the flexibility required for HCCI operation. After modeling more than 200 variations of the mechanism it was determined that the single cam design did not have enough flexibility to satisfy three critical OEM requirements simultaneously, (maximum valve lift variation, intake valve opening timing and valve closing duration), and a new approach would be necessary. After numerous internal design reviews including several with the OEM a dual cam design was developed that had the flexibility to meet all motion requirements. The second cam added complexity to the mechanism however the cost was offset by the deletion of the electric motor required in the previous design. New patent applications including detailed drawings and potential valve motion profiles were generated and alternate two cam designs were proposed and evaluated for function, cost, reliability and durability. Hardware was designed and built and testing of sample hardware was successfully completed on an engine test stand. The mechanism developed during the course of this investigation can be applied by Original Equipment Manufacturers, (OEM), to their advanced diesel engines with the ultimate goal of reducing emissions and improving fuel economy. The objectives are: (1) Develop an optimal, cost effective, variable valve actuation (VVA) system for advanced low temperature diesel combustion processes. (2) Design and model alternative mechanical approaches and down-select for optimum design. (3) Build and demonstrate a mechanism capable of application on running engines.

  6. Investigation of a rotary valving system with variable valve timing for internal combustion engines: Final technical report

    SciTech Connect (OSTI)

    Cross, P.C.; Hansen, C.N.

    1994-11-18

    The objective of the program was to provide a functional demonstration of the Hansen Rotary Valving System with Variable Valve timing (HRVS/VVT), capable of throttleless inlet charge control, as an alternative to conventional poppet-valves for use in spark ignited internal combustion engines. The goal of this new technology is to secure benefits in fuel economy, broadened torque band, vibration reduction, and overhaul accessibility. Additionally, use of the variable valve timing capability to vary the effective compression ratio is expected to improve multi-fuel tolerance and efficiency. Efforts directed at the design of HRVS components proved to be far more extensive than had been anticipated, ultimately requiring that proof-trial design/development work be performed. Although both time and funds were exhausted before optical or ion-probe types of in-cylinder investigation could be undertaken, a great deal of laboratory data was acquired during the course of the design/development work. This laboratory data is the basis for the information presented in this Final Report.

  7. Internal combustion engine with rotary valve assembly having variable intake valve timing

    SciTech Connect (OSTI)

    Hansen, C.N.; Cross, P.C.

    1995-12-12

    An internal combustion engine has rotary valves associated with movable shutters operable to vary the closing of intake air/fuel port sections to obtain peak volumetric efficiency over the entire range of speed of the engine. The shutters are moved automatically by a control mechanism that is responsive to the RPM of the engine. A foot-operated lever associated with the control mechanism is also used to move the shutters between their open and closed positions. 21 figs.

  8. Internal combustion engine with rotary valve assembly having variable intake valve timing

    DOE Patents [OSTI]

    Hansen, Craig N. (Eden Prairie, MN); Cross, Paul C. (Shorewood, MN)

    1995-01-01

    An internal combustion engine has rotary valves associated with movable shutters operable to vary the closing of intake air/fuel port sections to obtain peak volumetric efficiency over the entire range of speed of the engine. The shutters are moved automatically by a control mechanism that is responsive to the RPM of the engine. A foot-operated lever associated with the control mechanism is also used to move the shutters between their open and closed positions.

  9. Compact, electro-hydraulic, variable valve actuation system providing...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact,...

  10. Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control

    Broader source: Energy.gov [DOE]

    Discusses development of advanced variable valve actuation system to enable high efficiency combustion highlighting advances to improving system packaging while reducing cost

  11. System for detecting operating errors in a variable valve timing engine using pressure sensors

    DOE Patents [OSTI]

    Wiles, Matthew A.; Marriot, Craig D

    2013-07-02

    A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

  12. Production-Intent Lost-Motion Variable Valve Actuation Systems...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Production-Intent Lost-Motion Variable Valve Actuation Systems Production-Intent Lost-Motion Variable Valve Actuation Systems Variable valve actuation with onoff IEGR pre-bump is...

  13. Variable Valve Actuation for Advanced Mode Diesel Combustion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Valve Actuation for Advanced Mode Diesel Combustion Variable Valve Actuation for Advanced Mode Diesel Combustion Presentation from the U.S. DOE Office of Vehicle Technologies...

  14. Diagnostic for two-mode variable valve activation device

    DOE Patents [OSTI]

    Fedewa, Andrew M

    2014-01-07

    A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

  15. Turbo-generator control with variable valve actuation

    DOE Patents [OSTI]

    Vuk, Carl T. (Denver, IA)

    2011-02-22

    An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

  16. Production-Intent Lost-Motion Variable Valve Actuation Systems

    Broader source: Energy.gov [DOE]

    Variable valve actuation with on/off IEGR pre-bump is an enabling technology for HCCI, PCCI, LTC and other advanced combustion techniques, and designs for production-intent equipment have been developed

  17. Engine having a variable valve actuation system

    DOE Patents [OSTI]

    Hefler, Gregory W. (Chillicothe, IL)

    2004-10-12

    An engine has a cylinder head having a first surface and a second surface spaced from the first surface. A valve is moveably connected to the cylinder head. A rocker arm is connected to the valve, and a rocker shaft having a first location spaced a maximum distance from the cylinder head is connected to the rocker arm. A support member has and an actuator fluid passage network. The actuator fluid passage network defines a volume. The support member is connected to the cylinder head and is positioned such that a majority of the volume of the actuator fluid passage network is between the first location of the rocker shaft and the second surface of the cylinder head.

  18. Engine having a variable valve actuation system

    DOE Patents [OSTI]

    Hefler, Gregory W. (Chillicothe, IL)

    2005-10-12

    An engine has a cylinder head having a first surface and a second surface spaced from the first surface. A valve is moveably connected to the cylinder head. A rocker arm is connected to the valve, and a rocker shaft having a first location spaced a maximum distance from the cylinder head is connected to the rocker arm. A support member has and an actuator fluid passage network. The actuator fluid passage network defines a volume. The support member is connected to the cylinder head and is positioned such that a majority of the volume of the actuator fluid passage network is between the first location of the rocker shaft and the second surface of the cylinder head.

  19. VALVE: Variable Length Value Encoder for Off-Chip Data Buses. Dinesh C. Suresh, Banit Agrawal*

    E-Print Network [OSTI]

    Najjar, Walid A.

    VALVE: Variable Length Value Encoder for Off-Chip Data Buses. Dinesh C. Suresh, Banit Agrawal (VALVE) technique to reduce the power consumption in the off-chip data buses. While past research has proposed scheme is capable of detecting and encoding variable length bit patterns in the data values. VALVE

  20. Estimation and Control of Diesel Engine Processes Utilizing Variable Intake Valve Actuation

    Broader source: Energy.gov [DOE]

    Air handling system model for multi-cylinder variable geometry turbocharged diesel engine with cooled EGR and flexible intake valve actuation developed to capture dynamic effects of gas exchange actuators

  1. Using Real-Time Three-Dimensional Ultrasound to Characterize Mitral Valve Motion

    E-Print Network [OSTI]

    Ayache, Nicholas

    Using Real-Time Three-Dimensional Ultrasound to Characterize Mitral Valve Motion Paul M. Novotnya results aim to fully characterize the four-dimensional (3D + time) movement of the mitral valve for better understanding of its behavior prior to surgical interventions, such as mitral valve repair. A behavior model

  2. SYMBOLS FOR TIME = time variable

    E-Print Network [OSTI]

    Duchowski, Andrew T.

    =forever) Cost spent to build variation point i at time i = index over variation points #12;SYMBOLS FOR TIME to account for net present value of money r = assumed interest rate i = index over variation points Cost Expected cost summed over all relevant time intervals Cost spent to build variation point i at time r

  3. Simulation of a novel electromechanical engine valve drive to quantify performance gains in fuel consumption

    E-Print Network [OSTI]

    Miller, Justin (Justin Lee)

    2011-01-01

    This thesis describes the modeling and simulation of a novel electromechanical valve drive known as the MIT EMV. This valve drive allows an engine to achieve variable valve timing which has been shown to produce improvements ...

  4. Extremum Seeking Control for Soft Landing of an Electromechanical Valve Actuator

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Extremum Seeking Control for Soft Landing of an Electromechanical Valve Actuator Katherine S is the electromechanical valve actuator, recently receiving attention for enabling variable valve timing in internal: Electromagnetic Devices; Nonlinear Control; Extremum Seeking Control. 1 Introduction Electromechanical (EM

  5. Development of Lashless Valve Train Technology | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    this new product. p-16meistrick.pdf More Documents & Publications Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to...

  6. A CUSTOM-DESIG ED LIMITED-A GLE ACTUATOR FOR A ELECTROMECHA ICAL E GI E VALVE DRIVE

    E-Print Network [OSTI]

    Perreault, Dave

    A CUSTOM-DESIG ED LIMITED-A GLE ACTUATOR FOR A ELECTROMECHA ICAL E GI E VALVE DRIVE PART II@alum.mit.edu Keywords: Variable valve timing, electromechanical valve drive, limited-angle actuator, low inertia armature, aluminium conductor. Abstract Research has shown that variable valve timing (VVT) can improve

  7. A CUSTOM-DESIG ED LIMITED-A GLE ACTUATOR FOR A ELECTROMECHA ICAL E GI E VALVE DRIVE

    E-Print Network [OSTI]

    Perreault, Dave

    A CUSTOM-DESIG ED LIMITED-A GLE ACTUATOR FOR A ELECTROMECHA ICAL E GI E VALVE DRIVE PART I: CO@alum.mit.edu Keywords: Variable valve timing, electromechanical valve drive, limited-angle actuator, low inertia armature, aluminium conductor. Abstract Research has shown that variable valve timing (VVT) can improve

  8. 1302. P6.51. Using Real-Time Three-Dimensional Ultrasound To Characterize Mitral Valve Motion , M. LINGURARU

    E-Print Network [OSTI]

    1302. P6.51. Using Real-Time Three-Dimensional Ultrasound To Characterize Mitral Valve Motion P results aim to fully characterize the four-dimensional (3D + time) movement of the mitral valve for better understanding of its behavior prior to surgical interventions, such as mitral valve repair. A behavior model

  9. Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines

    E-Print Network [OSTI]

    Zell, Andreas

    Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines Philippe Komma T¨ubingen, Germany {philippe.komma, andreas.zell}@uni-tuebingen.de system for a diesel engine

  10. Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive

    E-Print Network [OSTI]

    Qiu, Yihui

    A cam-based shear force-actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform this concept into a competitive ...

  11. Depressurization valve

    DOE Patents [OSTI]

    Skoda, G.I.

    1989-03-28

    A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring-preferably of the Belleville variety-acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion.

  12. Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines

    E-Print Network [OSTI]

    Zell, Andreas

    Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines Philippe Komma T¨ubingen, Germany {philippe.komma, andreas.zell}@uni-tuebingen.de system for a diesel engine adapted from cylinder pressure was introduced by Yang [9]. In his work, he adopted a hybrid genetic

  13. Electronic waiting-time distribution of a quantum-dot spin valve

    E-Print Network [OSTI]

    Björn Sothmann

    2014-10-27

    We discuss the electronic waiting-time distribution of a quantum-dot spin valve, i.e. a single-level quantum dot coupled to two ferromagnetic electrodes with magnetizations that can point in arbitrary directions. We demonstrate that the rich transport physics of this setup such as dynamical channel blockade and spin precession in an interaction-driven exchange field shows up in the waiting-time distribution and analyze the conditions necessary to observe the various effects.

  14. MOTION PLANNING CONTROL OF THE AIRPATH OF AN S.I. ENGINE WITH VALVE

    E-Print Network [OSTI]

    Boyer, Edmond

    MOTION PLANNING CONTROL OF THE AIRPATH OF AN S.I. ENGINE WITH VALVE TIMING ACTUATORS T. Leroy , J with Variable Valve Timing actuators (VVT). Compared to standard configurations, the engine does not possess any as a disturbance by impacting on the air mass flow through the inlet valves. This impact can be estimated from real

  15. Depressurization valve

    DOE Patents [OSTI]

    Skoda, George I. (Santa Clara, CA)

    1989-01-01

    A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring--preferably of the Belleville variety--acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion. The latch plate in surrounding the stem is limited in its outward movement by a boss attached to the stem at the end of the stem remote from the disk. The latch plate is held normally closed by three radial latches spaced at 120.degree. around the periphery of the plate.

  16. TimeVariable Photo-Evaporation of

    E-Print Network [OSTI]

    Throop, Henry

    TimeVariable Photo-Evaporation of Protoplanetary Disks Henry Throop (SwRI) John Bally (U. Colorado) #12;Takeaway: Photo-evaporation alters the disk structure in essentially unpredictable ways, because for disks formed at the same time in the same cluster. #12;30 Doradus: 100+ O/B stars Photo

  17. TimeVariable Photo-Evaporation of

    E-Print Network [OSTI]

    Throop, Henry

    TimeVariable Photo-Evaporation of Protoplanetary Disks Henry Throop (PSI) DDA Meeting Mt. Hood clusters. #12;Work we have done involves ... ­ UV photo-evaporation from massive stars ­ Interaction; Moeckel & Throop 2009; Throop & Bally 2010; Pichardo et al 2010; Throop 2011. #12;Photo

  18. EXPERIMENTAL CONTROL OF VARIABLE CAM TIMING ACTUATORS

    E-Print Network [OSTI]

    . This dilution of the mixture in the cylinder re- duces HC and NOx feedgas emissions. Neverthe- less, retarding al., 1998). Table 1 illus- trates the sought after NOx emission reduction when the Variable Cam conditions (1500rpm, 30Nm). NOx pollutant emissions are lowered by retarding the cam timing. ically

  19. Time-resolved photometry of cataclysmic variables

    E-Print Network [OSTI]

    C. Papadaki; H. M. J. Boffin; J. Cuypers; V. Stanishev; Z. Kraicheva; V. Genkov

    2003-12-18

    We present time-resolved photometry of two cataclysmic variables whose CCD photometric observations were obtained with the 1m telescope at the South African Astronomical Observatory in October 2002 and August 2003 and with the 1m telescope at Hoher List in Germany. Concerning MCT 2347-3144 we detect for the first time a period of 6.65h. For V1193 Ori the 3.96 h periodicity has for the first time been confirmed through time-resolved photometry.

  20. Microblower assisted barometric valve

    DOE Patents [OSTI]

    Rossabi, Joseph; Hyde, Warren K.; Riha, Brian D.; Jackson, Dennis G.; Sappington, Frank

    2005-12-06

    A gas exchange apparatus is provided which provides for both passive fluid flow and blower associated fluid flow through a barometric valve. A battery powered blower is provided which allows for operation of the barometric valve during times when the barometric valve would otherwise be closed, and provides for enhanced volume of gas exchange.

  1. Safety valve

    DOE Patents [OSTI]

    Bergman, Ulf C. (Malmoe, SE)

    1984-01-01

    The safety valve contains a resilient gland to be held between a valve seat and a valve member and is secured to the valve member by a sleeve surrounding the end of the valve member adjacent to the valve seat. The sleeve is movable relative to the valve member through a limited axial distance and a gap exists between said valve member and said sleeve.

  2. Mesofluidic two stage digital valve

    DOE Patents [OSTI]

    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. An electromechanical valve drive incorporating a nonlinear mechanical transformer

    E-Print Network [OSTI]

    Chang, Woo Sok, 1964-

    2003-01-01

    In traditional internal combustion engines, a camshaft acts on the valve stems to open and close the valves. Valve timing is fixed relative to piston position. On the other hand, if a valve is flexibly controlled by a ...

  4. ESTIMATED SIL LEVELS AND RISK COMPARISONS FOR RELIEF VALVES AS A FUNCTION OF TIME-IN-SERVICE

    SciTech Connect (OSTI)

    Harris, S.

    2012-03-26

    Risk-based inspection methods enable estimation of the probability of spring-operated relief valves failing on demand at the United States Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. The paper illustrates an approach based on application of the Frechet and Weibull distributions to SRS and Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD) proof test results. The methodology enables the estimation of ANSI/ISA-84.00.01 Safety Integrity Levels (SILs) as well as the potential change in SIL level due to modification of the maintenance schedule. Current SRS practices are reviewed and recommendations are made for extending inspection intervals. The paper compares risk-based inspection with specific SILs as maintenance intervals are adjusted. Groups of valves are identified in which maintenance times can be extended as well as different groups in which an increased safety margin may be needed.

  5. Check valve

    DOE Patents [OSTI]

    Upton, Hubert Allen (Morgan Hill, CA); Garcia, Pablo (Stanford, CA)

    1999-08-24

    A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion.

  6. Check valve

    DOE Patents [OSTI]

    Upton, H.A.; Garcia, P.

    1999-08-24

    A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs.

  7. MOTION PLANNING CONTROL OF THE AIRPATH OF AN S.I. ENGINE WITH VALVE

    E-Print Network [OSTI]

    , France Abstract: We address the control of the airpath of a turbocharged S.I. engine equipped losses, turbochargers are used. For such engines, Variable Valve Timing (VVT) devices are used to improve

  8. Heart Valve Lesson Plan Biomedical Engineering

    E-Print Network [OSTI]

    Provancher, William

    Heart Valve Lesson Plan Biomedical Engineering Objective · Introduce students to biomedical Learning Outcomes · Students will understand the role and function of heart valves. · Students will learn does a heart valve work? · Why do we need to replace heart valves? Time Required (Itemized) · Lecture

  9. Fast acting multiple element valve

    DOE Patents [OSTI]

    Yang, Jefferson Y. S. (Orange, CA); Wada, James M. (Torrance, CA)

    1991-01-01

    A plurality of slide valve elements having plural axial-spaced annular parts and an internal slide are inserted into a bulkhead in a fluid conduit from a downstream side of the bulkhead, locked in place by a bayonet coupling and set screw, and project through the bulkhead into the upstream conduit. Pneumatic lines connecting the slide valve element actuator to pilot valves are brought out the throat of the valve element to the downstream side. Pilot valves are radially spaced around the exterior of the valve to permit the pneumatic lines to be made identical, thereby to minimize adverse timing tolerances in operation due to pressure variations. Ring manifolds surround the valve adjacent respective pilot valve arrangements to further reduce adverse timing tolerances due to pressure variations, the manifolds being directly connected to the respective pilot valves. Position sensors are provided the valve element slides to signal the precise time at which a slide reaches or passes through a particular point in its stroke to initiate a calibrated timing function.

  10. A custom-designed limited-angle actuator for an electromechanical engine valve drive Part I: Conceptual design

    E-Print Network [OSTI]

    Qiu, Yihui

    Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point ...

  11. A custom-designed limited-angle actuator for an electromechanical engine valve drive Part II: Fabrication and evaluation

    E-Print Network [OSTI]

    Kassakian, John G.

    Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point ...

  12. Motion planning for experimental air path control of a variable-valve-timing spark ignition engine

    E-Print Network [OSTI]

    of direct injection and turbocharging. This approach is of particular interest in the context of downsizing

  13. Self-regulating valve

    DOE Patents [OSTI]

    Humphreys, D.A.

    1982-07-20

    A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.

  14. Design of a gas force simulator for the MIT Electromechanical Valve Drive project

    E-Print Network [OSTI]

    Otten, James S. (James Stewart)

    2006-01-01

    The MIT electromechanical Valve Drive (EMVD) is a continuously variable valve actuation device for an automotive internal combustion engine. Current experimentation of the EMVD has been limited to intake valve events. When ...

  15. Design and Experimental Implementation of an Electromagnetic Engine Valve Drive

    E-Print Network [OSTI]

    Parlikar, T.A.

    In conventional internal combustion engines, engine valve displacements are fixed relative to crankshaft position. If these valves were actuated as a variable function of crankshaft angle, significant improvements in fuel ...

  16. Piezoelectric valve

    DOE Patents [OSTI]

    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.

  17. Miniature piezo electric vacuum inlet valve

    DOE Patents [OSTI]

    Keville, R.F.; Dietrich, D.D.

    1998-03-24

    A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability is disclosed. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional 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. 6 figs.

  18. Miniature piezo electric vacuum inlet valve

    DOE Patents [OSTI]

    Keville, Robert F. (Valley Springs, CA); Dietrich, Daniel D. (Livermore, CA)

    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 (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional 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.

  19. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    Dentz, Jordan; Ansanelli, Eric

    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.

  20. Force measuring valve assemblies, systems including such valve assemblies and related methods

    DOE Patents [OSTI]

    DeWall, Kevin George (Pocatello, ID); Garcia, Humberto Enrique (Idaho Falls, ID); McKellar, Michael George (Idaho Falls, ID)

    2012-04-17

    Methods of evaluating a fluid condition may include stroking a valve member and measuring a force acting on the valve member during the stroke. Methods of evaluating a fluid condition may include measuring a force acting on a valve member in the presence of fluid flow over a period of time and evaluating at least one of the frequency of changes in the measured force over the period of time and the magnitude of the changes in the measured force over the period of time to identify the presence of an anomaly in a fluid flow and, optionally, its estimated location. Methods of evaluating a valve condition may include directing a fluid flow through a valve while stroking a valve member, measuring a force acting on the valve member during the stroke, and comparing the measured force to a reference force. Valve assemblies and related systems are also disclosed.

  1. Plasma valve

    DOE Patents [OSTI]

    Hershcovitch, Ady (Mount Sinai, NY); Sharma, Sushil (Hinsdale, IL); Noonan, John (Naperville, IL); Rotela, Elbio (Clarendon Hills, IL); Khounsary, Ali (Hinsdale, IL)

    2003-01-01

    A plasma valve includes a confinement channel and primary anode and cathode disposed therein. An ignition cathode is disposed adjacent the primary cathode. Power supplies are joined to the cathodes and anode for rapidly igniting and maintaining a plasma in the channel for preventing leakage of atmospheric pressure through the channel.

  2. Artificial Heart Valve Design

    E-Print Network [OSTI]

    Provancher, William

    Artificial Heart Valve Design Your Chance to be a Biomedical Engineer #12;Circulatory System Video #12;What is a Heart Valve? · Heart Valve Video #12;#12;What Does a Heart Valve Do? · Maintain the one direction flow of blood through the heart · Heart valves allow blood to flow through in a forward direction

  3. A New Electromagnetic Valve Actuator W. S. Chang

    E-Print Network [OSTI]

    Perreault, Dave

    A New Electromagnetic Valve Actuator W. S. Chang , T. A. Parlikar , M. D. Seeman , D. J. Perreault--In conventional internal combustion (IC) engines, en- gine valve displacements are fixed relative to crankshaft position. If these valves are actuated as a variable function of crankshaft an- gle, significant

  4. Optimal Cam Design and System Control for an Electromechanical Engine Valve Drive

    E-Print Network [OSTI]

    Perreault, Dave

    Optimal Cam Design and System Control for an Electromechanical Engine Valve Drive Yihui Qiu, Member Fellow, IEEE E-mail: qiu@alum.mit.edu Abstract-An electromechanical valve drive system using a cam- based of previous proposals for variable valve actuation (VVA), an electromechanical valve (EMV) system

  5. Neural Network-Based Noise Suppressor and Predictor for Quantifying Valve Stiction in Oscillatory Control Loops 

    E-Print Network [OSTI]

    Annan, Carl Ashie

    2014-12-18

    (fd) friction in a physical valve model. Each simulation generates controller output OP(t) and process variable PV(t) time series data. A feed-forward neural network (the predictor) is trained to model the relationship between a given OP and PV pattern...

  6. Remote actuated valve implant

    DOE Patents [OSTI]

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

    2014-02-25

    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.

  7. Rotary pneumatic valve

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM)

    1991-01-01

    A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle.

  8. Bellows sealed plug valve

    DOE Patents [OSTI]

    Dukas, Jr., Stephen J. (Idaho Falls, ID)

    1990-01-01

    A bellows sealed plug valve includes a valve body having an inlet passage and an outlet passage, a valve chamber between the inlet and outlet passages. A valve plug has substantially the same shape as the valve chamber and is rotatably disposed therein. A shaft is movable linearly in response to a signal from a valve actuator. A bellows is sealingly disposed between the valve chamber and the valve actuator and means are located between the bellows and the valve plug for converting linear movement of the shaft connected to the valve actuator to rotational movement of the plug. Various means are disclosed including helical thread mechanism, clevis mechanism and rack and pinion mechanism, all for converting linear motion to rotational motion.

  9. Vacuum breaker valve assembly

    DOE Patents [OSTI]

    Thompson, J.L.; Upton, H.A.

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

  10. Vacuum breaker valve assembly

    DOE Patents [OSTI]

    Thompson, Jeffrey L. (San Jose, CA); Upton, Hubert Allen (Morgan Hill, CA)

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  11. Scissor thrust valve actuator

    DOE Patents [OSTI]

    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.

  12. Estimation and Control of Diesel Engine Processes Utilizing Variable...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Valve Actuation Air handling system model for multi-cylinder variable geometry turbocharged diesel engine with cooled EGR and flexible intake valve actuation developed to...

  13. Valve for fluid control

    DOE Patents [OSTI]

    Oborny, Michael C. (Albuquerque, NM); Paul, Phillip H. (Livermore, CA); Hencken, Kenneth R. (Pleasanton, CA); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

    2001-01-01

    A valve for controlling fluid flows. This valve, which includes both an actuation device and a valve body provides: the ability to incorporate both the actuation device and valve into a unitary structure that can be placed onto a microchip, the ability to generate higher actuation pressures and thus control higher fluid pressures than conventional microvalves, and a device that draws only microwatts of power. An electrokinetic pump that converts electric potential to hydraulic force is used to operate, or actuate, the valve.

  14. Time variability of AGN and heating of cooling flows

    E-Print Network [OSTI]

    Carlo Nipoti; James Binney

    2005-05-03

    There is increasing evidence that AGN mechanical feedback is important in the energetics of cooling flows in galaxies and galaxy clusters. We investigate the implications of the variability of AGN mechanical luminosity L_m on observations of cooling flows and radio galaxies in general. It is natural to assume that l=ln(L_m/L_x) is a Gaussian process. Then L_m will be log-normally distributed at fixed cooling luminosity L_x, and the variance in a measure of L_m will increase with the time-resolution of the measure. We test the consistency of these predictions with existing data. These tests hinge on the power spectrum of l(t). Monitoring of Seyfert galaxies combined with estimates of the duty cycle of quasars imply flicker noise spectra, similar to those of microquasars. We combine a sample of sources in cooling flows that have cavities with the assumption that the average mechanical luminosity of the AGN equals L_x. Given that the mechanical luminosities are characterized by flicker noise, we find that their spectral amplitudes lie between the estimated amplitudes of quasars and the measured values for the radio luminosities of microquasars. The model together with the observation that powerful radio galaxies lie within a narrow range in optical luminosity, predicts the luminosity function of radio galaxies, in agreement with observations. Forthcoming radio surveys will test the prediction that the luminosity function turns over at about the smallest luminosities so far probed. [Abridged

  15. Ball valve extractor

    DOE Patents [OSTI]

    Herndon, Charles (Walterboro, SC); Brown, Roger A. (North Augusta, SC)

    2002-01-01

    An apparatus and process for removing a ball valve is provided. The ball valve removal tool provides a handle sliding along the length of a shaft. One end of the shaft is secured within an interior cavity of a ball valve while the opposite end of the shaft defines a stop member. By providing a manual sliding force to the handle, the handle impacts the stop member and transmits the force to the ball valve. The direction of the force is along the shaft of the removal tool and disengages the ball valve from the ball valve housing.

  16. Rotary valve shaft

    SciTech Connect (OSTI)

    Lynch, R.M.

    1992-07-07

    This patent describes a rotary valve shaft for use with an internal combustion engine having a combustion chamber port, the rotary valve shaft including at least one gas passage means. It comprises groove on the periphery of the rotary valve shaft and a means for connecting the groove with the port upon rotation of the rotary valve shaft, wherein the connecting means comprising notch adjacent to and leading into the groove.

  17. Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve Timing

    E-Print Network [OSTI]

    Laboratories, School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA bIFP Energies, France Abstract-- Concern over the availability of fossil fuels and energy usage have produced

  18. Managing transient behaviors of a dual mode spark ignition-- controlled auto ignition engine with a variable valve timing system

    E-Print Network [OSTI]

    Santoso, Halim G. (Halim Gustiono), 1975-

    2005-01-01

    Gasoline Homogeneous Charge Compression Ignition (HCCI) engine has the potential of providing better fuel economy and emissions characteristics than current spark ignition engines. One implementation of this technology ...

  19. Airpath Control of a SI Engine with Variable Valve Timing Actuators Thomas Leroy, Jonathan Chauvin and Nicolas Petit

    E-Print Network [OSTI]

    injection and turbocharging. This approach is of particular interest in the context of downsizing (reduction

  20. Engine Valve Actuation For Combustion Enhancement

    DOE Patents [OSTI]

    Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

    2004-05-18

    A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

  1. Engine valve actuation for combustion enhancement

    DOE Patents [OSTI]

    Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

    2008-03-04

    A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

  2. Cycle time variability for a network under two queueing disciplines 

    E-Print Network [OSTI]

    Vasquez Pariente, Marta Irene

    1996-01-01

    A network of three single-server queues is investigated. Performance of two queueing disciplines is compared on the basis of the mean and variance of the network cycle time. The two queueing disciplines are first-in-system first-out (FISFO...

  3. RESEARCH Open Access Longitudinal variability of time-location/activity

    E-Print Network [OSTI]

    Leistikow, Bruce N.

    /weekend), season (warm/cool), sex, employment status, and over the follow-up period. Results: As expected, day- base (CHAD), which houses time-activity data from a large number of studies, are single-day diaries of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits

  4. MODELING AND VALIDATION OF A HIGH SPEED ROTARY PWM ON/OFF VALVE Haink C. Tu

    E-Print Network [OSTI]

    Li, Perry Y.

    MODELING AND VALIDATION OF A HIGH SPEED ROTARY PWM ON/OFF VALVE Haink C. Tu Center for Compact-speed on/off valves are a critical technology for enabling digital control of hydraulic systems via pulse-width- modulation (PWM). High-speed valves, when used in virtually variable displacement pumps (VVDP), increase

  5. Thermostatic Radiator Valve Evaluation

    SciTech Connect (OSTI)

    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. 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).

  6. VARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola

    E-Print Network [OSTI]

    Oregon, University of

    VARIABILITY OF SOLAR RADIATION DATA OVER SHORT TIME INTERVALS Frank Vignola Department of Physics ra- diation. This article examines at the variability of beam and global solar radiation over short solar radiation values with ground-based data. 1. INTRODUCTION It is difficult to evaluate solar

  7. Non-plugging injection valve

    DOE Patents [OSTI]

    Carey, Jr., Henry S. (Wilsonville, AL)

    1985-01-01

    A valve for injecting fluid into a conduit carrying a slurry subject to separation to form deposits capable of plugging openings into the conduit. The valve comprises a valve body that is sealed to the conduit about an aperture formed through the wall of the conduit to receive the fluid to be injected and the valve member of the valve includes a punch portion that extends through the injection aperture to the flow passage, when the valve is closed, to provide a clear channel into the conduit, when the valve is opened, through deposits which might have formed on portions of the valve adjacent the conduit.

  8. Isolation valve selections play important role in pipelining

    SciTech Connect (OSTI)

    Hingoraney, R.; Goto, D.N. [Saudi Aramco, Dhahran (Saudi Arabia)

    1995-08-01

    Isolation valves are an integral part of every pipeline and play an important role in safe and proper operation. For almost every project, pipeline designers wrestle with choosing between the through-conduit gate valves and ball valves and their associated actuating mechanisms. Complicating this selection process are variables such as individual preferences and the lack of broad-based operating experience. As expected, there is no single valve and actuator combination that is correct for every pipeline or every application. Variables which must be considered and specifically evaluated for each valve installation include: operating characteristics, function, location, process fluid, materials options, space availability, maintenance, repair capability, delivery schedule, and costs. This paper reviews these issues.

  9. Single photon continuous variable quantum key distribution based on energy-time uncertainty relation

    E-Print Network [OSTI]

    Bing Qi

    2006-02-20

    In previous quantum key distribution (QKD) protocols, information is encoded on either the discrete-variable of single-photon signal or continuous-variables of multi-photon signal. Here, we propose a new QKD protocol by encoding information on continuous-variables of a single photon. In this protocol, Alice randomly encodes her information on either the central frequency of a narrow-band single photon pulse or the time-delay of a broadband single photon pulse, while Bob randomly chooses to do either frequency measurement or time measurement. The security of this protocol rests on the energy-time uncertainty relation, which prevents Eve from simultaneously determining both frequency and time information with arbitrarily high resolution. In practice, this scheme may be more robust against various channel noises, such as polarization and phase fluctuations.

  10. A New Continuous-Time Scheduling Formulation for Continuous Plants under Variable Electricity Cost

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    usage. If electricity consumption exceeds this threshold, the plant incurs in stiff penalties, whereas1 A New Continuous-Time Scheduling Formulation for Continuous Plants under Variable Electricity the scheduling of continuous plants subject to energy constraints related to time-dependent electricity pricing

  11. Multiscale simulations of the aortic heart valve : applications in disease and surgery

    E-Print Network [OSTI]

    Weinberg, Eli, 1979-

    2008-01-01

    This thesis presents mathematical models describing the mechanical behavior of the human aortic heart valve over a range of length and time scales. In the human heart, the valves perform the vital function of controlling ...

  12. A Computational Model of Aging and Calcification in the Aortic Heart Valve

    E-Print Network [OSTI]

    Mofrad, Mohammad R. K.

    A Computational Model of Aging and Calcification in the Aortic Heart Valve Eli J. Weinberg1 of America Abstract The aortic heart valve undergoes geometric and mechanical changes over time. The cusps of a normal, healthy valve thicken and become less extensible over time. In the disease calcific aortic

  13. A hybrid tissue-engineered heart valve

    E-Print Network [OSTI]

    Alavi, SH; Kheradvar, A

    2015-01-01

    integrity of the engineered valve when sub- jected to theto engineering heart valves holds promise for combining thebility of mechanical valves with the improved biocompat-

  14. Valve for gas centrifuges

    DOE Patents [OSTI]

    Hahs, Charles A. (Oak Ridge, TN); Burbage, Charles H. (Oak Ridge, TN)

    1984-01-01

    The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  15. Sliding pressure control valve for pneumatic hammer drill

    DOE Patents [OSTI]

    Polsky, Yarom (Albuquerque, NM)

    2011-08-30

    A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.

  16. Time Variability-Based Hierarchic Recognition of Multiple Musical Instruments in Recordings

    E-Print Network [OSTI]

    Ras, Zbigniew W.

    Chapter 15 Time Variability-Based Hierarchic Recognition of Multiple Musical Instruments in this chapter is focused on automatic identifica- tion of musical instruments in polyphonic audio recordings pres- ence or absence of a target instrument. Feature set includes parameters describing frame

  17. Variable ecological effects of hurricanes: The importance of seasonal timing for survival

    E-Print Network [OSTI]

    Losos, Jonathan B.

    Variable ecological effects of hurricanes: The importance of seasonal timing for survival University, St. Louis, MO 63130 Contributed by Thomas W. Schoener, October 24, 2003 Two recent hurricanes populations inhabiting exactly the same islands. The hurricanes differed in two ways: one struck during

  18. Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine A. G of min- imizing exhaust emissions, providing increased fuel economy and satisfying driver perfor- mance that provides a tradeo among idle stability, fuel economy, and maximum torque performance. There are also

  19. 47 OTHER INSTRUMENTATION; VALVES; ACTUATORS; MINIATURIZATION...

    Office of Scientific and Technical Information (OSTI)

    characterization of active MEMS valves. Barnard, Casey Anderson 47 OTHER INSTRUMENTATION; VALVES; ACTUATORS; MINIATURIZATION; MICROELECTRONICS; PERFORMANCE TESTING; OPERATION;...

  20. Mechanically balanced tapered plug valve

    DOE Patents [OSTI]

    Anaya, Jose R. (Coacalco, MX)

    1985-01-01

    The invention is a novel hermetic tapered plug valve having a spring-like resilient mechanism for providing axial balance to the plug and thereby prevent valve lock up.

  1. Hydrogen gas relief valve

    DOE Patents [OSTI]

    Whittlesey, Curtis C. (Birmingham, MI)

    1985-01-01

    An improved battery stack design for an electrochemical system having at least one cell from which a gas is generated and an electrolyte in communication with the cell is described. The improved battery stack design features means for defining a substantially closed compartment for containing the battery cells and at least a portion of the electrolyte for the system, and means in association with the compartment means for selectively venting gas from the interior of the compartment means in response to the level of the electrolyte within the compartment means. The venting means includes a relief valve having a float member which is actuated in response to the level of the electrolyte within the compartment means. This float member is adapted to close the relief valve when the level of the electrolyte is above a predetermined level and open the relief valve when the level of electrolyte is below this predetermined level.

  2. Continuous-Variable Quantum Computing in Optical Time-Frequency Modes using Quantum Memories

    E-Print Network [OSTI]

    Peter C. Humphreys; W. Steven Kolthammer; Joshua Nunn; Marco Barbieri; Animesh Datta; Ian A. Walmsley

    2014-11-21

    We develop a scheme for time-frequency encoded continuous-variable cluster-state quantum computing using quantum memories. In particular, we propose a method to produce, manipulate and measure 2D cluster states in a single spatial mode by exploiting the intrinsic time-frequency selectivity of Raman quantum memories. Time-frequency encoding enables the scheme to be extremely compact, requiring a number of memories that is a linear function of only the number of different frequencies in which the computational state is encoded, independent of its temporal duration. We therefore show that quantum memories can be a powerful component for scalable photonic quantum information processing architectures.

  3. Time Scale and Feedback of Zonal-Mean-Flow Variability SEOK-WOO SON* AND SUKYOUNG LEE

    E-Print Network [OSTI]

    Son, Seok-Woo

    Time Scale and Feedback of Zonal-Mean-Flow Variability SEOK-WOO SON* AND SUKYOUNG LEE Department that determine the time scale of zonal-mean-flow variability are examined with an idealized numerical model that has a zonally symmetric lower boundary. In the part of the parameter space where the time-mean zonal

  4. Valve stem and packing assembly

    DOE Patents [OSTI]

    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.

  5. Valve stem and packing assembly

    DOE Patents [OSTI]

    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.

  6. Valve for gas centrifuges

    DOE Patents [OSTI]

    Hahs, C.A.; Rurbage, C.H.

    1982-03-17

    The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

  7. Field test comparison of natural gas engine exhaust valves

    SciTech Connect (OSTI)

    Bicknell, W.B.; Hay, S.C.; Shade, W.N.; Statler, G.R.

    1996-12-31

    As part of a product improvement program, an extensive spark-ignited, turbocharged, natural gas engine exhaust valve test program was conducted using laboratory and field engines. Program objectives were to identify a valve and seat insert combination that increased mean time between overhauls (MTBO) while reducing the risk of premature valve cracking and failure. Following a thorough design review, a large number of valve and seat insert configurations were tested in a popular 900 RPM, 166 BHP (0.123 Mw) per cylinder industrial gas engine series. Material, head geometry, seat angle and other parameters were compared. Careful in-place measurements and post-test inspections compared various configurations and identified optimal exhaust valving for deployment in new units and upgrades of existing engines.

  8. Spin transfer switching in current-perpendicular-to-plane spin valve observed by magneto-optical Kerr effect using visible light

    E-Print Network [OSTI]

    Otani, Yoshichika

    Spin transfer switching in current-perpendicular-to-plane spin valve observed by magneto-perpendicular-to-plane spin-valve device. The device consists of three spin-valve elements, each of which comprises-perpendicular-to- plane CPP spin-valve device has been directly observed by using a time resolved x-ray microscopy7 while

  9. Design, maintenance extend FGD system slurry valve life

    SciTech Connect (OSTI)

    LeMay, B. [St. John`s River Power Park, Jacksonville, FL (United States); Willyard, B. [Grand River Dam Authority, Chouteau, OK (United States); Polasek, S. [Lower Colorado River Authority, Austin, TX (United States); Clarkson, C.W. [Clarkson Co., Sparks, NV (United States)

    1995-08-01

    This article describes how power plants in Florida, Oklahoma and Texas adopted improved maintenance techniques and sought better design criteria to gain greater slurry valve reliability. Slurry valves, a vital part of a flue gas desulfurization (FGD) system, are critical to a power plant`s ability to meet or exceed acid rain emission requirements. The performance and reliability of these valves can significantly affect unit operation and load capacity. For example, slurry valves installed on the suction and discharge ends of scrubber tower pumps are a main point of isolation. When these valves malfunction, the scrubber tower must be shut down. Problems with valves that control the feed system and reaction tank alter slurry pH and density, and also affect unit load. In addition, a single valve that serves dual-pumping systems from the slurry storage tank to the reaction tank can cause a system outage. Because of their key role in system operation, specific maintenance approaches were developed at several power plants to improve slurry valve reliability and run times.

  10. Multi-port valve assembly

    DOE Patents [OSTI]

    Guggenheim, S. Frederic (Teaneck, NJ)

    1986-01-01

    A multi-port fluid valve apparatus is used to control the flow of fluids through a plurality of valves and includes a web, which preferably is a stainless steel endless belt. The belt has an aperture therethrough and is progressed, under motor drive and control, so that its aperture is moved from one valve mechanism to another. Each of the valve mechanisms comprises a pair of valve blocks which are held in fluid-tight relationship against the belt. Each valve block consists of a block having a bore through which the fluid flows, a first seal surrounding the bore and a second seal surrounding the first seal, with the distance between the first and second seals being greater than the size of the belt aperture. In order to open a valve, the motor progresses the belt aperture to where it is aligned with the two bores of a pair of valve blocks, such alignment permitting a flow of the fluid through the valve. The valve is closed by movement of the belt aperture and its replacement, within the pair of valve blocks, by a solid portion of the belt.

  11. Synchronization of time delay systems using variable delay with reset for enhanced security in communication

    E-Print Network [OSTI]

    G. Ambika; R. E. Amritkar

    2010-07-01

    We have introduced a mechanism for synchronizing chaotic systems by one way coupling with a variable delay that is reset at finite intervals. Here we extend this method to time delay systems and suggest a new cryptosystem based on this. We present the stability analysis as applied to time delay systems and supplement this by numerical simulations in a standard time delay system like Mackey Glass system. We extend the theory to multi- delay systems and propose a bi channel scheme for the implementation of the scheme for communication with enhanced security. We show that since the synchronizing channel carries information from transmitter only at intervals of reset time, it is not susceptible to reconstruction. The message channel being separate can be made complex by linear combination of transmitter variable at different delay times using mutiple delay systems. This method has the additional advantage that it can be adjusted to be delay or anticipatory in synchronization and these provide two additional basic keys that are independent of system delay.

  12. Mesoscale variability in time series data: Satellite-based estimates for the U.S. JGOFS Bermuda Atlantic

    E-Print Network [OSTI]

    Mesoscale variability in time series data: Satellite-based estimates for the U.S. JGOFS Bermuda TOPEX/Poseidon­ERS-1/2) are used to characterize, statistically, the mesoscale variability about the U to better understand the contribution of mesoscale eddies to the time series record and the model- data

  13. Emerging Trends in Heart Valve Engineering: Part II. Novel and Standard Technologies for Aortic Valve Replacement

    E-Print Network [OSTI]

    2015-01-01

    et mechanical valves. J. Heart Valve Dis. 11:275–282, 2002.series of st. Jude medical heart valve: in vivo hemodynamicwith narrowed aortic annulus. J. Heart Valve Dis. 6:535–541,

  14. Fast-acting valve and uses thereof

    DOE Patents [OSTI]

    Meyer, J.A.

    1980-05-16

    A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

  15. Rotary multiposition valve

    DOE Patents [OSTI]

    Barclay, J.A.; Dyson, J.E.

    1984-04-06

    The disclosure is directed to a rotary multiposition valve for selectively directing the flow of a fluid through a plurality of paths. The valve comprises an inner member and a hollow housing with a row of ducts on its outer surface. The ducts are in fluid communication with the housing. An engaging section of the inner member is received in the housing. A seal divides the engaging section into a hollow inlet segment and a hollow outlet segment. A plurality of inlet apertures are disposed in the inlet sgegment and a plurality of outlet apertures are disposed in the outlet segment. The inlet apertures are disposed in a longitudinally and radially spaced-apart pattern that can be a helix. The outlet apertures are disposed in a corresponding pattern. As the inner member is rotated, whenever an inlet aperture overlaps one of the ducts, the corresponding outlet aperture overlaps a different duct, thus forming a fluid pathway.

  16. Rotary multiposition valve

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM); Dyson, Jack E. (Los Alamos, NM)

    1985-01-01

    The disclosure is directed to a rotary multiposition valve for selectively directing the flow of a fluid through a plurality of paths. The valve comprises an inner member and a hollow housing with a row of ducts on its outer surface. The ducts are in fluid communication with the housing. An engaging section of the inner member is received in the housing. A seal divides the engaging section into a hollow inlet segment and a hollow outlet segment. A plurality of inlet apertures are disposed in the inlet segment and a plurality of outlet apertures are disposed in the outlet segment. The inlet apertures are disposed in a longitudinally and radially spaced-apart pattern that can be a helix. The outlet apertures are disposed in a corresponding pattern. As the inner member is rotated, whenever an inlet aperture overlaps one of the ducts, the corresponding outlet aperture overlaps a different duct, thus forming a fluid pathway.

  17. CONTROL VALVE TESTING PROCEDURES AND EQUATIONS

    E-Print Network [OSTI]

    Rahmeyer, William J.

    APPENDIX A CONTROL VALVE TESTING PROCEDURES AND EQUATIONS FOR LIQUID FLOWS #12;APPENDIX A CONTROL VALVE TESTING PROCEDURES AND EQUATIONS FOR LIQUID FLOWS 2 Cv Q P Sg net gpm net = / Cv = Q P / Sg 75 is used to relate the pressure loss of a valve to the discharge of the valve at a given valve opening

  18. NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES K. Peterson, J.W. Grizzle, and A, the controller is designed for and implemented on an electromagnetic valve actuator for use in automotive engines on an electromagnetic valve actuator for use in the actuation of automotive engine valves. 2. ELECTROMAGNETIC VALVE

  19. Operational experience using the novel FixCup collecting main valve

    SciTech Connect (OSTI)

    Giertz, J.; Huhn, F. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). Inst. for Cokemaking and Fuel Technology; Spitz, J. [Thyssen Stahl AG, Duisburg (Germany)

    1996-12-31

    On the occasion of the 1995 AIME conference the new PROven (Pressure Regulated Oven) process to control the pressure in coke ovens individually was introduced. This process was made feasible with a new collecting main valve, termed FixCup, with the aid of this valve a variable flow resistance to the raw gas discharge can be realized using a water immersion system. However, just the application of the FixCup system alone--without any pressure regulation--is very advantageous and cost saving. Thyssen has equipped 30 ovens with the new valve. The special constructive features as well as the operational experience using the FixCup valve are treated.

  20. Models of the Time Variability of BHC: Light Curves, PSD, Lags

    E-Print Network [OSTI]

    Demosthenes Kazanas

    2000-01-13

    We present a model for the aperiodic variablity of accreting Black Hole Candidates (BHC) along with model light curves. According to the model this variability is the combined outcome of random (Poisson) injection of soft photons near the center of an extended {\\sl inhomogeneous} distribution of hot electrons (similar to those advocated by the ADAF or ADIOS flows) and the stochastic nature of Compton scattering which converts these soft photons into the observed high energy radiation. Thus, the timing properties (PSD, lags, coherence) of the BHC light curves reflect, to a large extent, the properties of the scattering medium (which in this approximation acts as a combination of a {\\sl linear} amplifier/filter) and they can be used to probe its structure, most notably the density profile of the scattering medium. The model accounts well for the observed PSDs and lags and also the reduction in the RMS variability and the increase in the characteristic PSD frequencies with increasing source luminosity. The electron density profiles obtained to date are consistent mainly with those of ADIOS but also with pure ADAF flows.

  1. Streamline coal slurry letdown valve

    DOE Patents [OSTI]

    Platt, R.J.; Shadbolt, E.A.

    1983-11-08

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

  2. Semi-active compressor valve

    DOE Patents [OSTI]

    Brun, Klaus (Helotes, TX); Gernentz, Ryan S. (San Antonio, TX)

    2010-07-27

    A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

  3. EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING

    SciTech Connect (OSTI)

    Harris, S.; Gross, R.; Mitchell, E.

    2011-01-18

    The Savannah River Site (SRS) spring operated pressure relief valve (SORV) maintenance intervals were evaluated using an approach provided by the American Petroleum Institute (API RP 581) for risk-based inspection technology (RBI). In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo Simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating provided by SRS SORV proof testing experience. Initial Weibull parameter estimates were updated as per SRS's historical proof test records contained in the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The API RP 581 methodology was used to estimate the SORV's probability of failing on demand (PFD), and the annual expected risk. The API RP 581 methodology indicates that the current SRS maintenance plan is conservative. Cost savings may be attained in certain mild service applications that present low PFD and overall risk. Current practices are reviewed and recommendations are made for extending inspection intervals. The paper gives an illustration of the inspection costs versus the associated risks by using API RP 581 Risk Based Inspection (RBI) Technology. A cost effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.

  4. Whitey Gauge and Root Valves (VPS)

    SciTech Connect (OSTI)

    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.

  5. Whitey Gauge and Root Valves (VPS)

    SciTech Connect (OSTI)

    MISKA, C.

    2000-10-17

    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.

  6. Low energy high pressure miniature screw valve

    DOE Patents [OSTI]

    Fischer, Gary J. (Sandia Park, NM); Spletzer, Barry L. (Albuquerque, NM)

    2006-12-12

    A low energy high pressure screw valve having a valve body having an upper portion and a lower portion, said lower portion of said valve body defining an inlet flow passage and an outlet flow passage traversing said valve body to a valve seat, said upper portion of said valve body defining a cavity at said valve seat, a diaphragm restricting flow between said upper portion of said valve body and said lower portion, said diaphragm capable of engaging said valve seat to restrict fluid communication between said inlet passage and said outlet passage, a plunger within said cavity supporting said diaphragm, said plunger being capable of engaging said diaphragm with said valve seat at said inlet and outlet fluid passages, said plunger being in point contact with a drive screw having threads engaged with opposing threads within said upper portion of said valve body such engagement allowing motion of said drive screw within said valve body.

  7. A FAST OPENING TOROIDAL GAS VALVE

    E-Print Network [OSTI]

    Myers, B.R.

    2012-01-01

    FIGURE 1. Artists sketch of valve illustrating the dynamicsCross sectional view of valve. FIGURE 3. Oscilloscope recordcm (b) Gauge 5.0 em from valve Top trace; gauge, 0.5 volts/

  8. Serial siphon valving for centrifugal microfluidic platforms

    E-Print Network [OSTI]

    2010-01-01

    0523-5 RESEARCH PAPER Serial siphon valving for centrifugalshown, a novel serial siphon valve is introduced thatrelies on mul- tiple, inline siphons to provide for a better

  9. A hybrid tissue-engineered heart valve

    E-Print Network [OSTI]

    Alavi, SH; Kheradvar, A

    2015-01-01

    to the high pressure in the heart, particularly in the leftThis approach to engineering heart valves holds promise forhemodynamics of bioprosthetic heart valves. NEW TECHNOLOGY

  10. Running time variability and resource allocation : a data-driven analysis of high-frequency bus operations

    E-Print Network [OSTI]

    Sánchez-Martínez, Gabriel Eduardo

    2013-01-01

    Running time variability is one of the most important factors determining service quality and operating cost of high-frequency bus transit. This research aims to improve performance analysis tools currently used in the bus ...

  11. Utility Accrual Real-Time Scheduling Under Variable Cost Functions Haisang Wu Umut Balli Binoy Ravindran E. Douglas Jensen

    E-Print Network [OSTI]

    Ravindran, Binoy

    Utility Accrual Real-Time Scheduling Under Variable Cost Functions Haisang Wu Umut Balli Binoy,binoy}@vt.edu The MITRE Corporation Bedford, MA 01730, USA jensen@mitre.org Abstract We present a utility accrual real application activities that are subject to time/utility function time constraints, VCFs, and the multi

  12. Software Enabled Virtually Variable Displacement Pumps -Theoretical and Experimental Studies

    E-Print Network [OSTI]

    Li, Perry Y.

    Software Enabled Virtually Variable Displacement Pumps - Theoretical and Experimental Studies the functional equivalent of a variable displacement pump. This approach combines a fixed displacement pump valve control, without many of the shortcomings of commercially available variable displacement pumps

  13. FLUID-STRUCTURE INTERACTION MODELS OF THE MITRAL VALVE: FUNCTION IN NORMAL AND PATHOLOGIC STATES

    SciTech Connect (OSTI)

    Kunzelman, K. S.; Einstein, Daniel R.; Cochran, R. P.

    2007-08-29

    Successful mitral valve repair is dependent upon a full understanding of normal and abnormal mitral valve anatomy and function. Computational analysis is one such method that can be applied to simulate mitral valve function in order to analyze the roles of individual components, and evaluate proposed surgical repair. We developed the first three-dimensional, finite element (FE) computer model of the mitral valve including leaflets and chordae tendineae, however, one critical aspect that has been missing until the last few years was the evaluation of fluid flow, as coupled to the function of the mitral valve structure. We present here our latest results for normal function and specific pathologic changes using a fluid-structure interaction (FSI) model. Normal valve function was first assessed, followed by pathologic material changes in collagen fiber volume fraction, fiber stiffness, fiber splay, and isotropic stiffness. Leaflet and chordal stress and strain, and papillary muscle force was determined. In addition, transmitral flow, time to leaflet closure, and heart valve sound were assessed. Model predictions in the normal state agreed well with a wide range of available in-vivo and in-vitro data. Further, pathologic material changes that preserved the anisotropy of the valve leaflets were found to preserve valve function. By contrast, material changes that altered the anisotropy of the valve were found to profoundly alter valve function. The addition of blood flow and an experimentally driven microstructural description of mitral tissue represent significant advances in computational studies of the mitral valve, which allow further insight to be gained. This work is another building block in the foundation of a computational framework to aid in the refinement and development of a truly noninvasive diagnostic evaluation of the mitral valve. Ultimately, it represents the basis for simulation of surgical repair of pathologic valves in a clinical and educational setting.

  14. Development of a time-variable nuclear pulser for half life measurements

    SciTech Connect (OSTI)

    Zahn, Guilherme S.; Domienikan, Claudio; Carvalhaes, Roberto P. M.; Genezini, Frederico A. [Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP. P.O. Box 11049, Sao Paulo, 05422-970 (Brazil)

    2013-05-06

    In this work a time-variable pulser system with an exponentially-decaying pulse frequency is presented, which was developed using the low-cost, open-source Arduino microcontroler plataform. In this system, the microcontroller produces a TTL signal in the selected rate and a pulse shaper board adjusts it to be entered in an amplifier as a conventional pulser signal; both the decay constant and the initial pulse rate can be adjusted using a user-friendly control software, and the pulse amplitude can be adjusted using a potentiometer in the pulse shaper board. The pulser was tested using several combinations of initial pulse rate and decay constant, and the results show that the system is stable and reliable, and is suitable to be used in half-life measurements.

  15. The Oklo Natural Reactor and the Time Variability of the Fundamental Constants of Nature

    SciTech Connect (OSTI)

    Lamoreaux, Steve (LANL) [LANL

    2005-11-07

    Natural nuclear reactors? Changes in the speed of light? If either of these concepts seem implausible to you now they certainly won't once Dr. Steve Lamoreaux (LANL) delivers his SLAC Colloquium lecture in the Panofsky Auditorium on November 7th at 4:15 pm entitled The Oklo Natural Reactor and the Time Variability of the Fundamental Constants of Nature. This lecture is a rare opportunity to learn not only about Oklo's incredible natural nuclear reactors but also to gain understanding about how the present-day study of these sites may alter our understanding of fundamental constants such as the speed of light. This event is a must-see for the curious!

  16. A Black Hole Mass-Variability Time Scale Correlation at Submillimeter Wavelengths

    E-Print Network [OSTI]

    Bower, Geoffrey C; Markoff, Sera; Gurwell, Mark A; Rao, Ramprasad; McHardy, Ian

    2015-01-01

    We analyze the light curves of 413 radio sources at submillimeter wavelengths using data from the Submillimeter Array calibrator database. The database includes more than 20,000 observations at 1.3 and 0.8 mm that span 13 years. We model the light curves as a damped random walk and determine a characteristic time scale $\\tau$ at which the variability amplitude saturates. For the vast majority of sources, primarily blazars and BL Lac objects, we find only lower limits on $\\tau$. For two nearby low luminosity active galactic nuclei, M81 and M87, however, we measure $\\tau=1.6^{+3.0}_{-0.9}$ days and $\\tau=45^{+61}_{-24}$ days, respectively ($2\\sigma$ errors). Including the previously measured $\\tau=0.33\\pm 0.16$ days for Sgr A*, we show an approximately linear correlation between $\\tau$ and black hole mass for these nearby LLAGN. Other LLAGN with spectra that peak in the submm are expected to follow this correlation. These characteristic time scales are comparable to the minimum time scale for emission processes...

  17. Annular flow control safety valve

    SciTech Connect (OSTI)

    Black, P.W.; Pringle, R.E.

    1981-06-16

    A tubular housing having an inner tubular member forms an inner passageway inside of the inner member and an outer passageway between the inner member and the housing. The housing has valve openings leading from the outer passageway to the exterior of the housing and a tubular valve closure member telescopically moves on the interior of the housing. First means move the valve closure member in an upper direction for closing the openings and at least one actuating piston is telescopically movable within and has its longitudinal axis in the wall of the housing and engages the valve closure member. The piston is in communication with a hydraulic passageway adapted to extend to the well surface for actuating the closure member in a direction to open the valve openings. The closure member is positioned whereby upward flow through the outer passageway acts on the closure member to close the valve opening. At least one lockout piston telescopically moves within the housing and is actuated from the surface and is engageable with holding means in the housing for providing a hydraulic lockout for the valve. Shear means may be provided between the lockout piston and the housing for controlling the hydraulic lockout. A single seal is provided between the closure member and the housing and is positioned below the opening and exposed to the pressure on both sides when the valve is opened. Preferably the actuating pistons are connected to the valve closure member but the hydraulic lockout pistons engage but are unconnected to the valve closure member.

  18. Time-variability of NO{sub x} emissions from Portland cement kilns

    SciTech Connect (OSTI)

    Walters, L.J. Jr.; May, M.S. III [PSM International, Dallas, TX (United States)] [PSM International, Dallas, TX (United States); Johnson, D.E. [Kansas State Univ., Manhattan, KS (United States). Dept. of Statistics] [Kansas State Univ., Manhattan, KS (United States). Dept. of Statistics; MacMann, R.S. [Penta Engineering, St. Louis, MO (United States)] [Penta Engineering, St. Louis, MO (United States); Woodward, W.A. [Southern Methodist Univ., Dallas, TX (United States). Dept. of Statistics] [Southern Methodist Univ., Dallas, TX (United States). Dept. of Statistics

    1999-03-01

    Due to the presence of autocorrelation between sequentially measured nitrogen oxide (NO{sub x}) concentrations in stack gas from portland cement kilns, the determination of the average emission rates and the uncertainty of the average has been improperly calculated by the industry and regulatory agencies. Documentation of permit compliance, establishment of permit levels, and the development and testing of control techniques for reducing NO{sub x} emissions at specific cement plants requires accurate and precise statistical estimates of parameters such as means, standard deviations, and variances. Usual statistical formulas such as for the variance of the sample mean only apply if sequential measurements of NO{sub x} emissions are independent. Significant autocorrelation of NO{sub x} emission measurements revealed that NO{sub x} concentration values measured by continuous emission monitors are not independent but can be represented by an autoregressive, moving average time series. Three orders of time-variability of NO{sub x} emission rates were determined from examination of continuous emission measurements from several cement kilns.

  19. Using the Oxygen Plasma Machine 1. Turn on the O2 (g) valve on the wall.

    E-Print Network [OSTI]

    Using the Oxygen Plasma Machine 1. Turn on the O2 (g) valve on the wall. 2. Turn on the O2 inlet valve on the front of the machine just a tiny-bit ­ O2 should now be leaking through the black, chamber-right of the machine), just the Red Power Switch. 6. Turn off the O2 valve on the chamber door. At the same time, turn

  20. SCHE Helium bottles and associated isolation valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-06-21

    These gas bottles and associated valves provide the safety grade helium source for emergency MCO purge.

  1. Heart valve tissue engineering Frank Baaijens

    E-Print Network [OSTI]

    Stavroulakis, Georgios E.

    Heart valve tissue engineering Frank Baaijens Department of Biomedical Engineering Eindhoven University of Technology Netherlands Tissue engineered heart valves appear promising as autologous valvular functionality and durability of the heart valve relies on the strength and anisotropic properties of the valve

  2. NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES K. Peterson, J.W. Grizzle, and A, the controller is designed for and implemented on an electromagnetic valve actuator for use in automotive engines on an elec- tromagnetic valve actuator, designed for use in the actuation of automotive engine valves. 2

  3. Fig. 1. Comparison of search times on original logistics problems. Fig 2. Number of variables in logistics formulas after simplification.

    E-Print Network [OSTI]

    Kautz, Henry

    Fig. 1. Comparison of search times on original logistics problems. Fig 2. Number of variables in logistics formulas after simplification. Fig. 3. Number of clauses in logistics formulas after number of clauses log.a log.b log.c #12; Fig. 4: Solution times for walksat on logistics with different

  4. Fluid relief and check valve

    DOE Patents [OSTI]

    Blaedel, K.L.; Lord, S.C.; Murray, I.

    1986-07-17

    A passive fluid pressure relief and check valve allows the relief pressure to be slaved to a reference pressure independently of the exhaust pressure. The pressure relief valve is embodied by a submerged vent line in a sealing fluid, the relief pressure being a function of the submerged depth. A check valve is embodied by a vertical column of fluid (the maximum back pressure being a function of the height of the column of fluid). The pressure is vented into an exhaust system which keeps the exhaust out of the area providing the reference pressure.

  5. Multi-port valve

    DOE Patents [OSTI]

    Lewin, Keith F. (Calverton, NY)

    1997-04-15

    A multi-port valve for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO.sub.2) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets therethrough disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending therethrough disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind.

  6. Multi-port valve

    DOE Patents [OSTI]

    Lewin, K.F.

    1997-04-15

    A multi-port valve is described for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO{sub 2}) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets there through disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending there through disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind. 7 figs.

  7. Allocation of inventory to a variable, time-phased, on-line storage system under known demand 

    E-Print Network [OSTI]

    White, Charles Wesley

    1968-01-01

    ALLOCATION OF INVENTORY TO A VARIABLE, TIME-PHASED, ON-LINE STORAGE SYSTEM UNDER KNOWN DEMAND A Thesis By CHARLES WESLEY WHITE Submitted to the Graduate College of the Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE January, 1968 Major Subject: Industrial Engineering ALLOCATION OF INVENTORY TO A VARIABLE ~ T IME PHASED ~ ON L INE STORAGE SYSTEM UNDER KNOWN DEMAND A Thesis By CHARLES WESLEY WHITE Approved as to style...

  8. Replacement of outboard main steam isolation valves in a boiling water reactor plant

    SciTech Connect (OSTI)

    Schlereth, J.R.; Pennington, D.

    1996-12-01

    Most Boiling Water Reactor plants utilize wye pattern globe valves for main steam isolation valves for both inboard and outboard isolation. These valves have required a high degree of maintenance attention in order to pass the plant local leakage rate testing (LLRT) requirements at each outage. Northern States Power made a decision in 1993 to replace the outboard valves at it`s Monticello plant with double disc gate valves. The replacement of the outboard valves was completed during the fall outage in 1994. During the spring outage in April of 1996 the first LLRT testing was performed with excellent results. This presentation will address the decision process, time requirements and planning necessary to accomplish the task as well as the performance results and cost effectiveness of replacing these components.

  9. Emerging Trends in Heart Valve Engineering: Part III. Novel Technologies for Mitral Valve Repair and Replacement

    E-Print Network [OSTI]

    2015-01-01

    and J. D. Puskas. Mitral-valve repair versus replacement forbioprosthetic heart valves. Ann. Thorac. Surg. 71:S417–mechanics of arti?cial heart valves. Clin. Exp. Pharmacol.

  10. Emerging Trends in Heart Valve Engineering: Part II. Novel and Standard Technologies for Aortic Valve Replacement

    E-Print Network [OSTI]

    2015-01-01

    toronto stentless porcine valve. Ann. Thorac. Surg. 78:2076–medical mechanical cardiac valve prosthesis. Ann. Thorac.or surgical aortic-valve replacement. New Engl. J. Med. 366:

  11. Influence of Mean State on Climate Variability at Interannual and Decadal Time Scales 

    E-Print Network [OSTI]

    Zhu, Xiaojie

    2013-05-17

    for many phenomena associated with variables that are nonlinear by definition, such as the vertical wind shear and surface wind speed. In the first part of this dissertation, the influence of mean flow and anomalous flow on vertical wind shear variability...

  12. Emerging Trends in Heart Valve Engineering: Part II. Novel and Standard Technologies for Aortic Valve Replacement

    E-Print Network [OSTI]

    2015-01-01

    et mechanical heart valves during the leakage phase. Ann.leakage ?ow in the hinge of a st. Jude medical((r)) regent mechanical heart valve.

  13. Noninvasive valve monitor using alternating electromagnetic field

    DOE Patents [OSTI]

    Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.

    1993-03-16

    One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

  14. Noninvasive valve monitor using alternating electromagnetic field

    DOE Patents [OSTI]

    Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

    1993-01-01

    One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

  15. Real-time variable rate Pix® application system using a plant height sensor 

    E-Print Network [OSTI]

    Beck, Andy Dwayne

    2001-01-01

    . A cotton growth regulator (Pix) was applied at uniform and biomass-based variable rates in a replicated study that included two cotton fields. Plant mapping data was collected during the season. Plant heights were significantly shorter in areas...

  16. Valve system incorporating single failure protection logic

    DOE Patents [OSTI]

    Ryan, Rodger (San Jose, CA); Timmerman, Walter J. H. (Saratoga, CA)

    1980-01-01

    A valve system incorporating single failure protective logic. The system consists of a valve combination or composite valve which allows actuation or de-actuation of a device such as a hydraulic cylinder or other mechanism, integral with or separate from the valve assembly, by means of three independent input signals combined in a function commonly known as two-out-of-three logic. Using the input signals as independent and redundant actuation/de-actuation signals, a single signal failure, or failure of the corresponding valve or valve set, will neither prevent the desired action, nor cause the undesired action of the mechanism.

  17. Abstract--Time-frequency analysis of heart rate variability (HRV) makes it easier to evaluate how the balance

    E-Print Network [OSTI]

    Carvalho, João Luiz

    Abstract--Time-frequency analysis of heart rate variability (HRV) makes it easier to evaluate how-regressive model can be used to calculate the Power Spectrum Density of HRV and to create an auto of optimal orders for different interpolation rates of the HRV signal are presented. Keywords--AR model order

  18. Performance Improvement of Proportional Directional Control Valves: Methods and Experiments

    E-Print Network [OSTI]

    Yao, Bin

    Performance Improvement of Proportional Directional Control Valves: Methods and Experiments Fanping slow valves (e.g. proportional directional control valves). To im- prove the performance of proportional directional control valves, three different types of controllers are synthesized. Firstly, based

  19. Rotary valve internal combustion engine

    SciTech Connect (OSTI)

    Bunk, P.H.

    1989-03-28

    A rotary valve internal combustion engine is described, comprising: an engine block; at least one cylinder in the engine block; at least one cylinder having a top end; cylinder head means located adjacent the top end of at least one cylinder, the cylinder head means having a cylindrically shaped cavity therein, the cylindrically shaped cavity being oriented in perpendicular relation to at least one cylinder; a piston sealingly mounted in at least one cylinder for reciprocable movement therein, the reciprocable movement including an intake stroke and an exhaust stroke; engine shaft means rotatably mounted to the engine block; means within the engine block for converting the reciprocable movement of the piston into rotary motion of the engine shaft means; a cylinder port located at the top end of at least one cylinder; a rotary valve rotatably mounted in the cylindrically shaped cavity; means connected with the engine shaft means for rotating the rotary valve in a predetermined synchronization with the reciprocable movement of the piston; aspiration means in the rotary valve for selectively aspirating at least one cylinder during the intake an exhaust strokes; and a spark plug removably mounted within the rotary valve and rotatable therewith.

  20. American Valve: Order (2010-CW-1411)

    Broader source: Energy.gov [DOE]

    DOE ordered American Valve, Inc. to pay a $5,000 civil penalty after finding American Valve had failed to certify that certain showerhead models comply with the applicable water conservation standards.

  1. Serial siphon valving for centrifugal microfluidic platforms

    E-Print Network [OSTI]

    2010-01-01

    2006). 1.1 Valving on centrifugal micro?uidic platforms AsSerial siphon valving for centrifugal micro?uidic platformsThe advantages offered by centrifugal micro?uidic platforms

  2. Active combustion flow modulation valve

    DOE Patents [OSTI]

    Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

    2013-09-24

    A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

  3. Lockout housing and sleeve for safety valve

    SciTech Connect (OSTI)

    Dickson, R.L.; Davis, G.R.

    1992-07-07

    This patent describes apparatus for use in a subsurface valve. It comprises a lockout housing; and a lockout sleeve.

  4. The use of MAVIS II to integrate the modeling and analysis of explosive valve interactions

    SciTech Connect (OSTI)

    Ng, R.; Kwon, D.M.

    1998-12-31

    The MAVIS II computer program provides for the modeling and analysis of explosive valve interactions. This report describes the individual components of the program and how MAVIS II is used with other available tools to integrate the design and understanding of explosive valves. The rationale and model used for each valve interaction is described. Comparisons of the calculated results with available data have demonstrated the feasibility and accuracy of using MAVIS II for analytical studies of explosive valve interactions. The model used for the explosive or pyrotechnic used as the driving force in explosive valves is the most critical to be understood and modeled. MAVIS II is an advanced version that incorporates a plastic, as well as elastic, modeling of the deformations experienced when plungers are forced into a bore. The inclusion of a plastic model has greatly expanded the use of MAVIS for all categories (opening, closure, or combined) of valves, especially for the closure valves in which the sealing operation requires the plastic deformation of either a plunger or bore over a relatively large area. In order to increase its effectiveness, the use of MAVIS II should be integrated with the results from available experimental hardware. Test hardware such as the Velocity Interferometer System for Any Reflector (VISAR) and Velocity Generator test provide experimental data for accurate comparison of the actual valve functions. Variable Explosive Chamber (VEC) and Constant Explosive Volume (CEV) tests are used to provide the proper explosive equation-of-state for the MAVIS calculations of the explosive driving forces. The rationale and logistics of this integration is demonstrated through an example. A recent valve design is used to demonstrate how MAVIS II can be integrated with experimental tools to provide an understanding of the interactions in this valve.

  5. Separation of variables and exact solution of the Dirac equation in some cosmological space-times

    SciTech Connect (OSTI)

    Villalba, Victor M. [Centro de Fisica, IVIC, Apdo 21827 Caracas 1020A (Venezuela)

    2006-06-19

    We apply the algebraic method of separation of variables in order to reduce the Dirac equation to a set of coupled first-order ordinary differential equations. We obtain the sufficient conditions for partial or complete separability corresponding to homogeneous cosmological backgrounds.

  6. Whitey SCHE Gauge and Root Valves

    SciTech Connect (OSTI)

    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.

  7. Whitey SCHE Gauge and Root Valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-06-21

    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.

  8. Whitey SCHE Gauge and Root Valves

    SciTech Connect (OSTI)

    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.

  9. Automated Purge Valve Joseph Edward Farrell, III.

    E-Print Network [OSTI]

    Wood, Stephen L.

    Automated Purge Valve by Joseph Edward Farrell, III. Bachelor of Science Marine Engineering the undersigned committee hereby approve the attached thesis Automated Purge Valve by Joseph Edward Farrell, III.D. Department Head Department of Marine and Environmental Systems #12;iii Abstract Title: Automated Purge Valve

  10. STATE OF CALIFORNIA VALVE LEAKAGE TEST

    E-Print Network [OSTI]

    STATE OF CALIFORNIA VALVE LEAKAGE TEST CEC-MECH-8A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-8A NA7.5.7 Valve Leakage Test (Page 1 of 3) Project Name/Address: System Name VALVE LEAKAGE TEST CEC-MECH-8A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE

  11. Valve for fuel pin loading system

    DOE Patents [OSTI]

    Christiansen, D.W.

    1984-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  12. Valve for fuel pin loading system

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA)

    1985-01-01

    A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

  13. Generation and Eight-port Homodyne Characterization of Time-bin Qubits for Continuous-variable Quantum Information Processing

    E-Print Network [OSTI]

    Shuntaro Takeda; Takahiro Mizuta; Maria Fuwa; Jun-ichi Yoshikawa; Hidehiro Yonezawa; Akira Furusawa

    2013-02-05

    We experimentally generate arbitrary time-bin qubits using continuous-wave light. The advantage unique to our qubit is its compatibility with deterministic continuous-variable quantum information processing. This compatibility comes from its optical coherence with continuous waves, well-defined spatio-temporal mode, and frequency spectrum within the operational bandwidth of the current continuous-variable technology. We also demonstrate an efficient scheme to characterize time-bin qubits via eight-port homodyne measurement. This enables the complete characterization of the qubits as two-mode states, as well as a flexible analysis equivalent to the conventional scheme based on a Mach-Zehnder interferometer and photon-detection.

  14. Strategy for reducing the length and variability of aircraft lead time

    E-Print Network [OSTI]

    Bielat, Brendon (Brendon Michael)

    2010-01-01

    Helicopter manufacturers typically build each aircraft to order, and the lead time for make or buy parts and assemblies can be several months or more. The manufacturers generally have a backlog of orders at any given time, ...

  15. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  16. Variable Camshaft Timing Engine Control A. G. Stefanopoulou, J. S. Freudenberg, J. W. Grizzle

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Abstract| Retarding camshaft timing in an engine equipped with a dual equal camshaft timing phaser reduces this positive e ect to feedgas emissions, camshaft timing can cause large air-to-fuel ratio excursions if not coordinated with the fuel command. Large air-to-fuel ratio excursions can reduce the catalytic converter e

  17. Variable Camshaft Timing Engine Control A. G. Stefanopoulou, J. S. Freudenberg, J. W. Grizzle

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    Abstract| Retarding camshaft timing in an engine equipped with a dual equal camshaft timing phaser reduces e ect to feedgas emissions, camshaft timing can cause large air-to-fuel ratio excursions if not coordinated with the fuel command. Large air-to-fuel ratio excursions can reduce the catalytic converter e

  18. Gasoline-like Fuel Effects on High-load, Boosted HCCI Combustion Employing Negative Valve Overlap Strategy

    SciTech Connect (OSTI)

    Kalaskar, Vickey B; Szybist, James P; Splitter, Derek A

    2014-01-01

    In recent years a number of studies have demonstrated that boosted operation combined with external EGR is a path forward for expanding the high load limit of homogeneous charge compression ignition (HCCI) operation with the negative valve overlap (NVO) valve strategy. However, the effects of fuel composition with this strategy have not been fully explored. In this study boosted HCCI combustion is investigated in a single-cylinder research engine equipped with direct injection (DI) fueling, cooled external exhaust gas recirculation (EGR), laboratory pressurized intake air, and a fully-variable hydraulic valve actuation (HVA) valve train. Three fuels with significant compositional differences are investigated: regular grade gasoline (RON = 90.2), 30% ethanol-gasoline blend (E30, RON = 100.3), and 24% iso-butanol-gasoline blend (IB24, RON = 96.6). Results include engine loads from 350 to 800 kPa IMEPg for all fuels at three engine speeds 1600, 2000, and 2500 rpm. All operating conditions achieved thermal efficiency (gross indicated efficiency) between 38 and 47%, low NOX emissions ( 0.1 g/kWh), and high combustion efficiency ( 96.5%). Detailed sweeps of intake manifold pressure (atmospheric to 250 kPaa), EGR (0 25% EGR), and injection timing are conducted to identify fuel-specific effects. The major finding of this study is that while significant fuel compositional differences exist, in boosted HCCI operation only minor changes in operational conditions are required to achieve comparable operation for all fuels. In boosted HCCI operation all fuels were able to achieve matched load-speed operation, whereas in conventional SI operation the fuel-specific knock differences resulted in significant differences in the operable load-speed space. Although all fuels were operable in boosted HCCI, the respective air handling requirements are also discussed, including an analysis of the demanded turbocharger efficiency.

  19. Hydraulically actuated fuel injector including a pilot operated spool valve assembly and hydraulic system using same

    DOE Patents [OSTI]

    Shafer, Scott F. (Morton, IL)

    2002-01-01

    The present invention relates to hydraulic systems including hydraulically actuated fuel injectors that have a pilot operated spool valve assembly. One class of hydraulically actuated fuel injectors includes a solenoid driven pilot valve that controls the initiation of the injection event. However, during cold start conditions, hydraulic fluid, typically engine lubricating oil, is particularly viscous and is often difficult to displace through the relatively small drain path that is defined past the pilot valve member. Because the spool valve typically responds slower than expected during cold start due to the difficulty in displacing the relatively viscous oil, accurate start of injection timing can be difficult to achieve. There also exists a greater difficulty in reaching the higher end of the cold operating speed range. Therefore, the present invention utilizes a fluid evacuation valve to aid in displacement of the relatively viscous oil during cold start conditions.

  20. Solar energy operated irrigation surge valve

    SciTech Connect (OSTI)

    Spain, R. L.

    1985-08-20

    A valve body is provided having axially spaced annular valve seats defining fluid outlets for the body. The body includes an inlet opening into the interior thereof between the seats and a disc valve is supported within the body for axial shifting between the seats. A drive mechanism for the valve disc is drivingly connected thereto and is operative to slowly shift the valve disc from one seat toward engagement with the other seat. The drive mechanism includes a reversible electric motor, a timer, a storage battery and a solar panel for recharging the storage battery. The timer alternately operates the motor in opposite directions whereby the valve disc is shifted back and forth between seated engagement with the axially spaced valve seats.

  1. Design and Analysis of Robust Variability-Aware SRAM to Predict Optimum Access-Time to Achieve Yield Enhancement in Future Nano-Scaled CMOS.

    E-Print Network [OSTI]

    Samandari-Rad, Jeren

    2012-01-01

    Mean and standard deviation of Ideal Access-Time (ACI) forMean and standard deviation of Ideal Access-Time (ACI) forof the standard deviation, and therefore variability, of ACI

  2. A study of the effect of nonrandom sampling on the estimation of exposure variability using exposure-time series from the OSHA IMIS health inspection database

    SciTech Connect (OSTI)

    Martinez, L.T.

    1997-05-01

    The objective of this study was to determine the effect of nonrandom sampling over time may have on the estimation of variability, namely the geometric standard deviation, using time series of personal exposure data.

  3. An Extended MPC Algorithm for Processes with Variable and Unpredictable Time Delays

    E-Print Network [OSTI]

    Taylor, James H.

    through the vessel, the liquid volume in it, and the degree of mixing. In traditional design, the process]. Under steady flow conditions, the delay time can be calculated by dividing the volume in the vessel by a continuous stirred tank reactor. The division of the residence time into two parts is motivated by a simple

  4. Time-variability of alpha from realistic models of Oklo reactors

    E-Print Network [OSTI]

    C. R. Gould; E. I. Sharapov; S. K. Lamoreaux

    2007-04-30

    We reanalyze Oklo $^{149}$Sm data using realistic models of the natural nuclear reactors. Disagreements among recent Oklo determinations of the time evolution of $\\alpha$, the electromagnetic fine structure constant, are shown to be due to different reactor models, which led to different neutron spectra used in the calculations. We use known Oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models. Two Oklo reactors, RZ2 and RZ10, were modeled with MCNP. The resulting neutron spectra were used to calculate the change in the $^{149}$Sm effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-meV resonance. We independently deduce ancient $^{149}$Sm effective cross sections, and use these values to set limits on the time-variation of $\\alpha$. Our study resolves a contradictory situation with previous Oklo $\\alpha$-results. Our suggested $2 \\sigma$ bound on a possible time variation of $\\alpha$ over two billion years is stringent: $ -0.24 \\times 10^{-7} \\le \\frac{\\Delta \\alpha}{\\alpha} \\le 0.11 \\times 10^{-7}$, but model dependent in that it assumes only $\\alpha$ has varied over time.

  5. High volume fuel vapor release valve

    SciTech Connect (OSTI)

    Gimby, D.R.

    1991-09-03

    This patent describes a fuel vapor release valve for use in a vehicle fuel system. It comprises a valve housing 10 placed in a specific longitudinal orientation, the valve housing 10 defining an interior cavity 22 having an inlet 20 for admitting fuel vapor and an outlet 14 for discharging such fuel vapor; a valve member 24 positioned in the cavity 22 for movement between an outlet 14 opening position and an outlet 14 closing position, the valve member 24 including a cap member 34 having a seat surface 36 for mating with the outlet 14 and an orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 having a lesser radius than the outlet 14; the valve member 24 further including a plug member 30 engaged with the cap member 34 for movement between an orifice 42 opening position and an orifice 42 closing position; and, a valve housing tilt responsive means for moving the valve member 24 to an outlet 14 and orifice 42 closing position in response to tilting of the valve 10 about its longitudinal axis whereby, upon the return of the valve 10 to its specified longitudinal orientation, the plug member 30 first moves to an orifice 42 opening position and the cap member 34 subsequently moves to an outlet 14 opening position.

  6. SU-C-18C-02: Specifcation of X-Ray Projection Angles Which Are Aligned with the Aortic Valve Plane From a Planar Image of a Valvuloplasty Balloon Inflated Across the Aortic Valve

    SciTech Connect (OSTI)

    Fetterly, K; Mathew, V [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: Transcatheter aortic valve replacement (TAVR) procedures provide a method to implant a prosthetic aortic valve via a minimallyinvasive, catheter-based procedure. TAVR procedures require use of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane to minimize prosthetic valve positioning error due to x-ray imaging parallax. The purpose of this work is to calculate the continuous range of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane from a single planar image of a valvuloplasty balloon inflated across the aortic valve. Methods: Computational methods to measure the 3D angular orientation of the aortic valve were developed. Required inputs include a planar x-ray image of a known valvuloplasty balloon inflated across the aortic valve and specifications of x-ray imaging geometry from the DICOM header of the image. A-priori knowledge of the species-specific typical range of aortic orientation is required to specify the sign of the angle of the long axis of the balloon with respect to the x-ray beam. The methods were validated ex-vivo and in a live pig. Results: Ex-vivo experiments demonstrated that the angular orientation of a stationary inflated valvuloplasty balloon can be measured with precision less than 1 degree. In-vivo pig experiments demonstrated that cardiac motion contributed to measurement variability, with precision less than 3 degrees. Error in specification of x-ray geometry directly influences measurement accuracy. Conclusion: This work demonstrates that the 3D angular orientation of the aortic valve can be calculated precisely from a planar image of a valvuloplasty balloon inflated across the aortic valve and known x-ray geometry. This method could be used to determine appropriate c-arm angular projections during TAVR procedures to minimize x-ray imaging parallax and thereby minimize prosthetic valve positioning errors.

  7. Miniature electrically operated diaphragm valve

    DOE Patents [OSTI]

    Adkins, Douglas R. (Albuquerque, NM); Spletzer, Barry L. (Albuquerque, NM); Wong, Chungnin C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Fischer, Gary J. (Albuquerque, NM); Hesketh, Peter J. (Atlanta, GA)

    2001-01-01

    The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.

  8. Analysis and synthesis of the variability of irradiance and PV power time series with the wavelet transform

    SciTech Connect (OSTI)

    Perpinan, O.; Lorenzo, E.

    2011-01-15

    The irradiance fluctuations and the subsequent variability of the power output of a PV system are analysed with some mathematical tools based on the wavelet transform. It can be shown that the irradiance and power time series are nonstationary process whose behaviour resembles that of a long memory process. Besides, the long memory spectral exponent {alpha} is a useful indicator of the fluctuation level of a irradiance time series. On the other side, a time series of global irradiance on the horizontal plane can be simulated by means of the wavestrapping technique on the clearness index and the fluctuation behaviour of this simulated time series correctly resembles the original series. Moreover, a time series of global irradiance on the inclined plane can be simulated with the wavestrapping procedure applied over a signal previously detrended by a partial reconstruction with a wavelet multiresolution analysis, and, once again, the fluctuation behaviour of this simulated time series is correct. This procedure is a suitable tool for the simulation of irradiance incident over a group of distant PV plants. Finally, a wavelet variance analysis and the long memory spectral exponent show that a PV plant behaves as a low-pass filter. (author)

  9. ANALYSIS OF SAFETY RELIEF VALVE PROOF TEST DATA TO OPTIMIZE LIFECYCLE MAINTENANCE COSTS

    SciTech Connect (OSTI)

    Gross, Robert; Harris, Stephen

    2007-08-01

    Proof test results were analyzed and compared with a proposed life cycle curve or hazard function and the limit of useful life. Relief valve proof testing procedures, statistical modeling, data collection processes, and time-in-service trends are presented. The resulting analysis of test data allows for the estimation of the PFD. Extended maintenance intervals to the limit of useful life as well as methodologies and practices for improving relief valve performance and reliability are discussed. A generic cost-benefit analysis and an expected life cycle cost reduction concludes that $90 million maintenance dollars might be avoided for a population of 3000 valves over 20 years.

  10. Propellant actuated nuclear reactor steam depressurization valve

    DOE Patents [OSTI]

    Ehrke, Alan C. (San Jose, CA); Knepp, John B. (San Jose, CA); Skoda, George I. (Santa Clara, CA)

    1992-01-01

    A nuclear fission reactor combined with a propellant actuated depressurization and/or water injection valve is disclosed. The depressurization valve releases pressure from a water cooled, steam producing nuclear reactor when required to insure the safety of the reactor. Depressurization of the reactor pressure vessel enables gravity feeding of supplementary coolant water through the water injection valve to the reactor pressure vessel to prevent damage to the fuel core.

  11. American Valve: Proposed Penalty (2010-CW-1411)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that American Valve, Inc. failed to certify a variety of showerheads as compliant with the applicable water conservation standards.

  12. Double-reed exhaust valve engine

    DOE Patents [OSTI]

    Bennett, Charles L.

    2015-06-30

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

  13. Michigan: General Motors Optimizes Engine Valve Technology |...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    effort to increase energy efficiency, while maintaining low emissions, has resulted in new engine valve technology on the 2014 Chevrolet Impala. EERE's Vehicle Technologies...

  14. Emerging Trends in Heart Valve Engineering: Part III. Novel Technologies for Mitral Valve Repair and Replacement

    E-Print Network [OSTI]

    2015-01-01

    et mechanical heart valves during the leakage phase. Ann.leakage ?ow in the hinge of a St. Jude medical((r)) regent mechanical heart valve.leakage ?ow of regurgitation jets, 22,28 ori?ces, 23 and at the hinges 36 of mechanical valves.

  15. Hydraulic engine valve actuation system including independent feedback control

    DOE Patents [OSTI]

    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.

  16. Swing switching of spin-torque valves

    E-Print Network [OSTI]

    Tom Dunn; Alex Kamenev

    2012-10-10

    We propose a method for inducing magnetization reversal using an AC spin current polarized perpendicular to the equilibrium magnetization of the free magnetic layer. We show that the critical AC spin current is significantly smaller than the corresponding DC one. The effect is understood as a consequence of the underdamped nature of the spin-torque oscillators. It allows to use the kinetic inertia to overcome the residual energy barrier, rather than suppressing the latter by a large spin current. The effect is similar to a swing which may be set into high amplitude motion by a weak near-resonant push. The optimal AC frequency is identified as the upper bifurcation frequency of the corresponding driven nonlinear oscillator. Together with fast switching times it makes the perpendicular AC method to be the most efficient way to realize spin-torque memory valve.

  17. Vacuum/Compression Valving (VCV) Using Parrafin-Wax on a Centrifugal Microfluidic CD Platform

    E-Print Network [OSTI]

    2013-01-01

    Rg, et al. (2010) Serial siphon valving for centrifugalas hydrophobic, hydrophilic, siphon, Coriolis, flap valves [

  18. Low power integrated pumping and valving arrays for microfluidic...

    Office of Scientific and Technical Information (OSTI)

    Low power integrated pumping and valving arrays for microfluidic systems Citation Details In-Document Search Title: Low power integrated pumping and valving arrays for microfluidic...

  19. Requirements for the Valve Train and Technolgies for Enabling...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    for the Valve Train and Technolgies for Enabling HCCI over the Entire Operating Range Requirements for the Valve Train and Technolgies for Enabling HCCI over the Entire Operating...

  20. Advanced Materials for Lightweight Valve Train Components | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    for Lightweight Valve Train Components Advanced Materials for Lightweight Valve Train Components Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review...

  1. Design and Implementation of Silicon Nitride Valves for Heavy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Implementation of Silicon Nitride Valves for Heavy Duty Diesel Engines Design and Implementation of Silicon Nitride Valves for Heavy Duty Diesel Engines Poster presentation at the...

  2. Control Valve Trajectories for SOFC Hybrid System Startup

    SciTech Connect (OSTI)

    Gorrell, Megan; Banta, Larry; Rosen, William; Restrepo, Bernardo; Tucker, David

    2012-07-01

    Control and management of cathode airflow in a solid oxide fuel cell gas turbine hybrid power system was analyzed using the Hybrid Performance (HyPer) hardware simulation at the National Energy Technology (NETL), U.S. Department of Energy. This work delves into previously unexplored operating practices for HyPer, via simultaneous manipulation of bypass valves and the electric load on the generator. The work is preparatory to the development of a Multi-Input, Multi-Output (MIMO) controller for HyPer. A factorial design of experiments was conducted to acquire data for 81 different combinations of the manipulated variables, which consisted of three air flow control valves and the electric load on the turbine generator. From this data the response surface for the cathode airflow with respect to bypass valve positions was analyzed. Of particular interest is the control of airflow through the cathode during system startup and during large load swings. This paper presents an algorithm for controlling air mass flow through the cathode based on a modification of the steepest ascent method.

  3. Cylinder valve packing nut studies

    SciTech Connect (OSTI)

    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.

  4. THE COMPACT, TIME-VARIABLE RADIO SOURCE PROJECTED INSIDE W3(OH): EVIDENCE FOR A PHOTOEVAPORATED DISK?

    SciTech Connect (OSTI)

    Dzib, Sergio A.; Rodriguez-Garza, Carolina B.; Rodriguez, Luis F.; Kurtz, Stan E.; Loinard, Laurent; Zapata, Luis A.; Lizano, Susana, E-mail: s.dzib@crya.unam.mx [Centro de Radiostronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia 58089 (Mexico)

    2013-08-01

    We present new Karl G. Jansky Very Large Array (VLA) observations of the compact ({approx}0.''05), time-variable radio source projected near the center of the ultracompact H II region W3(OH). The analysis of our new data as well as of VLA archival observations confirms the variability of the source on timescales of years and for a given epoch indicates a spectral index of {alpha} = 1.3 {+-} 0.3 (S{sub {nu}}{proportional_to}{nu}{sup {alpha}}). This spectral index and the brightness temperature of the source ({approx}6500 K) suggest that we are most likely detecting partially optically thick free-free radiation. The radio source is probably associated with the ionizing star of W3(OH), but an interpretation in terms of an ionized stellar wind fails because the detected flux densities are orders of magnitude larger than expected. We discuss several scenarios and tentatively propose that the radio emission could arise in a static ionized atmosphere around a fossil photoevaporated disk.

  5. High speed exhaust gas recirculation valve

    DOE Patents [OSTI]

    Fensom, Rod (Peterborough, GB); Kidder, David J. (Peterborough, GB)

    2005-01-18

    In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve that can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled. It is desirable to have an EGR valve with fast-acting capabilities, and it is also desirable to have the EGR valve take up as little space as possible. An exhaust gas recirculation valve is provided that includes an exhaust passage tube, a valve element pivotally mounted within the exhaust passage tube, a linear actuator; and a gear train. The gear train includes a rack gear operatively connected to the linear actuator, and at least one rotatable gear meshing with the rack gear and operatively connected to the valve element to cause rotation of the valve element upon actuation of the linear actuator. The apparatus provides a highly compact package having a high-speed valve actuation capability.

  6. High precision high flow range control valve

    DOE Patents [OSTI]

    McCray, J.A.

    1999-07-13

    A fluid control valve is described having a valve housing having first and second valve housing openings for the ingress and egress of fluid through the control valve. Disposed within a void formed by the control valve is a sleeve having at least one sleeve opening to permit the flow of fluid therethrough. A flow restricter travels within the sleeve to progressively block off the sleeve opening and thereby control flow. A fluid passageway is formed between the first valve housing opening and the outer surface of the sleeve. A second fluid passageway is formed between the inside of the sleeve and the second valve housing opening. Neither fluid passageway contains more than one 90 [degree] turn. In the preferred embodiment only one of the two fluid passageways contains a 90[degree] turn. In another embodiment, the control valve housing is bifurcated by a control surface having control surface opening disposed therethrough. A flow restricter is in slidable contact with the control surface to restrict flow of fluid through the control surface openings. 12 figs.

  7. Dynamic Testing of Check Valves William Rahmeyer

    E-Print Network [OSTI]

    Rahmeyer, William J.

    Utah State University paper presented at the Nuclear Industry Check Valve Group, 1996 Winter Meeting deceleration is calculated from the piping system and flow change due to pump shutdown or closure of a control and Flomatic Valves. #12;2 BACKGROUND In a piping system, the shut down of a pump or the closure of a control

  8. High precision high flow range control valve

    DOE Patents [OSTI]

    McCray, John A. (Idaho Falls, ID)

    1999-01-01

    A fluid control valve is described having a valve housing having first and second valve housing openings for the ingress and egress of fluid through the control valve. Disposed within a void formed by the control valve is a sleeve having at least one sleeve opening to permit the flow of fluid therethrough. A flow restricter travels within the sleeve to progressively block off the sleeve opening and thereby control flow. A fluid passageway is formed between the first valve housing opening and the outer surface of the sleeve. A second fluid passageway is formed between the inside of the sleeve and the second valve housing opening. Neither fluid passageway contains more than one 90.degree. turn. In the preferred embodiment only one of the two fluid passageways contains a 90.degree. turn. In another embodiment, the control valve housing is bifurcated by a control surface having control surface opening disposed therethrough. A flow restricter is in slidable contact with the control surface to restrict flow of fluid through the control surface openings.

  9. Fuel injection of coal slurry using vortex nozzles and valves

    DOE Patents [OSTI]

    Holmes, Allen B. (Rockville, MD)

    1989-01-01

    Injection of atomized coal slurry fuel into an engine combustion chamber is achieved at relatively low pressures by means of a vortex swirl nozzle. The outlet opening of the vortex nozzle is considerably larger than conventional nozzle outlets, thereby eliminating major sources of failure due to clogging by contaminants in the fuel. Control fluid, such as air, may be used to impart vorticity to the slurry and/or purge the nozzle of contaminants during the times between measured slurry charges. The measured slurry charges may be produced by a diaphragm pump or by vortex valves controlled by a separate control fluid. Fluidic circuitry, employing vortex valves to alternatively block and pass cool slurry fuel flow, is disclosed.

  10. Subsea valve actuator for ultra deepwater

    SciTech Connect (OSTI)

    Ali, S.Z.; Skeels, H.B.; Montemayor, B.K.; Williams, M.R.

    1996-12-31

    This paper reviews the continuing development of gate valve and actuator technology for subsea completions extending into ultra deep water. The basic technical challenges inherent to subsea valve actuators are reviewed, along with the various factors which affect the design and performance of these devices in deepwater applications. The high external ambient pressures which occur in deep water, coupled with high specific gravity hydraulic control fluids, are shown to have a significant impact on the performance of the actuators. This paper presents design and analysis methods and the verification test procedures which are required to develop and qualify new deep water actuator designs. Gate valve actuators of the type described in this paper are currently in use on subsea christmas trees on the world`s deepest subsea wells offshore Brazil (water depths >3,000 feet). New applications of the deepwater actuators are in process for upcoming Gulf of Mexico subsea production systems in water depths approaching 6,000 feet. The actuator/valve development method described in this paper has been confirmed by performance verification testing of full scale valves and actuators using a hyperbaric chamber to simulate ultra deepwater operating conditions. Performance of the test valves and actuators correlated very well with analytical predictions. Test results have confirmed that the new valve actuator designs will satisfy API 17D performance requirements for water depths up to 7,500 feet, well in excess of the upcoming GOM application.

  11. Whitey SCHe Ball Valves Provide Test Port Isolation

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-10-19

    These valves are 1/4-inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as normally closed isolation valves for test ports in the SCHe System between the gage root valve and the pressure indicator.

  12. Whitey SCHe Ball Valves Provide Test Port Isolation

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-09-15

    These valves are 1/4 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as normally closed isolation valves for test ports in the SCHe System between the gage root valve and the pressure indicator.

  13. Computational model of aortic valve surgical repair using grafted pericardium

    E-Print Network [OSTI]

    1 Computational model of aortic valve surgical repair using grafted pericardium Peter E. Hammer1, aortic valve repair, membrane, surgical planning, leaflet graft, pericardium ABSTRACT Aortic valve leaflets. Difficulty is largely due to the complex geometry and function of the valve and the lower

  14. Design and sizing of electromagnetic linear actuators for valve applications

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Page 1/9 Design and sizing of electromagnetic linear actuators for valve applications J.C Vannier1. These structures have been studied in order to drive the valves of a car motor. According to general specifications magnet, valves. 1. Introduction, general specifications The valves which can be found in thermal engines

  15. Valve for controlling solids flow

    DOE Patents [OSTI]

    Staiger, M.D.

    1982-09-29

    A valve for controlling the flow of solids comprises a vessel having an overflow point, an inlet line for discharging solids into the vessel positioned within the vessel such that the inlet line's discharge point is lower than the vessel's overflow point, and means for introducing a fluidizing fluid into the vessel. The fluidizing fluid fluidizes the solids within the vessel so that they overflow at the vessel's overflow point. For the removal of nuclear waste product the vessel may be placed within a sealed container having a bottom connected transport line for transporting the solids to storage or other sites. The rate of solids flow is controlled by the flow rate of the fluidizing fluid and by V-notch weirs of different sizes spaced about the top of the vessel.

  16. Valve Cap For An Electric Storage Cell

    DOE Patents [OSTI]

    Verhoog, Roelof (Bordeaux, FR); Genton, Alain (Merignac, FR)

    2000-04-18

    The valve cap for an electric storage cell includes a central annular valve seat (23) and a membrane (5) fixed by its peripheral edge and urged against the seat by a piston (10) bearing thereagainst by means of a spring (12), the rear end of said spring (12) bearing on the endwall (8) of a chamber (20) formed in the cap and containing the piston (10) and the spring. A vent (19) puts the chamber (20) into communication with the atmosphere. A central orifice (26, 28) through the piston (10) and the membrane (5), enables gas from within the cell to escape via the top vent (19) when the valve opens.

  17. Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating

    DOE Patents [OSTI]

    Casada, Donald A. (Oak Ridge, TN)

    1996-01-01

    A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization.

  18. Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating

    DOE Patents [OSTI]

    Casada, D.A.

    1996-01-16

    A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization. 14 figs.

  19. Electric actuation of a surface controlled subsea safety valve 

    E-Print Network [OSTI]

    Bartlett, Timothy Joseph

    2013-02-22

    Flapper valve diameter Gravitational constant Flapper valve moment of inertia Power return spring coefficient Flapper valve coil spring coefficient Flov, tube/Flapper valve geometncal contact constrmnt Flow tube displacement limit Flow tube mass... Hydraulic piston mass Flapper valve mass National Association of Corrosion Engmeers Dynamic accumulator pressure Initial accumulator pre-chargc pressure Accumulator pressure Hydraulic control line pressure Working pressure Surface Controlled Subsca...

  20. Valve studies: Hydrogen fluoride monitoring of UF{sub 6} cylinder valves

    SciTech Connect (OSTI)

    Leedy, R.R.; Ellis, A.R.; Hoffmann, D.P.; Marsh, G.C. [and others

    1996-08-01

    Uranium hexafluoride (UF{sub 6}) cylinder valves have, like the cylinders, been in use and/or storage for periods ranging from 15 to 44 years. Visual inspection of the cylinders has shown that the extent of corrosion and the overall cylinder condition varies widely throughout the storage yards. One area of concern is the integrity of the cylinder valves. Visual inspection has found deposits which have been identified as radioactive material on or near the valves. These deposits suggest leakage of UF{sub 6} and may indicate valve degradation; however, these deposits may simply be residual material from cylinder filling operations.

  1. Method for valve seating control for an electro-hydraulic engine valve

    DOE Patents [OSTI]

    Sun, Zongxuan (Plymouth, MN)

    2011-01-11

    Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

  2. Large scale steam valve test: Performance testing of large butterfly valves and full scale high flowrate steam testing

    SciTech Connect (OSTI)

    Meadows, J.B.; Robbins, G.E.; Roselius, D.G. [and others

    1995-05-01

    This report presents the results of the design testing of large (36-inch diameter) butterfly valves under high flow conditions. The two butterfly valves were pneumatically operated air-open, air-shut valves (termed valves 1 and 2). These butterfly valves were redesigned to improve their ability to function under high flow conditions. Concern was raised regarding the ability of the butterfly valves to function as required with high flow-induced torque imposed on the valve discs during high steam flow conditions. High flow testing was required to address the flow-induced torque concerns. The valve testing was done using a heavily instrumented piping system. This test program was called the Large Scale Steam Valve Test (LSSVT). The LSSVT program demonstrated that the redesigned valves operated satisfactorily under high flow conditions.

  3. Self Contained Temperature Actuated Control Valves 

    E-Print Network [OSTI]

    Pirkle, F.

    1979-01-01

    There is a virtually unlimited potential for energy conservation by utilizing self contained temperature actuated valves. As steam costs soar it becomes more and more important to conserve feed stock dollars as well as the energy these dollars...

  4. The safety valve and climate policy

    E-Print Network [OSTI]

    Jacoby, Henry D.; Ellerman, A. Denny.

    In discussions of a cap-and-trade system for implementation of Kyoto Protocol-type quantity targets, a "safety valve" was proposed where, by government sales of emissions permits at a fixed price, the marginal cost of the ...

  5. A hybrid tissue-engineered heart valve

    E-Print Network [OSTI]

    Alavi, SH; Kheradvar, A

    2015-01-01

    load-bearing component of the hybrid lea?et, and it shouldin the left ventricle. Hybrid tissue was also previouslyA Hybrid Tissue-Engineered Heart Valve S. Hamed Alavi, PhD,

  6. Frostless heat pump having thermal expansion valves

    DOE Patents [OSTI]

    Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN)

    2002-10-22

    A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

  7. A hybrid tissue-engineered heart valve

    E-Print Network [OSTI]

    Alavi, SH; Kheradvar, A

    2015-01-01

    an extra-thin superelastic Nitinol mesh tightly enclosed byDescription. The trilea?et Nitinol mesh scaffolds underwentof the valves and their Nitinol scaffolds were tested in a

  8. Relation of aortic valve calcium to chronic kidney disease (from the Chronic Renal Insufficiency Cohort Study)

    E-Print Network [OSTI]

    2015-01-01

    with calcific aortic valve disease. Cardiovascular HealthA, et al. Cardiac valve calcification in haemodialysisCurtis JR. Aortic and mitral valve calcification in patients

  9. Effect of the Mitral Valve's Anterior Leaflet on Axisymmetry of Transmitral Vortex Ring.

    E-Print Network [OSTI]

    Falahatpisheh, A; Pahlevan, NM; Kheradvar, A

    2015-01-01

    and B. S. Rana. Anatomy of the mitral valve: understandingthe mitral valve complex in mitral regurgitation. Eur. J.and H. -H. Sievers. Heart valve macro- and microstructure.

  10. A congestion mechanism for uphill expressways, Part I: the shoulder lane "release valve"

    E-Print Network [OSTI]

    Patire, Anthony D.; Cassidy, Michael J.

    2010-01-01

    shoulder lane “release valve” Anthony D. Patire and Michaelshoulder lane “release valve” Anthony D. Patire and Michaelacting as a “ re- lease valve” for the excess accumulation

  11. Analysis of FRUITFULL promoter motifs and their influence on valve expression during fruit development

    E-Print Network [OSTI]

    Woods, Jennifer Carol

    2010-01-01

    motifs and their influence on valve expression during fruitappear WT-like with only valve expression remaining (Fig.motifs and their influence on valve expression during fruit

  12. Relation of Aortic Valve Calcium to Chronic Kidney Disease (from the Chronic Renal Insufficiency Cohort Study)

    E-Print Network [OSTI]

    2015-01-01

    with calcific aortic valve disease. Cardiovascular HealthA, et al. Cardiac valve calcification in haemodialysisCurtis JR. Aortic and mitral valve calcification in patients

  13. Emergent Presentation of Decompensated Mitral Valve Prolapse and Atrial Septal Defect

    E-Print Network [OSTI]

    Kang, Jessie; Das, Bijon

    2015-01-01

    E, Gring CN, Griffin BP. Mitral valve prolapse. Lancet. 2.NM. Myxomatous mitral valve disease bench to bedside: LDL-geometry and degree of mitral valve prolapse. Circulation.

  14. Percutaneous aortic valve replacement in a re-animated postmortem heart

    E-Print Network [OSTI]

    White, Jennifer; Sun, Amy; Killien, Lauren; Evangelista, Dennis

    2006-01-01

    implantation of heart valve prosthesis for the treatment ofF. Percutaneous aortic valve replacement: an experimentalA stentless trileaflet valve from a sheet of decellularized

  15. Proof of concept of FOLDAVALVE, a novel 14 Fr totally repositionable and retrievable transcatheter aortic valve.

    E-Print Network [OSTI]

    Kheradvar, A; Groves, EM; Tseng, E

    2015-01-01

    for transcatheter aortic valve therapy. Prog Cardiovasc Dis.Transcatheter aortic-valve implantation for aortic stenosisgators. Transcatheter aortic-valve replacement with a self-

  16. On the multiscale modeling of heart valve biomechanics in health and disease

    E-Print Network [OSTI]

    Weinberg, Eli J.; Shahmirzadi, Danial; Mofrad, Mohammad Reza

    2010-01-01

    mofrad@berkeley.edu healthy heart valve is described atan organ, each of the heart valves consists of a number ofpulmonary, and tricuspid valves each normally have three ?

  17. Well injection valve with retractable choke

    SciTech Connect (OSTI)

    Pringle, R.E.

    1986-07-22

    An injection valve is described for use in a well conduit consisting of: a housing having a bore, a valve closure member in the bore moving between open and closed positions, a flow tube telescopically movable in the housing for controlling the movement of the valve closure member, means for biasing the flow tube in a direction for allowing the valve closure member to move to the closed position, an expandable and contractible fluid restriction connected to the flow tube and extending into the bore for moving the flow tube to the open position in response to injection fluid, but allowing the passage of well tools through the valve, the restriction contractible in response to fluid flow, the restriction includes, segments movable into and out of the bore, and biasing means yieldably urging the segments into the bore, a no-go shoulder on the flow tube, and releasable lockout means between the flow tube and the housing for locking the flow tube and valve in the open position.

  18. Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY)

    2000-08-29

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

  19. Flow Split Venturi, Axially-Rotated Valve

    DOE Patents [OSTI]

    Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)

    2000-02-22

    The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

  20. On the new approach to variable separation in the time-dependent Schrödinger equation with two space dimensions

    E-Print Network [OSTI]

    Renat Z. Zhdanov; Ihor V. Revenko; Wilhelm I. Fushchych

    1995-07-20

    We suggest an effective approach to separation of variables in the Schr\\"odinger equation with two space variables. Using it we classify inequivalent potentials $V(x_1,x_2)$ such that the corresponding Schr\\" odinger equations admit separation of variables. Besides that, we carry out separation of variables in the Schr\\" odinger equation with the anisotropic harmonic oscillator potential $V=k_1x_1^2+k_2x_2^2$ and obtain a complete list of coordinate systems providing its separability. Most of these coordinate systems depend essentially on the form of the potential and do not provide separation of variables in the free Schr\\" odinger equation ($V=0$).

  1. Leakage characterization of a piloted power operated relief valve

    SciTech Connect (OSTI)

    Ezekoye, L.I. [Westinghouse Electric Corp, Pittsburgh, PA (United States). Nuclear Technology Division; Hess, M.D. [Northeast Utilities, Waterford, CT (United States). Millstone Station

    1995-11-01

    In Westinghouse Pressurized Water Reactors (PWRs), power operated relief valves (PORVs) are used to provide overpressure protection of the Pressurizer. The valves are fail closed globe valves which means that power is required to open the valves and, on loss of power, the valves close. There are two ways to operate the PORVs. The more common way is to directly couple the disc to an actuator via a disc-stem assembly. The type of design is not the object of this paper. The other and less common way of operating a PORV is by piloting the main valve such that the opening or closing of a pilot valve opens and closes the main valve. This is the design of interest. In most plants, the PORVs are installed with a water loop seal while in some plants no water loop seals are used. It is generally accepted that loop seal installation minimizes valve seat leakage. In non-loop seal installation, the valve seat is exposed to steam which increases the potential for seat leakage. This paper describes the results of some tests performed with nitrogen and steam to characterize the leakage potential of a pilot operated PORV. The test results were compared with seat leakage tests of check valves to provide insight on the leakage testing of pilot operated valves and check valves. The paper also compares the test data with leakage estimates using the ASME/ANSI OM Code guidance on valve leakage.

  2. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    SciTech Connect (OSTI)

    Blau, Peter Julian

    2009-11-01

    The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats run for hundreds of hours in heavy-duty diesels provided insights into the kinds of complexity that the contact conditions in engines can produce, and suggested the physical basis for the current approach to modeling. The model presented here involves four terms, two representing the valve response and two for its mating seat material. The model's structure assumes that wear that takes place under a complex combination of plastic deformation, tangential shear, and oxidation. Tribolayers form, are removed, and may reform. Layer formation affects the friction forces in the interface, and in turn, the energy available to do work on the materials to cause wear. To provide friction data for the model at various temperatures, sliding contact experiments were conducted from 22 to 850 C in a pin-on-disk apparatus at ORNL. In order to account for the behavior of different materials and engine designs, parameters in all four terms of the model can be adjusted to account for wear-in and incubation periods before the dominant wear processes evolve to their steady-state rates. For example, the deformation rate is assumed to be maximum during the early stages of operation, and then, due to material work-hardening and the increase in nominal contact area (which reduces the load per unit area), decreases to a lower rate at long times. Conversely, the rate of abrasion increases with time or number of cycles due to the build-up of oxides and tribo-layers between contact surfaces. The competition between deformation and abrasion results in complex, non-linear behavior of material loss per cycle of operation. Furthermore, these factors are affected by valve design features, such as the angle of incline of the valve seat. Several modeling scenarios are presented to demonstrate how the wear profile versus number of cycles changes in response to: (a) different relative abrasion rates of the seat and valve materials, (b) the friction coefficient as a function of temperature, (c) the relative deformation contribution of valve and seat materials, and (d) an interruption in the dominant we

  3. Griswold Tempered Water Flow Regulator Valves Used as Anti Siphon Valves

    SciTech Connect (OSTI)

    MISKA, C.

    2000-09-03

    FCV-1*22 and 1*23 are Griswold constant flow regulators used as anti-siphon valves in the tempered water system, they fail closed but valve cartridge orifice allows minimum flow to prevent loss of water from the MCO/CASK annulus.

  4. Simulant Development for Hanford Tank Farms Double Valve Isolation (DVI) Valves Testing

    SciTech Connect (OSTI)

    Wells, Beric E.

    2012-12-21

    Leakage testing of a representative sample of the safety-significant isolation valves for Double Valve Isolation (DVI) in an environment that simulates the abrasive characteristics of the Hanford Tank Farms Waste Transfer System during waste feed delivery to the Waste Treatment and Immobilization Plant (WTP) is to be conducted. The testing will consist of periodic leak performed on the DVI valves after prescribed numbers of valve cycles (open and close) in a simulated environment representative of the abrasive properties of the waste and the Waste Transfer System. The valve operations include exposure to cycling conditions that include gravity drain and flush operation following slurry transfer. The simulant test will establish the performance characteristics and verify compliance with the Documented Safety Analysis. Proper simulant development is essential to ensure that the critical process streams characteristics are represented, National Research Council report “Advice on the Department of Energy's Cleanup Technology Roadmap: Gaps and Bridges”

  5. Effects of aging and service wear on main steam isolation valves and valve operators

    SciTech Connect (OSTI)

    Clark, R.L. [Oak Ridge National Lab., TN (United States)

    1996-03-01

    In recent years main steam isolation valve (MSIV operating problems have resulted in significant operational transients (e.g., spurious reactor trips, steam generator dry out, excessive valve seat leakage), increased cost, and decreased plant availability. A key ingredient to an engineering-oriented reliability improvement effort is a thorough understanding of relevant historical experience. A detailed review of historical failure data available through the Institute of Nuclear Power Operation`s Nuclear Plant Reliability Data System has been conducted for several types of MSIVs and valve operators for both boiling-water reactors and pressurized-water reactors. The focus of this review is on MSIV failures modes, actuator failure modes, consequences of failure on plant operations, method of failure detection, and major stressors affecting both valves and valve operators.

  6. High-Compression-Ratio; Atkinson-Cycle Engine Using Low-Pressure Direct Injection and Pneumatic-Electronic Valve Actuation Enabled by Ionization Current and Foward-Backward Mass Air Flow Sensor Feedback

    SciTech Connect (OSTI)

    Harold Schock; Farhad Jaberi; Ahmed Naguib; Guoming Zhu; David Hung

    2007-12-31

    This report describes the work completed over a two and one half year effort sponsored by the US Department of Energy. The goal was to demonstrate the technology needed to produce a highly efficient engine enabled by several technologies which were to be developed in the course of the work. The technologies included: (1) A low-pressure direct injection system; (2) A mass air flow sensor which would measure the net airflow into the engine on a per cycle basis; (3) A feedback control system enabled by measuring ionization current signals from the spark plug gap; and (4) An infinitely variable cam actuation system based on a pneumatic-hydraulic valve actuation These developments were supplemented by the use of advanced large eddy simulations as well as evaluations of fuel air mixing using the KIVA and WAVE models. The simulations were accompanied by experimental verification when possible. In this effort a solid base has been established for continued development of the advanced engine concepts originally proposed. Due to problems with the valve actuation system a complete demonstration of the engine concept originally proposed was not possible. Some of the highlights that were accomplished during this effort are: (1) A forward-backward mass air flow sensor has been developed and a patent application for the device has been submitted. We are optimistic that this technology will have a particular application in variable valve timing direct injection systems for IC engines. (2) The biggest effort on this project has involved the development of the pneumatic-hydraulic valve actuation system. This system was originally purchased from Cargine, a Swedish supplier and is in the development stage. To date we have not been able to use the actuators to control the exhaust valves, although the actuators have been successfully employed to control the intake valves. The reason for this is the additional complication associated with variable back pressure on the exhaust valves when they are opened. As a result of this effort, we have devised a new design and have filed for a patent on a method of control which is believed to overcome this problem. The engine we have been working with originally had a single camshaft which controlled both the intake and exhaust valves. Single cycle lift and timing control was demonstrated with this system. (3) Large eddy simulations and KIVA based simulations were used in conjunction with flow visualizations in an optical engine to study fuel air mixing. During this effort we have devised a metric for quantifying fuel distribution and it is described in several of our papers. (4) A control system has been developed to enable us to test the benefits of the various technologies. This system used is based on Opal-RT hardware and is being used in a current DOE sponsored program.

  7. 1999 Hazeleger, W., 1 February 1999. Variability in Mode Water Formation on the Decadal Time Scale. University of Utrecht, the Netherlands.

    E-Print Network [OSTI]

    Haak, Hein

    PhD-Theses 1999 Hazeleger, W., 1 February 1999. Variability in Mode Water Formation on the Decadal Time Scale. University of Utrecht, the Netherlands. Lipzig, N.P.M. van, 6 October 1999. The surfaceD-Thesis, University of Utrecht, the Netherlands. Veefkind, J.P., 11 October 1999. Aerosol Satellite Remote Sensing. Ph

  8. A new measure of acceleration of heart rate: dependence on age and comparison with time domain conventional heart rate variability measures

    E-Print Network [OSTI]

    Cammarota, Camillo

    A new measure of acceleration of heart rate: dependence on age and comparison with time domain conventional heart rate variability measures Giuseppe Germanò, M.D., Gianfranco Piccirillo, M.D., *Camillo We introduce a new index, Acceleration Ratio (AR), in order to investigate the dependence of Heart

  9. An alternative approach to exact wave functions for time-dependent coupled oscillator model of charged particle in variable magnetic field

    E-Print Network [OSTI]

    Salah Menouar; Mustapha Maamache; Jeong Ryeol Choi

    2010-10-14

    A general treatment of the quantal time-dependent coupled oscillators in presence of the variable magnetic field is presented. The treatment is based on the use of an alternative canonical transformations, time-dependent unitary transformations and the invariant methods. Exact wave functions for Schr\\"{o}dinger equations of this system are constructed.We applied our theory to a particular case and, co,sequently, showed that our results recovers to the perviously known one.

  10. Emerging Trends in Heart Valve Engineering: Part I. Solutions for Future

    E-Print Network [OSTI]

    2015-01-01

    role in calci?c aortic valve disease. Cardiovasc. Pathol.heart valves. J. Heart Valve Dis. 10:105–110, 2001.B. , and K. E. Yutzey. Heart valve structure and function in

  11. Mechanisms of bioprosthetic heart valve failure: Fatigue causes collagen denaturation and glycosaminoglycan loss

    E-Print Network [OSTI]

    Zand, Robert

    Mechanisms of bioprosthetic heart valve failure: Fatigue causes collagen denaturation heart valve (BPHV) degeneration, characterized by extracellular matrix deterioration, remod- eling) with glutaraldehyde fixed porcine aortic valve bioprostheses, that the mechanical function of cardiac valve cusps

  12. Emerging Trends in Heart Valve Engineering: Part I. Solutions for Future

    E-Print Network [OSTI]

    2015-01-01

    polyurethane heart valves. J. Heart Valve Dis. 10:105–110,R. B. , and K. E. Yutzey. Heart valve structure and functionneering challenges for heart valve tissue engineering. Annu.

  13. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    DOE Patents [OSTI]

    Meisner, Gregory P

    2013-10-08

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  14. 2012-01-1106 Understanding the dynamic evolution of cyclic variability at the

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    an early closing of the exhaust valve [9]. To investigate the nature of CV, we perform a set of experiments of HCCI engines with negative valve overlap Erik Hellström, Anna Stefanopoulou, Jiri Vavra, Aristotelis of combustion cycles where important variables are residual gas temperature, combustion efficiency, heat release

  15. Programmable Valves: a Solution to Bypass Deadband Problem of Electro-Hydraulic Systems

    E-Print Network [OSTI]

    Yao, Bin

    cartridge valves. This paper will compare the programmable valves with traditional PDC/servo valves combination of five independently con- trolled poppet type cartridge valves. The programmable valves, while having the ability to hold position due to the virtually zero internal leakages when the cartridge valves

  16. Friction and Wear Reduction in Diesel Engine Valve Trains | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Reduction in Diesel Engine Valve Trains Friction and Wear Reduction in Diesel Engine Valve Trains Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review...

  17. Novel design of a rotary valve using axiomatic design

    E-Print Network [OSTI]

    Peliks, Robert Bilgor

    2005-01-01

    Rotary valves have existed for millennia; and while they have developed tremendously since the first Roman valves, many of the same problems have persisted. The basic problems are caused by the coupling of functional ...

  18. Study of collagen structure in canine myxomatous mitral valve disease 

    E-Print Network [OSTI]

    Hadian, Mojtaba

    2009-01-01

    Myxomatous mitral valve disease (MMVD) is the single most common acquired cardiac disease of dogs, and is a disease of significant veterinary importance. It also bears close similarities to mitral valve prolapse in humans ...

  19. Design of a Thermally-Actuated Gas Lift Safety Valve

    E-Print Network [OSTI]

    Gilbertson, Eric W.

    Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valve assemblies (GLV). One failure mode occurs when the GLV check valve fails and product passes into the well annulus, potentially reaching ...

  20. Incinerator thermal release valve risk assessment

    SciTech Connect (OSTI)

    Stevens, J.B.

    1998-12-31

    Human health risk assessments were conducted on emissions from several types of incinerators--a hazardous waste combustor, a medical waste/tire combustor, and a refuse derived fuel combustor in three different states. As part of these studies, the short-term emissions from thermal release valves operating during upset conditions were additionally evaluated. The latter assessments addressed two specific risk-related questions: (1) what are the incremental long-term risks/hazards associated with these short-term emissions; (2) what are the acute health hazards associated with these emissions? For each study, emission estimates for both the incinerator stack and the thermal release valve were obtained from the facility. Stack testing was utilized to obtain stack gas concentrations of emissions at one facility; engineering estimates were used to ascertain emissions from the thermal release valve. The two facilities were proposed incinerators, so literature-derived emissions were used throughout.

  1. 3 Continuous-time stochastic processes Definition 3.1. A continuous-time stochastic process is a collection of random variables (Xt, t R+)

    E-Print Network [OSTI]

    Lévêque, Olivier

    3 Continuous-time stochastic processes Definition 3.1. A continuous-time stochastic process to describe a continuous-time stochastic process, one generally needs a LARGE probability space ! Question. But having independent and stationary increments is a strong requirement for a continuous-time process

  2. Worchester Solenoid Actuated Gas Operated MCO Isolation Valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-06-06

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) to prevent MCO vent drain to either reduce air in-leakage or loss of He. The valves have couplings for transverse actuator mounting.

  3. Worcester Solenoid Actuated Gas Operated MCO Isolation Valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-06-06

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as Integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air in leakage or loss of He. All valves have coupling for transverse actuator mounting.

  4. Worcester Solenoid Actuated Gas Operated MCO Isolation Valves

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-11-13

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air leakage or loss of He. All valves have coupling for transverse actuator mounting.

  5. Worchester Solenoid Actuated Gas Operated MCO Isolation Valves

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-11-13

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in process streams within the CWF hood. The valves fail closed (on loss of pressure or electrical) to prevent MCO vent drain to either reduce air In-leakage or loss of He. The valves have couplings for transverse actuator mounting.

  6. Worcester Solenoid Actuated Gas Operated MCO Isolation Valves

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-09-03

    These valves are 1 inch gas-operated full-port ball valves incorporating a solenoid and limit switches as integral parts of the actuator that are used in different process streams within the CVDF hood. The valves fail closed (on loss of pressure or electrical) for MCO isolation to either reduce air in leakage or loss of He. All valves have coupling for transverse actuator mounting.

  7. Exhaust gas bypass valve control for thermoelectric generator

    DOE Patents [OSTI]

    Reynolds, Michael G; Yang, Jihui; Meisner, Greogry P.; Stabler, Francis R.; De Bock, Hendrik Pieter (Peter) Jacobus; Anderson, Todd Alan

    2012-09-04

    A method of controlling engine exhaust flow through at least one of an exhaust bypass and a thermoelectric device via a bypass valve is provided. The method includes: determining a mass flow of exhaust exiting an engine; determining a desired exhaust pressure based on the mass flow of exhaust; comparing the desired exhaust pressure to a determined exhaust pressure; and determining a bypass valve control value based on the comparing, wherein the bypass valve control value is used to control the bypass valve.

  8. AeroValve Experimental Test Data Final Report

    SciTech Connect (OSTI)

    Noakes, Mark W.

    2014-09-01

    This report documents the collection of experimental test data and presents performance characteristics for the AeroValve brand prototype pneumatic bidirectional solenoid valves tested at the Oak Ridge National Laboratory (ORNL) in July/August 2014 as part of a validation of AeroValve energy efficiency claims. The test stand and control programs were provided by AeroValve. All raw data and processing are included in the report attachments.

  9. Analysis of Flow in Pilot Operated Safety and Relief Valve of Nuclear Reactor Coolant System

    SciTech Connect (OSTI)

    Kwon, Soon-Bum; Lee, Dong-Won; Kim, In-Goo; Ahn, Hyung-Joon; Kim, Hho-Jung

    2004-07-01

    When the POSRV equipped in a nuclear power plant opens in instant by a failure in coolant system of PWR, a moving shock wave generates, and propagates downstream of the valve, inducing a complicated unsteadiness. The moving shock wave may exert severe load to the structure. In this connection, a method of gradual opening of the valve is used to reduce the load acting on the wall at the downstream of the POSRV. In the present study, experiments and calculations are performed to investigate the detail unsteady flow at the various pipe units and the effect of valve opening time on the flow downstream of the valve. In calculation by using of air as working fluid, 2-dimensional, unsteady compressible Navier-Stokes equations are solved by finite volume method. It was found that when the incident shock wave passes through the pipe unit, it may experience diffraction, reflection and interaction with a vortex. Furthermore, the geometry of the pipe unit affects the reflection type of shock wave and changes the load acting on the wall of pipe unit. It was also turned out that the maximum force acting on the wall of the pipe unit becomes in order of T-junction, 108 deg. elbow and branch in magnitude, respectively. And, the results obtained that show that the rapid pressure rise due to the moving shock wave by instant POSRV valve opening is attenuated by employing the gradual opening. (authors)

  10. OPTIMIZATION OF AUTOMOTIVE VALVE TRAIN COMPONENTS WITH IMPLICT FILTERING \\Lambda

    E-Print Network [OSTI]

    Filtering, Mechanical Systems, Automotive Valve Trains AMS subject classifications. 65K05, 65K10, 65L05, 65YOPTIMIZATION OF AUTOMOTIVE VALVE TRAIN COMPONENTS WITH IMPLICT FILTERING \\Lambda T. D. CHOI y , O identification and optimization in automotive valve train design. We extend our previous work by using a more

  11. Pressure Transient Flow Forces for Hydraulic Spool Valves

    E-Print Network [OSTI]

    Manring, Noah D.

    of the fluid passing through the valve itself. These mo- mentum effects are familiarly known as flow forces and are generally quite substantial when a large amount of flow is passing through the valve. The size of the flowPressure Transient Flow Forces for Hydraulic Spool Valves Noah D. Manring1 Shusen Zhang Mechanical

  12. Luminescent spin-valve transistor Ian Appelbaum,a)

    E-Print Network [OSTI]

    Russell, Kasey

    , the spin- valve transistor SVT , modulates a hot-electron current passing perpendicularly throughLuminescent spin-valve transistor Ian Appelbaum,a) K. J. Russell, D. J. Monsma, V. Narayanamurti Received 29 July 2003; accepted 7 October 2003 A magneto-optical sensor, the luminescent spin-valve

  13. Noise Reduction of a Turbofan Bleed Valve Vincent Phong1

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    Noise Reduction of a Turbofan Bleed Valve Vincent Phong1 , Shervin Taghavi Nezhad2 , Feng Liu3 and computational research effort investigated the noise sources of a pneumatic bleed valve used in turbofan engines, rapid-prototyped valve designs which enabled the exploration of a large parameter space. Microphone

  14. Collagen Bundle Orientation Explains Aortic Valve Leaflet Coaptation

    E-Print Network [OSTI]

    Collagen Bundle Orientation Explains Aortic Valve Leaflet Coaptation Peter E. Hammer1 , Christina A. The aortic valve owes its strength and durability to a network of collagen fibers within the leaflets. However, the pattern of these fibers and their role in valve function is not well understood. We imaged

  15. Modeling Mitral Valve Leaflets from Three-Dimensional Ultrasound

    E-Print Network [OSTI]

    Modeling Mitral Valve Leaflets from Three-Dimensional Ultrasound Robert J. Schneider1 , William C for mechani- cal models predicting valve closure. Current methods for leaflet modeling from ultrasound either. The presented method for modeling the mitral leaflets from three-dimensional ultrasound of an open mitral valve

  16. Spin-valve photodiode Ian Appelbaum,a)

    E-Print Network [OSTI]

    Russell, Kasey

    Spin-valve photodiode Ian Appelbaum,a) D. J. Monsma, K. J. Russell, V. Narayanamurti, and C. M; accepted 28 August 2003 An optical spin-valve effect is observed using sub-bandgap internal photoemission the ``spin-valve'' effect SVE , because the relative magnetizations of these layers, and thus the flow

  17. Avalanche spin-valve transistor K. J. Russell,a)

    E-Print Network [OSTI]

    Russell, Kasey

    Avalanche spin-valve transistor K. J. Russell,a) Ian Appelbaum,b) Wei Yi, D. J. Monsma, F. Capasso, California 93106 (Received 11 June 2004; accepted 10 September 2004) A spin-valve transistor with a Ga allow fabrication of spin-valve transistors with high gain in a variety of materials. © 2004 American

  18. VOICE SYNTHESIS USING THE GENERALIZED PRESSURE-CONTROLLED VALVE

    E-Print Network [OSTI]

    Li, Fei-Fei

    VOICE SYNTHESIS USING THE GENERALIZED PRESSURE-CONTROLLED VALVE Tamara Smyth and Alireza Fathi, and the vibration of vo- cal folds in the larynx, which function as a pressure-controlled valve regulating airflow into the the vocal tract. This re- search explores the application of the generalized dynamic pressure-control valve

  19. Department of Industrial Engineering Spring 2011 Machining Valve Seats

    E-Print Network [OSTI]

    Demirel, Melik C.

    PENNSTATE Department of Industrial Engineering Spring 2011 Machining Valve Seats Overview: The team worked with Quaker Chemical Corporation to machine valve seats using three different lubricants provided-degree chamfer on the valve seats are very specialized and expensive. For this project, the cutting tool

  20. Germanium Nanowire Spin-Valve Device (DMR-0819860)

    E-Print Network [OSTI]

    Petta, Jason

    Germanium Nanowire Spin-Valve Device (DMR-0819860) E-S Liu, J. Nah, K.Varahramyan, and E. Tutuc (Univ. of Texas at Austin) Figure 1 The spin-valve device comprised of a Ge nanowire bracketed by two in direction, the spin current is suppressed (spin-valve action). An applied magnetic field By is used

  1. Mechanobiology of the Aortic Heart Valve Jonathan T. Butcher1

    E-Print Network [OSTI]

    Simmons, Craig A.

    Review: Mechanobiology of the Aortic Heart Valve Jonathan T. Butcher1 , Craig A. Simmons2 , James N valve, positioned between the left ventri- cle and aortic root, prevents retrograde flow of blood into the ventricle during diastole. Opening and closing of the valve occurs passively in response to inertial forces

  2. Modelisation mathematique realiste de la valve mitrale Sabine Paeme

    E-Print Network [OSTI]

    Wolper, Pierre

    Mod´elisation math´ematique r´ealiste de la valve mitrale Sabine Paeme Mai 2009 #12;Table des mati . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2 Les valves cardiaques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.2.2 Anatomie de la valve mitrale . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.3 Physiologie

  3. Right Ventricular Outflow Tract Reconstruction with Bicuspid Valved Polytetrafluoroethylene Conduit

    E-Print Network [OSTI]

    Pekkan, Kerem

    Running Head. Bicuspid valved PTFE conduit Authors. MasahiroYoshida, MD1), Peter D.Wearden, MD, PhD1.yoshida@chp.edu Bicuspid valved PTFE conduit M. Yoshida et al -1- #12;Abstract Background: In general, all conduits we have developed and utilized a bicuspid valved polytetrafluoroethylene conduit (PTFE

  4. Nonlinear Control for Magnetic Levitation of Automotive Engine Valves

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    1 Nonlinear Control for Magnetic Levitation of Automotive Engine Valves Katherine Peterson, Member for and implemented on an electromagnetic valve actuator for use in automotive engines, the control methodology, it is experimentally eval- uated on an electromagnetic valve actuator designed for use in the actuation of automotive

  5. "Non-Reflective" Boundary Design via Remote Sensing and PID Control Valve

    SciTech Connect (OSTI)

    Zhang, Qin Fen; Karney, Professor Byran W.; Pejovic, Dr. Stanislav

    2011-01-01

    This paper develops the concept of a nonreflective (or semireflective) boundary condition using the combination of a remote sensor and a control system to modulate a relief valve. The essential idea is to sense the pressure change at a remote location and then to use the measured data to adjust the opening of an active control valve at the end of the line to eliminate or attenuate the wave reflections at the valve, thus controlling system transient pressures. This novel idea is shown here through numerical simulation to have considerable potential for transient protection. Using this model, wave reflections and resonance can be effectively eliminated for frictionless pipelines or initial no-flow conditions and can be better controlled in more realistic pipelines for a range of transient disturbances. In addition, the features of even-order harmonics and nonreflective boundary conditions during steady oscillation, obtained through time domain transient analysis, are verified by hydraulic impedance analysis in the frequency domain.

  6. OPTIMAL LOCATION OF ISOLATION VALVES IN WATER

    E-Print Network [OSTI]

    Mays, Larry W.

    CHAPTER 7 OPTIMAL LOCATION OF ISOLATION VALVES IN WATER DISTRIBUTION SYSTEMS: A RELIABILITY The cornerstone of any healthy population is access to safe drinking water. The goal of the United Nations International Drinking Water Supply and Sanitation Decade from 1981 to 1990 was safe drinking water for all

  7. Disc valve for sampling erosive process streams

    DOE Patents [OSTI]

    Mrochek, J.E.; Dinsmore, S.R.; Chandler, E.W.

    1984-08-16

    This is a patent for a disc-type, four-port sampling valve for service with erosive high temperature process streams. Inserts and liners of ..cap alpha..-silicon carbide respectively, in the faceplates and in the sampling cavities, limit erosion while providing lubricity for a smooth and precise operation. 1 fig.

  8. Microfluidic Cell Electroporation Using a Mechanical Valve

    E-Print Network [OSTI]

    Lu, Chang

    Microfluidic Cell Electroporation Using a Mechanical Valve Jun Wang, M. Jane Stine, and Chang Lu Center, and Bindley Bioscience Center, Purdue University, West Lafayette, Indiana 47907 A microfluidic of integrating electroporation as a unit operation in large- scale microfluidic systems with the increasing

  9. Energy-Saving Design for Pressure Difference Control in Variable Flow Air Conditioning Systems 

    E-Print Network [OSTI]

    Chen, Y.; Zhang, Z.

    2006-01-01

    This paper analyzes energy-saving design for pressure-difference control in a variable flow air conditioning system, including the application of a pressure-difference control valve and the installation position of a pressure-difference transducer...

  10. Statistical Performance Evaluation Of Soft Seat Pressure Relief Valves

    SciTech Connect (OSTI)

    Harris, Stephen P.; Gross, Robert E.

    2013-03-26

    Risk-based inspection methods enable estimation of the probability of failure on demand for spring-operated pressure relief valves at the United States Department of Energy's Savannah River Site in Aiken, South Carolina. This paper presents a statistical performance evaluation of soft seat spring operated pressure relief valves. These pressure relief valves are typically smaller and of lower cost than hard seat (metal to metal) pressure relief valves and can provide substantial cost savings in fluid service applications (air, gas, liquid, and steam) providing that probability of failure on demand (the probability that the pressure relief valve fails to perform its intended safety function during a potentially dangerous over pressurization) is at least as good as that for hard seat valves. The research in this paper shows that the proportion of soft seat spring operated pressure relief valves failing is the same or less than that of hard seat valves, and that for failed valves, soft seat valves typically have failure ratios of proof test pressure to set pressure less than that of hard seat valves.

  11. Mixed mode fuel injector with individually moveable needle valve members

    DOE Patents [OSTI]

    Stewart, Chris; Chockley, Scott A.; Ibrahim, Daniel R.; Lawrence, Keith; Tomaseki, Jay; Azam, Junru H.; Tian, Steven Ye; Shafer, Scott F.

    2004-08-03

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. One of the needle valve members moves to an open position while the other needle valve member remains stationary for a homogeneous charge injection event. The former needle valve member stays stationary while the other needle valve member moves to an open position for a conventional injection event. One of the needle valve members is at least partially positioned in the other needle valve member. Thus, the injector can perform homogeneous charge injection events, conventional injection events, or even a mixed mode having both types of injection events in a single engine cycle.

  12. Hydraulically actuated gas exchange valve assembly and engine using same

    DOE Patents [OSTI]

    Carroll, Thomas S. (Peoria, IL); Taylor, Gregory O. (Hinsdale, IL)

    2002-09-03

    An engine comprises a housing that defines a hollow piston cavity that is separated from a gas passage by a valve seat. The housing further defines a biasing hydraulic cavity and a control hydraulic cavity. A gas valve member is also included in the engine and is movable relative to the valve seat between an open position at which the hollow piston cavity is open to the gas passage and a closed position in which the hollow piston cavity is blocked from the gas passage. The gas valve member includes a ring mounted on a valve piece and a retainer positioned between the ring and the valve piece. A closing hydraulic surface is included on the gas valve member and is exposed to liquid pressure in the biasing hydraulic cavity.

  13. Technical evaluation: 300 Area steam line valve accident

    SciTech Connect (OSTI)

    Not Available

    1993-08-01

    On June 7, 1993, a journeyman power operator (JPO) was severely burned and later died as a result of the failure of a 6-in. valve that occurred when he attempted to open main steam supply (MSS) valve MSS-25 in the U-3 valve pit. The pit is located northwest of Building 331 in the 300 Area of the Hanford Site. Figure 1-1 shows a layout of the 300 Area steam piping system including the U-3 steam valve pit. Figure 1-2 shows a cutaway view of the approximately 10- by 13- by 16-ft-high valve pit with its various steam valves and connecting piping. Valve MSS-25, an 8-in. valve, is located at the bottom of the pit. The failed 6-in. valve was located at the top of the pit where it branched from the upper portion of the 8-in. line at the 8- by 8- by 6-in. tee and was then ``blanked off`` with a blind flange. The purpose of this technical evaluation was to determine the cause of the accident that led to the failure of the 6-in. valve. The probable cause for the 6-in. valve failure was determined by visual, nondestructive, and destructive examination of the failed valve and by metallurgical analysis of the fractured region of the valve. The cause of the accident was ultimately identified by correlating the observed failure mode to the most probable physical phenomenon. Thermal-hydraulic analyses, component stress analyses, and tests were performed to verify that the probable physical phenomenon could be reasonably expected to produce the failure in the valve that was observed.

  14. Development of a variable-temperature ion mobility/ time-of-flight mass spectrometer for separation of electronic isomers 

    E-Print Network [OSTI]

    Verbeck, Guido Fridolin

    2005-08-29

    The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to demonstrate the ability to discriminate between electronic isomers. Ion mobility allows for the separation...

  15. Are subsurface safety valves needed in deepwater?

    SciTech Connect (OSTI)

    Verret, A.; Hey, C.

    1995-11-01

    The object of this study was to evaluate SCSSV reliability and identify a preferred configuration for subsea completions in deepwater. A system design consisting of subsea, conventional, dual-bore tree, cluster wells was selected for evaluation. The study examined inherent risks associated with six tubing retrievable SCSSV configurations. Risks were evaluated for personnel and environmental safety, and operational and financial impact of: No SCSSV; Single SCSSV; Dual operating system single SCSSV; Tandem hot/hot (both valves active) SCSSVs without lockout features; Tandem hot/hot SCSSVs with lockout features; Tandem hot/cold (one valve active, the other dormant in open position) SCSSVs with lockout features. A ``fault tree`` identifying events that could lead to deleterious incidents was used to evaluate risks. Costs and consequences associated with potential events were determined using existing industry data, and resulting calculated risks were evaluated. Recommendations were developed and compared to current regulations, and potential regulatory conflicts were identified.

  16. Method and system for measuring gate valve clearances and seating force

    DOE Patents [OSTI]

    Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN); Moyers, John C. (Oak Ridge, TN); Stewart, Brian K. (Burns, TN)

    1996-01-01

    Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

  17. Developing a Training Tool for Intraoperative Mitral Valve Analysis Neil A. Tenenholtz, Robert D. Howe

    E-Print Network [OSTI]

    Developing a Training Tool for Intraoperative Mitral Valve Analysis Neil A. Tenenholtz, Robert D@seas.harvard.edu INTRODUCTION The mitral valve is one of the four valves of the human heart. Serving as a passive check valve, a healthy mitral valve permits the flow of oxygenated blood from the left atrium to the left ventricle while

  18. Cardiac Valve Annulus Manual Segmentation Using Computer Assisted Visual Feedback in Three-Dimensional Image Data

    E-Print Network [OSTI]

    Oxford, University of

    Cardiac Valve Annulus Manual Segmentation Using Computer Assisted Visual Feedback in Three is an important tool for the study of valve anatomy and physiology, for the four main valves of the heart (mitral rat hearts, on all four valves. I. INTRODUCTION There are four main cardiac valves in the heart, two

  19. Engine throttle valve position detecting system

    SciTech Connect (OSTI)

    Kamai, K.; Kikuchi, T.

    1987-03-31

    This patent describes an engine throttle valve position detecting system including: a throttle switch including a rotary detector member adapted to be rotated in accordance with the rotation of an engine throttle valve and having a guide portion including a section offset radially relative to the direction of rotation of the rotary detector member. A movable contact is movable by the rotation of the rotary detector member and a stationary contact disposed in opposed relationship to the movable contact. The stationary and movable contacts have opened and closed positions which are changed over at two different predetermined rotational positions of the rotary detector member; means for producing a signal related to the operation of the engine; means for comparing a temperature representative of the engine operating condition with a predetermined reference level; and judgment means operative, when the engine operating condition temperature is judged by the comparing means as being higher than predetermined reference level, to judge the position of the throttle valve based on one of the positions of the movable and stationary contacts and on the signal.

  20. Swing Check Valve Design Criteria and CFD Validation

    SciTech Connect (OSTI)

    Dallstream, Brian E.; Fricke, Brian A.; Becker, Bryan R. [University of Missouri-Kansas City (United States)

    2006-07-01

    This paper provides information on swing check valve selection criteria suitable for nuclear power plant applications. In this project, four swing check valves were analyzed to demonstrate the implementation and application of this information. In this example, swing check valves were selected according to 'ASME Boiler and Pressure Vessel Code, Section III' and 'ASME B16.34, Valves Flanged, Threaded, and Welding End'. This paper also discusses the utilization of Computational Fluid Dynamics Software (CFD) as a means to analyze valve design. The use of CFD is a relatively new approach for validation of valve design that is becoming invaluable due to the high cost of physical bench testing. The Instrument Society of America (ISA) Analysis Division and the American Society of Mechanical Engineers (ASME) Computational Fluid Dynamics Technical Committee have taken a proactive approach in setting standards and practices for the use of CFD in design and validation. (authors)

  1. A New Cone-Shaped Aortic Valve Prosthesis for Orthotopic Position: An Experimental Study in Swine

    SciTech Connect (OSTI)

    Sochman, Jan, E-mail: jan.sochman@medicon.c [Institute for Clinical and Experimental Medicine, Clinic of Cardiology (Czech Republic); Peregrin, Jan H.; Pulda, Zdenek [Institute for Clinical and Experimental Medicine, Department of Diagnostic and Interventional Radiology (Czech Republic); Pavcnik, Dusan; Uchida, Barry T.; Timmermans, Hans A.; Roesch, Josef [Oregon Health and Science University, Dotter Interventional Institute (United States)

    2010-04-15

    The aim of this experimental study was to evaluate a newly designed cone-shaped aortic valve prosthesis (CAVP) for one-step transcatheter placement in an orthotopic position. The study was conducted in 15 swine using either the transcarotid (11 animals) or the transfemoral (4 animals) artery approach. A 12- or 13-Fr sheath was inserted via arterial cutdown. The CAVP was deployed under fluoroscopic control and its struts, by design, induced significant native valve insufficiency. CAVP function was evaluated by aortography and aortic pressure curve tracing. In 11 of 15 swine the CAVP was properly deployed and functioned well throughout the scheduled period of 2-3 h. In three swine the CAVPs were placed lower than intended, however, they were functional even in the left ventricular outflow tract position. One swine expired due to inadvertent low CAVP placement that caused both aortic regurgitation and immobilization of the anterior mitral valve leaflet by the valve struts. We conclude that this design of CAVP is relatively easy to deploy, works well throughout a short time period (2-3 h), and, moreover, seems to be reliable even in a lower-than-orthotopic position (e.g., infra-annulary space). Longer-term studies are needed for its further evaluation.

  2. Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization

    SciTech Connect (OSTI)

    Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.; Agrawal, Nitin; Tang, Keqi; Smith, Richard D.

    2011-04-26

    A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (? 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersection geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ? 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (? 7.0 × 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, no sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed.

  3. High Performance Valve Materials (HPVM) (Agreement 16304) | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Materials (HPVM) (Agreement 16304) High Performance Valve Materials (HPVM) (Agreement 16304) Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008...

  4. Subsurface safety valve with lock-open system

    SciTech Connect (OSTI)

    Dickson, R.L.; Smith, R.R.

    1986-11-25

    A well safety valve is described comprising: a housing having a bore therethrough; a valve mounted in the housing to open and close to control the flow through the bore; an operator tube in the housing for opening the valve; means in the housing for moving the operator tube in a first direction to open and hold the valve open; means in the housing for moving the operator tube in a second direction to permit the valve to close; a temporary lockout sleeve in the housing in tandem with the operator tube for temporarily holding the valve open. The operator tube and the lockout sleeve are in end-to-end contact when the lockout sleeve is inoperative and the operator tube is holding the valve open, when the operator tube and the lockout sleeve are moving simultaneously in the housing between operating positions, and when the operator tube is inoperative and the lockout sleeve is holding the valve open; and the operator tube and the lockout sleeve each having means for coupling the operator tube and the lockout sleeve with a lockout tool for moving the operator tube and the lockout sleeve simultaneously when the lockout sleeve is moved from the inoperative to an operative position holding the valve open.

  5. Dual mode fuel injector with one piece needle valve member

    DOE Patents [OSTI]

    Lawrence, Keith E. (Peoria, IL); Hinrichsen, Michael H. (Goodfield, IL); Buckman, Colby (Bellville, MI)

    2005-01-18

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively by inner and outer needle value members. The homogenous charged nozzle outlet set is defined by an outer needle value member that is moveably positioned in an injector body, which defines the conventional nozzle outlet set. The inner needle valve member is positioned in the outer needle valve member. The outer needle valve member is a piece component that includes at least one external guide surface, an external value surface and an internal valve seat.

  6. Percutaneous aortic valve replacement in a re-animated postmortem heart

    E-Print Network [OSTI]

    White, Jennifer; Sun, Amy; Killien, Lauren; Evangelista, Dennis

    2006-01-01

    aortic valve replacements, para-valvular leakage wasof valves designed to prevent para-valvular leakage. Multi-leakage was minimal or absent, most likely due to the lack of native valve

  7. A MEMS Thin Film AlN Supercritical Carbon Dioxide Valve

    E-Print Network [OSTI]

    Chen, Ya-Mei

    2011-01-01

    will contribute the leakage of the valve system and shouldAlignment The leakage of the valve system is determined byof the valve system without increasing the leakage. If we

  8. Vacuum/Compression Valving (VCV) Using Parrafin-Wax on a Centrifugal Microfluidic CD Platform

    E-Print Network [OSTI]

    2013-01-01

    Volume 8 | Issue 3 | e58523 Vacuum/Compression Valving (VCV)Vacuum/Compression Valving (VCV) Using Parrafin-Wax on aThis paper introduces novel vacuum/compression valves (VCVs)

  9. A MEMS Thin Film AlN Supercritical Carbon Dioxide Valve

    E-Print Network [OSTI]

    Chen, Ya-Mei

    2011-01-01

    and T. K. Tang, “MEMS micro-valve for space applications”,of the fabricated thermal MEMS valve by Kim et al. [An electrostatically actuated gas valve with an s-shape film

  10. Hemodynamic Environments from Opposing Sides of Human Aortic Valve Leaflets Evoke Distinct Endothelial Phenotypes In Vitro

    E-Print Network [OSTI]

    Weinberg, Eli J.; Mack, Peter J.; Schoen, Frederick J.; García-Cardeña, Guillermo; Kaazempur Mofrad, Mohammad R.

    2010-01-01

    the most frequent heart valve disease in developed countriesand glutaraldehyde treated aortic valve cusp-part II: aof a tri-lea?et prosthetic valve. J Biomed Eng. 1989;12:13–

  11. Collaborative Research: Advancing the Diagnosis and Quantification of Mitral Valve Regurgitation with

    E-Print Network [OSTI]

    Canic, Suncica

    Collaborative Research: Advancing the Diagnosis and Quantification of Mitral Valve Regurgitation in concept development and CAD design of experimental mitral valve prolapse constructs as an summer intern Workshop "Mathematics Guide Bioartificial Heart Valve Design" (Colombus, October 2013), Biomedical

  12. Emerging Trends in Heart Valve Engineering: Part IV. Computational Modeling and Experimental Studies

    E-Print Network [OSTI]

    2015-01-01

    tissue failure (structural valve deterio- ration) by ageof excised porcine mitral valve lea?ets. Am. J. Physiol.A constitutive law for mitral valve tissue. J. Biomech. Eng.

  13. Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson and Anna G. Stefanopoulou*

    E-Print Network [OSTI]

    Sontag, Eduardo

    Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson on Sontag's feedback to render the electromechanical valve actuator (EVA) globally asymptotically stable (GAS). Elec- tromechanical valve actuators have received much attention recently due to their potential

  14. Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson*

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson to render the electromechanical valve actuator (EVA) globally asymptotically stable (GAS). Elec], piezo's [17], and hydraulic systems [8]. Electromechanical valve actuators (EVA) which use

  15. Numerical Investigation of the Performance of Three Hinge Designs of Bileaflet Mechanical Heart Valves

    E-Print Network [OSTI]

    Simon, Hélène A.; Ge, Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P.

    2010-01-01

    parameters on bilea?et mechanical heart valve ?ow dynamics.J. Heart Valve Dis. 18:535–545, 2009. Gross, J. M. , M. C.two bilea?et mechanical heart valves under aortic and mitral

  16. Flexible semi-transparent organic spin valve based on bathocuproine

    SciTech Connect (OSTI)

    Sun, Xiangnan; Bedoya-Pinto, Amilcar; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2014-08-25

    Organic semiconductors are attractive materials for advanced spintronic applications due to their long spin lifetimes and, simultaneously, their mechanical flexibility. With the aim of combining these advantages in a single device, we report on the fabrication and properties of a mechanically flexible bathocuproine-based spin valve. This organic spin device shows great stability on both electrical and magneto-transport properties upon mechanical bending at different radius (up to r?=?5?mm), while featuring long-lasting endurance (on bending over 50 times). The room-temperature magnetoresistance ratio reaches up to 3.5%, and is notably preserved under air atmosphere. The observation of spin transport at room-temperature, combined with the outstanding mechanical properties and air stability, highlights the potential of bathocuproine-based spin devices towards applications.

  17. System and method for controlling engine knock using electro-hydraulic valve actuation

    DOE Patents [OSTI]

    Brennan, Daniel G

    2013-12-10

    A control system for an engine includes a knock control module and a valve control module. The knock control module adjusts a period that one or more of an intake valve and an exhaust valve of a cylinder are open based on engine knock corresponding to the cylinder. The valve control module, based on the adjusted period, controls the one or more of the intake valve and the exhaust valve using one or more hydraulic actuators.

  18. Early-type stars observed in the ESO UVES Paranal Observatory Project - V. Time-variable interstellar absorption

    E-Print Network [OSTI]

    McEvoy, Catherine M; Dufton, Philip L; Smith, Keith T; Kennedy, Michael B; Keenan, Francis P; Lambert, David L; Welty, Daniel E; Lauroesch, James T

    2015-01-01

    The structure and properties of the diffuse interstellar medium (ISM) on small scales, sub-au to 1 pc, are poorly understood. We compare interstellar absorption-lines, observed towards a selection of O- and B-type stars at two or more epochs, to search for variations over time caused by the transverse motion of each star combined with changes in the structure in the foreground ISM. Two sets of data were used: 83 VLT- UVES spectra with approximately 6 yr between epochs and 21 McDonald observatory 2.7m telescope echelle spectra with 6 - 20 yr between epochs, over a range of scales from 0 - 360 au. The interstellar absorption-lines observed at the two epochs were subtracted and searched for any residuals due to changes in the foreground ISM. Of the 104 sightlines investigated with typically five or more components in Na I D, possible temporal variation was identified in five UVES spectra (six components), in Ca II, Ca I and/or Na I absorption-lines. The variations detected range from 7\\% to a factor of 3.6 in co...

  19. Advanced modeling ,control, and design of an electromechanical engine value drive system with a limited-angle actuator

    E-Print Network [OSTI]

    Qiu, Yihui, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    This thesis addresses a specific variable valve actuation (VVA) system ---- an electromechanical valvetrain ---- in order to provide variable valve timing (VVT) in internal combustion (IC) engines. This electromechanical ...

  20. Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket

    DOE Patents [OSTI]

    Christiansen, D.W.; Schively, D.P.

    1982-01-19

    The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  1. On the multiscale modeling of heart valve biomechanics in health and disease

    E-Print Network [OSTI]

    Weinberg, Eli J.; Shahmirzadi, Danial; Mofrad, Mohammad Reza

    2010-01-01

    carried out on simulating biomechanics of mechan- ical andmodeling of heart valve biomechanics in health and diseasemodeling of heart valve biomechanics in health and disease

  2. Disc valve for sampling erosive process streams

    DOE Patents [OSTI]

    Mrochek, J.E.; Dinsmore, S.R.; Chandler, E.W.

    1986-01-07

    A four-port disc valve is described for sampling erosive, high temperature process streams. A rotatable disc defining opposed first and second sampling cavities rotates between fired faceplates defining flow passageways positioned to be alternatively in axial alignment with the first and second cavities. Silicon carbide inserts and liners composed of [alpha] silicon carbide are provided in the faceplates and in the sampling cavities to limit erosion while providing lubricity for a smooth and precise operation when used under harsh process conditions. 1 fig.

  3. High Performance Valve Materials | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,ExecutiveFinancing ProgramsDepartment of¡High PerformancePerformance Valve

  4. Influence of pressurizer relief valves on success of ``feed and bleed`` procedure

    SciTech Connect (OSTI)

    Petelin, S.; Mavko, B.; Gortnar, O. [Univ. of Ljubljana (Slovenia). Reactor Engineering Division

    1994-12-31

    The RELAP5/MOD3.1 analysis of the accident with total loss of secondary heat sink was performed for Krsko nuclear power plant which is a two loop Westinghouse PWR power plant of 1,876 MW thermal power. In the study of ``feed and bleed`` accident managing the particular attention was given to the emergency operating procedures foreseen operator actions. This paper deals with the modeling of saturated liquid and two-phase mixture critical discharge through the pressurizer power operated relief valves and aims to evaluate its influence on the simulation of other thermal-hydraulic processes in the reactor coolant system. The time evolution of simulated accident and the determination of the longest allowed operator response time for the successful accident managing were shown to be much dependent on the prediction of critical flow through the pressurizer relief valves.

  5. Effect of reactor conditions on MSIV (main steam isolation valves)-ATWS power level

    SciTech Connect (OSTI)

    Diamond, D.J.

    1987-01-01

    In a boiling water reactor (BWR) when there is closure of the main steam isolation valves (MSIVs), the energy generated in the core will be transferred to the pressure suppression pool (PSP) via steam flows out of the relief valves. The pool has limited capacity as a heat sink and hence, if there is no reactor trip (an ATWS event), there is the possibility that the pool temperature may rise beyond acceptable limits. The present study was undertaken to determine how the initial reactor conditions affect the power during an MSIV-ATWS event. The time of interest is during the 20-30 minute period when it is assumed that the reactor is in a quasi-equilibrium condition with the water level and pressure fixed, natural circulation conditions and no control rod movement or significant boron in the core. The initial conditions of interest are the time during the cycle and the operating state. 4 refs., 2 tabs.

  6. ON CONDITION MONITORING OF EXHAUST VALVES IN MARINE DIESEL ENGINES

    E-Print Network [OSTI]

    Mosegaard, Klaus

    ON CONDITION MONITORING OF EXHAUST VALVES IN MARINE DIESEL ENGINES T. L. Fog x L. K. Hansen z , J : Research & Development, MAN B&W Diesel A/S Teglholmsgade 41, DK­2450, Copenhagen SV, Denmark. E­mail: tof­invasive characterisation of ex­ haust valve conditions in large marine diesel engines, were exper­ imentally investigated

  7. Negative Valve Overlap Reforming Chemistry in Low-Oxygen Environments

    SciTech Connect (OSTI)

    Szybist, James P [ORNL] [ORNL; Steeper, Richard R. [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Splitter, Derek A [ORNL] [ORNL; Kalaskar, Vickey B [ORNL] [ORNL; Pihl, Josh A [ORNL] [ORNL; Daw, C Stuart [ORNL] [ORNL

    2014-01-01

    Fuel injection into the negative valve overlap (NVO) period is a common method for controlling combustion phasing in homogeneous charge compression ignition (HCCI) and other forms of advanced combustion. When fuel is injected into O2-deficient NVO conditions, a portion of the fuel can be converted to products containing significant levels of H2 and CO. Additionally, other short chain hydrocarbons are produced by means of thermal cracking, water-gas shift, and partial oxidation reactions. The present study experimentally investigates the fuel reforming chemistry that occurs during NVO. To this end, two very different experimental facilities are utilized and their results are compared. One facility is located at Oak Ridge National Laboratory, which uses a custom research engine cycle developed to isolate the NVO event from main combustion, allowing a steady stream of NVO reformate to be exhausted from the engine and chemically analyzed. The other experimental facility, located at Sandia National Laboratories, uses a dump valve to capture the exhaust from a single NVO event for analysis. Results from the two experiments are in excellent trend-wise agreement and indicate that the reforming process under low-O2 conditions produces substantial concentrations of H2, CO, methane, and other short-chain hydrocarbon species. The concentration of these species is found to be strongly dependent on fuel injection timing and injected fuel type, with weaker dependencies on NVO duration and initial temperature, indicating that NVO reforming is kinetically slow. Further, NVO reforming does not require a large energy input from the engine, meaning that it is not thermodynamically expensive. The implications of these results on HCCI and other forms of combustion are discussed in detail.

  8. Throttle valve control device for internal combustion engines

    SciTech Connect (OSTI)

    Ejiri, Y.; Ito, T.

    1988-05-31

    In a throttle valve control device for controlling a position of an engine throttle valve secured to a rotary shaft, which includes a control unit operative to produce a first electrical signal in accordance with a movement of an engine accelerator and an electro-mechanical force transducer operative to impart a first rotational torque to the rotary shaft and thereby to the throttle valve, the first rotational torque corresponding to the first electrical signal, the improvement is described comprising: a throttle valve returning means operative to produce a second rotational torque for biasing the throttle valve to a fully closed position irrespective of the movement of the engine accelerator and means responsive to the second electrical signal to transmit the second rotational torque to the rotary shaft irrespective of the movement of the engine accelerator.

  9. SOFTWARE ENABLED VARIABLE DISPLACEMENT PUMPS -EXPERIMENTAL Michael B. Rannow, Haink C. Tu, Perry Y. Liand Thomas R. Chase

    E-Print Network [OSTI]

    Li, Perry Y.

    SOFTWARE ENABLED VARIABLE DISPLACEMENT PUMPS - EXPERIMENTAL STUDIES Michael B. Rannow, Haink C. Tu of hydraulic systems are controlled using a me- tering valve or the use of variable displacement pumps to throttling losses. Variable displace- ment pumps are far more efficient as the pump only produces

  10. In-line real time air monitor

    DOE Patents [OSTI]

    Wise, Marcus B. (Kingston, TN); Thompson, Cyril V. (Knoxville, TN)

    1998-01-01

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds.

  11. In-line real time air monitor

    DOE Patents [OSTI]

    Wise, M.B.; Thompson, C.V.

    1998-07-14

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds. 3 figs.

  12. Rotary acting shear valve for drilling fluid telemetry systems

    SciTech Connect (OSTI)

    Larronde, M.L.

    1986-12-16

    This patent describes a valve apparatus useful in a borehole drilling fluid telemetry system for transmitting data pulses from one end of a pipe string to another by imparting pressure pulses to a drilling fluid circulating down the pipe string, through a drilling member and up the annulus between the pipe string and borehole wall. The valve is operated in the drilling fluid flow path to modulate the flow of the drilling fluid and thereby impart detectable pressure pulses to the drilling fluid. The apparatus comprises a housing disposable within the drill string, adapted for the flow of drilling fluid therearound and formed with a passage therethrough for selectable flow communication between the drill string and the borehole annulus; a shear valve mounted within the housing across the passage and comprising a valve seat and rotational gate member having alignable seat and gate openings formed therethrough, the gate opening being movable in an arc into and out of axial alignment with the seat opening; and valve actuation means for coupling to the gate for rotationally moving the gate opening through an arc relative to the seat opening to open the passage and generate a pressure pulse. The valve actuation means comprises a first solenoid and cam means coupled thereto for translating the non-linear, axial forces of the solenoid into generally linear, rotational forces for rotating the valve gate.

  13. Automated Modelling of Cartridge Valve Flow Mapping Song Liu and Bin Yao

    E-Print Network [OSTI]

    Yao, Bin

    significantly saving energy usage. Unlike costly conventional four-way valves, the cartridge valve has simple poppet-type cartridge valves are the key elements of the energy saving programmable valves, which have and practicality of the proposed novel automated modelling method. I. INTRODUCTION The energy saving programmable

  14. Micromagnetics Simulation of Asymmetric Pseudo-Spin Valve Dots C. A. Ross,2

    E-Print Network [OSTI]

    Donahue, Michael J.

    Micromagnetics Simulation of Asymmetric Pseudo-Spin Valve Dots N. Dao,1 C. A. Ross,2 F. J. Castaño)/Co (4nm) pseudo-spin valves. These simulations have been conducted on several different aspect ratios and pseudo-spin valves [2-4]. There have been recent reports of fabrication of pseudo-spin valves with sub

  15. Massive Gas Injection Experiments at JET – Performance and Characterisation of the Disruption Mitigation Valve

    E-Print Network [OSTI]

    Massive Gas Injection Experiments at JET – Performance and Characterisation of the Disruption Mitigation Valve

  16. Phase diagram of magnetic domain walls in spin valve nano-stripes N. Rougemaille,1

    E-Print Network [OSTI]

    Boyer, Edmond

    Phase diagram of magnetic domain walls in spin valve nano-stripes N. Rougemaille,1 V. Uhlí,2, 1 O walls in Co/Cu/Py spin valve nano-stripes (Py: Permalloy), in which the Co layer is mostly single domain Magneto- Resistance. These stacking are called spin valve for a metal spacer layer, and pseudo spin valve

  17. Review Article The aortic valve microenvironment and its role in calcific aortic

    E-Print Network [OSTI]

    Simmons, Craig A.

    Review Article The aortic valve microenvironment and its role in calcific aortic valve disease 21 November 2010; accepted 1 December 2010 Abstract In calcific aortic valve disease, fibrotic and calcific lesions form focally in the fibrosa layer of the valve leaflets. Layer

  18. IN-PLANE BANDPASS REGULATION CHECK VALVE IN HEAT-SHRINK PACKAGING FOR DRUG DELIVERY

    E-Print Network [OSTI]

    Meng, Ellis

    IN-PLANE BANDPASS REGULATION CHECK VALVE IN HEAT-SHRINK PACKAGING FOR DRUG DELIVERY R. Lo and E. Meng University of Southern California, Los Angeles, California, USA ABSTRACT The first check valve valve design and these results were confirmed experimentally. The valve regulates flow between 150

  19. Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve

    E-Print Network [OSTI]

    Petta, Jason

    Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve Michael Hsu Advisor heart valve · Static analysis of leaflet under uniform pressure of 10 MPa Summer Objectives · Find Heart valve disease · Over 5 million affected · Over 225,000 valve- replacement surgeries performed

  20. MODELING AND VALIDATION OF A HIGH SPEED ROTARY PWM ON/OFF VALVE Haink C. Tu

    E-Print Network [OSTI]

    Li, Perry Y.

    MODELING AND VALIDATION OF A HIGH SPEED ROTARY PWM ON/OFF VALVE Haink C. Tu Center for Compact and Efficient Fluid Power Department of Mechanical Engineering University of Minnesota Minneapolis, Minnesota designed specifically for PWM. In comparison to con- ventional valves, the rotary valve reduces valve

  1. Noninvasive valve monitor using constant magnetic and/or DC electromagnetic field

    DOE Patents [OSTI]

    Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN)

    1993-01-01

    One or more sources of steady magnetic field are carefully located on the outside of a valve body. The constant magnetic field is transmitted into the valve body and valve internals. A magnetic field detector carefully located on the outside of the valve body detects the intensity of the magnetic field at its location. As the position of a valve internal part is changed, there is an alteration in the magnetic field in the valve, and a consequent change in the detected magnetic field. Changes in the detected signal provide an indication of the position and motion of the valve internals.

  2. DISCRETE-TIME SIMULATION OF AIR-FLOW CUT-OFF IN PRESSURE-CONTROLLED Tamara Smyth, Jonathan Abel, Julius Smith

    E-Print Network [OSTI]

    Smyth, Tamara

    is similar to that of a leaky valve where the leakage decreases as the volume flow decreases. 1. INTRODUCTIONDISCRETE-TIME SIMULATION OF AIR-FLOW CUT-OFF IN PRESSURE-CONTROLLED VALVES Tamara Smyth, Jonathan of the differential equation govern- ing volume flow through a pressure-controlled valve is examined with particular

  3. Hemodynamic Changes following Aortic Valve Bypass: A Mathematical Approach

    E-Print Network [OSTI]

    Benevento, Emilia

    Aortic valve bypass (AVB) has been shown to be a viable solution for patients with severe aortic stenosis (AS). Under this circumstance, the left ventricle (LV) has a double outlet. The objective was to develop a mathematical ...

  4. Design of an electronically-actuated gas lift safety valve

    E-Print Network [OSTI]

    Yu, Changkuan, S.M. Massachusetts Institute of Technology

    2013-01-01

    Gas lift valves are widely used in oil production fields to pump recycled gas and nitrogen into the production tubing, to sustain production by aerating the oil and lifting it to the ground or sea surface. Today's industry ...

  5. Analog and digital control of an electronic throttle valve

    E-Print Network [OSTI]

    Martins, Tomás V

    2012-01-01

    Two electronic throttler controllers were designed and implemented for an automotive throttle valve on a four-cylinder, spark-ignition gasoline engine. The first controller was designed using operational amplifiers and ...

  6. Replace Pressure-Reducing Valves with Backpressure Turbogenerators

    SciTech Connect (OSTI)

    Not Available

    2006-01-01

    This revised ITP steam tip sheet on replacing pressure-reducing valves provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

  7. Nonlinear springs with applications to flow regulation valves and mechanisms

    E-Print Network [OSTI]

    Freeman, David Calvin

    2008-01-01

    This thesis focuses on the application of nonlinear springs for fluid flow control valves where geometric constraints, or fabrication technologies, limit the use of available solutions. Types of existing nonlinear springs ...

  8. Covered Product Category: Pre-Rinse Spray Valves | Department...

    Energy Savers [EERE]

    Using the Cost-Effectiveness Table In Table 2 above, the Required pre-rinse spray valve is cost-effective if its purchase price is no more than 435 above that of the Base...

  9. Pinch valves fight clogging, leaking and wear in FGD systems

    SciTech Connect (OSTI)

    Schneider, L.

    1982-12-01

    Pinch valves can provide a non-sticking, non-leaking, low maintenance system capable of controlling the flow of abrasive limestone slurries such as are found in flue gas desulphurisation units.

  10. Failure Mode and Sensitivity Analysis of Gas Lift Valves

    E-Print Network [OSTI]

    Gilbertson, Eric W.

    Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

  11. Energy Savings Potential of Process Control Valve Replacement 

    E-Print Network [OSTI]

    Holzenthal, L. Jr.

    1994-01-01

    A review of current design methods for industrial process control systems that utilize modulated control valves as their final element is presented. The infornUltion that is available is then used to find the theoretic ...

  12. Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies

    SciTech Connect (OSTI)

    Szybist, J. P.; Confer, K.

    2012-09-11

    Delphi Automotive Systems and ORNL established this CRADA to advance the commercialization potential of the homogeneous charge compression ignition (HCCI) advanced combustion strategy for gasoline engine platforms. HCCI combustion has been shown by others to produce high diesel-like efficiency on a gasoline engine platform while simultaneously producing low NOX and particulate matter emissions. However, the commercialization barriers that face HCCI combustion are significant, with requirements for a more active engine control system, likely with next-cycle closed-loop feedback control, and with advanced valve train technologies to enable negative valve overlap conditions. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has made a number of breakthroughs with production-intent valve train technologies and controls in recent years to make a part time production-intent HCCI engine plausible. ORNL has extensive knowledge and expertise with HCCI combustion, and also has a versatile research engine with hydraulic valve actuation (HVA) that is useful for guiding production of a cam-based HCCI system. Partnering these knowledge bases and capabilities was essential towards making progress to better understand HCCI combustion and the commercialization barriers that it faces. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided guidance to ORNL regarding operational strategies to investigate on their single-cylinder research engine with HVA and data from their experimental multi-cylinder engine for modeling. ORNL provided single-cylinder engine data and modeling results.

  13. Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-09-03

    1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

  14. Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-11-13

    1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

  15. Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-06-06

    1 inch Gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

  16. Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves

    SciTech Connect (OSTI)

    VAN KATWIJK, C.

    2000-10-23

    1 inch Gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fall closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

  17. The Mercedez-Benz four-valve diesel

    SciTech Connect (OSTI)

    Not Available

    1995-01-01

    This article describes changes made to the standard two-valve-per-cylinder naturally aspirated prechamber engine series produced by Mercedes-Benz since 1983. These changes to valves, prechamber location and intake systems improve torque and allow this diesel engine to be sold in all of the US. Topics of the article include improving air charge, emission behavior, fuel-heating system, and intake system.

  18. Valving for controlling a fluid-driven reciprocating apparatus

    DOE Patents [OSTI]

    Whitehead, John C. (Davis, CA)

    1995-01-01

    A pair of control valve assemblies for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve assembly is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. Each of the valve assemblies uses an intake-exhaust valve and a signal valve with the signal valve of one pump being connected to be pressure responsive to the piston of the opposite cylinder or pump.

  19. Valving for controlling a fluid-driven reciprocating apparatus

    DOE Patents [OSTI]

    Whitehead, J.C.

    1995-06-27

    A pair of control valve assemblies is described for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve assembly is switched by a pressure signal depending on the state of its counterpart`s piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. Each of the valve assemblies uses an intake-exhaust valve and a signal valve with the signal valve of one pump being connected to be pressure responsive to the piston of the opposite cylinder or pump. 15 figs.

  20. Tissue-engineered canine mitral valve constructs as In vitro research models for myxomatous mitral valve disease 

    E-Print Network [OSTI]

    Liu, Mengmeng

    2014-11-28

    Myxomatous mitral valve disease (MMVD) is one of the most common degenerative cardiac diseases affecting humans and dogs; however, its pathogenesis is not completely understood. This study focussed on developing ...

  1. Gas lift valve failure mode analysis and the design of a thermally-actuated positive-locking safety valve

    E-Print Network [OSTI]

    Gilbertson, Eric (Eric W.)

    2010-01-01

    Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

  2. High pressure capillary micro-fluidic valve device and a method of fabricating same

    DOE Patents [OSTI]

    Crocker, Robert W. (Fremont, CA); Caton, Pamela F. (Berkely, CA); Gerhardt, Geoff C. (Milbury, MA)

    2007-04-17

    A freeze-thaw valve and a method of micro-machining the freeze-thaw valve is provided and includes a valve housing, wherein the valve housing defines a housing cavity and includes a housing inlet, a housing vent, a capillary tubing inlet and a capillary tubing outlet. A valve body is provided, at least a portion of which is lithographically constructed, wherein the valve body includes a refrigerant inlet, a refrigerant outlet and an expansion chamber. The expansion chamber is disposed to communicate the refrigerant inlet with the refrigerant outlet and includes a restriction region having a flow restriction. Additionally, the valve body is disposed within the housing cavity to form an insulating channel between the valve housing and the valve body.

  3. Engine including hydraulically actuated valvetrain and method of valve overlap control

    DOE Patents [OSTI]

    Cowgill, Joel (White Lake, MI)

    2012-05-08

    An exhaust valve control method may include displacing an exhaust valve in communication with the combustion chamber of an engine to an open position using a hydraulic exhaust valve actuation system and returning the exhaust valve to a closed position using the hydraulic exhaust valve actuation assembly. During closing, the exhaust valve may be displaced for a first duration from the open position to an intermediate closing position at a first velocity by operating the hydraulic exhaust valve actuation assembly in a first mode. The exhaust valve may be displaced for a second duration greater than the first duration from the intermediate closing position to a fully closed position at a second velocity at least eighty percent less than the first velocity by operating the hydraulic exhaust valve actuation assembly in a second mode.

  4. Monovalve with integrated fuel injector and port control valve, and engine using same

    DOE Patents [OSTI]

    Milam, David M. (Metamora, IL)

    2001-11-06

    An engine includes an engine casing that defines a hollow piston cavity separated from an exhaust passage and an intake passage by a valve seat. A gas exchange valve member is positioned adjacent the valve seat and is moveable between an open position and a closed position. The gas exchange valve member also defines an opening that opens into the hollow piston cavity. A needle valve member is positioned in the gas exchange valve member adjacent a nozzle outlet and is moveable between an inject position and a blocked position. A port control valve member, which has a hydraulic surface, is mounted around the gas exchange valve member and moveable between an intake position and an exhaust position. A pilot valve is moveable between a first position at which the port control hydraulic surface is exposed to a source of high pressure fluid, and a second position at which the port control hydraulic surface is exposed to a source of low pressure fluid.

  5. Externally heated valve engine -- An alternative to the Stirling engine

    SciTech Connect (OSTI)

    Kazimierski, Z.; Brzeski, L.

    1996-12-31

    A new concept of the Externally Heated Valve (EHV) engine is presented. The principle of the engine operation is described in the introduction to the paper. Heat delivered to the working medium (air) in the heater, or several heaters working commutatively, can come from a combustion chamber or other heat generator such as nuclear reactors or solar collectors. The engine construction is original entirely different from the well-known Stirling engine. New results of the EHV engine computer modeling are presented. This is connected with a new kind of the annular heater applied to the EHV engine. A whirl motion inside the heater is caused to ensure the proper condition of the heat exchanger during the whole engine cycle. Three heaters working commutatively have been considered in this model. Comparisons between the power and efficiency of the Stirling engine and EHV engine have been performed for the same engine capacity, rotational frequency, maximum and minimum temperatures of the working gas and for the same mean pressures of both the engine cycles. The power of the EHV engine is in this case over three times higher than the Stirling engine power, while the efficiency of both the engines is almost the same.

  6. System and method for controlling hydraulic pressure in electro-hydraulic valve actuation systems

    DOE Patents [OSTI]

    Brennan, Daniel G; Marriott, Craig D; Cowgill, Joel; Wiles, Matthew A; Patton, Kenneth James

    2014-09-23

    A control system for an engine includes a first lift control module and a second lift control module. The first lift control module increases lift of M valves of the engine to a predetermined valve lift during a period before disabling or re-enabling N valves of the engine. The second lift control module decreases the lift of the M valves to a desired valve lift during a period after enabling or re-enabling the N valves of the engine, wherein N and M are integers greater than or equal to one.

  7. Design and Testing of Vacuum Breaker Check Valve for Simplified Boiling Water Reactor

    SciTech Connect (OSTI)

    Ishii, M.; Xu, Y.; Revankar, S.T.

    2002-07-01

    A new design of the vacuum breaker check valve was developed to replace the mechanical valve in a simplified boiling water reactor. Scaling and design calculations were performed to obtain the geometry of new passive hydraulic vacuum breaker check valve. In order to check the valve performance, a RELAP5 model of the simplified boiling water reactor system with the new valve was developed. The valve was implemented in an integral facility, PUMA and was tested for large break loss of coolant accident. (authors)

  8. Reduced-impact sliding pressure control valve for pneumatic hammer drill

    DOE Patents [OSTI]

    Polsky, Yarom (Oak Ridge, TN); Grubelich, Mark C. (Albuquerque, NM); Vaughn, Mark R. (Albuquerque, NM)

    2012-05-15

    A method and means of minimizing the effect of elastic valve recoil in impact applications, such as percussive drilling, where sliding spool valves used inside the percussive device are subject to poor positioning control due to elastic recoil effects experienced when the valve impacts a stroke limiting surface. The improved valve design reduces the reflected velocity of the valve by using either an energy damping material, or a valve assembly with internal damping built-in, to dissipate the compression stress wave produced during impact.

  9. ISOLOK VALVE ACCEPTANCE TESTING FOR DWPF SME SAMPLING PROCESS

    SciTech Connect (OSTI)

    Edwards, T.; Hera, K.; Coleman, C.; Jones, M.; Wiedenman, B.

    2011-12-05

    Evaluation of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. Of the opportunities, a focus area related to optimizing the equipment and efficiency of the sample turnaround time for DWPF Analytical Laboratory was identified. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) evaluated the possibility of using an Isolok{reg_sign} sampling valve as an alternative to the Hydragard{reg_sign} valve for taking process samples. Previous viability testing was conducted with favorable results using the Isolok sampler and reported in SRNL-STI-2010-00749 (1). This task has the potential to improve operability, reduce maintenance time and decrease CPC cycle time. This report summarizes the results from acceptance testing which was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 (2) and which was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNL-RP-2011-00145 (3). The Isolok to be tested is the same model which was tested, qualified, and installed in the Sludge Receipt Adjustment Tank (SRAT) sample system. RW-0333P QA requirements apply to this task. This task was to qualify the Isolok sampler for use in the DWPF Slurry Mix Evaporator (SME) sampling process. The Hydragard, which is the current baseline sampling method, was used for comparison to the Isolok sampling data. The Isolok sampler is an air powered grab sampler used to 'pull' a sample volume from a process line. The operation of the sampler is shown in Figure 1. The image on the left shows the Isolok's spool extended into the process line and the image on the right shows the sampler retracted and then dispensing the liquid into the sampling container. To determine tank homogeneity, a Coliwasa sampler was used to grab samples at a high and low location within the mixing tank. Data from the two locations were compared to determine if the contents of the tank were well mixed. The Coliwasa sampler is a tube with a stopper at the bottom and is designed to obtain grab samples from specific locations within the drum contents. A position paper (4) was issued to address the prototypic flow loop issues and simulant selections. A statistically designed plan (5) was issued to address the total number of samples each sampler needed to pull, to provide the random order in which samples were pulled and to group samples for elemental analysis. The TTR required that the Isolok sampler perform as well as the Hydragard sampler during these tests to ensure the acceptability of the Isolok sampler for use in the DWPF sampling cells. Procedure No.L9.4-5015 was used to document the sample parameters and process steps. Completed procedures are located in R&D Engineering job folder 23269.

  10. Simulation of the Three-Dimensional Hinge Flow Fields of a Bileaflet Mechanical Heart Valve Under Aortic Conditions

    E-Print Network [OSTI]

    Simon, Hélène A.; Ge, Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P.

    2010-01-01

    G. Rau. Leakage ?ow at mechanical heart valve prostheses:and the valve housing and forms two strong leakage jets onleakage ?ow rate Simulation of the Three-Dimensional Hinge Flow Fields through the closed valve

  11. Simulation of the Three-Dimensional Hinge Flow Fields of a Bileaflet Mechanical Heart Valve Under Aortic Conditions

    E-Print Network [OSTI]

    Simon, Hélène A.; Ge, Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P.

    2010-01-01

    a bilea?et mechanical heart valve in an axisymmetric aorta.parallel bilea?et mechanical heart valve with clear housing.J. Heart Valve Dis. 5:591–599, 1996. Ellis, J. T. , T. M.

  12. Engine control system having pressure-based timing

    DOE Patents [OSTI]

    Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

    2011-10-04

    A control system for an engine having a first cylinder and a second cylinder is disclosed having a first engine valve movable to regulate a fluid flow of the first cylinder and a first actuator associated with the first engine valve. The control system also has a second engine valve movable to regulate a fluid flow of the second cylinder and a sensor configured to generate a signal indicative of a pressure within the first cylinder. The control system also has a controller that is in communication with the first actuator and the sensor. The controller is configured to compare the pressure within the first cylinder with a desired pressure and selectively regulate the first actuator to adjust a timing of the first engine valve independently of the timing of the second engine valve based on the comparison.

  13. Throttle valve position-detecting device for a vehicle engine

    SciTech Connect (OSTI)

    Minagawa, K.

    1987-08-25

    A throttle valve position-detecting device is described for a vehicle, for detecting the position of a throttle valve in a throttle body provided for an engine mounted on the vehicle, by detecting rotation of a throttle shaft of the throttle valve, and in which the throttle shaft is supported to the throttle body through a bearing. The throttle valve position-detecting device consists of: a first rotary element fixed to the throttle shaft for rotating together with the throttle shaft; a second rotary element contacting the first rotary element for rotating with the first rotary element by receiving rotary power from the first rotary element; spring means for pressing the second rotary element towards the first rotary element against the rotary power; and detecting means for detecting from a rotary position of the second rotary element at least a position of the throttle valve corresponding to an idling condition of the engine; the first and second rotary elements being positioned with such a relationship as a crossing angle of a moving direction of the throttle shaft by clearance between the throttle shaft and the bearing and a transmitting direction of the rotary power from the first rotary element to the second rotary element during the idling condition of the engine being within a range from 45 to 90 degrees.

  14. Control device of an infinitely variable transmission

    SciTech Connect (OSTI)

    Tanaka, H.

    1987-01-27

    An automatic control system is described for a toric type infinitely variable transmission of a running vehicle, the speed of which is changed by varying a gear ratio corresponding to a running mode of the vehicle selected by a driver. The transmission comprises coaxially disposed input and output shafts with input and output disks having toroidal surfaces and respectively secured to the input and output shafts, a traction roller engaged with the toroidal surfaces of the disks, and a trunnion rotatably supporting the traction roller on a rotary shaft. The trunnion is linearly movable in the direction of a pivot axis which is perpendicular to the rotary shaft of the traction roller and is pivotable around the pivot axis so that the gear ratio between the input shaft and the output shaft may be changed. The control system comprises: a hydraulic cylinder receiving an axial end of the trunnion; and a hydraulic circuit connecting the hydraulic cylinder with a hydraulic source, the hydraulic circuit including a solenoid valve. The valve has means for repeatedly opening and closing the valve at predetermined intervals and controlling hydraulic supply to the hydraulic cylinder and thereby controlling the linear movement of the trunnion in the direction of the pivot axis so as to vary the gear ratio.

  15. Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide)

    E-Print Network [OSTI]

    Reticker-Flynn, Nathan Edward

    2008-01-01

    A compact printable microfluidic valve composed of poly(N-isopropylacrylamide) has been designed, fabricated, and tested. The design of the valve consists of filling microwells with poly(NIPAAm) and bonding PDMS channels ...

  16. Department of Mechanical and Nuclear Engineering Spring 2012 Electro-Mechanically Actuated Trip and Throttle Valve

    E-Print Network [OSTI]

    Demirel, Melik C.

    a special type of fail-safe valve for steam turbines. This valve closes rapidly to stop steam flow into a turbine, during emergency situations, to prevent injury and damage to the turbine. Some steam turbine

  17. Vacuum/Compression Valving (VCV) Using Parrafin-Wax on a Centrifugal Microfluidic CD Platform

    E-Print Network [OSTI]

    2013-01-01

    implementing two valves using a single VCV wax plug. This isvalves such that melted wax from a normally-closed valve (releases it when the wax is melted) is later transferred to

  18. Simultaneous Detection and Registration for Ileo-Cecal Valve Detection in 3D CT Colonography

    E-Print Network [OSTI]

    Barbu, Adrian

    Simultaneous Detection and Registration for Ileo-Cecal Valve Detection in 3D CT Colonography Le Lu1-Cecal Valve (ICV) detection in both clean and tagged 3D CT colonography scans. Our final ICV detection system

  19. Morphological, cellular and proteomic features of canine myxomatous mitral valve disease 

    E-Print Network [OSTI]

    Han, Richard I-Ming

    2009-01-01

    Myxomatous mitral valve degeneration (MMVD) is the single most common cardiac disease of the dog, and is analogous to Mitral Valve Prolapse in humans. Very little is known about the aetiopathogenesis of this disease or ...

  20. A MEMS Thin Film AlN Supercritical Carbon Dioxide Valve

    E-Print Network [OSTI]

    Chen, Ya-Mei

    2011-01-01

    D. P. Bame, and T. K. Tang, “MEMS micro-valve for spaceof the fabricated thermal MEMS valve by Kim et al. [Y. -C. Tai, and C-M. Ho, “A MEMS thermopneumatic silicone

  1. Drive piston assembly for a valve actuator assembly

    DOE Patents [OSTI]

    Sun, Zongxuan (Troy, MI)

    2010-02-23

    A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

  2. Development of a rotary valve for pulse-combustion applications. Annual report, June 1986-June 1987

    SciTech Connect (OSTI)

    George, P.E.; Corliss, J.M.

    1987-10-05

    Development of a rotary-valve air inlet for pulse-combustor systems in a variety of industrial applications is reviewed. The work focuses on development of a rotary-valve pulse combustor that will operate at input rates of up to 100,000 Btu/hr with computer control capable of synchronizing a motor-driven valve to combustor pressure oscillations. Activities included integrating the valve and combustor, conducting baseline experiments, developing computer control, integrating components, and performing laboratory evaluation.

  3. Fuel Composition Effects at Constant RON and MON in an HCCI Engine Operated with Negative Valve Overlap

    SciTech Connect (OSTI)

    Bunting, Bruce G; Farrell, John T

    2006-01-01

    The effects of fuel properties on gasoline HCCI operation have been investigated in a single cylinder, 500 cc, 11.3 CR port fuel injected research engine, operated at lambda=1 and equipped with hydraulic valve actuation. HCCI is promoted by early exhaust valve closing to retain hot exhaust in the cylinder, thereby increasing the cylinder gas temperature. Test fuels were formulated with pure components to have the same RON, MON, and octane sensitivity as an indolene reference fuel, but with a wide range of fuel composition differences. Experiments have been carried out to determine if fuel composition plays a role in HCCI combustion properties, independent of octane numbers. Fuel economy, emissions, and combustion parameters have been measured at several fixed speed/load conditions over a range of exhaust valve closing angles. When the data are compared at constant combustion phasing, fuel effects on emissions and other combustion properties are small. However, when compared at constant exhaust valve closing angle, fuel composition effects are more pronounced, specifically regarding ignition. Operability range differences are also related to fuel composition. An all-paraffinic (normal, iso, and cycloparaffins) fuel exhibited distinctly earlier combustion phasing, increased rate of cylinder pressure rise, and increased rate of maximum heat release compared to the indolene reference fuel. Conversely, olefin-containing fuels exhibited retarded combustion phasing. The fuels with the most advanced ignition showed a wider operating range in terms of engine speed and load, irrespective of exhaust closing angle. These ignition differences reflect contributions from both fuel and EGR kinetics, the effects of which are discussed. The fuel composition variables are somewhat inter-correlated, which makes the experimental separation their effects imprecise with this small set of fuels, though clear trends are evident. The overall effects of fuel composition on engine performance and emissions are small. However, the results suggest that the effects on combustion phasing and engine operability range may need to be considered in the practical implementation of HCCI for fuels with large compositional variations.

  4. Spherical rotary valve assembly for an internal combustion engine

    SciTech Connect (OSTI)

    Coates, G.J.

    1991-02-05

    This patent describes an improved rotary intake valve for use in a rotary valved internal combustion engine. It comprises: a drum body of spherical section formed by two parallel planar side walls of a sphere disposed about a center thereof thereby defining a spherically-shaped end wall and formed with a shaft receiving aperture, the drum body formed with a circularly-shaped cavity in a side wall thereof and with a channel extending between the circularly-shaped cavity and an aperture formed in the spherically-shaped end wall.

  5. SOFT SWITCHING APPROACH TO REDUCING TRANSITION LOSSES IN AN ON/OFF HYDRAULIC VALVE

    E-Print Network [OSTI]

    Li, Perry Y.

    energy by eliminating high pressure throttling of hydraulic oil through metering or relief valves controlled hydraulic system. Cao et. al. [3] suggest that energy can be lost in an on/off valve systemSOFT SWITCHING APPROACH TO REDUCING TRANSITION LOSSES IN AN ON/OFF HYDRAULIC VALVE Michael B

  6. Check all SCHE Supply Purge Check Valves to Prevent Back Flow from SCHE into Helium Supply

    SciTech Connect (OSTI)

    MISKA, C.R.

    2000-10-23

    These valves are 1/2-inch check valves used to prevent SCHe backflow into the Helium System if pressure in the Helium System drops below the pressure of the control valve downstream of the SCHe supply bottles. (14 psig in trains A and B and 2 psig in trains C and D).

  7. Role of Interface Transparency and Exchange Field in the Superconducting Triplet Spin-Valve Effect

    E-Print Network [OSTI]

    Fominov, Yakov

    Role of Interface Transparency and Exchange Field in the Superconducting Triplet Spin-Valve Effect, The Netherlands a Raphael.Deminov@kpfu.ru Keywords: proximity effect, superconducting, ferromagnetic, triplet spin-valve layers. In this paper we show that it is possible to realize different spin-valve effect modes

  8. Demonstration of spin valve effects in silicon nanowires Jean Tarun,1,2

    E-Print Network [OSTI]

    Otani, Yoshichika

    Demonstration of spin valve effects in silicon nanowires Jean Tarun,1,2 Shaoyun Huang,1 Yasuhiro April 2011) We have successfully demonstrated a lateral spin valve device using a silicon nanowire valve behavior with two switching fields. In the nonlocal voltage configuration, distinct dips were

  9. Spin-current-induced dynamics in ferromagnetic nanopillars of lateral spin-valve structures

    E-Print Network [OSTI]

    Otani, Yoshichika

    Spin-current-induced dynamics in ferromagnetic nanopillars of lateral spin-valve structures J 4 February 2009 Under electrical injection, spin accumulation occurs in lateral spin valves in a lateral spin valve while simultaneously sweeping an external magnetic field. We observe changes

  10. Mathematical Modeling of Flow-Generated Forces in an In Vitro System of Cardiac Valve Development

    E-Print Network [OSTI]

    Weidner, John W.

    Mathematical Modeling of Flow-Generated Forces in an In Vitro System of Cardiac Valve Development) Abstract--Heart valve defects are the most common cardiac defects. Therefore, defining the mechanisms of cardiac valve development is critical to our understanding and treatment of these disorders. At early

  11. Determination of magnetic vortex chirality using lateral spin-valve and Y. Otani

    E-Print Network [OSTI]

    Otani, Yoshichika

    Determination of magnetic vortex chirality using lateral spin-valve geometry T. Kimuraa and Y October 2005 We demonstrate the determination of the vortex chirality using a nonlocal spin-valve measurement technique in a lateral spin valve consisting of a Permalloy Py disk 1 m in diameter and a Py wire

  12. LOWER TRANSIENT STRESSES IN AN AORTIC VALVE LEAFLET WITH OBLIQUE REINFORCEMENT FIBERS: A FINITE ELEMENT STUDY

    E-Print Network [OSTI]

    LOWER TRANSIENT STRESSES IN AN AORTIC VALVE LEAFLET WITH OBLIQUE REINFORCEMENT FIBERS: A FINITE Cambridge, MA, USA INTRODUCTION Native aortic valve leaflets contain a network of strong collagen fibers the stresses of cyclic loading over billions of heart beats. Replacement valves that consist of animal tissues

  13. Closed-Loop Compensation Method for Oscillations Caused by Control Valve Stiction

    E-Print Network [OSTI]

    Wang, Jiandong

    Closed-Loop Compensation Method for Oscillations Caused by Control Valve Stiction Jiandong Wang-loop compensation method to remove oscillations caused by control valve stiction. With the control loop operating movements for the control valve to arrive at a desired position. A systematic way to design the parameters

  14. Potential Viability of a Fast-Acting Micro-Solenoid Valve for Pulsed Detonation Fuel Injection

    E-Print Network [OSTI]

    Texas at Arlington, University of

    1 Potential Viability of a Fast-Acting Micro-Solenoid Valve for Pulsed Detonation Fuel Injection F-acting solenoid valves to meet the demands of pulsed detonation fuel injection and other high-frequency devices is presented. The micro-valve was found to performance well above the manufacturer's rated frequency under no

  15. Monovalve with integrated fuel injector and port control valve, and engine using same

    DOE Patents [OSTI]

    Milam, David M. (Metamora, IL)

    2002-01-01

    Each cylinder of an internal combustion engine includes a combined gas exchange valve and fuel injector with a port control valve. The port control valve operates to open either an intake passage or an exhaust passage. The operation of the combined device is controlled by a pair of electrical actuators. The device is hydraulically actuated.

  16. Scaling properties of a low-actuation pressure microfluidic valve Vincent Studer and Giao Hang

    E-Print Network [OSTI]

    Quake, Stephen R.

    Scaling properties of a low-actuation pressure microfluidic valve Vincent Studer and Giao Hang a design and method for the fabrication of microfluidic valves using multilayer soft lithography. These on-off valves have extremely low actuation pressures and can be used to fabricate active functions

  17. HIGH-FREQUENCY MAGNETOCAPACITANCE EFFECT IN ORGANIC SPIN VALVE WITH A

    E-Print Network [OSTI]

    Lin, Minn-Tsong

    HIGH-FREQUENCY MAGNETOCAPACITANCE EFFECT IN ORGANIC SPIN VALVE WITH A 3,4,9,10-PERYLENE of a series of ferromagnet (FM)/organic semiconductor (OSC)/FM tri-layered organic spin valves (OSV accumulation at the organic­FM interfaces. Keywords: Organic spin valve; magnetoresistance; magnetocapacitance

  18. EXTRACTING GEOMETRIC FEATURES OF AORTIC VALVE ANNULUS MOTION FROM DYNAMIC MRI FOR GUIDING INTERVENTIONS

    E-Print Network [OSTI]

    Deng, Zhigang

    EXTRACTING GEOMETRIC FEATURES OF AORTIC VALVE ANNULUS MOTION FROM DYNAMIC MRI FOR GUIDING, Houston, TX 77030, USA ABSTRACT Transcatheter aortic valve implant (TAVI) has emerged as a prominent of the geometric features such as the diameter, center and orien- tation of the aortic valve annulus (AVA

  19. Evidence for Triplet Superconductivity in a Superconductor-Ferromagnet Spin Valve P. V. Leksin,1

    E-Print Network [OSTI]

    Fominov, Yakov

    Evidence for Triplet Superconductivity in a Superconductor-Ferromagnet Spin Valve P. V. Leksin,1 N on the mutual orientation of magnetizations of Fe1 and Fe2 layers in the spin valve system CoOx=Fe1=Cu=Fe2=Pb of the SC triplet spin valve theory gives direct evidence for the long-range triplet superconductivity

  20. Sensors and Actuators A 136 (2007) 426433 A bi-polymer micro one-way valve

    E-Print Network [OSTI]

    Beebe, David J.

    2007-01-01

    Sensors and Actuators A 136 (2007) 426­433 A bi-polymer micro one-way valve Dongshin Kima,b,, David December 2006 Abstract We have developed an in-plane bi-polymer check-valve for controlling microfluidic hydrogel. The valve was created using microfluidic tectonics, a fabrication procedure that allows

  1. Electrical bistability and spin valve effect in a ferromagnet/organic semiconductor/ferromagnet heterojunction

    E-Print Network [OSTI]

    Eom, Chang Beom

    Letter Electrical bistability and spin valve effect in a ferromagnet/organic semiconductor online 2 April 2010 Keywords: Bistable device Spin valve Organic semiconductor Magnetoresistance a b s t r a c t We report a study of the electrical bistability and bias-controlled spin valve effect

  2. Cyclic strain induces dual-mode endothelial-mesenchymal transformation of the cardiac valve

    E-Print Network [OSTI]

    Parker, Kevin Kit

    Cyclic strain induces dual-mode endothelial- mesenchymal transformation of the cardiac valve Kartik) is a critical event for the embryonic morphogenesis of cardiac valves. Inducers of EMT during valvulogenesis observed in diseased, strain-over- loaded valve leaflets, suggesting a regulatory role for mechanical

  3. PHYSICAL REVIEW B 91, 214508 (2015) Superconducting spin-valve effect and triplet superconductivity

    E-Print Network [OSTI]

    Fominov, Yakov

    2015-01-01

    PHYSICAL REVIEW B 91, 214508 (2015) Superconducting spin-valve effect and triplet superconductivity 12 June 2015) We report magnetic and superconducting properties of the modified spin-valve system Co theoretical description of the superconducting spin-valve effect and of the manifestation of the long

  4. Second-Best Instruments for Near-Term Climate Policy: Intensity Targets vs. the Safety Valve

    E-Print Network [OSTI]

    Wing, Ian Sue

    Second-Best Instruments for Near-Term Climate Policy: Intensity Targets vs. the Safety Valve Mort Keywords: Uncertainty, climate change, instrument choice, safety valve, intensity target. Abstract Current to be preferred over a safety valve. 1 #12;1. Introduction As many countries prepare to begin their implementation

  5. Quantification of Mitral Valve Morphology with Three-dimensional Echocardiography: Can Measurement Lead to

    E-Print Network [OSTI]

    Wong, Kenneth K.Y.

    ForReview Only Quantification of Mitral Valve Morphology with Three- dimensional Echocardiography. of Medicine & Therapeutics Keywords: mitral valve, echocardiography, imaging Category: Diagnostic imaging/Nuclear medicine Japanese Circulation Society Circulation Journal #12;ForReview Only Quantification of Mitral Valve

  6. The role of protein solubilization in antigen removal from xenogeneic tissue for heart valve tissue engineering

    E-Print Network [OSTI]

    Athanasiou, Kyriacos

    The role of protein solubilization in antigen removal from xenogeneic tissue for heart valve tissue Extracellular matrix Heart valve tissue engineering a b s t r a c t Decellularization techniques have been of bovine pericardium (BP) for heart valve tissue engineering. Bovine pericardium following AR (BP

  7. Passivity based compressor surge control using a close-coupled valve

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Passivity based compressor surge control using a close-coupled valve Jan Tommy Gravdahl and Olav-coupled valve. The analysis shows that the system has certain passivity properties which leads to a simple controller for the close- coupled valve. 1 Introduction If the ow through a compressor is throttled

  8. Fast Interactive Simulations of Mitral Valve Repair Neil A. Tenenholtz, Peter E. Hammer, Robert D. Howe

    E-Print Network [OSTI]

    Fast Interactive Simulations of Mitral Valve Repair Neil A. Tenenholtz, Peter E. Hammer, Robert D. Howe Keywords: Surgical simulation, human-computer interaction, haptics, mitral valve, cardiac surgery. I. Problem Solved A healthy mitral valve ensures the one-way flow of oxygenated blood from the left

  9. Quantification of Valve Stiction for Control Loop Performance Assessment Guohua Wang and liandong Wang*

    E-Print Network [OSTI]

    Wang, Jiandong

    Quantification of Valve Stiction for Control Loop Performance Assessment Guohua Wang and liandong, Beijing, P. R. China (*Email: jiandong@pku.edu.cn) Abstract - Control valves are extensively used in the process industry and valve stiction limits the performance of control loops. This study aims

  10. Chaotic Dynamics of Spin-Valve Oscillators Z. Yang and S. Zhang

    E-Print Network [OSTI]

    Li, Charles

    Chaotic Dynamics of Spin-Valve Oscillators Z. Yang and S. Zhang Department of Physics and Astronomy oscillators with tunable mi- crowave frequencies in spin valves are very desirable for magnetic storage it is not an intrinsic property of the current-driven oscillator. Here we consider a single-domain current-driven spin-valve

  11. Magnetization process of a single magnetic ring detected by nonlocal spin valve measurement

    E-Print Network [OSTI]

    Otani, Yoshichika

    Magnetization process of a single magnetic ring detected by nonlocal spin valve measurement T of a 200-nm-wide Permalloy ring using a nonlocal spin-valve measurement technique in a lateral geometry state using lateral spin-valve geometry.13­15 The chirality is found to be easily determined from

  12. Large Spin Accumulation in a Permalloy-Silver Lateral Spin Valve T. Kimura and Y. Otani

    E-Print Network [OSTI]

    Otani, Yoshichika

    Large Spin Accumulation in a Permalloy-Silver Lateral Spin Valve T. Kimura and Y. Otani Institute accumulation due to the electrical spin injection has been observed in Permalloy-silver lateral spin-valve structures. The observed resistance change is the largest among the reported metallic lateral spin valves

  13. On the Design of an Interactive, Patient-Specific Surgical Simulator for Mitral Valve Repair

    E-Print Network [OSTI]

    On the Design of an Interactive, Patient-Specific Surgical Simulator for Mitral Valve Repair Neil A repair of the mitral valve is a difficult procedure that is often avoided in favor of less effective valve replacement because of the associated technical challenges facing non-expert surgeons

  14. AC electroosmotic pump with bubble-free palladium electrodes and rectifying polymer membrane valves

    E-Print Network [OSTI]

    AC electroosmotic pump with bubble-free palladium electrodes and rectifying polymer membrane valves valve system. Individual valves are based on a flexible membrane with a slit. Bubble-free palladium As a second novelty, we suppress the generation of bubbles by employing palladium electrodes that can store

  15. Establishment of the mathematical model for diagnosing the engine valve faults by genetic

    E-Print Network [OSTI]

    Fernandez, Thomas

    1 Establishment of the mathematical model for diagnosing the engine valve faults by genetic of the proposed strategy is validated by an illustrative example, in which three kinds of valve states inherent in a six- cylinders/four-stroke cycle diesel engine, i.e. normal condition, valve-tappet clearance and gas

  16. Computational analysis of an aortic valve jet with Lagrangian coherent structures1

    E-Print Network [OSTI]

    Boyer, Edmond

    Computational analysis of an aortic valve jet with Lagrangian coherent structures1 Shawn C. Shadden valves. An important step in making these computational tools useful to clinical practice. This work focuses on flow through the aortic valve and il- lustrates how the computation of Lagrangian

  17. Design and Operation of a Fast Electromagnetic Inductive Massive Gas Injection Valve for NSTX-Ua)

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    Design and Operation of a Fast Electromagnetic Inductive Massive Gas Injection Valve for NSTX-Ua) R the operation of an electromagnetic valve, that does not incorporate ferromagnetic materials, are presented baratron gauge. The valve injects over 200 Torr.L of nitrogen in less than 3 ms, which remains unchanged

  18. Magnetic domain wall propagation in a submicron spin-valve stripe: influence of the pinned layer

    E-Print Network [OSTI]

    Boyer, Edmond

    1/10 Magnetic domain wall propagation in a submicron spin-valve stripe: influence of the pinned ferromagnetic spin-valve stripe is investigated using giant magnetoresistance. A notch in the stripe efficiently generated in the vicinity of the notch by the pinned layer of the spin-valve. PACS: 72.25.Ba; 73.43.Qt; 75

  19. Department of Industrial Engineering Fall 2010 Reverse Osmosis: Valve Performance Improvement

    E-Print Network [OSTI]

    Demirel, Melik C.

    PENNSTATE Department of Industrial Engineering Fall 2010 Reverse Osmosis: Valve Performance butterfly valves for their reverse osmosis desalination systems, they must find a material or coating for use of a valve disc made out of ductile iron, which is highly susceptible to corrosion so it is coated

  20. Aortic Valve Turning Over a New Leaf(let) in Endothelial Phenotypic Heterogeneity

    E-Print Network [OSTI]

    Simmons, Craig A.

    Aortic Valve Turning Over a New Leaf(let) in Endothelial Phenotypic Heterogeneity Peter F. Davies, Anthony G. Passerini, Craig A. Simmons A ortic valve diseases are debilitating cardiovascular disorders the longevity of replacement valves and to improve tissue engineered substitutes,1 the underlying mech- anisms

  1. Cost effective combined axial fan and throttling valve control of ventilation rate

    E-Print Network [OSTI]

    Sengun, Mehmet Haluk

    Cost effective combined axial fan and throttling valve control of ventilation rate C.J. Taylor 1 P. In partic- ular, it develops a unique fan and throttling valve control system for a 22m3 test chamber, the throttling valve is employed to restrict airflow at the outlet, so generating a higher static pressure differ

  2. Thermal Shock Effects Modeling on a Globe Valve Body-Bonnet Bolted Flange Joint

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Thermal Shock Effects Modeling on a Globe Valve Body-Bonnet Bolted Flange Joint Jean, thermal shock, globe valve, body-bonnet bolted flange joint, Code_Aster, nuclear industry, Abstract : This paper attends to show efforts made at EDF R&D to improve comprehension of valve parts loadings during

  3. Vascular Biology, Atherosclerosis and Endothelium Biology Identification and Characterization of Aortic Valve

    E-Print Network [OSTI]

    Simmons, Craig A.

    of Aortic Valve Mesenchymal Progenitor Cells with Robust Osteogenic Calcification Potential Jan-Hung Chen by an unidentified multipotent progenitor subpopulation within the valve interstitium. The identity, frequency were to determine whether valve intersti- tial cells (VICs) contain a subpopulation of multipo- tent

  4. Controlling flow in microfluidic channels with a manually actuated pin valve

    E-Print Network [OSTI]

    Eddington, David T.

    Controlling flow in microfluidic channels with a manually actuated pin valve Marie-Elena Brett to be placed within the microchannel to obstruct flow. This new valve design can attain on/off control of fluid flow without an external power source using readily-available, low-cost materials. The valve consists

  5. Experimental study on the cause of insufficiency of a transcutaneous pulmonary valve replacement

    E-Print Network [OSTI]

    Berlin,Technische Universität

    Experimental study on the cause of insufficiency of a transcutaneous pulmonary valve replacement Peter Jülg, Sason von der Heyde Purpose: Within the EU-funded research project LifeValve the German for the replacement of pulmonary heart valves. This technique is a minimally invasive alternative to the replacement

  6. Title: Predictors of 6-months clinical poor outcomes after transcatheter aortic valve implantation.

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Title: Predictors of 6-months clinical poor outcomes after transcatheter aortic valve.acvd.2013.10.005 #12;2 Abstract Background: Patients' selection for transcatheter aortic valve implantation institution with a transcatheter-implanted aortic valve were prospectively followed. Our population

  7. Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions-sur-Loing, France. Working on fluid mechanics aspects of nuclear valves since 2004. Zachary Leutwyler zleutwyler and numerical investigation of flow- induced forces and torque acting on linear and quarter turn valves. hal

  8. T EFFECT OF STORAGE ON TENSILE PROPERTIES OF NATURAL HEART VALVE TISSUE

    E-Print Network [OSTI]

    Stevenson, Paul

    T EFFECT OF STORAGE ON TENSILE PROPERTIES OF NATURAL HEART VALVE TISSUE Sophia Nishat Mohammad "" Yourheartisyourlanternandyourselfisyourlight. ( IQBAL the poet of the east ) #12;ABSTRACT Aortic homograft valves are the preferred choiceof replacementvalve in aortic valve replacementprocedures.The major drawbackto their use is their availability

  9. SAE 2002-01-1106 Modeling and Control of Electromechanical Valve Actuator

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    SAE 2002-01-1106 Modeling and Control of Electromechanical Valve Actuator Y. Wang, T. Megli, and M for an electromechanical valve actuator will be presented. The model-based control methodology utilizes position feedback. INTRODUCTION Electro-Mechanical Valve (EMV) actuators shown in Fig.1 are currently being developed by many

  10. Molecular-Flow Properties of RIB Type Vapor-Transport Systems Using a Fast-Valve

    SciTech Connect (OSTI)

    Alton, Gerald D [ORNL] [ORNL; Bilheux, Hassina Z [ORNL] [ORNL; Zhang, Y. [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Liu, Yuan [ORNL] [ORNL

    2014-01-01

    The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target ion source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.

  11. Prognostics for Ground Support Systems: Case Study on Pneumatic Valves

    E-Print Network [OSTI]

    Daigle, Matthew

    are used to control the flow of propellant, so failures may have a significant impact on launch to control the flow of propellant, failures may have a significant impact on launch availability. HencePrognostics for Ground Support Systems: Case Study on Pneumatic Valves Matthew Daigle University

  12. Covered Product Category: Pre-Rinse Spray Valves

    Broader source: Energy.gov [DOE]

    The Federal Energy Management Program (FEMP) provides acquisition guidance and Federal efficiency requirements across a variety of product categories, including pre-rinse spray valves, which are a FEMP-designated product category. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

  13. Workshop on gate valve pressure locking and thermal binding

    SciTech Connect (OSTI)

    Brown, E.J.

    1995-07-01

    The purpose of the Workshop on Gate Valve Pressure Locking and Thermal Binding was to discuss pressure locking and thermal binding issues that could lead to inoperable gate valves in both boiling water and pressurized water reactors. The goal was to foster exchange of information to develop the technical bases to understand the phenomena, identify the components that are susceptible, discuss actual events, discuss the safety significance, and illustrate known corrective actions that can prevent or limit the occurrence of pressure locking or thermal binding. The presentations were structured to cover U.S. Nuclear Regulatory Commission staff evaluation of operating experience and planned regulatory activity; industry discussions of specific events, including foreign experience, and efforts to determine causes and alleviate the affects; and valve vendor experience and recommended corrective action. The discussions indicated that identifying valves susceptible to pressure locking and thermal binding was a complex process involving knowledge of components, systems, and plant operations. The corrective action options are varied and straightforward.

  14. LIQUID MIXING STUDIES WITH AN INTEGRATED MIXER/VALVE

    E-Print Network [OSTI]

    Voldman, Joel

    and fluid ports, and 2) an upper glass wafer which contains the fluidic channel. The inset of Figure 1 reveals a blow-up of the reagent-inlet port area. The cantilever-plate flapper valve is shown atop to mix a reagent with the sample, Sample Reagent Mixed Liquids Silicon Glass Cantilever-plate flapper

  15. Aging and service wear of air-operated valves used in safety-related systems at nuclear power plants

    SciTech Connect (OSTI)

    Cox, D.F.; McElhaney, K.L.; Staunton, R.H.

    1995-05-01

    Air-operated valves (AOVs) are used in a variety of safety-related applications at nuclear power plants. They are often used where rapid stroke times are required or precise control of the valve obturator is required. They can be designed to operate automatically upon loss of power, which is often desirable when selecting components for response to design basis conditions. The purpose of this report is to examine the reported failures of AOVs and determine whether there are identifiable trends in the failures related to predictable causes. This report examines the specific components that comprise a typical AOV, how those components fail, when they fail, and how such failures are discovered. It also examines whether current testing frequencies and methods are effective in predicting such failures.

  16. Measurement of spin diffusion length in sputtered Ni films using a special exchange-biased spin valve geometry

    E-Print Network [OSTI]

    Birge, Norman

    valve geometry Charles E. Moreaua Department of Physics, Albion College, Albion, Michigan 49224 Ion C exchange-biased spin valve geometry that inserts a Ni "spoiler" layer into a Py/Cu/Py spin valve. Fits In the context of ferromagnetic/nonmagnetic F/N multilayers or spin valves, the size of the giant

  17. Depth Profiling Photoelectron-Spectroscopic Study of an Organic Spin Valve with a Plasma-Modified Pentacene Spacer

    E-Print Network [OSTI]

    Lin, Minn-Tsong

    Depth Profiling Photoelectron-Spectroscopic Study of an Organic Spin Valve with a Plasma) in an organic spin valve with an oxygen plasma-treated pentacene (PC) spacer. The spin valve containing PC and in turn to enhance the MR performance in organic spin valves. INTRODUCTION Organic semiconductors (OSC

  18. Mitral Web -A New Concept for Mitral Valve Repair: Improved Engineering Design and In-Vitro Studies

    E-Print Network [OSTI]

    Pekkan, Kerem

    Mitral Web - A New Concept for Mitral Valve Repair: Improved Engineering Design and In of Biomedical Engineering, Georgia Institute of Technology, GA, USA Myxomatous mitral valve disease is currently reported that mitral valve repair is preferable to valve replace- ment, as it offers certain advantages

  19. Proximity effects in superconducting triplet spin-valve F2/F1/S R.G. Deminov a,n

    E-Print Network [OSTI]

    Fominov, Yakov

    Proximity effects in superconducting triplet spin-valve F2/F1/S R.G. Deminov a,n , L.R. Tagirov a effect Superconducting Ferromagnetic Triplet spin-valve Magnetization Transition temperature Interface of the spin-valve effect mode selection (standard switching effect, the triplet spin-valve effect or reentrant

  20. 11-05-15 Issuance: Energy Conservation Standards for Commercial Prerinse Spray Valves: Availability of Provisional Analysis Tools; NODA

    Broader source: Energy.gov [DOE]

    Energy Conservation Standards for Commercial Prerinse Spray Valves: Availability of Provisional Analysis Tools; NODA

  1. ISSUANCE 2015-06-17: Energy Conservation Program: Energy Conservation Standards for Commercial Prerinse Spray Valves, Notice of Proposed Rulemaking

    Office of Energy Efficiency and Renewable Energy (EERE)

    Energy Conservation Program: Energy Conservation Standards for Commercial Prerinse Spray Valves, Notice of Proposed Rulemaking

  2. A novel mathematical technique to assess of the mitral valve dynamics based on echocardiography

    E-Print Network [OSTI]

    Karvandi, Mersedeh; Hassantash, Seyed Ahmad; Foroughi, Mahnoosh

    2015-01-01

    Purpose: The mechanics of the mitral valve leaflet as a nonlinear, inelastic and anisotropic soft tissue results from an integrated response of many mathematical/physical indexes' that illustrate the tissue. In the past decade, finite element modeling of complete heart valves has greatly aided evaluation of heart valve surgery, design of bioprosthetic valve replacements, and general understanding of healthy and abnormal cardiac function. Such a model must be based on an accurate description of the mechanical behavior of the valve material. It is essential to calculate velocity/displacement and strain rate/strain at a component level that is to work at the cellular level. In this study we developed the first three-dimensional displacement vectors field in the characterization of mitral valve leaflets in continuum equations of inelasticity framework based on echocardiography. Method: Much of our knowledge of abnormal mitral valve function is based on surgical and post-mortem studies while these studies are quan...

  3. Magnetism reflectometer study shows LiF layers improve efficiency in spin valve devices

    SciTech Connect (OSTI)

    Bardoel, Agatha A [ORNL; Lauter, Valeria [ORNL; Szulczewski, Greg J [ORNL

    2012-01-01

    New, more efficient materials for spin valves - a device used in magnetic sensors, random access memories, and hard disk drives - may be on the way based on research using the magnetism reflectometer at Oak Ridge National Laboratory (ORNL). Spin valve devices work by means of two or more conducting magnetic material layers that alternate their electrical resistance depending on the layers alignment. Giant magnetoresistance is a quantum mechanical effect first observed in thin film structures about 20 years ago. The effect is observed as a significant change in electrical resistance, depending on whether the magnetization of adjacent ferromagnetic layers is in a parallel or an antiparallel magnetic alignment. 'What we are doing here is developing new materials. The search for new materials suitable for injecting and transferring carriers with a preferential spin orientation is most important for the development of spintronics,' said Valeria Lauter, lead instrument scientist on the magnetism reflectometer at the Spallation Neutron Source (SNS), who collaborated on the experiment. The researchers discovered that the conductivity of such materials is improved when an organic polymer semiconductor layer is placed between the magnetic materials. Organic semiconductors are now the material of choice for future spin valve devices because they preserve spin coherence over longer times and distances than conventional semiconductors. While research into spin valves has been ongoing, research into organic semiconductors is recent. Previous research has shown that a 'conductivity mismatch' exists in spin valve systems in which ferromagnetic metal electrodes interface with such organic semiconductors as Alq3 ({pi}-conjugated molecule tris(8-hydroxy-quinoline) aluminium). This mismatch limits the efficient injection of the electrons from the electrodes at the interface with the semiconductor material. However, lithium fluoride (LiF), commonly used in light-emitting diodes, has been found to enhance the injection of electrons through the semiconductor. Researchers from the University of Alabama and ORNL used polarized neutrons at the magnetism reflectometer at SNS to investigate the electronic, magnetic, and structural properties of the electrodes in a novel system. In this system, the magnetic layers cobalt and Ni{sub 80}Fe{sub 20} are interfaced with spacer layers composed of the organic semiconductor Alq3. A coupling layer of LiF is inserted to separate the magnetized layers from the semiconductor. 'ALQ3 is an organic semiconductor material,' said Lauter. 'Normally in these systems a first magnetic layer is grown on a hard substrate so that one can get the controlled magnetic parameters. Then you grow the organic semiconductor layer, followed by another magnetic material layer, such as cobalt.' In addition to determining the effect of the LiF layers on the efficiency of the electron injection, the researchers wanted to determine the magnetic properties of the cobalt and Ni{sub 80}Fe{sub 20} as well as the interfacial properties: whether there is interdiffusion of cobalt through the LiF layer to the semiconductor, for example. The researchers used polarized neutrons at beam line 4A to probe the entire, layer-by-layer assembly of the system. 'Reflectometry with polarized neutrons is a perfect method to study thin magnetic films,' Lauter said. 'These thin films - if you put one on a substrate, you see it just like a mirror. However, this mirror has a very complicated internal multilayer structure. The neutrons look inside this complicated structure and characterize each and every interface. Due to the depth sensitivity of the method, we measure the structural and magnetic properties of each layer with the resolution of 0.5 nm. The neutron scattering results found that inserting LiF as a barrier significantly improves the quality of the interface, increasing the injection of electrons from the magnetic layer through the organic semiconductor in the spin valve and enhancing the overall properties of the system. In related work the magneti

  4. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23

    Cataclysmic variables are binary stars in which a relatively normal star is transferring mass to its compact companion. This interaction gives rise to a rich range of behaviour, of which the most noticeable are the outbursts that give the class its name. Novae belong to the class, as do the less well known dwarf novae and magnetic systems. Novae draw their energy from nuclear reactions, while dwarf novae rely on gravity to power their smaller eruptions. All the different classes of cataclysmic variable can be accommodated within a single framework and this article will describe the framework, review the properties of the main types of system and discuss models of the outbursts and of the long-term evolution.

  5. THE EFFECTS OF MAINTENANCE ACTIONS ON THE PFDavg OF SPRING OPERATED PRESSURE RELIEF VALVES

    SciTech Connect (OSTI)

    Harris, S.; Gross, R.

    2014-04-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

  6. The Effects of Maintenance Actions on the PFDavg of Spring Operated Pressure Relief Valves

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Harris, S.; Gross, R.; Goble, W; Bukowski, J

    2015-12-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accountedmore »for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.« less

  7. Engine control system having speed-based timing

    DOE Patents [OSTI]

    Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

    2012-02-14

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

  8. Engine control system having fuel-based timing

    DOE Patents [OSTI]

    Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

    2012-04-03

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a sensor configured to generate a signal indicative of an amount of an air/fuel mixture remaining within the cylinder after completion of a first combustion event and a controller in communication with the actuator and the sensor. The controller may be configured to compare the amount with a desired amount, and to selectively regulate the actuator to adjust a timing of the engine valve associated with a subsequent combustion event based on the comparison.

  9. Development of Glassy Carbon Blade for LHC Fast Vacuum Valve

    E-Print Network [OSTI]

    Coly, P

    2012-01-01

    An unexpected gas inrush in a vacuum chamber leads to the development of a fast pressure wave. It carries small particles that can compromise functionality of sensitive machine systems such as the RF cavities or kickers. In the LHC machine, it has been proposed to protect this sensitive equipment by the installation of fast vacuum valves. The main requirements for the fast valves and in particular for the blade are: fast closure in the 20 ms range, high transparency and melting temperature in case of closure with beam in, dust free material to not contaminate sensitive adjacent elements, and last but not least vacuum compatibility and adequate leak tightness across the blade. In this paper, different designs based on a vitreous carbon blade are presented and a solution is proposed. The main reasons for this material choice are given. The mechanical study of the blade behaviour under dynamic forces is shown.

  10. Optimized fabrication and characterization of carbon nanotube spin valves

    SciTech Connect (OSTI)

    Samm, J.; Gramich, J.; Baumgartner, A. Weiss, M.; Schönenberger, C.

    2014-05-07

    We report an improved fabrication scheme for carbon based nanospintronic devices and demonstrate the necessity for a careful data analysis to investigate the fundamental physical mechanisms leading to magnetoresistance. The processing with a low-density polymer and an optimised recipe allows us to improve the electrical, magnetic, and structural quality of ferromagnetic Permalloy contacts on lateral carbon nanotube (CNT) quantum dot spin valve devices, with comparable results for thermal and sputter deposition of the material. We show that spintronic nanostructures require an extended data analysis, since the magnetization can affect all characteristic parameters of the conductance features and lead to seemingly anomalous spin transport. In addition, we report measurements on CNT quantum dot spin valves that seem not to be compatible with the orthodox theories for spin transport in such structures.

  11. Removable check valve for use in a nuclear reactor

    DOE Patents [OSTI]

    Dunn, Charlton (Calabasas, CA); Gutzmann, Edward A. (Simi Valley, CA)

    1988-01-01

    A removable check valve for interconnecting the discharge duct of a pump and an inlet coolant duct of a reactor core in a pool-type nuclear reactor. A manifold assembly is provided having an outer periphery affixed to and in fluid communication with the discharge duct of the pump and has an inner periphery having at least one opening therethrough. A housing containing a check valve is located within the inner periphery of the manifold. The upper end of the housing has an opening in alignment with the opening in the manifold assembly, and seals are provided above and below the openings. The lower end of the housing is adapted for fluid communication with the inlet duct of the reactor core.

  12. The selection and maintenance of valves for the control of fugitive emissions

    SciTech Connect (OSTI)

    Dresch, C. (NIBCO Inc., Elkhart, IN (United States))

    1994-08-01

    The pulp and paper industry has long needed valves that (a) have extremely low stem leakage when they are new and (b) need little or no maintenance to retain that low leakage over their service life. The EPA fugitive emission regulations provide additional impetus for the pulp and paper industry to buy such valves and for the valve and packing industry to produce such valves. Even if particular operations are not covered by the fugitive emissions regulations, it is--and always has been--in a mill's best interest to have valves whose stems don't leak and need little or no maintenance to prevent that leakage. The paper gives some recommendations on how to meet that objective: selection the right packing materials; apply the right amount of stress to the packing; install the packing correctly; and use rotary valves where practical.

  13. A unifying method for sizing throttling valves under laminar or transitional flow conditions

    SciTech Connect (OSTI)

    Baumann, H.D. (H.D. Baumann Assoc., Ltd., Portsmouth, NH (United States))

    1993-03-01

    The mass flow passing through a given valve will decrease in Reynolds number ranges below approximately 10,000 due to the transition from fully developed turbulent to laminar flow. The objective of this study is to provide a uniform prediction method to establish, with reasonable accuracy, the ratio between the turbulent and transitional or laminar flow rate passing through a given valve, taking into account the valve's hydraulic diameter and the initial turbulent velocity head loss coefficient. Experimental data from prior research tends to support a proposed unified sizing method that is applicable for all single-stage valves regardless of size or type.

  14. Purchasing Water-Efficient Faucets, Pre-Rinse Spray Valves, Showerhead...

    Energy Savers [EERE]

    Products & Technologies Energy-Efficient Products Purchasing Water-Efficient Faucets, Pre-Rinse Spray Valves, Showerheads, Toilets, and Urinals Purchasing Water-Efficient...

  15. Vacuum/Compression Valving (VCV) Using Parrafin-Wax on a Centrifugal Microfluidic CD Platform

    E-Print Network [OSTI]

    2013-01-01

    wax solidifies) by centrifugal force. Author ContributionsF, et al. (2007) The centrifugal microfluidic Bio-Diskswitching valves on a centrifugal microfluidic platform.

  16. Spin transport in lateral spin valves and across a metal- insulator transition in V?O? /

    E-Print Network [OSTI]

    Erekhinsky, Mikhail

    2013-01-01

    Spin valves is a class of spintronic devices that use spinsuch as integrated spintronic circuits in semiconductors [for the development of these spintronic devices. Many device

  17. Failure Modes and Causes for Swing and Lift Type Check Valves

    Office of Scientific and Technical Information (OSTI)

    Group (NIC), ORNL has reviewed and analyzed check valve failures from the Institute of Nuclear Power Operations' (INPOs') Nuclear Plant Reliability Database System (NPRDS)...

  18. Failure Modes and Causes for Swing and Lift Type Check Valves...

    Office of Scientific and Technical Information (OSTI)

    to the recent work performed by Oak Ridge National Laboratory (ORNL)relative to nuclear industry check valve performance, no information was readily available regarding the...

  19. Means for positively seating a piezoceramic element in a piezoelectric valve during inlet gas injection

    DOE Patents [OSTI]

    Wright, K.E.

    1994-08-23

    A piezoelectric valve in a gas delivery system includes a piezoceramic element bonded to a valve seal and disposed over a valve seat, and retained in position by an O-ring and a retainer; an insulating ball normally biased by a preload spring against the piezoceramic element; an inlet gas port positioned such that upon admission of inlet gas into the valve, the piezoceramic element is positively seated. The inlet gas port is located only on the side of the piezoceramic element opposite the seal. 3 figs.

  20. Rotating drum variable depth sampler

    DOE Patents [OSTI]

    Nance, Thomas A. (Aiken, SC); Steeper, Timothy J. (Trenton, SC)

    2008-07-01

    A sampling device for collecting depth-specific samples in silt, sludge and granular media has three chambers separated by a pair of iris valves. Rotation of the middle chamber closes the valves and isolates a sample in a middle chamber.

  1. Ocean color and atmospheric dimethyl sulfide: On their mesoscale variability

    E-Print Network [OSTI]

    Matrai, Patricia A; Balch, William M; Cooper, David J; Saltzman, Eric S

    1993-01-01

    periods of' time, covering mesoscale Campbell, J. W. and W.Dimethyl Sulfide' On Their Mesoscale Variability PATRICIA A.Miami, Miami, Florida The mesoscale variability of dimethyl

  2. Andreas A. Malikopoulos e-mail: amaliko@umich.edu

    E-Print Network [OSTI]

    Papalambros, Panos

    , which learns the values of injection timing and variable geometry turbocharging vane position, variable geometry turbocharging VGT , exhaust gas recirculation EGR , and variable valve actuation VVA

  3. SOFT SWITCHING APPROACH TO REDUCING TRANSITION LOSSES IN AN ON/OFF HYDRAULIC VALVE

    E-Print Network [OSTI]

    Li, Perry Y.

    energy by eliminating high pressure throttling of hydraulic oil through metering or relief valvesSOFT SWITCHING APPROACH TO REDUCING TRANSITION LOSSES IN AN ON/OFF HYDRAULIC VALVE Michael B@me.umn.edu ABSTRACT A method for significantly reducing the losses associated with an on/off controlled hydraulic

  4. OPTIMIZATION OF AUTOMOTIVE VALVE TRAIN COMPONENTS WITH IMPLICT , O. J. ELSINGER

    E-Print Network [OSTI]

    OPTIMIZATION OF AUTOMOTIVE VALVE TRAIN COMPONENTS WITH IMPLICT FILTERING T. D. CHOI ¡ , O. J and optimization in automotive valve train design. We extend our previous work by using a more refined model to obtain optimal profiles for camshaft lobes. Key words. Noisy Optimization, Implicit Filtering, Mechanical

  5. Adaptive Robust Control of Programmable Valves with Manufacturer Supplied Flow Mapping Only

    E-Print Network [OSTI]

    Yao, Bin

    independently controlled poppet type cartridge valves, have been shown to significantly reduce energy usage-hydraulic systems become increasingly widespread: is it possible to reduce the energy usage while still having Liu and Bin Yao Abstract-- The energy-saving programmable valves, a unique combination of five

  6. Valve characterization to implement feed-forward control of hydraulically actuated joints

    E-Print Network [OSTI]

    Carey, Abby (Abby M.)

    2008-01-01

    This thesis characterizes the flow behavior of a Hydraforce SP08-47CL valve given a specific pulse-width modulation (pwm) duty cycle. With a description of valve behavior, a feed-forward term can be implemented in the ...

  7. Experimentally validated quantitative linear model for the device physics of elastomeric microfluidic valves

    E-Print Network [OSTI]

    Quake, Stephen R.

    microfluidic valves Emil P. Kartalova) Department of Pathology, Keck School of Medicine, University of Southern" microfluidic valves are presented. The phase space is charted by 1587 dimension combinations and encompasses 45 springs. INTRODUCTION Within a decade, polymethylsiloxane (PDMS) microfluidics has negotiated the long

  8. Microfluidic very large scale integration (mVLSI) with integrated micromechanical valves{

    E-Print Network [OSTI]

    Quake, Stephen R.

    Microfluidic very large scale integration (mVLSI) with integrated micromechanical valves{ Ismail40258k Microfluidic chips with a high density of control elements are required to improve device and accessible high-density microfluidic chips, we have fabricated a monolithic PDMS valve architecture

  9. Design Technical Briefs Valve-Plate Design for an Axial Piston

    E-Print Network [OSTI]

    Manring, Noah D.

    standby when they are used to hold pressure at low displacements. Noisy pumps also tend to wear outJournal of Mechanical Design Technical Briefs Valve-Plate Design for an Axial Piston Pump Operating advantages of using various valve-plate slot geometries within an axial piston pump. In particular, three

  10. CONTROL OF AN ELECTROMECHANICAL CAMLESS VALVE ACTUATOR Chun Tai, Tsu-Chin Tsao

    E-Print Network [OSTI]

    Tsao, Tsu-Chin

    CONTROL OF AN ELECTROMECHANICAL CAMLESS VALVE ACTUATOR Chun Tai, Tsu-Chin Tsao 1 Department in electromechanical camless valvetrains. Our mathematical modeling analysis reveals the instability of the actuator][7] and electromechanical valve (EMV) [1][2][3][6][8][9][12] actuators. This paper deals with the EMV type of actuator

  11. Jet-controlled freeze valve for use in a glass melter

    DOE Patents [OSTI]

    Routt, Kenneth R. (Aiken, SC)

    1986-01-01

    A drain valve for use in a furnace for the melting of thermoplastic material. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The flow member is adapted to fit in mating relationship in the drain cavity. A freeze valve member is disposed adjacent the outlet of the flow member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct streams of pressurized air at the outlet to control the flow of thermoplastic material through the flow members. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace. The drain valve includes a flow tube member having an inlet and outlet, and having heating and cooling means. The tube member is adapted to fit in mating relationship with the drain cavity. A freeze valve member is disposed at the outlet of the flow tube member. The freeze valve member includes heating means and has a plurality of air jets adapted to direct a stream of pressurized air at the outlet to control the flow of glass through the flow tube member.

  12. Proceedings of the 2nd symposium on valves for coal conversion and utilization

    SciTech Connect (OSTI)

    Maxfield, D.A. (ed.)

    1981-01-01

    The 2nd symposium on valves for coal conversion and utilization was held October 15 to 17, 1980. It was sponsored by the US Department of Energy, Morgantown Energy Technology Center, in cooperation with the Valve Manufacturers Association. Seventeen papers have been entered individually into EDB and ERA. (LTN)

  13. Nanostructural considerations in giant magnetoresistive Co-Cu-based symmetric spin valves Harsh Deep Chopra*

    E-Print Network [OSTI]

    Chopra, Harsh Deep

    , for example, magnetic-field sensors and read-heads in data- storage devices.11 A key impedimentNanostructural considerations in giant magnetoresistive Co-Cu-based symmetric spin valves Harsh, on the nanostructure and resulting giant magnetoresistive properties of symmetric spin valves of the type Ni

  14. Automatic measuring of quality criteria for heart valves Alexandru Paul Condurachea, Tobias Hahna, Ulrich G. Hofmanna, Michael Scharfschwerdtb,

    E-Print Network [OSTI]

    Lübeck, Universität zu

    passing an input compliance (5) the fluid is pressed through the inspected heart valve (11) and an orifice curve (c). above the heart valve. Passing an aortic compliance (9) the fluid reaches a heightAutomatic measuring of quality criteria for heart valves Alexandru Paul Condurachea, Tobias Hahna

  15. Temperature Evolution of Spin-Polarized Electron Tunneling in Silicon NanowirePermalloy Lateral Spin Valve System

    E-Print Network [OSTI]

    Otani, Yoshichika

    Spin Valve System Jean Tarun1;2 , Shaoyun Huang1Ã , Yasuhiro Fukuma1 , Hiroshi Idzuchi1;5 , Yoshi, 2012; accepted February 22, 2012; published online March 16, 2012 A huge nonlocal spin valve signal over 700 has been observed in silicon-nanowire-based lateral spin valve with permalloy electrodes

  16. Mass-Spring Model for Simulation of Heart Valve Tissue Mechanical Behavior Peter E. Hammer1,2,4,*

    E-Print Network [OSTI]

    1 Mass-Spring Model for Simulation of Heart Valve Tissue Mechanical Behavior Peter E. Hammer1, Cambridge, MA Abbreviated title: Mass-Spring Model for Simulation of Heart Valve Tissue * Address, MA, USA. E-mail address: peter.hammer@childrens.harvard.edu. #12;2 Abstract Heart valves

  17. Automatic Systole-Diastole Classification of Mitral Valve Complex from RT-3D Echocardiography based on Multiresolution Processing

    E-Print Network [OSTI]

    Wong, Kenneth K.Y.

    Automatic Systole-Diastole Classification of Mitral Valve Complex from RT-3D Echocardiography based, The Chinese University of Hong Kong, Hong Kong ABSTRACT Mitral valve repair is one of the most prevalent operations for various mitral valve conditions. Echocardiography, being famous for its low-cost, non

  18. Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization, modification, and chaos

    E-Print Network [OSTI]

    Li, Charles

    Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization and numerical calculations of dynamic magnetization states of a spin valve in the presence of dc and ac currents are expected to appear. In this paper, we consider a simple spin valve as a model system to study the problem

  19. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 9, NO. 3, SEPTEMBER 2000 295 An Integrated Liquid Mixer/Valve

    E-Print Network [OSTI]

    Voldman, Joel

    Mixer/Valve Joel Voldman, Student Member, IEEE, Martha L. Gray, Member, IEEE, and Martin A. Schmidt, Member, IEEE Abstract--We present an integrated liquid mixer/valve to be used for sample preparation for bioscience analysis systems. The mixer/valve is a glass-silicon bonded structure with a wafer

  20. Interdiffusion in CoFeCu multilayers and its application to spin-valve structures for data storage

    E-Print Network [OSTI]

    Laughlin, David E.

    Interdiffusion in CoFeÕCu multilayers and its application to spin-valve structures for data storage, Pennsylvania 15213-3890 Received 13 February 2003; accepted 30 April 2003 Spin-valve structures might, the interdiffusion coefficients for all layers in the spin valve have to be determined. For diffusion driven

  1. Local domain structure of exchange-coupled NiFe/CoO nanowire probed by nonlocal spin valve measurement

    E-Print Network [OSTI]

    Otani, Yoshichika

    Local domain structure of exchange-coupled NiFe/CoO nanowire probed by nonlocal spin valve magnetization process in a 100-nm-wide Permalloy/CoO exchange-coupled wire by means of nonlocal spin valve valve structures.1 This phenomenon is described by the Meiklejohn­Bean model, which is based

  2. Suitability of boron-nitride single-walled nanotubes as fluid-flow conduits in nano-valve applications

    E-Print Network [OSTI]

    Grujicic, Mica

    Suitability of boron-nitride single-walled nanotubes as fluid-flow conduits in nano-valve the suitability of boron-nitride single-walled nanotubes (SWNTs) as fluid- flow conduits in the nano-valve reserved. doi:10.1016/j.apsusc.2004.11.007 #12;control nano-valve based on a silicon nano-beam actuator

  3. Mitral annulus segmentation from four-dimensional ultrasound using a valve state predictor and constrained optical flow

    E-Print Network [OSTI]

    Mitral annulus segmentation from four-dimensional ultrasound using a valve state predictor, Children's Hospital, Boston, MA, USA Abstract Measurement of the shape and motion of the mitral valve annulus has proven useful in a number of applications, including pathology diagnosis and mitral valve

  4. Optimal Design of a High-Speed On/Off Valve for a Hydraulic Hybrid Vehicle Application

    E-Print Network [OSTI]

    Li, Perry Y.

    Optimal Design of a High-Speed On/Off Valve for a Hydraulic Hybrid Vehicle Application Michael of Minnesota, Minneapolis, MN, USA ABSTRACT Control of hydraulic systems using high-speed on/off valves has been proposed as a way to avoid the inefficiency associated with throttling valves. However, on

  5. In situ magnetic a.nd structural analysis of epitaxial NisoFezothin films for spin-valve heterostructures

    E-Print Network [OSTI]

    Atwater, Harry

    In situ magnetic a.nd structural analysis of epitaxial NisoFezothin films for spin-valve-coupling and giant magnetoresistance (.GMRj in NiseFez,,/Cu multilayers' and spin-valves.' To date, all" Furthermore, FeMn, which is typically used in spin valves to exchange bias one of the ferromagnetic layers

  6. Event based Kalman filter observer for rotary high speed on/off valve Meng Wang, Perry Y. Li

    E-Print Network [OSTI]

    Li, Perry Y.

    Event based Kalman filter observer for rotary high speed on/off valve Meng Wang, Perry Y. Li ERC, pli}@me.umn.edu Abstract-- A novel hydraulic rotary self-spinning high speed on/off valve is being- width-modulation (PWM). The valve is designed to operate at a spool frequency of 20Hz to 40Hz. A coarse

  7. Thermodynamics -2 Two insulated rigid tanks are connected with a valve. The surroundings are at a constant temperature

    E-Print Network [OSTI]

    Virginia Tech

    Thermodynamics - 2 Two insulated rigid tanks are connected with a valve. The surroundings and is initially evacuated. The valve connecting the tanks is initially closed. Then, the insulation is removed from the tanks, the valve is opened, air is allowed to flow from tank A to tank B until the pressure

  8. Relationship between valve activity, microalgae concentration in the water1 and toxin accumulation in the digestive gland2

    E-Print Network [OSTI]

    Brest, Université de

    1 Relationship between valve activity, microalgae concentration in the water1 and toxin ([PSP]dg) and valve behavior was explored in oysters Crassostrea gigas. Two experiments24 were conducted, during which oysters' valve behaviour were analyzed. Oysters, first25 acclimated for 10-days with the non

  9. CFD Analysis of a Novel High Speed Rotary On/Off Valve 283 Proc. of 6th

    E-Print Network [OSTI]

    Li, Perry Y.

    CFD Analysis of a Novel High Speed Rotary On/Off Valve 283 Proc. of 6th FPNI-PhD Symp. West Lafayette 2010, pp. 283-294 CFD ANALYSIS OFA NOVEL HIGH SPEED ROTARY ON/OFF VALVE Meng WANG1 , Haink TU a novel type of high speed rotary on/off valve is analyzed using CFD (Computational Fluid Dynamics

  10. Intraoperative Tracking of Aortic Valve Plane* DLH Nguyen, M Garreau, V Auffret, H Le Breton, JP Verhoye, P Haigron

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Intraoperative Tracking of Aortic Valve Plane* DLH Nguyen, M Garreau, V Auffret, H Le Breton, JP Verhoye, P Haigron Abstract--The main objective of this work is to track the aortic valve plane in intra-operative fluoroscopic images in order to optimize and secure Transcatheter Aortic Valve Implantation (TAVI) procedure

  11. Bmp2 instructs cardiac progenitors to form the heart-valve-inducing field Jos Rivera-Feliciano, Clifford J. Tabin

    E-Print Network [OSTI]

    Tabin, Cliff

    Bmp2 instructs cardiac progenitors to form the heart-valve-inducing field José Rivera Abstract A hallmark of heart-valve development is the swelling and deposition of extracellular matrix in the heart-valve region. Only myocardium overlying this region can signal to underlying endothelium and cause

  12. Summary -Procedure For Shutting Off The Oxygen Zone Valve 1. Implement RACE Call the Emergency Operator at 4-2012.

    E-Print Network [OSTI]

    Acton, Scott

    Summary - Procedure For Shutting Off The Oxygen Zone Valve 1. Implement RACE ­ Call the Emergency-cylinders for low oxygen needs and bag ventilated patients using E-cylinders. 4. Identify oxygen zone valve for the affected rooms/areas. 5. Turn off the flow of oxygen at the zone valve if the oxygen cannot be turned off

  13. Simple Passive Valves for Addressable Pneumatic Actuation Nils Napp, Brandon Araki+, Michael T. Tolley, Radhika Nagpal, Robert J. Wood

    E-Print Network [OSTI]

    Napp, Nils

    Simple Passive Valves for Addressable Pneumatic Actuation Nils Napp, Brandon Araki+, Michael T simple passive devices that behave like leaky check valves. We present the theory of operation and design, and demonstrate the approach by building prototype valves and using them to control serially connected soft

  14. Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine

    SciTech Connect (OSTI)

    Sochman, Jan [Institute for Clinical and Experimental Medicine, Intensive Care Unit, Clinic of Cardiology (Czech Republic)], E-mail: jan.sochman@medicon.cz; Peregrin, Jan H.; Rocek, Miloslav [Institute for Clinical and Experimental Medicine, Department of Diagnostic and Interventional Radiology (Czech Republic); Timmermans, Hans A.; Pavcnik, Dusan; Roesch, Josef [Oregon Health and Sciences University, Dotter Interventional Institute (United States)

    2006-02-15

    Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.

  15. Fluid-driven reciprocating apparatus and valving for controlling same

    DOE Patents [OSTI]

    Whitehead, John C. (Davis, CA); Toews, Hans G. (East Aurora, NY)

    1993-01-01

    A control valve assembly for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. One embodiment of the invention utilized two pairs of fluid-driven free-piston devices whereby a bipropellant liquid propulsion system may be operated, so as to provide continuous flow of both fuel and oxidizer liquids when used in rocket applications, for example.

  16. Flow-Force Compensation in a Hydraulic Valve

    E-Print Network [OSTI]

    Lugowski, Jan

    2015-01-01

    Flow-reaction forces acting in hydraulic valves have been studied for many decades. Despite this, they are difficult to account for due to the complexities of the jet flow. This paper focuses only on the reduction, also referred to as compensation, of the flow force as applied to a valve spool featuring a profile of a turbine bucket. Fluid power textbooks explain the compensation taking place on such a profile by applying Newton laws of motion to the profile and deliver an equation for the magnitude and the direction of the flow force. This paper shows that both the magnitude and the direction of the compensating flow force are incorrect if calculated from the textbook equation. A corrected analysis of the dynamic forces is presented that are in agreement with earlier experiments by this author. It follows that the compensating flow force should be calculated from the static-pressure imbalance on the spool profile. That is, not Newton but Pascal law should be applied to calculate the compensating flow force.

  17. Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control

    SciTech Connect (OSTI)

    Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y.

    2006-07-01

    The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

  18. Variable camshaft timing for internal combustion engine

    SciTech Connect (OSTI)

    Butterfield, R.P.; Smith, F.R.; Dembosky, S.K.

    1991-09-10

    This patent describes an internal combustion engine. It comprises a rotatable crankshaft; a camshaft, the camshaft being rotatable about its longitudinal central axis and being subject to a unidirectionally acting torque during the rotation thereof; first means mounted on the camshaft, the first means being oscillatable with respect to the camshaft about the longitudinal central axis of the camshaft at least through a limited arc; second means keyed to the camshaft for rotation therewith; rotary movement transmitting means interconnecting the crankshaft and one of the first means and the second means for transmitting rotary movement from the crankshaft to the camshaft; a first hydraulic cylinder having a body end pivotably attached to one of the first means and the second means and a piston end pivotably attached to the other of the first means and the second means; a second hydraulic cylinder having a body end pivotably attached to the one of the first means and the second means and a piston end pivotably attached to the other of the first means and the second means, the second hydraulic cylinder and the first hydraulic cylinder being disposed to act in opposite directions.

  19. Subsea intensifier supplies high pressure to downhole safety valves

    SciTech Connect (OSTI)

    1996-07-01

    A subsea high-pressure hydraulic intensifier (HPI) is now available as an alternative method of operating downhole surface-controlled subsea safety valves (SCSSVs). By generating high hydraulic pressures on the seafloor, the system eliminates need for transmitting high pressure via hose from surface. The new intensifier can generate up to 15,000 psi (1,035 bar) from the 3,000-psi (210-bar) low pressure actuator supply already within the umbilical. It uses low pressure hydraulic fluid acting on a large-area piston to push a second piston, one-fifth the cross sectional area, acting in a second hydraulic circuit. To reduce pulsation, the unit is double acting, with one piston drawing in fluid while the other discharges it. This paper reviews the design, performance, and construction of this equipment.

  20. Electromagnetic valve for controlling the flow of molten, magnetic material

    DOE Patents [OSTI]

    Richter, Tomas (State College, PA)

    1998-01-01

    An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.