Inkjet 3D printed check microvalve

NASA Astrophysics Data System (ADS)

Walczak, Rafał; Adamski, Krzysztof; Lizanets, Danylo

2017-04-01

3D printing enables fast and relatively easy fabrication of various microfluidic structures including microvalves. A check microvalve is the simplest valve enabling control of the fluid flow in microchannels. Proper operation of the check valve is ensured by a movable element that tightens the valve seat during backward flow and enables free flow for forward pressure. Thus, knowledge of the mechanical properties of the movable element is crucial for optimal design and operation of the valve. In this paper, we present for the first time the results of investigations on basic mechanical properties of the building material used in multijet 3D printing. Specified mechanical properties were used in the design and fabrication of two types of check microvalve—with deflecting or hinge-fixed microflap—with 200 µm and 300 µm thickness. Results of numerical simulation and experimental data of the microflap deflection were obtained and compared. The valves were successfully 3D printed and characterised. Opening/closing characteristics of the microvalve for forward and backward pressures were determined. Thus, proper operation of the check microvalve so developed was confirmed.

Apparatus and method for pumping hot, erosive slurry of coal solids in coal derived, water immiscible liquid

DOEpatents

Ackerman, Carl D.

1983-03-29

An apparatus for and method of pumping hot, erosive slurry of coal solids in a coal derived, water immiscible liquid to higher pressure involves the use of a motive fluid which is miscible with the liquid of the slurry. The apparatus includes a pump 12, a remote check valve 14 and a chamber 16 between and in fluid communication with the pump 12 and check valve 14 through conduits 18,20. Pump 12 exerts pressure on the motive fluid and thereby on the slurry through a concentration gradient of coal solids within chamber 16 to alternately discharge slurry under pressure from the outlet port of check valve 14 and draw slurry in through the inlet port of check valve 14.

Development of a novel passive top-down uniflow scavenged two-stroke GDI engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciccarelli, G.; Reynolds, Steve; Oliver, Phillip

2010-02-15

The design and performance characteristics of a novel top-down uniflow scavenged gasoline direct-injection two-stroke engine are presented. The novelty of the engine lies in the cylinder head that contains multiple check valves that control scavenging airflow into the cylinder from a supercharged air plenum. When the cylinder pressure drops below the intake plenum pressure during the expansion stroke, air flows into the cylinder through the check valves. During compression the cylinder pressure increases to a level above the intake plenum pressure and the check valves close preventing back-flow into the intake plenum. The engine head design provides asymmetrical intake valvemore » timing without the use of poppet valves and the associated valve-train. In combination with an external Roots-type supercharger that supplies the plenum and exhaust ports at the bottom of the cylinder wall, the novel head provides top-down uniflow air scavenging. Motoring tests indicated that the check valves seal and the peak pressure is governed by the compression ratio. The only drawback observed is that valve closing is delayed as the engine speed increases. In order to investigate the valve dynamics, additional tests were performed in an optically-accessible cold flow test rig that enabled the direct measurement of valve opening and closing time under various conditions. (author)« less

Fast acting check valve

NASA Technical Reports Server (NTRS)

Perkins, Gerald S. (Inventor)

1979-01-01

A check valve which closes more rapidly to prevent wearing of the valve seat and of the valve member that seals thereagainst, including a solenoid or other actuator that aids the normal spring to quickly close the valve at approximately the time when downpath fluid flow would stop, the actuator then being deenergized. The control circuit that operates the actuator can include a pair of pressure sensors sensing pressure both upstream and downstream from the valve seat. Where the valve is utilized to control flow to or from a piston pump, energization of the actuator can be controlled by sensing when the pump piston reaches its extreme of travel.

Magnetic Check Valve

NASA Technical Reports Server (NTRS)

Morris, Brian G.; Bozeman, Richard J., Jr.

1994-01-01

Poppet in proposed check valve restored to closed condition by magnetic attraction instead of spring force. Oscillations suppressed, with consequent reduction of wear. Stationary magnetic disk mounted just upstream of poppet, also containing magnet. Valve body nonmagnetic. Forward pressure or flow would push poppet away from stationary magnetic disk so fluid flows easily around poppet. Stop in valve body prevents poppet from being swept away. When flow stopped or started to reverse, magnetic attraction draws poppet back to disk. Poppet then engages floating O-ring, thereby closing valve and preventing reverse flow. Floating O-ring facilitates sealing at low loads.

Reliability of excess-flow check-valves in turbine lubrication systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dundas, R.E.

1996-12-31

Reliability studies on excess-flow check valves installed in a gas turbine lubrication system for prevention of spray fires subsequent to fracture or separation of lube lines were conducted. Fault-tree analyses are presented for the case of failure of a valve to close when called upon by separation of a downstream line, as well as for the case of accidental closure during normal operation, leading to interruption of lubricating oil flow to a bearing. The probabilities of either of these occurrences are evaluated. The results of a statistical analysis of accidental closure of excess-flow check valves in commercial airplanes in themore » period 1986--91 are also given, as well as a summary of reliability studies on the use of these valves in residential gas installations, conducted under the sponsorship of the Gas Research Institute.« less

78 FR 26716 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

... currently requires a repetitive inspection program on certain check valves in the hydraulic systems that... hydraulic systems on airplanes that have had a certain modification embodied during production or in-service... hydraulic leaks, possibly leading to the loss of all three hydraulic systems and consequent loss of control...

Chemical Safety Alert: Shaft Blow-Out Hazard of Check and Butterfly Valves

EPA Pesticide Factsheets

Certain types of check and butterfly valves can undergo shaft-disk separation and fail catastrophically, even when operated within their design limits of pressure and temperature, causing toxic/flammable gas releases, fires, and vapor cloud explosions.

Liquid blocking check valve

DOEpatents

Merrill, John T.

1984-01-01

A liquid blocking check valve useful particularly in a pneumatic system utilizing a pressurized liquid fill chamber. The valve includes a floatable ball disposed within a housing defining a chamber. The housing is provided with an inlet aperture disposed in the top of said chamber, and an outlet aperture disposed in the bottom of said chamber in an offset relation to said inlet aperture and in communication with a cutaway side wall section of said housing.

Vein-style air pumping tube and tire system and method of assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benedict, Robert Leon; Gobinath, Thulasiram; Lin, Cheng-Hsiung

An air pumping tube and tire system and method of assembling is provided in which a tire groove is formed to extend into a flexing region of a tire sidewall and a complementary air pumping tube inserts into the tire groove. In the green, uncured air pumping tube condition, one or more check valves are assembled into the air pumping tube through access shafts and align with an internal air passageway of the air pumping tube. Plug components of the system enclose the check valves in the air pumping tube and the check valve-containing green air pumping tube is thenmore » cured.« less

Fabrication of micro metallic valve and pump

NASA Astrophysics Data System (ADS)

Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi

2010-03-01

Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

Environmental Assessment for Renovation and Small Addition for AGE Facility MacDill AFB, Florida

DTIC Science & Technology

2005-05-01

one lift station, all of the sanitary sewer lines have, in essence , at least one check valve to stop the inflow of floodwater to the WWTP. The...Force Base Installation Restoration Program 7621 Hillsborough Loop Dr. MacDill AFB, FL 33621-5207 Jasmine Raffington FL Coastal Management

49 CFR 180.416 - Discharge system inspection and maintenance program for cargo tanks transporting liquefied...

Code of Federal Regulations, 2011 CFR

2011-10-01

... unique identification number and maximum working pressure. (c) Post-delivery hose check. After each... unloading. (d) Monthly inspections and tests. (1) The operator must visually inspect each delivery hose... actuate all emergency discharge control devices designed to close the internal self-closing stop valve to...

49 CFR 180.416 - Discharge system inspection and maintenance program for cargo tanks transporting liquefied...

Code of Federal Regulations, 2014 CFR

2014-10-01

... unique identification number and maximum working pressure. (c) Post-delivery hose check. After each... unloading. (d) Monthly inspections and tests. (1) The operator must visually inspect each delivery hose... actuate all emergency discharge control devices designed to close the internal self-closing stop valve to...

49 CFR 180.416 - Discharge system inspection and maintenance program for cargo tanks transporting liquefied...

Code of Federal Regulations, 2013 CFR

2013-10-01

... unique identification number and maximum working pressure. (c) Post-delivery hose check. After each... unloading. (d) Monthly inspections and tests. (1) The operator must visually inspect each delivery hose... actuate all emergency discharge control devices designed to close the internal self-closing stop valve to...

49 CFR 180.416 - Discharge system inspection and maintenance program for cargo tanks transporting liquefied...

Code of Federal Regulations, 2012 CFR

2012-10-01

... unique identification number and maximum working pressure. (c) Post-delivery hose check. After each... unloading. (d) Monthly inspections and tests. (1) The operator must visually inspect each delivery hose... actuate all emergency discharge control devices designed to close the internal self-closing stop valve to...

Solid state lift for micrometering in a fuel injector

DOEpatents

Milam, David M.; Carroll, Thomas S.; Lee, Chien-Chang; Miller, Charles R.

2002-01-01

A fuel injector performs main fuel injection by raising fuel pressure in a nozzle chamber to lift a check valve member to a fully open position, and performs preinjection or microinjection by operating a solid state motor to lift the check valve member a much smaller distance.

An Apparatus for Measuring Rates of Discharge of a Fuel-Injection System

NASA Technical Reports Server (NTRS)

Dutee, Francis J

1941-01-01

A portable apparatus for rapidly determining rates of discharge of a fuel-injection system is described. Satisfactory operation of this apparatus with injection-pump speeds up to 2400 r.p.m was obtained. Rate-of-discharge tests were made with several cam-plunger-valve injection systems with long injection tubes. A check valve designed to reduce secondary discharges was tested. This check valve was operated with injection-pump speeds up to 2400 r.p.m without the occurrence of large secondary discharges.

SU8 diaphragm micropump with monolithically integrated cantilever check valves.

PubMed

Ezkerra, Aitor; Fernández, Luis José; Mayora, Kepa; Ruano-López, Jesús Miguel

2011-10-07

This paper presents a SU8 unidirectional diaphragm micropump with embedded out-of-plane cantilever check valves. The device represents a reliable and low-cost solution for integration of microfluidic control in lab-on-a-chip devices. Its planar architecture allows monolithic definition of its components in a single step and potential integration with previously reported PCR, electrophoresis and flow-sensing SU8 microdevices. Pneumatic actuation is applied on a PDMS diaphragm, which is bonded to the SU8 body at wafer level, further enhancing its integration and mass production capabilities. The cantilever check valves move synchronously with the diaphragm, feature fast response (10ms), low dead volume (86nl) and a 94% flow blockage up to 300kPa. The micropump achieves a maximum flow rate of 177 μl min(-1) at 6 Hz and 200 kPa with an effective area of 10 mm(2). The device is reliable, self-priming and tolerant to particles and big bubbles. To the knowledge of the authors, this is the first micropump in SU8 with monolithically integrated cantilever check valves.

Dynamic modeling and simulation of an integral bipropellant propulsion double-valve combined test system

NASA Astrophysics Data System (ADS)

Chen, Yang; Wang, Huasheng; Xia, Jixia; Cai, Guobiao; Zhang, Zhenpeng

2017-04-01

For the pressure reducing regulator and check valve double-valve combined test system in an integral bipropellant propulsion system, a system model is established with modular models of various typical components. The simulation research is conducted on the whole working process of an experiment of 9 MPa working condition from startup to rated working condition and finally to shutdown. Comparison of simulation results with test data shows: five working conditions including standby, startup, rated pressurization, shutdown and halt and nine stages of the combined test system are comprehensively disclosed; valve-spool opening and closing details of the regulator and two check valves are accurately revealed; the simulation also clarifies two phenomena which test data are unable to clarify, one is the critical opening state in which the check valve spools slightly open and close alternately in their own fully closed positions, the other is the obvious effects of flow-field temperature drop and temperature rise in pipeline network with helium gas flowing. Moreover, simulation results with consideration of component wall heat transfer are closer to the test data than those under the adiabatic-wall condition, and more able to reveal the dynamic characteristics of the system in various working stages.

Refuge alternatives relief valve testing and design

PubMed Central

Lutz, T.J.; Bissert, P.T.; Homce, G.T.; Yonkey, J.A.

2016-01-01

The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork. Relief pressures and flow characteristics were measured for three units: (1) a modified polyvinyl chloride check valve, (2) an off-the-shelf brass/cast-iron butterfly check valve and (3) a commercially available valve that was designed specifically for one manufacturer’s steel prefabricated RAs and had been adapted for use in one mine operator’s built-in-place RA. PRVs used in tent-style RAs were not investigated. The units were tested with different modifications and configurations in order to check compliance with Title 30 Code of Federal Regulations, or 30 CFR, regulations. The commercially available relief valve did not meet the 30 CFR relief pressure specification but may meet the manufacturer’s specification. Alternative valve designs were modified to meet the 30 CFR relief pressure specification, but all valve designs will need further design research to examine survivability in the event of a 103 kPa (15.0 psi) impulse overpressure during a disaster. PMID:28018003

Remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems.

PubMed

Pan, Tingrui; Baldi, Antonio; Ziaie, Babak

2007-06-01

In this paper, we present two remotely adjustable check-valves with an electrochemical release mechanism for implantable biomedical microsystems. These valves allow one to vary the opening pressure set-point and flow resistance over a period of time. The first design consists of a micromachined check-valve array using a SU-8 polymer structural layer deposited on the top of a gold sacrificial layer. The second design is based on a variable length cantilever beam structure with a gold sacrificial layer. The adjustable cantilever-beam structure is fabricated by gold thermo-compression bond of a thin silicon wafer over a glass substrate. In both designs, the evaporated gold can be electrochemically dissolved using a constant DC current via a telemetry link. In the first design the dissolution simply opens up individual outlets, while in the second design, gold anchors are sequentially dissolved hence increasing the effective length of the cantilever beam (reducing the opening pressure). A current density of 35 mA/cm(2) is used to dissolve the gold sacrificial layers. Both gravity and syringe-pump driven flow are used to characterize the valve performance. A multi-stage fluidic performance (e.g. flow resistance and opening pressure) is clearly demonstrated.

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA Technical Reports Server (NTRS)

Engler, Charles; Canham, John

2014-01-01

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the initial valve design and subsequent improvements that resulted from prototype testing. The initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated. Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the initial Valve design was used to develop a second, more robust Aperture Valve. Based on a check-ball design, the ETU / flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, non-magnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA Technical Reports Server (NTRS)

Hakun, Claef F.; Engler, Charles D.; Barber, Willie E.; Canham, John S.

2014-01-01

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the Initial valve design and subsequent improvements that resulted from prototype testing. The Initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the Titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated.Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the Initial Valve design was used to develop a second, more robust Aperture valve. Based on a check-ball design, the ETU flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, nonmagnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

Aperture Valve for the Mars Organic Molecule Analyzer (MOMA)

NASA Technical Reports Server (NTRS)

Engler, Charles D.; Canham, John S.

2014-01-01

NASA's participation in the multi-nation ExoMars 2018 Rover mission includes a critical astrobiology Mass Spectrometer Instrument on the Rover called the Mars Organic Molecule Analyzer (MOMA). The Aperture Valve is a critical electromechanical valve used by the Mass Spectrometer to facilitate the transfer of ions from Martian soil to the Mass Spectrometer for analysis. The MOMA Aperture Valve development program will be discussed in terms of the Initial valve design and subsequent improvements that resulted from prototype testing. The Initial Aperture Valve concept seemed promising, based on calculations and perceived merits. However, performance results of this design were disappointing, due to delamination of TiN and DLC coatings applied to the Titanium base metals, causing debris from the coatings to seize the valve. While peer reviews and design trade studies are important forums to vet a concept design, results from testing should not be underestimated. Despite the lack of development progress to meet requirements, valuable information from weakness discovered in the Initial Valve design was used to develop a second, more robust Aperture valve. Based on a check-ball design, the ETU /flight valve design resulted in significantly less surface area to create the seal. Moreover, PVD coatings were eliminated in favor of hardened, nonmagnetic corrosion resistant alloys. Test results were impressive, with the valve achieving five orders of magnitude better sealing leak rate over end of life requirements. Cycle life was equally impressive, achieving 280,000 cycles without failure.

30 CFR 250.1624 - Blowout prevention equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... station and one BOP-control station on the rig floor; and (5) A choke line and a kill line each equipped with two full-opening valves and a choke manifold. One of the choke-line valves and one of the kill-line valves shall be remotely controlled except that a check valve may be installed on the kill line in...

30 CFR 250.1624 - Blowout prevention equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... station and one BOP-control station on the rig floor; and (5) A choke line and a kill line each equipped with two full-opening valves and a choke manifold. One of the choke-line valves and one of the kill-line valves shall be remotely controlled except that a check valve may be installed on the kill line in...

30 CFR 250.1624 - Blowout prevention equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... station and one BOP-control station on the rig floor; and (5) A choke line and a kill line each equipped with two full-opening valves and a choke manifold. One of the choke-line valves and one of the kill-line valves shall be remotely controlled except that a check valve may be installed on the kill line in...

30 CFR 250.1624 - Blowout prevention equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... station and one BOP-control station on the rig floor; and (5) A choke line and a kill line each equipped with two full-opening valves and a choke manifold. One of the choke-line valves and one of the kill-line valves shall be remotely controlled except that a check valve may be installed on the kill line in...

Water system microbial check valve development

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Greenley, D. R.; Putnam, D. F.

1978-01-01

A residual iodine microbial check valve (RIMCV) assembly was developed and tested. The assembly is designed to be used in the space shuttle potable water system. The RIMCV is based on an anion exchange resin that is supersaturated with an iodine solution. This system causes a residual to be present in the effluent water which provides continuing bactericidal action. A flight prototype design was finalized and five units were manufactured and delivered.

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

49 CFR 195.450 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... remote control valve as follows: (1) Check valve means a valve that permits fluid to flow freely in one direction and contains a mechanism to automatically prevent flow in the other direction. (2) Remote control.... The RCV is usually operated by the supervisory control and data acquisition (SCADA) system. The...

Conceptual design of ACB-CP for ITER cryogenic system

NASA Astrophysics Data System (ADS)

Jiang, Yongcheng; Xiong, Lianyou; Peng, Nan; Tang, Jiancheng; Liu, Liqiang; Zhang, Liang

2012-06-01

ACB-CP (Auxiliary Cold Box for Cryopumps) is used to supply the cryopumps system with necessary cryogen in ITER (International Thermonuclear Experimental Reactor) cryogenic distribution system. The conceptual design of ACB-CP contains thermo-hydraulic analysis, 3D structure design and strength checking. Through the thermohydraulic analysis, the main specifications of process valves, pressure safety valves, pipes, heat exchangers can be decided. During the 3D structure design process, vacuum requirement, adiabatic requirement, assembly constraints and maintenance requirement have been considered to arrange the pipes, valves and other components. The strength checking has been performed to crosscheck if the 3D design meets the strength requirements for the ACB-CP.

Design criteria monograph for pressure regulators, relief valves, check valves, burst disks, and explosive valves

NASA Technical Reports Server (NTRS)

1974-01-01

Monograph reviews and assesses current design practices, and from them establishes firm guidance for achieving greater consistency in design, increased reliability in end product, and greater efficiency in design effort. Five devices are treated separately. Guides to aid in configuration selection are outlined.

Dual Check Valve and Method of Controlling Flow Through the Same

NASA Technical Reports Server (NTRS)

Corallo, Roger (Inventor)

2016-01-01

A dual check valve includes, a housing having a cavity fluidically connecting three ports, a movable member movably engaged within the cavity from at least a first position occluding a first port of the three ports, a second position occluding a second port of the three ports, and a third position allowing flow between both the first port, the second port and a third port of the three ports.

Refuge alternatives relief valve testing and design with updated test stand.

PubMed

Lutz, T J; Bissert, P T; Homce, G T; Yonkey, J A

2018-03-01

Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-the-shelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m 3 /min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification.

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY... constructed to allow airflow toward the facepiece only shall be provided in the connections to the facepiece...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY... constructed to allow airflow toward the facepiece only shall be provided in the connections to the facepiece...

Developmental testing resulting in a simplified liquid oxygen check valve for the Space Shuttle Main Propulsion System

NASA Technical Reports Server (NTRS)

Aber, Gregory S.; Barrett, Michael J.; Reith, Timothy W.

1993-01-01

The coil spring in a Space Shuttle liquid oxygen check valve failed due to cyclic fatigue in September, 1991. The dual-flapper, swing check valve is used to prevent reverse flow to the Space Shuttle Main Engines. Upon inspection of the failed component, the spring tangs were found to be missing and heavy wear was observed on the inner diameter of the spring coils. The fracture surfaces revealed that the metal had been steadily worn away until a simple overload caused the final fracture. A series of flow tests using water and a water/gas mixture was conducted to identify the flow phenomenon which produced the cyclic wear. A Plexiglas outlet housing was utilized to view the flapper behavior under different flow conditions and to aid in high speed photography. The tests revealed that flow instabilities induced two oscillatory flapper responses: a rocking mode and a chattering mode. Initially, attempts were made to reduce the spring-flapper oscillations. However, the final solution to the problem was a springless configuration which satisfied the valve's design requirements and eliminated the oscillations. The springless design relied on the inherent ability of the reverse flow momentum to close the flappers.

Polymeric check valve with an elevated pedestal for precise cracking pressure in a glaucoma drainage device.

PubMed

Park, Chang-Ju; Yang, Dong-Seong; Cha, Jung-Joon; Lee, Jong-Hyun

2016-02-01

This paper presents the design, fabrication, and characterization of a polymeric micro check valve for a glaucoma drainage device (GDD) featuring the precise regulation of intraocular pressure (IOP) and effective aqueous humor turnover (AHT). The pedestal, slightly elevated by selective coating of a parylene C film, induces pre-stress in the thin valve membrane, which enhances the predictability of the cracking pressure of the GDD. The proposed GDD comprises a cannula and a normally closed polymeric micro check valve, which are made of PDMS, a biocompatible polymer, with three layers: top (cover), intermediate (thin valve membrane), and bottom (base plate). A feedback channel, located between the top and intermediate layers, prevents reverse flow by feeding the pressure of the outlet channel back to the thin valve membrane. To achieve a precise cracking pressure and sufficient drainage of humor for humans, the thicknesses of the valve membrane and parylene C film are designed to be 58 μm and 1 μm, respectively, which are confirmed using a COMSOL simulation. The experimental results show that the cracking pressure of the fabricated GDD lies within the range of normal IOP (1.33-2.67 kPa). The forward flow rate (drainage rate), 4.3 ± 0.9 μL/min at 2.5 kPa, is adequate to accommodate the rate of AHT in a normal human eye (2.4 ± 0.6 μL/min). The reverse flow was not observed when a hydrostatic pressure of up to 4 kPa was applied to the outlet and the feedback channel.

Experimental investigation of a new method for advanced fast reactor shutdown cooling

NASA Astrophysics Data System (ADS)

Pakholkov, V. V.; Kandaurov, A. A.; Potseluev, A. I.; Rogozhkin, S. A.; Sergeev, D. A.; Troitskaya, Yu. I.; Shepelev, S. F.

2017-07-01

We consider a new method for fast reactor shutdown cooling using a decay heat removal system (DHRS) with a check valve. In this method, a coolant from the decay heat exchanger (DHX) immersed into the reactor upper plenum is supplied to the high-pressure plenum and, then, inside the fuel subassemblies (SAs). A check valve installed at the DHX outlet opens by the force of gravity after primary pumps (PP-1) are shut down. Experimental studies of the new and alternative methods of shutdown cooling were performed at the TISEY test facility at OKBM. The velocity fields in the upper plenum of the reactor model were obtained using the optical particle image velocimetry developed at the Institute of Applied Physics (Russian Academy of Sciences). The study considers the process of development of natural circulation in the reactor and the DHRS models and the corresponding evolution of the temperature and velocity fields. A considerable influence of the valve position in the displacer of the primary pump on the natural circulation of water in the reactor through the DHX was discovered (in some modes, circulation reversal through the DHX was obtained). Alternative DHRS designs without a shell at the DHX outlet with open and closed check valve are also studied. For an open check valve, in spite of the absence of a shell, part of the flow is supplied through the DHX pipeline and then inside the SA simulators. When simulating power modes of the reactor operation, temperature stratification of the liquid was observed, which increased in the cooling mode via the DHRS. These data qualitatively agree with the results of tests at BN-600 and BN-800 reactors.

Std 598, valve inspection and testing, sixth edition, September 1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-01-01

This book covers inspection, supplementary examination, and pressure test requirements for both resilient-seated and metal-to-metal-seated gate, globe, plug, ball, check, and butterfly valves for the petroleum refinery service. The inspection requirements pertain to inspection by the purchaser and to any supplementary examinations the purchaser may require at the valve manufacturer's plant. The testing requirements cover both required and optional pressure tests by the valve manufacturer at his plant.

Development of a 30mm Frangible Projectile Crimper

DTIC Science & Technology

1977-02-01

located at end of tank. Open drain valve to drain condensation Tht outomatic lank drain equipped compressor makes this unnecessary. PRESSURE SWITCH : The... pressure switch is automatic and will start compressor at the low pressure and stop when the maximum pressure is leached. It is adjusted to start...of the check valve, located between the compressor and the tank, together with the relief valve on pressure switch relief valve units, and the cen

STS-55 pad abort: Engine 2011 oxidizer preburner augmented spark igniter check valve leak

NASA Technical Reports Server (NTRS)

1993-01-01

The STS-55 initial launch attempt of Columbia (OV102) was terminated on KSC launch pad A March 22, 1993 at 9:51 AM E.S.T. due to violation of an ME-3 (Engine 2011) Launch Commit Criteria (LCC) limit exceedance. The event description and timeline are summarized. Propellant loading was initiated on 22 March, 1993 at 1:15 AM EST. All SSME chill parameters and launch commit criteria (LCC) were nominal. At engine start plus 1.44 seconds, a Failure Identification (FID) was posted against Engine 2011 for exceeding the 50 psia Oxidizer Preburner (OPB) purge pressure redline. The engine was shut down at 1.50 seconds followed by Engines 2034 and 2030. All shut down sequences were nominal and the mission was safely aborted. The OPB purge pressure redline violation and the abort profile/overlay for all three engines are depicted. SSME Avionics hardware and software performed nominally during the incident. A review of vehicle data table (VDT) data and controller software logic revealed no failure indications other than the single FID 013-414, OPB purge pressure redline exceeded. Software logic was executed according to requirements and there was no anomalous controller software operation. Immediately following the abort, a Rocketdyne/NASA failure investigation team was assembled. The team successfully isolated the failure cause to the oxidizer preburner augmented spark igniter purge check valve not being fully closed due to contamination. The source of the contaminant was traced to a cut segment from a rubber O-ring which was used in a fine clean tool during valve production prior to 1992. The valve was apparently contaminated during its fabrication in 1985. The valve had performed acceptably on four previous flights of the engine, and SSME flight history shows 780 combined check valve flights without failure. The failure of an Engine 3 (SSME No. 2011) check valve to close was sensed by onboard engine instruments even though all other engine operations were normal. This resulted in an engine shutdown and safe sequential shutdown of all three engines prior to ignition of the solid boosters.

Space shuttle prototype check valve development

NASA Technical Reports Server (NTRS)

Tellier, G. F.

1976-01-01

Contaminant-resistant seal designs and a dynamically stable prototype check valve for the orbital maneuvering and reaction control helium pressurization systems of the space shuttle were developed. Polymer and carbide seal models were designed and tested. Perfluoroelastomers compatible with N2O4 and N2H4 types were evaluated and compared with Teflon in flat and captive seal models. Low load sealing and contamination resistance tests demonstrated cutter seal superiority over polymer seals. Ceramic and carbide materials were evaluated for N2O4 service using exposure to RFNA as a worst case screen; chemically vapor deposited tungsten carbide was shown to be impervious to the acid after 6 months immersion. A unique carbide shell poppet/cutter seat check valve was designed and tested to demonstrate low cracking pressure ( 2.0 psid), dynamic stability under all test bench flow conditions, contamination resistance (0.001 inch CRES wires cut with 1.5 pound seat load) and long life of 100,000 cycles (leakage 1.0 scc/hr helium from 0.1 to 400 psig).

Refuge alternatives relief valve testing and design with updated test stand

PubMed Central

Lutz, T.J.; Bissert, P.T.; Homce, G.T.; Yonkey, J.A.

2018-01-01

Underground refuge alternatives require an air source to supply breathable air to the occupants. This requires pressure relief valves to prevent unsafe pressures from building up within the refuge alternative. The U.S. Mine Safety and Health Administration (MSHA) mandates that pressure relief valves prevent pressure from exceeding 1.25 kPa (0.18 psi), or as specified by the manufacturer, above mine atmospheric pressure when a fan or compressor is used for the air supply. The U.S. National Institute for Occupational Safety and Health (NIOSH) tested a variety of pressure relief valves using an instrumented test fixture consisting of data acquisition equipment, a centrifugal blower, ductwork and various sensors to determine if the subject pressure relief valves meet the MSHA requirement. Relief pressures and flow characteristics, including opening pressure and flow rate, were measured for five different pressure relief valves under a variety of conditions. The subject pressure relief valves included two off-the-shelf modified check valves, two check valves used in MSHA-approved built-in-place refuge alternatives, and a commercially available valve that was designed for a steel refuge alternative and is currently being used in some built-in-place refuge alternatives. The test results showed relief pressures ranging from 0.20 to 1.53 kPa (0.03 to 0.22 psi) and flow rates up to 19.3 m3/min (683 scfm). As tested, some of the pressure relief valves did not meet the 1.25 kPa (0.18 psi) relief specification. PMID:29563650

Impact characteristics for high-pressure large-flow water-based emulsion pilot operated check valve reverse opening

NASA Astrophysics Data System (ADS)

Liu, Lei; Huang, Chuanhui; Yu, Ping; Zhang, Lei

2017-10-01

To improve the dynamic characteristics and cavitation characteristics of large-flow pilot operated check valve, consider the pilot poppet as the research object, analyses working principle and design three different kinds of pilot poppets. The vibration characteristics and impact characteristics are analyzed. The simulation model is established through flow field simulation software. The cavitation characteristics of large-flow pilot operated check valve are studied and discussed. On this basis, high-pressure large-flow impact experimental system is used for impact experiment, and the cavitation index is discussed. Then optimal structure is obtained. Simulation results indicate that the increase of pilot poppet half cone angle can effectively reduce the cavitation area, reducing the generation of cavitation. Experimental results show that the pressure impact is not decreasing with increasing of pilot poppet half cone angle in process of unloading, but the unloading capacity, response speed and pilot poppet half cone angle are positively correlated. The impact characteristics of 60° pilot poppet, and its cavitation index is lesser, which indicates 60° pilot poppet is the optimal structure, with the theory results are basically identical.

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

40 CFR 86.328-79 - Leak checks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (Figure D79-1) may be excluded from the leak check. (b) Pressure side leak...

Quantifying In Situ Metal and Organic Contaminant Mobility in Marine Sediments

DTIC Science & Technology

2009-01-01

and west of Ford Island, within the Pearl Harbor Naval Base. Sediments are fine grain silts and clays of basaltic origins and contain various... fiber filters for organics), and check valves (Figure 8) connected to synchronized parallel rotary valves connected to the collection chamber. Samples

Remote control spill reduction technology : a survey and analysis of applications for liquid pipeline systems

DOT National Transportation Integrated Search

1995-01-01

Given the 1988 directive, the OPS conducted a study on the potential for EFRDs : to minimize the volume of pipeline spills. They concluded that Remote Controlled Valves : (RCVs) and check valves are the only EFRDs that are effective on hazardous liqu...

DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, SIXTH LEVEL OF THE EXTERNAL TANK CHECK-OUT CELLS, HB-2, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

76 FR 9982 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-23

... manufactured with an outlet fitting containing red anodized threads. These MFCV do not provide adequate... that some motive flow check valves (MFCV) were manufactured with an outlet fitting containing red... containing red anodized threads. These MFCV do not provide adequate electrical bonding between the valve and...

46 CFR 56.50-30 - Boiler feed piping.

Code of Federal Regulations, 2013 CFR

2013-10-01

... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-30 Boiler feed piping. (a) General... paragraph (d) or (e) of this section. (2) Feed pump supply to power boilers may utilize the group feed... required stop and stop-check valves, shall be designed for either the feed pump relief valve setting or the...

46 CFR 56.50-30 - Boiler feed piping.

Code of Federal Regulations, 2012 CFR

2012-10-01

... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-30 Boiler feed piping. (a) General... paragraph (d) or (e) of this section. (2) Feed pump supply to power boilers may utilize the group feed... required stop and stop-check valves, shall be designed for either the feed pump relief valve setting or the...

GAS METERING PUMP

DOEpatents

George, C.M.

1957-12-31

A liquid piston gas pump is described, capable of pumping minute amounts of gas in accurately measurable quantities. The pump consists of a flanged cylindrical regulating chamber and a mercury filled bellows. Sealed to the ABSTRACTS regulating chamber is a value and having a gas inlet and outlet, the inlet being connected by a helical channel to the bellows. A gravity check valve is in the gas outlet, so the gas passes through the inlet and the helical channel to the bellows where the pumping action as well as the metering is accomplished by the actuation of the mercury filled bellows. The gas then flows through the check valve and outlet to any associated apparatus.

Microbial Check Valve for Shuttle

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Putnam, D. F.; Sauer, R. L.

1978-01-01

The Microbial Check Valve (MCV) is a device developed for the Space Shuttle that prevents the transfer of viable microorganisms within water systems. The device is essentially a bed of resin material, impregnated with iodine, that kills microorganisms on contact. It prevents the cross-contamination of microorganisms from a nonpotable system into the potable water system when these systems are interconnected. In this regard, the function of the device is similar to that of the 'air gap' found in conventional one-gravity systems. Basic design data are presented including pressure drop, scaling factors, sizing criteria, and the results of challenging the device with suspensions of seven microorganisms including aerobes, anaerobes and spore formers.

Sludge sampler

DOEpatents

Ward, Ralph C.

1983-01-01

The disclosure relates to a sludge sampler comprising an elongated generally cylindrical housing containing a baffle containing an aperture. Connected to the aperture is a flexible tubing having a valve for maintaining and releasing pressure in the lower end of the housing and exiting the upper end of the housing. The lower end of the housing contains a ball check valve maintained in closed position by pressure. When the lower end of the device contacts the sludge bed, the pressure valve is opened, enabling sludge to enter the lower end of the housing. After the sample is collected the valve is closed. An upsetting pin opens the valve to empty a sludge sample after the sample is removed from the fluid.

A simple device for the collection of water and dissolved gases at defined depths

USDA-ARS?s Scientific Manuscript database

A device, consisting of a jar fitted with an inlet comprised of a gas-tight check valve and 2-way ball valve outlet connected via tubing to a portable peristaltic pump, was constructed to collect water samples without atmospheric contamination or loss of dissolved gases. A headspace void for dissol...

AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT X, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEMS (PART II).

ERIC Educational Resources Information Center

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO PROVIDE A SUMMARY OF MAINTENANCE PROCEDURES FOR AUTOMATIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) CHECKING THE HYDRAULIC SYSTEM, (2) SERVICING THE HYDRAULIC SYSTEM, (3) EXAMINING THE RANGE CONTROL VALVE, (4) EXAMINING THE LOCK-UP AND FLOW VALVE, (5) EXAMINING THE MAIN REGULATOR…

Primary cooling check valve steam generator and loose parts events of November 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1985-12-23

On November 10, 1985, a primary coolant check valve, CV-3-8, was opened for inspection. The valve flapper and mounting bracket were found to have become detached from the valve body and were resting in the bottom of the valve. Normally, the bracket is secured to the valve body with three studs and nuts. All three sets of studs, nuts and stud retainers were missing. As part of the effort to locate the missing valve parts, the primary side of the No. 2A steam generator was opened for inspection. Three cap screws and an associated locking bar used to secure certainmore » internals were found to be missing. In response, the Director, Reactor Engineering Department was assigned lead responsibility for developing and directing the implementation of a plan to correct deficiencies and ready the plant to return to operation. Next, a Special Safety Assessment Team was established to provide a structured assessment of the safety aspect of the component failures and the implications of such failures to other components in the primary coolant system. This structured assessment was to result in the development of an action plan that included the development of specific safety criteria, and identification and conduct of special investigations and analyses required for recovery from the event. Finally, an independent Management Review Team was created. The purpose of this report is to document the work of the Management Review Team, including the causal factors analyses, and various reviews required to support the recovery process.« less

Water system microbial check valve development

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Greenley, D. R.; Putnam, D. F.

1978-01-01

Development work on a device for the Space Shuttle that will prevent the transfer of viable microorganisms within water systems is described. The device serves as a check valve in that it prevents the transfer or cross-contamination of microorganisms from a nonpotable system into a potable water system when these systems are interconnected. In this regard, the function of the device is similar to that of the air gap found in conventional one gravity systems. The device is essentially a bed of resin material impregnated with iodine. Basic design data for a variety of flow and temperature conditions are presented, together with results of challenging the beds with suspensions of seven microorganisms including aerobes, anaerobes, and spore formers.

Penetration and Duration of Fuel Sprays from a Pump Injection System

NASA Technical Reports Server (NTRS)

Rothrock, A M; Marsh, E T

1934-01-01

High-speed motion pictures were taken of individual fuel sprays from a pump injection system. The changes in the spray-tip penetration with changes in the pump speed, injection-valve opening and closing pressures, discharge-orifice area, injection-tube length and diameter, and pump throttle setting were measured. The pump was used with and without a check valve. The results show that the penetration of the spray tip can be controlled by the dimensions of the injection tube, the area of the discharge orifice, and the injection-valve opening and closing pressures.

Programming jammed Codman Hakim programmable valves: study of an explanted valve and successful programming in a patient.

PubMed

Wong, Sui-To; Wen, Eleanor; Fong, Dawson

2013-08-01

Malfunction of a Codman Hakim programmable valve due to jamming of its programmable component may necessitate shunt revision. The authors report a method for programming jammed Codman Hakim programmable valves by using a Strata II magnet and additional neodymium magnets. The programming method was derived after studying a jammed valve in the laboratory that was explanted from an 10-year-old boy with a history of fourth ventricle ependymoma. Programming the explanted valve with a Codman programmer failed, but rotating a Strata II magnet above the valve resulted in rotation of the spiral cam in the valve. It was found that the Strata II magnet could be used to program the jammed valve by rotating the magnet 90° or multiples of 90° above the valve. The strength of the magnetic field of the Strata II magnet was able to be increased by putting neodymium magnets on it. The programming method was then successfully used in a patient with a jammed Codman Hakim programmable valve. After successful programming using this method, clinical and radiological follow-up of the patient was advised.

Survey of the Literature: Controlled Generation of Liquid Droplets

DTIC Science & Technology

1988-08-01

modified to permit greater reproducibility and drop size consistency utilizes a hypodermic syringe positioned in a soleniod , with its plunger filled...1.0 SOLENOID ATM. XCESS VALVE FROM CLOCK CIRCUIT CENTERING SCREWS Figure 3. Apparatus of Reil and Hallett (1969) for Production of Uniform nrops Using...Generator, Using an Inverted Aerosol Outlet. 49 Drop Generating System NOZZLE POWDERED IRON FILL ELECTRIC SOLENOID MICROMETER SCREW CHECK VALVE

Cryogenic cooler apparatus

DOEpatents

Wheatley, J.C.; Paulson, D.N.; Allen, P.C.

1983-01-04

A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. [sup 4]He, [sup 3]He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3--4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel. 10 figs.

Cryogenic cooler apparatus

DOEpatents

Wheatley, John C.; Paulson, Douglas N.; Allen, Paul C.

1983-01-01

A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. .sup.4 He, .sup.3 He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3-4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel.

Integral isolation valve systems for loss of coolant accident protection

DOEpatents

Kanuch, David J.; DiFilipo, Paul P.

2018-03-20

A nuclear reactor includes a nuclear reactor core comprising fissile material disposed in a reactor pressure vessel having vessel penetrations that exclusively carry flow into the nuclear reactor and at least one vessel penetration that carries flow out of the nuclear reactor. An integral isolation valve (IIV) system includes passive IIVs each comprising a check valve built into a forged flange and not including an actuator, and one or more active IIVs each comprising an active valve built into a forged flange and including an actuator. Each vessel penetration exclusively carrying flow into the nuclear reactor is protected by a passive IIV whose forged flange is directly connected to the vessel penetration. Each vessel penetration carrying flow out of the nuclear reactor is protected by an active IIV whose forged flange is directly connected to the vessel penetration. Each active valve may be a normally closed valve.

New Hardware for Tethered Balloons,

DTIC Science & Technology

1980-01-01

package contained a differential- pressure switch , and a command receiver. Long wires extended up to the gas valves to actuate them, and a long tube was...similar in appear- ance to the former valve, but does contain batteries, an aneroid- operated switch, and a differential- pressure switch . Design is such...that either the aneroid-operated switch or the differential- pressure switch can be easily removed for checking Or setting in the laboratory. Likewise the

Piezoelectric Pulsed Microjets

DTIC Science & Technology

2011-04-29

microjets presents new design capabilities [ 9 , 18, 19]. An actuator is developed and tested here that integrates these two subsystems together to produce... actuator during testing. A digital pressure gauge was placed in-line after the accumulator to monitor bias pressure during testing. A check valve is used...bled off from the hydraulic actuator without affecting the pressure maintained in the accumulator. Air is bled from the system via a bleed valve within

Phi29 Connector-DNA Interactions Govern DNA Crunching and Rotation, Supporting the Check-Valve Model

PubMed Central

Kumar, Rajendra; Grubmüller, Helmut

2016-01-01

During replication of the ϕ29 bacteriophage inside a bacterial host cell, a DNA packaging motor transports the viral DNA into the procapsid against a pressure difference of up to 40 ± 20 atm. Several models have been proposed for the underlying molecular mechanism. Here we have used molecular dynamics simulations to examine the role of the connector part of the motor, and specifically the one-way revolution and the push-roll model. We have focused at the structure and intermolecular interactions between the DNA and the connector, for which a near-complete structure is available. The connector is found to induce considerable DNA deformations with respect to its canonical B-form. We further assessed by force-probe simulations to which extent the connector is able to prevent DNA leakage and found that the connector can act as a partial one-way valve by a check-valve mechanism via its mobile loops. Analysis of the geometry, flexibility, and energetics of channel lysine residues suggested that this arrangement of residues is incompatible with the observed DNA packaging step-size of ∼2.5 bp, such that the step-size is probably determined by the other components of the motor. Previously proposed DNA revolution and rolling motions inside the connector channel are both found implausible due to structural entanglement between the DNA and connector loops that have not been resolved in the crystal structure. Rather, in the simulations, the connector facilitates minor DNA rotation during the packaging process compatible with recent optical-tweezers experiments. Combined with the available experimental data, our simulation results suggest that the connector acts as a check-valve that prevents DNA leakage and induces DNA compression and rotation during DNA packaging. PMID:26789768

Systems for delivering liquified natural gas to an engine

DOEpatents

Bingham, Dennis N.; Wilding, Bruce M.; O'Brien, James E.; Siahpush, Ali S.; Brown, Kevin B.

2000-01-01

A fuel delivery system includes a fuel tank configured to receive liquid natural gas. A first conduit extends from a vapor holding portion of the fuel tank to an economizer valve. A second conduit extends from a liquid holding portion of the fuel tank to the economizer valve. Fluid coupled to the economizer valve is a vaporizer which is heated by coolant from the engine and is positioned below the fuel tank. The economizer valve selectively withdraws either liquid natural gas or vaporized natural gas from the fuel tank depending on the pressure within the vapor holding portion of the fuel tank. A delivery conduit extends from the vaporizer to the engine. A return conduit having a check valve formed therein extends from the delivery conduit to the vapor holding portion of the fuel tank for pressurizing the fuel tank.

Valve malfunction detection apparatus

NASA Astrophysics Data System (ADS)

Burley, Richard K.

1993-07-01

A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer. Upon cessation of the signal while the valve is still closed, the computer responsively generates a signal indicating that the valve, or another portion of the detection system, is leaking.

Valve malfunction detection apparatus

NASA Technical Reports Server (NTRS)

Burley, Richard K. (Inventor)

1993-01-01

A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer. Upon cessation of the signal while the valve is still closed, the computer responsively generates a signal indicating that the valve, or another portion of the detection system, is leaking.

40 CFR 92.118 - Analyzer checks and calibrations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.118... sampling system at the sample probe or valve V2 at atmospheric pressure. Simultaneously, start the time...

Thermodynamic Pressure/Temperature Transducer Health Check

NASA Technical Reports Server (NTRS)

Immer, Christopher D. (Inventor); Eckhoff, Anthony (Inventor); Medelius, Pedro J. (Inventor); Deyoe, Richard T. (Inventor); Starr, Stanley O. (Inventor)

2004-01-01

A device and procedure for checking the health of a pressure transducer in situ is provided. The procedure includes measuring a fixed change in pressure above ambient pressure and a fixed change in pressure below ambient pressure. This is done by first sealing an enclosed volume around the transducer with a valve. A piston inside the sealed volume is increasing the pressure. A fixed pressure below ambient pressure is obtained by opening the valve, driving the piston The output of the pressure transducer is recorded for both the overpressuring and the underpressuring. By comparing this data with data taken during a preoperative calibration, the health of the transducer is determined from the linearity, the hysteresis, and the repeatability of its output. The further addition of a thermometer allows constant offset error in the transducer output to be determined.

Advanced Microbial Check Valve development. [for Space Shuttle

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Greenley, D. R.; Putnam, D. F.; Sauer, R. L.

1981-01-01

The Microbial Check Valve (MCV) is a flight qualified assembly that provides bacteriologically safe drinking water for the Space Shuttle. The 1-lb unit is basically a canister packed with an iodinated ion-exchange resin. The device is used to destroy organisms in a water stream as the water passes through it. It is equally effective for fluid flow in either direction and its primary method of disinfection is killing rather than filtering. The MCV was developed to disinfect the fuel cell water and to prevent back contamination of stored potable water on the Space Shuttle. This paper reports its potential for space applications beyond the basic Shuttle mission. Data are presented that indicate the MCV is suitable for use in advanced systems that NASA has under development for the reclamation of humidity condensate, wash water and human urine.

A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

PubMed

Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

2017-02-14

The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

Managing aging in nuclear power plants: Insights from NRC maintenance team inspection reports

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fresco, A.; Subudhi, M.; Gunther, W.

1993-12-01

A plant`s maintenance program is the principal vehicle through which age-related degradation is managed. From 1988 to 1991, the NRC evaluated the maintenance program of every nuclear power plant in the United States. Forty-four out of a total of 67 of the reports issued on these in-depth team inspections were reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant systems, structures, and components. Relevant information was extracted from these inspection reports and sorted into several categories, including Specific Aging Insights, Preventive Maintenance,more » Predictive Maintenance and Condition Monitoring, Post Maintenance Testing, Failure Trending, Root Cause Analysis and Usage of Probabilistic Risk Assessment in the Maintenance Process. Specific examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging have been identified. The information also was sorted according to systems and components, including: Auxiliary Feedwater, Main Feedwater, High Pressure Injection for both BWRs and PWRs, Service Water, Instrument Air, and Emergency Diesel Generator Air Start Systems, and Emergency Diesel Generators Air Start Systems, emergency diesel generators, electrical components such as switchgear, breakers, relays, and motor control centers, motor operated valves and check valves. This information was compared to insights gained from the Nuclear Plant Aging Research (NPAR) Program. Attributes of plant maintenance programs where the NRC inspectors felt that improvement was needed to properly address the aging issue also are discussed.« less

Foot pedal operated fluid type exercising device

NASA Technical Reports Server (NTRS)

Crum, G. W.; Sauter, R. J. (Inventor)

1973-01-01

A foot pedal operated exercising device is reported that contains a dynamometer formed of a pair of cylinders each containing a piston. The pistons are linked to each other. The upper portions of the two cylinders are joined together by a common opening to provide a common fluid reservoir and each piston is provided with a one way check valve to maintain an adequate supply of working fluid. Fluid from the driven cylinder is transmitted to the other cylinder through separate constant force spring biased valves each valve takes the predominant portion of the pressure drop thereby providing a constant force hydraulic dynamometer. A device is provided to determine the amount of movement of piston travel.

Long life assurance study for manned spacecraft long life hardware. Volume 3: Long life assurance studies of components

NASA Technical Reports Server (NTRS)

1972-01-01

The guidelines for selecting hardware to be used in manned spacecraft to obtain a five year operational lifetime without maintenance were developed. An analysis was conducted on the design, application, failure mechanisms, manufacturing processes and controls, screen and burn-in techniques, and quality control of hardware items. The equipment considered for evaluation include: (1) electric motors and bearings; (2) accelerometers; (3) gyroscopes and bearings; (4) compressors and pumps, (5) magnetic tape recorders; (6) plumbing components and tubing; (7) check valves; (8) pressure regulators and solenoid valves; (9) thermal control valves; (10) pressure vessels and positive expulsion devices; (11) nickel cadmium batteries; and (12) transducers.

Development of seals for a geothermal downhole intensifier. Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Captain, K.M.; Harvey, A.C.; Caskey, B.C.

1985-08-01

A system using high-velocity fluid jets in conjunction with a rotary diamond bit is currently considered as the best candidate for reducing the cost of drilling geothermal wells. Technical, safety and cost considerations indicate that the required jet supply pressure can best be established by a downhole pressure intensifier. Key intensifier components are the check valve and plunger seals, which must prevent leakage of the high-pressure, high-temperature abrasive fluid (drilling mud). To achieve the required performance, novel ceramic seals are currently being developed. The check valve seal includes a tapered polymeric plug and ceramic stop acting against a ceramic seat.more » The ceramic plunger seal is a variant of the ''stepped-joint'' piston ring and is designed to minimize contact pressure and abrasive wear. Initial testing of these seals in the laboratory shows encouraging results; design refinement and further testing is in progress. 2 refs., 6 figs., 3 tabs.« less

Two-phase flow patterns of a top heat mode closed loop oscillating heat pipe with check valves (THMCLOHP/CV)

NASA Astrophysics Data System (ADS)

Thongdaeng, S.; Bubphachot, B.; Rittidech, S.

2016-11-01

This research is aimed at studying the two-phase flow pattern of a top heat mode closed loop oscillating heat pipe with check valves. The working fluids used are ethanol and R141b and R11 coolants with a filling ratio of 50% of the total volume. It is found that the maximum heat flux occurs for the R11 coolant used as the working fluid in the case with the inner diameter of 1.8 mm, inclination angle of -90°, evaporator temperature of 125°C, and evaporator length of 50 mm. The internal flow patterns are found to be slug flow/disperse bubble flow/annular flow, slug flow/disperse bubble flow/churn flow, slug flow/bubble flow/annular flow, slug flow/disperse bubble flow, bubble flow/annular flow, and slug flow/annular flow.

A molecular-sized tunnel-porous crystal with a ratchet gear structure and its one-way guest-molecule transportation property

NASA Astrophysics Data System (ADS)

Kataoka, Keisuke; Yasumoto, Tetsuaki; Manabe, Yousuke; Sato, Hiroyasu; Yamano, Akihito; Katagiri, Toshimasa

2013-01-01

An anisotropic tunnel microporous crystal was prepared. Active transportation of anthracene as a guest molecule in the anisotropic tunnels was observed. The direction of anthracene movement implies that the anisotropic tunnel did not work as a flap-check valve. The direction of the movement was consistent with that caused by a Brownian ratchet.An anisotropic tunnel microporous crystal was prepared. Active transportation of anthracene as a guest molecule in the anisotropic tunnels was observed. The direction of anthracene movement implies that the anisotropic tunnel did not work as a flap-check valve. The direction of the movement was consistent with that caused by a Brownian ratchet. Electronic supplementary information (ESI) available. CCDC reference numbers 837539 and 837540. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2nr30880k

Reduction of shunt current in buffer-free IrMn based spin-valve structures

NASA Astrophysics Data System (ADS)

Kocaman, B.; Akdoğan, N.

2018-06-01

The presence of thick buffer layers in magnetic sensor devices decreases sensor sensitivity due to shunt currents. With this motivation, we produced IrMn-based spin-valve multilayers without using buffer layer. We also studied the effects of post-annealing and IrMn thickness on exchange bias field (HEB) and blocking temperature (TB) of the system. Magnetization measurements indicate that both HEB and TB values are significantly enhanced with post-annealing of IrMn layer. In addition, we report that IrMn thickness of the system strongly influences the magnetization and transport characteristics of the spin-valve structures. We found that the minimum thickness of IrMn layer is 6 nm in order to achieve the lowest shunt current and high blocking temperature (>300 K). We also investigated the training of exchange bias to check the long-term durability of IrMn-based spin-valve structures for device applications.

Regenerable biocide delivery unit, volume 1

NASA Technical Reports Server (NTRS)

Atwater, James E.; Wheeler, Richard R., Jr.

1992-01-01

The Microbial Check Valve (MCV), which is currently used aboard the Shuttle Orbiter for disinfection of the potable water supply, is an expendable flow-through canister containing iodinated ion exchange resin. Means for extension of MCV life are desirable to avoid resupply penalties. The Phase 1 Regenerable Biocide Delivery Unit program demonstrated the feasibility of regenerating an MCV in situ, using a strong aqueous elemental iodine solution resulting from diversion of the MCV influent to a packed bed containing iodine crystals. In small column tests, eight manual regenerations of an MCV resin were accomplished. The term Regenerative Microbial Check Valve (RMCV) was adopted describing this new technology. The Phase 2 program resulted in the development of a full scale and fully autonomous prototype RMCV, capable of maintaining residual I(sub 2) levels between 2.0 - 4.0 mg/L for prolonged periods. During six months of testing at the Space Station baseline flow rate of 120 cm(sup 3)/min, the prototype RMCV underwent nine regenerations. RMCV life cycle tests, using a variety of influent streams, were conducted over an eighteen month period to determine the useful lives of MCV's incorporating this new technology and to determine ultimate failure mechanisms. MCV life extensions of 130 fold were demonstrated, limited only by the Phase 2 performance period. Based upon this work, it is certain that RMCV units can be developed to provide unattended biocide addition for the thirty year life of Space Station Freedom, or for other longer duration applications such as a Lunar Base or Mars mission. RMCV technology was also demonstrated capable of delivering, on demand, a concentrated aqueous I(sub 2) solution for potential use as a disinfectant during transient episodes of microbial surface contamination, for the control of biofilm formation, or as a preventative measure in systems which are particularly susceptible to the growth of microorganisms.

40 CFR 91.324 - Analyzer leakage check.

Code of Federal Regulations, 2013 CFR

2013-07-01

... flows and bypass flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (see Figure 1 in appendix B of this subpart) may be excluded...

40 CFR 91.324 - Analyzer leakage check.

Code of Federal Regulations, 2010 CFR

2010-07-01

... flows and bypass flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (see Figure 1 in appendix B of this subpart) may be excluded...

40 CFR 91.324 - Analyzer leakage check.

Code of Federal Regulations, 2011 CFR

2011-07-01

... flows and bypass flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (see Figure 1 in appendix B of this subpart) may be excluded...

40 CFR 91.324 - Analyzer leakage check.

Code of Federal Regulations, 2014 CFR

2014-07-01

... flows and bypass flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (see Figure 1 in appendix B of this subpart) may be excluded...

40 CFR 91.324 - Analyzer leakage check.

Code of Federal Regulations, 2012 CFR

2012-07-01

... flows and bypass flows may be used to estimate the in-use flow rates. (3) The sample probe and the connection between the sample probe and valve V2 (see Figure 1 in appendix B of this subpart) may be excluded...

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14470 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14473 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14469 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Expedition Seven Lu with EMU in Quest airlock

NASA Image and Video Library

2003-09-05

ISS007-E-14472 (5 September 2003) --- Astronaut Edward T. Lu, Expedition 7 NASA ISS science officer and flight engineer, performs routine maintenance on an Extravehicular Mobility Unit (EMU) space suit in the Quest airlock on the International Space Station (ISS). The work represents a mid-term checkout and included emptying and refilling the suit’s water tank and loops, cycling relief valves, checking sensors and collecting data, a leak check and running the suit’s fan for two hours to lubricate it.

Field joint environmental protection system vibration/pressurization qualification

NASA Technical Reports Server (NTRS)

Cook, M.

1989-01-01

The procedures used and results obtained from vibration testing the redesigned solid rocket motor (RSRM) field joint environmental protection system (FJEPS), hereafter referred to as the joint protection system (JPS) are documented. The major purposes were to certify that the flight-designed JPS will withstand the dynamic environmental conditions of the redesigned solid rocket booster, and to certify that the cartridge check valve (vent valve) will relieve pressure build-up under the JPS during the initial 120 sec of flight. Also, an evaluation of the extruded cork insulation bonding was performed after the vibration testing.

Northwest Boundary Containment/Treatment System Baseline Conditions, System Startup, and Operational Assessment. Volume 1.

DTIC Science & Technology

1987-12-01

combination pressure reducing check valve that is manually I controlled. A shutoff valve is installed on each well discharge line to iso - late the well from...3are 10 to 70 ft thick. The greatest thickness of surficial deposits pene- trated in borings in the study area was 69.7 ft in Well 27002 , in which...approximately 37 ft of silty clay and fine sand overlie 33 ft of gravelly sand. The gravelly sand of well 27002 is typical of the sediments comprising the

Recommendations for the management of individuals with acquired valvular heart diseases who are involved in leisure-time physical activities or competitive sports.

PubMed

Mellwig, Klaus Peter; van Buuren, Frank; Gohlke-Baerwolf, Christa; Bjørnstad, Hans Halvor

2008-02-01

Physical check-ups among athletes with valvular heart disease are of significant relevance. In athletes with mitral valve stenosis the extent of allowed physical activity is dependant on the size of the left atrium and the severity of the valve defect. Patients with mild-to-moderate mitral valve regurgitation can participate in all types of sport associated with low and moderate isometric stress and moderate dynamic stress. Patients under anticoagulation should not participate in any type of contact sport. Asymptomatic athletes with mild aortic valve stenosis can take part in all types of sport, as long as left ventricular function and size are normal, a normal response to exercise at the level performed during athletic activities is present and there are no arrhythmias. Asymptomatic athletes with moderate aortic valve stenosis should only take part in sports with low dynamic and static stress. Aortic valve regurgitation is often present due to connective tissue disease of a bicuspid valve. Athletes with mild aortic valve regurgitation, with normal end diastolic left ventricular size and systolic function can participate in all types of sport. A mitral valve prolapse is often associated with structural diseases of the myocardium and endocardium. In patients with mitral valve prolapse Holter-ECG monitoring should also be performed to detect significant arrhythmias. All athletes with known valvular heart disease, a previous history of infective endocarditis and valve surgery should receive endocarditis prophylaxis before dental, oral, respiratory, intestinal and genitourinary procedures associated with bacteraemia. Sport activities have to be avoided during active infection with fever.

Beating Back Bacteria

NASA Technical Reports Server (NTRS)

1998-01-01

Under a NASA-Johnson Space Center contract, Umpqua Research developed the MCV (Trademark) (Microbial Check Valve) which uses iodinated ion exchange resin used for water purification systems aboard space missions. Using this resin, MRLB International, Inc., developed and commercialized the Dentapure purification cartridge used by dentists nationwide.

Environmental control system transducer development study. [for space shuttles

NASA Technical Reports Server (NTRS)

Brudnicki, M. J.

1974-01-01

A development test program of transducers for aerospace projects is described. Stability and performance of existing transducers, and improvements compatible with shuttle ECS requirements are investigated. These requirements incorporate design and development features into the transducers, and include the following: (1) improvement of overall transducer ruggedness and reliability; (2) common transducers for all ECS fluids that will be unaffected by long quiescent periods in the space environment, that will require no maintenance or refurbishing for at least 100 launches; and (3) appropriate self-check features that simplify checkout and maintenance. Models of three different transducers, a three-way valve for pressure transducers from closed liquid loops, surface-type platinum-wire resistance temperature sensors, and a nuclenics gaging system are evaluated. Tests and development improvements are described.

Kate's Model Verification Tools

NASA Technical Reports Server (NTRS)

Morgan, Steve

1991-01-01

Kennedy Space Center's Knowledge-based Autonomous Test Engineer (KATE) is capable of monitoring electromechanical systems, diagnosing their errors, and even repairing them when they crash. A survey of KATE's developer/modelers revealed that they were already using a sophisticated set of productivity enhancing tools. They did request five more, however, and those make up the body of the information presented here: (1) a transfer function code fitter; (2) a FORTRAN-Lisp translator; (3) three existing structural consistency checkers to aid in syntax checking their modeled device frames; (4) an automated procedure for calibrating knowledge base admittances to protect KATE's hardware mockups from inadvertent hand valve twiddling; and (5) three alternatives for the 'pseudo object', a programming patch that currently apprises KATE's modeling devices of their operational environments.

Internal flow patterns on heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves using ethanol and a silver nano-ethanol mixture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhuwakietkumjohn, N.; Rittidech, S.

The aim of this research was to investigate the internal flow patterns and heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV). The ratio of number of check valves to meandering turns was 0.2. Ethanol and a silver nano-ethanol mixture were used as working fluids with a filling ratio of 50% by total volume of tube. The CLOHP/CV was made of a glass tube with an inside diameter of 2.4 mm. The evaporator section was 50 mm and 100 mm in length and there were 10 meandering turns. An inclination angle of 90 from horizontal axis wasmore » established. The evaporator section was heated by an electric heater and the condenser section was cooled by distilled water. Temperature at the evaporator section was controlled at 85 C, 105 C and 125 C. The inlet and outlet temperatures were measured. A digital camera and video camera were used to observe the flow patterns at the evaporator. The silver nano-ethanol mixture gave higher heat flux than ethanol. When the temperature at the evaporator section was increased from 85 C to 105 C and 125 C. It was found that, the flow patterns occurred as annular flow + slug flow, slug flow + bubble flow and dispersed bubble flow + bubble flow respectively. The main regime of each flow pattern can be determined from the flow pattern map ethanol and a silver nano-ethanol mixture. Each of the two working fluids gave corresponding flow patterns. (author)« less

46 CFR 176.810 - Fire protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Inspection of each hand portable fire extinguisher, semiportable fire extinguisher, and fixed gas fire..., and valves, and the inspection and testing of alarms and ventilation shutdowns, for each fixed gas...) Checking of each cylinder containing compressed gas to ensure it has been tested and marked in accordance...

Heat driven pulse pump

NASA Technical Reports Server (NTRS)

Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

2000-01-01

A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

Heat exchanger efficiently operable alternatively as evaporator or condenser

DOEpatents

Ecker, Amir L.

1981-01-01

A heat exchanger adapted for efficient operation alternatively as evaporator or condenser and characterized by flexible outer tube having a plurality of inner conduits and check valves sealingly disposed within the outer tube and connected with respective inlet and outlet master flow conduits and configured so as to define a parallel flow path for a first fluid such as a refrigerant when flowed in one direction and to define a serpentine and series flow path for the first fluid when flowed in the opposite direction. The flexible outer tube has a heat exchange fluid, such as water, flowed therethrough by way of suitable inlet and outlet connections. The inner conduits and check valves form a package that is twistable so as to define a spiral annular flow path within the flexible outer tube for the heat exchange fluid. The inner conduits have thin walls of highly efficient heat transfer material for transferring heat between the first and second fluids. Also disclosed are specific materials and configurations.

Electromagnetically-Actuated Reciprocating Pump for High-Flow-Rate Microfluidic Applications

PubMed Central

Ke, Ming-Tsun; Zhong, Jian-Hao; Lee, Chia-Yen

2012-01-01

This study presents an electromagnetically-actuated reciprocating pump for high-flow-rate microfluidic applications. The pump comprises four major components, namely a lower glass plate containing a copper microcoil, a middle PMMA plate incorporating a PDMS diaphragm with a surface-mounted magnet, upper PMMA channel plates, and a ball-type check valve located at the channel inlet. When an AC current is passed through the microcoil, an alternating electromagnetic force is established between the coil and the magnet. The resulting bi-directional deflection of the PDMS diaphragm causes the check-valve to open and close; thereby creating a pumping effect. The experimental results show that a coil input current of 0.4 A generates an electromagnetic force of 47 mN and a diaphragm deflection of 108 μm. Given an actuating voltage of 3 V and a driving frequency of 15 Hz, the flow rate is found to be 13.2 mL/min under zero head pressure conditions. PMID:23201986

Launch Vehicle Sizing Benefits Utilizing Main Propulsion System Crossfeed and Project Status

NASA Technical Reports Server (NTRS)

Chandler, Frank; Scheiern, M.; Champion, R.; Mazurkivich, P.; Lyles, Garry (Technical Monitor)

2002-01-01

To meet the goals for a next generation Reusable Launch Vehicle (RLV), a unique propulsion feed system concept was identified using crossfeed between the booster and orbiter stages that could reduce the Two-Stage-to-Orbit (TSTO) vehicle weight and Design, Development, Test and Evaluation (DDT&E) costs by approximately 25%, while increasing safety and reliability. The Main Propulsion System (MPS) crossfeed water demonstration test program addresses all activities required to reduce the risks for the MPS crossfeed system from a Technology Readiness Level (TRL) of 2 to 4 by the completion of testing and analysis by June 2003. During the initial period, that ended in March 2002, a subscale water flow test article was defined. Procurement of a subscale crossfeed check valve was initiated and the specifications for the various components were developed. The fluid transient and pressurization analytical models were developed separately and successfully integrated. The test matrix for the water flow test was developed to correlate the integrated model. A computational fluid dynamics (CFD) model of the crossfeed check valve was developed to assess flow disturbances and internal flow dynamics. Based on the results, the passive crossfeed system concept was very feasible and offered a safe system to be used in an RLV architecture. A water flow test article was designed to accommodate a wide range of flows simulating a number of different types of propellant systems. During the follow-on period, the crossfeed system model will be further refined, the test article will be completed, the water flow test will be performed, and finally the crossfeed system model will be correlated with the test data. This validated computer model will be used to predict the full-scale vehicle crossfeed system performance.

46 CFR 76.25-20 - Pressure tank.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... Suitable check valves shall be installed to prevent salt water from entering the pressure tank, and low water and low pressure alarms shall be fitted. (b) [Reserved] ... 46 Shipping 3 2010-10-01 2010-10-01 false Pressure tank. 76.25-20 Section 76.25-20 Shipping COAST...

46 CFR 172.150 - Survival conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Subchapter O of This Chapter § 172.150 Survival conditions. A tankship is presumed to survive assumed damage...) Each submerged opening must be weathertight. (d) Progressive flooding. Pipes, ducts or tunnels within the assumed extent of damage must be either— (1) Equipped with arrangements such as stop check valves...

46 CFR 172.150 - Survival conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Subchapter O of This Chapter § 172.150 Survival conditions. A tankship is presumed to survive assumed damage...) Each submerged opening must be weathertight. (d) Progressive flooding. Pipes, ducts or tunnels within the assumed extent of damage must be either— (1) Equipped with arrangements such as stop check valves...

46 CFR 172.150 - Survival conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Subchapter O of This Chapter § 172.150 Survival conditions. A tankship is presumed to survive assumed damage...) Each submerged opening must be weathertight. (d) Progressive flooding. Pipes, ducts or tunnels within the assumed extent of damage must be either— (1) Equipped with arrangements such as stop check valves...

High-pressure microfluidic control in lab-on-a-chip devices using mobile polymer monoliths.

PubMed

Hasselbrink, Ernest F; Shepodd, Timothy J; Rehm, Jason E

2002-10-01

We have developed a nonstick polymer formulation for creating moving parts inside of microfluidic channels and have applied the technique to create piston-based devices that overcome several microfluidic flow control challenges. The parts were created bycompletely filling the channels of a glass microfluidic chip with the monomer/ solvent/initiator components of a nonstick photopolymer and then selectively exposing the chip to UV light in order to define mobile pistons (or other quasi-two-dimensional shapes) inside the channels. Stops defined in the substrate prevent the part from flushing out of the device but also provide sealing surfaces so that valves and other flow control devices are possible. Sealing against pressures greater than 30 MPa (4,500 psi) and actuation times less than 33 ms are observed. An on-chip check valve, a diverter valve, and a 10-nL pipet are demonstrated. This valving technology, coupled with high-pressure electrokinetic pumps, should make it possible to create a completely integrated HPLC system on a chip.

Carotenoids co-localize with hydroxyapatite, cholesterol, and other lipids in calcified stenotic aortic valves. Ex vivo Raman maps compared to histological patterns.

PubMed

Bonetti, A; Bonifacio, A; Della Mora, A; Livi, U; Marchini, M; Ortolani, F

2015-04-20

Unlike its application for atherosclerotic plaque analysis, Raman microspectroscopy was sporadically used to check the sole nature of bioapatite deposits in stenotic aortic valves, neglecting the involvement of accumulated lipids/lipoproteins in the calcific process. Here, Raman microspectroscopy was employed for examination of stenotic aortic valve leaflets to add information on nature and distribution of accumulated lipids and their correlation with mineralization in the light of its potential precocious diagnostic use. Cryosections from surgically explanted stenotic aortic valves (n=4) were studied matching Raman maps against specific histological patterns. Raman maps revealed the presence of phospholipids/triglycerides and cholesterol, which showed spatial overlapping with one another and Raman-identified hydroxyapatite. Moreover, the Raman patterns correlated with those displayed by both von-Kossa-calcium- and Nile-blue-stained serial cryosections. Raman analysis also provided the first identification of carotenoids, which co-localized with the identified lipid moieties. Additional fit concerned the distribution of collagen and elastin. The good correlation of Raman maps with high-affinity staining patterns proved that Raman microspectroscopy is a reliable tool in evaluating calcification degree, alteration/displacement of extracellular matrix components, and accumulation rate of different lipid forms in calcified heart valves. In addition, the novel identification of carotenoids supports the concept that valve stenosis is an atherosclerosis-like valve lesion, consistently with their previous Raman microspectroscopical identification inside atherosclerotic plaques.

Independent Orbiter Assessment (IOA): Analysis of the elevon subsystem

NASA Technical Reports Server (NTRS)

Wilson, R. E.; Riccio, J. R.

1986-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Orbiter Elevon system hardware. The elevon actuators are located at the trailing edge of the wing surface. The proper function of the elevons is essential during the dynamic flight phases of ascent and entry. In the ascent phase of flight, the elevons are used for relieving high wing loads. For entry, the elevons are used to pitch and roll the vehicle. Specifically, the elevon system hardware comprises the following components: flow cutoff valve; switching valve; electro-hydraulic (EH) servoactuator; secondary delta pressure transducer; bypass valve; power valve; power valve check valve; primary actuator; primary delta pressure transducer; and primary actuator position transducer. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 25 failure modes analyzed, 18 were determined to be PCIs.

Two-tank working gas storage system for heat engine

DOEpatents

Hindes, Clyde J.

1987-01-01

A two-tank working gas supply and pump-down system is coupled to a hot gas engine, such as a Stirling engine. The system has a power control valve for admitting the working gas to the engine when increased power is needed, and for releasing the working gas from the engine when engine power is to be decreased. A compressor pumps the working gas that is released from the engine. Two storage vessels or tanks are provided, one for storing the working gas at a modest pressure (i.e., half maximum pressure), and another for storing the working gas at a higher pressure (i.e., about full engine pressure). Solenoid valves are associated with the gas line to each of the storage vessels, and are selectively actuated to couple the vessels one at a time to the compressor during pumpdown to fill the high-pressure vessel with working gas at high pressure and then to fill the low-pressure vessel with the gas at low pressure. When more power is needed, the solenoid valves first supply the low-pressure gas from the low-pressure vessel to the engine and then supply the high-pressure gas from the high-pressure vessel. The solenoid valves each act as a check-valve when unactuated, and as an open valve when actuated.

49 CFR 230.57 - Injectors and feedwater pumps.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.57 Injectors and feedwater pumps. (a) Water... water to the boiler, at least one of which is a live steam injector. (b) Maintenance and testing... delivering water to the boiler. Boiler checks, delivery pipes, feed water pipes, tank hose and tank valves...

46 CFR 174.207 - Damaged stability criteria.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this...) Equipped with arrangements, such as stop check-valves, to prevent progressive flooding of the spaces with... permit progressive flooding of the spaces with which they connect. (d) Buoyancy of superstructure. For...

46 CFR 174.207 - Damaged stability criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this...) Equipped with arrangements, such as stop check-valves, to prevent progressive flooding of the spaces with... permit progressive flooding of the spaces with which they connect. (d) Buoyancy of superstructure. For...

46 CFR 174.207 - Damaged stability criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this...) Equipped with arrangements, such as stop check-valves, to prevent progressive flooding of the spaces with... permit progressive flooding of the spaces with which they connect. (d) Buoyancy of superstructure. For...

46 CFR 174.207 - Damaged stability criteria.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Permeability of spaces. The permeability of a floodable space must be as specified by Table 174.207(b) of this...) Equipped with arrangements, such as stop check-valves, to prevent progressive flooding of the spaces with... permit progressive flooding of the spaces with which they connect. (d) Buoyancy of superstructure. For...

Pressure-Application Device for Testing Pressure Sensors

NASA Technical Reports Server (NTRS)

2002-01-01

A portable pressure-application device has been designed and built for use in testing and calibrating piezoelectric pressure transducers in the field. The device generates pressure pulses of known amplitude. A pressure pulse (in contradistinction to a steady pressure) is needed because in the presence of a steady pressure, the electrical output of a piezoelectric pressure transducer decays rapidly with time. The device includes a stainless- steel compressed-air-storage cylinder of 500 cu cm volume. A manual hand pump with check valves and a pressure gauge are located at one end of the cylinder. A three-way solenoid valve that controls the release of pressurized air is located at the other end of the cylinder. Power for the device is provided by a 3.7-V cordless-telephone battery. The valve is controlled by means of a pushbutton switch, which activates a 5 V to +/-15 V DC-to-DC converter that powers the solenoid. The outlet of the solenoid valve is connected to the pressure transducer to be tested. Before the solenoid is energized, the transducer to be tested is at atmospheric pressure. When the solenoid is actuated by the push button, pressurized air from inside the cylinder is applied to the transducer. Once the pushbutton is released, the cylinder pressure is removed from the transducer and the pressurized air applied to the transducer is vented, bringing the transducer back to atmospheric pressure. Before this device was used for actual calibration, its accuracy was checked with a NIST (National Institute of Standards and Technology) traceable calibrator and commercially calibrated pressure transducers. This work was done by Wanda Solano of Stennis Space Center and Greg Richardson of Lockheed Martin Corp.

An in-situ Mobile pH Calibrator for application with HOV and ROV platform in deep sea environments

NASA Astrophysics Data System (ADS)

Tan, C.; Ding, K.; Seyfried, W. E., Jr.

2014-12-01

Recently, a novel in-situ sensor calibration instrument, Mobile pH Calibrator (MpHC), was developed for application with HOV Alvin. It was specifically designed to conduct in-situ pH measurement in deep sea hydrothermal diffuse fluids with in-situ calibration function. In general, the sensor calibrator involves three integrated electrodes (pH, dissolved H2 and H2S) and a temperature sensor, all of which are installed in a cell with a volume of ~ 1 ml. A PEEK check valve cartridge is installed at the inlet end of the cell to guide the flow path during the measurement and calibration processes. Two PEEK tubes are connected at outlet end of the cell for drawing out hydrothermal fluid and delivering pH buffer fluids. During its measurement operation, the pump draws in hydrothermal fluid, which then passes through the check valve directly into the sensing cell. When in calibration mode, the pump delivers pH buffers into the cell, while automatically closing the check valve to the outside environment. This probe has two advantages compared to our previous unit used during KNOX18RR MAR cruise in 2008 and MARS cabled observatory deployment in 2012. First, in the former design, a 5 cm solenoid valve was equipped with the probe. This enlarged size prevented its application in specific point or small area. In this version, the probe has only a dimension of 1.6 cm for an easy access to hydrothermal biological environments. Secondly, the maximum temperature condition of the earlier system was limited by the solenoid valve precluding operation in excess of 50 ºC. The new design avoids this problem, which improves its temperature tolerance. The upper limit of temperature condition is now up to 100oC, therefore enabling broader application in hydrothermal diffuse flow system on the seafloor. During SVC cruise (AT26-12) in the Gulf of Mexico this year, the MpHC was successfully tested with Alvin dives at the depth up to 2600 m for measuring pH with in-situ calibration in seafloor cold seep environment. The measurement and calibration were also conducted in hydrothermal diffuse flow at temperature condition exceeding 70 ºC with Alvin dives during a recent cruise AT26-17 in ASHES vent field and Main Endeavour Field on Juan de Fuca Ridge. Data from these seagoing deployments will be presented, with emphasis on both technical and scientific aplications.

Explosive-actuated valve design concept that eliminates blow-by. [for the TOPS spacecraft trajectory correction propulsion subsystem

NASA Technical Reports Server (NTRS)

Hagler, R., Jr.

1974-01-01

A method of evaluating the normally open normally closed, explosive actuated valves that were selected for use in the trajectory correction propulsion subsystem of the Thermoelectric Outer Planet Spacecraft (TOPS) program is presented. The design philosophy which determined the requirements for highly reliable valves that could provide the performance capability during long duration (10 year) missions to the outer planets is discussed. The techniques that were used to fabricate the valves and manifold ten valves into an assembly with the capability of five propellant-flow initiation/isolation sequences are described. The test program, which was conducted to verify valve design requirements, is outlined and the more significant results are shown.

Experimental and Analytical Investigation of Pressure Differentials for Clean and Loaded Wire Meshes Used in Zeolite Retention

NASA Technical Reports Server (NTRS)

Knox, James C.

2004-01-01

Following failure of the carbon dioxide removal assembly (CDRA) on the ISS, a CDRA teardown, test, and evaluation (TT&E) effort found that the sorbent material was not retained as intended by the packed beds and that presence of the sorbent in the check valve and selector valve was the cause of the failure of these components. This paper documents the development of design data for an in-line filter element. The purpose of the in-line filter is to provide temporary protection for on-orbit CDRA hardware until the bed retainment system can be redesigned and replaced.

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

49 CFR 178.42 - Specification 3E seamless steel cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (valves, fuse plugs, etc.) for those openings. Threads conforming to the following are required on openings. (1) Threads must be clean cut, even, without checks, and to gauge. (2) Taper threads, when used, must be of length not less than as specified for American Standard taper pipe threads. (3) Straight...

76 FR 64801 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-19

.... But we might have found it necessary to use different words from those in the MCAI to ensure the AD is... blocked by water, which fails to enter the drain bottles. Investigation revealed that drain bottles used in the primary pitot-static system include check valves, which impede the entry of water into the...

40 CFR 63.148 - Leak inspection provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry... line; or (2) Secure the bypass line valve in the closed position with a car-seal or a lock-and-key type... configuration has been checked out, and records of any car-seal that has broken. (4) For each inspection during...

40 CFR 63.148 - Leak inspection provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry... line; or (2) Secure the bypass line valve in the closed position with a car-seal or a lock-and-key type... configuration has been checked out, and records of any car-seal that has broken. (4) For each inspection during...

40 CFR 63.148 - Leak inspection provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry... line; or (2) Secure the bypass line valve in the closed position with a car-seal or a lock-and-key type... configuration has been checked out, and records of any car-seal that has broken. (4) For each inspection during...

40 CFR 63.148 - Leak inspection provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry... line; or (2) Secure the bypass line valve in the closed position with a car-seal or a lock-and-key type... configuration has been checked out, and records of any car-seal that has broken. (4) For each inspection during...

A Flush Toilet Model for the Transistor

NASA Astrophysics Data System (ADS)

Organtini, Giovanni

2012-04-01

In introductory physics textbooks, diodes working principles are usually well described in a relatively simple manner. According to our experience, they are well understood by students. Even when no formal derivation of the physics laws governing the current flow through a diode is given, the use of this device as a check valve is easily accepted. This is not true for transistors. In most textbooks the behavior of a transistor is given without formal explanation. When the amplification is computed, for some reason, students have difficulties in identifying the basic physical mechanisms that give rise to such an effect. In this paper we give a simple and captivating illustration of the working principles of a transistor as an amplifier, tailored to high school students even with almost no background in electronics nor in modern physics. We assume that the target audience is familiar with the idea that a diode works as a check valve for currents. The lecture emphasis is on the illustration of physics principles governing the behavior of a transistor, rather than on a formal description of the processes leading to amplification.

Advanced microbial check valve development

NASA Technical Reports Server (NTRS)

Colombo, G. V.; Greenley, D. R.

1980-01-01

A flight certified assembly identified as a Microbial Check Valve (MCV) was developed and tested. The MCV is a canister packed with an iodinated anionic exchange resin. The device is used to destroy organisms in a water stream as the water passes through the device. The device is equally effective for fluid flow in either direction and its primary method of organism removal is killing rather than filtering. The MCV was successfully developed for the space shuttle to: disinfect fuel cell water; and prevent back contamination of the stored potable water supply. One version of the device consists of a high residual iodinated resin bed that imparts approximately 2 ppm of iodine to the fuel cell water as it flows to the potable water tanks. A second version of the device consists of a low residual iodinated resin bed. One of these low residual beds is located at each use port in the potable water system for the dual purpose of removing some iodine from the potable water as it is dispensed and also to prevent back contamination of the potable supply.

Electrochemical control of iodine disinfectant for space transportation system and space station potable water

NASA Technical Reports Server (NTRS)

Geer, Richard D.

1989-01-01

An electrochemical microbial check valve method (EC-MCV) for controlling the iodine disinfectant in potable water (PW) for NASA's space operations was proposed. The factors affecting the design and performance of the unit were analyzed. This showed that it would be feasible to construct a recyclable unit in a small volume that will operate in either an iodine removal or addition mode. The EC-MCV should remove active iodine species rapidly from PW, but the rapid delivery rates at end-use may make complete removal of excess I(-) difficult under some conditions. Its performace change with AgI buildup needs to be investigated, as this controls the time for recycling the unit. The EC-MCV has advantages over the passive microbial check valve (MCV) method currently in use, as it would allow precise control of the I2 level and would not introduce excess I(-) to the water. The presence of oxygen in the EC-MCV needs to be investigated as it could affect the efficiency of I2 addition and excess I(-) removal.

Micro Linear Pump with Electromagnetic Actuator

NASA Astrophysics Data System (ADS)

Suzumori, Koichi; Furusawa, Hiroaki; Kanda, Takefumi; Yamada, Yoshiaki; Nagata, Takashi

In recent years, research and development of the micro-fluid systems have been activated in the field of chemical technology and biotechnology. Micro-fluid systems are realized by micromachine technology and MEMS technology. Micro pump is an essential element for miniaturization of chemical analysis reaction systems. The aim of this research is development of a micro linear pump which will be built into micro-fluid systems. This pump aims to take a sample of very-small-quantity of liquids. Taking a sample of very-small-quantity of liquids reduce the amount used and waste fluid of a reagent. Full length and diameter of this pump are 32.5mm and 6mm respectively. The features of this pump are (1) the pump is built with actuator, (2) the gap of 7μm between piston and cylinder is achieved through fine machining process, and (3) micro check-valves of 2mm diameter made of stainless-steel film are fabricated and integrated. In this paper, the structure and the characteristics of this pump were shown. And the characteristics after improvement of micro check-valves were shown.

Carotenoids Co-Localize with Hydroxyapatite, Cholesterol, and Other Lipids in Calcified Stenotic Aortic Valves. Ex Vivo Raman Maps Compared to Histological Patterns

PubMed Central

Bonetti, A.; Bonifacio, A.; Mora, A. Della; Livi, U.; Marchini, M.; Ortolani, F.

2015-01-01

Unlike its application for atherosclerotic plaque analysis, Raman microspectroscopy was sporadically used to check the sole nature of bioapatite deposits in stenotic aortic valves, neglecting the involvement of accumulated lipids/lipoproteins in the calcific process. Here, Raman microspectroscopy was employed for examination of stenotic aortic valve leaflets to add information on nature and distribution of accumulated lipids and their correlation with mineralization in the light of its potential precocious diagnostic use. Cryosections from surgically explanted stenotic aortic valves (n=4) were studied matching Raman maps against specific histological patterns. Raman maps revealed the presence of phospholipids/triglycerides and cholesterol, which showed spatial overlapping with one another and Raman-identified hydroxyapatite. Moreover, the Raman patterns correlated with those displayed by both von-Kossa-calcium- and Nile-blue-stained serial cryosections. Raman analysis also provided the first identification of carotenoids, which co-localized with the identified lipid moieties. Additional fit concerned the distribution of collagen and elastin. The good correlation of Raman maps with high-affinity staining patterns proved that Raman microspectroscopy is a reliable tool in evaluating calcification degree, alteration/displacement of extracellular matrix components, and accumulation rate of different lipid forms in calcified heart valves. In addition, the novel identification of carotenoids supports the concept that valve stenosis is an atherosclerosis-like valve lesion, consistently with their previous Raman microspectroscopical identification inside atherosclerotic plaques. PMID:26150160

A rigorous approach to self-checking programming

NASA Technical Reports Server (NTRS)

Hua, Kien A.; Abraham, Jacob A.

1986-01-01

Self-checking programming is shown to be an effective concurrent error detection technique. The reliability of a self-checking program however relies on the quality of its assertion statements. A self-checking program written without formal guidelines could provide a poor coverage of the errors. A constructive technique for self-checking programming is presented. A Structured Program Design Language (SPDL) suitable for self-checking software development is defined. A set of formal rules, was also developed, that allows the transfromation of SPDL designs into self-checking designs to be done in a systematic manner.

A jazz-based approach for optimal setting of pressure reducing valves in water distribution networks

NASA Astrophysics Data System (ADS)

De Paola, Francesco; Galdiero, Enzo; Giugni, Maurizio

2016-05-01

This study presents a model for valve setting in water distribution networks (WDNs), with the aim of reducing the level of leakage. The approach is based on the harmony search (HS) optimization algorithm. The HS mimics a jazz improvisation process able to find the best solutions, in this case corresponding to valve settings in a WDN. The model also interfaces with the improved version of a popular hydraulic simulator, EPANET 2.0, to check the hydraulic constraints and to evaluate the performances of the solutions. Penalties are introduced in the objective function in case of violation of the hydraulic constraints. The model is applied to two case studies, and the obtained results in terms of pressure reductions are comparable with those of competitive metaheuristic algorithms (e.g. genetic algorithms). The results demonstrate the suitability of the HS algorithm for water network management and optimization.

40 CFR 63.175 - Quality improvement program for valves.

Code of Federal Regulations, 2010 CFR

2010-07-01

... improvement program for valves. (a) In Phase III, an owner or operator may elect to comply with one of the... use one of these alternative provisions to comply with the requirements of § 63.168(d)(1)(ii) of this... exceeds 2 percent leaking valves, and in such case, monthly monitoring will be required. (d) The following...

40 CFR 63.175 - Quality improvement program for valves.

Code of Federal Regulations, 2014 CFR

2014-07-01

... improvement program for valves. (a) In Phase III, an owner or operator may elect to comply with one of the... use one of these alternative provisions to comply with the requirements of § 63.168(d)(1)(ii) of this... exceeds 2 percent leaking valves, and in such case, monthly monitoring will be required. (d) The following...

Guide for Oxygen Component Qualification Tests

NASA Technical Reports Server (NTRS)

Bamford, Larry J.; Rucker, Michelle A.; Dobbin, Douglas

1996-01-01

Although oxygen is a chemically stable element, it is not shock sensitive, will not decompose, and is not flammable. Oxygen use therefore carries a risk that should never be overlooked, because oxygen is a strong oxidizer that vigorously supports combustion. Safety is of primary concern in oxygen service. To promote safety in oxygen systems, the flammability of materials used in them should be analyzed. At the NASA White Sands Test Facility (WSTF), we have performed configurational tests of components specifically engineered for oxygen service. These tests follow a detailed WSTF oxygen hazards analysis. The stated objective of the tests was to provide performance test data for customer use as part of a qualification plan for a particular component in a particular configuration, and under worst-case conditions. In this document - the 'Guide for Oxygen Component Qualification Tests' - we outline recommended test systems, and cleaning, handling, and test procedures that address worst-case conditions. It should be noted that test results apply specifically to: manual valves, remotely operated valves, check valves, relief valves, filters, regulators, flexible hoses, and intensifiers. Component systems are not covered.

Load control system. [for space shuttle external tank ground tests

NASA Technical Reports Server (NTRS)

Grosse, J. C.

1977-01-01

The load control system developed for the shuttle external structural tests is described. The system consists of a load programming/display module, and a load control module along with the following hydraulic system components: servo valves, dump valves, hydraulic system components, and servo valve manifold blocks. One load programming/display subsystem can support multiple load control subsystem modules.

40 CFR 86.309-79 - Sampling and analytical system; schematic drawing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or parts of components that are wetted by the sample or corrosive calibration gases shall be either... must be within 2 inches of the analyzer entrance port. (vi) Calibration or span gases for the NOX... calibration gases. (ii) V2—optional heated selector valve to purge the sample probe, perform leak checks, or...

40 CFR 86.309-79 - Sampling and analytical system; schematic drawing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... or parts of components that are wetted by the sample or corrosive calibration gases shall be either... must be within 2 inches of the analyzer entrance port. (vi) Calibration or span gases for the NOX... calibration gases. (ii) V2—optional heated selector valve to purge the sample probe, perform leak checks, or...

A Flush Toilet Model for the Transistor

ERIC Educational Resources Information Center

Organtini, Giovanni

2012-01-01

In introductory physics textbooks, diodes working principles are usually well described in a relatively simple manner. According to our experience, they are well understood by students. Even when no formal derivation of the physics laws governing the current flow through a diode is given, the use of this device as a check valve is easily accepted.…

Line Fluid Actuated Valve Development Program. [for application on the space shuttle

NASA Technical Reports Server (NTRS)

Lynch, R. A.

1975-01-01

The feasibility of a line-fluid actuated valve design for potential application as a propellant-control valve on the space shuttle was examined. Design and analysis studies of two prototype valve units were conducted and demonstrated performance is reported. It was shown that the line-fluid actuated valve concept offers distinct weight and electrical advantages over alternate valve concepts. Summaries of projected performance and design goals are also included.

KSC-06pd0616

NASA Image and Video Library

2006-04-13

KENNEDY SPACE CENTER, FLA. - In the transfer aisle of the Vehicle Assembly Building, workers check the rim around the nose cap of external tank number 119, the tank designated for mission STS-121. The cap was removed in order to install a new gaseous oxygen vent valve underneath. Vapors are created prior to launch as the liquid oxygen in the external tank boils off. At the forward end of each external tank propellant tank is a vent and relief valve that can be opened before launch for venting or by excessive tank pressure for relief. The vent function is available only before launch. Mission STS-121 to the International Space Station is scheduled for launch in July. Photo credit: NASA/Jim Grossmann

Design considerations and quantitative assessment for the development of percutaneous mitral valve stent.

PubMed

Kumar, Gideon Praveen; Cui, Fangsen; Phang, Hui Qun; Su, Boyang; Leo, Hwa Liang; Hon, Jimmy Kim Fatt

2014-07-01

Percutaneous heart valve replacement is gaining popularity, as more positive reports of satisfactory early clinical experiences are published. However this technique is mostly used for the replacement of pulmonary and aortic valves and less often for the repair and replacement of atrioventricular valves mainly due to their anatomical complexity. While the challenges posed by the complexity of the mitral annulus anatomy cannot be mitigated, it is possible to design mitral stents that could offer good anchorage and support to the valve prosthesis. This paper describes four new Nitinol based mitral valve designs with specific features intended to address migration and paravalvular leaks associated with mitral valve designs. The paper also describes maximum possible crimpability assessment of these mitral stent designs using a crimpability index formulation based on the various stent design parameters. The actual crimpability of the designs was further evaluated using finite element analysis (FEA). Furthermore, fatigue modeling and analysis was also done on these designs. One of the models was then coated with polytetrafluoroethylene (PTFE) with leaflets sutured and put to: (i) leaflet functional tests to check for proper coaptation of the leaflet and regurgitation leakages on a phantom model and (ii) anchorage test where the stented valve was deployed in an explanted pig heart. Simulations results showed that all the stents designs could be crimped to 18F without mechanical failure. Leaflet functional test results showed that the valve leaflets in the fabricated stented valve coapted properly and the regurgitation leakage being within acceptable limits. Deployment of the stented valve in the explanted heart showed that it anchors well in the mitral annulus. Based on these promising results of the one design tested, the other stent models proposed here were also considered to be promising for percutaneous replacement of mitral valves for the treatment of mitral regurgitation, by virtue of their key features as well as effective crimping. These models will be fabricated and put to all the aforementioned tests before being taken for animal trials. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

AeroValve Experimental Test Data Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noakes, Mark W.

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.

High-performance space shuttle auxiliary propellant valve system

NASA Technical Reports Server (NTRS)

Smith, G. M.

1973-01-01

Several potential valve closures for the space shuttle auxiliary propulsion system (SS/APS) were investigated analytically and experimentally in a modeling program. The most promising of these were analyzed and experimentally evaluated in a full-size functional valve test fixture of novel design. The engineering investigations conducted for both model and scale evaluations of the SS/APS valve closures and functional valve fixture are described. Preliminary designs, laboratory tests, and overall valve test fixture designs are presented, and a final recommended flightweight SS/APS valve design is presented.

40 CFR 63.167 - Standards: Open-ended valves or lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards: Open-ended valves or lines... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES...: Open-ended valves or lines. (a)(1) Each open-ended valve or line shall be equipped with a cap, blind...

40 CFR 60.482-6 - Standards: Open-ended valves or lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Open-ended valves or lines... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for... Standards: Open-ended valves or lines. (a)(1) Each open-ended valve or line shall be equipped with a cap...

40 CFR 86.140-94 - Exhaust sample analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) and (2) of this section if required. (4) Check flow rates and pressures. (5) Measure THC, CO, CO2, CH4... accomplished by either of the following methods: (i) Close heated valve in THC sample (see Figures B94-5 or B94... pressure. (ii) Connect zero and span line directly to THC sample probe and introduce gases at a flow rate...

40 CFR 86.140-94 - Exhaust sample analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) and (2) of this section if required. (4) Check flow rates and pressures. (5) Measure THC, CO, CO2, CH4... accomplished by either of the following methods: (i) Close heated valve in THC sample (see Figures B94-5 or B94... pressure. (ii) Connect zero and span line directly to THC sample probe and introduce gases at a flow rate...

40 CFR 86.140-94 - Exhaust sample analysis.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) and (2) of this section if required. (4) Check flow rates and pressures. (5) Measure THC, CO, CO2, CH4... accomplished by either of the following methods: (i) Close heated valve in THC sample (see Figures B94-5 or B94... pressure. (ii) Connect zero and span line directly to THC sample probe and introduce gases at a flow rate...

Tidal sampler

DOEpatents

Hayes, David W.

1978-01-01

An apparatus for pumping a sample of water or other liquid that uses the energy generated from the rise and fall of the liquid level to force a sample of the liquid into a collection vessel. A suction vessel and booster vessel with interconnecting tubing and check valves are responsive to an oscillating liquid level to pump a portion of said liquid into a collection vessel.

A check valve controlled laser-induced microjet for uniform transdermal drug delivery

NASA Astrophysics Data System (ADS)

Ham, Hwi-chan; Jang, Hun-jae; Yoh, Jack J.

2017-12-01

A narrow nozzle ejects a microjet of 150 μm in diameter with a velocity of 140 m/s a by the laser-induced bubble expansion in the designed injector. The pulsed form of the driving force at a period of 10 Hz from the connected Er:YAG laser makes it possible for multiple microjet ejections aimed at delivery of drugs into a skin target. The pulsed actuation of the microjet generation is however susceptible to the air leak which can cause the outside air to enter into the momentarily de-pressurized nozzle, leading to a significant reduction of the microjet speed during the pulsed administering of the drug. In the present study, we designed a ball-check valve injector which is less prone to an unwanted air build up inside the nozzle by controlling the nozzle pressure to remain above ambient pressure at all times. The new device is rigorously compared against the reported performance of the previous injector and has shown to maintain about 97% of the initial microjet speed regardless of the number of shots administered; likewise, the drug penetration depth into a porcine skin is improved to 1.5 to 2.25 times the previously reported penetration depths.

Nonlinear dynamic modeling for smart material electro-hydraulic actuator development

NASA Astrophysics Data System (ADS)

Larson, John P.; Dapino, Marcelo J.

2013-03-01

Smart material electro-hydraulic actuators use hydraulic rectification by one-way check valves to amplify the motion of smart materials, such as magnetostrictives and piezoelectrics, in order to create compact, lightweight actuators. A piston pump driven by a smart material is combined with a hydraulic cylinder to form a self-contained, power-by-wire actuator that can be used in place of a conventional hydraulic system without the need for hydraulic lines and a centralized pump. The performance of an experimental actuator driven by a 12.7 mm diameter, 114 mm length Terfenol-D rod is evaluated over a range of applied input frequencies, loads, and currents. The peak performance achieved is 37 W, moving a 220 N load at a rate of 17 cm/s and producing a blocked pressure of 12.5 MPa. Additional tests are conducted to quantify the dynamic behavior of the one-way reed valves using a scanning laser vibrometer to identify the frequency response of the reeds and the effect of the valve seat and fluid mass loading. A lumped-parameter model is developed for the system that includes valve inertia and fluid response nonlinearities, and the model results are compared with the experimental data.

Is mitral valve repair superior to replacement for chronic ischemic mitral regurgitation with left ventricular dysfunction?

PubMed Central

2010-01-01

Background This study was undertaken to compare mitral valve repair and replacement as treatments for ischemic mitral regurgitation (IMR) with left ventricular dysfunction (LVD). Specifically, we sought to determine whether the choice of mitral valve procedure affected survival, and discover which patients were predicted to benefit from mitral valve repair and which from replacement. Methods A total of 218 consecutive patients underwent either mitral valve repair (MVP, n = 112) or mitral valve replacement (MVR, n = 106). We retrospectively reviewed the clinical material, operation methods, echocardiography check during operation and follow-up. Patients details and follow-up outcomes were compared using multivariate and Kaplan-Meier analyses. Results No statistical difference was found between the two groups in term of intraoperative data. Early mortality was 3.2% (MVP 2.7% and MVR 3.8%). At discharge, Left ventricular end-systolic and end-diastolic diameter and left ventricular ejection fraction (LVEF) were improved more in the MVP group than MVR group (P < 0.05), however, in follow-up no statistically significant difference was observed between the MVR and MVP group (P > 0.05). Follow-up mitral regurgitation grade was significantly improved in the MVR group compared with the MVP group (P < 0.05). The Kaplan-Meier survival estimates at 1, 3, and 5 years were simlar between MVP and MVR group. Logistic regression revealed poor survival was associated with old age(#75), preoperative renal insufficiency and low left ventricular ejection fraction (< 30%). Conclusion Mitral valve repair is the procedure of choice in the majority of patients having surgery for severe ischemic mitral regurgitation with left ventricular dysfunction. Early results of MVP treatment seem to be satisfactory, but several lines of data indicate that mitral valve repair provided less long-term benefit than mitral valve replacement in the LVD patients. PMID:21059216

Banking cryopreserved heart valves in Europe: assessment of a 5-year operation in an international tissue bank in Brussels.

PubMed

Goffin, Y; Grandmougin, D; Van Hoeck, B

1996-01-01

The heart valve bank of the European Homograft Bank has been set up in 1988 to meet the growing demand of cardiac surgeons for various sized and quality controlled cryopreserved homografts. Heart valve donors less than 60 years of age were classified in 3 categories: multiorgan donors with non transplantable hearts, recipients of cardiac transplantation and non beating heart cadavers with a warm ischemic time of less than 6 hours. Past history and biology were checked for transmissible diseases. Preparation, progressive freezing and storage in liquid nitrogen vapors, and quality control were according to the standards of the Belgian Ministry of Health. From end January 1989 to end May 1994, 989 homograft valves were cryopreserved (514 pulmonary, 475 aortic and 3 mitral) whereas 962 valves were discarded. The first cause of rejection being a major macroscopic lesion (41.48%). 138 hearts accepted at inspection were contaminated and 43 cases remained so after antibiotics. 38 cases were positive for hepatitis B or C. Complication at distribution and thawing included 10 instances of bag rupture and 15 of transversal fracture through the wall of the conduit. 477 aortic, 474 pulmonary valves as well as one mitral were implanted between May 1989 and May 1994, either for left or right ventricular outflow tract reconstruction. In the left ventricular outflow tract series 111 aortic and 23 pulmonary homograft valves were used in cases of native endocarditis, prosthetic endocarditis or recurrent endocarditis after homograft implantation. 9.6% of the requests could no be satisfied. Regular follow up information was available from 382 implants-40.1% only. The assessment of 5 years operation of the heart valve bank indicates: 1) the efficiency of selecting, cryopreserving and allocating quality controlled homograft valves from a large pool of donor hearts provided by a network of hospitals; 2) the difficulty of obtaining regular follow up information on the implants.

Nonlinear solid finite element analysis of mitral valves with heterogeneous leaflet layers

NASA Astrophysics Data System (ADS)

Prot, V.; Skallerud, B.

2009-02-01

An incompressible transversely isotropic hyperelastic material for solid finite element analysis of a porcine mitral valve response is described. The material model implementation is checked in single element tests and compared with a membrane implementation in an out-of-plane loading test to study how the layered structures modify the stress response for a simple geometry. Three different collagen layer arrangements are used in finite element analysis of the mitral valve. When the leaflets are arranged in two layers with the collagen on the ventricular side, the stress in the fibre direction through the thickness in the central part of the anterior leaflet is homogenized and the peak stress is reduced. A simulation using membrane elements is also carried out for comparison with the solid finite element results. Compared to echocardiographic measurements, the finite element models bulge too much in the left atrium. This may be due to evidence of active muscle fibres in some parts of the anterior leaflet, whereas our constitutive modelling is based on passive material.

Multi-bottle, no compressor, mean pressure control system for a Stirling engine

DOEpatents

Corey, John A.

1990-01-01

The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

Improved multiple-shot gun for use as a combustion stability rating device

NASA Technical Reports Server (NTRS)

Sokolowski, D. E.

1973-01-01

A program was conducted to develop and experimentally evaluate an improved version of a modified machine gun for use as a device for rating the relative combustion stability of various rocket combustors. Following the results of a previous study involving a caliber .30 machine gun, a caliber .50 machine gun was modified in order to extend the charge-size range of the device. Nitrocellulose charge sizes ranging from 1.004 to 9.720 grams were fired at rates up to four shots per second. Shock pressures up to 25,512 kN/sq m were measured near the end of a shortened gun barrel. A minimal resistance type of check valve permitted the gun to fire into pressurized regions; back pressures up to 3448 kN/sq m abs were tested. The final modified assembly was evaluated during combustion stability tests on rocket combustors burning a FLOX-methane propellant combination.

Evaluation test program, valve, explosive actuated, normally closed Pyronetics model 1400

NASA Technical Reports Server (NTRS)

Avalos, E.

1971-01-01

Evaluation tests of the explosive actuated normally closed valves used to control and isolate hydrazine flow in the TOPS spacecraft, are presented. The malfunctions, modifications, service life, and reliability of the valve are also outlined.

Pressure Relief Devices

NASA Astrophysics Data System (ADS)

Manha, William D.

2010-09-01

Pressure relief devices are used in pressure systems and on pressure vessels to prevent catastrophic rupture or explosion from excessive pressure. Pressure systems and pressure vessels have manufacturers maximum rated operating pressures or maximum design pressures(MDP) for which there are relatively high safety factors and minimum risk of rupture or explosion. Pressure systems and pressure vessels that have a potential to exceed the MDP by being connected to another higher pressure source, a compressor, or heat to water(boiler) are required to have over-pressure protecting devices. Such devices can be relief valves and/or burst discs to safely relieve potentially excessive pressure and prevent unacceptable ruptures and explosions which result in fail-safe pressure systems and pressure vessels. Common aerospace relief valve and burst disc requirements and standards will be presented. This will include the NASA PSRP Interpretation Letter TA-88-074 Fault Tolerance of Systems Using Specially Certified Burst Disks that dictates burst disc requirements for payloads on Shuttle. Two recent undesirable manned space payloads pressure relief devices and practices will be discussed, as well as why these practices should not be continued. One example for discussion is the use of three burst discs that have been placed in series to comply with safety requirements of three controls to prevent a catastrophic hazard of the over-pressurization and rupture of pressure system and/or vessels. The cavities between the burst discs are evacuated and are the reference pressures for activating the two upstream burst discs. If the upstream burst disc leaks into the reference cavity, the reference pressure increases and it can increase the burst disc activating pressure and potentially result in the burst disc assembly being ineffective for over pressure protection. The three burst discs-in-series assembly was found acceptable because the burst discs are designed for minimum risk(DFMR) of leakage into the reference cavity. Since the burst discs are DFMR, a single burst disc would suffice, without adding the two leak-into-reference cavity failure modes. A single DFMR burst disc is preferable. An Alpha Magnetic Spectrometer - 02 burst disc assembly, with three-in-series burst discs test failure, necessitated the deletion of one of the burst discs, will be presented. Payload relief valves require periodic retests were extended significantly beyond the normal one year retest period because of the reduced ISS down mass capability which followed the Columbia accident. The acceptability of the extended retest period was determined by analysis, materials stability, benign environment, relatively inert fluid exposure, etc.(The policy letter, NC4-02-205 Guidelines for Certification and Verification of Pressure System Control Hardware, that permitted this action will be provided even though this application is not recommended for extending relief valve annual retest requirements.) The first crack pressure of a relief valve after an extended inactive period can be higher than the set crack pressure. Extrapolation of the extended inactive period and increased crack pressure could result in ineffective over pressure protection. Thus, relief valves with a ring or lever for activation are recommended so the relief valve can periodically be verified to open, functionality verified and the extended relief valve retest period should be discouraged. Stainless Steel cylindrical poppet-in-cylindrical housing check valves should never be used in a fluid with ions for an extended period of time, because the poppet is vulnerable to seizing or not functioning as a relief valve, even though the specifications, crack pressure, reseat pressure, maximum flow, and reseat leak look very much like the specifications for a relief valve. The technical reasons for this avoidance of using check valves as a relief valve will be discussed. The presentation will be summarized and recommendations made.

Independent Orbiter Assessment (IOA): Analysis of the orbiter main propulsion system

NASA Technical Reports Server (NTRS)

Mcnicoll, W. J.; Mcneely, M.; Holden, K. A.; Emmons, T. E.; Lowery, H. J.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Main Propulsion System (MPS) hardware are documented. The Orbiter MPS consists of two subsystems: the Propellant Management Subsystem (PMS) and the Helium Subsystem. The PMS is a system of manifolds, distribution lines and valves by which the liquid propellants pass from the External Tank (ET) to the Space Shuttle Main Engines (SSMEs) and gaseous propellants pass from the SSMEs to the ET. The Helium Subsystem consists of a series of helium supply tanks and their associated regulators, check valves, distribution lines, and control valves. The Helium Subsystem supplies helium that is used within the SSMEs for inflight purges and provides pressure for actuation of SSME valves during emergency pneumatic shutdowns. The balance of the helium is used to provide pressure to operate the pneumatically actuated valves within the PMS. Each component was evaluated and analyzed for possible failure modes and effects. Criticalities were assigned based on the worst possible effect of each failure mode. Of the 690 failure modes analyzed, 349 were determined to be PCIs.

KSC-2009-1950

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians prepare to install three gaseous hydrogen flow control valves on space shuttle Discovery. The valves were retested after installation. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

KSC-2009-1951

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians install three gaseous hydrogen flow control valves on space shuttle Discovery. The valves were retested after installation. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

Advanced technology for space shuttle auxiliary propellant valves

NASA Technical Reports Server (NTRS)

Wichmann, H.

1973-01-01

Valves for the gaseous hydrogen/gaseous oxygen shuttle auxiliary propulsion system are required to feature low leakage over a wide temperature range coupled with high cycle life, long term compatibility and minimum maintenance. In addition, those valves used as thruster shutoff valves must feature fast response characteristics to achieve small, repeatable minimum impulse bits. These valve technology problems are solved by developing unique valve components such as sealing closures, guidance devices, and actuation means and by demonstrating two prototype valve concepts. One of the prototype valves is cycled over one million cycles without exceeding a leakage rate of 27 scc's per hour at 450 psia helium inlet pressure throughout the cycling program.

ETR HEAT EXCHANGER BUILDING, TRA644. A PRIMARY COOLANT PUMP AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR HEAT EXCHANGER BUILDING, TRA-644. A PRIMARY COOLANT PUMP AND 24-INCH CHECK VALVE ARE MOUNTED IN A SHIELDED CUBICLE. NOTE CONNECTION AT RIGHT THROUGH SHIELD WALL TO PUMP MOTOR ON OTHER SIDE. INL NEGATIVE NO. 56-4177. Jack L. Anderson, Photographer, 12/21/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Active Diagnosis of Navy Machinery Rev 2.0

DTIC Science & Technology

2016-10-01

electrical distribution and potable water supply systems. Because of these dependencies, ship auxiliary system failures can cause combat load failure...buildup generally causes a pipe to disconnect from a junction, causing water to leak . This limits the faults that are testable, since many of the faults...pipes, junctions, pumps, flow meters, thermal loads, check valve, and water tank. Each agent is responsible for maintaining its constraints locally

How to start a minimal access mitral valve program.

PubMed

Hunter, Steven

2013-11-01

The seven pillars of governance established by the National Health Service in the United Kingdom provide a useful framework for the process of introducing new procedures to a hospital. Drawing from local experience, the author present guidance for institutions considering establishing a minimal access mitral valve program. The seven pillars of governance apply to the practice of minimally invasive mitral valve surgery, based on the principle of patient-centred practice. The author delineate the benefits of minimally invasive mitral valve surgery in terms of: "clinical effectiveness", including reduced length of hospital stay, "risk management effectiveness", including conversion to sternotomy and aortic dissection, "patient experience" including improved cosmesis and quicker recovery, and the effectiveness of communication, resources and strategies in the implementation of minimally invasive mitral valve surgery. Finally, the author have identified seven learning curves experienced by surgeons involved in introducing a minimal access mitral valve program. The learning curves are defined as: techniques of mitral valve repair, Transoesophageal Echocardiography-guided cannulation, incisions, instruments, visualization, aortic occlusion and cardiopulmonary bypass strategies. From local experience, the author provide advice on how to reduce the learning curves, such as practising with the specialised instruments and visualization techniques during sternotomy cases. Underpinning the NHS pillars are the principles of systems awareness, teamwork, communication, ownership and leadership, all of which are paramount to performing any surgery but more so with minimal access surgery, as will be highlighted throughout this paper.

Addressing Dynamic Issues of Program Model Checking

NASA Technical Reports Server (NTRS)

Lerda, Flavio; Visser, Willem

2001-01-01

Model checking real programs has recently become an active research area. Programs however exhibit two characteristics that make model checking difficult: the complexity of their state and the dynamic nature of many programs. Here we address both these issues within the context of the Java PathFinder (JPF) model checker. Firstly, we will show how the state of a Java program can be encoded efficiently and how this encoding can be exploited to improve model checking. Next we show how to use symmetry reductions to alleviate some of the problems introduced by the dynamic nature of Java programs. Lastly, we show how distributed model checking of a dynamic program can be achieved, and furthermore, how dynamic partitions of the state space can improve model checking. We support all our findings with results from applying these techniques within the JPF model checker.

10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial prerinse spray valves. 431.262 Section 431.262 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves § 431.262 Definitions...

[Incorrect programming of a target controlled infusion pump. Case SENSAR of the trimester].

PubMed

2014-10-01

We report the case of a patient who underwent surgical aortic valve replacement. During general anaesthesia maintenance, the patient received a remifentanyl infusion via a target controlled infusion (TCI) system. The infusion pump that was prepared to deliver the infusion showed malfunction at the beginning of the surgery, so it was quickly replaced with a second pump. After a few minutes into the surgery, the patient presented with hypotension refractory to treatment. The remifentanyl syringe also emptied faster than expected. On reviewing the TCI pump, it was found that it was erroneously programmed for propofol instead of remifentanyl, thus the patient had received a very high dose of remifentanyl that was probably the cause of the haemodynamic disturbances. The incident was an error in equipment use, facilitated by hurry, lack of checking of the equipment prior to its use, and the complex and unclear design of the devices' screens. After analysis of this incident, all TCI pumps were reviewed, and all the programs for infrequently used drugs were deleted. Furthermore, 2 pumps were selected for exclusive use in the cardiac surgery theatre, one with propofol-only programming, and the other with remifentanyl-only programming, both clearly marked and situated in fixed places in that theatre. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Pulsation damping of the reciprocating compressor with Helmholtz resonator

NASA Astrophysics Data System (ADS)

Wang, W.; Zhang, Y.; Zhou, Q.; Peng, X.; Feng, J.; Jia, X.

2017-08-01

Research presented in this paper investigated the mounting of a Helmholtz resonator near the valve chamber of a reciprocating compressor to attenuate the gas pulsation in the valve chamber as well as the pipeline downstream. Its attenuation characteristics were simulated with the plane wave theory together with the transfer matrix method, and the damping effect was checked by comparing the pressure pulsation levels before and after mounting the resonator. The results show that the Helmholtz resonator was effective in attenuating the gas pulsation in the valve chamber and piping downstream, and the pulsation level was decreased by 40% in the valve chamber and 30% at maximum in the piping downstream. The damping effect of the resonator was sensitive to its resonant frequency, and various resonators working simultaneously didn’t interfere with each other. When two resonators were mounted in parallel, with resonant frequencies equal to the second and fourth harmonic frequencies, the pressure pulsation components corresponding to the resonant frequencies were remarkably decreased at the same time, while the pulsation levels at other harmonic frequencies kept almost unchanged. After a series of simulations and experiments a design criterion of chock tube and volume parameter has been proposed for the targeted frequencies to be damped. Furthermore, the frequency-adjustable Helmholtz resonator which was applied to the variable speed compressor was investigated.

System for the removal of contaminant soil-gas vapors

DOEpatents

Weidner, Jerry R.; Downs, Wayne C.; Kaser, Timothy G.; Hall, H. James

1997-01-01

A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources.

System for the removal of contaminant soil-gas vapors

DOEpatents

Weidner, J.R.; Downs, W.C.; Kaser, T.G.; Hall, H.J.

1997-12-16

A system extracts contaminated vapors from soil or other subsurface regions by using changes in barometric pressure to operate sensitive check valves that control air entry and removal from wells in the ground. The system creates an efficient subterranean flow of air through a contaminated soil plume and causes final extraction of the contaminants from the soil to ambient air above ground without any external energy sources. 4 figs.

An Innovation for Global Clean Water

NASA Technical Reports Server (NTRS)

1995-01-01

Under contract to NASA, Umpqua Research developed the Microbial Check Valve (MCV) iodine-dispensing system for the Space Shuttle Orbiter, introduced in 1979 to purify astronauts' drinking water. In 1989, NASA awarded the company a new contract to develop a system for continuous iodine release over long periods for use in the International Space Station. In 1993, the company demonstrated the Regenerable Biocide Delivery Unit, and NASA granted it an exclusive license.

Asset Management and Facility Equipment Maintenance Nexus: Maintenance Effectiveness

DTIC Science & Technology

2013-09-01

only include the top-level asset, “recreational facility” and its associated buildings, while the asset/component hierarchy of a hydroelectric turbine ...motor windings that can’t be maintained but might indicate a manufacturer defect. What conditions? — If every USACE lock were constructed with a...13-16 99 5. Slip Clutch 5. Sprocket 5. Spur/Pinnion Gear 4. Direct Acting Hydraulic Cylinder 5. Check Valve 5

40 CFR 63.1014 - Open-ended valves or lines standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Open-ended valves or lines standards... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Equipment Leaks-Control Level 1 § 63.1014 Open-ended valves or...

How to start a minimal access mitral valve program

PubMed Central

2013-01-01

The seven pillars of governance established by the National Health Service in the United Kingdom provide a useful framework for the process of introducing new procedures to a hospital. Drawing from local experience, the author present guidance for institutions considering establishing a minimal access mitral valve program. The seven pillars of governance apply to the practice of minimally invasive mitral valve surgery, based on the principle of patient-centred practice. The author delineate the benefits of minimally invasive mitral valve surgery in terms of: “clinical effectiveness”, including reduced length of hospital stay, “risk management effectiveness”, including conversion to sternotomy and aortic dissection, “patient experience” including improved cosmesis and quicker recovery, and the effectiveness of communication, resources and strategies in the implementation of minimally invasive mitral valve surgery. Finally, the author have identified seven learning curves experienced by surgeons involved in introducing a minimal access mitral valve program. The learning curves are defined as: techniques of mitral valve repair, Transoesophageal Echocardiography-guided cannulation, incisions, instruments, visualization, aortic occlusion and cardiopulmonary bypass strategies. From local experience, the author provide advice on how to reduce the learning curves, such as practising with the specialised instruments and visualization techniques during sternotomy cases. Underpinning the NHS pillars are the principles of systems awareness, teamwork, communication, ownership and leadership, all of which are paramount to performing any surgery but more so with minimal access surgery, as will be highlighted throughout this paper. PMID:24349981

Program Model Checking: A Practitioner's Guide

NASA Technical Reports Server (NTRS)

Pressburger, Thomas T.; Mansouri-Samani, Masoud; Mehlitz, Peter C.; Pasareanu, Corina S.; Markosian, Lawrence Z.; Penix, John J.; Brat, Guillaume P.; Visser, Willem C.

2008-01-01

Program model checking is a verification technology that uses state-space exploration to evaluate large numbers of potential program executions. Program model checking provides improved coverage over testing by systematically evaluating all possible test inputs and all possible interleavings of threads in a multithreaded system. Model-checking algorithms use several classes of optimizations to reduce the time and memory requirements for analysis, as well as heuristics for meaningful analysis of partial areas of the state space Our goal in this guidebook is to assemble, distill, and demonstrate emerging best practices for applying program model checking. We offer it as a starting point and introduction for those who want to apply model checking to software verification and validation. The guidebook will not discuss any specific tool in great detail, but we provide references for specific tools.

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

NASA Technical Reports Server (NTRS)

Gebben, V. D.

1976-01-01

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

40 CFR 60.482-6a - Standards: Open-ended valves or lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Open-ended valves or lines... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for..., Reconstruction, or Modification Commenced After November 7, 2006 § 60.482-6a Standards: Open-ended valves or...

Integrated Heat Switch/Oxide Sorption Compressor

NASA Technical Reports Server (NTRS)

Bard, Steven

1989-01-01

Thermally-driven, nonmechanical compressor uses container filled with compressed praseodymium cerium oxide powder (PrCeOx) to provide high-pressure flow of oxygen gas for driving closed-cycle Joule-Thomson-expansion refrigeration unit. Integrated heat switch/oxide sorption compressor has no moving parts except check valves, which control flow of oxygen gas between compressor and closed-cycle Joule-Thomson refrigeration system. Oxygen expelled from sorbent at high pressure by evacuating heat-switch gap and turning on heater.

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XIX, I--ENGINE TUNE-UP--CUMMINS DIESEL ENGINE, II--FRONT END SUSPENSION AND AXLES.

ERIC Educational Resources Information Center

Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF DIESEL ENGINE TUNE-UP PROCEDURES AND THE DESIGN OF FRONT END SUSPENSION AND AXLES USED ON DIESEL ENGINE EQUIPMENT. TOPICS ARE (1) PRE-TUNE-UP CHECKS, (2) TIMING THE ENGINE, (3) INJECTOR PLUNGER AND VALVE ADJUSTMENTS, (4) FUEL PUMP ADJUSTMENTS ON THE ENGINE (PTR AND PTG),…

Assessing the Health Effects of Blast Injuries and Embedded Metal Fragments

DTIC Science & Technology

2017-10-01

isoflurane and open oxygen tank valve (check psi) Prep Vetbond, buprenorphine, 1 ml syringes and #10 scalpel blades In the vivarium, weigh each...with #10 blade over gastrocnemius Inject pellets into muscle tissue using 14 or 16 gauge needle and plunger (one at a time) Repeat incision and...Fluovac canister and record on adsorber canister (dispose of canister at 1400 grams) Clean clippers in Blade Wash, wipe down with isopropyl alcohol, then

Duct having oscillatory side wall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprouse, Kenneth M.

A pump system includes a particulate consolidator pump that has a pump outlet. A duct is coupled to the pump outlet. The duct has a wall that is coupled with an oscillator. The oscillator is operable to oscillate the wall at a controlled frequency. The controlled frequency is selected with respect to breaking static bridging of particulate in the duct due, at least in part, to consolidation of the particulate from a downstream check valve.

Burbank performs Part 1 of the WRS-1 Repair

NASA Image and Video Library

2012-03-08

ISS030-E-128752 (8 March 2012) --- NASA astronaut Dan Burbank, Expedition 30 commander, performs part one of the Water Recovery System-1 (WRS-1) repair in the Tranquility node of the International Space Station. Burbank removed and replaced the failed Catalytic Reactor (CR), and installed a temporary filter kit between the new CR and the Microbial Check Valve (MCV) to support a system flush of the new Orbital Replacement Unit (ORU).

KSC-2009-1949

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – One of the three thoroughly inspected gaseous hydrogen flow control valves is shown after its arrival at NASA's Kennedy Space Center in Florida. Technicians installed and retested them in space shuttle Discovery. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

KSC-2009-1948

NASA Image and Video Library

2009-03-03

CAPE CANAVERAL, Fla. – One of the three thoroughly inspected gaseous hydrogen flow control valves is shown after its arrival at NASA's Kennedy Space Center in Florida. Technicians installed and retested them in space shuttle Discovery. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have worked to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Space Shuttle Program managers decided to replace Discovery's valves with others that have undergone a detailed eddy current inspection. Program managers will review the testing and determine whether to meet on March 6 for the Flight Readiness Review for the STS-119 mission. Launch of Discovery tentatively is targeted for March 12. Photo credit: NASA/Chris Rhodes

Intelligent Flow Control Valve

NASA Technical Reports Server (NTRS)

Kelley, Anthony R (Inventor)

2015-01-01

The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

Sample Processor for Life on Icy Worlds (SPLIce): Design and Test Results

NASA Technical Reports Server (NTRS)

Chinn, Tori N.; Lee, Anthony K.; Boone, Travis D.; Tan, Ming X.; Chin, Matthew M.; McCutcheon, Griffin C.; Horne, Mera F.; Padgen, Michael R.; Blaich, Justin T.; Forgione, Joshua B.;

Texas International Airlines LOFT program

NASA Technical Reports Server (NTRS)

Sommerville, J.

1981-01-01

A line-oriented flight training program which allows the crew to work as a team to solve all problems, abnormal or emergency, within the crew concept. A line-oriented check ride takes place every six months for the pilot as a proficiency check. There are advantages and disadvantages to this program. One disadvantage is that since it is designed as a check-ride, the scenarios must be structured so that the average pilot will complete the check-ride without complication. This system is different from a proficiency check which can be stopped at a problem area so training to proficiency can take place before proceeding with the check.

Activation of the E1 Ultra High Pressure Propulsion Test Facility at Stennis Space Center

NASA Technical Reports Server (NTRS)

Messer, Bradley; Messer, Elisabeth; Sewell, Dale; Sass, Jared; Lott, Jeff; Dutreix, Lionel, III

2001-01-01

After a decade of construction and a year of activation the El Ultra High Pressure Propulsion Test Facility at NASA's Stennis Space Center is fully operational. The El UHP Propulsion Test Facility is a multi-cell, multi-purpose component and engine test facility . The facility is capable of delivering cryogenic propellants at low, high, and ultra high pressures with flow rates ranging from a few pounds per second up to two thousand pounds per second. Facility activation is defined as a series of tasks required to transition between completion of construction and facility operational readiness. Activating the El UHP Propulsion Test Facility involved independent system checkouts, propellant system leak checks, fluid and gas sampling, gaseous system blow downs, pressurization and vent system checkouts, valve stability testing, valve tuning cryogenic cold flows, and functional readiness tests.

Determining optimal preventive maintenance interval for component of Well Barrier Element in an Oil & Gas Company

NASA Astrophysics Data System (ADS)

Siswanto, A.; Kurniati, N.

2018-04-01

An oil and gas company has 2,268 oil and gas wells. Well Barrier Element (WBE) is installed in a well to protect human, prevent asset damage and minimize harm to the environment. The primary WBE component is Surface Controlled Subsurface Safety Valve (SCSSV). The secondary WBE component is Christmas Tree Valves that consist of four valves i.e. Lower Master Valve (LMV), Upper Master Valve (UMV), Swab Valve (SV) and Wing Valve (WV). Current practice on WBE Preventive Maintenance (PM) program is conducted by considering the suggested schedule as stated on manual. Corrective Maintenance (CM) program is conducted when the component fails unexpectedly. Both PM and CM need cost and may cause production loss. This paper attempts to analyze the failure data and reliability based on historical data. Optimal PM interval is determined in order to minimize the total cost of maintenance per unit time. The optimal PM interval for SCSSV is 730 days, LMV is 985 days, UMV is 910 days, SV is 900 days and WV is 780 days. In average of all components, the cost reduction by implementing the suggested interval is 52%, while the reliability is improved by 4% and the availability is increased by 5%.

Combined effects of hydrazine exposure and endurance testing on solenoid-actuated valve performance

NASA Technical Reports Server (NTRS)

Hagler, R., Jr.

1974-01-01

Results are presented from a test program which was conducted to assess the capability of various solenoid-actuated valve design concepts to provide performance characteristics commensurate with long-duration (ten-year) missions to explore the outer planets. The valves were installed in a hydrazine flow test setup and periodically cycled during a nine-month test period under test conditions comparable to anticipated mission operating conditions. In situ valve performance was periodically determined, and leakage was continuously monitored.

Automatic amino acid analyzer

NASA Technical Reports Server (NTRS)

Berdahl, B. J.; Carle, G. C.; Oyama, V. I.

1971-01-01

Analyzer operates unattended or up to 15 hours. It has an automatic sample injection system and can be programmed. All fluid-flow valve switching is accomplished pneumatically from miniature three-way solenoid pilot valves.

Recycle dynamics during centrifugal compressor ESD, start-up and surge control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Botros, K.K.; Jones, B.J.; Richards, D.J.

1996-12-31

Recycle systems are important components in the operation of centrifugal compressor stations. They are essential during a start-up operation, for surge protection and for emergency shutdown (ESD). These operations are inherently dynamic where interactions between equipment, control and gas flow occur in a complex manner with the associated risk of compressor surge. Of particular importance are the effects or recycle system capacity, the recycle valve characteristics, check valve dynamic behavior, piping geometry and capacitance around the compressor unit, and the performance characteristics of the centrifugal compressor itself. This paper presents numerical results of the effects of some of these parametersmore » on surge control, ESD and unit startup. These parameters are: (1) The effects of damping the surge control flow signal in an attempt to suppress the signal noise, on the integrity of the surge control system; (2) The effects of recycle valve characteristics, stroke time and valve capacity on ESD; (3) The effects of recycle line size on ESD; and (4) The effects of the recycle valve closing time (or rate) on the startup operation, with the intent of shortening this time to minimum for environmental reasons. Results were obtained from the solution of the pertinent dynamic equations describing the gas and equipment dynamics which has been verified against field and laboratory measurements. The samples presented in this paper were applied to a 24 MW natural gas compressor station on the NOVA Gas Transmission system, and to a scale-down laboratory model. Influence of other parameters from this investigation were published elsewhere and are cited in the reference section.« less

Banking of cryopreserved heart valves in Europe: assessment of a 10-year operation in the European Homograft Bank (EHB).

PubMed

Goffin, Y A; Van Hoeck, B; Jashari, R; Soots, G; Kalmar, P

2000-03-01

The preparation, banking and distribution of cryopreserved heart valves has been carried out at the European Homograft Bank (EHB) in Brussels without interruption since January 1989. We present an assessment of the Bank's activities during this 10-year period. Heart valve donors aged <62 years form three categories: multiorgan donors with non-transplantable hearts; recipients of cardiac transplantation; and non-beating heart cadavers with a warm ischemia time of less than 6 h. Past history and biology are checked for transmissible diseases. Dissection, incubation in antibiotics and cryopreservation in 10% dimethylsulfoxide with storage in liquid nitrogen vapors (about -150 degrees C), and quality control are according to the standards of the Belgian Ministry of Health. Cryopreserved valves are shipped to the implantation centers in a dry shipper at about -150 degrees C. Between January 30th 1989 and December 31st 1998, 1,817 non-transplantable hearts and 12 excised semilunar valves were obtained. In total, 2,077 valves (1,032 pulmonary, 931 aortic and 13 mitral) were decontaminated, cryopreserved and stored in liquid nitrogen vapor (six more valves were refrigerated). In total, 1,515 valves were discarded at different stages of the protocol, the main causes of rejection being significant macroscopic lesions (68.2% aortic and 26.67% pulmonary). Inadequate excision at procurement (10.37% pulmonary), persistent contamination after antibiotics (5.6%) and positive serology for hepatitis B and C and Q fever (5.4%) were other frequent causes for rejection. Among the 2,117 accepted valves, 1,398 were graded first and 719 second choice, mainly on the basis of morphology. In total, 2,090 cryopreserved valves and one refrigerated valve were implanted in 39 institutions between May 1989 and December 1998. Of requests, 10.02% could not be satisfied. In total, 967 pulmonary valves were implanted in the right ventricular outflow tract (RVOT); 424 during a Ross procedure, and 76 in the left ventricular outflow tract (LVOT). Of the aortic valves, 732 were implanted in the LVOT and 266 in the RVOT. Mitral homografts were used for tricuspid valve replacement in two cases, and in the mitral position in seven. Complications at distribution and thawing included 10 bag ruptures and 16 transversal conduit wall fractures. Of the valves shipped, 317 (13.16%) were not used and were returned safely in the dry shipper. Comparison of distribution rates in the first 5.5 and last 4.5 years of EHB activity shows: (i) a significant increase in pulmonary valve implantations in the RVOT (from 71.95% to 81.95%); and (ii) a marked increase (265%) in pulmonary homograft implantations as part of a Ross operation, and a significant decrease (28%) in aortic homograft implantation in the LVOT. While macroscopic lesions of procured aortic valves remain the most frequent and unavoidable cause of homograft rejection during quality control, the high percentage of inadequate surgical heart valve excision should be corrected. The rates of bacterial contamination and positive serology seem acceptable. Storage and shipping of cryopreserved homografts in liquid nitrogen vapor permits them to be spared very efficiently. The increasing use of pulmonary valves for RVOT reconstruction either in congenital heart disease or as part of the Ross procedure compensates for the limited availability of good quality aortic valves.

Durability Tests of Ball Valve Prototype with Flowmeter Operation

NASA Astrophysics Data System (ADS)

Rogula, J.; Romanik, G.

2018-02-01

The results of the investigation of the prototypical ball valve are presented in this article. The innovation of the tested valve is a ball with a built-in measuring orifice. The valve has been subjected to durability tests. Leakage under three temperatures: ambient, -30°C and +100°C was analyzed. Sealing elements of the valve were tested for roughness and deviation of shape before and after the cycles of operation. Ball valve operation means cycles of open/close. It was planned to perform 1000 cycles at each temperature condition accordingly. Tests of the valve were performed under gas pressure equal to 10 MPa. The research was carried out under the Operational Program "Intelligent Development" (POIR 01.01.01-00-0013 / 15 "Development of devices for measurement of media flow on industrial trunk-lines".

Evaluation of tilting disc valves after fatigue life testing: preliminary results within a comparison program.

PubMed

Barbaro, V; Boccanera, G; Daniele, C; Grigioni, M; Palombo, A

1995-09-01

A fatigue life test, by accelerating the beat rate, simulates several years of virtual life of a prosthetic heart valve in a short period of time. The correlation between the in vivo life of a valve and in vitro testing expectations is as yet not well established, but reproducible test conditions yield precious information about wear and failure. The paper reports a qualitative analysis of mechanical valve wear as part of a comparison program designed to investigate the significance of fatigue testing with the ultimate aim of defining standard guidelines for these type of tests. Two tilting disc valves (29 mm) were subjected to 16 years of fatigue life simulated by means of a Rowan Ash fatigue tester (accelerated rate of 1,200 bpm). Fatigue-induced effects on valve disc and ring surfaces were observed under a monitor microscope to identify wear sites and patterns. A high speed cinematographic system was used to investigate the mechanisms responsible for the wear (wear modes). Valve closure was inspected at a 6,000 frame/s rate. Because of disc rotation during the tilting movement, the points of contact between disc and ring are distributed all around the disc edge but focally on the ring. On both sides of the disc, the surfaces present ring-like concentric grooves. After 16 years of fatigue life the valves showed neither severe wear nor alteration of their fluidodynamic behavior in the pulsatile flow test.

Internal combustion engine for natural gas compressor operation

DOEpatents

Hagen, Christopher; Babbitt, Guy

2016-12-27

This application concerns systems and methods for compressing natural gas with an internal combustion engine. In a representative embodiment, a method is featured which includes placing a first cylinder of an internal combustion engine in a compressor mode, and compressing a gas within the first cylinder, using the cylinder as a reciprocating compressor. In some embodiments a compression check valve system is used to regulate pressure and flow within cylinders of the engine during a compression process.

Oscillating-Linear-Drive Vacuum Compressor for CO2

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Shimko, Martin

2005-01-01

A vacuum compressor has been designed to compress CO2 from approximately equal to 1 psia (approximately equal to 6.9 kPa absolute pressure) to approximately equal to 75 psia (approximately equal to 0.52 MPa), to be insensitive to moisture, to have a long operational life, and to be lightweight, compact, and efficient. The compressor consists mainly of (1) a compression head that includes hydraulic diaphragms, a gas-compression diaphragm, and check valves; and (2) oscillating linear drive that includes a linear motor and a drive spring, through which compression force is applied to the hydraulic diaphragms. The motor is driven at the resonance vibrational frequency of the motor/spring/compression-head system, the compression head acting as a damper that takes energy out of the oscillation. The net effect of the oscillation is to cause cyclic expansion and contraction of the gas-compression diaphragm, and, hence, of the volume bounded by this diaphragm. One-way check valves admit gas into this volume from the low-pressure side during expansion and allow the gas to flow out to the high-pressure side during contraction. Fatigue data and the results of diaphragm stress calculations have been interpreted as signifying that the compressor can be expected to have an operational life of greater than 30 years with a confidence level of 99.9 percent.

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

PubMed Central

Schipke, Kimberly J.; Filip To, S. D.; Warnock, James N.

2011-01-01

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage1-3. Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease4. The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve5. Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves6-9. Pulsatile bioreactors have also been developed to study a range of tissues including cartilage10, bone11 and bladder12. The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed air into the system at the appropriate rate. The system mimicked the dynamic transvalvular pressure levels associated with the aortic valve; a saw tooth wave produced a gradual increase in pressure, typical of the transvalvular pressure gradient that is present across the valve during diastole, followed by a sharp pressure drop depicting valve opening in systole. The LabVIEW program allowed users to control the magnitude and frequency of cyclic pressure. The system was able to subject tissue samples to physiological and pathological pressure conditions. This device can be used to increase our understanding of how heart valves respond to changes in the local mechanical environment. PMID:21876532

Design of a cyclic pressure bioreactor for the ex vivo study of aortic heart valves.

PubMed

Schipke, Kimberly J; To, S D Filip; Warnock, James N

2011-08-23

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage(1-3). Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease(4). The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve(5). Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves(6-9). Pulsatile bioreactors have also been developed to study a range of tissues including cartilage(10), bone(11) and bladder(12). The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed air into the system at the appropriate rate. The system mimicked the dynamic transvalvular pressure levels associated with the aortic valve; a saw tooth wave produced a gradual increase in pressure, typical of the transvalvular pressure gradient that is present across the valve during diastole, followed by a sharp pressure drop depicting valve opening in systole. The LabVIEW program allowed users to control the magnitude and frequency of cyclic pressure. The system was able to subject tissue samples to physiological and pathological pressure conditions. This device can be used to increase our understanding of how heart valves respond to changes in the local mechanical environment.

Modeling the Mitral Valve

NASA Astrophysics Data System (ADS)

Kaiser, Alexander

2016-11-01

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

A voice-actuated wind tunnel model leak checking system

NASA Technical Reports Server (NTRS)

Larson, William E.

1989-01-01

A computer program has been developed that improves the efficiency of wind tunnel model leak checking. The program uses a voice recognition unit to relay a technician's commands to the computer. The computer, after receiving a command, can respond to the technician via a voice response unit. Information about the model pressure orifice being checked is displayed on a gas-plasma terminal. On command, the program records up to 30 seconds of pressure data. After the recording is complete, the raw data and a straight line fit of the data are plotted on the terminal. This allows the technician to make a decision on the integrity of the orifice being checked. All results of the leak check program are stored in a database file that can be listed on the line printer for record keeping purposes or displayed on the terminal to help the technician find unchecked orifices. This program allows one technician to check a model for leaks instead of the two or three previously required.

Property Differencing for Incremental Checking

NASA Technical Reports Server (NTRS)

Yang, Guowei; Khurshid, Sarfraz; Person, Suzette; Rungta, Neha

2014-01-01

This paper introduces iProperty, a novel approach that facilitates incremental checking of programs based on a property di erencing technique. Speci cally, iProperty aims to reduce the cost of checking properties as they are initially developed and as they co-evolve with the program. The key novelty of iProperty is to compute the di erences between the new and old versions of expected properties to reduce the number and size of the properties that need to be checked during the initial development of the properties. Furthermore, property di erencing is used in synergy with program behavior di erencing techniques to optimize common regression scenarios, such as detecting regression errors or checking feature additions for conformance to new expected properties. Experimental results in the context of symbolic execution of Java programs annotated with properties written as assertions show the e ectiveness of iProperty in utilizing change information to enable more ecient checking.

Regression Verification Using Impact Summaries

NASA Technical Reports Server (NTRS)

Backes, John; Person, Suzette J.; Rungta, Neha; Thachuk, Oksana

2013-01-01

Regression verification techniques are used to prove equivalence of syntactically similar programs. Checking equivalence of large programs, however, can be computationally expensive. Existing regression verification techniques rely on abstraction and decomposition techniques to reduce the computational effort of checking equivalence of the entire program. These techniques are sound but not complete. In this work, we propose a novel approach to improve scalability of regression verification by classifying the program behaviors generated during symbolic execution as either impacted or unimpacted. Our technique uses a combination of static analysis and symbolic execution to generate summaries of impacted program behaviors. The impact summaries are then checked for equivalence using an o-the-shelf decision procedure. We prove that our approach is both sound and complete for sequential programs, with respect to the depth bound of symbolic execution. Our evaluation on a set of sequential C artifacts shows that reducing the size of the summaries can help reduce the cost of software equivalence checking. Various reduction, abstraction, and compositional techniques have been developed to help scale software verification techniques to industrial-sized systems. Although such techniques have greatly increased the size and complexity of systems that can be checked, analysis of large software systems remains costly. Regression analysis techniques, e.g., regression testing [16], regression model checking [22], and regression verification [19], restrict the scope of the analysis by leveraging the differences between program versions. These techniques are based on the idea that if code is checked early in development, then subsequent versions can be checked against a prior (checked) version, leveraging the results of the previous analysis to reduce analysis cost of the current version. Regression verification addresses the problem of proving equivalence of closely related program versions [19]. These techniques compare two programs with a large degree of syntactic similarity to prove that portions of one program version are equivalent to the other. Regression verification can be used for guaranteeing backward compatibility, and for showing behavioral equivalence in programs with syntactic differences, e.g., when a program is refactored to improve its performance, maintainability, or readability. Existing regression verification techniques leverage similarities between program versions by using abstraction and decomposition techniques to improve scalability of the analysis [10, 12, 19]. The abstractions and decomposition in the these techniques, e.g., summaries of unchanged code [12] or semantically equivalent methods [19], compute an over-approximation of the program behaviors. The equivalence checking results of these techniques are sound but not complete-they may characterize programs as not functionally equivalent when, in fact, they are equivalent. In this work we describe a novel approach that leverages the impact of the differences between two programs for scaling regression verification. We partition program behaviors of each version into (a) behaviors impacted by the changes and (b) behaviors not impacted (unimpacted) by the changes. Only the impacted program behaviors are used during equivalence checking. We then prove that checking equivalence of the impacted program behaviors is equivalent to checking equivalence of all program behaviors for a given depth bound. In this work we use symbolic execution to generate the program behaviors and leverage control- and data-dependence information to facilitate the partitioning of program behaviors. The impacted program behaviors are termed as impact summaries. The dependence analyses that facilitate the generation of the impact summaries, we believe, could be used in conjunction with other abstraction and decomposition based approaches, [10, 12], as a complementary reduction technique. An evaluation of our regression verification technique shows that our approach is capable of leveraging similarities between program versions to reduce the size of the queries and the time required to check for logical equivalence. The main contributions of this work are: - A regression verification technique to generate impact summaries that can be checked for functional equivalence using an off-the-shelf decision procedure. - A proof that our approach is sound and complete with respect to the depth bound of symbolic execution. - An implementation of our technique using the LLVMcompiler infrastructure, the klee Symbolic Virtual Machine [4], and a variety of Satisfiability Modulo Theory (SMT) solvers, e.g., STP [7] and Z3 [6]. - An empirical evaluation on a set of C artifacts which shows that the use of impact summaries can reduce the cost of regression verification.

Modelling and study of active vibration control for off-road vehicle

NASA Astrophysics Data System (ADS)

Zhang, Junwei; Chen, Sizhong

2014-05-01

In view of special working characteristics and structure, engineering machineries do not have conventional suspension system typically. Consequently, operators have to endure severe vibrations which are detrimental both to their health and to the productivity of the loader. Based on displacement control, a kind of active damping method is developed for a skid-steer loader. In this paper, the whole hydraulic system for active damping method is modelled which include swash plate dynamics model, proportional valve model, piston accumulator model, pilot-operated check valve model, relief valve model, pump loss model, and cylinder model. A new road excitation model is developed for the skid-steer loader specially. The response of chassis vibration acceleration to road excitation is verified through simulation. The simulation result of passive accumulator damping is compared with measurements and the comparison shows that they are close. Based on this, parallel PID controller and track PID controller with acceleration feedback are brought into the simulation model, and the simulation results are compared with passive accumulator damping. It shows that the active damping methods with PID controllers are better in reducing chassis vibration acceleration and pitch movement. In the end, the test work for active damping method is proposed for the future work.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 6: Primary nozzle diffuser analysis

NASA Technical Reports Server (NTRS)

Foley, Michael J.

1989-01-01

The primary nozzle diffuser routes fuel from the main fuel valve on the Space Shuttle Main Engine (SSME) to the nozzle coolant inlet mainfold, main combustion chamber coolant inlet mainfold, chamber coolant valve, and the augmented spark igniters. The diffuser also includes the fuel system purge check valve connection. A static stress analysis was performed on the diffuser because no detailed analysis was done on this part in the past. Structural concerns were in the area of the welds because approximately 10 percent are in areas inaccessible by X-ray testing devices. Flow dynamics and thermodynamics were not included in the analysis load case. Constant internal pressure at maximum SSME power was used instead. A three-dimensional, finite element method was generated using ANSYS version 4.3A on the Lockheed VAX 11/785 computer to perform the stress computations. IDEAS Supertab on a Sun 3/60 computer was used to create the finite element model. Rocketdyne drawing number RS009156 was used for the model interpretation. The flight diffuser is denoted as -101. A description of the model, boundary conditions/load case, material properties, structural analysis/results, and a summary are included for documentation.

Flapper Valve and Hayfork: Functional anatomy and taxonomic potential of the Gastric Mill of Bairdioidea (Ostracoda, Podocopida).

PubMed

Maddocks, Rosalie F

2018-02-07

The chewing apparatus of the Bairdioidea has been described just once and is rarely illustrated, but it might have more taxonomic significance than commonly supposed. It is constructed as a flapper valve (hinged check valve), which is unique among Ostracoda and unusual among animals. It projects into the midgut and is substantially enveloped by it. It serves three functions: to move bites of food into the stomach, to close the esophagus against back-flow, and to pack strands of food and mucus onto the rotating food ball. It is probably less effective for macerating the food to reduce particle size. Two braces anchor this structure to the lateral wall of the forehead. It is lined by cuticle that is shed at each molt, and the formation of food balls is interrupted during molting. In its construction and action, this apparatus is quite unlike the gastric mill of decapod crustaceans, and it shows only distant homology to the dorsal Wulst of Cypridoidea. Some architectural details differ among families and genera. The well-sclerotized plate has some potential for fossil preservation in exceptional circumstances. A revised anatomical analysis is presented, together with an annotated glossary of terms.

Vapor-Compression Heat Pumps for Operation Aboard Spacecraft

NASA Technical Reports Server (NTRS)

Ruemmele, Warren; Ungar, Eugene; Cornwell, John

2006-01-01

Vapor-compression heat pumps (including both refrigerators and heat pumps) of a proposed type would be capable of operating in microgravity and would be safe to use in enclosed environments like those of spacecraft. The designs of these pumps would incorporate modifications of, and additions to, vapor-compression cycles of heat pumps now used in normal Earth gravitation, in order to ensure efficiency and reliability during all phases of operation, including startup, shutdown, nominal continuous operation, and peak operation. Features of such a design might include any or all of the following: (1) Configuring the compressor, condenser, evaporator, valves, capillary tubes (if any), and controls to function in microgravitation; (2) Selection of a working fluid that satisfies thermodynamic requirements and is safe to use in a closed crew compartment; (3) Incorporation of a solenoid valve and/or a check valve to prevent influx of liquid to the compressor upon startup (such influx could damage the compressor); (4) Use of a diode heat pipe between the cold volume and the evaporator to limit the influx of liquid to the compressor upon startup; and (5) Use of a heated block to vaporize any liquid that arrives at the compressor inlet.

KSC-2009-1875

NASA Image and Video Library

2009-02-25

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a technician holds one of space shuttle Discovery's gaseous hydrogen flow control valves after its removal. Two of the three valves being removed will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-1876

NASA Image and Video Library

2009-02-25

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a technician holds one of space shuttle Discovery's gaseous hydrogen flow control valves after its removal. Two of the three valves being removed will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis

KSC-2009-1874

NASA Image and Video Library

2009-02-25

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, a technician bags one of space shuttle Discovery's gaseous hydrogen flow control valves after its removal. Two of the three valves being removed will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis

WaterSense Specification for Flushometer-Valve Water Closets Supporting Statement

EPA Pesticide Factsheets

The U.S. Environmental Protection Agency’s (EPA’s) WaterSense program released its specification for flushometer-valve water closets to further promote and enhance the market for water-efficient commercial restroom plumbing fixtures.

The use of self checks and voting in software error detection - An empirical study

NASA Technical Reports Server (NTRS)

Leveson, Nancy G.; Cha, Stephen S.; Knight, John C.; Shimeall, Timothy J.

1990-01-01

The results of an empirical study of software error detection using self checks and N-version voting are presented. Working independently, each of 24 programmers first prepared a set of self checks using just the requirements specification of an aerospace application, and then each added self checks to an existing implementation of that specification. The modified programs were executed to measure the error-detection performance of the checks and to compare this with error detection using simple voting among multiple versions. The analysis of the checks revealed that there are great differences in the ability of individual programmers to design effective checks. It was found that some checks that might have been effective failed to detect an error because they were badly placed, and there were numerous instances of checks signaling nonexistent errors. In general, specification-based checks alone were not as effective as specification-based checks combined with code-based checks. Self checks made it possible to identify faults that had not been detected previously by voting 28 versions of the program over a million randomly generated inputs. This appeared to result from the fact that the self checks could examine the internal state of the executing program, whereas voting examines only final results of computations. If internal states had to be identical in N-version voting systems, then there would be no reason to write multiple versions.

Thrombolysis Is an Effective and Safe Therapy in Stuck Mitral Valves With Delayed Presentation as Well as Hemodynamically Unstable Patients: A Single Centre Study

PubMed Central

Bade, Arun Shivajirao; Shaikh, Shakil Sattar Ahmed; Khemani, Hemant; Singh, Gurkirat; Bansal, Narender Omprakash

2018-01-01

Background Thrombosis is a complication of prosthetic valves on oral anticoagulants which is associated with significant morbidity and mortality. A re-operation carries a substantial risk, with mortality rate from 10% to 15% in selected series, which may be 2- or 3-folds higher in critically ill patients. This study conducted in a tertiary care cardiology unit aimed to evaluate the effectiveness and safety of thrombolytic therapy in stuck mitral bileaflet heart valves. Methods As a prospective observational study, clinical symptoms and fluoroscopy were the mainstay in diagnosis of stuck mitral valve. Gradient across the valve by transthoracic echocardiography was used to monitor the therapy every 6 h. Fall of mean gradient more than 50% was considered as successful thrombolysis. And final results were again checked by fluoroscopy with documentation of improved leaflet movement. Results Totally we studied 34 patients. Patients receiving thrombolytic therapy with streptokinase achieved an overall 91.2% freedom from a repeat operation or major complications, a large subcutaneous hematoma occurred in one ( 2.9%), reoperation required in two due to failure of treatment (5.9%), allergic reaction in one (2.9%), one patient developed transient neurologic dysfunction (2.9%) and one patient died during therapy due to refractory cardiogenic shock(2.9%). All patients including those with delayed presentation (> 14 days) and hemodynamically unstable patients had good results similar to those who presented within 14 days and hemodynamically stable. Mortality was higher in unstable patients and reoperation was higher with delayed presentation. Conclusions Thrombolysis with streptokinase is highly successful and safe therapy in hemodynamically stable as well as unstable patients, or those with early or delayed presentation with stuck bileaflet mitral valves, especially in centers where round the clock cardiothoracic surgery backup is not available. PMID:29904451

Implementation of transcatheter aortic valve replacement in California: Influence on aortic valve surgery.

PubMed

Maximus, Steven; Milliken, Jeffrey C; Danielsen, Beate; Shemin, Richard; Khan, Junaid; Carey, Joseph S

2018-04-01

Transcatheter aortic valve replacement (TAVR) procedures were introduced in 2011. Initially, procedures were limited to patients who were not surgical candidates, but subsequently high-risk surgical candidates were considered for TAVR. The influence on aortic valve surgery in California is unknown. The California Office of Statewide Health Planning and Development hospitalized patient discharge database was queried for the years 2009 through 2014. isolated surgical aortic valve and aortic valve/coronary artery bypass graft (SAVR) and TAVR procedures were identified by International Classification of Diseases-9th revision clinical modification procedure codes. Seven TAVR programs were introduced in 2011, 12 in 2012, 3 in 2013, and 6 in 2014. SAVR procedure volumes were compared from the 2 years before institution with SAVR volumes during the year(s) after institution of the TAVR program in these 28 hospitals. Overall, surgical volumes increased during the first, second, and third years after implementation of TAVR procedures. Among 7 hospitals with 4-year programs, surgical volumes increased to a maximum of 15.5% during the third year, then began to decrease. The hospital performing the largest number of TAVR procedures showed a marked decrease in SAVR volume by the fourth year, suggesting a shift of SAVR candidates to TAVR. Among all hospitals with 4-year programs, TAVR exceeded SAVR procedures by the fourth year. In California overall, SAVR increased during 2011 through 2013, due primarily to increasing volume of isolated SAVR procedures. Statewide, isolated SAVR increased from a yearly average of 3111 procedures during 2009-2010 to 3592 (+15.5%) in 2013, then decreased slightly in 2014. SAVR plus coronary artery bypass graft procedures decreased during the same time period. After implementation of TAVR, hospital SAVR volumes increased moderately, then began to decrease by the fourth year, when TAVR volume exceeded SAVR. Surgical candidates may be identified during evaluation for TAVR, resulting in increased SAVR volume. Increasing SAVR volume may also be related to improved patient and provider awareness of aortic valve disease. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

KSC-2009-1873

NASA Image and Video Library

2009-02-25

CAPE CANAVERAL, Fla. – On Launch Pad 39A at NASA's Kennedy Space Center in Florida, technicians have removed space shuttle Discovery's three gaseous hydrogen flow control valves, two of which will undergo detailed inspection. Part of the main propulsion system, the valves channel gaseous hydrogen from the main engines to the external tank. NASA and contractor teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. Approximately 4,000 images of each valve removed will be reviewed for evidence of cracks. Valves that have flown fewer times will be installed in Discovery. NASA's Space Shuttle Program has established a plan that could support shuttle Discovery's launch to the International Space Station, tentatively targeted for March 12. An exact target launch date will be determined as work on the valves progresses. Photo credit: NASA/Dimitri Gerondidakis

The Next Generation of Cold Immersion Dry Suit Design Evolution for Hypothermia Prevention

NASA Technical Reports Server (NTRS)

Galofaro, Joel

2013-01-01

This new utility patent is an active design that relies on the lung's role as an organic heat exchanger for providing deep body core heating of air. It is based on the fact that the greatest heat loss mechanism for an insulated human body immersed in a cold water environment is due to heat loss through respiration. This innovation successfully merges two existing technologies (cold immersion suit and existing valve technologies) to produce a new product that helps prevent against the onset of hypothermia at sea. During normal operations, a human maintains an approximate body temperature of [98.6 F (37 C)]. A mechanism was developed to recover the warm temperature from the body and reticulate it in a survival suit. The primary intention is to develop an encompassing systems design that can both easily and cost effectively be integrated in all existing currently manufactured cold water survival suits, and as such, it should be noted that the cold water immersion suit is only used as a framework or tool for laying out the required design elements. At the heart of the suit is the Warm Air Recovery (WAR) system, which relies on a single, large Main Purge Valve (MPV) and secondary Purge Valves (PV) to operate. The main purge valve has a thin membrane, which is normally closed, and acts as a one-way check valve. When warm air is expelled from the lungs, it causes the main purge valve to open. Air forced from the MPV is dumped directly into the suit, thereby providing warmth to the torso, legs, and arms. A slight positive over-pressure in the suit causes warm waste air (or water if the suit is punctured) to be safely vented into the sea through large PVs located at the bottom of each arm and leg. The secondary purge valves act to prevent the buildup of large concentrations of CO2 gas and help guard against asphyxia. It is noted that the MPV causes the inhalation and exhalation cycles to be completely isolated from one another in the current suit design.

Deceleration system for kinematic linkages of positioning

NASA Astrophysics Data System (ADS)

Stan, G.

2017-08-01

Flexible automation is used more and more in various production processes, so that both machining itself on CNC machine tools and workpiece handling means are performed through programming the needed working cycle. In order to obtain a successful precise positioning, each motion degree needs a certain deceleration before stopping at a programmed point. The increase of motion speed of moving elements within the manipulators structure depends directly on deceleration duty quality before the programmed stop. Proportional valves as well as servo-valves that can perform hydraulic decelerations are well known, but they feature several disadvantages, such as: high price, severe conditions for oil filtering and low reliability under industrial conditions. This work presents a new deceleration system that allows adjustment of deceleration slope according to actual conditions: inertial mass, speed etc. The new solution of hydraulic decelerator allows its integration to a position loop or its usage in case of positioning large elements that only perform fixed cycles. The results being obtained on the positioning accuracy of a linear axis using the new solution of the hydraulic decelerator are presented, too. The price of the new deceleration system is much lower compared to the price of proportional valves or servo-valves.

Functional Performance of Pyrovalves

NASA Technical Reports Server (NTRS)

Bement, Laurence J.

1996-01-01

Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a government/industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to improve performance-based requirements for the procurement of pyrovalves. Specific objectives included the demonstration of performance test methods, the measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted in-house at NASA on several units each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. All but two designs had adequate functional margins with the pyrotechnic cartridges evaluated.

Long-term corrosion evaluation of stainless steels in Space Shuttle iodinated resin and water

NASA Technical Reports Server (NTRS)

Krohn, Douglas D.

1992-01-01

The effects of stainless steel exposure to iodinated water is a concern in developing the Integrated Water System (IWS) for Space Station Freedom. The IWS has a life requirement of 30 years, but the effects of general and localized corrosion over such a long period have not been determined for the candidate materials. In 1978, Umpqua Research Center immersed stainless steel 316L, 321, and 347 specimens in a solution of deionized water and the Space Shuttle microbial check valve resin. In April 1990, the solution was chemically analyzed to determine the level of corrosion formed, and the surface of each specimen was examined with scanning electron microscopy and metallography to determine the extent of general and pitting corrosion. This examination showed that the attack on the stainless steels was negligible and never penetrated past the first grain boundary layer. Of the three alloys, 316L performed the best; however, all three materials proved to be compatible with an aqueous iodine environment. In addition to the specimens exposed to aqueous iodine, a stainless steel specimen (unspecified alloy) was exposed to moist microbial check valve resin and air for a comparable period. This environment allowed contact of the metal to the resin as well as to the iodine vapor. Since the particular stainless steel alloy was not known, energy dispersive spectroscopy was used to determine that this alloy was stainless steel 301. The intergranular corrosion found on the specimen was limited to the first grain boundary layer.

75 FR 24970 - FBI Records Management Division National Name Check Program Section User Fees

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-06

... Division National Name Check Program Section User Fees AGENCY: Federal Bureau of Investigation (FBI), Justice. ACTION: Notice. SUMMARY: This notice establishes the user fee schedule for federal agencies... user fees for federal agencies requesting noncriminal name-based background checks of the Central...

14 CFR 91.1051 - Pilot safety background check.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Pilot safety background check. 91.1051... Operations Program Management § 91.1051 Pilot safety background check. Within 90 days of an individual beginning service as a pilot, the program manager must request the following information: (a) FAA records...

Actuation and system design and evaluation OMS engine shutoff valve, Volume 1. [space shuttles

NASA Technical Reports Server (NTRS)

Dunn, V. B.

1975-01-01

A technology program was conducted to identify and verify the optimum valve and actuation system concept for the Space Shuttle Orbit Maneuvering System engine. Of major importance to the valve and actuation system selection was the ten-year, 100-mission, 10,000-cycle life requirement, while maintaining high reliability, low leakage, and low weight. Valve and actuation system concepts were comparatively evaluated against past valve failure reports and potential failure modes due to the shuttle mission profile to aid in the selection of the most optimum concept for design, manufacture and verification testing. Two valve concepts were considered during the preliminary design stage; i.e., the moving seat and lifting ball. Two actuation systems were manufactured and tested. Test results demonstrate the viability of a lifting ball concept as well as the applicability of an ac motor actuation system to best meet the requirements of the shuttle mission.

Check & Connect: The Importance of Relationships for Promoting Engagement with School

ERIC Educational Resources Information Center

Anderson, Amy R.; Christenson, Sandra L.; Sinclair, Mary F.; Lehr, Camilla A.

2004-01-01

The purpose of this study was to examine whether the closeness and quality of relationships between intervention staff and students involved in the Check & Connect program were associated with improved student engagement in school. Participants included 80 elementary and middle school students referred to the Check & Connect program for poor…

Dielectric elastomer pump for artificial organisms

NASA Astrophysics Data System (ADS)

Bowers, Amy E.; Rossiter, Jonathan M.; Walters, Peter J.; Ieropoulos, Ioannis A.

2011-04-01

This paper presents a bio-inspired, dielectric elastomer (DE) based tubular pumping unit, developed for eventual use as a component of an artificial digestive tract onboard a microbial fuel cell powered robot (EcoBot). The pump effects fluid displacement by direct actuation of the tube wall as opposed to excitation by an external body. The actuator consists of a DE tube moulded from silicone, held in a negative pressure chamber, which is used for prestraining the tube. The pump is coupled with custom designed polymeric check valves in order to rectify the fluid flow and assess the performance of the unit. The valves exhibited the necessary low opening pressures required for use with the actuator. The tube's actuation characteristics were measured both with and without liquid in the system. Based on these data the optimal operating conditions for the pump are discussed. The pump and valve system has achieved flowrates in excess of 40μl/s. This radially contracting/expanding actuator element is the fundamental component of a peristaltic pump. This 'soft pump' concept is suitable for biomimetic robotic systems, or for the medical or food industries where hard contact with the delivered substrate may be undesirable. Future work will look at connecting multiple tubes in series in order to achieve peristalsis.

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Qualifications: Check pilots (aircraft) and check pilots (simulator). 91.1089 Section 91.1089 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Fractional Ownership Operations Program Management § 91.1089 Qualifications: Check pilots...

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Qualifications: Check pilots (aircraft) and check pilots (simulator). 91.1089 Section 91.1089 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Fractional Ownership Operations Program Management § 91.1089 Qualifications: Check pilots...

Industrial application of low voltage bidirectional automatic release of reserve

NASA Astrophysics Data System (ADS)

Popa, G. N.; Diniş, C. M.; Iagăr, A.; Deaconu, S. I.; Popa, I.

2018-01-01

The paper presents an analysis on low voltage industrial electrical installation controlled by bidirectional automatic release of reserve. Industrial electrical installation is for removing smoke in case of fire from a textile company. The main parts of the installation of removing smoke in case of fire are: general electrical panel; reserve electrical panel; three-phase induction motors for driven fans; electrical actuators for inlet and outlet valves; clean air inlet pipe, respectively, the outlet pipe for smoke. The operation and checking of bidirectional automatic release of reserve are present in the paper.

THERMTRAJ: A FORTRAN program to compute the trajectory and gas film temperatures of zero pressure balloons

NASA Technical Reports Server (NTRS)

Horn, W. J.; Carlson, L. A.

1983-01-01

A FORTRAN computer program called THERMTRAJ is presented which can be used to compute the trajectory of high altitude scientific zero pressure balloons from launch through all subsequent phases of the balloon flight. In addition, balloon gas and film temperatures can be computed at every point of the flight. The program has the ability to account for ballasting, changes in cloud cover, variable atmospheric temperature profiles, and both unconditional valving and scheduled valving of the balloon gas. The program was verified for an extensive range of balloon sizes (from 0.5 to 41.47 million cubic feet). Instructions on program usage, listing of the program source deck, input data and printed and plotted output for a verification case are included.

Coverage Metrics for Model Checking

NASA Technical Reports Server (NTRS)

Penix, John; Visser, Willem; Norvig, Peter (Technical Monitor)

2001-01-01

When using model checking to verify programs in practice, it is not usually possible to achieve complete coverage of the system. In this position paper we describe ongoing research within the Automated Software Engineering group at NASA Ames on the use of test coverage metrics to measure partial coverage and provide heuristic guidance for program model checking. We are specifically interested in applying and developing coverage metrics for concurrent programs that might be used to support certification of next generation avionics software.

10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Definitions concerning commercial prerinse spray valves. 431.262 Section 431.262 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... (or class thereof) manufactured by one manufacturer, having the same primary energy source, and which...

10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Definitions concerning commercial prerinse spray valves. 431.262 Section 431.262 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... (or class thereof) manufactured by one manufacturer, having the same primary energy source, and which...

10 CFR 431.262 - Definitions concerning commercial prerinse spray valves.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Definitions concerning commercial prerinse spray valves. 431.262 Section 431.262 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... (or class thereof) manufactured by one manufacturer, having the same primary energy source, and which...

Minimally Invasive Mitral Valve Surgery III

PubMed Central

Lehr, Eric J.; Guy, T. Sloane; Smith, Robert L.; Grossi, Eugene A.; Shemin, Richard J.; Rodriguez, Evelio; Ailawadi, Gorav; Agnihotri, Arvind K.; Fayers, Trevor M.; Hargrove, W. Clark; Hummel, Brian W.; Khan, Junaid H.; Malaisrie, S. Chris; Mehall, John R.; Murphy, Douglas A.; Ryan, William H.; Salemi, Arash; Segurola, Romualdo J.; Smith, J. Michael; Wolfe, J. Alan; Weldner, Paul W.; Barnhart, Glenn R.; Goldman, Scott M.; Lewis, Clifton T. P.

2016-01-01

Abstract Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program. PMID:27662478

40 CFR 63.1033 - Open-ended valves or lines standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Open-ended valves or lines standards... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Equipment Leaks-Control Level 2 Standards § 63.1033 Open-ended...

A Discussion of Issues in Integrity Constraint Monitoring

NASA Technical Reports Server (NTRS)

Fernandez, Francisco G.; Gates, Ann Q.; Cooke, Daniel E.

1998-01-01

In the development of large-scale software systems, analysts, designers, and programmers identify properties of data objects in the system. The ability to check those assertions during runtime is desirable as a means of verifying the integrity of the program. Typically, programmers ensure the satisfaction of such properties through the use of some form of manually embedded assertion check. The disadvantage to this approach is that these assertions become entangled within the program code. The goal of the research is to develop an integrity constraint monitoring mechanism whereby a repository of software system properties (called integrity constraints) are automatically inserted into the program by the mechanism to check for incorrect program behaviors. Such a mechanism would overcome many of the deficiencies of manually embedded assertion checks. This paper gives an overview of the preliminary work performed toward this goal. The manual instrumentation of constraint checking on a series of test programs is discussed, This review then is used as the basis for a discussion of issues to be considered in developing an automated integrity constraint monitor.

Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eldiwany, B.; Alvarez, P.D.; Wolfe, K.

1996-12-01

An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging andmore » unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during {Delta}P closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data.« less

Functional performance of pyrovalves

NASA Technical Reports Server (NTRS)

Bement, Laurence J.

1996-01-01

Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a Government/Industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to provide information on functional performance of pyrovalves to allow users the opportunity to improve procurement requirements. Specific objectives included the demonstration of performance test methods, the seating; these gases/particles entered the fluid path of measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted at NASA's Langley Research Center on several units for each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. Two of the five designs had inadequate functional margins with the pyrotechnic cartridges evaluated.

Proceedings of the symposium on inservice testing of pumps and valves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-10-01

The 1990 Symposium on Inservice Testing of Pumps and Valves, jointly sponsored by the Board on Nuclear Codes and Standards of the American Society of Mechanical Engineers and by the Nuclear Regulatory Commission, provided a forum for the discussion of current programs and methods for inservice testing at nuclear power plants. The symposium also provided an opportunity to discuss the need to improve inservice testing in order to ensure the reliable performance of pumps and valves. The participation of industry representatives, regulators, and consultants resulted in the discussion of a broad spectrum of ideas and perspectives regarding the improvement ofmore » inservice testing of pumps and valves at nuclear power plants.« less

Access to Employee Wellness Programs and Use of Preventive Care Services Among U.S. Adults.

PubMed

Isehunwa, Oluwaseyi O; Carlton, Erik L; Wang, Yang; Jiang, Yu; Kedia, Satish; Chang, Cyril F; Fijabi, Daniel; Bhuyan, Soumitra S

2017-12-01

There is little research at the national level on access to employee wellness programs and the use of preventive care services. This study examined the use of seven preventive care services among U.S working adults with access to employee wellness programs. The study population comprised 17,699 working adults aged ≥18 years, obtained from the 2015 National Health Interview Survey. Multivariate logistic regression models examined the relationship between access to employee wellness programs and use of seven preventive care services: influenza vaccination, blood pressure check, diabetes check, cholesterol check, Pap smear test, mammogram, and colon cancer screening. Data analysis began in Fall 2016. Overall, 46.6% of working adults reported having access to employee wellness programs in 2015. Working adults with access to employee wellness programs had higher odds of receiving influenza vaccination (OR=1.57, 95% CI=1.43, 1.72, p<0.001), blood pressure check (OR=2.46, 95% CI=2.17, 2.78, p<0.001), diabetes check (OR=1.30, 95% CI=1.12, 1.50, p<0.001), cholesterol check (OR=1.48, 95% CI=1.33, 1.67, p<0.001), and mammogram (OR=1.57, 95% CI=1.24, 1.98, p<0.001). However, there was no significant difference between access to employee wellness programs and the use of Pap smear test and colon cancer screening services. Using a nationally representative sample of individuals, this study found a positive association between access to employee wellness programs and the use of preventive care services. The results support favorable policies to encourage implementing wellness programs in all worksites, especially those with <50 employees. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

klf2a couples mechanotransduction and zebrafish valve morphogenesis through fibronectin synthesis

PubMed Central

Steed, Emily; Faggianelli, Nathalie; Roth, Stéphane; Ramspacher, Caroline; Concordet, Jean-Paul; Vermot, Julien

2016-01-01

The heartbeat and blood flow signal to endocardial cell progenitors through mechanosensitive proteins that modulate the genetic program controlling heart valve morphogenesis. To date, the mechanism by which mechanical forces coordinate tissue morphogenesis is poorly understood. Here we use high-resolution imaging to uncover the coordinated cell behaviours leading to heart valve formation. We find that heart valves originate from progenitors located in the ventricle and atrium that generate the valve leaflets through a coordinated set of endocardial tissue movements. Gene profiling analyses and live imaging reveal that this reorganization is dependent on extracellular matrix proteins, in particular on the expression of fibronectin1b. We show that blood flow and klf2a, a major endocardial flow-responsive gene, control these cell behaviours and fibronectin1b synthesis. Our results uncover a unique multicellular layering process leading to leaflet formation and demonstrate that endocardial mechanotransduction and valve morphogenesis are coupled via cellular rearrangements mediated by fibronectin synthesis. PMID:27221222

Investigation of a rotary valving system with variable valve timing for internal combustion engines

NASA Astrophysics Data System (ADS)

Cross, Paul C.; Hansen, Craig N.

1994-11-01

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 multifuel 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.

UTP and Temporal Logic Model Checking

NASA Astrophysics Data System (ADS)

Anderson, Hugh; Ciobanu, Gabriel; Freitas, Leo

In this paper we give an additional perspective to the formal verification of programs through temporal logic model checking, which uses Hoare and He Unifying Theories of Programming (UTP). Our perspective emphasizes the use of UTP designs, an alphabetised relational calculus expressed as a pre/post condition pair of relations, to verify state or temporal assertions about programs. The temporal model checking relation is derived from a satisfaction relation between the model and its properties. The contribution of this paper is that it shows a UTP perspective to temporal logic model checking. The approach includes the notion of efficiency found in traditional model checkers, which reduced a state explosion problem through the use of efficient data structures

Foundations of the Bandera Abstraction Tools

NASA Technical Reports Server (NTRS)

Hatcliff, John; Dwyer, Matthew B.; Pasareanu, Corina S.; Robby

2003-01-01

Current research is demonstrating that model-checking and other forms of automated finite-state verification can be effective for checking properties of software systems. Due to the exponential costs associated with model-checking, multiple forms of abstraction are often necessary to obtain system models that are tractable for automated checking. The Bandera Tool Set provides multiple forms of automated support for compiling concurrent Java software systems to models that can be supplied to several different model-checking tools. In this paper, we describe the foundations of Bandera's data abstraction mechanism which is used to reduce the cardinality (and the program's state-space) of data domains in software to be model-checked. From a technical standpoint, the form of data abstraction used in Bandera is simple, and it is based on classical presentations of abstract interpretation. We describe the mechanisms that Bandera provides for declaring abstractions, for attaching abstractions to programs, and for generating abstracted programs and properties. The contributions of this work are the design and implementation of various forms of tool support required for effective application of data abstraction to software components written in a programming language like Java which has a rich set of linguistic features.

Health Care–Associated Native Valve Endocarditis in Patients with no History of Injection Drug Use: Current Importance of Non-Nosocomial Acquisition

PubMed Central

Benito, Natividad; Miró, José M.; de Lazzari, Elisa; Cabell, Christopher H; del Río, Ana; Altclas, Javier; Commerford, Patrick; Delahaye, Francois; Dragulescu, Stefan; Giamarellou, Helen; Habib, Gilbert; Kamarulzaman, Adeeba; Kumar, A. Sampath; Nacinovich, Francisco M.; Suter, Fredy; Tribouilloy, Christophe; Venugopal, K; Moreno, Asuncion; Fowler, Vance G.

2013-01-01

Background The clinical profile and outcome of nosocomial and non-nosocomial health care–associated native valve endocarditis are not well defined. Objective To describe the prevalence, clinical characteristics, and outcomes of nosocomial and non-nosocomial health care–associated native valve endocarditis. Design Prospective observational study. Setting 61 hospitals in 28 countries. Patients Patients with definite native valve endocarditis and no history of injection drug use who were enrolled in the International Collaboration on Endocarditis–Prospective Cohort Study from June 2000 to August 2005. Measurements Characteristics of nosocomial and non-nosocomial health care–associated native valve endocarditis cases were described and compared with those cases acquired in the community. Results Health care–associated native valve endocarditis was present in 557 (34%) of 1622 patients with native valve endocarditis and no history of injection drug use (nosocomial native valve endocarditis 303 patients [54%]; non-nosocomial health care–associated native valve endocarditis 254 patients [46%]). Staphylococcus aureus was the most common cause of health care-associated native valve endocarditis (nosocomial native valve endocarditis, 47%; non-nosocomial health care–associated native valve endocarditis, 42%; p=0.3), with a notable proportion of methicillin-resistant S. aureus (nosocomial native valve endocarditis, 57%; non-nosocomial health care–associated native valve endocarditis, 41%; p=0.014). Patients with health care–associated native valve endocarditis had lower rates of cardiac surgery (41% health care–associated native valve endocarditis vs 51% community-acquired native valve endocarditis, p<0.001) and higher in-hospital mortality rates than patients with community-acquired native valve endocarditis (25% health care–associated native valve endocarditis vs. 13% community-acquired native valve endocarditis vs., p<0.001). Multivariable analysis confirmed a higher mortality associated with health care–associated native valve endocarditis (incidence risk ratio=1.20 (CI 95%, 1.03–1.61). Limitations This study involves tertiary hospitals with cardiac surgery programs. The results may not be generalized to patient populations receiving care in other types of facility. Conclusions More than one-third of all cases of native valve endocarditis in non-drug users involve contact with health care. S. aureus is the leading cause of health care–associated native valve endocarditis. Non-nosocomial health care–associated native valve endocarditis is common, especially in the US. Patients with health care-associated and community-acquired native valve endocarditis differ in their presentation, microbiology, and outcome. By contrast, patients with nosocomial and non-nosocomial healthcare-associated endocarditis are similar. PMID:19414837

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VIII. ENGINE COMPONENTS--PART I.

ERIC Educational Resources Information Center

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION AND MAINTENANCE OF DIESEL ENGINE CYLINDER HEADS AND CYLINDER ASSEMBLIES. TOPICS ARE CYLINDER ASSEMBLY (LINERS), CYLINDER HEADS, VALVES AND VALVE MECHANISMS, AND PISTON AND PISTON RINGS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

Bypass control valve seal and bearing life cycle test report

NASA Technical Reports Server (NTRS)

Lundback, A. V.

1972-01-01

The operating characteristics of a bypass control valve seal and bearing life cycle tests are reported. Data from the initial assembly, leak, torque, and deflection tests are included along with the cycle life test results and conclusions. The equipment involved was to be used in the nuclear engine for the rocket vehicles program.

Advanced diesel engine component development program, tasks 4-14

NASA Astrophysics Data System (ADS)

Kaushal, Tony S.; Weber, Karen E.

1994-11-01

This report summarizes the Advanced Diesel Engine Component Development (ADECD) Program to develop and demonstrate critical technology needed to advance the heavy-duty low heat rejection engine concept. Major development activities reported are the design, analysis, and fabrication of monolithic ceramic components; vapor phase and solid film lubrication; electrohydraulic valve actuation; and high pressure common rail injection. An advanced single cylinder test bed was fabricated as a laboratory tool in studying these advanced technologies. This test bed simulates the reciprocator for a system having no cooling system, turbo compounding, Rankine bottoming cycle, common rail injection, and variable valve actuation to achieve fuel consumption of 160 g/kW-hr (.26 lb/hp-hr). The advanced concepts were successfully integrated into the test engine. All ceramic components met their functional and reliability requirements. The firedeck, cast-in-place ports, valves, valve guides, piston cap, and piston ring were made from silicon nitride. Breakthroughs required to implement a 'ceramic' engine included the fabrication of air-gap cylinder heads, elimination of compression gaskets, machining of ceramic valve seats within the ceramic firedeck, fabrication of cast-in-place ceramic port liners, implementation of vapor phase lubrication, and elimination of the engine coolant system. Silicon nitride valves were successfully developed to meet several production abuse test requirements and incorporated into the test bed with a ceramic valve guide and solid film lubrication. The ADECD cylinder head features ceramic port shields to increase insulation and exhaust energy recovery. The combustion chamber includes a ceramic firedeck and piston cap. The tribological challenge posed by top ring reversal temperatures of 550 C was met through the development of vapor phase lubrication using tricresyl phosphate at the ring-liner interface. A solenoid-controlled, variable valve actuation system that eliminated the conventional camshaft was demonstrated on the test bed. High pressure fuel injection via a common rail system was also developed to reduce particulate emissions.

Advanced diesel engine component development program, tasks 4-14

NASA Technical Reports Server (NTRS)

Kaushal, Tony S.; Weber, Karen E.

1994-01-01

This report summarizes the Advanced Diesel Engine Component Development (ADECD) Program to develop and demonstrate critical technology needed to advance the heavy-duty low heat rejection engine concept. Major development activities reported are the design, analysis, and fabrication of monolithic ceramic components; vapor phase and solid film lubrication; electrohydraulic valve actuation; and high pressure common rail injection. An advanced single cylinder test bed was fabricated as a laboratory tool in studying these advanced technologies. This test bed simulates the reciprocator for a system having no cooling system, turbo compounding, Rankine bottoming cycle, common rail injection, and variable valve actuation to achieve fuel consumption of 160 g/kW-hr (.26 lb/hp-hr). The advanced concepts were successfully integrated into the test engine. All ceramic components met their functional and reliability requirements. The firedeck, cast-in-place ports, valves, valve guides, piston cap, and piston ring were made from silicon nitride. Breakthroughs required to implement a 'ceramic' engine included the fabrication of air-gap cylinder heads, elimination of compression gaskets, machining of ceramic valve seats within the ceramic firedeck, fabrication of cast-in-place ceramic port liners, implementation of vapor phase lubrication, and elimination of the engine coolant system. Silicon nitride valves were successfully developed to meet several production abuse test requirements and incorporated into the test bed with a ceramic valve guide and solid film lubrication. The ADECD cylinder head features ceramic port shields to increase insulation and exhaust energy recovery. The combustion chamber includes a ceramic firedeck and piston cap. The tribological challenge posed by top ring reversal temperatures of 550 C was met through the development of vapor phase lubrication using tricresyl phosphate at the ring-liner interface. A solenoid-controlled, variable valve actuation system that eliminated the conventional camshaft was demonstrated on the test bed. High pressure fuel injection via a common rail system was also developed to reduce particulate emissions.

Integrated Reconfigurable Intelligent Systems (IRIS) for Complex Naval Systems

DTIC Science & Technology

2009-10-31

water system. This simplified chilled water system includes one chiller -pump plant and two service loads. • X- p«cM*MJ<w*4tf -a ’.•.wVlniX’i • V...and valve7. Pumps and chiller operation states are observable. Valve 7 is STUCKCLOSE at time / = 440sec (me 11th iteration). Valve 11 is STUCKCLOSE...framework is a product from Adobe called Flex. The product is a mixture of the Adobe Action script programming language and a markup language call MXML

National Dam Safety Program, Mill Pond Dam (Inventory Number NY 368), Lake Champlain Basin, Essex County, New York. Phase I Inspection Report

DTIC Science & Technology

1980-08-28

displaced timbers on the downstream face, replace broken timbers, repair of the valve on the drain, and repair of the spalling concrete on the wingwall which...repair of the valve on the drain, and repair of the spalling concrete on the wingwall which extends downstream of the north abutment. In addition, a...long. The gatehouse at the northern end of the dam contains the control mechanism for a valve which regulates flow at the reservoir drain inlet, an 84

Leaflet escape in a new bileaflet mechanical valve: TRI technologies.

PubMed

Bottio, Tomaso; Casarotto, Dino; Thiene, Gaetano; Caprili, Luca; Angelini, Annalisa; Gerosa, Gino

2003-05-13

Leaflet escape is a mode of structural valve failure for mechanical prostheses. This complication previously has been reported for both monoleaflet and bileaflet valve models. We report 2 leaflet escape occurrences observed in 2 patients who underwent valve replacement with a TRI Technologies valve prosthesis. At the University of Padua, between November 2000 and February 2002, 36 TRI Technologies valve prostheses (26 aortic and 10 mitral) were implanted in 34 patients (12 women and 22 men) with a mean age of 59.9+/-10.3 years (range, 30 to 75 years). There were 5 deaths: 3 in hospital, 1 early after discharge, and 1 late. Two patients experienced a catastrophic prosthetic leaflet escape; the first patient was a 52-year-old man who died 10 days after aortic valve and ascending aorta replacement, and the second was a 58-year-old man who underwent a successful emergency reoperation 20 months after mitral valve replacement. Examination of the explanted prostheses showed in both cases a leaflet escape caused by a leaflet's pivoting system fracture. Prophylactic replacement was then successfully accomplished so far in 12 patients, without evidence of structural valve failure in any of them. Among other significant postoperative complications, we observed 3 major thromboembolisms, 1 hemorrhage, and 1 paravalvular leak. These catastrophes prompted us to interrupt the implantation program, and they cast a shadow on the durability of the TRI Technologies valve prosthesis because of its high risk of structural failure.

Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

NASA Technical Reports Server (NTRS)

Lueders, Kathy; Buntain, Nick; Fries, Joseph (Technical Monitor)

1999-01-01

Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

[Extracorporeal ventriculoatrial shunt with the use of one-way ball valve].

PubMed

Kubo, Shigeki; Takimoto, Hiroshi; Hosoi, Kazuki; Toyota, Shingo; Takakura, Shuji; Hayashi, Yasuhiro; Ueno, Masato; Morisako, Toshitaka; Karasawa, Jun; Ninaga, Hideo; Yoshimine, Toshiki

2002-04-01

We developed a simple system of an "extracorporeal" ventriculoatrial (VA) shunt using a one-way ball valve (Acty valve II, Kaneka Medix) to release the patient from postoperative constraint during the ventricular drainage. The system is constructed in such a way that the ventricular drainage tube is connected to the central venous catheter via a one-way valve. The CSF is regulated by using the valve and is diverted into the systemic circulation as in the conventional ventriculoatrial shunt. After 2 or 3 weeks of CSF diversion through the extracorporeal VA shunt, a ventriculoperitoneal shunt is placed if hydrocephalus is apparent by temporary occlusion of the system. We applied this system to 4 patients with hydrocephalus, and we found it useful and free from adverse effects. The patient was freed from physical constraint involved in conventional ventricular drainage and an effective program of early rehabilitation was able to be started.

Proceedings of the Third NRC/ASME Symposium on Valve and Pump Testing. Session 1A--Session 2C: Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-07-01

The 1994 Symposium on Valve and Pump Testing, jointly sponsored by the Board of Nuclear Codes and Standards of the American Society of Mechanical Engineers and by the Nuclear Regulatory Commission, provides a forum for the discussion of current programs and methods for inservice testing and motor-operated valve testing at nuclear power plants. The symposium also provides an opportunity to discuss the need to improve that testing in order to help ensure the reliable performance of pumps and valves. The participation of industry representatives, regulators, and consultants results in the discussion of a broad spectrum of ideas and perspectives regardingmore » the improvement of inservice testing of pumps and valves at nuclear power plants. This document, Volume 1, covers sessions 1A through session 2C. The individual papers have been cataloged separately.« less

Enforcing the minimum drinking age: state, local and agency characteristics associated with compliance checks and Cops in Shops programs.

PubMed

Montgomery, Jacob M; Foley, Kristie Long; Wolfson, Mark

2006-02-01

To identify state, local and organizational characteristics associated with local law enforcement agencies' implementation of two dramatically different approaches to enforcement of underage drinking laws: compliance checks and Cops in Shops programs. Compliance checks use underage decoys to attempt to purchase alcohol from retail merchants, while Cops in Shops programs deploy undercover law enforcement officers in alcohol outlets to detect and cite persons under the age of 21 who attempt to purchase alcohol. Cross-sectional telephone interview conducted as part of the Tobacco Enforcement Study (TES), which examined enforcement of laws related to youth access to tobacco. Data were collected in 1999 among law enforcement agencies in all 50 states of the United States. Representatives of city police departments, departments of public safety, sheriffs or county police were included (n = 920 local agencies). Alcohol compliance checks and Cops in Shops programs were the primary outcomes. Covariates included state level policies (e.g. beer tax), agency resources (e.g. number of sworn officers) and community demographics (e.g. college dormitory population). Local enforcement agencies were more likely to perform alcohol compliance checks than to have a Cops in Shops program (73.9% compared to 41.1% in cities > 25 000 and 55.7% compared to 23.9% in cities < or = 25 000). Conducting compliance checks for tobacco age-of-sale laws was positively associated with alcohol compliance checks and Cops in Shops (OR 3.30, P < 0.001; OR 1.84, P = 0.001, respectively). Having a Drug Abuse Resistance Education (DARE) officer was negatively related to conducting compliance checks (OR 0.67, P = 0.03). Special community policing units were associated with departments having Cops in Shops programs (OR 1.80, P = 0.006). This study used a nationally representative sample of communities to better understand state and local factors that shape local law enforcement agencies' use of two distinct approaches to underage drinking enforcement. The strong link observed between tobacco and alcohol compliance checks may indicate a culture within some law enforcement agencies supporting strict enforcement of age-of-sale laws.

Computerized system for the follow-up of patients with heart valve replacements.

PubMed

Bain, W H; Fyfe, I C; Rodger, R A

1985-04-01

A system is described which will accept, store, retrieve and analyze information on large numbers of patients who undergo valve replacement surgery. The purpose of the database is to yield readily available facts concerning the patient's clinical course, prosthetic valve function, length of survival, and incidence of complications. The system uses the Apple Macintosh computer, which is one of the current examples of small, desk-top microprocessors. The software for the input, editing and analysis programs has been written by a professional software writer in close collaboration with a cardiac surgeon. Its content is based on 8 years' experience of computer-based valve follow-up. The system is inexpensive and has proved easy to use in practice.

Regional Systems of Care to Optimize Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement.

PubMed

Stub, Dion; Lauck, Sandra; Lee, May; Gao, Min; Humphries, Karin; Chan, Albert; Cheung, Anson; Cook, Richard; Della Siega, Anthony; Leipsic, Jonathon; Charania, Jay; Dvir, Danny; Latham, Tim; Polderman, Jopie; Robinson, Simon; Wong, Daniel; Thompson, Christopher R; Wood, David; Ye, Jian; Webb, John

2015-12-28

This study sought to describe the development of a multicenter, transcatheter aortic valve replacement program and regional systems of care intended to optimize coordinated, efficient, and appropriate delivery of this new therapy. Transcatheter aortic valve replacement (TAVR) has become an accepted treatment option for patients with severe aortic stenosis who are at high surgical risk. Regional systems of care have led to improvements in outcomes for patients undergoing intervention for myocardial infarction, cardiac arrest, and stroke. We implemented a regional system of care for patients undergoing TAVR in British Columbia, Canada. We describe a prospective observational cohort of 583 patients who underwent TAVR in British Columbia between 2012 and 2014. Regionalization of TAVR care in British Columbia refers to a centrally coordinated, funded, and evaluated program led by a medical director and a multidisciplinary advisory group that oversees planning, access to care, and quality of outcomes at the 4 provincial sites. Risk-stratified case selection for transfemoral TAVR is performed by heart teams at each site on the basis of consensus provincial indications. Referrals for lower volume and more complicated TAVR, including nontransfemoral access and valve-in-valve procedures, are concentrated at a single site. In-hospital and 30-day outcomes are reported. The median age was 83 years (interquartile range [IQR]: 78 to 87 years) and median STS score was 6% (IQR: 4% to 8%). Transfemoral access was performed in 499 (85.6%) cases and nontransfemoral in 84 (14.4%). Transcatheter valve-in-valve procedures in for failed bioprosthetic valves were performed in 43 patients (7.4%). A balloon-expandable valve was inserted in 386 (66.2%) and a self-expanding valve in 189 (32.4%). All-cause 30-day mortality was 3.5%. All-cause in-hospital mortality and disabling stroke occurred in 3.1% and 1.9%, respectively. Median length of stay was 3 days (IQR: 3 to 6 days), with 92.8% of patients discharged directly home. This experience demonstrates the potential benefits of a regional system of care for TAVR. Excellent outcomes were demonstrated: most patients had short in-hospital stays and were discharged directly home. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

45 CFR 2540.205 - What procedures must I follow in conducting a National Service Criminal History Check for a...

Code of Federal Regulations, 2014 CFR

2014-10-01

... National Service Criminal History Check for a covered position? 2540.205 Section 2540.205 Public Welfare... What procedures must I follow in conducting a National Service Criminal History Check for a covered... criminal history check, and for the appropriate sharing of the results of the checks within the program...

A Support System for Error Correction Questions in Programming Education

ERIC Educational Resources Information Center

Hachisu, Yoshinari; Yoshida, Atsushi

2014-01-01

For supporting the education of debugging skills, we propose a system for generating error correction questions of programs and checking the correctness. The system generates HTML files for answering questions and CGI programs for checking answers. Learners read and answer questions on Web browsers. For management of error injection, we have…

DARPA Advanced Cannon Propellant (ACP) Library User’s Guide. Appendix E. Patents Dealing with LP Gun Hardware

DTIC Science & Technology

1981-06-15

clip 30. A spool 32 in- than as herein specifically illustrated or described, and r 3,782,241 3 4 that certain changes in the form and arrangement of...34 storke " to -- stroke--. 5igncd and 5caicd this Fourteenth Day of March 1978 ISEA 1.I .4 test: Rk TH C. MASON LITRELLE F. PARKER A ttesting Officer Acting...10.67 cells. One thereby closing the check valve 36. This quantity of 45 would select 10 cells and increase the storke length compressed air and

HERMIES-3: A step toward autonomous mobility, manipulation, and perception

NASA Technical Reports Server (NTRS)

Weisbin, C. R.; Burks, B. L.; Einstein, J. R.; Feezell, R. R.; Manges, W. W.; Thompson, D. H.

1989-01-01

HERMIES-III is an autonomous robot comprised of a seven degree-of-freedom (DOF) manipulator designed for human scale tasks, a laser range finder, a sonar array, an omni-directional wheel-driven chassis, multiple cameras, and a dual computer system containing a 16-node hypercube expandable to 128 nodes. The current experimental program involves performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES-III). The environment in which the robots operate has been designed to include multiple valves, pipes, meters, obstacles on the floor, valves occluded from view, and multiple paths of differing navigation complexity. The ongoing research program supports the development of autonomous capability for HERMIES-IIB and III to perform complex navigation and manipulation under time constraints, while dealing with imprecise sensory information.

Notification: Fiscal Year 2015 Risk Assessment of EPA's Purchase Card and Convenience Check Programs

EPA Pesticide Factsheets

Project #OA-FY15-0064, August 26, 2015. The U.S. Environmental Protection Agency (EPA) Office oflnspector General (OIG) plans to begin the preliminary research phase ofauditing the agency's purchase card and convenience check programs.

Notification: Review of the U.S. Environmental Protection Agency's Purchase Card and Convenience Check Program

EPA Pesticide Factsheets

Project #OA-FY13-0116, December 20, 2012. The U.S. Environmental Protection Agency, Office of Inspector General, plans to begin preliminary research for an audit of the agency’s purchase card and convenience check programs.

A new design and application of bioelastomers for better control of intraocular pressure in a glaucoma drainage device.

PubMed

Luong, Quang Minh; Shang, Lei; Ang, Marcus; Kong, Jen Fong; Peng, Yan; Wong, Tina T; Venkatraman, Subbu S

2014-02-01

Glaucoma drainage device (GDD) implantation is an effective method of lowering the intraocular pressure (IOP). Commonly used GDDs can be classified into nonvalved and valved. Although a stable IOP is critical, currently available devices often cause extreme IOP fluctuations: nonvalved GDDs suffer from a risk of hypotony (IOP<5 mmHg), whereas valved GDDs have a higher risk ocular hypertensive (IOP>22 mmHg). It is hypothesized that a GDD with a valve designed to open around the time of onset of the hypertensive phase, would minimize IOP fluctuation. Accordingly, a valve fabricated from a biodegradable polymer poly(L-lactide-co-ϵ-caprolactone) (PLC 70/30) is evaluated in vitro and in vivo. The pressure response is compared with its non-degradable counterpart in in vitro studies of IOP. It is also established that in vitro, the biodegradability of the valve is programmed to occur over 12 weeks. In vivo, a steady and low IOP is achieved with the biodegradable valve and the hypertensive phase is significantly attenuated compared with the commercial device. Fibrotic encapsulation of the device is also minimized with the biodegradable valve in vivo. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device.

PubMed

Fujimura, R; Lober, R; Kamian, K; Kleiner, L

2018-01-01

Programmable ventricular shunt valves are commonly used to treat hydrocephalus. They can be adjusted to allow for varying amounts of cerebrospinal fluid (CSF) flow using an external magnetic programming device, and are susceptible to maladjustment from inadvertent exposure to magnetic fields. We describe the case of a 3-month-old girl treated for hydrocephalus with a programmable Strata TM II valve found at the incorrect setting on multiple occasions during her hospitalization despite frequent reprogramming and surveillance. We found that the Vocera badge, a common hands-free wireless communication system worn by our nursing staff, had a strong enough magnetic field to unintentionally change the shunt setting. The device is worn on the chest bringing it into close proximity to the shunt valve when care providers hold the baby, resulting in the maladjustment. Some commonly used medical devices have a magnetic field strong enough to alter programmable shunt valve settings. Here, we report that the magnetic field from the Vocera hands-free wireless communication system, combined with the worn position, results in shunt maladjustment for the Strata TM II valve. Healthcare facilities using the Vocera badges need to put protocols in place and properly educate staff members to ensure the safety of patients with Strata TM II valves.

Which way in? The Necessity of Multiple Approaches to Transcatheter Valve Therapy

PubMed Central

Bleiziffer, S.; Krane, M.; Deutsch, M.A.; Elhmidi, Y.; Piazza, N.; Voss, B.; Lange, R.

2013-01-01

TAVI (transcatheter aortic valve implantation) is a less invasive treatment of the stenotic aortic valve while avoiding midline sternotomy and cardiopulmonary bypass. A crimped biological valve on a self-expanding or balloon-expandable stent is inserted antegradely or retrogradely under fluoroscopy, and deployed on the beating heart. Among the worldwide TAVI programs, many different concepts have been established for the choice of the access site. Whether retrograde or antegrade TAVI should be considered the superior approach is matter of an ongoing debate. The published literature demonstrates safety of all techniques if performed within a dedicated multidisciplinary team. Since there is no data providing evidence if one approach is superior to another, we conclude that an individualized patient-centered decision making process is most beneficial, taking advantage of the complementarity of the different access options. The aim of this article is to give an overview of the current practice of access techniques for transcatheter based valve treatment and to outline the respective special characteristics. PMID:24313647

MRO Sequence Checking Tool

NASA Technical Reports Server (NTRS)

Fisher, Forest; Gladden, Roy; Khanampornpan, Teerapat

2008-01-01

The MRO Sequence Checking Tool program, mro_check, automates significant portions of the MRO (Mars Reconnaissance Orbiter) sequence checking procedure. Though MRO has similar checks to the ODY s (Mars Odyssey) Mega Check tool, the checks needed for MRO are unique to the MRO spacecraft. The MRO sequence checking tool automates the majority of the sequence validation procedure and check lists that are used to validate the sequences generated by MRO MPST (mission planning and sequencing team). The tool performs more than 50 different checks on the sequence. The automation varies from summarizing data about the sequence needed for visual verification of the sequence, to performing automated checks on the sequence and providing a report for each step. To allow for the addition of new checks as needed, this tool is built in a modular fashion.

Program Model Checking as a New Trend

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Visser, Willem; Clancy, Daniel (Technical Monitor)

2002-01-01

This paper introduces a special section of STTT (International Journal on Software Tools for Technology Transfer) containing a selection of papers that were presented at the 7th International SPIN workshop, Stanford, August 30 - September 1, 2000. The workshop was named SPIN Model Checking and Software Verification, with an emphasis on model checking of programs. The paper outlines the motivation for stressing software verification, rather than only design and model verification, by presenting the work done in the Automated Software Engineering group at NASA Ames Research Center within the last 5 years. This includes work in software model checking, testing like technologies and static analysis.

Metallurgical Laboratory (MetLab) Treatability Study: An Analysis of Passive Soil Vapor Extraction Wells (PSVE) FY1999 Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riha, B.D.

1999-10-20

The results to date on the treatability study of the PSVE system at the MetLab of the Savannah River Site (SRS) indicate the technology is performing well. Well concentrations are decreasing and contour maps of the vadose zone soil gas plume show a decrease in the extent of the plume. In the 18 months of operation approximately 200 pounds of chlorinated organic contaminants have been removed by natural barometric pumping of wells fitted with BaroBall valves (low pressure check valves). The mass removal estimates are approximate since the flow rates are estimated, the concentration data is based on exponential fitsmore » of a limited data set, and the concentration data is normalized to the average CO2.The concentration values presented in this report should be taken as the general trend or order of magnitude of concentration until longer-term data is collected. These trends are of exponentially decreasing concentration showing the same characteristics as the concentration trends at the SRS Miscellaneous Chemical Basin after three years of PSVE (Riha et. al., 1999).« less

High precision innovative micropump for artificial pancreas

NASA Astrophysics Data System (ADS)

Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.

2014-03-01

The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.

42 CFR 455.19 - Provider's statement on check.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Provider's statement on check. 455.19 Section 455.19 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS PROGRAM INTEGRITY: MEDICAID Medicaid Agency Fraud Detection and...

The Stress Check Program: a new national policy for monitoring and screening psychosocial stress in the workplace in Japan.

PubMed

Kawakami, Norito; Tsutsumi, Akizumi

2016-01-01

The Japanese government launched a new occupational health policy called the Stress Check Program. This program mandates that all workplaces with 50 or more employees conduct the Stress Check Program for workers at least once a year. This article gives a brief overview and critical review of the program. We reviewed relevant laws, guidelines, and manuals, as well as the policy development process. The policy and the components of the program were compared using available scientific evidence and trends in the management of psychosocial factors at work according to the policies and guidelines of international bodies and European countries. The process of program policy development was based on a discussion among employer and employee representatives, occupational health professionals, and mental health experts. Scientific evidence shows that mandated components of the program (i.e., feedback of stress survey results and physician's interview) may be ineffective. However, additional components recommended to employers, such as stress management skill provision and work environment improvement, in conjunction with the program may be effective in improving psychosocial stress at work. The Stress Check Program is unique compared with the global trend for psychosocial risk management because it focuses on the assessment of stress among individual workers. The new program may be effective in improving worker mental health by facilitating the psychosocial risk management approach in Japan. Concerns regarding the program include mass leakage of collected information, and possible disadvantages for workers labeled as having high stress.

Design of a Magnetostrictive-Hydraulic Actuator Considering Nonlinear System Dynamics and Fluid-Structure Coupling

NASA Astrophysics Data System (ADS)

Larson, John Philip

Smart material electro-hydraulic actuators (EHAs) utilize fluid rectification via one-way check valves to amplify the small, high-frequency vibrations of certain smart materials into large motions of a hydraulic cylinder. Although the concept has been demonstrated in previously, the operating frequency of smart material EHA systems has been limited to a small fraction of the available bandwidth of the driver materials. The focus of this work is to characterize and model the mechanical performance of a magnetostrictive EHA considering key system components: rectification valves, smart material driver, and fluid-system components, leading to an improved actuator design relative to prior work. The one-way valves were modeled using 3-D finite element analysis, and their behavior was characterized experimentally by static and dynamic experimental measurement. Taking into account the effect of the fluid and mechanical conditions applied to the valves within the pump, the dynamic response of the valve was quantified and applied to determine rectification bandwidth of different valve configurations. A novel miniature reed valve, designed for a frequency response above 10~kHz, was fabricated and tested within a magnetostrictive EHA. The nonlinear response of the magnetostrictive driver, including saturation and hysteresis effects, was modeled using the Jiles-Atherton approach to calculate the magnetization and the resulting magnetostriction based on the applied field calculated within the rod from Maxwell's equations. The dynamic pressure response of the fluid system components (pumping chamber, hydraulic cylinder, and connecting passages) was measured over a range of input frequencies. For the magnetostrictive EHA tested, the peak performance frequency was found to be limited by the fluid resonances within the system. A lumped-parameter modeling approach was applied to model the overall behavior of a magnetostrictive EHA, incorporating models for the reed valve response, nonlinear magnetostrictive behavior, and fluid behavior (including inertia and compliance). This model was validated by experimental study of a magnetostrictive EHA with a reduced volume manifold. The model was subsequently applied to design a compact magnetostrictive EHA for aircraft applications. Testing of the system shows that the output performance increases with frequency up to a peak unloaded flow rate of 100 cm3/s (6.4 cu in/s) at 1200 Hz, which is a 100% to 500% increase over previous state-of-the-art systems. A blocked differential pressure of 12.1 MPa (1750 psi) was measured, resulting in a power capacity of 310 W, more than 100 W higher than previously reported values. The design and modeling approach used to scale up the performance to create a compact aircraft EHA can also be applied to reduce the size and weight of smart material EHAs for lower power level applications.

National Program for Inspection of Non-Federal Dams. Reuben Hart Reservoir Dam (CT 00096), Naugatuck River Basin, Torrington, Connecticut. Phase I Inspection Report.

DTIC Science & Technology

1978-10-01

24 in. dia. pipe, which turns 90° about 100 ft. from the toe, where a valve controls discharges through an 18 in. dia. pipe into a small pond on Hart...tower to a chamber about 100 ft. beyond the downstream toe of the dam where a control valve is housed. Two 18 in. dia. pipes are carried under the...dam and then join into one 24 in. dia. pipe continuing to the valve chamber. The outlet pipe turns 90 degrees at the chamber and reduces to 18 in

Design and Development of Sequential Rotary Valve

NASA Technical Reports Server (NTRS)

D’Orsi, Nicholas; Castillo, Priscilla

2017-01-01

Valves are used to regulate the flow of fluids through systems. This rotary valve's main purpose is to fill, pressurize, empty, and vent three smaller tanks with the supply of one larger tank. Many different designs are being taken into consideration, which are each at different stages of development. The furthest along uses three ball valves on a common shaft to open and close their respective ports as the shaft completes one full rotation or cycle. We were tasked with advancing this design to its first test as a plastic model for flow verification, as well as sizing and ordering the necessary O-rings and fasteners. A motor will also be sized to satisfy the torque requirements, and will then be programmed using a Raspberry Pi to rotate the shaft at the calculated speed and dwelling times needed to fill each tank equally. In addition, we have also been advancing designs that use a camshaft and poppets. These are earlier on in their development, currently being sized to replicate the expected flow patterns of the rotary ball valve. Expected outcomes of this valve include bi-directionality, successful sealing under pressure, and accurate cycling.

The boundary condition at the valve for numerical modelling of transient pipe flow with fluid structure interaction

NASA Astrophysics Data System (ADS)

Henclik, S.

2014-08-01

Transient flows in pipes (water hammer = WH) do appear in various situations and the accompanying pressure waves may involve serious perturbations in system functioning. To model these effects properly in the case of elastic pipe the dynamic fluid-structure interaction (FSI) should be taken into account. Fluid-structure couplings appear in various manners and the junction coupling is considered to be the strongest. This effect can be especially significant if the pipe can move as a whole body, which is possible when all its supports are not rigid. In the current paper a similar effect is numerically modelled. The pipe is fixed rigidly, but the valve at the end has a spring-dashpot mounting system, thus its motion is possible when WH is excited by the valve closuring. The boundary condition at the moving valve is modelled as a differential equation of motion. The valve hydraulic characteristics during closuring period are assumed by a time dependence of its loss factor. Preliminary numerical tests of that algorithm were done with an own computer program and it was found that the proper valve fixing system may produce significant lowering of WH pressures.

Report: EPA's Fiscal Year 2015 Purchase Card and Convenience Check Program Assessed as Low Risk

EPA Pesticide Factsheets

Report #16-P-0124, March 29, 2016. We determined the EPA's purchase card and convenience check program for FY 2015 to be at a low risk for illegal, improper or erroneous purchases and payments due to strengthened internal controls.

Monitoring Java Programs with Java PathExplorer

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Rosu, Grigore; Clancy, Daniel (Technical Monitor)

2001-01-01

We present recent work on the development Java PathExplorer (JPAX), a tool for monitoring the execution of Java programs. JPAX can be used during program testing to gain increased information about program executions, and can potentially furthermore be applied during operation to survey safety critical systems. The tool facilitates automated instrumentation of a program's late code which will then omit events to an observer during its execution. The observer checks the events against user provided high level requirement specifications, for example temporal logic formulae, and against lower level error detection procedures, for example concurrency related such as deadlock and data race algorithms. High level requirement specifications together with their underlying logics are defined in the Maude rewriting logic, and then can either be directly checked using the Maude rewriting engine, or be first translated to efficient data structures and then checked in Java.

Notification: Fiscal Year 2016 Risk Assessment of EPA’s Purchase Card and Convenience Check Program

EPA Pesticide Factsheets

Project #OA-FY16-0229, July 14, 2016. The EPA OIG plans to begin a risk assessment of the EPA’s purchase card and convenience check program with the Office of Acquisition Management (OAM) within the Office of Administration and Resources Management (OARM).

Implementation and Impact of the Check & Connect Mentoring Program

ERIC Educational Resources Information Center

Heppen, Jessica; O'Cummings, Mindee; Poland, Lindsay; Zeiser, Krissy; Mills, Nicholas

2015-01-01

High school graduation rates remain unacceptably low in the U.S., especially among disadvantaged youth (Chapman, Laird, Ifill, & KelalRamani, 2011; Stillwell, 2010), with troubling implications for future earnings and employment status (Bureau of Labor Statistics, 2012). Check & Connect (C&C) is an individualized program that pairs…

User's manual for computer program BASEPLOT

USGS Publications Warehouse

Sanders, Curtis L.

2002-01-01

The checking and reviewing of daily records of streamflow within the U.S. Geological Survey is traditionally accomplished by hand-plotting and mentally collating tables of data. The process is time consuming, difficult to standardize, and subject to errors in computation, data entry, and logic. In addition, the presentation of flow data on the internet requires more timely and accurate computation of daily flow records. BASEPLOT was developed for checking and review of primary streamflow records within the U.S. Geological Survey. Use of BASEPLOT enables users to (1) provide efficiencies during the record checking and review process, (2) improve quality control, (3) achieve uniformity of checking and review techniques of simple stage-discharge relations, and (4) provide a tool for teaching streamflow computation techniques. The BASEPLOT program produces tables of quality control checks and produces plots of rating curves and discharge measurements; variable shift (V-shift) diagrams; and V-shifts converted to stage-discharge plots, using data stored in the U.S. Geological Survey Automatic Data Processing System database. In addition, the program plots unit-value hydrographs that show unit-value stages, shifts, and datum corrections; input shifts, datum corrections, and effective dates; discharge measurements; effective dates for rating tables; and numeric quality control checks. Checklist/tutorial forms are provided for reviewers to ensure completeness of review and standardize the review process. The program was written for the U.S. Geological Survey SUN computer using the Statistical Analysis System (SAS) software produced by SAS Institute, Incorporated.

Assembly and method for testing the integrity of stuffing tubes

DOEpatents

Morrison, Edward Francis

1997-01-01

A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally therealong and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube.

75 FR 23196 - Exchange Visitor Program-Secondary School Students

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

.... diplomatic and foreign policy goals by encouraging this positive academic and social interaction. Experience... currently requires a private vendor name and social security number check of all potential host family... check or the name and social security number criminal background check. NCMEC would interpret...

Evaluation of the interpretative skills of participants of a limited transthoracic echocardiography training course (H.A.R.T.scan course).

PubMed

Royse, C F; Haji, D L; Faris, J G; Veltman, M G; Kumar, A; Royse, A G

2012-05-01

Limited transthoracic echocardiography performed by treating physicians may facilitate assessment of haemodynamic abnormalities in perioperative and critical care patients. The interpretative skills of one hundred participants who completed an education program in limited transthoracic echocardiography were assessed by reporting five pre-recorded case studies. A high level of agreement was observed in ventricular volume assessment (left 95%, right 96%), systolic function (left 99%, right 96%), left atrial pressure (96%) and haemodynamic state (97%). The highest failure to report answers (that is, no answer given) was for right ventricular volume and function. For moderate or severe valve lesions, agreement ranged from 90 to 98%, with failure to report <5% in all cases except for mitral stenosis (18%). For mild valve lesions, the range of agreement was lower (53 to 100%) due to overestimation of severity. Medical practitioners who completed the structured educational program showed good agreement with experts in interpretation of valve and ventricular function.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions.

PubMed

Lee, Jong-Beom; Ahn, Ho-Young; Lee, Hong-Jae; Yang, Ji-Ho; Yi, Jin-Seok; Lee, Il-Woo

2017-01-01

The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH 2 O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was -3.69±19.20 mmH 2 O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH 2 O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH 2 O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant ( p =0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH 2 O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

Propellant isolation shutoff valve program

NASA Technical Reports Server (NTRS)

Merritt, F. L.

1973-01-01

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

Staying out of the Cold.

ERIC Educational Resources Information Center

Levinson, Patrick J.

1996-01-01

Discusses how annual boiler maintenance can help cut fuel costs and prevent downtime. Outlines a cleaning program, which includes inspecting the fireside of the boiler, checking the refractory, and checking the waterside. Describes other maintenance measures, such as checking hydraulic fluid levels, and offers tips for analyzing combustion. (RJM)

Automated generation of a World Wide Web-based data entry and check program for medical applications.

PubMed

Kiuchi, T; Kaihara, S

1997-02-01

The World Wide Web-based form is a promising method for the construction of an on-line data collection system for clinical and epidemiological research. It is, however, laborious to prepare a common gateway interface (CGI) program for each project, which the World Wide Web server needs to handle the submitted data. In medicine, it is even more laborious because the CGI program must check deficits, type, ranges, and logical errors (bad combination of data) of entered data for quality assurance as well as data length and meta-characters of the entered data to enhance the security of the server. We have extended the specification of the hypertext markup language (HTML) form to accommodate information necessary for such data checking and we have developed software named AUTOFORM for this purpose. The software automatically analyzes the extended HTML form and generates the corresponding ordinary HTML form, 'Makefile', and C source of CGI programs. The resultant CGI program checks the entered data through the HTML form, records them in a computer, and returns them to the end-user. AUTOFORM drastically reduces the burden of development of the World Wide Web-based data entry system and allows the CGI programs to be more securely and reliably prepared than had they been written from scratch.

Minimum impulse thruster valve design and development

NASA Technical Reports Server (NTRS)

Huftalen, Richard L.; Platt, Andrea L.; Parker, Morgan J.; Yankura, George A.

2003-01-01

The design and development of a minimum impulse thruster valve was conducted, by Moog, under contract by NASA's Jet Propulsion Laboratory, California Institute of Technology, for deep space propulsion systems. The effort was focused on applying known solenoid design techniques scaled to provide a 1 -millisecond response capability for monopropellant, hydrazine ACS thruster applications. The valve has an extended operating temperature range of 20(deg)F to +350(deg)F with a total mass of less than 25 grams and nominal power draw of 7 watts. The design solution resulted in providing a solenoid valve that is one-tenth the scale of the standard product line. The valve has the capability of providing a mass flow rate of 0.0009 pounds per second hydrazine. The design life of 1,000,000 cycles was demonstrated both dry and wet. Not all design factors scaled as expected and proved to be the focus of the final development effort. These included the surface interactions, hydrodynamics and driver electronics. The resulting solution applied matured design approaches to minimize the program risk with innovative methods to address the impacts of scale.

Implementing a Tier 2 Behavioral Intervention in a Therapeutic Alternative High School Program

ERIC Educational Resources Information Center

Fallon, Lindsay M.; Feinberg, Adam B.

2017-01-01

The research base for Check-in, Check-out (CICO), a targeted behavioral intervention within a schoolwide positive behavioral interventions and supports framework, is growing. However, little has been written about its application in therapeutic alternative programs. To extend the literature base, the current article describes a study conducted…

Adapting the Behavior Education Program for Preschool Settings

ERIC Educational Resources Information Center

Steed, Elizabeth A.

2011-01-01

Behavior Education Program (BEP) is the most researched targeted intervention that is used in schoolwide positive behavior intervention and supports (PBIS). It is a daily check-in and check-out system in which students receive extra attention for positive social behavior throughout their school day. This extra attention is intended to prevent…

Automata-Based Verification of Temporal Properties on Running Programs

NASA Technical Reports Server (NTRS)

Giannakopoulou, Dimitra; Havelund, Klaus; Lan, Sonie (Technical Monitor)

2001-01-01

This paper presents an approach to checking a running program against its Linear Temporal Logic (LTL) specifications. LTL is a widely used logic for expressing properties of programs viewed as sets of executions. Our approach consists of translating LTL formulae to finite-state automata, which are used as observers of the program behavior. The translation algorithm we propose modifies standard LTL to Buchi automata conversion techniques to generate automata that check finite program traces. The algorithm has been implemented in a tool, which has been integrated with the generic JPaX framework for runtime analysis of Java programs.

40 CFR 63.175 - Quality improvement program for valves.

Code of Federal Regulations, 2011 CFR

2011-07-01

... program for technology review as specified in paragraph (e) of this section. If the owner or operator... quality improvement program of technology review and improvement: (1) The owner or operator shall comply... designs or technologies that have poorer than average emission performance and those that have better than...

40 CFR 63.175 - Quality improvement program for valves.

Code of Federal Regulations, 2013 CFR

2013-07-01

... program for technology review as specified in paragraph (e) of this section. If the owner or operator... quality improvement program of technology review and improvement: (1) The owner or operator shall comply... designs or technologies that have poorer than average emission performance and those that have better than...

40 CFR 63.175 - Quality improvement program for valves.

Code of Federal Regulations, 2012 CFR

2012-07-01

... program for technology review as specified in paragraph (e) of this section. If the owner or operator... quality improvement program of technology review and improvement: (1) The owner or operator shall comply... designs or technologies that have poorer than average emission performance and those that have better than...

45 CFR 2540.203 - When must I conduct a State criminal registry check and a National Sex Offender Public Web site...

Code of Federal Regulations, 2010 CFR

2010-10-01

... check and a National Sex Offender Public Web site check on an individual in a covered position? 2540.203... National Sex Offender Public Web site check on an individual in a covered position? (a) The State criminal... enrolls in, or is hired by, your program on or after October 1, 2009. (b) The National Sex Offender Public...

45 CFR 2540.203 - When must I conduct a State criminal registry check and a National Sex Offender Public Web site...

Code of Federal Regulations, 2012 CFR

2012-10-01

... check and a National Sex Offender Public Web site check on an individual in a covered position? 2540.203... National Sex Offender Public Web site check on an individual in a covered position? (a) The State criminal... enrolls in, or is hired by, your program on or after October 1, 2009. (b) The National Sex Offender Public...

45 CFR 2540.203 - When must I conduct a State criminal registry check and a National Sex Offender Public Web site...

Code of Federal Regulations, 2011 CFR

2011-10-01

... check and a National Sex Offender Public Web site check on an individual in a covered position? 2540.203... National Sex Offender Public Web site check on an individual in a covered position? (a) The State criminal... enrolls in, or is hired by, your program on or after October 1, 2009. (b) The National Sex Offender Public...

Seal material development test program

NASA Technical Reports Server (NTRS)

1971-01-01

A program designed to characterize an experimental fluoroelastomer material designated AF-E-124D, is examined. Tests conducted include liquid nitrogen load compression tests, flexure tests and valve seal tests, ambient and elevated temperature compression set tests, and cleaning and flushing fluid exposure tests. The results of these tests indicate the AF-E-124D is a good choice for a cryogenic seal, since it exhibits good low temperature sealing characteristics and resistance to permanent set. The status of this material as an experimental fluorelastomer is stressed and recommended. Activity includes definition and control of critical processing to ensure consistent material properties. Design, fabrication and test of this and other materials is recommended in valve and static seal applications.

45 CFR 2551.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2012 CFR

2012-10-01

... National Service Criminal History Check? 2551.29 Section 2551.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

45 CFR 2551.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2011 CFR

2011-10-01

... National Service Criminal History Check? 2551.29 Section 2551.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

45 CFR 2552.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2012 CFR

2012-10-01

... National Service Criminal History Check? 2552.29 Section 2552.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

45 CFR 2552.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2011 CFR

2011-10-01

... National Service Criminal History Check? 2552.29 Section 2552.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

Progress Check Module; Basic Electricity and Electronics Individualized Learning System. Progress Check Booklet.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

The Progress Check Booklet is designed to be used by the student working in the programed course to determine if he has mastered the concepts in the course booklets on: electrical current; voltage; resistance; measuring current and voltage in series circuits; relationships of current, voltage, and resistance; parellel circuits; combination…

76 FR 34744 - Notice of Proposed Information Collection for Public Comment; Continuum of Care Check-up...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-14

... Information Collection for Public Comment; Continuum of Care Check-up Assessment Tool AGENCY: U.S. Department...: Continuum of Care Check-up Assessment Tool. Description of the need for the information proposed: The CoC... FURTHER INFORMATION CONTACT: Ann Marie Oliva, Director, Office of Special Needs Assistance Programs...

45 CFR 2552.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2010 CFR

2010-10-01

... National Service Criminal History Check? 2552.29 Section 2552.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

45 CFR 2551.29 - What procedures must I follow in conducting a National Service Criminal History Check?

Code of Federal Regulations, 2010 CFR

2010-10-01

... National Service Criminal History Check? 2551.29 Section 2551.29 Public Welfare Regulations Relating to... Service Criminal History Check? You are responsible for ensuring that the following procedures are... program is contingent upon the organization's review of the individual's criminal history, if any; (d...

10 CFR 26.111 - Checking the acceptability of the urine specimen.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Checking the acceptability of the urine specimen. 26.111 Section 26.111 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.111 Checking the acceptability of the urine specimen. (a) Immediately after the donor...

10 CFR 26.111 - Checking the acceptability of the urine specimen.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Checking the acceptability of the urine specimen. 26.111 Section 26.111 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for Testing § 26.111 Checking the acceptability of the urine specimen. (a) Immediately after the donor...

Runtime Analysis of Linear Temporal Logic Specifications

NASA Technical Reports Server (NTRS)

Giannakopoulou, Dimitra; Havelund, Klaus

2001-01-01

This report presents an approach to checking a running program against its Linear Temporal Logic (LTL) specifications. LTL is a widely used logic for expressing properties of programs viewed as sets of executions. Our approach consists of translating LTL formulae to finite-state automata, which are used as observers of the program behavior. The translation algorithm we propose modifies standard LTL to B chi automata conversion techniques to generate automata that check finite program traces. The algorithm has been implemented in a tool, which has been integrated with the generic JPaX framework for runtime analysis of Java programs.

Critically safe volume vacuum pickup for use in wet or dry cleanup of radioactive enclosures

DOEpatents

Zeren, J.D.

1993-12-28

A physical compact vacuum pickup device of critically safe volume and geometric shape is provided for use in radioactive enclosures, such as a small glove box, to facilitate manual cleanup of either wet or dry radioactive material. The device is constructed and arranged so as to remain safe when filled to capacity with plutonium-239 oxide. Two fine mesh filter bags are supported on the exterior of a rigid fine mesh stainless steel cup. This assembly is sealed within, and spaced from, the interior walls of a stainless steel canister. An air inlet communicates with the interior of the canister. A modified conventional vacuum head is physically connected to, and associated with, the interior of the mesh cup. The volume of the canister, as defined by the space between the mesh cup and the interior walls of the canister, forms a critically safe volume and geometric shape for dry radioactive particles that are gathered within the canister. A critically safe liquid volume is maintained by operation of a suction terminating float valve, and/or by operation of redundant vacuum check/liquid drain valves and placement of the air inlet. 5 figures.

Critically safe volume vacuum pickup for use in wet or dry cleanup of radioactive enclosures

DOEpatents

Zeren, Joseph D.

1993-12-28

A physical compact vacuum pickup device of critically safe volume and geometric shape is provided for use in radioactive enclosures, such as a small glove box, to facilitate manual cleanup of either wet or dry radioactive material. The device is constructed and arranged so as to remain safe when filled to capacity with plutonium-239 oxide. Two fine mesh filter bags are supported on the exterior of a rigid fine mesh stainless steel cup. This assembly is sealed within, and spaced from, the interior walls of a stainless steel canister. An air inlet communicates with the interior of the canister. A modified conventional vacuum head is physically connected to, and associated with, the interior of the mesh cup. The volume of the canister, as defined by the space between the mesh cup and the interior walls of the canister, forms a critically safe volume and geometric shape for dry radioactive particles that are gathered within the canister. A critically safe liquid volume is maintained by operation of a suction terminating float valve, and/or by operation of redundant vacuum check/liquid drain valves and placement of the air inlet.

Shuttle Gaseous Hydrogen Venting Risk from Flow Control Valve Failure

NASA Technical Reports Server (NTRS)

Drummond, J. Philip; Baurle, Robert A.; Gafney, Richard L.; Norris, Andrew T.; Pellett, Gerald L.; Rock, Kenneth E.

2009-01-01

This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.

CheckDen, a program to compute quantum molecular properties on spatial grids.

PubMed

Pacios, Luis F; Fernandez, Alberto

2009-09-01

CheckDen, a program to compute quantum molecular properties on a variety of spatial grids is presented. The program reads as unique input wavefunction files written by standard quantum packages and calculates the electron density rho(r), promolecule and density difference function, gradient of rho(r), Laplacian of rho(r), information entropy, electrostatic potential, kinetic energy densities G(r) and K(r), electron localization function (ELF), and localized orbital locator (LOL) function. These properties can be calculated on a wide range of one-, two-, and three-dimensional grids that can be processed by widely used graphics programs to render high-resolution images. CheckDen offers also other options as extracting separate atom contributions to the property computed, converting grid output data into CUBE and OpenDX volumetric data formats, and perform arithmetic combinations with grid files in all the recognized formats.

Assembly and method for testing the integrity of stuffing tubes

DOEpatents

Morrison, E.F.

1997-08-26

A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally there along and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube. 5 figs.

Development of a thermodynamic model for a cold cycle 3He-4He dilution refrigerator

NASA Astrophysics Data System (ADS)

Mueller, B. W.; Miller, F. K.

2016-10-01

A thermodynamic model of a 3He-4He cold cycle dilution refrigerator with no actively-driven mechanical components is developed and investigated. The refrigerator employs a reversible superfluid magnetic pump, passive check valves, a phase separation chamber, and a series of recuperative heat exchangers to continuously circulate 3He-4He and maintain a 3He concentration gradient across the mixing chamber. The model predicts cooling power and mixing chamber temperature for a range of design and operating parameters, allowing an evaluation of feasibility for potential 3He-4He cold cycle dilution refrigerator prototype designs. Model simulations for a prototype refrigerator design are presented.

Some Characteristics of Fuel Sprays from Open Nozzles

NASA Technical Reports Server (NTRS)

Rothrock, A M; Lee, D W

1930-01-01

The penetration and cone-angle of fuel sprays from open nozzles were recorded with the NACA Spray Photography Equipment. The results show that for injection systems in which the rate of pressure rise at the discharge orifice is high, open nozzles give spray-tip velocities and penetrations which compare favorably with those of closed nozzles. The spray cone-angle was the same for all tests, although open nozzles having different orifice diameters were used, and one nozzle was used both as an open and as a closed nozzle. In designing a fuel system using open nozzles, particular care must be taken to avoid air pockets. The check valve should be placed close to the discharge orifice.

Performance Qualification Test of the ISS Water Processor Assembly (WPA) Expendables

NASA Technical Reports Server (NTRS)

Carter, Layne; Tabb, David; Tatara, James D.; Mason, Richard K.

2005-01-01

The Water Processor Assembly (WPA) for use on the International Space Station (ISS) includes various technologies for the treatment of waste water. These technologies include filtration, ion exchange, adsorption, catalytic oxidation, and iodination. The WPA hardware implementing portions of these technologies, including the Particulate Filter, Multifiltration Bed, Ion Exchange Bed, and Microbial Check Valve, was recently qualified for chemical performance at the Marshall Space Flight Center. Waste water representing the quality of that produced on the ISS was generated by test subjects and processed by the WPA. Water quality analysis and instrumentation data was acquired throughout the test to monitor hardware performance. This paper documents operation of the test and the assessment of the hardware performance.

Description of a new species of the costata-group (Cladocera, Chydoridae, Aloninae) from Brazil.

PubMed

Sousa, Francisco Diogo R; Santos, Sandro; Güntzel, Adriana Maria; Diniz, Leidiane Pereira; De Melo Júnior, Mauro; Elmoor-Loureiro, Lourdes M A

2015-11-12

The aim of this study is to describe a new species of the costata-group from Brazil. Alona margipluma sp. nov. shares morphological traits with A. costata Sars, 1862, A. natalensis Sinev, 2008, and A. cheni Sinev, 1999, but differs from them in: (i) thin setulae between the marginal setae on the valves, (ii) setae 4-5 on the exopodite of limb III long and different in length, (iii) bottle-shaped sensillum on the basal endite of limb IV. For identification of Alona margipluma sp. nov. it is necessary to check carefully the main head pores and postabdomen characters since the former superficially resemble A. iheringula, A. setigera and Alona guttata.

Effects of the "Behavior Education Program" (BEP) on Office Discipline Referrals of Elementary School Students

ERIC Educational Resources Information Center

Hawken, Leanne S.; Sandra MacLeod, K.; Rawlings, Linda

2007-01-01

The "Behavior Education Program" (BEP; Crone et al., 2004) is a modified check-in, check-out intervention implemented with students who are at risk for more severe problem behaviors. The purpose of this study was to evaluate the effects of the BEP on problem behavior with 12 elementary school students. Results indicated that the BEP was…

Referral to Cardiac Rehabilitation After Percutaneous Coronary Intervention, Coronary Artery Bypass Surgery, and Valve Surgery: Data From the Clinical Outcomes Assessment Program.

PubMed

Beatty, Alexis L; Bradley, Steven M; Maynard, Charles; McCabe, James M

2017-06-01

Despite guideline recommendations that patients undergoing percutaneous coronary intervention (PCI), coronary artery bypass surgery, or valve surgery be referred to cardiac rehabilitation, cardiac rehabilitation is underused. The objective of this study was to examine hospital-level variation in cardiac rehabilitation referral after PCI, coronary artery bypass surgery, and valve surgery. We analyzed data from the Clinical Outcomes Assessment Program, a registry of all nonfederal hospitals performing PCI and cardiac surgery in Washington State. We included eligible PCI, coronary artery bypass surgery, and valve surgery patients from 2010 to 2015. We analyzed PCI and cardiac surgery separately by performing multivariable hierarchical logistic regression for the outcome of cardiac rehabilitation referral at discharge, clustered by hospital. Patient-level covariates included age, sex, race/ethnicity, comorbidities, and procedure indication/status. Cardiac rehabilitation referral was reported in 48% (34 047/71 556) of PCI patients and 91% (21 831/23 972) of cardiac surgery patients. The hospital performing the procedure was a stronger predictor of referral than any individual patient characteristic for PCI (hospital referral range 3%-97%; median odds ratio, 5.94; 95% confidence interval, 4.10-9.49) and cardiac surgery (range 54%-100%; median odds ratio, 7.09; 95% confidence interval, 3.79-17.80). Hospitals having an outpatient cardiac rehabilitation program explained only 10% of PCI variation and 0% of cardiac surgery variation. Cardiac rehabilitation referral at discharge was less prevalent after PCI than cardiac surgery. The strongest predictor of cardiac rehabilitation referral was the hospital performing the procedure. Efforts to improve cardiac rehabilitation referral should focus on increasing referral after PCI, especially in low referral hospitals. © 2017 American Heart Association, Inc.

Generalized Symbolic Execution for Model Checking and Testing

NASA Technical Reports Server (NTRS)

Khurshid, Sarfraz; Pasareanu, Corina; Visser, Willem; Kofmeyer, David (Technical Monitor)

2003-01-01

Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. We present a novel framework based on symbolic execution, for automated checking of such systems. We provide a two-fold generalization of traditional symbolic execution based approaches: one, we define a program instrumentation, which enables standard model checkers to perform symbolic execution; two, we give a novel symbolic execution algorithm that handles dynamically allocated structures (e.g., lists and trees), method preconditions (e.g., acyclicity of lists), data (e.g., integers and strings) and concurrency. The program instrumentation enables a model checker to automatically explore program heap configurations (using a systematic treatment of aliasing) and manipulate logical formulae on program data values (using a decision procedure). We illustrate two applications of our framework: checking correctness of multi-threaded programs that take inputs from unbounded domains with complex structure and generation of non-isomorphic test inputs that satisfy a testing criterion. Our implementation for Java uses the Java PathFinder model checker.

A Categorization of Dynamic Analyzers

NASA Technical Reports Server (NTRS)

Lujan, Michelle R.

1997-01-01

Program analysis techniques and tools are essential to the development process because of the support they provide in detecting errors and deficiencies at different phases of development. The types of information rendered through analysis includes the following: statistical measurements of code, type checks, dataflow analysis, consistency checks, test data,verification of code, and debugging information. Analyzers can be broken into two major categories: dynamic and static. Static analyzers examine programs with respect to syntax errors and structural properties., This includes gathering statistical information on program content, such as the number of lines of executable code, source lines. and cyclomatic complexity. In addition, static analyzers provide the ability to check for the consistency of programs with respect to variables. Dynamic analyzers in contrast are dependent on input and the execution of a program providing the ability to find errors that cannot be detected through the use of static analysis alone. Dynamic analysis provides information on the behavior of a program rather than on the syntax. Both types of analysis detect errors in a program, but dynamic analyzers accomplish this through run-time behavior. This paper focuses on the following broad classification of dynamic analyzers: 1) Metrics; 2) Models; and 3) Monitors. Metrics are those analyzers that provide measurement. The next category, models, captures those analyzers that present the state of the program to the user at specified points in time. The last category, monitors, checks specified code based on some criteria. The paper discusses each classification and the techniques that are included under them. In addition, the role of each technique in the software life cycle is discussed. Familiarization with the tools that measure, model and monitor programs provides a framework for understanding the program's dynamic behavior from different, perspectives through analysis of the input/output data.

Verification and Planning Based on Coinductive Logic Programming

NASA Technical Reports Server (NTRS)

Bansal, Ajay; Min, Richard; Simon, Luke; Mallya, Ajay; Gupta, Gopal

2008-01-01

Coinduction is a powerful technique for reasoning about unfounded sets, unbounded structures, infinite automata, and interactive computations [6]. Where induction corresponds to least fixed point's semantics, coinduction corresponds to greatest fixed point semantics. Recently coinduction has been incorporated into logic programming and an elegant operational semantics developed for it [11, 12]. This operational semantics is the greatest fix point counterpart of SLD resolution (SLD resolution imparts operational semantics to least fix point based computations) and is termed co- SLD resolution. In co-SLD resolution, a predicate goal p( t) succeeds if it unifies with one of its ancestor calls. In addition, rational infinite terms are allowed as arguments of predicates. Infinite terms are represented as solutions to unification equations and the occurs check is omitted during the unification process. Coinductive Logic Programming (Co-LP) and Co-SLD resolution can be used to elegantly perform model checking and planning. A combined SLD and Co-SLD resolution based LP system forms the common basis for planning, scheduling, verification, model checking, and constraint solving [9, 4]. This is achieved by amalgamating SLD resolution, co-SLD resolution, and constraint logic programming [13] in a single logic programming system. Given that parallelism in logic programs can be implicitly exploited [8], complex, compute-intensive applications (planning, scheduling, model checking, etc.) can be executed in parallel on multi-core machines. Parallel execution can result in speed-ups as well as in larger instances of the problems being solved. In the remainder we elaborate on (i) how planning can be elegantly and efficiently performed under real-time constraints, (ii) how real-time systems can be elegantly and efficiently model- checked, as well as (iii) how hybrid systems can be verified in a combined system with both co-SLD and SLD resolution. Implementations of co-SLD resolution as well as preliminary implementations of the planning and verification applications have been developed [4]. Co-LP and Model Checking: The vast majority of properties that are to be verified can be classified into safety properties and liveness properties. It is well known within model checking that safety properties can be verified by reachability analysis, i.e, if a counter-example to the property exists, it can be finitely determined by enumerating all the reachable states of the Kripke structure.

A Mixed-Method Efficacy and Fidelity Study of Check and Connect

ERIC Educational Resources Information Center

Powers, Kristin; Hagans, Kristi; Linn, Megan

2017-01-01

The effectiveness of the Check and Connect dropout prevention program was examined, over the course of 2.5 years, with 54 middle school students from diverse backgrounds experiencing one or more conditions of risk for dropout. Participants were randomly assigned to receive the Check and Connect intervention or business as usual (i.e., control) in…

40 CFR 86.322-79 - NDIR CO2 rejection ratio check.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false NDIR CO2 rejection ratio check. 86.322... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission....322-79 NDIR CO2 rejection ratio check. (a) Zero and span the analyzer on the lowest range that will be...

40 CFR 86.322-79 - NDIR CO2 rejection ratio check.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false NDIR CO2 rejection ratio check. 86.322... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission....322-79 NDIR CO2 rejection ratio check. (a) Zero and span the analyzer on the lowest range that will be...

40 CFR 86.322-79 - NDIR CO2 rejection ratio check.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false NDIR CO2 rejection ratio check. 86.322... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission....322-79 NDIR CO2 rejection ratio check. (a) Zero and span the analyzer on the lowest range that will be...

40 CFR 86.322-79 - NDIR CO2 rejection ratio check.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false NDIR CO2 rejection ratio check. 86.322... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission....322-79 NDIR CO2 rejection ratio check. (a) Zero and span the analyzer on the lowest range that will be...

GUI for Computational Simulation of a Propellant Mixer

NASA Technical Reports Server (NTRS)

Figueroa, Fernando; Richter, Hanz; Barbieri, Enrique; Granger, Jamie

2005-01-01

Control Panel is a computer program that generates a graphical user interface (GUI) for computational simulation of a rocket-test-stand propellant mixer in which gaseous hydrogen (GH2) is injected into flowing liquid hydrogen (LH2) to obtain a combined flow having desired thermodynamic properties. The GUI is used in conjunction with software that models the mixer as a system having three inputs (the positions of the GH2 and LH2 inlet valves and an outlet valve) and three outputs (the pressure inside the mixer and the outlet flow temperature and flow rate). The user can specify valve characteristics and thermodynamic properties of the input fluids via userfriendly dialog boxes. The user can enter temporally varying input values or temporally varying desired output values. The GUI provides (1) a set-point calculator function for determining fixed valve positions that yield desired output values and (2) simulation functions that predict the response of the mixer to variations in the properties of the LH2 and GH2 and manual- or feedback-control variations in valve positions. The GUI enables scheduling of a sequence of operations that includes switching from manual to feedback control when a certain event occurs.

Using State Merging and State Pruning to Address the Path Explosion Problem Faced by Symbolic Execution

DTIC Science & Technology

2014-06-19

urgent and compelling. Recent efforts in this area automate program analysis techniques using model checking and symbolic execution [2, 5–7]. These...bounded model checking tool for x86 binary programs developed at the Air Force Institute of Technology (AFIT). Jiseki creates a bit-vector logic model based...assume there are n different paths through the function foo . The program could potentially call the function foo a bound number of times, resulting in n

PIV measurements of in-cylinder, large-scale structures in a water-analogue Diesel engine

NASA Astrophysics Data System (ADS)

Kalpakli Vester, A.; Nishio, Y.; Alfredsson, P. H.

2016-11-01

Swirl and tumble are large-scale structures that develop in an engine cylinder during the intake stroke. Their structure and strength depend on the design of the inlet ports and valves, but also on the valve lift history. Engine manufacturers make their design to obtain a specific flow structure that is assumed to give the best engine performance. Despite many efforts, there are still open questions, such as how swirl and tumble depend on the dynamics of the valves/piston as well as how cycle-to-cycle variations should be minimized. In collaboration with Swedish vehicle industry we perform PIV measurements of the flow dynamics during the intake stroke inside a cylinder of a water-analogue engine model having the same geometrical characteristics as a typical truck Diesel engine. Water can be used since during the intake stroke the flow is nearly incompressible. The flow from the valves moves radially outwards, hits the vertical walls of the cylinder, entrains surrounding fluid, moves along the cylinder walls and creates a central backflow, i.e. a tumble motion. Depending on the port and valve design and orientation none, low, or high swirl can be established. For the first time, the effect of the dynamic motion of the piston/valves on the large-scale structures is captured. Supported by the Swedish Energy Agency, Scania CV AB and Volvo GTT, through the FFI program.

Coupled rotor/airframe vibration analysis program manual. Volume 2: Sample input and output listings

NASA Technical Reports Server (NTRS)

Cassarino, S.; Sopher, R.

1982-01-01

Sample input and output listings obtained with the base program (SIMVIB) of the coupled rotor/airframe vibration analysis and the external programs, G400/F389 and E927 are presented. Results for five of the base program test cases are shown. They represent different applications of the SIMVIB program to study the vibration characteristics of various dynamic configurations. Input and output listings obtained for one cycle of the G400/F389 coupled program are presented. Results from the rotor aeroelastic analysis E927 also appear. A brief description of the check cases is provided. A summary of the check cases for all the external programs interacting with the SIMVIB program is illustrated.

Health care-associated native valve endocarditis: importance of non-nosocomial acquisition.

PubMed

Benito, Natividad; Miró, José M; de Lazzari, Elisa; Cabell, Christopher H; del Río, Ana; Altclas, Javier; Commerford, Patrick; Delahaye, Francois; Dragulescu, Stefan; Giamarellou, Helen; Habib, Gilbert; Kamarulzaman, Adeeba; Kumar, A Sampath; Nacinovich, Francisco M; Suter, Fredy; Tribouilloy, Christophe; Venugopal, Krishnan; Moreno, Asuncion; Fowler, Vance G

2009-05-05

The clinical profile and outcome of nosocomial and non-nosocomial health care-associated native valve endocarditis are not well defined. To compare the characteristics and outcomes of community-associated and nosocomial and non-nosocomial health care-associated native valve endocarditis. Prospective cohort study. 61 hospitals in 28 countries. Patients with definite native valve endocarditis and no history of injection drug use who were enrolled in the ICE-PCS (International Collaboration on Endocarditis Prospective Cohort Study) from June 2000 to August 2005. Clinical and echocardiographic findings, microbiology, complications, and mortality. Health care-associated native valve endocarditis was present in 557 (34%) of 1622 patients (303 with nosocomial infection [54%] and 254 with non-nosocomial infection [46%]). Staphylococcus aureus was the most common cause of health care-associated infection (nosocomial, 47%; non-nosocomial, 42%; P = 0.30); a high proportion of patients had methicillin-resistant S. aureus (nosocomial, 57%; non-nosocomial, 41%; P = 0.014). Fewer patients with health care-associated native valve endocarditis had cardiac surgery (41% vs. 51% of community-associated cases; P < 0.001), but more of the former patients died (25% vs. 13%; P < 0.001). Multivariable analysis confirmed greater mortality associated with health care-associated native valve endocarditis (incidence risk ratio, 1.28 [95% CI, 1.02 to 1.59]). Patients were treated at hospitals with cardiac surgery programs. The results may not be generalizable to patients receiving care in other types of facilities or to those with prosthetic valves or past injection drug use. More than one third of cases of native valve endocarditis in non-injection drug users involve contact with health care, and non-nosocomial infection is common, especially in the United States. Clinicians should recognize that outpatients with extensive out-of-hospital health care contacts who develop endocarditis have clinical characteristics and outcomes similar to those of patients with nosocomial infection. None.

Halon Replacement Program for Aviation, Aircraft Engine Nacelle Application Phase II - Operational Comparison of Selected Extinguishants

DTIC Science & Technology

1997-05-01

Control Butterfly Hi-Pressure High Flow Control Butterfly Ejector Primary Clycol Control Valve Scrubber Fan Pressure Control Butterfly 8" Venturi ...the scrubber . 20 ■ SCRUBBER FAN BLOWER INLET VALVE VP-2 VP-3 VP-4 VP-5 VP-6 VP-7 VP-8 VP-9 VP-10 SV-1 SV-2 DESCRIPTION Atmospheric...Blower Bypass Butterfly 24" Venturi Control Butterfly 24" Test Section Exit Butterfly Ejector 10’ Secondary Inlet-Butterfly Hi-pressure Low Flow

The European Office of Aerospace Research and Development’s Small Satellite Propulsion System Research Program

DTIC Science & Technology

2000-04-12

Investigation S..showed that the pressure reading saturated at 13 bar (maximum limit) compared to 10 bar which the pressure switch should have...controlled to. It was concluded that the commercial grade pressure switch had failed and that the pressure Figure 5: Nitrous Oxide feed system control valve...firing on 11 th April 2000. The performance using a pressure switch to control a solenoid results of this firing are shown in Figure 7. valve giving

Failure Analysis of Fractured Poppet from Space Shuttle Orbiter Flow Control Valve

NASA Technical Reports Server (NTRS)

Russell, Richard

2010-01-01

This slide presentation reviews the failure analysis of a fractured poppet from a flow control valve (FCV) used on the space shuttle. This presentation has focused on the laboratory analysis of the failed hardware. The use of Scanning electron fractography during the investigation led to the conclusion that the poppet failed due to fatigue cracking that, most likely, occurred under changing loading conditions. The initial investigation led to a more thorough test of poppets that had been retired, this testing led to the conclusion that the thumbnail cracks in the flight hardware had existed for the life of the shuttle program. This led to a program to develop an eddy current technique that was capable of detecting small very tight cracks.

Alternative Fuels Data Center

Science.gov Websites

AirCheckTexas Drive a Clean Machine program, which provides vehicle replacement assistance for qualified requirements, and how to apply in specific areas, see the AirCheckTexas Drive a Clean Machine website

Random Testing and Model Checking: Building a Common Framework for Nondeterministic Exploration

NASA Technical Reports Server (NTRS)

Groce, Alex; Joshi, Rajeev

2008-01-01

Two popular forms of dynamic analysis, random testing and explicit-state software model checking, are perhaps best viewed as search strategies for exploring the state spaces introduced by nondeterminism in program inputs. We present an approach that enables this nondeterminism to be expressed in the SPIN model checker's PROMELA language, and then lets users generate either model checkers or random testers from a single harness for a tested C program. Our approach makes it easy to compare model checking and random testing for models with precisely the same input ranges and probabilities and allows us to mix random testing with model checking's exhaustive exploration of non-determinism. The PROMELA language, as intended in its design, serves as a convenient notation for expressing nondeterminism and mixing random choices with nondeterministic choices. We present and discuss a comparison of random testing and model checking. The results derive from using our framework to test a C program with an effectively infinite state space, a module in JPL's next Mars rover mission. More generally, we show how the ability of the SPIN model checker to call C code can be used to extend SPIN's features, and hope to inspire others to use the same methods to implement dynamic analyses that can make use of efficient state storage, matching, and backtracking.

CheckMATE 2: From the model to the limit

NASA Astrophysics Data System (ADS)

Dercks, Daniel; Desai, Nishita; Kim, Jong Soo; Rolbiecki, Krzysztof; Tattersall, Jamie; Weber, Torsten

2017-12-01

We present the latest developments to the CheckMATE program that allows models of new physics to be easily tested against the recent LHC data. To achieve this goal, the core of CheckMATE now contains over 60 LHC analyses of which 12 are from the 13 TeV run. The main new feature is that CheckMATE 2 now integrates the Monte Carlo event generation via MadGraph5_aMC@NLO and Pythia 8. This allows users to go directly from a SLHA file or UFO model to the result of whether a model is allowed or not. In addition, the integration of the event generation leads to a significant increase in the speed of the program. Many other improvements have also been made, including the possibility to now combine signal regions to give a total likelihood for a model.

The instant sequencing task: Toward constraint-checking a complex spacecraft command sequence interactively

NASA Technical Reports Server (NTRS)

Horvath, Joan C.; Alkalaj, Leon J.; Schneider, Karl M.; Amador, Arthur V.; Spitale, Joseph N.

1993-01-01

Robotic spacecraft are controlled by sets of commands called 'sequences.' These sequences must be checked against mission constraints. Making our existing constraint checking program faster would enable new capabilities in our uplink process. Therefore, we are rewriting this program to run on a parallel computer. To do so, we had to determine how to run constraint-checking algorithms in parallel and create a new method of specifying spacecraft models and constraints. This new specification gives us a means of representing flight systems and their predicted response to commands which could be used in a variety of applications throughout the command process, particularly during anomaly or high-activity operations. This commonality could reduce operations cost and risk for future complex missions. Lessons learned in applying some parts of this system to the TOPEX/Poseidon mission will be described.

Network Flow Simulation of Fluid Transients in Rocket Propulsion Systems

NASA Technical Reports Server (NTRS)

Bandyopadhyay, Alak; Hamill, Brian; Ramachandran, Narayanan; Majumdar, Alok

2011-01-01

Fluid transients, also known as water hammer, can have a significant impact on the design and operation of both spacecraft and launch vehicle propulsion systems. These transients often occur at system activation and shutdown. The pressure rise due to sudden opening and closing of valves of propulsion feed lines can cause serious damage during activation and shutdown of propulsion systems. During activation (valve opening) and shutdown (valve closing), pressure surges must be predicted accurately to ensure structural integrity of the propulsion system fluid network. In the current work, a network flow simulation software (Generalized Fluid System Simulation Program) based on Finite Volume Method has been used to predict the pressure surges in the feed line due to both valve closing and valve opening using two separate geometrical configurations. The valve opening pressure surge results are compared with experimental data available in the literature and the numerical results compared very well within reasonable accuracy (< 5%) for a wide range of inlet-to-initial pressure ratios. A Fast Fourier Transform is preformed on the pressure oscillations to predict the various modal frequencies of the pressure wave. The shutdown problem, i.e. valve closing problem, the simulation results are compared with the results of Method of Characteristics. Most rocket engines experience a longitudinal acceleration, known as "pogo" during the later stage of engine burn. In the shutdown example problem, an accumulator has been used in the feed system to demonstrate the "pogo" mitigation effects in the feed system of propellant. The simulation results using GFSSP compared very well with the results of Method of Characteristics.

Failure and life cycle evaluation of watering valves.

PubMed

Gonzalez, David M; Graciano, Sandy J; Karlstad, John; Leblanc, Mathias; Clark, Tom; Holmes, Scott; Reuter, Jon D

2011-09-01

Automated watering systems provide a reliable source of ad libitum water to animal cages. Our facility uses an automated water delivery system to support approximately 95% of the housed population (approximately 14,000 mouse cages). Drinking valve failure rates from 2002 through 2006 never exceeded the manufacturer standard of 0.1% total failure, based on monthly cage census and the number of floods. In 2007, we noted an increase in both flooding and cases of clinical dehydration in our mouse population. Using manufacturer's specifications for a water flow rate of 25 to 50 mL/min, we initiated a wide-scale screening of all valves used. During a 4-mo period, approximately 17,000 valves were assessed, of which 2200 failed according to scoring criteria (12.9% overall; 7.2% low flow; 1.6% no flow; 4.1% leaky). Factors leading to valve failures included residual metal shavings, silicone flash, introduced debris or bedding, and (most common) distortion of the autoclave-rated internal diaphragm and O-ring. Further evaluation revealed that despite normal autoclave conditions of heat, pressure, and steam, an extreme negative vacuum pull caused the valves' internal silicone components (diaphragm and O-ring) to become distorted and water-permeable. Normal flow rate often returned after a 'drying out' period, but components then reabsorbed water while on the animal rack or during subsequent autoclave cycles to revert to a variable flow condition. On the basis of our findings, we recalibrated autoclaves and initiated a preventative maintenance program to mitigate the risk of future valve failure.

Analytical solution and numerical study on water hammer in a pipeline closed with an elastically attached valve

NASA Astrophysics Data System (ADS)

Henclik, Sławomir

2018-03-01

The influence of dynamic fluid-structure interaction (FSI) onto the course of water hammer (WH) can be significant in non-rigid pipeline systems. The essence of this effect is the dynamic transfer of liquid energy to the pipeline structure and back, which is important for elastic structures and can be negligible for rigid ones. In the paper a special model of such behavior is analyzed. A straight pipeline with a steady flow, fixed to the floor with several rigid supports is assumed. The transient is generated by a quickly closed valve installed at the end of the pipeline. FSI effects are assumed to be present mainly at the valve which is fixed with a spring dash-pot attachment. Analysis of WH runs, especially transient pressure changes, for various stiffness and damping parameters of the spring dash-pot valve attachment is presented in the paper. The solutions are found analytically and numerically. Numerical results have been computed with the use of an own computer program developed on the basis of the four equation model of WH-FSI and the specific boundary conditions formulated at the valve. Analytical solutions have been found with the separation of variables method for slightly simplified assumptions. Damping at the dash-pot is taken into account within the numerical study. The influence of valve attachment parameters onto the WH courses was discovered and it was found the transient amplitudes can be reduced. Such a system, elastically attached shut-off valve in a pipeline or other, equivalent design can be a real solution applicable in practice.

An Investigation of the Impact of Function of Problem Behavior on Effectiveness of the Behavior Education Program (BEP)

ERIC Educational Resources Information Center

Hawken, Leanne S.; O'Neill, Robert E.; MacLeod, K. Sandra

2011-01-01

The Behavior Education Program (BEP) is a check-in, check-out intervention implemented with students who are at-risk for engaging in more severe problem behavior. Previous research with middle and elementary school students found that the BEP was more effective with students who had adult attention maintained problem behavior. The purposes of this…

Evaluating the accuracy of technicians and pharmacists in checking unit dose medication cassettes.

PubMed

Ambrose, Peter J; Saya, Frank G; Lovett, Larry T; Tan, Sandy; Adams, Dale W; Shane, Rita

2002-06-15

The accuracy rates of board-registered pharmacy technicians and pharmacists in checking unit dose medication cassettes in the inpatient setting at two separate institutions were examined. Cedars-Sinai Medical Center and Long Beach Memorial Medical Center, both in Los Angeles county, petitioned the California State Board of Pharmacy to approve a waiver of the California Code of Regulations to conduct an experimental program to compare the accuracy of unit dose medication cassettes checked by pharmacists with that of cassettes checked by trained, certified pharmacy technicians. The study consisted of three parts: assessing pharmacist baseline checking accuracy (Phase I), developing a technician-training program and certifying technicians who completed the didactic and practical training (Phase II), and evaluating the accuracy of certified technicians checking unit dose medication cassettes as a daily function (Phase III). Twenty-nine pharmacists and 41 technicians (3 of whom were pharmacy interns) participated in the study. Of the technicians, all 41 successfully completed the didactic and practical training, 39 successfully completed the audits and became certified checkers, and 2 (including 1 of the interns) did not complete the certification audits because they were reassigned to another work area or had resigned. In Phase II, the observed accuracy rate and its lower confidence limit exceeded the predetermined minimum requirement of 99.8% for a certified checker. The mean accuracy rates for technicians were identical at the two institutions (p = 1.0). The difference in mean accuracy rates between pharmacists (99.52%; 95% confidence interval [CI] 99.44-99.58%) and technicians, (99.89%; 95% CI 99.87-99.90%) was significant (p < 0.0001). Inpatient technicians who had been trained and certified in a closely supervised program that incorporated quality assurance mechanisms could safely and accurately check unit dose medication cassettes filled by other technicians.

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR FORM QA AND QC CHECKS (UA-C-2.0)

EPA Science Inventory

The purpose of this SOP is to outline the process of field quality assurance and quality control checks. This procedure was followed to ensure consistent data retrieval during the Arizona NHEXAS project and the Border study. Keywords: custody; QA/QC; field checks.

The U.S.-Mex...

Integration of Computer-Based Virtual Check Ride System--Pre-Trip Inspection in Commercial Driver License Training Program

ERIC Educational Resources Information Center

Makwana, Alpesh P.

2009-01-01

"Pre-Trip Inspection" of the truck and trailer is one of the components of the current Commercial Driver's License (CDL) test. This part of the CDL test checks the ability of the student to identify the important parts of the commercial vehicle and their potential defects. The "Virtual Check Ride System" (VCRS), a…

Design of experiments enhanced statistical process control for wind tunnel check standard testing

NASA Astrophysics Data System (ADS)

Phillips, Ben D.

The current wind tunnel check standard testing program at NASA Langley Research Center is focused on increasing data quality, uncertainty quantification and overall control and improvement of wind tunnel measurement processes. The statistical process control (SPC) methodology employed in the check standard testing program allows for the tracking of variations in measurements over time as well as an overall assessment of facility health. While the SPC approach can and does provide researchers with valuable information, it has certain limitations in the areas of process improvement and uncertainty quantification. It is thought by utilizing design of experiments methodology in conjunction with the current SPC practices that one can efficiently and more robustly characterize uncertainties and develop enhanced process improvement procedures. In this research, methodologies were developed to generate regression models for wind tunnel calibration coefficients, balance force coefficients and wind tunnel flow angularities. The coefficients of these regression models were then tracked in statistical process control charts, giving a higher level of understanding of the processes. The methodology outlined is sufficiently generic such that this research can be applicable to any wind tunnel check standard testing program.

Variable Step Integration Coupled with the Method of Characteristics Solution for Water-Hammer Analysis, A Case Study

NASA Technical Reports Server (NTRS)

Turpin, Jason B.

2004-01-01

One-dimensional water-hammer modeling involves the solution of two coupled non-linear hyperbolic partial differential equations (PDEs). These equations result from applying the principles of conservation of mass and momentum to flow through a pipe, and usually the assumption that the speed at which pressure waves propagate through the pipe is constant. In order to solve these equations for the interested quantities (i.e. pressures and flow rates), they must first be converted to a system of ordinary differential equations (ODEs) by either approximating the spatial derivative terms with numerical techniques or using the Method of Characteristics (MOC). The MOC approach is ideal in that no numerical approximation errors are introduced in converting the original system of PDEs into an equivalent system of ODEs. Unfortunately this resulting system of ODEs is bound by a time step constraint so that when integrating the equations the solution can only be obtained at fixed time intervals. If the fluid system to be modeled also contains dynamic components (i.e. components that are best modeled by a system of ODEs), it may be necessary to take extremely small time steps during certain points of the model simulation in order to achieve stability and/or accuracy in the solution. Coupled together, the fixed time step constraint invoked by the MOC, and the occasional need for extremely small time steps in order to obtain stability and/or accuracy, can greatly increase simulation run times. As one solution to this problem, a method for combining variable step integration (VSI) algorithms with the MOC was developed for modeling water-hammer in systems with highly dynamic components. A case study is presented in which reverse flow through a dual-flapper check valve introduces a water-hammer event. The predicted pressure responses upstream of the check-valve are compared with test data.

Notification: Purchase Card and Convenience Check Audit

EPA Pesticide Factsheets

Project #OA-FY13-0116, April 11, 2013. The U.S. Environmental Protection Agency, Office of Inspector General, is beginning the fieldwork phase of its audit of the agency’s purchase card and convenience check programs.

Compressed air demand-type firefighter's breathing system, volume 1. [design analysis and performance tests

NASA Technical Reports Server (NTRS)

Sullivan, J. L.

1975-01-01

The commercial availability of lightweight high pressure compressed air vessels has resulted in a lightweight firefighter's breathing apparatus. The improved apparatus, and details of its design and development are described. The apparatus includes a compact harness assembly, a backplate mounted pressure reducer assembly, a lightweight bubble-type facemask with a mask mounted demand breathing regulator. Incorporated in the breathing regulator is exhalation valve, a purge valve and a whistle-type low pressure warning that sounds only during inhalation. The pressure reducer assembly includes two pressure reducers, an automatic transfer valve and a signaling device for the low pressure warning. Twenty systems were fabricated, tested, refined through an alternating development and test sequence, and extensively examined in a field evaluation program. Photographs of the apparatus are included.

Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions

PubMed Central

Lee, Jong-Beom; Ahn, Ho-Young; Lee, Hong-Jae; Yang, Ji-Ho; Yi, Jin-Seok; Lee, Il-Woo

2017-01-01

Objective The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. Methods We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. Results The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH2O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was −3.69±19.20 mmH2O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH2O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH2O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. Conclusion Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH2O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made. PMID:28061484

In-patient international normalized ratio self-testing instruction after mechanical heart valve implantation.

PubMed

Thompson, Jess L; Sundt, Thoralf M; Sarano, Maurice E; Santrach, Paula J; Schaff, Hartzell V

2008-06-01

Patient self-testing of the international normalized ratio (INR) has been shown to improve management of anticoagulation with warfarin and reduce risks of thromboembolism and bleeding. Self-testing instruction usually begins several weeks after hospital discharge. We evaluated the feasibility of in-hospital INR self-testing instruction in patients recovering from valve replacement. We instituted an education program on a self-testing device before hospital discharge in 50 adult patients (median age, 54 years; 66% men) undergoing cardiac valve replacement with mechanical prostheses. Patients were monitored for 1 month to assess their ability to self-test and the accuracy of the INR measurements. Self-testing instruction began on postoperative day 4 (range, 1 to 8 days). Each patient had an average of 3.5 teaching sessions; each session lasted approximately 20 minutes. One month after discharge, all patients (98%) but 1 were able to self-test. No patient required interval instruction. One bleeding episode occurred in a patient whose INR exceeded the therapeutic range. Once warfarin doses were stabilized, 5 patients had subtherapeutic INR values on self-testing. The mean INR test result obtained from the coagulometer correlated well with values obtained by laboratory determination (r = 0.79). This evaluation of an in-hospital education program demonstrates that patients are able to learn INR self-testing and that most will continue to use the method without the need for interval instruction. Improved anticoagulation management by early introduction of INR self-testing should reduce thromboembolic and hemorrhagic complications after valve replacement.

Model Checker for Java Programs

NASA Technical Reports Server (NTRS)

Visser, Willem

2007-01-01

Java Pathfinder (JPF) is a verification and testing environment for Java that integrates model checking, program analysis, and testing. JPF consists of a custom-made Java Virtual Machine (JVM) that interprets bytecode, combined with a search interface to allow the complete behavior of a Java program to be analyzed, including interleavings of concurrent programs. JPF is implemented in Java, and its architecture is highly modular to support rapid prototyping of new features. JPF is an explicit-state model checker, because it enumerates all visited states and, therefore, suffers from the state-explosion problem inherent in analyzing large programs. It is suited to analyzing programs less than 10kLOC, but has been successfully applied to finding errors in concurrent programs up to 100kLOC. When an error is found, a trace from the initial state to the error is produced to guide the debugging. JPF works at the bytecode level, meaning that all of Java can be model-checked. By default, the software checks for all runtime errors (uncaught exceptions), assertions violations (supports Java s assert), and deadlocks. JPF uses garbage collection and symmetry reductions of the heap during model checking to reduce state-explosion, as well as dynamic partial order reductions to lower the number of interleavings analyzed. JPF is capable of symbolic execution of Java programs, including symbolic execution of complex data such as linked lists and trees. JPF is extensible as it allows for the creation of listeners that can subscribe to events during searches. The creation of dedicated code to be executed in place of regular classes is supported and allows users to easily handle native calls and to improve the efficiency of the analysis.

42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... rehabilitation treatment, and psychosocial evaluation of the individual's response to and rate of progress under... coronary artery bypass surgery; (iii) Current stable angina pectoris; (iv) Heart valve repair or replacement; (v) Percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting; (vi) A heart or...

42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... rehabilitation treatment, and psychosocial evaluation of the individual's response to and rate of progress under... coronary artery bypass surgery; (iii) Current stable angina pectoris; (iv) Heart valve repair or replacement; (v) Percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting; (vi) A heart or...

42 CFR 410.49 - Cardiac rehabilitation program and intensive cardiac rehabilitation program: Conditions of coverage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... rehabilitation treatment, and psychosocial evaluation of the individual's response to and rate of progress under... coronary artery bypass surgery; (iii) Current stable angina pectoris; (iv) Heart valve repair or replacement; (v) Percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting; (vi) A heart or...

Effectiveness of a national cardiovascular disease risk assessment program (NHS Health Check): results after one year.

PubMed

Artac, Macide; Dalton, Andrew R H; Majeed, Azeem; Car, Josip; Millett, Christopher

2013-08-01

We aimed to assess whether the National Health Service (NHS) Health Check, a systematic cardiovascular disease (CVD) risk assessment and management program, was associated with reduction in CVD risk in attendees after one year. We extracted data from patients aged 40-74 years, with high estimated CVD risk, who were registered with general practices in a deprived, culturally diverse setting in England. We included 4748 patients at baseline (July 2008-November 2009), with 3712 at follow-up (December 2009-March 2011). We used a pre-post study design to assess changes in global CVD risk, individual CVD risk factors and statin prescription in patients with a complete and partial Health Check. There were significant reductions in mean CVD risk score (28.2%; 95% confidence interval (CI)=27.3-29.1 to 26.2%; 95% CI, 25.4-27.1), diastolic blood pressure, total cholesterol levels and lipid ratios after one year in patients with a complete Health Check. Statin prescription increased from 14.0% (95% CI=11.9-16.0) to 60.6% (95% CI=57.7-63.5). The introduction of NHS Health Check was associated with significant but modest reductions in CVD risk among screened high-risk individuals. Further cost-effectiveness analysis and work accounting for uptake is required to assess whether the program can make significant changes to population health. Copyright © 2013 Elsevier Inc. All rights reserved.

Oxygen Generation System Laptop Bus Controller Flight Software

NASA Technical Reports Server (NTRS)

Rowe, Chad; Panter, Donna

2009-01-01

The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.

Method for Statically Checking an Object-oriented Computer Program Module

NASA Technical Reports Server (NTRS)

Bierhoff, Kevin M. (Inventor); Aldrich, Jonathan (Inventor)

2012-01-01

A method for statically checking an object-oriented computer program module includes the step of identifying objects within a computer program module, at least one of the objects having a plurality of references thereto, possibly from multiple clients. A discipline of permissions is imposed on the objects identified within the computer program module. The permissions enable tracking, from among a discrete set of changeable states, a subset of states each object might be in. A determination is made regarding whether the imposed permissions are violated by a potential reference to any of the identified objects. The results of the determination are output to a user.

Numerical simulation of compressible fluid flow in an ultrasonic suction pump.

PubMed

Wada, Yuji; Koyama, Daisuke; Nakamura, Kentaro

2016-08-01

Characteristics of an ultrasonic suction pump that uses a vibrating piston surface and a pipe are numerically simulated and compared with experimental results. Fluid analysis based on the finite-difference time-domain (FDTD) routine is performed, where the nonlinear term and the moving fluid-surface boundary condition are considered. As a result, the suction mechanism of the pump is found to be similar to that of a check valve, where the gap is open during the inflow phase, and it is nearly closed during the outflow phase. The effects of Reynolds number, vibration amplitude and gap thickness on the pump performance are analyzed. The calculated result is in good agreement with the previously measured results. Copyright © 2016 Elsevier B.V. All rights reserved.

Pretest analysis document for Test S-FS-7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, D.G.

This report documents the pretest calculations completed for Semiscale Test S-FS-7. This test will simulate a transient initiated by a 14.3% break in a steam generator bottom feedwater line downstream of the check valve. The initial conditions represent normal operating conditions for a C-E System 80 nuclear power plant. Predictions of transients resulting from feedwater line breaks in these plants have indicated that significant primary system overpressurization may occur. The results of a RELAP5/MOD2/CY21 code calculation indicate that the test objectives for Test S-FS-7 can be achieved. The primary system overpressurization will occur but pose no threat to personnel ormore » to plant integrity. 3 refs., 15 figs., 5 tabs.« less

Pretest analysis document for Test S-FS-11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, D.G.; Shaw, R.A.

This report documents the pretest calculations completed for Semiscale Test S-FS-11. This test will simulate a transient initiated by a 50% break in a steam generator bottom feedwater line downstream of the check valve. The initial conditions represents normal operating conditions for a C-E System 80 nuclear plant. Prediction of transients resulting from feedwater line breaks in these plants have indicated that significant primary system overpressurization may occur. The results of a RELAP5/MOD2/CY21 code calculation indicate that the test objectives for Test S-FS-11 can be achieved. The primary system overpressurization will occur but pose no threat to personnel or plantmore » integrity. 3 refs., 15 figs., 5 tabs.« less

Advanced software development workstation: Effectiveness of constraint-checking. [spaceflight simulation and planning

NASA Technical Reports Server (NTRS)

Izygon, Michel

1992-01-01

This report summarizes the findings and lessons learned from the development of an intelligent user interface for a space flight planning simulation program, in the specific area related to constraint-checking. The different functionalities of the Graphical User Interface part and of the rule-based part of the system have been identified. Their respective domain of applicability for error prevention and error checking have been specified.

Proportional assist ventilation system based on proportional solenoid valve control.

PubMed

Lua, A C; Shi, K C; Chua, L P

2001-07-01

A new proportional assist ventilation (PAV) method using a proportional solenoid valve (PSV) to control air supply to patients suffering from respiratory disabilities, was studied. The outlet flow and pressure from the proportional solenoid valve at various air supply pressures were tested and proven to be suitable for pressure and flow control in a PAV system. In vitro tests using a breathing simulator, which has been proven to possess the general characteristics of human respiratory system in spontaneous breathing tests, were conducted and the results demonstrated the viability of this PAV system in normalizing the breathing patterns of patients with abnormally high resistances and elastances as well as neuromuscular weaknesses. With a back-up safety mechanism incorporated in the control program, pressure "run-away" can be effectively prevented and safe operation of the system can be guaranteed.

[Factors Associated with Stress Check Attendance: Possible Effect of Timing of Annual Health Examination].

PubMed

Ishimaru, Tomohiro; Hattori, Michihiro; Nagata, Masako; Kuwahara, Keisuke; Watanabe, Seiji; Mori, Koji

2018-01-01

The stress check program has been part of annual employees' health screening since 2015. Employees are recommended, but not obliged, to undergo the stress check offered. This study was designed to examine the factors associated with stress check attendance. A total of 31,156 Japanese employees who underwent an annual health examination and a stress check service at an Occupational Health Service Center in 2016 participated in this study. Data from the annual health examination and stress check service included stress check attendance, date of attendance (if implemented), gender, age, workplace industry, number of employees at the workplace, and tobacco and alcohol consumption. Data were analyzed using multiple logistic regression. The mean rate of stress check attendance was 90.8%. A higher rate of stress check attendance was associated with a lower duration from the annual health examination, age ≥30 years, construction and transport industry, and 50-999 employees at the workplace. A lower rate of stress check attendance was associated with medical and welfare industry and ≥1,000 employees at the workplace. These findings provide insights into developing strategies for improving the rate of stress check attendance. In particular, stress check attendance may improve if the stress check service and annual health examination are conducted simultaneously.

Symbolic Analysis of Concurrent Programs with Polymorphism

NASA Technical Reports Server (NTRS)

Rungta, Neha Shyam

2010-01-01

The current trend of multi-core and multi-processor computing is causing a paradigm shift from inherently sequential to highly concurrent and parallel applications. Certain thread interleavings, data input values, or combinations of both often cause errors in the system. Systematic verification techniques such as explicit state model checking and symbolic execution are extensively used to detect errors in such systems [7, 9]. Explicit state model checking enumerates possible thread schedules and input data values of a program in order to check for errors [3, 9]. To partially mitigate the state space explosion from data input values, symbolic execution techniques substitute data input values with symbolic values [5, 7, 6]. Explicit state model checking and symbolic execution techniques used in conjunction with exhaustive search techniques such as depth-first search are unable to detect errors in medium to large-sized concurrent programs because the number of behaviors caused by data and thread non-determinism is extremely large. We present an overview of abstraction-guided symbolic execution for concurrent programs that detects errors manifested by a combination of thread schedules and data values [8]. The technique generates a set of key program locations relevant in testing the reachability of the target locations. The symbolic execution is then guided along these locations in an attempt to generate a feasible execution path to the error state. This allows the execution to focus in parts of the behavior space more likely to contain an error.

From the ground up: building a minimally invasive aortic valve surgery program

PubMed Central

Lamelas, Joseph

2015-01-01

Minimally invasive aortic valve replacement (MIAVR) is associated with numerous advantages including improved patient satisfaction, cosmesis, decreased transfusion requirements, and cost-effectiveness. Despite these advantages, little information exists on how to build a MIAVR program from the ground up. The steps to build a MIAVR program include compiling a multi-disciplinary team composed of surgeons, cardiologists, anesthesiologists, perfusionists, operating room (OR) technicians, and nurses. Once assembled, this team can then approach hospital administrators to present a cost-benefit analysis of MIAVR, emphasizing the importance of reduced resource utilization in the long-term to offset the initial financial investment that will be required. With hospital approval, training can commence to provide surgeons and other staff with the necessary knowledge and skills in MIAVR procedures and outcomes. Marketing and advertising of the program through the use of social media, educational conferences, grand rounds, and printed media will attract the initial patients. A dedicated website for the program can function as a “virtual lobby” for patients wanting to learn more. Initially, conservative selection criteria of cases that qualify for MIAVR will set the program up for success by avoiding complex co-morbidities and surgical techniques. During the learning curve phase of the program, patient safety should be a priority. PMID:25870815

From the ground up: building a minimally invasive aortic valve surgery program.

PubMed

Nguyen, Tom C; Lamelas, Joseph

2015-03-01

Minimally invasive aortic valve replacement (MIAVR) is associated with numerous advantages including improved patient satisfaction, cosmesis, decreased transfusion requirements, and cost-effectiveness. Despite these advantages, little information exists on how to build a MIAVR program from the ground up. The steps to build a MIAVR program include compiling a multi-disciplinary team composed of surgeons, cardiologists, anesthesiologists, perfusionists, operating room (OR) technicians, and nurses. Once assembled, this team can then approach hospital administrators to present a cost-benefit analysis of MIAVR, emphasizing the importance of reduced resource utilization in the long-term to offset the initial financial investment that will be required. With hospital approval, training can commence to provide surgeons and other staff with the necessary knowledge and skills in MIAVR procedures and outcomes. Marketing and advertising of the program through the use of social media, educational conferences, grand rounds, and printed media will attract the initial patients. A dedicated website for the program can function as a "virtual lobby" for patients wanting to learn more. Initially, conservative selection criteria of cases that qualify for MIAVR will set the program up for success by avoiding complex co-morbidities and surgical techniques. During the learning curve phase of the program, patient safety should be a priority.

Simulations of Micropumps Based on Tilted Flexible Fibers

NASA Astrophysics Data System (ADS)

Hancock, Matthew; Elabbasi, Nagi; Demirel, Melik

2015-11-01

Pumping liquids at low Reynolds numbers is challenging because of the principle of reversibility. We report here a class of microfluidic pump designs based on tilted flexible structures that combines the concepts of cilia (flexible elastic elements) and rectifiers (e.g., Tesla valves, check valves). We demonstrate proof-of-concept with 2D and 3D fluid-structure interaction (FSI) simulations in COMSOL Multiphysics®of micropumps consisting of a source for oscillatory fluidic motion, e.g. a piston, and a channel lined with tilted flexible rods or sheets to provide rectification. When flow is against the rod tilt direction, the rods bend backward, narrowing the channel and increasing flow resistance; when flow is in the direction of rod tilt, the rods bend forward, widening the channel and decreasing flow resistance. The 2D and 3D simulations involve moving meshes whose quality is maintained by prescribing the mesh displacement on guide surfaces positioned on either side of each flexible structure. The prescribed displacement depends on structure bending and maintains mesh quality even for large deformations. Simulations demonstrate effective pumping even at Reynolds numbers as low as 0.001. Because rod rigidity may be specified independently of Reynolds number, in principle, rod rigidity may be reduced to enable pumping at arbitrarily low Reynolds numbers.

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

NASA Technical Reports Server (NTRS)

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

2015-01-01

It is advantageous for gas-fed pulsed electric thrusters to employ pulsed valves so propellant is only flowing to the device during operation. The propellant utilization of the thruster will be maximized when all the gas injected into the thruster is acted upon by the fields produced by the electrical pulse. Gas that is injected too early will diffuse away from the thruster before the electrical pulse can act to accelerate the propellant. Gas that is injected too late will miss being accelerated by the already-completed electrical pulse. As a consequence, the valve must open quickly and close equally quickly, only remaining open for a short duration. In addition, the valve must have only a small amount of volume between the sealing body and the thruster so the front and back ends of the pulse are as coincident as possible with the valve cycling, with very little latent propellant remaining in the feed lines after the valve is closed. For a real mission of interest, a pulsed thruster can be expected to pulse at least 10(exp 10) - 10(exp 11) times, setting the range for the number of times a valve must open and close. The valves described in this paper have been fabricated and tested for operation in an inductive pulsed plasma thruster (IPPT) for in-space propulsion. In general, an IPPT is an electrodeless space propulsion device where a capacitor is charged to an initial voltage and then discharged, producing a high-current pulse through a coil. The field produced by this pulse ionizes propellant, inductively driving current in a plasma located near the face of the coil. Once the plasma is formed, it can be accelerated and expelled at a high exhaust velocity by the electromagnetic Lorentz body force arising from the interaction of the induced plasma current and the magnetic field produced by the current in the coil. The valve characteristics needed for the IPPT application require a fast-acting valve capable of a minimum of 10(exp 10) valve actuation cycles. Since even 10(exp 9) cycles is well above anything demonstrated, this lower value was selected as the design point for the present work. The valve seal must remain leak-tight throughout operation, and the body must maintain a low internal leakage at relatively high operating temperatures. The full set of design requirements used for this program are summarized in Table 1. In this work, we describe two pulsed gas valves that have been fabricated to have long lifetime and demonstrate the characteristics listed above. The first is a miniaturized, conventional electromagnet-based valve while the second is a piezoelectric-based valve design. The conventional valve, shown in Fig. 1, is opened by use of a solenoid electromagnetic actuator. When current is applied to the solenoid coil, magnetic forces pull the plunger away from the valve seat, allowing fluid to flow through the valve. Removal of electrical current permits the spring and fluid pressure to seat the plunger, halting the flow of fluid. The valve body is fabricated from 304L corrosion resistant steel (CRES) and while the parts that form the magnetic circuit are fabricated from 430 CRES. This material does not have optimum magnetic properties, but its corrosion resistance permits incorporation into a design without requiring an additional plating process. A viton O-ring compound (Parker V0884-75), selected for its mechanical strength at elevated temperatures, was used for the valve seat seal. The design was based solely on the use of analytical sizing calculations, as opposed to a more rigorous finite element analysis. While this valve is small and relatively lightweight, it does not represent a design that is optimized for mass and/or a given volume envelope. The piezoelectric valve is a "puller" valve design. Applying a voltage to the piezo crystal causes it to elongate and pull a pintle off the seat, opening the valve. The valve seal consists of the pintle with an external, spherically-formed tip fabricated from Inconel 625 and the seat fabricated from Inconel 718 and possessing a spherical surface that permits the pintle to align with the valve body centerline after each cycle, maintaining the circumferential metal-on-metal seal. The contact stress on the valve pintle is expected in the worst case to be 96.5 MPa (14 ksi), which is well below the work hardening value of 413.7 MPa (60 ksi) for Inconel 615. Results presented in this work will compare the performance of each valve, both to each other and to the valve design requirements given in Table 1. In general, both valves meet all the performance envelope requirements, but the piezoelectric valve consumes considerably less power and has a faster response time over the conventional solenoid-driven valves.

Mariner Jupiter/Saturn LCSSE thruster/valve assembly and injection propulsion unit rocket engine assemblies: 0.2-lbf T/VA development and margin limit test report

NASA Technical Reports Server (NTRS)

Clark, E. C.

1975-01-01

Thruster valve assemblies (T/VA's) were subjected to the development test program for the combined JPL Low-Cost Standardized Spacecraft Equipment (LCSSE) and Mariner Jupiter/Saturn '77 spacecraft (MJS) programs. The development test program was designed to achieve the following program goals: (1) demonstrate T/VA design compliance with JPL Specifications, (2) to conduct a complete performance Cf map of the T/VA over the full operating range of environment, (3) demonstrate T/VA life capability and characteristics of life margin for steady-state limit cycle and momentum wheel desaturation duty cycles, (4) verification of structural design capability, and (5) generate a computerized performance model capable of predicting T/VA operation over pressures ranging from 420 to 70 psia, propellant temperatures ranging from 140 F to 40 F, pulse widths of 0.008 to steady-state operation with unlimited duty cycle capability, and finally predict the transient performance associated with reactor heatup during any given duty cycle, start temperature, feed pressure, and propellant temperature conditions.

Commentary: criminal background checks for entering medical students: history, current issues, and future considerations.

PubMed

Kleshinski, James; Case, Steven T; Davis, Dwight; Heinrich, George F; Witzburg, Robert A

2011-07-01

In this commentary, the authors aim to contextualize the history and rationale for what has become the Association of American Medical Colleges-facilitated criminal background check process for entering medical students. As the process was being considered, many issues with a standardized process were identified. There were concerns that demographic or socioeconomic factors might unfairly burden certain applicants or discourage them from applying to medical school. On the other hand, a unified, national program would minimize cost and enhance quality assurance. The authors discuss these issues. Lessons learned in the first three years of the program are also addressed, including some unexpected and favorable consequences such as the identification of accepted applicants with at-risk behaviors (e.g., substance abuse), who would have otherwise gone undetected. Several challenges remain, including the fact that the criminal background check process creates an enhanced role for prehealth advisors and encourages undergraduate institutions to establish standards and processes relating to professionalism. While this is, no doubt, an evolving program which needs continued oversight and ongoing reevaluation, the authors support the continued advancement of the criminal background check process for entering medical students.

Model Checking Abstract PLEXIL Programs with SMART

NASA Technical Reports Server (NTRS)

Siminiceanu, Radu I.

2007-01-01

We describe a method to automatically generate discrete-state models of abstract Plan Execution Interchange Language (PLEXIL) programs that can be analyzed using model checking tools. Starting from a high-level description of a PLEXIL program or a family of programs with common characteristics, the generator lays the framework that models the principles of program execution. The concrete parts of the program are not automatically generated, but require the modeler to introduce them by hand. As a case study, we generate models to verify properties of the PLEXIL macro constructs that are introduced as shorthand notation. After an exhaustive analysis, we conclude that the macro definitions obey the intended semantics and behave as expected, but contingently on a few specific requirements on the timing semantics of micro-steps in the concrete executive implementation.

Interventional Treatment of Severe Tricuspid Regurgitation: Early Clinical Experience in a Multicenter, Observational, First-in-Man Study.

PubMed

Lauten, Alexander; Figulla, Hans R; Unbehaun, Axel; Fam, Neil; Schofer, Joachim; Doenst, Torsten; Hausleiter, Joerg; Franz, Marcus; Jung, Christian; Dreger, Henryk; Leistner, David; Alushi, Brunilda; Stundl, Anja; Landmesser, Ulf; Falk, Volkmar; Stangl, Karl; Laule, Michael

2018-02-01

Transcatheter caval valve implantation is under evaluation as a treatment option for inoperable patients with severe tricuspid regurgitation (TR). The procedure involves the catheter-based implantation of bioprosthetic valves in the inferior vena cava and superior vena cava to treat symptoms associated with TR. This study is the first to evaluate the feasibility, safety, and efficacy of this interventional concept. Twenty-five patients (mean age, 73.9±7.6 years; women, 52.0%) with severe symptomatic TR despite optimal medical treatment deemed unsuitable for surgery were treated with caval valve implantation under a compassionate clinical use program. Technical feasibility defined as procedural success, hemodynamic effect defined as venous pressure reduction, and safety defined as periprocedural adverse events were evaluated, with clinical follow-up at discharge and up to 12 months. The functional impact was evaluated by assessment of New York Heart Association class at the time of hospital discharge. The total number of valves implanted in the caval position was 31. Patients were treated with single (inferior vena cava-only; n=19; 76.0%) or bicaval valve implantation (inferior vena cava+superior vena cava; n=6; 24.0%). Either balloon-expandable valves (Sapien XT/3: n=18; 72.0%) or self-expandable valves (TricValve: n=6; 24.0%; Directflow: n=1; 4.0%) were used. Procedural success was achieved in 96% (n=24). Early and late valve migration requiring surgical intervention occurred in 1 patient each. Thirty-day and in-hospital mortality were 8% (2 of 25) and 16% (4 of 25). Causes of in-hospital mortality included respiratory (n=1) or multiple organ failure (n=3) and were not linked to the procedure. Mean overall survival in the study cohort was 316±453 days (14-1540 days). Caval valve implantation for the treatment of severe TR and advanced right ventricular failure is associated with a high procedural success rate and seems safe and feasible in an excessive-risk cohort. The study demonstrates hemodynamic efficacy with consistent elimination of TR-associated venous backflow and initial clinical improvement. These results encourage further trials to determine which patients benefit most from this interventional approach. © 2018 American Heart Association, Inc.

Velocity control propulsion subsystem of the Radio Astronomy Explorer satellite for Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Braught, W.; Moore, E. K.; Steinberg, R. L.

1973-01-01

The Velocity Control Propulsion Subsystem (VCPS) was designed the propulsion required for trajectory and lunar orbit corrections of the spacecraft. A GFE clamp assembly physically attaches the VCPS to the spacecraft and the unit is ejected after completing the required corrections. The VCPS is physically and functionally separated from the spacecraft except for the electrical and telemetry interfaces. A GFE transtage provides the superstructure on which the VCPS is assembled. The subsystem consists of two 5 foot pound rocket engine assemblies, 4 propellant tanks, 2 latching valves, 2 fill and drain valves, a system filter, pressure transducer, gas and propellant manifolds and electrical heaters and thermostats. The RAE-B VCPS program covered the design, manufacture and qualification of one subsystem. This subsystem was to be manufactured, subjected to qualification tests; and refurbished, if necessary, prior to flight. The VCPS design and test program precluded the need for refurbishing the subsystem and the unit was delivered to GSFC at the conclusion of the program.

14 CFR 91.1073 - Training program: General.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Provide enough flight instructors, check pilots, and simulator instructors to conduct required flight training and flight checks, and simulator training courses allowed under this subpart. (b) Whenever a... ensure that each pilot annually completes at least one flight training session in an approved simulator...

14 CFR 91.1073 - Training program: General.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Provide enough flight instructors, check pilots, and simulator instructors to conduct required flight training and flight checks, and simulator training courses allowed under this subpart. (b) Whenever a... ensure that each pilot annually completes at least one flight training session in an approved simulator...

14 CFR 91.1073 - Training program: General.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Provide enough flight instructors, check pilots, and simulator instructors to conduct required flight training and flight checks, and simulator training courses allowed under this subpart. (b) Whenever a... ensure that each pilot annually completes at least one flight training session in an approved simulator...

14 CFR 91.1073 - Training program: General.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) Provide enough flight instructors, check pilots, and simulator instructors to conduct required flight training and flight checks, and simulator training courses allowed under this subpart. (b) Whenever a... ensure that each pilot annually completes at least one flight training session in an approved simulator...

DNA methylation of a PLPP3 MIR transposon-based enhancer promotes an osteogenic program in calcific aortic valve disease.

PubMed

Mkannez, Ghada; Gagné-Ouellet, Valérie; Nsaibia, Mohamed Jalloul; Boulanger, Marie-Chloé; Rosa, Mickael; Argaud, Deborah; Hadji, Fayez; Gaudreault, Nathalie; Rhéaume, Gabrielle; Bouchard, Luigi; Bossé, Yohan; Mathieu, Patrick

2018-05-02

Calcific aortic valve disease (CAVD) is characterized by the osteogenic transition of valve interstitial cells (VICs). In CAVD, lysophosphatidic acid (LysoPA), a lipid mediator with potent osteogenic activity, is produced in the aortic valve (AV) and is degraded by membrane-associated phospholipid phosphatases (PLPPs). We thus hypothesized that a dysregulation of PLPPs could participate to the osteogenic reprograming of VICs during CAVD. The expression of PLPPs was examined in human control and mineralized AVs and comprehensive analyses were performed to document the gene regulation and impact of PLPPs on the osteogenic transition of VICs. We found that PLPP3 gene and enzymatic activity were downregulated in mineralized AVs. Multidimensional gene profiling in 21 human AVs showed that expression of PLPP3 was inversely correlated with the level of 5-methylcytosine (5meC) located in an intronic mammalian interspersed repeat element (MIR). Bisulfite pyrosequencing in a larger series of 67 AVs confirmed that 5meC in intron 1 was increased by 2.2-fold in CAVD compared to control AVs. In isolated cells, epigenome editing with CRISPR-Cas9 system containing a deficient Cas9 fused with DNA methyltransferase (dCas9-DNMT) was used to increase 5meC in the intronic enhancer and showed that it reduced significantly the expression of PLPP3. Knockdown experiments showed that lower expression of PLPP3 in VICs promotes an osteogenic program. DNA methylation of a MIR-based enhancer downregulates the expression of PLPP3 and promotes the mineralization of the AV.

Can the learning curve of totally endoscopic robotic mitral valve repair be short-circuited?

PubMed

Yaffee, David W; Loulmet, Didier F; Kelly, Lauren A; Ward, Alison F; Ursomanno, Patricia A; Rabinovich, Annette E; Neuburger, Peter J; Krishnan, Sandeep; Hill, Frederick T; Grossi, Eugene A

2014-01-01

A concern with the initiation of totally endoscopic robotic mitral valve repair (TERMR) programs has been the risk for the learning curve. To minimize this risk, we initiated a TERMR program with a defined team and structured learning approach before clinical implementation. A dedicated team (two surgeons, one cardiac anesthesiologist, one perfusionist, and two nurses) was trained with clinical scenarios, simulations, wet laboratories, and "expert" observation for 3 months. This team then performed a series of TERMRs of varying complexity. Thirty-two isolated TERMRs were performed during the first programmatic year. All operations included mitral valve repair, left atrial appendage exclusion, and annuloplasty device implantation. Additional procedures included leaflet resection, neochordae insertion, atrial ablation, and papillary muscle shortening. Longer clamp times were associated with number of neochordae (P < 0.01), papillary muscle procedures (P < 0.01), and leaflet resection (P = 0.06). Sequential case number had no impact on cross-clamp time (P = 0.3). Analysis of nonclamp time demonstrated a 71.3% learning percentage (P < 0.01; ie, 28.7% reduction in nonclamp time with each doubling of case number). There were no hospital deaths or incidences of stroke, myocardial infarction, unplanned reoperation, respiratory failure, or renal failure. Median length of stay was 4 days. All patients were discharged home. Totally endoscopic robotic mitral valve repair can be safely performed after a pretraining regimen with emphasis on experts' current practice and team training. After a pretraining regimen, cross-clamp times were not subject to learning curve phenomena but were dependent on procedural complexity. Nonclamp times were associated with a short learning curve.

Model checking for linear temporal logic: An efficient implementation

NASA Technical Reports Server (NTRS)

Sherman, Rivi; Pnueli, Amir

1990-01-01

This report provides evidence to support the claim that model checking for linear temporal logic (LTL) is practically efficient. Two implementations of a linear temporal logic model checker is described. One is based on transforming the model checking problem into a satisfiability problem; the other checks an LTL formula for a finite model by computing the cross-product of the finite state transition graph of the program with a structure containing all possible models for the property. An experiment was done with a set of mutual exclusion algorithms and tested safety and liveness under fairness for these algorithms.

Comparative evaluation of the drug interaction screening programs MediQ and ID PHARMA CHECK in neurological inpatients.

PubMed

Zorina, Olesya I; Haueis, Patrick; Semmler, Alexander; Marti, Isabelle; Gonzenbach, Roman R; Guzek, Markus; Kullak-Ublick, Gerd A; Weller, Michael; Russmann, Stefan

2012-08-01

The comparative evaluation of clinical decision support software (CDSS) programs regarding their sensitivity and positive predictive value for the identification of clinically relevant drug interactions. In this research, we used a cross-sectional study that identified potential drug interactions using the CDSS MediQ and the ID PHARMA CHECK in 484 neurological inpatients. Interactions were reclassified according to the Zurich Interaction System, a multidimensional classification that incorporates the Operational Classification of Drug Interactions. In 484 patients with 2812 prescriptions, MediQ and ID PHARMA CHECK generated a total of 1759 and 1082 alerts, respectively. MediQ identified 658 unique potentially interacting combinations, 8 classified as "high danger," 164 as "average danger," and 486 as "low danger." ID PHARMA CHECK detected 336 combinations assigned to one or several of 12 risk and management categories. Altogether, both CDSS issued alerts relating to 808 unique potentially interacting combinations. According to the Zurich Interaction System, 6 of these were contraindicated, 25 were provisionally contraindicated, 190 carried a conditional risk, and 587 had a minimal risk of adverse events. The positive predictive value for alerts having at least a conditional risk was 0.24 for MediQ and 0.48 for ID PHARMA CHECK. CDSS showed major differences in the identification and grading of interactions, and many interactions were only identified by one of the two CDSS. For both programs, only a small proportion of all identified interactions appeared clinically relevant, and the selected display of alerts that imply management changes is a key issue in the further development and local setup of such programs. Copyright © 2012 John Wiley & Sons, Ltd.

[The project "Don Carlo Gnocchi Foundation--Cardio-Thoracic Department De Gasperis--Lombardy Region" for the care of children from socio-economically deprived areas affected by cardiac disease].

PubMed

Ferratini, Maurizio; Marianeschi, Stefano; Vitali, Ettore; Iorio, Fiore; Moraschi, Andrea; Pezzano, Antonio; Mauri, Luigi; Lorini, Saverio; Rambaldi, Roberto; Tersalvi, Carlo Alberto; Pesaresi, Marilena; Pllumi, Arketa; Santoro, Francesco

2007-08-01

In 2001 the Cardiac Rehabilitation Unit IRCCS S. Maria Nascente Center and the International Area of Don Carlo Gnocchi Foundation, in collaboration with the Cardiac Surgery Department "De Gasperis" of Niguarda Ca' Granda Hospital in Milan, planned a project to treat children from impoverished countries. The "Fondo Sanitario Regionale" of the Lombard Region cosponsored the program. From October 2001 to November 2006, 32 patients (25 from Zimbabwe and 7 from Albania) were selected and submitted to cardiac surgery: 22 patients were affected by acquired valvular heart disease in NYHA class III-IV, 10 by congenital heart disease. After surgery the patients admitted to our rehabilitation unit underwent a period of comprehensive cardiac rehabilitation. Afterwards, the patients were in the care of selected Italian families for about 3 months. In both populations the problems faced in the selection, management and surgical approach are discussed. At 21 months the survival of the whole study population was 93 % (2 valvular patients died during the follow-up); 2 patients who initially underwent mitral valve repair were submitted to valve replacement for late appearance of severe regurgitation. In 3 patients with mitral valve bioprosthesis a significant structural valve deterioration occurred in the follow-up and 2 of them underwent valve replacement. The advantage of the excellent performance in durability of mechanical prosthetic valves (with respect to the limited durability of porcine bioprostheses), the problems with long-term anticoagulation have to be taken into consideration in the management of patients coming from socio-economically deprived areas.

Failure and Life Cycle Evaluation of Watering Valves

PubMed Central

Gonzalez, David M; Graciano, Sandy J; Karlstad, John; Leblanc, Mathias; Clark, Tom; Holmes, Scott; Reuter, Jon D

2011-01-01

Automated watering systems provide a reliable source of ad libitum water to animal cages. Our facility uses an automated water delivery system to support approximately 95% of the housed population (approximately 14,000 mouse cages). Drinking valve failure rates from 2002 through 2006 never exceeded the manufacturer standard of 0.1% total failure, based on monthly cage census and the number of floods. In 2007, we noted an increase in both flooding and cases of clinical dehydration in our mouse population. Using manufacturer's specifications for a water flow rate of 25 to 50 mL/min, we initiated a wide-scale screening of all valves used. During a 4-mo period, approximately 17,000 valves were assessed, of which 2200 failed according to scoring criteria (12.9% overall; 7.2% low flow; 1.6% no flow; 4.1% leaky). Factors leading to valve failures included residual metal shavings, silicone flash, introduced debris or bedding, and (most common) distortion of the autoclave-rated internal diaphragm and O-ring. Further evaluation revealed that despite normal autoclave conditions of heat, pressure, and steam, an extreme negative vacuum pull caused the valves’ internal silicone components (diaphragm and O-ring) to become distorted and water-permeable. Normal flow rate often returned after a ‘drying out’ period, but components then reabsorbed water while on the animal rack or during subsequent autoclave cycles to revert to a variable flow condition. On the basis of our findings, we recalibrated autoclaves and initiated a preventative maintenance program to mitigate the risk of future valve failure. PMID:22330720

[Preparation, storage, transportation and use of heart valves for allotransplantation].

PubMed

Spatenka, J; Kostelka, M; Kobylka, P; Hucín, B; Honĕk, T; Lochmann, O; Hájek, T; Tláskal, T; Povýsilová, V; Fiser, B

1997-03-01

Thanks to the co-operation with Czech and Slovak Transplant Centres and with some of the Departments of Pathology and Forensic Medicine 274 hearts were collected for allograft heart valves (AHV) processing during 1992-1995. The Cardiac surgeon dissected the aortic valve with the root and the pulmonary artery trunk with the valve. Tissues were antibiotically (ATB) sterilised in cultivation medium E 199 (24 hours at 37 degrees C). ATB concentrations (mg/ml): Cepharin 0.2, Azlocilin 0.2, Tobramycin 0.08 and Amphotericin B 0.1 for harvesting at post-mortem (P) or Miconazol 0.05 for sterile retrieval during multiorgan harvesting (MOH). After sterilisation AHV were stored at 4 degrees C. 49 AHV were infected even after ATB treatment-15 of 35 collected at P (43%) and 35 of 218 procured during MOH (16%)-(p < 0.01-ch2 test). After serological screening of the donor and microbiological testing the AHV were released for clinical use. Most AHV were programmed cooled to the temperature of liquid nitrogen (-196 degrees C), in which they were stored at the Allograft Heart Valves Cryobank. Cryoprotection was achieved by 10% dimethylsulphidoxide. A technology of harvesting, processing, storage and transportation of AHV, was introduced. It enabled the routine use in many cardiac surgical units. The AHV Cryobank was established. 131 AHV were used clinically between 1992 and 1995 (transportation as far as 1300 km). 108 AHV (82.4%) were used for repair of complex congenital heart defects, while 23 (17.6%) were used for aortic valve and/or root replacement.

Coincident steam generator tube rupture and stuck-open safety relief valve carryover tests: MB-2 steam generator transient response test program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garbett, K; Mendler, O J; Gardner, G C

In PWR steam generator tube rupture (SGTR) faults, a direct pathway for the release of radioactive fission products can exist if there is a coincident stuck-open safety relief valve (SORV) or if the safety relief valve is cycled. In addition to the release of fission products from the bulk steam generator water by moisture carryover, there exists the possibility that some primary coolant may be released without having first mixed with the bulk water - a process called primary coolant bypassing. The MB-2 Phase II test program was designed specifically to identify the processes for droplet carryover during SGTR faultsmore » and to provide data of sufficient accuracy for use in developing physical models and computer codes to describe activity release. The test program consisted of sixteen separate tests designed to cover a range of steady-state and transient fault conditions. These included a full SGTR/SORV transient simulation, two SGTR overfill tests, ten steady-state SGTR tests at water levels ranging from very low levels in the bundle up to those when the dryer was flooded, and three moisture carryover tests without SGTR. In these tests the influence of break location and the effect of bypassing the dryer were also studied. In a final test the behavior with respect to aerosol particles in a dry steam generator, appropriate to a severe accident fault, was investigated.« less

77 FR 12175 - Airworthiness Directives; DASSAULT AVIATION Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-29

... specified products. The MCAI states: The Maintenance Procedure (MP) 57-607, related to non destructive check... Recommended Maintenance Schedules chapter of the Aircraft Maintenance Documentation. After the implementation... maintenance program to include ``Non-Destructive Check of Flap Tracks 2 and 5,'' Maintenance Procedure 57-607...

Posterior Predictive Model Checking in Bayesian Networks

ERIC Educational Resources Information Center

Crawford, Aaron

2014-01-01

This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

14 CFR 91.1075 - Training program: Special rules.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership... the following are eligible under this subpart to conduct training, testing, and checking under... chapter to conduct training, testing, and checking required by this subpart if the training center— (1...

14 CFR 91.1075 - Training program: Special rules.

Code of Federal Regulations, 2012 CFR

2012-01-01

... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership... the following are eligible under this subpart to conduct training, testing, and checking under... chapter to conduct training, testing, and checking required by this subpart if the training center— (1...

14 CFR 91.1075 - Training program: Special rules.

Code of Federal Regulations, 2013 CFR

2013-01-01

... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership... the following are eligible under this subpart to conduct training, testing, and checking under... chapter to conduct training, testing, and checking required by this subpart if the training center— (1...

14 CFR 91.1075 - Training program: Special rules.

Code of Federal Regulations, 2010 CFR

2010-01-01

... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership... the following are eligible under this subpart to conduct training, testing, and checking under... chapter to conduct training, testing, and checking required by this subpart if the training center— (1...

14 CFR 91.1075 - Training program: Special rules.

Code of Federal Regulations, 2014 CFR

2014-01-01

... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership... the following are eligible under this subpart to conduct training, testing, and checking under... chapter to conduct training, testing, and checking required by this subpart if the training center— (1...

Drug checking: a potential solution to the opioid overdose epidemic?

PubMed

Bardwell, Geoff; Kerr, Thomas

2018-05-25

North America is experiencing an overdose epidemic driven in part by the proliferation of illicitly-manufactured fentanyl and related analogues. In response, communities are scaling up novel overdose prevention interventions. Included are drug checking technologies. Drug checking technologies aim to identify the contents of illicit drugs. These technologies vary considerably in terms of cost, accuracy, and usability, and while efforts are now underway to implement drug checking programs for people who inject drugs, there remains a lack of rigorous evaluation of their impacts. Given the ongoing overdose crisis and the urgent need for effective responses, research on drug checking should be prioritized. However, while such research should be supported, it should be completed before these technologies are widely implemented.

Propulsive Reaction Control System Model

NASA Technical Reports Server (NTRS)

Brugarolas, Paul; Phan, Linh H.; Serricchio, Frederick; San Martin, Alejandro M.

2011-01-01

This software models a propulsive reaction control system (RCS) for guidance, navigation, and control simulation purposes. The model includes the drive electronics, the electromechanical valve dynamics, the combustion dynamics, and thrust. This innovation follows the Mars Science Laboratory entry reaction control system design, and has been created to meet the Mars Science Laboratory (MSL) entry, descent, and landing simulation needs. It has been built to be plug-and-play on multiple MSL testbeds [analysis, Monte Carlo, flight software development, hardware-in-the-loop, and ATLO (assembly, test and launch operations) testbeds]. This RCS model is a C language program. It contains two main functions: the RCS electronics model function that models the RCS FPGA (field-programmable-gate-array) processing and commanding of the RCS valve, and the RCS dynamic model function that models the valve and combustion dynamics. In addition, this software provides support functions to initialize the model states, set parameters, access model telemetry, and access calculated thruster forces.

Permanent pacemaker insertion following isolated aortic valve replacement before and after the introduction of TAVI.

PubMed

Kogan, Alexander; Sternik, Leonid; Beinart, Roy; Shalabi, Amjad; Glikson, Michael; Spiegelstein, Danny; Levin, Shany; Raanani, Ehud

2015-04-01

Permanent pacemaker (PPM) implantation is required in 3-12% of all patients undergoing surgical aortic valve replacement (AVR). Our aim was to evaluate the contemporary incidence and impact of the introduction of transcatheter aortic valve implantation (TAVI) for PPM insertion after isolated AVR. Since 2004, during a 10-year period, a total of 858 patients underwent isolated AVR at our institution. Forty-one patients with PPM before operation were excluded from the study and 817 patients were included in the statistical analysis. Of these, 20 patients (2.45%) developed significant conduction disorders, leading to PPM implantation within 120 days postoperatively. Patients were further divided into two groups. Before (Group I: June 2004 to September 2008) and after (Group II: October 2008 to May 2014) the introduction of the TAVI program. There were 343 patients in Group I and 475 patients in Group II. The incidence of PPM implantation decreased from 3.79% (13 patients) in Group I to 1.47% (seven patients) in Group II (P < 0.001). Risk factors for permanent pacing identified by univariate analysis were: Group I (before introducing TAVI program), pulmonary hypertension, preoperative anemia, age older than 75 years, and previous myocardial infarction. Multivariate analysis identified Group I (before introducing TAVI program; P < 0.005; odds ratio [OR] 15.2, 95% confidence interval [CI] 6.3-19.9) and pulmonary hypertension (P < 0.005; OR 12.5, 95% CI 3.2-18.3) to be significant. Irreversible atrio-ventricular block or symptomatic bradycardia requiring PPM implantation is a relatively rare complication. The incidence of PPM implantation after isolated surgical AVR decreased in a contemporary setting after the introduction of the TAVI program. ©2015 Wiley Periodicals, Inc.

Towards a Certified Lightweight Array Bound Checker for Java Bytecode

NASA Technical Reports Server (NTRS)

Pichardie, David

2009-01-01

Dynamic array bound checks are crucial elements for the security of a Java Virtual Machines. These dynamic checks are however expensive and several static analysis techniques have been proposed to eliminate explicit bounds checks. Such analyses require advanced numerical and symbolic manipulations that 1) penalize bytecode loading or dynamic compilation, 2) complexify the trusted computing base. Following the Foundational Proof Carrying Code methodology, our goal is to provide a lightweight bytecode verifier for eliminating array bound checks that is both efficient and trustable. In this work, we define a generic relational program analysis for an imperative, stackoriented byte code language with procedures, arrays and global variables and instantiate it with a relational abstract domain as polyhedra. The analysis has automatic inference of loop invariants and method pre-/post-conditions, and efficient checking of analysis results by a simple checker. Invariants, which can be large, can be specialized for proving a safety policy using an automatic pruning technique which reduces their size. The result of the analysis can be checked efficiently by annotating the program with parts of the invariant together with certificates of polyhedral inclusions. The resulting checker is sufficiently simple to be entirely certified within the Coq proof assistant for a simple fragment of the Java bytecode language. During the talk, we will also report on our ongoing effort to scale this approach for the full sequential JVM.

"Tech-check-tech": a review of the evidence on its safety and benefits.

PubMed

Adams, Alex J; Martin, Steven J; Stolpe, Samuel F

2011-10-01

The published evidence on state-authorized programs permitting final verification of medication orders by pharmacy technicians, including the programs' impact on pharmacist work hours and clinical activities, is reviewed. Some form of "tech-check-tech" (TCT)--the checking of a technician's order-filling accuracy by another technician rather than a pharmacist--is authorized for use by pharmacies in at least nine states. The results of 11 studies published since 1978 indicate that technicians' accuracy in performing final dispensing checks is very comparable to pharmacists' accuracy (mean ± S.D., 99.6% ± 0.55% versus 99.3% ± 0.68%, respectively). In 6 of those studies, significant differences in accuracy or error detection rates favoring TCT were reported (p < 0.05), although published TCT studies to date have had important limitations. In states with active or pilot TCT programs, pharmacists surveyed have reported that the practice has yielded time savings (estimates range from 10 hours per month to 1 hour per day), enabling them to spend more time providing clinical services. States permitting TCT programs require technicians to complete special training before assuming TCT duties, which are generally limited to restocking automated dispensing machines and filling unit dose batches of refills in hospitals and other institutional settings. The published evidence demonstrates that pharmacy technicians can perform as accurately as pharmacists, perhaps more accurately, in the final verification of unit dose orders in institutional settings. Current TCT programs have fairly consistent elements, including the limitation of TCT to institutional settings, advanced education and training requirements for pharmacy technicians, and ongoing quality assurance.

Development of Advanced Low Emission Injectors and High-Bandwidth Fuel Flow Modulation Valves

NASA Technical Reports Server (NTRS)

Mansour, Adel

2015-01-01

Parker Hannifin Corporation developed the 3-Zone fuel nozzle for NASA's Environmentally Responsible Aviation Program to meet NASAs target of 75 LTO NOx reduction from CAEP6 regulation. The nozzle concept was envisioned as a drop-in replacement for currently used fuel nozzle stem, and is built up from laminates to provide energetic mixing suitable for lean direct injection mode at high combustor pressure. A high frequency fuel valve was also developed to provide fuel modulation for the pilot injector. Final testing result shows the LTO NOx level falling just shy of NASAs goal at 31.

VASCOMP II. The V/STOL Aircraft Sizing and Performance Computer Program. Volume VI. User’s Manual. Revision 3

DTIC Science & Technology

1980-05-01

idlers, etc. Main hydraulic systems including pumps, reservoirs, accumulators, filters, valves , lines, fluid, and supports (Figure 4-40). 4-159 -4...SPEED CORRECTION Ny DN-(VALUES OF N. v VALUES OF KPR VALUES OF *111OPT VALUES OF KPN 4.OC VAL.UE LOC VALVE LOC VALU~E LOC VALUE 1207 _______ 1225...TCVT (t/c)qT 0131 TENN NUMBER OF M 0309 TF REFERRED THRUST AS A 1609 - 1616 FUNCTION OF (T/0) TF1 REFERRED N1 AS A FUNCTION 16k1 - 1648 OF (T/e) TF2

45 CFR 201.70 - Treatment of replacement checks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Treatment of replacement checks. 201.70 Section 201.70 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS TO...

45 CFR 201.70 - Treatment of replacement checks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 2 2013-10-01 2012-10-01 true Treatment of replacement checks. 201.70 Section 201.70 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS TO...

45 CFR 201.70 - Treatment of replacement checks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 2 2012-10-01 2012-10-01 false Treatment of replacement checks. 201.70 Section 201.70 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS TO...

45 CFR 201.70 - Treatment of replacement checks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 2 2014-10-01 2012-10-01 true Treatment of replacement checks. 201.70 Section 201.70 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS TO...

45 CFR 201.70 - Treatment of replacement checks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 2 2011-10-01 2011-10-01 false Treatment of replacement checks. 201.70 Section 201.70 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS TO...

Attitude Control Propulsion Components, Volume 2

NASA Technical Reports Server (NTRS)

1974-01-01

Attitude control propulsion components are described, including hydrazine thrusters, hydrazine thruster and cold gas jet valves, and pressure and temperature transducers. Component-ordered data are presented in tabular form; the manufacturer and specific space program are included.

Model Checking JAVA Programs Using Java Pathfinder

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Pressburger, Thomas

2000-01-01

This paper describes a translator called JAVA PATHFINDER from JAVA to PROMELA, the "programming language" of the SPIN model checker. The purpose is to establish a framework for verification and debugging of JAVA programs based on model checking. This work should be seen in a broader attempt to make formal methods applicable "in the loop" of programming within NASA's areas such as space, aviation, and robotics. Our main goal is to create automated formal methods such that programmers themselves can apply these in their daily work (in the loop) without the need for specialists to manually reformulate a program into a different notation in order to analyze the program. This work is a continuation of an effort to formally verify, using SPIN, a multi-threaded operating system programmed in Lisp for the Deep-Space 1 spacecraft, and of previous work in applying existing model checkers and theorem provers to real applications.

KSC-2011-7775

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, technicians install the shuttle orbiter repackaged galley (SORG) in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-7772

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, technicians prepare to install the shuttle orbiter repackaged galley (SORG) in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-7776

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, the shuttle orbiter repackaged galley (SORG) is installed in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-7771

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, the shuttle orbiter repackaged galley (SORG) is being installed in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-7773

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, technicians prepare to install the shuttle orbiter repackaged galley (SORG) in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-7774

NASA Image and Video Library

2011-11-15

CAPE CANAVERAL, Fla. – Inside Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, technicians install the shuttle orbiter repackaged galley (SORG) in the middeck of space shuttle Discovery. After Discovery’s final mission, STS-133, the SORG was removed and sent to a United Space Alliance lab in Houston where it was cleaned and deserviced. Water in the microbial check valve and the orbiter water system was drained and dried. The SORG was returned to Kennedy Space Center. The work is part of the Space Shuttle Program’s transition and retirement processing of shuttle Discovery, which is being prepared for display at Smithsonian’s National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Dimitri Gerondidakis

14 CFR 91.1109 - Aircraft maintenance: Inspection program.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

14 CFR 91.1109 - Aircraft maintenance: Inspection program.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

14 CFR 91.1109 - Aircraft maintenance: Inspection program.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aircraft maintenance: Inspection program... Ownership Operations Program Management § 91.1109 Aircraft maintenance: Inspection program. Each program... conduct of inspections for the particular make and model aircraft, including necessary tests and checks...

Some attributes of a language for property-based testing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neagoe, Vicentiu; Bishop, Matt

Property-based testing is a testing technique that evaluates executions of a program. The method checks that specifications, called properties, hold throughout the execution of the program. TASpec is a language used to specify these properties. This paper compares some attributes of the language with the specification patterns used for model-checking languages, and then presents some descriptions of properties that can be used to detect common security flaws in programs. This report describes the results of a one year research project at the University of California, Davis, which was funded by a University Collaboration LDRD entitled ''Property-based Testing for Cyber Securitymore » Assurance''.« less

Software Model Checking Without Source Code

NASA Technical Reports Server (NTRS)

Chaki, Sagar; Ivers, James

2009-01-01

We present a framework, called AIR, for verifying safety properties of assembly language programs via software model checking. AIR extends the applicability of predicate abstraction and counterexample guided abstraction refinement to the automated verification of low-level software. By working at the assembly level, AIR allows verification of programs for which source code is unavailable-such as legacy and COTS software-and programs that use features-such as pointers, structures, and object-orientation-that are problematic for source-level software verification tools. In addition, AIR makes no assumptions about the underlying compiler technology. We have implemented a prototype of AIR and present encouraging results on several non-trivial examples.

Medicaid program: adjustment of federal share for uncashed or cancelled (voided) checks--HCFA. Proposed rule.

PubMed

1985-05-31

These proposed regulations require a State agency to refund to the Federal government the Federal share of Medicaid checks issued by the State or its fiscal agent that remain uncashed 180 days after the date of issuance. In addition, we would require that the Federal share of cancelled (voided) Medicaid checks be refunded quarterly since there has been no expenditure by the State. This proposal is intended to implement in part a 1981 General Accounting Office recommendation that procedures be established for States to credit the Federal government for its portion of uncashed Medicaid checks issues by the State or its fiscal agent.

Medicaid program; adjustment of federal share for uncashed or cancelled (voided) checks--HCFA. Final rule.

PubMed

1986-10-09

These final regulations require that a State agency refund to the Federal Government the Federal share of Medicaid checks issued by the State or its fiscal agent that remain uncashed 180 days after the date of issuance. In addition, we are requiring that the Federal share of cancelled (voided) Medicaid checks be refunded quarterly since there has been no expenditure by the State. These regulations implement, in part, a 1981 General Accounting Office recommendation that procedures be established for States to credit the Federal Government for the Federal portion of uncashed Medicaid checks issued by the State or its fiscal agent.

Integrated control and health management. Orbit transfer rocket engine technology program

NASA Technical Reports Server (NTRS)

Holzmann, Wilfried A.; Hayden, Warren R.

1988-01-01

To insure controllability of the baseline design for a 7500 pound thrust, 10:1 throttleable, dual expanded cycle, Hydrogen-Oxygen, orbit transfer rocket engine, an Integrated Controls and Health Monitoring concept was developed. This included: (1) Dynamic engine simulations using a TUTSIM derived computer code; (2) analysis of various control methods; (3) Failure Modes Analysis to identify critical sensors; (4) Survey of applicable sensors technology; and, (5) Study of Health Monitoring philosophies. The engine design was found to be controllable over the full throttling range by using 13 valves, including an oxygen turbine bypass valve to control mixture ratio, and a hydrogen turbine bypass valve, used in conjunction with the oxygen bypass to control thrust. Classic feedback control methods are proposed along with specific requirements for valves, sensors, and the controller. Expanding on the control system, a Health Monitoring system is proposed including suggested computing methods and the following recommended sensors: (1) Fiber optic and silicon bearing deflectometers; (2) Capacitive shaft displacement sensors; and (3) Hot spot thermocouple arrays. Further work is needed to refine and verify the dynamic simulations and control algorithms, to advance sensor capabilities, and to develop the Health Monitoring computational methods.

A method for calculating transient thrust and flow-rate levels for Mariner type attitude control nitrogen gas jets

NASA Technical Reports Server (NTRS)

Ferrera, J. D.

1972-01-01

The purpose of this report is to define and program the transient pneumatic flow equations necessary to determine, for a given set of conditions (geometry, pressures, temperatures, valve on time, etc.), the total nitrogen impulse and mass flow per pulse for the single pulsing of a Mariner type reaction control assembly valve. The rates of opening and closing of the valves are modeled, and electrical pulse durations from 20 to 100 ms are investigated. In developing the transient flow analysis, maximum use was made of the steady-state analysis. The impulse results are also compared to an equivalent square-wave impulse for both the Mariner Mars 1971 (MM'71) and Mariner Mars 1964 (MM'64) systems. It is demonstrated that, whereas in the MM'64 system, the actual impulse was as much as 56 percent higher than an assumed impulse (which is the product of the steady-state thrust and value on time i.e., the square wave), in the MM'71 system, these two values were in error in the same direction by only approximately 4 percent because of the larger nozzle areas and shorter valve stroke used.

GSD Update: Checking the range for signs of climate change in the past, present and future

Treesearch

Lisa-Natalie Anjozian

2011-01-01

The July 2011 inaugural issue of GSDUpdate: Checking the Range for Signs of Climate Change In the Past, Present and Future, a research review of the Program, focuses on the efforts toward understanding the role of climate in shaping the environment.

10 CFR 26.111 - Checking the acceptability of the urine specimen.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Checking the acceptability of the urine specimen. 26.111 Section 26.111 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for..., the collector shall measure the temperature of the specimen. The temperature-measuring device used...

10 CFR 26.111 - Checking the acceptability of the urine specimen.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Checking the acceptability of the urine specimen. 26.111 Section 26.111 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for..., the collector shall measure the temperature of the specimen. The temperature-measuring device used...

10 CFR 26.111 - Checking the acceptability of the urine specimen.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 1 2014-01-01 2014-01-01 false Checking the acceptability of the urine specimen. 26.111 Section 26.111 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for..., the collector shall measure the temperature of the specimen. The temperature-measuring device used...

75 FR 21064 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

...) make publicly available in BrokerCheck all historic customer complaints that were archived after the... logical extension of the BrokerCheck program that will help protect investors and other users of Broker...., reportable customer complaints or Historic Complaints, criminal charges, terminations, bankruptcies, liens...

Cap check helps reconcile payments with eligibility lists to improve cash flow.

PubMed

2003-05-01

Some capitated provider groups are becoming more adept at using software solutions to effectively manage retroactive deletions, additions and changes in membership enrollment. While a variety of software programs are available, several sources recommend using Cap Check to help match up eligibility lists with capitation payment.

45 CFR 201.67 - Treatment of uncashed or cancelled checks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 2 2014-10-01 2012-10-01 true Treatment of uncashed or cancelled checks. 201.67 Section 201.67 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 201.67 - Treatment of uncashed or cancelled checks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 2 2012-10-01 2012-10-01 false Treatment of uncashed or cancelled checks. 201.67 Section 201.67 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 205.32 - Procedures for issuance of replacement checks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 2 2012-10-01 2012-10-01 false Procedures for issuance of replacement checks. 205.32 Section 205.32 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 201.67 - Treatment of uncashed or cancelled checks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Treatment of uncashed or cancelled checks. 201.67 Section 201.67 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 205.32 - Procedures for issuance of replacement checks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 2 2014-10-01 2012-10-01 true Procedures for issuance of replacement checks. 205.32 Section 205.32 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 205.32 - Procedures for issuance of replacement checks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 2 2013-10-01 2012-10-01 true Procedures for issuance of replacement checks. 205.32 Section 205.32 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 205.32 - Procedures for issuance of replacement checks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Procedures for issuance of replacement checks. 205.32 Section 205.32 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 205.32 - Procedures for issuance of replacement checks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 2 2011-10-01 2011-10-01 false Procedures for issuance of replacement checks. 205.32 Section 205.32 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 201.67 - Treatment of uncashed or cancelled checks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 2 2013-10-01 2012-10-01 true Treatment of uncashed or cancelled checks. 201.67 Section 201.67 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

45 CFR 201.67 - Treatment of uncashed or cancelled checks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 2 2011-10-01 2011-10-01 false Treatment of uncashed or cancelled checks. 201.67 Section 201.67 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY ASSISTANCE (ASSISTANCE PROGRAMS), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

Serials Management by Microcomputer: The Potential of DBMS.

ERIC Educational Resources Information Center

Vogel, J. Thomas; Burns, Lynn W.

1984-01-01

Describes serials management at Philadelphia College of Textiles and Science library via a microcomputer, a file manager called PFS, and a relational database management system called dBase II. Check-in procedures, programing with dBase II, "static" and "active" databases, and claim procedures are discussed. Check-in forms are…

The ALL-OUT Library; A Design for Computer-Powered, Multidimensional Services.

ERIC Educational Resources Information Center

Sleeth, Jim; LaRue, James

1983-01-01

Preliminary description of design of electronic library and home information delivery system highlights potentials of personal computer interface program (applying for service, assuring that users are valid, checking for measures, searching, locating titles) and incorporation of concepts used in other information systems (security checks,…

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

Check Sample Abstracts.

PubMed

Alter, David; Grenache, David G; Bosler, David S; Karcher, Raymond E; Nichols, James; Rajadhyaksha, Aparna; Camelo-Piragua, Sandra; Rauch, Carol; Huddleston, Brent J; Frank, Elizabeth L; Sluss, Patrick M; Lewandrowski, Kent; Eichhorn, John H; Hall, Janet E; Rahman, Saud S; McPherson, Richard A; Kiechle, Frederick L; Hammett-Stabler, Catherine; Pierce, Kristin A; Kloehn, Erica A; Thomas, Patricia A; Walts, Ann E; Madan, Rashna; Schlesinger, Kathie; Nawgiri, Ranjana; Bhutani, Manoop; Kanber, Yonca; Abati, Andrea; Atkins, Kristen A; Farrar, Robert; Gopez, Evelyn Valencerina; Jhala, Darshana; Griffin, Sonya; Jhala, Khushboo; Jhala, Nirag; Bentz, Joel S; Emerson, Lyska; Chadwick, Barbara E; Barroeta, Julieta E; Baloch, Zubair W; Collins, Brian T; Middleton, Owen L; Davis, Gregory G; Haden-Pinneri, Kathryn; Chu, Albert Y; Keylock, Joren B; Ramoso, Robert; Thoene, Cynthia A; Stewart, Donna; Pierce, Arand; Barry, Michelle; Aljinovic, Nika; Gardner, David L; Barry, Michelle; Shields, Lisa B E; Arnold, Jack; Stewart, Donna; Martin, Erica L; Rakow, Rex J; Paddock, Christopher; Zaki, Sherif R; Prahlow, Joseph A; Stewart, Donna; Shields, Lisa B E; Rolf, Cristin M; Falzon, Andrew L; Hudacki, Rachel; Mazzella, Fermina M; Bethel, Melissa; Zarrin-Khameh, Neda; Gresik, M Vicky; Gill, Ryan; Karlon, William; Etzell, Joan; Deftos, Michael; Karlon, William J; Etzell, Joan E; Wang, Endi; Lu, Chuanyi M; Manion, Elizabeth; Rosenthal, Nancy; Wang, Endi; Lu, Chuanyi M; Tang, Patrick; Petric, Martin; Schade, Andrew E; Hall, Geraldine S; Oethinger, Margret; Hall, Geraldine; Picton, Avis R; Hoang, Linda; Imperial, Miguel Ranoa; Kibsey, Pamela; Waites, Ken; Duffy, Lynn; Hall, Geraldine S; Salangsang, Jo-Anne M; Bravo, Lulette Tricia C; Oethinger, Margaret D; Veras, Emanuela; Silva, Elvia; Vicens, Jimena; Silva, Elvio; Keylock, Joren; Hempel, James; Rushing, Elizabeth; Posligua, Lorena E; Deavers, Michael T; Nash, Jason W; Basturk, Olca; Perle, Mary Ann; Greco, Alba; Lee, Peng; Maru, Dipen; Weydert, Jamie Allen; Stevens, Todd M; Brownlee, Noel A; Kemper, April E; Williams, H James; Oliverio, Brock J; Al-Agha, Osama M; Eskue, Kyle L; Newlands, Shawn D; Eltorky, Mahmoud A; Puri, Puja K; Royer, Michael C; Rush, Walter L; Tavora, Fabio; Galvin, Jeffrey R; Franks, Teri J; Carter, James Elliot; Kahn, Andrea Graciela; Lozada Muñoz, Luis R; Houghton, Dan; Land, Kevin J; Nester, Theresa; Gildea, Jacob; Lefkowitz, Jerry; Lacount, Rachel A; Thompson, Hannis W; Refaai, Majed A; Quillen, Karen; Lopez, Ana Ortega; Goldfinger, Dennis; Muram, Talia; Thompson, Hannis

2009-02-01

The following abstracts are compiled from Check Sample exercises published in 2008. These peer-reviewed case studies assist laboratory professionals with continuing medical education and are developed in the areas of clinical chemistry, cytopathology, forensic pathology, hematology, microbiology, surgical pathology, and transfusion medicine. Abstracts for all exercises published in the program will appear annually in AJCP.

14 CFR 121.402 - Training program: Special rules.

Code of Federal Regulations, 2013 CFR

2013-01-01

... part or a flight training center certificated under part 142 of this chapter is eligible under this subpart to provide flight training, testing, and checking under contract or other arrangement to those... provide training, testing, and checking required by this part only if the training center— (1) Holds...

14 CFR 121.402 - Training program: Special rules.

Code of Federal Regulations, 2011 CFR

2011-01-01

... part or a flight training center certificated under part 142 of this chapter is eligible under this subpart to provide flight training, testing, and checking under contract or other arrangement to those... provide training, testing, and checking required by this part only if the training center— (1) Holds...

14 CFR 121.402 - Training program: Special rules.

Code of Federal Regulations, 2012 CFR

2012-01-01

... part or a flight training center certificated under part 142 of this chapter is eligible under this subpart to provide flight training, testing, and checking under contract or other arrangement to those... provide training, testing, and checking required by this part only if the training center— (1) Holds...

14 CFR 121.402 - Training program: Special rules.

Code of Federal Regulations, 2010 CFR

2010-01-01

... part or a flight training center certificated under part 142 of this chapter is eligible under this subpart to provide flight training, testing, and checking under contract or other arrangement to those... provide training, testing, and checking required by this part only if the training center— (1) Holds...

14 CFR 121.402 - Training program: Special rules.

Code of Federal Regulations, 2014 CFR

2014-01-01

... part or a flight training center certificated under part 142 of this chapter is eligible under this subpart to provide flight training, testing, and checking under contract or other arrangement to those... provide training, testing, and checking required by this part only if the training center— (1) Holds...

Building Program Verifiers from Compilers and Theorem Provers

DTIC Science & Technology

2015-05-14

Checking with SMT UFO • LLVM-based front-end (partially reused in SeaHorn) • Combines Abstract Interpretation with Interpolation-Based Model Checking • (no...assertions Counter-examples are long Hard to determine (from main) what is relevant Assertion Main 35 Building Verifiers from Comp and SMT Gurfinkel, 2015

Cost-Effective CNC Part Program Verification Development for Laboratory Instruction.

ERIC Educational Resources Information Center

Chen, Joseph C.; Chang, Ted C.

2000-01-01

Describes a computer numerical control program verification system that checks a part program before its execution. The system includes character recognition, word recognition, a fuzzy-nets system, and a tool path viewer. (SK)

Tank 30 and 37 Supernatant Sample Cross-Check and Evaporator Feed Qualification Analysis-2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L. N.

2013-03-07

This report summarizes the analytical data reported by the F/H and Savannah River National Laboratories for the 2012 cross-check analysis for high level waste supernatant liquid samples from SRS Tanks 30 and 37. The intent of this Tank 30 and 37 sample analyses was to perform cross-checks against routine F/H Laboratory analyses (corrosion and evaporator feed qualification programs) using samples collected at the same time from both tanks as well as split samples from the tanks.

Expert System For Heat Exchanger

NASA Technical Reports Server (NTRS)

Bagby, D. Gordon; Cormier, Reginald A.

1991-01-01

Diagnosis simplified for non-engineers. Developmental expert-system computer program assists operator in controlling, monitoring operation, diagnosing malfunctions, and ordering repairs of heat-exchanger system dissipating heat generated by 20-kW radio transmitter. System includes not only heat exchanger but also pumps, fans, sensors, valves, reservoir, and associated plumbing. Program conceived to assist operator while avoiding cost of keeping engineer in full-time attendance. Similar programs developed for heating, ventilating, and air-conditioning systems.

Update to the study protocol, including statistical analysis plan for a randomized clinical trial comparing comprehensive cardiac rehabilitation after heart valve surgery with control: the CopenHeartVR trial.

PubMed

Sibilitz, Kirstine Laerum; Berg, Selina Kikkenborg; Hansen, Tina Birgitte; Risom, Signe Stelling; Rasmussen, Trine Bernholdt; Hassager, Christian; Køber, Lars; Gluud, Christian; Thygesen, Lau Caspar; Lindschou, Jane; Schmid, Jean Paul; Taylor, Rod S; Zwisler, Ann-Dorthe

2015-02-05

Heart valve diseases are common with an estimated prevalence of 2.5% in the Western world. The number is rising because of an ageing population. Once symptomatic, heart valve diseases are potentially lethal, and heavily influence daily living and quality of life. Surgical treatment, either valve replacement or repair, remains the treatment of choice. However, post-surgery, the transition to daily living may become a physical, mental and social challenge. We hypothesize that a comprehensive cardiac rehabilitation program can improve physical capacity and self-assessed mental health and reduce hospitalization and healthcare costs after heart valve surgery. This randomized clinical trial, CopenHeartVR, aims to investigate whether cardiac rehabilitation in addition to usual care is superior to treatment as usual after heart valve surgery. The trial will randomly allocate 210 patients 1:1 to an intervention or a control group, using central randomization, and blinded outcome assessment and statistical analyses. The intervention consists of 12 weeks of physical exercise and a psycho-educational intervention comprising five consultations. The primary outcome is peak oxygen uptake (VO2 peak) measured by cardiopulmonary exercise testing with ventilatory gas analysis. The secondary outcome is self-assessed mental health measured by the standardized questionnaire Short Form-36. Long-term healthcare utilization and mortality as well as biochemistry, echocardiography and cost-benefit will be assessed. A mixed-method design will be used to evaluate qualitative and quantitative findings, encompassing a survey-based study before the trial and a qualitative pre- and post-intervention study. This randomized clinical trial will contribute with evidence of whether cardiac rehabilitation should be provided after heart valve surgery. The study is approved by the local regional Research Ethics Committee (H-1-2011-157), and the Danish Data Protection Agency (j.nr. 2007-58-0015). Trial registered 16 March 2012; ClinicalTrials.gov ( NCT01558765 ).

[The spectra of a laser-produced plasma source with CO2, O2 and CF4 liquid aerosol spray target].

PubMed

Ni, Qi-Liang; Chen, Bo

2008-11-01

A laser-produced plasma (LPP) source with liquid aerosol spray target and nanosecond laser was developed, based on both soft X-ray radiation metrology and extreme ultraviolet projection lithography (EUVL). The LPP source is composed of a stainless steel solenoid valve whose temperature can be continuously controlled, a Nd : YAG laser with pulse width, working wavelength and pulse energy being 7 ns, 1.064 microm and 1J respectively, and a pulse generator which can synchronously control the valve and the laser. A standard General Valve Corporation series 99 stainless steel solenoid valve with copper gasket seals and a Kel-F poppet are used in order to minimize leakage and poppet deformation during high-pressure cryogenic operation. A close fitting copper cooling jacket surrounds the valve body. The jacket clamps a copper coolant carrying tube 3 mm in diameter, which is fed by an automatically pressurized liquid nitrogen-filled dewar. The valve temperature can be controlled between 77 and 473 K. For sufficiently high backing pressure and low temperature, the valve reservoir gas can undergo a gas-to-liquid phase transition. Upon valve pulsing, the liquid is ejected into a vacuum and breaks up into droplets, which is called liquid aerosol spray target. For the above-mentioned LPP source, firstly, by the use of Cowan program on the basis of non-relativistic quantum mechanics, the authors computed the radiative transition wavelengths and probabilities in soft X-ray region for O4+, O5+, O6+, O7+, F5+, F6+ and F7+ ions which were correspondingly produced from the interaction of the 10(11)-10(12) W x cm(-2) power laser with liquid O2, CO2 and CF4 aerosol spray targets. Secondly, the authors measured the spectra of liquid O2, CO2 and CF4 aerosol spray target LPP sources in the 6-20 nm band for the 8 x 10(11) W x cm(-2) laser irradiance. The measured results were compared with the Cowan calculated results ones, and the radiative transition wavelength and probability for the measured spectral lines were obtained.

77 FR 49001 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

...: Stem Cells, Heart Regeneration, Congenital Heart Defect and Cardiac Valve Disease. Date: September 10... Program Nos. 93.306, Comparative Medicine; 93.333, Clinical Research, 93.306, 93.333, 93.337, 93.393-93...

Wyoming | Solar Research | NREL

Science.gov Websites

There are currently no statewide community solar policies or programs in Wyoming. State Incentive Programs There are currently no statewide solar financial incentive programs in Wyoming. Utility Incentive Programs Please check with your distribution utility for utility incentive programs for midmarket solar

Program for improved electrical harness documentation and fabrication

NASA Technical Reports Server (NTRS)

1971-01-01

Computer program provides automated print-out of harness interconnection table and automated cross-check of reciprocal pin/connector assignments, and improves accuracy and reliability of final documented data. Programs and corresponding library tapes are successfully and continuously employed on Nimbus spacecraft programs.

School Vouchers and Student Achievement: What We Know So Far. Policy Briefs: Education Reform. Volume 3, Number 1

ERIC Educational Resources Information Center

Ladd, Helen F.

2003-01-01

Although small, carefully managed voucher programs might provide a helpful safety valve for some disadvantaged children, policy makers should be under no illusion that such programs will address the fundamental challenge of providing an adequate education to the large numbers of such students in many urban centers. Contrary to the claims of many…