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1

Measurement of static pressure on aircraft  

NASA Technical Reports Server (NTRS)

Existing data on the errors involved in the measurement of static pressure by means of static-pressure tubes and fuselage vents are presented. The errors associated with the various design features of static-pressure tubes are discussed for the condition of zero angle of attack and for the case where the tube is inclined to flow. Errors which result from variations in the configuration of static-pressure vents are also presented. Errors due to the position of a static-pressure tube in the flow field of the airplane are given for locations ahead of the fuselage nose, ahead of the wing tip, and ahead of the vertical tail fin. The errors of static-pressure vents on the fuselage of an airplane are also presented. Various methods of calibrating static-pressure installations in flight are briefly discussed.

Gracey, William

1958-01-01

2

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Static pressure systems. 25.1325 Section 25...Installation § 25.1325 Static pressure systems. (a) Each instrument...located in such manner that the static pressure system performance is least...

2012-01-01

3

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Static pressure systems. 25.1325 Section 25...Installation § 25.1325 Static pressure systems. (a) Each instrument...located in such manner that the static pressure system performance is least...

2013-01-01

4

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Static pressure system. 23.1325 Section 23.1325...Installation § 23.1325 Static pressure system. (a) Each instrument provided with static pressure case connections must be so...

2011-01-01

5

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Static pressure systems. 25.1325 Section 25...Installation § 25.1325 Static pressure systems. (a) Each instrument...located in such manner that the static pressure system performance is least...

2010-01-01

6

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Static pressure system. 23.1325 Section 23.1325...Installation § 23.1325 Static pressure system. (a) Each instrument provided with static pressure case connections must be so...

2013-01-01

7

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Static pressure system. 23.1325 Section 23.1325...Installation § 23.1325 Static pressure system. (a) Each instrument provided with static pressure case connections must be so...

2014-01-01

8

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Static pressure systems. 25.1325 Section 25...Installation § 25.1325 Static pressure systems. (a) Each instrument...located in such manner that the static pressure system performance is least...

2011-01-01

9

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Static pressure system. 23.1325 Section 23.1325...Installation § 23.1325 Static pressure system. (a) Each instrument provided with static pressure case connections must be so...

2012-01-01

10

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Static pressure systems. 25.1325 Section 25...Installation § 25.1325 Static pressure systems. (a) Each instrument...located in such manner that the static pressure system performance is least...

2014-01-01

11

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Static pressure system. 23.1325 Section 23.1325...Installation § 23.1325 Static pressure system. (a) Each instrument provided with static pressure case connections must be so...

2010-01-01

12

Martian Atmospheric Pressure Static Charge Elimination Tool  

NASA Technical Reports Server (NTRS)

A Martian pressure static charge elimination tool is currently in development in the Electrostatics and Surface Physics Laboratory (ESPL) at NASA's Kennedy Space Center. In standard Earth atmosphere conditions, static charge can be neutralized from an insulating surface using air ionizers. These air ionizers generate ions through corona breakdown. The Martian atmosphere is 7 Torr of mostly carbon dioxide, which makes it inherently difficult to use similar methods as those used for standard atmosphere static elimination tools. An initial prototype has been developed to show feasibility of static charge elimination at low pressure, using corona discharge. A needle point and thin wire loop are used as the corona generating electrodes. A photo of the test apparatus is shown below. Positive and negative high voltage pulses are sent to the needle point. This creates positive and negative ions that can be used for static charge neutralization. In a preliminary test, a floating metal plate was charged to approximately 600 volts under Martian atmospheric conditions. The static elimination tool was enabled and the voltage on the metal plate dropped rapidly to -100 volts. This test data is displayed below. Optimization is necessary to improve the electrostatic balance of the static elimination tool.

Johansen, Michael R.

2014-01-01

13

14 CFR 27.1325 - Static pressure systems.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Static pressure systems. 27.1325 Section 27...Installation § 27.1325 Static pressure systems. (a) Each instrument...affect its accuracy. (b) Each static pressure port must be designed and located...

2012-01-01

14

14 CFR 27.1325 - Static pressure systems.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Static pressure systems. 27.1325 Section 27...Installation § 27.1325 Static pressure systems. (a) Each instrument...affect its accuracy. (b) Each static pressure port must be designed and located...

2014-01-01

15

14 CFR 27.1325 - Static pressure systems.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Static pressure systems. 27.1325 Section 27...Installation § 27.1325 Static pressure systems. (a) Each instrument...affect its accuracy. (b) Each static pressure port must be designed and located...

2013-01-01

16

14 CFR 27.1325 - Static pressure systems.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Static pressure systems. 27.1325 Section 27...Installation § 27.1325 Static pressure systems. (a) Each instrument...affect its accuracy. (b) Each static pressure port must be designed and located...

2011-01-01

17

14 CFR 27.1325 - Static pressure systems.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Static pressure systems. 27.1325 Section 27...Installation § 27.1325 Static pressure systems. (a) Each instrument...affect its accuracy. (b) Each static pressure port must be designed and located...

2010-01-01

18

14 CFR 29.1325 - Static pressure and pressure altimeter systems.  

Code of Federal Regulations, 2013 CFR

...through an appropriate piping system. (b) Each vent must...pressure in the static pressure system and true ambient atmospheric...encounters icing conditions. An anti-icing means or an alternate source...the alternate static pressure system, differs from the...

2013-01-01

19

14 CFR 29.1325 - Static pressure and pressure altimeter systems.  

Code of Federal Regulations, 2011 CFR

...through an appropriate piping system. (b) Each vent must...pressure in the static pressure system and true ambient atmospheric...encounters icing conditions. An anti-icing means or an alternate source...the alternate static pressure system, differs from the...

2011-01-01

20

14 CFR 29.1325 - Static pressure and pressure altimeter systems.  

Code of Federal Regulations, 2010 CFR

...through an appropriate piping system. (b) Each vent must...pressure in the static pressure system and true ambient atmospheric...encounters icing conditions. An anti-icing means or an alternate source...the alternate static pressure system, differs from the...

2010-01-01

21

14 CFR 29.1325 - Static pressure and pressure altimeter systems.  

Code of Federal Regulations, 2014 CFR

...through an appropriate piping system. (b) Each vent must...pressure in the static pressure system and true ambient atmospheric...encounters icing conditions. An anti-icing means or an alternate source...the alternate static pressure system, differs from the...

2014-01-01

22

14 CFR 29.1325 - Static pressure and pressure altimeter systems.  

Code of Federal Regulations, 2012 CFR

...through an appropriate piping system. (b) Each vent must...pressure in the static pressure system and true ambient atmospheric...encounters icing conditions. An anti-icing means or an alternate source...the alternate static pressure system, differs from the...

2012-01-01

23

Pressure  

NSDL National Science Digital Library

This page contains three Physlets that are able to share data using a connection made by a common superclass, SApplet. The ensemble walls keep track of the change in momentum, i.e., the pressure, during each time step, dt, and provides this data to the DataGraph Physlet and the DataTable Physlet.

Wolfgang Christian

24

30 CFR 550.1153 - When must I conduct a static bottomhole pressure survey?  

Code of Federal Regulations, 2014 CFR

...When must I conduct a static bottomhole pressure survey? 550.1153 Section 550...When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the following...

2014-07-01

25

30 CFR 550.1153 - When must I conduct a static bottomhole pressure survey?  

Code of Federal Regulations, 2012 CFR

...When must I conduct a static bottomhole pressure survey? 550.1153 Section 550...When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the following...

2012-07-01

26

30 CFR 250.1153 - When must I conduct a static bottomhole pressure survey?  

Code of Federal Regulations, 2010 CFR

...When must I conduct a static bottomhole pressure survey? 250.1153 Section 250...When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the following...

2010-07-01

27

30 CFR 250.1153 - When must I conduct a static bottomhole pressure survey?  

Code of Federal Regulations, 2011 CFR

...When must I conduct a static bottomhole pressure survey? 250.1153 Section 250...When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the following...

2011-07-01

28

30 CFR 550.1153 - When must I conduct a static bottomhole pressure survey?  

Code of Federal Regulations, 2013 CFR

...When must I conduct a static bottomhole pressure survey? 550.1153 Section 550...When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the following...

2013-07-01

29

Plasticity under pressure: static experiments and models  

NASA Astrophysics Data System (ADS)

Over the last few years, we developed new methods for the study of plastic properties of materials under high pressures and temperatures. These include a broad range of experimental techniques, such as radial diffraction in the diamond anvil cell (DAC), usage of the D-DIA deformation apparatus and, more recently, 3D x-ray diffraction in the DAC. Overall, we can now study the behavior of materials up to 300 GPa at ambient temperature, 70 GPa and 1500 K in the DAC and 20 GPa and 2500 K in the D-DIA. In most experiments, in-situ x-ray diffraction in used to extract quantitative texture information and elastic strains within the sample. The experimental data is then combined with self-consistent plasticity numerical models in order to understand the behavior of the material. In this presentation, I will show results on the hcp phase of Co deformed at 300 K between 0 and 42 GPa and results on the hcp phase of Fe deformed at pressures and temperatures reaching 19 GPa and 600 K. I will highlight how the combination of x-ray diffraction and EPSC modeling can be used to infer important information, such as the average stress within the sample, identify and constrain the plastic deformation mechanisms that were activated, and evaluate stress heterogeneity with the sample. In the last part of the talk, I will introduce techniques based on 3D x-ray diffraction and show how they can be used to constrain grain to grain stress heterogeneities and identify dislocations, in-situ, within a sample under high pressure. In the future, a combination of 3D methods and average techniques of the radial diffraction combined with self-consistent models will offer great opportunities to understand and model plastic behavior under pressure.

Merkel, Sebastien

2011-06-01

30

Behavior of Static Pressure Heads at High Speeds  

NASA Technical Reports Server (NTRS)

These tests proved the practicability of static pressure heads at speeds up to 400 km/h (248.5 mph). It weighs 6.5 kg or 2.5 times as much as the old head. The position of the pressure head below the airplane was determined by bearing method at different speeds and for different lengths of suspension. It was established that for the measured speed range a 20 to 24 meter suspension length was sufficient to assure a minimum distance of 6 meters from the airplane without introducing any appreciable errors in the results due to wrong static pressure.

Danielzig, Helmut

1938-01-01

31

Portable dynamic pressure generator for static and dynamic calibration of in situ pressure transducers  

NASA Technical Reports Server (NTRS)

A portable dynamic pressure generator was developed to meet the requirements of determining the dynamic sensitivities of in situ pressure transducers at low frequencies. The device is designed to operate in a frequency range of 0 to 100 Hz, although it was only tested up to 30 Hz, and to generate dynamic pressures up to 13.8 kPa (2 psi). A description of the operating characteristics and instrumentation used for pressure, frequency, and displacement measurements is given. The pressure generator was used to statically and dynamically calibrate transducers. Test results demonstrated that a difference an exist between the static and dynamic sensitivity of a transducer, confirming the need for dynamic calibrations of in situ pressure transducers.

Bolt, P. A.; Hess, R. W.; Davis, W. T.

1983-01-01

32

Description of a Pressure Measurement Technique for Obtaining Surface Static Pressures of a Radial Turbine  

NASA Technical Reports Server (NTRS)

The aerodynamic performance of a solid uncooled version of a cooled radial turbine was evaluated in the Small Engine Components Test Facility Turbine rig at the NASA Lewis Research Center. Specifically, an experiment was conducted to rotor surface static pressures. This was the first time surface static pressures had been measured on a radial turbine at NASA Lewis. These pressures were measured by a modified Rotating Data Package (RDP), a standard product manufactured by Scanivalve, Inc. Described here are the RDP, and the modifications that were made, as well as the checkout, installation, and testing procedures. The data presented are compared to analytical results obtained from NASA's MERIDL TSONIC BLAYER (MTSB) code.

Dicicco, L. Danielle; Nowlin, Brent C.; Tirres, Lizet

1992-01-01

33

Static pressure and temperature compensated wideband fiber laser hydrophone  

NASA Astrophysics Data System (ADS)

Sensitive optical hydrophone is a key component for the design of compact fully optical acoustic arrays and one major issue about this kind of sensors is their sensitivity to hydrostatic pressure and temperature. We present in this paper a compact hydrophone which is optimized for reduced temperature sensitivity and high static pressure capability. High acoustic sensitivity is obtained through wideband mechanical amplification design. Two mock-ups have been realized and the measurements show good agreements with finite-element model. We present acoustic measurements as well as measurements in environmental conditions (temperature and pressure) obtained with a low noise opto-electronic interrogation system.

Launay, F.-X.; Lardat, R.; Bouffaron, R.; Roux, G.; Doisy, M.; Bergogne, C.

2013-05-01

34

Blood pressure response to low level static contractions  

Microsoft Academic Search

Summary  The present study re-examines the 15% MVC concept, i.e. the existence of a circulatory steady-state in low intensity static contractions below 15% of maximal voluntary contraction (MVC). Mean arterial blood pressure was studied during static endurance contractions of the elbow flexor and extensor muscles at forces corresponding to 10% and 40% MVC. Mean value for endurance time at 10% MVC

Nils Fallentin I; Kurt Jørgensen

1992-01-01

35

Radio jet refraction in galactic atmospheres with static pressure gradients  

NASA Technical Reports Server (NTRS)

A theory of double radio sources which have a 'Z' or 'S' morphology is proposed, based on the refraction of radio jets in the extended atmosphere of an elliptical galaxy. The model describes a collimated jet of supersonic material bending self-consistently under the influence of external static pressure gradients. Gravity and magnetic fields are neglected in the simplest case except insofar as they determine the static pressure distribution. The calculation is a straightforward extension of a method used to calculate a ram-pressure model for twin radio trails ('C' morphology). It may also be described as a continuous-jet version of a buoyancy model proposed in 1973. The model has the added virtue of invoking a galactic atmosphere similar to those already indicated by X-ray measurements of some other radio galaxies and by models for the collimation of other radio jets.

Henriksen, R. N.; Vallee, J. P.; Bridle, A. H.

1981-01-01

36

A hot-film static-pressure probe  

NASA Technical Reports Server (NTRS)

The procedure described involves calibrating the probe in the gas of interest over the range of temperatures and pressures anticipated in the wind-tunnel tests and then applying the calibration to reduce the data from those tests. Pressure readings from two probes, one having two hot-film sensors and an internal sonic orifice and the other connected to a conventional pressure gage, are recorded for several Reynolds numbers and compared. The conventional static-pressure probe with a pair of hot-film sensors and an interior sonic orifice is shown to provide the means of surveying flowfields in hypersonic flow at a rapid rate and with an accuracy of better than + or - 10%.

Ashby, G. C., Jr.; Weinstein, L. M.

1982-01-01

37

Static and dynamic high pressure experiments on cerium  

SciTech Connect

There is a scientific need to obtain dynamic data to develop and validate multi phase equation-of-state (EOS) models for metals. Experiments are needed to examine the relevant pure phases, to locate phase boundaries and the associated transition kinetics, and other material properties such as strength. Cerium is an ideal material for such work because it exhibits a complex multiphase diagram at relatively moderate pressures readily accessible using standard shock wave methods. In the current work, shock wave (dynamic) and diamond anvil cell (static) experiments were performed to examine the high pressure, low temperature region of the phase diagram to obtain EOS data and to search for the {alpha}-{var_epsilon} boundary. Past work examining the shock-melt transition and the low-pressure {gamma}-{alpha} transition will be presented in brief followed by details of recent results obtained from DAC and double-shock experiments.

Jensen, Brian J [Los Alamos National Laboratory; Velisavljevic, Nenad [Los Alamos National Laboratory; Cherne, Frank J [Los Alamos National Laboratory; Stevens, Gerald [NST, STL; Tschauner, Oliver [UNIV OF NEVADA

2011-01-25

38

Plume diagnostics of SRM static firings for pressure perturbation studies  

NASA Technical Reports Server (NTRS)

During the shuttle launches, the solid rocket motors (SRM) occasionally experience pressure perturbations (8-13 psi) between 65 and 75 seconds into the motor burn time. The magnitudes of these perturbations are very small in comparison with the operating motor chamber pressure, which is over 600 psi during this time frame. These SRM pressure perturbations are believed to be caused primarily by the expulsion of slag (aluminum oxide). Two SRM static tests, TEM-11 and FSM-4, were instrumented extensive]y for the study of the phenomenon associated with pressure perturbations. The test instrumentation used included nonintrusive optical and infrared diagnostics of the plume, such as high-speed photography, radiometers, and thermal image cameras. Results from all these nonintrusive observations strongly support the scenario that the pressure perturbation event in the shuttle SRM is caused primarily by the expulsion of molten slag. The slag was also expelled preferentially near the bottom of the nozzle due to slag accumulation at the bottom of the aft end of the horizontally oriented motor.

Sambamurthi, J. K.; Alvarado, Alexis; Mathias, Edward C.

1995-01-01

39

14 CFR 33.64 - Pressurized engine static parts.  

Code of Federal Regulations, 2010 CFR

...normal working pressure; or (iii) 35 kPa (5 p.s.i.) above the normal working pressure. (2) Exhibit fracture or burst when subjected to the greater of the following pressures: (i) 1.15 times the maximum possible pressure; (ii)...

2010-01-01

40

Investigation of the Circumferential Static Pressure Non-Uniformity Caused by a Centrifugal Compressor Discharge Volute  

Microsoft Academic Search

The paper describes experimental and computational fluid dynamics analyses of the non-uniform static pressure distortion caused by the discharge volute in a high pressure, centrifugal compressor. The experiments described in this paper were done using a heavily instrumented gas re-injection compressor operating at over 6000 psia discharge. Instrumentation was installed to measure static, total, and dynamic pressure as well as

James M. Sorokes; Cyril J. Borer; Jay M. Koch

41

Static Pressure of Hot Gas: Its Effect on the Gas Disks of Galaxies  

E-print Network

The static pressure of the hot gas that fills clusters and groups of galaxies can affect significantly the volume density and thickness of the gas disks in galaxies. In combination with the dynamic pressure, the static pressure allows several observed peculiarities of spiral galaxies surrounded by a hot medium to be explained.

Anatoly V. Zasov; Alexander V. Khoperskov

2008-10-29

42

Static method to measure vapor pressure in the temperature range below 1100 K  

NASA Astrophysics Data System (ADS)

In this paper, a static method of measuring vapor pressure with an optically flat glass-membrane pressure sensor in the temperature range below 1100 K is described. The furnace is designed so that the pressure can be measured contactlessly by the null method. A method of automatic pressure control using this sensor is described as well. The method is capable of controlling the pressure to the order of the sensitivity of the membrane.

Nishimura, Jiro; Numata, Takashi; Ogasawara, Hiromitsu; Sakanoue, Yoshio

1985-12-01

43

Impacts of Static Pressure Set Level on the HVAC Energy Consumption and Indoor Conditions  

E-print Network

Air static pressure must be maintained at a certain level leaving the air-handing unit (AHU) to force a suitable amount of air through the terminal boxes. However, an excessive static pressure level is often used due to ( 1 ) lack of a control...

Liu, M.; Zhu, Y.; Claridge, D. E.; White, E.

1996-01-01

44

Mechanical characteristics of human skin subjected to static versus cyclic normal pressures  

Microsoft Academic Search

Several hypotheses exist for the etiology of decubitus ulcers, with external pressures exceeding internal capillary pressures over bony prominences claimed to be the major factor. This investigation evaluated the mechanical changes that occurred in human skin as a result of its exposure to static versus cyclic normal pressures of the magnitudes earlier recorded for the heels of human subjects on

Laura E. Edsberg; Robert E. Mates; Robert E. Baier; Mark Lauren

1999-01-01

45

Effects of static fingertip loading on carpal tunnel pressure  

NASA Technical Reports Server (NTRS)

The purpose of this study was to explore the relationship between carpal tunnel pressure and fingertip force during a simple pressing task. Carpal tunnel pressure was measured in 15 healthy volunteers by means of a saline-filled catheter inserted percutaneously into the carpal tunnel of the nondominant hand. The subjects pressed on a load cell with the tip of the index finger and with 0, 6, 9, and 12 N of force. The task was repeated in 10 wrist postures: neutral; 10 and 20 degrees of ulnar deviation; 10 degrees of radial deviation; and 15, 30, and 45 degrees of both flexion and extension. Fingertip loading significantly increased carpal tunnel pressure for all wrist angles (p = 0.0001). Post hoc analyses identified significant increase (p < 0.05) in carpal tunnel pressure between unloaded (0 N) and all loaded conditions, as well as between the 6 and 12 N load conditions. This study demonstrates that the process whereby fingertip loading elevates carpal tunnel pressure is independent of wrist posture and that relatively small fingertip loads have a large effect on carpal tunnel pressure. It also reveals the response characteristics of carpal tunnel pressure to fingertip loading, which is one step in understanding the relationship between sustained grip and pinch activities and the aggravation or development of median neuropathy at the wrist.

Rempel, D.; Keir, P. J.; Smutz, W. P.; Hargens, A.

1997-01-01

46

Warm Pressurant Gas Effects on the Static Bubble Point Pressure for Cryogenic LADs  

NASA Technical Reports Server (NTRS)

This paper presents experimental results for the liquid hydrogen and nitrogen bubble point tests using warm pressurant gases conducted at the NASA Glenn Research Center. The purpose of the test series was to determine the effect of elevating the temperature of the pressurant gas on the performance of a liquid acquisition device (LAD). Three fine mesh screen samples (325x2300, 450x2750, 510x3600) were tested in liquid hydrogen and liquid nitrogen using cold and warm non-condensable (gaseous helium) and condensable (gaseous hydrogen or nitrogen) pressurization schemes. Gases were conditioned from 0K - 90K above the liquid temperature. Results clearly indicate degradation in bubble point pressure using warm gas, with a greater reduction in performance using condensable over non-condensable pressurization. Degradation in the bubble point pressure is inversely proportional to screen porosity, as the coarsest mesh demonstrated the highest degradation. Results here have implication on both pressurization and LAD system design for all future cryogenic propulsion systems. A detailed review of historical heated gas tests is also presented for comparison to current results.

Hartwig, Jason W.; McQuillen, John; Chato, Daniel J.

2014-01-01

47

DEFLAGRATION RATES OF SECONDARY EXPLOSIVES UNDER STATIC MPA - GPA PRESSURE  

SciTech Connect

We provide measurements of the chemical reaction propagation rate (RPR) as a function of pressure using diamond anvil cell (DAC) and strand burner technologies. Materials investigated include HMX and RDX crystalline powders, LX-04 (85% HMX and 15% Viton A), and Composition B (63% RDX, 36% TNT, 1% wax). The anomalous correspondence between crystal structure, including in some instances isostructural phase transitions, on pressure dependent RPRs of HMX and RDX are correlated to confocal micro-Raman spectroscopic results. The contrast between DAC GPa and strand burner MPa regime measurements yield insight into explosive material burn phenomena. Here we highlight pressure dependent physicochemical mechanisms that appear to affect the deflagration rate of precompressed energetic materials.

Zaug, J; Young, C; Long, G; Maienschein, J; Glascoe, E; Hansen, D; Wardell, J; Black, C; Sykora, G

2009-07-30

48

An Investigation of Alternative Methods for Measuring Static Pressure of Unitary Air Conditioners and Heat Pumps  

E-print Network

This project was created to address an important issue currently faced by test facilities measuring static pressure for air-conditioning and heat pumps. Specifically, ASHRAE Standard 37, the industry standard for test setup, requires an outlet duct...

Wheeler, Grant Benson

2013-08-12

49

Static Pressure Losses in 6 in., 8 in., and 10 in. Nonmetallic Flexible Duct (RP-1333)  

E-print Network

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Static Pressure Losses in Nonmetallic Flexible Duct Weaver, Kevin;Culp, Charles ASHRAE Transactions; 2007; 113, ProQuest pg. 400 Reproduced...

Weaver, K.; Culp, C.H.

50

Analysis of static and wave-induced pore pressures in marine sediments  

E-print Network

ANALYSIS OF STATIC AND WAVE-INDUCED PORE PRESSURES IN MARINE SEDIMENTS A Thesis by GARRETT EDWIN WILLIAMS Submitted to the Graduate College of Texas ALII University in partial fulfillment of the requirement for the degree of I1ASTER DF... SCIENCE August 1979 Major Subject. : Civil Engineering ANALYSIS OF STATIC AND WAVE-INDUCED PORE PRESSURES IN MARINE SEDIMENTS A Thesis by GARRETT EDWIN WILLIAMS Approved as to style and content by: Wayne A. Dunlap (CE)(Chairm of Committee) Harry...

Williams, Garrett Edwin

1979-01-01

51

Hot-film static-pressure probe for surveying flow fields  

NASA Technical Reports Server (NTRS)

A static pressure probe employing hot-film sensors has been developed for the rapid measurement of the static pressure fields surrounding analytic shapes in hypersonic flows. The hot-film probe is a modification of the standard static pressure probe, consisting of a front hot-film sensor operated as a resistance thermometer, a rear sensor operated at an overheat ratio of 1.5 to 1.8 and a small sonic orifice installed inside the tubing of a conventional device. The probe has been calibrated in helium and air over a range of temperatures and pressures in a bell jar apparatus, with a repeatability of the data to within + or - 0.015 mm Hg. Comparative tests of the hot-film and conventional static pressure probes in a hypersonic helium wind tunnel at Mach 20 and various Reynolds numbers have indicated the settling time of the hot-film probe to be on the order of milliseconds, as compared with 30 sec for the conventional probe. The pressures measured by the two probes were found to be within 10% of each other. Although the hot-film probe makes flow-field static pressure surveys more practical in blowdown hypersonic wind tunnels, viscous and flow angle effects still must be assessed under the conditions of use.

Ashby, G. C., Jr.; Weinstein, L. M.

1981-01-01

52

Instrumentation for measuring static pressure fluctuations within the atmospheric boundary layer  

Microsoft Academic Search

An instrument is described which is capable of making Eulerian measurements of microscale fluctuations in the static pressure when it is placed within the turbulent flow of the lower atmospheric boundary layer. The sampling ports are located on an accurately shaped streamlined circular disc; dynamic pressure changes at these ports, due to the flow fluctuations, are small when compared to

J. A. Elliott

1972-01-01

53

Effect of empennage arrangement on single-engine nozzle/afterbody static pressures at transonic speeds  

NASA Technical Reports Server (NTRS)

An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects on empennage arrangement on single-engine nozzle/afterbody static pressures. Tests were done at Mach numbers from 0.60 to 1.20, nozzle pressure ratios from 1.0 (jet off) to 8.0. and angles of attack from -3 to 9 deg (at jet off conditions), depending on Mach number. Three empennage arrangements (aft, staggered, and forward) were investigated. Extensive measurements were made of static pressure on the nozzle/afterbody in the vicinity of the tail surfaces.

Henderson, William P.; Burley, James R., II

1987-01-01

54

A simple apparatus for time-resolved x-ray diffraction biostructure studies using static and oscillating pressures and pressure jumps  

Microsoft Academic Search

A beryllium rod with an internal bore diameter of 1.5 mm and a wall thickness of 2.4 mm constitutes an x-ray compatible cell for hydrostatic pressures rated up to 1800 bar (180 MPa, 26 000 psi) at temperatures up to 90 °C. The system can be used to produce static and oscillating pressures, pressure ramps, and pressure jumps. Pressure is

Andrés Mencke; An-Chi Cheng; Martin Caffrey

1993-01-01

55

Relationship between Entrainment and Static Pressure Field on 2-D Jets.  

NASA Astrophysics Data System (ADS)

It is well know that entrainment carried out in wakes and jets. This experimental study aimes at investigation the relationship between the entrainment and the pressure field in 2-D jet. The 2-D jet was generated by 2-D rectangular wind tunnel. The velocity and prressure fields were observed in order to investigate the free shear layer of jet. These value were measured by the x type hot-wire anemometer, LDV and the newly developed static pressure probe. Jet diffusion process is visualized by smoke wire method. The result of the experiment was that the static pressure fluctuated intensively, and was negative mean value because of the velocity intermittence in the free shear layer of the 2-D jet. It seems reasonable to suppose that entrainment occurs owing to the negative static pressure by the eddy motion and large scale convection in the free shear layer.

Kimura, M.; Ono, K.; Saima, A.

1996-11-01

56

OILMUD; A microcomputer program for predicting oil-based mud densities and static pressures  

SciTech Connect

This paper reports on OILMUD which is a program for predicting the densities and hydrostatic pressures in oil-based mud columns at high pressures an temperatures. The program uses multiple-linear-regression analysis on experimental data to calculate the densities and static pressures for diesel-oil-based mud and for four less-toxic mineral-oil-based muds. This menu-driven, easy-to-use program runs on an IBM personal computer and compatible systems. It can be used by a drilling engineer to estimate downhole densities and pressures during drilling on the basis of surface measurements or to plan the mud program for a new well.

Peters, E.J.; Chenevert, M.E.; Alhamadah, A.M. (Univ. of Texas (US))

1991-03-01

57

Helium at elevated pressures: Quantum liquid with non-static shear rigidity  

NASA Astrophysics Data System (ADS)

The properties of liquid helium have always been a fascinating subject to scientists. The phonon theory of liquids, taking into account liquid non-static shear rigidity, is employed here for studying internal energy and heat capacity of compressed liquid 4He. We demonstrate the good agreement of calculated and experimental heat capacity of liquid helium at elevated pressures and supercritical temperatures. Unexpectedly, helium remains a quantum liquid at elevated pressures for a wide range of temperature supporting both longitudinal and transverse-like phonon excitations. We have found that in the very wide pressure range of 5 MPa-500 MPa, liquid helium near melting temperature is both solid-like and quantum.

Bolmatov, D.; Brazhkin, V. V.; Trachenko, K.

2013-03-01

58

The effect of static pressure on the strength of inertial cavitation events.  

PubMed

Recent investigations of cavitation in fluids pressurized up to 30 MPa found that the intensity of light emissions increased by 1000-fold over that measured for single bubble sonoluminescence. A series of measurements is reported here to extend this original work by resolving the static pressure dependence of the shock wave and light emissions from the first and the most energetic collapses, along with the total shock wave energy and light emissions for the event. Each of these parameters was found to increase with the static pressure of the fluid. Furthermore, the energy of these shock wave and light emissions was found to increase in proportion to the stored acoustic energy in the system. These findings were corroborated using the Gilmore equation to numerically compute the work done by the liquid during the bubble collapse. The overall findings suggest that the increased collapse strength at high static pressure is due to the increased tension required to generate inertial cavitation, and not an increased pressure gradient between the interior of the vaporous bubble and the surrounding liquid. PMID:23039425

Bader, Kenneth B; Mobley, Joel; Church, Charles C; Gaitan, D Felipe

2012-10-01

59

Energy concentration and positional stability of sonoluminescent bubbles in sulfuric acid for different static pressures  

NASA Astrophysics Data System (ADS)

In this study we report several experimental and numerical results on the influence of static pressure (P0) over the main parameters in single bubble sonoluminescence (SBSL), using a sulfuric acid aqueous solution (SA) with low concentrations of argon gas dissolved. Bifrequency driving was used in the experiments to enhance spatial stability of the bubbles. The experimental results were compared with simulations provided by a numerical code that models the radial dynamics of the bubbles. The results showed that an increase on the static pressure of the system shifts the Bjerknes instability threshold, allowing the bubble to access higher acoustic pressures (PAc). Furthermore, a decrease in the measured ambient radius R0 and the calculated relative gas concentration c?/c0 were observed. A notorious increment in the bubble collapse violence and energy focusing for P0 above 1 bar was achieved. These were mainly indicated by the growth of the bubble expansion ratio (Rmax/R0), the bubble mechanical energy density, and the maximum bubble wall velocity dR/dt. In agreement with the previous statement, the maximum temperature during the bubble collapse predicted by the model is augmented as well. The use of different harmonics in the ultrasound pressure field regarding energy focusing is also discussed. Finally, we analyzed the stability regions of the R0-PAc parameter space via numerical predictions for P0 above the measured, identifying the shape instabilities as the main limiting agent to obtain further energy concentration in SA systems at high static pressures.

Rosselló, Juan Manuel; Dellavale, Damián; Bonetto, Fabián José

2013-09-01

60

Effects of microgravity on interstitial muscle receptors affecting heart rate and blood pressure during static exercise  

Microsoft Academic Search

Afferent nerve fibers from receptors situated in the interstitium of skeletal muscles can induce cardiovascular reflexes. It has been shown that these interstitial muscle receptors are also sensitive to the local state of hydration: increased heart rates and blood pressure values were seen during dynamic and static exercise after local dehydration on earth. Since weightlessness leads to a persisting fluid

D. Essfeld; K. Baum; U. Hoffmann; J. Stegemann

1993-01-01

61

ROLE OF STATIC LOAD (OVERBURDEN) PRESSURE IN COALIFICATION OF BITUMINOUS AND ANTHRACITIC COAL.  

USGS Publications Warehouse

Tissue from a calcite concretion (coal ball) and attached coal of semianthracite rank from the Belgium Bouxharmont coal bed were analyzed separately by elemental chemical, **1**3C nuclear magnetic resonance, reflectance, and paleobotanical techniques to compare relative degrees of coalification. The results indicate that static load pressure has no perceptible effect on coalification up to and including a rank of semianthracite.

Lyons, P.C.; Hatcher, P.G.; Brown, F.W.; Krasnow, M.R.; Larson, R.R.; Millay, M.A.

1985-01-01

62

Static Pressure Losses in 6, 8, and 10-inch Non-Metallic Flexible Ducts  

E-print Network

This study measured airflow static pressure losses through non-metallic flexible ducts in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6, 8...

Weaver, K.; Culp, C.

2006-01-01

63

Non-linear optical properties of molecular systems under high static pressures  

NASA Astrophysics Data System (ADS)

Applied static pressure can largely modify the structure and dynamics of molecular systems, with consequences on their optical properties and chemical stability. When photochemical effects are exploited in conjunction with the structural and dynamical conditions attained at high density, chemical reactivity may become highly selective and efficient, yielding technologically attractive products. Non-linear optical spectroscopies are a powerful tool to investigate molecular energetics and dynamics, and thus unveil key aspects of the chemical reactivity at a molecular level. Their application to high-pressure samples is experimentally challenging, mainly because of the small sample dimensions and the non-linear effects generated in the anvil materials. In this paper we review the main results on the behavior of electronic states at high pressure, obtained by non-linear optical techniques, discussing the relationship between pressure-induced structural modifications and chemical reactivity, and the state of the art of ongoing research.

Citroni, M.; Fanetti, S.; Foggi, P.; Bini, R.

2014-05-01

64

Determination of the Thermodynamic Scaling Exponent from Static, Ambient-Pressure Quantities  

E-print Network

An equation is derived that expresses the thermodynamic scaling exponent, g, which superposes relaxation times and other measures of molecular mobility determined over a range of temperatures and densities, in terms of static, physical quantities. The latter are available in the literature or can be measured at ambient pressure. We show for 13 materials, both molecular liquids and polymers, that the calculated g are equivalent to the scaling exponents obtained directly by superpositioning. The assumptions of the analysis are that the glass transition is isochronal and that the first Ehrenfest relation is valid; the first assumption is true by definition, while the second has been corroborated for many glass-forming materials at ambient pressure. However, we find that the Ehrenfest relation breaks down at elevated pressure, although this limitation is of no consequence herein, since the appeal of the new equation is its applicability to ambient pressure data.

R. Casalini; C. M. Roland

2014-03-18

65

Spectral scaling of static pressure fluctuations in the atmospheric surface layer: The interaction between large and small scales  

E-print Network

Spectral scaling of static pressure fluctuations in the atmospheric surface layer: The interaction, University of Iowa, Iowa City, Iowa 52242 Received 17 March 1997; accepted 2 February 1998 Static pressure fluctuations measured in the atmospheric surface layer over a grass covered forest clearing are studied

Katul, Gabriel

66

Plume Diagnostics of the RSRM Static Firings for the Pressure Perturbation Studies  

NASA Technical Reports Server (NTRS)

During the STS-54 launch (RSRM-29), the right hand solid rocket motor experienced a 13.9 psi chamber pressure perturbation at 67 seconds into the motor operation. This pressure augmentation equated to a thrust change of 51 klb. Concerns were raised regarding the adverse effects of this thrust imbalance on the shuttle system and the overall thrust into the external tank structural elements. Pressure perturbations have been observed in solid rocket motors due to expulsion of igniter or insulation materials; the motor thrust during such events drop abruptly before rising. However, the RSRM motors do not exhibit such behavior during the large chamber pressure perturbation events. Several scenarios were investigated to explain these pressure perturbations in the RSRM motors based on a fault tree developed after STS-54. Of these, the expulsion of the slag accumulated in the submerged nozzle region appeared to be the most plausible scenario to explain the observations. Slag is a natural combustion product of aluminized solid rocket motors. The RSRM propellant contains 16% by weight of aluminum. Any ejection of this slag mass during nozzle vectoring or other side loads on the motor will result in the chamber pressure perturbation. Two RSRM static firings were instrumented extensively to further understand the slag expulsion phenomenon in the RSRM and the associated pressure perturbations.

Mathias, Edward C.; Sambamurthi, Jay K.; Alvarado, Alexis

1995-01-01

67

Effects of geometric scaling on static pressure measurements in orifice flow-meters  

E-print Network

of the flange tap in typical orifice meters on pipes of different sizes. This was accomplished by comparing the static pressure distribution in a 60. 96 cm (2 foot) diameter orifice run to that on a 5. 08 cm (2 inch) diameter orifice run using air... pressure distributions along the wall of the pipe at various Reynolds numbers in the 60. 96 cm (2 foot) orifice run for p ratios of 0. 5 and 0. 75 and Reynolds numbers overlapping at least four flow cases previously studied on the 5. 08 cm (2 inch) pipe...

Sarker, Arunava

1993-01-01

68

Role of potassium in the reflex regulation of blood pressure during static exercise in man.  

PubMed Central

1. The relationship between [K+] in venous effluent blood and alterations in mean arterial blood pressure was studied during static handgrip contractions at 15 and 30% of maximal voluntary contraction (MVC). 2. To further elucidate the importance of K+ in the reflex regulation of blood pressure a situation with normal recovery was compared with a situation in which 3 min of post-exercise occlusion was applied by arresting the circulation to the forearm just prior to the cessation of the contraction. 3. There was a temporal as well as quantitative correlation between venous [K+] and the blood pressure response during and after static exercise. During 30% MVC mean arterial blood pressure (MAP) attained 161.7 mmHg and venous [K+] 5.8 mM, while the corresponding values during 15% MVC were 121.5 mmHg and 5.0 mM. 4. In the occlusion period mean arterial blood pressure remained elevated above resting level and provided a measure of the magnitude of muscle chemoreflexes. In the same period venous [K+] was maintained at 5.3 mM and 4.6 mM following 30% MVC and 15% MVC respectively. This is indicative of interstitial concentrations of above 8-10 mM. This level is sufficiently high to stimulate type III and IV muscle afferents involved in the reflex regulation of blood pressure, and strengthens the notion that K+ may play an important role in eliciting the pressor reflex. 5. In contrast to [K+] the time course of venous blood concentrations of lactate and ammonia (NH3) exhibited a clear dissociation from the blood pressure recordings. PMID:1403829

Fallentin, N; Jensen, B R; Byström, S; Sjøgaard, G

1992-01-01

69

Heart Rate Variability and Blood Pressure during Dynamic and Static Exercise at Similar Heart Rate Levels  

PubMed Central

Aim was to elucidate autonomic responses to dynamic and static (isometric) exercise of the lower limbs eliciting the same moderate heart rate (HR) response. Method: 23 males performed two kinds of voluntary exercise in a supine position at similar heart rates: static exercise (SE) of the lower limbs (static leg press) and dynamic exercise (DE) of the lower limbs (cycling). Subjective effort, systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), rate pressure product (RPP) and the time between consecutive heart beats (RR-intervals) were measured. Time-domain (SDNN, RMSSD), frequency-domain (power in the low and high frequency band (LFP, HFP)) and geometric measures (SD1, SD2) as well as non-linear measures of regularity (approximate entropy (ApEn), sample entropy (SampEn) and correlation dimension D2) were calculated. Results: Although HR was similar during both exercise conditions (88±10 bpm), subjective effort, SBP, DBP, MAP and RPP were significantly enhanced during SE. HRV indicators representing overall variability (SDNN, SD 2) and vagal modulated variability (RMSSD, HFP, SD 1) were increased. LFP, thought to be modulated by both autonomic branches, tended to be higher during SE. ApEn and SampEn were decreased whereas D2 was enhanced during SE. It can be concluded that autonomic control processes during SE and DE were qualitatively different despite similar heart rate levels. The differences were reflected by blood pressure and HRV indices. HRV-measures indicated a stronger vagal cardiac activity during SE, while blood pressure response indicated a stronger sympathetic efferent activity to the vessels. The elevated vagal cardiac activity during SE might be a response mechanism, compensating a possible co-activation of sympathetic cardiac efferents, as HR and LF/HF was similar and LFP tended to be higher. However, this conclusion must be drawn cautiously as there is no HRV-marker reflecting “pure” sympathetic cardiac activity. PMID:24349546

Weippert, Matthias; Behrens, Kristin; Rieger, Annika; Stoll, Regina; Kreuzfeld, Steffi

2013-01-01

70

Energy concentration and positional stability of sonoluminescent bubbles in sulfuric acid for different static pressures.  

PubMed

In this study we report several experimental and numerical results on the influence of static pressure (P_{0}) over the main parameters in single bubble sonoluminescence (SBSL), using a sulfuric acid aqueous solution (SA) with low concentrations of argon gas dissolved. Bifrequency driving was used in the experiments to enhance spatial stability of the bubbles. The experimental results were compared with simulations provided by a numerical code that models the radial dynamics of the bubbles. The results showed that an increase on the static pressure of the system shifts the Bjerknes instability threshold, allowing the bubble to access higher acoustic pressures (P_{Ac}^{}). Furthermore, a decrease in the measured ambient radius R_{0} and the calculated relative gas concentration c_{?}/c_{0} were observed. A notorious increment in the bubble collapse violence and energy focusing for P_{0} above 1 bar was achieved. These were mainly indicated by the growth of the bubble expansion ratio (R_{max}/R_{0}), the bubble mechanical energy density, and the maximum bubble wall velocity dR/dt. In agreement with the previous statement, the maximum temperature during the bubble collapse predicted by the model is augmented as well. The use of different harmonics in the ultrasound pressure field regarding energy focusing is also discussed. Finally, we analyzed the stability regions of the R_{0}-P_{Ac}^{} parameter space via numerical predictions for P_{0} above the measured, identifying the shape instabilities as the main limiting agent to obtain further energy concentration in SA systems at high static pressures. PMID:24125363

Rosselló, Juan Manuel; Dellavale, Damián; Bonetto, Fabián José

2013-09-01

71

Analysis of Fluctuating Static Pressure Measurements in the National Transonic Facility  

NASA Technical Reports Server (NTRS)

Dynamic measurements of fluctuating static pressure levels were taken with flush-mounted, high-frequency response pressure transducers at 11 locations in the circuit of the National Transonic Facility (NTF) across the complete operating range of this wind tunnel. Measurements were taken at test-section Mach numbers from 0.1 to 1.2, at pressures from 1 to 8.6 atm, and at temperatures from ambient to -250 F, which resulted in dynamic flow disturbance measurements at the highest Reynolds numbers available in a transonic ground test facility. Tests were also made by independent variation of the Mach number, the Reynolds number, or the fan drive power while the other two parameters were held constant, which for the first time resulted in a distinct separation of the effects of these three important parameters.

Igoe, William B.

1996-01-01

72

Variation with Mach Number of Static and Total Pressures Through Various Screens  

NASA Technical Reports Server (NTRS)

Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached. Since choking imposes a restriction on the mass rate of flow and maximum losses are incurred at this condition, great care must be taken in selecting the screen mesh and wire dimmeter for an installation so that the choking Mach number is

Adler, Alfred A

1946-01-01

73

Static pressure drives proliferation of vascular smooth muscle cells via caveolin-1/ERK1/2 pathway  

SciTech Connect

Intimal hyperplasia plays an important role in various types of vascular remodeling. Mechanical forces derived from blood flow are associated with the proliferation of vascular smooth muscle cells (VSMC). This contributes to many vascular disorders such as hypertension, atherosclerosis and restenosis after percutaneous transluminal angioplasty (PTA). In this study, we show that static pressure induces the proliferation of VSMC and activates its related signal pathway. VSMC from a rat aorta were treated with different pressures (0, 60, 90, 120, 150 and 180 mm Hg) in a custom-made pressure incubator for 24 h. The most active proliferation of VSMC was detected at a pressure of 120 mm Hg. VSMC was also incubated under a static pressure of 120 mm Hg for different time intervals (0, 2, 4, 8, 12 and 24 h). We found that static pressure significantly stimulates VSMC proliferation. Extracellular signal-regulated kinases 1/2 (ERK1/2) activation showed a peak at the pressure of 120 mm Hg at 4-h time point. Moreover, caveolin-1 expression was significantly inhibited by rising static pressure. Downregulation of VSMC proliferation could be found after PD98059 (ERK1/2 phosphorylation inhibitor) treatment. Our data also showed that a siRNA-mediated caveolin-1 knock down increased ERK1/2 phosphorylation and VSMC proliferation. These results demonstrate that static pressure promotes VSMC proliferation via the Caveolin-1/ERK1/2 pathway.

Luo, Di-xian, E-mail: luodixian_2@163.com [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China) [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China); Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha, Hunan 410083 (China); The First People's Hospital of Chenzhou City, Chenzhou, Hunan 421001 (China); Cheng, Jiming [Internal Medicine and SimmonsCooper Cancer Institute, Southern Illinois University School of Medicine, 911 N. Rutledge Street, Springfield, IL 62794-9626 (United States) [Internal Medicine and SimmonsCooper Cancer Institute, Southern Illinois University School of Medicine, 911 N. Rutledge Street, Springfield, IL 62794-9626 (United States); Suzhou Health College of Technology, 20 Shuyuanxiang, Suzhou, Jiangsu 215002 (China); Xiong, Yan [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha, Hunan 410083 (China)] [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha, Hunan 410083 (China); Li, Junmo [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China)] [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China); Xia, Chenglai [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China) [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China); School of Pharmaceutics, Southern Medical University, Guangzhou, Guangdong 510515 (China); Xu, Canxin; Wang, Chun; Zhu, Bingyang [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China)] [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China); Hu, Zhuowei [Institute of Materia Medical, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730 (China)] [Institute of Materia Medical, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730 (China); Liao, Duan-fang, E-mail: dfliao66@yahoo.com.cn [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China)] [Division of Pharmacoproteomics, Institute of Pharmacy and Pharmacology, Research Center of Life Science, University of South China, Hengyang, Hunan 421001 (China)

2010-01-22

74

Transient cavitation in high-quality-factor resonators at high static pressures.  

PubMed

It is well known that cavitation collapse can generate intense concentrations of mechanical energy, sufficient to erode even the hardest metals and to generate light emissions visible to the naked eye [sonoluminescence (SL)]. Considerable attention has been devoted to the phenomenon of "single bubble sonoluminescence" (SBSL) in which a single stable cavitation bubble radiates light flashes each and every acoustic cycle. Most of these studies involve acoustic resonators in which the ambient pressure is near 0.1 MPa (1 bar), and with acoustic driving pressures on the order of 0.1 MPa. This study describes a high-quality factor, spherical resonator capable of achieving acoustic cavitation at ambient pressures in excess of 30 MPa (300 bars). This system generates bursts of violent inertial cavitation events lasting only a few milliseconds (hundreds of acoustic cycles), in contrast with the repetitive cavitation events (lasting several minutes) observed in SBSL; accordingly, these events are described as "inertial transient cavitation." Cavitation observed in this high pressure resonator is characterized by flashes of light with intensities up to 1000 times brighter than SBSL flashes, as well as spherical shock waves with amplitudes exceeding 30 MPa at the resonator wall. Both SL and shock amplitudes increase with static pressure. PMID:20550245

Gaitan, D Felipe; Tessien, Ross A; Hiller, Robert A; Gutierrez, Joel; Scott, Corey; Tardif, Henry; Callahan, Brant; Matula, Thomas J; Crum, Lawrence A; Holt, R Glynn; Church, Charles C; Raymond, Jason L

2010-06-01

75

Au-Ag Alloy Static High Pressure EOS measurements: FY09 summary of results  

SciTech Connect

Static high-pressure measurements of the equation of state of a Gold-Silver alloy (23.5 wt-% Ag) at room temperature were performed up to a pressure of approximately 100 GPA (1 megabar). Measurements were made using an energy-dispersive x-ray diffraction method. The data was analyzed, yielding crystal structure lattice constants and volume/density as a function of pressure. The results are extremely precise yielding accuracy of better than 1%. The experiments were carried out at the HPCAT 16BM-D beamline at the Advanced Photon Source. Two experiments on separate samples were carried out using conventional membrane diamond anvil cells. To achieve hydrostatic conditions, we loaded a 50-100 micron piece of the Au-Ag alloy into the cell and surrounded it with neon and mineral oil pressure media in the respective experiments. The differing pressure media demonstrated no measurable difference on the resultant crystal structures, lattice constants or pressure-volume curves. Results of our work are shown in the figures below. Up to the maximum pressure of 100 GPa the sample remained in the face-centered cubic structure, e.g., we observed no change in crystal structure. EOS curves of silver and gold, taken from the literature, are shown for comparison. We fit our data to a Vinet EOS functional form, and the parameters for this EOS were found to be, Reference (ambient pressure) volume, V{sub 0} = 16.965435 {angstrom}{sup 3}; Reference (ambient pressure) density, {rho}{sub 0} = 16.14584 g/cm{sup 3}; Bulk Modulus, K{sub 0} = 144 GPa; and Bulk Mod Derivative, K{prime}{sub 0} = 5.66. As one might expect the Au-Ag alloy lies between the gold and silver EOS curves, and tracks more closely to the gold EOS. These data are useful in validating and developing predictive EOS models of the pressure-dependent behavior of Au-Ag alloys.

Evans, W J; Jenei, Z

2009-09-17

76

Ultrafast high strain rate acoustic wave measurements at high static pressure in a diamond anvil cell  

SciTech Connect

We have used sub-picosecond laser pulses to launch ultra-high strain rate ({approx} 10{sup 9} s{sup -1}) nonlinear acoustic waves into a 4:1 methanol-ethanol pressure medium which has been precompressed in a standard diamond anvil cell. Using ultrafast interferometry, we have characterized acoustic wave propagation into the pressure medium at static compression up to 24 GPa. We find that the velocity is dependent on the incident laser fluence, demonstrating a nonlinear acoustic response which may result in shock wave behavior. We compare our results with low strain, low strain-rate acoustic data. This technique provides controlled access to regions of thermodynamic phase space that are otherwise difficult to obtain.

Armstrong, M; Crowhurst, J; Reed, E; Zaug, J

2008-02-04

77

Modeling and testing of static pressure within an optical fiber cable spool using distributed fiber Bragg gratings  

NASA Astrophysics Data System (ADS)

Based on the force analysis, we establish a theoretical model to study the static pressure distribution of the fiber cable spool for the fiber optic guided missile (FOG-M). Simulations indicate that for each fiber layer in the fiber cable spool, the applied static pressure on it asymptotically converges as the number of fiber layers increases. Using the distributed fiber Bragg grating (FBG) sensing technique, the static pressure of fiber cable layers in the spool on the cable winding device was measured. Experiments show that the Bragg wavelength of FBG in every layer varies very quickly at the beginning and then becomes gently as the subsequent fiber cable was twisted onto the spool layer by layer. Theoretical simulations agree qualitatively with experimental results. This technology provides us a real-time method to monitor the pressure within the fiber cable layer during the cable winding process.

Ma, Chengju; Ren, Liyong; Qu, Enshi; Tang, Feng; Liang, Quan

2012-11-01

78

Static and unsteady pressure measurements on a 50 degree clipped delta wing at M = 0.9  

NASA Technical Reports Server (NTRS)

Static and unsteady pressures were measured on a 50.45 degree clipped delta wing in the Langley Transonic Dynamics Tunnel with Freon as the test medium. Data taken at M = 0.9 is presented for static and oscillatory deflections of the trailing edge control surface and for the wing in pitch. Comparisons of the static measured data are made with results computed using the Bailey-Ballhaus small disturbance code.

Hess, R. W.; Wynne, E. C.; Cazier, F. W.

1982-01-01

79

The effects of confining pressure and stress difference on static fatigue of granite  

NASA Technical Reports Server (NTRS)

Samples of Barre granite were creep tested at room temperature at confining pressures up to 2 kilobars. The time to fracture increased with decreasing stress difference at every pressure, but the rate of change of fracture time with respect to the stress difference increased with pressure. At 87% of the short-term fracture strength, the time to fracture increased from about 4 minutes at atmospheric pressure to longer than one day at 2 Kb of pressure. The inelastic volumetric strain at the onset of tertiary creep, delta, was constant within 25% at any particular pressure but increased with pressure in a manner analogous to the increase of strength with pressure. At the onset of tertiary creep, the number of cracks and their average length increased with pressure. The crack angle and crack length spectra were quite similar, however, at each pressure at the onset of tertiary creep.

Kranz, R. L.

1979-01-01

80

Static and dynamic pressure effects on the thermolysis of nitroalkanes in solution  

SciTech Connect

The authors have measured the effects of static and shock-induced pressures on the decomposition rates and mechanisms of various nitroalkanes dissolved in different solvents with and without organic amine catalysts. While nitroalkanes without {alpha}-hydrogen decompose by homolysis of the C-NO{sub 2} bond over a wide range of conditions, the decomposition pathway of nitroalkanes having {alpha}-hydrogens (i.e., acidic nitroalkanes) is complicated and follows different decomposition mechanisms depending on the availability of organic base and reaction pressure. The Nef reaction is also an important reaction pathway. The five known decomposition pathways, homolysis of the C-NO{sub 2} bond, bimolecular reaction between the aci-form and aci-ion, cyclization of the aci-form, elimination of nitrous acid, and the Nef reaction, are highly dependent on the reaction conditions, such as pressure, presence of organic amines, water, alcohols, and polarity of solvent. The authors discuss the results of several tests used to support these various decomposition mechanisms.

Brower, K.R. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Chemistry; Davis, L.L.; Naud, D.L. [Los Alamos National Lab., NM (United States); Wang, J. [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Chemistry

1998-12-31

81

Plantar Static Pressure Distribution in Healthy Individuals: Percentiles for the Evaluation of Forefoot Loading.  

PubMed

In literature, one finds little scientific statements regarding plantar static pressure distribution in healthy individuals. Miscellaneous studies, however, characterize pathologies of feet and associate those with abnormal static or dynamic plantar load sharing. Our study reveals that healthy individuals show significant age-dependent differences in forefoot and rear foot load measured in standing position. The forefoot and rear foot load of 238 female and 193 male individuals aged between 2 and 69 years were measured. Using a pressure distribution measurement platform, the measurements were taken barefooted in standing position. Those measurements are presented as percentage of the overall load. The measurements within the age groups A1 (2-6 years), A2 (7-10 years), and A3 (11-69 years) showed significantly different forefoot loading means of the left foot (A1, 19.9%; A2, 28.2%; A3, 39.7%) and the right foot (A1, 22.6%; A2, 29.7%; A3, 39.6%). The forefoot loadings are graphically displayed as a function of the percentiles 5, 10, 25, 50, 75, 90, and 95. Forefoot loadings are referred to as "prominent" if the measured values lie off the interquartile range; if either below the percentile 10 or above 90 the loadings are referred to as "very prominent." Our study contains significant data regarding the extent of the static load sharing of the forefoot and rear foot of healthy individuals; the data are suited for being standard values to evaluate plantar load sharing. PMID:24756116

Pomarino, David; Pomarino, Andrea

2014-04-21

82

The development of large diameter, high pressure, cryogenic radial static seals  

NASA Technical Reports Server (NTRS)

Two configurations of radial static seals are developed for high-pressure 773 kg per sq cm cryogenic applications: a U-shaped fluorocarbon seal and a delta-shaped PTFE seal. The U-seal is a common commercial design consisting of a spring-loaded cup-shaped jacket; the basic principle is that the soft plastic jacket provides the interface between the piston and the bore, the jacket being held in place by a metal spring. The delta seal is based on the principle that the soft plastic delta cross section furnishes the interface at the metal face and circumferential face of the gland and cylinder. Test results indicate that both the plastic U-seal and the delta seal designs are sufficiently flexible to accommodate assembly in bore or piston grooves. Of these two configurations, the delta seal is found to be superior as it meets all the design requirements for proof pressure testing the turbopump components of the main engine in the Space Shuttle.

Burr, M. E.

1976-01-01

83

Response of the cat eardrum to static pressures: Mobile versus immobile malleus  

NASA Astrophysics Data System (ADS)

A phase-shift shadow moiré interferometer was used to measure the shape of the cat eardrum with a normal mobile malleus and with an immobile malleus as it was cyclically loaded with static middle-ear pressures up to +/-2.2 kPa. The shape was monitored throughout the loading and unloading phases, and three complete cycles were observed. The mobile-manubrium measurements were made in five ears. In three ears, the malleus was then immobilized with a drop of glue placed on the head of the malleus. Eardrum displacements were calculated by subtracting shape images pixel by pixel. The measurements are presented in the form of gray-level full-field shape and displacement images, of displacement profiles, and of pressure-displacement curves for selected points. Displacement patterns with a mobile malleus show that pars-tensa displacements are larger than manubrial displacements, with the maximum pars-tensa displacement occurring in the posterior region in all cats except one. Displacements vary from cycle to cycle and display hysteresis. For both the mobile-malleus and immobile-malleus cases, the eardrum response is nonlinear. The response is asymmetric, with lateral displacements being larger than medial displacements. With a mobile malleus, manubrial displacements exhibit more pronounced asymmetry than do pars-tensa displacements. .

Ladak, Hanif M.; Decraemer, Willem F.; Dirckx, Joris J. J.; Funnell, W. Robert J.

2004-11-01

84

Impacts of Static Pressure Reset on VAV System Air Leakage, Fan Power and Thermal Energy - Part I: Theoretical Model and Simulation  

E-print Network

Impacts of Static Pressure Reset on VAV System Air Leakage, Fan Power and Thermal Energy ???Part I: Theoretical Model and Simulation Mingsheng Liu, Jingjuan Feng, Zhan Wang, Lixia Wu, Keke Zheng, Xiufeng Pang PKI243 University... not be achieved due to higher pressure before the terminal box dampers [2] . Liu et al studied the impact of low static pressure in dual-duct system on fan energy consumption [3] . Wu et.al presented the fan power saving models for both pressure...

Liu, M.; Feng, J.; Wang, Z.; Wu, L.; Zheng, K.; Pang, W.

2007-01-01

85

Static Water Contact Angle Analysis of Cyclonic Atmospheric Pressure Plasma-Activated Polycarbonate  

NASA Astrophysics Data System (ADS)

Polycarbonate (PC) films were activated using cyclonic atmospheric pressure plasma. The experimentally measured gas phase temperature was from 30 to 95 °C, demonstrating that this cyclonic atmospheric pressure plasma can treat heat-sensitive polymeric materials at the low temperatures. The surface hydrophilicity changes of cyclonic atmospheric pressure plasma-treated PC films were determined by water contact angle analysis. The activation effects of plasma operational parameters including treatment time, plasma power, and distance of nozzle to substrate on the PC surface features were investigated. The glow feature and luminous plasma species in the cyclonic atmospheric pressure plasma were identified by optical emission spectroscopy (OES). Cyclonic atmospheric pressure plasma-activated PC films showed a significant decrease in water contact angle. In this investigation, we developed an innovative technique for chamberless polymeric surface activation by this atmospheric pressure plasma processing.

Huang, Chun; Wu, Shin-Yi; Liu, Yu-Chia; Chang, Ya-Chi; Tsai, Ching-Yuan

2011-01-01

86

Curvature pressure: Sufficient fo a static and stable cosmology; important for solar neutrino production and black hole formation  

E-print Network

A hypothesis is presented that electromagnetic forces that prevent ions from following geodesics results in a curvature pressure that is very important in astrophysics. It may partly explain the solar neutrino deficiency and it may be the engine that drives astrophysical jets. However its most important consequence is that it leads to a static and stable cosmology using general relativity without a cosmological constant.

David F. Crawford

1998-03-02

87

A Novel Procedure to Determine Optimal Air Static Pressure Set-points and Reset Schedules in VAV Air Handling Units  

E-print Network

static pressure set-point First, the minimum air flow rate of the AHU is calculated by equation (3): CFM- = A Q (3) where A is the conditioned area served by the unit, sq-ft; Q is often considered to be 0.3 or 0.4 CFM/sq-ft to maintain suitable air...

Zhu, Y.; Liu, M.; Claridge, D. E.; Turner, W. D.; Powell, T.

1998-01-01

88

Perimeter Measure Analysis of Chaotic Attractor for Tube-Wall Pressure Fluctuations Signal in the Horizontal Kenics Static Mixer  

Microsoft Academic Search

Static mixers are widely used in process industry especially in process intensification fields. Fluctuations information of tube-wall pressure in the KSM with a diameter 100mm and an aspect ratio 2 was got by high speed collector under different inlet velocities. Perimeter measure analysis had been used to characterize the chaotic attractor characterization. Experiments result indicated that the attractor area and

Hui-Bo Meng; Qiang Xiong; Yan-Fang Yu; Jian-Hua Wu

2011-01-01

89

Blood pressure  

MedlinePLUS Videos and Cool Tools

Normal blood pressure is important for proper blood flow to the body’s organs and tissues. The force of the blood on the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart ...

90

Pressure Sores  

MedlinePLUS

... form. Pressure sores are also called bedsores, pressure ulcers and decubitus ulcers. Symptoms What are the symptoms of a pressure ... Also, use pillows to keep your knees and ankles apart. When lying on your back, place a ...

91

Air Pressure  

NSDL National Science Digital Library

Air pressure is pushing on us all the time although we do not usually notice it. In this activity, students learn about the units of pressure and get a sense of just how much air pressure is pushing on them.

2014-09-18

92

A Lagrange-multiplier-based XFEM to solve pressure Poisson equations in problems with quasi-static interfaces  

NASA Astrophysics Data System (ADS)

The XFEM (extended finite element method) has a lot of advantages over other numerical methods to resolve discontinuities across quasi-static interfaces due to the jump in fluidic parameters or surface tension. However, singularities corresponding to enriched degrees of freedom (DOFs) embedded in XFEM arise in the discrete pressure Poisson equations. In this paper, constraints on these DOFs are derived from the interfacial equilibrium condition and introduced in terms of stabilized Lagrange multipliers designed for non-boundary-fitted meshes to address this issue. Numerical results show that the weak and strong discontinuities in pressure with straight and circular interfaces are accurately reproduced by the constraints. Comparisons with the SUPG/PSPG (streamline upwind/pressure stabilizing Petrov-Galerkin) method without Lagrange multipliers validate the applicability and flexibility of the proposed constrained algorithm to model problems with quasi-static interfaces.

Liao, JianHui; Zhuang, Zhuo

2012-04-01

93

Modeling subharmonic response from contrast microbubbles as a function of ambient static pressure  

PubMed Central

Variation of subharmonic response from contrast microbubbles with ambient pressure is numerically investigated for non-invasive monitoring of organ-level blood pressure. Previously, several contrast microbubbles both in vitro and in vivo registered approximately linear (5–15 dB) subharmonic response reduction with 188 mm Hg change in ambient pressure. In contrast, simulated subharmonic response from a single microbubble is seen here to either increase or decrease with ambient pressure. This is shown using the code BUBBLESIM for encapsulated microbubbles, and then the underlying dynamics is investigated using a free bubble model. The ratio of the excitation frequency to the natural frequency of the bubble is the determining parameter—increasing ambient pressure increases natural frequency thereby changing this ratio. For frequency ratio below a lower critical value, increasing ambient pressure monotonically decreases subharmonic response. Above an upper critical value of the same ratio, increasing ambient pressure increases subharmonic response; in between, the subharmonic variation is non-monotonic. The precise values of frequency ratio for these three different trends depend on bubble radius and excitation amplitude. The modeled increase or decrease of subharmonic with ambient pressure, when one happens, is approximately linear only for certain range of excitation levels. Possible reasons for discrepancies between model and previous experiments are discussed. PMID:21476688

Katiyar, Amit; Sarkar, Kausik; Forsberg, Flemming

2011-01-01

94

Pressure distributions in a static physical model of the hemilarynx: measurements and computations.  

PubMed

An experimental study of the pressure distributions in an asymmetric larynx, hereafter referred to as a hemilarynx, was carried out at a glottal diameter of 0.04 cm and transglottal pressures of 3, 5, 10, 20, and 40 cm H(2)O. In each case, the glottal wall "on the left" was chosen to have an angle of 0 degrees with the midline, and the angle of the glottal wall "on the right" was varied through converging angles of 5 degrees, 10 degrees, and 20 degrees and diverging angles of 5 degrees, 10 degrees, and 20 degrees. The case of two parallel glottal walls, or the uniform glottis, was also examined. With the exception of the 20 degrees convergent case, the pressure distributions for most angles and pressures were bistable; that is, a stable flow situation persisted when the glottal exit flow jet was directed downstream either to the right or to the left in the rectangular "pharynx" tunnel. Bistability also occurred for the uniform glottis. Pressure differences arising from the different directions of the flow jet were often found to be small; however, differences for the diverging 10 degrees case were as large as 7% or 8%, and for the 20 degrees divergent case, 12%. Calculations with FLUENT, a computational package, gave excellent agreement with observed pressures. Implications of the pressure distribution data for the functional similarity of normal and hemilaryngeal phonation, hypothesized by Jiang and Titze, are discussed. In particular, the intraglottal pressures for converging and diverging angles for the hemilarynx were found to be quite similar to those of the full larynx with the same diameter and included angle or twice the diameter and twice the included angle, suggesting that the same mechanism of energy transfer operates in the two cases. Nondimensionalizing the pressure distributions with the transglottal pressures suggests that the shapes of the distributions at P=3, 5, 10, 20, and 40 cm H(2)O for a given geometry are similar. The pressure average of these dimensionless distributions may be interpreted as a template at that geometry, a description referred to as successful pressure scaling. When the entire data set is considered, variations from consistent pressure scaling averaged 1.4%, although these variations tend to be somewhat larger near the glottal entrance and for diverging angles of 10 degrees and 20 degrees. Some possible implications of the observed pressures for phonosurgery are discussed. PMID:18538986

Fulcher, Lewis P; Scherer, Ronald C; De Witt, Kenneth J; Thapa, Pushkal; Bo, Yang; Kucinschi, Bogdan R

2010-01-01

95

Impacts of Static Pressure Reset on VAV System Air Leakage, Fan Power and Thermal Energy - Part 2: Case Demonstration for a Typical Climate System  

E-print Network

. In this part, a simulated air handling unit (AHU) system in Omaha NE is used to demonstrate the energy savings performance in one typical climate year. This AHU system has a static pressure reset system and two constant static pressure systems, one having...

Liu, M.; Zheng, K.; Wu, L.; Wang, Z.; Johnson, C.

2007-01-01

96

Optimized Fan Control In Variable Air Volume HVAC Systems Using Static Pressure Resets: Strategy Selection and Savings Analysis  

E-print Network

speed saved about 68 to 75% of the annual fan power. 1.3.2.2 Outside Air Temperature Based Zheng et al. (2007) stated that linearly resetting the static pressure setpoint based on outside air temperature was an effective control strategy for envelope... using an outside air temperature based load function. A 32% reduction in annual fan energy usage was calculated for a system with unsealed rectangular metal ductwork and pressure independent terminal boxes (Liu et al. 2007b). Zheng et al. (2007...

Kimla, John

2010-07-14

97

Consequences of static and pulsatile pressure on transmembrane exchanges during in vitro microdialysis: implication for studies in cardiac physiology.  

PubMed

Microdialysis is an established technique for measuring the kinetics of various neurotransmitters within the extracellular space in the field of neurochemistry. Recently, its use has been extended to sampling in other tissues, including liver, kidney and the heart. A persistent problem in cardiac microdialysis concerns two parameters related to myocardial function: pressure and frequency (heart rate). The aim of the study is to evaluate the consequences of pressure and frequency on transmembrane exchanges. Linear flexible microdialysis probes (membrane length: 12 mm, outside diameter: 390 microns, MWCO 50,000 Daltons) were designed in our laboratory. The probes, perfused at 2 microL/min with sterile water, were placed in a system filled with a glucose solution (2 g/L) and able to generate either static: 0 to 400 mmHg (0 to 53.31 kPa) or pulsatile pressure: 0-100; 0-200; 0-300 mmHg (0-13.32; 0-26.65; 0-39.98 kPa) at different frequencies: 1, 2 and 3 Hz. At 2 mu litre min-1 perfusion rate, the pressure inside the probe is estimated to be 80 mmHg (10.66 kPa). Under static pressure conditions, the glucose recovery rate can be expressed as an exponential function, and the outflow rate can be expressed as a linear function of the external pressure level. Under dynamic conditions, the external mean pressure must be accounted for. When external mean pressure exceeds 80 mmHg (10.66 kPa) (pressure generated by the flow rate of perfusion inside the probe), the recovery rate increases with frequency. Conversely, if the outer mean pressure is lower than 80 mmHg (10.66 kPa), the recovery rate decreases with frequency. Theoretical and experimental modelling results in a nomogram that can be used to estimate in vivo recovery. In conclusion, mass transfer across a microdialysis membrane is dependent on the direction of the transmembrane pressure gradient and increases with heart rate. These findings must be taken into account when in vivo recovery rates during cardiac microdialysis are determined. PMID:10396823

Siaghy, E M; Oesterlé, B; Kheiri, A; Halejcio-Delophont, P; Ungureanu-Longrois, D; Villemot, J P; Mertes, P M

1999-03-01

98

X-ray diffraction and Raman studies of beryllium: Static and elastic properties at high pressures  

NASA Astrophysics Data System (ADS)

We report combined x-ray and Raman studies of beryllium in helium and argon pressure media at pressures approaching 200 GPa. Our results are generally consistent with recent studies confirming the stability of the hexagonal close-packed phase to the highest pressures. However, the quasihydrostatic conditions of our studies lead to a stiffer equation of state ( K0=109.88 , K0'=3.59 ) and a gradual approach toward a more ideal c/a ratio of 1.60 at 180 GPa. Combining our Raman and equation of state data, we are able to evaluate the pressure dependence of the elastic shear modulus ( C44=109.3 , C44'=1.959 ). We discuss the comparison of our results with measurements using ultrasonic and dynamic techniques.

Evans, W. J.; Lipp, M. J.; Cynn, H.; Yoo, C. S.; Somayazulu, M.; Häusermann, D.; Shen, G.; Prakapenka, V.

2005-09-01

99

Under Pressure: Your Blood Pressure  

NSDL National Science Digital Library

During this lesson, learners will determine their blood pressure and learn about systolic and diastolic pressures. They also investigate how blood pressure works with an activity that uses a balloon and a film canister, and learn about factors that contribute to high blood pressure.

Science Museum of Minnesota

2000-01-01

100

Pressure &Pressure & TemperatureTemperature  

E-print Network

Pressure &Pressure & TemperatureTemperature vs.vs. AltitudeAltitude #12;Presented by:Presented by ­ February 22, 2003 #12;Why We Did It?Why We Did It? z Measure the pressure in relation to altitude z MeasureProLabProLabProLabPro to record data, pressureto record data, pressureto record data, pressureto record data, pressure probe

California at Santa Cruz, University of

101

The effects of confining pressure and stress difference on static fatigue of granite  

NASA Technical Reports Server (NTRS)

Samples of Barre granite have been creep tested at room temperature at confining pressures up to 2 kbar. Experimental procedures are described and the results of observations and analysis are presented. It is noted that the effect of pressure is to increase the amount of inelastic deformation the rock can sustain before becoming unstable. It is also shown that this increased deformation is due to longer and more numerous microcracks.

Kranz, R. L.

1980-01-01

102

Brine flow up a borehole caused by pressure perturbation from CO2 storage: Static and dynamic evaluations  

SciTech Connect

Industrial-scale storage of CO{sub 2} in saline sedimentary basins will cause zones of elevated pressure, larger than the CO{sub 2} plume itself. If permeable conduits (e.g., leaking wells) exist between the injection reservoir and overlying shallow aquifers, brine could be pushed upwards along these conduits and mix with groundwater resources. This paper discusses the potential for such brine leakage to occur in temperature- and salinity-stratified systems. Using static mass-balance calculations as well as dynamic well flow simulations, we evaluate the minimum reservoir pressure that would generate continuous migration of brine up a leaking wellbore into a freshwater aquifer. Since the brine invading the well is denser than the initial fluid in the wellbore, continuous flow only occurs if the pressure perturbation in the reservoir is large enough to overcome the increased fluid column weight after full invasion of brine into the well. If the threshold pressure is exceeded, brine flow rates are dependent on various hydraulic (and other) properties, in particular the effective permeability of the wellbore and the magnitude of pressure increase. If brine flow occurs outside of the well casing, e.g., in a permeable fracture zone between the well cement and the formation, the fluid/solute transfer between the migrating fluid and the surrounding rock units can strongly retard brine flow. At the same time, the threshold pressure for continuous flow to occur decreases compared to a case with no fluid/solute transfer.

Birkholzer, J.T.; Nicot, J.-P.; Oldenburg, C.M.; Zhou, Q.; Kraemer, S.; Bandilla, K.W.

2011-05-01

103

Study on Fuzzy Control of Supply Air Static Pressure for a Marine Variable-Air-Volume Air-Conditioning System  

Microsoft Academic Search

In this paper, the advanced marine variable-air-volume (VAV) air-conditioning (A\\/C) system was taken to be the control object. By using fuzzy control theory, a fuzzy controller was developed for the variable-frequency supply air fan in the marine VAV A\\/C system to control its supply air static pressure. An experimental test for the fuzzy controller developed was carried out. Step changes

Wu Chen; Yanjie Lei

2010-01-01

104

Standard Test Method for Water Penetration of Flat Plate Solar Collectors by Uniform Static Air Pressure Difference  

E-print Network

1.1 This test method covers the determination of the resistance of flat plate solar collectors to water penetration when water is applied to their outer surfaces with a static air pressure at the outer surface higher than the pressure at the interior of the collector. 1.2 This test method is applicable to any flat plate solar collector. 1.3 The proper use of this test method requires a knowledge of the principles of pressure and deflection measurement. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary information is contained in Section 6.

American Society for Testing and Materials. Philadelphia

1986-01-01

105

Static pressure accelerates ox-LDL-induced cholesterol accumulation via SREBP-1-mediated caveolin-1 downregulation in cultured vascular smooth muscle cells  

SciTech Connect

Research highlights: {yields} Vertical static pressure accelerates ox-LDL-induced cholesterol accumulation in cultured vascular smooth muscle cells. {yields} Static pressure induces SREBP-1 activation. {yields} Static pressure downregulates the expressions of caveolin-1 by activating SREBP-1. {yields} Static pressure also downregulates the transcription of ABCA1 by activating SREBP-1. {yields} Static pressure increases ox-LDL-induced cholesterol accumulation by SREBP-1-mediated caveolin-1 downregulation in vascular smooth muscle cells cultured in vitro. -- Abstract: Objective: To investigate the effect of static pressure on cholesterol accumulation in vascular smooth muscle cells (VSMCs) and its mechanism. Methods: Rat-derived VSMC cell line A10 treated with 50 mg/L ox-LDL and different static pressures (0, 60, 90, 120, 150, 180 mm Hg) in a custom-made pressure incubator for 48 h. Intracellular lipid droplets and lipid levels were assayed by oil red O staining and HPLC; The mRNA levels of caveolin-1 and ABCA1, the protein levels of caveolin-1 SREBP-1 and mature SREBP-1 were respectively detected by RT-PCR or western blot. ALLN, an inhibitor of SREBP metabolism, was used to elevate SREBP-1 protein level in VSMCs treated with static pressure. Results: Static pressures significantly not only increase intracellular lipid droplets in VSMCs, but also elevate cellular lipid content in a pressure-dependent manner. Intracellular free cholesterol (FC), cholesterol ester (CE), total cholesterol (TC) were respectively increased from 60.5 {+-} 2.8 mg/g, 31.8 {+-} 0.7 mg/g, 92.3 {+-} 2.1 mg/g at atmosphere pressure (ATM, 0 mm Hg) to 150.8 {+-} 9.4 mg/g, 235.9 {+-} 3.0 mg/g, 386.7 {+-} 6.4 mg/g at 180 mm Hg. At the same time, static pressures decrease the mRNA and protein levels of caveolin-1, and induce the activation and nuclear translocation of SREBP-1. ALLN increases the protein level of mature SREBP-1 and decreases caveolin-1 expression, so that cellular lipid levels were upregulated. Conclusion: Static pressures stimulate ox-LDL-induced cholesterol accumulation in cultured VSMCs through decreasing caveolin-1 expression via inducing the maturation and nuclear translocation of SREBP-1.

Luo, Di-xian, E-mail: luodixian_2@163.com [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha 410083, Hunan (China) [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha 410083, Hunan (China); Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); First People's Hospital of Chenzhou City, Chenzhou 423000, Hunan (China); Xia, Cheng-lai [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China) [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); Department of Pharmacy, Third Affiliated Hospital Medical College of Guangzhou, Guangzhou 510150, Guangdong (China); Li, Jun-mu [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China)] [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); Xiong, Yan [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha 410083, Hunan (China)] [Department of Pharmacology, School of Pharmaceutics, Central South University, Changsha 410083, Hunan (China); Yuan, Hao-yu [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China) [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); Lusong Center for Disease Control and Prevention, Zhuzhou 412000, Hunan (China); TANG, Zhen-Wang; Zeng, Yixin [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China)] [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); Liao, Duan-fang, E-mail: dfliao66@yahoo.com.cn [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China) [Institute of Pharmacy and Pharmacology, College of Science and Technology, University of South China, Hengyang 421001, Hunan (China); Department of Traditional Chinese Diagnostics, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 420108, Hunan (China)

2010-12-03

106

Structural phase stability in group IV metals under static high pressure  

SciTech Connect

In group IV metals (Ti, Zr, and Hf) room temperature compression leads to a martensitic transformation from a ductile {alpha} to a brittle {omega} phase. {alpha} {yields} {omega} phase boundary decreases to lower pressure at high temperature and can limit the use of group IV metals in industrial applications. There is a large discrepancy in the transition pressure reported in literature, with some of the variation attributed to experimental conditions (i.e. hydrostatic vs. non-hydrostatic). Shear deformation in non-hydrostatic experiments drives {alpha} {yields} {omega} transition and decreases transition pressure. Impurities can also aid or suppress {alpha} {yields} {omega} transition. By performing x-ray diffraction experiments on samples in a diamond anvil cell we show that interstitial impurities, such as C, N, and O can obstruct {alpha} {yields} {omega} transition and stabilize {alpha} phase to higher pressure. We also show that reduction in grain size can also influence {alpha} {yields} {omega} phase boundary and help stabilize {alpha} phase to higher pressure under non-hydrostatic conditions.

Velisavljevic, Nenad [Los Alamos National Laboratory; Chesnut, Garry N [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Vohra, Yogesh K [U OF ALABAMA AT BIRMINGHAM; Stemshorn, Andrew [U OF ALABAMA AT BIRMINGHAM

2009-01-01

107

Pressure Sores  

MedlinePLUS

Pressure sores are areas of damaged skin caused by staying in one position for too long. They ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which ...

108

Peer Pressure  

MedlinePLUS

... for the school play. Back Continue When the Pressure's On Sometimes, though, the stresses in your life ... the ability to make good decisions. Back Continue Pressure Pointers Nearly everyone ends up in a sticky ...

109

Under Pressure  

NSDL National Science Digital Library

The contents of this chapter deal with air pressure and water pressure and what causes those things to increase and decrease. In addition, the real-world results of those increases and decreases in air and water pressure will be addressed.

William C. Robertson, Ph.D.

2005-01-01

110

Air Pressure  

NSDL National Science Digital Library

In this experiment, learners use a blow dryer and water bottle to observe and record changes in air pressure caused by changes in temperature. Educators can use this activity to explain how changes in temperature cause changes in air pressure which cause wind. This activity guide contains background information on air pressure, instructions for an extension experiment, and links to useful online resources.

University of Illinois

2009-01-01

111

Feeling Pressured  

NSDL National Science Digital Library

In this activity, learners (at least three) work together to explore the effects of atmospheric pressure. A learner (at least 100 lbs) will step inside an extra large trash bag, while another reduces the air pressure in the bag slightly with a vacuum cleaner. The bag will squeeze the occupant due to the differences in external and internal pressure.

Eric Muller

1998-01-01

112

Static internal pressure capacity of Hanford Single-Shell Waste Tanks  

SciTech Connect

Underground single-shell waste storage tanks located at the Hanford Site in Richland, Washington, generate gaseous mixtures that could be ignited, challenging the structural integrity of the tanks. The structural capacity of the single-shell tanks to internal pressure is estimated through nonlinear finite-element structural analyses of the reinforced concrete tank. To determine their internal pressure capacity, designs for both the million-gallon and the half-million-gallon tank are evaluated on the basis of gross structural instability.

Julyk, L.J.

1994-07-19

113

Inelastic X-ray scattering experiments on B[subscript 4]C under high static pressures  

SciTech Connect

Boron K-edge inelastic X-ray scattering experiments were performed on clean B{sub 4}C and shock impact recovered boron carbide up to 30 GPa and at ambient temperature to understand the pressure induced bonding changes. The spectral features corresponding to the boron site in the interlinking chain remained unchanged up to 30 GPa. The results of our experiments indicate that pressure induces less distortion to the boron sites and the local amorphization observed in the previous reports are due to the rearrangement of carbon atoms under extreme conditions without affecting the boron environment.

Kumar, Ravhi S.; Dandekar, Dattatraya; Leithe-Jasper, Andres; Tanaka, Takaho; Xiao, Yuming; Chow, Paul; Nicol, Malcolm F.; Cornelius, Andrew L. (UNLV); (MXPL-M); (CIW); (USARL)

2010-05-04

114

Selection and static calibration of the Marsh J1678 pressure gauge  

NASA Technical Reports Server (NTRS)

During the experimental testing of the ultralight, it was determined that a pressure gauge would be required to monitor the simulated flight loads. After analyzing several factors, which are indicated in the discussion section of this report, the Marsh J1678 pressure gauge appeared to be the prominent candidate for the task. However, prior to the final selection, the Marsh pressure gauge was calibrated twice by two different techniques. As a result of the calibration, the Marsh gauge was selected as the appropriate measuring device during the structural testing of the ultralight. Although, there are commerical pressure gauges available on the market that would have proven to be more efficient and accurate. However, in order to obtain these characteristics in a gauge, one has to pay the price on the price tag, and this value is an exponential function of the degree of accuracy efficiency, precision, and many other features that may be designed into the gauge. After analyzing the extent of precision and accuracy that would be required, a more expensive gauge wouldn't have proven to be a financial benefit towards the outcome of the experiment.

Oxendine, Charles R.; Smith, Howard W.

1993-01-01

115

High pressure stability of protein complexes studied by static and dynamic light scattering  

Microsoft Academic Search

The high pressure dissociation of hemocyanin prepared from the lobster Homarus americanus and casein micelles from cow milk were observed by in situ light scattering. The hemocyanin dodecamer dissociated via a hexamer into monomers in a two-step three-species reaction. The influence of ligands and the effector l-lactate on the dissociation behavior was investigated. While no effect by carbon monoxide after

Ronald Gebhardt; Ulrich Kulozik

2011-01-01

116

Temperatures in the earth's core from melting-point measurements of iron at high static pressures  

Microsoft Academic Search

The most reliable method for determining the temperature gradient at the earth's core is the estimation of Fe and Fe-rich compounds' melting temperature at the pressure of the inner core boundary. Attention is presently given to melting-point measurements on Fe and Fe-O compounds at up to 2 Mbar. An extrapolation of these results to 3.3 Mbar yields an inner core

R. Boehler

1993-01-01

117

Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise  

NASA Astrophysics Data System (ADS)

To investigate the effect of ?g-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and ?g- exercise.

Baum, K.; Essfeld, D.; Stegemann, J.

118

Phenomenon of labyrinth weal with Low static pressure difference and large clearance  

Microsoft Academic Search

Absract  The low pressure axial flow fans with an outer ring, used for cooling automobile radiators, have a significantly large tip\\u000a clearance between the ring tip and the fan shroud. It has been found that the turbulent reverse flow, or leakage flow, which\\u000a occurs at the tip clearance, greatly affects the fan performance and noise level. Therefore, in order to improve

K. Kimura; H. Ohta; K. Aoki

2003-01-01

119

Analytic representation of volume flow as a function of geometry and pressure in a static physical model of the glottis.  

PubMed

A static physical model of the larynx (model M5) was used to obtain a large set of volume flows as a function of symmetric glottal geometry and transglottal pressure. The measurements cover ranges of these variables relevant to human phonation. A generalized equation was created to accurately estimate the glottal volume flow given specific glottal geometries and transglottal pressures. Both the data and the generalized formula give insights into the flow behavior for different glottal geometries, especially the contrast between convergent and divergent glottal angles at different glottal diameters. The generalized equation produced a fit to the entire M5 dataset (267 points) with an average accuracy of 3.4%. The accuracy was about seven times better than that of the Ishizaka-Flanagan approach to glottal flow and about four times better than that of a pressure coefficient approach. Thus, for synthesis purposes, the generalized equation presented here should provide more realistic glottal flows (based on steady flow conditions) as suitable inputs to the vocal tract, for given values of transglottal pressure and glottal geometry. Applications of the generalized formula to pulses generated by vocal fold motions typical of those produced by the Ishizaka-Flanagan coupled-oscillator model and the more recent body-cover model of Story and Titze are also included. PMID:16434169

Fulcher, Lewis P; Scherer, Ronald C; Zhai, Guangnian; Zhu, Zipeng

2006-12-01

120

Under Pressure  

NSDL National Science Digital Library

In this experiment, learners examine how pressure affects water flow. In small groups, learners work with water and a soda bottle, and then relate their findings to pressure in the deep ocean. The printable six-page handout includes: a series of inquiry-based questions to get students thinking about pressure, both in the air and under water; illustrated experiment directions; and a worksheet that includes thought-provoking questions along with areas for recording experiment data.

2012-08-06

121

An in vitro study comparing a peripherally inserted central catheter to a conventional central venous catheter: no difference in static and dynamic pressure transmission  

Microsoft Academic Search

BACKGROUND: Early goal directed therapy improves survival in patients with septic shock. Central venous pressure (CVP) monitoring is essential to guide adequate resuscitation. Use of peripherally inserted central catheters (PICC) is increasing, but little data exists comparing a PICC to a conventional CVP catheter. We studied the accuracy of a novel PICC to transmit static and dynamic pressures in vitro.

Heath E Latham; Timothy T Dwyer; Bethene L Gregg; Steven Q Simpson

2010-01-01

122

Review of Aircraft Altitude Errors Due to Static-Pressure Source and Description of Nose-Boom Installations for Aerodynamic Compensation of Error  

NASA Technical Reports Server (NTRS)

A brief review of airplane altitude errors due to typical pressure installations at the fuselage nose, the wing tip, and the vertical fins is presented. A static-pressure tube designed to compensate for the position errors of fuselage-nose installations in the subsonic speed range is described. This type of tube has an ogival nose shape with the static-pressure orifices located in the low-pressure region near the tip. The results of wind-tunnel tests of these compensated tubes at two distances ahead of a model of an aircraft showed the position errors to be compensated to within 1/2 percent of the static pressure through a Mach number range up to about 1.0. This accuracy of sensing free-stream static pressure was extended up to a Mach number of about 1.15 by use of an orifice arrangement for producing approximate free-stream pressures at supersonic speeds and induced pressures for compensation of error at subsonic speeds.

Gracey, William; Ritchie, Virgil S.

1959-01-01

123

Analysis of Fluctuating Static Pressure Measurements in a Large High Reynolds Number Transonic Cryogenic Wind Tunnel. Ph.D. Thesis  

NASA Technical Reports Server (NTRS)

Dynamic measurements of fluctuating static pressure levels were made using flush mounted high frequency response pressure transducers at eleven locations in the circuit of the National Transonic Facility (NTF) over the complete operating range of this wind tunnel. Measurements were made at test section Mach numbers from 0.2 to 1.2, at pressure from 1 to 8.6 atmospheres and at temperatures from ambient to -250 F, resulting in dynamic flow disturbance measurements at the highest Reynolds numbers available in a transonic ground test facility. Tests were also made independently at variable Mach number, variable Reynolds number, and variable drivepower, each time keeping the other two variables constant thus allowing for the first time, a distinct separation of these three important variables. A description of the NTF emphasizing its flow quality features, details on the calibration of the instrumentation, results of measurements with the test section slots covered, downstream choke, effects of liquid nitrogen injection and gaseous nitrogen venting, comparisons between air and nitrogen, isolation of the effects of Mach number, Reynolds number, and fan drive power, and identification of the sources of significant flow disturbances is included. The results indicate that primary sources of flow disturbance in the NTF may be edge-tones generated by test section sidewall re-entry flaps and the venting of nitrogen gas from the return leg of the tunnel circuit between turns 3 and 4 in the cryogenic mode of operation. The tests to isolate the effects of Mach number, Reynolds number, and drive power indicate that Mach number effects predominate. A comparison with other transonic wind tunnels shows that the NTF has low levels of test section fluctuating static pressure especially in the high subsonic Mach number range from 0.7 to 0.9.

Igoe, William B.

1991-01-01

124

Static and unsteady pressure measurements on a 50 degree clipped delta wing at M = 0.9. [conducted in the Langley Transonic Dynamics Tunnel  

NASA Technical Reports Server (NTRS)

Pressures were measured with Freon as the test medium. Data taken at M = 0.9 is presented for static and oscillatory deflections of the trailing edge control surface and for the wing in pitch. Comparisons of the static measured data are made with results computed using the Bailey-Ballhaus small disturbance code.

Hess, R. W.; Wynne, E. C.; Cazier, F. W.

1982-01-01

125

Static inflation and deflation pressure-volume curves from excised lungs of marine mammals.  

PubMed

Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas) and harbor porpoise (Phocoena phocoena)] were used to determine the minimum air volume of the relaxed lung (MAV, N=15), the elastic properties (pressure-volume curves, N=24) of the respiratory system and the total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l kg(-1)) does not differ between species or groups (odontocete vs phocid) and agree with that estimated (TLC(est)) from body mass (M(b)) by applying the equation: TLC(est)=0.135 M(b)(0.92). Measured MAV was on average 7% of TLC, with a range from 0 to 16%. The pressure-volume curves were similar among species on inflation but diverged during deflation in phocids in comparison with odontocetes. These differences provide a structural basis for observed species differences in the depth at which lungs collapse and gas exchange ceases. PMID:22031747

Fahlman, Andreas; Loring, Stephen H; Ferrigno, Massimo; Moore, Colby; Early, Greg; Niemeyer, Misty; Lentell, Betty; Wenzel, Frederic; Joy, Ruth; Moore, Michael J

2011-11-15

126

Static inflation and deflation pressure–volume curves from excised lungs of marine mammals  

PubMed Central

SUMMARY Excised lungs from eight marine mammal species [harp seal (Pagophilus groenlandicus), harbor seal (Phoca vitulina), gray seal (Halichoerus grypush), Atlantic white-sided dolphin (Lagenorhynchus acutus), common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), long-finned pilot whale (Globicephala melas) and harbor porpoise (Phocoena phocoena)] were used to determine the minimum air volume of the relaxed lung (MAV, N=15), the elastic properties (pressure–volume curves, N=24) of the respiratory system and the total lung capacity (TLC). Our data indicate that mass-specific TLC (sTLC, l kg–1) does not differ between species or groups (odontocete vs phocid) and agree with that estimated (TLCest) from body mass (Mb) by applying the equation: TLCest=0.135 Mb0.92. Measured MAV was on average 7% of TLC, with a range from 0 to 16%. The pressure–volume curves were similar among species on inflation but diverged during deflation in phocids in comparison with odontocetes. These differences provide a structural basis for observed species differences in the depth at which lungs collapse and gas exchange ceases. PMID:22031747

Fahlman, Andreas; Loring, Stephen H.; Ferrigno, Massimo; Moore, Colby; Early, Greg; Niemeyer, Misty; Lentell, Betty; Wenzel, Frederic; Joy, Ruth; Moore, Michael J.

2011-01-01

127

Evaluation of static pressure drops and PM10 and TSP emissions for modified 1D-3D cyclones  

SciTech Connect

Five modifications of a standard 1D3D cyclone were tested and compared against the standard 1D3D design in the areas of particulate emissions and static pressure drop across the cyclone. The modifications to the 1D3D design included a 2D2D inlet, a 2D2D air outlet, a D/3 trash exit, an expansion chamber with a D/3 trash exit, and a tapered air outlet duct. The 1D3D modifications that exhibited a significant improvement in reducing both PM10 and total suspended particulate (TSP) emissions were the designs with the 2D2D inlet and air exhaust combined with either the conical D/3 tail cone or the expansion chamber. In reference to the standard 1D3D cyclone, the average reduction in PM10 emissions was 24 to 29% with a 29 to 35% reduction observed in TSP emissions. The modifications with the tapered air outlets did not show any significant improvements in controlling PM10 emissions. However, the modification with the tapered air outlet/expansion chamber combination exhibited statistical significance in reducing TSP emissions by 18% compared to the 1D3D cyclone. All modifications tested exhibited lower static pressure drops than the standard 1D3D.

Holt, G.A.; Baker, R.V.; Hughs, S.E.

1999-12-01

128

Differential Pressures on a Pitot-venturi and a Pitot-static Nozzle over 360 Degrees Pitch and Yaw  

NASA Technical Reports Server (NTRS)

Measurements of the differential pressures on two navy air-speed nozzles, consisting of a Zahm type Pitot-Venturi tube and a SQ-16 two-pronged Pitot-static tube, in a tunnel air stream of fixed speed at various angles of pitch and yaw between 0 degrees and plus or minus 180 degrees. This shows for a range over -20 degrees to +20 degrees pitch and yaw, indicated air speeds varying very slightly over 2 per cent for the Zahm type and a maximum of about 5 per cent for the SQ-16 type from the calibrated speed at 0 degree. For both types of air-speed nozzle the indicated air speed increases slightly as the tubes are pitched or yawed several degrees from their normal 0 degrees altitude, attains a maximum around plus or minus 15 degrees to 25 degrees, declines rapidly therefrom as plus or minus 40 degrees is passed, to zero in the vicinity of plus or minus 70 degrees to 100 degrees, and thence fluctuates irregular from thereabouts to plus or minus 180 degrees. The complete variation in indicated air speed for the two tubes over 360 degree pitch and yaw is graphically portrayed in figures 9 and 10. For the same air speed and 0 degree pitch and yaw the differential pressure of the Zahm type Pitot-Venturi nozzle is about seven times that of the SQ-16 type two-prolonged Pitot-static nozzle.

Bear, R M

1928-01-01

129

Under Pressure  

NSDL National Science Digital Library

This experiment can be completed in a single class period and examines how pressure affects water flow. In small groups, students work with water and a soda bottle, and then relate their findings to pressure in the deep ocean. The printable six-page handout includes a series of inquiry-based questions to get students thinking about pressure, both in the air and under water, illustrated experiment directions, and a worksheet that includes thought-provoking questions along with areas for recording experiment data.

130

Measuring Pressure  

NSDL National Science Digital Library

Students learn first-hand the relationship between force, area and pressure. They use a force sensor built from a LEGO® MINDSTORMS® NXT kit to measure the force required to break through a paper napkin. An interchangeable top at the end of the force sensor enables testing of different-sized areas upon which to apply pressure. Measuring the force, and knowing the area, students compute the pressure. This leads to a concluding discussion on how these concepts are found and used in engineering and nature.

AMPS GK-12 Program,

131

Under Pressure  

NSDL National Science Digital Library

This experiment, which can be completed in a single class period, examines how pressure affects water flow. In small groups, students work with water and a soda bottle, and then relate their findings to pressure in the deep ocean. The printable six-page handout includes a series of inquiry-based questions to get students thinking about pressure, both in the air and under water, illustrated experiment directions and a worksheet that includes thought-provoking questions along with areas for recording experiment data.

132

Pressure ulcer  

MedlinePLUS

... now develops an open, sunken hole called a crater. There is damage to the tissue below the ... turn white. Also look for blisters, sores, or craters. Take the following steps to prevent pressure ulcers: ...

133

Deformation measurements of the human tympanic membrane under static pressure using automated moire topography  

NASA Astrophysics Data System (ADS)

To measure the surface shape and shape change of soft biological material, the use of a noncontacting metrological technique is imperative. One of these techniques is moire contouring, which is particularly interesting because of its simplicity and low cost. We propose a method to mathematically reconstruct a surface shape from moire topograms. The method is based on the recording of three topograms which are shifted in phase by translating the object. The method is implemented in an apparatus which fully automatically performs all required steps to finally yield a 512 by 512 point matrix of surface height values, with a height measuring resolution of 20 micrometers . The resolution for measuring small height displacements is 2 micrometers . Due to this high resolution, it is possible to investigate the deformation of the tympanic membrane, caused by small pressure changes in the middle ear cavity. Full field deformation data are shown. The data can be used to obtain information on the movement of the manubrium, or to calculate volume displacements and surface area changes.

Dirckx, Joris J.; Decraemer, Willem F.

1991-08-01

134

Flutter Sensitivity to Boundary Layer Thickness, Structural Damping, and Static Pressure Differential for a Shuttle Tile Overlay Repair Concept  

NASA Technical Reports Server (NTRS)

This paper examines the aeroelastic stability of an on-orbit installable Space Shuttle patch panel. CFD flutter solutions were obtained for thick and thin boundary layers at a free stream Mach number of 2.0 and several Mach numbers near sonic speed. The effect of structural damping on these flutter solutions was also examined, and the effect of structural nonlinearities associated with in-plane forces in the panel was considered on the worst case linear flutter solution. The results of the study indicated that adequate flutter margins exist for the panel at the Mach numbers examined. The addition of structural damping improved flutter margins as did the inclusion of nonlinear effects associated with a static pressure difference across the panel.

Scott, Robert C.; Bartels, Robert E.

2009-01-01

135

Influence of static pressure on dynamic characteristics of laser-induced cavitation and hard-tissue ablation under liquid environment  

NASA Astrophysics Data System (ADS)

Several studies have demonstrated that laser-induced hard tissue ablation effects can be enhanced by applying an additional water-layer on tissue surface. However, the related mechanism has not yet been presented clearly. In this paper, the influence of static pressure on dynamic characteristics of cavitation induced by pulse laser in liquid and its effect on bovine shank bone ablation were investigated. The laser source is fiber-guided free-running Ho:YAG laser with wavelength of 2080 nm, pulse duration of 350 ?s and energy of 1600 mJ. The tissue samples were immerged in pure water at different depths of 11, 16, 21, 26 and 31 mm. The working distance between the fiber tip and tissue surface was fixed at 1 mm for all studies. The dynamic interaction between laser, water and tissue were recorded by high-speed camera, and the morphological changes of bone tissue were assessed by stereomicroscope and OCT. The results showed that many times expansion and collapse of bubble were observed, more than four pulsation periods were accurately achieved with the most energy deposited in the first period and the bubble became more and more irregular in shape. The longitudinal length (7.49--6.74 mm) and transverse width (6.69--6.08 mm) of bubble were slowly decreased while volume (0.0586--0.0124 mm3) of ablation craters were drastically reduced, with static pressure increasing. The results also presented that the water-layer on hard-tissue surface can not only reduce thermal injury but also improve lubricity of craters, although the water-layer reduced ablation efficiency.

Chen, Chuanguo; Li, Xuwei; Zhang, Xianzeng; Zhan, Zhenlin; Xie, Shusen

2014-11-01

136

Static high pressure study of nitric oxide chemistry: proposed mechanism for nitric oxide detonation. [Shock initiated detonation  

SciTech Connect

The chemistry of nitric oxide under static high pressure conditions has been studied using diamond anvil cells and spectroscopic methods. Pressurized samples warmed rapidly to room temperature undergo facile disproportionation to form N/sub 2/O, N/sub 2/O/sub 3/, N/sub 2/O/sub 4/, and NO/sup +/NO/sub 3//sup -/. Nitric oxide maintained at 80 K is observed to react at ca. 2.5 GPa to form, dominantly, N/sub 2/, O/sub 2/, and NO/sup +/NO/sub 3//sup -/. The complex chemistry of nitric oxide is best explained in terms of two competing primary reaction mechanisms involving the direct formation of N/sub 2/ and O/sub 2/, and disproportionation to form N/sub 2/O and NO/sup +/NO/sub 3//sup -/. The disproportionation reaction, which is favored under higher temperature conditions, releases two-thirds of the total energy content, and is believed to be important in the early chemistry accompanying shock-initiation of nitric oxide. Laboratory scale detonation studies, where the gaseous products are analyzed spectroscopically, show evidence for, dominantly, disproportionation and a small amount of N/sub 2//O/sub 2/ production. This study points to the importance of condensed phase concerted reactions as well as ions and ionic reaction mechanisms in the shock initiated detonation of HE's. 14 refs., 3 figs., 1 tab.

Swanson, B.I.; Agnew, S.F.; Greiner, N.R.

1985-01-01

137

Performance of Compressor of XJ-41-V Turbojet Engine. 3; Compressor Static-Pressure Rise at Equivalent Compressor Speeds of 5000, 7000, 8000, and 9000 rpm  

NASA Technical Reports Server (NTRS)

At the request of the Air Materiel Command, Army Air Forces, an investigation is being conducted at the NACA Cleveland laboratory to determine the performance characteristics of the XJ-41-V turbojet-engine compressor. The static-pressure variation in the direction of flow through the compressor was presented in reference 1 for an equivalent speed of 8000 rpm. An analysis of these pressure indicated that the maximum-flow limitation of the compressor was caused by separation, which reduced the effective flow area at the vaned-collector entrance. As a result of this analysis, the flow area at the vaned-collector entrance was increased to obtain larger mass flows. The area increase was obtained by cutting back the entrance edges of the collector vanes, which resulted in an increased vaneless-diffuser radius. Comparative performance of the original and revised compressors at an equivalent speed of 8000 rpm is presented. The static-pressure rise through the compressor, determined from static pressures at the impeller entrance and the vaned-collector exit, is also presented together with the compressor adiabatic efficiency and the mass flow over an equivalent speed range from 5000 to 9000 rpm. These static-pressure data are presented for the purpose of correlating the compressor performance with the turbojet-engine performance.

Creagh, John W. R.; Ginsburg, Ambrose

1947-01-01

138

Abnormal pressures as hydrodynamic phenomena  

USGS Publications Warehouse

So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

Neuzil, C.E.

1995-01-01

139

Intracranial pressure  

Microsoft Academic Search

Background: The effects of pneumoperitoneum on intracranial pressure (ICP) have received relatively little attention. This study was\\u000a undertaken to investigate the changes in ICP occurring as a result of increased intraabdominal pressure (IAP) and positioning\\u000a in animals with normal and elevated ICP.\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a Method: Five pigs (average weight 60 lb) were studied. A subarachnoid screw was placed for ICP monitoring. End

R. J. Rosenthal; J. R. Hiatt; E. H. Phillips; W. Hewitt; A. A. Demetriou; M. Grode

1997-01-01

140

Quasi-static compression of granular materials (sand) at high pressures (~3 GPA)  

NASA Astrophysics Data System (ADS)

This investigation presents the results on the static behavior of confined sand (from Eglin Air Force Base) subjected to axial compressive stresses up to 3 GPa. A self-aligning compression fixture was developed to statically compress sand specimen in a cylindrical steel confinement using tungsten carbide pins. A strain gage was mounted on the confining cylinder to measure the circumferential strain. Using axial stress, axial strain, and hoop strain the multi axial behavior of the confined sand is investigated. Compressive tests were conducted up to axial strains of 35%. The static response of the dry sand was tested at four different initial densities, namely, 1.55, 1.60, 1.65, and 1.75 g/cm 3. Effects of particle size, primarily classified as coarse and fine, were investigated. The effect of moisture was also investigated at four different degrees of saturation, namely, 0%, 20%, 40%, and 100%. The dense sand provided a much stiffer response than the loosely packed ones. The coarse sand grains showed significant crushing of particles followed by compaction of the powdered grains.

Subramanian, Vijay Krishnan

141

Pressure Interactions  

NSDL National Science Digital Library

This page allows you to change the state variables in the two ensembles and observe the interactions between the state variables. The piston mass is 50x the particles mass. This large piston mass produces a slow mechanical oscillation about the equal-pressure equilibrium point whenever a disequilibrium is created.

Wolfgang Christian

142

Under Pressure  

NSDL National Science Digital Library

In this simple activity, learners discover how a mere piece of paper can be used to hold up the weight of a heavy book. Learners are encouraged to modify their materials, using the steps of the design process, to explore how such modification changes the amount of pressure paper can withstand. This inexpensive activity is great used with engineering or architecture units.

WGBH

2007-01-01

143

Effects of static electric field and of mechanical pressure on surface acoustic waves propagation in La3Ga5SiO 14 piezoelectric single crystals  

Microsoft Academic Search

The complete set of tensorial components of linear and nonlinear electromechanical properties for La3Ga5SiO14 , piezoelectric crystals have been obtained. These data were used for the analysis of influence of static electric field and of uniaxial homogeneous mechanical pressure on the propagation of surface acoustic waves

K. S. Aleksandrov; B. P. Sorokin; P. P. Turchin; S. I. Burkov; D. A. Glushkov; A. A. Karpovich

1995-01-01

144

Blood pressure measurement  

MedlinePLUS

Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... your health care provider will wrap the blood pressure cuff snugly around your upper arm. The lower ...

145

Hypertension (High Blood Pressure)  

MedlinePLUS

... they think about their blood pressure. Understanding Blood Pressure Every person needs blood pressure to live. Without ... women get this condition. How Does High Blood Pressure Affect the Body? High blood pressure adds to ...

146

Pressure transducer  

DOEpatents

A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output.

Anderson, Thomas T. (Downers Grove, IL); Roop, Conard J. (Lockport, IL); Schmidt, Kenneth J. (Midlothian, IL); Gunchin, Elmer R. (Lockport, IL)

1989-01-01

147

Pressure transducer  

DOEpatents

A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output. 7 figs.

Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Gunchin, E.R.

1987-02-13

148

Pressurized hopper  

SciTech Connect

A Secure Automated Fuel Fabrication Line is being developed to reduce personnel exposure and to improve safeguards. Fertile and fissile fuel powders are blended in the line for making fuel pellets. A pressurized hopper was developed for use not only as a blender, but also as a storage and feeding device. It works with or without injection tubes to produce a well-blended powder with reduced agglomerate population. Results of blending experiments using dry Kaolin clay and Tempra pigment are given. (DLC)

Densley, P.J.; Goldmann, L.H. Jr.

1980-04-01

149

Inflation pressures  

Microsoft Academic Search

If the sum of the energy density rho and thrice the pressure rho is negative, then a Robertson-Walker universe can inflate or even oscillate. But we show at the one-loop level that in a generic grandly unified theory rho +3 rho cannot be negative at the absolute minimum of the finite-temperature effective potential. We discuss the implications of this result

K. Cahill; J. Podolsky

1994-01-01

150

Static and dynamic pressure measurements on a NACA 0012 airfoil in the Ames High Reynolds Number Facility  

NASA Technical Reports Server (NTRS)

The supercritical flows at high subsonic speeds over a NACA 0012 airfoil were studied to acquire aerodynamic data suitable for evaluating numerical-flow codes. The measurements consisted primarily of static and dynamic pressures on the airfoil and test-channel walls. Shadowgraphs were also taken of the flow field near the airfoil. The tests were performed at free-stream Mach numbers from approximately 0.7 to 0.8, at angles of attack sufficient to include the onset of buffet, and at Reynolds numbers from 1 million to 14 million. A test action was designed specifically to obtain two-dimensional airfoil data with a minimum of wall interference effects. Boundary-layer suction panels were used to minimize sidewall interference effects. Flexible upper and lower walls allow test-channel area-ruling to nullify Mach number changes induced by the mass removal, to correct for longitudinal boundary-layer growth, and to provide contouring compatible with the streamlines of the model in free air.

Mcdevitt, J. B.; Okuno, A. F.

1985-01-01

151

Space shuttle: Static surface pressures of the 0.004 scale 049 orbiter in the launch configuration  

NASA Technical Reports Server (NTRS)

Wing and lower body surface static pressure data for the space shuttle 049 orbiter while in the launch configuration were obtained. The purpose of the test was to determine the optimum incidence position of the orbiter relative to the hydrogen-oxygen (HO) tank and the optimum radial position of the solid rocket motors (SRM) on the HO tank. The orbiter was mounted on the HO tank at incidence angles of 0 and -1.5 degrees to determine the optimum incidence position. The SRM boosters were tested at radial positions of 75, 90, and 135 degrees on the HO tank to determine their optimum position with respect to the loads imposed on the orbiter. The test was conducted in the tunnel over a Mach number range of 0.6 to 4.96. Angle of attack was varied from -8 to +8 degrees at zero degree angle of sideslip, and at sideslip angles varying from -6 to +6 degrees at zero degree angle of attack.

Buchholz, R. E.; Gamble, M.

1972-01-01

152

Flat Feet, Happy Feet? Comparison of the Dynamic Plantar Pressure Distribution and Static Medial Foot Geometry between Malawian and Dutch Adults  

PubMed Central

In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI) and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA). We found that Malawian adults: (1) loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2) had significantly lower plantar pressures under the heel and a part of the forefoot, and (3) had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints. PMID:23468936

Stolwijk, Niki M.; Duysens, Jacques; Louwerens, Jan Willem K.; van de Ven, Yvonne HM.; Keijsers, Noël LW.

2013-01-01

153

Differential pressure pin discharge apparatus  

DOEpatents

Disclosed is a discharge assembly for allowing elongate pins to be discharged from an area of relatively low pressure to an area of relatively greater pressure. The discharge assembly includes a duck valve having a lip piece made of flexible material. The flexible lip piece responds to a fluctuating pressure created downstream by an aspirator. The aspirator reduces the downstream pressure sensed by the duck valve when the discharge assembly is in the open position. This allows elongate pins to be moved through the duck valve with no backflow because the aspirator pressure is less than the pressure in the low pressure area from which the pins originate. Closure of the assembly causes the aspirator static pressure to force the flexible duck valve lip piece into a tightly sealed position also preventing backflow. The discharge assembly can be easily controlled using a single control valve which blocks the flow of aspirator gas and closes the pin passageway extending through the assembly.

Oakley, David J. (Richland, WA)

1987-01-01

154

Differential pressure pin discharge apparatus  

DOEpatents

Disclosed is a discharge assembly for allowing elongate pins to be discharged from an area of relatively low pressure to an area of relatively greater pressure. The discharge assembly includes a duck valve having a lip piece made of flexible material. The flexible lip piece responds to a fluctuating pressure created downstream by an aspirator. The aspirator reduces the downstream pressure sensed by the duck valve when the discharge assembly is in the open position. This allows elongate pins to be moved through the duck valve with no backflow because the aspirator pressure is less than the pressure in the low pressure area from which the pins originate. Closure of the assembly causes the aspirator static pressure to force the flexible duck valve lip piece into a tightly sealed position also preventing backflow. The discharge assembly can be easily controlled using a single control valve which blocks the flow of aspirator gas and closes the pins passageway extending through the assembly.

Oakley, D.J.

1984-05-30

155

Understanding Blood Pressure Readings  

MedlinePLUS

Understanding Blood Pressure Readings Updated:Nov 17,2014 Blood pressure is typically recorded as two numbers, written as a ratio like ... What is the AHA recommendation for healthy blood pressure? This chart reflects blood pressure categories defined by ...

156

Influence of static electric field, mechanical pressure and temperature on the propagation of acoustic waves in La3Ga5SiO14 piezoelectric single crystals  

Microsoft Academic Search

On the fundamental of our original experimental results the full set of tensorial components of linear and nonlinear electromechanical properties and temperature coefficients of material properties for La 3Ga5SiO14 piezoelectric crystals have been obtained. These data were used for the analysis of influence of static electrical field and of uniaxial homogeneous mechanical pressure on the propagation anisotropy of acoustic waves

B. P. Sorokin; P. P. Turchin; S. I. Burkov; D. A. Glushkov; K. S. Aleksandrov

1996-01-01

157

Active Mass Under Pressure  

E-print Network

After a historical introduction to Poisson's equation for Newtonian gravity, its analog for static gravitational fields in Einstein's theory is reviewed. It appears that the pressure contribution to the active mass density in Einstein's theory might also be noticeable at the Newtonian level. A form of its surprising appearance, first noticed by Richard Chase Tolman, was discussed half a century ago in the Hamburg Relativity Seminar and is resolved here.

Juergen Ehlers; Istvan Ozsvath; Engelbert Schucking

2005-05-10

158

On the propagation of a quasi-static disturbance in a heterogeneous, deformable, and porous medium with pressure-dependent properties  

SciTech Connect

Using an asymptotic technique, valid when the medium properties are smoothly-varying, I derive a semi-analytic expression for the propagation velocity of a quasi-static disturbance traveling within a nonlinear-elastic porous medium. The phase, a function related to the propagation time, depends upon the properties of the medium, including the pressure-sensitivities of the medium parameters, and on pressure and displacement amplitude changes. Thus, the propagation velocity of a disturbance depends upon its amplitude, as might be expected for a nonlinear process. As a check, the expression for the phase function is evaluated for a poroelastic medium, when the material properties do not depend upon the fluid pressure. In that case, the travel time estimates agree with conventional analytic estimates, and with values calculated using a numerical simulator. For a medium with pressure-dependent permeability I find general agreement between the semi-analytic estimates and estimates from a numerical simulation. In this case the pressure amplitude changes are obtained from the numerical simulator.

Vasco, D.W.

2011-10-01

159

The coefficient of earth pressure at rest and deformation and densification of granular soils subjected to static and dynamic loading  

Microsoft Academic Search

The coefficient of earth pressure at rest, Ko, of granular soil deposits and backfills is a significant parameter in geotechnical engineering profession. A knowledge of Ko value in granular deposits and backfills not only is necessary for many geotechnical construction, but could also assist engineers and researchers in interpretations of laboratory and in situ tests. The primary purpose of the

Barames Vardhanabhuti

2006-01-01

160

Measurements of Capillary Pressure-Saturation Relationships for Silica Sands Using Light Transmission Visualization and a Rapid Pseudo Static Methods  

EPA Science Inventory

Measurement of water saturation in porous media is essential for many types of studies including subsurface water flow, subsurface colloids transport and contaminant remediation to name a few. Water saturation (S) in porous media is dependent on the capillary pressure (Pc) which,...

161

Pressure drop and cavitation investigations on static helical-grooved square, triangular and curved cavity liquid labyrinth seals  

Microsoft Academic Search

Sodium cooled Fast Breeder Reactors (FBR) form the second stage of India's Nuclear power programme. Through a narrow annular space in the grid plate assembly of a prototype FBR, a very low leakage flow of liquid metal sodium should pass, experiencing a stipulated high pressure drop, and without much cavitation. To achieve this, a suitable labyrinth seal is required to

S. P. Asok; K. Sankaranarayanasamy; T. Sundararajan; G. Vaidyanathan; K. Udhaya Kumar

2011-01-01

162

Nonlinear response of a post-tensioned concrete structure to static and dynamic internal-pressure loads  

SciTech Connect

A nonlinear finite element model of a nuclear power plant containment building was developed to determine its ultimate pressure capability under quasistatic and impulsive dynamic loads. The ADINA finite element computer code was used to develop the model because of its capability to handle concrete cracking and crushing. Results indicate that, even though excessive concrete cracking occurs, failure is ultimately caused by rupture of post-tensioning tendons.

Butler, T.A.; Bennett, J.G.

1981-01-01

163

Round-robin pretest analyses of a 1:6-scale reinforced concrete containment model subject to static internal pressurization  

SciTech Connect

Analyses of a 1:6-scale reinforced concrete containment model that will be tested to failure at Sandia National Laboratories in the spring of 1987 were conducted by the following organizations in the United States and Europe: Sandia National Laboratories (USA), Argonne National Laboratory (USA), Electric Power Research Institute (USA), Commissariat a L'Energie Atomique (France), HM Nuclear Installations Inspectorate (UK), Comitato Nazionale per la ricerca e per lo sviluppo dell'Energia Nucleare e delle Energie Alternative (Italy), UK Atomic Energy Authority, Safety and Reliability Directorate (UK), Gesellschaft fuer Reaktorsicherheit (FRG), Brookhaven National Laboratory (USA), and Central Electricity Generating Board (UK). Each organization was supplied with a standard information package, which included construction drawings and actual material properties for most of the materials used in the model. Each organization worked independently using their own analytical methods. This report includes descriptions of the various analytical approaches and pretest predictions submitted by each organization. Significant milestones that occur with increasing pressure, such as damage to the concrete (cracking and crushing) and yielding of the steel components, and the failure pressure (capacity) and failure mechanism are described. Analytical predictions for pressure histories of strain in the liner and rebar and displacements are compared at locations where experimental results will be available after the test. Thus, these predictions can be compared to one another and to experimental results after the test.

Clauss, D.B. (ed.)

1987-05-01

164

Low Blood Pressure  

MedlinePLUS

... are normal for them. In other people, blood pressure drops below normal because of a medical condition or certain medicines. Some people may have symptoms of low blood pressure when standing up too quickly. Low blood pressure ...

165

Preventing pressure ulcers  

MedlinePLUS

Pressure ulcers are also called bedsores, or pressure sores. They can form when your skin and soft tissue press ... damaged or die. When this happens, a pressure ulcer may form. You have a risk of developing ...

166

High Blood Pressure (Hypertension)  

MedlinePLUS

... Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... your doctor prescribes it, medicine. What Is Blood Pressure? Blood pressure is the force of blood flow ...

167

High Blood Pressure (Hypertension)  

MedlinePLUS

... Consumer Information by Audience For Women High Blood Pressure (Hypertension) Print and Share (PDF 109 KB) En ... Who is at risk? How is high blood pressure treated? Understanding your blood pressure: What do the ...

168

Skin (Pressure) Sores  

MedlinePLUS

... Topic Skin dryness Next Topic Sleep problems Skin (pressure) sores A skin or pressure sore develops when the blood supply to an ... is bedridden or always in a wheelchair puts pressure on the same places much of the time. ...

169

High Blood Pressure  

MedlinePLUS

... light physical activity or exercise. What Is Blood Pressure? Blood pressure is the force of blood pushing ... as 120/80. Do You Have High Blood Pressure? One reason to have regular visits to the ...

170

Low blood pressure  

MedlinePLUS

Low blood pressure; Blood pressure - low; Postprandial hypotension; Orthostatic hypotension; Neurally mediated hypotension; NMH ... Blood pressure varies from one person to another. A drop as little as 20 mmHg, can cause problems for ...

171

Intracranial pressure monitoring  

MedlinePLUS

ICP monitoring; CSF pressure monitoring ... There are three ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

172

The StenTec gauge for measuring static intra-access pressure ratio (P(Ia Ratio) ) of fistulas and grafts.  

PubMed

The StenTec™ Gauge provides a method to determine the static intra-access pressure ratio (P(Ia Ratio) ) within a fistula or graft. The StenTec Gauge estimates the peak systolic pressure within the fistula or graft by measurement of the distance that the blood-air interface progresses into the tubing of the fistula needle, after the needle is inserted "dry" into the fistula or graft and before the cap is removed from the tubing. The peak systolic pressure is graphically compared with the systolic arterial blood pressure of the patient, to determine P(Ia Ratio) . For best accuracy, the StenTec Gauge should be chosen that best matches the internal volume of the fistula needle tubing (2.3-2.6 ml for 12-inch tubing and 3.6 ml for 16-inch tubing) and the approximate elevation of the city in which it is used (0-1000, 1000-3000, and 3000-6000 feet above sea level). In this article, we explain the rationale for this method of surveillance, evidence for accuracy of the StenTec Gauge, and the correlation of changes in the P(Ia Ratio) to the development of stenosis in a fistula or graft. PMID:22356546

Ash, Stephen R; Dhamija, Rajiv; Zaroura, Mohamad Y; Hentschel, Dirk M

2012-07-01

173

Ultrasonic pressure measurement in pressure vessels  

NASA Astrophysics Data System (ADS)

Based on the reflected longitudinal wave, a new non-intrusive method for pressure measurement is proposed. The acoustoelastic theory and the thin-shell theory are introduced to develop the pressure measurement model in cylindrical pressure vessels. And a pressure measurement system is constructed to evaluate the effectiveness of the proposed method. The pressure measurement is implemented by measuring the travel-time change between two received ultrasonic sensors. The experimental results verify the feasibility and effectiveness of this new non-intrusive method. Compared with the non-intrusive pressure measurement method based on the critically refracted longitudinal wave (LCR wave), the proposed non-intrusive pressure measurement method has the advantages of higher sensitivity and higher signal-to-noise ratio.

Bi, Yao; Zhou, Hongliang; Huang, Zhiyao; Zhou, Hanhua; Yang, Xianglong

2014-12-01

174

Neural Network Burst Pressure Prediction in Composite Overwrapped Pressure Vessels  

NASA Technical Reports Server (NTRS)

Acoustic emission data were collected during the hydroburst testing of eleven 15 inch diameter filament wound composite overwrapped pressure vessels. A neural network burst pressure prediction was generated from the resulting AE amplitude data. The bottles shared commonality of graphite fiber, epoxy resin, and cure time. Individual bottles varied by cure mode (rotisserie versus static oven curing), types of inflicted damage, temperature of the pressurant, and pressurization scheme. Three categorical variables were selected to represent undamaged bottles, impact damaged bottles, and bottles with lacerated hoop fibers. This categorization along with the removal of the AE data from the disbonding noise between the aluminum liner and the composite overwrap allowed the prediction of burst pressures in all three sets of bottles using a single backpropagation neural network. Here the worst case error was 3.38 percent.

Hill, Eric v. K.; Dion, Seth-Andrew T.; Karl, Justin O.; Spivey, Nicholas S.; Walker, James L., II

2007-01-01

175

High blood pressure  

MedlinePLUS

... body. Hypertension is another term used to describe high blood pressure. Blood pressure readings are given as two numbers. ... than 120/80 mmHg most of the time. High blood pressure (hypertension) is when your blood pressure is 140/ ...

176

The static pressure field as a driving mechanism for the streamwise corner flow in the presence of an inclined transverse plane  

NASA Astrophysics Data System (ADS)

Streamwise corner flows are characterized by the strong interaction among the boundary layers on the two walls that create the junction. The nature of this interaction defines some critical aspects of the corner flow, such as instability and laminar-turbulent transition, turbulence statistics and local shear friction and heat transfer intensities. The studies so far (both experimental and analytical) have investigated the configurations where the mainstream is mostly parallel to both walls. Under such conditions, the interaction is mainly viscous. Hence, a correct understanding of the flow dynamics requires a comprehensive knowledge of the velocity (mean and turbulent) field. In a number, however, of important applications (especially in turbomachinery blades and aircraft wing junctions), the mainstream flow is inclined against the blocking wall. This generates strong pressure gradients that modify significantly the structure of the relevant flowfield. The present study investigates experimentally the significance of the static pressure field associated with such geometries, focusing on the magnitudes and the directions along which the pressure pushes the flow. The results indicate that (1) the basic model explaining the flow interactions near a streamwise corner must be modified, and (2) the presence of an inclined wall modifies the relevant field significantly, by forcing a more intensive rotation on the mainstream, which leads to more intensive streamwise accelerations and wall jet effects near the corner.

Georgiou, Demos P.; Milidonis, Kypros F.

2014-03-01

177

An investigation to determine the static pressure distribution of the 0.00548 scale shuttle solid rocket booster (MSFC model number 468) during reentry in the NASA/MSFC 14 inch trisonic wind tunnel (SA28F)  

NASA Technical Reports Server (NTRS)

The results of a pressure test of a .00548 scale 146 inch Space Shuttle Solid Rocket Booster (SRB) with and without protuberances, conducted in a 14 x 14 inch trisonic wind tunnel are presented. Static pressure distributions for the SRB at reentry attitudes and flight conditions were obtained. Local longitudinal and ring pressure distributions are presented in tabulated form. Integration of the pressure data was performed. The test was conducted at Mach numbers of 0.40 to 4.45 over an angle of attack range from 60 to 185 degrees. Roll angles of 0, 45, 90 and 315 degrees were investigated. Reynolds numbers per foot varied for selected Mach numbers.

Braddock, W. F.; Streby, G. D.

1977-01-01

178

What Causes Pressure?  

NSDL National Science Digital Library

In this kinesthetic activity that demonstrates pressure, learners act as air molecules in a "container" as defined by a rope. Learners explore how air molecules move in different scenarios: added pressure, reduced volume of the container, increased heat, etc. Learners will make "beeps" to help the group measure the pressure and hear the difference between low and high pressure. This is a great way to introduce the concept of air pressure and illustrate how it varies with density and temperature.

Colorado State University

2009-01-01

179

Your Blood Pressure  

NSDL National Science Digital Library

Keeping your blood pressure at healthy levels is an important factor in preventing cardiovascular disease and stroke. This activity will help you: Understand the categories for blood pressure levels. Know your own blood pressure level Determine ways to prevent hypertension Understand the lifestyle factors that put you at risk for hypertension. Read about blood pressure categories. Read preventing hypertension. Read measuring your blood pressure. Print a copy of the directions on how to use a digital monitor. Check ...

Mrs. Cross

2005-11-29

180

HTGR PRESSURE AND DIFFERENTIAL PRESSURE INSTRUMENTS  

Microsoft Academic Search

The possibility of separating pressure and differential pressure ; indicating instruments from the helium systems of the HTGR by means of a ; diaphragm-sealed filled system is discussed. lt is recommended that conventional ; instrumentation be used in the reactor, main coolant system, helium handling and ; storage system, and control rod drive system and that diaphragm-sealed filled ; systems

1961-01-01

181

PressurePressure Indiana Coal Characteristics  

E-print Network

TimeTime PressurePressure · Indiana Coal Characteristics · Indiana Coals for Coke · CoalTransportation in Indiana · Coal Slurry Ponds Evaluation · Site Selection for Coal Gasification · Coal-To-Liquids Study, CTL · Indiana Coal Forecasting · Under-Ground Coal Gasification · Benefits of Oxyfuel Combustion · Economic

Fernández-Juricic, Esteban

182

Air flow and pressure inside a pressure-swirl spray and their effects on spray development  

SciTech Connect

Air flow and pressure inside a pressure-swirl spray for direct injection (DI) gasoline engines and their effects on spray development have been analyzed at different injector operating conditions. A simulation tool was utilized and the static air pressure at the centerline of the spray was measured to investigate the static pressure and flow structure inside the swirl spray. To investigate the effect of static air pressure on swirl spray development, a liquid film model was applied and the Mie-scattered images were captured. The simulation and experiment showed that recirculation vortex and air pressure drop inside the swirl spray were observable and the air pressure drop was greater at high injection pressure. At high fuel temperature, the air pressure at the nozzle exit showed higher value compared to the atmospheric pressure and then continuously decreased up to few millimeters distance from the nozzle exit. The pressure drop at high fuel temperatures was more than that of atmospheric temperature. This reduced air pressure was recovered to the atmospheric pressure at further downstream. The results from the liquid film model and macroscopic spray images showed that the air pressure started to affect the liquid film trajectory about 3 mm from the nozzle exit and this effect was sustained until the air pressure recovered to the atmospheric pressure. However, the entrained air motion and droplet size have more significant influence on the spray development after the most of the liquid sheet is broken-up and the spray loses its initial momentum. (author)

Moon, Seoksu; Bae, Choongsik [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Guseong-dong, Yuseong-gu, Daejon 305-701 (Korea); Abo-Serie, Essam [Department of Mechanical Engineering and Design, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom)

2009-01-15

183

Dome pressure maintaining valve  

SciTech Connect

This patent describes a system for maintaining dome fluid pressure in a pilot operated relief valve. It comprises: a fluid pressure maintenance means having an inlet port for receiving pressurized fluid supply from a source requiring pressure relief maintenance and an outlet port for expelling the pressurized fluid from the fluid pressure maintenance means; the fluid pressure maintenance means being placed in a circuit between a sensor inlet and the pilot valve, means capable of being adapted with fixed or adjustable pressure setting functionality; the fluid pressure maintenance means outlet port in communication with a dome of the relief valve through the pilot; the fluid pressure maintenance means functioning through a poppet check valve for equalizing inlet and outlet pressure. The poppet check valve providing inlet flow and check for reverse flow; the poppet check valve and a piston valve integrated into one piston valve embodiment with the piston valve providing outlet flow in a backflow relief mode; and the fluid pressure maintenance means having a pressure storage chamber for providing a maintaining fluid pressure in the relief valve dome.

Snyder, D.E.

1990-12-04

184

Pressure Dome for High-Pressure Electrolyzer  

NASA Technical Reports Server (NTRS)

A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom segment and is trapped by the flange on the top dome segment when these components are bolted together with high-strength bolts. The pressure dome has several unique features. It is made (to ASME Pressure Vessel guidelines) in a high-strength aluminum alloy with the strength of stainless steel and the weight benefits of aluminum. The flange of the upper dome portion contains specially machined flats for mounting the dome, and other flats dedicated to the special feedthroughs for electrical connections. A pressure dome can be increased in length to house larger stacks (more cells) of the same diameter with the simple addition of a cylindrical segment. To aid in dome assembly, two stainless steel rings are employed. One is used beneath the heads of the high-strength bolts in lieu of individual hardened washers, and another is used instead of individual nuts. Like electrolyzers could be operated at low or high pressures simply by operating the electrolyzer outside or inside a pressurized dome.

Norman, Timothy; Schmitt, Edwin

2012-01-01

185

External pressure measurement system  

NASA Astrophysics Data System (ADS)

Hydraulic systems comprise an important part of jet aircraft and their pressure needs must be checked constantly. Tests of the prototype external pressure measurement system show that it is possible to accurately convert the small expansion of tubing with pressure into a direct pressure reading without inserting a pressure gage into the piping system. The tool described in the paper is a clamp-on displacement transducer that can read pressure directly in PSI from 0 to 5000. Some limitations concerning temperature and accuracy should be remedied by additional design work. The system promises to streamline troubleshooting of all types of piping systems.

Chandler, Jon K.; Fowler, Don P.

186

Externally Pressurized Porous Thrust Bearings  

Microsoft Academic Search

The use of porous material in the bearing surface of externally pressurized thrust bearings leads to a compact design by eliminating the need for an external restrictor and has other potential advantages.An experimental and theoretical investigation of the performance of such bearings, using liquid lubricants is described: the investigation is limited to static conditions but considers the effect of bearing

R. B. Howarth

1976-01-01

187

Simultaneous monitoring of static and dynamic intracranial pressure parameters from two separate sensors in patients with cerebral bleeds: comparison of findings  

PubMed Central

Background We recently reported that in an experimental setting the zero pressure level of solid intracranial pressure (ICP) sensors can be altered by electrostatics discharges. Changes in the zero pressure level would alter the ICP level (mean ICP); whether spontaneous changes in mean ICP happen in clinical settings is not known. This can be addressed by comparing the ICP parameters level and waveform of simultaneous ICP signals. To this end, we retrieved our recordings in patients with cerebral bleeds wherein the ICP had been recorded simultaneously from two different sensors. Materials and Methods: During a time period of 10?years, 17 patients with cerebral bleeds were monitored with two ICP sensors simultaneously; sensor 1 was always a solid sensor while Sensor 2 was a solid -, a fluid - or an air-pouch sensor. The simultaneous signals were analyzed with automatic identification of the cardiac induced ICP waves. The output was determined in consecutive 6-s time windows, both with regard to the static parameter mean ICP and the dynamic parameters (mean wave amplitude, MWA, and mean wave rise time, MWRT). Differences in mean ICP, MWA and MWRT between the two sensors were determined. Transfer functions between the sensors were determined to evaluate how sensors reproduce the ICP waveform. Results Comparing findings in two solid sensors disclosed major differences in mean ICP in 2 of 5 patients (40%), despite marginal differences in MWA, MWRT, and linear phase magnitude and phase. Qualitative assessment of trend plots of mean ICP and MWA revealed shifts and drifts of mean ICP in the clinical setting. The transfer function analysis comparing the solid sensor with either the fluid or air-pouch sensors revealed more variable transfer function magnitude and greater differences in the ICP waveform derived indices. Conclusions Simultaneous monitoring of ICP using two solid sensors may show marked differences in static ICP but close to identity in dynamic ICP waveforms. This indicates that shifts in ICP baseline pressure (sensor zero level) occur clinically; trend plots of the ICP parameters also confirm this. Solid sensors are superior to fluid – and air pouch sensors when evaluating the dynamic ICP parameters. PMID:22958653

2012-01-01

188

High Blood Pressure  

MedlinePLUS

... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ...

189

Pressure Sensitive Paints  

NASA Technical Reports Server (NTRS)

This article reviews new advances and applications of pressure sensitive paints in aerodynamic testing. Emphasis is placed on important technical aspects of pressure sensitive paint including instrumentation, data processing, and uncertainty analysis.

Liu, Tianshu; Bencic, T.; Sullivan, J. P.

1999-01-01

190

Pressure surge attenuator  

DOEpatents

A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

Christie, Alan M. (Swissvale, PA); Snyder, Kurt I. (Murrysville, PA)

1985-01-01

191

The Root Pressure Phenomenon  

ERIC Educational Resources Information Center

Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

Marsh, A. R.

1972-01-01

192

Blood Pressure Medicines  

MedlinePLUS

High blood pressure, also called hypertension, usually has no symptoms. But it can cause serious problems such as stroke, heart failure, ... failure. If you cannot control your high blood pressure through lifestyle changes such as losing weight and ...

193

Dealing with Peer Pressure  

MedlinePLUS

... Page The Pink Locker Society Dealing With Peer Pressure KidsHealth > Kids > Feelings > My Emotions & Behaviors > Dealing With ... talk about how to handle it. Defining Peer Pressure Peers influence your life, even if you don' ...

194

High Blood Pressure  

MedlinePLUS

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart ... it pumps blood into the arteries. Your blood pressure is highest when your heart beats, pumping the ...

195

What is Blood Pressure?  

NSDL National Science Digital Library

In this activity about heart health (on page 34 of the PDF), learners measure their own blood pressure using an electronic blood pressure monitor with a self-inflating cuff (included in cost of materials) and learn about the health effects of high blood pressure. Learners also discover how to interpret the blood pressure number (diastolic vs. systolic) and healthy ranges. This lesson guide includes background information, setup and management tips, and web resources.

Barbara Z. Tharp

2009-01-01

196

Pressure-sensitive optrode  

DOEpatents

An apparatus is provided for sensing changes in pressure and for generating optical signals related to said changes in pressure. Light from a fiber optic illuminates a fluorescent composition causing it to fluoresce. The fluorescent composition is caused to fluoresce more relative to the end of the fiber optic in response to changes in pressure so that the intensity of fluorescent emissions collected by the same fiber optic used for illumination varies monotonically with pressure. 10 figs.

Hirschfeld, T.B.

1986-07-15

197

The pressure multiplier revisited  

NASA Technical Reports Server (NTRS)

Pressure multipliers, which were originally intended to continuously sample an unknown pressure and increase it by a known factor, so that measurements could be conducted at low pressures with liquid-in-gas gauges, may be usefully applied to the increasing number of components available for use in molecular flow networks. An intriguing possibility involves the electric control of pressure multiplier gain by means of a piezoelectric valve.

Kendall, B. R. F.

1983-01-01

198

Portable Potable Pressure  

NSDL National Science Digital Library

In this activity, learners use plastic water bottles, wood, and water to build an inexpensive and portable tool to demonstrate one atmosphere of pressure at sea level. Once the tool is assembled learners use it to explore atmospheric pressure and how humans respond to this pressure on Earth. This resource includes optional extensions to investigate non-metric units and atmospheric pressure on Venus, Mars, and in the deep ocean.

Eric Muller

2004-01-01

199

The coefficient of earth pressure at rest and deformation and densification of granular soils subjected to static and dynamic loading  

NASA Astrophysics Data System (ADS)

The coefficient of earth pressure at rest, Ko, of granular soil deposits and backfills is a significant parameter in geotechnical engineering profession. A knowledge of Ko value in granular deposits and backfills not only is necessary for many geotechnical construction, but could also assist engineers and researchers in interpretations of laboratory and in situ tests. The primary purpose of the study is to gain a better understanding of K o behavior of granular soils during loading, unloading, and vibration, especially produced by vibratory surface compaction equipments. Compressibility and rebound behaviors of granular soils were studied, and effect of particle damage on Ko and one-dimensional compression behavior were also reviewed. Influence of dynamic stress characteristics, including maximum dynamic vertical stress increase and frequency, on the change in Ko and minimum achievable void ratio of granular soils during vibration were determined. A comprehensive laboratory testing program, mainly the series of oedometer test with lateral stress measurement, were conducted on Ottawa, Lake Michigan Beach, Niigata, and Toyoura sand. Reconstituted dry sand specimens were subjected to 7 different loading histories, and the maximum effective vertical stress was 341 kPa. Different characteristics of dynamic vertical stresses, including periodic impulse stresses (f = 61 Hz, fp = 1,170 Hz), approximately sinusoidal dynamic stresses (f = 60 to 120 Hz, fp = 120 to 180 Hz), as well as 'cyclic loading' (loading-unloading-reloading, f ? 0 Hz), with various maximum dynamic stress amplitudes and durations of vibration, were applied to the sand specimens. A total of 155 oedometer tests with lateral stress measurement were completed. Particle modification, if any occurred during the oedometer test, was investigated through results of grain size and SEM analyses of sand particles before and after the oedometer test, and compression behavior of sand specimens observed during the oedometer test.

Vardhanabhuti, Barames

200

Magnetic fluid pressure sensor  

NASA Astrophysics Data System (ADS)

A new, powerful and sensitive pressure sensor has been developed to detect deformations of a magnetic fluid (MF) membrane. The output voltage is a linear function of the differential pressure experienced by the MF membrane, which acts as a safety valve beyond some breaking conditions. Increasing or decreasing the pressure leads to reproducible measurements with no hysteresis.

Bacri, J.-C.; Lenglet, J.; Perzynski, R.; Servais, J.

1993-04-01

201

A Shot Under Pressure  

NSDL National Science Digital Library

Students use their understanding of projectile physics and fluid dynamics to find the water pressure in water guns. By measuring the range of the water jets, they are able to calculate the theoretical pressure. Students create graphs to analyze how the predicted pressure relates to the number of times they pump the water gun before shooting.

2014-09-18

202

Aircraft Performance: Atmospheric Pressure  

E-print Network

Aircraft Performance: Atmospheric Pressure FAA Handbook of Aeronautical Knowledge Chap 10 #12 ­ 21% Oxygen ­ 1% other gases (argon, helium, etc) · Most oxygen Atmospheric Pressure;High Density Altitude (worse performance) · High elevations · Low atmospheric pressures · High

203

Brain Pressure Monitoring  

NASA Technical Reports Server (NTRS)

A transducer originally used to measure air pressure in aircraft wind tunnel tests is the basis for a development important in diagnosis and treatment of certain types of brain damage. A totally implantable device, tbe intracranial pressure monitor measures and reports brain pressure by telemetry.

1977-01-01

204

Variable pressure regulating valve  

Microsoft Academic Search

This patent describes an apparatus for metering the weight flow of fuel (WF) to a gas turbine engine characterized by: a metering valve for metering the weight flow; PRV means for providing a constant pressure drop across the fuel metering valve by comparing a supply pressure of the weight flow with a metered pressure of the weight flow, the PRV

R. H. Perkinson; C. E. Reuter

1989-01-01

205

Fuel pressure regulator valve  

Microsoft Academic Search

This patent describes a fuel pressure regulator valve. It comprises: a housing containing a diaphragm assembly that divides the housing into two chambers, one chamber being a fuel chamber, and the other chamber being a control chamber, the fuel chamber having an inlet adapted to be communicated to a supply of pressurized fluid whose pressure is to be regulated and

Hornby

1990-01-01

206

Optional Barometric Pressure Protocol  

NSDL National Science Digital Library

The purpose of this activity is to measure air pressure. Students record atmospheric pressure using a barometer or altimeter. Intended outcomes are that students gain an understanding that barometric or altimeter pressure varies and its increase or decrease indicates an upcoming change in the weather. Students also learn that the air has weight. Supporting background materials for both student and teacher are included.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

207

High pressure ices  

PubMed Central

H2O will be more resistant to metallization than previously thought. From computational evolutionary structure searches, we find a sequence of new stable and meta-stable structures for the ground state of ice in the 1–5 TPa (10 to 50 Mbar) regime, in the static approximation. The previously proposed Pbcm structure is superseded by a Pmc21 phase at p = 930 GPa, followed by a predicted transition to a P21 crystal structure at p = 1.3 TPa. This phase, featuring higher coordination at O and H, is stable over a wide pressure range, reaching 4.8 TPa. We analyze carefully the geometrical changes in the calculated structures, especially the buckling at the H in O-H-O motifs. All structures are insulating—chemistry burns a deep and (with pressure increase) lasting hole in the density of states near the highest occupied electronic levels of what might be component metallic lattices. Metallization of ice in our calculations occurs only near 4.8 TPa, where the metallic C2/m phase becomes most stable. In this regime, zero-point energies much larger than typical enthalpy differences suggest possible melting of the H sublattice, or even the entire crystal. PMID:22207625

Hermann, Andreas; Ashcroft, N. W.; Hoffmann, Roald

2012-01-01

208

Respiratory monitoring system based on the nasal pressure technique for the analysis of sleep breathing disorders: Reduction of static and dynamic errors, and comparisons with thermistors and pneumotachographs  

NASA Astrophysics Data System (ADS)

Thermally sensitive devices—thermistors—have usually been used to monitor sleep-breathing disorders. However, because of their long time constant, these devices are not able to provide a good characterization of fast events, like hypopneas. Nasal pressure recording technique (NPR) has recently been suggested to quantify airflow during sleep. It is claimed that the short time constants of the devices used to implement this technique would allow an accurate analysis of fast abnormal respiratory events. However, these devices present errors associated with nonlinearities and acoustic resonance that could reduce the diagnostic value of the NPR. Moreover, in spite of the high scientific and clinical potential, there is no detailed description of a complete instrumentation system to implement this promising technique in sleep studies. In this context, the purpose of this work was twofold: (1) describe the development of a flexible NPR device and (2) evaluate the performance of this device when compared to pneumotachographs (PNTs) and thermistors. After the design details are described, the system static accuracy is evaluated by a comparative analysis with a PNT. This analysis revealed a significant reduction (p<0.001) of the static error when system nonlinearities were reduced. The dynamic performance of the NPR system was investigated by frequency response analysis and time constant evaluations and the results showed that the developed device response was as good as PNT and around 100 times faster (?=5,3 ms) than thermistors (?=512 ms). Experimental results obtained in simulated clinical conditions and in a patient are presented as examples, and confirmed the good features achieved in engineering tests. These results are in close agreement with physiological fundamentals, supplying substantial evidence that the improved dynamic and static characteristics of this device can contribute to a more accurate implementation of medical research projects and to improve the diagnoses of sleep-breathing disorders.

Alves de Mesquita, Jayme; Lopes de Melo, Pedro

2004-03-01

209

Pressure reducing regulator  

DOEpatents

A pressure reducing regulator that controls its downstream or outlet pressure to a fixed fraction of its upstream or inlet pressure. The regulator includes a housing which may be of a titanium alloy, within which is located a seal or gasket at the outlet end which may be made of annealed copper, a rod, and piston, each of which may be made of high density graphite. The regulator is insensitive to temperature by virtue of being without a spring or gas sealed behind a diaphragm, and provides a reference for a system in which it is being used. The rod and piston of the regulator are constructed, for example, to have a 1/20 ratio such that when the downstream pressure is less than 1/20 of the upstream pressure the regulator opens and when the downstream pressure exceeds 1/20 of the upstream pressure the regulator closes.

Whitehead, John C. (Davis, CA); Dilgard, Lemoyne W. (Willits, CA)

1995-01-01

210

Pressure reducing regulator  

DOEpatents

A pressure reducing regulator that controls its downstream or outlet pressure to a fixed fraction of its upstream or inlet pressure is disclosed. The regulator includes a housing which may be of a titanium alloy, within which is located a seal or gasket at the outlet end which may be made of annealed copper, a rod, and piston, each of which may be made of high density graphite. The regulator is insensitive to temperature by virtue of being without a spring or gas sealed behind a diaphragm, and provides a reference for a system in which it is being used. The rod and piston of the regulator are constructed, for example, to have a 1/20 ratio such that when the downstream pressure is less than 1/20 of the upstream pressure the regulator opens and when the downstream pressure exceeds 1/20 of the upstream pressure the regulator closes. 10 figs.

Whitehead, J.C.; Dilgard, L.W.

1995-10-10

211

Miniaturized pressurization system  

DOEpatents

The invention uses a fluid stored at a low pressure and provides the fluid at a high pressure. The invention allows the low pressure fluid to flow to a fluid bore of a differential pump and from the pump to a fluid pressure regulator. After flowing through the regulator the fluid is converted to a gas which is directed to a gas bore of the differential pump. By controlling the flow of gas entering and being exhausted from the gas bore, the invention provides pressure to the fluid. By setting the regulator, the high pressure fluid can be set at predetermined values. Because the invention only needs a low pressure fluid, the inventive apparatus has a low mass, and therefore would be useful in rocket propulsion systems.

Whitehead, John C. (Davis, CA); Swink, Don G. (Woodinville, WA)

1991-01-01

212

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2014 CFR

... (5) When pressure tests are conducted on pressure vessels or pressure piping, the test pressure shall be maintained for a period of time sufficient...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2014-10-01

213

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2013 CFR

... (5) When pressure tests are conducted on pressure vessels or pressure piping, the test pressure shall be maintained for a period of time sufficient...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2013-10-01

214

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2012 CFR

... (5) When pressure tests are conducted on pressure vessels or pressure piping, the test pressure shall be maintained for a period of time sufficient...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2012-10-01

215

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2011 CFR

... (5) When pressure tests are conducted on pressure vessels or pressure piping, the test pressure shall be maintained for a period of time sufficient...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2011-10-01

216

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2010 CFR

... (5) When pressure tests are conducted on pressure vessels or pressure piping, the test pressure shall be maintained for a period of time sufficient...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2010-10-01

217

High Blood Pressure: Using an Ambulatory Blood Pressure Monitor  

MedlinePLUS

MENU Return to Web version High Blood Pressure | Using an Ambulatory Blood Pressure Monitor What is an ambulatory blood pressure monitor? An ambulatory blood pressure monitor is a small machine, about ...

218

Pressure regulating valve controller  

SciTech Connect

In an aircraft cabin air conditioning system comprising a pair of air cycle refrigeration systems which provide chilled air to the cabin, airflow through the air cycle refrigeration systems being controllable by a pair of pressure regulating valves, each of the pressure regulating valves being disposed in a corresponding main airflow conduit and operated by a corresponding pneumatic valve actuator, the improvement is described by: one of the pneumatic valve actuators associated with one of the pressure regulating valves being operated by a controller comprising: a main servo conduit communicating with one of the main airflow conduits and the pneumatic valve actuator for channeling pneumatic pressure thereto from the main airflow; a first pressure regulator communicating with the main servo conduit for continuously adjusting pneumatic pressure therewithin in response to ram air temperature; a second pressure regulator communicating with the main servo conduit for providing step function adjustment in pneumatic pressure; and means communicating with the main servo conduit for overriding the second pressure regulator to effect partial closing of the one pressure regulating valve despite the deactivation of the air cycle system.

Goodman, R.B.

1988-04-05

219

Pressure natriuresis in hypertension.  

PubMed

Pressure natriuresis, defined as the relationship between sodium excretion and mean arterial pressure (MAP), was assessed during graded reduction of arterial pressure with nitroprusside in 16 essential hypertensives (EH). In all patients, sodium excretion fell linearly with reductions in arterial pressure (r greater than 0.68; p less than 0.05). The per cent change of sodium excretion from control per mmHg change in MAP (delta UNaV/delta MAP) was less in patients with resting MAP above 120 mmHg than in those with lower blood pressure (1.4 +/- 0.1 versus 3.0 +/- 0.3; p less than 0.001), but the pressure at which urine flow extrapolated to zero (75 +/- 3 mmHg) was not significantly different in the two groups. The slope of the relationship between sodium excretion and arterial pressure was significantly correlated with resting MAP (r = -0.67; p less than 0.05) and with plasma volume (r = 0.61; p less than 0.05). Furthermore, the ratio delta UNaV/delta MAP also rose in concert with body fluid volumes when a salt load of 8 g of sodium chloride was added to the regular diet. Thus, the sensitivity of pressure natriuresis was determined by level of resting arterial pressure and body fluid volumes. These experiments suggest tht two mechanisms might be activated in EH to avoid dangerous sodium and volume depletion: 1) attenuation of pressure natriuresis at higher levels of arterial pressure, and 2) blunting of pressure natriuresis by volume contraction. By this hypothesis, the lower slope of pressure natriuresis is secondary to hypertension rather than its cause. PMID:6941671

Omvik, P

1981-01-01

220

Direct measurement of cutaneous pressures generated by pressure garments  

Microsoft Academic Search

Pressure garments are the mainstay of burn scar management despite limited scientific evidence. This study demonstrates a simple method of directly measuring the cutaneous pressures generated by a pressure garment. The results show pressure garments generate an increase in subdermal pressures in the range 9–90 mmHg depending on the anatomical site. Garments over soft sites generate pressures ranging from 9

H. P. Giele; K. Liddiard; K. Currie; F. M. Wood

1997-01-01

221

Under Pressure A 4-week Blood Pressure Program  

E-print Network

Under Pressure A 4-week Blood Pressure Program Under Pressure is a month long blood pressure program to teach you the basic facts about blood pressure, give you the tools to take charge of your health, and reward you for daily healthy habits. · Raffle prizes, healthy snacks, and free blood pressure

Reed, Christopher A.

222

PressureText: Pressure Input for Mobile Phone Text Entry  

E-print Network

PressureText: Pressure Input for Mobile Phone Text Entry Abstract Pressure sensitive buttons presses are currently necessary to record an action. We present PressureText, a text-entry technique for a pressure augmented mobile phone. In a study comparing PressureText to MultiTap, we found that despite

223

BIOMACROMOLECULES UNDER HIGH HYDROSTATIC PRESSURE  

E-print Network

BIOMACROMOLECULES UNDER HIGH HYDROSTATIC PRESSURE A Dissertation Presented to the Faculty HIGH HYDROSTATIC PRESSURE Nozomi Ando, Ph.D. Cornell University 2009 Protein pressure denaturation denaturation studies. Recent studies imply that the mechanism of pressure denaturation is the penetration

Gruner, Sol M.

224

Helping Teens Resist Sexual Pressure  

MedlinePLUS

... Pressure Ages & Stages Listen Helping Teens Resist Sexual Pressure Article Body Teens are more likely to have ... time they had intercourse. Helping Teens Resist Sexual Pressure “The pressure on teenagers to have sex is ...

225

Blade pressure measurements  

NASA Astrophysics Data System (ADS)

Three measurement techniques which enable rotating pressures to be measured during the normal operation of a gas turbine or a component test rig are described. The first technique was developed specifically to provide steady and transient blade surface pressure data to aid both fan flutter research and general fan performance development. This technique involves the insertion of miniature high frequency response pressure transducers into the fan blades of a large civil gas turbine. The other two techniques were developed to measure steady rotating pressures inside and on the surface of engine or rig turbine blades and also rotating pressures in cooling feed systems. These two low frequency response systems are known as the "pressure pineapple' (a name which resulted from the shape of the original prototype) and the rotating scanivalve.

Chivers, J. W. H.

226

Measurement of endolymphatic pressure.  

PubMed

Endolymphatic pressure measurement is of interest both to researchers in the physiology and pathophysiology of hearing and ENT physicians dealing with Menière's disease or similar conditions. It is generally agreed that endolymphatic hydrops is associated with Menière's disease and is accompanied by increased hydrostatic pressure. Endolymphatic pressure, however, cannot be measured precisely without endangering hearing, making the association between hydrops and increased endolymphatic pressure difficult to demonstrate. Several integrated in vivo models have been developed since the 1960s, but only a few allow measurement of endolymphatic hydrostatic pressure. Models associating measurement of hydrostatic pressure and endolymphatic potential and assessment of cochlear function are of value to elucidate the pathophysiology of endolymphatic hydrops. The present article presents the main types of models and discusses their respective interest. PMID:25467202

Mom, T; Pavier, Y; Giraudet, F; Gilain, L; Avan, P

2015-04-01

227

Bag pressure monitor  

DOEpatents

An inexpensive mechanical indicator for measuring low pressure in an inflating bag includes a pair of sides connected to each other at one edge and pivotally connected at spaced parallel locations on the bag. A spring biases the sides towards each other in opposition to tension in the inflating bag. The distance between the sides is indicative of the pressure in the bag. The device is accurate at pressures below 0.05 psi.

Vaughn, Mark Roy (Albuquerque, NM); Miller, Alva Keith (Albuquerque, NM)

2000-01-01

228

High temperature pressure gauge  

DOEpatents

A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

Echtler, J. Paul (Pittsburgh, PA); Scandrol, Roy O. (Library, PA)

1981-01-01

229

Pressure cryocooling protein crystals  

DOEpatents

Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

Kim, Chae Un (Ithaca, NY); Gruner, Sol M. (Ithaca, NY)

2011-10-04

230

Ruby under pressure  

Microsoft Academic Search

The ruby luminescence method is widely used for pressure measurement in the diamond anvil cell and other optically transparent pressure cells. With this application in mind, we briefly review the ground-state physical properties of corundum (?-Al2O3) with some emphasis on its behavior under high pressure, survey the effects of temperature and stress on the R-line luminescence of ruby (Cr-doped corundum),

K. Syassen

2008-01-01

231

In situ measurement of magnesium carbonate formation from CO2 using static high-pressure and -temperature 13C NMR.  

PubMed

We explore a new in situ NMR spectroscopy method that possesses the ability to monitor the chemical evolution of supercritical CO(2) in relevant conditions for geological CO(2) sequestration. As a model, we use the fast reaction of the mineral brucite, Mg(OH)(2), with supercritical CO(2) (88 bar) in aqueous conditions at 80 °C. The in situ conversion of CO(2) into metastable and stable carbonates is observed throughout the reaction. After more than 58 h of reaction, the sample was depressurized and analyzed using in situ Raman spectroscopy, where the laser was focused on the undisturbed products through the glass reaction tube. Postreaction, ex situ analysis was performed on the extracted and dried products using Raman spectroscopy, powder X-ray diffraction, and magic-angle spinning (1)H-decoupled (13)C NMR. These separate methods of analysis confirmed a spatial dependence of products, possibly caused by a gradient of reactant availability, pH, and/or a reaction mechanism that involves first forming hydroxy-hydrated (basic, hydrated) carbonates that convert to the end-product, anhydrous magnesite. This carbonation reaction illustrates the importance of static (unmixed) reaction systems at sequestration-like conditions. PMID:22676479

Surface, J Andrew; Skemer, Philip; Hayes, Sophia E; Conradi, Mark S

2013-01-01

232

Blood Pressure Control  

NASA Technical Reports Server (NTRS)

Engineering Development Laboratory developed a system for the cardiovascular study of weightless astronauts. This was designed to aid people with congestive heart failure and diabetes. While in space, astronauts' blood pressure rises, heart rate becomes unstable, and there are sometimes postflight lightheadedness or blackouts. The Baro-Cuff studies the resetting of blood pressure. When a silicone rubber chamber is strapped to the neck, the Baro-Cuff stimulates the carotid arteries by electronically controlled pressure application. Blood pressure controls in patients may be studied.

1986-01-01

233

Pressure-sensitive optrode  

DOEpatents

An apparatus and method are disclosed for sensing changes in pressure and for generating optical signals related to changes in pressure. Light from a fiber optic is directed to a movable surface which is coated with a light-responsive material, and which moves relative to the end of the fiber optic in response to changes in pressure. The same fiber optic collects a portion of the reflected or emitted light from the movable surface. Changes in pressure are determined by measuring changes in the amount of light collected. 5 figs.

Hirschfeld, T.B.

1985-04-09

234

Pressure-sensitive optrode  

DOEpatents

Apparatus and method for sensing changes in pressure and for generating optical signals related to changes in pressure. Light from a fiber optic is directed to a movable surface which is coated with a light-responsive material, and which moves relative to the end of the fiber optic in response to changes in pressure. The same fiber optic collects a portion of the reflected or emitted light from the movable surface. Changes in pressure are determined by measuring changes in the amount of light collected.

Hirschfeld, T.B.

1982-09-30

235

Putting on the Pressure  

NSDL National Science Digital Library

Students build a simple aneroid barometer that can be used to measure changes in air pressure. Materials required include a large jar, ruler, large balloon, 2 drinking straws, and clay. The instrument is used to track changes in air pressure, and students observe that sunny days usually have higher pressure and rainy days have lower pressure. The resource is part of the teacher's guide accompanying the video, NASA SCI Files: The Case of the Phenomenal Weather. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

236

Pressurized fluidized bed reactor  

DOEpatents

A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

Isaksson, J.

1996-03-19

237

Dual shell pressure balanced vessel  

DOEpatents

A dual-wall pressure balanced vessel for processing high viscosity slurries at high temperatures and pressures having an outer pressure vessel and an inner vessel with an annular space between the vessels pressurized at a pressure slightly less than or equivalent to the pressure within the inner vessel.

Fassbender, Alexander G. (West Richland, WA)

1992-01-01

238

Manufacturing Diamond Under Very High Pressure  

NASA Technical Reports Server (NTRS)

A process for manufacturing bulk diamond has been made practical by the invention of the High Pressure and Temperature Apparatus capable of applying the combination of very high temperature and high pressure needed to melt carbon in a sufficiently large volume. The apparatus includes a reaction cell wherein a controlled static pressure as high as 20 GPa and a controlled temperature as high as 5,000 C can be maintained.

Voronov, Oleg

2007-01-01

239

Modeling Scala Media as a Pressure Vessel  

NASA Astrophysics Data System (ADS)

The clinical condition known as endolymphatic hydrops is the swelling of scala media and may result in loss in hearing sensitivity consistent with other forms of low-frequency biasing. Because outer hair cells (OHCs) are displacement-sensitive and hearing levels tend to be preserved despite large changes in blood pressure and CSF pressure, it seems unlikely that the OHC respond passively to changes in static pressures in the chambers. This suggests the operation of a major feedback control loop which jointly regulates homeostasis and hearing sensitivity. Therefore the internal forces affecting the cochlear signal processing amplifier cannot be just motile responses. A complete account of the cochlear amplifier must include static pressures. To this end we have added a third, pressure vessel to our 1-D 140-segment, wave-digital filter active model of cochlear mechanics, incorporating the usual nonlinear forward transduction. In each segment the instantaneous pressure is the sum of acoustic pressure and global static pressure. The object of the model is to maintain stable OHC operating point despite any global rise in pressure in the third chamber. Such accumulated pressure is allowed to dissipate exponentially. In this first 3-chamber implementation we explore the possibility that acoustic pressures are rectified. The behavior of the model is critically dependent upon scaling factors and time-constants, yet by initial assumption, the pressure tends to accumulate in proportion to sound level. We further explore setting of the control parameters so that the accumulated pressure either stays within limits or may rise without bound.

Lepage, Eric; Olofsson, A.?Ke

2011-11-01

240

Performance of Compressor of XJ-41-V Turbojet Engine II - Static-Pressure Ratios and Limitation of Maximum Flow at Equivalent Compressor Speed of 8000 rpm  

NASA Technical Reports Server (NTRS)

At the request of the Air Material Command, Army Air Forces, an investigation was conducted by the NACA Cleveland laboratory to determine the performance characteristics of the compressor of the XJ-41-V turbojet engine. This report is the second in a series presenting the compressor performance and analysis of flow conditions in the compressor. The static-pressure variation in the direction of flow through the compressor and the location and the cause of the maximum flow restriction at an equivalent speed of 8000 rpm are presented. After the initial runs were reported, the leading edges of the impeller blades and the diffuser surfaces were found to have been roughened by steel particles from a minor failure of auxiliary equipment. The leading edges of the impeller blades were refinished and all high spots resulting from scratches in the diffuser and the accessible parts of the vaned collector passages were removed. The initial overall performance and that obtained with the refinished blades are presented.

Dildine, Dean M.; Arthur, W. Lewis

1948-01-01

241

Vapor Pressure Data  

NSDL National Science Digital Library

Created by Professor Shuzo Ohe of the Graduate School of Chemical Engineering and the Science University or Tokyo, this site offers vapor pressure data. Available in graph form, data represent vapor pressure (mmHg) as a function of temperature (C, or F). Substances are listed alphabetically and include acetaldehyde, acetic acid, benzene, butane, carbon dioxide, and water, to name a few.

Ohe, Shuzo.

242

Gas Laws: Pressure  

NSDL National Science Digital Library

This site offers an interactive tutorial in which students are taken thrugh three exercises: reading a manometer, measuring pressure when the manometer contains a liquid other than water, compensating for the vapor pressure of a volatile liquid in the manometer. This tutorial is coupled to others to further guide the student to a better understanding of the principles which govern the behavior of gases.

David N. Blauch

243

Winds and Pressure  

NSDL National Science Digital Library

This undergraduate meteorology tutorial discusses the different ways that the air responds to pressure gradients on a small scale and on a large scale, defines and explains geostrophic balance, and describes how to infer the large-scale wind pattern from maps of pressure or height.

John Nielsen-Gammon

1996-01-01

244

Understanding Blood Pressure  

E-print Network

Understanding Blood Pressure · Monitorathomewithadigitalmonitor. · Useleftarmwithcorrectsizecuff. · Avoidcaffeine,alcohol,andtobacco. Steps to Follow FOR AN ACCURATE MEASUREMENT Blood pressure is the measurement of the force of blood on the walls of the arteries. Bottom number = Diastolic (force between heart beats) Top

245

Families under Economic Pressure.  

ERIC Educational Resources Information Center

Data from two-parent families in midwestern rural county revealed that adverse economic change increased economic pressures and hardship adaptations in ways that matched effect of income level and exceeded influence of unstable work. Pressures and adaptations mediated negative effects of economic adversity on emotional health and family…

Elder, Glen H., Jr.; And Others

1992-01-01

246

Pressure regulating valve controller  

Microsoft Academic Search

In an aircraft cabin air conditioning system comprising a pair of air cycle refrigeration systems which provide chilled air to the cabin, airflow through the air cycle refrigeration systems being controllable by a pair of pressure regulating valves, each of the pressure regulating valves being disposed in a corresponding main airflow conduit and operated by a corresponding pneumatic valve actuator,

1988-01-01

247

Pressure regulating valve  

Microsoft Academic Search

This patent describes a pressure regulating valve for regulating a pressure of fuel to be supplied to a fuel injection device, comprising: a diaphragm chamber having a connecting portion for inducing an intake manifold vacuum in the vicinity of a nozzle hold of the fuel injection device; a fuel chamber having a connecting portion for inducing a fuel and located

Hayashi

1988-01-01

248

Too Much Pressure!  

NSDL National Science Digital Library

In this activity, students learn how engineers design faucets. Students will learn about water pressure by building a simple system to model faucets and test the relationship between pressure, area and force. This is a great outdoor activity on a warm day.

2014-09-18

249

Pressure Ulcer Prevention  

PubMed Central

Executive Summary In April 2008, the Medical Advisory Secretariat began an evidence-based review of the literature concerning pressure ulcers. Please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/tech/tech_mn.html to review these titles that are currently available within the Pressure Ulcers series. Pressure ulcer prevention: an evidence based analysis The cost-effectiveness of prevention strategies for pressure ulcers in long-term care homes in Ontario: projections of the Ontario Pressure Ulcer Model (field evaluation) Management of chronic pressure ulcers: an evidence-based analysis (anticipated pubicstion date - mid-2009) Purpose A pressure ulcer, also known as a pressure sore, decubitus ulcer, or bedsore, is defined as a localized injury to the skin/and or underlying tissue occurring most often over a bony prominence and caused by pressure, shear, or friction, alone or in combination. (1) Those at risk for developing pressure ulcers include the elderly and critically ill as well as persons with neurological impairments and those who suffer conditions associated with immobility. Pressure ulcers are graded or staged with a 4-point classification system denoting severity. Stage I represents the beginnings of a pressure ulcer and stage IV, the severest grade, consists of full thickness tissue loss with exposed bone, tendon, and or muscle. (1) In a 2004 survey of Canadian health care settings, Woodbury and Houghton (2) estimated that the prevalence of pressure ulcers at a stage 1 or greater in Ontario ranged between 13.1% and 53% with nonacute health care settings having the highest prevalence rate (Table 1). Executive Summary Table 1: Prevalence of Pressure Ulcers* Setting Canadian Prevalence,% (95% CI) Ontario Prevalence,Range % (n) Acute care 25 (23.8–26.3) 23.9–29.7 (3418) Nonacute care† 30 (29.3–31.4) 30.0–53.3 (1165) Community care 15 (13.4–16.8) 13.2 (91) Mixed health care‡ 22 (20.9–23.4) 13.1–25.7 (3100) All health care settings 26 (25.2–26.8) 13.1–53.3 (7774) * CI indicates confidence interval. † Nonacute care included sub-acute care, chronic care, complex continuing care, long-term care, and nursing home care. ‡ Mixed health care includes a mixture of acute, nonacute, and/or community care health care delivery settings. Pressure ulcers have a considerable economic impact on health care systems. In Australia, the cost of treating a single stage IV ulcer has been estimated to be greater than $61,000 (AUD) (approximately $54,000 CDN), (3) while in the United Kingdom the total cost of pressure ulcers has been estimated at £1.4–£2.1 billion annually or 4% of the National Health Service expenditure. (4) Because of the high physical and economic burden of pressure ulcers, this review was undertaken to determine which interventions are effective at preventing the development of pressure ulcers in an at-risk population. Review Strategy The main objective of this systematic review is to determine the effectiveness of pressure ulcer preventive interventions including Risk Assessment, Distribution Devices, Nutritional Supplementation, Repositioning, and Incontinence Management. A comprehensive literature search was completed for each of the above 5 preventive interventions. The electronic databases searched included MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cochrane Library, and the Cumulative Index to Nursing and Allied Health Literature. As well, the bibliographic references of selected studies were searched. All studies meeting explicit inclusion and exclusion criteria for each systematic review section were retained and the quality of the body of evidence was determined using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) system. (5) Where appropriate, a meta-analysis was undertaken to determine the overall estimate of effect of the preventive intervention under review. Summary of Findings Ris

2009-01-01

250

Pressurizer tank upper support  

DOEpatents

A pressurizer tank in a pressurized water nuclear reactor is mounted between structural walls of the reactor on a substructure of the reactor, the tank extending upwardly from the substructure. For bearing lateral loads such as seismic shocks, a girder substantially encircles the pressurizer tank at a space above the substructure and is coupled to the structural walls via opposed sway struts. Each sway strut is attached at one end to the girder and at an opposite end to one of the structural walls, and the sway struts are oriented substantially horizontally in pairs aligned substantially along tangents to the wall of the circular tank. Preferably, eight sway struts attach to the girder at 90[degree] intervals. A compartment encloses the pressurizer tank and forms the structural wall. The sway struts attach to corners of the compartment for maximum stiffness and load bearing capacity. A valve support frame carrying the relief/discharge piping and valves of an automatic depressurization arrangement is fixed to the girder, whereby lateral loads on the relief/discharge piping are coupled directly to the compartment rather than through any portion of the pressurizer tank. Thermal insulation for the valve support frame prevents thermal loading of the piping and valves. The girder is shimmed to define a gap for reducing thermal transfer, and the girder is free to move vertically relative to the compartment walls, for accommodating dimensional variation of the pressurizer tank with changes in temperature and pressure. 10 figures.

Baker, T.H.; Ott, H.L.

1994-01-11

251

Pressurizer tank upper support  

DOEpatents

A pressurizer tank in a pressurized water nuclear reactor is mounted between structural walls of the reactor on a substructure of the reactor, the tank extending upwardly from the substructure. For bearing lateral loads such as seismic shocks, a girder substantially encircles the pressurizer tank at a space above the substructure and is coupled to the structural walls via opposed sway struts. Each sway strut is attached at one end to the girder and at an opposite end to one of the structural walls, and the sway struts are oriented substantially horizontally in pairs aligned substantially along tangents to the wall of the circular tank. Preferably, eight sway struts attach to the girder at 90.degree. intervals. A compartment encloses the pressurizer tank and forms the structural wall. The sway struts attach to corners of the compartment for maximum stiffness and load bearing capacity. A valve support frame carrying the relief/discharge piping and valves of an automatic depressurization arrangement is fixed to the girder, whereby lateral loads on the relief/discharge piping are coupled directly to the compartment rather than through any portion of the pressurizer tank. Thermal insulation for the valve support frame prevents thermal loading of the piping and valves. The girder is shimmed to define a gap for reducing thermal transfer, and the girder is free to move vertically relative to the compartment walls, for accommodating dimensional variation of the pressurizer tank with changes in temperature and pressure.

Baker, Tod H. (O'Hara Township, Allegheny County, PA); Ott, Howard L. (Kiski Township, Armstrong County, PA)

1994-01-01

252

Aluminium at terapascal pressures.  

PubMed

Studying materials at terapascal (TPa) pressures will provide insights into the deep interiors of large planets and chemistry under extreme conditions. The equation of state of aluminium is of interest because it is used as a standard material in shock-wave experiments and because it is a typical sp-bonded metal. Here we use density-functional-theory methods and a random-searching approach to predict stable structures of aluminium at multiterapascal pressures, finding that the low-pressure close-packed structures transform to more open structures above 3.2 TPa (nearly ten times the pressure at the centre of the Earth), with an incommensurate host-guest structure being stable over a wide range of pressures and temperatures. We show that the high-pressure phases may be described by a two-component model consisting of positive ions and interstitial electron 'blobs', and propose that such structures are common in sp-bonded materials up to multiterapascal pressures. PMID:20622863

Pickard, Chris J; Needs, R J

2010-08-01

253

Pressure Measurement Systems  

NASA Technical Reports Server (NTRS)

System 8400 is an advanced system for measurement of gas and liquid pressure, along with a variety of other parameters, including voltage, frequency and digital inputs. System 8400 offers exceptionally high speed data acquisition through parallel processing, and its modular design allows expansion from a relatively inexpensive entry level system by the addition of modular Input Units that can be installed or removed in minutes. Douglas Juanarena was on the team of engineers that developed a new technology known as ESP (electronically scanned pressure). The Langley ESP measurement system was based on miniature integrated circuit pressure-sensing transducers that communicated pressure information to a minicomputer. In 1977, Juanarena formed PSI to exploit the NASA technology. In 1978 he left Langley, obtained a NASA license for the technology, introduced the first commercial product, the 780B pressure measurement system. PSI developed a pressure scanner for automation of industrial processes. Now in its second design generation, the DPT-6400 is capable of making 2,000 measurements a second and has 64 channels by addition of slave units. New system 8400 represents PSI's bid to further exploit the $600 million U.S. industrial pressure measurement market. It is geared to provide a turnkey solution to physical measurement.

1990-01-01

254

High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors  

NASA Technical Reports Server (NTRS)

Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

2014-01-01

255

Atmospheric Pressure During Landing  

NASA Technical Reports Server (NTRS)

This figure shows the variation with time of pressure (dots) measured by the Pathfinder MET instrument during the landing period shown in image PIA00797. The two diamonds indicate the times of bridal cutting and 1st impact. The overall trend in the data is of pressure increasing with time. This is almost certainly due to the lander rolling downhill by roughly 10 m. The spacing of the horizontal dotted lines indicates the pressure change expected from 10 m changes in altitude. Bounces may also be visible in the data.

1997-01-01

256

Pressure Versus Depth  

NSDL National Science Digital Library

In this inquiry activity, students do not know the equation for pressure versus depth before beginning, but through guided activities they discover it themselves. This is a powerful way to get students to conceptually understand the equation and remember

Michael Horton

2009-05-30

257

Preventing Pressure Sores  

MedlinePLUS Videos and Cool Tools

... Pressure Sores Transition from Hospital to Home Spasticity, Physical Therapy-Lokomat Sex and Fertility After Spinal Cord ... does not provide medical advice, recommend or endorse health care products or services, or control the information ...

258

Internal pressure sensor  

DOEpatents

A pressure sensor for sensing changes in pressure in an enclosed vessel may include a first chamber having at least one expandable section therein that allows that first chamber to change in length. A reference member mounted within the first chamber moves as a result of changes in length of the first chamber. A second chamber having an expandable section therein allows the second chamber to change in length in response to changes in pressure in the enclosed vessel. The second chamber is operatively associated with the first chamber so that changes in length of the second chamber result in changes in length of the first chamber. A sensor operatively associated with the reference member detects changes in position of the reference member. Changes in position of the reference member are related to changes in pressure in the enclosed vessel.

Dowalo, James A. (Blackfoot, ID) [Blackfoot, ID

2010-03-16

259

High pressure counterflow CHF.  

E-print Network

This is a report of the experimental results of a program in countercurrent flow critical heat flux. These experiments were performed with Freon 113 at 200 psia in order to model a high pressure water system. An internally ...

Walkush, Joseph Patrick

1975-01-01

260

The Pressure's On  

NSDL National Science Digital Library

If the pressure's on to enhance the growth and development of students' inquiry skills, use a discrepant event. A discrepant event is a demonstration designed to present a situation or phenomenon that has an unexpected and sometimes very surprising outcom

Frank L. Misiti Jr.

2000-09-01

261

High Pressure Synthetic Chemistry.  

ERIC Educational Resources Information Center

Describes several experimental results selected from typical inorganic and organic reaction systems, along with a brief description of the physical parameters needed to determine if a pressure increase will help solve a synthetic problem. (HM)

Hagen, Arnulf P.

1978-01-01

262

MEMS Pressure Sensor Operation  

NSDL National Science Digital Library

This animation, created by Southwest Center for Microsystems Education (SCME), allows viewers to observe the operation of a micropressure sensor and the packaging of a micropressure sensor array. The animation illustrates "the sensing circuit for the pressure sensor is a Wheatstone Bridge configuration with two variable resistors (strain gauges) that change in resistance with a change in pressure. The sensing circuit is mounted on top of a fixed pressure chamber referred to as the reference chamber. When the pressures above and below the sensing circuit are different, the membrane flexes causing a change in bridge resistance." A supporting learning module, Wheatstone Bridge, can be downloaded from the SCME website under Educational Materials.

263

Capacitance pressure sensor  

DOEpatents

A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

Eaton, William P. (Tijeras, NM); Staple, Bevan D. (Albuquerque, NM); Smith, James H. (Albuquerque, NM)

2000-01-01

264

On Time Performance Pressure  

NASA Technical Reports Server (NTRS)

Within many operations, the pressures for on-time performance are high. Each month, on-time statistics are reported to the Department of Transportation and made public. There is a natural tendency for employees under pressure to do their best to meet these objectives. As a result, pressure to get the job done within the allotted time may cause personnel to deviate from procedures and policies. Additionally, inadequate or unavailable resources may drive employees to work around standard processes that are seen as barriers. However, bypassing practices to enable on-time performance may affect more than the statistics. ASRS reports often highlight on-time performance pressures which may result in impact across all workgroups in an attempt to achieve on-time performance. Reporters often provide in-depth insights into their experiences which can be used by industry to identify and focus on the implementation of systemic fixes.

Connell, Linda; Wichner, David; Jakey, Abegael

2013-01-01

265

Pressure multiplying dispenser  

DOEpatents

A pressure multiplying dispenser for delivering fluid, preferably as a spray to the atmosphere, from a source of fluid, preferably a spray bottle, is described. The dispenser includes in combination a hollow cylindrical member, a nozzle delivery tube within the cylindrical member and a hollow actuator piston slideable within the cylindrical member which acts to multiply the pressure of a squeeze applied to the spray bottle.

DeFord, Henry S. (Kennewick, WA); Moss, Owen R. (Kennewick, WA)

1986-01-01

266

Radial pressure flange seal  

DOEpatents

This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side. 5 figs.

Batzer, T.H.; Call, W.R.

1989-01-24

267

Radial pressure flange seal  

DOEpatents

This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side.

Batzer, Thomas H. (Livermore, CA); Call, Wayne R. (Tracy, CA)

1989-01-01

268

Air Under Pressure  

NSDL National Science Digital Library

Students are introduced to air masses, with an emphasis on the differences between and characteristics of high- versus low-pressure air systems. Students explore actual data by comparing maps of high- and low-pressure air masses to radar data showing where weather is occurring. Students also hear about weather forecasting instrumentation and how engineers work to improve these instruments for atmospheric measurements on Earth and in space.

Integrated Teaching and Learning Program,

269

Fluctuating shells under pressure  

PubMed Central

Thermal fluctuations strongly modify the large length-scale elastic behavior of cross-linked membranes, giving rise to scale-dependent elastic moduli. Whereas thermal effects in flat membranes are well understood, many natural and artificial microstructures are modeled as thin elastic shells. Shells are distinguished from flat membranes by their nonzero curvature, which provides a size-dependent coupling between the in-plane stretching modes and the out-of-plane undulations. In addition, a shell can support a pressure difference between its interior and its exterior. Little is known about the effect of thermal fluctuations on the elastic properties of shells. Here, we study the statistical mechanics of shape fluctuations in a pressurized spherical shell, using perturbation theory and Monte Carlo computer simulations, explicitly including the effects of curvature and an inward pressure. We predict novel properties of fluctuating thin shells under point indentations and pressure-induced deformations. The contribution due to thermal fluctuations increases with increasing ratio of shell radius to thickness and dominates the response when the product of this ratio and the thermal energy becomes large compared with the bending rigidity of the shell. Thermal effects are enhanced when a large uniform inward pressure acts on the shell and diverge as this pressure approaches the classical buckling transition of the shell. Our results are relevant for the elasticity and osmotic collapse of microcapsules. PMID:23150558

Paulose, Jayson; Vliegenthart, Gerard A.; Gompper, Gerhard; Nelson, David R.

2012-01-01

270

ECN Pressure Test  

SciTech Connect

This note describes: the rationale for the test pressure of the inner ECN cryostat vessel, the equipment to be used in this test, the test procedure, the status of the vessel prior to the test, the actual test results, and a schematic diagram of the testing set up and the pressure testing permit. The test, performed in the evening of July 17, 1991, was a major success. Based on a neglible pressure drop indicated on the pressure gages (1/4 psi), the vessel appeared to be structurally sound throughout the duration of the test (approx. 1.5 hrs.). No pressure increases were observed on the indicators looking at the beam tube bellows volumes. There was no indication of bubbles form the soap test on the welds and most of the fittings that were checked. There were some slight deviations in the actual procedure used. The UO filter was removed after the vessel had bled down to about 18 psig in order to speed up that aspect of the test. The rationale was that the higher velocity gas had already passed through at the higher pressures and there was no visible traces of the black uo particles. The rate of 4 psi/10 minutes seemed incredibly slow and often that time was reduced to just over half that rate. The testing personnel was allowed to stay in the pit throughout the duration of the test; this was a slight relaxation of the rules.

Dixon, K.; /Fermilab

1991-07-18

271

Optical zero-differential pressure switch and its evaluation in a multiple pressure measuring system  

NASA Technical Reports Server (NTRS)

The design of a clamped-diaphragm pressure switch is described in which diaphragm motion is detected by a simple fiber-optic displacement sensor. The switch was evaluated in a pressure measurement system where it detected the zero crossing of the differential pressure between a static test pressure and a tank pressure that was periodically ramped from near zero to fullscale gage pressure. With a ramping frequency of 1 hertz and a full-scale tank pressure of 69 N/sq cm gage (100 psig), the switch delay was as long as 2 milliseconds. Pressure measurement accuracies were 0.25 to 0.75 percent of full scale. Factors affecting switch performance are also discussed.

Powell, J. A.

1977-01-01

272

Automated high pressure cell for pressure jump x-ray diffraction  

SciTech Connect

A high pressure cell for small and wide-angle x-ray diffraction measurements of soft condensed matter samples has been developed, incorporating a fully automated pressure generating network. The system allows both static and pressure jump measurements in the range of 0.1-500 MPa. Pressure jumps can be performed as quickly as 5 ms, both with increasing and decreasing pressures. Pressure is generated by a motorized high pressure pump, and the system is controlled remotely via a graphical user interface to allow operation by a broad user base, many of whom may have little previous experience of high pressure technology. Samples are loaded through a dedicated port allowing the x-ray windows to remain in place throughout an experiment; this facilitates accurate subtraction of background scattering. The system has been designed specifically for use at beamline I22 at the Diamond Light Source, United Kingdom, and has been fully integrated with the I22 beamline control systems.

Brooks, Nicholas J.; Gauthe, Beatrice L. L. E.; Templer, Richard H.; Ces, Oscar; Seddon, John M. [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Terrill, Nick J. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Rogers, Sarah E. [ISIS, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0QX (United Kingdom)

2010-06-15

273

Reotemp Pressure Indicator Local Pressure Indication to Monitor the SCHE Supply Bottle Pressure  

SciTech Connect

These 0-3000 psig range pressure indicators are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. These accident monitoring local pressure indicators monitor the SCHe supply bottle pressure. There is one pressure indicator for each SCHe supply (4).

VAN KATWIJK, C.

1999-07-01

274

Blood pressure monitors for home  

MedlinePLUS

... a button. After the cuff is inflated, the pressure will slowly drop on its own. The screen will show a digital readout of your systolic and diastolic blood pressure. After showing your blood pressure, the cuff will ...

275

High Blood Pressure Fact Sheet  

MedlinePLUS

... this? Submit What's this? Submit Button Related CDC Web Sites Heart Disease Stroke High Blood Pressure Salt ... blood pressure tests and other chronic disease screening. Web Sites with More Information About High Blood Pressure ...

276

Pregnancy and High Blood Pressure  

MedlinePLUS Videos and Cool Tools

... the lower right-hand corner of the player. Pregnancy and High Blood Pressure HealthDay January 29, 2015 Related MedlinePlus Page High Blood Pressure in Pregnancy Transcript Does keeping tight control of blood pressure ...

277

Can You Take the Pressure?  

NSDL National Science Digital Library

This lesson introduces students to the concept of air pressure. Students will explore how air pressure creates force on an object. They will study the relationship between air pressure and the velocity of moving air.

2014-09-18

278

Cryogenic High Pressure Sensor Module  

NASA Technical Reports Server (NTRS)

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Chapman, John J. (Inventor); Shams, Qamar A. (Inventor); Powers, William T. (Inventor)

1999-01-01

279

Cryogenic, Absolute, High Pressure Sensor  

NASA Technical Reports Server (NTRS)

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

2001-01-01

280

Dynamic surface pressure measurements on a square cylinder with pressure sensitive paint  

Microsoft Academic Search

The dynamic and static surface pressure on a square cylinder during vortex shedding was measured with pressure sensitive paints\\u000a (PSPs) at three angles of incidence and a Reynolds number of 8.9×104. Oscillations in the phosphorescence intensity of the PSP that occurred at the vortex shedding frequency were observed. From\\u000a these phosphorescent oscillations, the time-dependent changes in pressure distribution were calculated.

C. M. McGraw; J. H. Bell; G. Khalil; J. B. Callis

2006-01-01

281

Dynamic surface pressure measurements on a square cylinder with pressure sensitive paint  

Microsoft Academic Search

The dynamic and static surface pressure on a square cylinder during vortex shedding was measured with pressure sensitive paints (PSPs) at three angles of incidence and a Reynolds number of 8.9×104. Oscillations in the phosphorescence intensity of the PSP that occurred at the vortex shedding frequency were observed. From these phosphorescent oscillations, the time-dependent changes in pressure distribution were calculated.

C. M. McGraw; J. H. Bell; G. Khalil; J. B. Callis

2006-01-01

282

Automated Blood Pressure Measurement  

NASA Technical Reports Server (NTRS)

The Vital-2 unit pictured is a semi-automatic device that permits highly accurate blood pressure measurement, even by untrained personnel. Developed by Meditron Instrument Corporation, Milford, New Hampshire, it is based in part on NASA technology found in a similar system designed for automatic monitoring of astronauts' blood pressure. Vital-2 is an advancement over the familiar arm cuff, dial and bulb apparatus customarily used for blood pressure checks. In that method, the physician squeezes the bulb to inflate the arm cuff, which restricts the flow of blood through the arteries. As he eases the pressure on the arm, he listens, through a stethoscope, to the sounds of resumed blood flow as the arteries expand and contract. Taking dial readings related to sound changes, he gets the systolic (contracting) and diastolic (expanding) blood pressure measurements. The accuracy of the method depends on the physician's skill in interpreting the sounds. Hospitals sometimes employ a more accurate procedure, but it is "invasive," involving insertion of a catheter in the artery.

1978-01-01

283

Wall Pressure Spectral Model Including the Adverse Pressure Gradient Effects  

E-print Network

Wall Pressure Spectral Model Including the Adverse Pressure Gradient Effects Yannick Rozenberg 1 Sherbrooke, Sherbrooke, QC, J1K2R1, Canada An empirical model to predict the wall-pressure fluctuations spectra beneath ad- verse pressure gradient flows is presented. It is based on Goody's model which already

Paris-Sud XI, Université de

284

High Blood Pressure  

NSDL National Science Digital Library

The Science Inside: High Blood PressureThis booklet explains what health professionals know about high blood pressure or hypertension, one of the leading causes of heart disease and stroke. It shows how to prevent high blood pressure, as well as how to care for yourself if you have been diagnosed with the disease. The Science Inside e-book series is intended to be a bridge between the consumer health brochure and the scientific paper, the booklets in this series focus on the science that is inside of, or behind, the disease its cause, its possible cure, its treatment, promising research, and so on. These booklets are designed to appeal to people who have not had the opportunity to study the science and to understand why they may have been given some of the advice that they have been given through some of the more consumer-oriented materials.

American Association for the Advancement of Science (; )

2004-01-01

285

A Microwave Pressure Sounder  

NASA Technical Reports Server (NTRS)

An instrument to measure atmospheric pressure at the earth's surface from an orbiting satellite would be a valuable addition to the expanding inventory of remote sensors. The subject of this report is such an instrument - the Microwave Pressure Sounder (MPS). It is shown that global-ocean coverage is attainable with sufficient accuracy, resolution and observational frequency for meteorological, oceanographic and climate research applications. Surface pressure can be deduced from a measurement of the absorption by an atmospheric column at a frequency in the wing of the oxygen band centered on 60 GHz. An active multifrequency instrument is needed to make this measurement with sufficient accuracy. The selection of optimum operating frequencies is based upon accepted models of surface reflection, oxygen, water vapor and cloud absorption. Numerical simulation using a range of real atmospheres defined by radiosonde observations were used to validate the frequency selection procedure. Analyses are presented of alternative system configurations that define the balance between accuracy and achievable resolution.

Flower, D. A.; Peckham, G. E.

1978-01-01

286

Oxygen partial pressure sensor  

DOEpatents

A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured. 1 fig.

Dees, D.W.

1994-09-06

287

Magnetostrictive Pressure Regulating System  

NASA Technical Reports Server (NTRS)

A magnetostrictive pressure regulating system includes a magnetostrictive valve that incorporates a magnetostrictive actuator with at least one current-carrying coil disposed thereabout. A pressure force sensor, in fluid communication with the fluid exiting the valve, includes (i) a magnetostrictive material, (ii) a magnetic field generator in proximity to the magnetostrictive material for inducing a magnetic field in and surrounding the magnetostrictive material wherein lines of magnetic flux passing through the magnetostrictive material are defined, and (iii) a sensor positioned adjacent to the magnetostrictive material and in the magnetic field for measuring changes in at least one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux. The pressure of the fluid exiting the valve causes the applied force. A controller coupled to the sensor and to the current-carrying coil adjusts a current supplied to the current-carrying coil based on the changes so-measured.

Richard, James A. (Inventor); Pickens, Herman L. (Inventor)

2013-01-01

288

Oxygen partial pressure sensor  

DOEpatents

A method for detecting oxygen partial pressure and an oxygen partial pressure sensor are provided. The method for measuring oxygen partial pressure includes contacting oxygen to a solid oxide electrolyte and measuring the subsequent change in electrical conductivity of the solid oxide electrolyte. A solid oxide electrolyte is utilized that contacts both a porous electrode and a nonporous electrode. The electrical conductivity of the solid oxide electrolyte is affected when oxygen from an exhaust stream permeates through the porous electrode to establish an equilibrium of oxygen anions in the electrolyte, thereby displacing electrons throughout the electrolyte to form an electron gradient. By adapting the two electrodes to sense a voltage potential between them, the change in electrolyte conductivity due to oxygen presence can be measured.

Dees, Dennis W. (Downers Grove, IL)

1994-01-01

289

Circumferential pressure probe  

NASA Technical Reports Server (NTRS)

A probe for measuring circumferential pressure inside a body cavity is disclosed. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors which typically comprise support tube sections with flexible side wall areas. These are arranged along the length of the probe in two areas, one just proximal to the tip for the sensing of fluid pressure inside the bladder, and five in the sensing section which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections interspersed with flexible support tube sections in the form of bellows to provide flexibility.

Holmes, Harlan K. (inventor); Moore, Thomas C. (inventor); Fantl, Andrew J. (inventor)

1989-01-01

290

Pressure suppression containment system  

DOEpatents

A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto.

Gluntz, Douglas M. (San Jose, CA); Townsend, Harold E. (San Jose, CA)

1994-03-15

291

Pressure suppression containment system  

DOEpatents

A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of-coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto. 6 figures.

Gluntz, D.M.; Townsend, H.E.

1994-03-15

292

Pressure as a Source of Gravity  

E-print Network

The active mass density in Einstein's theory of gravitation in the analog of Poisson's equation in a local inertial system is proportional to $\\rho+3p/c^2$. Here $\\rho$ is the density of energy and $p$ its pressure for a perfect fluid. By using exact solutions of Einstein's field equations in the static case we study whether the pressure term contributes towards the mass.

J. Ehlers; I. Ozsvath; E. L. Schucking; Y. Shang

2005-10-08

293

Blood Pressure Control  

NASA Technical Reports Server (NTRS)

Engineering Development Lab., Inc.'s E-2000 Neck Baro Reflex System was developed for cardiovascular studies of astronauts. It is regularly used on Space Shuttle Missions, and a parallel version has been developed as a research tool to facilitate studies of blood pressure reflex controls in patients with congestive heart failure, diabetes, etc. An advanced version, the PPC-1000, was developed in 1991, and the technology has been refined substantially. The PPC provides an accurate means of generating pressure for a broad array of laboratory applications. An improved version, the E2010 Barosystem, is anticipated.

1992-01-01

294

Plating under reduced pressure  

SciTech Connect

Plating under reduced pressure was evaluated for both electroless nickel and electrodeposited copper systems. The objective was to reduce pitting of these coatings thereby further enhancing their usage for diamond turning applications. Cursory experiments with electroless nickel showed reduced porosity when deposition was done at around 500 torr. Detailed experiments with electrodeposited copper at around 100 torr provided similar results. Scanning tunneling microscopy was effectively used to show the improvement in the copper deposits plated under reduced pressure. Benefits included reduced surface roughness and finer and denser grain structure.

Dini, J.W.; Beat, T.G.; Cowden, W.C. (Lawrence Livermore National Lab., CA (United States)); Ryan, L.E.; Hewitt, W.B. (TRW, Inc., Redondo Beach, CA (United States))

1992-06-01

295

Measurement of portal pressure.  

PubMed

Portal pressure is estimated through measuring the hepatic venous pressure gradient (HVPG). The main clinical applications of HVPG measurements include diagnosis, classification, and monitoring of portal hypertension, risk stratification, identification of candidates for liver resection, and monitoring efficacy of ?-adrenergic blockers. Clinically significant portal hypertension is defined as an HVPG of 10 mm Hg or greater. Patients who experience a reduction in the HVPG of 20% or greater or to lower than 12 mm Hg in response to ?-blocker therapy have a markedly decreased risk of bleeding (or rebleeding), ascites, and spontaneous bacterial peritonitis, resulting in improved survival rates. PMID:25438283

Abraldes, Juan G; Sarlieve, Philippe; Tandon, Puneeta

2014-11-01

296

Variable pressure washer  

NASA Technical Reports Server (NTRS)

A variable pressure washer has two interlocking channel rings separated by a channel and retained by a captive set of fasteners. Within the channel between the rings are multiple rows of springs having at least two different spring moduli. The washer is particularly suited for use with a polar boss assembly secured to a bulkhead of a pressure vessel such as of propellent tank dome structure where the washer allows for the substantially uniform deflection of multiple O-rings as affected by the curved structure.

Smeltzer, III, Stanley S. (Inventor); Estrada, Hector (Inventor)

2004-01-01

297

Pressure dependence of elastic moduli  

Microsoft Academic Search

In a recent review [l] on the effects of hydrostatic pressure on the mechanical behavior of polymers, two of us noted that the pressure dependence of the Young's modulus is large if the value of the modulus at atmospheric pressure is low and that it is comparatively modest if the modulus at atmospheric pressure is high [l, p. 611. It

Hans-Georg Elias; S. K. Bhateja; K. D. Pae

1976-01-01

298

Protein crystallization under high pressure  

Microsoft Academic Search

Pressure is expected to be an important parameter to control protein crystallization, since hydrostatic pressure affects the whole system uniformly and can be changed very rapidly. So far, a lot of studies on protein crystallization have been done. Solubility of protein depends on pressure. For instance, the solubility of tetragonal lysozyme crystal increased with increasing pressure, while that of orthorhombic

Yoshihisa Suzuki; Gen Sazaki; Satoru Miyashita; Tsutomu Sawada; Katsuhiro Tamura; Hiroshi Komatsu

2002-01-01

299

High Blood Pressure and Women  

MedlinePLUS

High Blood Pressure and Women Updated:Aug 13,2014 Many people mistakenly believe that high blood pressure, also called HBP or ... last reviewed on 08/04/14. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

300

Saltstone Osmotic Pressure  

SciTech Connect

Recent research into the moisture retention properties of saltstone suggest that osmotic pressure may play a potentially significant role in contaminant transport (Dixon et al., 2009 and Dixon, 2011). The Savannah River Remediation Closure and Disposal Assessments Group requested the Savannah River National Laboratory (SRNL) to conduct a literature search on osmotic potential as it relates to contaminant transport and to develop a conceptual model of saltstone that incorporates osmotic potential. This report presents the findings of the literature review and presents a conceptual model for saltstone that incorporates osmotic potential. The task was requested through Task Technical Request HLW-SSF-TTR-2013-0004. Simulated saltstone typically has very low permeability (Dixon et al. 2008) and pore water that contains a large concentration of dissolved salts (Flach and Smith 2013). Pore water in simulated saltstone has a high salt concentration relative to pore water in concrete and groundwater. This contrast in salt concentration can generate high osmotic pressures if simulated saltstone has the properties of a semipermeable membrane. Estimates of osmotic pressure using results from the analysis of pore water collected from simulated saltstone show that an osmotic pressure up to 2790 psig could be generated within the saltstone. Most semi-permeable materials are non-ideal and have an osmotic efficiency <1 and as a result actual osmotic pressures are less than theoretical pressures. Observations from laboratory tests of simulated saltstone indicate that it may exhibit the behavior of a semi-permeable membrane. After several weeks of back pressure saturation in a flexible wall permeameter (FWP) the membrane containing a simulated saltstone sample appeared to have bubbles underneath it. Upon removal from the FWP the specimen was examined and it was determined that the bubbles were due to liquid that had accumulated between the membrane and the sample. One possible explanation for the accumulation of solution between the membrane and sample is the development of osmotic pressure within the sample. Osmotic pressure will affect fluid flow and contaminant transport and may result in the changes to the internal structure of the semi-permeable material. B?nard et al. 2008 reported swelling of wet cured Portland cement mortars containing salts of NaNO{sub 3}, KNO{sub 3}, Na{sub 3}PO{sub 4}x12H {sub 2}O, and K{sub 3}PO{sub 4} when exposed to a dilute solution. Typically hydraulic head is considered the only driving force for groundwater in groundwater models. If a low permeability material containing a concentrated salt solution is present in the hydrogeologic sequence large osmotic pressures may develop and lead to misinterpretation of groundwater flow and solute transport. The osmotic pressure in the semi-permeable material can significantly impact groundwater flow in the vicinity of the semi-permeable material. One possible outcome is that groundwater will flow into the semi-permeable material resulting in hydrologic containment within the membrane. Additionally, hyperfiltration can occur within semi-permeable materials when water moves through a membrane into the more concentrated solution and dissolved constituents are retained in the lower concentration solution. Groundwater flow and transport equations that incorporate chemical gradients (osmosis) have been developed. These equations are referred to as coupled flow equations. Currently groundwater modeling to assess the performance of saltstone waste forms is conducted using the PORFLOW groundwater flow and transport model. PORFLOW does not include coupled flow from chemico-osmotic gradients and therefore numerical simulation of the effect of coupled flow on contaminant transport in and around saltstone cannot be assessed. Most natural semi-permeable membranes are non-ideal membranes and do not restrict all movement of solutes and as a result theoretical osmotic potential is not realized. Osmotic efficiency is a parameter in the coupled flow equation that accounts for the

Nichols, Ralph L.; Dixon, Kenneth L.

2013-09-23

301

Microscale pressure fluctuations in a mature deciduous forest  

Microsoft Academic Search

Static pressure fluctuations in the microscale range were measured in a mature deciduous forest. Pressure measurements were taken at the ground and above the canopy, and mean profile data of windspeed were collected from above the canopy to near the forest floor. Time series, spectra, and cross-correlations were calculated under different canopy conditions, and relationships between surface pressure fluctuations and

J. T. Sigmon; K. R. Knoerr; E. J. Shaughnessy

1983-01-01

302

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2014 CFR

...Systems Tests § 183.586 Pressure impulse test. A fuel... (a) Perform the static pressure test under § 183.580. ...fuel in the tank at 21 °C or higher for 30 days prior to testing...Apply 25,000 cycles of pressure impulse at the rate of...

2014-07-01

303

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2010 CFR

...Systems Tests § 183.586 Pressure impulse test. A fuel... (a) Perform the static pressure test under § 183.580. ...fuel in the tank at 21 °C or higher for 30 days prior to testing...Apply 25,000 cycles of pressure impulse at the rate of...

2010-07-01

304

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2013 CFR

...Systems Tests § 183.586 Pressure impulse test. A fuel... (a) Perform the static pressure test under § 183.580. ...fuel in the tank at 21 °C or higher for 30 days prior to testing...Apply 25,000 cycles of pressure impulse at the rate of...

2013-07-01

305

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2012 CFR

...Systems Tests § 183.586 Pressure impulse test. A fuel... (a) Perform the static pressure test under § 183.580. ...fuel in the tank at 21 °C or higher for 30 days prior to testing...Apply 25,000 cycles of pressure impulse at the rate of...

2012-07-01

306

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2011 CFR

...Systems Tests § 183.586 Pressure impulse test. A fuel... (a) Perform the static pressure test under § 183.580. ...fuel in the tank at 21 °C or higher for 30 days prior to testing...Apply 25,000 cycles of pressure impulse at the rate of...

2011-07-01

307

Reactor pressure vessel nozzle  

DOEpatents

A nozzle for joining a pool of water to a nuclear reactor pressure vessel includes a tubular body having a proximal end joinable to the pressure vessel and a distal end joinable in flow communication with the pool. The body includes a flow passage therethrough having in serial flow communication a first port at the distal end, a throat spaced axially from the first port, a conical channel extending axially from the throat, and a second port at the proximal end which is joinable in flow communication with the pressure vessel. The inner diameter of the flow passage decreases from the first port to the throat and then increases along the conical channel to the second port. In this way, the conical channel acts as a diverging channel or diffuser in the forward flow direction from the first port to the second port for recovering pressure due to the flow restriction provided by the throat. In the backflow direction from the second port to the first port, the conical channel is a converging channel and with the abrupt increase in flow area from the throat to the first port collectively increase resistance to flow therethrough.

Challberg, Roy C. (Livermore, CA); Upton, Hubert A. (Morgan Hill, CA)

1994-01-01

308

Pressure vessel integrity 1991  

SciTech Connect

This volume contains papers relating to the structural integrity assessment of pressure vessels and piping, with special emphasis on nuclear industry applications. The papers were prepared for technical sessions developed under the sponsorship of the ASME Pressure Vessels and Piping Division Committees for Codes and Standards, Computer Technology, Design and Analysis, and Materials Fabrication. They were presented at the 1991 Pressure Vessels and Piping Division Conference in San Diego, California, June 23-27. The primary objective of the sponsoring organization is to provide a forum for the dissemination and discussion of information on development and application of technology for the structural integrity assessment of pressure vessels and piping. This publication includes contributions from authors from Australia, France, Japan, Sweden, Switzerland, the United Kingdom, and the United States. The papers here are organized in six sections, each with a particular emphasis as indicated in the following section titles: Fracture Technology Status and Application Experience; Crack Initiation, Propagation and Arrest; Ductile Tearing; Constraint, Stress State, and Local-Brittle-Zones Effects; Computational Techniques for Fracture and Corrosion Fatigue; and Codes and Standards for Fatigue, Fracture and Erosion/Corrosion.

Bhandari, S. (Framatome (FR)); Doney, R.O.; McDonald, M.S. (ABB Combustion Engineering Nuclear Power (US)); Jones, D.P.; Wilson, W.K. (Westinghouse Bettis Atomic Power Laboratory (US)); Pennell, W.E. (Oak Ridge National Laboratory (US))

1991-01-01

309

[Managing perilesional pressure ulcers].  

PubMed

The skin of elderly patients is very fragile and dry which impairs its function as a barrier and renders it more exposed to external attacks, perilesional complications around pressure ulcers are often linked to several interrelated mechanisms. These complications require, from the teams, in-depth knowledge of the care protocols. PMID:23785860

Perceau, Géraldine

2013-01-01

310

Barometric pressure variations  

SciTech Connect

This report presents Hanford Site barometric data that can be used to determine the breathing rate of Hanford Site tanks and details the derivation of the data. The barometric pressure data recorded at the Hanford Weather Station were used for this analysis. Data for 1988, 1989, 1990, and 1991 were used.

Crippen, M.D.

1993-06-01

311

High pressure steam pipe  

Microsoft Academic Search

A detailed dynamic analysis, presented in a series of reports, was conducted on the seismic response and structural safety of key subsystems (steam generator, high pressure steam piping, coal handling equipment, cooling tower, chimney) of Unit No. 3 of TVA at Paradise, Kentucky in order to: (1) determine for the key components the natural frequencies below 50 Hz and the

C. T. Sun; A. S. Ledger; H. Lo

1976-01-01

312

The Pressure Group Cooker.  

ERIC Educational Resources Information Center

Administrators across the nation have encountered vigorous challenges against textbooks, practices, and procedures that critics find laden with occult and New Age values. Attacks are becoming more aggressive, better organized, and well financed. This article and accompanying sidebars discuss pressure group tactics and ways to counter them. The…

Graves, Bill

1992-01-01

313

Arterial Pressure Analog.  

ERIC Educational Resources Information Center

Describes a simple hydraulic analog which allows students to explore some physical aspects of the cardiovascular system and provides them with a means to visualize and conceptualize these basic principles. Simulates the behavior of arterial pressure in response to changes in heart rate, stroke volume, arterial compliance, and peripheral…

Heusner, A. A.; Tracy, M. L.

1980-01-01

314

High Blood Pressure Medicines  

MedlinePLUS

... help your body get rid of extra sodium (salt) and water so your blood vessels don't have to hold so much fluid. Renin inhibitors slow down your body’s production of renin, the enzyme that starts the many chemical reactions that raise your blood pressure. Do these medicines ...

315

Reactor pressure vessel nozzle  

DOEpatents

A nozzle for joining a pool of water to a nuclear reactor pressure vessel includes a tubular body having a proximal end joinable to the pressure vessel and a distal end joinable in flow communication with the pool. The body includes a flow passage therethrough having in serial flow communication a first port at the distal end, a throat spaced axially from the first port, a conical channel extending axially from the throat, and a second port at the proximal end which is joinable in flow communication with the pressure vessel. The inner diameter of the flow passage decreases from the first port to the throat and then increases along the conical channel to the second port. In this way, the conical channel acts as a diverging channel or diffuser in the forward flow direction from the first port to the second port for recovering pressure due to the flow restriction provided by the throat. In the backflow direction from the second port to the first port, the conical channel is a converging channel and with the abrupt increase in flow area from the throat to the first port collectively increase resistance to flow therethrough. 2 figs.

Challberg, R.C.; Upton, H.A.

1994-10-04

316

INTERMITTENT POSITIVE PRESSURE BREATHING  

EPA Science Inventory

Efficacy of long-term intermittent positive pressure breathing (IPPB) treatment when used as an adjunct to the overall care of ambulatory outpatients with chronic obstructive pulmonary disease. The evaluation compared the use of IPPB with use of a powered nebulizer....

317

Bedsores (Pressure Ulcers)  

MedlinePLUS

... is raised. Dampness (such as from perspiration or incontinence) makes the skin even more liable to develop pressure sores. Who's ... not get good nutrition (malnourished or undernourished), have incontinence ... appears first as a reddened area of skin, which then starts to break down to form ...

318

Pressure in Fluids  

NSDL National Science Digital Library

This simple resource, created by Porter W. Johnson of Illinois Institute of Technology, features activities for upper level high school students about the properties of fluids under a variety of circumstances. Students will also understand the importance of pressure in fluid behavior and how it pertains to everyday life. The page includes objectives, needed materials, strategy, performance assessments and conclusions.

2008-02-07

319

Peer Pressure and Partnerships  

Microsoft Academic Search

Partnerships and profit sharing are often claimed to motivate workers by giving them a share of the pie. But in organizations of any significant size, the free-rider effects would seem to choke off any motivational forces. This analysis explores how peer pressure operates and how factors such as profit sharing, shame, guilt, norms, mutual monitoring, and empathy interact to create

Eugene Kandel; Edward P. Lazear

1992-01-01

320

Cellular Pressure-Actuated Joint  

NASA Technical Reports Server (NTRS)

A modification of a pressure-actuated joint has been proposed to improve its pressure actuation in such a manner as to reduce the potential for leakage of the pressurizing fluid. The specific joint for which the modification is proposed is a field joint in a reusable solid-fuel rocket motor (RSRM), in which the pressurizing fluid is a mixture of hot combustion gases. The proposed modification could also be applicable to other pressure-actuated joints of similar configuration.

McGuire, John R.

2003-01-01

321

Design by analysis of ductile failure and buckling in torispherical pressure vessel heads  

Microsoft Academic Search

Thin shell torispherical pressure vessel heads are known to exhibit complex elastic–plastic deformation and buckling behaviour under static pressure. In pressure vessel Design by Analysis, the designer is required to assess both of these behaviour modes when specifying the allowable static load. The EN and ASME boiler and pressure vessel codes permit the use of inelastic analysis in design by

Donald Mackenzie; Duncan Camilleri; Robert Hamilton

2008-01-01

322

Metallic GGG at TPa pressure  

NASA Astrophysics Data System (ADS)

The Gadolinium Gallium Garnet (GGG) Gd3Ga5O12 has attracted a strong interest since Gas gun shock wave experiments unraveled a high pressure phase stiffer than diamond in the 100 GPa to 250 GPa range [Mashimo], recently confirmed by DAC static compression experiments up to 180 GPa [Mao]. The quasi uncompressible phase has been found to remain much more insulating than metallic fluid Hydrogen and appeared as a potential perfect anvil for off-Hugoniot Hydrogen shock compression to very high density. We have conducted laser driven shock experiments on GGG and determined the EoS through using velocimetry (VISAR) and pyrometry (SOP) diagnostics and an impedance match analysis with quartz standards at Omega-LLE and Jupiter-LLNL facilities. We have observed metallic reflectivity in GGG from ˜200 GPa to ˜2500 GPa. However, GGG is found to remain highly incompressible in this very high density and temperature range. References: [Mashimo] Mashimo et al., Transition to a Virtually Incompressible Oxide Phase at a Shock Pressure of 120 GPa (1.2 Mbar): Gd3Ga5O12, PRL 96, 105504 (2006) [Mao] Mao et al., Equation of state of a high-pressure phase of Gd3Ga5O12, PRB in press

Millot, Marius; Ali, Suzanne; Jeanloz, Raymond; Barrios, Maria; Boehly, Tom; Eggert, Jon; Collins, Gilbert

2011-06-01

323

Pressure natriuresis and the renal control of arterial blood pressure.  

PubMed

The regulation of extracellular fluid volume by renal sodium excretion lies at the centre of blood pressure homeostasis. Renal perfusion pressure can directly regulate sodium reabsorption in the proximal tubule. This acute pressure natriuresis response is a uniquely powerful means of stabilizing long-term blood pressure around a set point. By logical extension, deviation from the set point can only be sustained if the pressure natriuresis mechanism is impaired, suggesting that hypertension is caused or sustained by a defect in the relationship between renal perfusion pressure and sodium excretion. Here we describe the role of pressure natriuresis in blood pressure control and outline the cascade of biophysical and paracrine events in the renal medulla that integrate the vascular and tubular response to altered perfusion pressure. Pressure natriuresis is impaired in hypertension and mechanistic insight into dysfunction comes from genetic analysis of blood pressure disorders. Transplantation studies in rats show that blood pressure is determined by the genotype of the kidney and Mendelian hypertension indicates that the distal nephron influences the overall natriuretic efficiency. These approaches and the outcomes of genome-wide-association studies broaden our view of blood pressure control, suggesting that renal sympathetic nerve activity and local inflammation can impair pressure natriuresis to cause hypertension. Understanding how these systems interact is necessary to tackle the global burden of hypertension. PMID:25107929

Ivy, Jessica R; Bailey, Matthew A

2014-09-15

324

Dynamic surface pressure measurements on a square cylinder with pressure sensitive paint  

NASA Astrophysics Data System (ADS)

The dynamic and static surface pressure on a square cylinder during vortex shedding was measured with pressure sensitive paints (PSPs) at three angles of incidence and a Reynolds number of 8.9×104. Oscillations in the phosphorescence intensity of the PSP that occurred at the vortex shedding frequency were observed. From these phosphorescent oscillations, the time-dependent changes in pressure distribution were calculated. This work extends PSP’s useful range to dynamic systems where oscillating pressure changes are on the order of 230 Pa and occur at frequencies in the range of 95-125 Hz.

McGraw, C. M.; Bell, J. H.; Khalil, G.; Callis, J. B.

2006-02-01

325

Pressure Drop in Radiator Air Tubes  

NASA Technical Reports Server (NTRS)

This report describes a method for measuring the drop in static pressure of air flowing through a radiator and shows (1) a reason for the discrepancy noted by various observers between head resistance and drop in pressure; (2) a difference in degree of contraction of the jet in entering a circular cell and a square cell; (3) the ratio of internal frictional resistance to total head resistance for two representative types; (4) the effect of smoothness of surface on pressure gradient; and (5) the effects of supplying heat to the radiator on pressure gradient. The fact that the pressure gradients are found to be approximately proportional to the square of the rate of flow of air appears to indicate turbulent flow, even in the short tubes of the radiator. It was found that the drop in the static pressure in the air stream through a cellular radiator and the pressure gradient in the air tubes are practically proportional to the square of the air flow in a given air density; that the difference between the head resistance per unit area and the fall of static pressure through the air tubes in radiators is apparent rather than real; and that radiators of different types differ widely in the amount of contraction of the jet at entrance. The frictional resistance was found to vary considerably, and in one case to be two-thirds of the head resistance in the type using circular cells and one-half of the head resistance of the radiator type using square cells of approximately the same dimensions.

Parsons, S R

1921-01-01

326

The Measurement of Pressure Through Tubes in Pressure Distribution Tests  

NASA Technical Reports Server (NTRS)

The tests described in this report were made to determine the error caused by using small tubes to connect orifices on the surface of aircraft to central pressure capsules in making pressure distribution tests. Aluminum tubes of 3/16-inch inside diameter were used to determine this error. Lengths from 20 feet to 226 feet and pressures whose maxima varied from 2 inches to 140 inches of water were used. Single-pressure impulses for which the time of rise of pressure from zero to a maximum varied from 0.25 second to 3 seconds were investigated. The results show that the pressure recorded at the capsule on the far end of the tube lags behind the pressure at the orifice end and experiences also a change in magnitude. For the values used in these tests the time lag and pressure change vary principally with the time of rise of pressure from zero to a maximum and the tube length. Curves are constructed showing the time lag and pressure change. Empirical formulas are also given for computing the time lag. Analysis of pressure distribution tests made on airplanes in flight shows that the recorded pressures are slightly higher than the pressures at the orifice and that the time lag is negligible. The apparent increase in pressure is usually within the experimental error, but in the case of the modern pursuit type of airplane the pressure increase may be 5 per cent. For pressure-distribution tests on airships the analysis shows that the time lag and pressure change may be neglected.

Hemke, Paul E

1928-01-01

327

Protein crystallization under high pressure.  

PubMed

Pressure is expected to be an important parameter to control protein crystallization, since hydrostatic pressure affects the whole system uniformly and can be changed very rapidly. So far, a lot of studies on protein crystallization have been done. Solubility of protein depends on pressure. For instance, the solubility of tetragonal lysozyme crystal increased with increasing pressure, while that of orthorhombic crystal decreased. The solubility of subtilisin increased with increasing pressure. Crystal growth rates of protein also depend on pressure. The growth rate of glucose isomerase was significantly enhanced with increasing pressure. The growth rate of tetragonal lysozyme crystal and subtilisin decreased with increasing pressure. To study the effects of pressure on the crystallization more precisely and systematically, hen egg white lysozyme is the most suitable protein at this stage, since a lot of data can be used. We focused on growth kinetics under high pressure, since extensive studies on growth kinetics have already been done at atmospheric pressure, and almost all of them have explained the growth mechanisms well. The growth rates of tetragonal lysozyme decreased with pressure under the same supersaturation. This means that the surface growth kinetics significantly depends on pressure. By analyzing the dependence of supersaturation on growth rate, it was found that the increase in average ledge surface energy of the two-dimensional nuclei with pressure explained the decrease in growth rate. At this stage, it is not clear whether the increase in surface energy with increasing pressure is the main reason or not. Fundamental studies on protein crystallization under high pressure will be useful for high pressure crystallography and high pressure protein science. PMID:11983407

Suzuki, Yoshihisa; Sazaki, Gen; Miyashita, Satoru; Sawada, Tsutomu; Tamura, Katsuhiro; Komatsu, Hiroshi

2002-03-25

328

Continuous pressure letdown system  

DOEpatents

A continuous pressure letdown system connected to a hopper decreases a pressure of a 2-phase (gas and solid) dusty gas stream flowing through the system. The system includes a discharge line for receiving the dusty gas from the hopper, a valve, a cascade nozzle assembly positioned downstream of the discharge line, a purge ring, an inert gas supply connected to the purge ring, an inert gas throttle, and a filter. The valve connects the hopper to the discharge line and controls introduction of the dusty gas stream into the discharge line. The purge ring is connected between the discharge line and the cascade nozzle assembly. The inert gas throttle controls a flow rate of an inert gas into the cascade nozzle assembly. The filter is connected downstream of the cascade nozzle assembly.

Sprouse, Kenneth M.; Matthews, David R.; Langowski, Terry

2010-06-08

329

High pressure furnace  

DOEpatents

A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum)). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 19 figures.

Morris, D.E.

1993-09-14

330

High pressure oxygen furnace  

DOEpatents

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized, the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 5 figs.

Morris, D.E.

1992-07-14

331

High pressure oxygen furnace  

DOEpatents

A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

Morris, Donald E. (Kensington, CA)

1992-01-01

332

High pressure furnace  

DOEpatents

A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

Morris, Donald E. (Kensington, CA)

1993-01-01

333

Intracranial pressure at altitude.  

PubMed

Rapid ascent to high altitude can result in high altitude headache, acute mountain sickness, and less commonly, high altitude cerebral or pulmonary edema. The exact mechanisms by which these clinical syndromes develop remain to be fully elucidated. Direct and indirect measures of intracranial pressure (ICP) usually demonstrate a rise in pressure when human subjects and animals are exposed to acute hypoxia. However, the correlation of ICP changes to symptoms and altitude-related illnesses has been difficult to establish. Headache, for example, may occur with vessel distension prior to a rise in ICP. This article reviews the literature both supporting and refuting an increase in ICP as the underlying mechanism of headaches and other related neurological sequelae experienced at high altitude. PMID:24971766

Wilson, Mark H; Wright, Alex; Imray, Christopher H E

2014-06-01

334

Pressure suppression system  

DOEpatents

A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein. 3 figs.

Gluntz, D.M.

1994-10-04

335

Pressure suppression system  

DOEpatents

A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein.

Gluntz, Douglas M. (San Jose, CA)

1994-01-01

336

A flexible pressure monitoring system for pressure ulcer prevention  

E-print Network

Pressure ulcers are painful sores that arise from prolonged exposure to high pressure points, which restricts blood flow and leads to tissue necrosis. This is a common occurrence among patients with impaired mobility, ...

Yip, Marcus

337

Management of intracranial pressure  

Microsoft Academic Search

Although intracranial hypertension may arise from diverse pathology, several basic principles remain paramount to understanding\\u000a its dynamics; however, the management of elevated intracranial pressure (ICP) may be very complex. Initial management of common\\u000a ICP exacerbants is important, such as addressing venous outflow obstruction with upright midline head positioning and treating\\u000a agitation and pain with sedation and analgesia. Surgical decompression of

Thomas J. Wolfe; Michel T. Torbey

2009-01-01

338

Variable-Pressure Washer  

NASA Technical Reports Server (NTRS)

The variable-pressure washer (VPW) is a proposed device that is so named because (1) it would play the role similar to that played by an ordinary washer, except that (2) the clamping pressure applied by it would vary with either circumferential or radial position. In a typical contemplated application, the radially varying clamping pressure would be used to obtain more nearly uniform compression on a pair of concentric seals (e.g., an O-ring or a gasket) in an assembly that experiences larger deformations normal to the sealing surface for locations around the outer diameter of the attachment flange when compared to locations around the inner diameter. The VPW (see figure) would include two interlocking channel rings pushed axially away from each other by compression spring-like components located at two or more radial positions. Each spring would have a different stiffness based on the radial location. Overlapping splits in each interlocking channel ring would allow for the non-uniform deformation in the rings. Each spring would be held in place by retaining cups attached to the inner flat surfaces of the channel rings. A plunger attached to one channel ring on the central axis would be captured in a plunger housing attached to the other channel ring: The capture of the plunger would hold the VPW together. When the VPW was clamped between two flat surfaces, the clamping force would be distributed unevenly across the face of the washer in the radial direction. The different stiffnesses of the springs would be chosen, in conjunction with other design parameters, to obtain a specified radial variation of clamping pressure in the presence of a specified clamping force.

Smeltzer, Stanley S., III; Estrada, Hector

2005-01-01

339

Columbus pressurized module verification  

NASA Technical Reports Server (NTRS)

The baseline verification approach of the COLUMBUS Pressurized Module was defined during the A and B1 project phases. Peculiarities of the verification program are the testing requirements derived from the permanent manned presence in space. The model philosophy and the test program have been developed in line with the overall verification concept. Such critical areas as meteoroid protections, heat pipe radiators and module seals are identified and tested. Verification problem areas are identified and recommendations for the next development are proposed.

Messidoro, Piero; Comandatore, Emanuele

1986-01-01

340

High pressure storage vessel  

DOEpatents

Disclosed herein is a composite pressure vessel with a liner having a polar boss and a blind boss a shell is formed around the liner via one or more filament wrappings continuously disposed around at least a substantial portion of the liner assembly combined the liner and filament wrapping have a support profile. To reduce susceptible to rupture a locally disposed filament fiber is added.

Liu, Qiang

2013-08-27

341

Surface pressure measurements by using pressure-sensitive paints  

Microsoft Academic Search

Until recently, wind tunnel measurements were made solely by pressure taps. But now an optical measurement method has been introduced and is replacing the usual instrumentation, at least for transonic wind tunnels: Pressure-Sensitive Paint, or PSP, which is a method generating an image of the pressure on the surface. The enthusiasm for this technique is prompted by the considerable savings

Y. Le Sant; M.-C. Mérienne

2005-01-01

342

Pressure sensitive paint: application to a sinusoidal pressure fluctuation  

Microsoft Academic Search

An experimental characterization of the frequency response of a Pressure Sensitive Paint (PSP) has been performed. The PSP response to a sinusoidal pressure field was investigated. A Fourier analysis was then used to extended the results to a general periodic pressure field. Amplitude response and phase shift as a function of frequency are presented. The techniques developed in this paper

Bruce F. Carroll; Andy Winslow; John Abbitt; Kirk Schanze; Marty Morris

1995-01-01

343

High-pressure regulating system prevents pressure surges  

NASA Technical Reports Server (NTRS)

Gas flow is controlled by means of a pressure regulating system which prevents pressure surges. A high-pressure fluid source, a spring-loaded fluid-damped regulator valve, an accumulator, a conventional normally closed command valve, and a control valve are the main components.

Keller, O. F.; Mac Glashan, W. F.

1964-01-01

344

Aschroft Pressure Switch Monitor for Low SCHe Supply Bottle Pressure  

SciTech Connect

These pressure switches are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. The switches monitor the SCHe supply bottle pressure and are set to alarm at 2200 psig. There is one switch for each SCHe supply (4). Electronic output signal is NON-SAFETY (GS).

VAN KATWIJK, C.

2000-09-03

345

Ashcroft Pressure Switch Monitor for Low SCHe Supply Bottle Pressure  

SciTech Connect

These pressure switches are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. The switches monitor the SCHe supply bottle pressure and are set to alarm at 2200 psig. There is one switch for each SCHe supply (4). Electronic output signal is NON-SAFETY (GS).

VAN KATWIJK, C.

2000-06-21

346

Hybrid Inflatable Pressure Vessel  

NASA Technical Reports Server (NTRS)

Figure 1 shows a prototype of a large pressure vessel under development for eventual use as a habitable module for long spaceflight (e.g., for transporting humans to Mars). The vessel is a hybrid that comprises an inflatable shell attached to a rigid central structural core. The inflatable shell is, itself, a hybrid that comprises (1) a pressure bladder restrained against expansion by (2) a web of straps made from high-strength polymeric fabrics. On Earth, pressure vessels like this could be used, for example, as portable habitats that could be set up quickly in remote locations, portable hyperbaric chambers for treatment of decompression sickness, or flotation devices for offshore platforms. In addition, some aspects of the design of the fabric straps could be adapted to such other items as lifting straps, parachute straps, and automotive safety belts. Figure 2 depicts selected aspects of the design of a vessel of this type with a toroidal configuration. The bladder serves as an impermeable layer to keep air within the pressure vessel and, for this purpose, is sealed to the central structural core. The web includes longitudinal and circumferential straps. To help maintain the proper shape upon inflation after storage, longitudinal and circumferential straps are indexed together at several of their intersections. Because the web is not required to provide a pressure seal and the bladder is not required to sustain structural loads, the bladder and the web can be optimized for their respective functions. Thus, the bladder can be sealed directly to the rigid core without having to include the web in the seal substructure, and the web can be designed for strength. The ends of the longitudinal straps are attached to the ends of the rigid structural core by means of clevises. Each clevis pin is surrounded by a roller, around which a longitudinal strap is wrapped to form a lap seam with itself. The roller is of a large diameter chosen to reduce bending of the fibers in the strap. The roller also serves to equalize the load in the portions of the strap on both sides of the clevis pin. The lap seam is formed near the clevis by use of a tapered diamond stitch: This stitch is designed specifically to allow fibers in the stitch and strap to relax under load in such a manner that the load becomes more nearly evenly distributed among all fibers in the stitch region. Thus, the tapered diamond stitch prevents load concentrations that could cause premature failure of the strap and thereby increases the strength of the strap/structural-core joint. The lap seam can be rated at >90 percent of the strength of the strap material.

Raboin, Jasen; Valle, Gerard D.; Edeen, Gregg; DeLaFuente, Horacio M.; Schneider, William C.; Spexarth, Gary R.; Johnson, Christopher J.; Pandya, Shalini

2004-01-01

347

Pressure sensitive paint measurement on a rotor  

NASA Astrophysics Data System (ADS)

Toward the development of a measurement system for transonic compressor rotors, the static pressure field over a high-speed test rotor was recorded using pressure sensitive paint (PSP) and an electronically-gated, intensified CCD video camera and frame-grabber. Semi-conductor digital logic circuits were developed to form a phase-locked image capture system which acquired ultra-high-speed, low-light-level gated images once per revolution (1/Rev). A monostable pulse circuit was developed to sum more than 200 gated images over a one-second integration period to build a single image. Rotor speed was measured on an oscilloscope using the 1/Rev trigger-pulse. Also, a pressure vessel was constructed and used to calibrate the PSP over varying pressure and temperature ranges to yield qualitative image intensity versus pressure data. Finally, the static pressure field data over the rotor surface was measured and presented as a 256 grey-scale and color image.

Varner, Donald R.

1995-03-01

348

Air Pressure, Height and Temperature  

NSDL National Science Digital Library

This undergraduate meteorology tutorial uses the balancing of gravity/centrifugal forces and the vertical pressure gradient with the ideal gas law to explain how pressure, temperature, and height are related in the atmosphere.

John Nielsen-Gammon

1996-01-01

349

What Causes High Blood Pressure?  

MedlinePLUS

... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ...

350

Living with High Blood Pressure  

MedlinePLUS

... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ... pressure - a hypertension Google+ hangout in honor of World Hypertension Day 10/15/2014 The NHLBI "Grand ...

351

Controlling your high blood pressure  

MedlinePLUS

Hypertension is another term used to describe high blood pressure. High blood pressure can lead to stroke, heart attack, heart failure, kidney disease, and early death. You are more likely to have high ...

352

High Blood Pressure in Pregnancy  

MedlinePLUS

... of the baby. Controlling your blood pressure during pregnancy and getting regular prenatal care are important for ... your baby. Treatments for high blood pressure in pregnancy may include close monitoring of the baby, lifestyle ...

353

Vapor Pressure measurements for dichlorosilane  

E-print Network

trichlorosilane and silicon tetrachloride, or other chemicals which are not in the silane family. Accurate information about the vapor pressure is necessary in the production of these mixtures. Measurements reported previously for the vapor pressure of pure...

Morris, Tony Knimbula

1997-01-01

354

Medications for High Blood Pressure  

MedlinePLUS

... For Consumers Consumer Updates Medications for High Blood Pressure Search the Consumer Updates Section Hypertension tends to ... you cannot tell if you have high blood pressure by the way you feel, so have your ...

355

Systolic pressure in wound scarring  

PubMed Central

The recommended goal of a systolic pressure under 13 mmHg in hypertensive diabetic patients results in a significant drop in blood pressure that often has caused conflicts in respect to maintaining a minimum systolic pressure for wound scaring in patients with peripheral artery disease. This, as long as the patient remains asymptomatic, is no problem, however if the patient has a peripheral wound, the low systolic pressures may affect scarring. PMID:25644733

DE GODOY, J.M. PEREIRA

2014-01-01

356

Mechanical Design of Pressure Parts  

Microsoft Academic Search

\\u000a A boiler is classified as a fired pressure vessel. Parts of the boiler that are subjected to high internal pressure of steam\\u000a or water are referred to here aspressure parts.Tubes, drum, and headers are examples of pressure parts. Other components likes burners, etc., are not subjected to such internal\\u000a pressure. As such they are classified as nonpressure parts. Selection of

Prabir Basu; Cen Kefa; Louis Jestin

357

What's with All the Pressure?  

NSDL National Science Digital Library

Students learn how to take blood pressure by observing a teacher demonstration and then practicing on fellow classmates in small groups. Once the hands-on component of this activity is completed, the class brainstorms and discusses how blood pressure might affect a person's health. This activity acts as hook for the second lesson in this unit, in which blood pressure is presented in detail, as well as how variances in blood pressure can affect a person's cardiovascular system.

2014-09-18

358

Mechanical characteristics of filament-wound pressure vessel (burst pressure)  

NASA Technical Reports Server (NTRS)

The finite element method is used to analyze the mechanical characteristics of a pressurized filament-wound (FW) pressure vessel, and to predict its burst pressure. The analysis takes into account the bending moment, the stretch-bend coupling effect, nonlinear stress-strain relations, and finite deflection. The analysis is based on two initial failure criteria for laminae, and two ultimate fracture criteria for laminated structures. The numerical results, obtained by applying the load incremental method to the isotensoid CFRP pressure vessel used in the launching of the Zikiken satellite, are in good agreement with the experimental burst pressure and fracture behaviors.

Iida, H.; Uemura, M.

1987-01-01

359

A temperature and pressure controlled calibration system for pressure sensors  

NASA Technical Reports Server (NTRS)

A data acquisition and experiment control system capable of simulating temperatures from -184 to +220 C and pressures either absolute or differential from 0 to 344.74 kPa is developed to characterize silicon pressure sensor response to temperature and pressure. System software is described that includes sensor data acquisition, algorithms for numerically derived thermal offset and sensitivity correction, and operation of the environmental chamber and pressure standard. This system is shown to be capable of computer interfaced cryogenic testing to within 1 C and 34.47 Pa of single channel or multiplexed arrays of silicon pressure sensors.

Chapman, John J.; Kahng, Seun K.

1989-01-01

360

Correlation and spectral measurements of fluctuating pressures and velocities in annular turbulent flow. [PWR; BWR  

SciTech Connect

An experimental study of the fluctuating velocity field, the fluctuating static wall pressure and the in-stream fluctuating static pressure in an annular turbulent air flow system with a radius ratio of 4.314 has been conducted. The study included direct measurements of the mean velocity profile, turbulent velocity field; fluctuating static wall pressure and in-stream fluctuating static pressure from which the statistical values of the turbulent intensity levels, power spectral densities of the turbulent quantities, the cross-correlation between the fluctuating static wall pressure and the fluctuating static pressure in the core region of the flow and the cross-correlation between the fluctuating static wall pressure and the fluctuating velocity field in the core region of the flow were obtained.

Wilson, R.J.; Jones, B.G.; Roy, R.P.

1980-02-01

361

Pressure melting and ice skating  

Microsoft Academic Search

Pressure melting cannot be responsible for the low friction of ice. The pressure needed to reach the melting temperature is above the compressive failure stress and, if it did occur, high squeeze losses would result in very thin films. Pure liquid water cannot coexist with ice much below -20 °C at any pressure and friction does not increase suddenly in

S. C. Colbeck

1995-01-01

362

Cavitation processes and negative pressure  

Microsoft Academic Search

Molecular dynamics simulations of a Lennard–Jones fluid under negative pressure are carried out to investigate the inception of vapor phase in the liquid (i.e., cavitation) and properties of liquid under negative pressure. The pressure of the system is reduced by uniform system expansion. In the case of larger expansion ratios, the nuclei of bubbles immediately appear, whereas finite waiting time

Tomoyuki Kinjo; Mitsuhiro Matsumoto

1998-01-01

363

Types of Blood Pressure Medications  

MedlinePLUS

... and open up narrowed blood vessels, reduce heart rate and lower blood pressure. Generic name Common brand names amlodipine besylate Norvasc*, ... of High Blood Pressure? 5 All About Heart Rate (Pulse) 6 Low Blood Pressure 7 What Your Cholesterol Levels Mean 8 Warning ...

364

Modeling of high pressure thawing  

Microsoft Academic Search

Modeling of freezing and thawing of foodstuffs has been extensively studied. Our application looks at thawing of foodstuffs under high pressure (HP). The phase change temperature of water to ice decreases with increasing pressure below 220 MPa [1] and then allows to achieve higher thawing rate than at atmospheric pressure. Experimental thawing was realised in a HP vessel with pure

J. M. Chourot; R. Lemaire; G. Cornier; A. Le Bail

1996-01-01

365

Abnormal pressure in hydrocarbon environments  

USGS Publications Warehouse

Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

Law, B.E.; Spencer, C.W.

1998-01-01

366

Gas Pressure-Drop Experiment  

ERIC Educational Resources Information Center

Most chemical engineering undergraduate laboratories have fluid mechanics experiments in which pressure drops through pipes are measured over a range of Reynolds numbers. The standard fluid is liquid water, which is essentially incompressible. Since density is constant, pressure drop does not depend on the pressure in the pipe. In addition, flow…

Luyben, William L.; Tuzla, Kemal

2010-01-01

367

Blood Pressure Medicine: Special Instructions  

E-print Network

Blood Pressure Medicine: Special Instructions: U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Heart, Lung, and Blood Institute · What is my blood pressure reading in numbers? · What is my goal blood pressure? · Is there a healthy eating plan that I should follow to help

Bandettini, Peter A.

368

Applications of the Radiation Pressure  

E-print Network

Applications of the Radiation Pressure Prepared: Volodymyr Borshch Course: LC Optics and Photonics in 1871 · The predicted value of the light pressure 4.7 x 10-6 Pa · And also Adolfo Bartoli in 1876 #12 and 10-6 torr (maximum effect 10-2 torr) · DOES NOT demonstrate radiation pressure #12;8 Nichols

Palffy-Muhoray, Peter

369

Pressure-confined Lyman-alpha clouds  

SciTech Connect

Results are presented of numerical models of pressure-confined spherical gas clouds which produce absorption resembling the low to intermediate atomic column density lines found in high-redshift QSO spectra. One-dimensional hydrodynamical models including electron conduction are described, and the rate equations are solved to find ionization and excitation states. Results are presented for both static and adiabatically expanding confining media covering a range of initial pressures. It is found that Ly-alpha lines are very similar over a wide range of conditions and that the most promising diagnostic of pressure is to compare the column density in H I to that in He I and He II. No single-pressure model can explain the wide range of observed H I column densities. 18 references.

Baron, E.; Carswell, R.F.; Hogan, C.J.; Weymann, R.J.

1989-02-01

370

Unibody Composite Pressurized Structure  

NASA Technical Reports Server (NTRS)

An integrated, generic unibody composite pressurized structure (UCPS) combined with a positive expulsion device (PED), consisting of an elastomeric bladder for monopropellant hydrazine, has been quasi-standardized for spacecraft use. The combination functions as an all-composite, non-metallic, propellant tank with bladder. The integrated UCPS combines several previous innovations - specifically, the linerless, all-composite cryogenic tank technology; all-composite boss; resin formulation; and integrated stringer system. The innovation combines the UCPS with an integrated propellant management device (PMD), the PED or bladder, to create an entirely unique system for in-space use. The UCPS is a pressure vessel that incorporates skirts, stringers, and other structures so that it is both an in-space hydrazine tank, and also a structural support system for a spacecraft in a single, all-composite unit. This innovation builds on the progress in the development of a previous SBIR (Small Business Innovation Research) Phase I with Glenn Research Center and an SBIR III with Johnson Space Center that included the fabrication of two 42-in. (˜107-cm) diameter all-composite cryogenic (LOX and liquid methane) UCPS test tanks for a lunar lander. This Phase II provides hydra zine compatibility testing of the elastomeric bladder, a see-through PED to validate the expulsion process and model, and a complete UCPS-based PED with stringers and skirts that will be used to conduct initial qualification and expulsion tests. This extends the UCPS technology to include hydrazine-based, in-space pro - pulsion applications and can also be used for electric propulsion. This innovation creates a system that, in comparison to the traditional approach, is lower in weight, cost, volume, and production time; is stronger; and is capable of much higher pressures. It also has fewer failure modes, and is applicable to both chemical and electric propulsion systems.

Rufer, Markus; Conger, Robert; Bauer, Thomas; Newman, John

2013-01-01

371

Urodynamic pressure sensor  

NASA Technical Reports Server (NTRS)

A transducer system was developed for measuring the closing pressure profile along the female urethra, which provides up to five sensors within the functional length of the urethra. This new development is an improvement over an earlier measurement method that has a smaller sensor area and was unable to respond to transient events. Three sensors were constructed; one of them was subjected to approximately eight hours of use in a clinical setting during which 576 data points were obtained. The complete instrument system, including the signal conditioning electronics, data acquisition unit, and the computer with its display and printer is described and illustrated.

Moore, Thomas

1991-01-01

372

Research in pressure broadening  

NASA Astrophysics Data System (ADS)

This report presents the basic structure and workings of a rigorous and comprehensive formalism applicable to the study of gaseous mixtures interacting with an electromagnetic field. It presents new analyses and characterizations of the physical effects produced by increasing the density of pressure of the gas. A brief discussion on the overall versatility of the general approach relative to strategic areas such as Brillouin scattering and Rydberg-state interactions, the extension of its theoretical limits to include such important current thrusts as adverse-condition imaging in fog or mist, and a rigorous study of the dynamics of the free-electron laser are also presented.

Howgate, David W.

1986-08-01

373

Conflicting Selection Pressures  

NSDL National Science Digital Library

Explore how populations change over time in a NetLogo model of sheep and grass. Experiment with the initial number of sheep, the sheep birthrate, the amount of energy sheep gain from the grass, and the rate at which the grass re-grows. Remove sheep that have a particular trait (better teeth) from the population, then watch what happens to the sheep teeth trait in the population as a whole. Consider conflicting selection pressures to make predictions about other instances of natural selection.

The Concord Consortium

2012-01-13

374

Management of Chronic Pressure Ulcers  

PubMed Central

Executive Summary In April 2008, the Medical Advisory Secretariat began an evidence-based review of the literature concerning pressure ulcers. Please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/tech/tech_mn.html to review these titles that are currently available within the Pressure Ulcers series. Pressure ulcer prevention: an evidence based analysis The cost-effectiveness of prevention strategies for pressure ulcers in long-term care homes in Ontario: projections of the Ontario Pressure Ulcer Model (field evaluation) Management of chronic pressure ulcers: an evidence-based analysis Objective The Medical Advisory Secretariat (MAS) conducted a systematic review on interventions used to treat pressure ulcers in order to answer the following questions: Do currently available interventions for the treatment of pressure ulcers increase the healing rate of pressure ulcers compared with standard care, a placebo, or other similar interventions? Within each category of intervention, which one is most effective in promoting the healing of existing pressure ulcers? Background A pressure ulcer is a localized injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure, or pressure in conjunction with shear and/or friction. Many areas of the body, especially the sacrum and the heel, are prone to the development of pressure ulcers. People with impaired mobility (e.g., stroke or spinal cord injury patients) are most vulnerable to pressure ulcers. Other factors that predispose people to pressure ulcer formation are poor nutrition, poor sensation, urinary and fecal incontinence, and poor overall physical and mental health. The prevalence of pressure ulcers in Ontario has been estimated to range from a median of 22.1% in community settings to a median of 29.9% in nonacute care facilities. Pressure ulcers have been shown to increase the risk of mortality among geriatric patients by as much as 400%, to increase the frequency and duration of hospitalization, and to decrease the quality of life of affected patients. The cost of treating pressure ulcers has been estimated at approximately $9,000 (Cdn) per patient per month in the community setting. Considering the high prevalence of pressure ulcers in the Ontario health care system, the total cost of treating pressure ulcers is substantial. Technology Wounds normally heal in 3 phases (inflammatory phase, a proliferative phase of new tissue and matrix formation, and a remodelling phase). However, pressure ulcers often fail to progress past the inflammatory stage. Current practice for treating pressure ulcers includes treating the underlying causes, debridement to remove necrotic tissues and contaminated tissues, dressings to provide a moist wound environment and to manage exudates, devices and frequent turning of patients to provide pressure relief, topical applications of biologic agents, and nutritional support to correct nutritional deficiencies. A variety of adjunctive physical therapies are also in use. Method Health technology assessment databases and medical databases were searched from 1996 (Medline), 1980 (EMBASE), and 1982 (CINAHL) systematically up to March 2008 to identify randomized controlled trials (RCTs) on the following treatments of pressure ulcers: cleansing, debridement, dressings, biological therapies, pressure-relieving devices, physical therapies, nutritional therapies, and multidisciplinary wound care teams. Full literature search strategies are reported in appendix 1. English-language studies in previous systematic reviews and studies published since the last systematic review were included if they had more than 10 subjects, were randomized, and provided objective outcome measures on the healing of pressure ulcers. In the absence of RCTs, studies of the highest level of evidence available were included. Studies on wounds other than pressure ulcers and on surgical treatment of pressure ulcers were excluded. A total of 18 systematic reviews, 104 RCTs, and 4 observational

2009-01-01

375

High-pressure neutron diffraction  

SciTech Connect

This lecture will cover progress and prospect of applications of high-pressure neutron diffraction techniques to Earth and materials sciences. I will first introduce general high-pressure research topics and available in-situ high-pressure techniques. Then I'll talk about high-pressure neutron diffraction techniques using two types of pressure cells: fluid-driven and anvil-type cells. Lastly, I will give several case studies using these techniques, particularly, those on hydrogen-bearing materials and magnetic transitions.

Xu, Hongwu [Los Alamos National Laboratory

2011-01-10

376

Assessment of fiber optic pressure sensors  

SciTech Connect

This report presents the results of a six-month Phase 1 study to establish the state-of-the-art in fiber optic pressure sensing and describes the design and principle of operation of various fiber optic pressure sensors. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. In addition, current requirements for environmental and seismic qualification of sensors for nuclear power plants were reviewed to determine the extent of the qualification tests that fiber optic pressure sensors may have to meet before they can be used in nuclear power plants. This project has concluded that fiber optic pressure sensors are still in the research and development stage and only a few manufacturers exist in the US and abroad which supply suitable fiber optic pressure sensors for industrial applications. Presently, fiber optic pressure sensors are mostly used in special applications for which conventional sensors are not able to meet the requirements.

Hashemian, H.M.; Black, C.L.; Farmer, J.P. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

1995-04-01

377

High pressure capillary connector  

DOEpatents

A high pressure connector capable of operating at pressures of 40,000 psi or higher is provided. This connector can be employed to position a first fluid-bearing conduit that has a proximal end and a distal end to a second fluid-bearing conduit thereby providing fluid communication between the first and second fluid-bearing conduits. The connector includes (a) an internal fitting assembly having a body cavity with (i) a lower segment that defines a lower segment aperture and (ii) an interiorly threaded upper segment, (b) a first member having a first member aperture that traverses its length wherein the first member aperture is configured to accommodate the first fluid-bearing conduit and wherein the first member is positioned in the lower segment of the internal fitting assembly, and (c) a second member having a second member aperture that traverses its length wherein the second member is positioned in the upper segment of the fitting assembly and wherein a lower surface of the second member is in contact with an upper surface of the first member to assert a compressive force onto the first member and wherein the first member aperture and the second member aperture are coaxial.

Renzi, Ronald F.

2005-08-09

378

Pressure polymerization of polyester  

DOEpatents

A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about 220.degree. C. to about 320.degree. C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

Maurer, Charles J. (Matthews, NC); Shaw, Gordon (Charlotte, NC); Smith, Vicky S. (Greer, SC); Buelow, Steven J. (Los Alamos, NM); Tumas, William (Los Alamos, NM); Contreras, Veronica (San Antonio, TX); Martinez, Ronald J. (Santa Cruz, NM)

2000-08-29

379

Airway obstruction with cricoid pressure.  

PubMed

Cricoid pressure may cause airway obstruction. We investigated whether this is related to the force applied and to the technique of application. We recorded expired tidal volumes and inflation pressures during ventilation via a face-mask and oral airway in 52 female patients who were anaesthetised and about to undergo elective surgery. An inspired tidal volume of 900 ml was delivered using a ventilator. Ventilation was assessed under five different conditions: no cricoid pressure, backwards cricoid pressure applied with a force of 30 N, cricoid pressure applied in an upward and backward direction with a force of 30 N, backwards cricoid pressure with a force of 44 N and through a tracheal tube. An expired tidal volume of < 200 ml was taken to indicate airway obstruction. Airway obstruction did not occur without cricoid pressure, but did occur in one patient (2%) with cricoid pressure at 30 N, in 29 patients (56%) with 30 N applied in an upward and backward direction and in 18 (35%) patients with cricoid pressure at 44 N. Cricoid pressure applied with a force of 44 N can cause airway obstruction but if cricoid pressure is applied with a force of 30 N, airway obstruction occurs less frequently (p = 0.0001) unless the force is applied in an upward and backward direction. PMID:10671836

Hartsilver, E L; Vanner, R G

2000-03-01

380

Pressure, Force, Muscles and Massage  

NSDL National Science Digital Library

The human body is constantly being subjected to external forces. The relation between force and pressure is straightforward. The more force exerted, the greater the pressure, but the effect of area on pressure is somewhat more subtle. Through the process of massage students apply their understanding of forces and pressures to enhance the relaxation of their lab partner's forearm. A proper understanding of the concept of pressure is essential to an understanding of most areas of physiology. This activity provides students with a feeling for what pressure is and how it is related to force and area. Students determine the pressure exerted on the bottoms of their feet under a variety of circumstances. In each case, the force exerted is body weight. But the area over which that force is exerted differs, depending on whether one is standing on two feet, one foot or tiptoe (one-foot.)

BEGIN:VCARD VERSION:2.1 FN:Kristin Shields N:Shields; Kristin ORG:Vanden High School REV:2005-04-12 END:VCARD

1995-06-30

381

Thermodynamic equilibrium at heterogeneous pressure  

NASA Astrophysics Data System (ADS)

Recent advances in metamorphic petrology point out the importance of grain-scale pressure variations in high-temperature metamorphic rocks. Pressures derived from chemical zonation using unconventional geobarometry based on equal chemical potentials fit mechanically feasible pressure variations. Here a thermodynamic equilibrium method is presented that predicts chemical zoning as a result of pressure variations by Gibbs energy minimization. Equilibrium thermodynamic prediction of the chemical zoning in the case of pressure heterogeneity is done by constraint Gibbs minimization using linear programming techniques. Compositions of phases considered in the calculation are discretized into 'pseudo-compounds' spanning the entire compositional space. Gibbs energies of these discrete compounds are generated for a given range and resolution of pressures for example derived by barometry or from mechanical model predictions. Gibbs energy minimization is subsequently performed considering all compounds of different composition and pressure. In addition to constraining the system composition a certain proportion of the system is constraint at a specified pressure. Input pressure variations need to be discretized and each discrete pressure defines an additional constraint for the minimization. The proportion of the system at each different pressure is equally distributed over the number of input pressures. For example if two input pressures P1 and P2 are specified, two constraints are added: 50 percent of the system is constraint at P1 while the remaining 50 percent is constraint at P2. The method has been tested for a set of 10 input pressures obtained by Taj?manová et al. (2014) using their unconventional geobarometry method in a plagioclase rim around kyanite. Each input pressure is added as constraint to the minimization (1/10 percent of the system for each discrete pressure). Constraining the system composition to the average composition of the plagioclase rim successfully predicts the observed chemical zoning. In conclusion, Gibbs minimization provides identical results to the geobarometry approach based on chemical potentials thus validating the inferred pressure gradient. The thermodynamic consistency of the calculation is supported by the similar result obtained from two different approaches. Reference: Taj?manová, L., Podladchikov, Y., Powell, R., Moulas, E., Vrijmoed, J. C. & Connolly, J. A. D. (2014). Grain scale pressure variations and chemical equilibrium in high-grade metamorphic rocks. Journal of Metamorphic Geology, (in press).

Vrijmoed, Johannes C.; Podladchikov, Yuri Y.

2014-05-01

382

Solvation pressure as real pressure: I. Ethanol and starch under negative pressure  

NASA Astrophysics Data System (ADS)

The reality of the solvation pressure generated by the cohesive energy density of liquids is demonstrated by three methods. Firstly, the Raman spectrum of ethanol as a function of cohesive energy density (solvation pressure) in ethanol-water and ethanol-chloroform mixtures is compared with the Raman spectrum of pure ethanol under external hydrostatic pressure and the solvation pressure and hydrostatic pressure are found to be equivalent for some transitions. Secondly, the bond lengths of ethanol are calculated by molecular dynamics modelling for liquid ethanol under pressure and for ethanol vapour. The difference in bond lengths between vapour and liquid are found to be equivalent to the solvation pressure for the C-H3, C-H2 and O-H bond lengths, with discrepancies for the C-C and C-O bond lengths. Thirdly, the pressure-induced gelation of potato starch is measured in pure water and in mixtures of water and ethanol. The phase transition pressure varies in accordance with the change in solvation pressure of the solvent. These results demonstrate the reality of 'negative pressures' generated by reductions in the cohesive energy density of solvent mixtures.

van Uden, N. W. A.; Hubel, H.; Faux, D. A.; Tanczos, A. C.; Howlin, B.; Dunstan, D. J.

2003-03-01

383

Possible Pressure Waves of Supersolid Helium at High Pressure  

E-print Network

We make comments on Kim and Chan's [{\\it Phys. Rev. Lett.} 97, 115302 (2006)] letter. Based on their pressure-dependent measurements (by a torsional oscillator technique), we propose that the {\\it supersolid} fraction ($\\rho_s/\\rho$) might be relevant to an sound absorption or attenuation (fluctuations of pressure waves) in microscopic domain since there is no apparent change in $T_c$ with pressure.

Kwang-Hua W. Chu

2006-10-02

384

A Constant Pressure Bomb  

NASA Technical Reports Server (NTRS)

This report describes a new optical method of unusual simplicity and of good accuracy suitable to study the kinetics of gaseous reactions. The device is the complement of the spherical bomb of constant volume, and extends the applicability of the relationship, pv=rt for gaseous equilibrium conditions, to the use of both factors p and v. The method substitutes for the mechanical complications of a manometer placed at some distance from the seat of reaction the possibility of allowing the radiant effects of reaction to record themselves directly upon a sensitive film. It is possible the device may be of use in the study of the photoelectric effects of radiation. The method makes possible a greater precision in the measurement of normal flame velocities than was previously possible. An approximate analysis shows that the increase of pressure and density ahead of the flame is negligible until the velocity of the flame approaches that of sound.

Stevens, F W

1924-01-01

385

High pressure mechanical seal  

NASA Technical Reports Server (NTRS)

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After compression, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as measured using the Helium leak test.

Babel, Henry W. (Inventor); Anderson, Raymond H. (Inventor)

1996-01-01

386

High pressure mechanical seal  

NASA Technical Reports Server (NTRS)

A relatively impervious mechanical seal is formed between the outer surface of a tube and the inside surface of a mechanical fitting of a high pressure fluid or hydraulic system by applying a very thin soft metal layer onto the outer surface of the hard metal tube and/or inner surface of the hard metal fitting, prior to swaging the fitting onto the tube. The thickness of such thin metal layer is independent of the size of the tube and/or fittings. Many metals and alloys of those metals exhibit the requisite softness, including silver, gold, nickel, tin, platinum, indium, rhodium and cadmium. Suitably, the coating is about 0.0025 millimeters (0.10 mils) in thickness. After swaging, the tube and fitting combination exhibits very low leak rates on the order or 10.sup.-8 cubic centimeters per second or less as meaured using the Helium leak test.

Babel, Henry W. (Inventor); Fuson, Phillip L. (Inventor); Chickles, Colin D. (Inventor); Jones, Cherie A. (Inventor); Anderson, Raymond H. (Inventor)

1995-01-01

387

Cradle and pressure grippers  

DOEpatents

A gripper that is designed to incorporate the functions of gripping, supporting and pressure tongs into one device. The gripper has two opposing finger sections with interlocking fingers that incline and taper to form a wedge. The interlocking fingers are vertically off-set so that the opposing finger sections may close together allowing the inclined, tapered tips of the fingers to extend beyond the plane defined by the opposing finger section's engagement surface. The range of motion defined by the interlocking relationship of the finger sections allows the gripper to grab, lift and support objects of varying size and shape. The gripper has one stationary and one moveable finger section. Power is provided to the moveable finger section by an actuating device enabling the gripper to close around an object to be lifted. A lifting bail is attached to the gripper and is supported by a crane that provides vertical lift.

Muniak, John E. (New York, NY)

2001-01-01

388

Pressurized downdraft gasifier  

SciTech Connect

A pressurized downdraft gasifier is described for extracting high quality gas products from solid carbonaceous fuels having low rates of gasification comprising; gasifying chamber means with a lower burning zone therein, gas lock means connected to the gasifying chamber means for supplying fuel and downdraft combustion air to the gasifying chamber means, ash collection chamber means connected to the gasifying chamber means to receive ash emanating from the burning zone through a throated zone in the bottom of the gasifying chamber means, a cylindrical grate bar assembly concentrically depending from the gasifying chamber means below the throated zone and extending downwardly into the ash collection chamber means, the cylindrical grate bar assembly including circular grate bars vertically-spaced from one another.

Weaver, L.E.

1987-04-21

389

Planet Under Pressure  

NSDL National Science Digital Library

Planet Under Pressure is a six-part British Broadcasting Company (BBC) News Online series looking at some of the most pressing environmental issues facing the human race today. The series takes a detailed look at six areas where most experts agree that a crisis is brewing. They include food, water, energy, climate change, biodiversity, and pollution. In addition there are special features including: an animated guide that shows how the greenhouse effect might shape our climate; before and after images of the effects of climate change; the European Union (EU) emissions trading scheme and the carbon revolution; opinions about the Kyoto Protocol; graphic climate evidence of a warming world, rising sea, and melting ice; teenagers' opinions on how they would tackle environmental damage; the results of an eco-friendly garden competition; pictures of environmental change around the world; and a link to a BBC website exploring the UN's goals for the planet in 2015.

390

Pressure Measurement Sensor  

NASA Technical Reports Server (NTRS)

FFPI Industries Inc. is the manufacturer of fiber-optic sensors that furnish accurate pressure measurements in internal combustion chambers. Such an assessment can help reduce pollution emitted by these engines. A chief component in the sensor owes its seven year- long development to Lewis Research Center funding to embed optical fibers and sensors in metal parts. NASA support to Texas A&M University played a critical role in developing this fiber optic technology and led to the formation of FFPI Industries and the production of fiber sensor products. The simple, rugged design of the sensor offers the potential for mass production at low cost. Widespread application of the new technology is forseen, from natural gas transmission, oil refining and electrical power generation to rail transport and the petrochemical paper product industry.

1997-01-01

391

Pressure vessel bottle mount  

NASA Technical Reports Server (NTRS)

A mounting assembly for mounting a composite pressure vessel to a vehicle includes a saddle having a curved surface extending between two pillars for receiving the vessel. The saddle also has flanged portions which can be bolted to the vehicle. Each of the pillars has hole in which is mounted the shaft portion of an attachment member. A resilient member is disposed between each of the shaft portions and the holes and loaded by a tightening nut. External to the holes, each of the attachment members has a head portion to which a steel band is attached. The steel band circumscribes the vessel and translates the load on the springs into a clamping force on the vessel. As the vessel expands and contracts, the resilient members expand and contract so that the clamping force applied by the band to the vessel remains constant.

Wingett, Paul (Inventor)

2001-01-01

392

Collapse pressure of coiled tubing  

SciTech Connect

The collapse pressure is a measure of an external force required to collapse a tube in the absence of internal pressure. It is defined as the minimum pressure required to yield the tube in the absence of internal pressure. Coiled tubing is sometimes used in high-pressure wells. If the external pressure becomes too high, the coiled tubing will collapse. This could not only lead to serious well-control problems, but may result in extensive fishing operations. A reliable safety criterion of collapse pressure for the coiled tubing is needed by the coiled tubing operators. Theoretical models of collapse pressure are well developed for perfectly round coiled tubing but not for oval coiled tubing. Coiled tubing is initially manufactured with nearly perfect roundness, sometimes having a small ovality (typically {le} 0.5%). Perfectly round CT becomes oval owing to the plastic mechanical deformation of the coiled tubing as it spooled on and off the reel and over the gooseneck. As the cycling continues, the ovality usually increases. This ovality significantly decreases the collapse failure pressure as compared to perfectly round tubing. In this paper, an analytical model of collapse pressure for oval tubing under axial tension or compression is developed based on elastic instability theory and the von Mises criterion. The theoretical model shows satisfactory agreement with experimental data.

Yang, Y.S. [Precision Tube Technology, Inc., Houston, TX (United States)

1996-09-01

393

Pressure inactivation of Bacillus endospores.  

PubMed

The inactivation of bacterial endospores by hydrostatic pressure requires the combined application of heat and pressure. We have determined the resistance of spores of 14 food isolates and 5 laboratory strains of Bacillus subtilis, B. amyloliquefaciens, and B. licheniformis to treatments with pressure and temperature (200 to 800 MPa and 60 to 80 degrees C) in mashed carrots. A large variation in the pressure resistance of spores was observed, and their reduction by treatments with 800 MPa and 70 degrees C for 4 min ranged from more than 6 log units to no reduction. The sporulation conditions further influenced their pressure resistance. The loss of dipicolinic acid (DPA) from spores that varied in their pressure resistance was determined, and spore sublethal injury was assessed by determination of the detection times for individual spores. Treatment of spores with pressure and temperature resulted in DPA-free, phase-bright spores. These spores were sensitive to moderate heat and exhibited strongly increased detection times as judged by the time required for single spores to grow to visible turbidity of the growth medium. The role of DPA in heat and pressure resistance was further substantiated by the use of the DPA-deficient mutant strain B. subtilis CIP 76.26. Taken together, these results indicate that inactivation of spores by combined pressure and temperature processing is achieved by a two-stage mechanism that does not involve germination. At a pressure between 600 and 800 MPa and a temperature greater than 60 degrees C, DPA is released predominantly by a physicochemical rather than a physiological process, and the DPA-free spores are inactivated by moderate heat independent of the pressure level. Relevant target organisms for pressure and temperature treatment of foods are proposed, namely, strains of B. amyloliquefaciens, which form highly pressure-resistant spores. PMID:15574932

Margosch, Dirk; Gänzle, Michael G; Ehrmann, Matthias A; Vogel, Rudi F

2004-12-01

394

Determining Pressure Losses For Airflow In Residential Ductwork  

E-print Network

.................................................................................25 Figure 6. Static pressure sensor array and daq input block..............................................26 Figure 7. Raw materials for piezometer ring tap..............................................................27 Figure 8. Soldering... tools ..................................................................................................28 Figure 9. Soldering of copper tubing ...............................................................................29 Figure 10. Quenching...

Weaver, Kevin Douglas

2012-02-14

395

Gas/oil capillary pressure at chalk at elevated pressures  

SciTech Connect

Accurate capillary pressure curves are essential for studying the recovery of oil by gas injection in naturally fractured chalk reservoirs. A simple and fast method to determine high-pressure drainage capillary pressure curves has been developed. The effect of gas/oil interfacial tension (IFT) on the capillary pressure of chalk cores has been determined for a methane/n-pentane system. Measurements on a 5-md outcrop chalk core were made at pressures of 70, 105, and 130 bar, with corresponding IFT`s of 6.3, 3.2, and 1.5 mN/m. The results were both accurate and reproducible. The measured capillary pressure curves were not a linear function of IFT when compared with low-pressure centrifuge data. Measured capillary pressures were considerably lower than IFT-scaled centrifuge data. It appears that the deviation starts at an IFT of about 5 mN/m. According to the results of this study, the recovery of oil by gravity drainage in naturally fractured chalk reservoirs may be significantly underestimated if standard laboratory capillary pressure curves are scaled by IFT only. However, general conclusions cannot be made on the basis on only this series of experiments on one chalk core.

Christoffersen, K.R. [Statoil Research Centre, Trondheim (Norway); Whitson, C.H. [Univ. of Trondheim (Norway)

1995-09-01

396

Pressure measurements on aircraft wing using phase-shifted fibre Bragg grating sensors  

Microsoft Academic Search

Experimental results of static pressure measurements from specially packaged pi-phase shifted optical fibre Bragg gratings (FBGs) that were installed into a 2D, 3 element high lift wing are presented. The static pressure measurements from the fibre sensors are found to be in good agreement with theory. Further pressure calibrations are currently under investigation.

Edmon Chehura; Stephen W. James; Nicholas Lawson; Kevin P. Garry; Ralph P. Tatam

2009-01-01

397

21 CFR 868.2700 - Pressure regulator.  

Code of Federal Regulations, 2011 CFR

...pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working...

2011-04-01

398

21 CFR 868.2700 - Pressure regulator.  

Code of Federal Regulations, 2013 CFR

...pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working...

2013-04-01

399

21 CFR 868.2700 - Pressure regulator.  

Code of Federal Regulations, 2010 CFR

...pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working...

2010-04-01

400

21 CFR 868.2700 - Pressure regulator.  

Code of Federal Regulations, 2014 CFR

...pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working...

2014-04-01

401

21 CFR 868.2700 - Pressure regulator.  

Code of Federal Regulations, 2012 CFR

...pressure regulator is a device, often called a pressure-reducing valve, that is intended for medical purposes and that is used to convert a medical gas pressure from a high variable pressure to a lower, more constant working...

2012-04-01

402

49 CFR 195.304 - Test pressure.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Test pressure. 195.304 Section 195.304 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.304 Test pressure. The test pressure for each...

2012-10-01

403

49 CFR 195.304 - Test pressure.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Test pressure. 195.304 Section 195.304 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.304 Test pressure. The test pressure for each...

2011-10-01

404

49 CFR 195.304 - Test pressure.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Test pressure. 195.304 Section 195.304 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.304 Test pressure. The test pressure for each...

2013-10-01

405

49 CFR 195.304 - Test pressure.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Test pressure. 195.304 Section 195.304 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.304 Test pressure. The test pressure for each...

2014-10-01

406

46 CFR 154.452 - External pressure.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false External pressure. 154.452 Section 154.452 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure, Pe...

2013-10-01

407

46 CFR 154.452 - External pressure.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false External pressure. 154.452 Section 154.452 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure, Pe...

2011-10-01

408

46 CFR 154.452 - External pressure.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false External pressure. 154.452 Section 154.452 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure, Pe...

2012-10-01

409

46 CFR 154.452 - External pressure.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false External pressure. 154.452 Section 154.452 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure, Pe...

2014-10-01

410

46 CFR 154.452 - External pressure.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false External pressure. 154.452 Section 154.452 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.452 External pressure. The design external pressure, Pe...

2010-10-01

411

49 CFR 195.304 - Test pressure.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Test pressure. 195.304 Section 195.304 Transportation...TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.304 Test pressure. The test pressure for each...

2010-10-01

412

Steam Oxidation at High Pressure  

SciTech Connect

A first high pressure test was completed: 293 hr at 267 bar and 670{degrees}C; A parallel 1 bar test was done for comparison; Mass gains were higher for all alloys at 267 bar than at 1 bar; Longer term exposures, over a range of temperatures and pressures, are planned to provide information as to the commercial implications of pressure effects; The planned tests are at a higher combination of temperatures and pressures than in the existing literature. A comparison was made with longer-term literature data: The short term exposures are largely consistent with the longer-term corrosion literature; Ferritic steels--no consistent pressure effect; Austenitic steels--fine grain alloys less able to maintain protective chromia scale as pressure increases; Ni-base alloys--more mass gains above 105 bar than below. Not based on many data points.

Holcomb, Gordon R. [NETL; Carney, Casey [URS

2013-07-19

413

High pressure, high temperature transducer  

NASA Technical Reports Server (NTRS)

The pressure measurement system utilizes two bourdon tubes with an active side connected to a test specimen and a reference side connected to an outside source. The tubes are attached to a single extensometer measuring relative displacement. The active side deflects when gases vent a specimen failure. The reference side is independently pressurized to a test pressure and provides a zero reference while providing a pressure calibration reference for the active side. The deflection noted by the active side at specimen failure is duplicated on the reference side by venting until an appropriate magnitude of pressure versus deflection is determined. In this way the pressure which existed inside the specimen prior to failure can be determined.

Vrolyk, John J. (Inventor)

1977-01-01

414

Ocular perfusion pressure in glaucoma.  

PubMed

This review article discusses the relationship between ocular perfusion pressure and glaucoma, including its definition, factors that influence its calculation and epidemiological studies investigating the influence of ocular perfusion pressure on the prevalence, incidence and progression of glaucoma. We also list the possible mechanisms behind this association, and discuss whether it is secondary to changes in intraocular pressure, blood pressure or both. Finally, we describe the circadian variation of ocular perfusion pressure and the effects of systemic and topical medications on it. We believe that the balance between IOP and BP, influenced by the autoregulatory capacity of the eye, is part of what determines whether an individual will develop optic nerve damage. However, prospective, longitudinal studies are needed to better define the role of ocular perfusion pressure in the development and progression of glaucoma. PMID:24238296

Costa, Vital P; Harris, Alon; Anderson, Douglas; Stodtmeister, Richard; Cremasco, Fernanda; Kergoat, Helene; Lovasik, John; Stalmans, Ingborg; Zeitz, Oliver; Lanzl, Ines; Gugleta, Konstantin; Schmetterer, Leopold

2014-06-01

415

42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...  

Code of Federal Regulations, 2014 CFR

...supplied-air respirator, pressure-demand class; minimum...requirements. (a) The static pressure in the facepiece shall...water-column height. (b) The pressure in the facepiece shall not fall below atmospheric at inhalation...

2014-10-01

416

42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...  

Code of Federal Regulations, 2011 CFR

...supplied-air respirator, pressure-demand class; minimum...requirements. (a) The static pressure in the facepiece shall...water-column height. (b) The pressure in the facepiece shall not fall below atmospheric at inhalation...

2011-10-01

417

42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...  

Code of Federal Regulations, 2012 CFR

...supplied-air respirator, pressure-demand class; minimum...requirements. (a) The static pressure in the facepiece shall...water-column height. (b) The pressure in the facepiece shall not fall below atmospheric at inhalation...

2012-10-01

418

42 CFR 84.157 - Airflow resistance test; Type C supplied-air respirator, pressure-demand class; minimum...  

Code of Federal Regulations, 2013 CFR

...supplied-air respirator, pressure-demand class; minimum...requirements. (a) The static pressure in the facepiece shall...water-column height. (b) The pressure in the facepiece shall not fall below atmospheric at inhalation...

2013-10-01

419

A novel target-type low pressure drop bidirectional optoelectronic air flow sensor for infant artificial ventilation: measurement principle and static calibration.  

PubMed

An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 °C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min(-1). The nonlinear behavior allows sensitivities equal to 0.6 V l(-1) min for flow rates ranging from -2.0 to +2.0 l min(-1), equal to 2.0 V l(-1) min for flow rates ranging from -3.0 to -2.0 l min(-1) and from +2.0 to +3.0 l min(-1), up to 5.7 V l(-1) min at higher flow rates ranging from -7.0 to -3.0 l min(-1) and from +3.0 to +7.0 l min(-1). The linear range extends from 3.0 to 7.0 l min(-1) with constant sensitivity equal to 5.7 V l(-1) min. The sensor is able to detect a flow-rate equal to 1.0 l min(-1) with a sensitivity of about 400 mV l(-1) min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min(-1), corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l(-1) min. PMID:21361616

Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio

2011-02-01

420

High pressure synthesis gas fermentation  

SciTech Connect

Construction of the high pressure gas phase fermentation system is nearing completion. All non-explosion proof components will be housed separately in a gas-monitored plexiglas cabinet. A gas-monitoring system has been designed to ensure the safety of the operations in case of small or large accidental gas releases. Preliminary experiments investigating the effects of high pressure on Clostridium 1jungdahlii have shown that growth and CO uptake are not negatively affected and CO uptake by an increased total pressure of 100 psig at a syngas partial pressure of 10 psig.

Not Available

1991-01-01

421

Apollo experience report: Pressure vessels  

NASA Technical Reports Server (NTRS)

The Apollo spacecraft pressure vessels, associated problems and resolutions, and related experience in evaluating potential problem areas are discussed. Information is provided that can be used as a guideline in the establishment of baseline criteria for the design and use of lightweight pressure vessels. One of the first practical applications of the use of fracture-mechanics technology to protect against service failures was made on Apollo pressure vessels. Recommendations are made, based on Apollo experience, that are designed to reduce the incidence of failure in pressure-vessel operation and service.

Ecord, G. M.

1972-01-01

422

Nutrition systems for pressure suits.  

NASA Technical Reports Server (NTRS)

Nutrition systems were successfully developed in the Apollo Program for astronauts wearing pressure suits during emergency decompression situations and during lunar surface explorations. These nutrition systems consisted of unique dispensers, water, flavored beverages, nutrient-fortified beverages, and intermediate moisture food bars. The emergency decompression system dispensed the nutrition from outside the pressure suit by interfacing with a suit helmet penetration port. The lunar exploration system utilized dispensers stowed within the interior layers of the pressure suit. These systems could be adapted for provision of nutrients in other situations requiring the use of pressure suits.

Huber, C. S.; Heidelbaugh, N. D.; Rapp, R. M.; Smith, M. C., Jr.

1973-01-01

423

Multilayer Composite Pressure Vessels  

NASA Technical Reports Server (NTRS)

A method has been devised to enable the fabrication of lightweight pressure vessels from multilayer composite materials. This method is related to, but not the same as, the method described in gMaking a Metal- Lined Composite-Overwrapped Pressure Vessel h (MFS-31814), NASA Tech Briefs, Vol. 29, No. 3 (March 2005), page 59. The method is flexible in that it poses no major impediment to changes in tank design and is applicable to a wide range of tank sizes. The figure depicts a finished tank fabricated by this method, showing layers added at various stages of the fabrication process. In the first step of the process, a mandrel that defines the size and shape of the interior of the tank is machined from a polyurethane foam or other suitable lightweight tooling material. The mandrel is outfitted with metallic end fittings on a shaft. Each end fitting includes an outer flange that has a small step to accommodate a thin layer of graphite/epoxy or other suitable composite material. The outer surface of the mandrel (but not the fittings) is covered with a suitable release material. The composite material is filament- wound so as to cover the entire surface of the mandrel from the step on one end fitting to the step on the other end fitting. The composite material is then cured in place. The entire workpiece is cut in half in a plane perpendicular to the axis of symmetry at its mid-length point, yielding two composite-material half shells, each containing half of the foam mandrel. The halves of the mandrel are removed from within the composite shells, then the shells are reassembled and bonded together with a belly band of cured composite material. The resulting composite shell becomes a mandrel for the subsequent steps of the fabrication process and remains inside the final tank. The outer surface of the composite shell is covered with a layer of material designed to be impermeable by the pressurized fluid to be contained in the tank. A second step on the outer flange of each end fitting accommodates this layer. Depending on the application, this layer could be, for example, a layer of rubber, a polymer film, or an electrodeposited layer of metal. If the fluid to be contained in the tank is a gas, then the best permeation barrier is electrodeposited metal (typically copper or nickel), which can be effective at a thickness of as little as 0.005 in (.0.13 mm). The electrodeposited metal becomes molecularly bonded to the second step on each metallic end fitting. The permeation-barrier layer is covered with many layers of filament-wound composite material, which could be the same as, or different from, the composite material of the inner shell. Finally, the filament-wound composite material is cured in an ov

DeLay, Tom

2005-01-01

424

Determination of impact sensitivity of materials at high pressures  

NASA Technical Reports Server (NTRS)

Compact device is used to determine impact sensitivity of material in static, high pressure, gaseous environment. It can also be instrumented to monitor and record pressure, temperature, and striker impact force. Device is used in conjunction with commercially available liquid oxygen impact tester which provides impact energy.

Davis, L.; Pippen, D.; Stradling, J.; Whitaker, D.

1972-01-01

425

Influence of high pressure processing on protein solutions and emulsions  

Microsoft Academic Search

Static high-pressure technology is likely to be used increasingly over the next few years in the preservation and processing of food. This ‘clean’ technology offers an effective and safe method of modifying protein structure, and self-assembly properties. Pressure processing can lead to globular protein denaturation, and different states of aggregation or gelation depending on the protein system, the treatment temperature,

Vanda B Galazka; Eric Dickinson; Dave A Ledward

2000-01-01

426

High-pressure and temperature investigations of energetic materials  

NASA Astrophysics Data System (ADS)

Static high-pressure measurements are extremely useful for obtaining thermodynamic and phase stability information from a wide variety of materials. However, studying energetic materials can be challenging when extracting information from static high-pressure measurements. Energetic materials are traditionally C, H, N, O compounds with low crystalline symmetry, producing weak signal in commonly performed x-ray diffraction measurements. The small sample volume available in a static high-pressure cell exacerbates this issue. Additionally, typical hydrostatic compression media, such as methanol/ethanol, may react with many energetic materials. However, characterization of their thermodynamic parameters and phase stability is critical to understanding explosive performance and sensitivity. Crystalline properties, such as bulk modulus and thermal expansion, are necessary to accurately predict the behaviour of shocked solids using hydrodynamic codes. In order to obtain these values, equations of state of various energetic materials were investigated using synchrotron angle-dispersive x-ray diffraction experiments at static high-pressure and temperature. Intense synchrotron radiation overcomes the weak x-ray scattering of energetic materials in a pressure cell. The samples were hydrostatically compressed using a non-reactive hydrostatic medium and heated using a heated diamond anvil cell. Pressure - volume data for the materials were fit to the Birch-Murnaghan and Vinet formalisms to obtain bulk modulus and its first pressure derivative. Temperature - volume data at ambient pressure were fit to obtain the volume thermal expansion coefficient. Data from several energetic materials will be presented and compared.

Gump, J. C.

2014-05-01

427

[High Pressure Gas Tanks  

NASA Technical Reports Server (NTRS)

Four high-pressure gas tanks, the basis of this study, were especially made by a private contractor and tested before being delivered to NASA Kennedy Space Center. In order to insure 100% reliability of each individual tank the staff at KSC decided to again submit the four tanks under more rigorous tests. These tests were conducted during a period from April 10 through May 8 at KSC. This application further validates the predictive safety model for accident prevention and system failure in the testing of four high-pressure gas tanks at Kennedy Space Center, called Continuous Hazard Tracking and Failure Prediction Methodology (CHTFPM). It is apparent from the variety of barriers available for a hazard control that some barriers will be more successful than others in providing protection. In order to complete the Barrier Analysis of the system, a Task Analysis and a Biomechanical Study were performed to establish the relationship between the degree of biomechanical non-conformities and the anomalies found within the system on particular joints of the body. This relationship was possible to obtain by conducting a Regression Analysis to the previously generated data. From the information derived the body segment with the lowest percentage of non-conformities was the neck flexion with 46.7%. Intense analysis of the system was conducted including Preliminary Hazard Analysis (PHA), Failure Mode and Effect Analysis (FMEA), and Barrier Analysis. These analyses resulted in the identification of occurrences of conditions, which may be becoming hazardous in the given system. These conditions, known as dendritics, may become hazards and could result in an accident, system malfunction, or unacceptable risk conditions. A total of 56 possible dendritics were identified. Work sampling was performed to observe the occurrence each dendritic. The out of control points generated from a Weighted c control chart along with a Pareto analysis indicate that the dendritics "Personnel not Wearing Proper Protective and Hose/tubing located in high-traffic area" which account for 59.18% of total dendritic frequency need to be addressed to reduce the chance of a hazard from occurring. However, the occurrences of some dendritics are more important than others. As a result immediate, from a Weighted c perspective, corrective action should be taken to ameliorate the cause of the Class A dendritic "Personnel located under suspended or moving loads" rather than just the most commonly occurring dendritics. In any case the vast majority of data obtained indicates that testing operations possess a relatively high degree of safety.

Quintana, Rolando

2002-01-01

428

High-pressure, high-temperature opposed anvil device described  

Microsoft Academic Search

Static high-temperature, high-pressure technology is an important technique for researching solid state phase changes and synthesis of materials. At present, many kinds of devices are used for conducting different high-temperature, high-pressure experiments. The structure of the Bridgman type hard alloy opposed anvil is simple but it can withstand high pressure above 100kbar, and using internal heating method, the temperature can

Yi He; Songtao Wang; Zhicheng Qin; Yaoji Wang; Wenkui Wang

1985-01-01

429

A pressurized gas squeeze film journal damper  

NASA Technical Reports Server (NTRS)

A lumped parameter model is developed to determine the stiffness and damping characteristics of inherently compensated gas film bearings. The model relies on the average static pressure over a one dimensional strip bearing. Results of the model are compared with known computer solutions for the distributed strip and a two dimensional square bearing. The results for the stiffness agree well with the computer solutions although the model proved to be inadequate for predicting the film damping.

Stiffler, A. K.

1977-01-01

430

Pressure sensitive paint for oscillating pressure fields measurements  

Microsoft Academic Search

The paper describes the main problems encountered during investigations of the oscillating pressure fields by the Fast Binary Pressure Sensitive Paint (FBPSP). This formulation has response time in the millisecond range and provides compensation of the model displacements and excitation light instability. Measurement methodology, and theoretical and experimental estimations of the FBPSP dynamic characteristics are presented. It is shown that

S. D. Fonov; R. H. Engler; C. Klein; S. V. Mihailov; V. E. Mosharov; V. P. Kulesh; V. N. Radchenko

1999-01-01

431

High pressure and high temperature apparatus  

DOEpatents

A design for high pressure/high temperature apparatus and reaction cell to achieve .about.30 GPa pressure in .about.1 cm volume and .about.100 GPa pressure in .about.1 mm volumes and 20-5000.degree. C. temperatures in a static regime. The device includes profiled anvils (28) action on a reaction cell (14, 16) containing the material (26) to be processed. The reaction cell includes a heater (18) surrounded by insulating layers and screens. Surrounding the anvils are cylindrical inserts and supporting rings (30-48) whose hardness increases towards the reaction cell. These volumes may be increased considerably if applications require it, making use of presses that have larger loading force capability, larger frames and using larger anvils.

Voronov, Oleg A.

2005-09-13

432

Pressure boosting system  

SciTech Connect

Airco Industrial Gases in Claymont, DE, increased production capacity by replacing its aging air-separation plant with a new facility. Transporting nitrogen gas to pipeline customers was a major energy user. Because critical safety blanketing and purging are primary uses, the plant must receive a reliable, uninterrupted supply of gas. Six reciprocating compressors, rated at a total of about 4,000 hp, boosted the gas pressure to 550 psig before it entered the pipeline. Airco investigated energy-saving alternatives for the new installation. Plant officials ruled out replacing six old compressors with identical new ones. The mechanical energy losses inherent in using six machines and the product loss from gas escaping through seals on the multiple machines were significant efficiency considerations. A single reciprocating compressor would have operated efficiently, but a six-stage compressor, large enough to process the volume of gas produced by the plant's air-separation unit, would have cost more than $1 million. Airco installed a combination centrifugal/reciprocating compressor to boost the nitrogen gas from 1.5 psig to 550 psig.

Hobson, R. (Airco Industrial Gases, Claymont, DE (United States))

1993-01-01

433

Advanced Pressure Boundary Materials  

SciTech Connect

Increasing the operating temperatures of fossil power plants is fundamental to improving thermal efficiencies and reducing undesirable emissions such as CO{sub 2}. One group of alloys with the potential to satisfy the conditions required of higher operating temperatures is the advanced ferritic steels such as ASTM Grade 91, 9Cr-2W, and 12Cr-2W. These are Cr-Mo steels containing 9-12 wt% Cr that have martensitic microstructures. Research aimed at increasing the operating temperature limits of the 9-12 wt% Cr steels and optimizing them for specific power plant applications has been actively pursued since the 1970's. As with all of the high strength martensitic steels, specifying upper temperature limits for tempering the alloys and heat treating weldments is a critical issue. To support this aspect of development, thermodynamic analysis was used to estimate how this critical temperature, the A{sub 1} in steel terminology, varies with alloy composition. The results from the thermodynamic analysis were presented to the Strength of Weldments subgroup of the ASME Boiler & Pressure Vessel Code and are being considered in establishing maximum postweld heat treatment temperatures. Experiments are also being planned to verify predictions. This is part of a CRADA project being done with Alstom Power, Inc.

Santella, Michael L [ORNL; Shingledecker, John P [ORNL

2007-01-01

434

Pressure-induced polymerization in substituted acetylenes  

SciTech Connect

A fundamental understanding of shock-induced chemical reactions in organics is still lacking and there are limited studies devoted to determining reaction mechanisms, evolution of bonding, and effect of functional group substitutions. The fast timescale of reactions occurring during shock compression create significant experimental challenges (diagnostics) to fully quantify the mechanisms involved. Static compression combined with temperature provides a complementary route to investigate the equilibrium phase space and metastable intermediates under extreme P-T conditions. In this study, we present our results from our ongoing high pressure in situ synchrotron x-ray diffraction experiments on substituted acetylenes: tert-butyl acetylene [TBA: (CH{sub 3}){sub 3}-C=CH] and ethynyl trimethylsilane [ETMS: (CH{sub 3}){sub 3}-SiC=CH]. We observed that the onset pressure of chemical reactions (at room temperature) in these compounds is higher under static compression (TBA: 12 GPa and ETMS: 17.6 GPa) when compared to shock input pressures (TBA: 6.1 GPa and ETMS: 6.6 GPa). At elevated temperatures, reactivity was observed to occur at pressures comparable to shock conditions. The products were polymeric in nature, recovered to ambient conditions with little degradation.

Chellappa, Raja S.; Dattelbaum, Dana M.; Sheffield, Stephen; Robbins, David (LANL)

2012-04-10

435

An experimental study of transonic flow about a supercritical airfoil. Static pressure and drag data obtained from tests of a supercritical airfoil and an NACA 0012 airfoil at transonic speeds, supplement  

NASA Technical Reports Server (NTRS)

Surface static-pressure and drag data obtained from tests of two slightly modified versions of the original NASA Whitcomb airfoil and a model of the NACA 0012 airfoil section are presented. Data for the supercritical airfoil were obtained for a free-stream Mach number range of 0.5 to 0.9, and a chord Reynolds number range of 2 x 10 to the 6th power to 4 x 10 to the 6th power. The NACA 0012 airfoil was tested at a constant chord Reynolds number of 2 x 10 to the 6th power and a free-stream Mach number range of 0.6 to 0.8.

Spaid, F. W.; Dahlin, J. A.; Roos, F. W.; Stivers, L. S., Jr.

1983-01-01

436

Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 2: Laser velocimeter data, static pressures and shadowgraph photos  

NASA Technical Reports Server (NTRS)

Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Mean velocity and turbulence velocity measurements of 25 selected flow conditions were performed employing a laser Doppler velocimeter. Static pressure measurements were made to define the actual convergence-divergence condition. Test point definition, tabulation of aerodynamic test conditions, velocity histograms, and shadowgraph photographs are presented. Flow visualization through shadowgraph photography can contribute to the development of an analytical prediction model for shock noise from coannular plug nozzles.

Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

1984-01-01

437

Using cavitation to measure statistics of low-pressure events in large-Reynolds-number turbulence  

E-print Network

is reduced until large negative pressure fluctuations trigger cavitation. Cavitation is detected via light. In this paper, we report studies using cavitation to detect large negative pressure fluctuations in a turbulent bubbles and the hydro- static pressure is adjusted so that negative pressure fluctua- tions go below

La Porta, Arthur

438

Particle pressures in fluidized beds  

SciTech Connect

This is an experimental project to make detailed measurements of the particle pressures generated in fluidized beds. The focus lies in two principle areas: (1) the particle pressure distribution around single bubbles rising in a two-dimensional gas-fluidized bed and (2) the particle pressures measured in liquid-fluidized beds. This first year has largely been to constructing the experiments The design of the particle pressure probe has been improved and tested. A two-dimensional gas-fluidized bed has been constructed in order to measure the particle pressure generated around injected bubbles. The probe is also being adapted to work in a liquid fluidized bed. Finally, a two-dimensional liquid fluidized bed is also under construction. Preliminary measurements show that the majority of the particle pressures are generated in the wake of a bubble. However, the particle pressures generated in the liquid bed appear to be extremely small. Finally, while not directly associated with the particle pressure studies, some NERSC supercomputer time was granted alongside this project. This is being used to make large scale computer simulation of the flow of granular materials in hoppers.

Campbell, C.S.; Rahman, K.; Hu, X.; Jin, C.; Potapov, A.V.

1992-01-01

439

Pressure Reducer for Coal Gasifiers  

NASA Technical Reports Server (NTRS)

Quasi-porous-plug pressure reducer is designed for gases containing abrasive particles. Gas used to generate high pressure steam to drive electric power generators. In giving up heat to steam, gas drops in temperature. Device used for coal gasification plants.

Kendall, James M., Sr.

1983-01-01

440

Possible Pressure Effect for Superconductors  

E-print Network

We make an estimate of the possible range of $\\Delta T_c$ induced by high-pressure effects in post-metallic superconductors by using the theory of {\\it extended irreversible/reversible thermodynamics} and Pippard's length scale. The relationship between the increment of the superconducting temperature and the increase of the pressure is parabolic.

A. Kwang-Hua Chu

2005-08-30

441

High pressure gas transmission compressor  

Microsoft Academic Search

A high-pressure gas transmission compressor is described for admitting gas at a suction inlet and discharging gas at increased pressure from a discharge outlet comprising: a block-like compressor housing having a substantially horizontal elongated smooth bore cylindrical cylinder extending longitudinally therethrough; cylindrical piston slidably received for reciprocating movement within the cylinder; a pair of vertically extending spaced valve housings positioned

Deminski

1987-01-01

442

Electrokinetically pumped high pressure sprays  

DOEpatents

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

Schoeniger, Joseph S. (Oakland, CA); Paul, Phillip H. (Livermore, CA); Schoeniger, Luke (Pittsford, NY)

2002-01-01

443

High blood pressure and diet  

MedlinePLUS

... diet is a proven way to help control high blood pressure . These changes can also help you lose weight ... meal plan. Ask your doctor what your blood pressure target is. ... limit foods that are high in saturated fat (more than 20% of the ...

444

Electrokinetically pumped high pressure sprays  

DOEpatents

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

Schoeniger, Joseph S. (Oakland, CA); Paul, Phillip H. (Livermore, CA); Schoeniger, Luke (Pittsford, NY)

2005-11-01

445

Microwave Atmospheric-Pressure Sensor  

NASA Technical Reports Server (NTRS)

Report describes tests of microwave pressure sounder (MPS) for use in satellite measurements of atmospheric pressure. MPS is multifrequency radar operating between 25 and 80 GHz. Determines signal absorption over vertical path through atmosphere by measuring strength of echoes from ocean surface. MPS operates with cloud cover, and suitable for use on current meteorological satellites.

Flower, D. A.; Peckham, G. E.; Bradford, W. J.

1986-01-01

446

Paediatric blood pressure and anaesthesia.  

PubMed

One percent of children have appreciably and consistently raised arterial blood pressure. A 7-year-old girl admitted for routine tonsillectomy, had unrecognised hypertension which put her at increased risk. Should anaesthetic practice take more note of paediatric blood pressures? PMID:2035786

Mather, C M

1991-05-01

447

JAMA Patient Page: Pressure Ulcers  

MedlinePLUS

... Lower Back Hip Sacrum Sacrum Between Knees and Ankles Ear Hip Elbow Elbow Heel Heel S K I N C O N D I T I O N S The Journal of the American Medical Association JAMA PATIENT PAGE Pressure Ulcers A pressure ulcer is an injury to the ...

448

Pressure sensitive paint flight test  

Microsoft Academic Search

Measurements based on pressure-sensitive paint were successfully demonstrated during flight test. A Mk76 practice bomb was painted with pressure sensitive paint and mounted on an A-6 attack jet. The PSP on the bomb was illuminated with a battery operated strobe and the luminescence was detected using film and a 35 mm camera. The hardware adapted to make PSP measurements for

S. W. Houck; R. G. Hepp; M. J. Morris; M. E. Benne

1996-01-01

449

Economics of Steam Pressure Reduction  

E-print Network

and disadvantages associated with the decreased steam pressure 3. The economics of steam pressure reduction. Appropriate visual aids will be utilized as part of the discussion. ',: 566 I ESL-IE-85-05-112 Proceedings from the Seventh National Industrial...

Sylva, D. M.

450

Micro-diaphragm pressure sensor  

Microsoft Academic Search

A micro-diaphragm pressure sensor with silicon nitride diaphragm of 80 µm × 80 µm was fabricated by applying micromachining technique. The main feature is that it is a complete planar type pressure sensor formed by single-side processing solely on the top surface of

S. Sugiyama; T. Suzuki; K. Kawahata; K. Shimaoka; M. Takigawa; I. Igarashi

1986-01-01

451

Magnetospheric equilibrium with anisotropic pressure  

SciTech Connect

Self-consistent magnetospheric equilibrium with anisotropic pressure is obtained by employing an iterative metric method for solving the inverse equilibrium equation in an optimal flux coordinate system. A method of determining plasma parallel and perpendicular pressures from either analytic particle distribution or particle distribution measured along the satellite's path is presented. The numerical results of axisymmetric magnetospheric equilibrium including the effects of finite beta, pressure anisotropy, and boundary conditions are presented for a bi-Maxwellian particle distribution. For the isotropic pressure cases, the finite beta effect produces an outward expansion of the constant magnetic flux surfaces in relation to the dipole field lines, and along the magnetic field the toroidal ring current is maximum at the magnetic equator. The effect of pressure anisotropy is found to further expand the flux surfaces outward. Along the magnetic field lines the westward ring current can be peak away from the equator due to an eastward current contribution resulting from pressure anisotropy. As pressure anisotropy increases, the peak westward current can become more singular. The outer boundary flux surface has significant effect on the magnetospheric equilibrium. For the outer flux boundary resembling dayside compressed flux surface due to solar wind pressure, the deformation of the magnetic field can be quite different from that for the outer flux boundary resembling the tail-like surface. 23 refs., 17 figs.

Cheng, C.Z.

1991-07-01

452

OVERBURDEN PRESSURE AFFECTS FRACTURE APERTURE  

E-print Network

.S. Department of Energy-sponsored pilot project "Investigation of Efficiency Improvements During CO2 Injection investigated permeability changes at different overburden conditions. The reduction in permeability in permeability with pressures at ranges of 0 to 15,000 psig and found that overburden pressure caused a reduction

Schechter, David S.

453

Surveillance of WWER-440C reactor pressure vessels  

SciTech Connect

In Czechoslovakia there are six units of Water-Water Power Reactor (WWER)-440 C type reactors (pressurized water reactor [PWR] type) incorporated with pressure vessel surveillance specimens. These sets of specimens are kept for carrying out static tensile testing, impact notch toughness testing, and static fracture toughness testing, and are supplemented by necessary sets of neutron flux monitors. Results of mechanical testing of these specimens evaluated after one to five years of reactor operation are summarized and discussed with respect to the effect of individual heats and welding joints, radiation embrittlement laws, and lead factor and pressure vessel lifetime assessment.

Brumovsky, M. [Nuclear Research Inst., Rez (Czechoslovakia). Div. of Integrity; Pav, T. [Nuclear Research Inst., Rez (Czechoslovakia). Dept. of Nuclear Materials

1993-12-01

454

Stability and breakdown of Ca{sup 13}CO{sub 3} melt associated with formation of {sup 13}C-diamond in static high pressure experiments up to 43 GPa and 3900 K  

SciTech Connect

Melting of calcium carbonate Ca{sup 13}CO{sub 3}, stability of the melt and its decomposition were studied in static high pressure experiments at pressures of 11-43 GPa and temperatures of 1600-3900 K using diamond anvil cell technique with laser heating. We observed formation of {sup 13}C-graphite (below 16 GPa) and {sup 13}C-diamond (between 16 and 43 GPa) on decomposition of the Ca{sup 13}CO{sub 3} melt at temperatures above 3400 K. At temperatures below 3400 K congruent melting of calcium carbonate was confirmed. The experimental results were applied to construction of the phase diagram of CaCO{sub 3} up to 43 GPa and 3900 K focusing at the melting curve of calcium carbonate and the decomposition phase boundary of CaCO{sub 3} melt. - Graphical abstract: Highlights: Black-Right-Pointing-Pointer Phase states of CaCO{sub 3} were studied at P=11-43 GPa and T=1600-3900 K. Black-Right-Pointing-Pointer {sup 13}C-diamond easily crystallizes in carbonate-carbon (Ca{sup 13}CO{sub 3-}{sup 13}C-graphite) melt-solutions. Black-Right-Pointing-Pointer Ca-carbonate melts congruently that was observed in experiments in DAC with laser heating. Black-Right-Pointing-Pointer Decomposition of CaCO{sub 3} melt, indicated by formation of graphite and/or diamond. Black-Right-Pointing-Pointer Decomposition of CaCO{sub 3} was observed at temperatures above 3400 K in the pressure interval studied.

Spivak, A.V., E-mail: spivak@iem.ac.ru [Institute of Experimental Mineralogy of the Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Litvin, Yu.A. [Institute of Experimental Mineralogy of the Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation); Ovsyannikov, S.V. [Bayerishes Geoinstitut, University of Bayreuth, Bayreuth (Germany); Dubrovinskaia, N.A. [Material Physics and Technology at Extreme Conditions, Laboratory of Crystallography, University of Bayreuth, Bayreuth (Germany); Dubrovinsky, L.S. [Bayerishes Geoinstitut, University of Bayreuth, Bayreuth (Germany)

2012-07-15

455

Pressure rig for repetitive casting  

NASA Technical Reports Server (NTRS)

The invention is a pressure rig for repetitive casting of metal. The pressure rig performs like a piston for feeding molten metal into a mold. Pressure is applied to an expandable rubber diaphragm which expands like a balloon to force the metal into the mold. A ceramic cavity which holds molten metal is lined with blanket-type insulating material, necessitating only a relining for subsequent use and eliminating the lengthy cavity preparation inherent in previous rigs. In addition, the expandable rubber diaphragm is protected by the insulating material thereby decreasing its vulnerability to heat damage. As a result of the improved design the life expectancy of the pressure rig contemplated by the present invention is more than doubled. Moreover, the improved heat protection has allowed the casting of brass and other alloys with higher melting temperatures than possible in the conventional pressure rigs.

Vasquez, Peter (inventor); Hutto, William R. (inventor); Philips, Albert R. (inventor)

1989-01-01

456

Balanced pressure gerotor fuel pump  

DOEpatents

A gerotor pump for pressurizing gasoline fuel is capable of developing pressures up to 2.0 MPa with good mechanical and volumetric efficiency and satisfying the durability requirements for an automotive fuel pump. The pump has been designed with optimized clearances and by including features that promote the formation of lubricating films of pressurized fuel. Features of the improved pump include the use of a shadow port in the side plate opposite the outlet port to promote balancing of high fuel pressures on the opposite sides of the rotors. Inner and outer rotors have predetermined side clearances with the clearances of the outer rotor being greater than those of the inner rotor in order to promote fuel pressure balance on the sides of the outer rotor. Support of the inner rotor and a drive shaft on a single bushing with bearing sleeves maintains concentricity. Additional features are disclosed.

Raney, Michael Raymond; Maier, Eugen

2004-08-03

457

Pressure difference receiving ears.  

PubMed

Directional sound receivers are useful for locating sound sources, and they can also partly compensate for the signal degradations caused by noise and reverberations. Ears may become inherently directional if sound can reach both surfaces of the eardrum. Attempts to understand the physics of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface of the eardrum. The mere existence of sound transmission to the inner surface does not ensure a useful directional hearing, since a proper amplitude and phase relationship must exist between the sounds acting on the two surfaces of the eardrum. The gain of the sound pathway must match the amplitude and phase of the sounds at the outer surfaces of the eardrums, which are determined by diffraction and by the arrival time of the sound, that is by the size and shape of the animal and by the frequency of sound. Many users of hearing aids do not obtain a satisfactory improvement of their ability to localize sound sources. We suggest that some of the mechanisms of directional hearing evolved in Nature may serve as inspiration for technical improvements. PMID:18364558

Michelsen, Axel; Larsen, Ole Naesbye

2008-03-01

458

30 CFR 18.98 - Enclosures, joints, and fastenings; pressure testing.  

Code of Federal Regulations, 2012 CFR

...field testing of explosion-proof enclosures shall be conducted by determining: (1) Leak performance with a peak dynamic or static pressure of 150 pounds per square inch (gage); or (2) A pressure rise and rate of decay consistent with...

2012-07-01

459

30 CFR 18.98 - Enclosures, joints, and fastenings; pressure testing.  

Code of Federal Regulations, 2014 CFR

...field testing of explosion-proof enclosures shall be conducted by determining: (1) Leak performance with a peak dynamic or static pressure of 150 pounds per square inch (gage); or (2) A pressure rise and rate of decay consistent with...

2014-07-01

460

Organic electronics based pressure sensor towards intracranial pressure monitoring  

NASA Astrophysics Data System (ADS)

The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

Rai, Pratyush; Varadan, Vijay K.

2010-04-01

461

Dynamic-pressure measurements using an electronically scanned pressure module  

NASA Technical Reports Server (NTRS)

Frequency response was measured for different lengths and diameters of tubing between a sinusoidal pressure source and a pressure sensing module from an electronically scanned pressure measuring system. Measurements were made for straight runs of both steel and vinyl tubing. For steel tubing, measured results are compared with results calculated by using equations developed by Tijdeman and Bergh. Measurements were also made with a bend in the vinyl tubing at the module. In addition, measurements were made with two coils placed in the tubing near the middle of the run.

Chapin, W. G.

1983-01-01

462

MOEMS pressure sensors for propulsion applications  

NASA Astrophysics Data System (ADS)

Pressure sensors utilizing MEMS technology for fabrication of the sensing element, interrogation by fiber optics, and which are suitable for propulsion applications are described. Devices utilizing micro-opto-electro-mechanical systems (MOEMS) technology are often better suited for harsh environments than electrically interrogated MEMS devices, so with sturdy packaging these optical devices may be useful to many propulsion applications. MOEMS pressure sensors can also be incorporated into arrays for detailed spatial characterization along with inherent high speed temporal characterization. Such characterization is expected to be very useful for propulsion systems. This presentation will first review optical-MEMS pressure sensor configurations. We will then concentrate on configurations most suitable for high speed applications in harsh environments. Examples of experimental results for static pressure test as well as for dynamic pressure test carried out in a shock tube demonstrating good linearity, sensitivity and time response will then be presented. Hybrid and monolithic array configurations will be presented. A discussion of the use of wavelength division multiplexing for efficient accessing of array elements will also be included.

Boyd, Joseph T.; Dasgupta, Samhita; Jackson, Howard E.

2000-08-01

463

Quasi-dynamic pressure and temperature  

SciTech Connect

The phase transformation of {beta}-HMX (< 0.5% RDX) to the {delta} phase has been studied for over twenty years and more recently with an optically sensitive second harmonic generation technique. Shock studies of the plastic binder composites of HMX have indicated that the transition is perhaps irreversible, a result that concurs with the static pressure results published by F. Goetz et al. [l] in 1978. However the stability field favors the {beta} polymorph over {delta} as pressure is increased (up to 5.4 GPa) along any sensible isotherm. In this experiment strict control of pressure and temperature is maintained while x-ray and optical diagnostics are applied to monitor the conformational dynamics of HMX. Unlike the temperature induced {beta} -> {delta} transition, the pressure induced is heterogeneous in nature. The room pressure and temperature {delta} -> {beta} transition is not immediate although it seems to occur over tens of hours. Transition points and kinetics are path dependent and so this paper describes our work in progress.

Zaug, J M, Farber, D L; Blosch, L L; Craig, I M; Hansen, D W; Aracne-Ruddle, C M; Shuh, D K

1998-08-26

464

In-shoe plantar pressure measurement and analysis system based on fabric pressure sensing array.  

PubMed

Spatial and temporal plantar pressure distributions are important and useful measures in footwear evaluation, athletic training, clinical gait analysis, and pathology foot diagnosis. However, present plantar pressure measurement and analysis systems are more or less uncomfortable to wear and expensive. This paper presents an in-shoe plantar pressure measurement and analysis system based on a textile fabric sensor array, which is soft, light, and has a high-pressure sensitivity and a long service life. The sensors are connected with a soft polymeric board through conductive yarns and integrated into an insole. A stable data acquisition system interfaces with the insole, wirelessly transmits the acquired data to remote receiver through Bluetooth path. Three configuration modes are incorporated to gain connection with desktop, laptop, or smart phone, which can be configured to comfortably work in research laboratories, clinics, sport ground, and other outdoor environments. A real-time display and analysis software is presented to calculate parameters such as mean pressure, peak pressure, center of pressure (COP), and shift speed of COP. Experimental results show that this system has stable performance in both static and dynamic measurements. PMID:20071266

Shu, Lin; Hua, Tao; Wang, Yangyong; Qiao Li, Qiao; Feng, David Dagan; Tao, Xiaoming

2010-05-01

465

Pressurized lunar rover  

NASA Technical Reports Server (NTRS)

The pressurized lunar rover (PLR) consists of a 7 m long, 3 m diameter cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, directional lighting, cameras, and equipment for exploratory experiments. The PLR shell is constructed of a layered carbon-fiber/foam composite. The rover has six 1.5 m diameter wheels on the main body and two 1.5 m diameter wheels on the trailer. The wheels are constructed of composites and flex to increase traction and shock absorption. The wheels are each attached to a double A-arm aluminum suspension, which allows each wheel 1 m of vertical motion. In conjunction with a 0.75 m ground clearance, the suspension aids the rover in negotiating the uneven lunar terrain. The 15 N-m torque brushless electric motors are mounted with harmonic drive units inside each of the wheels. The rover is steered by electrically varying the speeds of the wheels on either side of the rover. The PLR trailer contains a radiosotope thermoelectric generator providing 6.7 kW. A secondary back-up energy storage system for short-term high-power needs is provided by a bank of batteries. The trailer can be detached to facilitate docking of the main body with the lunar base via an airlock located in the rear of the PLR. The airlock is also used for EVA operation during missions. Life support is a partly regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center. The water absorbs any damaging radiation, allowing the command center to be used as a safe haven during solar flares. Guidance, navigation, and control are supplied by a strapdown inertial measurement unit that works with the on-board computer. Star mappers provide periodic error correction. The PLR is capable of voice, video, and data transmission. It is equipped with two 5 W X-band transponder, allowing simultaneous transmission and reception. An S-band transponder is used to communicate with the crew during EVA. The PLR has a total mass of 6197 kg. It has a nominal speed of 10 km/hr and a top speed of 18 km/hr. The rover is capable of towing 3 metric tons (in addition to the RTG trailer).

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; Mcclure, Kerry; Zeinali, Mazyar

1992-01-01

466

Serotonin and Blood Pressure Regulation  

PubMed Central

5-Hydroxytryptamine (5-HT; serotonin) was discovered more than 60 years ago as a substance isolated from blood. The neural effects of 5-HT have been well investigated and understood, thanks in part to the pharmacological tools available to dissect the serotonergic system and the development of the frequently prescribed selective serotonin-reuptake inhibitors. By contrast, our understanding of the role of 5-HT in the control and modification of blood pressure pales in comparison. Here we focus on the role of 5-HT in systemic blood pressure control. This review provides an in-depth study of the function and pharmacology of 5-HT in those tissues that can modify blood pressure (blood, vasculature, heart, adrenal gland, kidney, brain), with a focus on the autonomic nervous system that includes mechanisms of action and pharmacology of 5-HT within each system. We compare the change in blood pressure produced in different species by short- and long-term administration of 5-HT or selective serotonin receptor agonists. To further our understanding of the mechanisms through which 5-HT modifies blood pressure, we also describe the blood pressure effects of commonly used drugs that modify the actions of 5-HT. The pharmacology and physiological actions of 5-HT in modifying blood pressure are important, given its involvement in circulatory shock, orthostatic hypotension, serotonin syndrome and hypertension. PMID:22407614

Morrison, Shaun F.; Davis, Robert Patrick; Barman, Susan M.

2012-01-01

467

Blood Pressure Control in Diabetes  

PubMed Central

OBJECTIVE Despite widespread dissemination of target values, achieving a blood pressure of <130/80 mmHg is challenging for many individuals with diabetes. The purpose of the present study was to examine temporal trends in blood pressure control in hypertensive individuals with diabetes as well as the potential for race, sex, and geographic disparities. RESEARCH DESIGN AND METHODS We analyzed baseline data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, a national, population-based, longitudinal cohort study of 30,228 adults (58% European American and 42% African American), examining the causes of excess stroke mortality in the southeastern U.S. We calculated mean blood pressure and blood pressure control rates (proportion with blood pressure <130/80 mmHg) for 5,217 hypertensive diabetic participants by year of enrollment (2003–2007) using multivariable logistic regression models. RESULTS Only 43 and 30% of European American and African American diabetic hypertensive participants, respectively, demonstrated a target blood pressure of <130/80 mmHg (P < 0.001). However, a temporal trend of improved control was evident; the odds of having a blood pressure <130/80 mmHg among diabetic hypertensive participants of both races enrolled in 2007 (as compared with those enrolled in 2003) were ?50% greater (P < 0.001) in multivariate models. CONCLUSIONS These data suggest temporal improvements in blood pressure control in diabetes that may reflect broad dissemination of tighter blood pressure control targets and improving medication access. However, control rates remain low, and significant racial disparities persist among African Americans that may contribute to an increased risk for premature cardiovascular disease. PMID:20097785

Cummings, Doyle M.; Doherty, Lisa; Howard, George; Howard, Virginia J.; Safford, Monika M.; Prince, Valerie; Kissela, Brett; Lackland, Daniel T.

2010-01-01

468

Pressure Systems Energy Release Protection (Gas Pressurized Systems)  

NASA Technical Reports Server (NTRS)

A survey of studies into hazards associated with closed or pressurized system rupture and preliminary guidelines for the performance design of primary, secondary, and protective receptors of these hazards are provided. The hazards discussed in the survey are: blast, fragments, ground motion, heat radiation, biological, and chemical. Performance guidelines for receptors are limited to pressurized systems that contain inert gas. The performance guidelines for protection against the remaining unaddressed degenerative hazards are to be covered in another study.

Brown, S. J. (editor)

1986-01-01

469

Micro Electro-Mechanical System (MEMS) Pressure Sensor for Footwear  

DOEpatents

Footwear comprises a sole and a plurality of sealed cavities contained within the sole. The sealed cavities can be incorporated as deformable containers within an elastic medium, comprising the sole. A plurality of micro electro-mechanical system (MEMS) pressure sensors are respectively contained within the sealed cavity plurality, and can be adapted to measure static and dynamic pressure within each of the sealed cavities. The pressure measurements can provide information relating to the contact pressure distribution between the sole of the footwear and the wearer's environment.

Kholwadwala, Deepesh K. (Albuquerque, NM); Rohrer, Brandon R. (Albuquerque, NM); Spletzer, Barry L. (Albuquerque, NM); Galambos, Paul C. (Albuquerque, NM); Wheeler, Jason W. (Albuquerque, NM); Hobart, Clinton G. (Albuquerque, NM); Givler, Richard C. (Albuquerque, NM)

2008-09-23

470

Graphite filament wound pressure vessels  

NASA Technical Reports Server (NTRS)

Filament wound NOL rings, 4-inch and 8-inch diameter closed-end vessels involving three epoxy resin systems and three graphite fibers were tested to develop property data and fabrication technology for filament wound graphite/epoxy pressure vessels. Vessels were subjected to single-cycle burst tests at room temperature. Manufacturing parameters were established for tooling, winding, and curing that resulted in the development of a pressure/vessel performance factor (pressure x volume/weight) or more than 900,000 in. for an oblate spheroid specimen.

Feldman, A.; Damico, J. J.

1972-01-01

471

Electrokinetic high pressure hydraulic system  

DOEpatents

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA)

2000-01-01

472

High pressure pulsed capillary viscometry  

NASA Technical Reports Server (NTRS)

An analytical and test program was conducted in order to establish the feasibility of a multichamber pulsed-capillary viscometer. The initial design incorporated a piston, ram, and seals which produced measured pulses up to 30,000 psi in the closed chamber system. Pressure pulses from one to ten milliseconds were investigated in a system volume of 1 cuin. Four test fluids: a MIL-L-7808, a 5P4E polyphenyl ether, a MIL-L-23699A, and a synthetic hydrocarbon were examined in the test pressure assembly. The pressure-viscosity coefficient and viscosity delay time were determined for the MIL-L-7808 lubricant tested.

Smith, R. L.; Walowitt, J. A.; Pan, C. H. T.

1972-01-01

473

Lower body negative pressure device  

NASA Technical Reports Server (NTRS)

The Lower Body Negative Pressure Device was used, in the space environment, to stress the astronaut's cardiovascular system, to determine the extent and time course of his cardiovascular deconditioning and to determine whether in-flight data from experiment M092, Lower Body Negative Pressure, would be useful in predicting postflight status of orthostatic tolerance. The lower portion of the subject's body was enclosed in this device for the purpose of applying regulated and controlled negative pressure. A description is given of the device.

Nolte, R. W.

1977-01-01

474

Arterial pulse wave pressure transducer  

NASA Technical Reports Server (NTRS)

An arterial pulse wave pressure transducer is introduced. The transducer is comprised of a fluid filled cavity having a flexible membrane disposed over the cavity and adapted to be placed on the skin over an artery. An arterial pulse wave creates pressure pulses in the fluid which are transduced, by a pressure sensitive transistor in direct contact with the fluid, into an electric signal. The electrical signal is representative of the pulse waves and can be recorded so as to monitor changes in the elasticity of the arterial walls.

Kim, C.; Gorelick, D.; Chen, W. (inventors)

1974-01-01

475

Gas Hydrate and Pore Pressure  

NASA Astrophysics Data System (ADS)

Many efforts have been devoted to quantify excess pore pressures related to gas hydrate dissociation in marine sediments below the BSR using several approaches. Dissociation of gas hydrates in proximity of the BSR, in response to a change in the physical environment (i.e., temperature and/or pressure regime), can liberate excess gas incrising the local pore fluid pressure in the sediment, so decreasing the effective normal stress. So, gas hydrate dissociation may lead to excess pore pressure resulting in sediment deformation or failure, such as submarine landslides, sediment slumping, pockmarks and mud volcanoes, soft-sediment deformation and giant hummocks. Moreover, excess pore pressure may be the result of gas hydrate dissociation due to continuous sedimentation, tectonic uplift, sea level fall, heating or inhibitor injection. In order to detect the presence of the overpressure below the BSR, we propose two approachs. The fist approach models the BSR depth versus pore pressure; in fact, if the free gas below the BSR is in overpressure condition, the base of the gas hydrate stability is deeper with respect to the hydrostatic case. This effect causes a discrepancy between seismic and theoretical BSR depths. The second approach models the velocities versus gas hydrate and free gas concentrations and pore pressure, considering the approximation of the Biot theory in case of low frequency, i.e. seismic frequency. Knowing the P and S seismic velocity from seismic data analysis, it is possibile to jointly estimate the gas hydrate and free gas concentrations and the pore pressure regime. Alternatively, if the S-wave velocity is not availbale (due to lack of OBS/OBC data), an AVO analysis can be performed in order to extract information about Poisson ratio. Our modeling suggests that the areas characterized by shallow waters (i.e., areas in which human infrastructures, such as pipelines, are present) are significantly affected by the presence of overpressure condition. Moreover, the knoweledge of seismic velocities can be considered an powerful tool to detect the overpressure in case that the pore pressure is equal to the hydrostatic pressure plus the 50% of the difference between the lithostatic and the hydrostatic pressure. In conclusions, an accurate analysis of the BSR nature and the pore pressure are required to improve the reliability of the gas-phase estimation for different target, such as gas hydrate and free gas exploitations and environmental studies.

Tinivella, Umberta; Giustiniani, Michela

2014-05-01

476

PRESSURE DISTRIBUTION AND ERGONOMICS SHAPE CONCEPTUALIZATION  

Microsoft Academic Search

The pressure distribution was measured for subjects sitting on a flat, hard and horizontal support. The pressure data were analyzed for the seat force, the mag- nitude of the contact area, the average pressure in the contact area, the maximum pres- sure, and the pressure gradient. Using multiple regression relationships were found between these pressure distribution parameters, the body characteristics

Niels C. C. M. Moes

2000-01-01

477

Pressurizing System for Observation of Marine Zooplankton  

Microsoft Academic Search

Planktonic animals occur from the surface to the sea bottom and they are exposed to hydrostatic pressure throughout their lifetime. A hydrostatic pressure apparatus integrating ideas of past apparatuses was developed to investigate effects of hydrostatic pressure on marine zooplankton. The pressure apparatus system is composed of a peristaltic pump, a pressure chamber, a specimen holder which is placed in

T. Yoshiki; A. Shimizu; T. Toda

2007-01-01

478

High pressure equipment for food processing  

Microsoft Academic Search

Processing food with pressure improves the quality and shelf life of the product. The pressure required is normally 600 to 900 MPa (approximately 6000 to 9000 atm). Equipment for high pressure food processing is available today from ABB Pressure Systems AB. The plant can have a through-put of 300 to 6000 litres per hour at 600 MPa pressure depending on

Jan Westerlund

1994-01-01

479

MEASURING VARIATIONS IN TEMPERATURE AND PRESSURE  

E-print Network

MEASURING VARIATIONS IN TEMPERATURE AND PRESSURE A Balloon Experiment by: John Bertinetti and Chip Keating #12;Purpose of the Balloon Experiment Pressure and temperature vary with altitude: pressure;Pressure: P vs. h #12;Temperature: Exponential Curve Fit Note: this is a curve, not a line #12;Our pressure

California at Santa Cruz, University of

480

Hydrogen at extreme pressures (Review Article)  

NASA Astrophysics Data System (ADS)

Here we review recent experimental and theoretical studies of hydrogen approaching metallization regime. Experimental techniques have made great advances over the last several years making it possible to reach previously unachievable conditions of pressure and temperature and to probe hydrogen at these conditions. Theoretical methods have also greatly improved; exemplified through the prediction of new structural and ordered quantum states. Recently, a new solid phase of hydrogen, phase IV, has been discovered in a high-pressure high-temperature domain. This phase is quite unusual structurally and chemically as it represents an intermediate state between common molecular and monatomic configurations. Moreover, it shows remarkable fluxional characteristics related to its quantum nature, which makes it unique among the solid phases, even of light elements. However, phase IV shows the presence of a band gap and exhibits distinct phonon and libron characteristic of classical solids. The quantum behavior of hydrogen in the limit of very high pressure remains an open question. Prospects of studying hydrogen at more extreme conditions by static and combined static-dynamic methods are also presented.

Goncharov, Alexander F.; Howie, Ross T.; Gregoryanz, Eugene

2013-05-01

481

Pressure-actuated joint system  

NASA Technical Reports Server (NTRS)

A pressure vessel is provided that includes first and second case segments mated with one another. First and second annular rubber layers are disposed inboard of the first and second case segments, respectively. The second annular rubber layer has a slot extending from the radial inner surface across a portion of its thickness to define a main body portion and a flexible portion. The flexible portion has an interfacing surface portion abutting against an interfacing surface portion of the first annular rubber layer to follow movement of the first annular rubber layer during operation of the pressure vessel. The slot receives pressurized gas and establishes a pressure-actuated joint between the interfacing surface portions. At least one of the interfacing surface portions has a plurality of enclosed and sealed recesses formed therein.

McGuire, John R. (Inventor)

2004-01-01

482

Pressure compensated flow control valve  

DOEpatents

The invention is an air flow control valve which is capable of maintaining a constant flow at the outlet despite changes in the inlet or outlet pressure. The device consists of a shell assembly with an inlet chamber and outlet chamber separated by a separation plate. The chambers are connected by an orifice. Also located within the inlet chamber is a port controller assembly. The port controller assembly consists of a differential pressure plate and port cap affixed thereon. The cap is able to slide in and out of the orifice separating the inlet and outlet chambers. When the pressure differential is sufficient, the differential pressure plate rises or falls to maintain a constant air flow. Movement of the port controller assembly does not require the use of seals, diaphragms, tight tolerances, bushings, bearings, hinges, guides, or lubricants.

Minteer, Daniel J. (West Richland, WA)

1999-01-01

483

High pressure synthesis gas fermentation  

SciTech Connect

The construction of the high pressure gas phase fermentation system has been completed. Photographs of the various components of the system are presented, along with an operating procedure for the equipment.

Not Available

1992-01-01

484

Self-Calibrating Pressure Transducer  

NASA Technical Reports Server (NTRS)

A self-calibrating pressure transducer is disclosed. The device uses an embedded zirconia membrane which pumps a determined quantity of oxygen into the device. The associated pressure can be determined, and thus, the transducer pressure readings can be calibrated. The zirconia membrane obtains oxygen .from the surrounding environment when possible. Otherwise, an oxygen reservoir or other source is utilized. In another embodiment, a reversible fuel cell assembly is used to pump oxygen and hydrogen into the system. Since a known amount of gas is pumped across the cell, the pressure produced can be determined, and thus, the device can be calibrated. An isolation valve system is used to allow the device to be calibrated in situ. Calibration is optionally automated so that calibration can be continuously monitored. The device is preferably a fully integrated MEMS device. Since the device can be calibrated without removing it from the process, reductions in costs and down time are realized.

Lueck, Dale E. (Inventor)

2006-01-01

485

Intraocular pressure reduction and regulation  

NASA Technical Reports Server (NTRS)

System designed to reduce intraocular pressure hydraulically to any level desired by physician over set time and in controlled manner has number of uses in ophthalmology. Device may be most immediately useful in treatment of glaucoma.

Baehr, E. F.; Mcgannon, W. J.

1979-01-01

486

Early morning blood pressure surge.  

PubMed

Alterations in the circadian rhythm of blood pressure, whether a loss of the nighttime dip or an exaggeration of the early morning increase that occurs upon rising, indicate increased cardiovascular risk. Estimates of the magnitude of the blood pressure surge on rising vary depending on technique and population, but it is usually around 10-30 mm Hg systolic and 7-23 mm Hg diastolic. The magnitude of the surge increases with age, alcohol consumption, and smoking and is greater in whites. Blood pressure variations and morning plasma aldosterone are closely correlated. A high morning surge is linked to increased target organ damage as well as strokes and other cardiovascular complications. Therapeutic options exist to reduce the magnitude of the morning blood pressure surge-notably, the use of drugs with a long duration of action, the use of medications that specifically antagonize the morning surge (such as alpha blockers), and the administration of drugs upon awakening but before rising. PMID:16896274

Gosse, Philippe; Schumacher, Helmut

2006-08-01

487

Electrokinetic high pressure hydraulic system  

DOEpatents

An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based systems. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (Microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

Paul, Phillip H. (Livermore, CA); Rakestraw, David J. (Fremont, CA); Arnold, Don W. (Livermore, CA); Hencken, Kenneth R. (Pleasanton, CA); Schoeniger, Joseph S. (Oakland, CA); Neyer, David W. (Castro Valley, CA)

2001-01-01

488

Electrokinetic high pressure hydraulic system  

DOEpatents

An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based system. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

Paul, Phillip H.; Rakestraw, David J.; Arnold, Don W.; Hencken, Kenneth R.; Schoeniger, Joseph S.; Neyer, David W.

2003-06-03

489

Potassium and High Blood Pressure  

MedlinePLUS

A diet that includes natural sources of potassium is important in controlling blood pressure because potassium lessens the effects of sodium. The recommended daily intake of potassium for an average adult ...

490

High-pressure gas hydrates   

E-print Network

pressures. Clathrate hydrates have been extensively studied because they occur widely in nature, have important industrial applications, and provide insight into water-guest hydrophobic interactions. Until recently, the expectation-based on calculations...

Loveday, J. S.; Nelmes, R. J.

491

Weather Stations: Temperature and Pressure  

NSDL National Science Digital Library

In this activity, learners discover the relationship between temperature and pressure in the lower atmospheres of Jupiter and Earth. Learners chart the increasing temperature as they add pressure to a 2-L soda bottle with a Fizz-Keeper Pump. This activity is one station that can be combined with other stations for an hour and half lesson on weather patterns on Jupiter and Earth.

2014-07-11

492

An atmospheric pressure plasma source  

Microsoft Academic Search

An atmospheric pressure plasma source operated by radio frequency power has been developed. This source produces a unique discharge that is volumetric and homogeneous at atmospheric pressure with a gas temperature below 300 °C. It also produces a large quantity of oxygen atoms, ~5×1015 cm-3, which has important value for materials applications. A theoretical model shows electron densities of 0.2-2×1011

Jaeyoung Park; I. Henins; H. W. Herrmann; G. S. Selwyn; J. Y. Jeong; R. F. Hicks; D. Shim; C. S. Chang

2000-01-01

493

Membrane Bioreactor With Pressure Cycle  

NASA Technical Reports Server (NTRS)

Improved class of multilayer membrane bioreactors uses convention forced by differences in pressure to overcome some of diffusional limitations of prior bioreactors. In reactor of new class, flow of nutrient solution reduces adverse gradients of concentration, keeps cells supplied with fresh nutrient, and sweeps away products faster than diffusion alone. As result, overall yield and rate of reaction increased. Pressures in sweeping gas and nutrient alternated to force nutrient liquid into and out of biocatalyst layer through hyrophilic membrane.

Efthymiou, George S.; Shuler, Michael L.

1991-01-01

494

Extrusion energy and pressure requirements  

SciTech Connect

Corn gluten meal samples at moisture contents of 14, 20 and 26% dry basis were extruded at barrel temperatures of 120, 145 and 170/sup 0/C with screw speeds of 100, 150 and 200 rpm. The specific energy requirements and specific operating pressure decreases as the moisture content and temperature were increased. The effect of screw speed on specific energy and pressure was inconclusive.

Bhattacharya, M.; Hanna, M.A.

1984-01-01

495

SCALE Wounds: Unavoidable Pressure Injury.  

PubMed

Skin Changes at Life's End (SCALE) wounds include wounds of many underlying etiologies that accompany the dying process. These wounds occur due to unmodifiable intrinsic and extrinsic factors unique to each individual. This article describes the case of a dying patient who sustained a skin tear that deteriorated into a SCALE wound that meets the criteria for a National Pressure Ulcer Advisory Panel unavoidable pressure injury. PMID:25855852

Krasner, Diane L; Stewart, Thomas P

2015-04-01

496

Pressure Modulator Radiometer (PMR) tests  

NASA Technical Reports Server (NTRS)

The pressure modulator technique was evaluated for monitoring pollutant gases in the Earth's atmosphere of altitude levels corresponding to the mid and lower troposphere. Using an experimental set up and a 110 cm sample cell, pressure modulator output signals resulting from a range of gas concentrations in the sample cell were examined. Then a 20 cm sample cell was modified so that trace gas properties in the atmosphere could be simulated in the laboratory. These gas properties were measured using an infrared sensor.

Odell, E. L. G.; Cosmi, F. M.; Kreft, A. E.; Racette, G. W.; Maresca, T. J.; Pancoast, F. O.; Rutecki, D. J.; Yager, W. C.

1979-01-01

497

Psoriasis and High Blood Pressure  

PubMed Central

Introduction: Psoriasis is a chronic skin ailment which can be connected with an increased occurrence of other illnesses, including high blood pressure. Examinees and methods: A prospective study has been conducted which included 70 patients affected by psoriasis, both genders, older than 18 years. Average age being 47,14 (SD= ±15,41) years, from that there were 36 men or 51,43 and 34 women or 48,57%. Average duration of psoriasis was 15,52 (SD=±12,54) years. Results: Frequency of high blood pressure in those affected by psoriasis was 54,28%. Average age of the patients with psoriasis and high blood pressure was 53,79 year (SD=±14,15) and average duration of psoriasis was 17,19 years (SD=±13,51). Average values of PASI score were 16,65. Increase in values of PASI score and high blood pressure were statistically highly related (r=0,36, p=0,0001). Conclusion: Psoriasis was related to high blood pressure and there was a correlation between the severity of psoriasis and high blood pressure.

Salihbegovic, Eldina Malkic; Hadzigrahic, Nermina; Suljagic, Edin; Kurtalic, Nermina; Sadic, Sena; Zejcirovic, Alema; Mujacic, Almina

2015-01-01

498

Hazards in high pressure systems  

NASA Astrophysics Data System (ADS)

The High Pressure Systems Committee (HPSC) of the American Society of Mechanical Engineers is writing a set of rules and guides which will eventually be approved for treatment of safety concerns in high pressure operations. An introductory section of the proposed standard is being written to describe the hazards in high pressure. This paper is an edited version of the early draft of that section which is numbered 2000. Taking Section 2000 out of context (separately printing it from the remainder of the proposed standard) poses a possible misunderstanding in that high pressure is not necessarily synonymous with a lack of safety. There are many high pressure systems in operation with very acceptable safety records. However, when the potential for damage is great, it becomes more essential that safety be comprehensively engineered and practiced. Everyone concerned should be aware to some degree of the dangers that could happen in such operations. This paper is written in an attempt to share the concerns (appraisal of the risks) that members of the HPSC have for high pressure as interpreted and edited by this author.

Priddy, T. G.

1985-08-01

499

Pressure Ratio to Thermal Environments  

NASA Technical Reports Server (NTRS)

A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

Lopez, Pedro; Wang, Winston

2012-01-01