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1

Static Pressure Losses in 6\\  

Microsoft Academic Search

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\\

Kevin Weaver; Charles Culp

2

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2013 CFR

...is greater. (3) If a static pressure system is provided for any instrument...rules of this chapter, each static pressure port must be designed or located...manner that the correlation between air pressure in the static pressure system...

2013-01-01

3

14 CFR 23.1325 - Static pressure system.  

Code of Federal Regulations, 2012 CFR

...is greater. (3) If a static pressure system is provided for any instrument...rules of this chapter, each static pressure port must be designed or located...manner that the correlation between air pressure in the static pressure system...

2012-01-01

4

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2012 CFR

... § 25.1325 Static pressure systems. (a) Each instrument with static air case connections must...manner that the static pressure system performance is...the correlation between air pressure in the static...

2012-01-01

5

14 CFR 25.1325 - Static pressure systems.  

Code of Federal Regulations, 2013 CFR

... § 25.1325 Static pressure systems. (a) Each instrument with static air case connections must...manner that the static pressure system performance is...the correlation between air pressure in the static...

2013-01-01

6

14 CFR 25.1325 - Static pressure systems.  

... § 25.1325 Static pressure systems. (a) Each instrument with static air case connections must...manner that the static pressure system performance is...the correlation between air pressure in the static...

2014-01-01

7

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

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 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

10

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

11

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

12

30 CFR 18.67 - Static-pressure tests.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Static-pressure tests. 18.67 Section 18.67 Mineral Resources...Inspections and Tests § 18.67 Static-pressure tests. Static-pressure tests shall be conducted by the applicant...

2010-07-01

13

30 CFR 7.307 - Static pressure test.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Static pressure test. 7.307 Section 7.307 Mineral...Motor Assemblies § 7.307 Static pressure test. (a) Test procedure. (1) The enclosure...pressurized to a minimum of 150 psig and the pressure maintained for a minimum of 10...

2010-07-01

14

30 CFR 7.104 - Internal static pressure test.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Internal static pressure test. 7.104 Section 7.104 Mineral...Required § 7.104 Internal static pressure test. (a) Test procedures. (1...exhaust system to four times the maximum pressure observed in each segment during the tests of § 7.100, or 150 psig ±5...

2010-07-01

15

30 CFR 7.307 - Static pressure test.  

Code of Federal Regulations, 2013 CFR

...Mineral Resources 1 2013-07-01 2013-07-01 false Static pressure test. 7.307 Section 7.307 Mineral Resources...APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.307 Static pressure test. (a) Test procedure. (1) The...

2013-07-01

16

30 CFR 7.307 - Static pressure test.  

Code of Federal Regulations, 2011 CFR

...Mineral Resources 1 2011-07-01 2011-07-01 false Static pressure test. 7.307 Section 7.307 Mineral Resources...APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.307 Static pressure test. (a) Test procedure. (1) The...

2011-07-01

17

A short static-pressure probe design for supersonic flow  

NASA Technical Reports Server (NTRS)

A static-pressure probe design concept was developed which has the static holes located close to the probe tip and is relatively insensitive to probe angle of attack and circumferential static hole location. Probes were constructed with 10 and 20 deg half-angle cone tips followed by a tangent conic curve section and a tangent cone section of 2, 3, or 3.5 deg, and were tested at Mach numbers of 2.5 and 4.0 and angles of attack up to 12 deg. Experimental results indicate that for stream Mach numbers of 2.5 and 4.0 and probe angle of attack within + or - 10 deg, values of stream static pressure can be determined from probe calibration to within about + or - 4 percent. If the probe is aligned within about 7 deg of the flow experimental results indicated, the stream static pressures can be determined to within 2 percent from probe calibration.

Pinckney, S. Z.

1975-01-01

18

VALIDATION OF THE STATIC PRESSURE AND WAVE PRESSURE BY MPS WITH NEW GRADIENT OPERATOR  

NASA Astrophysics Data System (ADS)

Accuracy of a highly precised Moving-particle semi-implicit (MPS) method, proposed by the authors, is compared with that of the traditional MPS method on the static fluid pressure and water wave propagation. The MPS method is modified with a precise estimation of the gradient. In a static fluid analysis, a good accuracy is obtained in the modified MPS for static pressure than in the original MPS. In case of progressive water wave propagation analysis, the oscillation of wave pressure can also be simulated with high accuracy. The study suggests that the proposed method for the gradient operator can contribute to improve the accuracy of the MPS method.

Itori, Seiya; Iribe, Tsunakiyo; Nakaza, Eizo

19

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

20

Pressure Measurements in Jets Diffusion using a Developed Hot-Wire Static Pressure Sensor  

NASA Astrophysics Data System (ADS)

The aim of this experimental study is to investigate the diffusion of jets, with particular attention focused on the relationship between the static pressure and the stream wise mean velocity on the development of a two-dimensional air jet. A jet with three injection velocities (11.7, 23.3 and 35.0 m/s) was generated in a two-dimensional wind tunnel. The velocity distributions were measured by an X-type hot-wire anemometer. The static pressure distributions were measured by a static pressure probe developed in our laboratory, which incorporates a hot-wire anemometer. The probe is designed to be able to measure the mean static pressure and pressure fluctuation simultaneously. The sensitivity is 92.3 mV/Pa. The frequency response is flat from 16 Hz to 2.5 kHz. As a result of the experiment, it was found that negative static pressure exists in the turbulent shear layer. It is considered that the entrainment process from the negative static pressure by the vortex structure motion of the turbulent shear layer.

Kimura, Motoaki; Miyagi, Norimasa

21

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false When must I conduct a static bottomhole pressure survey? 550.1153... § 550.1153 When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the...

2013-07-01

22

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 false When must I conduct a static bottomhole pressure survey? 550.1153... § 550.1153 When must I conduct a static bottomhole pressure survey? (a) You must conduct a static bottomhole pressure survey under the...

2012-07-01

23

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

24

Pressure  

NSDL National Science Digital Library

This lab is not inquiry-based because the teacher must explain how to calculate pressure before doing the activity, but the lab gives students a great concept of what PSI means. They usually have no idea if 10 PSI is a lot or a little. They also don't und

Horton, Michael

2009-05-30

25

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

26

Static filling pressure in patients during induced ventricular fibrillation.  

PubMed

The static pressure resulting after the cessation of flow is thought to reflect the filling of the cardiovascular system. In the past, static filling pressures or mean circulatory filling pressures have only been reported in experimental animals and in human corpses, respectively. We investigated arterial and central venous pressures in supine, anesthetized humans with longer fibrillation/defibrillation sequences (FDSs) during cardioverter/defibrillator implantation. In 82 patients, the average number of FDSs was 4 +/- 2 (mean +/- SD), and their duration was 13 +/- 2 s. In a total of 323 FDSs, arterial blood pressure decreased with a time constant of 2.9 +/- 1.0 s from 77.5 +/- 34.4 to 24.2 +/- 5.3 mmHg. Central venous pressure increased with a time constant of 3.6 +/- 1.3 s from 7.5 +/- 5.2 to 11.0 +/- 5.4 mmHg (36 points, 141 FDS). The average arteriocentral venous blood pressure difference remained at 13.2 +/- 6.2 mmHg. Although it slowly decreased, the pressure difference persisted even with FDSs lasting 20 s. Lack of true equilibrium pressure could possibly be due to a waterfall mechanism. However, waterfalls were identified neither between the left ventricle and large arteries nor at the level of the diaphragm in supine patients. We therefore suggest that static filling pressures/mean circulatory pressures can only be directly assessed if the time after termination of cardiac pumping is adequate, i.e., >20 s. For humans, such times are beyond ethical options. PMID:12907428

Schipke, J D; Heusch, G; Sanii, A P; Gams, E; Winter, J

2003-12-01

27

Linking dynamic to static pressure by laser interferometry  

NASA Astrophysics Data System (ADS)

The primary calibration of pressure transducers is at present realized by static methods. This paper describes a new route to gaining traceability for dynamic calibration using the acousto-optic effect. The pressure range under consideration is up to 100 MPa. We set out a description of the general principle employed to gain traceability, the experimental set-ups that are used for the realization and the thermophysical background of the measurements, and some numerical estimates on the expected results for two different pressure-transmitting media are shown.

Bruns, Th; Franke, E.; Kobusch, M.

2013-12-01

28

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

29

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

30

33 CFR 183.580 - Static pressure test for fuel tanks.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Static pressure test for fuel tanks. 183...Tests § 183.580 Static pressure test for fuel tanks. A... (a) Fill the tank with air or inert gas to the pressure marked on the tank label...

2012-07-01

31

33 CFR 183.580 - Static pressure test for fuel tanks.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Static pressure test for fuel tanks. 183...Tests § 183.580 Static pressure test for fuel tanks. A... (a) Fill the tank with air or inert gas to the pressure marked on the tank label...

2013-07-01

32

33 CFR 183.580 - Static pressure test for fuel tanks.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Static pressure test for fuel tanks. 183...Tests § 183.580 Static pressure test for fuel tanks. A... (a) Fill the tank with air or inert gas to the pressure marked on the tank label...

2011-07-01

33

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

34

Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements  

NASA Astrophysics Data System (ADS)

Geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system on the University of Wyoming King Air research aircraft are used to estimate acceleration effects on static pressure measurement. Using data collected during periods of accelerated flight, comparison of measured pressure with that derived from GNSS/IMU geometric altitude show that errors exceeding 150 Pa can occur which is significant in airspeed and atmospheric air motion determination. A method is developed to predict static pressure errors from analysis of differential pressure measurements from a Rosemount model 858 differential pressure air velocity probe. The method was evaluated with a carefully designed probe towed on connecting tubing behind the aircraft - a "trailing cone" - in steady flight, and shown to have a precision of about ±10 Pa over a wide range of conditions including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, compared to the GNSS/IMU data, this algorithm predicts corrections to a precision of better than ±20 Pa. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are examined.

Rodi, A. R.; Leon, D. C.

2012-05-01

35

Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements  

NASA Astrophysics Data System (ADS)

A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns - angle of attack, angle of sideslip, dynamic pressure and the error in static pressure - if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft - a trailing cone - and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

Rodi, A. R.; Leon, D. C.

2012-11-01

36

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

37

Blood pressure response to low level static contractions.  

PubMed

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 was significantly longer for flexion [111.3 (SD 56.1) min] than for extension [18.1 (SD 7.5) min; n = 7]. At 40% MVC the difference in mean endurance time disappeared [2.3 (SD 0.7) min for elbow flexion and 2.3 (SD 0.7) min for elbow extension]. Mean arterial blood pressure exhibited a continuous and progressive increase during the 10% MVC contractions indicating that the 15% MVC concept would not appear to be valid. The terminal blood pressure value recorded at the point of exhaustion in the 10% MVC elbow extension experiment was identical to the peak pressure attained in the 40% MVC contraction. For the elbow flexors the terminal pressor response was slightly but significantly lower at 10% MVC [122.3 (SD 10.1) mmHg, 16.3 (SD 1.4) kPa] in comparison with 40% MVC [130.4 (SD 7.4) mmHg, 17.4 (SD 1.0) kPa]. When the circulation to the muscles was arrested just prior to the cessation of the contraction, blood pressure only partly recovered and remained elevated for as long as the occlusion persisted, indicating the level of pressure-raising muscle chemoreflexes.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1612087

Fallentin, N; Jørgensen, K

1992-01-01

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

33 CFR 183.580 - Static pressure test for fuel tanks.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Static pressure test for fuel tanks. 183.580 Section 183...BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Tests § 183.580 Static pressure test for fuel tanks. A fuel tank is...

2010-07-01

40

New findings in static high-pressure science  

SciTech Connect

Recent static high P-T experiments using diamond anvil cell techniques reveal an array of phenomena and provide new links to dynamic compression experiments. Selected recent developments are reviewed, including new findings in hot dense hydrogen, the creation of new metals and superconductors, new transitions in molecular and other low-Z systems, the behavior of iron and transition metals, chemical changes of importance in geoscience and planetary science, and the creation of new classes of high-pressure devices based on CVD diamond. These advances have set the stage for the next set of developments in this rapidly growing area.

Hemley, R.J.; Mao, H.-k. (CIW)

2010-11-16

41

Uncertainty of Five-Hole Probe Measurements. [of total flow pressure, static pressure, and flow  

NASA Technical Reports Server (NTRS)

A new algorithm for five-hole probe calibration and data reduction using a non-nulling technique was developed, verified, and reported earlier (Wendt and Reichert, 1993). The new algorithm's simplicity permits an analytical treatment of the propagation of uncertainty in five-hole probe measurement. The objectives of the uncertainty analysis are to quantify the uncertainty of five-hole probe results (e.g., total pressure, static pressure, and flow direction) and to determine the dependence of the result uncertainty on the uncertainty of all underlying experimental and calibration measurands. This study outlines a general procedure that other researchers may use to determine five-hole probe result uncertainty and provides guidance for improving the measurement technique.

Reichert, Bruce A.; Wendt, Bruce J.

1994-01-01

42

30 CFR 7.104 - Internal static pressure test.  

Code of Federal Regulations, 2013 CFR

... (1) Isolate and seal each segment of the intake system...Internally pressurize each segment of the intake system...pressure observed in each segment during the tests of...affecting the length or gap of any...

2013-07-01

43

30 CFR 7.104 - Internal static pressure test.  

Code of Federal Regulations, 2012 CFR

... (1) Isolate and seal each segment of the intake system...Internally pressurize each segment of the intake system...pressure observed in each segment during the tests of...affecting the length or gap of any...

2012-07-01

44

30 CFR 7.104 - Internal static pressure test.  

Code of Federal Regulations, 2011 CFR

... (1) Isolate and seal each segment of the intake system...Internally pressurize each segment of the intake system...pressure observed in each segment during the tests of...affecting the length or gap of any...

2011-07-01

45

30 CFR 7.307 - Static pressure test.  

Code of Federal Regulations, 2012 CFR

...pressurization shall not exhibit— (i) Leakage through welds or casting; or (ii) Rupture of any part that affects the...pressurizing agent shall not exhibit— (i) Visible cracks in welds; (ii) Permanent deformation exceeding 0.040 inches...

2012-07-01

46

Radio jet refraction in galactic atmospheres with static pressure gradients  

NASA Technical Reports Server (NTRS)

A theory based on the refraction of radio jets in the extended atmosphere of an elliptical galaxy, is proposed for double radio sources with a Z or S morphology. The model describes a collimated jet of supersonic material that bends self-consistently under the influence of external static pressure gradients, and may alternatively be seen as a continuous-jet version of the buoyancy model proposed by Gull (1973). Emphasis is placed on (1) S-shaped radio sources identified with isolated galaxies, such as 3C 293, whose radio structures should be free of distortions resulting from motion relative to a cluster medium, and (2) small-scale, galaxy-dominated rather than environment-dominated S-shaped sources such as the inner jet structure of Fornax A.

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

1981-01-01

47

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

48

On Static Pressure Fluctuation between Sirocco Fan Blades in a Car Air-Conditioning System  

Microsoft Academic Search

In this study, special attention is directed to static pressure fluctuation in a sirocco fan for a car air-conditioning system, because it is expected that there is a close connection between the fluid noise and the pressure fluctuation. The final purpose of this study is to clarify the relationship between the static pressure fluctuation between fan blades and the sound

Yasuhiko Sakai; Takaaki Kato; Yuu Moriguchi; Masaharu Sakai; Kouji Ito; Yasushi Mitsuishi; Kouji Nagata; Takashi Kubo

2008-01-01

49

Comparative study of air and water measurements of peak and stabilized static urethral pressures.  

PubMed

Air and water were forced through female dogs' urethras to determine static urethral pressures. The cauda equina was sectioned to eliminate reflex responses to urethral manipulation, and the urethras were compressed circumferentially with inflatable Silastic cuffs. The peak and stabilized urethral pressures were recorded at flow rates between 20 and 150 ml./min. while cuff pressures were varied between 0 and 100 cm. of water. When the fluid recordings of static urethral pressure were compared with Millar transducer tip catheter measurements of urethral pressure, there were no statistically significant differences between the air cystometer, aneroid sphygmomanometer, and Millar catheter recordings of urethral pressure. At these high flow rates, the water recordings of urethral pressure were significantly higher than the Millar catheter determinations of static uretheral pressure. PMID:568841

Teague, C T; Merrill, D C

1978-10-01

50

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

51

Static pressure effects on calibration of velocity transducers at nozzle exits  

Microsoft Academic Search

Calibrations of velocity transducers are generally performed at nozzle exits where the turbulence level is minimal. Such nozzles require a high contraction ratio and are usually short with a consequent effect on stream static pressure due to formation of a vena contracta. Calibrations performed with a Pitot tube and no static pressure correction can lead to a significant velocity error.

K. Bremhorst; J. Listijono

1987-01-01

52

Flight evaluation of an engine static pressure noseprobe in an F-15 airplane  

NASA Technical Reports Server (NTRS)

The flight testing of an inlet static pressure probe and instrumented inlet case produced results consistent with sea-level and altitude stand testing. The F-15 flight test verified the basic relationship of total to static pressure ratio versus corrected airflow and automatic distortion downmatch with the engine pressure ratio control mode. Additionally, the backup control inlet case statics demonstrated sufficient accuracy for backup control fuel flow scheduling, and the station 6 manifolded production probe was in agreement with the flight test station 6 tota pressure probes.

Foote, C. H.; Jaekel, R. F.

1981-01-01

53

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

54

ON RADIATION PRESSURE IN STATIC, DUSTY H II REGIONS  

SciTech Connect

Radiation pressure acting on gas and dust causes H II regions to have central densities that are lower than the density near the ionized boundary. H II regions in static equilibrium comprise a family of similarity solutions with three parameters: {beta}, {gamma}, and the product Q{sub 0} n{sub rms}; {beta} characterizes the stellar spectrum, {gamma} characterizes the dust/gas ratio, Q{sub 0} is the stellar ionizing output (photons/s), and n{sub rms} is the rms density within the ionized region. Adopting standard values for {beta} and {gamma}, varying Q{sub 0} n{sub rms} generates a one-parameter family of density profiles, ranging from nearly uniform density (small Q{sub 0} n{sub rms}) to shell-like (large Q{sub 0} n{sub rms}). When Q{sub 0} n{sub rms} {approx}> 10{sup 52} cm{sup -3} s{sup -1}, dusty H II regions have conspicuous central cavities, even if no stellar wind is present. For given {beta}, {gamma}, and Q{sub 0} n{sub rms}, a fourth quantity, which can be Q{sub 0}, determines the overall size and density of the H II region. Examples of density and emissivity profiles are given. We show how quantities of interest-such as the peak-to-central emission measure ratio, the rms-to-mean density ratio, the edge-to-rms density ratio, and the fraction of the ionizing photons absorbed by the gas-depend on {beta}, {gamma}, and Q{sub 0} n{sub rms}. For dusty H II regions, compression of the gas and dust into an ionized shell results in a substantial increase in the fraction of the stellar photons that actually ionize H (relative to a uniform-density H II region with the same dust/gas ratio and density n = n{sub rms}). We discuss the extent to which radial drift of dust grains in H II regions can alter the dust-to-gas ratio. The applicability of these solutions to real H II regions is discussed.

Draine, B. T., E-mail: draine@astro.princeton.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

2011-05-10

55

Exact solutions: neutral and charged static perfect fluids with pressure  

NASA Astrophysics Data System (ADS)

We show in this article that charged fluid with pressure derived by Bijalwan (Astrophys. Space. Sci. doi:10.1007/s10509-011-0691-0, 011a) can be used to model classical electron, quark, neutron stars and pulsar with charge matter, quasi black hole, white dwarf, super-dense star etc. Recent analysis by Bijalwan (Astrophys. Space. Sci., 2011d) that all charged fluid solutions in terms of pressure mimic the classical electron model are partially correct because solutions by Bijalwan (Astrophys. Space. Sci. doi:10.1007/s10509-011-0691-0, 011a) may possess a neutral counterpart. In this paper we characterized solutions in terms of pressure for charged fluids that have and do not have a well behaved neutral counter part considering same spatial component of metric e ? for neutral and charged fluids. We discussed solution by Gupta and Maurya (Astrophys. Space Sci. 331(1):135-144, 2010a) and solutions by Bijalwan (Astrophys. Space Sci. doi:10.1007/s10509-011-0735-5, 2011b; Astrophys. Space Sci. doi:10.1007/s10509-011-0780-0, 2011c; Astrophys. Space Sci., 2011d) such that charged fluids possess and do not possess a neutral counterpart as special cases, respectively. For brevity, we only present some analytical results in this paper.

Bijalwan, Naveen

2012-01-01

56

Static pressure effects on calibration of velocity transducers at nozzle exits  

NASA Astrophysics Data System (ADS)

Calibrations of velocity transducers are generally performed at nozzle exits where the turbulence level is minimal. Such nozzles require a high contraction ratio and are usually short with a consequent effect on stream static pressure due to formation of a vena contracta. Calibrations performed with a Pitot tube and no static pressure correction can lead to a significant velocity error. Measurements of static pressure, mean velocity and turbulence intensity are presented for a typical high contraction ratio nozzle. These show two distinct flow regimes which can be described very simply by the Reynolds form of the Navier-Stokes equations.

Bremhorst, K.; Listijono, J.

1987-09-01

57

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

58

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

59

Static lung compliance and body pressures in Tupinambis merianae with and without post-hepatic septum.  

PubMed

The surgical removal of the post-hepatic septum (PHS) in the tegu lizard, Tupinambis merianae, significantly reduces resting lung volume (V(Lr)) and maximal lung volume (V(Lm)) when compared with tegus with intact PHS. Standardised for body mass (M(B)), static lung compliance was significantly less in tegus without PHS. Pleural and abdominal pressures followed, like ventilation, a biphasic pattern. In general, pressures increased during expiration and decreased during inspiration. However, during expiration pressure changes showed a marked intra- and interindividual variation. The removal of the PHS resulted in a lower cranio-caudal intracoelomic pressure differential, but had no effect on the general pattern of pressure changes accompanying ventilation. These results show that a perforated PHS that lacks striated muscle has significant influence on static breathing mechanics in Tupinambis and by analogy provides valuable insight into similar processes that led to the evolution of the mammalian diaphragm. PMID:12706067

Klein, Wilfried; Abe, Augusto S; Perry, Steven F

2003-04-15

60

Pressure distribution and critical exponent in statically jammed and shear-driven frictionless disks  

NASA Astrophysics Data System (ADS)

We numerically study the distributions of global pressure that are found in ensembles of statically jammed and quasistatically sheared systems of bidisperse, frictionless disks at fixed packing fraction ? in two dimensions. We use these distributions to address the question of how pressure increases as ? increases above the jamming point ?J, p ˜|?-?J|y. For statically jammed ensembles, our results are consistent with the exponent y being simply related to the power law of the interparticle soft-core interaction. For sheared systems, however, the value of y is consistent with a nontrivial value, as found previously in rheological simulations.

Vâgberg, Daniel; Wu, Yegang; Olsson, Peter; Teitel, S.

2014-02-01

61

Sideslip-induced static pressure errors in flight-test measurements  

NASA Technical Reports Server (NTRS)

During lateral flight-test maneuvers of a V/STOL research aircraft, large errors in static pressure were observed. An investigation of the data showed a strong correlation of the pressure record with variations in sideslip angle. The sensors for both measurements were located on a standard air-data nose boom. This paper descries an algorithm based on potential flow over a cylinder that was developed to correct the pressure record for sideslip-induced errors. In order to properly apply the correction algorithm, it was necessary to estimate and correct the lag error in the pressure system. The method developed for estimating pressure lag is based on the coupling of sideslip activity into the static ports and can be used as a standard flight-test procedure. The paper discusses the estimation procedure and presents the corrected static-pressure record for a typical lateral maneuver. It is shown that application of the correction algorithm effectifvely attenuates sideslip-induced errors.

Parks, Edwin K.; Bach, Ralph E., Jr.; Tran, Duc

1990-01-01

62

Radial forces in a centrifugal compressor; Experimental investigation by using magnetic bearings and static pressure distribution  

NASA Astrophysics Data System (ADS)

The volute of a centrifugal compressor causes a non-uniform pressure distribution which leads to a radial force on the impeller. This force was measured using magnetic bearings. In addition, the radial force was estimated using the static pressure distribution measured at the impeller outlet. The impeller force was found to be the highest at choke, the lowest at the design flow and moderate at stall. The radial force determined from the pressure measurements was only slightly different from the force obtained from the bearing measurements. The rotational speed was seen to affect the force to some extent.

Reunanen, Arttu; Larjola, Jaakko

2005-03-01

63

Measurements of Mean Static Pressure and Far Field Acoustics of Shock Containing Supersonic Jets  

NASA Technical Reports Server (NTRS)

The far field acoustic data base generated in studies of broadband shock noise from supersonic jets is presented. Both conical and contoured nozzles of exit Mach numbers 1.0, 1.5, and 2.0 were tested using unheated air at pressure ratios ranging from 1.9 to 14. Tests were performed both with and without screech suppression tabs. Overall sound pressure variations and representative 1/3-octave and narrowband spectra are presented. The mean static pressure measured within these jets is also surveyed.

Norum, T. D.; Seiner, J. M.

1982-01-01

64

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

65

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

66

An experimental investigation of the static pressure fluctuation mechanism for porous transonic wind tunnel wall configurations  

Microsoft Academic Search

An experimental investigation of the static pressure fluctuation generation mechanism was performed for different transonic wind tunnel test section perforated wall configurations. Different hole diameters and geometrical configurations were investigated. Most tests were carried out with isolated perforations, while some were done with a three hole, 16° perforation pattern. To suppress the oscillation amplitudes generated by perforations, splitter-plates as flow

B. L. Medved

1993-01-01

67

Static Pressure Loss in 12”, 14”, and 16” Non-metallic Flexible Duct  

E-print Network

STATIC PRESSURE LOSS IN 12?, 14?, AND 16? NON-METALLIC FLEXIBLE DUCT A Thesis by David Lee Cantrill, Jr. Submitted to the Office of Graduate Studies Texas A&M University in partial fulfillment of the requirements for the degree.............................................. 73 Lawrence Berkeley National Laboratory (Lbnl) Research ................... 73 Texas A&M University Research .......................................................... 73 Trane Ductulator...

Cantrill, David Lee

2013-08-01

68

Maximum Static Respiratory Pressures in Healthy Elderly Men and Women: Issues of Reproducibility and Interpretation  

Microsoft Academic Search

Background: Respiratory muscle strength is assessed using the static pressure generated at the mouth during a maximal inspiratory or expiratory effort [PImax and PEmax, respectively (MSRPs)]. Interpretation of MSRPs relies upon comparison with ‘normal’ values, but MSRPs show very weak associations with predictors such as physical characteristics. The influence of habitual physical activity upon MSRPs remains undefined. Objectives: We examined

A. K. McConnell; A. J. Copestake

1999-01-01

69

Triboelectric active sensor array for self-powered static and dynamic pressure detection and tactile imaging.  

PubMed

We report an innovative, large-area, and self-powered pressure mapping approach based on the triboelectric effect, which converts the mechanical stimuli into electrical output signals. The working mechanism of the triboelectric active sensor (TEAS) was theoretically studied by both analytical method and numerical calculation to gain an intuitive understanding of the relationship between the applied pressure and the responsive signals. Relying on the unique pressure response characteristics of the open-circuit voltage and short-circuit current, we realize both static and dynamic pressure sensing on a single device for the first time. A series of comprehensive investigations were carried out to characterize the performance of the TEAS, and high sensitivity (0.31 kPa(-1)), ultrafast response time (<5 ms), long-term stability (30,000 cycles), as well as low detection limit (2.1 Pa) were achieved. The pressure measurement range of the TEAS was adjustable, which means both gentle pressure detection and large-scale pressure sensing were enabled. Through integrating multiple TEAS units into a sensor array, the as-fabricated TEAS matrix was capable of monitoring and mapping the local pressure distribution applied on the device with distinguishable spatial profiles. This work presents a technique for tactile imaging and progress toward practical applications of nanogenerators, providing potential solutions for accomplishment of artificial skin, human-electronic interfacing, and self-powered systems. PMID:23957827

Lin, Long; Xie, Yannan; Wang, Sihong; Wu, Wenzhuo; Niu, Simiao; Wen, Xiaonan; Wang, Zhong Lin

2013-09-24

70

Active control of static pressure drop caused by hydraulic servo-actuator engage  

SciTech Connect

Pressure drop caused by propagation of expansion waves in the source pipeline of fast high cyclic hydraulic actuator produces possible anomalies in its function. To prevent pressure drop it is possible to minimize wave effects by active control of actuator servo-valve throttle leakage. In the paper is presented synthesis of possible discrete active control of hydraulic actuator and its servo-valve for prevention expansion wave pressure drop. Control synthesis is based on static pressure increasing with decreasing of fluid flow velocity, which can be realized by lower throttle leakage. Some of the effects of assumed control are shown on corresponding diagrams of control valve throttle motion, piston displacement and its corresponding linear velocity.

Janlovic, J. [Univ. of Belgrade (Yugoslavia)

1994-12-31

71

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

72

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

73

Effects of inlet distortion on a static pressure probe mounted on the engine hub in an F-15 airplane  

NASA Technical Reports Server (NTRS)

An inlet static pressure (PS2) probe was mounted on the hub of an F100 engine in an F-15 airplane. Flight test results showed that for low distortion conditions, the ratio of engine-face total pressure to static pressure agreed well with previous altitude facility data. Off-schedule operation of the inlet third ramp angle caused increased distortion of the inlet airflow during steady-state flight conditions. Data are shown for inlet third ramp excursions leading to engine stall. The relationships of inlet face total to static pressure ratio as a function of several distortion descriptors are also described.

Hughes, D. L.; Myers, L. P.; Mackall, K. G.

1985-01-01

74

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

75

Probe systems for measuring static pressure and turbulence intensity in fluid streams  

NASA Technical Reports Server (NTRS)

A method and an apparatus for measuring time-averaged static or ambient pressure and turbulence intensity in a turbulent stream are discussed. The procedure involves placing a plurality of probes in the stream. Each probe responds in a different manner to characteristics of the fluid stream, preferably as a result of having varying cross sections. The responses from the probes are used to eliminate unwanted components in the measured quantities for accurate determination of selected characteristics.

Rossow, Vernon J. (inventor)

1993-01-01

76

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

77

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

78

Experimental investigation of power loss coefficients and static pressure ratios in an industrial exhaust ventilation system.  

PubMed

A study tested whether measures of equivalent resistance (X values) and ratios of static pressure (SPratio) for given ducts of contaminant control exhaust ventilation systems were independent of substantial changes to airflow level and to changes to resistance of other ducts within the same full-scale five-branch system. In a factorial study design, four airflow levels were achieved by changing fan rotation rate while resistances to flow for specific branch ducts were changed independently by adjusting slidegate dampers to various settings. For each damper insertion depth (including fully open), the results demonstrated substantial invariance for branch X values (few greater than 5%), SPratio (few greater than 3%), and fraction of airflow to each duct (few greater than 2%). X-values for submains were much less stable, changing by 20% or more with changes to other parts of the system. For the same conditions, hood static pressures changed by as much as 96% (with standard deviation of 40%). The results suggest that before and after values of X and SPratios should be more reliable bases for indicating alterations than comparison of observed static pressures. The stability of airflow distributions with substantial changes in airflow suggests that one could adjust airflow distribution (e.g., with dampers) without considering whether the fan speed was set correctly, leaving fan adjustments for a final step. PMID:10386358

Guffey, S E; Spann, J G

1999-01-01

79

Static and cyclic performance evaluation of sensors for human interface pressure measurement.  

PubMed

Researchers and clinicians often desire to monitor pressure distributions on soft tissues at interfaces to mechanical devices such as prosthetics, orthotics or shoes. The most common type of sensor used for this type of applications is a Force Sensitive Resistor (FSR) as these are convenient to use and inexpensive. Several other types of sensors exist that may have superior sensing performance but are less ubiquitous or more expensive, such as optical or capacitive sensors. We tested five sensors (two FSRs, one optical, one capacitive and one fluid pressure) in a static drift and cyclic loading configuration. The results show that relative to the important performance characteristics for soft tissue pressure monitoring (i.e. hysteresis, drift), many of the sensors tested have significant limitations. The FSRs exhibited hysteresis, drift and loss of sensitivity under cyclic loading. The capacitive sensor had substantial drift. The optical sensor had some hysteresis and temperature-related drift. The fluid pressure sensor performed well in these tests but is not as flat as the other sensors and is not commercially available. Researchers and clinicians should carefully consider the convenience and performance trade-offs when choosing a sensor for soft-tissue pressure monitoring. PMID:23365857

Dabling, Jeffrey G; Filatov, Anton; Wheeler, Jason W

2012-01-01

80

Time to onset of pain: effects of magnitude and location for static pressures applied to the plantar foot.  

PubMed

Mechanisms that cause foot discomfort during prolonged standing are poorly understood. There is currently no method for evaluating discomfort associated with low levels of static pressure that are typical during standing. Pain thresholds were measured for 20 healthy participants by applying five levels of static pressure at different plantar foot locations. A survival analysis was performed to determine the effects of pressure magnitude and foot location on the time until pain onset. Time to pain onset was significantly affected by pressure magnitude (P < 0.001); time decreased as pressure increased. Foot location was also significant (P < 0.001); greatest times to pain onset (least sensitive) were observed under the heel and fifth metatarsal head, shortest times (most sensitive) were found under the midfoot. This research presents a novel methodology for evaluating static pressure that may be applicable to product design. PMID:25118168

Wiggermann, Neal; Keyserling, W Monroe

2015-01-01

81

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

82

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

E-print Network

and static pressure reduction on energy consumption [6-8] . The impact of static air pressure on the fan power was recognized by Warren and Norford [9] . The static air pressure reset schedule was investigated by Rose and Kopko [10] . 1 Even.... [8] Liu M., 1995. Measured Impact of VFD and Static Pressure Reduction on Energy Consumption. Internal Report of Energy Systems Laboratory, Texas A&M University, College Station, TX. [9] Warren M., and L. K. Norford. 1993. Integrating VAV Zone...

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

2007-01-01

83

Application of Wireless Sensor Network (WSN) Technologies in Optimal Static Pressure Reset in Variable Air Volume (VAV) System  

E-print Network

unit damper position based, outside air temperature based and air flow based, and proposed an optimal static pressure reset method. Subsequently, hourly simulations of a building in Omaha, Nebraska, USA, was implemented and validated that the VAV system...

Zheng, K.; Li, H.; Yang, H.

2007-01-01

84

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

E-print Network

PRESSURE MEASUREMENTS; DAYS 71-74 36 46 47 49 X1 Figure 26 27 ANALOG PLATFORI4 TAPE RECORD ILLUSTRATING WAVE AND BOTTOM MOTIONS FOR THE FEBRUARY, 1977, STORM EXCESS PORE PRESSURE MEASUREMENTS; DAYS 52-59 Page 50 51 28 EXCESS PORE PRESSURES... AND CALCULATED OVERBURDEN PRESSURES VERSUS DEPTH; FEBRUARY STORl'1 53 29 30 31 32 33 34 35 37 38 39 HYDROSTATIC AND TOTAL PORE PRESSURE MEASUR-MENTS; DAYS 52-59 EXCESS PORE PRESSURE MEASUREMENTS; DAYS 241-246 EXCESS PORE PRESSURE MEASUREMENTS; DAYS...

Williams, Garrett Edwin

2012-06-07

85

A static pressure sensitive receptor APJ promote H9c2 cardiomyocyte hypertrophy via PI3K-autophagy pathway.  

PubMed

This study is designed to investigate whether APJ receptor acts as a sensor in static pressure-induced cardiomyocyte hypertrophy and to investigate the mechanism of PI3K-autophagy pathway. The left ventricular hypertrophy rat model was established by coarctation of abdominal aorta. H9c2 rat cardiomyocytes were cultured in the presence of static pressure which was given by a custom-made pressure incubator. The results revealed that the expression of apelin/APJ system, PI3K, Akt and their phosphorylation were significantly increased in the operation group. Static pressure up-regulated the APJ expression, PI3K phosphorylation, Akt phosphorylation, LC3-II/I and beclin-1 expression in cardiomyocytes. APJ shRNA pGPU6/Neo-rat-399, PI3K inhibitor LY294002, Akt inhibitor 1701-1 blocked the up-regulation of APJ, PI3K phosphorylation, Akt phosphorylation, LC3-II/I and beclin-1 expression, respectively. Moreover, static pressure increased the diameter, volume, protein content of cells, and these could be reversed when the cells were treated with pGPU6/Neo-rat-399, LY294002, and autophagy inhibitor 3-methyladenine, respectively. These results suggested that static pressure up-regulates APJ expression to promote cardiomyocyte hypertrophy by a PI3K-autophagy pathway. PMID:24966188

Xie, Feng; Liu, Wei; Feng, Fen; Li, Xin; Yang, Li; Lv, Deguan; Qin, Xuping; Li, Lanfang; Chen, Linxi

2014-08-01

86

Static and dynamic fatigue behavior of glass filament-wound pressure vessels at ambient and cryogenic temperatures.  

NASA Technical Reports Server (NTRS)

Investigation of the pressure load carrying capacity and fatigue strength of filament-wound glass-reinforced plastic pressure vessels subjected to static and cyclic loading at ambient and cryogenic (liquid nitrogen) temperature environments. The results indicate that the static fatigue problem is not critical at cryogenic temperatures. Under static loading at liquid nitrogen temperature, a reinforced plastic cylinder sustained pressurization for 88 days without failure at about 90% of the single cycle burst strength. At ambient temperature, the static life at 90% of the burst strength was about 7 min. Under cyclic loading in liquid nitrogen, no failure resulted after 1509 cycles at 55% of the single cycle burst strength. Under the same cyclic loading at ambient temperature, the test results would predict failure in the reinforced plastic. The results of similar tests upon adhesively bonded polyimide aluminum-foil lined cylinders are also reviewed.-

Hanson, M. P.

1972-01-01

87

Accurate method to study static volume-pressure relationships in small fetal and neonatal animals.  

PubMed

We designed an accurate method to study respiratory static volume-pressure relationships in small fetal and neonatal animals on the basis of Archimedes' principle. Our method eliminates the error caused by the compressibility of air (Boyle's law) and is sensitive to a volume change of as little as 1 microliters. Fetal and neonatal rats during the period of rapid lung development from day 19.5 of gestation (term = day 22) to day 3.5 postnatum were studied. The absolute lung volume at a transrespiratory pressure of 30-40 cmH2O increased 28-fold from 0.036 +/- 0.006 (SE) to 0.994 +/- 0.042 ml, the volume per gram of lung increased 14-fold from 0.39 +/- 0.07 to 5.59 +/- 0.66 ml/g, compliance increased 12-fold from 2.3 +/- 0.4 to 27.3 +/- 2.7 microliters/cmH2O, and specific compliance increased 6-fold from 24.9 +/- 4.5 to 152.3 +/- 22.8 microliters.cmH2O-1.g lung-1. This technique, which allowed us to compare changes during late gestation and the early neonatal period in small rodents, can be used to monitor and evaluate pulmonary functional changes after in utero pharmacological therapies in experimentally induced abnormalities such as pulmonary hypoplasia, surfactant deficiency, and congenital diaphragmatic hernia. PMID:8002489

Suen, H C; Losty, P D; Donahoe, P K; Schnitzer, J J

1994-08-01

88

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

89

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

Code of Federal Regulations, 2010 CFR

...in a sufficient number of key wells to establish an average reservoir...surveys be performed on specific wells. (b) Your bottomhole pressure...1) You must shut-in the well for a minimum period of 4 hours...and pressure measurements and gradient information for at least...

2010-07-01

90

The static, total pressure method is the preferred experimental approach to measure infinite dilution phase behavior for highly  

E-print Network

point. While potentially eliminating the statistical correlation, the results may become biased if non at the bubble point will eliminate bias. This paper discusses a proposed modified static total pressure method. [ ]nllvllvllvllvtottotbign T TTPVVDdddZ ,1,1,2,1,21 .....= r [ ]sat nnn T xvvlllvvll 11,2,1,22,22,11,21,11,21,1 ..... = r

Howat, Colin S. "Chip"

91

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

E-print Network

Air static pressure set-point or schedule for VAV AHLJ systems is one of the most crucial operational parameters for satisfy lug the building load, maintaining the room comfort level and saving energy costs. This paper presents a novel procedure...

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

1998-01-01

92

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

E-print Network

, which naturally contracted to about 4% with respect to the fully stretched case. Pressure loss calculation methods exist within the Air Conditioning Contractors of America (ACCA) Manual D (ACCA 1995). The ASHRAE Handbook ? Fundamentals Chapter 35... (ASHRAE 2005) also contains pressure loss data, which has linear correction factors based on the percent of compression extending to 30%. Existing research by Abushakra et al. has shown the data included in the ACCA and ASHRAE Handbook references...

Weaver, K.; Culp, C.

2006-01-01

93

Study of stator-vane fluctuating pressures in a turbofan engine for static and flight tests  

Microsoft Academic Search

As part of a program to study the fan noise generated from turbofan engines, fluctuating surface pressures induced by fan-rotor wakes were measured on core- and bypass-stator outlet guide vanes of a modified JT15D-1 engine. Tests were conducted with the engine operating on an outdoor test stand and in flight. The amplitudes of pressures measured at fan-rotor blade-passage fundamental frequencies

A. W. Mueller

1984-01-01

94

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

95

Pressure Sores  

MedlinePLUS

... may form. Pressure sores are also called bedsores, pressure ulcers and decubitus ulcers. Symptoms What are the symptoms of a ... put in a vein) or orally (by mouth). Prevention How can pressure sores be prevented? The most ...

96

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.

Integrated Teaching And Learning Program

97

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

98

Significant static pressure increase in a precompression cell target for laser-driven advanced dynamic compression experiments  

SciTech Connect

Laser shock compression experiments on precompressed samples offer the possibility to explore extreme material states unreachable by static or single-shock compression techniques alone. We have found significant increases in static compression pressure in a wide-opening and thin diamond precompression cell. This suggests that the precompression target is adaptable to advanced coupling techniques with laser-driven dynamic compression methods. The novel coupling techniques proposed give the potential to access outstanding material states required in planetary and condensed-matter physics.

Kimura, T.; Ozaki, N.; Terai, T.; Sano, T.; Hirose, A.; Kakeshita, T.; Kodama, R. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Okuchi, T. [Institute for Study of the Earth's Interior, Okayama University, Misasa, Tottori 682-0193 (Japan); Shimizu, K. [KYOKUGEN, Center for Quantum Science and Technology Under Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Sano, T.; Sakawa, Y. [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Koenig, M. [Laboratoire pour l'Utilisation des Lasers Intenses, UMR7605, CNRS-CEA-Universite Paris VI-Ecole Polytechnique, 91128 Palaiseau Cedex (France)

2010-05-15

99

In-flight measurement of static pressures and boundary layer state with integrated sensors  

NASA Astrophysics Data System (ADS)

The reliable, integrated sensors for control-system feedback required by advanced transport aircraft wing designs incorporating adaptive geometry features for load control and performance optimization are presently evaluated. Absolute pressure transducers from various manufacturers were tested and adapted to the flight test environment; both laboratory and flight test results indicate steady measurement capabilities. It is shown that the sensing of pressure fluctuations in the wing-buffet regime will improve the prediction of operational limits. The pressure transducers were also used to investigate the laminar/turbulent transition in the attachment-line flow of a swept wing. A comparison of these results with those of hot film probes shows the transducers' effectiveness.

Greff, E.

100

Assessment of the percentages of maximum static pressure in the anal canal for postoperative continence in patients with imperforate anus  

Microsoft Academic Search

The maximum static pressure in the anal canal was measured using an open-tip manometric method with a continuous infusion\\u000a system. The values obtained from 49 postoperative patients with imperforate anus were expressed as a percentage of those values\\u000a obtained from 108 aged-matched controls. The value was observed to be 50 per cent or more in those patients with translevator\\u000a type,

Michiomi Ishihara; Ikuo Okabe; Ken Morita

1987-01-01

101

Dynamic and static shell properties of white and brown shell eggs exposed to modified pressure microcrack detection technology.  

PubMed

Dynamic and static shell properties of eggs provide important insight to egg quality. Understanding how processing and handling procedures affect both dynamic and static shell properties can enhance the safety and quality of eggs reaching the consumer. A study was conducted to determine if dynamic shell properties were altered due to modified pressure microcrack detection technology exposure in brown and white shell eggs. Three replicates of 100 eggs each of brown and white retail shell eggs were conducted. Dynamic stiffness (K(dyn)) and egg weight were monitored immediately before and after microcrack detection. No changes in K(dyn) or egg weight were detected for either shell color. Static compression shell strength and deformation were subsequently monitored and a correlation analysis conducted. A strong correlation (R(2) = 0.53; P < 0.0001) between K(dyn) and static compression shell strength was seen for extra large white shell eggs. A smaller (R(2) = 0.31; P < 0.0001) correlation was found for large brown eggs. The use of modified pressure microcrack detection technology did not affect shell dynamic properties. PMID:22991554

Jones, D R; Broussard, V; Lawrence, K C; Yoon, S C; Heitschmidt, G W

2012-10-01

102

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

103

Pressure ulcer  

MedlinePLUS

A pressure ulcer is an area of skin that breaks down when something keeps rubbing or pressing against the skin. ... form. You are more likely to get a pressure ulcer if you: Use a wheelchair or stay in ...

104

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

105

Barometric pressure  

NASA Technical Reports Server (NTRS)

The effects of alterations in barometric pressure on human beings are described. Human tolerances for gaseous environments and low and high barometric pressure are discussed, including effects on specific areas, such as the ear, lungs, teeth, and sinuses. Problems due to trapped gas within the body, high dynamic pressures on the body, and blasts are also considered.

Billings, C. E.

1973-01-01

106

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.

Robertson, William C.

2005-01-01

107

Development of flightweight static face seals for 75.84 MPa /11 000 psi/ pressure and cryogenic temperatures  

NASA Technical Reports Server (NTRS)

The development of a static seal configuration to meet the lightweight low-leakage requirements of the Space Shuttle Main Engine (pressure carrying capability of up to 75.84 MPa) is discussed. The design features, fabrication methods, lab testing, and performance of seal are examined. Flange and bolt details of the joint assembly are considered with attention to an ultrasonic technique for measuring preload in the bolts. Methods used for leak testing in the laboratory and in the field are described; the practicality of the procedures is considered. Attention is directed to hydrogen-environment embrittlement and its influence on seal and joint design.

Daniels, C. M.

1978-01-01

108

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

109

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

110

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.

History, American M.

2002-01-01

111

Pressure ulcers  

PubMed Central

Introduction Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions in people at risk of developing pressure ulcers? What are the effects of treatments in people with pressure ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 64 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: air-filled vinyl boots, air-fluidised supports, alternating-pressure surfaces (including mattresses), alternative foam mattresses, constant low-pressure supports, debridement, electric profiling beds, electrotherapy, hydrocellular heel supports, low-air-loss beds (including hydrotherapy beds), low-level laser therapy, low-tech constant-low-pressure supports, medical sheepskin overlays, nutritional supplements, orthopaedic wool padding, pressure-relieving overlays on operating tables, pressure-relieving surfaces, repositioning (regular "turning"), seat cushions, standard beds, standard care, standard foam mattresses, standard tables, surgery, therapeutic ultrasound, topical lotions and dressings, topical negative pressure, and topical phenytoin. PMID:21524319

2011-01-01

112

Pressure ulcers  

PubMed Central

Introduction Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to a third of people in hospitals or community care, and a fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions in people at risk of developing pressure ulcers? What are the effects of treatments in people with pressure ulcers? We searched: Medline, Embase, The Cochrane Library and other important databases up to February 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 60 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: air-filled vinyl boots, air-fluidised supports, alternating pressure surfaces (including mattresses), alternative foam mattresses, constant low-pressure supports, debridement, electric profiling beds, electrotherapy, hydrocellular heel supports, low-air-loss beds (including hydrotherapy beds), low-level laser therapy, low-tech constant low-pressure supports, medical sheepskin overlays, nutritional supplements, orthopaedic wool padding, pressure-relieving overlays on operating tables, pressure-relieving surfaces, repositioning (regular "turning"), seat cushions, standard beds, standard care, standard foam mattresses, standard tables, surgery, therapeutic ultrasound, topical lotions and dressings, topical negative pressure, and topical phenytoin. PMID:19450317

2008-01-01

113

Pressurized Sleeve  

NASA Technical Reports Server (NTRS)

Garment part sustains pressure differential without unduly restricting the user. Sleeve withstands pressure difference of 8 lb/in2 while allowing wearer fairly easy movement. Sleeve consists of low-torque joint hardware, sewn fabric sections, and lengthwise strips of fabric that restrain sections.

Lerner, Amy

1988-01-01

114

Tritium pressure gauge  

SciTech Connect

A pressure gauge based on a tritium beta source is described. The working pressure range is 10/sup -3/-10/sup -5/ torr, and the output voltage of the gauge is measured by a static voltmeter. The advantages and disadvantages of the gauge are discussed.

Voitenko, V.A.; Gul'ko, V.M.; Kolomiets, N.F.; Sviridov, A.M.; Shikanov, A.E.; Yakovlev, K.I.

1987-10-01

115

Wetting and spreading of nanofluids on solid surfaces driven by the structural disjoining pressure: statics analysis and experiments.  

PubMed

The wetting and spreading of nanofluids composed of liquid suspensions of nanoparticles have significant technological applications. Recent studies have revealed that, compared to the spreading of base liquids without nanoparticles, the spreading of wetting nanofluids on solid surfaces is enhanced by the structural disjoining pressure. Here, we present our experimental observations and the results of the statics analysis based on the augmented Laplace equation (which takes into account the contribution of the structural disjoining pressure) on the effects of the nanoparticle concentration, nanoparticle size, contact angle, and drop size (i.e., the capillary and hydrostatic pressure); we examined the effects on the displacement of the drop-meniscus profile and spontaneous spreading of a nanofluid as a film on a solid surface. Our analyses indicate that a suitable combination of the nanoparticle concentration, nanoparticle size, contact angle, and capillary pressure can result not only in the displacement of the three-phase contact line but also in the spontaneous spreading of the nanofluid as a film on a solid surface. We show here, for the first time, that the complete wetting and spontaneous spreading of the nanofluid as a film driven by the structural disjoining pressure gradient (arising due to the nanoparticle ordering in the confined wedge film) is possible by decreasing the nanoparticle size and the interfacial tension, even at a nonzero equilibrium contact angle. Experiments were conducted on the spreading of a nanofluid composed of 5, 10, 12.5, and 20 vol % silica suspensions of 20 nm (geometric diameter) particles. A drop of canola oil was placed underneath the glass surface surrounded by the nanofluid, and the spreading of the nanofluid was monitored using an advanced optical technique. The effect of an electrolyte, such as sodium chloride, on the nanofluid spreading phenomena was also explored. On the basis of the experimental results, we can conclude that a nanofluid with an effective particle size (including the electrical double layer) of about 40 nm, a low equilibrium contact angle (<3°), and a high effective volume concentration (>30 vol %) is desirable for the dynamic spreading of a nanofluid system with an interfacial tension of 0.5 mN/m. Our experimental observations also validate the major predications of our theoretical analysis. PMID:21395240

Kondiparty, Kirti; Nikolov, Alex; Wu, Stanley; Wasan, Darsh

2011-04-01

116

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

117

The Effect of Static Ear Canal Pressure on Human Spontaneous Otoacoustic Emissions: Spectral Width as a Measure of the Intra-cochlear Oscillation Amplitude  

PubMed Central

Spontaneous otoacoustic emissions can be detected as peaks in the Fourier spectrum of a microphone signal recorded from the ear canal. The height, center frequency, and spectral width of SOAE peaks changed when a static pressure was applied to the ear canal. Most commonly, with either increasing or decreasing static pressure, the frequency increased, the amplitude decreased, and the width increased. These changes are believed to result from changes in the middle ear properties. Specifically, reduced middle ear transmission is assumed to attenuate the amplitude of emissions. We reconsidered this explanation by investigating the relation between peak height and width. We showed that the spectral width of SOAE peaks is approximately proportional to \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ 1/\\sqrt {{{\\hbox{peak}}\\;{\\hbox{height}}}} $$\\end{document}. This is consistent with a (Rayleigh) oscillator model in which broadening of the SOAE peak is caused by broadband intra-cochlear noise, which is assumed to be independent of static ear canal pressure. The relation between emission peak height and width implicates that the intra-cochlear oscillation amplitude attentuates relative to the intra-cochlear noise level when a static ear canal pressure is applied. Apparently, ear canal static pressure directly affects the active mechanics in the inner ear. PMID:21061039

Maat, Bert; de Kleine, Emile

2010-01-01

118

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.

119

Static ultra-high pressure study of lanthanide and actinide metals using a diamond-anvil cell  

SciTech Connect

Structural phase transformation in lanthanides and actinides were investigated as a function of pressure up to 300 GPa at room temperature. Except in Ce and Pr, no large volume changes were noticed for these metals as thy went through several phase changes. The appearance of a bct ultra-high pressure phase in Ce, Sm, Th, and possibly in Np, raises the possibility that the ultimate high pressure structure for the 4f and 5f metals may be the bct structure. On the other hand, it is also possible that this is a precursor to another close-packed structure at even higher pressure.

Akella, J.; Smith, G.S.; Weir, S.T.

1993-06-30

120

Under Pressure  

NSDL National Science Digital Library

Students learn about Pascal's law, an important concept behind the engineering of dam and lock systems, such as the one that Thirsty County wants Splash Engineering to design for the Birdseye River (an ongoing hypothetical engineering scenario). Students observe the behavior of water in plastic water bottles spilling through holes punctured at different heights, seeing the distance water spurts from the holes, learning how water at a given depth exerts equal pressure in all directions, and how water at increasing depths is under increasing pressure.

Integrated Teaching And Learning Program

121

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

122

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.

Christian, Wolfgang; Belloni, Mario

2008-02-09

123

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

124

Blood pressure measurement  

MedlinePLUS

Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... bare. You or your doctor will wrap the blood pressure cuff snugly around your upper arm. The ...

125

Brine Flow Up a Borehole Caused by Pressure Perturbation From CO2 Storage: Static and Dynamic Evaluations  

EPA Science Inventory

Industrial-scale storage of CO2 in saline sedimentary basins will cause zones of elevated pressure, larger than the CO2 plume itself. If permeable conduits (e.g., leaking wells) exist between the injection reservoir and overlying shallow aquifers, brine could be pushed upwards al...

126

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

127

Understanding Blood Pressure Readings  

MedlinePLUS

Understanding Blood Pressure Readings Updated:Sep 3,2014 Blood pressure is typically recorded as two numbers, written as a ... blood). What is the AHA recommendation for healthy blood pressure? This chart reflects blood pressure categories defined ...

128

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

129

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

130

Measuring Absolute Oxygen Pressure  

NASA Technical Reports Server (NTRS)

Sensor determines absolute pressure of oxygen without reference pressure source. Absolute oxygen pressure transducer with control circuit enables measurement without reference pressure. Transducer, two part device, combines solid electrolyte membranes sensor with diffusional orifice. Device adapted for direct control of oxygen pressure in combustion mixtures.

Richter, R.

1985-01-01

131

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 ...

132

High Blood Pressure  

MedlinePLUS

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

133

High Blood Pressure (Hypertension)  

MedlinePLUS

... Women and Diabetes Heart Health for Women High Blood Pressure (Hypertension) Print and Share (PDF 109 KB) ... very sick or even die. What does high blood pressure do to your body? High blood pressure ...

134

High Blood Pressure  

MedlinePLUS

... normal blood pressure 140/90 or higher is high blood pressure Between 120 and 139 for the top number, ... prehypertension. Prehypertension means you may end up with high blood pressure, unless you take steps to prevent it. High ...

135

Hypertension (High Blood Pressure)  

MedlinePLUS

... of pregnant women get this condition. How Does High Blood Pressure Affect the Body? High blood pressure adds to ... treated immediately. Back Continue How Do Doctors Diagnose High Blood Pressure? For most teens, the only way to know ...

136

Pressure probe designs for dynamic pressure measurements in a supersonic flow field  

Microsoft Academic Search

A series of dynamic flow field pressure probes were developed for use in large-scale supersonic wind tunnels at NASA Glenn Research Center. These flow field probes include pitot, static, and five-hole conical pressure probes that are capable of capturing fast acting flow field pressure transients that occur on a millisecond time scale. The pitot and static probes can be used

A. Robert Porro

2001-01-01

137

In Situ Measurement of Magnesium Carbonate Formation from CO2 Using Static High-Pressure and -Temperature 13  

E-print Network

-like conditions. I. INTRODUCTION Due to rising carbon levels in the atmosphere, there is much interestIn Situ Measurement of Magnesium Carbonate Formation from CO2 Using Static High method that possesses the ability to monitor the chemical evolution of supercritical CO2 in relevant

Skemer, Philip

138

Confusion about Pressure.  

ERIC Educational Resources Information Center

Listed are errors students make by accepting misconceptions about pressure and precautions teachers might take to avoid fostering those misconceptions. Misconceptions discussed include pressure as a measure of energy per unit volume, fluid flow only from high to low pressure, and the lack of pressures lower than a vacuum. (CW)

Kuethe, Dean O.

1991-01-01

139

Pressure and Substitution Effects on Transport and Magnetic Properties of Y1-xRxCo2 Systems with Static Magnetic Disorder  

NASA Astrophysics Data System (ADS)

The electrical resistivity and thermopower of light- and heavy-rare-earth-based pseudo-binary Y1-xRxCo2 (R = Nd, Gd, and Tb) alloys are measured at temperatures from 2 to 300 K under pressures up to 3.5 GPa. The resistivity and thermopower of Y1-xRxCo2 show unusual large variations with atomic substitution and pressure in the range of xstatic magnetic disorder in the itinerant Co 3d electron subsystem. We found that there is a universal relationship between d ln TC/dP and x/xm in Y1-xRxCo2 alloys, where xm is the boundary composition, which separates the alloy phase diagram into regions with uniform and nonuniform magnetizations of the Co-3d electron subsystem.

Takeda, Masataka; Teruya, Atsushi; Watanabe, Shintaro; Hirakawa, Sentaro; Hiranaka, Yuichi; Nakamura, Ai; Takaesu, Yoshinao; Uchima, Kiyoharu; Hedo, Masato; Nakama, Takao; Yagasaki, Katsuma; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Burkov, Alexander T.

2013-01-01

140

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 ...

Cross, Mrs.

2005-11-29

141

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.

University, Colorado S.

2009-01-01

142

A comparative study on failure pressure estimations of GFRP pressure vessels using Acoustic Emission technique  

Microsoft Academic Search

There is a need of design a reliable light weight composite pressure vessel for a launch vehicle or missile system. The composite pressure vessel acted upon by static internal pressure and dynamic during flight, but for practical structural integrity purposes, consideration of internal pressure is all that is necessary. This paper examines the performance of 6-litre capacity cylindrical Glass fiber

R. Joselin; M. Enamuthu; K. M. Usha; E. S. Vasudev; T. Chelladurai

2010-01-01

143

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

144

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

145

Pressure transmitter accuracy.  

PubMed

This paper discusses the key causes of calibration drift in pressure transmitters and procedures for calibrating pressure transmitters to ensure their accuracy. Calibrating pressure transmitters involves adjusting the potentiometers in the sensor that controls the zero (lowest pressure at which a transmitter is calibrated) and span (the range of pressure the transmitter is to indicate) of the transmitter. The initial or bench calibration of pressure transmitters involves using a constant pressure source such as a deadweight tester. Once the transmitters are installed, temperature, pressure, humidity, vibration, maintenance activities, and normal aging can degrade their accuracy. Transmitter accuracy can also be degraded by transmitter sensing lines, when the water in a sensing line reference leg boils off, when non-condensable gases in the reference leg dissolve, and when voids, blockages, freezing, or leakage occur in sensing lines. On-line calibration techniques enable plants to avoid these accuracy problems by monitoring the output of an individual transmitter. PMID:19482281

Hashemian, H M; Jiang, Jin

2009-10-01

146

Blood Pressure Medicines  

MedlinePLUS

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

147

Bedsores (Pressure Ulcers)  

MedlinePLUS

... for adults A A A A well-defined superficial pressure ulcer. Overview Bedsores (pressure ulcers), also known ... wash the area with a mild soap and water. Clean open sores on the skin with salt ...

148

High blood pressure medications  

MedlinePLUS

... blood pressure medicine listed below comes in different brand and generic names. One or more of these ... blood vessels, which lowers your blood pressure. Angiotensin II receptor blockers (also called ARBs ) work in about ...

149

Preventing pressure ulcers  

MedlinePLUS

Decubitus ulcer prevention; Bedsore prevention; Pressure sores prevention ... care protocol: Skin safety protocol: Risk assessment and prevention of pressure ulcers . Institute for Clinical Systems Improvement. 2nd ed. 2007 ...

150

Low Blood Pressure  

MedlinePLUS

... to low blood pressure are an abnormally low heart rate (bradycardia), problems with heart valves, heart attack and ... Resistant Hypertension Pulmonary Hypertension Metabolic Syndrome BP vs. Heart Rate BP Quizzes Myths About High Blood Pressure Your ...

151

High blood pressure - infants  

MedlinePLUS

Hypertension - infants ... and blood vessels The health of the kidneys High blood pressure in infants may be due to kidney or ... Bronchopulmonary dysplasia Renal artery stenosis In newborn babies, high blood pressure is often caused by a blood clot in ...

152

Atmospheric Pressure Indicator.  

ERIC Educational Resources Information Center

Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

Salzsieder, John C.

1995-01-01

153

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

154

Blood pressure measurement.  

PubMed

Blood pressure measurement is an essential clinical skill for all nurses. However, if the procedure is not followed carefully there is potential for error that can adversely affect patient management. Nurses performing blood pressure measurement should be appropriately trained and updated on the procedure and the correct use of equipment. This article outlines the procedure for measuring blood pressure using a conventional mercury or aneroid sphygmomanometer and an electronic blood pressure monitor. It also identifies potential sources of error. PMID:18274413

Wallymahmed, M

155

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

156

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.

Muller, Eric

2004-01-01

157

Flutter spectral measurements using stationary pressure transducers  

NASA Technical Reports Server (NTRS)

Engine-order sampling was used to eliminate the integral harmonics from the flutter spectra corresponding to a case-mounted static pressure transducer. Using the optical displacement data, it was demonstrated that the blade-order sampling of pressure data may yield erroneous results due to the interference caused by blade vibration. Two methods are presented which effectively eliminate this interference yielding the blade-pressure-difference spectra. The phase difference between the differential-pressure and the displacement spectra was evaluated.

Kurkov, A. P.

1980-01-01

158

Peer Pressure and Incentives  

Microsoft Academic Search

AbstractWe study the effects of peer pressure on incentives. To this end, we extend a multiagent model with moral hazard and limited liability by introducing a peer pressure function. We show that the optimal incentive for the less productive agent is more high powered than that for the more productive agent in the case with peer pressure. Moreover, in comparison

Kohei Daido

2006-01-01

159

Microprocessors control pipeline pressure  

Microsoft Academic Search

This study presents a new concept in pipeline pressure limiting which in the past has been accomplished by pneumatic control equipment using gas from the pipeline as the power source. The concept uses a microprocessor-based system which controls pressure through electro hydraulically actuated valves having numerical solenoids as hydraulic pilots. This concept uses fluid under pressure (either air or hydraulic

1981-01-01

160

Neonatal blood pressure regulation  

Microsoft Academic Search

Hypertension is often viewed solely as a disease of the adult. However, early indicators of hypertension are frequently observed in young children and neonates. Having an adequate appreciation of the normal range of infant blood pressure is critical for the appropriate management of the conditions associated with elevated or abnormally low blood pressure. In healthy neonates, systolic blood pressure increases

John Edward Jones; Pedro A Jose

2004-01-01

161

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

162

Dilatometry under high pressure  

Microsoft Academic Search

In order to measure anisotropic compressibilities and thermal expansion of cubic, tetragonal or orthorhombic single crystals under pressure we have miniaturized a high resolution capacitive dilatometer and integrated this device in a high pressure cell within a cryostat which allows a temperature variation from 10 K to 320 K. To minimize the number of electrical lead-throughs from ambient pressure to

Walter H. Fietz; Kai Grube; Hanno Leibrock

2000-01-01

163

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.

Integrated Teaching And Learning Program

164

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

165

Air pressure measurement  

NASA Technical Reports Server (NTRS)

The pressure measurement was made by a Model 830J Rosemont sensor which utilized the principle of a changing pressure to change correspondingly the capacitance of the pressure sensitive element. The sensor's range was stated to be from zero to 100 Torr (14 km); however, the sensor was not activated until an altitude of 20 km (41 Torr) was reached during the balloon ascent. The resolution of the sensor was specified by the manufacturer as infinitesimal; however, associated electronic and pressure readout systems limit the resolution to .044 Torr. Thus in the vicinity of an altitude of 30 km the pressure resolution corresponded to an altitude resolution of approximately 33 meters.

Ballard, H. N.

1978-01-01

166

Gravastars must have anisotropic pressures  

NASA Astrophysics Data System (ADS)

One of the very small number of serious alternatives to the usual concept of an astrophysical black hole is the 'gravastar' model developed by Mazur and Mottola, and a related phase-transition model due to Laughlin et al. We consider a generalized class of similar models that exhibit continuous pressure—without the presence of infinitesimally thin shells. By considering the usual TOV equation for static solutions with negative central pressure, we find that gravastars cannot be perfect fluids—anisotropic pressures in the 'crust' of a gravastar-like object are unavoidable. The anisotropic TOV equation can then be used to bound the pressure anisotropy. The transverse stresses that support a gravastar permit a higher compactness than is given by the Buchdahl Bondi bound for perfect-fluid stars. Finally, we comment on the qualitative features of the equation of state that gravastar material must have if it is to do the desired job of preventing horizon formation.

Cattoen, Celine; Faber, Tristan; Visser, Matt

2005-10-01

167

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

168

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

169

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...examination of all joints, connections and high stress areas. [CGD 95-028, 62 FR...

2010-10-01

170

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

171

JAMA Patient Page: Pressure Ulcers  

MedlinePLUS

... the American Medical Association JAMA PATIENT PAGE Pressure Ulcers A pressure ulcer is an injury to the skin as a ... 203/259-8724. PREVENTION AND TREATMENT OF PRESSURE ULCERS Prevention of pressure ulcers is key because treatment ...

172

Living with High Blood Pressure  

MedlinePLUS

... page from the NHLBI on Twitter. Living With High Blood Pressure If you have high blood pressure (HBP), you' ... If You Have High Blood Pressure Web page. High Blood Pressure and Pregnancy Many pregnant women who have HBP ...

173

The MgSiO3 system at high pressure: Thermodynamic properties of perovskite, postperovskite, and melt from global inversion of shock and static compression data  

Microsoft Academic Search

We present new equation-of-state (EoS) data acquired by shock loading to pressures up to 245 GPa on both low-density samples (MgSiO3 glass) and high-density, polycrystalline aggregates (MgSiO3 perovskite + majorite). The latter samples were synthesized using a large-volume press. Modeling indicates that these materials transform to perovskite, postperovskite, and\\/or melt with increasing pressure on their Hugoniots. We fit our results

Jed L. Mosenfelder; Paul D. Asimow; Daniel J. Frost; David C. Rubie; Thomas J. Ahrens

2009-01-01

174

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

175

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

176

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.

177

Effects of neck exposure to 5.5 mT static magnetic field on pharmacologically modulated blood pressure in conscious rabbits.  

PubMed

Static magnetic fields (SMF) in the millitesla (mT) range have been reported to modulate microcirculatory hemodynamics and/or blood pressure (BP) under pharmacologically modified state in mammals. This study was designed to investigate the acute effects of local application of a SMF to neck or pelvic region under pharmacologically modulated BP; norepinephrine (NE)-induced hypertension as well as an L-type voltage-gated Ca(2+) channel blocker, nicardipine (NIC)-induced hypotension in conscious rabbits. Magnetic flux densities were up to 5.5 mT and the spatial magnetic gradient peaked in neck (carotid sinus baroreceptor) region at the level of approximately 0.06 mT/mm. The duration of exposure was 30 min (including 10 min of pretreatment) and the effects on BP were investigated up to 100 min postexposure. Baroreflex sensitivity (BRS) was estimated from invasive recordings of systolic BP and pulse interval. Neck exposure to 5.5 mT significantly attenuated the pharmacologically induced vasoconstriction or vasodilation, and subsequently suppressed the increase or decrease in BP compared with sham exposure. In contrast, pelvic exposure to 5.5 mT did not significantly antagonized NE-elevated BP or NIC-reduced BP. The neck exposure to 5.5 mT has a biphasic and restorative effect on vascular tone and BP acting to normalize the tone and BP. The neck exposure to 5.5 mT caused a significant increase in BRS in NE-elevated BP compared with sham exposure. The buffering effects of the SMF on increased hemodynamic variability under NE-induced high vascular tone and NIC-induced low vascular tone might be, in part, dependent on baroreflex pathways, which could modulate NE-mediated response in conjunction with Ca(2+) dynamics. PMID:16108042

Okano, Hideyuki; Ohkubo, Chiyoji

2005-09-01

178

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

179

Please cite this article in press as: Birkholzer, J.T., et al., Brine flow up a well caused by pressure perturbation from geologic carbon sequestration: Static and dynamic evaluations. Int. J. Greenhouse Gas Control (2011), doi:10.1016/j.ijggc.2011.01.003  

E-print Network

by pressure perturbation from geologic carbon sequestration: Static and dynamic evaluations. Int. J.elsevier.com/locate/ijggc Brine flow up a well caused by pressure perturbation from geologic carbon sequestration: Static carbon sequestration (GCS) has drawn increasing con- sideration as a promising method to mitigate

Zhou, Quanlin

180

Pressure vessel flex joint  

NASA Technical Reports Server (NTRS)

An airtight, flexible joint is disclosed for the interfacing of two pressure vessels such as between the Space Station docking tunnel and the Space Shuttle Orbiter bulkhead adapter. The joint provides for flexibility while still retaining a structural link between the two vessels required due to the loading created by the internal/external pressure differential. The joint design provides for limiting the axial load carried across the joint to a specific value, a function returned in the Orbiter/Station tunnel interface. The flex joint comprises a floating structural segment which is permanently attached to one of the pressure vessels through the use of an inflatable seal. The geometric configuration of the joint causes the tension between the vessels created by the internal gas pressure to compress the inflatable seal. The inflation pressure of the seal is kept at a value above the internal/external pressure differential of the vessels in order to maintain a controlled distance between the floating segment and pressure vessel. The inflatable seal consists of either a hollow torus-shaped flexible bladder or two rolling convoluted diaphragm seals which may be reinforced by a system of straps or fabric anchored to the hard structures. The joint acts as a flexible link to allow both angular motion and lateral displacement while it still contains the internal pressure and holds the axial tension between the vessels.

Kahn, Jon B. (inventor)

1992-01-01

181

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

182

Dealing with Peer Pressure  

MedlinePLUS

... neighborhood might want you to shoplift with him. Why Do People Give in to Peer Pressure? Some kids give ... friends wisely." Peer pressure is a big reason why they say this. If you choose friends who don't use drugs , cut class, smoke cigarettes, or lie to their parents, then you probably won't ...

183

Oscillometric blood pressure monitors.  

PubMed

The mercury sphygmomanometer has been used to measure blood pressure for over a century (O'Brien 2000, Smith 2000), but due to the hazards associated with mercury spillage, there is increasing reliance on other methods, such as automatic oscillometric blood pressure monitors and aneroid sphygmomanometers. Within the theatre and recovery areas, the oscillometric method appears to be most common (Ramsey 1991). PMID:11892330

Burton, J

2000-12-01

184

Systolic blood pressure  

Microsoft Academic Search

Once considered an inconsequential part of the aging process, an age-associated rise in systolic blood pressure (SBP) occurs as a consequence of increased arterial stiffness and contributes to a high prevalence of systolic hypertension after middle-age. Elevated SBP imparts a predilection toward the onset of vascular events, highlighting the importance of its control. Current philosophy ranks systolic pressure as the

Stanley S. Franklin

2004-01-01

185

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.

Blauch, David N.

186

High Blood Pressure Medicines  

MedlinePLUS

... 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 have any side effects? All medicines ... effects of high blood pressure medicines include the following: Chest ...

187

Dealing with time pressure  

Microsoft Academic Search

A sample of 250 people completed a questionnaire where they rated 30 statements describing their behavior and experiences during a recent time pressure situation. A factor analysis resulted in three factors: Personal Burden, Work Problems and Difficulties, and Challenge Orientation. People high on this last factor liked the excitement of being under pressure, were very absorbed in the task, and

Robert S. Lee; Patricia McGrath

1995-01-01

188

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.

189

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.

Integrated Teaching And Learning Program

190

33 CFR 183.586 - Pressure impulse test.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Pressure impulse test. 183.586 Section 183.586...order: (a) Perform the static pressure test under § 183.580. (b) If...water. (g) Perform the static pressure test under §...

2010-07-01

191

Telemetry of intracranial pressure  

NASA Technical Reports Server (NTRS)

A completely implantable epidural pressure telemetry system designed for accurate measurement of intracranial pressure (ICP) is described. The implant device is batteryless, providing unlimited operating life. The described system uses a capacitive pressure transducer with excellent long-term stability. Once detected with the transducer and converted to a frequency with the oscillator electronics, the pressure signal is digitized. It is then telemetered without the possibility of further degradation. After detection with the small external module, the data can be retransmitted by a radio link for complete patient mobility or the energizer signal pickup module can be wired to a bedside readout unit. Continuous data are available from the system so that the dynamic ICP changes reflecting arterial blood pressure can be observed and used for diagnosis.

Fryer, T. B.; Corbin, S. D.; Silverberg, G. D.; Schmidt, E. V.; Ream, A. K.

1978-01-01

192

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

193

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

194

Pressure Measurement Systems  

NASA Astrophysics Data System (ADS)

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

195

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

196

Master external pressure charts  

SciTech Connect

This paper presents a method to develop master external pressure charts from which individual external pressure charts for each material specification may be derived. The master external charts can represent a grouping of materials with similar chemical composition, similar stress-strain curves but produced to different strength levels. External pressure charts are used by various Sections of the ASME Boiler and Pressure Vessel and Piping Codes to design various components such as cylinders, sphered, formed heads, tubes, piping, rings and other components, subjected to external pressure or axial compression loads. These charts are pseudo stress-strain curves for groups of materials with similar stress-strain shapes. The traditional approach was originally developed in the 1940`s and is a graphical approach where slopes to the strain curves are drawn graphically from which pseudo-strain levels are calculated. The new method presented in this paper develops mathematical relationships for the material stress-strain curves and the external pressure charts. The method has the ability to calculate stress-strain curves from existing external pressure charts. The relationships are a function of temperature, the modulus of elasticity, yield strength, and two empirical material constants. In this approach, conservative assumptions used to assign materials to lower bound external pressure charts can be removed. This increases the buckling strength capability of many materials in the Code, providing economic benefits while maintaining the margin of safety specified by the Code criteria. The method can also reduce the number of material charts needed in the Code and provides for the capability to extend the existing pressure charts to higher design temperatures. The new method is shown to contain a number of improvements over the traditional approach and is presently under consideration by appropriate ASME Code committees.

Michalopoulos, E. [Hartford Steam Boiler Inspection and Insurance Co., CT (United States). Codes and Standards Dept.

1996-12-01

197

Pressure relieving support surfaces (PRESSURE) trial: cost effectiveness analysis  

Microsoft Academic Search

Objective To assess the cost effectiveness of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers in patients admitted to hospital. Design Cost effectiveness analysis carried out alongside the pressure relieving support surfaces (PRESSURE) trial; a multicentre UK based pragmatic randomised controlled trial. Setting 11 hospitals in six UK NHS trusts. Participants Intention to treat

Cynthia Iglesias; Jane Nixon; Gillian Cranny; E Andrea Nelson; Kim Hawkins; Angela Phillips; David Torgerson

2006-01-01

198

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

199

Past Work on Isolated Airways and ASM Previous studies have examined the static pressure-area relationships of isolated airways1  

E-print Network

· Labview GUI · Outputs pulse train and step function to stepper motor driver · Inputs and records flow Development for Measuring Dynamic Pressure-Area Relationships in Isolated Airways A.S. LaPrad, D.A. Affonce thicker in asthma · Causes reduction in airway diameter, increased airway resistance

Lutchen, Kenneth

200

Nonlinear optomechanical pressure  

E-print Network

A transparent material exhibits ultra-fast optical nonlinearity and is subject to optical pressure if irradiated by a laser beam. However, the effect of nonlinearity on optical pressure is often overlooked, even if a nonlinear optical pressure may be potentially employed in many applications, as optical manipulation, biophysics, cavity optomechanics, quantum optics, optical tractors, and is relevant in fundamental problems as the Abraham-Minkoswky dilemma, or the Casimir effect. Here we show that an ultra-fast nonlinear polarization gives indeed a contribution to the optical pressure that also is negative in certain spectral ranges; the theoretical analysis is confirmed by first-principles simulations. An order of magnitude estimate shows that the effect can be observable by measuring the deflection of a membrane made by graphene.

Claudio Conti; Robert Boyd

2014-03-08

201

Portable Dynamic Pressure Calibrator  

NASA Technical Reports Server (NTRS)

A portable, dynamic pressure calibrator was fabricated for use on wind tunnel models at NASA-Ames Research Center. The calibrator generates sine wave pressures at levels up to 1 PSIG P-P(168dB) at frequencies from 10Hz to 6KHz and .5 PSIG P.P (162dB) at frequencies from 6KHz to 20KHz. The calibrator consists of two units connected by a single cable. The handheld unit contains a pressure transducer, speaker, and deadman switch. This unit allows application of dynamic pressure to transducers/ports on installed wind tunnel models. The base unit contains all of power supplies, controls and displays. This unit allows amplitude and frequency to be set and verified at a safe location off of the model.

Wright, Morgan S.; Maynard, Everett (Technical Monitor)

1996-01-01

202

Nonlinear optomechanical pressure  

NASA Astrophysics Data System (ADS)

A transparent material exhibits ultrafast optical nonlinearity and is subject to optical pressure if irradiated by a laser beam. However, the effect of nonlinearity on optical pressure is often overlooked, even if a nonlinear optical pressure may be potentially employed in many applications, such as optical manipulation, biophysics, cavity optomechanics, quantum optics, and optical tractors, and is relevant in fundamental problems such as the Abraham-Minkoswky dilemma or the Casimir effect. Here, we show that an ultrafast nonlinear polarization gives indeed a contribution to the optical pressure that also is negative in certain spectral ranges; the theoretical analysis is confirmed by first-principles simulations. An order-of-magnitude estimate shows that the effect can be observable by measuring the deflection of a membrane made by graphene.

Conti, Claudio; Boyd, Robert

2014-03-01

203

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

204

Blood Pressure Checker  

NASA Technical Reports Server (NTRS)

An estimated 30 million people in the United States have high blood pressure, or hypertension. But a great many of them are unaware of it because hypertension, in its initial stages, displays no symptoms. Thus, the simply-operated blood pressure checking devices now widely located in public places are useful health aids. The one pictured above, called -Medimax 30, is a direct spinoff from NASA technology developed to monitor astronauts in space. For manned space flights, NASA wanted a compact, highly-reliable, extremely accurate method of checking astronauts' blood pressure without the need for a physician's interpretive skill. NASA's Johnson Space Center and Technology, Inc., a contractor, developed an electronic sound processor that automatically analyzes blood flow sounds to get both systolic (contracting arteries) and diastolic (expanding arteries) blood pressure measurements. NASA granted a patent license for this technology to Advanced Life Sciences, Inc., New York City, manufacturers of Medimax 30.

1979-01-01

205

High Blood Pressure  

MedlinePLUS

... need antihypertensive medicine? What are the risks and benefits of taking this medicine? Could alternative therapies such as meditation, yoga or acupuncture help lower my blood pressure? Bibliography American Heart ...

206

Fluid Pressure and Flow  

NSDL National Science Digital Library

Explore pressure in the atmosphere and underwater. Reshape a pipe to see how it changes fluid flow speed. Experiment with a leaky water tower to see how the height and water level determine the water trajectory.

Simulations, Phet I.; Reid, Sam; Podolefsky, Noah; Paul, Ariel; Loeblein, Trish; Perkins, Kathy

2012-05-29

207

Sustained Pressure Perfusion Method.  

National Technical Information Service (NTIS)

A reliable and effective method of perfusing animal tissue in vivo under a constantly monitored pressure was described. The method was successfully used for perfusion of brain tissues of Cebus apella monkeys. Using the proper fixative, this method can be ...

L. J. Ackerman, R. S. Demaree, D. L. Anderson

1971-01-01

208

High Blood Pressure in Pregnancy  

MedlinePLUS

High Blood Pressure in Pregnancy What Is High Blood Pressure? Blood pressure is the amount of force exerted by the blood against the walls of ... Are the Effects of High Blood Pressure in Pregnancy? Although many pregnant women with high blood pressure ...

209

Under Pressure A 4-week Blood Pressure Program  

E-print Network

health, and reward you for daily healthy habits. · Raffle prizes, healthy snacks, and free blood pressure. 2-1488 To enroll visit: ucrlearning.ucr.edu What is Blood Pressure? Nutrition and Blood Pressure

Reed, Christopher A.

210

Fullerenes under high pressures  

Microsoft Academic Search

This paper reviews the properties and phases of fullerenes and their derivatives and compounds under high pressures. For obvious reasons most of the paper deals with C60 but the materials reviewed also include C70, simple derivatives of C60, carbon nanotubes, and intercalation compounds of C60 with both acceptors and donors, mainly alkali metals. After a brief overview of high-pressure techniques

B. Sundqvist

1999-01-01

211

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

212

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

213

Liquefaction of sand under low confining pressure  

NASA Astrophysics Data System (ADS)

Undrained behaviour of sand under low cell pressure was studied in static and cyclic triaxial tests. It was found that very loose sand liquefies under static loading with the relative density being a key parameter for the undrained behaviour of sand. In cyclic triaxial tests, pore water pressures built up during the cyclic loading and exceeded the confining cell pressure. this process was accompanied by a large sudden increase in axial deformation. The necessary number of cycles to obtain liquefaction was related to the confining cell pressure, the amplitude of cyclic loading and the relative density of sand. In addition, the patterns of pore water pressure response are different from those of sand samples with different relative densities. The test results are very useful for expounding scour mechanism around coastal structures since they relate to the low stress behaviour of the sand.

Shaoli, Yang; Sandven, Rolf; Grande, Lars

2003-10-01

214

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

215

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

216

PressureMove: Pressure Input with Mouse Movement  

Microsoft Academic Search

We present PressureMove a pressure based interaction technique that enables simultaneous control of pressure input and mouse movement. Simultaneous\\u000a control of pressure and mouse movement can support tasks that require control of multiple parameters, like rotation and translation\\u000a of an object, or pan-and-zoom. We implemented four variations of PressureMove techniques for a 2D position and orientation\\u000a matching task where pressure

Kang Shi; Sriram Subramanian; Pourang Irani

2009-01-01

217

Types of Blood Pressure Medications  

MedlinePLUS

... content was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ... heart disease and stroke. Start exploring today ! Interactive High Blood Pressure Guide Find videos, quizzes, trackers and more with ...

218

What Causes High Blood Pressure?  

MedlinePLUS

... page from the NHLBI on Twitter. What Causes High Blood Pressure? Blood pressure tends to rise with age, unless ... cold-relief products. Other medicines also can cause high blood pressure (HBP). If you have HBP, let your doctor ...

219

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.

Integrated Teaching And Learning Program

220

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

221

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

222

Sealed pressure transmission system  

SciTech Connect

A comprehensive program was developed and carried out by The Babcock and Wilcox company (BandW) for the design, fabrication, and testing of both pressure and differential pressure transducers that will operate reliably, accurately, and safely at process operating conditions of 380 psi and 800/degree/F. All of the development work was preformed at the BandW Research and Development Division. The program included the following tasks: project work plan, survey of past experience, and preliminary design; detailed design; and construction, fabrication, and laboratory testing. The field testing was conducted at the Stearns-Catalytic, Inc. coal liquefaction pilot plant located in Wilsonville, Alabama. On completion of the field test, the instrumentation was returned to the BandW Research and Development Center for analysis. A previous report, DOE/PC/7005-9, Sept 1987, documented the development, testing, and evaluation of sealed pressure transmission systems for high-temperature, high-pressure applications such as coal liquefaction. This supplemental report documents the analysis of the pressure system components following the field tests. 12 figs., 1 tab.

Berthold, J.W.; Ghering, W.L.; McCue, T.R.

1988-07-01

223

Diamondoids under high pressure  

NASA Astrophysics Data System (ADS)

Diamondoid molecules are ultra-stable, saturated hydrocarbons consisting of fused carbon cages superimposing on the diamond lattice, originally found in petroleum. These hydrocarbons, especially higher diamondoids, have been of great interest in recent years due to their potential role in nanotechnology, electronics,and medical technologies. However, the large number of possible intermediates, reaction pathways, and complex reaction kinetics make the synthesis of higher diamondoids extremely difficult. Here we report our efforts in investigating the [121] tetramantane at high pressure by combining x-ray diffraction (XRD) and Raman spectroscopy up to 20 GPa. XRD shows that the [121] tetramantane in a monoclinic structure starts to transform into a high pressure phase at approximately 6 GPa and the transition was almost complete at around 20 GPa. In addition, the high pressure phase displays a large metastability field upon decompression. Raman studies also confirmed this phase transition and the metastability of the high pressure phase based on the peak splitting and pressure shifts, as well as changes in the relative intensity of the most intense peaks. Our study may have implications for developing alternative approaches to synthesize higher diamondoids.

Yang, F.; Lin, Y.; Mao, W. L.

2012-12-01

224

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

225

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

226

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

227

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

228

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

229

Questions and Answers about High Blood Pressure  

MedlinePLUS

... High Blood Pressure Questions and Answers About High Blood Pressure What is high blood pressure? Blood pressure is the force of blood ... a doctor. Am I at risk for high blood pressure? Anyone can develop high blood pressure. But ...

230

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

231

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

232

Response of pre-pressurized reinforced plates under blast loading  

Microsoft Academic Search

The effects of pre-pressurization on blast-loaded reinforced rectangular aluminum plates were studied experimentally. Rectangular clamped plates with rivet-attached stiffeners were used as a basic model of the fuselage skin of a commercial aircraft. Both non-pressurized and pre-pressurized plates (static pressure of 41.4kPa) were considered to simulate the typical in-flight loads experienced by a commercial aircraft due to cabin pressurization. This

R. L. Veldman; J. Ari-Gur; C. Clum

2008-01-01

233

For low-speed jet and other turbulent/unsteady flows, conclusion of meanspeed and transverse mean-square fluctuation velocity from sensed time-averaged static-probe and Pitot-probe pressure  

NASA Astrophysics Data System (ADS)

For a usual-form static pressure probe immersed in a low-speed turbulent/unsteady flow, in a meanflow-aligned manner, for the probe head tube diameter do small compared to a freestream large-scale turbulence scale-length l_t, a relation is presented, and explained, between time-averaged sensed pressure p_i, corresponding Pitot pressure P, flow transverse mean-square fluctuation velocity ( ˜ v'^2) = (v'^2)/U^2 (where U is flow meanspeed), and (secondarily) flow streamwise mean-square fluctuation velocity ( ˜ u'^2). A co-occurring relation between P, 0.5?U^2, and (secondarily) ( ˜ u'^2) also is presented, and explained. Here, both pi and P are referenced to a flow effective ambient edge pressure p_e. Each relation is limited to lower-turbulence-level flow. These relations, together with connecting hot-wire-anemometry (hwa) ( ˜ u'^2) determinations, have been used to determine U and (v'^2) distributions across low-speed planar and axisymmetric air jets. Example such distributions are considered. Distributions are compared with present-work hwa U and ( ˜ u'^2) distributions, and other-work hwa, LDA, and PIV distributions. Cross-sectionally inboard of a jet half-meanspeed station, U and (v'^2) values obtained using this approach are as accurate as ones on average determined using other methods. Important factors for present determinations are use of a high-accuracy pressure sensor and computer-implemented data-logging sensed-pressure averaging. Particular advantages and disadvantages for this approach are noted. Use of this approach for other flow forms is considered. Effects on determinations of allowing l_t/do to be only moderately large, or allowing probe meanflow yaw misalignments, are considered.

Fisher, S. S.

2003-11-01

234

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

235

A Pressure Sensitive Home Environment  

Microsoft Academic Search

Homes could be equipped with unobtrusive pressure sensors to monitor older adults. This paper deals with the processing, analysis and communication of pressure sensor outputs that would enable such monitoring. An example is shown of an adult of 63 years who slept over top of a pressure sensor array. Her nocturnal respiratory rate was monitored via the pressure sensor array.

M. Howell Jones; A. Arcelus; R. Goubran; F. Knoefel

2006-01-01

236

Submarine Coaxial Cable Pressure Characteristics  

Microsoft Academic Search

In equalization design of submarine coaxial cable system, the cable attenuation deviation due to pressure in deep sea bottom has significant weight. This paper treats the submarine coaxial cable characteristics pressure dependency. By using an artificial ocean test facility, 1.7 inch submarine coaxial cable attenuation, phase, capacitance and insulator core diameter were studied and their pressure coefficients under a pressure

K. Aida; M. Aiki

1978-01-01

237

What Is High Blood Pressure?  

MedlinePLUS

What is High Blood Pressure? Updated:Sep 4,2014 High blood pressure, also known as HBP or hypertension, is a widely misunderstood medical ... content was last reviewed on 08/04/2014. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

238

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 ... content was last reviewed on 08/04/14. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

239

Dynamic Calibration of Pressure Transducers  

NASA Technical Reports Server (NTRS)

Sinusoidal calibration signal produced in 4- to 100-Hz range. Portable oscillating-pressure device measures dynamic characteristics of pressure transducers installed in models or aircraft at frequency and oscillating-pressure ranges encountered during unsteady-pressure-measurement tests. Calibration is over range of frequencies and amplitudes not available with commercial acoustic calibration devices.

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

1985-01-01

240

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

241

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

242

Pressurized Lunar Rover (PLR)  

Microsoft Academic Search

The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a

Kenneth Creel; Jeffrey Frampton; David Honaker; Kerry McClure; Mazyar Zeinali; Manoj Bhardwaj; Vatsal Bulsara; David Kokan; Shaun Shariff; Eric Svarverud

1992-01-01

243

Pressurized lunar rover  

Microsoft Academic Search

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

Kenneth Creel; Jeffrey Frampton; David Honaker; Kerry McClure; Mazyar Zeinali

1992-01-01

244

Shoes Under Pressure  

NSDL National Science Digital Library

Students explore the basic physics behind walking, and the design and engineering of shoes to accommodate different gaits. They are introduced to pressure, force and impulse as they relate to shoes, walking and running. Students learn about the mechanics of walking, shoe design and common gait misalignments that often lead to injury.

Integrated Teaching And Learning Program

245

Pressure wall patch  

NASA Technical Reports Server (NTRS)

A rigid patch body for placing over a damaged portion (hole) of an external wall of a pressurized vessel, such as a space vehicle or a habitat, is discussed. The rigid patch body allows an astronaut to make temporary repairs to the pressurized vessel from the exterior of the vessel, which enables more permanent repairs to be made from the interior of the vessel. The pressure wall patch of the present invention includes a floor surrounded by four side members. Each side member includes a threaded screw for anchoring the patch body to the external wall of the pressurized vessel and a recess in its lower surface for supporting an inflatable bladder for surrounding the damaged portion (hole) of the external wall to seal the area surrounding the damaged portion. This allows the vessel to be repressurized. The floor of the rigid patch body supports a source of gas that is connected to the gas supply valve and a gas supply gauge in communication with the gas supply valve and the inflatable bladder.

Williamsen, Joel E. (inventor); Weddendorf, Bruce C. (inventor)

1994-01-01

246

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

247

Endoradiosondes for Pressure Telemetering  

Microsoft Academic Search

Two miniature radio transmitters have been developed for telemetering pressure values from internal body cavities. The large sonde has a volume of 4.1 cc and has a lifetime of up to three months when a mercury battery is used. It is employed for physiological studies on animals, and is attached to the wall of the gastrointestinal canal or other body

B. Jacobson; L. Nordberg

1961-01-01

248

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

249

Low pressure turbine installation  

Microsoft Academic Search

Low-pressure turbine installation is described comprising a casing, at least two groups of turbine stages mounted in said casing, each turbine stage having blades so arranged that a flow of steam passes through the respective turbine stages in contraflow manner, partition means in said casing for separating the opposed final stages of said turbine stages from each other, and steam

N. Iizuka; K. Hisano; S. Ninomiya; Y. Otawara

1976-01-01

250

Aircraft Performance: Atmospheric Pressure  

E-print Network

· Factors in: ­ Weather ­ Aerodynamic Lift ­ Flight Instrument · Altimeter · Vertical Speed Indicator is less efficient in thin air) ­ Reduces Lift (thin air exerts less force on the airfoils) #12;High Density Altitude (worse performance) · High elevations · Low atmospheric pressures · High

251

The Blood Pressure \\  

Microsoft Academic Search

A tremendous amount of scientific evidence regarding the physiology and physiopathology of high blood pressure combined with a sophisticated therapeutic arsenal is at the disposal of the medical community to counteract the overall public health burden of hypertension. Ample evidence has also been gathered from a multitude of large-scale randomized trials indicating the beneficial effects of current treatment strategies in

Cornel Pater

2005-01-01

252

Combustor oscillation pressure stabilizer  

Microsoft Academic Search

In accordance with the objective of the present invention, the active control of unsteady combustion induced oscillations in a combustion chamber fired by a suitable fuel and oxidizer mixture, such as a hydrocarbon fuel and air mixture, is provided by restructuring and moving the position of the main flame front and thereby increasing the transport time and displacing the pressure

R. S. Gemmen; G. A. Richards; M. T. J. Yip; E. Robey; S. R. Cully; R. E. Addis

1996-01-01

253

Negative Pressure Wound Therapy  

PubMed Central

Executive Summary Objective This review was conducted to assess the effectiveness of negative pressure wound therapy. Clinical Need: Target Population and Condition Many wounds are difficult to heal, despite medical and nursing care. They may result from complications of an underlying disease, like diabetes; or from surgery, constant pressure, trauma, or burns. Chronic wounds are more often found in elderly people and in those with immunologic or chronic diseases. Chronic wounds may lead to impaired quality of life and functioning, to amputation, or even to death. The prevalence of chronic ulcers is difficult to ascertain. It varies by condition and complications due to the condition that caused the ulcer. There are, however, some data on condition-specific prevalence rates; for example, of patients with diabetes, 15% are thought to have foot ulcers at some time during their lives. The approximate community care cost of treating leg ulcers in Canada, without reference to cause, has been estimated at upward of $100 million per year. Surgically created wounds can also become chronic, especially if they become infected. For example, the reported incidence of sternal wound infections after median sternotomy is 1% to 5%. Abdominal surgery also creates large open wounds. Because it is sometimes necessary to leave these wounds open and allow them to heal on their own (secondary intention), some may become infected and be difficult to heal. Yet, little is known about the wound healing process, and this makes treating wounds challenging. Many types of interventions are used to treat wounds. Current best practice for the treatment of ulcers and other chronic wounds includes debridement (the removal of dead or contaminated tissue), which can be surgical, mechanical, or chemical; bacterial balance; and moisture balance. Treating the cause, ensuring good nutrition, and preventing primary infection also help wounds to heal. Saline or wet-to-moist dressings are reported as traditional or conventional therapy in the literature, although they typically are not the first line of treatment in Ontario. Modern moist interactive dressings are foams, calcium alginates, hydrogels, hydrocolloids, and films. Topical antibacterial agents—antiseptics, topical antibiotics, and newer antimicrobial dressings—are used to treat infection. The Technology Being Reviewed Negative pressure wound therapy is not a new concept in wound therapy. It is also called subatmospheric pressure therapy, vacuum sealing, vacuum pack therapy, and sealing aspirative therapy. The aim of the procedure is to use negative pressure to create suction, which drains the wound of exudate (i.e., fluid, cells, and cellular waste that has escaped from blood vessels and seeped into tissue) and influences the shape and growth of the surface tissues in a way that helps healing. During the procedure, a piece of foam is placed over the wound, and a drain tube is placed over the foam. A large piece of transparent tape is placed over the whole area, including the healthy tissue, to secure the foam and drain the wound. The tube is connected to a vacuum source, and fluid is drawn from the wound through the foam into a disposable canister. Thus, the entire wound area is subjected to negative pressure. The device can be programmed to provide varying degrees of pressure either continuously or intermittently. It has an alarm to alert the provider or patient if the pressure seal breaks or the canister is full. Negative pressure wound therapy may be used for patients with chronic and acute wounds; subacute wounds (dehisced incisions); chronic, diabetic wounds or pressure ulcers; meshed grafts (before and after); or flaps. It should not be used for patients with fistulae to organs/body cavities, necrotic tissue that has not been debrided, untreated osteomyelitis, wound malignancy, wounds that require hemostasis, or for patients who are taking anticoagulants. Review Strategy The inclusion criteria were as follows: Randomized controlled trial (RCT) with a sample size of 20 or more Human s

2006-01-01

254

Dynamic Pressure Probes Developed for Supersonic Flow-Field Measurements  

NASA Technical Reports Server (NTRS)

A series of dynamic flow-field pressure probes were developed for use in large-scale supersonic wind tunnels at the NASA Glenn Research Center. These flow-field probes include pitot and static pressure probes that can capture fast-acting flow-field pressure transients occurring on a millisecond timescale. The pitot and static probes can be used to determine local Mach number time histories during a transient event. The flow-field pressure probe contains four major components: 1) Static pressure aerodynamic tip; 2) Pressure-sensing cartridge assembly; 3) Pitot pressure aerodynamic tip; 4) Mounting stem. This modular design allows for a variety of probe tips to be used for a specific application. Here, the focus is on flow-field pressure measurements in supersonic flows, so we developed a cone-cylinder static pressure tip and a pitot pressure tip. Alternatively, probe tips optimized for subsonic and transonic flows could be used with this design. The pressure-sensing cartridge assembly allows the simultaneous measurement of steady-state and transient pressure which allows continuous calibration of the dynamic pressure transducer.

Porro, A. Robert

2001-01-01

255

Does raised intraocular pressure begin in utero?  

PubMed Central

AIM—To determine whether fetal and infant growth, as assessed by weight at birth and weight at 1 year, are related to intraocular pressure.?METHODS—717 men and women born in Hertfordshire between 1920 and 1930, for whom records of birth weight and weight at 1 year were available, were examined. Visual fields were assessed using the Takagi central 25 degree 75 point static threshold screening program. Tonometry was performed using the Perkin's tonometer. The disc was assessed by direct ophthalmoscopy through dilated pupils.?RESULTS—A significant inverse relation was found between systolic blood pressure and birth weight. However, no association was found between birth weight or weight at 1 year and intraocular pressure, cup/disc ratio, or visual field defects.?CONCLUSIONS—There was no evidence to support fetal or infant growth as being important factors for the subsequent development of raised intraocular pressure.?? Keywords: birth weight; intraocular pressure; cup/disc ratio; visual field defects PMID:9924297

Foss, A; Rauf, A; Sayer, A; Evans, J; Cooper, C; Wormald, R; Barker, D

1998-01-01

256

Pressure activated diaphragm bonder  

DOEpatents

A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto.

Evans, Leland B. (Antioch, CA); Malba, Vincent (Livermore, CA)

1997-01-01

257

Pressure activated diaphragm bonder  

DOEpatents

A device is available for bonding one component to another, particularly for bonding electronic components of integrated circuits, such as chips, to a substrate. The bonder device in one embodiment includes a bottom metal block having a machined opening wherein a substrate is located, a template having machined openings which match solder patterns on the substrate, a thin diaphragm placed over the template after the chips have been positioned in the openings therein, and a top metal block positioned over the diaphragm and secured to the bottom block, with the diaphragm retained therebetween. The top block includes a countersink portion which extends over at least the area of the template and an opening through which a high pressure inert gas is supplied to exert uniform pressure distribution over the diaphragm to keep the chips in place during soldering. A heating means is provided to melt the solder patterns on the substrate and thereby solder the chips thereto. 4 figs.

Evans, L.B.; Malba, V.

1997-05-27

258

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

259

Disposable pressure transducers.  

PubMed

We evaluated 12 disposable pressure transducers from 11 manufacturers. All are rated Acceptable and are ranked in four groups. The first two groups have similar performance characteristics. Groups three and four are ranked primarily according to the effect of fluid spills and the ease of achieving accurate dynamic response. Although list prices are somewhat high, negotiated prices are usually lower. Users should weigh advantages and disadvantages against clinical preference and price. PMID:3273951

1988-03-01

260

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

261

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

262

Casual Blood Pressure Methodology  

Microsoft Academic Search

\\u000a The concept of measuring blood pressure (BP) has significantly evolved over the past two centuries, overcoming the challenge\\u000a posed by the well-established, but clearly subjective, art of palpation of the pulse for ‘measures’ other than simply determining\\u000a heart rate. In the United States, the BP cuff was introduced by Cushing in Baltimore in 1901 and in Boston in 1903 (1,2)

Lavjay Butani; Bruce Z. Morgenstern

263

High pressure gas target  

NASA Astrophysics Data System (ADS)

Compact, high pressure, high current gas target features all metal construction and semi-automatic window assembly change. The unique aspect of this target is the domed-shaped window. The Havar alloy window is electron beam welded to a metal ring, thus forming one, interchangeable assembly. The window assembly is sealed by knife-edges locked by a pneumatic toggle allowing a quick, in situ window change.

Gelbart, W.; Johnson, R. R.; Abeysekera, B.

2012-12-01

264

Wideband piezoelectric pressure transducer  

NASA Astrophysics Data System (ADS)

A piezoelectric pressure transducer for pressures of up to 100 MPa was developed, with an operating frequency range from 100 Hz to 1 MHz on the electrical side - sufficiently wide to reproduce pressure profiles of arc discharges with microsecond rise times and millisecond fall times. The sensing element is a disk of TsTS-19 piezoceramic material, 1 mm thick and 5 mm in diameter. It is thermally and electrically insulated from the arc plasma by a compound transmission rod consisting of two quartz crystals 5 mm in diameter and freely sliding inside a teflon sleeve. The 50 mm long waveguide for absorbing acoustic vibrations and thus separating the valid signal from the reflected one consists of brass wires acoustically insulated with epoxy resin and encapsulated into a textolite sleeve with epoxy resin at the other end. A copper housing shields the transducer from electromagnetic interference. The transducer output signal passes through a matching circuit and then a high-impedance voltage divider to a differential amplifier, the latter being shunted by a stabilizing low 1 Mohm resistance at the input. A special feature of this transducer is low-frequency compensation by means of a corrective RC-circuit. After calibration of oscillograms, the transducer has a sensitivity of 1 V/MPa over the 10(-2) to 10 MPa range. Its resolution corresponds to the 2 microsecond maximum rise time of its output signal, with the sensing element located at the end of a shock tube.

Godonyuk, V. A.; Zhuravlev, B. V.; Shedko, I. P.

1986-02-01

265

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

266

Preventing and Caring for Pressure Ulcers (Pressure Sores, Bedsores)  

MedlinePLUS

... new ulcers (see “How do you prevent pressure ulcers? ”). In addition, the doctor or nurse may suggest ... recommendations: Relieve pressure on the area near the ulcer • Do not allow the person to lie or ...

267

Ashcroft Pressure Switch Monitor for Low SCHe Purge Pressure  

SciTech Connect

These 0-15 psig pressure switches are located in the SCHe helium purge lines after PCV-5*23 and before PCV-5*27. The pressure switches monitor the pressure being maintained between the two PCVs and actuate on low pressure of 15 psig. This design is used for each of the SCHe supply lines (4). Electronic output signal is NON-SAFETY (GS).

VAN KATWIJK, C.

2000-06-21

268

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

269

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

SciTech Connect

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 deg. C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min{sup -1}. The nonlinear behavior allows sensitivities equal to 0.6 V l{sup -1} min for flow rates ranging from -2.0 to +2.0 l min{sup -1}, equal to 2.0 V l{sup -1} min for flow rates ranging from -3.0 to -2.0 l min{sup -1} and from +2.0 to +3.0 l min{sup -1}, up to 5.7 V l{sup -1} min at higher flow rates ranging from -7.0 to -3.0 l min{sup -1} and from +3.0 to +7.0 l min{sup -1}. The linear range extends from 3.0 to 7.0 l min{sup -1} with constant sensitivity equal to 5.7 V l{sup -1} min. The sensor is able to detect a flow-rate equal to 1.0 l min{sup -1} with a sensitivity of about 400 mV l{sup -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{sup -1}, corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l{sup -1} min.

Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio [Faculty of Biomedical Engineering, University Campus Bio-Medico, Via Alvaro del Portillo, 21, 00128 Rome (Italy)

2011-02-15

270

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

NASA Astrophysics Data System (ADS)

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.

Saccomandi, Paola; Schena, Emiliano; Silvestri, Sergio

2011-02-01

271

Cryogenic Multichannel Silicon Pressure Sensor  

NASA Technical Reports Server (NTRS)

The dark squares are silicon pressure sensors. They are bonded to a pre-drilled substrate which supports the sensors and multiplex chips. The substrate is bonded to a metallic tubing plate which has individual pressure ports.

1991-01-01

272

Economics of Steam Pressure Reduction  

E-print Network

Economics of Steam Pressure Reduction is a technical paper that addresses the operating and economic advantages associated with the program to lower the steam operating pressure. Evaluation of a testing program will be discussed. The paper...

Sylva, D. M.

273

Stroke and High Blood Pressure  

MedlinePLUS

Stroke and High Blood Pressure Updated:Aug 13,2014 Stroke is America's no. 4 killer and a leading cause of severe, long-term disability. Since managing high blood pressure, also called HBP or hypertension, is the most ...

274

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 ...

275

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 ...

276

Myths about High Blood Pressure  

MedlinePLUS

... you. Keep reading to learn some blood pressure myths. 1) Myth. High blood pressure runs in my family. There ... medication prescriptions. If you drink, limit alcohol. 2) Myth. I don’t use table salt, so I’ ...

277

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

278

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.

Vu Bioengineering Ret Program

279

Pressure alopecia from orthodontic headgear.  

PubMed

Pressure alopecia is a form of nonscarring hair loss that occurs because of chronic pressure. This article reports the appearance of an unusual area of pressure alopecia in a patient who wore headgear. Early diagnosis of this rare pathology is fundamental to obtaining total regression of the disease; although pressure alopecia is initially nonscarring, scarring can develop over time. Orthodontists should be aware that alopecia in predisposed patients can be caused by headgear. PMID:18774092

Leonardi, Rosalia; Lombardo, Claudia; Loreto, Carla; Caltabiano, Rosario

2008-09-01

280

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.

Consortium, The C.

2012-01-13

281

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

282

The Myth of Peer Pressure.  

ERIC Educational Resources Information Center

The construct of peer pressure was examined as part of a qualitative study of the determinants of mental health for 41 high-risk adolescents. While the concept of peer pressure enables adults to explain youths' troubling behaviors, content analysis of the participants' accounts of their lives reveals peer pressure to be a myth. (Author/MKA)

Ungar, Michael T.

2000-01-01

283

Systolic blood pressure and mortality  

Microsoft Academic Search

Summary Background The current systolic blood-pressure threshold for hypertension treatment is 140 mm Hg for all adults. WHO and the International Society of Hypertension have proposed that normal pressure be lower than 130 mm Hg, with an optimum pressure of less than 120 mm Hg. These recommendations are based largely on the assumption that cardiovascular and overall mortality depend in

Sidney Port; Linda Demer; Robert Jennrich; Donald Walter; Alan Garfinkel

2000-01-01

284

Blood Pressure Medicine: Special Instructions  

E-print Network

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 lower my blood pressure and lose weight? · Is it safe for me to do regular physical activity? · What

Bandettini, Peter A.

285

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

286

Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial  

Microsoft Academic Search

Objective To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Design Pragmatic, open, multicentre, randomised controlled trial. Setting 11 hospitals in six NHS trusts. Participants 1972 people admitted to hospital as acute or elective patients. Interventions Participants were randomised to an

Jane Nixon; Gillian Cranny; Cynthia Iglesias; E Andrea Nelson; Kim Hawkins; Angela Phillips; David Torgerson

2006-01-01

287

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

288

Combustor oscillation pressure stabilizer  

SciTech Connect

In accordance with the objective of the present invention, the active control of unsteady combustion induced oscillations in a combustion chamber fired by a suitable fuel and oxidizer mixture, such as a hydrocarbon fuel and air mixture, is provided by restructuring and moving the position of the main flame front and thereby increasing the transport time and displacing the pressure wave further away from the in-phase relationship with the periodic heat release. The restructuring and repositioning of the main flame are achieved by utilizing a pilot flame which is pulsed at a predetermined frequency corresponding to less than about one-half the frequency of the combustion oscillation frequency with the duration of each pulse being sufficient to produce adequate secondary thermal energy to restructure the main flame and thereby decouple the heat release from the acoustic coupling so as to lead to a reduction in the dynamic pressure amplitude. The pulsating pilot flame produces a relatively small and intermittently existing flame front in the combustion zone that is separate from the oscillating main flame front but which provides the thermal energy necessary to effectively reposition the location of the oscillating main flame front out of the region in the combustion zone where the acoustic coupling can occur with the main flame and thereby effectively altering the oscillation-causing phase relationship with the heat of combustion.

Gemmen, R.S.; Richards, G.A.; Yip, M.T.J.; Robey, E.; Cully, S.R.; Addis, R.E.

1996-12-31

289

Clinical management of pressure ulcers.  

PubMed

Pressure ulcers are chronic and difficult to heal. Pressure-reducing devices are clearly superior to a standard hospital mattress in preventing pressure ulcers, but only limited evidence and clinical intuition supports pressure-reducing devices in improving the healing rate of pressure ulcers. Local wound treatment should aim at maintaining a moist wound environment. The choice of a particular dressing depends on wound characteristics, such as the amount of exudate, dead space, or wound location. Nutritional status should be addressed as a process of good care. Debridement may improve time to a clean wound bed, but no clearly superior approach has been demonstrated. PMID:23571035

Thomas, David R

2013-05-01

290

Pressure limiting propellant actuating system  

NASA Technical Reports Server (NTRS)

A pressure limiting propellant activating system for simultaneously limiting the output force while maintaining a constant output pressure from the combustion chamber is described. The propellant actuated system includes an outer barrel, outer housing and a combustion chamber. A main piston is movable in the barrel housing when gas pressure is developed in the combustion chamber. A relief piston is concentrically mounted and fixedly movable with the main piston when gas pressure is exerted from the combustion. A relief piston has a force-activated separation mechanism for limiting the output force while simultaneously maintaining constant output pressure on the main piston from the combustion chamber.

Reese, P. B.; Murphy, D. W. (inventors)

1980-01-01

291

Pressure-confined Lyman-alpha clouds  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

292

The vapor pressures of explosives  

SciTech Connect

The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

2013-01-05

293

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.)

Kristin Shields (Vanden High School REV)

1995-06-30

294

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

295

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

296

Effects of pressure waves  

NASA Technical Reports Server (NTRS)

Two parameters, side on overpressure and side on impulse loads, and their application to the determination of structural damage to buildings and vehicles in the vicinity of an explosion are investigated. Special consideration was given to what constitutes damage and what level of damage is acceptable. Solutions were sorted through the examination of glass breakage, curve fit to bomb damage, overturning of marginal structures (buses, trucks, mobile homes) subject to toppling, and initiation of yielding in either beam or plate structural components. Three different empirical pressure versus impulse diagrams were presented - the first is for minor structural damage involving wrenched joints and partitions, the second is for major damage structural damage with load bearing members at least partially destroyed, and the third is for 50% to 75% of the building demolished. General guidelines were obtained from the results when the accurate structural details are unknown.

1977-01-01

297

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

298

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.

299

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

300

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

301

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

302

High-pressure cryogenic seals for pressure vessels  

NASA Technical Reports Server (NTRS)

This investigation of the problems associated with reliably containing gaseous helium pressurized to 1530 bars (22 500 psi) between 4.2 K and 150 K led to the following conclusions: (1) common seal designs used in existing elevated-temperature pressure vessels are unsuitable for high-pressure cryogenic operation, (2) extrusion seal-ring materials such as Teflon, tin, and lead are not good seal materials for cryogenic high-pressure operation; and (3) several high-pressure cryogenic seal systems suitable for large-pressure vessel applications were developed; two seals required prepressurization, and one seal functioned repeatedly without any prepressurization. These designs used indium seal rings, brass or 304 stainless-steel anvil rings, and two O-rings of silicone rubber or Kel-F.

Buggele, A. E.

1977-01-01

303

CubicPressure, a program to calculate pressure with uncertainty  

NASA Astrophysics Data System (ADS)

A program named CubicPressure has been created and posted on-line at http://netfiles.uiuc.edu/liligao2/CubicPressure/. Its main function is to calculate pressure and its uncertainty at high temperature from the lattice parameters of pressure calibrants with cubic structure. The program includes a number of well-established equations of state (EOS) of MgO, Au, Pt, and NaCl. Users are also allowed to input new EOS in the forms of the 3rd-order Birch-Murnaghan EOS at room temperature and Debye thermal EOS at high temperature. Compared with existing programs, CubicPressure is unique in that it allows the calculation of the uncertainty in pressure, which originates not only from the uncertainties in lattice parameters and temperature, but also from the uncertainties in EOS parameters.

Gao, L.; Li, J.

2006-12-01

304

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

305

Effects of pre-pressurization on blast response of clamped aluminum plates  

Microsoft Academic Search

The effects of static pre-pressurization on the blast response of square aluminum plates were studied both experimentally and numerically. Static pre-pressurization values in the range of 0–62.1kPa (0–9.0psi) were chosen to represent in-flight loads experienced by the outer skin of a commercial aircraft fuselage due to cabin pressurization. Experimentally, a vacuum vessel system was used to apply a static pressure

R. L. Veldman; J. Ari-Gur; C. Clum; A. DeYoung; J. Folkert

2006-01-01

306

Comparison of the existing internally consistent pressure scales at high pressures and high temperatures  

NASA Astrophysics Data System (ADS)

There have been several efforts to determine internally consistent pressure scales for static diamond anvil high pressure study. We decide to extend the choice of pressure scales to include W and Cu. A recent study of Cu claims that electronic theory can constrain cold curve and possibly room temperature isotherm (Greeff et al., 2006, JPCS). We will present our comparison of 6 different pressure scales in regards with the suggested Cu EOS. We have measured angle-dispersive x-ray diffraction of Au, Pt, W, Cu, Ne, and NaCl to directly compare with the current existing EOS. We will also discuss discrepancies in the precise determination of pressure of phase transformations.

Cynn, Hyunchae; Baer, B. J.; MacLeod, S. G.; Evans, W. J.; Lipp, M. J.; Klepeis, J. P.; Jenei, Zs.; Chen, J. Y.; Catalli, K.; Popov, D.; Park, C. Y.

2012-02-01

307

Advanced strain-gage pressure transducer  

NASA Astrophysics Data System (ADS)

Gould, Inc. has developed new strain gage deposition and lead wire attachment processes that have shown significant promise for improved accuracy, higher reliability, and lower cost when applied to strain gage pressure transducers now being used in gas turbine control and diagnostic systems. This report summarizes work efforts to experimentally identify and to validate, via bench tests, the benefits of these new fabrication processes. The results of static accuracy, temperature and pressure cycling, acceleration, vibration, thermal and mechanical shock, and humidity testing are discussed.

Delmonte, J.; Albaugh, H.; Baker, D. S.; Spence, C. B.

1983-03-01

308

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

309

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

310

Practical Management of Pressure Sores  

PubMed Central

Pressure sores are common in the debilitated elderly. Causal factors are unrelieved pressure, shearing forces, friction, and moisture. Preventive measures should be used for all high-risk patients, defined by general condition, mental status, degree of incontinence, amount of activity, and mobility. Principles of treating ulcers include pressure relief, reducing bacterial counts, debriding necrotic tissue, and providing a moist, clean environment. Imagesp2385-ap2389-ap2392-a PMID:21221298

Jordan, John M.

1992-01-01

311

High-Pressure Transducer Package  

NASA Technical Reports Server (NTRS)

Enclosure for silicon device ensures accurate measurements of cryogenic liquids. Package holds silicon sensor in uniform compression around periphery and helps ensure accurate, stable, and repeatable pressure measurements. Mounting assembly housed in package of stainless steel. Materials selected for equality of thermal expansion and for pressure-sealing properties. Besides its high-pressure, low-temperature characteristics, package withstands vibrations as severe as 400 times standard gravitational acceleration at 0 to 2,000 Hz.

Wamstad, D.; Glenn, M.

1987-01-01

312

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

313

14 CFR 23.841 - Pressurized cabins.  

Code of Federal Regulations, 2011 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS...maintain a cabin pressure altitude of not...pressure: (1) Two pressure relief valves to automatically limit the positive pressure differential to...compressor bleed air will create a...

2011-01-01

314

14 CFR 23.841 - Pressurized cabins.  

Code of Federal Regulations, 2013 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS...maintain a cabin pressure altitude of...pressure: (1) Two pressure relief valves to automatically limit the positive pressure differential to...compressor bleed air will create a...

2013-01-01

315

14 CFR 23.841 - Pressurized cabins.  

Code of Federal Regulations, 2012 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS...maintain a cabin pressure altitude of not...pressure: (1) Two pressure relief valves to automatically limit the positive pressure differential to...compressor bleed air will create a...

2012-01-01

316

14 CFR 23.841 - Pressurized cabins.  

...TRANSPORTATION AIRCRAFT AIRWORTHINESS...maintain a cabin pressure altitude of...pressure: (1) Two pressure relief valves to automatically limit the positive pressure differential to...compressor bleed air will create a...

2014-01-01

317

14 CFR 23.841 - Pressurized cabins.  

Code of Federal Regulations, 2010 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS...maintain a cabin pressure altitude of not...pressure: (1) Two pressure relief valves to automatically limit the positive pressure differential to...compressor bleed air will create a...

2010-01-01

318

14 CFR 25.841 - Pressurized cabins.  

Code of Federal Regulations, 2011 CFR

... false Pressurized cabins. 25.841 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...25.841 Pressurized cabins. (a) Pressurized...equipped to provide a cabin pressure altitude of not...

2011-01-01

319

14 CFR 23.843 - Pressurization tests.  

Code of Federal Regulations, 2013 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...complete pressurized cabin, including doors...must be tested as a pressure vessel for the pressure differential specified...positive and negative pressure differential...

2013-01-01

320

14 CFR 23.843 - Pressurization tests.  

Code of Federal Regulations, 2010 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...complete pressurized cabin, including doors...must be tested as a pressure vessel for the pressure differential specified...positive and negative pressure differential...

2010-01-01

321

14 CFR 25.841 - Pressurized cabins.  

Code of Federal Regulations, 2012 CFR

... false Pressurized cabins. 25.841 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...25.841 Pressurized cabins. (a) Pressurized...equipped to provide a cabin pressure altitude of not...

2012-01-01

322

14 CFR 25.841 - Pressurized cabins.  

Code of Federal Regulations, 2013 CFR

... false Pressurized cabins. 25.841 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...25.841 Pressurized cabins. (a) Pressurized...equipped to provide a cabin pressure altitude of not...

2013-01-01

323

14 CFR 23.843 - Pressurization tests.  

Code of Federal Regulations, 2011 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...complete pressurized cabin, including doors...must be tested as a pressure vessel for the pressure differential specified...positive and negative pressure differential...

2011-01-01

324

14 CFR 25.841 - Pressurized cabins.  

... false Pressurized cabins. 25.841 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...25.841 Pressurized cabins. (a) Pressurized...equipped to provide a cabin pressure altitude of not...

2014-01-01

325

14 CFR 25.841 - Pressurized cabins.  

Code of Federal Regulations, 2010 CFR

... false Pressurized cabins. 25.841 Section...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...25.841 Pressurized cabins. (a) Pressurized...equipped to provide a cabin pressure altitude of not...

2010-01-01

326

14 CFR 23.843 - Pressurization tests.  

Code of Federal Regulations, 2012 CFR

...OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS...complete pressurized cabin, including doors...must be tested as a pressure vessel for the pressure differential specified...positive and negative pressure differential...

2012-01-01

327

How Can High Blood Pressure Be Prevented?  

MedlinePLUS

... page from the NHLBI on Twitter. How Can High Blood Pressure Be Prevented? If You Have Normal Blood Pressure ... Is High Blood Pressure Treated?" If You Have High Blood Pressure If you have HBP, you can still take ...

328

33 CFR 159.109 - Pressure test.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Pressure test. 159.109 Section 159.109...Construction, and Testing § 159.109 Pressure test. Any sewage retention tank that is designed to operate under pressure must be pressurized...

2010-07-01

329

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

330

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

331

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

332

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

333

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

334

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

335

High pressure heterogeneous catalysis in a low pressure UHV environment  

SciTech Connect

The major thrust of our research is to carry out for the first time a heterogeneous catalytic reaction that normally is observed only at high pressures (>1 atm) of reactant gas at low pressures (<10{sup {minus}4} Torr) in an ultrahigh vacuum environment. The reaction we have chosen is the steam reforming of methane on a Ni(111) crystal.

Ceyer, S.T.

1990-01-01

336

Statistics of pressure and pressure gradient in homogeneous isotropic turbulence  

NASA Technical Reports Server (NTRS)

The statistics of pressure and pressure gradient in stationary isotropic turbulence are measured within direct numerical simulations at low to moderate Reynolds numbers. It is found that the one-point pdf of the pressure is highly skewed and that the pdf of the pressure gradient is of stretched exponential form. The power spectrum of the pressure P(k) is found to be larger than the corresponding spectrum P(sub G)(k) computed from a Gaussian velocity field having the same energy spectrum as that of the DNS field. The ratio P(k)/P(sub G)(k), a measure of the pressure-field intermittence, grows with wavenumber and Reynolds number as -R(sub lambda)(exp 1/2)log(k/k(sub d)) for k less than k(sub d)/2 where k(sub d) is the Kolmogorov wavenumber. The Lagrangian correlations of pressure gradient and velocity are compared and the Lagrangian time scale of the pressure gradient is observed to be much shorter than that of the velocity.

Gotoh, T.; Rogallo, R. S.

1994-01-01

337

Role of topical negative pressure in pressure ulcer management.  

PubMed

The literature suggests that topical negative pressure can be an effective treatment for severe pressure ulcers. However, research is needed on its effects on variables such as dressing change frequency, quality of life, pain relief and cost-effectiveness. PMID:17334144

Mandal, A

2007-01-01

338

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2013 CFR

...shall be either hydrostatic tests or pneumatic tests. (1) When a hydrostatic test...allowable working pressure. (2) When a pneumatic test is conducted on a pressure vessel...stamped on the nameplate. (3) When a pneumatic test is conducted on piping, the...

2013-10-01

339

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2011 CFR

...shall be either hydrostatic tests or pneumatic tests. (1) When a hydrostatic test...allowable working pressure. (2) When a pneumatic test is conducted on a pressure vessel...stamped on the nameplate. (3) When a pneumatic test is conducted on piping, the...

2011-10-01

340

46 CFR 197.462 - Pressure vessels and pressure piping.  

Code of Federal Regulations, 2012 CFR

...shall be either hydrostatic tests or pneumatic tests. (1) When a hydrostatic test...allowable working pressure. (2) When a pneumatic test is conducted on a pressure vessel...stamped on the nameplate. (3) When a pneumatic test is conducted on piping, the...

2012-10-01

341

A dynamic pressure source for the calibration of pressure transducers  

NASA Technical Reports Server (NTRS)

A dynamic pressure source is described for producing sinusoidally varying pressures of up to 34 kPa zero to peak, over the frequency range of approximately 50 Hz to 2 kHz. The source is intended for the dynamic calibration of pressure transducers. The transducer to be calibrated is mounted near the base of the thick walled aluminum tube forming the vessel so that the pressure sensitive element is in contact with the liquid in the tube. A section of the tube is filled with small steel balls to damp the motion of the 10-St dimethyl siloxane working fluid in order to extend the useful frquency range to higher frequencies than would be provided by an undamped system. The dynamic response of six transducers provided by the sponsor was evaluated using the pressure sources; the results of these calibrations are given.

Vezzetti, C. F.; Hilten, J. S.; Mayo-Wells, J. F.; Lederer, P. S.

1976-01-01

342

Pressurized Lunar Rover (PLR)  

NASA Technical Reports Server (NTRS)

The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long 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, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double Ackermann steering. The primary power of 8 kW is supplied by a dynamic isotope system using a closed Brayton cycle with a xenon-hydrogen mixture as the working fluid. A sodium-sulfur battery serves as the secondary power source. Excess heat produced by the primary power system and other rover systems is rejected by radiators located on the top of the rear cylinder. The total mass of the PLR 2 is 7015 kg. Simplicity and low total weight have been the driving principles behind the design of PLR 1. The overall configuration consists of a 7-m-long, 3-m-diameter cylindrical main vehicle and a two-wheeled trailer. The cylinder of the main body is capped by eight-section, faceted, semi-hemispherical ends. The trailer contains the RTG power source and is not pressurized. The shell of the main body is constructed of a layered carbon fiber/foam/Kevlar sandwich structure. Included in the shell is a layer of water for radiation protection. The layer of water extends from the front of the rover over the crew compartment and creates a safe haven for the crew during a solar flare-up. The carbon fiber provides the majority of the strength and stiffness and the Kevlar provides protection from micrometeoroids. The Kevlar is covered with a gold foil and multi-layer insulation (MLI) to reduce radiation degradation and heat transfer through the wall. A thin thermoplastic layer seals the fiber and provides additional strength.

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; Mcclure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

1992-01-01

343

Pressurized Lunar Rover (PLR)  

NASA Astrophysics Data System (ADS)

The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long 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, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double Ackermann steering. The primary power of 8 kW is supplied by a dynamic isotope system using a closed Brayton cycle with a xenon-hydrogen mixture as the working fluid. pressurized. The shell of the main body is constructed of a layered carbon fiber/foam/Kevlar sandwich structure. %Included in the shell is a layer of water for radiation protection. The layer of water extends from the front of the rover over the crew compartment and creates a safe haven for the crew during a solar flare-up. The carbon fiber provides the majority of the strength and stiffness and the Kevlar provides protection from micrometeoroids. The Kevlar is covered with a gold foil and multi-layer insulation (MLI) to reduce radiation degradation and heat transfer through the wall. @A thin thermoplastic layer seals the fiber and provides additional strength.

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; McClure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

344

Tank Pressure Control Experiment (TPCE)  

NASA Technical Reports Server (NTRS)

The Tank Pressure Control Experiment (TPCE) is a small self-contained STS payload designed to test a jet mixer for cryogenic fluid pressure control. Viewgraphs are presented that describe project organization, experiment objectives and approach, risk management, payload concept and mission plan, and initial test data.

Bentz, Mike

1992-01-01

345

Performance low pressure end blading  

SciTech Connect

This patent describes a method for optimizing thermodynamic performance of a steam turbine by matching a last stage blade flow area to condenser pressure without changing blade sizing and shape. It comprises: the step of adjusting blade angular orientation to set the gaging for an optimum flow area for the designed condenser pressure.

Davids, J.; Silvestri, G.J.

1990-09-25

346

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

347

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

348

Atmospheric-pressure plasma technology  

Microsoft Academic Search

Major industrial plasma processes operating close to atmospheric pressure are discussed. Applications of thermal plasmas include electric arc furnaces and plasma torches for generation of powders, for spraying refractory materials, for cutting and welding and for destruction of hazardous waste. Other applications include miniature circuit breakers and electrical discharge machining. Non-equilibrium cold plasmas at atmospheric pressure are obtained in corona

U. Kogelschatz

2004-01-01

349

Pressure transient in liquid lines  

Microsoft Academic Search

The pressure surge that results from a step change of flow in liquid pipelines, commonly known as water hammer, was analyzed by an eigenfunction method. A differential-integral Pressure wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless

J. G. Sun; X. Q. Wang

1995-01-01

350

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

351

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

352

Pressure-induced Polymerization in Substituted Acetylenes  

NASA Astrophysics Data System (ADS)

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 provides a complementary route to investigate the equilibrium phase space and metastable intermediates during high pressure chemistry, although at a much slower timescale. In this study, we present our results from our ongoing high pressure in situ synchrotron x-ray diffraction and vibrational spectroscopy experiments on substituted acetylenes: tert-butyl acetylene [TBA: (CH3)3-C?CH] and ethynyl trimethylsilane [ETMS: (CH3)3-Si?CH]. We observed that the onset pressure of chemical reactions (at room temperature) in these compounds is significantly higher in static compression (TBA: 11 GPa and ETMS: 26 GPa) when compared to shock input pressures (TBA: 6.1 GPa and ETMS: 6.6 GPa). The products were polymeric in nature, recovered to ambient conditions with little degradation and fully characterized using spectroscopy, calorimetry, and other techniques to identify reaction mechanisms.

Chellappa, Raja; Dattelbaum, Dana; Sheffield, Stephen; Robbins, David

2011-06-01

353

Pressure-induced polymerization in substituted acetylenes  

NASA Astrophysics Data System (ADS)

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: (CH3)3-C=CH] and ethynyl trimethylsilane [ETMS: (CH3)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; Dattelbaum, Dana M.; Sheffield, S. A.; Robbins, David L.

2012-03-01

354

Pressure-induced Polymerization in Substituted Acetylenes  

NASA Astrophysics Data System (ADS)

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 provides a complementary route to investigate the equilibrium phase space and metastable intermediates during high pressure chemistry, although at a much slower timescale. In this study, we present our results from our ongoing high pressure in situ synchrotron x-ray diffraction and vibrational spectroscopy experiments on substituted acetylenes: tert-butyl acetylene [TBA: (CH3)3-C?CH] and ethynyl trimethylsilane [ETMS: (CH3)3-SiC?CH]. We observed that the onset pressure of chemical reactions (at room temperature) in these compounds is significantly higher in static compression (TBA: 11 GPa and ETMS: 26 GPa) when compared to shock input pressures (TBA: 6.1 GPa and ETMS: 6.6 GPa). The products were polymeric in nature, recovered to ambient conditions with little degradation and fully characterized using spectroscopy, calorimetry, and other techniques to identify reaction mechanisms.

Chellappa, Raja; Dattelbaum, Dana; Sheffield, Stephen

2012-02-01

355

Semicontinuous, pressure-swing distillation  

SciTech Connect

The merits of semicontinuous, pressure-swing, azeotropic distillation are examined. In continuous operation, two columns at different pressures are fed streams having compositions on opposite sides of the azeotropic compositions. The distillates, which approach the azeotropic compositions at high and low pressure, are cycled between the columns. In contrast, semicontinuous operation involves only a single distillation column, which has lower investment costs and, when the mixture to be separated is changed, shorter downtimes. An optimal-control algorithm is employed to determine desirable campaigns, and to schedule pressure switch-over policies. Simulation results for the dehydration of tetrahydrofuran, involving a pressure-sensitive azeotrope, indicate that switch-over between steady states occurs quickly with on-spec product removed during 93% of the campaign. The column achieves production rates near 89% of the maximum throughput of a single column in the continuous process and shows superior performance when compared to reverse-batch operation.

Phimister, J.R.; Seider, W.D.

2000-01-01

356

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

357

Challenging the pressure sore paradigm.  

PubMed

This study determines the effectiveness of a new low-unit-cost support system in patients at very high risk of developing pressure sores. In a prospective randomised controlled trial, a low-pressure inflatable mattress and cushion system (Repose) was compared to a dynamic support mattress (Nimbus II) used in conjunction with an alternating-pressure cushion (Alpha TranCell) in 80 patients with fractured neck of femur and high scores on a pressure sore risk assessment scale. All patients received best standard care, including turning at regular intervals. Skin condition was assessed in 17 locations on admission, preoperatively, and seven and 14 days postoperatively. No difference was found between the groups in skin condition or the occurrence and severity of pressure sores at any time point. PMID:10455633

Price, P; Bale, S; Newcombe, R; Harding, K

1999-04-01

358

Pressure transient in liquid lines  

SciTech Connect

The pressure surge that results from a step change of flow in liquid pipelines, commonly known as water hammer, was analyzed by an eigenfunction method. A differential-integral Pressure wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number K. The pressure surge condition, which is mathematically singular, was used in the solution procedure. The exact solutions from numerical calculation of the differential-integral equation provide a complete Pressure transient in the pipe. The problems are also calculated With the general-purpose computer code COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. These solutions were compared with published experimental results, and agreement was good. The effect of turbulence on the pressure transient is discussed in the light of COMMIX calculational results.

Sun, J.G. [Argonne National Lab., IL (United States); Wang, X.Q. [Nuclear Industry Management Institute, Beijing (China)

1995-07-01

359

Pressurized lunar rover  

NASA Astrophysics Data System (ADS)

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.

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

1992-05-01

360

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

361

Airway pressures during positive-pressure ventilation with superimposed oscillations.  

PubMed

This study was undertaken to determine whether oscillations superimposed on a regular ventilatory pattern influence the arterial blood gases and pH and the airway pressures at adequate alveolar ventilation at the onset of inhibition of inspiratory activity. The peak, mean and end-expiratory airway pressures were therefore measured at inhibition of this activity with and without superimposition of oscillations on the ventilatory pattern. It was found that superimposed oscillations lowered the airway pressure only at a low ventilatory frequency, whereas inhibition occurred at almost equal arterial PCO2 and pH values with and without superimposed oscillations on the ventilatory pattern. PMID:2120835

Jonzon, A; Tantalean, J A; Norsted, T; Sedin, G

1990-01-01

362

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

363

Pressure ulcer prevention and management.  

PubMed

This chapter reviews 218 published and unpublished research reports of pressure ulcer prevention and management by nurse researchers and researchers from other disciplines. The electronic databases MEDLINE (1966-July 2001), CINAHL (1982-June 2001), AMED (1985-July 2001), and EI Compedex Plus (1980-June 2001) were selected for the searches because of their focus on health and applied research. Moreover, evaluations of previous review articles and seminal studies that were published before 1966 are also included. Research conducted worldwide and published in English between 1930 and 2001 was included for review. Studies using descriptive, correlational, longitudinal, and randomized control trials were included. This review found that numerous gaps remain in our understanding of effective pressure ulcer prevention and management. Moreover, the majority of pressure ulcer care is derived from expert opinion rather than empirical evidence. Thus, additional research is needed to investigate pressure ulcer risk factors of ethnic minorities. Further studies are needed that examine the impact of specific preventive interventions (e.g., turning intervals based on risk stratification) and the cost-effectiveness of comprehensive prevention programs to prevent pressure ulcers. Finally, an evaluation is needed of various aspects of pressure ulcer management (e.g., use of support surfaces, use of adjunctive therapies) and healing of pressure ulcers. PMID:12092517

Lyder, Courtney H

2002-01-01

364

Parametric instability of pressurized propellant tanks  

NASA Astrophysics Data System (ADS)

Pressurized propellant tanks might become dynamically unstable with detrimental dynamic responses if a dynamic excitation leads to a coupling of pressure oscillations (especially due to the response of axisymmetric modes) with very low damped ovalizing modes. This phenomenon can be described and identified as the so-called parametric instability. During the dynamic qualification test campaign of the new Ariane 5 Cryogenic Upper Stage ESC-A, a parametric instability was observed for sinusoidal tests under certain test conditions with low static pressure in the propellant tank. The parametric instability was identified and an analytical simulation was performed that confirmed the instability. During flight, harmonic excitations might occur due to pressure oscillations within the solid rocket booster. However, the application of the analytical model on flight conditions indicates that the flight behaviour will be stable. This was confirmed by results from additional tests. This paper describes the phenomenon of the parametric instability of pressurized propellant tanks and presents an analytical methodology to assess the risk of the occurrence of a parametric instability.

Albus, Jochen; Dieker, Stefan; ?ry, Huba; Rittweger, Andreas

2008-01-01

365

Blood Pressure and Physical Function  

PubMed Central

Background: Hypertension in older adults is a dynamic process, with significant diurnal fluctuation. Little research has been done on the associations between increased short-term blood pressure variability and blunted night-time dipping in respect to decreased physical function in the elderly. Our aim is to use a cross-sectional analysis to illuminate any associations. Methods: A cross-sectional sub-study (mean age: 72, 67.5% female) was performed on selected participants from the San Diego Population Study (Criqui, et al, 2003). Blood pressure was measured both in the office (3 independent blood pressure readings) and using a 24-hour ambulatory blood pressure monitoring cuff. Blood pressure variability was measured using average real variability (ARV). Physical function was measured using the Short Physical Performance Battery (SPPB) test. Statistical analysis was performed on IBM SPSS Statistics (1911) software. Results: An unadjusted univariate analysis adjusted for age and gender showed associations between 24-hr ARV of SBP (P = .001), 24-hr ARV pulse pressure (P < .001), and percent systolic dipping (P = .011) and SPPB score. After multivariate analysis adjusted for age and gender was performed, the results were substantially attenuated. However, the association of ARV of SBP was not significant with a P-value of .052 and the ARV of pulse pressure remained significant with a P-value of .022. Multivariate hierarchical linear regression models revealed insignificant trends. Conclusions: Increased short-term variability and blunted night-time dipping were associated physical function but were not independent of age and body mass index (BMI). Further research can be done as to the biology of how both age and BMI influence blood pressure patterns. The trends observed in this study may warrant the investigation of abnormal blood pressure patterns in those who are either elderly or have increased BMI.

Forbang, Nketi; Ix, Joachim; Criqui, Michael; Rifkin, Dena

2014-01-01

366

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

367

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

368

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

369

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

370

Study of capillary pressure-saturation relationships using a dynamic pore-scale network model  

Microsoft Academic Search

Current theories of multiphase flow rely on capillary pressure and saturation relationships that are commonly measured under static conditions. Recently, new multiphase flow theories have been proposed that include a new capillary pressure-saturation relationship that is valid under dynamic conditions. In this relationship, the difference between the two fluid pressures is called dynamic capillary pressure, and is assumed to be

T. Gielen; H. Nordhaug; H. Dahle; M. Celia; S. Hassanizadeh

2001-01-01

371

Heat transfer and pressure measurements for the SSME fuel turbine  

NASA Technical Reports Server (NTRS)

A measurement program is underway using the Rocketdyne two-stage Space Shuttle Main Engine (SSME) fuel turbine. The measurements use a very large shock tunnel to produce a short-duration source of heated and pressurized gas which is subsequently passed through the turbine. Within this environment, the turbine is operated at the design values of flow function, stage pressure ratio, stage temperature ratio, and corrected speed. The first stage vane row and the first stage blade row are instrumented in both the spanwise and chordwise directions with pressure transducers and heat flux gages. The specific measurements to be taken include time averaged surface pressure and heat flux distributions on the vane and blade, flow passage static pressure, flow passage total pressure and total temperature distributions, and phase resolved surface pressure and heat flux on the blade.

Dunn, Michael G.; Kim, Jungho

1991-01-01

372

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

373

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

374

Nonlinear opto-mechanical pressure  

E-print Network

A transparent material exhibits ultra-fast optical nonlinearity and is subject to optical pressure if irradiated by a laser beam. However, the effect of nonlinearity on optical pressure is often overlooked, even if a nonlinear optical pressure may be potentially employed in many applications, as optical manipulation, biophysics, cavity optomechanics, quantum optics, optical tractors, and is relevant in fundamental problems as the Abraham-Minkoswky dilemma, or the Casimir effect. Here we show that an ultra-fast nonlinear polarization gives indeed a contribution to the optical pressure that also is negative in certain spectral ranges; the theoretical analysis is confirmed by first-principles simulations. An order of magnitude estimate shows that the effect can be observable by measuring the deflection of a membrane made by graphene.

Conti, Claudio

2014-01-01

375

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

376

Blood Pressure Drugs and AMD  

MedlinePLUS

... risk factors, including hereditary risk and smoking. Some studies have also found an association between AMD and high blood pressure, but this has been inconsistent. Vision Simulator: Age-related macular degeneration To help clarify the relationship between ...

377

High blood pressure tests (image)  

MedlinePLUS

Routine lab tests are recommended before beginning treatment of high blood pressure to determine organ or tissue damage or other risk factors. These lab tests include urinalysis, blood cell count, ...

378

Taking Care of Pressure Sores  

MedlinePLUS

... long. Shearing is also a kind of pressure injury. It happens when the skin moves one way ... you slouch when you sit. Another type of injury, an abrasion, can occur when pulling yourself across ...

379

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

380

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

381

Diet, blood pressure and hypertension.  

PubMed

Prevention of hypertension, and control of blood pressure in patients with hypertension, are necessary for the reduction of cardiovascular morbidity and mortality. Lifestyle modifications are one of the most important tools for effective lowering of blood pressure. Most randomized controlled studies have shown that even a modest weight loss of 3-9% is associated with a significant reduction in systolic and diastolic blood pressure of roughly 3 mm Hg in overweight people. Limitation of sodium chloride in food has historically been considered the critical change for reducing blood pressure. Changes in sodium intake do affect blood pressure in older persons and in patients with hypertension and diabetes, whereas its role in population blood pressure has proven controversial. Recent meta-analyses indicate that adequate intake of minerals, e.g. potassium and probably calcium, rather than restriction of sodium, should be the focus of dietary recommendations. Although epidemiological data point to a direct relation between the intake of saturated fat, starch and alcohol, as well as an inverse relationship to the intake of omega-3 fatty acids and protein, our knowledge about macronutrients and blood pressure is scanty. It may well prove more productive to look at food instead of placing emphasis on single nutrients. Thus the Dietary Approaches to Stop Hypertension (DASH) demonstrates that a diet rich in fruits, vegetables, low-fat dairy products, fibre and minerals (calcium, potassium and magnesium) produces a potent antihypertensive effect. Such a diet is not very restrictive and should not produce compliance problems. Further high-quality research on the influence of macronutrients and food will yield data for updated recommendations, enabling better prevention and control of the blood pressure problem. PMID:10889801

Hermansen, K

2000-03-01

382

Indirect Blood Pressure Measuring Device  

NASA Technical Reports Server (NTRS)

Design and performance of a blood pressure recording device for pediatric use are reported. A strain gage transducer with a copper-beryllium strip as force sensing element is used to monitor skin movements and to convert them into electrical signals proportional to those displacements. Experimental tests with this device in recording of force developed above the left femoral artery of a dog accurately produced a blood pressure curve.

Hum, L.; Cole, C. E.

1973-01-01

383

Ultra high pressure liquid chromatography  

Microsoft Academic Search

The behavior of four similar liquid chromatography columns (2.1mm i.d. ×30, 50, 100, and 150mm, all packed with fine particles, average dp?1.7?m, of bridged ethylsiloxane\\/silica hybrid-C18, named BEH-C18) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived,

Fabrice Gritti; Georges A Guiochon

2008-01-01

384

Monolithic Integrated Pressure Sensor ICs  

Microsoft Academic Search

\\u000a Infineon Technologies AG (formerly Siemens HL) developed a novel surface micromachining technology for pressure sensors. These\\u000a sensors are designed for barometric air pressure sensing in automotive applications. The surface micromachining technology\\u000a enables the product to be calibrated in the final package through on-chip calibration by means of low-power fuses and offers\\u000a the possibility of digital interfacing. A specifically developed SMD-package

V. Gussmann

385

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

386

CC Cryostat Vapor Pressure Thermometers  

SciTech Connect

Vapor pressure thermometers will be used to measure the temperature or the liquid argon in the cryostat at two different levels. One bulb will be positioned near the top of the vessel, and a second bulb will be located near the bottom of the vessel. The volume of the bulbs is dependent upon the charge temperature and pressure chosen, the temperature range of the thermometer desired, the size and length of tubing used, and the warm volume involved.

Kurita, C.H.; /Fermilab

1987-10-01

387

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

388

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.

Institute, Lunar A.; Nasa

2011-01-01

389

MEASURING INTERSTITIAL FLUID PRESSURE WITH FIBEROPTIC PRESSURE TRANSDUCERS  

PubMed Central

In this report we describe a practical procedure for measuring interstitial fluid pressure (IFP) using fiberoptic pressure transducers based on optical interferometry. Eight mice were used for subcutaneous IFP measurements and four mice for intramuscular IFP measurements with a FOBPS-18 fiberoptic pressure transducer. We used four mice for subcutaneous IFP measurements with a SAMBA-420 MR fiberoptic pressure transducer. One measurement was made for each mouse simultaneously by using a fiberoptic system and an established approach, either transducer-tipped catheter or wick-in-needle technique. The mean IFP values obtained in subcutaneous tissues were ?3.00 mm Hg (SEM ?/+?0.462, n=8), ?3.25 mmHg (SEM ?/+ 0.478, n=4), ?3.34mm Hg (SEM?/+ 0.312, n=6), and ?2.85 (SEM ?/+ 0.57, n= 6) for the FOBPS fiberoptic transducer, the SAMBA fiberoptic transducer, the transducer-tipped catheter, and the wick-in–needle technique, respectively. There was no difference between these techniques to measure IFP (Friedman test, p=0.7997). The subcutaneous IFP measurements showed strong linear correlation between fiberoptic transducer and transducer-tipped catheter (R2= 0.9950) and fiberoptic transducer and wick–in-needle technique (R2= 0.9966). Fiberoptic pressure transducers measure the interstitial fluid pressure accurately, comparable to conventional techniques. The simplified IFP measurement procedures described in this report will allow investigators to easily measure IFP, and elucidate the unit pressure change per unit volume change (dP/dV) in normal or cancer tissues in the presence of strong electromagnetic fields encountered in MRI. PMID:18809414

Ozerdem, Ugur

2008-01-01

390

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

391

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

392

Automatic blood pressure measuring system (M092)  

NASA Technical Reports Server (NTRS)

The Blood Pressure Measuring System is described. It measures blood pressure by the noninvasive Korotkoff sound technique on a continual basis as physical stress is imposed during experiment M092, Lower Body Negative Pressure, and experiment M171, Metabolic Activity.

Nolte, R. W.

1977-01-01

393

Pressure ulcers - what to ask your doctor  

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. Below are some questions you may ...

394

Spray bottle apparatus with pressure multiplying pistons  

DOEpatents

The present invention comprises a spray bottle in which the pressure resulting from the gripping force applied by the user is amplified and this increased pressure used in generating a spray such as an aerosol or fluid stream. In its preferred embodiment, the invention includes a high pressure chamber and a corresponding piston which is operative for driving fluid out of this chamber at high pressure through a spray nozzle and a low pressure chamber and a corresponding piston which is acted upon the hydraulic pressure within the bottle resulting from the gripping force. The low pressure chamber and piston are of larger size than the high pressure chamber and piston. The pistons are rigidly connected so that the force created by the pressure acting on the piston in the low pressure chamber is transmitted to the piston in the high pressure chamber where it is applied over a more limited area thereby generating greater hydraulic pressure for use in forming the spray.

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

1990-01-01

395

49 CFR 195.108 - External pressure.  

Code of Federal Regulations, 2010 CFR

... 3 2010-10-01 2010-10-01 false External pressure. 195.108 Section 195.108 Transportation...PIPELINE Design Requirements § 195.108 External pressure. Any external pressure that will be exerted on the pipe must...

2010-10-01

396

Avoid the Consequences of High Blood Pressure  

MedlinePLUS

... Tools & Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

397

Atmospheric-Pressure Plasma Process and Applications.  

National Technical Information Service (NTIS)

This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those ...

P. Kong

2006-01-01

398

49 CFR 230.35 - Pressure testing.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Pressure testing. 230.35 Section 230.35 ...MAINTENANCE STANDARDS Boilers and Appurtenances Pressure Testing of Boilers § 230.35 Pressure testing. The temperature of the...

2010-10-01

399

49 CFR 230.35 - Pressure testing.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Pressure testing. 230.35 Section 230.35 ...MAINTENANCE STANDARDS Boilers and Appurtenances Pressure Testing of Boilers § 230.35 Pressure testing. The temperature of the...

2011-10-01

400

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Maximum allowable operating pressure: High-pressure distribution systems. 192.621 Section 192...Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems....

2010-10-01

401

49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Maximum allowable operating pressure: High-pressure distribution systems. 192.621 Section 192...Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems....

2011-10-01

402

49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems.  

Code of Federal Regulations, 2011 CFR

... false Maximum and minimum allowable operating pressure; Low-pressure distribution systems. 192.623 Section 192...623 Maximum and minimum allowable operating pressure; Low-pressure distribution systems....

2011-10-01

403

49 CFR 192.623 - Maximum and minimum allowable operating pressure; Low-pressure distribution systems.  

Code of Federal Regulations, 2010 CFR

... false Maximum and minimum allowable operating pressure; Low-pressure distribution systems. 192.623 Section 192...623 Maximum and minimum allowable operating pressure; Low-pressure distribution systems....

2010-10-01

404

High pressure synthesis gas conversion. Task 3: High pressure profiles  

SciTech Connect

The purpose of this research project was to build and test a high pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system were procured or fabricated and assembled in our laboratory. This system was then used to determine the effects of high pressure on growth and ethanol production by C. 1jungdahlii. The limits of cell concentration and mass transport relationships were found in CSTR and immobilized cell reactors (ICR). The minimum retention times and reactor volumes were found for ethanol production in these reactors.

Not Available

1993-05-01

405

A microwave pressure sounder. [for remote measurement of atmospheric pressure  

NASA Technical Reports Server (NTRS)

A technique for the remote measurement of atmospheric surface pressure will be described. Such measurements could be made from a satellite in polar orbit and would cover many areas for which conventional meteorological data are not available. An active microwave instrument is used to measure the strength of return echoes from the ocean surface at a number of frequencies near the 60 GHz oxygen absorption band. Factors which affect the accuracy with which surface pressure can be deduced from these measurements will be discussed and an instrument designed to test the method by making measurements from an aircraft will be described.

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

1981-01-01

406

Transformational acoustic metamaterials based on pressure gradients  

E-print Network

We apply a homogenization process to the acoustic velocity potential wave equation. The study of various examples shows that the resulting effective properties are different from those of the homogenized pressure wave equation for the same underlying acoustic parameters. A careful analysis reveals that a given set of inhomogeneous parameters represents an entirely different physical system depending on the considered equation. Our findings unveil a different way of tailoring acoustic properties through gradients of the static pressure. In contrast to standard metafluids based on isobaric composites, this alternative kind of metafluids is suitable for the implementation of transformational devices designed via the velocity potential equation. This includes acoustic systems in a moving background or arising from general space-time transformations. As an example, we design a device able to cloak the acoustic velocity potential.

C. García-Meca; S. Carloni; C. Barceló; G. Jannes; J. Sánchez-Dehesa; A. Martínez

2014-09-18

407

Transformational acoustic metamaterials based on pressure gradients  

E-print Network

We apply a homogenization process to the acoustic velocity potential wave equation. The study of various examples shows that the resulting effective properties are different from those of the homogenized pressure wave equation for the same underlying acoustic parameters. A careful analysis reveals that a given set of inhomogeneous parameters represents an entirely different physical system depending on the considered equation. Our findings unveil a different way of tailoring acoustic properties through gradients of the static pressure. In contrast to standard metafluids based on isobaric composites, this alternative kind of metafluids is suitable for the implementation of transformational devices designed via the velocity potential equation. This includes acoustic systems in a moving background or arising from general space-time transformations. As an example, we design a device able to cloak the acoustic velocity potential.

García-Meca, C; Barceló, C; Jannes, G; Sánchez-Dehesa, J; Martínez, A

2014-01-01

408

Subglottal pressure oscillations accompanying phonation.  

PubMed

Acoustic and aerodynamic properties of the voice source and vocal tract have been extensively analyzed during the last half century. Corresponding investigations of the subglottal system are rare but can be assumed to be relevant to voice production. In the present exploratory study, subglottal pressure was recorded in a male adult subject by means of tracheal puncture. Also recorded were the oral airflow and audio signals. Effects of vowel, phonation type, and vocal register shifts on the subglottal pressure waveform were examined. The moment of maximum flow declination rate was synchronous with the main positive peak of the subglottal pressure waveform. The three lowest subglottal resonance frequencies, determined by inverse filtering and long-term average spectra of the subglottal pressure during speech, were found to be about 500, 1220, and 2000Hz, irrespective of supraglottal variations and phonation type. However, the subglottal pressure waveform was affected by the supraglottal formants, whereas the radiated vowel spectra did not show clear influence by the subglottal resonances. The fundamental frequency immediately preceding and immediately following a register break in pitch glides did not show systematic relationships with formants or with the lowest subglottal resonance. PMID:23809566

Sundberg, Johan; Scherer, Ronald; Hess, Markus; Müller, Frank; Granqvist, Svante

2013-07-01

409

FEA of CMUTs Suitable for Wide Gas Pressure Range Applications  

PubMed Central

The ability of ultrasound transducers to operate over a wide and varying pressure range is essential in applications such as ultrasonic flow metering (UFM) of flare gas. We propose a new operational mode for capacitive micromachined ultrasonic transducers (CMUTs), in which the plate is in permanent contact with the bottom of the cavity, even at zero DC bias and 1 atm pressure. Finite element analysis (FEA) software was used to investigate the performance of these CMUTs within the pressure range of 1 to 20 atm. First, we performed a static analysis to determine the plate deflection and, thus, the gap height. Further, from the static analysis, we obtained the static and free capacitances for calculating the coupling efficiency, and a modal analysis identified possible design geometries for frequencies lower than ~ 300 kHz. Our calculations show that conventionally operated CMUTs have huge changes in static operational point at different pressures, while our proposed mode exhibits an acceptable frequency range (73 – 340 kHz) over 1 – 20 atm pressure and an improved coupling efficiency at lower dc bias voltages. A donut shape partial electrode further allows us to tune the coupling efficiency, which translates into a better performance, especially at the higher pressure range. FEA shows that our proposed operation mode is a promising solution for flare gas metering applications. PMID:21874100

Ho, Min-Chieh; Kupnik, Mario; Khuri-Yakub, Butrus T.

2010-01-01

410

High Pressure Research, 2002, Vol. 22, pp. 121126 PRESSURE EFFECTS ON THE COOPERATIVE  

E-print Network

as pressure transmitting media in order to avoid crystal hydration. The pressure in the hydrostatic cavityHigh Pressure Research, 2002, Vol. 22, pp. 121­126 PRESSURE EFFECTS ON THE COOPERATIVE JAHN variation with the pressure. We show that the crystal-field transition energies and their pressure shifts

Rodríguez, Fernando

411

Linear ruby scale and one megabar. [high pressure fluorescence  

NASA Technical Reports Server (NTRS)

The accuracy and validity of certain techniques used in studying high-pressure transitions have been investigated. Experiments which place upper limits of about 20 GPa and about 50 GPa on pressures practically attainable using uniaxial supported opposed anvil devices with tungsten carbide pistons and uniaxial opposed flat anvil diamond devices, respectively, are reported. Direct static determinations of the transition pressures of GaP by two different methods are described. The values obtained indicate that the linear ruby scale increasingly overestimates the transition pressure as the pressure rises above 10 GPa. It is further shown that the use of shock-based marker materials, such as silver, as the basis of pressure measurement in X-ray diffraction studies leads to bulk moduli of cubic carbides which are in extreme disagreement with expected values.

Ruoff, A. L.

1979-01-01

412

High pressure liquid level monitor  

DOEpatents

A liquid level monitor for tracking the level of a coal slurry in a high-pressure vessel including a toroidal-shaped float with magnetically permeable bands thereon disposed within the vessel, two pairs of magnetic field generators and detectors disposed outside the vessel adjacent the top and bottom thereof and magnetically coupled to the magnetically permeable bands on the float, and signal processing circuitry for combining signals from the top and bottom detectors for generating a monotonically increasing analog control signal which is a function of liquid level. The control signal may be utilized to operate high-pressure control valves associated with processes in which the high-pressure vessel is used.

Bean, Vern E. (Frederick, MD); Long, Frederick G. (Ijamsville, MD)

1984-01-01

413

Welding wire pressure sensor assembly  

NASA Technical Reports Server (NTRS)

The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

Morris, Timothy B. (inventor); Milly, Peter F., Sr. (inventor); White, J. Kevin (inventor)

1994-01-01

414

Optical pressure sealing coupling apparatus  

NASA Technical Reports Server (NTRS)

An apparatus is presented for optically coupling and pressure sealing sections of an instrument probe, one of the section being at a high pressure cryogenic environment and the other section being at ambient pressure. The apparatus includes a housing having a passageway within which elements are mounted for precisely locating a rigid optical fiber coupler and the probe sections so as to optically connect and maintain the ends of the probe sections together to permit signals to pass in both directions through the joint in two or more discrete channels. An adjustable positioning member acts to connect the external section of the probe to the housing in axial and rotation alignment with the interior section.

Irvin, Timothy B. (inventor); French, Richard E. (inventor)

1989-01-01

415

Level indicator for pressure vessels  

DOEpatents

A liquid-level monitor for tracking the level of a coal slurry in a high-pressure vessel including a toroidal-shaped float with magnetically permeable bands thereon disposed within the vessel, two pairs of magnetic-field generators and detectors disposed outside the vessel adjacent the top and bottom thereof and magnetically coupled to the magnetically permeable bands on the float, and signal-processing circuitry for combining signals from the top and bottom detectors for generating a monotonically increasing analog control signal which is a function of liquid level. The control signal may be utilized to operate high-pressure control valves associated with processes in which the high-pressure vessel is used.

Not Available

1982-04-28

416

Melting of Ice under Pressure  

SciTech Connect

The melting of ice under pressure is investigated with a series of first principles molecular dynamics simulations. In particular, a two-phase approach is used to determine the melting temperature of the ice-VII phase in the range of 10 to 50 GPa. Our computed melting temperatures are consistent with existing diamond anvil cell experiments. We find that for pressures between 10 to 40 GPa, ice melts as a molecular solid. For pressures above {approx}45 GPa there is a sharp increase in the slope of the melting curve due to the presence of molecular dissociation and proton diffusion in the solid, prior to melting. The onset of significant proton diffusion in ice-VII as a function of increasing temperature is found to be gradual and bears many similarities to that of a type-II superionic solid.

Schwegler, E; Sharma, M; Gygi, F; Galli, G

2008-07-31

417

Abbreviation Table Abp Blood pressure cvp Central venous pressure  

E-print Network

nur A nurse or Operating room pa Pulmonary artery Pco2 Partial pressure of carbon dioxide Peri-op Peri-operative per A perfusionist Post-op Post-operative Pre-op Pre-operative prp Peer review protocols pt Patient re- geons, nurses, patients) will not appear in any written reports (including transcripts from recorded

Milgram, Paul

418

Stagnation pressure probe. [for measuring pressure of supersonic gas streams  

NASA Technical Reports Server (NTRS)

A method and apparatus for measuring the stagnation pressure of supersonic velocity gas streams without the generation of shock waves which interfere with such measurements are given. The technique is insensitive to the type of gas and Mach number and is therefore particularly useful in the study of jet engine exhausts.

Goodyer, M. J. (inventor)

1974-01-01

419

Pressure relief subsystem design description  

SciTech Connect

The primary function of the Pressure Relief Subsystem, a subsystem of the Vessel System, is to provide overpressure protection to the Vessel System. When the overpressure setpoint is reached, pressure is reduced by permitting the flow of primary coolant out of the Vessel System. This subsystem also provides the flow path by which purified helium is returned to the vessel system, either as circulating purge/flow from the Helium Purification Subsystem or make-up helium from the Helium Storage and Transfer Subsystem.

NONE

1986-07-01

420

Measuring Blood Pressure in Space  

NSDL National Science Digital Library

In this activity (page 105 of the PDF), learners measure heart rate and blood pressure and learn how to obtain consistent measurements during repeated tests. This activity teaches learners how to measure a pulse manually as well as how to use the sphygmomanometer and the stethoscope. Use this activity to discuss how astronauts in space measure their blood pressure and heart rate in space differently. The lesson guide, part of NASA's "The Brain in Space: A Teacher's Guide with Activities for Neuroscience," includes background information, evaluation strategies, and handouts. Note: cost of materials does not include cost of stethoscope or sphygmomanometer; these may be borrowed from a nurse.

Macleish, Marlene Y.; Mclean, Bernice R.

2012-06-26

421

Atmospheric-pressure plasma technology  

NASA Astrophysics Data System (ADS)

Major industrial plasma processes operating close to atmospheric pressure are discussed. Applications of thermal plasmas include electric arc furnaces and plasma torches for generation of powders, for spraying refractory materials, for cutting and welding and for destruction of hazardous waste. Other applications include miniature circuit breakers and electrical discharge machining. Non-equilibrium cold plasmas at atmospheric pressure are obtained in corona discharges used in electrostatic precipitators and in dielectric-barrier discharges used for generation of ozone, for pollution control and for surface treatment. More recent applications include UV excimer lamps, mercury-free fluorescent lamps and flat plasma displays.

Kogelschatz, U.

2004-12-01

422

Partial pressure analysis of plasmas  

SciTech Connect

The application of partial pressure analysis for plasma diagnostic measurements is reviewed. A comparison is made between the techniques of plasma flux analysis and partial pressure analysis for mass spectrometry of plasmas. Emphasis is given to the application of quadrupole mass spectrometers (QMS). The interface problems associated with the coupling of a QMS to a plasma device are discussed including: differential-pumping requirements, electromagnetic interferences from the plasma environment, the detection of surface-active species, ion source interactions, and calibration procedures. Example measurements are presented from process monitoring of glow discharge plasmas which are useful for cleaning and conditioning vacuum vessels.

Dylla, H.F.

1984-11-01

423

Wind pressure distribution on shell structures  

E-print Network

states that since stagnation pressure coefficients cannot exceed +1.0, this will be the maximum pressure that can be expected on a structure (22). This study has proven that it is not the positive pressures but the negative pressures that should govern...

Yancey, Kenneth Earl, Jr

2012-06-07

424

Distortion Of Pressure Signals In Pneumatic Tubes  

NASA Technical Reports Server (NTRS)

NASA technical memorandum describes experimental investigation of distorting effects of propagation of pressure signals along narrow pneumatic tubes from pressure-sensing orifices on surfaces of models or aircraft to pressure sensors distant from orifices. Pressure signals distorted principally by frictional damping along walls of tubes and by reflections at orifice and sensor ends.

Whitmore, Stephen A.; Gilyard, Glenn B.; Curry, Robert; Lindsey, William

1993-01-01

425

Miniature telemetry system accurately measures pressure  

NASA Technical Reports Server (NTRS)

Miniature, low power, telemetry system that can be used with commercially available strain gage pressure transducers accurately measures pressure with a small implantable pressure cell and transmitter. The system has been used to date only with pressure transducers, but the circuit is equally applicable to any measurement using a strain gage sensor.

Fryer, T. B.

1966-01-01

426

How Is High Blood Pressure Treated?  

MedlinePLUS

... page from the NHLBI on Twitter. How Is High Blood Pressure Treated? High blood pressure (HBP) is treated with lifestyle changes and medicines. ... The NHLBI "Grand Opportunity" Exome Sequencing Project Managing High Blood Pressure With Lifestyle Changes Myth-busting blood pressure - a ...

427

A Cutaneous Feeling Display Using Suction Pressure  

E-print Network

that support the principle. Keywords: tactile display, haptic interface, air pressure, suction pressure 1 of an illusion that we feel as if a stick is pushed on the skin when we lower the air pressure in a dimple is based on air pressure control, the stimulators are easily integrated using re- mote valves. In section 2

Shinoda, Hiroyuki

428

Noninvasive Positive Pressure Ventilation in the Emergency  

E-print Network

an Electrolux or Hoover vacuum cleaner to supply air at positive pressure to treat patients with ``cardiacNoninvasive Positive Pressure Ventilation in the Emergency Department Mei-Ean Yeow, MDa , Jairo I ventilators consist of both negative and positive pressure ventilators. Because negative pressure ventilation

429

Intraocular pressure reduction and regulation system  

NASA Technical Reports Server (NTRS)

An intraocular pressure reduction and regulation system is described and data are presented covering performance in: (1) reducing intraocular pressure to a preselected value, (2) maintaining a set minimum intraocular pressure, and (3) reducing the dynamic increases in intraocular pressure resulting from external loads applied to the eye.

Baehr, E. F.; Burnett, J. E.; Felder, S. F.; Mcgannon, W. J.

1979-01-01

430

Vapor Pressure Measurements in a Closed System  

ERIC Educational Resources Information Center

An alternative method that uses a simple apparatus to measure vapor pressure versus temperature in a closed system, in which the total pressure is the vapor pressure of the liquid sample, is described. The use of this apparatus gives students a more direct picture of vapor pressure than the isoteniscope method and results have generally been quite…

Iannone, Mark

2006-01-01

431

The Power of Peer Pressure  

ERIC Educational Resources Information Center

In a religion class of 26 bright creative sixth graders, one student demonstrates the power of peer pressure. Part of the morning ritual is to say prayer petitions. Students seems to be calmed by their expressions of care for their families, friends, pets, their military troops, victims of natural disasters, the homeless, etc. However, one student…

Wingle, Jane

2006-01-01

432

Peer Pressure for Automatic Troubleshooting  

Microsoft Academic Search

Technical support contributes 17% of the total cost of ownership of today's desktop PCs. An important element of technical support is troubleshooting misconfigured applications. Misconfiguration troubleshooting is particularly challenging, because configuration information is shared and altered by multiple applications. In this paper, we present a novel troubleshooting algorithm, PeerPressure, which uses statistics from a set of sample machines to diagnose

Helen J. Wang; John C. Platt; Yu Chen; Ruyun Zhang; Yi-Min Wang

2004-01-01

433

Cavitation pressure in liquid helium  

Microsoft Academic Search

Recent experiments have suggested that, at low enough temperature, the homogeneous nucleation of bubbles occurs in liquid helium near the calculated spinodal limit. This was done in pure superfluid helium 4 and in pure normal liquid helium 3. However, in such experiments, where the negative pressure is produced by focusing an acoustic wave in the bulk liquid, the local amplitude

Frederic Caupin; Sebastien Balibar

2001-01-01

434

The Pressure in Polarized Systems  

NASA Astrophysics Data System (ADS)

Controversies concerning notation rather than physics have consumed a great amount of attention, and time, of those working on the thermodynamics of polarized systems. This pertains especially to the definition of the pressure and to the question of what is "material" and what "field" in an interacting system. For all measurable quantities, recently definite expressions were derived. In this paper, the observable facts are interpreted in terms of familiar concepts. We identify the different observables associated with the notion of pressure and show that, in a polarized system, "the pressure" does not exist. We propose definitions of the field and the material momentum, of the field and the internal energy, the field Stress tensor, the pressure, and the force. None of these quantities has any precise meaning nor is independently measurable. Our scheme of definitions is fully consistent, from covariant language to irreversible thermodynamics and hydrodynamics. We discuss alternatives and point out the extent of arbitrariness between common usage on one side and convenience on the other.

Henjes, K.

1993-05-01

435

Main tank injection pressurization program  

NASA Technical Reports Server (NTRS)

Computer program predicts performance of fluorine-hydrogen main tank injection pressurization system for full range of liquid-hydrogen-fueled space vehicles. Analytical model includes provisions for heat transfer, injectant jet penetration, and ullage gas mixing. Analysis predicts GF2 usage, ullage gas and tank wall temperatures, and LH2 evaporation.

Cady, E. C.; Kendle, D. W.

1972-01-01

436

Stirling engine with pressurized crankcase  

DOEpatents

A two piston Stirling engine wherein the pistons are coupled to a common crankshaft via bearing means, the pistons include pad means to minimize friction between the pistons and the cylinders during reciprocation of the pistons, means for pressurizing the engine crankcase, and means for cooling the crankshaft and the bearing means eliminating the need for oil in the crankcase.

Corey, John A. (Melrose, NY)

1988-01-01

437

ORIGINAL ARTICLE Blood pressure, antihypertensive  

E-print Network

ORIGINAL ARTICLE Blood pressure, antihypertensive treatment and factors associated with good blood and that intensive antihypertensive treatment is more beneficial to diabetic than to nondiabetic hypertensive and the effects of antihypertensive drugs in the medical management of hypertension in diabetic patients

Cai, Long

438

Pressure processable block copolymers: Baroplastics  

NASA Astrophysics Data System (ADS)

There has been great interest in recent years in the effect of pressure on the miscibility of polymer pairs; this effect is present in the displacement of the order/disorder temperature of block copolymers, which has been shown to be significant in some cases. In an attempt to exploit this effect, we have synthesized block copolymers that consist of one rubbery block and one glassy block, chosen to present enhanced miscibility under pressure. These materials can undergo an order/disorder transition with pressure that reflects macroscopically in a radical change in the material's rheological behavior, going from a solid (ordered) state to a liquid (disordered) state by the application of pressure. Such materials, termed baroplastics, can be melt-processed at temperatures well below the glass transition of the glassy component. For example, polystyrene-containing baroplastics were compression molded at room temperature. Mechanical property measurements on baroplastics as-processed and after multiple recycles showed these materials to exhibit excellent recyclability, with no apparent processing-related degradation. TEM and SAXS studies of the processed baroplastics were conducted to elucidate their low-temperature post-processing morphology.

Gonzalez, Juan; Acar, Metin H.; Mayes, Anne M.

2003-03-01

439

Pressure filtration of flocculated suspensions  

Microsoft Academic Search

From the development of a compressional rheology of a flocculated suspension, a number of separation processes have been modeled. With respect to the two-stage pressure filtration process of compact formation and then consolidation, the rheological formulation appears at first examination to be significantly at variance with the conventional engineering approach. The present model may be reconciled to the early engineering

Kerry A. Landman; Lee R. White; Maria Eberl

1995-01-01

440

Pressure compensated flow control valve  

Microsoft Academic Search

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

Minteer; Daniel J

1999-01-01

441

Optical Trapping at Gigapascal Pressures  

NASA Astrophysics Data System (ADS)

Diamond anvil cells allow the behavior of materials to be studied at pressures up to hundreds of gigapascals in a small and convenient instrument. However, physical access to the sample is impossible once it is pressurized. We show that optical tweezers can be used to hold and manipulate particles in such a cell, confining micron-sized transparent beads in the focus of a laser beam. Here, we use a modified optical tweezers geometry, allowing us to trap through an objective lens with a higher working distance, overcoming the constraints imposed by the limited angular acceptance of the anvil cell. We demonstrate the effectiveness of the technique by measuring water’s viscosity at pressures of up to 1.3 GPa. In contrast to previous viscosity measurements in anvil cells, our technique measures absolute viscosity and does not require scaling to the accepted value at atmospheric pressure. This method could also measure the frequency dependence of viscosity as well as being sensitive to anisotropy in the medium’s viscosity.

Bowman, Richard W.; Gibson, Graham M.; Padgett, Miles J.; Saglimbeni, Filippo; Di Leonardo, Roberto

2013-03-01

442

Mass gap from pressure inequalities  

E-print Network

We prove that a temperature independent mass distribution is identically zero below a mass threshold (mass gap) value, if the pressure satisfies certain inequalities. This supports the finding of a minimal mass in quark matter equation of state by numerical estimates and by substitution of analytic formulas. We present a few inequalities for the mass distribution based on the Markov inequality.

Tamas S. Biro; Andras Laszlo; Peter Van

2006-12-07

443

Thermal Expansion at High Pressures  

Microsoft Academic Search

Estimates of the coefficient of thermal expansion, at pressures up to several megabars, are needed for various geophysical calculations. As experimental determinations are scanty and limited to a few tens of kilobars, we must depend on largely untested deductions from solid-state theory and equations of state. The recent treatment by Anderson [1967], a discussion by Gilvarry [1957], and questions from

Francis Birch

1968-01-01

444

Low pressure solar thermal converter  

Microsoft Academic Search

The current development of solar power converters with air as working fluid focuses mostly on concentrating collectors combined with hot-air engines, and on very low temperature solar tower concepts. Whilst concentrating collectors and Stirling engines need complex technology, solar tower converters have very low efficiencies and require large installations. Pressurized containers as energy converters offer the advantage of simplicity, but

Gerald Muller

445

Pitfalls in pressure guage performance  

SciTech Connect

Often, pressure gauge systems for surface read-out (SRO) wireline work or for permanent installations do not perform according to their specifications i.e. the pressure resolution obtained is lower than the gauge design values. This seems natural because the borehole environment is nastier than the quiescence of laboratory calibration setup. Nevertheless, it is difficult to attribute the loss of resolution to a single problem. This paper introduces the functional components of the pressure gauge system where loss of resolution may occur. Specifically, cable related problems, crossover, signal transmission, signal processing, time stamping and temperature compensation are addressed. Determination of pressure resolution from a processed signal is shown via example calculations. The role of transducer specifications on overall data quality is addressed. In other words, what causes a 0.01 psi rated transducer to yield a signal of only 0.75 psi quality? Field data from prospects Tahoe and Bullwinkle are used to illustrate some of the gauge related problems and the solutions being proposed by the industry to overcome some of them.

Kikani, J.; Fair, P.S.; Hite, R.H. [SPE, Richardson, TX (United States)

1995-12-31

446

Water Pressure. Water in Africa.  

ERIC Educational Resources Information Center

The Water in Africa Project was realized over a 2-year period by a team of Peace Corps volunteers. As part of an expanded, detailed design, resources were collected from over 90 volunteers serving in African countries, photos and stories were prepared, and standards-based learning units were created for K-12 students. This unit, "Water Pressure,"…

Garrett, Carly Sporer

447

Pressure sensor using liquid crystals  

NASA Technical Reports Server (NTRS)

A pressure sensor includes a liquid crystal positioned between transparent, electrically conductive films (18 and 20), that are biased by a voltage (V) which induces an electric field (E) that causes the liquid crystal to assume a first state of orientation. Application of pressure (P) to a flexible, transparent film (24) causes the conductive film (20) to move closer to or farther from the conductive film (18), thereby causing a change in the electric field (E'(P)) which causes the liquid crystal to assume a second state of orientation. Polarized light (P.sub.1) is directed into the liquid crystal and transmitted or reflected to an analyzer (A or 30). Changes in the state of orientation of the liquid crystal induced by applied pressure (P) result in a different light intensity being detected at the analyzer (A or 30) as a function of the applied pressure (P). In particular embodiments, the liquid crystal is present as droplets (10) in a polymer matrix (12) or in cells (14) in a polymeric or dielectric grid (16) material in the form of a layer (13) between the electrically conductive films (18 and 20). The liquid crystal fills the open wells in the polymer matrix (12) or grid (16) only partially.

Parmar, Devendra S. (Inventor); Holmes, Harlan K. (Inventor)

1994-01-01

448

"Can" You Stand the Pressure  

NSDL National Science Digital Library

In this activity about states of matter, learners get to witness firsthand the awesome power of air pressure. They watch as an ordinary soda can is crushed by invisible forces. This activity is only to be done with adult supervision, as it involves very hot water.

Cosi

2009-01-01

449

Research study of pressure instrumentation  

NASA Technical Reports Server (NTRS)

To obtain a more vibration resistant pressure sensor for use on the Space Shuttle Main Engine, a proximity probe based, diaphragm type pressure sensor breadboard was developed. A fiber optic proximity probe was selected as the sensor. In combination with existing electronics, a thermal stability evaluation of the entire probe system was made. Based upon the results, a breadboard design of the pressure sensor and electronics was made and fabricated. A brief series of functional experiments was made with the breadboard to calibrate, thermally compensate, and linearize its response. In these experiments, the performance obtained in the temperature range of -320 F (liquid N2) to +200 F was comparable to that of the strain gage based sensor presently in use on the engine. In tests at NASA-Marshall Space Flight Center (MSFC), after some time at or near liquid nitrogen temperatures, the sensor output varied over the entire output range. These large spurious signals were attributed to condensation of air in the sensing gap. In the next phase of development of this sensor, an evaluation of fabrication techniques toward greater thermal and mechanical stability of the fiber probe assembly must be made. In addition to this, a positive optics to metal seal must be developed to withstand the pressure that would result from a diaphragm failure.

Hoogenboom, L.; Hull-Allen, G.

1984-01-01

450

High-pressure water facility  

NASA Technical Reports Server (NTRS)

NASA Test Operations Group employees, from left, Todd Pearson, Tim Delcuze and Rodney Wilkinson maintain a water pump in Stennis Space Center's high-pressure water facility. The three were part of a group of employees who rode out Hurricane Katrina at the facility and helped protect NASA's rocket engine test complex.

2006-01-01

451

Atmospheric-pressure plasma jet  

DOEpatents

Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

Selwyn, Gary S. (Los Alamos, NM)

1999-01-01

452

Cryogenic Pressure Seal for Wires  

NASA Technical Reports Server (NTRS)

High-pressure-seal formed by forcing polyurethane into space surrounding wire or cable in special fitting. Wire or cable routed through fitting then through a tightly fitting cap. Wire insulation left intact. Cap filled with sealant and forced onto the fitting: this pushes sealant into fitting so it seals wire or cable in fitting as well as in cap.

Ciana, J. J.

1984-01-01

453

SOL Tests Create Unfair Pressure.  

ERIC Educational Resources Information Center

A seventh-grader explains why the Virginia Standards of Learning tests unfairly pressure her and her teachers. She wants her free reading time restored and wishes politicians would worry more about students understanding--not just memorizing--facts. She praises teachers who go beyond the SOL. (MLH)

Ernst, Katie

2000-01-01

454

Assessing Inflationary Pressures in Colombia  

Microsoft Academic Search

The assessment of inflationary pressures in Colombia has faced two important challenges in the present decade. The first one occurred in 2006 and consisted of detecting an overheating economy in the midst of fast growing investment and increasing measured productivity. The second challenge took place in 2007-2008, when the economy was hit by a number of \\

Hernando Vargas; Andrés González; Eliana González; Jose Vicente Romero; Luis Eduardo Rojas

2009-01-01

455

Mechanics and Applications of Pressure Adaptive Honeycomb  

E-print Network

.2.2 Longitudinal Compression-Tension Test 141 5.2.3 Lateral Compression-Tension Test 142 vii 5.3 Multi-Cell Rigid-Member Pressurized Honeycomb 144 5.4 Multi-Cell Pressurized Aluminum Honeycomb 148 5.5 Wind Tunnel Experiment with Pressure adaptive Flap 158 6....1 Aluminum Honeycomb Test Results 170 6.2 Single-Cell Rigid-Member Pressurized Honeycomb 172 6.3 Multi-Cell Rigid-Member Pressurized Honeycomb 177 6.4 Validation of Constant assumption 183 6.5 Multi-Cell Pressurized Aluminum Honeycomb 184 6.6 Pressure...

Vos, Roelof

2009-07-31

456

Heat transfer in pressurized circulating fluidized beds  

SciTech Connect

The wall-to-suspension heat transfer in circulating fluidized beds (CFBs) operated at almost atmospheric pressure depends on the fluid mechanics immediately near the wall and on the thermal properties of the gas used. No influence of the superficial gas velocity adjusted is present. Consequently, the wall-to-suspension heat transfer coefficient in the form of the Nusselt number can be described by the Archimedes number of the gas-solid-system and the pressure drop number. The last number relates the cross-sectional average solids concentration to the solids concentration at minimum fluidization condition. However, with pressurized CFBs an influence of the superficial gas velocity on the wall-to-suspension heat transfer can be observed. Normalizing the superficial gas velocity in the form of the particle Froude number, two cases for the heat transfer in pressurized CFBs can be detected: with small particle Froude numbers (smaller than four) the same flow behavior and consequently the same heat transfer correlation is valid as it is for CFBs operated at almost atmospheric conditions; and with high particle Froude numbers (for example higher than four) the flow behavior immediately near the heat exchanger surface (CFB wall) can change. Instead of curtains of solids falling down with almost atmospheric pressure swirls of gas and solids can occur in the vicinity of the CFB wall when the static pressure is increased. With the change of the flow pattern near the CFB wall, i.e., the heat exchanger surface, a change of the heat transfer coefficient takes place. For the same Archimedes number, i.e., the same gas-solid system, and the same pressure drop number, i.e., the same cross-sectional average solids concentration, the Nusselt number, i.e., the heat transfer coefficient, increases when the flow pattern near the CFB wall changes from the curtain-type flow to that of the swirl-type flow. From experimentally obtained data in a cold running CFB a very simple correlation was obtained for the heat transfer coefficient.

Wirth, K.E. [Univ. Erlangen-Nuernberg, Erlangen (Germany). Lehrstuhl fuer Mechanische Verfahrenstechnik

1997-12-31

457

A model for the influence of pressure on the bulk modulus and the influence of temperature on the solidification pressure for liquid lubricants  

NASA Astrophysics Data System (ADS)

Two pressure chambers, for compression experiments with liquids from zero to 2.2 GPa pressure, are described. The experimentally measured compressions are then compared to theoretical values given by an isothermal model of equation of state recently introduced for solids. The model describes the pressure and bulk modulus as a function of compression for different types of lubricants with a very high accuracy up to the pressure limit of the high pressure chamber used (2.2 GPa). In addition the influence of temperature on static solidification pressure was found to be a simple function of the thermal expansion of the fluid.

Jacobson, Bo O.; Vinet, Pascal

1987-10-01

458

A model for the influence of pressure on the bulk modulus and the influence of temperature on the solidification pressure for liquid lubricants  

NASA Astrophysics Data System (ADS)

Two pressure chambers, for compression experiments with liquids from zero to 2.2 GPa pressure, are described. The experimentally measured compressions are then compared to theoretical values given by an isothermal model of equation of state recently introduced for solids. The model describes the pressure and bulk modulus as a function of compression for different types of lubricants with a very high accuracy up to the pressure limit of the high pressure chamber used (2.2 GPa). In addition the influence of temperature on static solidification pressure was found to be a simple function of the thermal expansion of the fluid.

Jacobson, B. O.; Vinet, P.

1986-01-01

459

Calculation Of Pneumatic Attenuation In Pressure Sensors  

NASA Technical Reports Server (NTRS)

Errors caused by attenuation of air-pressure waves in narrow tubes calculated by method based on fundamental equations of flow. Changes in ambient pressure transmitted along narrow tube to sensor. Attenuation of high-frequency components of pressure wave calculated from wave equation derived from Navier-Stokes equations of viscous flow in tube. Developed to understand and compensate for frictional attenuation in narrow tubes used to connect aircraft pressure sensors with pressure taps on affected surfaces.

Whitmore, Stephen A.

1991-01-01

460

Effect of respiration on Korotkoff sounds and oscillometric cuff pressure pulses during blood pressure measurement.  

PubMed

Blood pressure (BP) measurement accuracy depends on consistent changes in Korotkoff sounds (KorS) for manual measurement and oscillometric pulses for automated measurement, yet little is known about the direct effect of respiration on these physiological signals. The aim of this research was to quantitatively assess the modulation effect of respiration on Korotkoff sounds and oscillometric pulses. Systolic and diastolic blood pressures were measured manually from 30 healthy subjects (age 41 ± 12 years). Three static cuff pressure conditions were studied for two respiratory rates. Cuff pressure [with oscillometric pulses (OscP)], ECG, chest motion respiration [respiration signal (Resp), from magnetometer] and Korotkoff sounds (KorS, from digital stethoscope) were recorded twice for 20 s. The physiological data were evenly resampled. Respiratory frequency was calculated from Resp (fR), OscP (fO) and KorS (fK) from peak spectral frequency. There was no statistically significant difference between fR and fO or fK. Respiratory modulation was observed in all subjects. OscP amplitude modulation changed significantly between the two respiratory rates (p < 0.05) and between the three cuff pressures (p < 0.0001), and decreased significantly with decreasing cuff pressure (p < 0.05). The phase shift between Resp and modulation of OscP was statistically significant with respiratory rates (p < 0.05), but not with cuff pressures. It is accepted that BP in individuals is variable and that this relates to respiration; we now show that this respiration modulates oscillometric pulse and Korotkoff sound amplitudes from which BP is measured. PMID:24668326

Zheng, Dingchang; Di Marco, Luigi Yuri; Murray, Alan

2014-05-01

461

Demodulation System for Fiber Optic Bragg Grating Dynamic Pressure Sensing  

NASA Technical Reports Server (NTRS)

Fiber optic Bragg gratings have been used for years to measure quasi-static phenomena. In aircraft engine applications there is a need to measure dynamic signals such as variable pressures. In order to monitor these pressures a detection system with broad dynamic range is needed. This paper describes an interferometric demodulator that was developed and optimized for this particular application. The signal to noise ratio was maximized through temporal coherence analysis. The demodulator was incorporated in a laboratory system that simulates conditions to be measured. Several pressure sensor configurations incorporating a fiber optic Bragg grating were also explored. The results of the experiments are reported in this paper.

Lekki, John D.; Adamovsky, Grigory; Floyd, Bertram

2001-01-01

462

Genome-Wide Linkage Analysis for Loci Affecting Pulse Pressure The Family Blood Pressure Program  

Microsoft Academic Search

Pulse pressure, the difference between systolic and diastolic blood pressure, is an independent risk factor for cardiovascular disease. Increased pulse pressure reflects reduced compliance of arteries and is a marker of atherosclerosis. To locate genes that affect pulse pressure, a genome-wide linkage scan for quantitative trait loci influencing pulse pressure was performed using variance components methods as implemented in sequential

Suzette J. Bielinski; Amy I. Lynch; Michael B. Miller; Alan Weder; Richard Cooper; Albert Oberman; Yii-Der Ida Chen; Stephen T. Turner; Myriam Fornage; Michael Province; Donna K. Arnett

463

Dynamics of Low-Pressure and High-Pressure Fuel Cell Air Supply System1  

E-print Network

Dynamics of Low-Pressure and High-Pressure Fuel Cell Air Supply System1 Sylvain Gelfi2 , Anna G. On the contrary, low-pressure systems have a benefit of low parasitic loss on air flow devices. Here, we look pressure of the FC that is defined as the pressure at which the reactant hydrogen and oxygen (air

Peng, Huei

464

Structural stability of WS2 under high pressure  

NASA Astrophysics Data System (ADS)

Structural behavior of bulk WS2 under high pressure was investigated using synchrotron X-ray diffraction and diamond anvil cell up to 52 GPa along with high temperature X-ray diffraction and high pressure Raman spectroscopy analysis. The high pressure results obtained from X-ray diffraction and Raman analysis did not show any pressure induced structural phase transformations up to 52 GPa. The high temperature results show that the WS2 crystal structure is stable upon heating up to 600°C. Furthermore, the powder X-ray diffraction obtained on shock subjected WS2 to high pressures up to 10 GPa also did not reveal any structural changes. Our results suggest that even though WS2 is less compressible than the isostructural MoS2, its crystal structure is stable under static and dynamic compressions up to the experimental limit.

Bandaru, Nirup; Kumar, Ravhi S.; Baker, Jason; Tschauner, Oliver; Hartmann, Thomas; Zhao, Yusheng; Venkat, Rama

2014-07-01

465

Estimating the Collapse Pressure of an Inflatable Aerodynamic Decelerator  

NASA Technical Reports Server (NTRS)

The collapse pressure of an inflatable membrane is the minimum differential pressure which will sustain a specific desired shape under an applied load. In this paper, we present a method for estimating the collapse pressure of a tension-cone inflatable aerodynamic decelerator (IAD) that is subject to a static aerodynamic load. The IAD surface is modeled as an elastic membrane. For a given aerodynamic load and sufficiently high torus differential pressure, the IAD assumes a stable axisymmetric equilibrium shape. When the torus pressure is reduced sufficiently, the symmetric equilibrium state becomes unstable and we define this instance to be the critical pressure Pcr. In this paper, we will compare our predicted critical torus pressure with the corresponding observed torus collapse pressure (OTCP) for fifteen tests that were conducted by the third author and his collaborators at the NASA Glenn Research Center 10x10 Supersonic Wind Tunnel in April 2008. One of the difficulties with these types of comparisons is establishing the instance of torus collapse and determining the OTCP from quantities measured during the experiment. In many cases, torus collapse is gradual and the OTCP is not well-defined. However, in eight of the fifteen wind tunnel tests where the OTCP is well-defined, we find that the average of the relative differences (Pcr - OTCP/Pcr) was 8.9%. For completeness, we will also discuss the seven tests where the observed torus collapse pressure is not well-defined.

Baginski, Frank E.; Brakke, Kenneth A.; Cruz, Juan R.

2013-01-01

466

Symmetric differential capacitive pressure sensor  

NASA Astrophysics Data System (ADS)

Differential capacitive sensors are common to pressure gauges. Previous sensors of the bridge type have utilized only two variable (active) components, resulting in a half-bridge electrical equivalent circuit. There are numerous advantages of a symmetric full bridge, using four active components. The symmetry improves linearity and increases signal to noise ratio, especially when supported by electronics based on synchronous detection. Another advantage of symmetry is invariance to scaling, through immunity to stray capacitance. This feature is especially important in relationship to the current trend toward micro-electro-mechanical systems. A crude, inexpensive, macroscopic prototype of the present design was built with attention to high sensitivity. Constructed with a thin aluminized Mylar diaphragm, this device can readily resolve pressure changes smaller than 10-2 Pa.

Peters, Randall D.

1993-08-01

467

Pressure/vacuum relief valve  

SciTech Connect

This patent describes a pressure/vacuum relief valve for a fluid containing vessel. It comprises: an elongated cylinder having a wall and having end walls closing the cylinder ends, one end portion of the cylinder wall having a first port communicating with the fluid in the vessel and the other end portion of the cylinder having a second port communicating with the atmosphere; a piston in the cylinder normally sealed with the inner wall surface thereof between the first and second ports; a piston rod axially projecting from the piston through the respective cylinder end wall; elongated cage means having a closed end and an open end axially connected with the respective cylinder end wall around the respective end portion of the piston rod; and, pressure responsive elongated pin means interposed between the respective end of the piston rod and the closed end of the respective cage for normally maintaining the piston in valve closed position.

Taylor, J.S.

1990-12-18

468

Low cerebrospinal fluid pressure headache  

Microsoft Academic Search

Opinion statement  \\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a Alterations in cerebrospinal fluid (CSF) pressure lead to neurologic symptoms, the most common clinical manifestation of which\\u000a is headache. Typically, the headache is orthostatic and related to traction on pain-sensitive intracranial and meningeal structures,\\u000a distention on periventricular pain-sensitive areas, and direct pressure on pain conveying cranial nerves.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a Low CSF headache is a distinct and familiar syndrome

Christine M. Lay

2002-01-01

469

Pressurization systems for liquid rockets  

NASA Technical Reports Server (NTRS)

Guidelines for the successful design of pressurization systems for main propulsion, auxiliary propulsion, and attitude control systems for boosters, upper stages, and spacecraft were presented, drawing on the wealth of design experience that has accumulated in the development of pressurization systems for liquid rockets operational in the last 15 years. The design begins with a preliminary phase in which the system requirements are received and evaluated. Next comes a detail-design and integration phase in which the controls and the hardware components that make up the system are determined. The final phase, design evaluation, provides analysis of problems that may arise at any point in the design when components are combined and considered for operation as a system. Throughout the monograph, the design tasks are considered in the order and manner in which the designer must handle them.

1975-01-01

470

Performance of fuselage pressure structure  

NASA Technical Reports Server (NTRS)

There are currently more than 1,000 Boeing airplanes around the world over 20 years old. That number is expected to double by the year 1995. With these statistics comes the reality that structural airworthiness will be in the forefront of aviation issues well into the next century. The results of previous and recent test programs Boeing has implemented to study the structural performance of older airplanes relative to pressurized fuselage sections are described. Included in testing were flat panels with multiple site damage (MSD), a full-scale 737 and 2 747s as well as panels representing a 737 and 777, and a generic aircraft in large pressure-test fixtures. Because damage is a normal part of aging, focus is on the degree to which structural integrity is maintained after failure or partial failure of any structural element, including multiple site damage (MSD), and multiple element damage (MED).

Maclin, James R.

1992-01-01

471

A Microminiature Solid-State Capacitive Blood Pressure Transducer with Improved Sensitivity  

Microsoft Academic Search

A microminiature pressure transducer is described utilizing a variable air capacitor driven by a pressure-sensitive deflectible silicon membrane as the detection mechanism. Silicon integrated circuit technology is used throughout for economical batch fabrication of the device. Prototype devices have been fabricated and initial test results under static pressure conditions are reported. Equivalent gauge factors of over 500 for this variable

Wolf D. Frobenius; A. C. Sanderson; H. C. Nathanson

1973-01-01

472

Response of Periodically Stiffened Shells to a Moving Projectile Propelled by an Internal Pressure Wave  

Microsoft Academic Search

The vibrations of cylindrical shells induced by a moving projectile propelled by an internal pressure wave are controlled by placing stiffening rings periodically along the length of the shell. An expanding pressure step causes the axisymmetric radial displacement of the shell to be several times higher than that produced by the static application of the same pressure. The displacement depends

M. Ruzzene; A. Baz

2006-01-01

473

Articular Cartilage Contact Pressure after Tibial Tuberosity TransferA Cadaveric Study  

Microsoft Academic Search

Medial transfer of the tibial tuberosity has been commonly used for treatment of recurrent dislocation of the patella and patellofemoral malalignment. In this study, six fresh human cadaveric knees were used. Static intrajoint loads were recorded using Fuji Prescale pressure-sensitive film for contact pressure and contact area determination in a closed kinetic chain knee testing protocol. Peak pressures, average contact

Ryosuke Kuroda; Helen Kambic; Antonio Valdevit; Jack T. Andrish

2001-01-01

474

Minority game with peer pressure  

Microsoft Academic Search

To study the interplay between global market choice and local peer pressure, we construct a minority-game-like econophysical model. In this so-called networked minority game model, every selfish player uses both the historical minority choice of the population and the historical choice of one's neighbors in an unbiased manner to make decision. Results of numerical simulation show that the level of

H. F. Chau; F. K. Chow; K. H. Ho

2004-01-01

475

Barometric pressure and gas composition  

NASA Technical Reports Server (NTRS)

Many factors affecting artificial gas atmosphere, which is used to maintain life during space flight, are considered. The wide variability of barometric pressure in spacecraft, due in large measure to spacecraft design is discussed. Explosive decompression is described; this develops from instantaneous depressurization of the cabin. Decompression sickness is reviewed, including bubble growth and evolution of gas bubbles in organisms. Dysbarism, hypoxia, and hypercapnia are also discussed.

Malkin, V. B.

1975-01-01

476

Pressure induced ageing of polymers  

NASA Technical Reports Server (NTRS)

The nonlinearly viscoelastic response of an amorphous homopolymer is considered under aspects of time dependent free volume behavior. In contrast to linearly viscoelastic solids, this model couples shear and volume deformation through a shift function which influences the rate of molecular relaxation or creep. Sample computations produce all those qualitative features one observes normally in uniaxial tension including the rate dependent formation of a yield point as a consequence of the history of an imposed pressure.

Emri, I.; Knauss, W. G.

1988-01-01

477

Profits, pressure and corporate lawbreaking  

Microsoft Academic Search

While neglect, exploitation, denial of human rights and abuse of nursing home residents can be found in both non-profit and for-profit nursing homes, substantially higher non-compliance with the law is found among for-profits. A significant source of non-compliance is pressure on senior management from proprietors to reach financial goals that can only be attained by cutting corners on quality of

Anne Jenkins; John Braithwaite

1993-01-01

478

Variable pressure thermal insulating jacket  

DOEpatents

A device for controlled insulation of a thermal device. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communcation with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket.

Nelson, Paul A. (Wheaton, IL); Malecha, Richard F. (Naperville, IL); Chilenskas, Albert A. (Chicago, IL)

1994-01-01

479

Applications of the Radiation Pressure  

E-print Network

) of the Sun at the Earth's surface: I = 1.2 kW/m2 · The total energy of all photons falling on 1 m2 per 1;12 Theory · Photon's energy: E = h (400 pN nm) · Photon's momentum: p = h/ · Energy and momentum of photon second · From Maxwell's equations, the energy density of an EM wave: · In terms of irradiance: Pressure P

Palffy-Muhoray, Peter

480

Precise ultrahigh-pressure experiments  

SciTech Connect

A nuclear-explosive-generated shock has been used to obtain Hugoniot data at pressures corresponding to threefold compressions. The shock passed through a 12-mm-thick by 180-mm-dia molybdenum base plates and into 13 samples; 80 electrical-contact pins were used to determine shock velocities with uncertainties of 1.4 to 2.6%. The measured molybdenum shock velocity of 30.60 km/s corresponds to a pressure of 6.43 TPa, based on its SESAME equation of state. Impedance-matching analyses provided Hugoniot data in pressure (TPa)-particle velocity (km/s) coordinates (P, u) for the following materials; Al(2.93, 27.57), 19%-porosity Mo(4.65, 19.99), C(2.64, 28.38), LiH(1.225, 35.52), Cu(6.06, 21.15), Fe(5.71, 21.73), and crystalline quartz (2.75, 26.76). These results indicate the need for improved theoretical calculations for some materials.

Ragan, C. E. III; Diven, B.C.; Rich, M.; Teasdale, W.A.; Robinson, E.E.

1983-01-01

481

High Pressure Electrolyzer System Evaluation  

NASA Technical Reports Server (NTRS)

This report documents the continuing efforts to evaluate the operational state of a high pressure PEM based electrolyzer located at the NASA Glenn Research Center. This electrolyzer is a prototype system built by General Electric and refurbished by Hamilton Standard (now named Hamilton Sunstrand). It is capable of producing hydrogen and oxygen at an output pressure of 3000 psi. The electrolyzer has been in storage for a number of years. Evaluation and testing was performed to determine the state of the electrolyzer and provide an estimate of the cost for refurbishment. Pressure testing was performed using nitrogen gas through the oxygen ports to ascertain the status of the internal membranes and seals. It was determined that the integrity of the electrolyzer stack was good as there were no appreciable leaks in the membranes or seals within the stack. In addition to the integrity testing, an itemized list and part cost estimate was produced for the components of the electrolyzer system. An evaluation of the system s present state and an estimate of the cost to bring it back to operational status was also produced.

Prokopius, Kevin; Coloza, Anthony

2010-01-01

482

Internal pressurization and convective gas flow in some emergent freshwater macrophytes  

Microsoft Academic Search

Internal pressurization and convective through-flow are demonstrated to be common attributes of wetland plants with cylindrical culms or linear leaves. Eight of 14 species tested produced static internal gas pressure differentials of 200-1,300 Pa relative to ambient and internal convective airflows of 0.2 to > 10 cm3 min-' culm-I, depending on species. Four species produced internal static pressure differentials of

HANS BRIX; BRIAN K. SORRELL; PHILIP T. ORR

1992-01-01

483

Vacuum-sealed high temperature high bandwidth fiber optic pressure and acoustic sensors  

Microsoft Academic Search

A novel vacuum-sealed miniature optical fiber sensor for static pressure or acoustic wave measurement is presented. This pressure sensor functions as a diaphragm-based extrinsic Fabry-Perot interferometric (DEFPI) sensor. The sensor can work at high temperatures because of its all-silica structure. In static pressure measurement, the sensor's measurement range can be set up to 15,000psi with different thickness diaphragms. For acoustic

Juncheng Xu; Gary R. Pickrell; Xingwei Wang; Bing Yu; Kristie L. Cooper; Anbo Wang

2005-01-01

484

Estimating central pressures of oceanic midlatitude cyclones  

NASA Technical Reports Server (NTRS)

A method of determining surface pressures in oceanic storm systems using Earth Remote-Sensing Satellite (ERS-1) scatterometer data is employed to determine the lowest pressure in 25 storms. This method uses the surface winds as a lower boundary condition on a planetary boundary layer model to determine gradient winds and, thereby, pressure gradients. An optimization scheme referenced to a pressure outside the storm provides a pressure field and an estimate of the low pressure. The values are compared to European Center for Medium-Range Weather Forecasts (ECMWF) analyses in each case; there is good agreement, with some expected differences.

Brown, R. A.; Zeng, Lixin

1994-01-01