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1

The study on leakage reappearance test of high pressure hose for power steering system  

NASA Astrophysics Data System (ADS)

Generally, a leakage in a high pressure hose assembly can be determined if hydraulic fluid falls down through fitting which is swaged with a rubber hose. This study tried to visualize leakage, which is considered a failure occurring often in the hydraulic system. In the case of methods which verify leakage paths in the power steering hydraulic system equipped with a high pressure hose assembly, three types of leakage paths, which could be seen by cutting the swaging part, were generally found. However, it was difficult to find out leakage paths by using power steering oil. In this study, four methods, including the thermal burn image method, the hole drilling method of fitting metal, the white paint infiltration method, and the fluorescent infiltration method, were tried to introduce. The thermal burn image method failed to find out the leakage path between the fitting part and the rubber part. The hole drilling method is the way to check a leakage path on the fitting part, which doesn't need to cut a hose assembly. This method succeeds to visualize the leakage path partially but it could not check a sequential path of leakage, either, because it needs to drill more closely. The white paint infiltration method also could find the leakage path partially by using white paint mixed with thinner, which was pressurized by hand pump, instead of power steering oil. This method could check the leakage path by cutting the swaging part. The fluorescent infiltration method could verify the leakage path with naked eyes simply by holding the cutting swaging part closely to the ray of light. Reappearance test methods in the high pressure hose assembly, which include a hole drilling, a white paint infiltration, and a fluorescent infiltration method, can be applied to find the failure mode and to approve the test before the mass production of the high pressure hose.

Lee, Gi-Chun; Kim, Hyoung-Eui; Park, Jong-Won; Jeong, Won-Wook; Lee, Jong-Hwang; Lim, Young-Han; Hwang, Kwon-Tae; Lee, Young-Shin; Kim, Jae-Hoon

2009-07-01

2

High flexibility, noncollapsing light weight hose  

DOEpatents

This invention relates generally to a high-flexibility, light weight, noncollapsing hose and more particularly to such a hose having a large size and particularly useful as equipment draining a radioactively contaminated fluid through a noncontaiminated, isolated and restricted space with high confidence against kinking, collapse, or leaking even with large relative motion between the inlet and outlet ends of the hose. In the operation of nuclear facilities, such as nuclear reactors, processing plants for nuclear fuels and related materials, and chemical processing plants, for example, it is necessary to handle radioactively and/or chemically contaminated fluids which in many instances must be conducted, such as for draining purposes, through a noncontaminated, isolated area. Conduction of such contaminated fluids through uncontaminated environments in practice requires the highest confidence that the hose will not kink, collapse, break, or leak even though the hose may be subject to a large amount of motion relative to the inlet and outlet ends of the hose. Any such breaking, or leaking would result in undesirable contamination of the area through which the hose passes which could result in major damage and/or in the requirement to shut down the operation for cleanup and decontamination processing of the area. Additional problems are also encountered in processing plants for contaminated materials due to the fact that hoses conducting the contaminated liquids or gases pass through inaccessible, restricted spaces requiring extreme flexibility in the hose, but with the assurance that the hose will neither kink nor collapse to close off the flow.

Williams, D.A.

1991-02-01

3

High-flexibility, noncollapsing lightweight hose  

DOEpatents

A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

Williams, David A. (Pittsburgh, PA)

1993-01-01

4

High-flexibility, noncollapsing lightweight hose  

DOEpatents

A high-flexibility, noncollapsing, lightweight, large-bore, wire-reinforced hose is inside fiber-reinforced PVC tubing that is flexible, lightweight, and abrasion resistant. It provides a strong, kink- and collapse-free conduit for moving large quantities of dangerous fluids, e.g., removing radioactive waste water or processing chemicals.

Williams, D.A.

1993-04-20

5

30 CFR 57.7802 - Oxygen hose lines.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Oxygen hose lines. 57.7802 Section 57...Piercing-Surface Only § 57.7802 Oxygen hose lines. Safety chains or other...connections to and between high pressure oxygen hose lines of 1-inch inside...

2013-07-01

6

30 CFR 56.7802 - Oxygen hose lines.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Oxygen hose lines. 56.7802 Section 56... Rotary Jet Piercing § 56.7802 Oxygen hose lines. Safety chains or other...connections to and between high pressure oxygen hose lines of 1-inch inside...

2013-07-01

7

Observation of a long-wavelength hosing modulation of a high-intensity laser pulse in underdense plasma.  

PubMed

We report the first experimental observation of a long-wavelength hosing modulation of a high-intensity laser pulse. Side-view images of the scattered optical radiation at the fundamental wavelength of the laser reveal a transverse oscillation of the laser pulse during its propagation through underdense plasma. The wavelength of the oscillation ?(hosing) depends on the background plasma density n(e) and scales as ?(hosing)?n(e)(-3/2). Comparisons with an analytical model and two-dimensional particle-in-cell simulations reveal that this laser hosing can be induced by a spatiotemporal asymmetry of the intensity distribution in the laser focus which can be caused by a misalignment of the parabolic focusing mirror or of the diffraction gratings in the pulse compressor. PMID:20868169

Kaluza, M C; Mangles, S P D; Thomas, A G R; Najmudin, Z; Dangor, A E; Murphy, C D; Collier, J L; Divall, E J; Foster, P S; Hooker, C J; Langley, A J; Smith, J; Krushelnick, K

2010-08-26

8

Observation of a Long-Wavelength Hosing Modulation of a High-Intensity Laser Pulse in Underdense Plasma  

SciTech Connect

We report the first experimental observation of a long-wavelength hosing modulation of a high-intensity laser pulse. Side-view images of the scattered optical radiation at the fundamental wavelength of the laser reveal a transverse oscillation of the laser pulse during its propagation through underdense plasma. The wavelength of the oscillation {lambda}{sub hosing} depends on the background plasma density n{sub e} and scales as {lambda}{sub hosing{approx}}n{sub e}{sup -3/2}. Comparisons with an analytical model and two-dimensional particle-in-cell simulations reveal that this laser hosing can be induced by a spatiotemporal asymmetry of the intensity distribution in the laser focus which can be caused by a misalignment of the parabolic focusing mirror or of the diffraction gratings in the pulse compressor.

Kaluza, M. C. [Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Institut fuer Optik und Quantenelektronik, Friedrich-Schiller-Universitaet, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Helmholtzweg 4, 07743 Jena (Germany); Mangles, S. P. D.; Najmudin, Z.; Dangor, A. E. [Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Thomas, A. G. R.; Krushelnick, K. [Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Center for Ultrafast Optical Science (CUOS), University of Michigan, Ann Arbor, Michigan 48109 (United States); Murphy, C. D. [Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom); Central Laser Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom); Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Collier, J. L.; Divall, E. J.; Foster, P. S.; Hooker, C. J.; Langley, A. J.; Smith, J. [Central Laser Facility, Rutherford Appleton Laboratory, Oxon OX11 0QX (United Kingdom)

2010-08-27

9

Fatigue testing of corrugated and Teflon hoses  

NASA Astrophysics Data System (ADS)

Single and two-phase heat transport systems for the thermal control of large space facilities require fluid lines that traverse joints and either rotate or move in some other manner. Flexible hoses are being considered as one means of traversing these joints. To test the resilience of flexible hoses to bending stress, a test assembly was constructed to determine the number of flexing cycles the hoses could withstand before losing their ability to maintain a constant pressure. Corrugated metal hoses and Teflon hoses were tested at different pressures with nitrogen gas. The metal hoses had lives ranging from 30,000 to 100,000 flexing cycles. But, even after 400,000 cycles, the Teflon hoses remained essentially intact, though some leakage in the convoluted Teflon is noted.

Benner, Steve M.; Swanson, Theodore D.; Costello, Frederick A.

10

30 CFR 56.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL...connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices...

2013-07-01

11

30 CFR 57.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL...connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices...

2013-07-01

12

High-pressure mooring swivel passes test  

SciTech Connect

A key problem in marginal fields is how to offload the gas. Current technology can't cope with the high pressures of associated gas at the point where crude enters the mooring hose swivel. A prototype high-pressure swivel that tested to 1500 psi and 5000 psi with good results is described. Even after a large number of revolutions there was no pressure drop or leakages and the friction torque remained stable.

Not Available

1984-11-01

13

46 CFR 197.456 - Breathing supply hoses.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Breathing supply hoses. 197.456 Section 197.456...Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that (1) Each breathing supply hose is pressure tested prior to...

2011-10-01

14

Fluid Flow through Pipes--Another Look at Fire Hoses and Garden Hoses.  

ERIC Educational Resources Information Center

|The forward force of water on a hose is calculated using only the pressure gradient, the radius and length of the hose. The misconception about recoil on the nozzle is discussed. Dissipation energy and the consequent heat generation in a fluid flow are also described. (KR)|

Brouwer, W.; Paranjape, B. V.

1991-01-01

15

Influence of centering forces on IFR hose instability  

NASA Astrophysics Data System (ADS)

The appropriate centering force terms are added to the ion-focused regime hose equations and their effect on hose development is calculated. It is found that while hose at very high frequencies is stabilized, the overall suppression is only moderate and other stabilization processes need to be explored.

Buchanan, H. L.

1982-12-01

16

49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.  

Code of Federal Regulations, 2012 CFR

...false Brake tubing and hoses; hose assemblies and end fittings. 393.45 Section...45 Brake tubing and hoses; hose assemblies and end fittings. (a) General...construction requirements for tubing and hoses, assemblies, and end fittings. All brake...

2012-10-01

17

33 CFR 155.800 - Transfer hose.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Transfer hose. 155.800 Section 155...PREVENTION REGULATIONS FOR VESSELS Transfer Personnel, Procedures, Equipment, and Records § 155.800 Transfer hose. Hose used to transfer...

2013-07-01

18

46 CFR 64.97 - Cargo hose.  

Code of Federal Regulations, 2012 CFR

...hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose...

2012-10-01

19

46 CFR 64.97 - Cargo hose.  

Code of Federal Regulations, 2011 CFR

...hose. 64.97 Section 64.97 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Cargo Handling System § 64.97 Cargo hose. Each hose...

2011-10-01

20

46 CFR 169.735 - Fire hose stations.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel...must be identified in red letters and figures at least two inches high FIRE STATION NO. 1...hose is not stowed in the open or...

2011-10-01

21

46 CFR 169.735 - Fire hose stations.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel...must be identified in red letters and figures at least two inches high FIRE STATION NO. 1...hose is not stowed in the open or...

2012-10-01

22

Chlorine transfer hose failure.  

PubMed

On the morning of 14 August 2002, a 1 in. transfer hose used in a rail tank car unloading operation at DPC Enterprises, near Festus, Missouri, catastrophically ruptured and initiated a sequence of events that led to the release of 48,000 pounds of chlorine--a toxic gas--into neighboring areas. The facility repackages bulk dry liquid chlorine into 1 ton containers and 150 pound cylinders for commercial, industrial, and municipal use in the St. Louis metropolitan area. Fortunately, the wind direction on the day of the release limited the effects of the chlorine plume on the surrounding community. However, 63 people sought hospital treatment due to exposure, and hundreds of others were affected by the release (the community was advised to shelter-in-place for 4 h, and traffic was halted on Interstate 55 for 1.5 h). The US Chemical Safety and Hazard Investigation Board (CSB) investigated this incident for the following reasons: This paper presents the lesson-learned from this incident to help prevent similar occurrences. This paper is based on US Chemical Safety and Hazard Investigation Board Report Number 2002-04-I-MO, which was approved by the Board on 1 May 2003. This paper has not been independently approved by the Board and is published for general informational purposes only. Every effort has been made to accurately present the contents of the Board-approved report in this paper. Any material in the paper that did not originate in the Board-approved report is solely the responsibility of the author and does not represent an official finding, conclusion, or position of the Board. A complete copy of the Board investigation report upon which this paper is based is available on the CSB website at "Completed Investigations." PMID:15518973

Joseph, Giby

2004-11-11

23

Investigation of Radiation and Chemical Resistance of Flexible HLW Transfer Hose  

SciTech Connect

A chemical transfer hose constructed of an EPDM (ethylene-propylene diene monomer) outer covering with a modified cross-linked polyethylene (XLPE) lining was evaluated for use in high level radioactive waste transfer applications. Laboratory analysis involved characterization of the hose liner after irradiation to doses of 50 to 300 Mrad and subsequent exposure to 25% NaOH solution at 93 C for 30 days, simulating 6 months intermittent service. The XLPE liner mechanical and structural properties were characterized at varying dose levels. Burst testing of irradiated hose assemblies was also performed. Literature review and test results suggest that radiation effects below doses of 100 kGy are minimal, with acceptable property changes to 500 kGy. Higher doses may be feasible. At a bounding dose of 2.5 MGy, the burst pressure is reduced to the working pressure (1.38 MPa) at room temperature. Radiation exposure slightly reduces liner tensile strength, with more significant decrease in liner elongation. Subsequent exposure to caustic solutions at elevated temperature slightly increases elongation, suggesting an immersion/hydrolytic effect or possible thermal annealing of radiation damage. This paper summarizes the laboratory results and recommendations for field deployment.

E. Skidmore; Billings, K.; Hubbard, M.

2010-03-24

24

High pressure melt ejection  

Microsoft Academic Search

Recent probabilistic risk assessments have identified the potential for reactor pressure vessel failure while the reactor coolant system is at elevated pressure. The analyses postulate that the blowdown of steam and hydrogen into the reactor cavity will cause the core material to be swept from the cavity region into the containment building. The High Pressure Melt Streaming (HIPS) program is

W. W. Tarbell; J. E. Brockmann; M. Pilch

1983-01-01

25

High Pressure Experimental Methods  

Microsoft Academic Search

This book is a worthy addition to the literature on high-pressure techniques. Unlike earlier books, it emphasizes diamond - anvil cells, which are useful in the range from 1 kbar to multi-megabar pressures, while not neglecting the older techniques (piston - cylinder etc) which give much lower maximum pressures but in much larger volumes. The author take a refreshing approach

D J Dunstan

1996-01-01

26

Clamp for hydraulic hose bundles  

SciTech Connect

A clamping device secures a hydraulic hose bundle to a tubular riser system or to a wireline and comprises a generally cylindrical clamping body having an axial passage therethrough. The clamping body is formed having first and second semi-cylindrical body members and pivotal mount means provides pivotal movement of the first and second body members between an open and a closed position. First clamping means secures the first and second body members in the closed position and second clamping means releasably attaches the cylindrical clamping body to the tubular riser system or to a wireline.

Reynolds, G.E.

1984-03-20

27

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

28

Hydrazine at high pressure  

NASA Astrophysics Data System (ADS)

We report the first high pressure study of the important rocket fuel, hydrazine in a diamond anvil cell up to 19 GPa. Using Raman spectroscopy, two phase transitions were observed between 5.5 and 8 GPa. Above 8 GPa, a new peak emerged near 3000 cm-1. The pressure-induced changes appear to be reversible as pressure was cycled down to 3.5 GPa. We then performed a second experiment at this pressure examining X-ray induced decomposition of the material using an unfocused synchrotron white beam. After some 2.4 h of irradiation (estimated to be a dose of 1.6 105 Gy), molecular nitrogen was produced as confirmed with Raman spectroscopy.

Pravica, Michael; Bai, Ligang; Liu, Yu

2013-01-01

29

Laser Hosing in Relativistically Hot Plasmas  

NASA Astrophysics Data System (ADS)

Electron response in an intense laser is studied in the regime where the electron temperature is relativistic. Equations for laser envelope and plasma density evolution, both in the electron plasma wave and ion acoustic wave regimes, are rederived from the relativistic fluid equations to include relativistic plasma temperature effect. These equations are used to study short-pulse and long-pulse laser hosing instabilities using a variational method approach. The analysis shows that relativistic electron temperatures reduce the hosing growth rates and shift the fastest-growing modes to longer wavelengths. These results resolve a long-standing discrepancy between previous nonrelativistic theory and simulations or experiments on hosing.

Li, G.; Mori, W. B.; Ren, C.

2013-04-01

30

High Pressure Gas Tanks.  

National Technical Information Service (NTIS)

Four high-pressure gas tanks, the basis of this study, were especially made by a private contractor and tested before being delivered to NASA Kennedy Space Center. In order to insure 100% reliability of each individual tank the staff at KSC decided to aga...

R. Quintana

2002-01-01

31

High pressure furnace  

DOEpatents

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

Morris, Donald E. (Kensington, CA)

1993-01-01

32

High pressure oxygen furnace  

DOEpatents

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

Morris, Donald E. (Kensington, CA)

1992-01-01

33

Amorphous Materials at High Pressure  

NASA Astrophysics Data System (ADS)

This chapter reviews the different pathways towards high-pressure amorphization, how high-pressure amorphs may be characterized and what are the potential mechanisms causing pressure-induced amorphization and amorphous-amorphous transitions.

Sanloup, Chrystele

34

Beam hosing instability in overdense plasma  

SciTech Connect

Transverse stability of the drive beam is critical to plasma wakefield accelerators. A long, relativistic particle beam propagating in an overdense plasma is subject to beam envelope modulation and hosing (centroid displacement) instabilities. Coupled equations for the beam centroid and envelope are derived. The growth rate for beam hosing is examined including return current effects (where the beam radius is of order the plasma skin depth) in the long-beam, strongly-coupled, overdense regime.

Schroeder, C. B.; Benedetti, C.; Esarey, E.; Gruener, F. J.; Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2012-12-21

35

Shut-off mechanism for ventilation hose  

DOEpatents

A shut-off mechanism to provide automatic closure of a ventilation hose when the operation of drawing air through the hose is terminated. The mechanism includes a tube of light gauge metal inside of which are mounted a plurality of louver doors positioned in the closed position due to gravity when the ventilation unit is not operational. When the unit is operational, air flowing into the unit maintains the doors in the open position. 5 figs.

Huyett, J.D.; Meskanick, G.R.

1989-12-07

36

High Blood Pressure in Pregnancy  

MedlinePLUS

... and your baby. Treatments for high blood pressure in pregnancy may include close monitoring of the baby, ... blood pressure develop preeclampsia. It's a sudden increase in blood pressure after the 20th week of pregnancy. ...

37

HIGH PRESSURE DIES  

DOEpatents

A press was invented for subjecting specimens of bismuth, urania, yttria, or thoria to high pressures and temperatures. The press comprises die parts enclosing a space in which is placed an electric heater thermally insulated from the die parts so as not to damage them by heat. The die parts comprise two opposed inner frustoconical parts and an outer part having a double frustoconical recess receiving the inner parts. The die space decreases in size as the inner die parts move toward one another against the outer part and the inner parts, though very hard, do not fracture because of the mode of support provided by the outer part.

Wilson, W.B.

1960-05-31

38

Chromium at High Pressure  

NASA Astrophysics Data System (ADS)

Chromium has long served as the archetype of spin density wave magnetism. Recently, Jaramillo and collaborators have shown that Cr also serves as an archetype of magnetic quantum criticality. Using a combination of x-ray diffraction and electrical transport measurements at high pressures and cryogenic temperatures in a diamond anvil cell, they have demonstrated that the N'eel transition (TN) can be continuously suppressed to zero, with no sign of a concurrent structural transition. The order parameter undergoes a broad regime of exponential suppression, consistent with the weak coupling paradigm, before deviating from a BCS-like ground state within a narrow but accessible quantum critical regime. The quantum criticality is characterized by mean field scaling of TN and non mean field scaling of the transport coefficients, which points to a fluctuation-induced reconstruction of the critical Fermi surface. A comparison between pressure and chemical doping as means to suppress TN sheds light on different routes to the quantum critical point and the relevance of Fermi surface nesting and disorder at this quantum phase transition. The work by Jaramillo et al. is broadly relevant to the study of magnetic quantum criticality in a physically pure and theoretically tractable system that balances elements of weak and strong coupling. [4pt] [1] R. Jaramillo, Y. Feng, J. Wang & T. F. Rosenbaum. Signatures of quantum criticality in pure Cr at high pressure. Proc. Natl. Acad. Sci. USA 107, 13631 (2010). [0pt] [2] R. Jaramillo, Y. Feng, J. C. Lang, Z. Islam, G. Srajer, P. B. Littlewood, D. B. McWhan & T. F. Rosenbaum. Breakdown of the Bardeen-Cooper-Schrieffer ground state at a quantum phase transition. Nature 459, 405 (2009).

Jaramillo, Rafael

2012-02-01

39

Decorative storage device for garden hose  

US Patent & Trademark Office Database

A hose storage device has a tub shaped base and a hemispherical top that is attached to the base by a clamshell hinge. The storage device can be anchored in place in a yard by U-shaped stakes that are inserted through pairs of openings. The storage device is decorated to appear like a fanciful character statue, a galapagos tortoise, for example, so that it can remain in the yard as a lawn or garden decoration. A center post in the tub provides a bearing surface for a reel which includes a handle to facilitate coiling and fixtures to which the hose can be connected so that it need never be removed from the reel. A downwardly extending nipple provides a place to connect a short length of hose to a spigot, a clearance passageway being afforded by an inwardly extending reinforcing rib in the tub.

1999-11-23

40

Hazards in High Pressure Systems.  

National Technical Information Service (NTIS)

The High Pressure Systems Committee (HPSC) of the American Society of Mechanical Engineers is writing a set of rules and guides which will eventually be approved for treatment of safety concerns in high pressure operations. An introductory section of the ...

T. G. Priddy

1985-01-01

41

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2012 CFR

...Equipment Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must: (a) Not be...a valve to start and stop the flow of chemical; (e) Have a capacity of at...

2012-10-01

42

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2011 CFR

...Equipment Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must: (a) Not be...a valve to start and stop the flow of chemical; (e) Have a capacity of at...

2011-10-01

43

46 CFR 98.25-80 - Cargo hose.  

Code of Federal Regulations, 2012 CFR

...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-80 Cargo hose. (a) Cargo hose fabricated of seamless steel pipe with swivel joints,...

2012-10-01

44

49 CFR 193.2621 - Testing transfer hoses.  

Code of Federal Regulations, 2011 CFR

...FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable refrigerant transfer systems must be: (a) Tested once each calendar year, but with intervals not exceeding 15 months, to...

2011-10-01

45

49 CFR 193.2621 - Testing transfer hoses.  

Code of Federal Regulations, 2012 CFR

...FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2621 Testing transfer hoses. Hoses used in LNG or flammable refrigerant transfer systems must be: (a) Tested once each calendar year, but with intervals not exceeding 15 months, to...

2012-10-01

46

46 CFR 197.312 - Breathing supply hoses.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.312 Breathing supply hoses. (a) Each breathing supply hose must (1) Have a...

2012-10-01

47

29 CFR 1910.158 - Standpipe and hose systems.  

Code of Federal Regulations, 2013 CFR

...conspicuously identified and used only for fire equipment. (2) Hose outlets...with those used on the supporting fire equipment. (3) Hose. ...with equivalent protection such as extinguishers and fire watches. (v) The...

2013-07-01

48

46 CFR 118.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping...Fire Main System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire hydrant...

2012-10-01

49

46 CFR 193.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2012 CFR

...no protection is afforded to the hose in heavy weather, the hose may be temporarily removed...a garden hose nozzle that is bronze or metal with strength and corrosion resistance...of brass, bronze, or other equivalent metal. National Standard firehose coupling...

2012-10-01

50

30 CFR 18.65 - Flame test of hose.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Flame test of hose. 18.65 Section 18...Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen...by thickness of the hose. (b) Flame-test apparatus. The principal...

2010-07-01

51

30 CFR 18.65 - Flame test of hose.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Flame test of hose. 18.65 Section 18...Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen...by thickness of the hose. (b) Flame-test apparatus. The principal...

2009-07-01

52

46 CFR 131.880 - Fire hoses and axes.  

Code of Federal Regulations, 2012 CFR

... 4 2012-10-01 2012-10-01 false Fire hoses and axes. 131.880 Section 131.880 Shipping COAST GUARD...Equipment and Emergency Equipment § 131.880 Fire hoses and axes. Each fire hose and axe must be marked with the...

2012-10-01

53

Myths about High Blood Pressure  

MedlinePLUS

... High blood pressure is also the No. 1 cause of stroke. 5) Myth. People with high blood pressure have ... can increase blood pressure dramatically. It can also cause heart failure, lead to stroke and produce irregular heartbeats. Too much alcohol can ...

54

Amorphous Materials at High Pressure  

Microsoft Academic Search

\\u000a This chapter reviews the different pathways towards high-pressure amorphization, how high-pressure amorphs may be characterized\\u000a and what are the potential mechanisms causing pressure-induced amorphization and amorphous-amorphous transitions.

Chrystele Sanloup

2010-01-01

55

The Accurate Hose Model for VPN Provisioning  

Microsoft Academic Search

This work considers the problem of VPN provisioning, focusing on the process of dimensioning the links belonging to the route that connects VPN endpoints, according to the specified traffic demands. To accomplish this, we propose a new model, the Accurate Hose, which can take into consideration a complete or partial traffic matrix and supports group based bandwidth requirements, while maintaining

Dnio Mariz; Judith Kelner; Djamel Sadok; Carlos A. Kamienski

56

33 CFR 154.500 - Hose assemblies.  

Code of Federal Regulations, 2013 CFR

...Flanges that meet ANSI B16.5 or B16.24 (both incorporated by reference; see § 154.106); or (3) Quick-disconnect couplings that meet ASTM F 1122 (incorporated by reference, see § 154.106). (e) Each hose must be marked with one of the...

2013-07-01

57

High-pressure neutron diffraction  

SciTech Connect

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

Xu, Hongwu [Los Alamos National Laboratory

2011-01-10

58

Evaluation of Hose in Hose Transfer Line Service Life for Hanford's Interim Stabilization Program  

SciTech Connect

RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program, defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of transfer line equipment to support Hanford's Interim Stabilization Program. RPP-6028, Specification for Hose in Hose Transfer Lines for Hanford's Interim Stabilization Program, has been issued to define the specific requirements for the design, manufacture, and verification of transfer line assemblies for specific waste transfer applications. Included in RPP-6028 are tables defining the chemical constituents of concern to which transfer lines will be exposed. Current Interim Stabilization Program planning forecasts that the at-grade transfer lines will be required to convey pumpable waste for as much as three years after commissioning. Prudent engineering dictates that the equipment placed in service have a working life in excess of this forecasted time period, with some margin to allow for future adjustments to the planned schedule. This document evaluates the effective service life of the Hose-in-Hose Transfer Lines, based on information submitted by the manufacturer and published literature. The effective service life of transfer line assemblies is a function of several factors. Foremost among these are process fluid characteristics, ambient environmental conditions, and the manufacturer's stated shelf life. This evaluation examines the manufacturer's certification of shelf life, the manufacturer's certifications of chemical compatibility with waste, and published literature on the effects of exposure to ionizing radiation on the mechanical properties of elastomeric materials to evaluate transfer line service life.

TORRES, T.D.

2000-08-24

59

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

60

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

61

Electrokinetically pumped high pressure sprays  

DOEpatents

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

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

2005-11-01

62

Fundamentals of high pressure adsorption.  

PubMed

High-pressure adsorption attracts research interests following the world's attention to alternative fuels, and it exerts essential effect on the study of hydrogen/methane storage and the development of novel materials addressing to the storage. However, theoretical puzzles in high-pressure adsorption hindered the progress of application studies. Therefore, the present paper addresses the major theoretical problems that challenged researchers: i.e., how to model the isotherms with maximum observed in high-pressure adsorption; what is the adsorption mechanism at high pressures; how do we determine the quantity of absolute adsorption based on experimental data. Ideology and methods to tackle these problems are elucidated, which lead to new insights into the nature of high-pressure adsorption and progress in application studies, for example, in modeling multicomponent adsorption, hydrogen storage, natural gas storage, and coalbed methane enrichment, was achieved. PMID:19928941

Zhou, Yaping; Zhou, Li

2009-12-01

63

Laser hosing in relativistically hot plasmas  

NASA Astrophysics Data System (ADS)

Electron response in an intense laser is studied in the regime where the electron temperature is relativistic, which is recently accessible in laboratory with kJ-class, short-pulse lasers. Equations for laser envelope and plasma density evolution, both in the electron plasma wave and ion acoustic wave regimes, are re-derived from the relativistic Vlasov equation to include the plasma temperature effect. They show that the mass of an electron fluid element increases relativistically from its thermal energy as well as its fluid motion. These equations are used to study short-pulse and long-pulse laser hosing instabilities using a variational method approach. The analysis shows that relativistic electron temperatures reduce the hosing growth rates and shift the fastest-growing modes to longer wavelengths. These results resolve a long-standing discrepancy between previous non-relativistic theory and simulations/experiments on hosing. This work was supported by DOE under Grant DE-FG02-06ER54879 and Cooperate Agreement No. DE-FC52-08NA28302, by NSF under Grant PHY-0903797, and by NSFC under Grant No. 11129503. The research used resources of NERSC.

Ren, C.; Li, G.; Mori, W. B.

2012-10-01

64

High pressure study on gibbsite  

NASA Astrophysics Data System (ADS)

The water reservoir in the Earths mantle is one of the key subjects in geoscience, and recently Murakami M et al. (Science, 295, 1885, 2002) revealed that Earth's lower mantle may store more water than the oceans. The studies on hydrous minerals under high pressure and temperature are important for understanding the dynamics processes of water in the mantle environments. For gibbsite case, previous studies by Huang et al. (Phys. Chem. Minerals, 26, 576, 1999, &Geophys. Res. Lett, 23, 3083, 1996) reported high pressure induced phase transition above 3 GPa, and the high-pressure polymorph was identified as nordstrandite which is a triclinic phase. In this work, in situ high pressure X-ray diffraction experiments are performed by using various pressure transiting medium including of helium, argon, methanol-ethanol mixture, and mineral oil. The non-hydrostatic and quasi-hydrostatic high pressure results are compared, and the high-pressure phase above 3GPa can be indexed as a higher symmetry phase, i. e. from monoclinic (gibbsite) to orthorhombic structure which is in contrast to the previous reports. The compressibility of gibbsite and its high-pressure polymorph up to 50GPa at room temperature are obtained.

Liu, H.; Hu, J.; Xu, J.; Shu, J.; Mao, H.; Chen, J.

2003-04-01

65

High-pressure fluorescence applications.  

PubMed

Fluorescence is the most widely used technique to study the effect of pressure on biochemical systems. The use of pressure as a physical variable sheds light into volumetric characteristics of reactions. Here we focus on the effect of pressure on protein solutions using a simple unfolding example in order to illustrate the applications of the methodology. Topics covered in this review include the relationships between practical aspects and technical limitations; the effect of pressure and the study of protein cavities; the interpretation of thermodynamic and relaxation kinetics; and the study of relaxation amplitudes. Finally, we discuss the insights available from the combination of fluorescence and other methods adapted to high pressure, such as SAXS or NMR. Because of the simplicity and accessibility of high-pressure fluorescence, the technique is a starting point that complements appropriately multi-methodological approaches related to understanding protein function, disfunction, and folding from the volumetric point of view. PMID:24108623

Dellarole, Mariano; Royer, Catherine A

2014-01-01

66

High pressure and high temperature fluid fugacities  

Microsoft Academic Search

Available high-temperature and high-pressure shock wave data on fluids are combined with low-temperature and low-pressure data to generate empirical equations of state in the virial format in reduced pressure and temperature for many species. A similar equation of state is derived for H2O. The fugacities of the pure species in the C-H-O system can be calculated using the present equation

S. K. Saxena; Y. Fei

1987-01-01

67

High Pressure Thermodynamics of Mixtures  

Microsoft Academic Search

AbstractIn the present survey some important trends in the high pressure thermodynamics,of fluid mixtures of non-electrolytesare reviewed. First the pressure dependence,of excess functions such as the excess Gibbs energy GE, the excess enthalpy HE, the excess entropy SE and the excess heat capacity CE is discussed. It can be obtained from the knowledge,of the excess volume a function of pressure

G. M. Schneider

1976-01-01

68

High-pressure creep tests  

Microsoft Academic Search

The automotive Stirling engine, presently being developed by the U.S. Department of Energy and NASA, uses high-pressure hydrogen as a working fluid; its long-term effects on the properties of alloys are relatively unknown. Hence, creep-rupture testing of wrought and cast high-temperature alloys in high-pressure hydrogen is an essential part of the research supporting the development of the Stirling cycle engine.

S. Bhattacharyya; J. Lamoureux; C. Hales

1986-01-01

69

[Microbial contamination of water by pipe and hose material. 1. Detection of colony count changes].  

PubMed

Materials may produce a growth of microorganisms by contact with water. Pipes and hoses with a narrow diameter have not yet been tested on their influence on the microbial colonization of the water. A harmful change has been discussed especially in dental treatment units. Pipes and hoses were tested in their influence on the microbial growth for half a year. Glass, high grade steel, copper and PTFE showed no increase in microorganisms or only a little in the beginning. The other tested materials, PVC, PE, PA, silicon and rubber, produced an intensive microbial growth. PMID:3138830

Schoenen, D; Wehse, A

1988-05-01

70

High-pressure optical studies  

SciTech Connect

High pressure experimentation may concern intrinsically high pressure phenomena, or it may be used to gain a better understanding of states or processes at one atmosphere. The latter application is probably more prevelant in condensed matter physics. Under this second rubric one may either use high pressure to perturb various electronic energy levels and from this pressure tuning characterize states or processes, or one can use pressure to change a macroscopic parameter in a controlled way, then measure the effect on some molecular property. In this paper, the pressure tuning aspect is emphasized, with a lesser discussion of macroscopic - molecular relationships. In rare earth chelates the efficiency of 4f-4f emission of the rare earth is controlled by the feeding from the singlet and triplet levels of the organic ligand. These ligand levels can be strongly shifted by pressure. A study of the effect of pressure on the emission efficiency permits one to understand the effect of ligand modification at one atmosphere. Photochromic crystals change color upon irradiation due to occupation of a metastable ground state. In thermochromic crystals, raising the temperature accomplishes the same results. For a group of molecular crystals (anils) at high pressure, the metastable state can be occupied at room temperature. The relative displacement of the energy levels at high pressure also inhibits the optical process. Effects on luminescence intensity are shown to be consistent. In the area of microscopic - molecular relationships, the effect of viscosity and dielectric properties on rates of non-radiative (thermal) and radiative emission, and on peak energy for luminescence is demonstrated. For systems which can emit from either of two excited states depending on the interaction with the environment, the effect of rigidity of the medium on the rate of rearrangement of the excited state is shown.

Drickamer, H.G.

1981-01-01

71

High pressure synthesis gas fermentation  

SciTech Connect

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

Not Available

1992-01-01

72

Brillouin Scattering at High Pressures.  

National Technical Information Service (NTIS)

Technical advances which have made Brillouin scattering a useful tool in high pressure diamond anvil cell (DAC) studies, viz. multipassing and tandem operation of Fabry-Perot interferometers, are reviewed. Experimental aspects, such as allowed scattering ...

M. Grimsditch A. Polian

1988-01-01

73

Electrokinetic high pressure hydraulic system  

SciTech Connect

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

74

High pressure ceramic joint  

DOEpatents

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Ward, Michael E. (Poway, CA); Harkins, Bruce D. (San Diego, CA)

1993-01-01

75

Hazards in high pressure systems  

SciTech Connect

The High Pressure Systems Committee (HPSC) of the American Society of Mechanical Engineers is writing a set of rules and guides which will eventually be approved for treatment of safety concerns in high pressure operations. An introductory section of the proposed standard is being written to describe the hazards in high pressure. This paper is an edited version of the early draft of that section which is numbered 2000. Taking Section 2000 out of context (separately printing it from the remainder of the proposed standard) poses a possible misunderstanding in that high pressure is not necessarily synonymous with a lack of safety. There are many high pressure systems in operation with very acceptable safety records. However, when the potential for damage is great, it becomes more essential that safety be comprehensively engineered and practiced. Everyone concerned should be aware to some degree of the dangers that could happen in such operations. This paper is written in an attempt to share the concerns (appraisal of the risks) that members of the HPSC have for high pressure as interpreted and edited by this author. 22 refs.

Priddy, T.G.

1985-08-01

76

33 CFR 149.550 - What are the requirements for lights on a floating hose string?  

Code of Federal Regulations, 2013 CFR

...false What are the requirements for lights on a floating hose string? 149...AND EQUIPMENT Aids to Navigation Lights on Floating Hose Strings § 149.550 What are the requirements for lights on a floating hose string?...

2013-07-01

77

High-pressure creep tests  

SciTech Connect

The automotive Stirling engine, presently being developed by the U.S. Department of Energy and NASA, uses high-pressure hydrogen as a working fluid; its long-term effects on the properties of alloys are relatively unknown. Hence, creep-rupture testing of wrought and cast high-temperature alloys in high-pressure hydrogen is an essential part of the research supporting the development of the Stirling cycle engine. Attention is given to the design, development, and operation of a 20 MPa hydrogen high-temperature multispecimen creep-rupture possessing high sensitivity. This pressure vessel allows for the simultaneous yet independent testing of six specimens. The results from one alloy, XF-818, are presented to illustrate how reported results are derived from the raw test data. 13 references.

Bhattacharyya, S.; Lamoureux, J.; Hales, C.

1986-07-01

78

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

79

High pressure, high temperature scanning tunneling microscopy  

Microsoft Academic Search

The design and performance of a high pressure, high temperature scanning tunneling microscope (HPHT-STM) system is described. The system combines an ultrahigh vacuum surface analysis\\/preparation chamber with a variable pressure (510⁻¹°&hthinsp;Torr1 atm) and temperature (300675 K) STM. The STM chamber can be isolated by three gate valves and filled with 1 atm of any gas mixture. The composition of the

John A. Jensen; Keith B. Rider; Yong Chen; Miquel Salmeron; Gabor A. Somorjai

1999-01-01

80

Electrochemical studies at high pressure  

SciTech Connect

This research has dealt with the development and application of a methodology that permits electrochemical measurements at high pressure. The initial efforts focused on the design and construction of an electrochemical cell functional at hydrostatic pressures as high as 10 kbar. This cell was equipped with an Ag/AgCl/KCl (0.1M) reference electrode which provides reliable control of the potential at all pressures. The potential of this reference electrode can be considered to be constant with pressure. Measurements of formal potentials (E[degrees][prime]) of several transition-metal complexes vs the Ag/AgCl electrode rendered volumes of reactions whose magnitudes support the prediction of the negligible pressure dependence of the reference electrode. The main systems that have been investigated at high pressure are surface-modified electrodes. The author studied the effect of compression on the dynamics of charge transport in quaternized poly(4-vinylpyridine) (QPVP) films placed on gold electrodes, loaded with potassium ferricyanide, and equilibrated in potassium nitrate. Pressure accomplished the continuous change in the structure of the polymer network. This change causes a pronounced restriction in the propagation of charge and in the motion of mass. This high-pressure methodology has also allowed the spatial characterization of electron transfer events taking place between a gold electrode and ferrocene molecules covalently attached to the end of 1-undodecanethiol chains self-assembled on the electrode surface. The volumes of reaction and activation for the oxidation process are both positive, indicating that a volume expansion is associated with the formation of ferricinium. A model is proposed in which the creation of a vacancy in the self-assembled monolayer, for the accommodation of the ferricinium ion or a charge-compensating anion, is coupled with the electron transfer step.

Cruanes, M.T.

1993-01-01

81

Starch gelatinization under pressure studied by high pressure DSC  

Microsoft Academic Search

The gelatinization process of waxy corn starch under different pressures up to 10.0MPa was investigated using a high pressure DSC. Compressed air and carbon dioxide were used as pressure resources. Effect of pressure and annealing under pressure on gelatinization of waxy corn starch was systematically studied, in particular on the gelatinization temperature and enthalpy. The results show that the peak

Hongsheng Liu; Long Yu; Katherine Dean; George Simon; Eustathios Petinakis; Ling Chen

2009-01-01

82

LLL dynamic high pressure experiments  

Microsoft Academic Search

The Lawrence Livermore Laboratory has several experimental facilities to measure material properties at dynamic high pressures. These include an isobaric expansion experiment, a two-stage light-gas gun, and a high-power laser facility (Janus). Each of these are briefly described.

Nellis

1979-01-01

83

On the On-Line Hose-Model VPN Provisioning  

Microsoft Academic Search

The allocation of bandwidth for VPNs to meet the requirements specified by customers is now one of the most important research issues in the field of traffic engineering. A VPN resource provisioning model called hose model was developed to provide customers with flexible and convenient ways to specify the bandwidth requirement of a VPN. Several hose-model VPN provisioning algorithms have

Yu-liang Liu; Yeali S. Sun; Meng Chang Chen

2005-01-01

84

33 CFR 183.532 - Clips, straps, and hose clamps.  

Code of Federal Regulations, 2013 CFR

...the fuel line. (b) If tested in accordance with the fire test under § 183.590, a hose clamp installed on a fuel line system...USCG Type A1 hose must not separate under a one pound tensile force. [CGD 74-209, 42 FR 5950, Jan. 31, 1977,...

2013-07-01

85

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2012 CFR

...on open decks where no protection is afforded to the hose in heavy weather, or where the hose may be liable to damage from the...hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either: (i) Use National Standard...

2012-10-01

86

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

87

The High Pressure Nervous Syndrome and Other High Pressure Effects.  

National Technical Information Service (NTIS)

Many of the problems of exposing man to a high pressure environment depend overtly on the properties of gases in the gaseous phase--such as the various squeezes, voice distortion, thermal effects of helium, density effects, and decompression sickness. Oth...

T. C. Schmidt R. W. Hamilton

1973-01-01

88

Investigation of flexible hose insertion forces and selected factors.  

PubMed

Flexible hoses are widely used in automobiles. Understanding the force required to insert a hose, independent of worker variation, is important for engineers, designers and health professionals. Various parameters affect the insertion forces including the interference between the hose and flange. Also, it has been observed that workers often add motions during the insertion process, including rotation and oscillation. This paper describes the effects of these parameters on axial insertion forces. A programmable mill was used to isolate the effects of four variables on hose insertion force: fit, insertion speed, rotational velocity and oscillation magnitude. The results show that the magnitude of the interference of the 19 mm inside diameters (ID) heater hose and the flange, and the insertion technique affect the insertion forces; resulting in a range of insertion forces from 11.1+/-0.2 to 128.4+/-11.3N. PMID:18339355

Drinkaus, P; Armstrong, T; Foulke, J

2008-03-12

89

High Blood Pressure in Children  

MedlinePLUS

... adults unless they begin treatment. A common complication associated with high blood pressure in children is sleep apnea, a condition in which your child may snore or have abnormal breathing when he or she sleeps. Pay attention to breathing problems your child may have while sleeping. Children who ...

90

High Blood Pressure During Pregnancy  

MedlinePLUS

... in which there is high blood pressure, and protein is present in the urine. If you have further questions, contact your obstetriciangynecologist. FAQ034: Designed as an aid to patients, this document sets forth current information and opinions related to womens ...

91

High Pressure Hydrazine Gas Generator.  

National Technical Information Service (NTIS)

A high pressure hydrazine gas generator has a decomposition chamber which contains therein an initiator of I2O5 crystals and a plurality of heat retaining balls. The liquid hydrazine, which is initially introduced into the decomposition chamber, ignites u...

J. A. Speeds

1977-01-01

92

High pressure tubular swivel joint  

Microsoft Academic Search

A swivel joint and connection for abutting high pressure hydraulic manifolds are described. The joint consists of 2 flanged nonrotating swivel bodies, with one of the nonrotating swivel bodies having a rotating swivel body journaled in it. A flanged tubular sleeve is secured between the adjacent end faces of the 2 nonrotating swivel bodies. A static annular seal is disposed

Kendrick

1976-01-01

93

High pressure tubular swivel joint  

Microsoft Academic Search

A swivel joint and connection for abutting high pressure hydraulic manifolding are described. The joint consists of 2 flanged nonrotating swivel bodies, with one of the nonrotating swivel bodies having a rotating swivel body journaled in it. A flanged tubular sleeve is secured between the adjacent end faces of the 2 nonrotating swivel bodies, with the opposite ends of the

W. D. Kendrick; B. J. Frazier

1976-01-01

94

High pressure paint gun injuries.  

PubMed Central

Despite their use for the past 20 years the dangers of injuries from high pressure paint guns are not widely known. Two cases treated incorrectly through ignorance in our casualty department resulted in amputation of digits. Paint solvents are far moe damaging than paint of grease injection. All cases should be treated urgently by an experienced surgeon as fairly extensive surgery may be needed. Images FIG 1 FIG 2 FIG 3 FIG 4

Booth, C M

1977-01-01

95

Brillouin scattering at high pressures  

NASA Astrophysics Data System (ADS)

Technical advances which have made Brillouin scattering a useful tool in high pressure diamond anvil cell (DAC) studies, viz. multipassing and tandem operation of Fabry-Perot interferometers, are reviewed. Experimental aspects, such as allowed scattering geometries, are outlined and the data analysis required to transform Brillouin spectra into sound velocities and elastic constants is presented. Experimental results on H2, N2, Ar, and He are presented, and the close relationship between the Brillouin scattering results and equations of state is highlighted.

Grimsditch, M.; Polian, A.

1988-02-01

96

High pressure xenon ionization detector  

DOEpatents

A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0 to 30 C. 2 figs.

Markey, J.K.

1989-11-14

97

Transition in amorphous selenium under high pressure  

Microsoft Academic Search

The phase transition in amorphous selenium under high pressure was studied. The high pressures were generated using a diamond-indentor technique. From the behavior of electrical resistance of amorphous selenium under high pressure, it was found that amorphous selenium at room temperature starts transforming to a crystalline phase when the pressure is near 97 kbar. The effect of temperature on the

Mool C. Gupta; Arthur L. Ruoff

1978-01-01

98

High pressure synthesis gas fermentation  

SciTech Connect

The purpose of this research project is to build and test a pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system will be procured or fabricated and assembled in our laboratory. This system will then be used to determine the effects of high pressure on growth and ethanol production by clostridium ljungdahlii. The limits of cell concentration and mass transport relationships will be found in continuous stirred tank reactor and immobilized cell reactors. The minimum retention times and reactor volumes will be found for ethanol production in these reactors. Retention times of a few seconds are expected to result from these experiments. 2 figs., 2 tabs.

Not Available

1991-01-01

99

46 CFR 197.456 - Breathing supply hoses.  

Code of Federal Regulations, 2010 CFR

...SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that (1) Each...

2012-10-01

100

46 CFR 193.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2011 CFR

...garden hose nozzle that is bronze or metal with strength and corrosion resistance equivalent to bronze. Combination solid stream...for any other purpose than fire extinguishing, drills, and testing. (m) Fire hydrants, nozzles, and other fittings...

2011-10-01

101

Silicon nanowires under high pressure  

NASA Astrophysics Data System (ADS)

Silicon nanowires (Si NWs), one-dimensional single crystalline, have recently drawn extensive attention, thanks to their robust applications in electrical and optical devices as well as in the strengthening of diamond/SiC superhard composites. Here, we conducted high-pressure synchrotron diffraction experiments in a diamond anvil cell to study phase transitions and compressibility of Si NWs. Our results revealed that the onset pressure for the Si I-II transformation in Si NWs is approximately 2.0 GPa lower than previously determined values for bulk Si, a trend that is consistent with the analysis of misfit in strain energy. The bulk modulus of Si-I NWs derived from the pressure-volume measurements is 123 GPa, which is comparable to that of Si-V NWs but 25% larger than the reported values for bulk silicon. The reduced compressibility in Si NWs indicates that the unique wire-like structure in nanoscale plays vital roles in the elastic behavior of condensed matter..

Wang, Yuejian

2009-03-01

102

Electrokinetic high pressure hydraulic system  

SciTech Connect

A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.

Paul, P.H.; Rakestraw, D.J.

2000-01-11

103

Brillouin scattering at high pressures  

SciTech Connect

Technical advances which have made Brillouin scattering a useful tool in high pressure diamond anvil cell (DAC) studies, viz. multipassing and tandem operation of Fabry-Perot interferometers, are reviewed. Experimental aspects, such as allowed scattering geometries, are outlined and the data analysis required to transform Brillouin spectra into sound velocities and elastic constants is presented. Experimental results on H/sub 2/, N/sub 2/, Ar, and He are presented, and the close relationship between the Brillouin scattering results and equations of state is highlighted.

Grimsditch, M.; Polian, A.

1988-02-01

104

Electrical Transport Experiments at High Pressure  

SciTech Connect

High-pressure electrical measurements have a long history of use in the study of materials under ultra-high pressures. In recent years, electrical transport experiments have played a key role in the study of many interesting high pressure phenomena including pressure-induced superconductivity, insulator-to-metal transitions, and quantum critical behavior. High-pressure electrical transport experiments also play an important function in geophysics and the study of the Earth's interior. Besides electrical conductivity measurements, electrical transport experiments also encompass techniques for the study of the optoelectronic and thermoelectric properties of materials under high pressures. In addition, electrical transport techniques, i.e., the ability to extend electrically conductive wires from outside instrumentation into the high pressure sample chamber have been utilized to perform other types of experiments as well, such as high-pressure magnetic susceptibility and de Haas-van Alphen Fermi surface experiments. Finally, electrical transport techniques have also been utilized for delivering significant amounts of electrical power to high pressure samples, for the purpose of performing high-pressure and -temperature experiments. Thus, not only do high-pressure electrical transport experiments provide much interesting and valuable data on the physical properties of materials extreme compression, but the underlying high-pressure electrical transport techniques can be used in a number of ways to develop additional diagnostic techniques and to advance high pressure capabilities.

Weir, S

2009-02-11

105

High Blood Pressure: Treat it for Life.  

National Technical Information Service (NTIS)

High blood pressure will not simply go away. This comprehensive booklet describes how to take action against high blood pressure, including losing weight if overweight, increasing physical activity, choosing foods low in salt and sodium, and limiting alco...

1994-01-01

106

High-pressure microhydraulic actuator  

DOEpatents

Electrokinetic ("EK") pumps convert electric to mechanical work when an electric field exerts a body force on ions in the Debye layer of a fluid in a packed bed, which then viscously drags the fluid. Porous silica and polymer monoliths (2.5-mm O.D., and 6-mm to 10-mm length) having a narrow pore size distribution have been developed that are capable of large pressure gradients (250-500 psi/mm) when large electric fields (1000-1500 V/cm) are applied. Flowrates up to 200 .mu.L/min and delivery pressures up to 1200 psi have been demonstrated. Forces up to 5 lb-force at 0.5 mm/s (12 mW) have been demonstrated with a battery-powered DC-DC converter. Hydraulic power of 17 mW (900 psi@ 180 uL/min) has been demonstrated with wall-powered high voltage supplies. The force and stroke delivered by an actuator utilizing an EK pump are shown to exceed the output of solenoids, stepper motors, and DC motors of similar size, despite the low thermodynamic efficiency.

Mosier, Bruce P. (San Francisco, CA); Crocker, Robert W. (Fremont, CA); Patel, Kamlesh D. (Dublin, CA)

2008-06-10

107

Cheese Manufacture Assisted by High Pressure  

Microsoft Academic Search

The processing of foods by high pressure is gaining commercial acceptance. Various food products processed by high pressure are now available in stores and the list of commercialized products is expected to expand as new applications are developed. Currently, industrial applications within the dairy industry are being sought. This article describes what high pressure processing is, presents some of the

M. F. San Martn-Gonzlez; J. Welti-Chanes; G. V. Barbosa-Cnovas

2006-01-01

108

Laser techniques in high-pressure geophysics  

Microsoft Academic Search

Laser techniques in conjunction with the diamond-anvil cell can be used to study high-pressure properties of materials important to a wide range of problems in earth and planetary science. Spontaneous Raman scattering of crystalline and amorphous solids at high pressure demonstrates that dramatic changes in structure and bonding occur on compression. High-pressure Brillouin scattering is sensitive to the pressure variations

R. J. Hemley; P. M. Bell; H. K. Mao

1987-01-01

109

Climatic impacts of fresh water hosing under Last Glacial Maximum conditions: a multi-model study  

NASA Astrophysics Data System (ADS)

Fresh water hosing simulations, in which a fresh water flux is imposed in the North Atlantic to force fluctuations of the Atlantic Meridional Overturning Circulation, have been routinely performed, first to study the climatic signature of different states of this circulation, then, under present or future conditions, to investigate the potential impact of a partial melting of the Greenland ice sheet. The most compelling examples of climatic changes potentially related to AMOC abrupt variations, however, are found in high resolution palaeo-records from around the globe for the last glacial period. To study those more specifically, more and more fresh water hosing experiments have been performed under glacial conditions in the recent years. Here we compare an ensemble constituted by 11 such simulations run with 6 different climate models. All simulations follow a slightly different design, but are sufficiently close in their design to be compared. They all study the impact of a fresh water hosing imposed in the extra-tropical North Atlantic. Common features in the model responses to hosing are the cooling over the North Atlantic, extending along the sub-tropical gyre in the tropical North Atlantic, the southward shift of the Atlantic ITCZ and the weakening of the African and Indian monsoons. On the other hand, the expression of the bipolar see-saw, i.e., warming in the Southern Hemisphere, differs from model to model, with some restricting it to the South Atlantic and specific regions of the southern ocean while others simulate a widespread southern ocean warming. The relationships between the features common to most models, i.e., climate changes over the north and tropical Atlantic, African and Asian monsoon regions, are further quantified. These suggest a tight correlation between the temperature and precipitation changes over the extra-tropical North Atlantic, but different pathways for the teleconnections between the AMOC/North Atlantic region and the African and Indian monsoon regions.

Kageyama, M.; Merkel, U.; Otto-Bliesner, B.; Prange, M.; Abe-Ouchi, A.; Lohmann, G.; Ohgaito, R.; Roche, D. M.; Singarayer, J.; Swingedouw, D.; Zhang, X.

2013-04-01

110

High pressure EWOD digital microfluidics  

Microsoft Academic Search

We are developing new electrowetting-on-dielectric (EWOD) digital microfluidic systems for operating at non-atmospheric conditions. The first generation is a compact pressure chamber with an electric feed-through, enabling EWOD operation within a gaseous medium of well-controlled pressure and composition. EWOD performance is insensitive to chamber pressure because the chip is of open-channel architecture. We demonstrate two different types of previously unachievable

W. C. Nelson; M. Yen; P. Y. Keng; R. M. van Dam; C.-J. Kim

2011-01-01

111

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

112

High Blood Pressure and Metabolic Syndrome  

MedlinePLUS

... Blood Pressure Pulmonary Hypertension Metabolic Syndrome BP vs. Heart Rate BP Quizzes Myths About High Blood Pressure Your ... Warning Signs of a Heart Attack 7 Target Heart Rates 8 Good vs. Bad Cholesterol 9 Types of ...

113

Status of Plasma Electron Hose Instability Studies in FACET  

SciTech Connect

In the FACET plasma-wakefield acceleration experiment a dense 23 GeV electron beam will interact with lithium and cesium plasmas, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons may lead to a fast growing electron hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the plasma, we investigate the transverse behavior of the beam in the plasma as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future plasma wakefield accelerators due to the electron hose instability. The FACET plasma-wakefield experiment at SLAC will study beam driven plasma wakefield acceleration. A dense 23 GeV electron beam will interact with lithium or cesium plasma, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons drives the electron hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and plasma parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the plasma, and observing the transverse behavior of the beam in the plasma as function. The long-term objective of these studies is to quantify potential limitations on future plasma wakefield accelerators due to the electron hose instability.

Adli, Erik; /U. Oslo; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; /SLAC; An, Weiming; Mori, Warren; /UCLA

2011-12-13

114

Potassium and High Blood Pressure  

MedlinePLUS

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

115

Optical calibration of pressure sensors for high pressures and temperatures  

SciTech Connect

We present the results of Raman-scattering measurements of diamond ({sup 12}C) and of cubic boron nitride, and fluorescence measurements of ruby, Sm:yttrium aluminum garnet (Sm:YAG), and SrB{sub 4}O{sub 7}:Sm{sup 2+} in the diamond anvil cell at high pressures and temperatures. These measurements were accompanied by synchrotron x-ray-diffraction measurements on gold. We have extended the room-temperature calibration of Sm:YAG in a quasihydrostatic regime up to 100 GPa. The ruby scale is found to systematically underestimate pressure at high pressures and temperatures compared with all the other sensors. On this basis, we propose an alternative high-temperature ruby pressure scale that is valid to at least 100 GPa and 850 K.

Goncharov, Alexander F.; Zaug, Joseph M.; Crowhurst, Jonathan C.; Gregoryanz, Eugene [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551 (United States); Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, Northwest, Washington DC 20015 (United States)

2005-05-01

116

High pressure synthesis gas conversion. Final report  

SciTech Connect

The purpose of this research project is 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 Clostridium ljungdahlii. 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. A maximum operating pressure of 150 psig has been shown to be possible for C. ljungdahlli with the medium of Phillips et al. This medium was developed for atmospheric pressure operation in the CSTR to yield maximum ethanol concentrations and thus is not best for operation at elevated pressures. It is recommended that a medium development study be performed for C. ljungdahlii at increased pressure. Cell concentration, gas conversion and product concentration profiles were presented for C. ljungdahlii as a function of gas flow rate, the variable which affects bacterium performance the most. This pressure was chosen as a representative pressure over the 0--150 psig operating pressure range for the bacterium. Increased pressure negatively affected ethanol productivity probably due to the fact that medium composition was designed for atmospheric pressure operation. Medium development at increased pressure is necessary for high pressure development of the system.

Not Available

1993-05-01

117

High Precision Pressure Measurement with a Funnel  

ERIC Educational Resources Information Center

|A simple experimental device for high precision differential pressure measurements is presented. Its working mechanism recalls that of a hydraulic press, where pressure is supplied by insufflating air under a funnel. As an application, we measure air pressure inside a soap bubble. The soap bubble is inflated and connected to a funnel which is

Lopez-Arias, T.; Gratton, L. M.; Oss, S.

2008-01-01

118

New materials from high-pressure experiments  

Microsoft Academic Search

High-pressure synthesis on an industrial scale is applied to obtain synthetic diamonds and cubic boron nitride (c-BN), which are the superhard abrasives of choice for cutting and shaping hard metals and ceramics. Recently, high-pressure science has undergone a renaissance, with novel techniques and instrumentation permitting entirely new classes of high-pressure experiments. For example, superconducting behaviour was previously known for only

Paul F. McMillan

2002-01-01

119

Zirconate pyrochlores under high pressure  

SciTech Connect

Ab initio total-energy calculations and x-ray diffraction measurements have been combined to study the phase stability of zirconate pyrochlores (A2Zr2O7; A=La, Nd and Sm) under pressures up to 50 GPa. Phase transformations to the defect-cotunnite structure are theoretically predicted at pressures of 22, 20 and 18 GPa, in excellent agreement with the experimentally determined values of 21, 22 and 18 GPa for La2Zr2O7, Nd2Zr2O7 and Sm2Zr2O7, respectively. Analysis of the elastic properties indicate that elastic anisotropy may be one of the driving forces for the pressure-induced cubic-to-noncubic phase transformation.

Xiao, Haiyan [Pacific Northwest National Laboratory (PNNL); Zhang, Fuxiang [University of Michigan; Gao, Fei [Pacific Northwest National Laboratory (PNNL); Ewing, Rodney C. [University of Michigan; Weber, William J [ORNL

2010-01-01

120

High pressure melting of lithium.  

PubMed

The melting curve of lithium between ambient pressure and 64 GPa is measured by detection of an abrupt change in its electrical resistivity at melting and by visual observation. Here we have used a quasi-four-point resistance measurement in a diamond anvil cell and measured the resistance of lithium as it goes through melting. The resistivity near melting exhibits a well documented sharp increase which allowed us to pinpoint the melting transition from ambient pressure to 64 GPa. Our data show that lithium melts clearly above 300 K in all pressure regions and its melting behavior adheres to the classical model. Moreover, we observed an abrupt increase in the slope of the melting curve around 10 GPa. The onset of this increase fits well to the linear extrapolation of the lower temperature bcc-fcc phase boundary. PMID:23215297

Schaeffer, Anne Marie J; Talmadge, William B; Temple, Scott R; Deemyad, Shanti

2012-11-02

121

Zirconate pyrochlores under high pressure  

SciTech Connect

Ab initio total-energy calculations and x-ray diffraction measurements have been combined to study the phase stability of zirconate pyrochlores (A2Zr2O7; A=La, Nd and Sm) under pressures up to 50 GPa. Phase transformations to the defect-cotunnite structure are theoretically predicted at pressures of 22, 20 and 18 GPa, in excellent agreement with the experimentally determined values of 21, 22 and 18 GPa for La2Zr2O7, Nd2Zr2O7 and Sm2Zr2O7, respectively. Analysis of the elastic properties indicates that elastic anisotropy may be one of the driving forces for the pressure-induced cubic-to-noncubic phase transformation.

Xiao, Haiyan Y.; Zhang, F. X.; Gao, Fei; Lang, Maik; Ewing, Rodney C.; Weber, William J.

2010-07-12

122

46 CFR 181.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2012 CFR

...On a vessel of not more than 19.8 meters (65 feet) in length carrying more than...and on a vessel of more than 19.8 meters (65 feet) in length, each hose must...equivalent in performance; (2) Be 15.25 meters (50 feet) in length and 40...

2012-10-01

123

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

124

Infrasound Sensor and Porous-Hose Filter Characterization Results  

NASA Astrophysics Data System (ADS)

The Ground-Based Nuclear Explosion Monitoring Research and Development (GNEM R&D) program at Sandia National Laboratories (SNL) is regarded as the primary center for unbiased expertise in testing and evaluation of geophysical sensors and instrumentation for nuclear explosion monitoring. Over the past year much of our work has focused in the area of infrasound sensor characterization through the continuing development of an infrasound sensor characterization test-bed. Our main areas of focus have been in new sensor characterization and understanding the effects of porous-hose filters for reducing acoustic background signals. Three infrasound sensors were evaluated for characteristics of instrument response, linearity and self-noise. The sensors tested were Chaparral Physics model 2.5 low-gain, New Mexico Tech All-Sensor and the Inter-Mountain Labs model SS avalanche sensor. For the infrasound sensors tested, the test results allow us to conclude that two of the three sensors had sufficiently quiet noise floor to be at or below the Acoustic low-noise model from 0.1 to 7 Hz, which make those sensors suitable to explosion monitoring. The other area of focus has been to understand the characteristics of porous-hose filters used at some monitoring sites. For this, an experiment was designed in which two infrasound sensors were co- located. One sensor was connected to a typical porous-hose spatial filter consisting of eight individual hoses covering a 30m aperture and the second sensor was left open to unimpeded acoustic input. Data were collected for several days, power spectrum computed for two-hour windows and the relative gain of the porous-hose filters were estimated by dividing the power spectrum. The porous-hose filter appears to attenuate less than 3 dB (rel 1 Pa**2/Hz) below 0.1 Hz and as much as 25 dB at 1 Hz and between 20 to 10 dB above 10 Hz. Several more experiments will be designed to address the effects of different characteristics of the individual porous-hoses, such as length, number and geometric arrangement. This work directly impacts the Ground-Based Nuclear Explosion Monitoring mission by providing a facility, equipment, and personnel to give the operational monitoring agencies confidence in deployed instrumentation and capability for mission success.

Hart, D. M.; Harris, J. M.

2008-12-01

125

Multicomponent fuel vaporization at high pressures.  

SciTech Connect

We extend our multicomponent fuel model to high pressures using a Peng-Robinson equation of state, and implement the model into KIVA-3V. Phase equilibrium is achieved by equating liquid and vapor fugacities. The latent heat of vaporization and fuel enthalpies are also corrected for at high pressures. Numerical simulations of multicomponent evaporation are performed for single droplets for a diesel fuel surrogate at different pressures.

Torres, D. J. (David J.); O'Rourke, P. J. (Peter J.)

2002-01-01

126

Header-platen high-pressure heaters  

NASA Astrophysics Data System (ADS)

We present a new schematic design of high-pressure heaters for the regeneration systems of turbine units used at nuclear and thermal power stations, which features better reliability, smaller weight and overall dimensions, and higher thermal efficiency as compared with those characteristic for the design of the well-known types of heaters. We also show that it is possible to construct heaters for high pressures typical for supercritical-pressure boilers with the use of existing domestically made materials.

Avdeev, A. A.; Shamarokov, A. S.; Fal'Kovskii, L. N.

2009-02-01

127

Cagelike Diamondoid Nitrogen at High Pressures  

NASA Astrophysics Data System (ADS)

Under high pressure, triply bonded molecular nitrogen dissociates into singly bonded polymeric nitrogen, a potential high-energy-density material. The discovery of stable high-pressure forms of polymeric nitrogen is of great interest. We report the striking stabilization of cagelike diamondoid nitrogen at high pressures predicted by first-principles structural searches. The diamondoid structure of polymeric nitrogen has not been seen in any other elements, and it adopts a highly symmetric body-centered cubic structure with lattice sites occupied by diamondoids, each of which consists of ten nitrogen atoms, forming a N10 tetracyclic cage. Diamondoid nitrogen possesses a wide energy gap and is energetically most stable among all known polymeric structures above 263 GPa, a pressure that is accessible to a high-pressure experiment. Our findings represent a significant step toward the understanding of the behavior of solid nitrogen at extreme conditions.

Wang, Xiaoli; Wang, Yanchao; Miao, Maosheng; Zhong, Xin; Lv, Jian; Cui, Tian; Li, Jianfu; Chen, Li; Pickard, Chris J.; Ma, Yanming

2012-10-01

128

CHRONOBIOLOGY OF HIGH BLOOD PRESSURE  

PubMed Central

BIOCOS, the project aimed at studying BIOlogical systems in their COSmos, has obtained a great deal of expertise in the fields of blood pressure (BP) and heart rate (HR) monitoring and of marker rhythmometry for the purposes of screening, diagnosis, treatment, and prognosis. Prolonging the monitoring reduces the uncertainty in the estimation of circadian parameters; the current recommendation of BIOCOS requires monitoring for at least 7 days. The BIOCOS approach consists of a parametric and a non-parametric analysis of the data, in which the results from the individual subject are being compared with gender- and age-specified reference values in health. Chronobiological designs can offer important new information regarding the optimization of treatment by timing its administration as a function of circadian and other rhythms. New technological developments are needed to close the loop between the monitoring of blood pressure and the administration of antihypertensive drugs.

Cornelissen, G.; Halberg, F.; Bakken, E. E.; Wang, Z.; Tarquini, R.; Perfetto, F.; Laffi, G.; Maggioni, C.; Kumagai, Y.; Homolka, P.; Havelkova, A.; Dusek, J.; Svacinova, H.; Siegelova, J.; Fiser, B.

2008-01-01

129

High pressure Hugoniot of sapphire  

SciTech Connect

The Hugoniot of sapphire was measured from 80 GPa to 340 GPa in shock-wave experiments using projectiles accelerated by a two stage gas gun. Transit times of the shock waves were measured either optically with a streak camera or through electrical pin contacts. The Hugoniot in this pressure range fits U{sub s}=8.74+0.96 U{sub p}in km/s.

Erskine, D.

1993-07-01

130

Mechanism of High Pressure Denaturation of Proteins  

Microsoft Academic Search

High pressure denaturation of ovalbumin, bovine serum albumin (BSA) and ?-lactoglobulin was assessed by spectrofluorometry, specific rotation analysis and differential scanning calorimetry (DSC), and compared with heat and chemical denaturation. In all cases the denaturation caused by high pressure was similar to that caused by the cleavage of hydrogen bonds with urea or guanidine hydrochloride.

Isao Hayakawa; Yu-Yen Linko; Pekka Linko

1996-01-01

131

High Blood Pressure Medications and You: Infographic  

Center for Drug Evaluation (CDER)

... High Blood Pressure Medications and You: Infographic. Click here for a high-resolution, printable PDF (5.7 MB) of this infographic. ... More results from www.fda.gov/drugs/resourcesforyou/specialfeatures

132

A high temperature high pressure cell for quasielastic neutron scattering  

Microsoft Academic Search

We present our recent development of a high temperature high pressure cell for neutron scattering. Combining a water cooled Nb1Zr pressure cell body with an internal heating furnace, the sample environment can reach temperatures of up to 1500 K at a pressure of up to 200 MPa at the sample position, with an available sample volume of about 700 mm3.

F. Yang; J. Kaplonski; T. Unruh; E. Mamontov; A. Meyer

2011-01-01

133

Thermal Conductivity of Argon at High Pressures and High Temperatures  

Microsoft Academic Search

Accurate data on the thermal conductivity of argon at high pressures and high temperatures is essential to unraveling the nature of the Earth's interior. Argon is a common pressure-transmitting medium in diamond anvil cell (DAC) experiments, which is commonly used for studying the properties of minerals at pressures and temperatures native to the mantel and core. We used a transient

M. L. Wong; A. F. Goncharov; D. A. Dalton; J. Ojwang; V. Struzhkin; Z. Konopkova; P. Lazor

2010-01-01

134

High-resolution NMR probe for high pressure studies  

Microsoft Academic Search

Specialized design features of high-resolution, high-pressure NMR probe are discussed. A new design of the high-pressure NMR\\u000a probe is presented. The achieved performance characteristics such as high resolution, high sensitivity, large sample volume,\\u000a variable temperature, and wide range of pressures up to 1000 MPa make this instrumentation well suited for studies of biochemical\\u000a systems.

P. Koziol; C. Reiner; J. Jonas

1996-01-01

135

Pressure variations during ultra-high pressure metasomatism?  

NASA Astrophysics Data System (ADS)

Incomplete reactions or apparent disequilibrium between minerals in metamorphic rocks from high pressure (HP) and ultra-high pressure (UHP) terrains are commonly observed in field and thin section. Here we show an example of a peridotitic body enclosed in migmatitic felsic Proterozoic gneiss at the Svartberget locality in the northernmost UHP terrain of the Western Gneiss Region (WGR) in Western Norway. The WGR represents the basement of Baltica which became metamorphosed during the Caledonian Orogeny. In the highest grade parts of the WGR metamorphic temperatures were between 600-800 C for several Ma, pressures reached the diamond stability field, fluids were available and yet well known pressure sensitive reactions such as from spinel- to garnet-peridotite went only locally to completion in the studied peridotite. Previously reported field observations, major, trace and isotope geochemistry, geochronology, mineral-chemistry and textures suggest that this peridotite body became metasomatised by supercritical fluids from the host rock gneiss during the Caledonian Orogeny. Contrasting pressure estimates, incomplete reactions and preserved compositional gradients in minerals from this body may indicate very rapid exhumation, very sluggish kinetics of diffusion, metasomatically disturbed equilibrium at low temperatures or a combination of the three. These possibilities call for a re-evaluation of existing methods in geothermobarometry. Alternatively we may consider that pressure variations existed from the grain up to the outcrop scale during the metasomatism of the peridotite at UHP conditions. The mechanical responses to volume changes that are involved in chemical reactions in rocks may control the progress of reactions significantly (Schmid et al.1, 2009). Our main results, obtained from numerical modelling, show that pressure variations may be generated, and maintained on the geological time scale, as a result of the mechanical response of the rocks during melting reactions in confined space.

Vrijmoed, J. C.; Podladchikov, Y. Y.

2009-04-01

136

Portable high precision pressure transducer system  

NASA Astrophysics Data System (ADS)

A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank is presented. Since the response of the pressure transducer is temperature sensitive, it is continually housed in a battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on-board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display.

Piper, T. C.; Morgan, J. P.; Marchant, N. J.; Bolton, S. M.

137

Portable high precision pressure transducer system  

DOEpatents

A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.

Piper, Thomas C. (Idaho Falls, ID); Morgan, John P. (Idaho Falls, ID); Marchant, Norman J. (Idaho Falls, ID); Bolton, Steven M. (Pocatello, ID)

1994-01-01

138

Portable high precision pressure transducer system  

DOEpatents

A high precision pressure transducer system is described for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display. 2 figures.

Piper, T.C.; Morgan, J.P.; Marchant, N.J.; Bolton, S.M.

1994-04-26

139

Portable high precision pressure transducer system  

DOEpatents

A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.

Piper, T.C.; Morgan, J.P.; Marchant, N.J.; Bolton, S.M.

1992-12-31

140

HIGH-TEMPERATURE AND HIGH-PRESSURE PARTICULATE CONTROL REQUIREMENTS  

EPA Science Inventory

The report reviews and evaluates high-temperature and high-pressure particulate cleanup requirements of existing and proposed energy processes. The study's aims are to define specific high-temperature and high-pressure particle removal problems, to indicate potential solutions, a...

141

The Five Alkali Metals under High Pressure  

Microsoft Academic Search

Effect of high pressure on the melting constants, electrical resistance and volume of the alkali metals.-(1) New data for Rb and Cs, presented in detail elsewhere, are given in three tables. Then, since similar data have previously been obtained for Li, Na and K, the results of a comparative study of all five alkali metals under pressure are given and

P. W. Bridgman

1926-01-01

142

High-Pressure Synthesis of Lutetium Diantimonide.  

National Technical Information Service (NTIS)

The high-pressure orthorhombic form of LuSb2 was made from the elements at 73 kbars and 1000C or at higher pressures and temperatures. A Debye-Scherrer powder diffraction pattern for LuSb2 is given. (Author)

N. L. Eatough H. T. Hall

1969-01-01

143

Small, High-Pressure Liquid Hydrogen Turbopump.  

National Technical Information Service (NTIS)

A high pressure, liquid hydrogen turbopump was designed, fabricated, and tested to a maximum speed of 9739 rad/s and a maximum pump discharge pressure of 2861 N/sq. cm. The approaches used in the analysis and design of the turbopump are described, and fab...

A. Csomor R. Sutton

1977-01-01

144

High pressure thermoelasticity of vanadium  

NASA Astrophysics Data System (ADS)

To support a larger effort for a multi-phase constitutive strength model for vanadium, we discuss the calculations performed to determine the anharmonic thermoelasticity for bcc and rhombohedral phases of vanadium. In this investigation, we have performed extensive calculations of the elastic moduli over broad ranges of temperature (<10,000 K) and pressure (<3 Mbar), accounting for both the electron-thermal and ion-thermal contributions. Using density functional theory (DFT) with the projector augmented-wave (PAW) methodology to calculate the electron-thermal component, we have combined this with the ion-thermal component, which is calculated from Monte Carlo (MC) canonical distribution averages of the strain derivatives on a multi-ion potential itself. The ion-potential is described through a many-body, quantum-based interatomic potential---the model generalized pseudopotential theory (MGPT). We suggest regions of stability for the rhombohedral structure in the phase diagram. The resulting elastic moduli are compared to available experimental results and to sound speeds measured along the Hugoniot.

Orlikowski, Daniel

2009-03-01

145

High pressure processing effects on fish proteins.  

PubMed

Salted pastes of surimi, a myofibrillar concentrate of fish muscle, gel at pressures near 300 MPa. High pressure processing has been thought to induce denaturation and gelation of myofibrillar proteins mainly by disruption of protein intramolecular hydrophobic interactions which subsequently reform intennolecularly. We have shown that pressure-induced surimi gels evidence disulfide bonding as well. Endogenous transglutaminase (TGase) evidently survives the pressure treatment, and subsequent TGase-mediated setting of Alaska pollock surimi pastes at 25 degrees C results in very strong gels as compared to those prepared without prior pressurization. High pressure during freezing or thawing greatly accelerates these operations and can reduce ice crystal size and associated tissue damage. Yet pressure treatment can destabilize proteins which might lower fish quality. Infusion of certain carbohydrates into muscle prior to pressure-assisted freezing/thawing can achieve both baroprotection and cryoprotection of the muscle proteins. Pressure treatment has not proven useful for inactivation of proteolytic enzymes that degrade fish quality. PMID:9598189

Lanier, T C

1998-01-01

146

Raman Study of SWNT Under High Pressure  

NASA Astrophysics Data System (ADS)

A gasketed Merrill-Bassett-type diamond anvil cell was used for high pressure Raman measurements at room temperature. A 4:1 methanol-ethanol mixture served as the pressure transmitting medium. The radial mode (denoted as R, occuring at 186 cm-1 at 1 bar) and tangential modes (designated T_1, T_2, and T_3, located, respectively, at 1550, 1567, and 1593 cm-1 at 1 bar) were recorded for several representative pressures. With increasing pressure, both the R and T modes shift to higher frequencies with gradual weakening of intensity and broadening of linewidth. The radial mode disappears around ~ 2 GPa whereas the tangential modes, albeit weak in intensity, persist until 5.2 GPa. The decrease in Raman intensity under pressure can be attributed to a loss of resonance, since the strong Raman signals observed at ambient pressure have been interpreted as due a resonance with the electronic bands [1]. The R and T mode frequencies are fit to quadratic function of pressure i.e., ?=?(0)+aP+bP^2 where `a' represents the linear pressure shift of the mode frequency which is proportional to the mode Gruneisen parameter. The linear pressure coefficient for the R mode is found to be nearly twice that of the high frequency T mode. A. M. Rao et al., Science 275, 187, 1997

Venkateswaran, U.; Rao, A. M.; Richter, E.; Eklund, P. C.; Smalley, R. E.

1998-03-01

147

Development of High Pressure Liquid Chromatographic Techniques.  

National Technical Information Service (NTIS)

This is an interim report on a continuing study of the application of High Pressure Liquid Chromatographic (HPLC) techniques to water pollution problems. Reported herein are developmental data on three new detection systems; an ultrasonic velocity detecto...

E. A. Walters

1976-01-01

148

High Blood Pressure: The Science Inside  

NSDL National Science Digital Library

This booklet is a resource to help individuals at risk to high blood pressure. Supported by Science Education Partnership Award (SEPA) from the National Center for Research Resources Grant # 5R25RR15601

Healthy People Library Project;

2004-01-01

149

Compression of Mercury to High Pressure.  

National Technical Information Service (NTIS)

A method for calculating volume results from high pressure acoustic data was developed which is not limited to small compressions by the assumption of a constant ratio of isothermal to adiabatic compressibility. This method thereby extends the useful rang...

L. A. Davis

1966-01-01

150

High Pressure Oxygen Utilization by NASA.  

National Technical Information Service (NTIS)

Although NASA is not one of the country's major oxygen consumers, it uses oxygen under severe conditions including very high flow rates and pressure. Materials for such applications must be carefully selected for compatibility, because susceptibility to i...

F. E. Belles

1973-01-01

151

Hose in Hose, an S locus-linked mutant of Primula vulgaris, is caused by an unstable mutation at the Globosa locus.  

PubMed

Hose in Hose mutants of primrose and cowslip have been cultivated since the early 17th century and show dominant homeotic conversion of sepals to petals. The phenotype shows variable penetrance and expressivity and is linked to the S locus, which controls floral heteromorphy in Primula species. Here we demonstrate that the homeotic conversion of sepals to petals in Hose in Hose is associated with up-regulation of both Primula B-function MADS box genes PvDef and PvGlo in the first floral whorl. We have defined a restriction fragment length polymorphism associated with PvGlo that cosegregates with the Hose in Hose phenotype and have also identified and characterized a retrotransposon insertion in the PvGlo promoter which is associated with the up-regulated expression of PvGlo. Excision of this retrotransposon, associated with epigenetic changes at the locus, causes reversion toward normal calyces and restores wild-type flower development. These data define the molecular basis of the Hose in Hose mutation and provide an explanation for its long-documented phenotypic instability. PMID:20212126

Li, Jinhong; Dudas, Brigitta; Webster, Margaret A; Cook, Holly E; Davies, Brendan H; Gilmartin, Philip M

2010-03-08

152

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Maximum allowable operating pressure: High-pressure distribution systems. 192.621 Section 192...Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No...

2009-10-01

153

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. (a) No...

2010-10-01

154

High pressure techniques at low temperatures  

Microsoft Academic Search

The article reviews the experimental techniques used in high pressure-low temperature investigations to study a variety of\\u000a physico-chemical phenomena. The general principles of producing high pressures at low temperatures, the methods of measuring\\u000a P and T, the materials used for construction and the diamond anvil cell (DAC) are briefly given first. Specific pieces of\\u000a apparatus to measure the mechanical properties,

S. Ramaseshan; G. Parthasarthy; E S R Gopal

1987-01-01

155

Experimental Investigation of High Temperature and High Pressure Coal Gasification  

Microsoft Academic Search

Pyrolysis and gasification behavior is analyzed at operation conditions relevant to industrial scale entrained flow gasifiers. A wire mesh reactor and the Pressurized High Temperature Entrained Flow Reactor (PiTER) are used to measure volatile yield of Rhenish lignite, a bituminous coal and German anthracite at high temperature and high pressure. In the wire mesh reactor at 1000C a significant influence

Alexander Tremel; Thomas Haselsteiner; Christian Kunze; Hartmut Spliethoff

2012-01-01

156

Food preservation by high pressure  

Microsoft Academic Search

\\u000a AbstractNovel non-thermal food processing technologies aim to provide safe, high quality foods with desirable nutritional, physico-chemical\\u000a and sensorical properties. More recently with the use of minimal processing treatment concepts have been added to the already\\u000a existing food processing requirements. Some of them might be beneficial for the improvement of hygiene and the extension of\\u000a shelf life. This presentation will focus

Volker Heinz; Roman Buckow

2010-01-01

157

High frequency pressure oscillator for microcryocoolers  

NASA Astrophysics Data System (ADS)

Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency pressure oscillator is presented with the aim to power a micropulse tube cryocooler operating between 300 and 80 K, delivering a cooling power of 10 mW. Piezoelectric actuators operate efficiently at high frequencies and have high power density making them good candidates as drivers for high frequency pressure oscillator. The pressure oscillator described in this work consists of a membrane driven by a piezoelectric actuator. A pressure ratio of about 1.11 was achieved with a filling pressure of 2.5 MPa and compression volume of about 22.6 mm3 when operating the actuator with a peak-to-peak sinusoidal voltage of 100 V at a frequency of 1 kHz. The electrical power input was 2.73 W. The high pressure ratio and low electrical input power at high frequencies would herald development of microminiature cryocoolers.

Vanapalli, S.; Ter Brake, H. J. M.; Jansen, H. V.; Zhao, Y.; Holland, H. J.; Burger, J. F.; Elwenspoek, M. C.

2008-04-01

158

Elasticity of orthoenstatite at high-pressure  

NASA Astrophysics Data System (ADS)

Orthoenstatite is an abundant yet complex mineral in Earth's upper mantle. Despite its abundance, the properties of orthopyroxene at high pressure remain ambiguous (e.g., Zhang et al. 2011; Jahn 2008; Kung et al. 2004). We explored select properties of a synthetic powdered orthoenstatite (Mg0.8757Fe0.13)2Si2O6 sample by X-ray diffraction (XRD) and nuclear resonance inelastic X-ray scattering (NRIXS) as a function of pressure in a neon pressure medium at 300 K. The XRD measurements were carried out at beamline 12.2.2 of the Advanced Light Source (Berkeley, CA), and the sample was studied up to 34 GPa. NRIXS measurements were carried out at sector 3ID-B of the Advanced Photon Source (Chicago, IL) in the pressure range of 3 to 17 GPa. From the raw NRIXS data, the partial phonon density of states (DOS) was derived (e.g., Sturhahn 2004). The volume (or pressure) dependence of several properties, such as the Lamb-Mssbauer factor, mean force constant, specific heat, vibrational entropy, and vibrational kinetic energy were determined from the DOS. We will discuss our results from these combined studies and the implications for Earth's upper mantle. References Zhang, D., J.M. Jackson, W. Sturhahn, and Y. Xiao (2011): Local structure variations observed in orthoenstatite at high-pressures. American Mineralogist, in press. Jahn, S. (2008) High-pressure phase transitions in MgSiO3 orthoenstatite studied by atomistic computer simulation. American Mineralogist, 93(4), 528-532. Kung, J., Li, B., Uchida, T., Wang, Y., Neuville, D., and Liebermann, R. (2004) In situ measurements of sound velocities and densities across the orthopyroxene high-pressure clinopyroxene transition in MgSiO3 at high pressure. Physics of the Earth and Planetary Interiors, 147(1), 27-44. Sturhahn, W. (2004): Nuclear Resonant Spectroscopy. J. Phys. Condens. Matter, 16, S497-S530.

Zhang, D.; Jackson, J. M.; Chen, B.; Zhao, J.; Yan, J.

2011-12-01

159

High pressure ceramic heat exchanger  

DOEpatents

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the reinforcing member and having a strengthening member wrapped around the refractory material. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1999-01-01

160

High pressure ceramic heat exchanger  

DOEpatents

Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1998-01-01

161

Pressure sensor for high-temperature liquids  

DOEpatents

A pressure sensor for use in measuring pressures in liquid at high temperatures, especially such as liquid sodium or liquid potassium, comprises a soft diaphragm in contact with the liquid. The soft diaphragm is coupled mechanically to a stiff diaphragm. Pressure is measured by measuring the displacment of both diaphragms, typically by measuring the capacitance between the stiff diaphragm and a fixed plate when the stiff diaphragm is deflected in response to the measured pressure through mechanical coupling from the soft diaphragm. Absolute calibration is achieved by admitting gas under pressure to the region between diaphragms and to the region between the stiff diaphragm and the fixed plate, breaking the coupling between the soft and stiff diaphragms. The apparatus can be calibrated rapidly and absolutely.

Forster, George A. (Westmont, IL)

1978-01-01

162

New High-Pressure Excitations in Parahydrogen  

SciTech Connect

Raman and infrared spectroscopy of para-H{sub 2} to pressures in excess of 200GPa and to 8K using new ultrapure synthetic diamond anvils reveals numerous new vibrational excitations in the three high-pressure phases. Highly resolved Raman-active librons indicate differences in orientational ordering between phasesII and III, including evidence for changes within phaseII. The librons in phaseIII are strongly pressure dependent and reflect a substantial increase in ordering with pressure. Multiple vibrons in all three phases (I, II, and III) are observed. The results place new bounds on predicted crystal structures and dynamics of the dense molecular solid. {copyright} {ital 1997} {ital The American Physical Society}

Goncharov, A.F.; Hemley, R.J.; Mao, H.; Shu, J. [Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road N.W., Washington, D.C. 20015 (United States)

1998-01-01

163

Sample injector for high pressure liquid chromatography  

DOEpatents

Apparatus and method for driving a sample, having a well-defined volume, under pressure into a chromatography column. A conventional high pressure sampling valve is replaced by a sample injector composed of a pair of injector components connected in series to a common junction. The injector components are containers of porous dielectric material constructed so as to provide for electroosmotic flow of a sample into the junction. At an appropriate time, a pressure pulse from a high pressure source, that can be an electrokinetic pump, connected to the common junction, drives a portion of the sample, whose size is determined by the dead volume of the common junction, into the chromatographic column for subsequent separation and analysis. The apparatus can be fabricated on a substrate for microanalytical applications.

Paul, Phillip H. (Livermore, CA); Arnold, Don W. (Livermore, CA); Neyer, David W. (Castro Valley, CA)

2001-01-01

164

Mechanical Behavior of Explosives at High Pressures  

Microsoft Academic Search

The mechanical and ignition behaviors of heterogeneous explosives and pure polymeric binders used in plastic-bonded explosive are highly dependent on the pressure. New apparatus capable of testing small explosive samples under pressures reaching 10 kbar were developed. Unlike previous designs that use a cylinder-piston arrangement, here the samples are quasi-statically and dynamically compacted in a working fluid, thus ensuring isotropic

John Kelley; Vasant Joshi; Raafat Guirguis

2001-01-01

165

Effects of High Pressure on Vegetative Microorganisms  

Microsoft Academic Search

\\u000a Increasing consumer demand for minimally processed, additive-free, shelf-stable products prompted food scientists to explore\\u000a other physical preservation methods as alternatives to traditional heat treatments. Ultra high pressure is one of the most\\u000a promising of these techniques. Ideally, the pressure treatment should result in microbiologically safe and stable foods over\\u000a as wide a range of conditions as possible. Thus, there is

Jan P. Smelt; Johan C. Hellemons; Margaret Patterson

166

The Effects of High Pressure on Biomaterials  

Microsoft Academic Search

\\u000a The study of the effects of pressure on food macromolecules and colloids has received a great deal of attention in recent\\u000a years. Bridgman (1914) made considerable progress in the development of equipment not long after the initial attempts of Hite (1899), who referred to technical problems with high pressure equipment. Developments in France, primarily in the biomedical\\u000a field between the

Karel Heremans

167

Methane hydrate behavior under high pressure  

Microsoft Academic Search

Phases changes in a water-methane system were investigated in a pressure range from 0.2 to 5.5 GPa using a diamond anvil cell. In-situ X-ray diffractometry and optical microscopy revealed methane hydrate behavior from growth to decomposition into high-pressure ice and solid methane at room temperature. Methane hydrate crystallized at 0.2--0.3 GPa from liquid, and it was compressed continuously until 2.3

Hisako Hirai; Tadashi Kondo; Masashi Hasegawa; Takehiko Yagi; Yoshitaka Yamamoto; Takeshi Komai; Kazushige Nagashima; Mami Sakashita; Hiroyuki Fujihisa; Katsutoshi Aoki

2000-01-01

168

CARS thermometry in high pressure rocket combustors  

Microsoft Academic Search

Coherent anti-Stokes Raman spectroscopy (CARS) has been used to investigate high pressure cryogenic liquid oxygen\\/gaseous hydrogen (LOX\\/GH2) flames at pressures up to 6.5 MPa. The method employs two synchronized broadband CARS systems to probe simultaneously H2 and H2O. Temperature is deduced from the H2 and H2O CARS profiles while the H2O concentration is deduced from the modulation from the resonant

Frdric Grisch; Paul Bouchardy; Walter Clauss

2003-01-01

169

High pressure, high current, low inductance, high reliability sealed terminals  

DOEpatents

The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

Hsu, John S. (Oak Ridge, TN); McKeever, John W. (Oak Ridge, TN)

2010-03-23

170

Crystal structures at high pressures and temperatures  

NASA Astrophysics Data System (ADS)

The diamond anvil cell (DAC) is a unique instrument that can generate pressures equivalent to those inside planetary interiors (pressures on the order of 1 million atmospheres) under sustained conditions. When combined with a bright source of collimated x-rays, the DAC can be used to probe the structure of materials in-situ at ultra-high pressures. An understanding of the high-pressure structure of materials is important in determining what types of processes may take place in the Earth at great depths. Motivated by previous studies showing that xenon becomes metallic at pressures above 1 megabar (100 GPa), we examined the stable structures and reactivity of xenon at pressures approaching that of the core-mantle boundary in the Earth. Our findings indicate the transformation of xenon from face-centered cubic (fcc) to hexagonal close-packed (hcp) structures is kinetically hindered at room temperature, with the equilibrium fcc--hcp phase boundary at 21 (+/-3) gigapascals, a pressure lower than was previously thought. Additionally, we find no tendency on the part of xenon to form a metal alloy with iron or platinum to at least 100 to 150 gigapascals, making it unlikely that the Earth's core serves as a reservoir for primordial xenon. Measurements of the compressibility of natural (Mg.75,Fe .25)2SiO4 gamma-spinel at pressures of the Earth's transition zone yield a pressure derivative of the bulk modulus K0 ' = 6.3 (+/-0.3). As gamma-spinel is considered to be a dominant mineral phase of the transition-zone of the Earth's mantle (400--670 km depth), the relatively high value of K0' for gamma-spinel may help explain the rapid increase with depth of seismic velocities through the transition zone. The thermodynamics, mechanisms and kinetics of pressure-induced amorphization are not well understood. We report here new studies indicating little or no entropy difference between the crystalline and glassy states of Ca(OH) 2 (portlandite). Additional work on the pressure-induced amorphization of AlPO4 (berlinite) shows that this material, which is a close analog to quartz, shows a rich behavior that is dependent upon the pressure, temperature, stress-state and time-scales of the experimental conditions.

Caldwell, Wendel Alexander

2000-10-01

171

High Pressure Behavior of CO_2  

NASA Astrophysics Data System (ADS)

Extensive LAPW calculations were performed in order to study the high pressure behavior of CO_2. We start by constructing the equation of state of CO2 with the Cmca structure, which is its currently known highest pressure phase, stable above 10 GPa. Next, we test the possibility of a stable phase of CO2 with a cristobalite structure. The viability of this phase is based on a trend we see in the dioxides of the 4A group; SiO_2, GeO_2, SnO2 and PbO_2. At higher pressures, the lower atomic number phases adopt the structures of the higher atomic number phases; PbO2 and SnO2 exist in the rutile structure at one atmospheric pressure, GeO2 and SiO2 exist in the quartz structure and transform into a rutile structure at high pressures. This lends support to the possibility that CO_2, the first member of the 4A group, might adopt one of the SiO2 structures at high pressure. Using molecular orbitals calculations it was found that CO2 with the cristobalite structure would have a density about 1.3 times larger than that of the Cmca structure. The equation of state of CO2 with the cristobalite structure will be constructed and the pressure at which a transformation might occur can be found by calculating the common tangent of the two curves. X-ray diffraction experiments will be performed to search for higher pressure phases of CO2 and also address the controversial existence of the so called ``dry-ice II'' structure between 0.5 and 2.3 GPa at room temperature.

Inbar, Iris; Downs, R. T.; Somayazulu, M.; Teter, D.; Hazen, R.

1996-03-01

172

Coupled beam hose and self-modulation instabilities in overdense plasma  

NASA Astrophysics Data System (ADS)

Transverse stability of the drive beam is critical to plasma wakefield accelerators. A long, relativistic particle beam propagating in an overdense plasma is subject to beam envelope modulation and centroid displacement (hosing) instabilities. Coupled equations for the beam centroid and envelope are derived and solved. It is shown that the hosing growth rate is comparable to self-modulation, and coupling of the self-modulation enhances beam hosing and induces harmonic content. Large amounts of hosing significantly alters the structure of the plasma wakefields.

Schroeder, C. B.; Benedetti, C.; Esarey, E.; Grner, F. J.; Leemans, W. P.

2012-08-01

173

High pressure electrical insulated feed thru connector  

DOEpatents

A feed-thru type hermetic electrical connector including at least one connector pin feeding through an insulator block within the metallic body of the connector shell. A compression stop arrangement coaxially disposed about the insulator body is brazed to the shell, and the shoulder on the insulator block bears against this top in a compression mode, the high pressure or internal connector being at the opposite end of the shell. Seals between the pin and an internal bore at the high pressure end of the insulator block and between the insulator block and the metallic shell at the high pressure end are hermetically brazed in place, the first of these also functioning to transfer the axial compressive load without permitting appreciable shear action between the pin and insulator block.

Oeschger, Joseph E. (Palo Alto, CA); Berkeland, James E. (San Jose, CA)

1979-11-13

174

High pressure chemistry of substituted acetylenes  

SciTech Connect

High pressure in situ synchrotron x-ray diffraction experiments were performed on substituted polyacetylenes: tert-butyl acetylene [TBA: (CH{sub 3}){sub 3}-C{triple_bond}CH] and ethynyl trimethylsilane [ETMS: (CH{sub 3}){sub 3}-Si{triple_bond}CH] to investigate pressure-induced chemical reactions. The starting samples were the low temperature crystalline phases which persisted metastably at room temperature and polymerized beyond 11 GPa and 26 GPa for TBA and ETMS respectively. These reaction onset pressures are considerably higher than what we observed in the shockwave studies (6.1 GPa for TBA and 6.6 GPa for ETMS). Interestingly, in the case of ETMS, it was observed with fluid ETMS as starting sample, reacts to form a semi-crystalline polymer (crystalline domains corresponding to the low-T phase) at pressures less than {approx}2 GPa. Further characterization using vibrational spectroscopy is in progress.

Chellappa, Raja [Los Alamos National Laboratory; Dattelbaum, Dana [Los Alamos National Laboratory; Sheffield, Stephen [Los Alamos National Laboratory; Robbins, David [Los Alamos National Laboratory

2011-01-25

175

Phonon Drag Dislocations at High Pressures  

SciTech Connect

Phonon drag on dislocations is the dominant process which determines the flow stress of metals at elevated temperatures and at very high plastic deformation rates. The dependence of the phonon drag on pressure or density is derived using a Mie-Grueneisen equation of state. The phonon drag is shown to increase nearly linearly with temperature but to decrease with density or pressure. Numerical results are presented for its variation for shock-loaded copper and aluminum. In these cases, density and temperature increase simultaneously, resulting in a more modest net increase in the dislocation drag coefficient. Nevertheless, phonon drag increases by more than an order of magnitude during shock deformations which approach melting. Since the dependencies of elastic moduli and of the phonon drag coefficient on pressure and temperature are fundamentally different, the effect of pressure on the constitutive law for plastic deformation can not simply be accounted for by its effect on the elastic shear modulus.

Wolfer, W.G.

1999-10-19

176

High Blood Pressure and Sex: Overcome the Challenges  

MedlinePLUS

... personal, noncommercial use only. High blood pressure and sex: Overcome the challenges By Mayo Clinic staff Original ... mail address Sign up High blood pressure and sex: Overcome the challenges Treatment for high blood pressure ...

177

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2013 CFR

... false High pressure pumps and lines. 58.219 Section 58.219 ...AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) GRADING...58.219 High pressure pumps and lines. High pressure lines may be...

2013-01-01

178

The Future of High Pressure Organic Synthesis  

Microsoft Academic Search

\\u000a From the substantiation that, when compared to other activation processes, piezoactivation is hardly used as an organic synthetic\\u000a strategy, the merits of the high pressure methodology are emphasized: synthesis of thermal fragile molecules, synthesis of\\u000a molecules sensitive to Lewis acid catalysts, synthesis of strained or bulky structures, enhancement of chemo-and stereoselectivity,\\u000a asymmetric induction.\\u000a \\u000a \\u000a Perspectives of high pressure organic synthesis are

G. Jenner

179

Superelastic carbon spheres under high pressure  

NASA Astrophysics Data System (ADS)

We report a superelastic deformation behavior of carbon spheres by the in situ Raman spectroscopy in a high-pressure diamond anvil cell. The carbon spheres produced by arc discharging in toluene have a mean diameter of 200 nm and an onion-like multilayer graphitic structure. We find that the elastic coefficients, during both the compression and decompression processes, remain a constant up to 10 GPa, indicating a superior high-pressure structural stability. Such superelastic behavior is related to the isotropic and concentric configuration of carbon spheres and provides additional insight into improving the microscopic mechanical properties of small-scale particles.

Li, Meifen; Guo, Junjie; Xu, Bingshe

2013-03-01

180

High pressure water jet mining machine  

DOEpatents

A high pressure water jet mining machine for the longwall mining of coal is described. The machine is generally in the shape of a plowshare and is advanced in the direction in which the coal is cut. The machine has mounted thereon a plurality of nozzle modules each containing a high pressure water jet nozzle disposed to oscillate in a particular plane. The nozzle modules are oriented to cut in vertical and horizontal planes on the leading edge of the machine and the coal so cut is cleaved off by the wedge-shaped body.

Barker, Clark R. (Rolla, MO)

1981-05-05

181

A novel high pressure tool: the solvation pressure of liquids  

NASA Astrophysics Data System (ADS)

Co-solvents were studied to determine if the change in the cohesive energy density (CED) generates an effective solvation pressure equivalent to the application of an external hydrostatic pressure. Raman modes of chloroform under hydrostatic pressure with co-solvents (chloroform-ethanol, chloroform-acetone) and in the vapour phase were recorded. In some cases the Raman frequency shifts indicate that the solvation pressure behaves as a true hydrostatic pressure. The pressure-induced gelation of starch grains was studied in aqueous media. A higher co-solvent concentration is postulated to put the grains under effective negative pressure, and indeed an increase in the external pressure needed for gelation was seen after the introduction of solvents. The quantitative agreement between the change of solvation pressure and hydrostatic pressure is very good over a wide range of solvent concentration.

Hubel, H.; van Uden, N. W. A.; Faux, D. A.; Dunstan, D. J.

2004-04-01

182

Focal ischaemic normal pressure glaucoma versus high pressure glaucoma.  

PubMed

In a total group of 130 patients with Normal Pressure Glaucoma (NPG) twenty-six were classified as Focal Ischaemic NPG (FINPG). This subgroup has a typical defect at the disc with a comparable visual field defect in the corresponding half of the visual field. Visual field defects are more often seen in the upper than the lower half of the visual field. The defects in the upper half are on the average larger (stage 1.6) than those in the lower half (stage 0.9). Abnormalities of the chamber angle were observed in 12% of these patients, the same percentage as in the normal population. Hypertension and/or cardiovascular disorders were found significantly more frequently in FINPG patients (65.4%) than in a control group of High Pressure Glaucoma (HPG) patients (22.2%). Of the local vascular risk factors, papillary haemorrhages (46%) and choroidal sclerosis (30%) were seen significantly more frequently in FINPG than in HPG (11% and 0% respectively). The total amount of peripapillary atrophy (PPA) in FINPG and HPG is the same, but the distribution is clearly different: in FINPG there is more PPA on the side of the papillary defect. Wide veins were observed in a high percentage of cases in both groups. FINPGs were found to be more frequently progressive (38.5%) than had been thought at first. Recognition of subgroups in NPG, and of risk factors, has already made it possible to make a better prognosis in some types of NPG. PMID:2090404

Geijssen, H C; Greve, E L

1990-10-01

183

High pressure effects on allergen food proteins.  

PubMed

There are several proteins, which can cause allergic reaction if they are inhaled or ingested. Our everyday food can also contain such proteins. Food allergy is an IgE-mediated immune disorder, a growing health problem of great public concern. High pressure is known to affect the structure of proteins; typically few hundred MPa pressure can lead to denaturation. That is why several trials have been performed to alter the structure of the allergen proteins by high pressure, in order to reduce its allergenicity. Studies have been performed both on simple protein solutions and on complex food systems. Here we review those allergens which have been investigated under or after high pressure treatment by methods capable of detecting changes in the secondary and tertiary structure of the proteins. We focus on those allergenic proteins, whose structural changes were investigated by spectroscopic methods under pressure in correlation with the observed allergenicity (IgE binding) changes. According to this criterion we selected the following allergen proteins: Mal d 1 and Mal d 3 (apple), Bos d 5 (milk), Dau c 1 (carrot), Gal d 2 (egg), Ara h 2 and Ara h 6 (peanut), and Gad m 1 (cod). PMID:23850175

Somkuti, Judit; Smeller, Lszl

2013-06-21

184

Introduction to High-Pressure Science  

NASA Astrophysics Data System (ADS)

To a common person pressure is just one of the parameters that describe a thermodynamic state. We all hear about it in everyday weather forecasts, and most of us do not associate it with anything particularly unique. Probably the most intuitive idea of the effect of high-pressure comes from movies, where submarine sinking to the bottom of the ocean is gradually crushed by the surrounding water, until its hull implodes. Why, then hundreds of scientists throughout the world spent their lifelong careers studying high-pressure phenomena? Despite all the developments in experimental technologies and instrumentation, modern scientist has very few tools that allow him or her to "grab" two atoms and bring them, in a very controllable way, closer together. Being able to achieve this task means the ability to directly probe interatomic interaction potentials and can cause transformations as dramatic as turning of a common gas into solid metal. Before the reader delves into more advanced topics described later in this book, this introductory chapter aims to explain several elementary, but extremely important concepts in high-pressure science. We will start with a brief discussion of laboratory devices used to produce pressure, address the issue of hydrostaticity, elastic and plastic compression, and will conclude with a short discussion of unique effects of anisotropic stress.

Dera, Przemyslaw

185

HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT  

SciTech Connect

As part of the U.S. Department of Energy (DoE) initiative to improve the efficiency of coal-fired power plants and reduce the pollution generated by these facilities, DOE has funded the High-Pressure Coal Combustion Kinetics (HPCCK) Projects. A series of laboratory experiments were conducted on selected pulverized coals at elevated pressures with the specific goals to provide new data for pressurized coal combustion that will help extend to high pressure and validate models for burnout, pollutant formation, and generate samples of solid combustion products for analyses to fill crucial gaps in knowledge of char morphology and fly ash formation. Two series of high-pressure coal combustion experiments were performed using SRI's pressurized radiant coal flow reactor. The first series of tests characterized the near burner flame zone (NBFZ). Three coals were tested, two high volatile bituminous (Pittsburgh No.8 and Illinois No.6), and one sub-bituminous (Powder River Basin), at pressures of 1, 2, and 3 MPa (10, 20, and 30 atm). The second series of experiments, which covered high-pressure burnout (HPBO) conditions, utilized a range of substantially longer combustion residence times to produce char burnout levels from 50% to 100%. The same three coals were tested at 1, 2, and 3 MPa, as well as at 0.2 MPa. Tests were also conducted on Pittsburgh No.8 coal in CO2 entrainment gas at 0.2, 1, and 2 MPa to begin establishing a database of experiments relevant to carbon sequestration techniques. The HPBO test series included use of an impactor-type particle sampler to measure the particle size distribution of fly ash produced under complete burnout conditions. The collected data have been interpreted with the help of CFD and detailed kinetics simulation to extend and validate devolatilization, char combustion and pollutant model at elevated pressure. A global NOX production sub-model has been proposed. The submodel reproduces the performance of the detailed chemical reaction mechanism for the NBFZ tests.

Stefano Orsino

2005-03-30

186

Cold denaturation of proteins under high pressure  

Microsoft Academic Search

The advantageous usage of the high pressure technique in studies of cold denaturation of proteins is reviewed, with a brief explanation of the theoretical background of this universal phenomenon. Various experimental results are presented and discussed, explaining the plausible image of the cold denatured state of proteins. In order to understand more clearly this phenomenon and protein structure transition in

Shigeru Kunugi; Naoki Tanaka

2002-01-01

187

Hollow Cathodes in High Pressure Arc Discharges.  

National Technical Information Service (NTIS)

An orified hallow cathode was tested at high pressure to improve lifetime and efficiency in arcjet thrusters. It is indicated that the arc would not operate with emission from the insert above 200 torr in nitrogen regardless of insert material, orifice di...

T. L. Hardy F. M. Curran

1985-01-01

188

Hollow cathodes in high pressure arc discharges  

Microsoft Academic Search

An orified hallow cathode was tested at high pressure to improve lifetime and efficiency in arcjet thrusters. It is indicated that the arc would not operate with emission from the insert above 200 torr in nitrogen regardless of insert material, orifice diameter, or gas flow direction. Emission occurred from the insert in argon and xenon although it could not be

T. L. Hardy; F. M. Curran

1985-01-01

189

High pressure explosive processing of ceramics  

SciTech Connect

The use of high pressure explosive loading to consolidate and modify ceramic materials is newly emerging as a significant prospective materials processing technique. This book presents information in this materials area. Materials reported on include silicon nitride, silicon carbide, rutile, alumina, boron nitride, diamond, aluminum nitride, titanium carbide and titanium diboride.

Graham, R.A.; Sawaoka, A.B.

1986-01-01

190

Modelling of high pressure binary droplet collisions  

Microsoft Academic Search

Droplet collision efficiency is a rather uncharted area for real hydrocarbon systems under non-atmospheric conditions. It is also of great interest in many industrial applications. In this work binary head-on droplet collisions at high pressure have been simulated using the lattice Boltzmann method. A model that captures the physics of the coalescence process is used where no external criterion for

Pablo M. Dupuy; Yi Lin; Maria Fernandino; Hugo A. Jakobsen; Hallvard F. Svendsen

2011-01-01

191

Small, High-Pressure, Liquid Oxygen Turbopump.  

National Technical Information Service (NTIS)

A small, high-pressure, LOX turbopump was designed, fabricated, and tested. The pump was of a single-stage, centrifugal type; power to the pump was supplied by a single-stage, partial-admission, axial-impulse turbine. Design conditions included an operati...

A. Csomor

1978-01-01

192

Small, High-Pressure Liquid Oxygen Turbopump.  

National Technical Information Service (NTIS)

A small, high-pressure, liquid oxygen turbopump was designed, fabricated, and tested. The pump was of a single-stage, centrifugal type; power to the pump was supplied by a single-stage, partial emission, axial-impulse turbine. Design conditions included a...

A. Csomor R. Sutton

1977-01-01

193

High pressure studies of planetary matter  

SciTech Connect

Those materials which are of greatest interest to the physics of the deep planetary interiors are Fe, H/sub 2/, He and the Ices. These are sufficiently diverse and intensively studied to offer an overview of present day high pressure research. 13 refs., 1 fig.

Ross, M.

1989-06-01

194

A high temperature high pressure cell for quasielastic neutron scattering  

NASA Astrophysics Data System (ADS)

We present our recent development of a high temperature high pressure cell for neutron scattering. Combining a water cooled Nb1Zr pressure cell body with an internal heating furnace, the sample environment can reach temperatures of up to 1500 K at a pressure of up to 200 MPa at the sample position, with an available sample volume of about 700 mm3. The cell material Nb1Zr is specifically chosen due to its reasonable mechanical strength at elevated temperatures and fairly small neutron absorption and incoherent scattering cross sections. With this design, an acceptable signal-to-noise ratio of about 10:1 can be achieved. This opens new possibilities for quasielastic neutron scattering studies on different types of neutron spectrometers under high temperature high pressure conditions, which is particularly interesting for geological research on, e.g., water dynamics in silicate melts.

Yang, F.; Kaplonski, J.; Unruh, T.; Mamontov, E.; Meyer, A.

2011-08-01

195

High pressure neutron powder diffraction at LANSCE  

Microsoft Academic Search

By making use of the recently developed Paris-Edinburgh high pressure cell, we have successfully performed neutron powder experiments to l0GPa at ambient temperature. Results for the structural compression of the high Tc 1223-Hg superconductor to 9.2GPa, the compression and possible hydrogen bond formation in brucite, Mg(OD)2, to 9.3GPa, and the molecular reorientation in nitromethane to 5.5GPa are presented.

Robert B. Von Dreele

1995-01-01

196

Status report on high-pressure TPC  

Microsoft Academic Search

HELLAZ experiment intends to measure with high precision the low-energy solar neutrino (pp and 7Be) spectrum. The method uses the neutrino elastic scattering over the 21030 electrons contained in a 2000m3 TPC filled with helium (for its high radio isotopic purity, its low transverse diffusion and its low drift velocity), at a pressure of 20bar at 300K.Reconstructing the neutrino energy

P. Salin; P. Gorodetzky; J. Dolbeau; T. Patzak

2004-01-01

197

High sucrose concentration protects E. coli against high pressure inactivation but not against high pressure sensitization to the lactoperoxidase system  

Microsoft Academic Search

The inactivation of Escherichia coli by high hydrostatic pressure treatment at up to 550 MPa and 20 C was studied in potassium phosphate buffer containing high concentrations of sucrose. E. coli strain MG1655 was pressure-sensitive in the absence of sucrose, but became highly pressure resistant in the presence of 10% to 50% (w\\/v) sucrose. The pressure resistance of E. coli

Isabelle Van Opstal; Suzy C. M. Vanmuysen; Chris W. Michiels

2003-01-01

198

Photographic analysis of high pressure fluidization phenomena  

SciTech Connect

Experiments were conducted to investigate fluidized-bed characteristics at pressures up to 6485 kPa using nitrogen as the fluidizing gas. The particles under study were coal and char. A two-dimensional bed (1.9 cm x 10.16 cm) was used in the experiments. Photographs taken of this bed using a high-speed camera were studied to obtain a description of fluidized-bed bubbling behavior over a wide range of pressures. 15 references, 8 figures, 1 table.

Chitester, D.C.; Strakey, J.P.; Saroff, L.; Kornosky, R.M.; Fan, L.S.; Danko, J.P.

1983-01-01

199

Viscosity of albite melt at high pressure and high temperature  

Microsoft Academic Search

The viscosity of albite (NaAlSi3O8) melt was measured at high pressure by the in situ falling-sphere method using a high-resolution X-ray CCD camera and a large-volume\\u000a multianvil apparatus installed at SPring-8. This system enabled us to conduct in situ viscosity measurements more accurately\\u000a than that using the conventional technique at pressures of up to several gigapascals and viscosity in the

A. Suzuki; E. Ohtani; K. Funakoshi; H. Terasaki; T. Kubo

2002-01-01

200

Grimethorpe high temperature\\/high-pressure gas filter experimental program  

Microsoft Academic Search

A reliable high-temperature, high-pressure, gas-cleanup system is a vital component of pressurized fluidized-bed combustion (PFBC) power generation. This report reviews and summarizes the development, construction, and testing of such a system, a filter module containing an array of 130 porous ceramic elements. The filter, designed to protect the gas turbine from erosion and to meet particulate emission standards, operates with

G. P. Reed; J. E. Oakey; N. J. Simms

1992-01-01

201

High pressure discharges in cavities formed by microfabrication techniques  

Microsoft Academic Search

High pressure discharges are the basis of small high intensity light sources. In this work, we demonstrate the formation of high pressure discharges, in cavities formed by applying micromachining and integrated circuit techniques to quartz substrates. Cavities containing varying amounts of mercury and argon were fabricated to obtain high pressure discharges. A high pressure mercury discharge was formed in the

Babar A. Khan; David A. Cammack; Ronald D. Pinker; Jacqueline Racz

1997-01-01

202

Technical Evaluation for the Determination of CGI Designation for Safety Class Items Incorporated in Hose-in-Hose Transfer Line Assemblies  

SciTech Connect

The purpose of this technical evaluation is to determine whether the secondary hoses are to be categorized as Commercial Grade Items (CGI) or Engineered Equipment. This determination will identify whether or not use of the CGI Dedication process is appropriate.

BUCHANAN, J.R.

2000-05-16

203

Assessing the accuracy of Greenland ice sheet ice ablation measurements by pressure transducer  

NASA Astrophysics Data System (ADS)

In the glaciological community there is a need for reliable mass balance measurements of glaciers and ice sheets, ranging from daily to yearly time scales. Here we present a method to measure ice ablation using a pressure transducer. The pressure transducer is drilled into the ice, en-closed in a hose filled with a liquid that is non-freezable at common Greenlandic temperatures. The pressure signal registered by the transducer is that of the vertical column of liquid over the sensor, which can be translated in depth knowing the density of the liquid. As the free-standing AWS moves down with the ablating surface and the hose melts out of the ice, an increasingly large part of the hose will lay flat on the ice surface, and the hydrostatic pressure from the vertical column of liquid in the hose will get smaller. This reduction in pressure provides us with the ablation rate. By measuring at (sub-) daily timescales this assembly is well-suited to monitor ice ablation in remote regions, with clear advantages over other well-established methods of measuring ice ablation in the field. The pressure transducer system has the potential to monitor ice ablation for several years without re-drilling and the system is suitable for high ablation areas. A routine to transform raw measurements into ablation values will also be presented, including a physically based method to remove air pressure variability from the signal. The pressure transducer time-series is compared to that recorded by a sonic ranger for the climatically hostile setting on the Greenland ice sheet.

Fausto, R. S.; van As, D.; Ahlstrm, A. P.

2012-04-01

204

Uranium at high pressure from first principles  

NASA Astrophysics Data System (ADS)

The equation of state, structural behavior and phase stability of ?-uranium have been investigated up to 1.3 TPa using the density functional theory, adopting a simple description of electronic structure that neglects the spin-orbit coupling and strong electronic correlations. Comparison of the enthalpies of Cmcm (?-U), bcc, hcp, fcc and bct reveals that the ?-U phase is stable up to a pressure of 285 GPa, above which it transforms to a bct-U phase. The enthalpy differences between the bct and bcc phases decrease with pressure but bcc is energetically unfavorable at least up to 1.3 TPa, the upper pressure limit of this study. The enthalpies of the close-packed hcp and fcc phases are 0.7and 1.0 eV higher than that of the stable bct-U phase at a pressure of 1.3 TPa, supporting the wide stability field of the bcc phase. The equation of state, the lattice parameters and the anisotropic compression parameters are in good agreement with experiment up to 100 GPa and previous theory. The elastic constants at the equilibrium volume of ?-U confirm our bulk modulus. This suggests that our simplified description of electronic structure of uranium captures the relevant physics and may be used to describe bonding and other light actinides that show itinerant electronic behavior especially at high pressure.

Adak, S.; Nakotte, H.; de Chtel, P. F.; Kiefer, B.

2011-09-01

205

46 CFR 58.30-20 - Fluid power hose and fittings.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Fluid power hose and fittings. 58.30-20 Section...AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-20 Fluid power hose and fittings. (a) The...

2011-10-01

206

Failure analysis of oxygen hose of the lance equipment in LD shop of Tata steel  

Microsoft Academic Search

The hose of the oxygen lancing equipment in LD shop # 2 has failed at the weldbellows interface by reverse bending fatigue. The bending stresses were resulted due to inclined fitting of the hose at the fixed flange end. No metallurgical abnormalities or weld defects or mechanical damages were responsible for the fatigue crack initiation. It is recommended that if

Sandip Bhattacharyya; Atanu Banerjee; S. K. Bhaumik

2008-01-01

207

46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.  

Code of Federal Regulations, 2012 CFR

...on open decks where no protection is afforded to the hose in heavy weather, or where the hose may be liable to damage from the...hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either (i) Use National Standard...

2012-10-01

208

46 CFR 76.10-10 - Fire station hydrants, hose and nozzles-T/ALL.  

Code of Federal Regulations, 2011 CFR

...on open decks where no protection is afforded to the hose in heavy weather, or where the hose may be liable to damage from the...hydrant connections shall be brass, bronze, or other equivalent metal. Couplings shall either (i) Use National Standard...

2011-10-01

209

46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.  

Code of Federal Regulations, 2011 CFR

...other purpose other than fire extinguishing, drills, and testing. (3) Each length of fire hose must be a minimum of 3...lined commercial fire hose and be fitted with a nozzle made of corrosion resistant material capable of providing a solid stream...

2011-10-01

210

Insertion Loads and Forearm Muscle Activity During Flexible Hose Insertion Tasks  

Microsoft Academic Search

Objective: To quantify the physical demands of hose insertion tasks in automotive assembly operations and how they are affected by method and the mechanical interference between the hose and the flange. Background: Insertion tasks were identified by workers as physically demanding and can often lead to fatigue or losses in production attributable to pain or injury. Methods: Six male and

D. Christian Grieshaber; Thomas J. Armstrong

2007-01-01

211

46 CFR 167.45-25 - Fire mains and hose connections.  

Code of Federal Regulations, 2012 CFR

... § 167.45-25 Fire mains and hose connections. All pipes used as mains for conducting water from fire pumps on nautical school ships shall be of steel, wrought iron, brass, or copper with wrought iron brass, or composition hose...

2012-10-01

212

46 CFR 167.45-25 - Fire mains and hose connections.  

Code of Federal Regulations, 2011 CFR

... § 167.45-25 Fire mains and hose connections. All pipes used as mains for conducting water from fire pumps on nautical school ships shall be of steel, wrought iron, brass, or copper with wrought iron brass, or composition hose...

2011-10-01

213

High pressure-high temperature decomposition of ?-cyclotrimethylene trinitramine.  

PubMed

Decomposition of ?-cyclotrimethylene trinitramine (?-RDX) under high pressure-high temperature conditions was examined to elucidate the reactive behavior of RDX crystals. Vibrational spectroscopy measurements were obtained for single crystals in a diamond anvil cell (DAC) at pressures from 6 to 12 GPa and temperatures up to 600 K. Global decomposition rates, activation energies, and activation volumes at several pressures and temperatures below the P-T locus for the ?-RDX decomposition were obtained. Similar to ?-RDX, but in contrast to ?-RDX, we found that pressure decelerates the decomposition of ?-RDX. The decomposition deceleration with pressure in the ?-phase can be attributed to pressure-inhibiting bond homolysis step(s). The main decomposition species were identified as N(2)O, CO(2), and H(2)O, in accord with the species reported for the ?-phase decomposition at high pressures. This work complements previous studies on RDX at HP-HT conditions and provides comprehensive results on the reactive behavior of ?-RDX; the ?-phase plays a key role in RDX decomposition at P-T conditions relevant to shock wave initiation. PMID:22971173

Dreger, Zbigniew A; McCluskey, Matthew D; Gupta, Yogendra M

2012-09-19

214

High-pressure liquid chromatographic gradient mixer  

DOEpatents

A gradient mixer effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum band-broadening.

Daughton, C.G.; Sakaji, R.H.

1982-09-08

215

Field trial results of annular pressure behavior in a high-pressure/high-temperature well  

SciTech Connect

The problem of annular pressure buildup due to heating of the strings by the (hot) well effluent, will typically be of concern in the design of casing strings for high-pressure/high-temperature (HP/HT) subsea wells. In such completions bleeding off the pressure through the wellhead, as done routinely with surface wells, is not possible. Theoretical studies indicated that, potentially, extreme pressures could develop in confined sealed annuli of subsea completions, posing a severe threat to well integrity. To investigate the effect under realistic conditions, Shell Expro (UK) ran battery operated gauges in the 9 5/8 in. x 13 5/8 in. annulus of an offshore HP/HT well, to record pressure and temperature changes during drilling, cementing and production testing. This paper presents the results of these tests and a general model for pressure buildup in unconfined sealed annuli to correlate the field data. Since only pressure and temperature measurements were available certain assumptions had to be made with respect to, e.g., formation response to pressure buildup, insitu liquid properties, etc. Although these assumptions could be debatable, it is hoped that by publishing and sharing ideas, a better understanding of annular pressure behavior can be developed.

Oudeman, P. [Koninklijke Shell E and P Laboratorium, Rijswijk (Netherlands); Bacarreza, L.J.

1995-06-01

216

Large volume, nonequilibrium plasmas at high pressure  

NASA Astrophysics Data System (ADS)

Generation, stability, and the general behavior of large volume plasmas at high pressure (p > 10 Torr), have been intensively studied for many years. Applications such as high power lasers, opening switches, plasma processing and sputtering, plasma displays, and EM absorbers and reflectors have motivated detailed works of these phenomena. Dc, ac or pulsed self-sustained gas discharges are typically used to generate plasmas. Low-pressure self- sustained gas discharges are very stable. In contrast, self-sustained discharges at high pressures are unstable, having a tendency to contract into filamentary plasmas. This transition is known as ``the glow to arc instability''. In this work we demonstrate that a Capillary Electrode System (CES) in a gas discharge suppresses the glow to arc instability and permits the generation of large volume plasmas at high pressure. The CES is assembled by placing a perforated dielectric disk on top of the cathode. Analysis of the pulses of voltage and current across the plasma, along with the light pattern emitted, allows us to verify the mode of the plasma and the absence of instabilities in the range of work. A quantitative analysis was done by looking at the V vs. I curve. Our system allows us to generate non-equilibrium plasmas at atmospheric pressure in volumes of the order of 0.5 liter. Using a millimeter wave Mach-Zehnder interferometer and lock-in detection we were able to measure effective plasma frequency and effective collision frequency. We use a dielectric model to relate the output values of the lock-in detection to the plasma parameters. In this way, assuming a Maxwellian distribution for the electrons we calculate electron densities in plasmas generated with the CES at high pressures with a sensitivity Dne of 1.0* 107. Finally, we developed a code using Monte Carlo method to simulate the kinetics of particles in the capillary. This simulation includes elastic and inelastic collisions, ionization, charge exchange, secondary ionization at the electrodes and at the capillary walls and the self- consistent field. As result of this simulation we obtain the field threshold for electron amplification, transport parameters, and the distribution function for capillary plasmas.

Amorer, Luis E.

217

High pressure turbomachinery ground test facility  

Microsoft Academic Search

Turbomachinery test facilities are at present scarce to non-existent world-wide. The turbomachinery test facility at Stennis Space Center will provide for advanced development and research and development capabilities for liquid hydrogen\\/liquid oxygen propellant rocket engine components. The facility will provide ultra-high pressure via gas generators to deliver the needed turbine drive on various turbomachinery. State of the art process control

Patrick E. Scheuermann

1992-01-01

218

Changes in CNS Metabolism in High Pressure Nervous Syndrome, High Pressure Narcosis, and Methods of Protection.  

National Technical Information Service (NTIS)

The authors initial approach to the study of mechanisms of acute central nervous system high pressure toxicity was to study enzyme activities and concentrations of the series of metabolites (which have been shown to provide protection against O2 toxicity)...

A. P. Sanders W. D. Currie

1977-01-01

219

Autoignition of hydrogen at high pressure  

SciTech Connect

The spontaneous ignition of hydrogen at pressures between 3.5 and 7 MPa has been investigated. A free piston compressor was used to rapidly increase the temperature and pressure of a mixture of hydrogen, oxygen, and helium. Explosion occurred during the stroke, and was detected by a piezoelectric pressure transducer. The temperature at ignition is found to be independent of pressure, and is calculated to be approximately 1,150 K. A chemical kinetic analysis was conducted, and the results are in good agreement with the experiments. The analysis indicates that the ignition is initiated by the breakdown of H{sub 2}O{sub 2} to the highly reactive radical OH via the reaction H{sub 2}O{sub 2} + M {yields} 20H + M. A new analytical expression for the third limit is derived from the reaction mechanism by introducing the concept of a critical OH concentration; it is shown to be in agreement with the experimental data.

Cain, T.M. [Defence Research Agency, Farnborough (United Kingdom)

1997-10-01

220

Vapor Pressure of Fluids in High-Pressure Gas Atmospheres.  

National Technical Information Service (NTIS)

As part of the investigation of the critical parameters in the combustion of hydraulic fluids, experiments were conducted to verify the accuracy of the Poynting equation which predicts the effect of inert gas pressure upon the vapor pressure of a liquid. ...

D. R. Ventriglio R. W. McQuaid

1967-01-01

221

MEASUREMENT OF HIGH-TEMPERATURE, HIGH-PRESSURE PROCESSES  

EPA Science Inventory

The report reviews the first year's efforts under a planned 3-year program to develop measurement techniques for high-temperature, high-pressure (HTP) processes. Several related topics are discussed in detail, including: (1) the design, development, and successful demonstration o...

222

High-Temperature, High-Pressure Spherical Segment Valve.  

National Technical Information Service (NTIS)

The valve is used to start and stop the flow of high-temperature, high-pressure gas in a conduit connecting a gas heating unit and a wind tunnel, the gas to be used in wind tunnel tests on missile models. The valve mechanism has a housing for insertion in...

A. Giovannetti R. M. Himmelright K. A. Meyer H. Nitta

1964-01-01

223

Research on Rail Pressure Signal Processing Method of High Pressure Common Rail System  

Microsoft Academic Search

The rail pressure signal of electronic control high pressure common rail fuel injection system for diesel engines is used to the closed loop control for rail pressure and the determination of the energizing time for fuel injection. Traditionally rail pressure signal processing method uses 10 ms filter to get the average rail pressure for control the system. With the rail

Qiu Tao; Wang Changyuan; Fan Zhiqiang; Qi Zhiquan; Yin Wenhui

2010-01-01

224

Very high-pressure orogenic garnet peridotites.  

PubMed

Mantle-derived garnet peridotites are a minor component in many very high-pressure metamorphic terranes that formed during continental subduction and collision. Some of these mantle rocks contain trace amounts of zircon and micrometer-sized inclusions. The constituent minerals exhibit pre- and postsubduction microstructures, including polymorphic transformation and mineral exsolution. Experimental, mineralogical, petrochemical, and geochronological characterizations using novel techniques with high spatial, temporal, and energy resolutions are resulting in unexpected discoveries of new phases, providing better constraints on deep mantle processes. PMID:17519341

Liou, J G; Zhang, R Y; Ernst, W G

2007-05-22

225

Dissociation of methane under high pressure.  

PubMed

Methane is an extremely important energy source with a great abundance in nature and plays a significant role in planetary physics, being one of the major constituents of giant planets Uranus and Neptune. The stable crystal forms of methane under extreme conditions are of great fundamental interest. Using the ab initio evolutionary algorithm for crystal structure prediction, we found three novel insulating molecular structures with P2(1)2(1)2(1), Pnma, and Cmcm space groups. Remarkably, under high pressure, methane becomes unstable and dissociates into ethane (C(2)H(6)) at 95 GPa, butane (C(4)H(10)) at 158 GPa, and further, carbon (diamond) and hydrogen above 287 GPa at zero temperature. We have computed the pressure-temperature phase diagram, which sheds light into the seemingly conflicting observations of the unusually low formation pressure of diamond at high temperature and the failure of experimental observation of dissociation at room temperature. Our results support the idea of diamond formation in the interiors of giant planets such as Neptune. PMID:20950018

Gao, Guoying; Oganov, Artem R; Ma, Yanming; Wang, Hui; Li, Peifang; Li, Yinwei; Iitaka, Toshiaki; Zou, Guangtian

2010-10-14

226

X-ray microtomography at high pressure  

NASA Astrophysics Data System (ADS)

X-ray microtomography at high pressure is now possible with the rotating anvil apparatus (RAA) on the 13-BM- D beamline at the Advanced Photon Source (Argonne National Lab). The high-pressure X-ray tomography microscope (HPXTM) can be used to determine densities of amorphous materials (glasses and melts) and in situ characterization of 3D microstructure of multiphase materials subject to temperature and shear deformation [1, 2]. Densities may be obtained directly by volume rendering or from X-ray absorption. The rotating anvil apparatus is compressed by a 250-ton hydraulic press between concentric thrust bearings. Toroidal and truncated cylindrical (Drickamer) anvils can be accommodated. The latter anvils perform well up to 11.5 GPa and 1873K, using boron epoxy/diamond epoxy gaskets and X-ray transparent aluminum or polytherimide plastic containment rings. Differential rotation allows for controlled sample deformation. Pressure is determined by energy dispersive diffraction of an internal standard by convenient switching from monochromatic and polychromatic radiation. In-situ calibrations of linear attenuation coefficient permit bracketing of natural basalt density to better than 1 percent relative, while [2] used volume rendering to determine the compressibility of magnesium silicate glasses and supercooled liquid. The utility of the RRA to characterize microstructural evolution will be discussed. [1] Wang et al., Rev. Sci. Instrum., 76, 073709, 2005. [2] Lesher et al., PEPI, in press, DOI: 10.1016/j.pepi.2008.10.023, 2009

Lesher, C. E.; Wang, Y.; Gaudio, S.; Clark, A.; Yamada, A.; Sanehira, T.; Rivers, M.

2009-05-01

227

Arun field high pressure gas reinjection facilities  

SciTech Connect

This paper discusses the high pressure natural gas reinjection facilities at the Mobil Oil Arun natural gas field in North Sumatra. Each of the three compression trains at Arun comprises a 4 stage centrifugal compressor with a 28000 BHP gas turbine driver plus associated cooling, scrubbing, and control facilities. The present throughout of each train is around 220 MMSCFD at 6500 PSIG discharge pressure. The paper first discusses the overall Arun Field facilities and operation. It then describes in detail the compression train facilities including the causes of, and solutions to, the many and various problems associated with the commissioning and operation of prototype compression facilities. The paper also describes performance monitoring of the trains and the efforts made to optimize train capacity. The paper concludes with 12 specific practical recommendations based on the problems and experiences encountered at Arun during the last six years of operation.

Giles, A.J.

1984-02-01

228

Rheology of olivine at high temperature and high pressure  

NASA Astrophysics Data System (ADS)

Two major contributions were accomplished in this dissertation. From the scientific aspect, the rheological properties of olivine at mantle condition were investigated by defining the flow mechanism and quantifying the high-pressure and high temperature flow law for olivine. From the technical development aspect, a breakthrough to measure macroscopic differential stress and strain rate in situ under mantle pressure and temperature condition was recorded in this dissertation. Conventional deformation methods in defining the flow law of olivine have to face factors of large uncertainties of differential stress measurements and/or limited confining pressure for deformation. These two difficulties were overcome by conducting high-temperature (up to 1473 K) deformation experiments of polycrystalline olivine (average grain size <5 micron) at pressure up to 8 GPa using large-volume high-pressure apparatus and synchrotron x-ray radiation. Strain rates of the deformation from x-ray radiograph of the sample itself were measured. Image analysis software for strain rate measurement was developed. Macroscopic differential stress of olivine was measured by monitoring the elastic strain of lattice spacing. The algorithms and programs were developed to convert the elastic strain of samples deformed under uniaxial compression into the macroscopic differential stress. In summary, the flow law for olivine at high temperature and high pressure has been defined as dislocation creep, assisted by dynamic recrystallization. The activation volume is characterized as 05 cm3/mol. The technology developed in the course of this dissertation research opens new possibilities for rheological studies in the future. The accuracy of the results is comparable to the best rheological studies that are carried out in any system at the present.

Li, Li

229

High-Pressure Crystallography of Biomolecules: Recent Achievements. II - Applications  

NASA Astrophysics Data System (ADS)

This chapter gives various applications around the general theme of macromolecular crystallography (MX) and high pressure (HP). We first describe high-pressure cooling where crystallographic data collection is performed at ambient pressure. Then we give selected examples with data collection at high pressure (HPMX); they include compressibility measurements and structural studies on polynucleotides, an oligomeric protein and a virus capsid. Finally, we show that high pressure and methods developed for HPMX have impacts on conventional MX.

Fourme, Roger; Ascone, Isabella; Kahn, Richard; Girard, Eric

230

High Pressure Microwave Powered UV Light Sources  

NASA Astrophysics Data System (ADS)

Industrial microwave powered (*electrodeless*) light sources have been limited to quiescent pressures of 300 Torr of buffer gas and metal- halide fills. Recently developed multi-atmospheric electronegative bu lb fills (noble gas-halide excimers, metal halide) require electric field s for ionization that are often large multiples of the breakdown voltage for air. For these fills an auxiliary ignition system is necessary. The most successful scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to it's operating poin t Standard diagnostic techniques of high density discharges are inapplicable to the excimer bulbs, because of the ionic molecular exci ted state structure and absence of self-absorption. The method for temperature determination is based on the equilibrium population of certain vibrational levels of excimer ionic excited states. Electron d ensity was determined from the measurements of Stark profiles of H_? radiation from a small amount of hydrogen mixed with noble gas and halogens. At the present time, high pressure (Te 0.5eV, ne 3 x 10^17 cm-3) production bulbs produce over 900W of radiation in a 30nm band, centered at 30nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce 1 kW of radiation in 30nm wide bands, centered about the wavelength of interest.

Cekic, M.; Frank, J. D.; Popovic, S.; Wood, C. H.

1997-10-01

231

Solidification of High-Pressure Medium Daphne 7373  

Microsoft Academic Search

The solidification pressure of Daphne 7373, which is widely used as a pressure medium in high pressure studies, was examined at room temperature. Using a new generation clamp-type pressure cell, we found that Daphne 7373 solidifies at 2.2 GPa at room temperature. This is exactly on the natural extrapolation of the melting curve obtained at lower pressures and temperatures in

Keiichi Yokogawa; Keizo Murata; Harukazu Yoshino; Shoji Aoyama

2007-01-01

232

Methane hydrate behavior under high pressure  

SciTech Connect

Phases changes in a water-methane system were investigated in a pressure range from 0.2 to 5.5 GPa using a diamond anvil cell. In-situ X-ray diffractometry and optical microscopy revealed methane hydrate behavior from growth to decomposition into high-pressure ice and solid methane at room temperature. Methane hydrate crystallized at 0.2--0.3 GPa from liquid, and it was compressed continuously until 2.3 GPa, maintaining structure 1. Below 0.7 GPa the cage occupancy was unchanged. At 1.5 GPa methane hydrate partly decomposed to ice 4 and fluid methane. The remaining methane hydrate kept structure 1, but the cage occupancy was changed; i.e., small cages became vacant. At 2.1 GPa, coexisting ice 6 transformed to ice 7 and fluid methane solidified to phase 1, while methane hydrate remained. At this pressure, structure 1 of methane hydrate was still maintained, and an additional change of cage occupancy occurred. The change in the cage occupancy is consistent with the change in compressibility observed on the compression curve, At 2.3 GPa, all of the methane hydrate decomposed into ice 7 and phase 1 of solid methane.

Hirai, Hisako; Kondo, Tadashi; Hasegawa, Masahi [and others

2000-02-24

233

49 CFR 192.197 - Control of the pressure of gas delivered from high-pressure distribution systems.  

Code of Federal Regulations, 2010 CFR

...pressure of gas delivered from high-pressure distribution systems. 192...pressure of gas delivered from high-pressure distribution systems. (a...may not be set to maintain a pressure higher than 60 p.s.i. (414...

2010-10-01

234

49 CFR 192.197 - Control of the pressure of gas delivered from high-pressure distribution systems.  

Code of Federal Regulations, 2010 CFR

...pressure of gas delivered from high-pressure distribution systems. 192...pressure of gas delivered from high-pressure distribution systems. (a...may not be set to maintain a pressure higher than 60 p.s.i. (414...

2009-10-01

235

HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT  

SciTech Connect

SRI has completed the NBFZ test program, made modification to the experimental furnace for the HPBO test. The NBFZ datasets provide the information NEA needs to simulate the combustion and fuel-N conversion with detailed chemical reaction mechanisms. BU has determined a linear swell of 1.55 corresponding to a volumetric increase of a factor of 3.7 and a decrease in char density by the same factor. These results are highly significant, and indicate significantly faster burnout at elevated pressure due to the low char density and large diameter.

Chris Guenther, Ph.D.

2003-01-28

236

Hosing Instability in the Blow-Out Regime for Plasma-Wakefield Acceleration  

SciTech Connect

The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al. [in Phys. Rev. Lett. 96, 165002 (2006)]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al. [Phys. Rev. Lett. 67, 991 (1991)] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.

Huang, C.; Lu, W.; Zhou, M.; Clayton, C.E.; Joshi, C.; Mori, W.B.; /UCLA; Muggli, P.; Deng, S.; Oz, E.; Katsouleas, T.; /Southern California U.; Hogan, M.J.; Blumenfeld, I.; Decker, F.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Walz, D.; /SLAC

2008-02-13

237

Laser Driven High Pressure, High Strain-Rate Materials Experiments  

NASA Astrophysics Data System (ADS)

Laser-based experiments are being developed to study the response of solids under high pressure loading. Diagnostic techniques that have been applied include dynamic x-ray diffraction, VISAR wave profile measurements, and post-shock recovery and analysis. These techniques are presented with some results from shocked Si, Al, and Cu experiments.

Kalantar, D. H.; Allen, A. M.; Gregori, F.; Kad, B.; Kumar, M.; Lorenz, K. T.; Loveridge, A.; Meyers, M. A.; Pollaine, S.; Remington, B. A.

2002-07-01

238

Modelling heat transfer in high pressure food processing: a review  

Microsoft Academic Search

The most claimed advantage of high-pressure food processing as compared to thermal processing is that pressure acts instantaneously and uniformly through a mass of food independently of its size, shape or composition. Nevertheless, thermal gradients are established in the products after compression and cause inhomogeneities in the pursued pressure effect. Modelling heat transfer in high-pressure food processes can be a

Laura Otero; Pedro D. Sanz

2003-01-01

239

Stable structures of tantalum at high temperature and high pressure  

NASA Astrophysics Data System (ADS)

Knowledge of the structures of Ta that appear at high pressures and high temperatures is critical for addressing the recent controversies regarding the phase diagram and melting temperatures of this refractory metal. Structural searches based on a density functional metadynamics method were therefore employed to obtain candidate structures at high-pressure and finite-temperature conditions. A structural transformation from the initial body-centered cubic phase of Ta stable under ambient conditions to an orthorhombic structure with the space group Pnma is predicted. The Pnma structure is shown to be energetically more favorable and more reasonable than other candidate structures considered previously, since it was also confirmed to be mechanically and dynamically stable by phonon and metadynamics calculations. However, a recently proposed hexagonal-? phase for dense Ta is found to be mechanically and dynamically unstable when anharmonic effects are characterized by high-temperature, self-consistent phonon calculations.

Yao, Yansun; Klug, Dennis D.

2013-08-01

240

High-pressure coal fuel processor development  

SciTech Connect

The objective of Subtask 1.1 Engine Feasibility was to conduct research needed to establish the technical feasibility of ignition and stable combustion of directly injected, 3,000 psi, low-Btu gas with glow plug ignition assist at diesel engine compression ratios. This objective was accomplished by designing, fabricating, testing and analyzing the combustion performance of synthesized low-Btu coal gas in a single-cylinder test engine combustion rig located at the Caterpillar Technical Center engine lab in Mossville, Illinois. The objective of Subtask 1.2 Fuel Processor Feasibility was to conduct research needed to establish the technical feasibility of air-blown, fixed-bed, high-pressure coal fuel processing at up to 3,000 psi operating pressure, incorporating in-bed sulfur and particulate capture. This objective was accomplished by designing, fabricating, testing and analyzing the performance of bench-scale processors located at Coal Technology Corporation (subcontractor) facilities in Bristol, Virginia. These two subtasks were carried out at widely separated locations and will be discussed in separate sections of this report. They were, however, independent in that the composition of the synthetic coal gas used to fuel the combustion rig was adjusted to reflect the range of exit gas compositions being produced on the fuel processor rig. Two major conclusions resulted from this task. First, direct injected, ignition assisted Diesel cycle engine combustion systems can be suitably modified to efficiently utilize these low-Btu gas fuels. Second, high pressure gasification of selected run-of-the-mine coals in batch-loaded fuel processors is feasible. These two findings, taken together, significantly reduce the perceived technical risks associated with the further development of the proposed coal gas fueled Diesel cycle power plant concept.

Greenhalgh, M.L.

1992-11-01

241

Modeling of thermal processes in high pressure liquid chromatography II. Thermal heterogeneity at very high pressures  

SciTech Connect

Advanced instruments for liquid chromatography enables the operation of columns packed with sub-2 {micro}m particles at the very high inlet pressures, up to 1000 bar, that are necessary to achieve the high column efficiency and the short analysis times that can be provided by the use of these columns. However, operating rather short columns at high mobile phase velocities, under high pressure gradients causes the production of a large amount of heat due to the viscous friction of the eluent percolating through the column bed. The evacuation of this heat causes the formation of significant axial and radial temperature gradients. Due to these thermal gradients, the retention factors of analytes and the mobile phase velocity are no longer constant throughout the column. The consequence of this heat production is a loss of column efficiency. We previously developed a model combining the heat and mass balance of the column, the equations of flow through porous media, and a linear isotherm model of the analyte. This model was solved and validated for conventional columns operated under moderate pressures. We report here on the results obtained when this model is applied to columns packed with very fine particles, operated under very high pressures. These results prove that our model accounts well for all the experimental results. The same column that elutes symmetrical, nearly Gaussian peaks at low flow rates, under relatively low pressure drops, provides strongly deformed, unsymmetrical peaks when operated at high flow rates, under high pressures, and under different thermal environments. The loss in column efficiency is particularly important when the column wall is kept at constant temperature, by immersing the column in a water bath.

Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

2009-01-01

242

High pressure-resistant nonincendive emulsion explosive  

DOEpatents

An improved emulsion explosive composition including hollow microspheres/bulking agents having high density and high strength. The hollow microspheres/bulking agents have true particle densities of about 0.2 grams per cubic centimeter or greater and include glass, siliceous, ceramic and synthetic resin microspheres, expanded minerals, and mixtures thereof. The preferred weight percentage of hollow microspheres/bulking agents in the composition ranges from 3.0 to 10.0 A chlorinated paraffin oil, also present in the improved emulsion explosive composition, imparts a higher film strength to the oil phase in the emulsion. The emulsion is rendered nonincendive by the production of sodium chloride in situ via the decomposition of sodium nitrate, a chlorinated paraffin oil, and sodium perchlorate. The air-gap sensitivity is improved by the in situ formation of monomethylamine perchlorate from dissolved monomethylamine nitrate and sodium perchlorate. The emulsion explosive composition can withstand static pressures to 139 bars and dynamic pressure loads on the order of 567 bars.

Ruhe, Thomas C. (Duquesne, PA); Rao, Pilaka P. (Baghlingampalli, IN)

1994-01-01

243

Focal ischaemic normal pressure glaucoma versus high pressure glaucoma  

Microsoft Academic Search

In a total group of 130 patients with Normal Pressure Glaucoma (NPG) twenty-six were classified as Focal Ischaemic NPG (FINPG). This subgroup has a typical defect at the disc with a comparable visual field defect in the corresponding half of the visual field. Visual field defects are more often seen in the upper than the lower half of the visual

H. Caroline Geijssen; Erik L. Greve

1990-01-01

244

High-pressure coal fuel processor development  

SciTech Connect

Caterpillar shares DOE/METC interest in demonstrating the technology required to displace petroleum-based engine fuels with various forms of low cost coal. Current DOE/METC programs on mild gasification and coal-water-slurries are addressing two approaches to this end. Engine and fuel processor system concept studies by Caterpillar have identified a third, potentially promising, option. This option includes high-pressure fuel processing of run-of-the-mine coal and direct injection of the resulting low-Btu gas stream into an ignition assisted, high compression ratio diesel engine. The compactness and predicted efficiency of the system make it suitable for application to line-haul railroad locomotives. A successful conclusion of the program will enable further component development work and full-scale system demonstrations of this potentially important technology. This paper covers the work on fuel processor rig testing completed in FY92.

Greenhalgh, M.L.; Wen, C.S.; Smith, L.

1992-12-31

245

High-pressure coal fuel processor development  

SciTech Connect

Caterpillar shares DOE/METC interest in demonstrating the technology required to displace petroleum-based engine fuels with various forms of low cost coal. Current DOE/METC programs on mild gasification and coal-water-slurries are addressing two approaches to this end. Engine and fuel processor system concept studies by Caterpillar have identified a third, potentially promising, option. This option includes high-pressure fuel processing of run-of-the-mine coal and direct injection of the resulting low-Btu gas stream into an ignition assisted, high compression ratio diesel engine. The compactness and predicted efficiency of the system make it suitable for application to line-haul railroad locomotives. A successful conclusion of the program will enable further component development work and full-scale system demonstrations of this potentially important technology. This paper covers the work on fuel processor rig testing completed in FY92.

Greenhalgh, M.L.; Wen, C.S.; Smith, L.

1992-01-01

246

Thermal Conductivity of Argon at High Pressures and High Temperatures  

NASA Astrophysics Data System (ADS)

Accurate data on the thermal conductivity of argon at high pressures and high temperatures is essential to unraveling the nature of the Earths interior. Argon is a common pressure-transmitting medium in diamond anvil cell (DAC) experiments, which is commonly used for studying the properties of minerals at pressures and temperatures native to the mantel and core. We used a transient heating technique (Beck et al., 2007) in a symmetric DAC up to 50 GPa and 2500 K. A thin iridium foil (1 ?m thick) positioned in a recessed gasket hole filled with argon served as a heat absorber (coupler) to pump thermal energy into the sample. We used 6 ?s width pulses from electronically modulated Yb-based fiber laser. We determined the temperature of the coupler with 500 ns time resolution by applying the Planck function to its thermal emission spectrum, and doing this over time yields temperature verses time for the coupler. Using finite element (FE) calculation methods we simulated the heat flux transfer in the DAC cavity using the experimentally determined geometric and laser heating parameters. The thermochemical parameters of Ir and Ar were determined by scaling the ambient pressure data using the available equations of state. The temperature dependent thermal conductivity of Ar was determined by fitting the results of FE calculations to the experimentally determined time dependent coupler temperature. We used the results of the theoretical calculations (Tretiakov & Scandolo, 2004) as the initial input. The results for the pressure and temperature dependent thermal conductivity of Ar will be reported at the meeting. This work is supported by NSF EAR 0711358, NSF-REU, Carnegie Institution of Washington, and DOE-NNSA (CDAC). Beck, P; Goncharov, A.F., Struzhkin, V.V., Militzer, B, Mao, H.K, Hemley, R.J. (2007). Measurement of thermal diffusivity at high pressure using a transient heating technique, Appl Phys. Lett. 91, 181914-(1-3). Tretiakov, K. V. & S. Scandolo (2004). Thermal conductivity of solid argon at high pressure and high temperature: A molecular dynamics study. J. Chem. Phys. 121, 11177-11182.

Wong, M. L.; Goncharov, A. F.; Dalton, D. A.; Ojwang, J.; Struzhkin, V.; Konopkova, Z.; Lazor, P.

2010-12-01

247

Analysis on transient piping pressure and force caused by high pressure steam flow disturbances  

Microsoft Academic Search

This paper presents a quantitative analysis on transient responses of pressure and its resulting force to sudden operation of a pressure relief valve on the main steam line of a pressurized water reactor plant, which is initially in a closed system at high pressure. When the valve at closed position changes to the full open position suddenly, the shock can

Seon Oh Yu; Jong Chull Jo

2007-01-01

248

Working Group Report on High Blood Pressure in Pregnancy (Revised).  

National Technical Information Service (NTIS)

This report updates the 1990 National High Blood Pressure Education Program Working Group Report on High Blood Pressure in Pregnancy and focuses on classification, pathophysiology, and management of the hypertensive disorders of pregnancy.

2000-01-01

249

High-pressure coal fuel processor development  

SciTech Connect

Caterpillar shares DOE/METC interest in demonstrating the technology required to displace petroleum-based engine fuels with various forms of low cost coal. Current DOE/METC programs on mild gasification and coal-water-slurries are addressing two approaches to this end. Engine and fuel processor system concept studies by Caterpillar have identified a third, potentially promising, option. This option includes high-pressure fuel processing of run-of-the-mine coal and direct injection of the resulting low-Btu gas stream into an ignition assisted, high compression ratio diesel engine. The compactness and predicted efficiency of the system make it suitable for application to line-haul railroad locomotives. Two overall conclusions resulted from Task 1. First direct injected, ignition assisted Diesel cycle engine combustion systems can be suitably modified to efficiently utilize low-Btu gas fuels. Second, high pressure gasification of selected run-of-the-mine coals in batch-loaded fuel processors is feasible. These two findings, taken together, significantly reduce the perceived technical risk associated with the further development of the proposed coal gas fueled Diesel cycle power plant concept. The significant conclusions from Task 2 were: An engine concept, derived from a Caterpillar 3600 series engine, and a fuel processor concept, based on scaling up a removable-canister configuration from the test rig, appear feasible; and although the results of this concept study are encouraging, further, full-scale component research and development are required before attempting a full-scale integrated system demonstration effort.

Greenhalgh, M.L. (Caterpillar, Inc., Peoria, IL (United States))

1992-12-01

250

46 CFR 58.30-20 - Fluid power hose and fittings.  

Code of Federal Regulations, 2012 CFR

...subchapter. (c) Hose assemblies may be installed between two points of relative motion but shall not be subjected to torsional deflection (twisting) under any conditions of operation and shall be limited, in general, to reasonable lengths required for...

2012-10-01

251

Retrieval Pump Flexible Suction Hose Dynamic Response Induced by Impact of a Mixer Pump Jet  

SciTech Connect

Experiments were conducted to investigate whether it may be feasible to simultaneously mix and retrieve radioactive waste slurries that are stored in million-gallon, double-shell tanks at the Hanford Site in Richland, Washington. Oscillating mixer pumps, located near the floor of these tanks, are used to mobilize and mix the slurry prior to retrieval. Operational scenarios that may be beneficial for retrieval may require simultaneous operation of a decant/transfer pump and the jet mixer pumps. The effects of jet-induced agitation and jet impingement upon the decant/transfer pump's flexible suction hose have not previously been experimentally evaluated. Possible effects of the jet impacting the hose include hose fatigue, hose collision or entanglement with other structures, and induced static and dynamic loads on the decant/transfer pump equipment. The objective of this work was to create operating conditions in a test tank that produce a dynamic response (in the flexible suction hose upon impingement from an above-floor jet) that is similar to that anticipated in the actual tank. A scaling analysis was conducted to define the interactions between the jet, the tank floor and the suction hose. The complexity of scaling the multi-layer flexible hose (matching its hydroelastic parameters at full and 1/4-scale) led to an alternate approach, that of matching the expected full-scale forces on the full-scale hose in the scaled tank. Two types of tests were conducted: characterization of the jet velocity profile in the test tank at two axial locations from the nozzle and observation of the motion induced in the flexible retrieval hose from impact by the jet. The velocity profile of the jet in the test tank was measured to compare the measured profiles with profile predictions for an above-floor jet. These data were used to obtain a refined estimate of the velocity profile and therefore, the force acting upon the test article at a particular location in the tank. The hose motion and location within the test tank resulting from jet impingement were recorded by video. This visual record can be correlated with the data recorded by the data acquisition system. These data coupled with the velocity profile results, were used to estimate the forces required to induce motion in the hose.

Enderlin, C.W.; Terrones, G.; Bamberger, J.A.; White, M.; Combs, W.H.

1999-10-07

252

High pressure magnetic resonance imaging with metallic vessels.  

PubMed

High pressure measurements in most scientific fields rely on metal vessels given the superior tensile strength of metals. We introduce high pressure magnetic resonance imaging (MRI) measurements with metallic vessels. The developed MRI compatible metallic pressure vessel concept is very general in application. Macroscopic physical systems are now amenable to spatially resolved nuclear magnetic resonance (NMR) study at variable pressure and temperature. Metallic pressure vessels not only provide inherently high tensile strengths and efficient temperature control, they also permit optimization of the MRI RF probe sensitivity. An MRI compatible pressure vessel is demonstrated with a rock core holder fabricated using non-magnetic stainless steel. Water flooding through a porous rock under pressure is shown as an example of its applications. High pressure NMR spectroscopy plays an indispensable role in several science fields. This work will open new vistas of study for high pressure material science MRI and MR. PMID:21962929

Han, Hui; Ouellette, Matthew; MacMillan, Bryce; Goora, Frederic; MacGregor, Rodney; Green, Derrick; Balcom, Bruce J

2011-09-10

253

How Is High Blood Pressure Treated?  

MedlinePLUS

... so your blood pressure goes down. Angiotensin II Receptor Blockers Angiotensin II receptor blockers are newer blood pressure medicines that protect ... Nervous system inhibitors increase nerve impulses from the brain to relax and widen blood vessels. This causes ...

254

High pressure effects on thermal properties of MgO  

NASA Astrophysics Data System (ADS)

Using the non-empirical Variational Induced Breathing (VIB) model, the thermal properties of periclase (MgO) under high pressures and temperatures are investigated using molecular dynamics, which includes all anharmonic effects. Equations of state for temperatures up to 3000K and pressures up to 310 GPa were calculated. Bulk modulus, thermal expansivity, Anderson-Grneisen parameter, thermal pressure, Grneisen parameter and their pressure and temperature dependencies are studied in order to better understand high pressure effects on thermal properties. The results agree very well with experiments and show that the thermal expansivity decreases with pressure up to about 100 GPa (?=0.73), and is almost pressure and temperature independent above this compression. It is also effected by anharmonicity at zero pressure and temperatures above 2500K. The thermal pressure changes very little with increasing pressures and temperatures, and the Grneisen parameter is temperature independent and decreases slightly with pressure.

Inbar, Iris; Cohen, R. E.

255

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false High pressure pumps and lines. 58.219 Section 58...Service 1 Equipment and Utensils § 58.219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and...

2010-01-01

256

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 2009-01-01 false High pressure pumps and lines. 58.219 Section 58...Service1 Equipment and Utensils § 58.219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and...

2009-01-01

257

High pressure effects on lipid oxidation in minced pork  

Microsoft Academic Search

Washed muscle fibres and minced pork were subjected to high pressure treatment at 800 MPa for 20 min at 20 C prior to storage at 4 C. In both cases, high pressure treated samples oxidised more rapidly than the controls, as measured by 2-thiobarbituric (TBA) number. The rate of lipid oxidation of the high pressure treated samples was similar to

P. B. Cheah; D. A. Ledward

1996-01-01

258

Safety improvements in high pressure thermal machines  

SciTech Connect

In a thermal machine of the type including a machine body having a main axis extending between a thermal end and a work end, a working fluid at relatively high pressure in a working fluid chamber defined in the body and a displacer element reciprocable within the chamber for subjecting the fluid to a thermodynamic cycle in cooperation with a reciprocable work piston, the improvement is described comprising outer shell means enclosing the machine body for maintaining a substantially sealed atmosphere about the machine body, and diffuser means arranged between the machine body and the outer shell means for diffusing a shock wave traveling towards the outer shell means resulting from explosive failure of the machine body and for shielding the outer shell means against fragments projected upon such failure.

Otters, J.L.

1988-02-09

259

High pressure fiber optic connector plug  

NASA Astrophysics Data System (ADS)

A fiber optic cable connection for high pressure environments utilizes a fiber optic cable having (1) a multiplicity of fiber optic strands, extending axially therein, (2) a strength member extending axially in spaced relationship thereabout, (3) an outer jacket, and (4) a filler matrix within the strength member and in which the strands are encased, a precision connector with an inner face having an axially extending from the transverse wall of the recess to the outer face of the connector member and through which the fiber optic strands extend. A preload insert member is disposed about the strands with its outer end extending into the recess of the connector and a peripheral shoulder abutting the inner face of the connector member. A body member is disposed about the insert member and has its outer end extending over the inner end portion of the connector.

Morency, Roger L.; Holmberg, Gerald E.

1991-11-01

260

Condensed matter at high shock pressures  

SciTech Connect

Experimental techniques are described for shock waves in liquids: Hugoniot equation-of-state, shock temperature and emission spectroscopy, electrical conductivity, and Raman spectroscopy. Experimental data are reviewed and presented in terms of phenomena that occur at high densities and temperatures in shocked He, Ar, N/sub 2/, CO, SiO/sub 2/-aerogel, H/sub 2/O, and C/sub 6/H/sub 6/. The superconducting properties of Nb metal shocked to 100 GPa (1 Mbar) and recovered intact are discussed in terms of prospects for synthesizing novel, metastable materials. Ultrahigh pressure data for Cu is reviewed in the range 0.3 to 6TPa (3 to 60 Mbar). 56 refs., 9 figs., 1 tab.

Nellis, W.J.; Holmes, N.C.; Mitchell, A.C.; Radousky, H.B.; Hamilton, D.

1985-07-12

261

High-Pressure X-ray Tomography Microscope: Synchrotron Computed Microtomography at High Pressure and Temperature  

SciTech Connect

A new apparatus has been developed for microtomography studies under high pressure. The pressure generation mechanism is based on the concept of the widely used Drickamer anvil apparatus, with two opposed anvils compressed inside a containment ring. Modifications are made with thin aluminum alloy containment rings to allow transmission of x rays. Pressures up to 8 GPa have been generated with a hydraulic load of 25 T. The modified Drickamer cell is supported by thrust bearings so that the entire pressure cell can be rotated under load. Spatial resolution of the high pressure tomography apparatus has been evaluated using a sample containing vitreous carbon spheres embedded in FeS matrix, with diameters ranging from 0.01 to 0.2 mm. Spheres with diameters as small as 0.02 mm were well resolved, with measured surface-to-volume ratios approaching theoretical values. The sample was then subject to a large shear strain field by twisting the top and bottom Drickamer anvils. Imaging analysis showed that detailed microstructure evolution information can be obtained at various steps of the shear deformation, allowing strain partition determination between the matrix and the inclusions. A sample containing a vitreous Mg{sub 2}SiO{sub 4} sphere in FeS matrix was compressed to 5 GPa, in order to evaluate the feasibility of volume measurement by microtomography. The results demonstrated that quantitative inclusion volume information can be obtained, permitting in situ determination of P-V-T equation of state for noncrystalline materials.

Wang, Y.; Uchida, T.; Westferro, F.; Rivers, M.L.; Gebhardt, J.; Lesher, C.E.; Sutton, S.R. (UCD); (UC)

2010-07-20

262

High-pressure x-ray tomography microscope: Synchrotron computed microtomography at high pressure and temperature  

SciTech Connect

A new apparatus has been developed for microtomography studies under high pressure. The pressure generation mechanism is based on the concept of the widely used Drickamer anvil apparatus, with two opposed anvils compressed inside a containment ring. Modifications are made with thin aluminum alloy containment rings to allow transmission of x rays. Pressures up to 8 GPa have been generated with a hydraulic load of 25 T. The modified Drickamer cell is supported by thrust bearings so that the entire pressure cell can be rotated under load. Spatial resolution of the high pressure tomography apparatus has been evaluated using a sample containing vitreous carbon spheres embedded in FeS matrix, with diameters ranging from 0.01 to 0.2 mm. Spheres with diameters as small as 0.02 mm were well resolved, with measured surface-to-volume ratios approaching theoretical values. The sample was then subject to a large shear strain field by twisting the top and bottom Drickamer anvils. Imaging analysis showed that detailed microstructure evolution information can be obtained at various steps of the shear deformation, allowing strain partition determination between the matrix and the inclusions. A sample containing a vitreous Mg{sub 2}SiO{sub 4} sphere in FeS matrix was compressed to 5 GPa, in order to evaluate the feasibility of volume measurement by microtomography. The results demonstrated that quantitative inclusion volume information can be obtained, permitting in situ determination of P-V-T equation of state for noncrystalline materials.

Wang Yanbin; Uchida, Takeyuki; Westferro, Frank; Rivers, Mark L.; Nishiyama, Norimasa; Gebhardt, Jeff; Lesher, Charles E.; Sutton, Steve R. [GeoSoilEnviroCARS, Center for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States); ChemMatCARS, Center for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States); GeoSoilEnviroCARS, Center for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States); ChemMatCARS, Center for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States); Department of Geology, University of California at Davis, Davis, California 95616 (United States); GeoSoilEnviroCARS, Center for Advanced Radiation Sources, University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States)

2005-07-15

263

High Resolution Solid State Pressure Sensor.  

National Technical Information Service (NTIS)

A pressure sensor and pressure-sensing catheter in which a deformable pressure sensing membrane is separated from an inner metalized surface on a rigid support by an air gap. An input allows a voltage to be applied to an electrode on the sensing membrane ...

J. S. Son T. R. Parks

2004-01-01

264

High-pressure melting curve of hydrogen  

Microsoft Academic Search

The melting curve of hydrogen was computed for pressures up to 200 GPa, using molecular dynamics. The inter- and intramolecular interactions were described by the reactive force field (ReaxFF) model. The model describes the pressure-volume equation of state solid hydrogen in good agreement with experiment up to pressures over 150 GPa, however the corresponding equation of state for liquid deviates

Sergio M. Davis; Anatoly B. Belonoshko; Natalia V. Skorodumova; Adri C. T. van Duin

2008-01-01

265

Package design of pressure sensors for high volume consumer applications  

Microsoft Academic Search

In this abstract we outline the critical design aspects for the design of high volume pressure sensor for MEMS applications. Pressure sensor designs by their nature require the active device to be in contact with the pressure to be measured, this requirement has until now restricted the possibility of applying large volume semiconductor package manufacturing techniques to pressure sensors and

Mark Shaw; Federico Ziglioli; Chantal Combi; Lorenzo Baldo

2008-01-01

266

Electrical resistivity of iron at high pressure and high temperature  

NASA Astrophysics Data System (ADS)

Knowledge of thermal conductivity of iron under high-pressure and temperature conditions is crucial to understand the heat transport and the thermal evolution of planetary interior. However, measurements of thermal conductivity at high pressure and temperature are challenging and experimental data are limited. In this study, we report the measured electrical resistivity of iron at high pressure and temperature. The data are then translated to thermal conductivity through Wiedemann-Franz law. A four-probe method was employed to measure the resistances of a cylindrical wire during heating cycles at high pressure. Experiments at 5, 7 and 13 GPa were performed on an iron wire sample by using a multi-anvil apparatus at the Geophysical Laboratory. At 5, 7 and 13 GPa, the measured electrical resistivity of iron at room temperature are 9.06 m?-cm (bcc phase), 8.85 m?-cm (bcc phase) and 12.72 m?-cm (hcp phase), respectively. The results are in a good agreement with reported room-temperature data. The kinks in electrical resistivity associated with the phase transitions of iron were clearly observed in each run. At 5 and 7 GPa, kinks in the electrical resistivity can be noticed at 677 oC and 652 oC, respectively, due to the bcc to fcc phase transition. At 5 GPa and 1687 oC, melting led to a discontinuous change in electrical resistivity. The temperature dependence of the electrical resistivity for bcc, fcc, and hcp iron are well constrained from these measurements. The hcp iron displays the strongest temperature dependence compared with that of the bcc and fcc phases. Our results provide critical thermodynamic parameters to constrain heat transport in the planetary cores.

Deng, L.; Seagle, C.; Fei, Y.; Shahar, A.

2011-12-01

267

Energy Dissipation of Materials at High Pressure and High Temperature  

SciTech Connect

We report an experimental method to study the anelastic properties of materials at high pressure and high temperature. The multianvil high pressure deformation device, used to apply a cyclic loading force onto the sample, can reach 15 GPa and 2000 K. A synchrotron x-ray radiation source provides time resolved images of the sample and reference material. The images yield stress and strain as a function of time; stresses are derived from the reference material, and strains from the sample. This method has been tested by applying a sinusoidal stress at megahertz to hertz frequency on a San Carlos olivine specimen at 5 GPa and up to 2000 K. Strain as small as 10{sup -5} can be resolved. We have obtained experimental results which exhibit resolvable attenuation factor (Q{sup -1}) and shear modulus (M) at deep Earth conditions. These results are in quantitative agreement with previously reported lower pressure data and suggest that temperature and grain size have dominating effect on these properties.

Li,L.; Weidner, D.

2007-01-01

268

Structural Study of alpha-Rhombohedral Boron at High Pressures  

Microsoft Academic Search

Recently, it has been shown that, like beta-rhombohedral boron (beta-boron), alpha-rhombohedral boron (alpha-boron) exhibits superconductivity at high pressure. The transition pressure is similar to that of beta-boron, that is, about 160 GPa. This paper presents a theoretical and experimental study of the structural change in alpha-boron at high pressures. High-pressure (up to 200 GPa) X-ray experiments were performed at a

Koun Shirai; Haruhiko Dekura; Yoshihisa Mori; Yutaka Fujii; Hiroshi Hyodo; Kaoru Kimura

2011-01-01

269

Microhole High-Pressure Jet Drill for Coiled Tubing  

Microsoft Academic Search

Tempress Small Mechanically-Assisted High-Pressure Waterjet Drilling Tool project centered on the development of a downhole intensifier (DHI) to boost the hydraulic pressure available from conventional coiled tubing to the level required for high-pressure jet erosion of rock. We reviewed two techniques for implementing this technology (1) pure high-pressure jet drilling and (2) mechanically-assisted jet drilling. Due to the difficulties associated

Ken Theimer; Jack Kolle

2007-01-01

270

High-pressure Raman spectroscopy of carbon onions and nanocapsules  

NASA Astrophysics Data System (ADS)

We report high-pressure Raman spectra of carbon onions and nanocapsules investigated by diamond anvil cell experiments. The pressure coefficient and elastic behavior of carbon onions and nanocapsules are found to be very similar to those of multiwall carbon nanotubes. Additionally, detectable structure changes, particularly the collapse of the concentric graphite structure, cannot been seen at pressures as high as ~20 GPa, demonstrating that carbon onions and nanocapsules have significant hardness and can sustain very high pressures.

Guo, J. J.; Liu, G. H.; Wang, X. M.; Fujita, T.; Xu, B. S.; Chen, M. W.

2009-08-01

271

New High Pressure Encapsulation Material for Manganin Gauges  

NASA Astrophysics Data System (ADS)

Standard Manganin gauges are limited to pressures below 20 GPa because of encapsulation failure. Based on models of polymer behaviour at high pressure we proposed and tested new encapsulations made of silicone adhesive. Our results show that the silicone retains a relatively high resistance under pressures around 30 GPa. Manganin gauges fabricated with silicone glue and PTFE cover demonstrate a possibility to measure pressure histories inside fully detonated high explosive.

Be'Ery, I.; Rosenberg, Z.

2007-12-01

272

High Pressure Rotary Shaft Sealing Mechanism  

DOEpatents

A laterally translatable pressure staged rotary shaft sealing mechanism having a seal housing with a shaft passage therein being exposed to a fluid pressure P1 and with a rotary shaft being located within the shaft passage. At least one annular laterally translatable seal carrier is provided. First and second annular resilient sealing elements are supported in axially spaced relation by the annular seal carriers and have sealing relation with the rotary shaft. The seal housing and at least one seal carrier define a first pressure staging chamber exposed to the first annular resilient sealing element and a second pressure staging chamber located between and exposed to the first and second annular resilient sealing elements. A first fluid is circulated to the first pressure chamber at a pressure P1, and a second staging pressure fluid is circulated to the second pressure chamber at a fraction of pressure P1 to achieve pressure staging, cooling of the seals. Seal placement provides hydraulic force balancing of the annular seal carriers.

Dietle, Lannie (Sugar Land, TX); Gobeli, Jeffrey D. (Houston, TX)

2001-05-08

273

High Temperature High Pressure Thermodynamic Measurements for Coal Model Compounds  

SciTech Connect

The overall objective of this project is to develop a better thermodynamic model for predicting properties of high-boiling coal derived liquids, especially the phase equilibria of different fractions at elevated temperatures and pressures. The development of such a model requires data on vapor-liquid equilibria (VLE), enthalpy, and heat capacity which would be experimentally determined for binary systems of coal model compounds and compiled into a database. The data will be used to refine existing models such as UNIQUAC and UNIFAC. The flow VLE apparatus designed and built for a previous project was upgraded and recalibrated for data measurements for thk project. The modifications include better and more accurate sampling technique and addition of a digital recorder to monitor temperature, pressure and liquid level inside the VLE cell. VLE data measurements for system benzene-ethylbenzene have been completed. The vapor and liquid samples were analysed using the Perkin-Elmer Autosystem gas chromatography.

John C. Chen; Vinayak N. Kabadi

1998-11-12

274

High pressure Raman scattering study of cytidine  

NASA Astrophysics Data System (ADS)

We report a Raman scattering study of the vibrational modes of cytidine as a function of pressure. These experiments determine the vibrational frequencies of this molecule as a function of the interatomic distances. A Merrill-Bassett diamond anvil cell (DAC) was used to generate pressures up to about 10 GPa. The frequencies of most modes were observed to increase with applied pressure except for the hydrogen stretching modes associated with the hydrogen bonds of the solid. The lattice modes show the greatest changes with applied pressure. The goal of this work is to provide as much information as possible about the bonding within the DNA molecule.

Li, J.; Pinnick, D. A.; Lee, S. A.; Griffey, R. H.; Mohan, V.

2000-03-01

275

Carbon Nanotubes Under High Pressure Probed by Resonance Raman Scattering  

NASA Astrophysics Data System (ADS)

The power of Raman spectroscopy for the study of the high-pressure evolution of carbon nanotubes is shown. After an introduction to carbon nanotubes and its resonance Raman scattering signal, we discuss the high-pressure Raman studies on single-wall carbon nanotubes with particular emphasis on the identification of pressure-induced structural and electronic transitions.

San-Miguel, Alfonso; Cailler, Christophe; Machon, Denis; Barros, Eduardo B.; Aguiar, Acrisio L.; Filho, Antonio G. Souza

276

More on shear modulus collapse of lattices at high pressure  

Microsoft Academic Search

In his recent paper, Shear modulus collapse of lattices at high pressure, J. Phys. Cond. Matt. 16 (2004) L125, V.V. Kechin claims that the zero temperature shear modulus of a metallic solid vanishes at a high critical pressure, and the critical pressures for this shear modulus collapse lie in the range 0 250 Mbar for elemental metals. Here we demonstrate

Leonid Burakovsky; Carl W. Greef; Dean L. Preston

2006-01-01

277

Preliminary results of MUNDO high altitude pressure measurements  

SciTech Connect

Four high altitude pressure measurement canisters were deployed for the MUNDO event. All canister parachutes deployed and the placement of instruments was quite satisfactory in spite of an unusual wind change. Fouled leak plugs caused the two intermediate pressure transducers to be driven out of range but a new and reasonably successful procedure was developed for recovering the pressure histories of these canisters from acceleration histories. The measurements bridged across from the central radiation cone to the transition region. Pressure levels and pressure histories at outer stations are atypical with the unexpected appearances of shock fronts. Pressure histories were more complicated with peak pressures lower than observed on RUMMY.

Banister, J.R.; Hereford, W.V.; Solomon, O.M.

1987-01-01

278

Effects of High Pressure on Membrane Ion Binding and Transport.  

National Technical Information Service (NTIS)

Effects of hydrostatic pressures, ranging from 1 to 1000 atmospheres, on the transport and ion binding characteristics of human red cells were studied. A high pressure stopped-flow device was designed for rapid mixing and subsequent spectrophotometric stu...

R. I. Macey D. M. Karan

1980-01-01

279

Single-molecule imaging at high hydrostatic pressure  

NASA Astrophysics Data System (ADS)

Direct microscopic fluorescence imaging of single molecules can provide a wealth of mechanistic information, but up to now, it has not been possible under high pressure conditions, due to limitations in microscope pressure cell design. We describe a pressure cell window design that makes it possible to image directly single molecules at high hydrostatic pressure. We demonstrate our design by imaging single molecules of Alexa Fluor 647 dye bound to DNA, at 120 and 210 bar, and following their fluorescence photodynamics. We further show that the failure pressure of this type of pressure cell window can be in excess of 1 kbar.

Vass, Hugh; Lucas Black, S.; Flors, Cristina; Lloyd, Diarmuid; Bruce Ward, F.; Allen, Rosalind J.

2013-04-01

280

Single stage high pressure centrifugal slurry pump  

DOEpatents

Apparatus is shown for feeding a slurry to a pressurized housing. An impeller that includes radial passages is mounted in the loose fitting housing. The impeller hub is connected to a drive means and a slurry supply means which extends through the housing. Pressured gas is fed into the housing for substantially enveloping the impeller in a bubble of gas.

Meyer, John W. (Palo Alto, CA); Bonin, John H. (Sunnyvale, CA); Daniel, Arnold D. (Alameda, CA)

1984-03-27

281

Safety valve for high-pressure systems  

Microsoft Academic Search

rigidly connected large 3 and small cylinders 7 of the intensifier, and the pressure setting mechanism i. The pressure setting mechanism is connected with the chamber above the piston 2 of the large cylinder. The chamber below the piston of the large cylinder communicates through holes 5 with the atmosphere. The small cylinder of the intensifier communicates through channel 8

A. P. Kurshin; B. . Kanishchev

1985-01-01

282

Thermal conductivity of polymethylphenylsiloxanes at high pressures  

Microsoft Academic Search

Results are presented of an experimental investigation of the thermal conductivity of polymethylphenylsiloxanes in the 20200C temperature range and up to 200-MN\\/m2 pressure range. An equation is proposed to compute the heat conduction in the temperature and pressure ranges investigated.

A. M. Ishkhanov; V. G. Nemzer; V. V. Pugach; Yu. L. Rastorguev

1975-01-01

283

Thermal conductivity of polymethylphenylsiloxanes at high pressures  

Microsoft Academic Search

Results are presented of an experimental investigation of the thermal conductivity of polymethylphenylsiloxanes in the 20 200C temperature range and up to 200-MN\\/m2 pressure range. An equation is proposed to compute the heat conduction in the temperature and pressure ranges investigated.

A. M. Ishkhanov; V. G. Nemzer; V. V. Pugach; Yu. L. Rastorguev

1975-01-01

284

High pressure study of ferromagnetic US  

Microsoft Academic Search

We have investigated the variation of the ac magnetic susceptibility of a polycrystalline ferromagnet US as a function of hydrostatic pressure. The Curie temperature decreases linearly from 180.0 K at atmospheric pressure to 175.9 K at 18 kbar. 1. Introduction. - In the actinide series the great- er extent of the 5f atomic wavefunctions implies that the crystal field interactions

C. Y. Huang; R. J. Laskowski; C. E. Olsen; J. L. Smith

1979-01-01

285

Thermodynamic properties of nitrogen at high pressures  

Microsoft Academic Search

The thermodynamic properties of nitrogen and other industrially important gases have been adequately investigated in the range of parameters from the saturation line up to temperatures of 1300~ and pressures of 1000 bar [1] and, also, at temperatures up to 3000~ and pressures up to 100 bar [2]. These data were derived from the results of a considerable number of

A. A. Antanovich; Me A. Plotnikov; G. Ya. Savel'ev

1969-01-01

286

A High-Pressure Polymorph of Troilite, FeS  

NASA Astrophysics Data System (ADS)

A new polymorph of FeS was produced in a diamond-anvil cell and observed at high pressure both optically and by x-ray diffraction. Fourteen x-ray reflections of the high-pressure FeS were recorded; however, the crystal structure is unknown. This form of FeS is stable at 25 degrees C only at pressures above approximately 55 kilobars. The transition to the lower pressure polymorph, troilite, is rapid and reversible.

Taylor, L. A.; Mao, H. K.

1970-11-01

287

A High-Pressure Polymorph of Troilite, FeS.  

PubMed

A new polymorph of FeS was produced in a diamond-anvil cell and observed at high pressure both optically and by x-ray diffraction. Fourteen x-ray reflections of the high-pressure FeS were recorded; however, the crystal structure is unknown. This form of FeS is stable at 25 degrees C only at pressures above approximately 55 kilobars. The transition to the lower pressure polymorph, troilite, is rapid and reversible. PMID:17839060

Taylor, L A; Mao, H K

1970-11-20

288

Water Viscosity at High Pressure and Temperature  

NASA Astrophysics Data System (ADS)

We have documented a two-fold increase in the viscosity of water from 0.1 MPa (1 bar) to 1 GPa at room temperature and a 1.3-fold increase at 1.5 GPa and 70 degrees Celcius using an externally-heated, rolling sphere diamond-cell viscometer. Given the importance of water in planetary geophysics, it is surprising that almost no measurements of viscosity are available above 1 GPa. This is at least in part due to the difficulty in reliably measuring the rapid fall times of spheres used to determine viscosities in fluids. This problem has been eliminated by using a strobed light-emitting diode, allowing us to calibrate to ambient-condition viscosities and obtain high pressure viscosities consistent with accurate values given in the literature for water. In principle, our approach can be extended to over 30 GPa and 1000 K, thereby providing significant tests of theoretical models of fluid transport properties at conditions existing deep inside planets.

Grocholski, B.; Jeanloz, R.

2006-12-01

289

High pressure fiber optic connector plug  

NASA Astrophysics Data System (ADS)

A fiber optic cable connection for high pressure environments utilizes a fiber optic cable having (1) a multiplicity of fiber optic strands extending axially therein, (2) a strength member extending axially in spaced relationship there about, (3) an outer jacket, and (4) a filler matrix within the strength member and in which the strands are encased. It is a precision connector with an inner face having an axially extending recess and with axially extending passages extending from the transverse wall of the recess to the outer face of the connector member and through which the fiber optic strands extend. A preload insert member is disposed about the strands with its outer end extending into the recess of the connector and a peripheral shoulder abutting the inner face of the connector member. The strength member of the cable has its outer end portion extending outwardly from the end of the jacket and onto the reduced diameter portion. A body member is disposed about the insert member and has its outer end extending over the inner end portion of the connector.

Holmberg, Gerald; Morency, Roger

1990-12-01

290

Thermal conductivity of argon at high pressures and high temperatures  

NASA Astrophysics Data System (ADS)

Knowledge of the thermal conductivity of Ar under conditions of high pressures and temperatures (P-T) is important for model calculations of heat transfer in the laser heated diamond anvil cell (DAC) as it is commonly used as a pressure transmitting medium and for thermal insulation. We used a modified transient heating technique utilizing microsecond laser pulses in a symmetric DAC to determine the P-T dependent thermal conductivity of solid Ar up to 50 GPa and 2500 K. The temperature dependent thermal conductivity of Ar was obtained by fitting the results of finite element calculations to the experimentally determined time dependent temperature of a thin Ir foil surrounded by Ar. Our data for the thermal conductivity of Ar are larger than that theoretically calculated using the Green-Kubo formalism, but they agree well with those based on kinetic theory. These results are important for ongoing studies of the thermal transport properties of minerals at pressures and temperatures native to the mantle and core.

Goncharov, Alexander F.; Wong, Michael; Allen Dalton, D.; Ojwang, J. G. O.; Struzhkin, Viktor V.; Konpkov, Zuzana; Lazor, Peter

2012-06-01

291

Study on the Dynamic Pressure Modeling of High-Pressure Jet Homogenization  

Microsoft Academic Search

High-pressure jet homogenization is a key unit operation used in various industry sectors such as chemistry, pharmacy, special food and biotechnology. It is difficult to build the flow patterns and optimize the homogenizing unit for lacking of information on the flow conditions within the homogenizing valve. Based on the pressure measurements, the dynamic pressure change during homogenizing process was investigated

Wu Xue; Zhang Shaoying; Liu Bin

2010-01-01

292

The Evaluation of Pressure Under Heating in a High Pressure Apparatus  

Microsoft Academic Search

The possibility of high pressure evaluation at high temperature in the anvil type high pressure apparatus (HPA), is analyzed by a simple model. It is shown that at a certain moment after HPA loading the deformation of the compressible gasket may be described by equations for the elastic strains of matter, particularly by the Murnaghan equation. The latter can be

Andrei Alekseevich Potemkin; Vladimir Prokofievich Poliakov

1999-01-01

293

Pressure induced phase transformations and band structure of different high pressure phases in tellurium  

Microsoft Academic Search

We report here high-pressure x-ray diffraction (XRD) studies on tellurium (Te) at room temperature up to 40 GPa in the diamond\\u000a anvil cell (DAC). The XRD measurements clearly indicate a sequence of pressure-induced phase transitions with increasing pressure.\\u000a The data obtained in the pressure range 1 bar to 40 GPa fit five different crystalline phases out of Te: hexagonal Te

A. K. Bandyopadhyay; D. B. Singh

1999-01-01

294

High-pressure shift freezing versus high-pressure assisted freezing: Effects on the microstructure of a food model  

Microsoft Academic Search

Gelatin gel samples (10% gelatin, w\\/w) were frozen by high-pressure shift freezing (HPSF) and by high-pressure assisted freezing (HPAF) with the phase transition at identical pressure conditions (0.1, 50, and 100MPa) so as to allow valid comparisons. The corresponding temperature\\/pressure profiles were recorded in order to characterize the processes. Also, the ice crystal distributions were analyzed to estimate the effects

P. P. Fernndez; L. Otero; B. Guignon; P. D. Sanz

2006-01-01

295

System and method of delivering low\\/pressure\\/low temperature fluids into high pressure\\/high temperature heat exchangers by means of alternate pressure equalization  

Microsoft Academic Search

An improved system is described and method of introducing low pressure fluids into a high pressure heat exchanger wherein the method includes the following steps: delivering a fluid in the liquid state into a storage tank wherein atmospheric pressure equilibrium exists; delivering the liquid from the storage tank into alternating tanks, under alternating conditions; delivering atmospheric pressure equilibrium between the

1987-01-01

296

The impact of pressure, temperature and treatment time on starches: pressure-induced starch gelatinisation as pressure time temperature indicator for high hydrostatic pressure processing  

Microsoft Academic Search

The applicability of pressure-induced starch gelatinisation as a pressure time temperature indicator (PTTI) was investigated by examining the impact of pressure, temperature and treatment time on starches of A-type, B-type and C-type crystallinity. Pressure-induced starch gelatinisation was highly sensitive to changes of temperature, pressure and treatment time. At constant temperature and treatment time, the degree of gelatinisation increased with increasing

B. A. Bauer; D. Knorr

2005-01-01

297

High pressure/high temperature thermogravimetric apparatus. Final report  

SciTech Connect

The purpose of this instrumentation grant was to acquire a state-of-the-art, high pressure, high temperature thermogravimetric apparatus (HP/HT TGA) system for the study of the interactions between gases and carbonaceous solids for the purpose of solving problems related to coal utilization and applications of carbon materials. The instrument that we identified for this purpose was manufactured by DMT (Deutsche Montan Technologies)--Institute of Cokemaking and Coal Chemistry of Essen, Germany. Particular features of note include: Two reactors: a standard TGA reactor, capable of 1100 C at 100 bar; and a high temperature (HT) reactor, capable of operation at 1600 C and 100 bar; A steam generator capable of generating steam to 100 bar; Flow controllers and gas mixing system for up to three reaction gases, plus a separate circuit for steam, and another for purge gas; and An automated software system for data acquisition and control. The HP/TP DMT-TGA apparatus was purchased in 1996 and installed and commissioned during the summer of 1996. The apparatus was located in Room 128 of the Prince Engineering Building at Brown University. A hydrogen alarm and vent system were added for safety considerations. The system has been interfaced to an Ametek quadruple mass spectrometer (MA 100), pumped by a Varian V250 turbomolecular pump, as provided for in the original proposed. With this capability, a number of gas phase species of interest can be monitored in a near-simultaneous fashion. The MS can be used in a few different modes. During high pressure, steady-state gasification experiments, it is used to sample, measure, and monitor the reactant/product gases. It can also be used to monitor gas phase species during nonisothermal temperature programmed reaction (TPR) or temperature programmed desorption (TPD) experiments.

Calo, J.M.; Suuberg, E.M.

1999-12-01

298

High-speed drawing of optical fibers with pressurized coating  

Microsoft Academic Search

To make progress in high-speed drawing of optical fibers, a pressurized coating method was developed on the basis of viscous flow behavior of the coating resin. In a pressurized die, when the shear rate at the fiber surface is minimized, the pressure which is affected by the resin viscosity reaches on optimum condition, resulting in the coating diameter being dependent

Shigeki Sakaguchi; Takao Kimura

1985-01-01

299

High Hydrostatic Pressure Processing of Fruit and Vegetable Products  

Microsoft Academic Search

High hydrostatic pressure (HHP) as a minimal thermal technology is a valuable tool for microbiologically safe and shelf-stable fruit and vegetable production. Microorganisms and deteriorative enzymes can be inhibited or inactivated depending on the amount of pressure and time applied to the product. The resistance of microorganisms and enzymes to pressure in fruit and vegetable products also is dependent on

Jos A. Guerrero-Beltrn; Gustavo V. Barbosa-Cnovas; Barry G. Swanson

2005-01-01

300

Vibrational features of water's amorph at high pressures  

Microsoft Academic Search

The specific heat Cp and thermal conductivity kappa of water's high density amorph have been measured as a function of pressure up to 1.2GPa . Cp decreases on an increase in the pressure and kappa increases, both approaching a plateau value asymptotically. The decrease in Cp on an increase in pressure is shown to be due to increase in the

G. P. Johari; Ove Andersson

2006-01-01

301

AIR-BLAST PHENOMENA IN THE HIGH-PRESSURE REGION  

Microsoft Academic Search

Surface level and aboveground static overpressures, near-surface ; differential pressures, and near-surface total pressures were measured on Burst ; Priscilla. Gages were placed at ground ranges from 450 ft to 4500 ft, with a ; concentration of measurements in the high-pressure region. Blast swttches, which ; measured arrival time only, were placed at several ranges, the closest at 100-ft ;

L. M. Swift; D. C. Sachs; A. R. Kriebel

1960-01-01

302

High Pressure (>1 atm) Electrospray Ionization Mass Spectrometry  

NASA Astrophysics Data System (ADS)

High pressure electrospray ionization mass spectrometry has been performed by pressurizing a custom made ion source chamber with compressed air to a pressure higher than the atmospheric pressure. The ion source was coupled to a commercial time-of-flight mass spectrometer using a nozzle-skimmer arrangement. The onset voltage for the electrospray of aqueous solution was found to be independent on the operating pressure. The onset voltage for the corona discharge, however, increased with the rise of pressure following the Paschen's law. Thus, besides having more working gas for the desolvation process, gaseous breakdown could also be avoided by pressurizing the ESI ion source with air to an appropriate level. Stable electrospray ionization has been achieved for the sample solution with high surface tension such as pure water in both positive and negative ion modes. Fragmentation of labile compounds during the ionization process could also be reduced by optimizing the operating pressure of the ion source.

Chen, Lee Chuin; Mandal, Mridul Kanti; Hiraoka, Kenzo

2011-03-01

303

High pressure (>1 atm) electrospray ionization mass spectrometry.  

PubMed

High pressure electrospray ionization mass spectrometry has been performed by pressurizing a custom made ion source chamber with compressed air to a pressure higher than the atmospheric pressure. The ion source was coupled to a commercial time-of-flight mass spectrometer using a nozzle-skimmer arrangement. The onset voltage for the electrospray of aqueous solution was found to be independent on the operating pressure. The onset voltage for the corona discharge, however, increased with the rise of pressure following the Paschen's law. Thus, besides having more working gas for the desolvation process, gaseous breakdown could also be avoided by pressurizing the ESI ion source with air to an appropriate level. Stable electrospray ionization has been achieved for the sample solution with high surface tension such as pure water in both positive and negative ion modes. Fragmentation of labile compounds during the ionization process could also be reduced by optimizing the operating pressure of the ion source. PMID:21472572

Chen, Lee Chuin; Mandal, Mridul Kanti; Hiraoka, Kenzo

2011-02-01

304

Cyclic high-pressure torsion of nickel and Armco iron  

Microsoft Academic Search

Cyclic high-pressure torsion, a modified version of high-pressure torsion, is applied to Armco iron and nickel. The results in terms of microstructure and flow stress are compared to samples deformed by conventional high-pressure torsion. For both processes and both materials, a saturation in the decrease of the structure size and the increase in the flow stress is observed. The minimum

F. Wetscher; R. Pippan

2006-01-01

305

High pressure and anesthesia: pressure stimulates or inhibits bacterial bioluminescence depending upon temperature.  

PubMed

Although high pressure is often viewed as a nonspecific stimulus counteracting anesthesia, pressure can either excite or inhibit biological activity depending on the temperature at application. Temperature and pressure are two independent variables that determine equilibrium quantity, e.g., the state of organisms in terms of activity and anesthesia depth. We used the light intensity of luminous bacteria (Vibrio fischeri) as an activity parameter, and studied the effects of pressure and anesthetics on the bacteria's light intensity at various temperatures. The light intensity was greatest at about 30 degrees C at ambient pressure. When the system was pressurized up to 204 atm, the temperature for maximum light intensity was shifted to higher temperatures. Above the optimal temperature for the maximal light intensity, high pressure increased the light intensity. Below the optimal temperature, pressure decreased light intensity. Pressure only shifts the reaction equilibrium to the lower volume state (Le Chatelier's principle). When the volume of the excited state is larger than the resting state, high pressure inhibits excitation, and vice versa. Halothane 0.008 atm and isoflurane 0.021 atm inhibited the light intensity both above and below the optimal temperature. When pressurized, the light intensity increased in the high temperature range but decreased in the low temperature range, as in the control. Thus, high pressure seemingly potentiated the anesthetic action at low temperatures. When the ratio of the light intensity in bacteria exposed to anesthesia and those not exposed to anesthesia was plotted against the pressure, however, the value approached unity in proportion to the pressure increase.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3421502

Nosaka, S; Kamaya, H; Ueda, I

1988-10-01

306

Experimental Study on High Pressure Liquid Oxygen Pump.  

National Technical Information Service (NTIS)

In order to improve the performance of high pressure liquid oxygen and liquid hydrogen rocket engines, a small high pressure liquid oxygen pump was designed, fabricated and tested. The adjustment tests and the high loading tests were carried out in the Na...

M. Watanabe S. Hasegawa K. Kamijo H. Aoki

1988-01-01

307

High pressure-induced structural effects in plastic packaging  

Microsoft Academic Search

Today, flexible vacuum packages are predominantly used for products to be subjected to high pressure treatment. However, tray packages with a modified atmosphere are in demand, which provide a high failure rate with respect to gas and water vapour permeability and packaging integrity. Methods to follow permeation processes under high pressure were developed and used together with optical microscopy, confocal

Tobias Richter; Julia Sterr; Verena Jost; Horst-Christian Langowski

2010-01-01

308

High-pressure phases of titanium: First-principles calculations  

NASA Astrophysics Data System (ADS)

We investigate through first-principles calculations the controversial observation of the high-pressure orthorhombic ( ? and ? ) phases of titanium. Our calculations predict the transition sequence ?-?-? under pressure, and reveal that the ? phase is elastically unstable under isotropic compression. We attribute its observation to nonhydrostatic stresses present in the diamond-anvil cell experiments. We find the ? phase to be stable in the 102-112GPa pressure range, with the upper limit of this pressure range increasing under nonhydrostatic conditions.

Verma, A. K.; Modak, P.; Rao, R. S.; Godwal, B. K.; Jeanloz, R.

2007-01-01

309

Evidence of Tetragonal Nanodomains in the high pressure polymorph  

Microsoft Academic Search

The pressure induced P4mm Pm{bar 3}m phase transition in BaTiO perovskite was investigated by x-ray total scattering. The evolution of the structure was analyzed by fitting pair distribution functions over a pressure range from ambient pressure up to 6.85(7) GPa. Evidence for the existence of tetragonal ferroelectric nanodomains at high pressure was found. The average size of the nanodomains in

L. Ehm; L. A. Borkowski; Parise J. B; S. Ghose; Z. Chen

2010-01-01

310

Elasticity of Mantle Minerals and their High-Pressure Polymorphs at High Pressures and Temperatures  

NASA Astrophysics Data System (ADS)

In his 1952 paper, Francis Birch concluded "New phases are required to account for the high elasticity of the deeper part of the mantle (below 900 km), and it is suggested that, beginning at about 200 to 300 km, there is a gradual shift toward high-pressure modifications of the ferro-magnesian silicates, probably close-packed oxides, with the transition complete at about 800 to 900 km." In the subsequent quarter century, experimental evidence for such transitions to high-pressure polymorphs emerged in laboratories around the world, most notably in those of Akimoto in Japan and Ringwood in Australia; these studies confirmed the existence of stable silicate phases with the wadsleyite, ringwoodite, majorite, ilmenite [now akimotoite], and perovskite structures. In the 1970s and 1980s, single crystal and polycrystalline specimens of these high-pressure phases were synthesized, thereby enabling studies of their elastic properties in the laboratory at ambient conditions [see Brillouin studies of the Weidner and Basssett laboratories, and ultrasonic studies by Mizutani and Fujisawa in Japan and Liebermann and colleagues in Australia]. This work often started with experiments on crystal chemical analogues of mantle silicates, following the original suggestions of Goldschmidt and Bernal in the 1930s (repeated by Birch in 1952), and then moved on to the real mantle compositions. Prior to 1988, most of these acoustic experiments were conducted versus presssure at room temperature or versus temperature at room presssure; these conditions fell far short of those achieved in the Earth's mantle. Substantial progress has been made in the past decade, making it feasible to perform acoustic experiments at conditions approaching those for the transition zone (at depths greater than 400 km); this progress has been achieved in many laboratories, including those at the University of Washington, Geophysical Laboratory, Bayreuth Geoinstitut, Nagoya University, Australian National University, and Stony Brook. Recent experiments have vastly expanded our knowledge of the elasticity of the high-pressure phases of mantle silicates, whose existence Birch foreshadowed 50 years ago. We summarize and discuss the new data for the olivine, wadsleyite and ringwoodite phases of (Mg,Fe)2SiO4, pyrope-majorite garnets with pyroxene stoichiometry, the coesite and stishovite phases of SiO2, ferropericlase, and silicate perovskites, and the implications of these data for interpretations of seismic models of the Earth's interior.

Liebermann, R. C.; Li, B.; Kung, J.; Weidner, D. J.

2002-12-01

311

High Blood Pressure in Pregnancy - Multiple Languages: MedlinePlus  

MedlinePLUS

... trudno?i - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (????) High Blood Pressure in Pregnancy ????? - ???? (Chinese - Simplified) Bilingual PDF Health Information ...

312

Cardiovascular outcomes of treating high blood pressure.  

PubMed

Because hypertension is a major risk factor for cardiovascular disease, it has been anticipated that therapeutic reduction of blood pressure would protect patients from serious complications. In fact, this has been shown for strokes, congestive heart failure, and renal insufficiency. But in large trials of hypertension treatment, patients receiving active medications experienced an incidence of coronary events that averaged only 7% lower than that in placebo-treated patients. This report examines some of the reasons for this disappointing outcome. During therapeutic trials patients receiving placebo tended to have fewer cardiovascular events than predicted. However, patients on active therapy in large-scale studies may have suboptimal blood pressure control. They may also be exposed to the adverse effects of inappropriate therapy. Careful selection of modern drugs should allow blood pressure to be controlled in a safe manner, and possibly contribute directly to protection from coronary events and other cardiovascular complications. PMID:3310572

Weber, M A

1987-10-01

313

Synthesis of vanadium sulfides under high pressure  

NASA Astrophysics Data System (ADS)

Vanadium sulfides were synthesized in a temperature range of 350-750C and in a pressure range of 10-250 MPa (1 MPa = 9.87 atm), with an apparatus used for hydrothermal synthesis. The nonstoichiometric compositional range of the V1+xS2 phase, which cannot be prepared under atmospheric pressure, is VS1.661-VS1.732 (0.155 < x < 0.204). It was impossible to synthesize vanadium disulfide VS2 under the present experimental conditions. Equilibrium phase diagrams for the V5S8-S system under 100 and 200 MPa have been proposed on the basis of the present results. Also, the phase relationship between V5S8 and V1+xS2 has been established and a pressure-temperature phase diagram for the V-S system has been drawn.

Yokoyama, Masao; Yoshimura, Masahiro; Wakihara, Masataka; Somiya, Shigeyuki; Taniguchi, Masao

1985-11-01

314

High-pressure melting curve of hydrogen  

NASA Astrophysics Data System (ADS)

The melting curve of hydrogen was computed for pressures up to 200 GPa, using molecular dynamics. The inter- and intramolecular interactions were described by the reactive force field (ReaxFF) model. The model describes the pressure-volume equation of state solid hydrogen in good agreement with experiment up to pressures over 150 GPa, however the corresponding equation of state for liquid deviates considerably from density functional theory calculations. Due to this, the computed melting curve, although shares most of the known features, yields considerably lower melting temperatures compared to extrapolations of the available diamond anvil cell data. This failure of the ReaxFF model, which can reproduce many physical and chemical properties (including chemical reactions in hydrocarbons) of solid hydrogen, hints at an important change in the mechanism of interaction of hydrogen molecules in the liquid state.

Davis, Sergio M.; Belonoshko, Anatoly B.; Johansson, Brje; Skorodumova, Natalia V.; van Duin, Adri C. T.

2008-11-01

315

High-pressure melting curve of hydrogen.  

PubMed

The melting curve of hydrogen was computed for pressures up to 200 GPa, using molecular dynamics. The inter- and intramolecular interactions were described by the reactive force field (ReaxFF) model. The model describes the pressure-volume equation of state solid hydrogen in good agreement with experiment up to pressures over 150 GPa, however the corresponding equation of state for liquid deviates considerably from density functional theory calculations. Due to this, the computed melting curve, although shares most of the known features, yields considerably lower melting temperatures compared to extrapolations of the available diamond anvil cell data. This failure of the ReaxFF model, which can reproduce many physical and chemical properties (including chemical reactions in hydrocarbons) of solid hydrogen, hints at an important change in the mechanism of interaction of hydrogen molecules in the liquid state. PMID:19026067

Davis, Sergio M; Belonoshko, Anatoly B; Johansson, Brje; Skorodumova, Natalia V; van Duin, Adri C T

2008-11-21

316

Biomolecular electron transfer under high hydrostatic pressure  

Microsoft Academic Search

The dependence of the photoinduced electron transfer rate on hydrostatic pressure up to 8 kbar was studied at 295 K in a bridged Zn-porphyrin donor and pyromellitimide acceptor supermolecule dissolved in toluene. A picosecond fluorescence emission kinetics of the donor, limited by the electron transfer rate, was detected by using synchroscan streak camera. The experiment was complemented with model calculations

Mrt Tars; Aleksandr Ellervee; Michael R. Wasielewski; Arvi Freiberg

1998-01-01

317

Centrifugal Pump (High Pressure) for Power Transmissions.  

National Technical Information Service (NTIS)

This report describes the analytical study, design, and experimental investigation of a four-stage centrifugal pump capable of 30 gpm flow at a pressure of 4000 psi when pumping hydraulic fluid at an inlet temperature of 600 F. The hydrodynamic analysis i...

P. Hildebrand T. Vodopia J. Sanders L. Nagyszalanczy

1966-01-01

318

Melting curve equations at high pressure  

NASA Astrophysics Data System (ADS)

A number of equations for the melting temperature dependence on pressure, Tm(P), based on the two- and one-phase approaches to melting have been obtained. All melting curves have the form Tm=F(P)D(P), where F(P) is the Simon (rising) melting equation and D(P) is the damping function, which asymptotically slopes down under pressure. This form predicts that each solid phase has a maximum melting temperature at positive or negative pressure. The simplest equation of this form is Tm=T0(1+?P/a)b exp(-c?P), where ?P=P-P0, P0 is some reference pressure, and a, b, and c are parameter which are identified in terms of thermodynamic values. All melting curve data obey this equation. This implies that there exist no anomalous melting curves. All melting curves, rising, falling, and flattening, as well as curves with a maximum, are normal insofar as all of them can be described by the unified equation.

Kechin, Vladimir V.

2002-02-01

319

Nucleation and droplet growth at high pressure  

Microsoft Academic Search

Homogeneous nucleation, the first stage of droplet formation in the absence of foreign particles, usually takes place in the presence of one or more supercritical carrier gases. The present work aimed at a systematic investigation of the effects of carrier gas pressure on nucleation and droplet growth. Using the so-called nucleation pulse method, nucleation and droplet growth can be separated

Carlo Cornelis Maria Luijten

1998-01-01

320

High-Pressure Melting of Molybdenum  

Microsoft Academic Search

The melting curve of the body-centered cubic (bcc) phase of Mo has been determined for a wide pressure range using both direct abinitio molecular dynamics simulations of melting as well as a phenomenological theory of melting. These two methods show very good agreement. The simulations are based on density functional theory within the generalized gradient approximation. Our calculated equation of

A. B. Belonoshko; S. I. Simak; A. E. Kochetov; B. Johansson; L. Burakovsky; D. L. Preston

2004-01-01

321

HIGH TEMPERATURE PRESSURE TRANSDUCER (Mk. I)  

Microsoft Academic Search

A rugged and reliable pressure transducer was developed for use in ; molten sodium systems at temperatures from 100 to 400 deg C. The device gave ; results accurate to approximately plus or minus 1% in bench calibration tests at ; temperatures up to 400 deg C, and performed satisfactorily in the molten sodium ; primary stream of a sodium-pumped

Thacker

1962-01-01

322

High-pressure physics: Testing one's metal  

NASA Astrophysics Data System (ADS)

The search for the metallic state of hydrogen at ever higher static pressures has normally required experiments to be performed at temperatures near 100 K. Now, some 30 years after the first attempts at room-temperature compression, the observation of reflective dense hydrogen promises to bring it in from the cold.

Jephcoat, Andrew P.

2011-12-01

323

Hydrothermal decomposition of esters under high pressure  

Microsoft Academic Search

The hydrothermal decomposition of two esters (methyl formate and ethyl formate) was studied in the absence of oxygen over the temperature range of 373 673 K at pressures from 15 to 35MPa for residence times between 72 and 600s. At hydrothermal conditions, the esters were hydrolyzed to formic acid and the corresponding alcohols in equilibrium yields of more than

Takashi Moriyoshi; Keisuke Sam; Yasuhiro Uosaki

2001-01-01

324

High Pressure Study on Some HIGH-Tc Superconductors  

NASA Astrophysics Data System (ADS)

We present a brief review on the pressure effects of some high temperature super-conductors. The examined systems include RBa2Cu3O7, (R, Pr)Ba2Cu3O7 and (ZnPc)yBi2Sr2Ca2Cu3O10, with R=rare earth elements and Pc=phthalocyanine. The results of the presssure effects on the superconducting transition temperature Tc in these materials have, thus, not only revealed the origin of the Tc-variation induced by the chemical substitution or intercalation, but have also confirmed the important roles played by the carrier concentration and Tco (maximum Tc) on determining Tc. Based on our experimental results, along with good agreement between our data and theory, we have clearly demonstrated that the variation of Tc dominantly originates from the strains induced by the variation of the ionic radii or the intercalation of foreign molecules.

Huang, C. Y.; Lin, J. G.; Huang, Z. J.

325

High pressure and high flowrate induction pumps with permanent magnets  

NASA Astrophysics Data System (ADS)

Theoretical evaluations and modelling experiments demonstrated a rather high efficiency of electromagnetic induction pumps (EMIP) basing on permanent magnets, in which an alternating travelling magnetic field, inducing electromagnetic dragging forces in liquid metal, is generated by a system of rotating permanent magnets with alternating polarity. Basing on the gained experience at producing real pumps for pure Pb and eutectic alloy Pb-Bi, the evaluation of parameters of much more powerful pumps for mercury developing a head pressure over 5 bars and so providing flow rates over 10 L/s, had been carried out to show their reliability. These powerful pumps are supposed to be used in the proposed European Spallation neutron Source (ESS), in which mercury will be operated as a spallation target material and a cooling fluid at the same time. Tables 2, Figs 5, Refs 8.

Bucenieks, I. E.

2003-12-01

326

[Exploration of the broken parts of a brake hose by ATR-FTIR and SEM].  

PubMed

ATR-FTIR and SEM were respectively utilized to analyze the chemical components and to observe the micromorphology of a broken brake hose from a traffic case, which could be a supplementary for the traditional microscopic examination. The instrumental analysis results indicated that the rubber from the brake hose had already aged; the rubber from external side had experienced brittle fracture and there were original hollows in the rubber from internal side. The breaking of the brake hose resulted from all these reasons. The experimental results also demonstrated that the fact could be reflected efficiently, accurately and objectively by the application of ATR-FTIR and SEM to the physical evidence from a case. Therefore, it could be an effective complement for traditional traffic trace examination. PMID:21714231

Wang, Yuan-Feng; Wang, Lian-Ming; Li, Bing

2011-04-01

327

High-Temperature High-Pressure Bitumen Sand Laboratory Measurements  

NASA Astrophysics Data System (ADS)

The recent increase in the development and production of heavy-oil reservoirs has brought the need for a reliable, quantitative, reservoir characterization and monitoring methodology to the forefront. In order for this task to be successfully completed a dependable and robust rock physics model or transform needs to be established for these types of reservoirs. In order to calibrate this type of model there is a need for a large, reliable laboratory measured dataset of reservoir properties under various environmental conditions. However, due to the soft nature of these reservoirs, and the variation of properties with temperature, pressure, etc., this is a particularly challenging task. In order to fill this knowledge gap we have performed thorough modeling in order to design an optimum system to measure the acoustic and elastic properties of heavy-oil saturated sands over a temperature range of 0-200oC, and pressures of 0-35 MPa. The modeling effort focused on designing transducers that are able to produce high-amplitude broad-band pulse transmission signals through heavy-oil sand samples over a large temperature range. This includes 1) using a non-traditional end cap material, as well as piezoelectric crystals with high operating temperatures and 2) a priori testing of the performance of the transducers under varying conditions by modeling the signal output. This has been achieved by using the Krimholtz, Leedom and Matthaei (KLM) equivalent circuit model to ensure that the design of the transducer is optimal. While there are many challenges faced when creating a set of rock physics measurements in order to calibrate rock physics models for bitumen sands, we feel that our approach addresses many of the major obstacles. With our specially designed equipment and novel approaches to the measurement of bitumen sand properties we feel that we have made significant strides towards providing a robust dataset from which many rock physics models and principles related to bitumen and heavy oil reservoirs can be built.

Wolf, K.; Vanorio, T.

2008-12-01

328

Hosing and self-modulation competition in self-modulated plasma acceleration  

NASA Astrophysics Data System (ADS)

It was recently proposed that large amplitude plasma waves could be resonantly excited by the self-modulation instability (SMI) of long particle bunches [Kumar, PRL 104 255003 (2010)]. Best conditions for particle acceleration are met after the saturation of the SMI when the driver and wake phase velocities are similar. It is therefore crucial to understand whether beam breakup due to the growth of the hosing instability (HI) can occur once the SMI has saturated. Here we show analytically and numerically that the HI is suppressed after the saturation of the SMI. We find that each self-modulated beamlet centroid performs harmonic betatron oscillations driven by the transverse wake associated with the preceding beamlets. Hence, resonances between beamlet centroids are avoided in the linear regime as the wake amplitude grows along the bunch, leading to different betatron frequencies for different beamlets. This suppression mechanism is analogous to the BNS damping [Balakin et al, Proc. 12th Int. Conf. High Energy Accel., Fermilab, 1983, p.119] used in conventional linear accelerators. These findings are confirmed by direct numerical solutions of the model. 3D particle-in-cell simulations confirm our predictions for a wide range of conditions.

Vieira, Jorge; Fonseca, Ricardo; Mori, Warren; Muggli, Patric; Silva, Luis

2012-10-01

329

Evaluation of high-pressure drilling fluid supply systems  

SciTech Connect

A study was undertaken to help determine the technical and economic feasibility of developing a high-pressure fluid-jet drilling system for the production of geothermal wells. Three system concepts were developed and analyzed in terms of costs, component availability, and required new-component development. These concepts included a single-conduit system that supplies the downhole cutting nozzles directly via surface-located high-pressure pumps; a single-conduit system utilizing low-pressure surface pumps to supply and operate a high-pressure downhole pump, which in turn supplies the cutting nozzles; and a dual-conduit system supplying surface-generated high-pressure fluid for cutting via one conduit and low-pressure scavenging fluid via the other. It is concluded that the single-conduit downhole pump system concept has the greatest potential for success in this application. 28 figures, 11 tables.

McDonald, M.C.; Reichman, J.M.; Theimer, K.J.

1981-10-01

330

Single crystal structure investigations under high-pressure of the mineral cordierite with an improved high-pressure cell  

Microsoft Academic Search

An improved single-crystal high-pressure anvil cell with beryllium-gaskets was used for the investigations of structure and lattice parameters of cordierite which had been heated in an Ar stream at about 1,000 C to remove natural water from its structural channels. The influences of pressure transmitting media were studied by using water as a pressure medium at pressures of 0.3, 0.9,

J. Koepke; H. Schulz

1986-01-01

331

High Pressure Elastic Constants of High-Pressure Iron Analog Osmium  

NASA Astrophysics Data System (ADS)

Understanding the elasticity of hcp iron is important both for ascertaining the stable phase and for explaining the observed seismic anomalies of Earth's inner core. A systematic experimental study of analog materials is warranted because experiments at inner-core conditions remain exceptionally challenging and theory has yielded conflicting results for iron. The deformation of hexagonal close-packed (hcp) Os, an analog for the high-pressure hcp form of Fe, has been characterized under non-hydrostatic stresses using synchrotron-based angular-dispersive radial x-ray diffraction to pressures of 60 GPa at room temperature. Starting with published ultrasonic values of elastic constants and previous measurements of linear and volume compressibilities, we estimate the single-crystal elasticity tensor of osmium to 60 GPa and find that the crystal orientation with the largest shear modulus, (002), accommodates the largest shear stress (10 GPa) and a differential strain surpassing the Voigt iso-strain limit. We find the conventional elastic model, bounded by Reuss (iso-stress) and Voigt limits, inadequate for explaining our measurements. Instead, we infer that plastic deformation limits the amount of shear stress supported by the crystal planes near the a-axis, causing the more elastically strong c-axis to support the majority of the differential strain. This conclusion is consistent with the elasto-plastic self-consistent approach used to model the effect of plasticity on the high-pressure deformation of hcp-Co (Merkel et al, PRB 79, 064110 (2009)). Importantly, we document a strength anisotropy so large that the Voigt (elastic) limit is clearly surpassed.

Godwal, B. K.; Geballe, Z.; Jeanloz, R.

2011-12-01

332

Aging study of boiling water reactor high pressure injection systems  

Microsoft Academic Search

The purpose of high pressure injection systems is to maintain an adequate coolant level in reactor pressure vessels, so that the fuel cladding temperature does not exceed 1,200°C (2,200°F), and to permit plant shutdown during a variety of design basis loss-of-coolant accidents. This report presents the results of a study on aging performed for high pressure injection systems of boiling

D. A. Conley; J. L. Edson; C. F. Fineman

1995-01-01

333

High-Pressure Synthesis of Molybdates with the Wolframite Structure.  

PubMed

A series of small cation molybdates, MgMoO(4), MnMoO(4), FeMoO(4), CoMoO(4), NiMoO(4), and ZnMoO(4) with the wolframite structure characteristic of the corresponding tungstates have been synthesized at high pressure and temperature. The high-pressure compounds revert to the ambient pressure modifications if heated in air at 600 degrees C. PMID:17815990

Young, A P; Schwartz, C M

1963-07-26

334

More on shear modulus collapse of lattices at high pressure  

Microsoft Academic Search

In his recent paper, Shear modulus collapse of lattices at high pressure, J. Phys. Cond. Matt. 16 (2004) L125, V.V. Kechin claims that the zero temperature shear modulus of a metallic solid vanishes at a high critical pressure, and the critical pressures for this shear modulus collapse lie in the range 0250Mbar for elemental metals. Here we demonstrate that Kechin's

Leonid Burakovsky; Carl W. Greef; Dean L. Preston

2006-01-01

335

Food Sterilization by Combining High Pressure and Thermal Energy  

Microsoft Academic Search

High pressure processing (HPP) is an industrially tested technology that offers a more natural, environmentally friendly alternative\\u000a for pasteurization or shelf life extension of a wide range of food products (Welti-Chanes et al., 2005). Commercial high pressure,\\u000a low temperature methods achieve inactivation of vegetative microorganisms by subjecting vacuum-sealed food in flexible packaging\\u000a to treatment at hydrostatic pressures of 600 MPa

Gustavo V. Barbosa-Cnovas; P. Juliano

336

High-pressure chemistry of nitride-based materials.  

PubMed

Besides temperature at one atmosphere, the applied pressure is another important parameter for influencing and controlling reaction pathways and final reaction products. This is relevant not only for the genesis of natural minerals, but also for synthetic chemical products and technological materials. The present critical review (316 references) highlights recent developments that utilise high pressures and high-temperatures for the synthesis of new materials with unique properties, such as high hardness, or interesting magnetic or optoelectronic features. Novel metal nitrides, oxonitrides as well as the new class of nitride-diazenide compounds, all formed under high-pressure conditions, are highlighted. Pure oxides and carbides are not considered here. Moreover, syntheses under high-pressure conditions require special equipment and preparation techniques, completely different from those used for conventional synthetic approaches at ambient pressure. Therefore, we also summarize the high-pressure techniques used for the synthesis of new materials on a laboratory scale. In particular, our attention is focused on reactive gas pressure devices with pressures between 1.2 and 600 MPa, multi-anvil apparatus at P < 25 GPa and the diamond anvil cell, which allows work at pressures of 100 GPa and higher. For example, some of these techniques have been successfully upgraded to an industrial scale for the synthesis of diamond and cubic boron nitride. PMID:17003902

Horvath-Bordon, Elisabeta; Riedel, Ralf; Zerr, Andreas; McMillan, Paul F; Auffermann, Gudrun; Prots, Yurii; Bronger, Welf; Kniep, Rdiger; Kroll, Peter

2006-08-10

337

High pressure spectroscopy of Ce doped YAG crystal  

NASA Astrophysics Data System (ADS)

Electronic structure and optical properties of the Ce3+ in YAG has been investigated by standard spectroscopy (photoluminescence, absorption and excitation spectra) and high pressure spectroscopy. The bandshape of the emission spectrum for different pressures has been analyzed and influence of pressure on energy of the 5d(1) states and the electron-lattice coupling have been determined. The significant red shift of the peak of the emission band (the respective pressure coefficient has been equal to -12 cm(-1)/kbar) has been obtained. The shift has been understood by taking into account pressure induced increase of the 5d(1) level splitting and increase of the electron-lattice coupling strength.

Barzowska, J.; Grinberg, M.; Tsuboi, T.

2003-01-01

338

High pressure transformation of graphene nanoplates: A Raman study  

NASA Astrophysics Data System (ADS)

High pressure Raman study on graphene nanoplates, graphite and micro-graphite has been carried out in a diamond anvil cell. A phase transformation has been observed in graphene nanoplates at 15 GPa in the experiments with or without pressure medium, which can be explained by the interlayer coupling with sp3 bonds formed in the material. For graphite and micro-graphite, the transition pressure is 19 GPa. Different transition pressures for them are attributed to the thickness difference. The lower transition pressure in graphene nanoplates has been discussed in the framework of the special limited-number layer structure and nucleation process in phase transition.

Lu, Shuangchen; Yao, Mingguang; Yang, Xigui; Li, Quanjun; Xiao, Junping; Yao, Zhen; Jiang, Linhai; Liu, Ran; Liu, Bo; Chen, Shuanglong; Zou, Bo; Cui, Tian; Liu, Bingbing

2013-10-01

339

Journey to the Center of the Earth: Exploring High Pressure  

SciTech Connect

The deeper we go into the Earth, the higher the pressure. At the pressures found within the center of our planet, minerals do not simply compress. Pressure dramatically alters all materials properties, in the process creating numerous novel phases not found on the surface. This lecture will describe how we simulate the conditions found in planetary interiors in the lab, what kinds of new behavior we find, and how these observations can explain what is going on within the Earth. High pressure explorations also lead to discoveries of novel materials with potential for practical applications in our low-pressure, environment.

Mao, Wendy

2009-09-29

340

Journey to the Center of the Earth: Exploring High Pressure  

ScienceCinema

The deeper we go into the Earth, the higher the pressure. At the pressures found within the center of our planet, minerals do not simply compress. Pressure dramatically alters all materials properties, in the process creating numerous novel phases not found on the surface. This lecture will describe how we simulate the conditions found in planetary interiors in the lab, what kinds of new behavior we find, and how these observations can explain what is going on within the Earth. High pressure explorations also lead to discoveries of novel materials with potential for practical applications in our low-pressure, environment.

341

46 CFR 27.301 - What are the requirements for fire pumps, fire mains, and fire hoses on towing vessels?  

Code of Federal Regulations, 2012 CFR

...fire-pump, a fire main, and hoses and nozzles in accordance with paragraphs (a) through...section; or a portable pump, and hoses and nozzles, in accordance with paragraphs (d...50 feet) in length, and fitted with a nozzle made of corrosion-resistant...

2012-10-01

342

High pressure growth of nanocrystalline silicon films.  

PubMed

Nanocrystalline silicon thin films were grown using gaseous mixture of 5% silane (SiH4) diluted in hydrogen (H2) and argon (Ar) in a radio frequency (13.56 MHz) plasma enhanced chemical vapor deposition technique. These films were deposited as a function of pressure and were characterized using AFM, Laser Raman, UV-VIS transmission, photoluminescence and electrical conductivity techniques. AFM micrographs shows that these films contain nanocrystallites of 30-60 nm size. Laser Raman peaks at 520 cm(-1) and photoluminescence peaks at 2.75 and 2.85 eV have been observed. The crystalline fraction in these films was varied from 30% to 80% with the variation of deposition pressure from 2 Torr to 8 Torr. There is an optimum pressure of 4 Torr where the maximum growth of nanocrystalline phases was observed. It has been found that nanocrystallites in these film enhanced the optical band gap and electrical conductivity. Also a voltage-current (V-I) probe was used to evaluate the various electrical parameters of the plasma used to deposit the nc-Si:H films for the present investigation. Growth via a SiH3 precursor, diffusion of hydrogen in the sub-surface and argon etching of weak bonds are some of the processes that may be involved in the nano crystallization process. PMID:19049205

Kumar, Sushil; Gope, Jhuma; Kumar, Aravind; Parashar, A; Rauthan, C M S; Dixit, P N

2008-08-01

343

Towards system theory based adaptive strategies for high pressure bioprocesses  

Microsoft Academic Search

High pressure has been shown to offer unique possibilities for designing novel bioprocesses and generating new structures. However, high pressure processes have to be considered also as instantaneous but not homogeneous. As a consequence of this, thermofluiddynamical processes influence molecular and cellular mechanisms and kinetics. Thus, the urgent requirement for creating an adaptive process management, missing in the literature, is

A. Delgado; A. Baars; W. Kowalczyk; R. Benning; P. Kitsubun

2007-01-01

344

Advantages of high pressure sterilisation on quality of food products  

Microsoft Academic Search

High pressure processing can be used for sterilisation of food products if applied at elevated temperatures and using the temperature increase due to adiabatic compression. By choosing the appropriate process conditions, it is possible to completely inactivate both vegetative cells and microbial spores resulting in food products that are shelf stable. The quality of high pressure sterilised products is usually

Ariette M Matser; Bregje Krebbers; Robert W van den Berg; Paul V Bartels

2004-01-01

345

Applications and development of high pressure PEM systems  

Microsoft Academic Search

Many portable fuel cell applications require high pressure hydrogen, oxygen, or both. High pressure PEM systems that were originally designed and developed primarily for aerospace applications are being redesigned for use in portable applications. Historically, applications can be broken into weight sensitive and weight insensitive cell stack designs. Variants of the weight sensitive designs have been considered to refill oxygen

A Leonida; F Militsky; B Myers; A H Weisberg

1999-01-01

346

Genes Tied to High Blood Pressure Found in Black Americans  

MedlinePLUS

... this page, please enable JavaScript. Genes Tied to High Blood Pressure Found in Black Americans Study findings may lead ... Pages African American Health Genes and Gene Therapy High Blood Pressure MONDAY, Sept. 16 (HealthDay News) -- Black Americans are ...

347

Extra Vitamin D Doesn't Cut High Blood Pressure  

MedlinePLUS

... enable JavaScript. Extra vitamin D doesn't cut high blood pressure: study (*this news item will not be available ... 2013) Wednesday, August 14, 2013 Related MedlinePlus Pages High Blood Pressure Seniors' Health Vitamin D By Andrew M. Seaman ...

348

Effects of high pressure on meat: A review  

Microsoft Academic Search

Extensive investigations in the last decade have revealed the potential benefits of high pressure processing (100800 MPa) for the preservation and modification of foods. Simultaneously, a few pressurised foods have become commercially available in Japan, Europe and the USA. In the present review, the basic principles underlying the effects of high pressure on food constituents and quality attributes are first

J. Claude Cheftel; Joseph Culioli

1997-01-01

349

High pressure discharges in cavities formed by microfabrication techniques  

SciTech Connect

High pressure discharges are the basis of small high intensity light sources. In this work, we demonstrate the formation of high pressure discharges, in cavities formed by applying micromachining and integrated circuit techniques to quartz substrates. Cavities containing varying amounts of mercury and argon were fabricated to obtain high pressure discharges. A high pressure mercury discharge was formed in the electrodeless cavities by exciting them with a microwave source, operating at 2.45 GHz and in the electroded cavities by applying a dc voltage. The contraction of the discharge into a high pressure arc was observed. A broad emission spectrum due to self-absorption and collisions between excited atoms and normal atoms, typical of high pressure mercury discharges, was measured. The light output and efficacy increased with increasing pressure. The measured voltage was used to estimate the pressure within the electroded cavities, which is as high as 127 atm for one of the two cavities discussed in this work. Efficacies over 40 lumens per watt were obtained for the electrodeless cavities and over 50 scr(l)m/W for the electroded cavities. {copyright} {ital 1997 American Institute of Physics.}

Khan, B.A.; Cammack, D.A.; Pinker, R.D.; Racz, J. [Philips Electronics North America Corporation, Philips Research, Briarcliff Manor, New York 10510 (United States)

1997-07-01

350

Alterations in brain monoamine neurotransmitter release at high pressure  

Microsoft Academic Search

High pressure exposure produces neurological changes which manifest as tremors, EEG changes and convulsions. Since previous studies have implicated the involvement of the monoaminergic system in these symptoms, it was of interest to study monoamine release at high pressure. Synaptosomes isolated from guinea pig brain were used to follow monoamine efflux at 68 ATA. The major observation was a decrease

S. C. Gilman; J. S. Colton; A. J. Dutka

1989-01-01

351

Optimization of a high-pressure pore water extraction device  

NASA Astrophysics Data System (ADS)

High-pressure squeezing is a technique used for the extraction of the pore water of porous materials such as sediments, soils, rocks, and concrete. The efficiency of extraction depends on the maximum pressures on the materials. This article presents the design of a high-pressure device reaching an axial pressure of 1000 MPa which has been developed to improve the efficiency of extraction. The increase in squeezing pressure implies high stresses inside the chamber, so specialized expertise was required to design a safe, functional device that could withstand pressures significantly higher than common laboratory equipment. The design includes finite element calculations, selection of appropriate materials, and descriptive construction details for the apparatus. It also includes an experimental study of the performance of the apparatus in terms of extraction efficiency.

Cyr, Martin; Daidi, Alain

2007-02-01

352

A Comparison of the High-altitude and High-pressure Syndromes of Decompression Sickness  

Microsoft Academic Search

Decompression sickness is an illness which occurs in divers and caisson workers on return to normal atmospheric pressure after working at very high pressures, and in aiRMEN on reaching very low pressures at great altitude. The disease seen after exposure to high pressure is described and compared with that seen on exposure to great altitude. Mild cases show little difference,

M. de G. Gribble

1960-01-01

353

High-pressure minerals in the Earth and planetary materials  

NASA Astrophysics Data System (ADS)

Shocked meteorites are the most important sources of high-pressure minerals in addition to impact crater rocks, diamond inclusions and mantle xenoliths. In most cases, natural high-pressure minerals occur as submicron-sized grains. However, state-of-art techniques such as transmission electron microscopy and synchrotron X-ray diffractometry enabled the identification of such small crystalline grains. As a result, many of natural high-pressure phases of silicates and oxides have been discovered in the past 15 years. Textural, crystallographic and chemical characteristics of the natural high-pressure minerals provide us not only the clues to understand the impact events of meteorite parent bodies, but also insights on the structure and dynamics of the deep Earth. Here, we summarize the occurrences and discovery histories of the natural high-pressure minerals.

Miyahara, Masaaki; Tomioka, Naotaka

354

Surface seismic data identifies shallow high-pressure drilling hazards  

SciTech Connect

This article includes background into high pressure anomaly detection, along with an offshore case history. The case history discusses the reprocessing of shallow seismic data in order to obtain better resolution, as well as pattern recognition and interpretation. High pressure gas zone detection and prediction is critical to preventing blowouts during drilling. High-pressure gas bodies situated at depths of 1.0 to 1.2 sec seismic velocities have been identified through indirect evidences by enhancing conventional seismic-section resolution. The potential shallow high-pressure gas zones have been inferred from conventional seismic data using restricted angle stack and corresponding microgeometric interpretation sections. The microgeometric interpretation sections are obtained by a correlation process of all possible events across a seismic section on a computer using pattern recognition. High pressure zones detected by this methodology can be avoided while deciding drilling locations.

Chopra, S.; Rajagopala Rao, M.; Joseph, C.J. (ONGC, Dehradun (India)); Nanda, N.C. (ONGC, Madras (India). Cauvery Basin Interpretation Group)

1995-01-01

355

High Pressure Combustion Test Facility for Gas Turbine Research.  

National Technical Information Service (NTIS)

A new high pressure combustion test facility was constructed in the National Aerospace Laboratory, Tokyo, to assist the national project for developing a high efficiency combined cycle gas turbine. It enables continuous combustion tests by an air mass flo...

T. Tamaru K. Shimodaira S. Horiuchi T. Saito S. Hayashi

1984-01-01

356

Residual mode beating in a high-pressure-low-pressure hybrid CO2 laser system  

Microsoft Academic Search

Measurements of residual mode beating in the pulses from a hybrid high-pressure-low-pressure CO2 laser system are presented as a function of the gain of the low-pressure section. It is shown that the variation is approximately exponential and that a ratio of the longitudinal mode intensities of better than 100 million can be achieved. The operation of the system on various

N. R. Heckenberg; J. Meyer

1976-01-01

357

Fluorinert as a pressure-transmitting medium for high-pressure diffraction studies  

Microsoft Academic Search

Fluorinert is a liquid pressure-transmitting medium that is widely used in high-pressure diffraction work. A systematic study of five different fluorinerts was carried out using single-crystal x-ray diffraction in a diamond-anvil cell in order to determine the pressure range over which they provide a hydrostatic stress state to the sample. It was found that none of the fluorinerts studied can

Tamas Varga; Angus P. Wilkinson; Ross J. Angel

2003-01-01

358

Microgravity droplet combustion in high pressures near critical pressures of fuels  

NASA Astrophysics Data System (ADS)

Burning behavior of a fuel droplet in a quiescent high-pressure atmosphere has been studied experimentally to explore the effects of the ambient pressure just around the critical pressure of fuel. Since the natural convection changes the transport field around the burning droplet, microgravity field made by a falling apparatus were used to suppress the natural convection generated by the droplet burning. Experiments showed that spherical flames were obtained for ambient pressures both below and above the critical pressure of fuel. As the ambient pressure is increased, the burning life time decreases and reaches the minimum at the critical pressure of fuel, beyond which the burning life time increase. Flame diameter increases during the burning time to a maximum and then decreases to burnout. This behavior is the same both below and above the critical pressure of the fuel. The maximum flame diameter attained during burning is a function of pressure and decreases with ambient pressure throughout the range investigated. There is no change in slope or minimum at the critical pressure.

Jun'ichi Sato; Mitsuhiro Tsue; Mario Niwa; Michikata Kono

1990-01-01

359

Raman spectroscopy at high pressure and high temperature. Phase transitions and thermodynamic properties of minerals  

Microsoft Academic Search

An outline of recent developments in Raman spectroscopy at high pressure, high temperature and combined high pressure and high temperature is presented. The instrumental and technical aspects of Raman spectroscopy, and coupling of diamond anvil cells and miniature furnaces to Raman microspectrometers are discussed. Some potential pitfalls, such as the thermal pressure in laser heated diamond anvil cells or the

P. Gillet

1996-01-01

360

Arterial pressure fractality is highly dependent on wave reflection.  

PubMed

Wave reflection is an important factor that influences pressure wave morphology and becomes more significant with aging, when cardiovascular risk increases. A pressure wave, measured at any location in the arterial tree, can be decomposed into its forward and backward components and depends on the corresponding amplitude and shifting time delays. Fractal dimension (FD) quantifies the time series complexity defined by its geometrical representation. Objective: The aim of this study was to evaluate the arterial pressure and diameter time series in order to assess the relationship between wave reflection and arterial pressure fractal dimension (FD). Methods: Simultaneous aortic pressure and diameter were measured in 14 conscious dogs. A pair of ultrasonic crystals, a pressure microtransducer and a pneumatic cuff occluder were positioned in the upper third of the descending aorta. Results: Total reflection induced by the occlusion maneuver decreased FD concomitant to the aortic stiffening. Conclusion: Arterial pressure fractality is highly dependent on wave reflection. PMID:24110099

Armentano, Ricardo L; Cymberknop, Leandro J; Legnani, Walter; Pessana, Franco M; Craiem, Damian; Graf, Sebastian; Barra, Juan G

2013-07-01

361

Temperature control for high pressure processes up to 1400 MPa  

NASA Astrophysics Data System (ADS)

Pressure- assisted sterilisation is an emerging technology. Hydrostatic high pressure can reduce the thermal load of the product and this allows quality retention in food products. To guarantee the safety of the sterilisation process it is necessary to investigate inactivation kinetics especially of bacterial spores. A significant roll during the inactivation of microorganisms under high pressure has the thermodynamic effect of the adiabatic heating. To analyse the individual effect of pressure and temperature on microorganism inactivation an exact temperature control of the sample to reach ideal adiabatic conditions and isothermal dwell times is necessary. Hence a heating/cooling block for a high pressure unit (Stansted Mini-Food-lab; high pressure capillary with 300 ?L sample volume) was constructed. Without temperature control the sample would be cooled down during pressure built up, because of the non-adiabatic heating of the steel made vessel. The heating/cooling block allows an ideal adiabatic heat up and cooling of the pressure vessel during compression and decompression. The high pressure unit has a pressure build-up rate up to 250 MPa s-1 and a maximum pressure of 1400 MPa. Sebacate acid was chosen as pressure transmitting medium because it had no phase shift over the investigate pressure and temperature range. To eliminate the temperature difference between sample and vessel during compression and decompression phase, the mathematical model of the adiabatic heating/cooling of water and sebacate acid was implemented into a computational routine, written in Test Point. The calculated temperature is the setpoint of the PID controller for the heating/cooling block. This software allows an online measurement of the pressure and temperature in the vessel and the temperature at the outer wall of the vessel. The accurate temperature control, including the model of the adiabatic heating opens up the possibility to realise an ideal adiabatic heating and cooling as well as isotherm dwell time of the sample under high pressure. This research offers a useful tool to investigate the additive effect of high pressure and thermal treatment on the inactivation of microorganisms.

Reineke, K.; Mathys, A.; Heinz, V.; Knorr, D.

2008-07-01

362

Fate of Staphylococcus aureus in Cheese Treated by Ultrahigh Pressure Homogenization and High Hydrostatic Pressure  

Microsoft Academic Search

We evaluated the influence of ultrahigh pressure ho- mogenization (UHPH) treatment applied to milk con- taining Staphylococcus aureus CECT 976 before cheese making, and the benefit of applying a further high hy- drostatic pressure (HHP) treatment to cheese. The evo- lution of Staph. aureus counts during 30 d of storage at 8C and the formation of staphylococcal enterotoxins were also

T. Lpez-Pedemonte; A. X. Roig-Sagus; B. Guamis

2006-01-01

363

The effect of high pressure on nitrogen compounds of milk  

NASA Astrophysics Data System (ADS)

The effect of pressurization at different pressures (from 200 to 1000 MPa, at 200 MPa intervals, tconst. = 15 min) and periods of time (from 15 to 35 min, at 10 min intervals, pconst. = 800 MPa) on the changes of proteins and nitrogen compounds of skimmed milk was studied. The pressurization caused an increase in the amount of soluble casein and denaturation of whey proteins. The level of nonprotein nitrogen compounds and proteoso-peptone nitrogen compounds increased as a result of the high-pressure treatment. These changes increased with an increase in pressure and exposure time. High-pressure treatment considerably affected the changes in the conformation of milk proteins, which was reflected in the changes in the content of proteins sedimenting and an increase in their degree of hydration.

Kielczewska, Katarzyna; Czerniewicz, Maria; Michalak, Joanna; Brandt, Waldemar

2004-04-01

364

Vibrational features of water's amorph at high pressures  

NASA Astrophysics Data System (ADS)

The specific heat Cp and thermal conductivity ? of waters high density amorph have been measured as a function of pressure up to 1.2GPa . Cp decreases on an increase in the pressure and ? increases, both approaching a plateau value asymptotically. The decrease in Cp on an increase in pressure is shown to be due to increase in the phonon frequency. The Debye temperature calculated from the available sound velocity data increases asymptotically with an increase in pressure and increases approximately linearly with an increase in the density of the amorph. The Grneisen parameter of the high density amorph is 1.3. While the Debye theory explains the variation of Cp with pressure, it does not seem to do so for the variation of ? with pressure.

Johari, G. P.; Andersson, Ove

2006-03-01

365

Response of four types of coliphages to high hydrostatic pressure  

Microsoft Academic Search

Pressure inactivation of four types of coliphages, ?X 174 (ssDNA virus), MS2 (ssRNA virus), ? imm434 (dsDNA virus) and T4 (dsDNA virus), was studied to evaluate their potential as human enteric viral surrogates for use in validation of commercial pressure processing treatments. Phage ?X 174 demonstrated an unexpected high resistance to pressure with no more than 1-log10 reduction observed following

D. Guan; K. Kniel; K. R. Calci; D. T. Hicks; L. F. Pivarnik; D. G. Hoover

2006-01-01

366

Accident simulation tests for high conversion light water reactor using a high pressure water loop.  

National Technical Information Service (NTIS)

A high pressure water loop was constructed to investigate thermal-hydraulic characteristics under operational and transient conditions of a high conversion light water reactor (HCLWR). The maximum pressure, heating power and heating length of the loop are...

T. Iwamura H. Watanabe F. Araya T. Okubo Y. Murao

1992-01-01

367

High-pressure instrumentation at CHESS  

SciTech Connect

Diamond anvil cells have been used to generate a wide range of pressures, from 0.1 to over 400 GPa (for reference, the center of Earth is about 360 GPa). Samples are squeezed between two diamond anvils and studied using infrared, visible, and x-ray probes. Recently a bending magnet station at CHESS has become available for the general user for diamond anvil cell work using x rays. This has opened up new areas of research as the experimenters need only to bring a sample in a diamond anvil cell and can leave with the x-ray data mostly analyzed. Although most of the work has been with energy dispersive x-ray diffraction, some Laue work has been performed as well. Performing Laue diffraction studies with a station equipped for energy dispersive diffraction has the advantage that, with the addition of a rotation stage, the energy of a Laue diffracted spot can be analyzed.

Brister, K. (Cornell High Energy Synchrotron Source, Wilson Lab, Cornell University, Ithaca New York 14853 (United States))

1992-01-01

368

High-pressure structural study of muscovite  

Microsoft Academic Search

The compressibility and structural variations of two 2M1 muscovites having compositions (Na0.07K0.90 Ba0.01?0.02)(Al1.84Ti0.04Fe0.07Mg0.04)(Si3.02Al0.98) O10 (OH)2 (7 mole % paragonite) and (Na0.37K0.60?0.03)(Al1.84Ti0.02 Fe0.10Mg0.06)(Si3.03Al0.97) O10(OH)2 (37 mole % paragonite) were determined at pressures between 1 bar and 35 kbar, by single-crystal X-ray diffraction using a Merrill-Bassett diamond anvil cell.

Paola Comodi; Pier Francesco Zanazzi

1995-01-01

369

Chemistry of nitromethane at very high pressure  

SciTech Connect

Decomposition of nitromethane is reported over the range of 115- 180/degree/C and 0.6-8.5 GPa. About 5 /mu/g of nitromethane is compressed with a diamond-anvil cell, heated to the point that reaction occurs, and held typically 10-20 minutes at the reaction temperature. The cell is cooled and the volatile contents of the cell are frozen as a thin layer in vacuo and an infrared absorption spectrum is recorded. The three volatile products observed are N/sub 2/O, CO/sub 2/, and water, with N/sub 2/O production peaking at 1.5 GPa, 135/degree/C, and 35% of NME; CO/sub 2/ production peaking at 3.5 GPa, 135/degree/C, and 65% of NME, and water yields at 20-50% of NME at the highest pressure measured, 8.5 GPa and 175/degree/C. Water yields were difficult to quantify due to background contamination. Results indicate three different reactions for solid NME dependent primarily on the pressure of the reaction, and that fluid NME does not decompose at 0.6 GPa and 175/degree/C, although the solid decomposes readily at 1.1 GPa and 120/degree/C. The authors conclude that, while various decomposition mechanisms are possible, the initial step CH/sub 3/NO/sub 2/ /yields/ /center dot/CH/sub 3/ + /center dot/NO/sub 2/ is very unlikely. 14 refs., 5 figs.

Agnew, S.F.; Swanson, B.I.; Kenney, J.; Kenney, I.

1989-01-01

370

High pressure synthesis of single crystals of ?-boron  

Microsoft Academic Search

A method of synthesis of single crystals of alfa-boron (?-B) is presented. ?-Boron has been crystallized from a boronplatinum melt at high pressures (611GPa) and high temperatures (12001600C). The method is based on the high-pressure large volume (multi-anvil) press technique. An average size of the as-grown isometric crystals is 6080?m in maximum dimension. A refinement of an accurate crystal structure

Gleb Parakhonskiy; Natalia Dubrovinskaia; Leonid Dubrovinsky; Swastik Mondal; Sander van Smaalen

2011-01-01

371

High pressure synthesis gas conversion. Task 2: Determination of maximum operating pressure  

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. ljungdahlil. 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. The purpose of this report was to present the results of high pressure experiments aimed at determining the maximum operating pressure of C. ljungdahlil. Preliminary experiments carried out in approaching the pressure maximum are presented, as well as experimental results at the maximum pressure of 150 psig. This latter pressure was the maximum operating pressure when using the defined medium of Phillips et al., and is expected to change if alternative media are employed.

Not Available

1993-05-01

372

46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.  

Code of Federal Regulations, 2012 CFR

...having a throw of at least 12 meters (39.4 feet) from the nozzle, and capable of being connected to National Standard Fire...diameter lined commercial fire hose and be fitted with a nozzle made of corrosion resistant material capable of providing...

2012-10-01

373

46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.  

Code of Federal Regulations, 2011 CFR

...quarters, storerooms, working spaces and weather decks accessible to crew while...device must be provided. Hose racks on weather decks must be located to afford protection...length (feet) Living space 1 4 Weather deck 4 10 or 12 Machinery...

2011-10-01

374

46 CFR 34.10-10 - Fire station hydrants, hose and nozzles-T/ALL.  

Code of Federal Regulations, 2012 CFR

...quarters, storerooms, working spaces and weather decks accessible to crew while...device must be provided. Hose racks on weather decks must be located to afford protection...length (feet) Living space 1 4 Weather deck 4 10 or 12 Machinery...

2012-10-01

375

33 CFR 149.550 - What are the requirements for lights on a floating hose string?  

Code of Federal Regulations, 2010 CFR

...trestles must display the following lights at night and during periods of restricted...visibility: (a) One row of yellow lights that must be: (1) Flashing 50...string's length and course. (b) Two red lights at each end of the hose...

2010-07-01

376

33 CFR 149.550 - What are the requirements for lights on a floating hose string?  

Code of Federal Regulations, 2010 CFR

...trestles must display the following lights at night and during periods of restricted...visibility: (a) One row of yellow lights that must be: (1) Flashing 50...string's length and course. (b) Two red lights at each end of the hose...

2009-07-01

377

Phase transition dynamics in high-pressure VO2  

NASA Astrophysics Data System (ADS)

Vanadium dioxide VO2 is a prototypical strongly correlated material which presents an insulator-metal transition at both ambient and high pressures. We use synchrotron X-ray diffraction combined with a diamond anvil cell to determine the pressure-temperature phase diagram of VO2. We also use ultrafast coherent phonon spectroscopy to study its phase transition dynamics at high pressure. We find that, in contrast with ambient pressure experiments where strong photoexcitation promptly changes the lattice potential symmetry, at pressures as high as P=11 GPa the coherent phonons are still observed upon the photo-driven phase transition to the metallic state. The mechanism of the phase transition dynamics will be discussed.

Hsieh, Wen-Pin; Trigo, Mariano; Zhao, Zhao; Reis, David A.; Mao, Wendy L.

2013-03-01

378

Studies of Alkali Sorption Kinetics for Pressurized Fluidized Bed Combustion by High Pressure Mass Spectrometry  

SciTech Connect

This work describes the first approach to use High Pressure Mass Spectrometry (HPMS) for the quantification and analysis of alkali species in a gas stream downstream a sorbent bed of different tested alumosilicates.

Wolf, K.J.; Willenborg, W.; Fricke, C.; Prikhodovsky, A.; Hilpert, K.; Singheiser, L.

2002-09-20

379

Melting temperature of MgO at high pressures  

NASA Astrophysics Data System (ADS)

In this study, the melting temperature of MgO is determined at high pressures using the laser-heated diamond-anvil cell. Single-crystal MgO is coated with a variety of refractory metals as a laser absorber and laser heated from both sides. The melting is identified by recrystallization of the single crystal upon quenching, which is shown through the appearance of powder x-ray diffraction. Determining the melting temperature of MgO has profound implications for mantle rheology and melting relations at high pressure, furthermore, providing a crucial test for theoretical models of high-pressure melting.

Du, Z.; Lee, K. K.

2010-12-01

380

High Pressure Research at the National Synchrotron Light Source  

SciTech Connect

The National Synchrotron Light Source at Brookhaven National Laboratory has been home to a successful high-pressure program for over 20 years. The first dedicated high-pressure diffraction endstation, X17C, was etablished at NSLS in 1990. A large number of new techniques have been developed at this beamline, including double-sided laser heating, single crystal diffraction above 60 GPa, x-ray diffraction measurements in a resistive heated diamond anvil cell (DAC) at 1300 K and 1 megabar, the first high-pressure and low-temperature experiment, and radial diffraction in a DAC.

Ehm, L.; Vaughan, M; Duffy, T; Liu, Z; Wang, L; Weidner, D; Chen, Z; Ghose, S; Zhong, Z

2010-01-01

381

Kinetic study on pressure leaching of high iron sphalerite concentrate  

Microsoft Academic Search

The kinetics of pressure leaching high iron sphalerite concentrate was studied. The effects of agitation rate, temperature, oxygen partial pressure, initial acid concentration, particle size, iron content in the concentrate and concentration of Fe2- added into the solution on the leaching rate of zinc were examined. The experiment results indicate that if the agitation rate is greater than 600 r\\/min,

Ke-qiang XIE; Xian-wan YANG; Ji-kun WANG; Jiang-feng YAN; Qing-feng SHEN

2007-01-01

382

High Pressure Vulcanization Crosslinking of Diene Rubbers Without Vulcanization Agents  

Microsoft Academic Search

High pressure vulcanization (HPV) is defined in this thesis as crosslinking of rubber materials at elevated pressure and temperature, without the use of any vulcanization agents. This is a totally new vulcanization technique, not used in the industry today. The HPV technique, however, has an interesting potential since no hazardous chemicals need to be handled, the vulcanization fumes contain no

Martin Bellander

383

Soot-formation rate in premixed combustion at high pressures  

NASA Astrophysics Data System (ADS)

The soot formation rate at high pressures has been studied with a premixed propane-oxygen-inert gas combustion in a specially designed disk-type constant-volume combustion chamber. Premixtures are simultaneously ignited by eight spark plugs located on the circumference of chamber at 45 degree intervals in order to observe the soot formation rate under high pressure. The eight flames being converged compress the end gases to a high pressure. The laser schlieren and direct flame photographs for observation field with 10 mm in diameter are taken to investigate the effects of curvature for the optical path in the flame front and gas flow in the measured position on soot formation rate. The soot formation rate in the chamber center during the final stage of combustion at the highest pressure is measured by the in situ laser extinction technique at the following conditions; 0.4 to 5.0 MPa for pressure, 1600 to 1900 K for temperature and 2.0 to 2.2 for equivalence ratio. The burnt gas temperature is measured by the two-color pyrometry method. The pressure and temperature during soot formation are changed by varying the initial charge pressure and the volume fraction of inert gas in the premixture, respectively. In the present study, it is found that the soot formation rate can be expressed by an empirical pseudo- first-order kinetics for surface growth even at high pressures, and that the rate constant of soot formation is only dependent of the temperature.

Bae, Myung-Whan; Kamimoto, Takeyuki

1995-05-01

384

High Sensitivity Pressure Sensors Utilizing Advanced Polymer Coatings.  

National Technical Information Service (NTIS)

We report a high sensitivity pressure sensor utilizing optical fibers coated with novel polymers. Pressure sensitivity of 5 pico-m/psi for the fiber Bragg grating based and 155 dB radian/micro-Pa for interferometric sensor is reported.

A. Dandridge A. B. Tveten C. C. Chang G. A. Johnson S. T. Vohra

1999-01-01

385

Effects of cavitation on high-pressure atomization  

Microsoft Academic Search

Although disintegration and breakup of a liquid jet emerging from a nozzle has been studied for a long time, the effects of nozzle internal flow and specifically cavitation on the breakup of liquid jets have not been well understood. In the orifice of liquid injectors at high pressure, cavitation occurs behind the sharp corners, where a strong pressure drop is

Sadegh Dabiri Satari

2009-01-01

386

Performance of pulsed combustion jet at high pressures and temperatures  

Microsoft Academic Search

Ignition and combustion by Pulsed Combustion Jet (PCJ) at high pressures and temperatures were investigated using a compact rapid compression machine. The compression and stop motion of a compression piston in the rapid compression machine is controlled by the cam shape, and the cam is operated by a driving piston and compressed air. The combustion process was monitored by pressure

Eiichi Murase; Shinsuke Ono; Kunihiko Hanada; Jyong Ho Yun; Antoni K. Oppenheim

1996-01-01

387

Diamond Anvil Cells: A New Tool for High Pressure Studies.  

National Technical Information Service (NTIS)

Literally hundreds of papers have appeared in the last few years covering a myriad of uses of the diamond anvil cells. The crescendo shows no signs of abating. Static pressures as high as 1.8 megabar have been reported. Still higher pressures appear possi...

R. D. Taylor

1985-01-01

388

Ultra-Large Intensifier Pump for High Pressure Well Stimulation  

Microsoft Academic Search

Increased depths of drilling operations have produced the need for pumping equipment that will perform reliably during long duration, extreme pressure stimulation treatments. Treating pressures above 15,000 psi and pumping of hot concentrated acids have rapidly become more common practices in stimulation work. The first generation of high horsepower intensifier pumps was introduced for use on an experimental drilling project

Harold Labyer; Clinton Cole; Terry Bomgardner; Bill Maddox; Dale Riley

1973-01-01

389

Numerical Study on Liquid-Film Cooling at High Pressure  

Microsoft Academic Search

Physical and mathematical models for film cooling at high pressure are established, in which the solution of gas in liquid, real gas property, and its variable thermophysical properties are taken into account. Gas-liquid equilibrium at the interface is presumed based on which interface condition and thermodynamics properties of fluid at supercritical pressure are investigated. Model study has been performed for

H. W. Zhang; Y. L. He; W. Q. Tao

2010-01-01

390

High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant  

Microsoft Academic Search

High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's

E A Glascoe; N Tan

2010-01-01

391

CRYSTAL STRUCTURES OF TITANIUM, ZIRCONIUM, AND HAFNIUM AT HIGH PRESSURES  

Microsoft Academic Search

At high pressures, as determined by x-ray analysis, titanium and ; zirconium metal have a distorted, bodycentered-cubic structure. This phase ; persists on pressure release. The normal hexagonal close-packed structures are ; recovered when the metals are heated. An electronic shift must occur in the ; transition. Hafnium metal showed no such transition. (auth);

J. C. Jamieson

1963-01-01

392

Automated testing of the Space Shuttle high pressure turbopumps  

Microsoft Academic Search

Development testing of alternate turbopumps for the Space Shuttle Main Engine (SSME) is conducted in a test facility simulating a full engine environment. This test facility utilizes a real time, closed loop control system to provide high pressure hydrogen and liquid oxygen to the turbopump's preburner. The system controls the pressurization and flow of propellants and maintains various pump inlet

Craig W. Tiroff

1992-01-01

393

Acoustic wave propagation in high-pressure system.  

PubMed

Recently, substantial attention is paid to the development of methods of generation of pulsations in high-pressure systems to produce pulsating high-speed water jets. The reason is that the introduction of pulsations into the water jets enables to increase their cutting efficiency due to the fact that the impact pressure (so-called water-hammer pressure) generated by an impact of slug of water on the target material is considerably higher than the stagnation pressure generated by corresponding continuous jet. Special method of pulsating jet generation was developed and tested extensively under the laboratory conditions at the Institute of Geonics in Ostrava. The method is based on the action of acoustic transducer on the pressure liquid and transmission of generated acoustic waves via pressure system to the nozzle. The purpose of the paper is to present results obtained during the research oriented at the determination of acoustic wave propagation in high-pressure system. The final objective of the research is to solve the problem of transmission of acoustic waves through high-pressure water to generate pulsating jet effectively even at larger distances from the acoustic source. In order to be able to simulate numerically acoustic wave propagation in the system, it is necessary among others to determine dependence of the sound speed and second kinematical viscosity on operating pressure. Method of determination of the second kinematical viscosity and speed of sound in liquid using modal analysis of response of the tube filled with liquid to the impact was developed. The response was measured by pressure sensors placed at both ends of the tube. Results obtained and presented in the paper indicate good agreement between experimental data and values of speed of sound calculated from so-called "UNESCO equation". They also show that the value of the second kinematical viscosity of water depends on the pressure. PMID:16797665

Foldyna, Josef; Sitek, Libor; Habn, Vladimr

2006-06-08

394

Pasteurization of food by hydrostatic high pressure: chemical aspects.  

PubMed

Food pasteurized by hydrostatic high pressure have already been marketed in Japan. There is great interest in this method also in Europe and USA. Temperature and pressure are the essential parameters influencing the state of substances including foods. While the influence of temperature on food has been extensively investigated, effects of pressure, also in combination with temperature, are attracting increasing scientific attention now. Processes and reactions in food governed by Le Chatelier's principle are of special interest; they include chemical reactions of both low- and macromolecular compounds. Theoretical fundamentals and examples of pressure affected reactions are presented. PMID:7732731

Tauscher, B

1995-01-01

395

High pressure sample cell for total internal reflection fluorescence spectroscopy at pressures up to 2500 bar  

NASA Astrophysics Data System (ADS)

Total internal reflection fluorescence (TIRF) spectroscopy is a surface sensitive technique that is widely used to characterize the structure and dynamics of molecules at planar liquid-solid interfaces. In particular, biomolecular systems, such as protein adsorbates and lipid membranes can easily be studied by TIRF spectroscopy. Applying pressure to molecular systems offers access to all kinds of volume changes occurring during assembly of molecules, phase transitions, and chemical reactions. So far, most of these volume changes have been characterized in bulk solution, only. Here, we describe the design and performance of a high pressure sample cell that allows for TIRF spectroscopy under high pressures up to 2500 bar (2.5 108 Pa), in order to expand the understanding of volume effects from the bulk phase to liquid-solid interfaces. The new sample cell is based on a cylindrical body made of Nimonic 90 alloy and incorporates a pressure transmitting sample cuvette. This cuvette is composed of a fused silica prism and a flexible rubber gasket. It contains the sample solution and ensures a complete separation of the sample from the liquid pressure medium. The sample solution is in contact with the inner wall of the prism forming the interface under study, where fluorescent molecules are immobilized. In this way, the new high pressure TIRF sample cell is very useful for studying any biomolecular layer that can be deposited at a planar water-silica interface. As examples, high pressure TIRF data of adsorbed lysozyme and two phospholipid membranes are presented.

Koo, Juny; Czeslik, Claus

2012-08-01

396

HIGH PRESSURE COAL COMBUSTION KINETICS PROJECT  

SciTech Connect

The HPCCK project was initiated with a kickoff meeting held on June 12, 2001 in Morgantown, WV, which was attended by all project participants. SRI's existing g-RCFR reactor was reconfigured to a SRT-RCFR geometry (Task 1.1). This new design is suitable for performing the NBFZ experiments of Task 1.2. It was decided that the SRT-RCFR apparatus could be modified and used for the HPBO experiments. The purchase, assembly, and testing of required instrumentation and hardware is nearly complete (Task 1.1 and 1.2). Initial samples of PBR coal have been shipped from FWC to SRI (Task 1.1). The ECT device for coal flow measurements used at FWC will not be used in the SRI apparatus and a screw type feeder has been suggested instead (Task 5.1). NEA has completed a upgrade of an existing Fluent simulator for SRI's RCFR to a version that is suitable for interpreting results from tests in the NBFZ configuration (Task 1.3) this upgrade includes finite-rate submodels for devolatilization, secondary volatiles pyrolysis, volatiles combustion, and char oxidation. Plans for an enhanced version of CBK have been discussed and development of this enhanced version has begun (Task 2.5). A developmental framework for implementing pressure and oxygen effects on ash formation in an ash formation model (Task 3.3) has begun.

Chris Guenther; Bill Rogers

2001-09-15

397

Ultrasonic Investigation of Cerium under High Pressure  

NASA Astrophysics Data System (ADS)

The contribution of the lattice to the famous volume collapse transition in cerium is re-evaluated using a unique combination of several techniques available at sector 16 BMB / HPCAT. These eliminate any indirect /iterative procedures employed previously: Energy dispersive X-ray scattering provides the pressure of the sample (as well as quality control about the state of the sample), X-ray radiography delivers a shadow image allowing a precise length measurement and the ultrasound pulse overlap method gives the transit time of the longitudinal and transverse pulses. Our preliminary analysis indicates a larger contribution by the lattice as previously thought. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344. The X-ray studies were performed at HPCAT (Sector 16), APS/ANL. HPCAT is supported by CIW, CDAC, UNLV and LLNL through funding from DOE-NNSA, DOE-BES and NSF. APS is supported by DOE-BES, under Contract No. DE-AC02-06CH11357.

Lipp, Magnus; Jenei, Zsolt; Cynn, Hyunchae; Aracne-Ruddle, Chantel; Evans, William; Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong

2013-03-01

398

Water radiolysis at high temperatures and pressures.  

National Technical Information Service (NTIS)

The radiolysis of water at high temperatures is very important for nuclear technology, especially in the context of gas generation and corrosion of system surfaces in the coolant circuits of nuclear power reactors. The present report summarizes the curren...

G. R. Dey K. Kishore P. N. Moorthy V. Ramshesh S. B. Srivastava

1990-01-01

399

Epitaxial diamond encapsulation of metal microprobes for high pressure experiments  

SciTech Connect

Diamond anvils with diamond encapsulated thin-film microcircuits have been fabricated for ultrahigh pressure electrical conductivity experiments. The diamond films were homoepitaxially deposited onto the diamond anvil substrates with microwave plasma chemical vapor deposition using a 2% methane in hydrogen gas mixture and a diamond substrate temperature of 1300{sup o}C. The diamond embedded thin-film microprobes remain functional to megabar pressures. We have applied this technology to the study of the pressure-induced metallization of KI under pressures up to 1.8 Mbar. This technology has the potential of greatly advancing the pressure range of a number of existing high-pressure diagnostic techniques, and for expanding the capabilities of diamond anvil cells into new directions.

Weir, Samuel T.; Akella, Jagannadham; Aracne-Ruddle, Chantel; Vohra, Yogesh K.; Catledge, Shane A.

2000-11-20

400

Unsteady pressure measurements in a high-speed centrifugal compressor  

NASA Astrophysics Data System (ADS)

This paper presents the unsteady data acquisition system used to measure the pressure field in high speed compressors. Details and electronic sketches are given for the conditioners developed in-house that have been used to amplify and to filter the pressure signal with the aim of acquiring data up to 150 kHz. A discussion of the experimental results carried out in a centrifugal compressor is proposed. Through different processing of the pressure signals and a comparison with URANS simulations, the excitation of the pressure transducers by the pressure waves generated by shock waves that occur between the impeller and the diffuser is highlighted. The levels of pressure fluctuations measured when entering into surge are also presented and reveal very repetitive behaviour of the flow instabilities.

Bulot, N.; Ottavy, Xavier; Trebinjac, I.

2010-02-01

401

Energy Systems High Pressure Test Laboratory (Fact Sheet)  

SciTech Connect

This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Energy Systems High Pressure Test Laboratory at the Energy Systems Integration Facility. The purpose of the Energy Systems High Pressure Test Laboratory at NREL's Energy Systems Integration Facility (ESIF) is to provide space where high pressure hydrogen components can be safely tested. High pressure hydrogen storage is an integral part of energy storage technology for use in fuel cell and in other distributed energy scenarios designed to effectively utilize the variability inherent with renewable energy sources. The high pressure storage laboratory is co-located with energy storage activities such as ultra-capacitors, super conducting magnetic flywheel and mechanical energy storage systems laboratories for an integrated approach to system development and demonstration. Hazards associated with hydrogen storage at pressures up to 10,000 psi include oxygen displacement, combustion, explosion, and pressurization of room air due to fast release and physical hazards associated with burst failure modes. A critical understanding of component failure modes is essential in developing reliable, robust designs that will minimize failure risk beyond the end of service life. Development of test protocol for accelerated life testing to accurately scale to real world operating conditions is essential for developing regulations, codes and standards required for safe operation. NREL works closely with industry partners in providing support of advanced hydrogen technologies. Innovative approaches to product design will accelerate commercialization into new markets. NREL works with all phases of the product design life cycle from early prototype development to final certification testing. High pressure tests are performed on hydrogen components, primarily for the validation of developing new codes and standards for high pressure hydrogen applications. The following types of tests can be performed: Performance, Component and system level efficiency, Strength of materials and hydrogen compatibility, Safety demonstration, Model validation, and Life cycle reliability.

Not Available

2011-10-01

402

Elasticity of single-crystal methane hydrate at high pressure  

NASA Astrophysics Data System (ADS)

By using in situ high-pressure Brillouin spectroscopy in a diamond-anvil cell, we have determined the pressure dependence of acoustic velocities, adiabatic elastic moduli, bulk modulus, elastic anisotropy, and Cauchy violation of single-crystal methane hydrate (MH) at pressures up to 0.6 GPa and 296 K. Acoustic velocities show nearly isotropic behaviors with respect to the crystal orientation, and the slight TA-mode softening with pressure implies that the structure of MH is becoming less stable against the shear component under high pressures. Elastic moduli and bulk modulus indicate that MH is slightly more compressible than ice Ih. These results would help to investigate their mechanical and thermodynamical stabilities, and provide important constraints on the icy moons of the outer solar system.

Shimizu, Hiroyasu; Kumazaki, Tatsuya; Kume, Tetsuji; Sasaki, Shigeo

2002-06-01

403

Structural studies of gadolinium at high pressure and temperature  

NASA Astrophysics Data System (ADS)

High pressure and high temperature angle-dispersive x-ray diffraction measurements on gadolinium were performed up to 93GPa and nearly 2500K using argon as pressure medium. Our room temperature measurements confirmed the transition pressures reported in a previous study carried out using nitrogen as pressure medium, solving former discrepancies found in the literature. A new phase was observed above 1200K between 39GPa and 52GPa . Additionally, the structure of the previously observed dfcc and post-dfcc phases was determined, being the space group symmetry of the post-dfcc phase (C2/m) , different from what was predicted before. Finally, the room temperature equation of state was determined for Gd and its pressure-temperature phase diagram redefined.

Errandonea, D.; Boehler, R.; Schwager, B.; Mezouar, M.

2007-01-01

404

The United Kingdom Environmental Change Network: Anticyclones (High Pressure)  

NSDL National Science Digital Library

This resource briefly discusses anticyclones, or high pressure systems and how they form. This includes what kinds of weather occur when anticyclones develop, as well as the similarities and differences between summer and winter anticyclones.

405

High Pressure Burning Rates of Multi-Base Propellants.  

National Technical Information Service (NTIS)

Burning rates of multi-base, nitrocellulose propellants at high pressure were measured using recently developed techniques. Since the intended application is in-process control, as-manufactured multi-perforated grains (finished as well as interrupted-proc...

C. R. Felsheim L. H. Caveny L. M. Pokrocos

1977-01-01

406

Method for Working Dissimilar Materials with High or Ultrahigh Pressures.  

National Technical Information Service (NTIS)

The certificate introduces a method for working dissimilar materials under high or ultrahigh pressure. To change the surface characteristics or structure and properties of materials during strain hardening, strengthening, aging, cleaning or similar proces...

L. A. Yutkin L. I. Goltsova

1969-01-01

407

Fuel/Oxidizer-Rich High-Pressure Preburners.  

National Technical Information Service (NTIS)

The analyses, designs, fabrication, and cold-flow acceptance testing of LOX/RP-1 preburner components required for a high-pressure staged-combustion rocket engine are discussed. Separate designs of injectors, combustion chambers, turbine simulators, and h...

L. Schoenman

1981-01-01

408

Development of a High Response Differential Pressure Transducer.  

National Technical Information Service (NTIS)

The first 4 months progress toward development of a high response differential pressure transducer which will mate to an existing hydraulic actuator used as a hydraulic load cell at the AFRPL, Edwards, California, is reviewed. A frequency response test me...

J. Delmonte

1967-01-01

409

High Pressure Cosmochemistry Applied to Major Planetary Interiors: Experimental Studies.  

National Technical Information Service (NTIS)

The measurement of equilibria in binary fluid-solid systems in diamond anvil cells, represents a major advance of the art of high-pressure experimentation. Vibrational spectroscopy, direct visual observations, and X-ray diffraction crystallography of mate...

M. F. Nicol M. Johnson S. Boone

1985-01-01

410

High pressure working mode of hollow cathode arc discharges  

Microsoft Academic Search

The behavior of high pressure cathotrons is discussed. Methods of preheating either the gas or the cathode itself are detailed together with various geometries for the hollow cathode. Three special configurations were tested, and the results are analyzed.

H. Minoo; C. Popovici

1985-01-01

411

High pressure working mode of hollow cathode arc discharges  

NASA Astrophysics Data System (ADS)

The behavior of high pressure cathotrons is discussed. Methods of preheating either the gas or the cathode itself are detailed together with various geometries for the hollow cathode. Three special configurations were tested, and the results are analyzed.

Minoo, H.; Popovici, C.

1985-07-01

412

Research of a High Precision Sodium Pressure Transducer.  

National Technical Information Service (NTIS)

A high precision sodium pressure transducer using the dynamometric annulus as the Sensor is developed. The construction of the transducer, the calculation of the dynamometric annulus, the fixation of the strain gauge, the measurement circuits and the grad...

D. Chen

1986-01-01

413

Numerical Investigations of High Pressure Acoustic Waves in Resonators.  

National Technical Information Service (NTIS)

This presentation presents work on numerical investigations of nonlinear acoustic phenomena in resonators that can generate high-pressure waves using acoustic forcing of the flow. Time-accurate simulations of the flow in a closed cone resonator were perfo...

M. Athavale M. Pindera C. C. Daniels B. M. Steinetz

2004-01-01

414

46 CFR 197.312 - Breathing supply hoses.  

Code of Federal Regulations, 2011 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS...pressure; (3) Have connectors that (i) Are made of corrosion-resistant material; (ii) Are resistant to...

2011-10-01

415

Research on high pressure cryogenic combustion  

Microsoft Academic Search

Due to their high specific impulse, Oxygen\\/Hydrogen systems are often used to increase launcher performance and will probably continue to be the preferred option for the next decades. In order to get insight into complex processes involved in the combustion of such propellants, research efforts have been conducted in both France and Germany including theoretical and experimental activities. This article

O. J. Haidn; M. Habiballah

2003-01-01

416

High Pressure Equation of State Studies Using Ethanol-Methanol And Argon As Pressure Medium  

NASA Astrophysics Data System (ADS)

Experimental high pressure studies are extremely important to planetary science, material science and to the development of condensed matter theory. With experimental difficulties in creating the extreme pressure temperature conditions appropriate to planetary interiors, the approach used is to obtain the thermodynamic data on materials of interest by extrapolating the condensed matter theory which has been benchmarked with the outcome of high pressure experiments to the available high pressures. However the high pressure data used to match the theory heavily depends on the use of pressure media; like ethanol-methanol, silicon oil, argon and helium. Unfortunately still there exist controversy in the literature even with the use of helium as pressure medium as illustrated by the unsettled debate on Zn and Os among different groups. We have measured the equation of state of intermetallic compound AuIn2 and Cd0.8Hg0.2 alloy using ethanol-methanol and argon to the pressure of 20 GPa to confirm the appearance of anomalies in the data due to occurrence of subtle electronic phase transitions. However these anomalies can also be attributed to oriented lattice strains and local non-hydrostatic conditions. We have tried to remove these at room temperature by stabilizing the sample in argon medium in the diamond anvil cell with proper annealing as indicated by the uniformity of the pressure across the sample by ruby fluorescence measurements. We will present the data revealing the electronic transition in AuIn2 at 2.7 GPa and in Cd0.8Hg0.2 near 9 and 18 GPa.

Godwal, B. K.; Speziale, S.; Clark, S.; Yan, J.; Jeanloz, R.

2008-12-01

417

High hydrostatic pressure technology in dairy processing: a review  

Microsoft Academic Search

Consumers demand high quality foods, which are fresh, tasty and nutritious; this has created considerable interest in the\\u000a development of new food processing techniques. Presently, non-thermal techniques, including high hydrostatic pressure (HHP),\\u000a are regarded with special interest by the food industry. Pressure ranges between 100 and 1200MPa have been considered as\\u000a effective to inactivate microorganisms including food-borne pathogens. HHP also

Rekha Chawla; Girdhari Ramdass Patil; Ashish Kumar Singh

2011-01-01

418

A high-pressure MWPC detector for crystallography  

NASA Astrophysics Data System (ADS)

The application of the Multi-Wire Proportional Counter (MWPC) as a potential detector for protein crystallography and other wide-angle diffraction experiments is presented. Electrostatic problems found with our large area MWPC when operated at high pressure are discussed. We suggest that a solution to these problems is to use a glass micro-strip detector in place of the wire frames. The characteristics of a high-pressure Micro-Strip Gas Chamber (MSGC) tested in the laboratory are presented.

Ortuo-Prados, F.; Bazzano, A.; Berry, A.; Budtz-Jrgensen, C.; Hall, C.; Helsby, W.; Lewis, R.; Parker, B.; Ubertini, P.

1999-01-01

419

High pressure phase transformations in MgF2 (rutile)  

Microsoft Academic Search

Employing a diamond-anvil pressure cell and a YAG laser as a heating source, phase relationships in polycrystalline MgF2 (rutile) were investigated to ~330 kbar at both room temperature (~23C), and high temperature (~1300C). In situ high pressure X-ray diffraction data show that MgF2 (I) of rutile structure transforms into MgF2(II) of a cubic structure at ~300 kbar at room temperature,

Li-chung Ming; Murli H. Manghnana

1979-01-01

420

High-pressure injection injury of the finger  

PubMed Central

The high-pressure injection injuries are unusual injuries and the extent of tissue damage is often under estimated. They represent potentially disabling forms of trauma and have disastrous effects on tissues if not treated promptly. We present a case of high pressure injection injury to the finger from lubricant oil. The patient presented late with necrosis of volar tissue of left index finger. The patient was aggressively managed in stages, with delayed flap cover, with satisfactory functional and aesthetic outcome.

Saraf, Sanjay

2012-01-01

421

Reducing pressure on natural forests through high-yield forestry  

Microsoft Academic Search

Gladstone, W.T. and Ledig, F.T., 1990. Reducing pressure on natural forests through high-yield for- estry. For. Ecol. Manage., 35: 69-78. High-yield forestry can make a valuable contribution to the conservation and sustained use of forest ecosystems. Despite the pressing reasons for conserving forest resources, population growth creates pressures for exploiting them. Unless needs for forest products, export credits, and local

W. T. Gladstone; F THOMASLEDIG

1990-01-01

422

Performance evaluation of LE7 high pressure pumps  

Microsoft Academic Search

As a part of the development of the large high pressure liquid oxygen\\/liquid hydrogen (LOX\\/H2) engine (LE-7) of the large launch vehicle H-II, to evaluate the performance of large flow rate high delivery pressure cryogenic pumps, an efficiency and head similar to a polytropic efficiency and head for gas compressors were proposed as the evaluation index of pumps for compressible

Makoto Yoshida; Kenjiro Kamijo; Ryuji Nagao

1989-01-01

423

High-Pressure Minerals in RC106: Formation at Modest Shock Pressures and very High Temperatures  

Microsoft Academic Search

The controversy concerning the pressures required to produce shock effects in meteorites began with the interpretation that shock veins in chondrites crystallize at pressures about 25 GPa (Chen et al. 1996) rather than the 50 -90 GPa inferred from ``calibration'' of shock effects from shock-recovery experiments (Stffler et al. 1991). The 25 GPa estimate was based on phase equilibrium data

T. G. Sharp; R. Trickey; P. S. de Carli; Z. Xie

2009-01-01

424

High-pressure test loop design and application  

SciTech Connect

A high-pressure test loop (HPTL) has been constructed for the purpose of performing a number of chemistry experiments at simulated HTGR conditions of temperature, pressure, flow, and impurity content. The HPTL can be used to develop, modify, and verify computer codes for a variety of chemical processes involving gas phase transport in the reactor. Processes such as graphite oxidation, fission product transport, fuel reactions, purification systems, and dust entrainment can be studied at high pressure, which would largely eliminate difficulties in correlating existing laboratory data and reactor conditions.

Burnette, R.D.; Graves, J.N.; Blair, P.G.; Baldwin, N.L.

1980-07-01

425

Very high pressure Moessbauer spectroscopy using diamond anvil cells  

SciTech Connect

The technique of generating very high pressure by means of Diamond Anvil Cells (DAC) for Mossbauer Effect applications is outlined. A comprehensive description is presented of the principles of DAC, modification for the use in M/umlt o/ssbauer Spectroscopy (MS), the Merrill--Bassett and Bassett cells, of pressure measurements, of gasketing and collimation, and of hydrostatic media. Examples of /sup 151/Eu, /sup 119/Sn and /sup 129/I are given showing the feasibility of DAC applications in MS. Other isotopes with potential use for high pressure MS using DAC are suggested. 27 refs., 9 figs.

Pasternak, M.P.; Taylor, R.D.

1988-01-01

426

Effect of high pressure on physicochemical properties of meat.  

PubMed

The application of high pressure offers some interesting opportunities in the processing of muscle-based food products. It is well known that high-pressure processing can prolong the shelf life of meat products in addition to chilling but the pressure-labile nature of protein systems limits the commercial range of applications. High pressure can affect the texture and gel-forming properties of myofibrillar proteins and, hence, has been suggested as a physical and additive-free alternative to tenderize and soften or restructure meat and fish products. However, the rate and magnitude at which pressure and temperature effects take place in muscles are variable and depend on a number of circumstances and conditions that are still not precisely known. This review provides an overview of the current knowledge of the effects of high pressure on muscle tissue over a range of temperatures as it relates to meat texture, microstructure, color, enzymes, lipid oxidation, and pressure-induced gelation of myofibrillar proteins. PMID:23638936

Buckow, Roman; Sikes, Anita; Tume, Ron

2013-01-01

427

Hydrogen Storage in Mesoporous Materials under High Pressure  

NASA Astrophysics Data System (ADS)

To date, the materials considered best candidates for hydrogen storage fuel cells include activated carbon and metal organic frameworks. Both very high surface area activated carbon and MOF-5 have been shown to adsorb around 4.5 wt % of hydrogen gas at 78 K. We have investigated the fundamental structural response of these materials to high pressure, as well as their behavior at high pressure when packed with dense hydrogen. Further investigation of these materials at low temperatures while still at elevated pressures may in fact provide a route for recovery of these hydrogen-packed materials to near ambient conditions. Covalent organic frameworks offer the potential for even better hydrogen storage capacity. These materials have significantly lower densities than the MOF materials and offer a significantly larger number of adsorption sites. Diamond anvil cells are uniquely suited for the study of these materials, allowing in situ measurements at high pressure as well as at low temperatures. Using X-ray diffraction and Raman spectroscopy and Infrared Spectroscopy we probe the behavior of the hydrogen confined in these porous materials at high pressure by tracking changes in the in situ high pressure x-ray diffraction patterns and shifts in the hydrogen vibron peaks.

Weinberger, Michelle; Somayazulu, Maddury; Hemley, Russell

2008-03-01

428

Melt Viscosity at High Pressures: A complementary strategy.  

NASA Astrophysics Data System (ADS)

The pressure dependence of the viscosity of silicate melts continues to be one of the most important outstanding questions in the area of transport and state in the deep earth. The experimental challenges to viscosity determination at extreme pressures are multiple, primarily involving the feasibility of achieving large isothermal domains of liquid silicate where the significant strain involved in most viscometry methods can be adequately observed. Driven by the scientific questions regarding the nature and efficiency of processes at the estimated extreme thermal regime of the deep earth, the experimental progress has been dominated by the superliquidus temperature range of experimental viscosity determinations. The work is certainly delivering increasingly adequate coverage of the very high P high T range of melt viscosity - but it is not and cannot provide a comprehensive picture of melt rheology that is sufficient for the purpose of developing generalisable viscosity-composition relationships. This is because the very strongly non-Arrhenian temperature-dependence of viscosity observed universally for molten silicates at low pressure and anicipated at high pressure as well. Thus I propose thta the experimental task of describing melt viscosity at very high pressures. I propose therefore that the experimental strategy to obtain melt viscosity at very high pressures be complemented by lower temperature techniques. In this manner the complete viscosity-temperature relationships of molten silicates at very high pressures may become accessible. This strategy has been the key to the development of recent high-quailty multicomponent models of melt viscosity such as the GriD model (Giordano, Russell, Dingwell, EPSL, 2008). I urge the experimental testing of the feasibility of techniques aimed at obtaining glass transition temperatures and relaxation time determinations at temperatures just above this transition. I will present some possible lines of approach for such experimental strategies including the experience gained from lower pressure for handling such materials under what are metastable conditions.

Dingwell, D. B.

2008-12-01

429

Hemoglobin autoxidation under high oxygen pressure - effect of inositol hexaphosphate.  

PubMed

Hemoglobin A in 0.05 M bis-tris buffer was autoxidized under various oxygen pressures from 0.21 (oxygen pressure in air) to 8 atmospheres at pHs 6.5 and 8.5. All experiments were carried out without and with 5 molar excess of inositol hexaphosphate/heme at 37 degrees C. It is shown that increasing the oxygen pressure from 0.21 to 1 atmosphere decreases the autoxidation rate to about 80% whereas increasing the oxygen pressure further to 8 atmospheres has a reverse effect. This phenomenon is observed at both acid and alkaline pHs, although it is less marked at the latter pH. The stimulating effect of inositol hexaphosphate on the autoxidation is abolished at high oxygen pressure. It is suggested that moderate elevation of the oxygen pressure above the atmospheric pressure stabilizes further the hemoglobin R conformation which decreases the autoxidation rate. At very high oxygen pressure, the oxidizing potential of oxygen oxidizes the oxyhemoglobin directly in the R conformation. The maximal shift of hemoglobin T in equilibrium with R conformational equilibrium towards R conformation interferes with the binding of inositol hexaphosphate and hence abolishes its effect. PMID:7319827

Mansouri, A

1981-01-01

430

Interfacial tension in high-pressure carbon dioxide mixtures  

SciTech Connect

High-pressure interfacial- and surface-tension phenomena govern the migration and recovery of oil and gas from hydrocarbon reservoirs. The phenomena are of particular relevance to phase separation and mass transfer in light hydrocarbon fractionation plants and in propane deasphalting in lubricating oil refining. Interfacial tensions of carbon dioxide-water-alcohol mixtures were measured at temperatures in the range 5--71 C and pressures 0.1--18.6 MPa, using the capillary rise method. The alcohols were methanol (0.136 mf), ethanol (to 0.523 mf), and isopropyl alcohol (to 0.226 mf). Interfacial tension (IFT) decreased linearly with both temperature and pressure din the low-pressure range (gaseous CO{sub 2}) but was largely independent of pressure at high pressure (liquid or supercritical CO{sub 2}). There was a zone in the vicinity of the critical pressure of CO{sub 2}-as much as 20 C below and 10 C above the carbon dioxide critical temperature--where IFT became small. This is attributed to the formation of a second CO{sub 2}-rich phase. The isotherms exhibited a crossover pressure near 3 MPa for all systems examined.

Chun, B.S. [Pusan National Univ. of Technology (Korea, Republic of). Dept. of Food Engineering; Wilkinson, G.T. [Univ. of South Australia, The Levels, South Australia (Australia). School of Chemical Technology

1995-12-01

431

Advanced High-Temperature, High-Pressure Transport Reactor Gasification  

SciTech Connect

The transport reactor development unit (TRDU) was modified to accommodate oxygen-blown operation in support of a Vision 21-type energy plex that could produce power, chemicals, and fuel. These modifications consisted of changing the loop seal design from a J-leg to an L-valve configuration, thereby increasing the mixing zone length and residence time. In addition, the standpipe, dipleg, and L-valve diameters were increased to reduce slugging caused by bubble formation in the lightly fluidized sections of the solid return legs. A seal pot was added to the bottom of the dipleg so that the level of solids in the standpipe could be operated independently of the dipleg return leg. A separate coal feed nozzle was added that could inject the coal upward into the outlet of the mixing zone, thereby precluding any chance of the fresh coal feed back-mixing into the oxidizing zone of the mixing zone; however, difficulties with this coal feed configuration led to a switch back to the original downward configuration. Instrumentation to measure and control the flow of oxygen and steam to the burner and mix zone ports was added to allow the TRDU to be operated under full oxygen-blown conditions. In total, ten test campaigns have been conducted under enriched-air or full oxygen-blown conditions. During these tests, 1515 hours of coal feed with 660 hours of air-blown gasification and 720 hours of enriched-air or oxygen-blown coal gasification were completed under this particular contract. During these tests, approximately 366 hours of operation with Wyodak, 123 hours with Navajo sub-bituminous coal, 143 hours with Illinois No. 6, 106 hours with SUFCo, 110 hours with Prater Creek, 48 hours with Calumet, and 134 hours with a Pittsburgh No. 8 bituminous coal were completed. In addition, 331 hours of operation on low-rank coals such as North Dakota lignite, Australian brown coal, and a 90:10 wt% mixture of lignite and wood waste were completed. Also included in these test campaigns was 50 hours of gasification on a petroleum coke from the Hunt Oil Refinery and an additional 73 hours of operation on a high-ash coal from India. Data from these tests indicate that while acceptable fuel gas heating value was achieved with these fuels, the transport gasifier performs better on the lower-rank feedstocks because of their higher char reactivity. Comparable carbon conversions have been achieved at similar oxygen/coal ratios for both air-blown and oxygen-blown operation for each fuel; however, carbon conversion was lower for the less reactive feedstocks. While separation of fines from the feed coals is not needed with this technology, some testing has suggested that feedstocks with higher levels of fines have resulted in reduced carbon conversion, presumably due to the inability of the finer carbon particles to be captured by the cyclones. These data show that these low-rank feedstocks provided similar fuel gas heating values; however, even among the high-reactivity low-rank coals, the carbon conversion did appear to be lower for the fuels (brown coal in particular) that contained a significant amount of fines. The fuel gas under oxygen-blown operation has been higher in hydrogen and carbon dioxide concentration since the higher steam injection rate promotes the water-gas shift reaction to produce more CO{sub 2} and H{sub 2} at the expense of the CO and water vapor. However, the high water and CO{sub 2} partial pressures have also significantly reduced the reaction of (Abstract truncated)

Michael L. Swanson

2005-08-30

432

An experimental analysis of subcooled leakage flow through slits from high pressure high temperature pipelines  

Microsoft Academic Search

The work presented here is an experimental investigation of the critical flashing flow of initially subcooled water through circumferential slits in pipes. The study provides first hand information about the prediction of leak flow rates in piping and pressure vessels retaining high temperature and high pressure. The dedicated experimental facility loop simulates the thermal hydraulic condition of Pressurized Heavy Water

Sandip Ghosh; Deb Mukhopadhyay; Samir Kumar Saha

2011-01-01

433

Spontaneous Raman Scattering Diagnostics for High-Pressure Gaseous Flames.  

National Technical Information Service (NTIS)

A high-pressure (up to 60 atm) gaseous burner facility with optical access that provides steady, reproducible flames with high precision, and the ability to use multiple fuel/oxidizer combinations has been developed. In addition, a high-performance sponta...

J. Kojima Q. V. Nguyen

2002-01-01

434

High-pressure behavior of phosphorus from first principles calculations  

NASA Astrophysics Data System (ADS)

High-pressure structural behavior, electronic structure, and vibrational properties of P have been investigated by means of first principles calculations. We perform an ab initio search for the P-IV phase by analyzing the phonon dispersions of the simple cubic (sc) structure as a function of pressure. In particular, we use the dynamical instability of the sc structure above the transition into the simple hexagonal structure to extract a possible candidate structure for P-IV. Additionally, in contrast to general expectations, we show that the body-centered cubic (bcc) P-V phase cannot be the end member of the high-pressure structural sequence of P because it becomes dynamically unstable at high compression. We propose that at ultrahigh pressure above 280GPa , the bcc structure transforms first to the IM7 structure and then to the hexagonal close-packed structure.

Mikhaylushkin, A. S.; Simak, S. I.; Johansson, B.; Hussermann, U.

2007-09-01

435

High pressure rotary piston coal feeder for coal gasification applications  

DOEpatents

The subject development is directed to an apparatus for feeding pulverized coal into a coal gasifier operating at relatively high pressures and elevated temperatures. This apparatus is a rotary piston feeder which comprises a circular casing having a coal loading opening therein diametrically opposed from a coal discharge and contains a rotatable discoid rotor having a cylinder in which a reciprocateable piston is disposed. The reciprocation of the piston within the cylinder is provided by a stationary conjugate cam arrangement whereby the pulverized coal from a coal hopper at atmospheric pressure can be introduced into the cylinder cavity and then discharged therefrom into the high-pressure gasifier without the loss of high pressure gases from within the latter.

Gencsoy, Hasan T. (Morgantown, WV)

1977-05-24

436

Confinement of hydrogen at high pressure in carbon nanotubes  

DOEpatents

A high pressure hydrogen confinement apparatus according to one embodiment includes carbon nanotubes capped at one or both ends thereof with a hydrogen-permeable membrane to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough. A hydrogen confinement apparatus according to another embodiment includes an array of multi-walled carbon nanotubes each having first and second ends, the second ends being capped with palladium (Pd) to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough as a function of palladium temperature, wherein the array of carbon nanotubes is capable of storing hydrogen gas at a pressure of at least 1 GPa for greater than 24 hours. Additional apparatuses and methods are also presented.

Lassila, David H. (Aptos, CA); Bonner, Brian P. (Livermore, CA)

2011-12-13

437

High-pressure trickle-bed reactors: A review  

SciTech Connect

A concise review of relevant experimental observations and modeling of high-pressure trickle-bed reactors, based on recent studies, is presented. The following topics are considered: flow regime transitions, pressure drop, liquid holdup, gas-liquid interfacial area and mass-transfer coefficient, catalyst wetting efficiency, catalyst dilution with inert fines, and evaluation of trickle-bed models for liquid-limited and gas-limited reactions. The effects of high-pressure operation which is of industrial relevance, on the physicochemical and fluid dynamic parameters are discussed. Empirical and theoretical models developed to account for the effect of high pressure on the various parameters and phenomena pertinent to the topics discussed are briefly described. 200 refs.

Al-Dahhan, M.H.; Dudukovic, M.P. [Washington Univ., St. Louis, MO (United States); Larachi, F. [Laval Univ., Quebec City, Quebec (Canada). Dept. of Chemical Engineering; Laurent, A. [Lab. des Sciences du Genie Chimique, Nancy (France)

1997-08-01

438

High Rate Plasticity under Pressure using a Windowed Pressure-Shear Impact Experiment  

SciTech Connect

An experimental technique has been developed to study the strength of materials under conditions of moderate pressures and high shear strain rates. The technique is similar to the traditional pressure-shear plate-impact experiments except that window interferometry is used to measure both the normal and transverse particle velocities at a sample-window interface. Experimental and simulation results on vanadium samples backed with a sapphire window show the utility of the technique to measure the flow strength under dynamic loading conditions. The results show that the strength of the vanadium is 600 MPa at a pressure of 4.5 GPa and a plastic strain of 1.7%.

Florando, J N; Jiao, T; Grunschel, S E; Clifton, R J; Ferranti, L; Becker, R C; Minich, R W; Bazan, G

2009-07-29

439

Cathode erosion in high-current high-pressure arc  

Microsoft Academic Search

Cathode erosion rate was experimentally investigated for two types of arcs: one with tungsten cathode in nitrogen atmosphere and one with hafnium cathode in oxygen atmosphere. Conditions were typical for plasma arc cutting systems: gas pressure from 2 to 5 atm, arc current from 200 to 400 A, gas flow rate from 50 to 130 litre min-1. It was found

V. A. Nemchinsky; M. S. Showalter

2003-01-01

440

Cathode erosion in high-current high-pressure arc  

Microsoft Academic Search

Cathode erosion rate was experimentally investigated for two types of arcs: one with tungsten cathode in nitrogen atmosphere and one with hafnium cathode in oxygen atmosphere. Conditions were typical for plasma arc cutting systems: gas pressure from 2 to 5 atm, arc current from 200 to 400 A, gas flow rate from 50 to 130 litre min?1.It was found that

V A Nemchinsky; M S Showalter

2003-01-01

441

Opportunities and challenges in high pressure processing of foods.  

PubMed

Consumers increasingly demand convenience foods of the highest quality in terms of natural flavor and taste, and which are free from additives and preservatives. This demand has triggered the need for the development of a number of nonthermal approaches to food processing, of which high-pressure technology has proven to be very valuable. A number of recent publications have demonstrated novel and diverse uses of this technology. Its novel features, which include destruction of microorganisms at room temperature or lower, have made the technology commercially attractive. Enzymes and even spore forming bacteria can be inactivated by the application of pressure-thermal combinations, This review aims to identify the opportunities and challenges associated with this technology. In addition to discussing the effects of high pressure on food components, this review covers the combined effects of high pressure processing with: gamma irradiation, alternating current, ultrasound, and carbon dioxide or anti-microbial treatment. Further, the applications of this technology in various sectors - fruits and vegetables, dairy, and meat processing - have been dealt with extensively. The integration of high-pressure with other matured processing operations such as blanching, dehydration, osmotic dehydration, rehydration, frying, freezing / thawing and solid-liquid extraction has been shown to open up new processing options. The key challenges identified include: heat transfer problems and resulting non-uniformity in processing, obtaining reliable and reproducible data for process validation, lack of detailed knowledge about the interaction between high pressure, and a number of food constituents, packaging and statutory issues. PMID:17364696

Rastogi, N K; Raghavarao, K S M S; Balasubramaniam, V M; Niranjan, K; Knorr, D

2007-01-01

442

Generation of high pressure homogeneous dielectric barrier discharge in air  

NASA Astrophysics Data System (ADS)

We succeeded in generating an atmospheric pressure Townsend discharge (APTD) in air by using a simple DBD device that consists of alumina barriers and plane electrodes. So far, we applied the APTD to an ozonizer and found that the ozone generation efficiency was higher by the APTD mode than by the conventional DBD mode in larger specific input energy region. It is well known that an operation under an optimized high gas pressure is advantageous for efficient ozone generation from air. In this paper, we investigated whether the Townsend discharge (TD) in dry air in high pressure up to 0.17 MPa can be generated or not. From the observation results of current waveforms and discharge photographs, we found that (1) the discharge currents flow continuously and have only one peak in every half cycle in all gas pressure and (2) filamentary discharges are not recognized between barriers in all gas pressure. These features completely agree with the features of the APTD we reported. Therefore, we concluded that our TD can be generated even in dry air in the pressure range of 0.1 and 0.17 MPa. Contribution to the Topical Issue "13th International Symposium on High Pressure Low Temperature Plasma Chemistry (Hakone XIII)", Edited by Nicolas Gherardi, Henryca Danuta Stryczewska and Yvan Sgui.

Osawa, Naoki; Takashi, Ami; Yoshioka, Yoshio; Hanaoka, Ryoichi

2013-02-01

443

Design and characterization of a high temperature and high frequency infinite-line pressure probe  

SciTech Connect

This paper describes the design and development of an infinite-line pressure probe for high frequency acoustic pressure measurements in high temperature environments. In the infinite-line probe technique, one end of a long tube is placed at the pressure measurement location and the pressure transducer is inserted in the side of the tube a few inches away. The effectiveness of the infinite-line probe to measure high frequency noise in high temperature environments is experimentally demonstrated and the results are presented in this paper. In addition, these results are compared with simultaneous measurements made using a standard water-cooled pressure transducer. 9 references.

Salikuddin, M.; Burrin, R.H.; Brown, W.H.

1989-01-01

444

Boron under Pressure: Phase Diagram and Novel High-Pressure Phase  

Microsoft Academic Search

\\u000a Boron has a unique chemistry, responsible for remarkable complexities even in the pure element. I review some of the history\\u000a of the discovery of this element, and recent surprises found in boron under pressure. I discuss the recent discovery of a\\u000a new high-pressure phase, ?-B28, consisting of icosahedral B12 clusters and B2 pairs in a NaCl-type arrangement: (B2)?+(B12)?-, and displaying

Artem R. Oganov

445

High pressure system for 3-D study of elastic anisotropy  

NASA Astrophysics Data System (ADS)

New high pressure system was designed for the study of elastic anisotropy of condensed matter under high confining pressure up to 700 MPa. Simultaneously could be measured dynamic and static parameters: a) dynamic parameters by ultrasonic sounding, b) static parameters by measuring of spherical sample deformation. The measurement is carried out on spherical samples diameter 50 +/- 0.01 mm. Higher value of confining pressure was reached due to the new construction of sample positioning unit. The positioning unit is equipped with two Portecap step motors, which are located inside the vessel and make possible to rotate with the sphere and couple of piezoceramic transducers. Sample deformation is measured in the same direction as ultrasonic signal travel time. Only electric leads connects inner part of high pressure vessel with surrounding environment. Experimental set up enables: - simultaneous P-wave ultrasonic sounding, - measurement of current sample deformation at sounding points, - measurement of current value of confining pressure and - measurement of current stress media temperature. Air driven high pressure pump Haskel is used to produce high value of confining pressure up to 700 MPa. Ultrasonic signals are recorded by digital scope Agilent 54562 with sampling frequency 100 MHz. Control and measuring software was developed under Agilent VEE software environment working under MS Win 2000 operating system. Measuring set up was tested by measurement of monomineral spherical samples of quartz and corundum. Both of them have trigonal symmetry. The measurement showed that the P-wave velocity range of quartz was between 5.7-7.0 km/sec. and velocity range of corundum was between 9.7-10.9 km/sec. High pressure resistant LVDT transducers Mesing together with Intronix electronic unit were used to monitor sample deformation. Sample deformation is monitored with the accuracy of 0.1 micron. All test measurements proved the good accuracy of the whole measuring set up. This project was supported by Grant Agency of the Czech Republic No.: 205/01/1430.

Lokajicek, T.; Pros, Z.; Klima, K.

2003-04-01

446

[High blood pressure in obese children and adolescents].  

PubMed

Obesity is also an important risk factor in children and adolescents for "essential" arterial hypertension, and contrary to what was assumed earlier, high blood pressure does cause damage to the cardiovascular system. As known from adults, elevated blood pressure induces cardiac hypertrophy, calcifications and atherosclerosis at the coronary vessels and thickens the small blood vessels. These early vascular alterations are particularly pronounced, when increased blood pressure is accompanied by other risk factors, such as dyslipidemia, hyperinsulinemia or smoking. As in any child with elevated blood pressure, the diagnostic evaluation should focus on confirmation of hypertension, determine if an underlying cause can be identified and whether hypertensive target organ damage is present. New reference office blood pressure values were recently published by a large representative community-based study in Germany. Therapy should begin with lifestyle modifications; however, antihypertensive medications will often be needed. Hypertension in obese adolescents occurs frequently and must be diagnosed and treated adequately. PMID:23529593

Rascher, W; Kiess, W; Krner, A

2013-04-01

447

Raman spectroscopy study of ammonia borane at high pressure  

NASA Astrophysics Data System (ADS)

Ammonia borane, NH3BH3, has attracted significant interest as a promising candidate material for hydrogen storage. The effect of pressure on the bonding in NH3BH3 was investigated using Raman spectroscopy to over 20 GPa in a diamond anvil cell, and two new transitions were observed at approximately 5 and 12 GPa. Vibrational frequencies for the modes of the NH3 proton donor group exhibited negative pressure dependence, which is consistent with the behavior of conventional hydrogen bonds, while the vibrational frequencies of the BH3 proton acceptor group showed positive pressure dependence. The observed behavior of these stretching modes supports the presence of dihydrogen bonding at high pressure. In addition, the BH3 and NH3 bending modes showed an increase in spectral complexity with increasing pressure together with a discontinuity in d?/dP which suggests rotational disorder in this molecule. These results may provide guidance for understanding and developing improved hydrogen storage materials.

Lin, Yu; Mao, Wendy L.; Drozd, Vadym; Chen, Jiuhua; Daemen, Luke L.

2008-12-01

448

Influence of Azores High pressure on Middle Eastern rainfall  

NASA Astrophysics Data System (ADS)

Several studies demonstrate that North Atlantic Oscillation influences variability of climate over Middle East. We use the centers of action approach for the study of winter rainfall variability over Middle East, taking into account variations in the components of the North Atlantic Oscillation, the Azores High and the Icelandic Low pressure systems. The results show there is a negative relation between the interannual variations of winter rainfall over Middle East and Azores High pressure. The east-west shifts of Indian Ocean high pressure has also impact on precipitation over Middle East, there being more precipitation when the Indian Ocean High shifts eastward versus when it is westward. We present a regression model for Middle East precipitation in which the Azores High pressure and the Indian Ocean High longitude are independent variables and it explains 40 % of the variance of precipitation during 1952-2002. Furthermore, the ongoing decrease in winter precipitation over the Middle East is attributed to the increasing pressure of the Azores High over the same period.

Iqbal, M. J.; Hameed, Sultan; Khan, Farheen

2013-01-01

449

Probing and Modeling of Pressure-induced Structural Transformation in Oxide Melts at High Pressure  

NASA Astrophysics Data System (ADS)

Pressure-induced bonding transitions in oxide melts give improved prospects for the non-linear pressure dependence of their macroscopic transport properties in the earth's interior. The inherent difficulties of current experimental technologies, however, pose major challenges for probing structural changes of prototypical model oxide melts at high pressure, making it one of the unsolved problems in geophysics. Recent advances in element specific experimental probe of local structures, such as high resolution solid- state NMR and x-ray Raman scattering unveils new structural insights into the pressure-induced changes in the bonding nature (either gradual or abrupt) of the archetypal oxides melts (e.g. Lee SK et al. Proc. Nat. Aca. Sci. 2008, 105, 7925; Lee SK et al. J. Phys. Chem. B. 2008 in press). Here, we report recent progress that we have made using these techniques. Non-random spatial distribution of aluminum in oxide glasses were for the first time revealed via through-space correlation NMR spectroscopy: four, five, six coordinated aluminums have differential proximity among each other but favoring the formation of clusters mainly composed of six coordinated Al. While silicate glasses studied here exhibit a general trend of decreasing non-bridging oxygen fraction with pressure, the details of their pressure dependence is significantly affected by the composition of melts, such as Na/Si, Si/Al ratio as well as types of network modifying cations. We account for these differences with a conceptual model that utilizes pressure flexibility (the resistance to structural changes with increased pressurization). An oxide melts with a large pressure flexibility, thus, may undergo a gradual structural transformation. In contrast, a melts with the opposite behavior undergoes an abrupt coordination transformation. The observed information of connectivity among network forming cations was used to calculate the crystal-melt partitioning coefficient and activity of silica in melts where the fraction of Si-O-Si cluster increases with the activity coefficient of silica.

Cody, G.; Lee, S.; Mysen, B.; Fei, Y.; Eng, P.

2008-12-01

450

Frontiers of High-Pressure Research: Synchrotron Infrared Spectroscopy  

NASA Astrophysics Data System (ADS)

High-pressure spectroscopy provides crucial and often unique information on the properties of Earth and planetary materials from near-surface conditions to those of the deepest interiors. Vibrational infrared/Raman spectroscopy, for example, provides detailed information on bonding properties of crystals, glass, and melts, thereby yielding a microscopic description of thermochemical properties. The high brightness of synchrotron infrared radiation is ideally suited to high pressure investigations in which both small sample area and a narrow beam are required in order to generate extremely high pressure with a diamond anvil cell. The dedicated high-pressure beam line U2A on the VUV ring of the National Synchrotron Light Source, Brookhaven National Laboratory is an integrated facility for a wide range of microspectroscopic studies from ambient to ultrahigh pressures and at variable temperatures. The beam line has high IR brightness, particularly at long wavelengths, with its 40 x 40 mrad aperture. The facility includes a FT-IR vacuum spectrometer (Bruker IFS 66v/S) along with a nitrogen purged high-pressure, long working distance microscopes for high pressure (and variable temperature) applications, a vacuum microscope system for far IR high-pressure absorption measurements and a commercial, high-magnification infrared microscope for diffraction-limited micro-infrared measurements of samples at ambient and high pressures. Recently, the beamline has been upgraded to further improve the performance in far-IR range. The facility thus permits systematic high-pressure studies addressing a range of problems in Earth and planetary science. These studies include high pressure (and variable temperature) studies of planetary gases and ices; minerals of the Earth's crust, mantle, and core; geochemical reactions; organic geochemistry; surfaces and interfaces and whole-rock samples; and extraterrestrial samples. These investigations complement optical laser spectroscopy, x-ray diffraction and spectroscopy, and transport measurements carried out on the same materials. High-pressure studies of various ices continue, with new phases being uncovered by these methods. New far-IR measurements have been carried out to test proposed pressure-induced phase transformations in ice at low temperature. These techniques have also been applied to biological molecules under pressure. Far-IR spectroscopy measurements down to 20 cm-1 have been used to characterize the low-frequency dynamics of model heme Fe-CO compounds, including the long-sought doming mode in which the iron atom moves out of the porphyrin plane. New single-crystal CVD diamond has been characterized from the far- to near-IR, including both as-grown and annealed material. The method has also been used to examine a variety of natural diamonds. Examples of recent experiments also include studies of hydrous mineral, such as gypsum, OH-clinohumite, and OH-chondrodite.

Liu, Z.; Mao, H.; Hemley, R. J.

2003-12-01

451

Anomalous high pressure behaviour in nanosized rare earth sesquioxides.  

PubMed

We report Raman spectroscopic studies of the nanosized rare earth sesquioxides, namely yttrium sesquioxide (Y(2)O(3)), gadolinium sesquioxide (Gd(2)O(3)) and samarium sesquioxide (Sm(2)O(3)), under high pressure. The samples were characterized using x-ray diffraction, Raman spectroscopy and atomic force microscopy at atmospheric pressures. Y(2)O(3) and Gd(2)O(3) were found to be cubic at ambient, while Sm(2)O(3) was found to be predominantly cubic with a small fraction of monoclinic phase. The strongest Raman peaks are observed at 379, 344 and 363cm(-1), respectively, for Y(2)O(3), Sm(2)O(3) and Gd(2)O(3). All the samples were found to be nanosized with 50-90nm particle sizes. The high pressures were generated using a Mao-Bell type diamond anvil cell and a conventional laser Raman spectrometer is used to monitor the pressure-induced changes. Y(2)O(3) seems to undergo a crystalline to partial amorphous transition when pressurized up to about 19GPa, with traces of hexagonal phase. However, on release of pressure, the hexagonal phase develops into the dominant phase. Gd(2)O(3) is also seen to develop into a mixture of amorphous and hexagonal phases on pressurizing. However, on release of pressure Gd(2)O(3) does not show any change and the transformation is found to be irreversible. On the other hand, Sm(2)O(3) shows a weakening of cubic phase peaks while monoclinic phase peaks gain intensity up to about a pressure of 6.79GPa. However, thereafter the monoclinic phase peaks also reduce in intensity and mostly disordering sets in which does not show significant reversal as the pressure is released. The results obtained are discussed in detail. PMID:21730563

Dilawar, Nita; Varandani, Deepak; Mehrotra, Shalini; Poswal, Himanshu K; Sharma, Surinder M; Bandyopadhyay, Ashis K

2008-02-19

452

Magnetism in ErCo2 under high pressure  

NASA Astrophysics Data System (ADS)

We present results of experiments and ab initio calculations focused on the stability of Co magnetism in ErCo2 exerted to high pressures. In the experiments we have studied pressure effects on electrical-resistivity anomalies in the vicinity of Curie temperature (TC=33 K in ambient pressure) that are intimately related to the formation and ordering of Co itinerant 3d electron moments. The Co magnetism in this material is a consequence of the itinerant electron metamagnetism (IEM) induced in a large exchange field appearing at TC where the localized Er moments order ferromagnetically. At lower pressures, TC decreases linearly with increasing pressure p (? ln TC/?p=0.24 GPa-1). Magnetovolume measurements under pressure and magnetic-moment calculations performed for reduced lattice parameters reveal that also the Co moment decreases with increasing pressure. At higher pressures, the TC vs p dependence strongly deviates from the initial linear trend and above a critical pressure pc~4 GPa, the TC becomes nearly pressure independent. To explain this behavior we propose a scenario assuming that for p>pc the 3d band broadens to such extent that the projected Co-3d density of states in the vicinity of EF decreases critically and the Er-Co-Er exchange channel becomes ineffective to induce the IEM. The Er sublattice then orders at much lower temperature TC~13 K, which is determined by the Er-Er interaction channel mediated by conduction electrons. This scenario is corroborated by results of the ab initio calculations that indicate the collapse of IEM in pressures above a certain value.

Syshchenko, O.; Fujita, T.; Sechovsk, V.; Divi, M.; Fujii, H.

2001-02-01

453

High sensitive FBG pressure sensor using metal bellows  

NASA Astrophysics Data System (ADS)

A fiber-optic sensor scheme, capable of the simultaneous measurement of pressure and temperature using two in-line Fiber Bragg Gratings (FBGs) is reported. Sensor head is configured by embedding the two FBGs with metal bellows, such that FBG1 is sensitive to both pressure and temperature, whereas FBG2 is only sensitive to temperature. High pressure sensitivity is achieved because of the lower spring rate in longitudinal direction to that of the large elastic modulus in transverse direction of the metal bellows. Pressure and temperature measurement is made by monitoring the shift of Bragg wavelengths of the FBGs corresponds to variation in pressure and temperature. From the test results, the obtained pressure and temperature sensitivities are 86 pm/psi and 9.17 pm/C, over a dynamic range of 0-40 psi pressure, and 25-110C temperature measurements respectively. The experimental results well agreed with the theoretical results and show good linearity. This simple design, economical and all fiber optic sensors can be used for liquid and gas pressure measurements, and under-water applications.

Vengal Rao, P.; Srimannarayana, K.; Sai Shankar, M.; Kishore, P.

2013-09-01

454

Structural Study of ?-Rhombohedral Boron at High Pressures  

NASA Astrophysics Data System (ADS)

Recently, it has been shown that, like ?-rhombohedral boron (?-boron), ?-rhombohedral boron (?-boron) exhibits superconductivity at high pressure. The transition pressure is similar to that of ?-boron, that is, about 160 GPa. This paper presents a theoretical and experimental study of the structural change in ?-boron at high pressures. High-pressure (up to 200 GPa) X-ray experiments were performed at a synchrotron-radiation facility. At ambient temperature, the crystal of ?-boron is stable over the whole range of pressures examined. There is no phase transitions, such as to ?-Ga type, which were previously predicted. All the structural parameters vary continuously with pressure. The cause of metallization is a significant contraction of the intericosahedral three-center bond, which brings a higher coordination to the icosahedron and a transfer of charge from the intraicosahedoral bond to the three-center bond. Although everything is continuous, a careful analysis of the pressure dependence of the structural parameters by comparing experiment with ab initio calculation, reveals a characteristic change in the angle of the rhombohedral lattice and some of the internal coordinates of atoms at about 50 GPa. This is the pressure at which the metallization process begins. This structural change can be observed as the step in the pressure dependence of the electrical resistivity and the phonon softening. The interrelationships underlying these changes have been established on theoretical grounds. The long-debated issue of whether the intericosahedral bond is stronger than intraicosahedral bond has been resolved: the traditional understanding that the former is stronger has been proven. A direct piece of evidence for this is the initial deviation of the intericosahedral bond from the lattice vector.

Shirai, Koun; Dekura, Haruhiko; Mori, Yoshihisa; Fujii, Yutaka; Hyodo, Hiroshi; Kimura, Kaoru

2011-08-01

455

Experimental in situ investigations of turbulence under high pressure.  

PubMed

In tube injection systems applied in high-pressure processing of packed biomaterials and foods, the pressure-transmitting medium is injected into the vessel to increase the pressure up to 1000 MPa, generating a submerged liquid-free jet. The presence of a turbulent-free jet during the pressurization phase and its positive influence on the homogeneity of the product treatment has already been examined by computational fluid dynamics investigations. However, no experimental data have supported the existence and properties of turbulent flow under high-pressure (HP) conditions up to 400 MPa. This contribution presents the development of two experimental setups: HP-laser Doppler anemometry and HP-hot wire anemometry. For the first time the time-averaged velocity profiles of a free jet during pressurization up to 300 MPa at different Reynolds numbers (Re) have been obtained. In this article, the dependence of the velocity profiles on the Re is discussed in detail. Moreover, the relaminarization phenomenon of the turbulent pipe flow most likely caused by the compressibility effects and viscosity changes of the pressure-transmitting medium is examined. PMID:20233365

Song, Kwonyul; Al-Salaymeh, Ahmed; Jovanovic, Jovan; Rauh, Cornelia; Delgado, Antonio

2010-02-01

456

Microscopic Analysis of Bacterial Motility at High Pressure  

PubMed Central

The bacterial flagellar motor is a molecular machine that converts an ion flux to the rotation of a helical flagellar filament. Counterclockwise rotation of the filaments allows them to join in a bundle and propel the cell forward. Loss of motility can be caused by environmental factors such as temperature, pH, and solvation. Hydrostatic pressure is also a physical inhibitorof bacterial motility, but the detailed mechanism of this inhibition is still unknown. Here, we developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of applied pressures. We also characterized the pressure dependence of the motility of swimming Escherichia coli cells and the rotation of single flagellar motors. The fraction and speed of swimming cells decreased with increased pressure. At 80 MPa, all cells stopped swimming and simply diffused in solution. After the release of pressure, most cells immediately recovered their initial motility. Direct observation of the motility of single flagellar motors revealed that at 80 MPa, the motors generate torque that should be sufficient to join rotating filaments in a bundle. The discrepancy in the behavior of free swimming cells and individual motors could be due to the applied pressure inhibiting the formation of rotating filament bundles that can propel the cell body in an aqueous environment.

Nishiyama, Masayoshi; Sowa, Yoshiyuki

2012-01-01

457

Phase transformation of Ho2O3 at high pressure  

NASA Astrophysics Data System (ADS)

The structural stability of cubic Ho2O3 under high pressure has been investigated by angle-dispersive x-ray diffraction (ADXD) in a diamond anvil cell up to 63.0 GPa at room temperature. The diffraction data reveal two structural transformations on compression. The structural transformation from a cubic to a monoclinic structure starts at 8.9 GPa and is complete at 16.3 GPa with a ~8.1% volume collapse. A hexagonal phase begins to appear at ~14.8 GPa and becomes dominant at 26.4 GPa. This high-pressure hexagonal phase with a small amount of retained monoclinic phase is stable up to the highest pressure of 63.0 GPa in this study. After release of pressure, the hexagonal phase transforms to a monoclinic structure. A third-order Birch-Murnaghan fit yields zero pressure bulk moduli (B0) of 206(3), 200(7) and 204(19) GPa and their pressure derivatives (B0') of 4.8(4), 2.1(4), 3.8(5) for the cubic, monoclinic and hexagonal phases, respectively. Comparing with other rare-earth sesquioxides, it is suggested that the transition pressure from cubic to monoclinic phase, as well as the bulk modulus of the cubic phase, increases with the decreasing of the cation radius of rare-earth sesquioxides.

Jiang, Sheng; Liu, Jing; Li, Xiaodong; Bai, Ligang; Xiao, Wansheng; Zhang, Yufeng; Lin, Chuanlong; Li, Yanchun; Tang, Lingyun

2011-07-01

458

Thermomechanics of nanocrystalline nickel under high pressure-temperature conditions.  

PubMed

We present a comparative study of thermomechanical properties of nano-polycrystalline nickel (nano-Ni) and micrometer-polycrystalline nickel (micron-Ni) by in situ high pressure-temperature (P-T) diffraction experiments. The yield strength of 2.35 GPa for the nano-Ni measured under high-pressure triaxial compression is more than three times that of the micron-Ni value. Contrary to tensile experiments of uniaxial loading, we observe significant work-hardening for the nano-Ni in high-pressure plastic deformation stage, whereas the micron-Ni experiences minor high-pressure work-softening and considerable energy dissipation into heat. The significantly reduced energy dissipation for the nano-Ni during the loading-unloading cycle indicates that the nanostructured materials can endure much greater mechanical fatigue in cyclic loadings. The nano-Ni exhibits steady grain growth during bulk plastic deformation at high-pressure loading, and drastic stress reduction and grain growth occur during the high P-T cycle. Our experiments utilized novel approaches to comparatively study micro- and nanostructured materials revealing recoverability of elastic/plastic deformations, strain corrections by diffraction elasticity ratio, and identifying dominances of stress relaxation, grain growth, and intrinsic residual stresses. The results should be of considerable interest to the fields of materials science, condensed matter, and computational physics. PMID:17298011

Zhao, Yusheng; Zhang, Jianzhong; Clausen, Bjrn; Shen, T D; Gray, George T; Wang, Liping

2007-02-01

459

Thermoelastic Properties of Olivine and its High Pressure Polymorphs at High Pressures and Temperatures: A First-Principles Study  

NASA Astrophysics Data System (ADS)

We combine density functional theory (DFT) within the local density approximation (LDA), the quasiharmonic approximation (QHA), and a model of vibrational density of states (VDoS) to calculate aggregate elastic moduli and sound velocities of olivine (?-phase) (Fex,Mg1-x)2SiO4, and its high pressure polymorphs, wadsleyite (?-phase) and ringwoodite (?-phase), the most abundant minerals of the Earth's upper mantle (UM) and transition zone (TZ). Comparison of results with high-pressure and room-temperature data and ambient-pressure and high-temperature data shows very good agreement. Using our findings, we investigate the discontinuities in elastic moduli and velocities associated with the ? to ? and ? to ? transformations at pressures and temperatures relevant to seismic discontinuities near 410 km and 520 km depth. This information offers clearly defined reference values to advance understanding of the role that chemical composition and temperature play in these mantle boundary layers.

Nez Valdez, Maribel; Wu, Zhongqin; Yu, Younggang; Wentzcovitch, Renata

2012-02-01

460

High-temperature performance analysis of automotive combustion pressure sensor  

NASA Astrophysics Data System (ADS)

A theoretical approach is developed to evaluate pressure detection sensitivity and its temperature dependence for diaphragm-type fiber optic combustion pressure sensors. Temperature-induced mechanical response variations and diaphragm optical reflectivity degradation, particularly at high temperatures, are identified as the two major factors that produce errors in sensitivity, and hence in pressure measurement. Experimental results using hermetically sealed sensor construction prove the feasibility of maintaining diaphragm optical reflectivity under high temperatures. This analysis predicts that simple temperature compensation could reduce temperature-induced errors in sensor output, and obtain desired pressure measurement accuracies. Engine tests performed with the present fiber optic sensors demonstrate good signal-to-noise performance and temperature stability.

He, Gang; Wlodarczyk, Marek T.

1993-02-01

461

Measurements of plasma potential in high-pressure microwave plasmas.  

PubMed

Plasma potential of a high-pressure ( approximately 1 Torr) microwave-generated argon plasma is measured using a Langmuir probe and a cold emissive probe. The operation of a hot emissive probe in a high-pressure plasma has been very difficult due to frequent burn-outs and significantly reduced lifetime of the probe filament, which, in turn, limits the possibility of collecting a wide range of data. The I-V characteristics from both Langmuir and emissive probes are interpreted using the collisionless probe theory since the collision correction factor is not very significant. The plasma potential determined from both Langmuir and cold emissive probe characteristics agrees well with one another and is observed to be dependent on the operating gas pressure but relatively unchanged as a function of the microwave power. An average plasma potential determined over the operating range of microwave powers varies nonlinearly with the gas pressure. PMID:19405659

Tarasova, A V; Podder, N K; Clothiaux, E J

2009-04-01

462

Vanadium and V-Ti alloys at high pressure  

NASA Astrophysics Data System (ADS)

Experimental studies of vanadium found that during compression it undergoes a phase transition from the low pressure body centered cubic crystal structure to a rhombohedral phase at 65 GPa when compressed under quasihydrostatic conditions (PRB 83, 054101). Theoretical studies are in reasonable agreement with the transition pressure and predict that upon further compression above 200 GPa the bcc phase becomes stable again. The latest study (PRL 103, 235501) predicts that alloying vanadium with small amounts of the neighboring elements can increase or decrease the stability of the bcc phase relative to the rhombohedral phase. We performed powder x-ray diffraction experiments in diamond anvil cell of pure vanadium and V-Ti alloys at ambient temperature to very high pressures. We will discuss our results, including the equation of state and the stability of the rhombohedral phase at high pressures.

Jenei, Zsolt; Cynn, Hyunchae; Evans, William J.; MacLeod, Simon; Sinogeikin, Stanislav; Meng, Yue

2013-03-01

463

Oxygen Escape from Venus During High Dynamic Pressure ICMEs  

NASA Astrophysics Data System (ADS)

Previous studies using data from Pioneer Venus suggested that oxygen ion escape flux may be enhanced by orders of magnitude during Interplanetary Coronal Mass Ejections. However, this large enhancement has been ambiguous in Venus Express ion data - with some analyses showing no flux enhancement or a small enhancement (within 2 times undisturbed cases). One possible explanation is that high escape flux may be due to high dynamic pressure in the solar wind, and the dynamic pressure has been lower during the VEX time period. So, we focus on ICMEs with the largest dynamic pressure and with VEX sampling of the escaping ions during the sheath of the ICMEs (during which the highest dynamic pressures in the solar wind occur). We will show the characteristics of these large events measured by VEX, and compare them to the largest ICMEs measured by PVO. We will then discuss estimates of the oxygen ion escape flux during these events.

McEnulty, Tess; Luhmann, J. G.; Brain, D. A.; Fedorov, A.; Jian, L. K.; Russell, C. T.; Zhang, T.; Mstl, C.; Futaana, Y.; de Pater, I.

2013-10-01

464

A hydronitrogen solid: high pressure ab initio evolutionary structure searches  

NASA Astrophysics Data System (ADS)

High pressure ab initio evolutionary structure searches resulted in a hydronitrogen solid with a composition of (NH)4. The structure searches also provided two molecular isomers, ammonium azide (AA) and trans-tetrazene (TTZ) which were previously discovered experimentally and can be taken as molecular precursors for high pressure synthesis of the hydronitrogen solid. The computed pressure versus enthalpy diagram showed that the transformation pressure to the hydronitrogen solid is 36 GPa from AA and 75 GPa from TTZ. Its metastability was analyzed by the phonon dispersion spectrum and room-temperature vibrational density of state together with the transformation energy barrier back to molecular phases at 298 K. The predicted energy barrier of 0.21 eV/atom means that the proposed hydronitrogen solid should be very stable at ambient conditions.

Hu, Anguang; Zhang, Fan

2011-01-01

465

Note: visible reflectivity system for high-pressure studies.  

PubMed

A near-normal visible reflectivity system was constructed for investigating the optical properties of materials at high pressure and temperatures. The system consists of focusing optics, spectrometers, and imaging cameras for use with a resistively-heated membrane-controlled diamond anvil cell (DAC). The DAC allows optical access on two sides: one dedicated to pressure measurement via fluorescence, the other side dedicated to absolute reflectance measurements. With this configuration, pressure and temperature may be controlled and measured without disturbing the sample position, permitting quantitative reflectivity measurements as a function of thermodynamic state variables. The system was tested on gold at high pressure conditions, and compared to data obtained on a commercial ellipsometer system at 1 bar. PMID:23822391

Seagle, C T; Dolan, D H

2013-06-01

466

Protonic diffusion in high-pressure ice VII.  

PubMed

Near ambient pressures, molecular diffusion dominates protonic diffusion in ice. Theoretical studies have predicted that protonic diffusion will dominate at high pressures in ice. We measured the protonic diffusion coefficient for the highest temperature molecular phase of ice VII at 400 kelvin over its entire stable pressure region. The values ranged from 10(-17) to 10(-15) square meters per second at pressures of 10 to 63 gigapascals. The diffusion coefficients extrapolated to high temperatures close to the ice VII melting curve were less by a factor of 10(2) to 10(3) than a superionic criterion of approximately 10(-8) square meters per second, at which protons would diffuse freely. PMID:11847334

Katoh, Eriko; Yamawaki, H; Fujihisa, H; Sakashita, M; Aoki, K

2002-02-15

467

Determination of the partial pressure of thallium in high-pressure lamp arcs: A comparative study  

SciTech Connect

The partial pressure of thallium in high-pressure Hg-TlI discharges with different mercury, thallium, and electron pressures has been measured by using the optically thin line Tl 655 nm and the self-reversed line Tl 535 nm. The partial pressure of the arc axis has been measured from the line Tl 655nm. The effective partial pressure has been measured from the self-reversed line Tl 535 nm on the basis of the multiparameter method, and it has been calculated from the known axis pressure of thallium and the calculation of its radial variation by taking into account the chemical reactions. The experimental results confirm the dispersion character of the blue wing of the line Tl 535 nm. The systematic difference obtained between the measured and calculated effective pressure, particularly at the moment of minimum electron density, may be interpreted by deviations from the local thermodynamic equilibrium (LTE) caused by overpopulation of the upper level of the line Tl 535 nm.

Karabourniotis, D.; Couris, S.; Damelincourt, J.J.; Aubes, M.

1986-08-01

468

Further investigations of the effect of pressure on retention in ultra-high-pressure liquid chromatography.  

PubMed

In this study, we investigated further the large increases in retention with pressure that we observed previously in RP-LC especially for ionised solutes. These findings were initially confirmed on a conventional silica C(18) column, which gave extremely similar results to the hybrid C(18) phase originally used. Large increases in retention factor of approximately 50% for a pressure increase of 500 bar were also shown for high MW polar but neutral solutes. However, experiments with the same bases in ionised and non-ionised forms suggest that somewhat greater pressure-induced retention increases are found for ionised solutes. Retention increases with pressure were found to be considerably smaller for a C(1) column compared with a C(18) column; decreases in retention with increasing pressure were noted for ionised bases when using a bare silica column in the hydrophilic interaction chromatography (HILIC) mode. These observations are consistent with the partial loss of the solvation layer in RP-LC as the solute is forced into the hydrophobic environment of the stationary phase, and consequent reduction in the solute molar volume, while the water layer on the surface of a HILIC packing increases the hydration of a basic analyte. Finally, retention changes with pressure in RP-LC can also be observed at a mobile phase pH close to the solute pK(a), due to changes in pK(a) with pressure. However, this effect has no influence on the results of most of our studies. PMID:20015498

Fallas, Morgane M; Neue, Uwe D; Hadley, Mark R; McCalley, David V

2009-11-18

469

Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear  

DOEpatents

Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear.

Westerfield, Curtis L. (Espanola, NM); Morris, John S. (Los Alamos, NM); Agnew, Stephen F. (Los Alamos, NM)

1997-01-01

470

LOX vaporization in high-pressure, hydrogen-rich gas  

NASA Astrophysics Data System (ADS)

LOX droplet vaporization in high-pressure hydrogen-rich gas is analyzed, with special attention to thermodynamic effects which compel the surface to heat to the critical state and to supercritical vaporization processes on heating to criticality. Subcritical vaporization is modeled using a quasi-steady diffusion-controlled gas-phase transport formulation coupled to an effective-conductivity internal-energy-transport model accounting for circulation effects. It is demonstrated how the droplet surface might heat to the critical state, for ambient pressures slightly greater than the critical pressure of oxygen, such that the bulk of propellant within the droplet remains substantially below the critical mixing temperature.

Litchford, Ron J.; Jeng, San-Mou

1990-07-01

471

High-pressure study of tetramethylsilane by Raman spectroscopy.  

PubMed

High-pressure behavior of tetramethylsilane, one of the Group IVa hydrides, was investigated by Raman scattering measurements at pressures up to 142 GPa and room temperature. Our results revealed the phase transitions at 0.6, 9, and 16 GPa from both the mode frequency shifts with pressure and the changes of the full width half maxima of these modes. These transitions were suggested to result from the changes in the inter- and intra-molecular bonding of this material. We also observed two other possible phase transitions at 49-69 GPa and 96 GPa. No indication of metallization in tetramethylsilane was found with stepwise compression to 142 GPa. PMID:22260599

Qin, Zhen-Xing; Zhang, Jian-Bo; Troyan, Ivan; Palasyuk, Taras; Eremets, Mikhail; Chen, Xiao-Jia

2012-01-14

472

New high-pressure transformation in [alpha]-quartz  

SciTech Connect

Recent experimental and theoretical studies report that quenched pressure-amorphized [alpha]-quartz is elastically anisotropic and displays a reversal of anisotropy with respect to the original crystallographic orientation. We demonstrate that samples recovered from static compression experiments of [alpha]-quartz exhibit an unusual pressure-induced microstructure, which arises from a new phase transformation in [alpha]-quartz at 21 GPa. Upon decompression, the high-pressure phase reverts to a quartzlike structure in a twinned state, accounting for the previously reported elastic behavior.

Kingma, K.J.; Hemley, R.J.; Mao, H.; Veblen, D.R. (Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, D.C. 20015 (United States) Department of Earth and Planetary Sciences, The Johns Hopkins University, Baltimore, Maryland 21218 (United States))

1993-06-21

473

Structural Behaviour of Uranium Sulfide under High Pressure  

SciTech Connect

The study of pressure induced structural phase transition of uranium sulphide, which crystallizes in rock salt (B1) structure, has been performed using the well described three body interaction model (TBIPM). Our present TBIP model consists of long range coulombic interaction, three body interactions, Hafemeister and Flygare type short-range overlap repulsion extended upto the second neighbor ions and the van der Waals interaction. The present results are in good agreement with the available experimental data on the phase transition pressure (Pt = 80.2 GPa). So it can be considered as an adequate and suitable model to perform high pressure studies.

Shareef, F.; Singh, S.; Gour, A.; Bhardwaj, P.; Sarwan, M.; Dubey, R. [High Pressure Research Lab, Department of Physics, Barkatullah University, Bhopal-462026 (India); Singh, R. K. [ITM University, Gurgaon, Haryana-122017 (India)

2011-07-15

474

Possible mechanism for cold denaturation of proteins at high pressure.  

PubMed

We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase (approximately 2 kbars) the mechanism for cold denaturation with decreasing temperature is the loss of local low-density water structure. We find our results in agreement with data of bovine pancreatic ribonuclease A. PMID:14525339

Marqus, Manuel I; Borreguero, Jose M; Stanley, H Eugene; Dokholyan, Nikolay V

2003-09-26

475

Ab initio studies of solid bromine under high pressure  

Microsoft Academic Search

Crystal structures of bromine under high pressure have been studied by employing plane-wave pseudopotential method with the generalized gradient approximation. It is found that the band overlap in the molecular Cmca phase, which causes the pressure-induced insulator-to-metal transition, occurs at about 55GPa . Geometry optimization shows that the bromine changes to a face-centered orthorhombic (fco) phase with equal interatomic distances

Defang Duan; Yanhui Liu; Yanming Ma; Zhiming Liu; Tian Cui; Bingbing Liu; Guangtian Zou

2007-01-01

476

High-pressure phase transition in {gamma}-hexanitrohexaazaisowurtzitane  

SciTech Connect

FTIR, EDXD, and PLM; data for a new high-pressure polymorph, {zeta}-HNIW, which is formed from {gamma}-HNIW at 0.7 +/- 0.05 GPa and room temperature. The {gamma}-{zeta} transformation is rapid and reversible in single crystals in a hydrostatic pressure transmitting medium, but the {zeta} form could not be retrieved to ambient conditions. 12 refs., 6 figs., 2 tabs.

Russell, T.P.; Miller, P.J. [Naval Surface Warfare Center, White Oak, MD (United States); Piermarini, G.J.; Block, S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

1992-06-25

477

High hydrostatic pressure and biology: a brief history  

Microsoft Academic Search

Pressure as a thermodynamical parameter was successively introduced in physics, hydrometallurgy, geochemistry, and biology.\\u000a In all cases, the main objective was to recreate a natural phenomenon (gas or liquid compressibility, synthesis or crystal\\u000a growth of minerals, survival of deep sea microorganisms). The introduction of high hydrostatic pressure (HHP) in Biology\\u000a was an important scientific feature over the last hundred years.

Grard Demazeau; Nolwennig Rivalain

2011-01-01

478

Possible Mechanism for Cold Denaturation of Proteins at High Pressure  

NASA Astrophysics Data System (ADS)

We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase (?2 kbars) the mechanism for cold denaturation with decreasing temperature is the loss of local low-density water structure. We find our results in agreement with data of bovine pancreatic ribonuclease A.

Marqus, Manuel I.; Borreguero, Jose M.; Stanley, H. Eugene; Dokholyan, Nikolay V.

2003-09-01