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1

Hand-arm vibration syndrome from exposure to high-pressure hoses.  

PubMed

Hand-arm vibration syndrome has been reported in the literature to occur following exposure to vibration from the use of many tools, but to date there have been no case reports of its occurrence in workers who have used high-pressure hoses, alone or with other tools. To remedy this, the case histories of nine subjects (two without mixed exposure) examined in the UK and Canada are presented, together with their severity classified according to the Stockholm scales. Attention is drawn to the need to use multiple diagnostic tests to establish the diagnosis and the need to implement vibration isolation and damping methodologies, as and when feasible, with respect to hose nozzles in order to minimize the hazard. The ultimate goal for tool manufacturers, hygienists and engineers should be to reduce workplace vibration levels to meet national and international guidelines and legislation, including UK Health & Safety Executive guidelines and European Economic Community directives. The respective risk levels are presented, together with vibration measurements on hoses used by some of the cases. PMID:11584120

Cooke, R; House, R; Lawson, I J; Pelmear, P L; Wills, M

2001-09-01

2

Ignition of PTFE-lined flexible hoses by rapid pressurization with oxygen  

NASA Technical Reports Server (NTRS)

A high-volume pneumatic-impact system has been used to test PTFE-lined stainless steel braided hoses, in order to characterize the roles played in the mechanism of oxygen-induced ignition by impact pressure, pressurization rate, and upstream and downstream volumes of the hose. Ignitions are noted to have occurred at impact pressures well below the working pressure of the hoses, as well as at pressurization rates easily obtainable through manual operation of valves. The use of stainless steel hardlines downstream of the hose prevented ignitions at all pressures and pressurization rates; internal observations have shown evidence of shock ionization in the oxygen prior to ignition.

Janoff, Dwight; Bamford, Larry J.; Newton, Barry E.; Bryan, Coleman J.

1989-01-01

3

High-flexibility, noncollapsing lightweight hose  

SciTech Connect

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

Method for predicting frictional loss in metal bellows and flexible hose  

NASA Technical Reports Server (NTRS)

Test date obtained concerning the frictional pressure loss to fluids flowing in unsleeved bellows and flexible hose. This data should be useful in the design of fluid systems where high delivery velocities are involved and flexible hose or bellows must be employed.

Cleveland, J. R.; Daniels, C. M.

1966-01-01

6

Fatigue testing of corrugated and Teflon hoses  

NASA Technical Reports Server (NTRS)

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.

1990-01-01

7

Clamp Restrains Pressure Line  

NASA Technical Reports Server (NTRS)

Safety restraint protects people and property if a high-pressure fitting fails. As long as pressure line remains attached at the fitting, clamp exerts essentially no force on hose. If fitting fails, force of fluid leaving free end of hose causes the cam on the clamp to compress hose with a positive locking action.

Aliberti, J. A.

1982-01-01

8

49 CFR 178.337-9 - Pressure relief devices, piping, valves, hoses, and fittings.  

Code of Federal Regulations, 2013 CFR

...at not less than 225 psig using dry air or inert gas. (c) Marking inlets and outlets. Except for gauging devices, thermometer wells, and pressure relief valves, each cargo tank inlet and outlet must be marked âliquidâ or âvaporâ to designate...

2013-10-01

9

High Pressure.  

National Technical Information Service (NTIS)

A review is given of high-pressure research which touches on the following topics: Experimental techniques; Chemical kinetics and equilibria; Inorganic chemistry; Orientational disorder and related topics; High-pressure phases; Fluids.

E. Whalley

1967-01-01

10

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

11

Effects of operating conditions of high pressure washing on the removal of biofilms from stainless steel surfaces  

Microsoft Academic Search

Hosing with water is the most common approach to cleaning in the food industry. Measurements of the removal of Pseudomonas aeruginosa biofilm from stainless steel using a high pressure hose showed that, over the range of pressures tested, impact pressure does not significantly affect microbial removal. Nozzle pressures of 2.5×106 and 9.5×106Pa were used, and the distance between the nozzle

Dean Burfoot; Karen Middleton

2009-01-01

12

Model to Design Drip Hose Lateral Line  

NASA Astrophysics Data System (ADS)

Introduction The design criterion for non-pressure compensating drip hose is normally to have 10% of flow variation (?q) in the lateral line, corresponding to 20% of head pressure variation (?H). Longer lateral lines in drip irrigation systems using conventional drippers provide cost reduction, but it is necessary to obtain to the uniformity of irrigation [1]. The use of ?q higher levels can provide longer lateral lines. [4] proposes the use of a 30% ?q and he found that this value resulted in distribution uniformity over 80%. [1] considered it is possible to extend the lateral line length using two emitters spacing in different section. He assumed that the spacing changing point would be at 40% of the total length, because this is approximately the location of the average flow according with [2]. [3] found that, for practical purposes, the average pressure is located at 40% of the length of the lateral line and that until this point it has already consumed 75% of total pressure head loss (hf ). In this case, the challenge for designers is getting longer lateral lines with high values of uniformity. Objective The objective of this study was to develop a model to design longer lateral lines using non-pressure compensating drip hose. Using the developed model, the hypotheses to be evaluated were: a) the use of two different spacing between emitters in the same lateral line allows longer length; b) it is possible to get longer lateral lines using high values of pressure variation in the lateral lines since the distribution uniformity stays below allowable limits. Methodology A computer program was developed in Delphi® based on the model developed and it is able to design lateral lines in level using non-pressure compensating drip hose. The input data are: desired distribution uniformity (DU); initial and final pressure in the lateral line; coefficients of relationship between emitter discharge and pressure head; hose internal diameter; pipe cross-sectional area with the dripper; and roughness coefficient for the Hazen-Williams equation. The program allows calculate the lateral line length with three possibilities: selecting two spacing between emitters and defining the exchange point; using two pre-established spacing between emitters and calculating the length of each section with different spacing; using one emitter spacing. Results Results showed that the use of two sections with different spacing between drippers in the lateral line didn't allow longer length but got better uniformity when compared with lateral line with one spacing between emitters. The adoption of two spacing increased the flow rate per meter in the final section which represented approximately 80% of the lateral line total length and this justifies their use. The software allowed DU above 90% with pressure head variation of 40% and the use of two spacing between emitters. Conclusions The developed model/software showed to be accurate, easy to handle and useful for lateral line design using non-pressure compensating drip hose. References [1] ANDRADE, L. A. D. Estudo de uniformidade de emissão de água utilizando diferentes espaçamentos entre gotejadores na linha lateral. 2009. 87 f. Tese (Doutorado em Agronomia/Irigação e Drenagem) - Faculdade de Ciências Agronômicas, Universidade Estadual Paulista 'Julio de Mesquita Filho', Botucatu, (2009). [2] KELLER, J.; BLIESNER, R. D. Sprinkle and trickle irrigation. Caldwell: Blackburn Press, (1990). 652 p. [3] TALENS, J. A. M. Riego localizado y fertirrigacion. Madrid: Mundi-Prensa, (2002). 533 p. [4] WU, I. P. An assessment of hydraulic design of micro-irrigation systems. Agricultural Water Management, Amsterdan, v. 32, n. 3

Ludwig, Rafael; Cury Saad, João Carlos

2014-05-01

13

[High Pressure Gas Tanks  

NASA Technical Reports Server (NTRS)

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

Quintana, Rolando

2002-01-01

14

Effects of Long Hose Breathing.  

National Technical Information Service (NTIS)

The need for aircrew members to use long breathing hoses between regulator and mask arises in the design of new transport aircraft and in several cargo operations requiring an open rear door. In this study, induced work of breathing through long hoses, th...

R. M. Olson J. P. Cooke

1977-01-01

15

Solar-collector silicone hose life test  

SciTech Connect

A life-cycle test of the recommended silicone hose installation was performed to verify that this configuration would protect the integrity of the system. The test rig was filled with inhibited water which was circulated through the test article. The water was alternately heated and pressurized and then cooled to simulate day and night operation in Arizona. The test indicated that the recommended modification would provide an economical and long-range solution to the problem.

Donohue, H.F.; Morse, R.L.

1982-08-11

16

High Blood Pressure (Hypertension)  

MedlinePLUS

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

17

High Blood Pressure  

MedlinePLUS

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

18

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

Code of Federal Regulations, 2010 CFR

...106). (b) Brake tubing and hose installation. Brake tubing and hose mustâ (1) Be long and flexible...segment. (d) Brake tubing and hose connections. All connections for air, vacuum, or hydraulic braking systems...

2009-10-01

19

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

Code of Federal Regulations, 2010 CFR

...106). (b) Brake tubing and hose installation. Brake tubing and hose mustâ (1) Be long and flexible...segment. (d) Brake tubing and hose connections. All connections for air, vacuum, or hydraulic braking systems...

2010-10-01

20

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

Code of Federal Regulations, 2013 CFR

...Transportation 5 2013-10-01 2013-10-01 false Brake tubing and hoses; hose assemblies and end fittings...PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.45 Brake tubing and hoses; hose assemblies and end...

2013-10-01

21

Solar energy systems: Standards for rubber hose  

Microsoft Academic Search

A study of commercial rubber hose was made to develop standards for hoses used in solar energy systems. Twelve hoses were evaluated by cycling between temperatures of about 100 C and temperatures as low as -40 C during a period of about seven months. Laboratory tests for bursting strength, compatibility with metals, compression set, ozone resistance, and water vapor transmission

R. D. Stiehler; J. L. Michalak

1979-01-01

22

Dilatometry under high pressure  

Microsoft Academic Search

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

Walter H. Fietz; Kai Grube; Hanno Leibrock

2000-01-01

23

49 CFR 571.106 - Standard No. 106; Brake hoses.  

Code of Federal Regulations, 2011 CFR

...900 psi expansion test requirements. The...Table I—Maximum Expansion of Free Length Brake...inside diameter Test pressure 1,000...when bent around a cylinder as specified in S6...temperature impulse test. A brake hose...fittings. S6.1.Expansion test....

2011-10-01

24

High Blood Pressure  

MedlinePLUS

... to high blood pressure: A diet high in salt, fat, and/or cholesterol Chronic conditions such as kidney and hormone problems, diabetes, and high cholesterol Family history: You are more likely to have high blood ...

25

Living with High Blood Pressure  

MedlinePLUS

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

26

Alloys For Flexible Hoses In A Corrosive Environment  

NASA Technical Reports Server (NTRS)

High-nickel alloy resists pitting corrosion. Report evaluates metal alloys for flexible hoses in corrosive environment. Tested to find alternatives to 304L stainless steel. Nineteen alloys selected for testing on basis of reputation for resistance to corrosion. Top five, in order of decreasing resistance to corrosion: Hastelloy(R) C-22, Inconel(R) 625, Hastelloy(R) C-276, Hastelloy(R) C-4, and Inco(R) alloy G-3. Of these, Hastelloy(R) C-22 found best for flexible-hose application.

Macdowell, Louis G., III; Ontiveros, Cordelia

1992-01-01

27

Tritium high pressure target  

NASA Astrophysics Data System (ADS)

The design of a tritium high pressure target with a volume of 16.5 cm3, developed at the RFNC-VNIIEF for research of muon fusion catalyzed in a H-D-T hydrogen isotopic mixture at pressures up to 120 MPa in the range of operating temperatures 300-800 K, is presented.

Perevozchikov, V. V.; Yukhimchuk, A. A.; Demin, D. L.; Ganchuk, N. S.; Grebinnik, V. G.; Grishechkin, S. K.; Ishkov, P. D.; Khabarov, Yu. A.; Lobanov, V. N.; Malkov, I. L.; Tikhonov, V. I.; Zinov, V. G.

1999-06-01

28

Evaluation of Hose in Hose Transfer Line Service Life for Hanfords Interim Stabilization Program  

Microsoft Academic Search

RPP-6153, Engineering Task Plan for Hose-in-Hose Transfer System for the Interim Stabilization Program (Torres, 2000a), defines the programmatic goals, functional requirements, and technical criteria for the development and subsequent installation of waste 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 (Torres, 2000b), has been issued to

2001-01-01

29

Effects of long-hose breathing.  

PubMed

The need for aircrew members to use long breathing hoses between regulator and mask arises in the design of new transport aircraft and in several cargo operations requiring an open rear door. In this study, induced work of breathing through long hoses, the resulting changes in oxygen consumption, and comfort were studied in relation to altitude, hose length, and exercise level. Conclusions were that, above 18,000 ft (5.5 km), a 30-ft (9.1-m) hose is acceptable for all reasonable work levels; for altitudes between 13,000 and 18,000 ft (4.0 and 5.5 km), the hose length should preferably be 18 ft (5.5m), and at altitudes below 13,000 ft (4.0 km), hose length should be limited to 12 ft (3.6). Moreover, at ground level, the hose length should be limited to 6 ft (1.8 m) for all but sedentary activity. Should the potential for rapid decompression exist, at any altitude, volume considerations limit hose length to 18 ft (5.5 m) since larger hoses possess excessive regulator-to-mask dead space. PMID:637792

Olson, R M; Cooke, J P

1978-02-01

30

46 CFR 131.880 - Fire hoses and axes.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Fire hoses and axes. 131.880 Section 131...SUPPLY VESSELS OPERATIONS Markings for Fire Equipment and Emergency Equipment § 131.880 Fire hoses and axes. Each fire hose and...

2013-10-01

31

46 CFR 98.25-80 - Cargo hose.  

Code of Federal Regulations, 2010 CFR

...DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-80 Cargo hose. (a) Cargo hose fabricated of seamless steel pipe with swivel joints, wire braided armored rubber or other hose material acceptable to the Commandant, shall...

2009-10-01

32

49 CFR 571.106 - Standard No. 106; Brake hoses.  

Code of Federal Regulations, 2012 CFR

...fittings during a slow pull test, and shall withstand...fittings during a fast pull test (S6.4). S5.3...magnification when bent around a cylinder as specified in S6...12High temperature impulse test. A brake hose assembly...fittings. S6.1.Expansion test....

2012-10-01

33

Failure analysis of braided U-shaped metal bellows flexible hoses  

NASA Astrophysics Data System (ADS)

Most of the research performed extensively reviews the effects of non-reinforced metal bellows and their pressurized characteristics. However, the majority of flex hoses are manufactured with reinforcement by the means of interweaved wire braids. For this research, the outer braid reinforced metal bellows flex hoses will be examined for their failure at differing lengths. The relationship with the bellows expansion joints is such that as the length of the flex hoses increases, the pressure at which squirm occurs decreases. As such, for the testing being performed, the same approach to failure is expected. As the length of the flex hose increases, it is predicted that the hose will fail at a decreasing pressure. Since the braid is the only thing that prevents the squirm from occurring, more of the load will be displaced from the bellows and into the braid. This will ultimately cause failure of the braid to occur at a lower pressure as the length of the hoses increase due to more of the load being transmitted from the bellows and into the braid.

Pierce, Stephen O.

34

Dispensing system eliminates torsion in deployed hoses  

NASA Technical Reports Server (NTRS)

Dispensing system uses a rotating drum, transfer arm, and stationary drum to deploy, reel in, and store an attached hose. This system which eliminates torsion and minimizes strain and wear of flexible hoses, is used for handling flexible cables that have one end permanently attached to an outlet or connector.

1965-01-01

35

Diamondoids under high pressure  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

36

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

37

Safety Modification of Cam-and-Groove Hose Coupling  

NASA Technical Reports Server (NTRS)

A modification has been made in the mating halves of a cam-and-groove hose coupling to prevent rapid separation of the halves in the event that the cam levers are released while the fluid in the hose is pressurized. The need for this modification arises because commercial off-the-shelf cam-and-groove hose-coupling halves do not incorporate safety features to prevent separation in the pressurized state. Especially when the pressurized fluid is compressible (e.g., steam or compressed air), the separated halves can be propelled with considerable energy, causing personal injury and/or property damage. Therefore, one purpose served by the modification is to provide for venting to release compressive energy in a contained and safe manner while preventing personal injury and/or property damage. Another purpose served by the modification, during the process of connecting the coupling halves, is to ensure that the coupling halves are properly aligned before the cam levers can be locked into position.

Schwindt, Paul; Littlefield, Alan

2008-01-01

38

High Pressure Plasma Research.  

National Technical Information Service (NTIS)

The research goals, the approach, and the results of the High Pressure Plasma Research, Group V-4, are presented. Also included is a brief description of Air Force applications of this research as well as comprehensive list of publications and presentatio...

U. H. Bauder

1972-01-01

39

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

40

High pressure furnace  

DOEpatents

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

Morris, D.E.

1993-09-14

41

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

42

High pressure oxygen furnace  

DOEpatents

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

Morris, D.E.

1992-07-14

43

What Causes High Blood Pressure?  

MedlinePLUS

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

44

High pressure atomization  

NASA Astrophysics Data System (ADS)

The main objective of these grants has been to study the fundamental processes which lead to the atomization of high pressure jets injected into compressed gases through single hole nozzles. Specific topics include: Dependence of Spray Angle and Other Spray Parameters on Nozzle Design and Operating Conditions; Ultra High Speed Filming of Atomizing Jets; Mechanism of Breakup of Highly Super Heated Liquid Jets; Measurements of the Spray Angle of Atomizing Jets; Mechanism of Atomization of a Liquid Jet; Scaling of Transient Laminar, Turbulent, and Spray Jets; Computations of Drop Sizes in Pulsating Sprays and of Liquid Core Length in Vaporizing Sprays; and Scaling of Impulsively Started Sprays.

Bracco, F. V.

1982-03-01

45

33 CFR 183.560 - Hose clamps: Installation.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Hose clamps: Installation. 183.560 Section 183.560...Manufacturer Requirements § 183.560 Hose clamps: Installation. Each hose clamp on a hose from the fuel tank to the fuel...

2010-07-01

46

33 CFR 183.560 - Hose clamps: Installation.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Hose clamps: Installation. 183.560 Section 183.560...Manufacturer Requirements § 183.560 Hose clamps: Installation. Each hose clamp on a hose from the fuel tank to the fuel...

2009-07-01

47

Prediction of flow-induced failures of braided flexible hoses and bellows  

NASA Technical Reports Server (NTRS)

Analytical techniques were developed to evaluate braided hoses and bellows for possibility of flow induced resonance. These techniques determine likelihood of high cycle fatigue failure when such resonance exists.

Sack, L. E.; Nelson, R. L.; Mason, D. R.; Cooper, R. A.

1972-01-01

48

High Blood Pressure and Women  

MedlinePLUS

High Blood Pressure and Women Updated:Feb 5,2014 Many people mistakenly believe that high blood pressure, also called ... content was last reviewed on 02/04/14. High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

49

High pressure induced superconductivity  

Microsoft Academic Search

We have developed complex extreme condition of very low temperature down to 30 mK and ultra high pressure exceeding 200 GPa by assembling compact diamond anvil cell (DAC) on a powerful 3He\\/4He dilution refrigerator. We have also developed measuring techniques of electrical resistance, magnetization and optical measurement for the sample confined in the sample space of the DAC. Using the

K. Amaya; K. Shimizu

2003-01-01

50

Cryogenic High Pressure Sensor Module  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

51

Cryogenic, Absolute, High Pressure Sensor  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

52

Internal Thermal Control System Hose Heat Transfer Fluid Thermal Expansion Evaluation Test Report  

NASA Technical Reports Server (NTRS)

During assembly of the International Space Station, the Internal Thermal Control Systems in adjacent modules are connected by jumper hoses referred to as integrated hose assemblies (IHAs). A test of an IHA has been performed at the Marshall Space Flight Center to determine whether the pressure in an IHA filled with heat transfer fluid would exceed the maximum design pressure when subjected to elevated temperatures (up to 60 C (140 F)) that may be experienced during storage or transportation. The results of the test show that the pressure in the IHA remains below 227 kPa (33 psia) (well below the 689 kPa (100 psia) maximum design pressure) even at a temperature of 71 C (160 F), with no indication of leakage or damage to the hose. Therefore, based on the results of this test, the IHA can safely be filled with coolant prior to launch. The test and results are documented in this Technical Memorandum.

Wieland, P. O.; Hawk, H. D.

2001-01-01

53

Pressure Dome for High-Pressure Electrolyzer  

NASA Technical Reports Server (NTRS)

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

Norman, Timothy; Schmitt, Edwin

2012-01-01

54

Questions and Answers about High Blood Pressure  

MedlinePLUS

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

55

Stroke and High Blood Pressure  

MedlinePLUS

Stroke and High Blood Pressure Updated:May 30,2014 Stroke is America's no. 4 killer and a leading cause of severe, long-term disability. Since managing high blood pressure, also called hypertension, is the most important thing ...

56

High pressure mechanical seal  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

57

High pressure mechanical seal  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

58

Hosing in Laser Channeling in Fast Ignition  

NASA Astrophysics Data System (ADS)

Laser channeling aims to reduce the energy loss of an ignition pulse in the mm-scale underdense plasma of fast ignition targets. Previous full-scale particle-in-cell (PIC) simulations in 2D identified laser and channel hosing as an important instability that causes channel-bifurcation and limits channeling speed [1]. Hosing in 3D has also been observed in recent PIC simulations, which show that hosing grows slower in 3D than in 2D. Laser hosing in this long wavelength regime is through coupling with the ion acoustic waves. A variational analysis of hosing in 2D and 3D will also be presented. This work was supported by the U.S. Department of Energy under Cooperative Agreement Nos. DE-FC52-92SF19460, DE-FC02-04ER54789, and DE-FG02-06ER54879. [4pt] [1] G. Li et al., Phys. Rev. Lett. 100, 125002(2008).

Li, G.; Yan, R.; Ren, C.; Goncharov, V. N.; Tonge, J.; Mori, W. B.

2009-11-01

59

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

Code of Federal Regulations, 2013 CFR

...are the requirements for lights on a floating hose string? 149.550 Section... Aids to Navigation Lights on Floating Hose Strings § 149.550 What are the requirements for lights on a floating hose string? Hose strings...

2013-07-01

60

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

Code of Federal Regulations, 2010 CFR

...are the requirements for lights on a floating hose string? 149.550 Section... Aids to Navigation Lights on Floating Hose Strings § 149.550 What are the requirements for lights on a floating hose string? Hose strings...

2009-07-01

61

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

Code of Federal Regulations, 2010 CFR

...are the requirements for lights on a floating hose string? 149.550 Section... Aids to Navigation Lights on Floating Hose Strings § 149.550 What are the requirements for lights on a floating hose string? Hose strings...

2010-07-01

62

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

63

High Blood Pressure and Stroke  

MedlinePLUS Videos and Cool Tools

A service of the U.S. National Library of Medicine National Institutes of Health Home About MedlinePlus Site ... March 13, 2014 Related MedlinePlus Pages Blood Pressure Medicines High Blood Pressure Stroke Transcript A broad review ...

64

High Blood Pressure During Pregnancy  

MedlinePLUS

... blood pressure affect pregnancy? When a woman has high blood pressure in pregnancy, it may cause less blood to flow to the placenta . The fetus receives less of the oxygen and nutrients it needs. This can cause the ...

65

High Blood Pressure in Pregnancy  

MedlinePLUS

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

66

Aspirated High Pressure Compressor.  

National Technical Information Service (NTIS)

The design and test of a two-stage, vaneless, aspirated counter- rotating fan is presented in this paper. The fan nominal design objectives were a pressure ratio of 3:1 and adiabatic efficiency of 87%. A pressure ratio of 2.9 at 89% efficiency was measure...

A. A. Merchant A. H. Epstein G. R. Guenette J. L. Kerrebrock R. C. Maclaurin

2006-01-01

67

46 CFR 169.735 - Fire hose stations.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Fire hose stations. 169.735 ...SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.735 Fire hose stations. Each fire hydrant must be identified...

2013-10-01

68

Protein crystallization under high pressure.  

PubMed

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

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

2002-03-25

69

Electrochemical High Pressure Pump.  

National Technical Information Service (NTIS)

The invention provides electrochemically-based methods and devices for producing fluid flow and/or changes in fluid pressure. In the methods and devices of the invention, current is passed through a divided electrochemical cell. Adjacent compartments of t...

C. A. Koval C. E. Evans M. A. Norman R. D. Noble

2005-01-01

70

High Pressure Synthetic Chemistry.  

ERIC Educational Resources Information Center

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

Hagen, Arnulf P.

1978-01-01

71

Fire hose gripping device and process for fighting fires in oil refineries and the like  

SciTech Connect

This patent describes a firefighting process. It comprises the steps of: attaching one end of a fire hose to a fire hydrant when the end of the fire hose is in a generally collapsed flattened position; uncoiling the fire hose; attaching a manually grippable spray nozzle to the other end of the fire hose; inflating and substantially filling the fire hose with water from the water supply means to expand the hose to a semirigid expanded position; grasping, lifting, and carrying the filled fire hose with one hand; gripping a vertical elastomeric handle of a hose clamp with the other hand. The hose clamp having a generally U-shaped hose-engaging member. The U-shaped hose-engaging member having an open end defining an access opening for receiving the hose. The access opening being larger than the maximum diameter and transverse span of the uncoiled filled fire hose: inserting the hose-engaging member on the fire hose such that there is sufficient clearance between the hose-engaging member and the fire hose to side hose clamp to another position; moving the hose clamp at an acute angle of inclination relative to the hose to detachable secure and inter-lockingly engage the hose-engaging member to the filled fire hose; manually lifting the vertical elastomeric handle of the hose clamp to elevate the fire hose; pointing the nozzle towards the fire; and spraying water from the nozzle on the fire.

Lancaster, D.R.; Everding, R.J.

1989-08-15

72

Algorithms for provisioning virtual private networks in the hose model  

Microsoft Academic Search

Virtual Private Networks(VPNs) provide customers with predictable and secure network connections over a shared network. The recently proposed hose model for VPNs allows for greater flexibility since it permits traffic to and from a hose endpoint to be arbitrarily distributed to other endpoints. In this paper, we develop novel algorithms for provisioning VPNs in the hose model. We connect VPN

Amit Kumar; Rajeev Rastogi; Abraham Silberschatz; Bülent Yener

2001-01-01

73

33 CFR 183.558 - Hoses and connections.  

Code of Federal Regulations, 2013 CFR

...marked on the tank label under § 183.514(b)(3). (c) Each hose must be secured by: (1) A swaged sleeve; (2) A sleeve and threaded insert; or (3) A hose clamp. (d) The inside diameter of a hose must not exceed...

2013-07-01

74

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Clips, straps, and hose clamps. 183.532 Section 183.532 Navigation...Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a corrosion...

2010-07-01

75

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Clips, straps, and hose clamps. 183.532 Section 183.532 Navigation...Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a corrosion...

2009-07-01

76

46 CFR 105.35-15 - Fire hose.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Fire hose. 105.35-15 Section 105.35-15...FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose...

2013-10-01

77

46 CFR 154.1155 - Hand hose line: Coverage.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Hand hose line: Coverage. 154.1155 Section...Firefighting System: Dry Chemical § 154.1155 Hand hose line: Coverage. The coverage for the area for a hand hose line under § 154.1150 must not...

2013-10-01

78

Modeling of high pressure thawing  

Microsoft Academic Search

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

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

1996-01-01

79

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

80

High pressure storage vessel  

SciTech Connect

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

81

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

82

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

83

High Pressure Particulate Physics Facility.  

National Technical Information Service (NTIS)

This report documents the initial development of the High Pressure Particulate Physics (HP3) facility. The facility is anticipated to allow precision impact of two flat plates at a very high degree of precision with minimal misalignment when completed. A ...

L. C. Chhabildas W. L. Cooper W. R. Maines

2011-01-01

84

High pressure ices  

PubMed Central

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

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

2012-01-01

85

Centrifugal compressors handle high pressures  

Microsoft Academic Search

Applications for high-pressure centrifugal compressors include reinjection of gas associated with oil production or residue gas from NGL recovery into the producing formation. This application serves several purposes. It maintains oil-field pressure to obtain higher production rates and maintains gas-field pressures to maximize liquids recovery. Gas reinjection also conserves gas resources by eliminating flaring until the gas can be produced.

1979-01-01

86

High Pressure Thermodynamics of Mixtures  

Microsoft Academic Search

Abstract—In 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

87

Medications for High Blood Pressure  

MedlinePLUS

... and Angiotensin II receptor blockers (ARBs), reduce blood pressure by relaxing blood vessels Beta blockers, which also cause the heart to ... nerve impulses from the brain to relax blood vessels Many people with high blood pressure may need more than one medication to reach ...

88

Electrokinetic high pressure hydraulic system  

Microsoft Academic Search

A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force is described. The electrokinetic pump, which can generate hydraulic pressures greater than 2,500 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

P. H. Paul; D. J. Rakestraw

2000-01-01

89

Electrokinetic high pressure hydraulic system  

Microsoft Academic Search

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

Phillip H. Paul; David J. Rakestraw

2000-01-01

90

Steam Oxidation at High Pressure  

SciTech Connect

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

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

2013-07-19

91

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

92

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

93

High Pressure Industrial Water Facility  

NASA Technical Reports Server (NTRS)

In conjunction with Space Shuttle Main Engine testing at Stennis, the Nordberg Water Pumps at the High Pressure Industrial Water Facility provide water for cooling the flame deflectors at the test stands during test firings.

1992-01-01

94

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

95

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. 4 figures.

Ward, M.E.; Harkins, B.D.

1993-11-30

96

Electrokinetic high pressure hydraulic system  

DOEpatents

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

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

2000-01-01

97

Electrokinetic high pressure hydraulic system  

DOEpatents

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

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

2001-01-01

98

High-pressure creep tests  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

99

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

100

High Blood Pressure and Metabolic Syndrome  

MedlinePLUS

... Pressure High Blood Pressure Tools & Resources Stroke More High Blood Pressure and Metabolic Syndrome Updated:Aug 27,2012 Metabolic ... content was last reviewed on 04/04/2012. High Blood Pressure • Home • About High Blood Pressure (HBP) Introduction What ...

101

What Is High Blood Pressure Medicine?  

MedlinePLUS

(continued) Lifestyle + Risk Reduction High Blood Pressure What should I know about taking medicine? • Your doctor may prescribe one or more drugs to ... What Is High Blood Pressure Medicine? Lifestyle + Risk Reduction High Blood Pressure ANSWERS by heart Take a ...

102

Avoid the Consequences of High Blood Pressure  

MedlinePLUS

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

103

Efficient computation of three-dimensional flow in helically corrugated hoses including swirl  

Microsoft Academic Search

In this article we propose an ecient method to compute the friction factor of helically corrugated hoses carrying flow at high Reynolds numbers. A comparison between computations of sev- eral turbulence models is made with experimental results for cor- rugation sizes that fall outside the range of validity of the Moody diagram. To do this eciently we implement quasi-periodicity. Using

Bas J. van der Linden; M Pisarenco; Jacques Dam; Arris S. Tijsseling

2009-01-01

104

High-pressure water facility  

NASA Technical Reports Server (NTRS)

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

2006-01-01

105

46 CFR 181.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2013 CFR

...Shipping 7 2013-10-01 2013-10-01 false Fire hoses and nozzles. 181.320 Section 181.320...SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) FIRE PROTECTION EQUIPMENT Fire Main System § 181.320 Fire hoses and...

2013-10-01

106

46 CFR 118.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2013 CFR

...Shipping 4 2013-10-01 2013-10-01 false Fire hoses and nozzles. 118.320 Section 118.320...OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS FIRE PROTECTION EQUIPMENT Fire Main System § 118.320 Fire hoses and...

2013-10-01

107

46 CFR 108.425 - Fire hoses and associated equipment.  

Code of Federal Regulations, 2013 CFR

...Shipping 4 2013-10-01 2013-10-01 false Fire hoses and associated equipment. 108.425 Section...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fire Main System § 108.425 Fire hoses and...

2013-10-01

108

High Blood Pressure: Medicines to Help You  

MedlinePLUS

High Blood Pressure--Medicines to Help You Click here for the Color Version (PDF 533KB) High blood pressure is a serious illness. High ... your heart relaxes ( diastolic pressure ). High Blood Pressure Medicines Use this guide to help you talk to ...

109

Charge Transfer to MEMS Pressure Sensors By Glow Discharge Plasmas  

Microsoft Academic Search

Electrical charging resulting in temporary performance degradation of automotive MEMS pressure sensors has been observed. A method of charge transfer from the outside of a statically charged hose, along the inside the hose, through the module port, to a sensor inside the module is proposed. Specifically, the existence of a glow discharge plasma through the hose, is analyzed with respect

T. M. Betzner

2006-01-01

110

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.degree. to 30.degree. C.

Markey, John K. (New Haven, CT)

1989-01-01

111

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

112

Elevated toxicant yields with narghile waterpipes smoked using a plastic hose  

Microsoft Academic Search

The effect of hose permeability on toxicant yields for the narghile waterpipe is investigated, with special reference to the recent adoption of plastic as a hose construction material. Measurements of air infiltration rates for 23 leather and plastic hoses representing 11 types commonly available in Beirut, Lebanon were made, revealing that while leather hoses allowed significant outside air infiltration during

Rawad Saleh; Alan Shihadeh

2008-01-01

113

High Pressure Electrolyzer System Evaluation  

NASA Technical Reports Server (NTRS)

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

Prokopius, Kevin; Coloza, Anthony

2010-01-01

114

Electokinetic high pressure hydraulic system  

DOEpatents

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

2000-01-01

115

Improved high pressure turbine shroud  

NASA Technical Reports Server (NTRS)

A new high pressure turbine shroud material has been developed from the consolidation of prealloyed powders of Ni, Cr, Al and Y. The new material, a filler for cast turbine shroud body segments, is called Genaseal. The development followed the identification of oxidation resistance as the primary cause of prior shroud deterioration, since conversion to oxides reduces erosion resistance and increases spalling under thermal cycled engine conditions. The NICrAlY composition was selected in preference to NIAL and FeCRALY alloys, and was formulated to a prescribed density range that offers suitable erosion resistance, thermal conductivity and elastic modulus for improved behavior as a shroud.

Bessen, I. I.; Rigney, D. V.; Schwab, R. C.

1977-01-01

116

46 CFR 193.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2013 CFR

...Shipping 7 2013-10-01 2013-10-01 false Fire hydrants and hose. 193.10-10 Section 193...CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Fire Main System, Details § 193.10-10 Fire...

2013-10-01

117

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2013 CFR

...Shipping 4 2013-10-01 2013-10-01 false Fire hydrants and hose. 95.10-10 Section 95...CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Fire Main System, Details § 95.10-10 Fire...

2013-10-01

118

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2010 CFR

...in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily...Firehose and couplings must be as follows: (1) Fire station hydrant connections shall be brass, bronze, or...

2009-10-01

119

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2010 CFR

...in length, and only one hose will be required at each fire station; however, if all such stations can be satisfactorily...Firehose and couplings must be as follows: (1) Fire station hydrant connections shall be brass, bronze, or...

2010-10-01

120

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

121

How Is High Blood Pressure Diagnosed?  

MedlinePLUS Videos and Cool Tools

... Intramural Research 4 Home » Health Information for the Public » Health Topics » High Blood Pressure » Diagnosis High Blood Pressure ... The Heart Truth campaign offers a variety of public health resources to help educate women and health professionals ...

122

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

123

Infrared Spectra of High Pressure Carbon Monoxide.  

National Technical Information Service (NTIS)

We report infrared (IR) spectroscopic measurements of carbon monoxide (CO) at high pressures. Although CO is one of the simplest heteronuclear diatomic molecules, it displays surprisingly complex behavior at high pressures and has been the subject of seve...

W. J. Evans M. J. Lipp H. E. Lorenzana

2001-01-01

124

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

2008-06-10

125

High-pressure cryogenic seals for pressure vessels  

NASA Technical Reports Server (NTRS)

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

Buggele, A. E.

1977-01-01

126

Feedthrough Seal For High-Pressure Vessel  

NASA Technical Reports Server (NTRS)

Combination of ceramic and plastic withstands many depressurizations. Stack of washers surrounds leadthrough electrode. Under pressure washers expand to fill leadthrough hole in high-pressure vessel. Seal thus formed withstands 20 or more pressurization/depressurization cycles. Seal composed of neoprene, polytetrafluoroethylene, nylon and high-purity, high-density commercial alumina ceramic.

Williams, R.; Mullins, O.; Smith, D.; Teasley, G.

1984-01-01

127

The analysis of high pressure experimental data  

NASA Technical Reports Server (NTRS)

This letter is concerned with the analysis of high pressure experimental data. It is demonstrated that ln H plots based on the Vinet et al. (1988) universal equation of state are a simple sensitive means for identifying anomalous P-V data in high pressure experiments and for detecting structural and phase transitions in solids subjected to high pressure.

Schlosser, Herbert; Ferrante, John

1991-01-01

128

Pressure drop in cyclone separator at high pressure  

Microsoft Academic Search

For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter\\u000a and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from the stand pipe into\\u000a the cyclone was specially focused. A semi-empirical model was developed for the prediction of the pressure drop of the

Zhiping Zhu; Yongjie Na; Qinggang Lu

2008-01-01

129

High-pressure phase of magnetite  

Microsoft Academic Search

Mössbauer spectroscopy and x-ray diffraction were employed to investigate the magnetic and structural properties of the high-pressure monoclinic phase of magnetite. Measurements were performed to 66 GPa at 300 K using diamond anvil cells. Based primarily upon the Mössbauer parameters, the following features of the high-pressure phase were deduced. With increasing pressure the high-pressure phase evolves at P>=25 GPa and

Moshe Paz Pasternak; Saburo Nasu; Koji Wada; Shoichi Endo

1994-01-01

130

Evaluation of high temperature pressure sensors  

SciTech Connect

It is becoming more important to measure the pressure in high temperature environments in many industrial fields. However, there is no appropriate evaluation system and compensation method for high temperature pressure sensors since most pressure standards have been established at room temperature. In order to evaluate the high temperature pressure sensors used in harsh environments, such as high temperatures above 250 deg. C, a specialized system has been constructed and evaluated in this study. The pressure standard established at room temperature is connected to a high temperature pressure sensor through a chiller. The sensor can be evaluated in conditions of changing standard pressures at constant temperatures and of changing temperatures at constant pressures. According to the evaluation conditions, two compensation methods are proposed to eliminate deviation due to sensitivity changes and nonlinear behaviors except thermal hysteresis.

Choi, In-Mook; Woo, Sam-Yong; Kim, Yong-Kyu [Center for Mass-Related Quantities, Korea Research Institute of Standards and Science (KRISS), P.O. Box 102, Yuseong, Daejeon 305-600 (Korea, Republic of)

2011-03-15

131

Low-pressure wellhead for high-pressure stimulation  

SciTech Connect

Maturity of US Producing wells and constrained economics dictate careful planning and strict attention to details to optimize workover and recompletion operations. One aspect of operations that can significantly reduce costs is planned preparation of a wellheat for high-pressure stimulation. Historically, there have been four basic approaches to solving old wellhead configuration problems to prepare for high-pressure stimulation down casing. Some recent technical developments may provide a lower-cost solution. A casing spool is now available that features an external casing seal that cannot be pumped out. This seal is extremely reliable and has functioned on many extreme-pressure (15,000-psi) jobs without a single failure. Having the seal installed in a frac spool'' is very important because it provides convenient adaption from the low-pressure casing hanger to high-pressure control equipment with safety and reliability. Casing hanger seals are isolated from the harsh stimulation environment. While the newly available spool discussed above provides a partial solution to the low-pressure-wellhead/high-pressure-stimulation problem, valve performance must also be considered. Recent improvements in gate-valve design have produced a valve that meets all required performance criteria for efficient stimulation operations. The new frac valve'' features low maintenance with close tolerances on gate/seal surfaces, low operating torque, high corrosion and erosion resistance, sealing in both directions, and generally high performance in functionality.

Garvin, T.

1994-05-01

132

High-Pressure Lightweight Thrusters  

NASA Technical Reports Server (NTRS)

Returning samples of Martian soil and rock to Earth is of great interest to scientists. There were numerous studies to evaluate Mars Sample Return (MSR) mission architectures, technology needs, development plans, and requirements. The largest propulsion risk element of the MSR mission is the Mars Ascent Vehicle (MAV). Along with the baseline solid-propellant vehicle, liquid propellants have been considered. Similar requirements apply to other lander ascent engines and reaction control systems. The performance of current state-ofthe- art liquid propellant engines can be significantly improved by increasing both combustion temperature and pressure. Pump-fed propulsion is suggested for a single-stage bipropellant MAV. Achieving a 90-percent stage propellant fraction is thought to be possible on a 100-kg scale, including sufficient thrust for lifting off Mars. To increase the performance of storable bipropellant rocket engines, a high-pressure, lightweight combustion chamber was designed. Iridium liner electrodeposition was investigated on complex-shaped thrust chamber mandrels. Dense, uniform iridium liners were produced on chamber and cylindrical mandrels. Carbon/carbon composite (C/C) structures were braided over iridium-lined mandrels and densified by chemical vapor infiltration. Niobium deposition was evaluated for forming a metallic attachment flange on the carbon/ carbon structure. The new thrust chamber was designed to exceed state-of-the-art performance, and was manufactured with an 83-percent weight savings. High-performance C/Cs possess a unique set of properties that make them desirable materials for high-temperature structures used in rocket propulsion components, hypersonic vehicles, and aircraft brakes. In particular, more attention is focused on 3D braided C/Cs due to their mesh-work structure. Research on the properties of C/Cs has shown that the strength of composites is strongly affected by the fiber-matrix interfacial bonding, and that weakening interface realizes pseudo-plastic behavior with significant increase in the tensile strength. The investigation of high-temperature strength of C/Cs under high-rate heating (critical for thrust chambers) shows that tensile and compression strength increases from 70 MPa at room temperature to 110 MPa at 1,773 K, and up to 125 MPa at 2,473 K. Despite these unique properties, the use of C/Cs is limited by its high oxidation rate at elevated temperatures. Lining carbon/carbon chambers with a thin layer of iridium or iridium and rhenium is an innovative way to use proven refractory metals and provide the oxidation barrier necessary to enable the use of carbon/ carbon composites. Due to the lower density of C/Cs as compared to SiC/SiC composites, an iridium liner can be added to the C/C structure and still be below the overall thruster weight. Weight calculations show that C/C, C/C with 50 microns of Ir, and C/C with 100 microns of Ir are of less weight than alternative materials for the same construction.

Holmes, Richard; McKechnie, Timothy; Shchetkovskiy, Anatoliy; Smirnov, Alexander

2013-01-01

133

High-pressure polymorphism in amino acids  

Microsoft Academic Search

Pressure up to 10 GPa is a powerful method for studying polymorphism in organic crystal structures, and this review surveys work carried out on high-pressure polymorphism in amino acids. High-pressure polymorphs have been established crystallographically for glycine, alanine, serine, cysteine and leucine. Phase transitions can be driven by the avoidance of very short intermolecular contacts or by promotion of a

Stephen A. Moggach; Simon Parsons; Peter A. Wood

2008-01-01

134

Manufacturing Diamond Under Very High Pressure  

NASA Technical Reports Server (NTRS)

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

Voronov, Oleg

2007-01-01

135

Apparatus for Testing High Pressure Injector Elements.  

National Technical Information Service (NTIS)

An apparatus for testing and evaluating the spray pattern of high pressure fuel injector elements for use in supplying fuel to combustion engines is presented. Prior art fuel injector elements were normally tested by use of low pressure apparatuses which ...

W. N. Myers E. M. Scott J. C. Forbes M. D. Shadoan

1993-01-01

136

High pressure pulsed capillary viscometry  

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

137

Mössbauer spectroscopy at very high pressures  

Microsoft Academic Search

The generation of Very High Pressure (VHP) with Diamond Anvil Cells (DAC) and its applications to Mössbauer Spectroscopy (MS) are described. We emphasize the technical aspects of DACs relevant to VHP-MS such as collimation. generation of hydrostatic pressures, pressure calibration, and development of special cells. Examples are given showing the potential of VHP-MS in studies of molecular polymerization, order disorder

Moshe P. Pasternak; R. Dean Taylor

1990-01-01

138

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

139

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

140

High Pressure, Solid State Experiments for NIF.  

National Technical Information Service (NTIS)

In this report, we summarize our plan for using NIF for measuring solid-state deformation physics at very high pressures. There are several key uncertainties, the strength and phase being two of them. The deformation mechanisms at high pressure and high s...

B. Remington J. Belak J. Colvin J. Edwards D. Kalantar B. Lasinski

2001-01-01

141

NETL- High-Pressure Combustion Research Facility  

SciTech Connect

NETL's High-Pressure Combustion Facility is a unique resource within the National Laboratories system. It provides the test capabilities needed to evaluate new combustion concepts for high-pressure, high-temperature hydrogen and natural gas turbines. These concepts will be critical for the next generation of ultra clean, ultra efficient power systems.

None

2013-07-08

142

NETL- High-Pressure Combustion Research Facility  

ScienceCinema

NETL's High-Pressure Combustion Facility is a unique resource within the National Laboratories system. It provides the test capabilities needed to evaluate new combustion concepts for high-pressure, high-temperature hydrogen and natural gas turbines. These concepts will be critical for the next generation of ultra clean, ultra efficient power systems.

None

2014-06-26

143

PSG Flow in High-Pressure Steam  

Microsoft Academic Search

Phosphosilicate glass (PSG) flow in high-pressure gas ambient is examined. PSG flow is enhanced with increasing pressure of steam ambient. Annealing temperature can be reduced by 80°C or the phosphorous concentration can be decreased by about 2 wt% by increasing the steam partial pressure from 0.95 kg\\/cm2 to 8.5 kg\\/cm2 from the viewpoint of planarization. The increase in pressure of

Shuichi Mayumi; Seiji Ueda

1990-01-01

144

Oblique electron fire hose instability: Particle-in-cell simulations  

NASA Astrophysics Data System (ADS)

Nonlinear properties of the oblique resonant electron fire hose instability are investigated using two-dimensional particle-in-cell simulations in the Darwin approximation for weak initial growth rates. The weak electron fire hose instability has a self-destructive nonlinear behavior; it destabilizes a nonpropagating branch which only exists for a sufficiently strong temperature anisotropy. The nonlinear evolution leads to generation of nonpropagating waves which in turn scatter electrons and reduce their temperature anisotropy. As the temperature anisotropy is being reduced, the nonpropagating branch disappears and the generated standing waves are transformed to propagating whistler waves which are rapidly damped. Consequently, the oblique electron fire hose efficiently reduces the electron temperature anisotropy.

Hellinger, Petr; Trávní?ek, Pavel M.; Decyk, Victor K.; Schriver, David

2014-01-01

145

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

146

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

147

High-pressure gas hydrates.  

PubMed

It has long been known that crystalline hydrates are formed by many simple gases that do not interact strongly with water, and in most cases the gas molecules or atoms occupy 'cages' formed by a framework of water molecules. The majority of these gas hydrates adopt one of two cubic cage structures and are called clathrate hydrates. Notable exceptions are hydrogen and helium which form 'exotic' hydrates with structures based on ice structures, rather than clathrate hydrates, even at low pressures. Clathrate hydrates have been extensively studied because they occur widely in nature, have important industrial applications, and provide insight into water-guest hydrophobic interactions. Until recently, the expectation-based on calculations-had been that all clathrate hydrates were dissociated into ice and gas by the application of pressures of 1 GPa or so. However, over the past five years, studies have shown that this view is incorrect. Instead, all the systems so far studied undergo structural rearrangement to other, new types of hydrate structure that remain stable to much higher pressures than had been thought possible. In this paper we review work on gas hydrates at pressures above 0.5 GPa, identify common trends in transformations and structures, and note areas of uncertainty where further work is needed. PMID:18259632

Loveday, J S; Nelmes, R J

2008-02-21

148

Potassium and High Blood Pressure  

MedlinePLUS

... foods, fish, poultry, beans, seeds and unsalted nuts reduced systolic and diastolic blood pressure by 5.5/3.0 mm Hg compared to the control diet (what the average American eats). The D.A.S.H. eating plan also contained less salt and sodium; sweets, added sugars and sugar-containing beverages; fats; ...

149

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

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Fire mains and hose connections. 167.45-25...NAUTICAL SCHOOL SHIPS Special Firefighting and Fire Prevention Requirements § 167.45-25 Fire mains and hose connections. All pipes...

2013-10-01

150

Hosing Instability Suppression in Self-Modulated Plasma Wakefields  

NASA Astrophysics Data System (ADS)

We show that the hosing instability can be suppressed after the saturation of the self-modulation instability of a long particle bunch if the plasma density perturbation is linear. We derive scalings for maximum bunch tilts and seeds for the self-modulation instability to ensure stable propagation beyond saturation of self-modulation instability. Numerical solutions of the reduced hosing equations and three-dimensional particle-in-cell simulations confirm our analytical findings. Our results may also apply when a train of particle bunches or laser pulses excites a linear wake.

Vieira, J.; Mori, W. B.; Muggli, P.

2014-05-01

151

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

152

Thermopower of lead chalcogenides at high pressures  

Microsoft Academic Search

Thermopower measurements on PbX crystals (X=Te, Se, S) at high hydrostatic pressures of up to 35 GPa are reported. New data were obtained on the magnitude and on the\\u000a pressure dependence of the thermopower of high-pressure semiconducting and metallic phases. The phase transitions occurring\\u000a in PbX are treated in terms of a model in which the transition to an insulator

V. V. Shchennikov; S. V. Ovsyannikov; A. Yu. Derevskov

2002-01-01

153

Fuel droplet burning rates at high pressures.  

NASA Technical Reports Server (NTRS)

Combustion of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane was observed in air under natural convection conditions, at pressures up to 100 atm. The droplets were simulated by porous spheres, with diameters in the range from 0.63 to 1.90 cm. The pressure levels of the tests were high enough so that near-critical combustion was observed for methanol and ethanol. Due to the high pressures, the phase-equilibrium models of the analysis included both the conventional low-pressure approach as well as high-pressure versions, allowing for real gas effects and the solubility of combustion-product gases in the liquid phase. The burning-rate predictions of the various theories were similar, and in fair agreement with the data. The high-pressure theory gave the best prediction for the liquid-surface temperatures of ethanol and propanol-1 at high pressure. The experiments indicated the approach of critical burning conditions for methanol and ethanol at pressures on the order of 80 to 100 atm, which was in good agreement with the predictions of both the low- and high-pressure analysis.

Canada, G. S.; Faeth, G. M.

1973-01-01

154

Transient High-Pressure Fuel Injection Processes.  

National Technical Information Service (NTIS)

The transient behavior of the jet emerging from the orifice during the start-up and shut-down portion of a typical high-pressure diesel-engine fuel injection is addressed in the present work. The liquid jet injected into air at high pressure has been simu...

D. Jarrahbashi W. A. Sirignano

2012-01-01

155

High-pressure science and technology--1993  

Microsoft Academic Search

These proceedings represent papers presented at the joint meeting of the International Association for Research and Advancement of High Pressure Science and Technology and the American Physical Society Topical Group on shock compression of condensed matter. This conference dealt with the full spectrum of both static and dynamic high pressure investigations. Topics discussed include atomic and molecular structure, equations of

S. C. Schmidt; J. W. Shaner; G. A. Samara; M. Ross

1994-01-01

156

Melting of diamond at high pressure  

NASA Astrophysics Data System (ADS)

Melting of diamond at high pressure and the properties of liquid carbon at pressures greater than 1 megabar were investigated with a first-principles molecular dynamics technique. The results indicate an increase of the diamond melting temperature with pressure, which is opposite to the behavior of silicon and germanium. This is contrary to long-held assumptions, but agrees with recent experiments, and has important implications for geology and astrophysics. As is the case for the solid phase of carbon at low temperature, which changes greatly with pressure from graphite to diamond, the structural and bonding properties of liquid carbon vary strongly with pressure.

Galli, Giulia; Martin, Richard M.; Car, Roberto; Parrinello, Michele

1990-12-01

157

Design optimization of high pressure and high temperature piezoresistive pressure sensor for high sensitivity  

NASA Astrophysics Data System (ADS)

This paper describes a design method for optimizing sensitivity of piezoresistive pressure sensor in high-pressure and high-temperature environment. In order to prove the method, a piezoresistive pressure sensor (HPTSS) is designed. With the purpose of increasing sensitivity and to improve the measurement range, the piezoresistive sensor adopts rectangular membrane and thick film structure. The configuration of piezoresistors is arranged according to the characteristic of the rectangular membrane. The structure and configuration of the sensor chip are analyzed theoretically and simulated by the finite element method. This design enables the sensor chip to operate in high pressure condition (such as 150 MPa) with a high sensitivity and accuracy. The silicon on insulator wafer is selected to guarantee the thermo stability of the sensor chip. In order to optimize the fabrication and improve the yield of production, an electric conduction step is devised. Series of experiments demonstrates a favorable linearity of 0.13% and a high accuracy of 0.48%. And the sensitivity of HTPSS is about six times as high as a conventional square-membrane sensor chip in the experiment. Compared with the square-membrane pressure sensor and current production, the strength of HPTTS lies in sensitivity and measurement. The performance of the HPTSS indicates that it could be an ideal candidate for high-pressure and high-temperature sensing in real application.

Niu, Zhe; Zhao, Yulong; Tian, Bian

2014-01-01

158

46 CFR 35.40-15 - Fire hose stations-TB/ALL.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Fire hose stations-TB/ALL. 35.40-15 Section 35.40-15 Shipping...OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-15 Fire hose stationsâTB/ALL. At each fire hose valve there shall be...

2013-10-01

159

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Fire station hydrants, hose and nozzles-T...System, Details § 76.10-10 Fire station hydrants, hose and nozzles-T...one hose will be required at each fire station; however, if all such...

2009-10-01

160

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

Code of Federal Regulations, 2010 CFR

...2009-10-01 2009-10-01 false Fire station hydrants, hose and nozzles-T...System, Details § 34.10-10 Fire station hydrants, hose and nozzlesâT/ALL. (a) The size of fire station hydrants and hose required...

2009-10-01

161

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Fire station hydrants, hose and nozzles-T...System, Details § 76.10-10 Fire station hydrants, hose and nozzles-T...one hose will be required at each fire station; however, if all such...

2010-10-01

162

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Fire station hydrants, hose and nozzles-T...System, Details § 34.10-10 Fire station hydrants, hose and nozzlesâT/ALL. (a) The size of fire station hydrants and hose required...

2010-10-01

163

High-pressure phase of magnetite  

NASA Astrophysics Data System (ADS)

Mössbauer spectroscopy and x-ray diffraction were employed to investigate the magnetic and structural properties of the high-pressure monoclinic phase of magnetite. Measurements were performed to 66 GPa at 300 K using diamond anvil cells. Based primarily upon the Mössbauer parameters, the following features of the high-pressure phase were deduced. With increasing pressure the high-pressure phase evolves at P>=25 GPa and its abundance increases monotonically at the expense of the low-pressure cubic phase. The high-pressure phase is not magnetic at 300 K and its monoclinic structural features resemble that of the low-pressure phase. The tetrahedral and octahedral sites characteristic of the inverse spinel structure, albeit distorted, remain the building blocks of the high-pressure phase. The fast electron hopping between Fe3+ and Fe2+ at the octahedral sites prevails to the highest pressure. It is suggested that the cubic-->monoclinic-->cubic hysteretic cycle involves a mild displacive phase transition not affecting the coordination number of any of the iron cations.

Pasternak, Moshe Paz; Nasu, Saburo; Wada, Koji; Endo, Shoichi

1994-09-01

164

What Are the Signs and Symptoms of High Blood Pressure?  

MedlinePLUS

... Twitter. What Are the Signs and Symptoms of High Blood Pressure? High blood pressure (HBP) itself usually ... your risk for related health problems. Complications of High Blood Pressure When blood pressure stays high over ...

165

New High-Pressure Excitations in Parahydrogen  

NASA Astrophysics Data System (ADS)

Raman and infrared spectroscopy of para- H2 to pressures in excess of 200 GPa and to 8 K 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 phases II and III, including evidence for changes within phase II. The librons in phase III 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.

Goncharov, Alexander F.; Hemley, Russell J.; Mao, Ho-Kwang; Shu, Jinfu

1998-01-01

166

High Pressure Hollow Cathode Discharges  

NASA Astrophysics Data System (ADS)

The sustaining voltage of hollow cathode discharges is dependent on the product of pressure and cathode hole diameter. By reducing the dimension of the cathode hole to 0.2 mm we were able to operate micro-hollow cathode discharges at pressures up to 750 Torr in argon in a direct current mode. The current-voltage characteristics of the 0.2 mm cathode hole discharges was found to have a positive slope at currents below 0.25 mA. Up to this current level hollow cathode discharges can be operated in parallel without ballast. The negative slope observed above the threshold current seems to be due to the onset of thermionic electron emission caused by Joule heating of the cathode. This assumption is supported by the experimental observation that multi-hole operation without ballast even at currents far above the dc-threshold current was possible when the discharge was operated in a pulsed mode. The possibility of generating large arrays of ballast-free, pulsed micro-hollow cathode discharges suggests their use as flat panel light sources or electron sources.

Schoenbach, Karl H.; Tessnow, Thomas; Elhabachi, Ahmed

1996-10-01

167

PARTICLE COLLECTION IN CYCLONES AT HIGH TEMPERATURE AND HIGH PRESSURE  

EPA Science Inventory

The paper gives results of an experimental study of cyclone efficiency and pressure drop at temperatures up to 700C and pressures up to 25 atm. The cyclone efficiency was found to decrease at high temperature and increase at high pressure for a constant inlet velocity. Available ...

168

PBF Control Building auxiliary features, including fire hose house and ...  

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

PBF Control Building auxiliary features, including fire hose house and sewage system. Ebasco Services 1205 PER/PER-A-4. INEEL undex no. 760-0619-00-205-123024 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

169

60. Same view, showing technicians hosing down the timbers. Shortly ...  

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

60. Same view, showing technicians hosing down the timbers. Shortly after this photograph was made, the timbers were completely submerged in water, held down by heavy concrete castings. - Wabash & Erie Canal, Lock No. 2, 8 miles east of Fort Wayne, adjacent to U.S. Route 24, New Haven, Allen County, IN

170

46 CFR 181.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2010 CFR

...nozzles. (a) A fire hose with a nozzle must be attached to each...corrosion-resistant material. (d) Each nozzle must be of corrosion-resistant...changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

2010-10-01

171

46 CFR 181.320 - Fire hoses and nozzles.  

Code of Federal Regulations, 2010 CFR

...nozzles. (a) A fire hose with a nozzle must be attached to each...corrosion-resistant material. (d) Each nozzle must be of corrosion-resistant...changed between a solid stream and a spray pattern. A nozzle on a vessel of not more than...

2009-10-01

172

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

173

Combustion of liquid sprays at high pressures  

NASA Technical Reports Server (NTRS)

The combustion of pressure atomized fuel sprays in high pressure stagnant air was studied. Measurements were made of flame and spray boundaries at pressures in the range 0.1-9 MPa for methanol and n-pentane. At the higher test pressure levels, critical phenomena are important. The experiments are compared with theoretical predictions based on a locally homogeneous two-phase flow model. The theory correctly predicted the trends of the data, but underestimates flame and spray boundaries by 30-50 percent, indicating that slip is still important for the present experiments (Sauter mean diameters of 30 microns at atmospheric pressure under cold flow conditions). Since the sprays are shorter at high pressures, slip effects are still important even though the density ratio of the phases approach one another as the droplets heat up. The model indicates the presence of a region where condensed water is present within the spray and provides a convenient means of treating supercritical phenomena.

Shearer, A. J.; Faeth, G. M.

1977-01-01

174

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

175

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.

176

Mössbauer spectroscopy at very high pressures  

NASA Astrophysics Data System (ADS)

The generation of Very High Pressure (VHP) with Diamond Anvil Cells (DAC) and its applications to Mössbauer Spectroscopy (MS) are described. We emphasize the technical aspects of DACs relevant to VHP-MS such as collimation. generation of hydrostatic pressures, pressure calibration, and development of special cells. Examples are given showing the potential of VHP-MS in studies of molecular polymerization, order disorder phase transitions of molecular crystals, configuration transformations, and magnetic properties.

Pasternak, Moshe P.; Dean Taylor, R.

1990-08-01

177

Mössbauer spectroscopy at very high pressures  

Microsoft Academic Search

The generation of Very High Pressure (VHP) with Diamond Anvil Cells (DAC) and its applications to Mssbauer Spectroscopy (MS)\\u000a are described. We emphasize the technical aspects of DACs relevant to VHP-MS such as collimation. generation ofhydrostatic pressures, pressure calibration, and development of special cells. Examples are given showing the potential of VHP-MS in\\u000a studies of molecular polymerization, order disorder phase

Moshe P. Pasternak; R. Dean Taylor

1990-01-01

178

High-pressure mechanical instability in rocks  

USGS Publications Warehouse

At a confining pressure of a few kilobars, deformation of many sedimentary rocks, altered mafic rocks, porous volcanic rocks, and sand is ductile, in that instabilities leading to audible elastic shocks are absent. At pressures of 7 to 10 kilobars, however, unstable faulting and stick-slip in certain of these rocks was observed. This high pressure-low temperature instability might be responsible for earthquakes in deeply buried sedimentary or volcanic sequences.

Byerlee, J. D.; Brace, W. F.

1969-01-01

179

High-pressure cryogenic seals for pressure vessels  

NASA Technical Reports Server (NTRS)

Problems associated with maintaining high pressures at cryogenic temperatures in pressure vessels are investigated. The goals were to identify the appropriate materials and design for a seal intended for cryogenic applications at pressures up to 4,080 bars (60,000 psi), and to examine the factors affecting the seal performance. The method employed and the apparatus used in a series of experimental seal system tests, and the test results are described in detail. It is concluded that the common seal designs and extrusion seal-ring materials such as Teflon, tin, and lead are not suitable. However, new seal systems developed using indium seal rings, brass or 304 stainless steel anvil rings, and two 0-rings of silicone rubber or Kel-F did prove suitable.

Buggle, A. E.

1977-01-01

180

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...

181

Theory of droplet combustion at high pressures  

Microsoft Academic Search

A theory of liquid droplet combustion at subcritical, near-critical, and supercritical pressures is presented. At high pressures, the theoretical model is composed of two separate parts. During droplet heatup when the temperature within the droplet is below its thermodynamic critical temperature, a quasi-steady diffusion film model is used. Incorporated in this model are the effects of nonideal gas behavior, including

Baer

1980-01-01

182

Theory of droplet combustion at high pressures  

Microsoft Academic Search

A theory of liquid droplet combustion at subcritical, near-critical, and supercritical pressures is presented. At high pressures, the theoretical model is composed of two separate parts. During droplet heatup when the temperature within the droplet is below its thermodynamic critical temperature, a quasi-steady diffusion film model is used. Incorporated in this model are the effects of nonideal gas behavior including

Baer

1980-01-01

183

High pressure homogenization of a fungi ?-amylase  

Microsoft Academic Search

The activity and stability of ?-amylase after high pressure homogenization were investigated. The enzyme buffer solution was processed at homogenization pressures up to 1500bar. No changes in the enzymatic activity at 15, 45 and 75°C were observed after the homogenization process. The evaluation of calcium requirement to preserve the ?-amylase stability during homogenization was carried out and the results indicated

Alline Artigiani Lima Tribst; Marcelo Cristianini

184

High pressure study of acetophenone azine  

NASA Astrophysics Data System (ADS)

High pressure Raman spectra of acetophenone azine (APA) have been measured up to 17.7 GPa with a diamond anvil cell. Two crystalline-to-crystalline phase transformations are found at pressures about 3.6 and 5.8 GPa. A disappearance of external modes and the C-H vibration at pressures higher than 8.7 GPa suggests that the sample undergoes a phase transition to amorphous or orientationally disordered (plastic) state, and the amorphization was completed at about 12.1 GPa. The disordered state is unstable and, then, a polymerization transformation reaction occurs with a further pressure increase. After the pressure has been released, the polymerization state can remain at the ambient condition, indicating that the virgin crystalline state is not recovered. The results show that the phenomenon underlying the pressure induced phase transition of APA may involve profound changes in the coordination environments of the symmetric aromatic azine.

Tang, X. D.; Ding, Z. J.; Zhang, Z. M.

2009-02-01

185

Apparatus for High-Pressure Thermogravimetry.  

National Technical Information Service (NTIS)

Construction and operation of a high-pressure thermobalance usable to 300 psig and a temperature of 350C is described. A modified, commercially available balance mechanism and associated circuitry provide an apparatus that is easily constructed and has sa...

E. C. Penski H. A. Brown J. J. Callahan

1971-01-01

186

High Blood Pressure and Heart Disease  

MedlinePLUS Videos and Cool Tools

... corner of the player. High Blood Pressure and Heart Disease HealthDay February 5, 2014 Related MedlinePlus Pages ... middle age may mean a higher risk for heart disease. Now new research published in the Journal ...

187

High Blood Pressure: Unique to Older Adults  

MedlinePLUS

... of your life any risk factors in your life style, such as high blood pressure, heart disease, diabetes, excess alcohol consumption, lack of exercise and smoking. ... out normal functions of daily life. There are many reasons why this can happen, ...

188

Could Probiotics Help Tame High Blood Pressure?  

MedlinePLUS

... features on this page, please enable JavaScript. Could Probiotics Help Tame High Blood Pressure? Study suggests effect ... refrigerator. The study found that regular intake of probiotics, such as those found in certain yogurts or ...

189

Gauge for Measuring High Transient Pressures.  

National Technical Information Service (NTIS)

An article and method is provided for remotely optically measuring high transient isotropic pressures. The arrangement employs a fluorescent crystal (such as a ruby) secured to one end of an elongate optical fiber waveguide for placement in the vicinity o...

D. L. Lehto

1982-01-01

190

High-pressure chemical waveguide laser  

Microsoft Academic Search

The exothermic chain reactions between deuterium and fluorine have been used to produce laser emission from carbon dioxide in a high-pressure chemical waveguide laser. Chemical chain reactions initiated by flash photolysis of this system produced 10.6-micron radiation from a 3-mm-diam laser tube having an effective length of 50 cm. Lasing occurs in stable D2-F2-CO2-He mixtures at pressures as high as

T. O. Poehler; R. E. Walker; J. W. Leight

1975-01-01

191

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

192

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. 5 figs.

Harkins, B.D.; Ward, M.E.

1998-09-22

193

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

194

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

195

Crystal structure of oligoacenes under high pressure  

SciTech Connect

We report crystal structures of anthracene, tetracene, and pentacene under pressure. Energy dispersive x-ray diffraction experiments up to 9 GPa were performed. Quasiharmonic lattice dynamics calculations are compared to the experimental results and show excellent agreement. The results are discussed with particular emphasis on the pressure dependence of the unit cell dimensions and the rearrangement of the molecules. The high pressure data also allow an analysis of the equation of state of these substances as a function of molecular length. We report the bulk modulus of tetracene and pentacene (B{sub 0}=9.0 and 9.6 GPa, respectively) and its pressure derivative (B{sub 0}{sup '}=7.9 and 6.4, respectively). We find that the unit-cell volume and bulk modulus at ambient pressure follow a linear relationship with the molecular length.

Oehzelt, M.; Aichholzer, A.; Resel, R.; Heimel, G.; Venuti, E.; Della Valle, R. G. [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz (Austria); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400 (United States); Dipartimento di Chimica Fisica e Inorganica and INSTM-UdR Bologna, Universita di Bologna, Viale Risorgimento 4, I-40136 Bologna (Italy)

2006-09-01

196

High pressure Raman scattering of silicon nanowires.  

PubMed

We study the high pressure response, up to 8 GPa, of silicon nanowires (SiNWs) with ? 15 nm diameter, by Raman spectroscopy. The first order Raman peak shows a superlinear trend, more pronounced compared to bulk Si. Combining transmission electron microscopy and Raman measurements we estimate the SiNWs' bulk modulus and the Grüneisen parameters. We detect an increase of Raman linewidth at ? 4 GPa, and assign it to pressure induced activation of a decay process into LO and TA phonons. This pressure is smaller compared to the ? 7 GPa reported for bulk Si. We do not observe evidence of phase transitions, such as discontinuities or change in the pressure slopes, in the investigated pressure range. PMID:21430319

Khachadorian, Sevak; Papagelis, Konstantinos; Scheel, Harald; Colli, Alan; Ferrari, Andrea C; Thomsen, Christian

2011-05-13

197

High precision pressure measurement with a funnel  

NASA Astrophysics Data System (ADS)

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 placed, upside down, in a container filled with distilled water, placed on a scale. Our method provides a theoretical precision for the pressure measurement of the order of 0.01 Pa. Beyond this, the advantage of this method relies on the simplicity of the materials used and on the opportunity to discuss, at an undergraduate level, basic concepts regarding all those phenomena in which low or very low differential pressures are relevant.

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

2008-11-01

198

Fluid hydrogen at high density - Pressure ionization  

NASA Technical Reports Server (NTRS)

The Helmholtz-free-energy model for nonideal mixtures of hydrogen atoms and molecules by Saumon and Chabrier (1991) is extended to describe dissociation and ionization in similar mixtures in chemical equilibrium. A free-energy model is given that describes partial ionization in the pressure and temperature ionization region. The plasma-phase transition predicted by the model is described for hydrogen mixtures including such components as H2, H, H(+), and e(-). The plasma-phase transition has a critical point at Tc = 15,300 K and Pc = 0.614 Mbar, and thermodynamic instability is noted in the pressure-ionization regime. The pressure dissociation and ionization of fluid hydrogen are described well with the model yielding information on the nature of the plasma-phase transition. The model is shown to be valuable for studying dissociation and ionization in astrophysical objects and in high-pressure studies where pressure and temperature effects are significant.

Saumon, Didier; Chabrier, Gilles

1992-01-01

199

Phase transitions at high pressure in tetracyanoethylene  

NASA Astrophysics Data System (ADS)

We report in situ x-ray diffraction studies in tetracyanoethylene (TCNE) at high pressure using diamond anvil cell (DAC) at Elettra synchrotron source, Trieste, Italy. Experiments were performed with both the polymorphic phases (monoclinic and cubic) of TCNE as the starting phase. While starting with monoclinic (the high temperature stable) TCNE, it was found that the Bragg peaks get broadened with increase of pressure and above 5 GPa only few broad peaks remained to be observed. On release of pressure from 6.4 GPa, when the sample started turning black, the diffraction pattern at ambient pressure corresponds to cubic, the other crystalline phase of TCNE. Results reconfirm the monoclinic to cubic transition at high pressure but via an intermediate 'disordered' phase. This settles a number of conflicting issues. TCNE represents only system, which undergoes transition from one crystalline to another crystalline phase via a 'disordered' metastable phase at high pressure. When the starting phase was cubic (the low temperature stable) no apparent phase transition was observed up to 10.8 GPa.

Mukhopadhyay, R.; Deb, S. K.; Das, Amitabh; Chaplot, S. L.

2009-11-01

200

High-Pressure Fluorescence Correlation Spectroscopy  

PubMed Central

We demonstrate that a novel high-pressure cell is suitable for fluorescence correlation spectroscopy (FCS). The pressure cell consists of a single fused silica microcapillary. The cylindrical shape of the capillary leads to refraction of the excitation light, which affects the point spread function of the system. We characterize the influence of these beam distortions by FCS and photon-counting histogram (PCH) analysis and identify the optimal position for fluorescence fluctuation experiments in the capillary. At this position within the capillary, FCS and photon-counting histogram experiments are described by the same equations as used in standard FCS experiments. We report the first experimental realization of fluorescence fluctuation spectroscopy under high pressure. A fluorescent dye was used as a model system for evaluating the properties of the capillary under pressure. The autocorrelation function and the photon count distribution were measured in the pressure range from 0 to 300 MPa. The fluctuation amplitude and the diffusion coefficient show a small pressure dependence. The changes of these parameters, which are on the order of 10%, are due to the pressure changes of the viscosity and the density of the aqueous medium.

Muller, Joachim D.; Gratton, Enrico

2003-01-01

201

Efficient High-Pressure State Equations  

NASA Technical Reports Server (NTRS)

A method is presented for a relatively accurate, noniterative, computationally efficient calculation of high-pressure fluid-mixture equations of state, especially targeted to gas turbines and rocket engines. Pressures above I bar and temperatures above 100 K are addressed The method is based on curve fitting an effective reference state relative to departure functions formed using the Peng-Robinson cubic state equation Fit parameters for H2, O2, N2, propane, methane, n-heptane, and methanol are given.

Harstad, Kenneth G.; Miller, Richard S.; Bellan, Josette

1997-01-01

202

Liquid Rocket Lines, Bellows, Flexible Hoses, and Filters  

NASA Technical Reports Server (NTRS)

Fluid-flow components in a liquid propellant rocket engine and the rocket vehicle which it propels are interconnected by lines, bellows, and flexible hoses. Elements involved in the successful design of these components are identified and current technologies pertaining to these elements are reviewed, assessed, and summarized to provide a technology base for a checklist of rules to be followed by project managers in guiding a design or assessing its adequacy. Recommended procedures for satisfying each of the design criteria are included.

1977-01-01

203

What about African Americans and High Blood Pressure?  

MedlinePLUS

(continued) Lifestyle + Risk Reduction High Blood Pressure What’s blood pressure? Blood pressure is the pressure of the blood against the walls of the ... African Americans and High Blood Pressure? Lifestyle + Risk Reduction High Blood Pressure ANSWERS by heart Take a ...

204

High Pressure Viscosity Measurements of Planetary Fluids  

NASA Astrophysics Data System (ADS)

We have measured the viscosity of argon to 1.5 GPa and 353 Kelvin, 4% sodium-chloride water solution to 1.1 GPa at room temperature, and water up to 4.0 GPa and 500 Kelvin using an externally-heated, rolling-sphere diamond-cell viscometer. The viscosity of argon increases by a factor of three between 0.5 GPa and the crystallization pressure of 1.2 GPa. The viscosity of the sodium-chloride solution exhibits the same relative change as pure water, about a factor of 2 over 1 GPa. Surprisingly, we were able to compress water past the crystallization pressure at room temperature, and measure viscosity of metastable liquid water up to 1.4 GPa. The maximum viscosity attained was ~ 3 mPa*s, and appears to be consistent with simple extrapolations from both the low-pressure data (< 1 GPa) and the high-temperature, high-pressure data (> 323 K, ~1.5 GPa). Virtually no data previously existed for aqueous solutions at high pressures, and our experiments increase the pressure range for extensive viscosity measurements on H2O and Ar by 50%. Measurements using the diamond-cell viscometer with heating capability provide significant tests of theoretical models of fluid-transport properties at conditions existing deep inside planets.

Grocholski, B.; Jeanloz, R.

2007-12-01

205

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

SciTech Connect

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) [Oak Ridge, TN; McKeever, John W. (Oak Ridge, TN) [Oak Ridge, TN

2010-03-23

206

High-Current Superconductive Pressure Contact Studies.  

National Technical Information Service (NTIS)

Superconductive switches with a high-critical-current (100-200 A) capability have been shown to be practical. Materials thought most likely to be effective as high-critical-current pressure contacts were tested. The effects of oxidation, preloading at roo...

G. K. Gaule J. J. Winter J. T. Breslin

1971-01-01

207

Phase transitions at high pressure in tetracyanoethylene  

Microsoft Academic Search

We report in situ x-ray diffraction studies in tetracyanoethylene (TCNE) at high pressure using diamond anvil cell (DAC) at Elettra synchrotron source, Trieste, Italy. Experiments were performed with both the polymorphic phases (monoclinic and cubic) of TCNE as the starting phase. While starting with monoclinic (the high temperature stable) TCNE, it was found that the Bragg peaks get broadened with

R. Mukhopadhyay; S. K. Deb; Amitabh Das; S. L. Chaplot

2009-01-01

208

Effect of High Pressure on Uranyl Nanocages  

NASA Astrophysics Data System (ADS)

Uranyl nanocages U24Py12, U60, and U24 were studied in situ at high pressure in order to understand the response of these structures to pressure. Single crystals of the nanocage structures were analyzed by in situ Raman spectroscopy, synchrotron X-ray diffraction and small angle X-Ray scattering in diamond anvil cells, as well as electrospray ionization mass spectrometry. At ambient pressure conditions, U24Py12 is tetragonal (P42/mnm: a = 22.746(2) Å, c = 30.426(4) Å), U60 is isometric (Fm-3: a=37.884(2) Å), and U24 is triclinic (P1-: a=19.2111(11), b=31.003(2), c=32.252(2), ?=102.404(4)°, ?=99.506(4) °, ?=95.362(4) °). Pressures ranged from ambient to 50 GPa; single crystals less than 200 microns in diameter were used. Two symmetric stretch modes of the uranyl ion are evident in the Raman spectra of all three nanocages with Raman shifts of 810 and 830 cm-1. The modes are clearly evident at pressures ranging from ambient to 4-8 GPa. At pressures higher than this range, the uranyl ion vibrational mode broadens further and shifts to higher stretching frequencies. The signal for U60 is irreversibly lost at 17 GPa, but for U24 and U24Py12, the signal persists and continues to broaden at pressures up to 50 GPa. After pressure quenching, there was still no signal from the U60, but U24 and U24Py12 both show one broad Raman mode at 840 cm-1. High pressure synchrotron X-ray diffraction measurements were completed at Argonne National Laboratory to quantify structural unit cell changes over the pressure ranges investigated. U24Py12 undergoes a phase transition to higher symmetry at approximately 5 GPa, and eventually partially amorphizes at 17 GPa, irreversibly. U60 undergoes a phase transition from isometric to tetragonal at 4.4 GPa, and amorphizes irreversibly at 10 GPa. Small angle X-ray scattering measurements show that the cluster topology is maintained even after amorphization of U24Py12 and U60. Mass spectrometry data indicate that these clusters remain intact at high pressures, despite the loss of long-range periodicity. These experiments provide insight into the stability of different types of uranyl nanocages, as well the relation between cluster topology and stability with increasing pressure.

Turner, K. M.; Zhang, F.; Pellegrini, K.; McGrail, B. T.; Burns, P. C.; Ewing, R. C.

2013-12-01

209

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

210

High pressure and high temperature behaviour of ZnO  

NASA Astrophysics Data System (ADS)

The thermodynamic properties with the wurtzite (B4) and rocksalt (B1) phases of ZnO under high pressures and high temperatures have been investigated using Tait's Equation of state (EOS). The effects of pressures and temperatures on thermodynamic properties such as bulk modulus, thermal expansivity and thermal pressure are explored for both two structures. It is found that ZnO material gradually softens with increase of temperature while it hardens with the increment of the pressure. Our predicted results of thermodynamics properties for both the phases of ZnO are in overall agreement with the available data in the literature.

Thakar, Nilesh A.; Bhatt, Apoorva D.; Pandya, Tushar C.

2014-04-01

211

Sensitivity study on high pressurizer pressure trip margin of UCN 3 and 4.  

National Technical Information Service (NTIS)

Sensitivity studies for variables which affect high pressurizer pressure trip margin are performed using LTCUCN computer code which is performance analysis code of UCN 3 and 4. As the results of sensitivity study, initial pressurizer pressure, SBCS quick ...

S. H. Sohn W. S. Jeong H. T. Seo J. T. Seo

1996-01-01

212

Fluid hydrogen at high density - Pressure dissociation  

NASA Technical Reports Server (NTRS)

A model for the Helmholtz free energy of fluid hydrogen at high density and high temperature is developed. This model aims at describing both pressure and temperature dissociation and ionization and bears directly on equations of state of partially ionized plasmas, as encountered in astrophysical situations and high-pressure experiments. This paper focuses on a mixture of hydrogen atoms and molecules and is devoted to the study of the phenomenon of pressure dissociation at finite temperatures. In the present model, the strong interactions are described with realistic potentials and are computed with a modified Weeks-Chandler-Andersen fluid perturbation theory that reproduces Monte Carlo simulations to better than 3 percent. Theoretical Hugoniot curves derived from the model are in excellent agreement with experimental data.

Saumon, Didier; Chabrier, Gilles

1991-01-01

213

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

214

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

215

High pressure freon decontamination of remote equipment  

SciTech Connect

A series of decontamination tests using high pressure FREON 113 was conducted in the 200 Area of the Hanford site. The intent of these tests was to evaluate the effectiveness of FREON 113 in decontamination of manipulator components, tools, and equipment items contaminated with mixed fission products. The test results indicated that high pressure FREON 113 is very effective in removing fissile material from a variety of objects and can reduce both the quantity and the volume of the radioactive waste material presently being buried.

Wilson, C.E.

1987-01-01

216

High pressure water jet cutting and stripping  

NASA Technical Reports Server (NTRS)

High pressure water cutting techniques have a wide range of applications to the American space effort. Hydroblasting techniques are commonly used during the refurbishment of the reusable solid rocket motors. The process can be controlled to strip a thermal protective ablator without incurring any damage to the painted surface underneath by using a variation of possible parameters. Hydroblasting is a technique which is easily automated. Automation removes personnel from the hostile environment of the high pressure water. Computer controlled robots can perform the same task in a fraction of the time that would be required by manual operation.

Hoppe, David T.; Babai, Majid K.

1991-01-01

217

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

218

Hydrogen at high pressure and temperatures  

SciTech Connect

Hydrogen at high pressures and temperatures is challenging scientifically and has many real and potential applications. Minimum metallic conductivity of fluid hydrogen is observed at 140 GPa and 2600 K, based on electrical conductivity measurements to 180 GPa (1.8 Mbar), tenfold compression, and 3000 K obtained dynamically with a two-stage light-gas gun. Conditions up to 300 GPa, sixfold compression, and 30,000 K have been achieved in laser-driven Hugoniot experiments. Implications of these results for the interior of Jupiter, inertial confinement fusion, and possible uses of metastable solid hydrogen, if the metallic fluid could be quenched from high pressure, are discussed.

Nellis, W J

1999-09-30

219

Your Guide to Lowering High Blood Pressure: Pregnancy  

MedlinePLUS

High Blood Pressure Topics: Pregnancy Although many pregnant women with high blood pressure have healthy babies without serious problems, high blood pressure can be dangerous for both the mother and ...

220

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, László

2013-12-15

221

Raman study of opal at high pressure  

NASA Astrophysics Data System (ADS)

More commonly known for their beauty and lore as gemstones, opals are also intriguing geological materials which may have potential for materials science applications. Opal lacks a definite crystalline structure, and is composed of an amorphous packing of hydrated silica (SiO2) spheroids, which provides us with a unique nano-scaled mineraloid with properties unlike those of other amorphous materials like glass. Opals from different localities were studied at high pressure using a diamond anvil cell to apply pressure and Raman spectroscopy to look at changes in bonding as pressure was increased. We first tested different samples from Virgin Valley, NV, Spencer, ID, Juniper Ridge, OR, and Australia, which contain varying amounts of water at ambient conditions, using Raman spectroscopy to determine if they were opal-CT (semicrystalline cristobalite-trydimite volcanic origin) or opal-A (amorphous sedimentary origin). We then used x-ray diffraction and Raman spectroscopy in a diamond anvil cell to see how their bonding and structure changed under compression and to determine what effect water content had on their high pressure behavior. Comparison of our results on opal to other high pressure studies of amorphous materials like glass has implications from a geological and materials science standpoint.

Farfan, G.; Wang, S.; Mao, W. L.

2011-12-01

222

High pressure turbomachinery ground test facility  

NASA Technical Reports Server (NTRS)

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 systems will provide the vital pressure, temperature and flow requirements during tests. These systems will better control adverse transient conditions during start-up and shutdown, and by using advanced control theory, as well as incorporate test article health monitoring. Also, digital data acquisition systems will obtain high frequency (up to 20 KHz) and low frequency (up to 1 KHz) data during the test. Pressures of up to 15,000 psi will be generated to pressurize high pressure tanks supplying cryogens to various test article inlets thus pushing turbopump materials and manufacturing processes to their limits. By planning for future projects the test facility will be easily adaptable to multi-program test configurations over a range of thermodynamic positions.

Scheuermann, Patrick E.

1992-01-01

223

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

224

Design guide for high pressure oxygen systems  

NASA Technical Reports Server (NTRS)

A repository for critical and important detailed design data and information, hitherto unpublished, along with significant data on oxygen reactivity phenomena with metallic and nonmetallic materials in moderate to very high pressure environments is documented. This data and information provide a ready and easy to use reference for the guidance of designers of propulsion, power, and life support systems for use in space flight. The document is also applicable to designs for industrial and civilian uses of high pressure oxygen systems. The information presented herein are derived from data and design practices involving oxygen usage at pressures ranging from about 20 psia to 8000 psia equal with thermal conditions ranging from room temperatures up to 500 F.

Bond, A. C.; Pohl, H. O.; Chaffee, N. H.; Guy, W. W.; Allton, C. S.; Johnston, R. L.; Castner, W. L.; Stradling, J. S.

1983-01-01

225

Crystal structure of columbite under high pressure  

NASA Astrophysics Data System (ADS)

The structural evolution of two columbites under pressure, one ferrocolumbite from Raode (Africa) and one manganocolumbite from Kragero (Norway), has been determined by single-crystal X-ray diffraction. Structural investigations at high pressure have been carried out on samples which were preliminarily annealed to attain the complete cation-ordered state. For each crystal, five complete datasets have been collected from room pressure up to ca. 7 GPa. Structure refinements converged to final discrepancy factors R ranging between 5.2 and 5.8% for both the crystals. Structure refinements of X-ray diffraction data at different pressures allowed characterisation of the mechanisms by which the columbite structure accommodates variations in pressure. A and B octahedral volumes in both samples decrease linearly as pressure increases, with a larger compression of the larger A site. The difference in polyhedral bulk moduli of the A sites for the two samples does not appear to relate directly to the octahedral sizes, the A site being more compressible in the Fe-rich sample than in the Mn-rich one. By far the most compressible direction in both the analysed samples is along b. The cations are in fact free to move along this direction, thus allowing the octahedral chains to slide over each other; this effect is particularly evident in the manganocolumbite sample which shows a steep shortening of interchain A-B distances along b.

Tarantino, Serena C.; Zema, Michele; Boffa Ballaran, Tiziana

2010-12-01

226

Stability of xenon oxides at high pressures.  

PubMed

Xenon, which is quite inert under ambient conditions, may become reactive under pressure. The possibility of the formation of stable xenon oxides and silicates in the interior of the Earth could explain the atmospheric missing xenon paradox. Using an ab initio evolutionary algorithm, we predict the existence of thermodynamically stable Xe-O compounds at high pressures (XeO, XeO(2) and XeO(3) become stable at pressures above 83, 102 and 114 GPa, respectively). Our calculations indicate large charge transfer in these oxides, suggesting that large electronegativity difference and high pressure are the key factors favouring the formation of xenon compounds. However, xenon compounds cannot exist in the Earth's mantle: xenon oxides are unstable in equilibrium with the metallic iron occurring in the lower mantle, and xenon silicates are predicted to decompose spontaneously at all mantle pressures (<136 GPa). However, it is possible that xenon atoms may be retained at defects in mantle silicates and oxides. PMID:23247179

Zhu, Qiang; Jung, Daniel Y; Oganov, Artem R; Glass, Colin W; Gatti, Carlo; Lyakhov, Andriy O

2013-01-01

227

Nanoshells as a high-pressure gauge  

NASA Astrophysics Data System (ADS)

Nanoshells, consisting of multiple spherical layers, have an extensive list of applications, usually performing the function of a probe. We add a new application to this list in the form of a high-pressure gauge in a Diamond Anvil Cell (DAC). In a DAC, where high pressures are reached by pressing two diamonds together, existing gauges fail at higher pressures because of calibration difficulties and obscuring effects in the diamonds. The nanoshell gauge does not face this issue since its optical spectrum can be engineered by altering the thickness of its layers. Furthermore their properties are measured by broad band optical transmission spectroscopy leading to a very large signal-to-noise ratio even in the multi-megabar pressure regime where ruby measurements become challenging. Theoretical calculations based on the Maxwell equations in a spherical geometry combined with the Vinet equation of state show that a three-layer geometry (SiO2-Au-SiO2) indeed has a measurable pressure-dependent optical response desirable for gauges.

Tempere, Jacques; van den Broeck, Nick; Putteneers, Katrijn; Silvera, Isaac

2012-02-01

228

Breakup of Liquid Streams at High Pressures.  

National Technical Information Service (NTIS)

A theoretical and computational study of the break-up of injected liquid streams at high pressure by stress-induced cavitation is the research subject. The breakup criteria by stresses differs greatly from the traditional criterion in which a fluid cavita...

D. D. Joseph W. A. Sirignano

2006-01-01

229

Apparatus for manufacturing high pressure inert gas  

Microsoft Academic Search

At the present time, one of the biggest usages of inert gas is in the petroleum industry, wherein such gas is utilized in the recovery of petroleum. An apparatus is described for manufacturing high pressure inert gas utilizing hydrocarbon fuel. The gas is produced by the burning of hydrocarbon fuel in an internal combustion engine, the exhaust gases therefrom being

Gower

1971-01-01

230

High temperature pressure coupled ultrasonic waveguide  

DOEpatents

A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

Caines, Michael J. (Forest Park, IL)

1983-01-01

231

High pressure injection injury of the hand.  

PubMed

High pressure injection injury of the hand looks rather innocuous but has the potential of affecting the function. The radiological picture is quite alarming and it gives a fair idea about the extent of the damage. The description and the images which follow, emphasize the need for an early and aggressive surgical debridement for a good functional outcome. PMID:24799776

Quraishi, Abdul Haque M

2014-02-01

232

Hurricane risk mitigation - High Pressure Gas Facility  

NASA Technical Reports Server (NTRS)

A worker pours concrete as part of a nitrogen risk mitigation project at the High Pressure Gas Facility at Stennis Space Center. The concrete slab will provide the foundation needed to place new pumps at the site and is part of ongoing hurricane-related mitigation work at Stennis.

2008-01-01

233

Miscible displacement by high pressure nitrogen injection  

Microsoft Academic Search

Primary oil recovery frequently results in oil recoveries of only 10 to 20% of the original oil in place. Several hydrocarbon miscible methods have been tested and proven successful as a secondary or tertiary method of oil recovery under certain reservoir conditions. The use of nitrogen to develop a high-pressure miscible displacement-type recovery process has been studied in the laboratory.

M. D. Rushing; B. C. Thomasson; B. Reynolds; P. B. Crawford

1977-01-01

234

Miscible displacement by high pressure nitrogen injection  

Microsoft Academic Search

Primary oil recovery frquently results in oil recoveries of only 10 to 20% of the original oil in place. Several hydrocarbon miscible methods have been tested and proven successful as a secondary or tertiary method of oil recovery under certain reservoir conditions. The use of nitrogen to develop a high-pressure miscible displacement-type recovery process has been studied in the laboratory.

M. D. Rushing; B. C. Thomasson; B. Reynolds; P. B. Crawford

1977-01-01

235

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

236

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

237

High-Pressure Promoted-Combustion Chamber  

NASA Technical Reports Server (NTRS)

Proposed combustion-testing chamber burns specimens of materials in fully contained, high-pressure oxygen atmosphere. Test operator uses handles on threaded retaining rings to attach or remove top or bottom plates sealing combustion chamber. Tests conducted in static or flowing oxygen. Oxygen inlet and outlet far enough above burning specimen, little danger of entrainment of burning fragments in oxygen flowing out.

Rucker, Michelle A.; Stoltzfus, Joel M.

1990-01-01

238

High pressure flow cytometric sorting damages sperm.  

PubMed

Sexing sperm by high-speed flow cytometry subjects them to high pressure. The routine operating pressure of the MoFlo SX flow cytometer for sperm sorting for commercial production has been 50 pounds/square inch (psi), with a standard 70 microm standard nozzle tip. It was hypothesized that lowering the sorting pressure could reduce sperm damage. Therefore, a series of experiments using semen from six bulls, sorted with three MoFlo SX sorters, was conducted to determine optimal pressure. An additional experiment was done with stallion spermatozoa. In Experiment 1, sorting at 30 psi compared to 50 psi with the 70 microm nozzle tip increased sperm motility post-thaw at 30 min and 2h from 40.5 to 48.0% and 30.0 to 40.2%, respectively (P<0.05). In Experiment 2, 49, 43, 37, 31, and 25 psi resulted in 24.2, 32.8, 35.6, 37.5, and 39.8% progressively motile spermatozoa post-thaw (P<0.05). In Experiment 3, 3 pressures (50, 40, 30 psi)x2 sorting methods were further evaluated. At 50, 40, and 30 psi, respective mean sperm motilities at 30 min were 44.8, 48.6, and 49.6% (P<0.05), and percentage of live spermatozoa were 51.7, 55.7, and 57.8% (P<0.05). The improvement of post-sort sperm quality with lowered pressure was also evident in stallion spermatozoa. After sorting at 30, 40 and 50 psi were 40.6, 34.5 and 30.1% motile spermatozoa (P<0.1), and were 76.7, 72.5 and 67.8% (P<0.05) live spermatozoa (determined by SYBR-14/propidium iodide staining). In Experiment 4 sorter performance was evaluated with two pressures (40 and 50 psi)x2 staining concentrations of bovine spermatozoa (75 x 10(6) and 100 x 10(6)mL(-1)). Lowering pressure to 40 psi did not lower sort rate and purity when compared to 50 psi (P>0.05), and higher sperm concentration during staining increased sort rate (P<0.05). In conclusion, lowering pressure of the MoFlo SX flow cytometer for sperm sorting from 50 psi (standard pressure) to 40 psi clearly improved sperm quality without a significant decrease in sorter performance. PMID:16125550

Suh, T K; Schenk, J L; Seidel, G E

2005-09-15

239

Coupled beam hose and self-modulation instabilities in overdense plasma.  

PubMed

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. PMID:23005864

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

2012-08-01

240

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.; Grüner, F. J.; Leemans, W. P.

2012-08-01

241

STS-32 crewmembers use water hoses during fire fighting training at JSC  

NASA Technical Reports Server (NTRS)

STS-32 crewmembers use water hoses during fire fighting exercises at JSC's Fire Training Pit across from the Gilruth Center Bldg 207. Mission Specialist (MS) G. David Low with nozzle open directs water into the fire as fire/ security personnel coaches and instructs him on his attempt to extinguish the blaze. MS Bonnie J. Dunbar maneuvers the hose behind Low. A second group of crewmembers alongside Low and Dunbar, MS Marsha S. Ivins, holding hose nozzle, Commander Daniel C. Brandenstein, and Pilot James D. Wetherbee position themselves before opening hose nozzle.

1989-01-01

242

STS-46 crewmembers handle water hoses during fire training at JSC's Fire Pit  

NASA Technical Reports Server (NTRS)

STS-46 Atlantis, Orbiter Vehicle (OV) 104, crewmembers, directing the spray of two water hoses, approach a blaze in JSC's Fire Training Pit located across from the Gilruth Center Bldg 207. Manning the hose in the foreground are Commander Loren J. Shriver (left) and Italian Payload Specialist Franco Malerba. Holding a second hose are European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier and MS Franklin R. Chang-Diaz who is aiming nozzle at the fire. Between the water hoses is a fire fighting training instructor. In the distance JSC's water tower and building facilities can be seen.

1992-01-01

243

High hydrostatic pressure processing of tropical fruits.  

PubMed

Interest in the nonthermal method of high hydrostatic pressure (HHP) for food preservation has increased recently due to the possibility of inactivating microorganisms and enzymes while maintaining product sensorial and nutritional properties. This work deals with HHP use for the preservation of tropical fruit products. HHP is shown to be a practical approach to obtaining high-quality tropical fruit products that are both nutritive and safe. PMID:20233363

Lopes, Maria Lúcia M; Valente Mesquita, Vera L; Chiaradia, Ana Cristina N; Fernandes, Antônio Alberto R; Fernandes, Patricia M B

2010-02-01

244

A high temperature high pressure cell for quasielastic neutron scattering  

SciTech Connect

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 mm{sup 3}. 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.; Meyer, A. [Institut fuer Materialphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), 51170 Koeln (Germany); Physik Department E13, Technische Universitaet Muenchen, 85748 Garching (Germany); Kaplonski, J. [Physik Department E13, Technische Universitaet Muenchen, 85748 Garching (Germany); Unruh, T. [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universitaet Muenchen, 85748 Garching (Germany); Mamontov, E. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2011-08-15

245

Efficient High Pressure MixtureState Equations  

NASA Technical Reports Server (NTRS)

A method is presented for an accurate noniterative, computationally efficient calculation of high pressure fluid mixture equations of state, especially targeted to gas turbines and rocket engines. Pressures above 1 bar and temperatures above 100 K are addressed. The method is based on curve fitting an effective reference state relative to departure funcitons formed using the Peng-Robinson cubic state equation. Fit parameters for H(sub 2), O(sub 2), N(sub 2), propane, n-heptane and methanol are given.

Harstad, K. G.; Miller, R. S.; Bellan, J.

1996-01-01

246

Superconducting High Pressure Phase of Germane  

NASA Astrophysics Data System (ADS)

High-pressure structures of germane (GeH4) are explored through ab initio evolutionary methodology to reveal a metallic monoclinic structure of C2/c (4molecules/cell). The C2/c structure consists of layerlike motifs containing novel “H2” units. Enthalpy calculations suggest a remarkably wide decomposition (Ge+H2) pressure range of 0 196 GPa, above which C2/c structure is stable. Perturbative linear-response calculations for C2/c GeH4 at 220 GPa predict a large electron-phonon coupling parameter ? of 1.12 and the resulting superconducting critical temperature reaches 64 K.

Gao, Guoying; Oganov, Artem R.; Bergara, Aitor; Martinez-Canales, Miguel; Cui, Tian; Iitaka, Toshiaki; Ma, Yanming; Zou, Guangtian

2008-09-01

247

Superconducting high pressure phase of germane.  

PubMed

High-pressure structures of germane (GeH4) are explored through ab initio evolutionary methodology to reveal a metallic monoclinic structure of C2/c (4 molecules/cell). The C2/c structure consists of layerlike motifs containing novel "H2" units. Enthalpy calculations suggest a remarkably wide decomposition (Ge+H2) pressure range of 0-196 GPa, above which C2/c structure is stable. Perturbative linear-response calculations for C2/c GeH4 at 220 GPa predict a large electron-phonon coupling parameter lambda of 1.12 and the resulting superconducting critical temperature reaches 64 K. PMID:18851245

Gao, Guoying; Oganov, Artem R; Bergara, Aitor; Martinez-Canales, Miguel; Cui, Tian; Iitaka, Toshiaki; Ma, Yanming; Zou, Guangtian

2008-09-01

248

Apparatus for testing high pressure injector elements  

NASA Technical Reports Server (NTRS)

An apparatus for testing and evaluating the spray pattern of high pressure fuel injector elements for use in supplying fuel to combustion engines is presented. Prior art fuel injector elements were normally tested by use of low pressure apparatuses which did not provide a purge to prevent mist from obscuring the injector element or to prevent frosting of the view windows; could utilize only one fluid during each test; and had their viewing ports positioned one hundred eighty (180 deg) apart, thus preventing optimum use of laser diagnostics. The high pressure fluid injector test apparatus includes an upper hub, an upper weldment or housing, a first clamp and stud/nut assembly for securing the upper hub to the upper weldment, a standoff assembly within the upper weldment, a pair of window housings having view glasses within the upper weldment, an injector block assembly and purge plate within the upper weldment for holding an injector element to be tested and evaluated, a lower weldment or housing, a second clamp and stud/nut assembly for securing the lower weldment to the upper hub, a third clamp and stud/nut assembly for securing the lower hub to the lower weldment, mechanisms for introducing fluid under high pressure for testing an injector element, and mechanisms for purging the apparatus to prevent frosting of view glasses within the window housings and to permit unobstructed viewing of the injector element.

Myers, William Neill (inventor); Scott, Ewell M. (inventor); Forbes, John C. (inventor); Shadoan, Michael D. (inventor)

1995-01-01

249

High Pressure Study on Natural Chromite  

NASA Astrophysics Data System (ADS)

Spinel phase is generally found at crust and upper mantle. Moreover, spinel phase and its modified form play an important role at transition zone and therefore are geologically importance. Besides, spinel phase usually exhibits with solid-solution from a wide range of different size of cations and therefore study of the substation of cations within spinel structure and its high-pressure form are important to better understand the structure and evolution of the deep mantle. In this study, a natural chromite sample, a Cr-rich spinel and an important resource for chromium and iron, was investigated in a diamond anvil cell using synchrotron x-ray diffraction and Raman spectroscopy. In situ synchrotron x-ray diffraction was performed at GSECARS, Advance Photon Source and X17C, National Synchrotron Light Source. Our high-pressure x-ray diffraction study showed a new phase emerging at about 20 GPa which is slightly higher than previously reported transition pressure at about 12 GPa when using a synthetic chromite sample. Furthermore, our Raman study on chromite also did not observe any phase transition at 12 GPa. Instead, our Raman data shows several broad peaks at ambient and continuously observed at high pressures till 30 GPa. Above 30 GPa, the Raman signals of chromite showed new feature and became very weak. Our results suggest that the impurity within chromite may play a critical role for the phase transition.

Shieh, S. R.; Ali, W.; Xiong, Z.

2013-12-01

250

Apparatus for testing high pressure injector elements  

NASA Technical Reports Server (NTRS)

An apparatus for testing and evaluating the spray pattern of high pressure fuel injector elements for use in supplying fuel to combustion engines is presented. Prior art fuel injector elements were normally tested by use of low pressure apparatuses which did not provide a purge to prevent mist from obscuring the injector element or to prevent frosting of the view windows; could utilize only one fluid during each test; and had their viewing ports positioned one hundred eighty (180 deg) apart, thus preventing optimum use of laser diagnostics. The high pressure fluid injector test apparatus includes an upper hub, an upper weldment or housing, a first clamp and stud/nut assembly for securing the upper hub to the upper weldment, a standoff assembly within the upper weldment, a pair of window housings having view glasses within the upper weldment, an injector block assembly and purge plate within the upper weldment for holding an injector element to be tested and evaluated, a lower weldment or housing, a second clamp and stud/nut assembly for securing the lower weldment to the upper weldment, a lower hub, a third clamp and stud/nut assembly for securing the lower hub to the lower weldment, mechanisms for introducing fluid under high pressure for testing an injector element, and mechanisms for purging the apparatus to prevent frosting of view glasses within the window housings and to permit unobstructed viewing of the injector element.

Myers, William Neill (inventor); Scott, Ewell M. (inventor); Forbes, John C. (inventor); Shadoan, Michael D. (inventor)

1993-01-01

251

LHDAC setup for high temperature and high pressure studies  

NASA Astrophysics Data System (ADS)

A ytterbium fibre laser (? = 1.07 ?m) based laser heated diamond anvil cell (LHDAC) facility has been recently set up at HP&SRPD, BARC for simultaneous high temperature and high pressure investigation of material properties. Synthesis of GaN was carried out at pressure of ˜9 GPa and temperature of ˜1925 K in a Mao-Bell type diamond anvil cell (DAC) using the LHDAC facility. The retrieved sample has been characterized using our laboratory based micro Raman setup.

Patel, Nishant N.; Meenakshi, S.; Sharma, Surinder M.

2014-04-01

252

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

253

Small, high-pressure, liquid oxygen turbopump  

NASA Technical Reports Server (NTRS)

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 operating speed of 7330 rad/sec (70,000 rpm) pump discharge pressure of 2977 N/sq cm (4318 psia), and a pump flowrate of 16.4 kg/s (36.21 lb/sec). The turbine was propelled by LOX/LH2 combustion products at 1041 K (1874 R) inlet temperature, and at a design pressure ratio of 1.424. Test data obtained with the turbopump are presented and mechanical performance is discussed.

Csomor, A.

1978-01-01

254

Pressure reduction apparatus for solid particle-containing high pressure liquids  

Microsoft Academic Search

A pressure reduction apparatus for solid particle-containing high pressure liquids is described. The apparatus includes a gas and liquid pressure reduction tower having a gas phase zone and a liquid phase zone, a high pressure gas and liquid separation tower which has a gas phase zone connected to the gas phase zone of said gas and liquid pressure reduction tower

K. Beppu; Sh. Kawakami

1985-01-01

255

Zeeman Effect in Ruby at High Pressures  

NASA Astrophysics Data System (ADS)

We have developed a versatile fiber-coupled system for magneto-optical spectroscopy measurements at high pressure. The system is based on a miniature Cu-alloy Diamond Anvil Cell (from D'Anvils, Ltd) fitted with a custom-designed He gas-actuated membrane for in-situ pressure control, and coupled with a He transfer cryostat incorporating a superconducting magnet (from Quantum Designs). This system allows optical measurements (Raman, photoluminescence, reflectivity) within wide ranges of pressures (up to 100GPa), temperatures (4.2-300K) and magnetic fields (0-9T). We employ this system to examine the effect of pressure and non-hydrostatic stress on the Zeeman split d-d transitions of Cr^3+ in ruby (Al2O3: Cr^3+). We determine the effect of pressure and non-hydrostaticity on the trigonal crystal field in this material, and discuss the use of the Zeman-split ruby fluorescence as a possible probe for deviatoric stresses in diamond anvil cell experiments.

Dan, Ioana

2012-02-01

256

Picosecond High Pressure Gas Switch experiment  

SciTech Connect

A high Pressure Gas Switch has been developed and tested at LLNL. Risetimes on the order of 200 picoseconds have been observed at 1 kHz prf and 1 atmosphere pressures. Calculations show that switching closure times on the order of tens of picoseconds can be achieved at higher pressures and electric fields. A voltage hold-off of 1 MV/cm has been measured at 10 atmospheres and several MV/cm appears possible with the HPGS. With such high electric field levels, energy storage of tens of Joules in a reasonably sized package is achievable. Initial HPGS performance has been characterized using the WASP pulse generator at LLNL. A detailed description of the switch used for initial testing is given. Switch recovery times of 1-ms have been measured at 1 atmosphere. Data on the switching uniformity, voltage hold-off recovery, and pulse repeatability, is presented. In addition, a physics switch model is described and results are compared with experimental data. Modifications made to the WASP HV pulser in order to drive the HPGS will also be discussed. Recovery times of less than 1 ms were recorded without gas flow in the switch chambers. Low pressure synthetic air was used as the switch dielectric. Longer recovery times were required when it was necessary to over-voltage the switch.

Cravey, W.R.; Freytag, E.K.; Goerz, D.A.; Poulsen, P.; Pincosy, P.A.

1993-08-01

257

High-pressure droplet combustion studies  

NASA Technical Reports Server (NTRS)

This is a joint research program, pursued by investigators at the University of Tokyo, UCSD, and NASA Lewis Research Center. The focus is on high-pressure combustion of miscible binary fuel droplets. It involves construction of an experimental apparatus in Tokyo, mating of the apparatus to a NASA-Lewis 2.2-second drop-tower frame in San Diego, and performing experiments in the 2.2-second tower in Cleveland, with experimental results analyzed jointly by the Tokyo, UCSD, and NASA investigators. The project was initiated in December, 1990 and has now involved three periods of drop-tower testing by Mikami at Lewis. The research accomplished thus far concerns the combustion of individual fiber-supported droplets of mixtures of n-heptane and n-hexadecane, initially about 1 mm diameter, under free-fall microgravity conditions. Ambient pressures ranged up to 3.0 MPa, extending above the critical pressures of both pure fuels, in room-temperature nitrogen-oxygen atmospheres having oxygen mole fractions X of 0.12 and 0.13. The general objective is to study near-critical and super-critical combustion of these droplets and to see whether three-stage burning, observed at normal gravity, persists at high pressures in microgravity. Results of these investigations will be summarized here; a more complete account soon will be published.

Mikami, Masato; Kono, M.; Sato, Junichi; Dietrich, Daniel L.; Williams, Forman A.

1993-01-01

258

Improved SiC Leadless Pressure Sensors For High Temperature, Low and High Pressure Applications  

Microsoft Academic Search

This paper reports on the fabrication, packaging, and testing of improved SiC piezoresistive pressure sensors operational up to 600ºC in both low and high pressure ranges. Sensor fabrication was done using a combination of Deep Reactive Ion Etching (DRIE) and electrochemical etching. This paper also reports on the design and evaluation of sensors with optimized sensing diaphragms containing \\

Alexander A. Ned; Anthony D. Kurtz; Glenn Beheim; Fawzia Masheeb; Sorin Stefanescu

259

High pressure liquid chromatographic gradient mixer  

DOEpatents

A gradient mixer which 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, Christian G. (San Pablo, CA); Sakaji, Richard H. (El Cerrito, CA)

1985-01-01

260

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

261

High pressure polymorphism of ?-TaON.  

PubMed

The high pressure behavior of TaON was studied using a combination of Raman scattering, synchrotron X-ray diffraction, and X-ray absorption spectroscopy in diamond anvil cells to 70 GPa at ambient temperature. A Birch-Murnaghan equation of state fit for baddeleyite structured ?-TaON indicates a high bulk modulus value Ko = 328 ± 4 GPa with K = 4.3. EXAFS analysis of the high pressure XAS data provides additional information on changes in the Ta-(O,N) and Ta-Ta distances. Changes in the X-ray diffraction patterns and Raman spectra indicate onset of a pressure induced phase transition near 33 GPa. Our analysis indicates that the new phase has an orthorhombic cotunnite-type structure but that the phase transition may not be complete even by 70 GPa. Similar sluggish transformation kinetics are observed for the isostructural ZrO2 phase. Analysis of compressibility data for the new cotunnite-type TaON phase indicate a very high bulk modulus Ko ? 370 GPa, close to the theoretically predicted value. PMID:24831960

Woodhead, K; Pascarelli, S; Hector, A L; Briggs, R; Alderman, N; McMillan, P F

2014-06-01

262

A description of electron heating with an electrostatic potential jump in a parallel, collisionless, fire hose shock  

NASA Technical Reports Server (NTRS)

The electron heating required if protons scatter elastically in a parallel, collisionless shock is calculated. Near-elastic proton scattering off large amplitude background magnetic field fluctuations might be expected if the waves responsible for the shock dissipation are generated by the fire hose instability. The effects of an electrostatic potential jump in the shock layer are included by assuming that the energy lost by protons in traversing the potential jump is converted into electron thermal pressure. It is found that the electron temperature increase is a strong function of the potential jump. Comparison is made to the parallel shock plasma simulation of Quest (1987).

Ellison, Donald C.; Jones, Frank C.

1988-01-01

263

High pressure hydrogen time projection chamber  

SciTech Connect

We describe a high pressure hydrogen gas time projection chamber which consists of two cylindrical drift regions each 45 cm in diameter and 75 cm long. Typically, at 15 atm of H/sub 2/ with 2 kV/cm drift field and 7 kV on the 35..mu.. sense wires, the drift velocity is about 0.5 cm/..mu..sec and the spatial resolution +-200..mu...

Goulianos, K.

1983-01-01

264

Far Infrared Spectroscopy at High Pressures  

Microsoft Academic Search

PRESSURES sufficiently high to give significant distortion to crystal lattices or dense amorphous systems have been used in combination with spectroscopic observation for some years. The efforts of Drickamer et al.1 have been conspicuously successful in this field but their spectroscopy has been in the ultra-violet, visible and near infra-red regions where the primary transitions are electronic. We have developed

C. C. Bradley; H. A. Gebbie; A. C. Gilby; V. V. Kechin; J. H. King

1966-01-01

265

High pressure annealing of CVD diamond films  

Microsoft Academic Search

CVD diamond films were annealed from 600 to 1900 °C at 7.7 GPa in a toroidal high pressure (HP) apparatus, always inside the diamond-phase stability region. The annealed films were analyzed by Raman and infrared (IR) spectroscopy and the results showed that the diamond grains remained stable while the non-diamond carbon phases and impurities, responsible for the intricate film structure,

N. M. Balzaretti; J. A. H. da Jornada

2003-01-01

266

Engine having a high pressure hydraulic system and low pressure lubricating system  

DOEpatents

An engine includes a high pressure hydraulic system having a high pressure pump and at least one hydraulically-actuated device attached to an engine housing. A low pressure engine lubricating system is attached to the engine housing and includes a circulation conduit fluidly connected to an outlet from the high pressure pump.

Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

2000-01-01

267

Prediction of Production Power for High-pressure Hydrogen by High-pressure Water Electrolysis  

NASA Astrophysics Data System (ADS)

Recently the high attention for fuel cell electric vehicle (FCEV) is pushing to construct the hydrogen supplying station for FCEV in the world. The hydrogen pressure supplied at the current test station is intended to be high for increasing the FCEV’s driving distance. The water electrolysis can produce cleanly the hydrogen by utilizing the electricity from renewable energy without emitting CO2 to atmosphere, when it is compared to be the popular reforming process of fossil fuel in the industry. The power required for the high-pressure water electrolysis, where water is pumped up to high-pressure, may be smaller than the power for the atmospheric water electrolysis, where the produced atmospheric hydrogen is pumped up by compressor, since the compression power for water is much smaller than that for hydrogen gas. In this study the ideal water electrolysis voltage up to 70MPa and 523K is estimated referring to both the results by LeRoy et al up to 10MPa and 523K, and to the latest steam table. By using this high-pressure water electrolysis voltage, the power required for high-pressure hydrogen produced by the high-pressure water electrolysis method is estimated to be about 5% smaller than that by the atmospheric water electrolysis method, by assuming the compressor and pump efficiency of 50%.

Kyakuno, Takahiro; Hattori, Kikuo; Ito, Kohei; Onda, Kazuo

268

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

269

Prediction of production power for high-pressure hydrogen by high-pressure water electrolysis  

NASA Astrophysics Data System (ADS)

Recent attention focused on fuel cell electric vehicles (FCEVs) has created demand for the construction of hydrogen supply stations for FCEVs throughout the world. The hydrogen pressure supplied at the supply stations is intentionally high to increase the FCEVs driving mileage. Water electrolysis can produce clean hydrogen by utilizing electricity from renewable energy without CO 2 emission to the atmosphere when compared with the industrial fossil fuel reforming process. The power required for high-pressure water electrolysis, wherein water is pumped up to a high-pressure, may be less than the power required for atmospheric water electrolysis, wherein the produced atmospheric hydrogen is pumped by a compressor, since the compression power for water is much less than that for hydrogen-gas. In this study, the ideal water electrolysis voltage of up to 70 MPa and 250 °C is estimated by referring to both the results of LeRoy et al. up to 10 MPa and 250 °C, and the latest steam tables. Using this high-pressure water electrolysis voltage, the power required to produce high-pressure hydrogen by high-pressure water electrolysis is estimated to be about 5% less than that required for atmospheric water electrolysis, assuming compressor and pump efficiencies of 50%.

Onda, Kazuo; Kyakuno, Takahiro; Hattori, Kikuo; Ito, Kohei

270

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

2007-05-29

271

Very high-pressure orogenic garnet peridotites  

PubMed Central

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.

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

2007-01-01

272

A high frequency silicon pressure sensor  

NASA Technical Reports Server (NTRS)

Theoretical and design considerations as well as fabrication and experimental work involved in the development of high-frequency silicon pressure sensors with an ultra-small diaphragm are discussed. A sensor is presented with a rectangular diaphragm of 0.0127 cm x 0.0254 cm x 1.06 micron; the sensor has a natural frequency of 625 kHz and a sensitivity of 0.82 mv/v-psi. High-frequency results from shock tube testing and low-frequency (less than 50 kHz) comparison with microphones are given.

Kahng, S. K.; Gross, C.

1980-01-01

273

Generalization of the equation for the quasi-stationary relativistic electron beam envelope to the case of Resistive Hose instability  

NASA Astrophysics Data System (ADS)

The statement of an equation for the envelope of a quasi-stationary relativistic electron beam experiencing Resistive Hose instability is considered. The well-known Nordsieck equation is generalized to the case of Resistive Hose instability using analytical methods.

Kolesnikov, E. K.; Manuilov, A. S.

2013-11-01

274

46 CFR 35.40-17 - Foam hose/monitor stations-T/ALL.  

Code of Federal Regulations, 2013 CFR

... false Foam hose/monitor stations-T/ALL. 35.40-17 Section 35.40-17 Shipping...OPERATIONS Posting and Marking Requirements-TB/ALL § 35.40-17 Foam hose/monitor stationsâT/ALL. (a) At each required foam...

2013-10-01

275

High-pressure cell for a SQUID magnetometer with a plug for in situ pressure measurements  

Microsoft Academic Search

We describe the design of a miniature high-pressure cell built for a Magnetic Property Measurement System based on the Superconducting Quantum Interference Device technology magnetometer. The key feature of the cell is the plug for in situ pressure measurements with feed-through wires connected to a manganin pressure sensor, which has a known pressure dependence of electrical resistivity. By monitoring pressure

J. Sanchez-Benitez; S. Tancharakorn; M. K. Hutchison; K. V. Kamenev

2008-01-01

276

High temperature and pressure electrochemical test station  

NASA Astrophysics Data System (ADS)

An electrochemical test station capable of operating at pressures up to 100 bars and temperatures up to 400 °C has been established. It enables control of the partial pressures and mass flow of O2, N2, H2, CO2, and H2O in a single or dual environment arrangement, measurements with highly corrosive media, as well as localized sampling of gas evolved at the electrodes for gas analysis. A number of safety and engineering design challenges have been addressed. Furthermore, we present a series of electrochemical cell holders that have been constructed in order to accommodate different types of cells and facilitate different types of electrochemical measurements. Selected examples of materials and electrochemical cells examined in the test station are provided, ranging from the evaluation of the ionic conductivity of liquid electrolytic solutions immobilized in mesoporous ceramic structures, to the electrochemical characterization of high temperature and pressure alkaline electrolysis cells and the use of pseudo-reference electrodes for the separation of each electrode contribution. A future perspective of various electrochemical processes and devices that can be developed with the use of the established test station is provided.

Chatzichristodoulou, C.; Allebrod, F.; Mogensen, M.

2013-05-01

277

Application of high pressure treatment for cheese production  

Microsoft Academic Search

High hydrostatic-pressure treatment offers the food industry a new technology for food preservation. Interest in high pressure application on milk has recently increased. Pressures between 300 and 600 MPa can inactivate microorganisms including most infectious food-borne pathogens. In addition to microbial destruction, it has been reported that high pressure improves rennet or acid coagulation of milk and increases cheese yield.

A. J Trujillo; M Capellas; M Buffa; C Royo; R Gervilla; X Felipe; E Sendra; J Saldo; V Ferragut; B Guamis

2000-01-01

278

Filament wound pressure vessels - Effects of using liner tooling of low pressure vessels for high pressure vessels development  

NASA Astrophysics Data System (ADS)

High performance pressure vessels have been recently demanded for aerospace and defense applications. Filament wound pressure vessels consist of a metallic thin liner, which also acts as a mandrel, and composite/epoxy overwrap. Graphite/epoxy overwrapped vessels have been developed to obtain the performance ratio, PV/W, as high as one million inches. Under very high pressure the isotropic metallic liner deforms elasto-plastically, and orthotropic composite fibers deform elastically. Sometimes, for the development of ultra high pressure vessels, composite pressure vessels industry uses the existing liner tooling developed for low burst pressure capacity composite vessels. This work presents the effects of various design variables including the low pressure liner tooling for the development of the high burst pressure capacity Brilliant Pebbles helium tanks. Advance stress analysis and development of an ultra high pressure helium tank.

Lal, Krishna M.

279

CDC Vital Signs: High Blood Pressure and Cholesterol  

MedlinePLUS

... Delicious Digg Google Bookmarks High Blood Pressure and Cholesterol Out of Control February 2011 39 Every 39 ... cdc.gov/GISCVH2/ High Blood Pressure and High Cholesterol Among US Adults SOURCES: National Health and Nutrition ...

280

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] [and others

2000-02-24

281

High-pressure promoted combustion chamber  

NASA Technical Reports Server (NTRS)

In the preferred embodiment of the promoted combusiton chamber disclosed herein, a thick-walled tubular body that is capable of withstanding extreme pressures is arranged with removable upper and lower end closures to provide access to the chamber for dependently supporting a test sample of a material being evaluated in the chamber. To facilitate the real-time analysis of a test sample, several pressure-tight viewing ports capable of withstanding the simulated environmental conditions are arranged in the walls of the tubular body for observing the test sample during the course of the test. A replaceable heat-resistant tubular member and replaceable flame-resistant internal liners are arranged to be fitted inside of the chamber for protecting the interior wall surfaces of the combustion chamber during the evaluation tests. Inlet and outlet ports are provided for admitting high-pressure gases into the chamber as needed for performing dynamic analyses of the test sample during the course of an evaluation test.

Rucker, Michelle A. (inventor); Stoltzfus, Joel M. (inventor)

1991-01-01

282

Bubble Pinch-off at High Pressures  

NASA Astrophysics Data System (ADS)

Previously we have studied the pinch-off of conventional air bubbles in water [1]. For inviscid fluids, the shrinking of the neck radius of the bubble can be described by a power-law in time with an exponent close to 1/2. As the density of the interior gas is increased, instabilities are expected to occur in the liquid/gas interface [2]. We present high-speed videos and numerical simulations of the pinch-off of high-pressure gaseous bubbles in and exterior inviscid fluid. The density ratio between the exterior fluid and interior gas is D=?ext/?int. In the simple case of small D˜0.001, the pinch-off is similar to that of a water drop pinching-off in air, while at large D˜1000, the pinch-off is that of an air bubble in water. By using sulfur hexafluoride as a working gas, we are able to span a wide ranging of density ratios simply by increasing the pressure of the gas. A high-pressure (˜30 atm) chamber with optical access through sapphire windows was constructed in order to view the pinch-off. The numerical simulations are performed assuming perfectly inviscid fluids using boundary-integral techniques. Instabilities in the interface are seen for intermediate density ratios. Comparisons between experimental and numerical results will be discussed. [1] J.C. Burton, R. Waldrep, and P. Taborek. Phys. Rev. Lett. 94, 184502, (2005). [2] D. Leppinen and J.R. Lister. Phys. Fluids 15, 568, (2003).

Burton, J. C.; Taborek, P.

2008-03-01

283

A picosecond high pressure gas switch  

SciTech Connect

Work is being done to develop a high pressure gas switch (HPGS) with picosecond risetimes for UWB applications. Pulse risetimes on the order of 200 picoseconds have been observed at 1 kHz prf and 1 atmosphere. Calculations show that switching closure times on the order of tens of picoseconds can be achieved at high pressures and higher electric fields. A voltage hold-off of 1 MV/cm has been measured at 10 atmospheres and several MV/cm appears possible with the HPGS. With these high electric field levels, energy storage of tens of Joules in a reasonably sized package is achievable. Initial HPGS performance has been characterized on the WASP pulse generator at LLNL. A detailed description of the switch used for initial testing is given. Switch recovery times of 1-ms have been measured at 1 atmosphere. Data on the switching uniformity, voltage hold-off recovery, and pulse repeatability, is presented. In addition, a physics switch model is described and results are compared with lab data.

Cravey, W.R.; Poulsen, P.P.; Pincosy, P.A.

1992-06-01

284

High pressure-High temperature phases of Carbon Dioxide  

NASA Astrophysics Data System (ADS)

The phase diagram of CO2 has not been understood adequately above 40 GPa and high temperatures, particularly regarding the stabilities and boundaries of various extended phases that include a-carbonia, Phase V, Phase VI, and to an extent Phase III. We have studied the phase diagram of CO2 above 40 GPa and at high temperatures, using both ohmically and laser-heated diamond anvil cells. We found the co-existence of several extended phases over a large pressure region, which we attribute to the metastability of the extended phases and the extraordinarily large pressure gradients at these pressures. We determined the relative stability fields of the co-existing phases, which may offer the physico-chemical mechanism for the existence of carbonate minerals in deep Earth's mantle.

Sengupta, Amartya; Yoo, Choong-Shik

2009-03-01

285

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

286

DEVELOPMENT OF A HIGH-TEMPERATURE/HIGH-PRESSURE ELECTROSTATIC PRECIPITATOR  

EPA Science Inventory

The report gives results of a laboratory test demonstrating the feasibility of electrostatic precipitation at high temperatures (to 1366 K) and pressures (to 3550 kPa): corona currents were stable at all temperatures. Detailed current/voltage characteristics under negative and po...

287

Evaluation of candidate alloys for the construction of metal flex hoses in the STS launch environment  

NASA Technical Reports Server (NTRS)

Various vacuum jacketed cryogenic supply lines at the Shuttle launch site use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the flex hoses, which were made out of 304L stainless steel. A search was done to find a more corrosion resistant replacement material. Nineteen metal alloys were tested. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, long term exposure at the beach corrosion testing site, and pitting corrosion tests in ferric chloride solution. Based on the results, the most corrosion resistant alloys were found to be, in order, Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, and Inco Alloy G-3. Of these top five alloys, the Hastelloy C-22 stands out as being the best of the alloys tested.

Macdowell, Louis G., III; Ontiveros, Cordelia

1988-01-01

288

Replacement for a Flex Hose Coating at the Space Shuttle Launch Pad  

NASA Technical Reports Server (NTRS)

Aerocoat AR-7 is a coating that has been used to protect stainless steel flex hoses at NASA's Kennedy Space Center launch complex and hydraulic lines of the mobile launch platform (MLP). This coating has great corrosion control performance and low temperature application. AR-7 was developed by NASA and produced exclusively for NASA but its production has been discontinued due to its high content of volatile organic compounds (VOC) and significant environmental impact. The purpose of this project was to select and evaluate candidate coatings to find a replacement coating that is more environmentally friendly, with similar properties to AR-7. No coatings were identified that perform the same as AR-7 in all areas. Candidate coatings failed in comparison to AR-7 in salt fog, beachside atmospheric exposure, pencil hardness, Mandrel bend, chemical compatibility, adhesion, and ease of application tests. However, two coatings were selected for further evaluation.

Whitten, Mary; Vinje, Rubiela; Curran, Jerome; Meneghelli, Barry; Calle, Luz Marina

2009-01-01

289

Formation of Smectite Crystals at High Pressures and Temperatures  

Microsoft Academic Search

Smectite single crystals of superior quality were synthesized at high pressures and temperatures using a modified belt type high pressure apparatus. Pressure--temperature conditions were established for smectite formation by quenching experiments in the pressure range from 2-5.5 GPa and temperatures of 700\\

Hirohisa Yamada; HIROMOTO NAKAZAWA; HIDEO HASHIZUME

1994-01-01

290

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

291

High blood pressure and visual sensitivity  

NASA Astrophysics Data System (ADS)

The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

Eisner, Alvin; Samples, John R.

2003-09-01

292

General formulation for magnetohydrodynamic wave propagation, fire-hose, and mirror instabilities in Harris-type current sheets  

NASA Astrophysics Data System (ADS)

Harris-type current sheets with the magnetic field model of B?=Bx(z)?+By(z)? have many important applications to space, astrophysical, and laboratory plasmas for which the temperature or pressure usually exhibits the gyrotropic form of p<-->=p?b?b?+p?(I<-->-b?b?). Here, p? and p? are, respectively, to be the pressure component along and perpendicular to the local magnetic field, b?=Bvec /B. This study presents the general formulation for magnetohydrodynamic (MHD) wave propagation, fire-hose, and mirror instabilities in general Harris-type current sheets. The wave equations are expressed in terms of the four MHD characteristic speeds of fast, intermediate, slow, and cusp waves, and in the local (k?,k?,z) coordinates. Here, k? and k? are, respectively, to be the wave vector along and perpendicular to the local magnetic field. The parameter regimes for the existence of discrete and resonant modes are identified, which may become unstable at the local fire-hose and mirror instability thresholds. Numerical solutions for discrete eigenmodes are shown for stable and unstable cases. The results have important implications for the anomalous heating and stability of thin current sheets.

Hau, L.-N.; Lai, Y.-T.

2013-02-01

293

General formulation for magnetohydrodynamic wave propagation, fire-hose, and mirror instabilities in Harris-type current sheets  

SciTech Connect

Harris-type current sheets with the magnetic field model of B-vector=B{sub x}(z)x-caret+B{sub y}(z)y-caret have many important applications to space, astrophysical, and laboratory plasmas for which the temperature or pressure usually exhibits the gyrotropic form of p{r_reversible}=p{sub Parallel-To }b-caretb-caret+p{sub Up-Tack }(I{r_reversible}-b-caretb-caret). Here, p{sub Parallel-To} and p{sub Up-Tack} are, respectively, to be the pressure component along and perpendicular to the local magnetic field, b-caret=B-vector/B. This study presents the general formulation for magnetohydrodynamic (MHD) wave propagation, fire-hose, and mirror instabilities in general Harris-type current sheets. The wave equations are expressed in terms of the four MHD characteristic speeds of fast, intermediate, slow, and cusp waves, and in the local (k{sub Parallel-To },k{sub Up-Tack },z) coordinates. Here, k{sub Parallel-To} and k{sub Up-Tack} are, respectively, to be the wave vector along and perpendicular to the local magnetic field. The parameter regimes for the existence of discrete and resonant modes are identified, which may become unstable at the local fire-hose and mirror instability thresholds. Numerical solutions for discrete eigenmodes are shown for stable and unstable cases. The results have important implications for the anomalous heating and stability of thin current sheets.

Hau, L.-N. [Institute of Space Science, National Central University, Jhongli, Taiwan (China); Department of Physics, National Central University, Jhongli, Taiwan (China); Lai, Y.-T. [Institute of Space Science, National Central University, Jhongli, Taiwan (China)

2013-02-15

294

Pressure Distribution Over Airfoils at High Speeds  

NASA Technical Reports Server (NTRS)

This report deals with the pressure distribution over airfoils at high speeds, and describes an extension of an investigation of the aerodynamic characteristics of certain airfoils which was presented in NACA Technical Report no. 207. The results presented in report no. 207 have been confirmed and extended to higher speeds through a more extensive and systematic series of tests. Observations were also made of the air flow near the surface of the airfoils, and the large changes in lift coefficients were shown to be associated with a sudden breaking away of the flow from the upper surface. The tests were made on models of 1-inch chord and comparison with the earlier measurements on models of 3-inch chord shows that the sudden change in the lift coefficient is due to compressibility and not to a change in the Reynolds number. The Reynolds number still has a large effect, however, on the drag coefficient. The pressure distribution observations furnish the propeller designer with data on the load distribution at high speeds, and also give a better picture of the air-flow changes.

Briggs, L J; Dryden, H L

1927-01-01

295

Single-walled carbon nanotubes as high pressure nanocontainer  

NASA Astrophysics Data System (ADS)

The single-walled carbon nanotubes (SWCNTs) under high internal pressure are studied by the constant-pressure molecular dynamics method. The results show that SWCNTs are suitable candidates for high pressure nanocontainer, and they can resist 30 GPa to 110 GPa internal pressure. We find that the ultimate internal pressure that nanotubes can sustain is mainly determined by the radius of the tube, and it is not sensitive to the tube chirality. The breaking of the nanotube induced by high internal pressure is mainly due to bond stretching rather than bond angle changing. An elastic model is used to explain the size-dependent ultimate internal pressure behavior for SWCNTs.

Chen, Na; Xu, Qing; Ye, Xiang

2014-03-01

296

Experimental Attempt to Metallize Hydrogen at Very High Pressures.  

National Technical Information Service (NTIS)

Metallic hydrogen is potential candidate as a high energy density material. The possibility of metallizing hydrogen by submitting it to very high pressures has been experimentally investigated. Great advances have been made in this study. Pressures as hig...

I. F. Silvera

1992-01-01

297

Heart Risks Depend on Which Blood Pressure Number Is High  

MedlinePLUS

... Pressure Number Is High: Study Researchers also discovered lifetime heart risks were greater even with medications to ... high blood pressure, or "hypertension," still face greater lifetime health risks. For example, a 30-year-old ...

298

Very high temperature silicon on silicon pressure transducers  

NASA Technical Reports Server (NTRS)

A silicon on silicon pressure sensor has been developed for use at very high temperatures (1000 F). The design principles used to fabricate the pressure sensor are outlined and results are presented of its high temperature performance.

Kurtz, Anthony D.; Nunn, Timothy A.; Briggs, Stephen A.; Ned, Alexander

1992-01-01

299

[High blood pressure and physical exercise].  

PubMed

High blood pressure is a frequent pathology with many cardiovascular complications. As highlighted in guidelines, the therapeutic management of hypertension relies on non-pharmacological measures, which are diet and regular physical activity, but both patients and physicians are reluctant to physical activity prescription. To acquire the conviction that physical activity is beneficial, necessary and possible, we can take into account some fundamental and clinical studies, as well as the feedback of our clinical practice. Physical inactivity is a major risk factor for cardiovascular morbidity and mortality, and hypertension contributes to increase this risk. Conversely, regular practice of physical activity decreases very significantly the risk by up to 60%. The acute blood pressure changes during exercise and post-exercise hypotension differs according to the dynamic component (endurance or aerobic and/or strength exercises), but the repetition of the sessions leads to the chronic hypotensive benefit of physical activity. Moreover, physical activity prescription must take into account the assessment of global cardiovascular risk, the control of the hypertension, and the opportunities and desires of the patient in order to promote good adherence and beneficial lifestyle change. PMID:24928464

Sosner, P; Gremeaux, V; Bosquet, L; Herpin, D

2014-06-01

300

System design for buried high-pressure/high-temperature pipelines  

SciTech Connect

A pipeline expands or contracts when temperatures or pressures vary from the conditions at the time the pipeline was installed. Buried pipelines operating at high temperatures and pressures experience extreme compressive loads. Because radial expansion is limited by soil restraint, buried pipelines expand axially. High axial forces combined with imperfections in the seabed may overstress the pipeline or result in upheaval buckling. Methods to control expansion and upheaval buckling were investigated for the design of a buried high-pressure/high temperature (HP/HT) sour-gas flowline in Mobile Bay, Alabama. After investigating conventional and unconventional methods, the decision was made to use expansion loops over the length of the pipeline to protect the risers and reduce axial force in the middle of the pipeline. Expansion loops and doglegs act as springs to absorb pipeline expansion. Methods were investigated to prevent soil from accumulating around the buried expansion loops. Commercially available concrete dog houses used to protect pipelines and expansion loops from dropped objects were not suitable for burial, and fabrication of custom concrete housing was expensive. Fabrication of a steel enclosure was the solution chosen. A mathematical model based on internal-design guidelines and ultimate soil friction was used to determine placement and size of the expansion loops.

NONE

1998-06-01

301

High pressure fiber optic sensor system  

DOEpatents

The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

2013-11-26

302

High pressure magnetic resonance imaging with metallic vessels  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

303

Ceramic high pressure gas path seal  

NASA Technical Reports Server (NTRS)

Stage 1 ceramic shrouds (high pressure turbine gas path seal) were developed for the GE T700 turbine helicopter engine under the Army/NASA Contract NAS3-23174. This contract successfully proved the viability and benefits of a Stage 1 ceramic shroud for production application. Stage 1 ceramic shrouds were proven by extensive component and engine testing. This Stage 1 ceramic shroud, plasma sprayed ceramic (ZrOs-BY2O3) and bond coating (NiCrAlY) onto a cast metal backing, offers significant engine performance improvement. Due to the ceramic coating, the amount of cooling air required is reduced 20% resulting in a 0.5% increase in horsepower and a 0.3% decrease in specific fuel consumption. This is accomplished with a component which is lower in cost than the current production shroud. Stage 1 ceramic shrouds will be introduced into field service in late 1987.

Liotta, G. C.

1987-01-01

304

Low energy high pressure miniature screw valve  

DOEpatents

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

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

2006-12-12

305

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

306

Integrated optimization system for high pressure die casting processes  

Microsoft Academic Search

High pressure die casting (HPDC) is a versatile process for producing engineered metal parts by forcing molten metal under high pressure into reusable steel dies. However there are a large number of attributes involved which contribute to the complexity of the process. A novel integrated approach is developed to optimize the high pressure die casting processes. The die temperature profiles

L. X. Kong; F. H. She; W. M. Gao; S. Nahavandi; P. D. Hodgson

2008-01-01

307

Effect of high pressure on mesophilic lactic fermentation streptococci  

NASA Astrophysics Data System (ADS)

The research concerned the effect of high pressure on mesophilic lactic fermentation streptococci, present in two cheese-making commercial inocula produced by Christian-Hansen. Water solutions of inocula were pressurized at 50-800 MPa, at room temperature, for 30-120 min. Pressurization at 50-100 MPa slightly increased or reduced the number of lactic streptococci, depending on the inoculum and pressurization time. Pressurization at 200 MPa caused a reduction in the number of streptococci by over 99.9%, whereas the pressure of 400 MPa and above almost completely inactivated streptococci. Pressurization also reduced the dynamics of microorganism growth and acidification, to the degree depending on the pressure.

Reps, A.; Ku?micka, M.; Wi?niewska, K.

2008-07-01

308

Prediction of production power for high-pressure hydrogen by high-pressure water electrolysis  

Microsoft Academic Search

Recent attention focused on fuel cell electric vehicles (FCEVs) has created demand for the construction of hydrogen supply stations for FCEVs throughout the world. The hydrogen pressure supplied at the supply stations is intentionally high to increase the FCEVs driving mileage. Water electrolysis can produce clean hydrogen by utilizing electricity from renewable energy without CO2 emission to the atmosphere when

Kazuo Onda; Takahiro Kyakuno; Kikuo Hattori; Kohei Ito

2004-01-01

309

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

310

Investigating cavity pressure behavior in high-pressure RTM process variants  

NASA Astrophysics Data System (ADS)

The paper addresses new variants of the high pressure resin transfer molding (HP-RTM) process namely high pressure injection RTM (HP-IRTM) and high pressure compression RTM (HP-CRTM) for manufacturing of carbon fiber reinforced composites with high fiber volume content. Both these processes utilize high-pressure RTM equipment for precise dosing and mixing of highly reactive epoxy resin and amine hardener with relatively high throughput rates. The paper addresses results of a study which investigated cavity pressure measurement for both the HP-RTM process variants using a specially designed highpressure RTM mold. The investigations indicate that the cavity pressure built up is a characteristic of the selected process variant. Further the relationship between the applied press force and the cavity pressure in HP-CRTM process was studied.

Rosenberg, P.; Chaudhari, R.; Karcher, M.; Henning, F.; Elsner, P.

2014-05-01

311

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

312

Probing Hydrogen Diffusion under High Pressure  

NASA Astrophysics Data System (ADS)

The study of the microscopic mechanism governing hydrogen and hydrogen-based liquids (as water, ammonia and methane) diffusion is crucial for a variety of scientific issues spanning most of natural sciences. As an example, characterizing hydrogen diffusion in a confined medium, like in porous systems or zeolites, is fundamental in problems relating to environment, hydrogen storage and industrial applications [1]. The presence of water diffusion in the minerals of the Earth's mantle have strong incidence on the processes governing volcanic eruptions and intermediate-depth seismicity. As last example, knowing in details the microscopic dynamics of hydrogen-based simple liquids under extreme conditions is essential in order to interpret observations and develop models of planet interiors [2]. On the other hand, water and other simple hydrogen-based liquids have always been key systems in the development of modern condensed-matter physics, because of their simple electronic structure and the peculiar properties deriving from the hydrogen-bond network. Their high compressibility and chemical reactivity have made these systems very challenging to study experimentally under static high P-T conditions. In the last few years, a large effort has been undertaken by several groups around the world [2] to extend the static and dynamic techniques to high temperatures and pressures, a program in which our group has been actively involved [3-6]. However, while the structure of water and other hydrogenated liquids of geological interest, is now known up to almost 20 GPa, the study of their transport properties greatly lags behind. We have recently developed a new large-volume gasket-anvil ensemble for the Paris-Edinburgh press based on a novel toroidal design [7], which allows to perform quasi elastic neutron scattering measurements on hydrogen based liquids up to one order of magnitude higher pressures (5 GPa) respect to what was achievable with standard methods [8]. The large volume HP press can be now warmed up to 600K and the peculiar geometry of the gasket assure an excellent signal to background ratio. This new device has been recently settled up on neutron scattering facilities (PSI, ILL), successfully showing that very high quality data can be obtained on liquid water, and more generally on hydrogenated liquids dynamics under high pressure. Some new exciting results on the diffusion mechanism in hot dense water will be presented [9]. Possible future implementation of the device to reach the 20GPa and 1000K conditions will be also discussed. References [1] C. Cavazzoni et al., Science 283, 44 (1999) ; T. Guillot, Science 286 (1999), 72 . 77. [2] Some of the most active groups in this field are the Geophysical Laboratory (USA), Lawrence Livermore National Laboratory (USA), CEA/DAM (France) and the Bayerisches Geoinstitut (Allemagne). [3] Klotz S et al, Phys. Rev. Lett. 96 149602, 2006. [4] Nelmes R J Nature Phys. 2 414, 2006. [5] S. Klotz, L. Bove et al., Nature Mat. 8, 405 (2009). [6] L.E. Bove et al., Phys. Rev. Lett., 106 (2011) . [7] L. E. Bove et al., Phys. Appl. Lett., in preparation (2012). [8] A. Cunsolo et al., Journal of Chem. Phys. 124, 084503 (2006). [9] L.E. Bove et al., Phys. Rev. Lett., submitted (2012) .

Bove, L. E.; Klotz, S.; Strassle, T.; Saitta, M.

2012-12-01

313

Elastic Properties of New Pressure-Transmitting Medium Daphne 7474 under High Pressure  

NASA Astrophysics Data System (ADS)

High-pressure Brillouin measurements of a pressure-transmitting medium Daphne 7474 have been performed at pressures up to about 12 GPa. We have determined the acoustic phase velocity, refractive index, equation of state, and adiabatic bulk modulus for Daphne 7474 as a function of pressure, and have evaluated the performance of Daphne 7474 as a hydrostatic pressure-transmitting medium. The obtained elastic properties show that Daphne 7474 is an excellent pressure-transmitting medium for transport and optical experiments in comparison with the 4:1 methanol-ethanol mixture below the solidification pressure 3.7 GPa of Daphne 7474.

Sasaki, Shigeo; Kato, Seiichi; Kume, Tetsuji; Shimizu, Hiroyasu; Okada, Tahei; Aoyama, Shoji; Kusuyama, Fumihiko; Murata, Keizo

2010-10-01

314

Calculating Mass Diffusion in High-Pressure Binary Fluids  

NASA Technical Reports Server (NTRS)

A comprehensive mathematical model of mass diffusion has been developed for binary fluids at high pressures, including critical and supercritical pressures. Heretofore, diverse expressions, valid for limited parameter ranges, have been used to correlate high-pressure binary mass-diffusion-coefficient data. This model will likely be especially useful in the computational simulation and analysis of combustion phenomena in diesel engines, gas turbines, and liquid rocket engines, wherein mass diffusion at high pressure plays a major role.

Bellan, Josette; Harstad, Kenneth

2004-01-01

315

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

316

Negative pressure effects in high-pressure oxygen-intercalated C{sub 60}  

SciTech Connect

We have observed unexpected and as yet unexplained negative pressure effects in high-oxygen-pressure-treated C{sub 60} in which the orientational ordering temperature is greatly depressed. Such effects are not observed in identical studies with nitrogen.

Schirber, J.E.; Assink, R.A.; Samara, G.A.; Morosin, B.; Loy, D. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

1995-06-01

317

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

318

Effects of pressure in coal pyrolysis observed by high pressure TGA  

Microsoft Academic Search

High-pressure thermogravimetric analyzer was employed to investigate the effects of pressure on the thermal decomposition\\u000a process, which is the very first step in most coal utilizing processes, and pyrolyzates from TGA were analyzed by on-line\\u000a GC\\/MS. Results showed that pyrolysis of coal with steam under high-pressure conditions exhibited a slower reaction rate compared\\u000a to the lower pressure conditions, and the

Yongseung Yun; Gae-Bong Lee

1999-01-01

319

Filament wound pressure vessels - Effects of using liner tooling of low pressure vessels for high pressure vessels development  

Microsoft Academic Search

High performance pressure vessels have been recently demanded for aerospace and defense applications. Filament wound pressure vessels consist of a metallic thin liner, which also acts as a mandrel, and composite\\/epoxy overwrap. Graphite\\/epoxy overwrapped vessels have been developed to obtain the performance ratio, PV\\/W, as high as one million inches. Under very high pressure the isotropic metallic liner deforms elasto-plastically,

Krishna M. Lal

1992-01-01

320

High pressure high temperature elasticity study of sodium disilicate glass  

NASA Astrophysics Data System (ADS)

Many deep earth geophysical phenomena observed are related to physical properties of silicate melts under extreme conditions. Understanding the structures and physical properties of silicate melts at a fundamental level is essential to help us understand the dynamics of mineral crystallization and fractionation, thermal transport, etc. inside the Earth. Sodium disilicate (Na2Si2O5) glass is a good analog for studying amorphous phase basalt since they have similar ratios of non-bridging oxygen to tetrahedrally coordinated cations (NBO/T). Besides, sodium disilicate is not only simple in chemistry but also has a low melting point, thus permitting detailed experimental studies using currently available techniques. Synthesized sodium disilicate glass was ground into powder and loaded into a Paris-Edinburgh (PE) cell. The PE high pressure apparatus was installed inside the 16-BM-B hutch at the Advanced Photon Source. In our experiment, the glass sample was pressed up to 2GPa and heated up to 1000oC. At various pressure and temperature conditions, ultrasonic elastic wave velocities of the amorphous sample were collected using the pulse reflection method with a 10o Y-cut LiNbO3 transducer mounted on one end of the PE anvil. White beam x-ray radiographs that covered the entire length of the sample were also collected to determine the elastic wave travel distance. Experimental results show that before the glass transition temperature (~700oC at ambient pressure), the transverse wave velocity remains nearly constant with increasing temperature, while the longitudinal wave velocity decreases monotonically. A sudden drop in transverse wave velocity is observed above the glass transition temperature at 800oC. Within the 2GPa pressure range, we did not observe clear pressure dependence of the elastic wave velocities in sodium disilicate glass.

Yu, T.; Kono, Y.; Sakamaki, T.; Jing, Z.; Wang, Y.; Shen, G.

2011-12-01

321

PS foams at high pressure drop rates  

NASA Astrophysics Data System (ADS)

In this paper, we report data on PS foamed at 100 °C after CO2 saturation at 10 MPa in a new physical foaming batch that achieves pressure drop rates up to 120 MPa/s. Results show how average cell size of the foam nicely fit a linear behavior with the pressure drop rate in a double logarithmic plot. Furthermore, foam density initially decreases with the pressure drop rate, attaining a constant value at pressure drop rates higher than 40 MPa/s. Interestingly, furthermore, we observed that the shape of the pressure release curve has a large effect on the final foam morphology, as observed in tests in which the maximum pressure release rate was kept constant but the shape of the curve changed. These results allow for a fine tuning of the foam density and morphology for specific applications.

Tammaro, Daniele; De Maio, Attilio; Carbone, Maria Giovanna Pastore; Di Maio, Ernesto; Iannace, Salvatore

2014-05-01

322

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

Code of Federal Regulations, 2013 CFR

...being connected to National Standard Fire Hose of the size utilized on board...properly equipped to handle both fire fighting and flood control. (b) Each vessel must have a sufficient number of fire hydrants to reach any part of...

2013-10-01

323

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

Code of Federal Regulations, 2013 CFR

...Shipping 3 2013-10-01 2013-10-01 false Fire station hydrants, hose and nozzles-T/ALL...HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Fire Main System, Details § 76.10-10 Fire...

2013-10-01

324

High altitude and blood pressure in children.  

PubMed Central

We aimed to evaluate the blood pressure of children who had similar demographic characteristics but lived at different altitudes. Blood pressure of the children attending primary schools in Izmir (sea level: n = 425) and Van (altitude: 1725 m, n = 291) were measured by mercurial sphygmomanometer for this study. They were similar with respect to age, sex, weight, height, and BMI. Mean age of the children was 10.51 +/- 0.87 years (range: 9 to 12 years), and 358 (50 percent) of them were female. Mean systolic blood pressure was significantly higher in the children living in Van than in the children living in Izmir (104.72 +/- 11.2 vs. 97.96 +/- 25.5 mmHg, respectively, p < .001). Similarly mean diastolic blood pressure was significantly higher in the children living in Van than in the children living in Izmir (63.98 +/- 9.3 vs. 59.91 +/- 10.0 mmHg, respectively, p < .001). When blood pressure was evaluated with regard to height percentile, the number of children with a blood pressure over 90 percentile were 19 (4.5 percent) and 48 (16.5 percent) for systolic blood pressure, and 25 (5.9 percent) and 37 (12.7 percent) for diastolic blood pressure among the children living in Izmir and Van, respectively (p < .001). Systolic and diastolic blood pressures were found to increase in parallel to the increase in body mass index in children living in Van (r = 0.358, p < .001 and r = 0.235, p < .001, respectively). However, blood pressures were not correlated to body mass index in children living in Izmir. A difference of 1700 m in altitude was associated with higher systolic and diastolic blood pressure levels in children with similar demographic characteristics, and at this altitude, body mass index and blood pressure showed a positive correlation.

Arslan, Sukru; Arslan, Nur; Soylu, Alper; Akgun, Cihangir; Tepebasili, Ibrahim; Turkmen, Mehmet; Kavukcu, Salih

2003-01-01

325

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

326

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

Code of Federal Regulations, 2013 CFR

...false Control of the pressure of gas delivered from high-pressure distribution...PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY...197 Control of the pressure of gas delivered from high-pressure...

2013-10-01

327

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

328

Polyaniline thin films in situ polymerized under very high pressure  

Microsoft Academic Search

The conducting PANI films with network morphology were synthesized on glass substrate by in situ polymerization under various very high pressures (>108Pa). The effects of applied pressure on films were investigated by using UV–vis absorption spectroscopy, SEM, film thickness measurement and conductivity measurement. The high pressure used in polymerization played an important role in the formation of PANI films. Inferred

D. W. Gu; J. S. Li; J. L. Liu; Y. M. Cai; L. J. Shen

2005-01-01

329

Amplification and overexpression of aurora kinase A (AURKA) in immortalized human ovarian epithelial (HOSE) cells.  

PubMed

Immortalization is an early and essential step of human carcinogenesis. Amplification of chromosome 20q has been shown to be a common event in immortalized cells and cancers. We have previously reported that gain and amplification of chromosome 20q is a non-random and common event in immortalized human ovarian surface epithelial (HOSE) cells. The chromosome 20q harbors genes including TGIF2 (20q11.2-q12), AIB1 (20q12), PTPN1 (20q13.1), ZNF217 (20q13.2), and AURKA (20q13.2-q13.3), which were previously reported to be amplified and overexpressed in ovarian cancers. Some of these genes may be involved in immortalization of HOSE cells and represent crucial premalignant changes in ovarian surface epithelium. Investigation of the involvement of these genes was examined in four pairs of pre-crisis (preimmortalized) and post-crisis (immortalized) HOSE cells. Overexpression of AURKA (Aurora kinase A), also known as BTAK and STK15, by both real time-quantitative polymerase chain reaction (RT-QPCR) and Western blotting was detected in all the four immortalized HOSE cells examined while overexpression of AIB1 and ZNF217 was observed in two of four immortalized HOSE cells examined. Overexpression of TGIF2 and PTPN1 was not significant in our immortalized HOSE cell systems. The degree of overexpression of AURKA was shown to be closely associated with the amplification of chromosome 20q in immortalized HOSE cells. Fluorescence in situ hybridization (FISH) with labeled P1 artificial clone (PAC) confirmed the amplification of the chromosomal region (20q13.2-13.3) where AURKA resides. DNA amplification of AURKA was also confirmed using semi-quantitative PCR. Our study showed that amplification and overexpression of AURKA is a common and significant event during immortalization of HOSE cells and may represent an important premalignant change in ovarian carcinogenesis. PMID:15880741

Chung, C M; Man, C; Jin, Y; Jin, C; Guan, X Y; Wang, Q; Wan, T S K; Cheung, A L M; Tsao, S W

2005-07-01

330

Automated high pressure cell for pressure jump x-ray diffraction  

SciTech Connect

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

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

2010-06-15

331

Low Vitamin D Levels Linked to High Blood Pressure  

MedlinePLUS

... on this page, please enable JavaScript. Low Vitamin D Levels Linked to High Blood Pressure Researchers recommend more studies to see if vitamin D supplements can lower pressure (*this news item will ...

332

Cooled miniature pressure transducers effective at high temperatures  

NASA Technical Reports Server (NTRS)

Miniature pressure transducers in compact water-cooled mounts are placed in hotter and more confined environments than previously possible. It quantitatively measures high frequency total pressure fluctuations resulting from rotating stall in an axial flow engine compressor.

Armentrout, E. C.

1968-01-01

333

High Pressure Far Infrared Spectroscopy of Ionic Solids  

Microsoft Academic Search

A high pressure far infrared cell operating to truly hydrostatic pressures of 8 kbar is described and used to determine the anharmonic self-energies associated with the q ? 0 transverse optic modes of ionic solids.

R. P. Lowndes

1974-01-01

334

Impact of high pressures in solvothermal processes  

NASA Astrophysics Data System (ADS)

A solvothermal process can be define as a chemical reaction in a close system involving different reactants in presence of a solvent (aqueous or non aqueous) at a temperature higher than its boiling temperature. Consequently pressure is involved. Two different cases are possible :(i) pressure is autogeneous and closely dependent of the percentage of filling for the reaction vessel and of temperature, (ii) pressure is imposed. Solvothermal processes are governed by different key factors : (i) the composition of the reactants, (ii) the nature of the solvent (in particular its physico-chemical properties), (iii) the additives used and (iv) the thermodynamical parameters : temperature and pressure. The main objective being to control the chemical mechanisms governing the preparation of the target material the selection of the key parameters is an important challenge for Solvothermal processes. Solvothermal processes have been developed in different scientific fields as : (i) the synthesis of novel materials -in particular metastable materials with specific physical properties-, (ii) the crystal growth of functional materials for industrial applications, (iii) the preparation of nano-crystallites well defined in size and morphology and nano-composite systems, (iv) the deposition of thin nano-structured films... During these last fifteen years, pressure was in the major cases an autogeneous pressure (pressure developed in the reaction vessel by only the thermal expansion of the liquid phase versus temperature). An important challenge for the near future is to evaluate how pressure parameter can help the control of the reaction mechanisms governing the formation of the target product.

Demazeau, Gérard

2010-03-01

335

High Pressure Study of Ferromagnetic US.  

National Technical Information Service (NTIS)

The variation of the ac magnetic susceptibility of a polycrystalline ferromagnet US as a function of hydrostatic pressure was investigated. The Curie temperature decreases linearly from 180.0 exp 0 K at the atmospheric pressure to 175.9 exp 0 K at 17.6 kb...

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

1978-01-01

336

Optical properties of selenium under high pressure  

Microsoft Academic Search

Reflectivity spectra of Se have been measured at pressures up to 16 GPa using a diamond anvil cell. Optical conductivity spectra have been derived from the reflectivity by using an oscillator fitting analysis. In the amorphous phase, a broad peak assigned to the lone-pair to ?? optical transitions shifts to lower energy and grows with increasing pressure. When amorphous Se

Itsuro Yamamoto; Yoshinori Ohmasa; Hirohisa Endo

1999-01-01

337

Spectroscopy of high pressure cesium discharge  

NASA Astrophysics Data System (ADS)

Near UV, visible and NIR spectrum of Cs lamp has been studied in many experimental situations. We concentrate on the spectral region around resonance lines where numerous satellite bands appear. We followed the appearance of these satellite bands after the ignition. They first appear in emission, and then in absorption, due to the steady increase of cesium atom density. The origin of the satellite bands have been described ootnotetextD. Veza, R. Beuc, S. Milosevi' c and G. Pichler, Eur. Phys. J. D, 2, 45 (1998)^,ootnotetextR. Beuc, H. Skenderovi' c, T. Ban, D. Veza, G. Pichler, W. Meyer, Eur. Phys. J.D 15, 209 (2001). We observed the satellite band intensity behavior in several different burners filled with cesium and xenon. In one burner made out of crystalline sapphire we observed interesting spatial distribution of entire visible spectrum, during evolution in time after the ignition. The intensity behavior of satellite bands in the near-infrared spectral region will be used in further development of the white light source with pulsed cesium high-pressure discharge.

Pichler, Goran; Pichler, Marin

2008-05-01

338

Magnetic Properties of Layered Copper Hydroxides under High Pressure  

Microsoft Academic Search

The effects of high pressure up to 1 GPa were investigated on a layered copper hydroxides, Cu2(OH)3(n-C7H15CO2). which exhibits weak ferromagnetism of N=22 K at the ambient pressure. With an increase in pressure, the magnetization gradually decreases especially in the temperature range 20–30 K. The high pressure effect can be explained in terms of a weakening of the exchange interaction

Wataru Fujita; Kunio Awaga

2000-01-01

339

Starch pastes thinning during high-pressure homogenization  

Microsoft Academic Search

High-pressure homogenization induced thinning of potato and cassava starch paste was investigated. The starch slurries at a concentration of 2.0wt.% were heated at 90°C for 1h and then rapidly cooled in tap water. The cooled starch pastes were homogenized at various pressures ranging from 0 to 100MPa using a lab-scale high-pressure homogenizer. The influence of homogenizing pressure on the temperature,

Li-Ming Che; Li-Jun Wang; Dong Li; Bhesh Bhandari; Necati Özkan; Xiao Dong Chen; Zhi-Huai Mao

2009-01-01

340

A control system for maintaining high stability in gas pressure  

SciTech Connect

A pressure control system has been implemented on an experiment designed to detect the presence of fractional charges in bulk matter. The experiment utilizes a liquid-droplet generation technique requiring high-stability gas-pressure delivery to ensure accurate data collection. The pressure control system consists of a pressurized mercury reservoir containing a low-vapor-pressure, diffusion-pump oil. A commercially available differential pressure transducer, servo-driven valve, and controller sense the pressure fluctuations with respect to a static reference pressure. The system can maintain constant pressure to better than one part in 10,000 at working pressures in the range of 100 to 300 psi. 3 refs., 7 figs.

Wuest, C.R.; Hendricks, C.D.

1987-09-01

341

HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS  

SciTech Connect

It is well known that the fluid phase equilibria can be represented by a number of {gamma}-models , but unfortunately most of them do not function well under high temperature. In this calculation, we mainly investigate the performance of UNIQUAC and NRTL models under high temperature, using temperature dependent parameters rather than using the original formulas. the other feature of this calculation is that we try to relate the excess Gibbs energy G{sup E}and enthalpy of mixing H{sup E}simultaneously. In other words, we will use the high temperature and pressure G{sup E} and H{sup E}data to regress the temperature dependant parameters to find out which model and what kind of temperature dependant parameters should be used.

Vinayak N. Kabadi

1999-02-20

342

High-pressure studies on molecular crystals—relations between structure and high-pressure behavior  

NASA Astrophysics Data System (ADS)

This paper summarizes attempts to understand structure-property relationships for a large class of aromatic diphenyl-1,3,4-oxadiazole molecules. Starting from the investigation of the crystal structure several common packing motifs as well as characteristic differences are derived. Many different molecules show a rather planar conformation in the solid state. A stronger intermolecular twist is only observed for compounds with substituents occupying the ortho-positions of the phenyl rings. Most crystal structures are characterized by the formation of stacks leading to intense ?-? acceptor-donor interactions between oxadiazole and phenyl rings. High-pressure investigations result in a soft compression behavior typical for organic molecular crystals. The bulk behavior may be described by the Murnaghan equation of state with similar coefficients (bulk modulus and its pressure derivative) for nearly all investigated compounds but also for related substances. The compression shows a strong anisotropy resulting from the specific features and packing motifs of the crystal structure. This is clearly indicated by a corresponding strain analysis. Additionally to the crystal structure the Raman spectrum was also investigated under increasing pressure. The different pressure behavior of external and internal modes reflects the difference between intra- and intermolecular interactions.

Orgzall, Ingo; Emmerling, Franziska; Schulz, Burkhard; Franco, Olga

2008-07-01

343

Bacillus spore inactivation differences after combined mild temperature and high pressure processing using two pressurizing fluids.  

PubMed

Spores of six species (28 strains) of dairy Bacillus isolates were added to sterile reconstituted skim milk and pressure processed (600 MPa for 60 s at 75 degrees C) using either a water-based pressurizing fluid or silicon oil. Processing temperatures peaked at 88 and 90 degrees C, respectively, for both fluids. For all strains, the log inactivation was consistently higher in the silicon oil than in the water-based fluid. This has potential implications for food safety assessment of combined pressure-temperature processes. High pressure processing causes mild heating during pressurization of both the target sample (i.e., spores) and the pressurizing fluid used for pressure delivery. Primarily, the adiabatic heat of compression of the fluids as well as other heat-transfer properties of the fluids and equipment determines the magnitude of this heating. Pressure cycles run with silicon oil were 7 to 15 degrees C higher in temperature during pressurization than pressure cycles run with the water-based pressurizing fluid, due to the greater adiabatic heat of compression of silicon oil. At and around the target pressure, however, the temperatures of both pressurizing fluids were similar, and they both dropped at the same rate during the holding time at the target pressure. We propose that the increased spore inactivation in the silicon oil system can be attributed to additional heating of the spore preparation when pressurized in oil. This could be explained by the temperature difference between the silicon oil and the aqueous spore preparation established during the pressurization phase of the pressure cycle. These spore-inactivation differences have practical implications because it is common practice to develop inactivation kinetic data on small, jacketed laboratory systems pressurized in oil, with extensive heat loss. However, commercial deployment is invariably on large industrial systems pressurized in water, with limited heat loss. Such effects should be considered in food safety assessments of combined pressure-temperature processes. PMID:18592744

Robertson, Rosalind E; Carroll, Tim; Pearce, Lindsay E

2008-06-01

344

A High Pressure Cell for Far Infrared Spectroscopy Under Truly Hydrostatic Pressures.  

National Technical Information Service (NTIS)

A high pressure far infrared cell operating to truly hydrostatic pressures of 8 kbars is described. Results of experiments on the collision induced absorption in nitrogen gas and on the pressure dependence of the q approx. 0 transverse optic phonon freque...

R. P. Lowndes

1974-01-01

345

Elastic properties of anorthite at high temperature and high pressure  

NASA Astrophysics Data System (ADS)

To understand the elastic properties of subducted crustal minerals at P-T conditions of crust and upper most mantle, we performed in situ measurement of the elastic wave velocities of anorthite at temperatures up to 1100 oC at less than 2.0 GPa (in stability field) and up to 500 oC at 2.0-7.0 GPa. A fine grained polycrystalline anorthite was synthesised by using gas pressure apparatus installed at magma factory in Tokyo Institute of Technology. The quenched glass with anorthite composition was ground in ethanol and was loaded into a sealed Pt tube (3.0 mm inner diameter and 0.2 mm thickness) container. The sample was preheated at 900°C for 2 hours, and then keep at 1100°C for 20 hours at pressure of 0.3 GPa. The maximum grain size of the synthesized polycrystalline anorthite was about 15?m. The experiments were performed using the SPEED-1500 apparatus installed on beam line BL04B1 at synchrotron facility of SPring-8, Japan (Utsumi et al. 1998). The experimental design for in situ elastic wave velocities measurement at BL04B1 was presented by Higo et al. (2009). Pressure was generated by eight 26 mm tungsten carbide anvils with 11 mm truncated edge length. A Co-doped semi-sintered MgO octahedron with an 18 mm edge length was used as a pressure medium. The sample was enclosed in a BN sleeve container, and was placed in the central part (hot spot) of the furnace. Platinum foils (2.5 ?m in thickness) were inserted at the both side of the sample for determination of sample length by using X-ray radiographic imaging techniques. An Al2O3 rod (5.3 mm in length and 2.0 mm in diameter) was used as buffer rod which transmit ultrasonic wave to the sample. Temperature was measured by a W97Re3-W75Re25 thermocouple. MgO was used as a pressure marker, and it was mixed with BN (MgO:BN = 1:1 by weight) to prevent grain growth at high temperatures. The ultrasonic signals were generated and received by 10oY-cut LiNbO3 transducer of 50 ?m in thickness and 3.2 mm in diameter. We used the ultrasonic wave of the frequencies 30-60MHz with 3-5cycle. The P and S wave velocities of anorthite at room pressure and temperature calculated by using our data are 7.01 km/s and 3.75 km/s, respectively. In this study, we found a drop of elastic wave velocities at ~240oC in <2.5GPa, and gradual decrease of the velocities in >3GPa and <500oC. These velocity changes are considered to be caused by the elastic softening by the phase transitions from P(-1) to high-temperature I(-1), and P(-1) to high-pressure I(-1) , respectively.

Matsukage, K. N.; Nishihara, Y.; Noritake, F.; Tsujino, N.; Sakurai, M.; Higo, Y.; Kawamura, K.; Takahashi, E.

2012-12-01

346

High pressure resistivity of MnAs  

NASA Astrophysics Data System (ADS)

The equivalence between MnAs 1- xP x and MnAs under pressure, which is supported from the magnetic data, was investigated with regard to the transport properties. Therefore measurements of ?( T) on MnAs under pressure were carried out for 30 K < T < 300 K and 1 at < p < 9 kbar. In the temperature range above 100 K far-reaching equivalence was observed, but the low temperature anomaly of MnAs 1- xP x could not be found in MnAs under pressure.

Erle, A.; Bärner, K.

1988-09-01

347

High-temperature fiber optic pressure sensor  

NASA Technical Reports Server (NTRS)

Attention is given to a program to develop fiber optic methods to measure diaphragm deflection. The end application is intended for pressure transducers capable of operating to 540 C. In this paper are reported the results of a laboratory study to characterize the performance of the fiber-optic microbend sensor. The data presented include sensitivity and spring constant. The advantages and limitations of the microbend sensor for static pressure measurement applications are described. A proposed design is presented for a 540 C pressure transducer using the fiber optic microbend sensor.

Berthold, J. W.

1984-01-01

348

Thermodynamic properties of Cu under high pressure  

NASA Astrophysics Data System (ADS)

The total energies, structural properties and elastic constants of Cu at T=0 k have been calculated by the full-potential linearized muffin-tin orbital (FP-LMTO) scheme within the generalized gradient approximation (GGA) correction in the frame of density functional theory. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the dependences of relative volume V/ V0 on pressure P, cell volume V on temperature T, linear thermal expansion on temperature and Debye temperature ? and specific heat C V on pressure are successfully obtained. The obtained pressure dependence of the normalized volume at 300 K is in excellent agreement with the experimental results.

Liu, Yao-Bei; Li, Xu-Sheng; Feng, You-Li; Cui, Yan-Ling; Han, Xu

2007-05-01

349

Evidence of Tetragonal Nanodomains in the high pressure polymorph  

SciTech Connect

The pressure induced P4mm {yields} Pm{bar 3}m phase transition in BaTiO{sub 3} 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 the high-pressure phase decreases with increasing pressure. Extrapolation of the domain size to pressures higher than studied experimentally suggests a disappearance of the ferroelectric domains at about 9.3(5) GPa and a cubic symmetry of BaTiO{sub 3} high-pressure phase.

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

2010-12-17

350

Anorthite - Thermal equation of state to high pressures  

NASA Technical Reports Server (NTRS)

New shock-wave data are presented for anorthite from which a full high-temperature, high-pressure equation of state is derived. Whereas anorthite has relatively low values of thermal expansion and Grueneisen parameter at zero pressure, it is found that these attain relatively high values in the high density state corresponding to the high-pressure phase Hugoniot but decrease upon compression as expected. It is noted that higher order anharmonic contributions decrease more rapidly with pressure and that the thermal expansion therefore saturates to a high temperature value at pressures above about 100 GPa. Reduction of the Hugoniot data permits shock temperatures to be calculated; it also yields a principal adiabat for the high pressure branch of the Hugoniot. The initial bulk modulus of this adiabat is essentially identical to that of anorthite, whereas the initial density is about 3.40 Mg/cu m.

Jeanloz, R.; Ahrens, T. J.

1980-01-01

351

The influence of pressure during solidification of high pressure die cast aluminium telecommunications components  

Microsoft Academic Search

The effects of process variables on the quality of high-pressure die cast components was determined with the aid of in-cavity pressure sensors. In particular, the effects of set intensification pressure, delay time, and casting velocity have been investigated. The in-cavity pressure sensor has been used to determine how conditions within the die-cavity are related to the process parameters regulated by

Matthew S. Dargusch; G. Dour; N. Schauer; C. M. Dinnis; G. Savage

2006-01-01

352

Hydrogen-Helium Mixtures at High Pressures  

NASA Astrophysics Data System (ADS)

We extend our previous work on hydrogen-helium mixtures (Morales, M. A., et. al. PNAS 106, 1324 (2009).) to lower pressures and lower temperatures, across the molecular dissociation regime in hydrogen, to the low pressure molecular liquid. Using density functional theory-based molecular dynamics together with thermodynamic integration techniques, we calculate the Gibbs free energy of the dense liquid as a function of pressure, temperature, and composition. Our work focuses on the mixing properties of the liquid, the optical properties including conductivity and reflectivity, and the creation of accurate mixing models for thermodynamic properties, including pressure and entropy. The resulting models will provide the basis for accurate first-principles equations of state for planetary modeling. Prepared by LLNL under Contract DE-AC52-07NA27344.

Morales, Miguel A.; Hamel, Sebastien; Caspersen, Kyle; Schwegler, Eric

2012-02-01

353

Laser Hydrogen High-Pressure Streamer Chamber.  

National Technical Information Service (NTIS)

The results of experimental investigations into a laser hydrogen streamer chamber at a hydrogen pressure increased up to 2 at are described. A structural flowsheet and main chamber parameters are considered. Photographs of diffraction pictures taken at 43...

A. Budzyak I. T. Ivanov V. A. Panyushkin I. V. Falomkin Z. Tsisek

1980-01-01

354

High Pressure NMR Study of Ammonium Thiocyanate  

NASA Astrophysics Data System (ADS)

Wide-line proton NMR spectra of ammonium thiocyanate have been recorded at 77 K as a function of external hydrostatic pressure. Contrary to expectations the line-width and the second moment decrease with the increase of pressure. This, however, is in accordance with the anomalous behaviour observed in other magnetic resonance studies of this compound and can be understood in terms of the change of electron density around the nitrogen atom of the SCN- group.

Ramanathan, K. V.

1993-06-01

355

High pressure waterflood halts rapid decline  

Microsoft Academic Search

Two specially designed engine-powered centrifugal pumps provided the needed injection pressure and rates to continue retarding production decline in the Jameson Strawn Field of Coke County, Tex., when previous injection of 20,000 bbl\\/d at 2500 psi appeared to be losing ground. At this time, both units are injecting 42,000 bbl\\/d at 3125 psi discharge pressure. The original water injection efforts

T. Covington; F. Wilcox

1965-01-01

356

Synthesis of vanadium sulfides under high pressure  

Microsoft Academic Search

Vanadium sulfides were synthesized in a temperature range of 350-750°C 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

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

1985-01-01

357

Interactions of high hydrostatic pressure, pressurization temperature and pH on death and injury of pressure-resistant and pressure-sensitive strains of foodborne pathogens  

Microsoft Academic Search

The objective of this study is to determine the interactions between high hydrostatic pressure, pressurization temperature, time and pH during pressurization on death and injury of pressure-resistant and pressure-sensitive strains of four foodborne pathogens: Staphylococcus aureus 485 and 765, Listeria monocytogenes CA and OH2, Escherichia coli O157:H7 933 and 931, Salmonella enteritidis FDA and Salmonella typhimurium E21274. Among these strains

H Alpas; N Kalchayanand; F Bozoglu; B Ray

2000-01-01

358

HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS  

SciTech Connect

The Vapor Liquid Equilibrium measurement setup of this work was first established several years ago. It is a flow type high temperature high pressure apparatus which was designed to operate below 500 C temperature and 2000 psia pressure. Compared with the static method, this method has three major advantages: the first is that large quantity of sample can be obtained from the system without disturbing the equilibrium state which was established before; the second is that the residence time of the sample in the equilibrium cell is greatly reduced, thus decomposition or contamination of the sample can be effectively prevented; the third is that the flow system allows the sample to degas as it heats up since any non condensable gas will exit in the vapor stream, accumulate in the vapor condenser, and not be recirculated. The first few runs were made with Quinoline-Tetralin system, the results were fairly in agreement with the literature data . The former graduate student Amad used the same apparatus acquired the Benzene-Ethylbenzene system VLE data. This work used basically the same setup (several modifications had been made) to get the VLE data of Ethylbenzene-Quinoline system.

Vinayak N. Kabadi

2000-05-01

359

High-pressure structures and metallization of sodium chloride  

NASA Astrophysics Data System (ADS)

Sodium chloride (NaCl) is known as salt and an ionic insulator at ambient conditions. The high-pressure structures of NaCl have been extensively explored through a particle swarm structural search at zero temperature and pressure range of 0-800 GPa. In addition to the known low-pressure insulating phases, we find three novel orthorhombic high-pressure structures: oC8 (stable at 322-645 GPa), oI8 (stable at 645-683 GPa), and oP16 (stable at above 683 GPa). The oC8 structure can be metallized via band-gap closure under high pressure, while both oI8 and oP16 are metallic in their stable pressure ranges. Intriguingly, our predicted metallic high-pressure phases of NaCl retain predominant ionic behaviors. The peculiar conductive behaviors can be attributed to the extended anion sublattice.

Chen, Xin; Ma, Yanming

2012-10-01

360

High-pressure structural study of muscovite  

NASA Astrophysics Data System (ADS)

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. Isothermal bulk moduli, setting K' = 4, were 490 and 540 (± 30) kbar for the Na-poor and Na-rich samples respectively. Both samples show highly anisotropic compressibility patterns, with ? a ?? b ?? c = 1?1.15?3.95 for the Na-poor sample and ? a ?? b ?? c = 1?1.19?3.46 for the Na-rich one. HP structural refinements showed that the different compressibility was largely due to the partial substitution of Na for K in the interlayer region. Moreover, the different compressibility of the tetrahedral and octahedral layers, observed in both micas, increased the a rotation of the tetrahedral layer by about 2° in 28 kbar, as also indicated by the evolution of interlayer cation bond lengths. This increases the repulsion of oxygens of the basal layers and between the high-charged cations of the tetrahedral layer. As a consequence, phengitic substitution, reducing ? rotation, would increase the baric stability of mica. Comparison between the HP structures of muscovite and phlogopite indicated the lower compressibility of the latter, mainly due to the greater compressibility of the dioctahedral layer with respect to that of the trioctahedral layer. The H T and H P behaviour of di- and trioctahedral micas showed an anisotropy in the compressional pattern which was markedly greater than that observed in the dilatation pattern. This unexpected result was explained by the different evolution with P and T of alkaliO bond lengths. By combining HP and HT data, a tentative equation of state of muscovite is proposed.

Comodi, Paola; Francesco Zanazzi, Pier

1995-04-01

361

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

362

Elastic properties and equation of state of high pressure ice  

Microsoft Academic Search

Measurements of compressional and shear wave velocities at ?25 °C at pressures up to about 0.7 GPa show that the elastic properties of the high pressure polymorphs of ice are significantly different from the values for the room pressure phase. Data were obtained from ice Ih, III, V, and VI. The bulk modulus decreases slightly when ice Ih transforms to

George H. Shaw

1986-01-01

363

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

José A. Guerrero-Beltrán; Gustavo V. Barbosa-Cánovas; Barry G. Swanson

2005-01-01

364

Solidification of High-Pressure Medium Daphne 7373  

NASA Astrophysics Data System (ADS)

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 our previous report. The solidification pressure of Daphne 7373 is twice as high as that of another well-known medium Fluorinert 77/70 (0.9 GPa). This allows us to hold hydrostatic pressure even in the newly developed BeCu-NiCrAl clamp-type pressure cell, which exceeds the limit of 1.5 GPa generated by a conventional BeCu cell.

Yokogawa, Keiichi; Murata, Keizo; Yoshino, Harukazu; Aoyama, Shoji

2007-06-01

365

Performance evaluation of PVD coatings for high pressure die casting  

Microsoft Academic Search

During high-pressure die-casting (HPDC) of aluminium alloys, there is a tendency for the molten alloy to react with the tool steel die, core pins and inserts. This occurrence within the high pressure die casting (HPDC) industry is referred to as ‘soldering’. It is of concern to high-pressure die casters because of down-time due to the regular removal of the soldered

S. Gulizia; M. Z. Jahedi; E. D. Doyle

2001-01-01

366

High-pressure vibrational properties of polyethylene  

NASA Astrophysics Data System (ADS)

The pressure evolution of the vibrational spectrum of polyethylene was investigated up to 50 GPa along different isotherms by Fourier-transform infrared and Raman spectroscopy and at 0 K by density-functional theory calculations. The infrared data allow for the detection of the orthorhombic Pnam to monoclinic P21/m phase transition which is characterized by a strong hysteresis both on compression and decompression experiments. However, an upper and lower boundary for the transition pressure are identified. An even more pronounced hysteresis is observed for the higher-pressure transition to the monoclinic A2/m phase. The hysteresis does not allow in this case the determination of a well defined P-T transition line. The ambient structural properties of polyethylene are fully recovered after compression/decompression cycles indicating that the polymer is structurally and chemically stable up to 50 GPa. A phase diagram of polyethylene up to 50 GPa and 650 K is proposed. Analysis of the pressure evolution of the Davydov splittings and of the anomalous intensification with pressure of the IR active wagging mode provides insight about the nature of the intermolecular interactions in crystalline polyethylene.

Fontana, Luca; Santoro, Mario; Bini, Roberto; Vinh, Diep Q.; Scandolo, Sandro

2010-11-01

367

High Pressure Phase Transitions in Barium Tungstate  

NASA Astrophysics Data System (ADS)

Alkaline-earth tungstates exhibit an interesting phase diagram with respect to pressure. BaWO4 is found to undergo a pressure-driven phase transition at 7.1 GPa from tetragonal scheelite structure to monoclinic fergusonite structure. It is observed to become amorphous beyond 45 GPa. In this work, we report molecular dynamics simulation studies on transformations of the scheelite phase in BaWO4 with increasing pressure at ambient temperature. Our calculated equation of state is in very good agreement with reported experimental data and first principles calculations. In our calculations there is no apparent volume discontinuity at the scheelite to fergusonite transformation in BaWO4 around 7.5 GPa. The tungstate transforms to an amorphous phase beyond 35 GPa with discernable volume collapse. The pair correlation functions show that there are subtle changes in the arrangement of the BaO8 polyhedra with increasing pressure. However, the WO4 tetrahedra remain unperturbed with increasing pressure until amorphization occurs.

Goel, Prabhatasree; Mittal, R.; Chaplot, S. L.

2012-07-01

368

High-pressure Magic Angle Spinning Nuclear Magnetic Resonance  

SciTech Connect

A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve to include micro-groves at the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal penetration loss of pressure for 72 hours. As an application example, in situ 13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50?C are reported, with relevance to geological sequestration of carbon dioxide.

Hoyt, David W.; Turcu, Romulus VF; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Z.

2011-10-01

369

High-pressure magic angle spinning nuclear magnetic resonance.  

PubMed

A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ(13)C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg(2)SiO(4)) reacted with supercritical CO(2) and H(2)O at 150 bar and 50°C are reported, with relevance to geological sequestration of carbon dioxide. PMID:21862372

Hoyt, David W; Turcu, Romulus V F; Sears, Jesse A; Rosso, Kevin M; Burton, Sarah D; Felmy, Andrew R; Hu, Jian Zhi

2011-10-01

370

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

371

Transportable, small high-pressure preservation vessel for cells  

NASA Astrophysics Data System (ADS)

We have previously reported that the survival rate of astrocytes increases under high-pressure conditions at 4°C. However, pressure vessels generally have numerous problems for use in cell preservation and transportation: (1) they cannot be readily separated from the pressurizing pump in the pressurized state; (2) they are typically heavy and expensive due the use of materials such as stainless steel; and (3) it is difficult to regulate pressurization rate with hand pumps. Therefore, we developed a transportable high-pressure system suitable for cell preservation under high-pressure conditions. This high-pressure vessel has the following characteristics: (1) it can be easily separated from the pressurizing pump due to the use of a cock-type stop valve; (2) it is small and compact, is made of PEEK and weighs less than 200 g; and (3) pressurization rate is regulated by an electric pump instead of a hand pump. Using this transportable high-pressure vessel for cell preservation, we found that astrocytes can survive for 4 days at 1.6 MPa and 4°C.

Kamimura, N.; Sotome, S.; Nakajima, K.; Yoshimura, Y.; Shimizu, A.

2010-03-01

372

Partition Coefficients at High Pressure and Temperature  

NASA Astrophysics Data System (ADS)

Differentiation of terrestrial planets includes separation of a metallic core and possible later fractionation of mineral phases within either a solid or molten mantle (Figure 1). Lithophile and siderophile elements can be used to understand these two different physical processes, and ascertain whether they operated in the early Earth. The distribution of elements in planets can be understood by measuring the partition coefficient, D (ratio of concentrations of an element in different phases (minerals, metals, or melts)). (14K)Figure 1. Schematic cross-section through the Earth, showing: (a) an early magma ocean stage and (b) a later cool and differentiated stage. The siderophile elements (iron-loving) encompass over 30 elements and are defined as those elements for which D(metal/silicate)>1, and are useful for deciphering the details of core formation. This group of elements is commonly broken up into several subclasses, including the slightly siderophile elements (1highly siderophile elements (HSEs; D>104). Because these three groups encompass a wide range of partition coefficient values, they can be very useful in trying to determine the conditions under which metal may have equilibrated with the mantle (or a magma ocean). Because metal and silicate may equilibrate by several different mechanisms, such as at the base of a deep magma ocean, or as metal droplets descend through a molten mantle, partition coefficients can potentially shed light on which mechanism may be most important, thus linking the physics and chemistry of core formation. In this chapter, we summarize metal/silicate partitioning of siderophile elements and show how they may be used to understand planetary core formation.Once a planet is differentiated into core and mantle, a mantle will cool during convection, and can start in either a molten or solid state, depending upon the initial thermal conditions. If hot enough, minerals will crystallize from a molten mantle, and become entrained in the convecting melt, or eventually settle out at the bottom. The entrainment and settling process has been studied in detail (e.g., Tonks and Melosh, 1990), and is a potential mechanism for differentiation between the deep and shallow parts of Earth's mantle. The lithophile elements, those elements that have D(metal/silicate) <1, fall into many different subclasses and all hold information about the deep mineral structure of the mantle. Rare-earth elements (REEs) have proven to be useful: europium anomalies have helped elucidate the role of plagioclase in lunar crust formation (e.g., Schnetzler and Philpotts, 1971; Weill et al., 1974), and LREE/HREE depletion and enrichment are indicators of partial melting in the presence of garnet in the mantle. High-field-strength elements (HFSEs) - niobium, zirconium, tantalum, and hafnium - are all refractory and hence more resilient to fractionation processes such as volatility or condensation. They also have an affinity for ilmenite and rutile, and can explain differences between lunar and martian samples as well as features of Earth's continental crust ( Taylor and McLennan, 1985). Alkaline-earth and alkaline elements include rubidium, strontium, barium, potassium, caesium, and calcium, some of which are involved in radioactive decay couples, e.g., Rb-Sr and K-Ar. The latter is important in understanding the contribution of radioactive decay to planetary heat production, and potential deep sources of radiogenic argon (see Chapter 2.06). Rubidium and potassium are further useful as tracers of hydrous phases such as mica and amphibole. Possible fractionation of any of these elements from chondritic abundances (see Chapter 2.01) can be assessed with the knowledge of partition coefficients. In this chapter we summarize our understanding of mineral/melt fractionation of minor and trace elements at high pressures and temperatures and discuss the implications for mantle differentiation.

Righter, K.; Drake, M. J.

2003-12-01

373

Elasticity and Structure of Chromite at High Pressure  

NASA Astrophysics Data System (ADS)

Chromite is commonly found in the Earth's crust and mantle. Recently, a high-pressure chromite polymorph was discovered in the shocked Suizhou meteorite. Therefore, it would be of great interest to investigate the high-pressure phase in chromite composition that can be inferred as a shock scale for the meteorite. In this study, natural and synthetic chromites were studied by Raman spectroscopy and x-ray diffraction in a diamond anvil cell. Our high-pressure results show that cubic magnesiochromite transforms to tetragonal I41/amd structure at pressures above 20 GPa. The volume data for magnesiochromite fit to Birch-Murnaghan equation of state (EOS) yield K0 = 189(2) GPa, K0' = 7.2(3) and V0 = 578.68(4) Å3, in agreement with theoretical calculations. The EOS of the high pressure tetragonal phase was obtained as K0 = 191(8) GPa and V0 = 279(1) Å3 when K0' = 4. The volume reduction at phase transition is about 4.4%. The high pressure phase is unquenchable and transformed back to magnesiochromite with little hysteresis upon release of pressure. Similarly, the natural chromite also exhibits a phase transition near 21 GPa at 300 K and then another high-pressure phase was found at 31 GPa and 1800-2000 K. However, this high pressure and high temperature phase cannot be retained at ambient conditions.

Shieh, S. R.; Yong, W.; MI, Z.; Botis, S. M.; Shi, W.; Withers, A. C.

2012-12-01

374

High Pressure Compressor Component Performance Report.  

National Technical Information Service (NTIS)

A compressor optimization study defined a 10 stage configuration with a 22.6:1 pressure ratio, an adiabatic efficiency goal of 86.1%, and a polytropic efficiency of 90.6%; the corrected airflow is 53.5 kg/s. Subsequent component testing included three ful...

S. J. Cline W. Fesler H. S. Liu R. C. Lovell S. J. Shaffer

1983-01-01

375

High Pressure, Earth-Storable Rocket Technology.  

National Technical Information Service (NTIS)

The effect of elevated chamber pressure on combustion efficiency and heat transfer has been determined at the 100 lbf (445 N) thrust level for nitrogen tetroxide propellants. Measurements were made up to 500 psia (3.45Mpa) with testbed hardware; tests at ...

D. M. Jassowski

1997-01-01

376

Burn Rates of Explosives at High Pressures.  

National Technical Information Service (NTIS)

The burn rates of PETN, HMX, PBX-9404, PBX-9501, and PBX-9502 in inert gases have been determined as a function of pressure to 340 MPa by a closed bomb technique. The burn rates were fit to the de St.-Robert equation R = aP/sup n/. An abrupt transition to...

J. A. Holy

1985-01-01

377

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

378

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

379

High-temperature fiber optic cubic-zirconia pressure sensor  

NASA Astrophysics Data System (ADS)

There is a critical need for pressure sensors that can operate reliably at high temperatures in many industrial segments such as in the combustion section of gas turbine engines for both transportation and power generation, coal gasifiers, coal fired boilers, etc. Optical-based sensors are particularly attractive for the measurement of a wide variety of physical and chemical parameters in high-temperature and high-pressure industrial environments due to their small size and immunity to electromagnetic interference. A fiber optic pressure sensor utilizing single-crystal cubic zirconia as the sensing element is reported. The pressure response of this sensor has been measured at temperatures up to 1000 °C. Additional experimental results show that cubic zirconia could be used for pressure sensing at temperatures over 1000 °C. This study demonstrates the feasibility of using a novel cubic-zirconia sensor for pressure measurement at high temperatures.

Peng, Wei; Pickrell, Gary R.; Wang, Anbo

2005-12-01

380

High pressure synthesis and thermoelectric properties of PbSe  

NASA Astrophysics Data System (ADS)

Thermoelectric materials PbSe were successfully prepared by high pressure and high temperature technique (HPHT) and the pressure-dependent thermoelectric properties were studied from 300 to 600 K. The measurement results indicate that the electrical conduction type in PbSe can be changed from p- (<2.0 GPa) to n-type (>2.0 GPa) by application of pressure of about 2.0 GPa. And the electrical resistivity can be reduced effectively by pressure. Low thermal conductivity (~0.8 W/mK) is obtained for high pressure synthesized PbSe. These results indicate that high pressure provides a viable and controllable way of tuning the thermoelectric properties for PbSe.

Fan, Haotian; Su, Taichao; Li, Hongtao; Zheng, Youjin; Li, Shangsheng; Hu, Meihua; Zhou, Youmo; Ma, Hongan; Jia, Xiaopeng

2014-05-01

381

High-pressure trickle-bed reactors: A review  

Microsoft Academic Search

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

Muthanna H. Al-Dahhan; M. P. Dudukovic; F. Larachi; Andre Laurent

1997-01-01

382

High-pressure Raman scattering in wurtzite indium nitride  

NASA Astrophysics Data System (ADS)

We perform Raman-scattering measurements at high hydrostatic pressures on c-face and a-face InN layers to investigate the high-pressure behavior of the zone-center optical phonons of wurtzite InN. Linear pressure coefficients and mode Grüneisen parameters are obtained, and the experimental results are compared with theoretical values obtained from ab initio lattice-dynamical calculations. Good agreement is found between the experimental and calculated results.

Ibáñez, J.; Manjón, F. J.; Segura, A.; Oliva, R.; Cuscó, R.; Vilaplana, R.; Yamaguchi, T.; Nanishi, Y.; Artús, L.

2011-07-01

383

High pressure melting and crystallization of Nylon11  

Microsoft Academic Search

Differential thermal analysis (DTA), high pressure differential thermal analysis (HP-DTA), and high temperature X-ray studies are combined to elucidate the origin of the two melting peaks in Nylon-11. The results of the studies suggest that two species of crystals are involved in the melting of Nylon-11 for samples crystallized at atmospheric pressure or when the environmental pressure is below 4

P. K. Chen; B. A. Newman; J. I. Scheinbeim; K. D. Pae

1985-01-01

384

High-Pressure Peristaltic Membrane Micropump With Temperature Control  

Microsoft Academic Search

A high-pressure peristaltic membrane micropump, which is capable of pumping against a back pressure of 150 bar, has been evaluated. The main focus was to maintain the flow characteristics also at high back pressures. The pump was manufactured by fusion bonding of parylene-coated stainless-steel stencils. A large-volume expansion connected to the solid-to-liquid phase transition in paraffin was used to move

Stefan Svensson; Gunjana Sharma; Sam Ogden; Klas Hjort; Lena Klintberg

2010-01-01

385

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

386

Gradient index collimator lens for high pressure applications  

NASA Astrophysics Data System (ADS)

A modified gradient index (GRIN) lens is optimised for use in a liquid-type high pressure cell. It was found that high pressure changes the optical power of the gradient-index lenses by changing the index profile of the glass. In this paper, we present a modified GRIN lens in which these changes are compensated by the pressure-induced changes of the refraction index of the liquid used as a pressure medium. New lens was used for the collimation of the pressure tuned tapered laser working in external resonator. The lens proved to have the optical power almost independent of the pressure up to 1.6 GPa, as it allowed to obtain tuning range almost independent on pressure without the need of any modification of the optical setup.

Piechal, Bernard; Bercha, Artem; Dybala, Filip; Trzeciakowski, Witold

2014-06-01

387

Estimating high frequency ocean bottom pressure variability  

NASA Astrophysics Data System (ADS)

Knowledge of variability in ocean bottom pressure (pb) at periods < 60 days is essential for minimizing aliasing in satellite gravity missions. We assess how well we know such rapid, non-tidal pb signals by analyzing in-situ bottom pressure recorder (BPR) data and available global estimates from two very different modeling approaches. Estimated pb variance is generally lower than that measured by the BPRs, implying the presence of correlated model errors. Deriving uncertainties from differencing the model estimates can thus severely underestimate the aliasing errors. Removing estimated series from BPR data tends to reduce the variance by up to ˜5 cm2 but residual variance is still ˜5-20 cm2 and not negligible relative to expected variance in climate pb signals. The residual pb variability can be correlated over hundreds of kilometers. Results indicate the need to improve estimates of rapid pb variability in order to minimize aliasing noise in current and future satellite-based pb observations.

Quinn, Katherine J.; Ponte, Rui M.

2011-04-01

388

Impurity trapped excitons under high hydrostatic pressure  

NASA Astrophysics Data System (ADS)

Paper summarizes the results on pressure effect on energies of the 4fn ? 4fn and 4fn-15d1 ? 4fn transitions as well as influence of pressure on anomalous luminescence in Ln?+ doped oxides and fluorides. A model of impurity trapped exciton (ITE) was developed. Two types of ITE were considered. The first where a hole is localized at the Ln?+ ion (creation of Ln(?+1)+) and an electron is attracted by Coulomb potential at Rydberg-like states and the second where an electron captured at the Ln?+ ion (creation of Ln(?-1)+) and a hole is attracted by Coulomb potential at Rydberg-like states. Paper presents detailed analysis of nonlinear changes of energy of anomalous luminescence of BaxSr1-xF2:Eu2+ (x > 0.3) and LiBaF3:Eu2+, and relate them to ITE-4f65d1 states mixing.

Grinberg, Marek

2013-09-01

389

Hydrogasification of chars under high pressures  

Microsoft Academic Search

Two Turkish lignites are carbonized at 700°C and 900°C, and the methane formation rates of these chars and of the char prepared from an activated bituminous coal are investigated at temperatures between 700°C and 900°C and at hydrogen pressures of 2.5MPa, 5MPa and 7.5MPa. The dependence of methane formation rate on time during gasification shows that the type of carbon

Zarife M?s?rl?o?lu; Muammer Canel; Ali S?na?

2007-01-01

390

Estimating high frequency ocean bottom pressure variability  

Microsoft Academic Search

Current ocean model estimates of high frequency OBP have significant errorsNeed to improve high frequency OBP estimates to minimise satellite aliasingNeed to improve knowledge of high frequency OBP errors

Katherine J. Quinn; Rui M. Ponte

2011-01-01

391

Characterization of High-Pressure Iron-Sulfur Compounds  

NASA Astrophysics Data System (ADS)

Iron and sulfur are considered to be the major elements in the Martian core. Recent high-pressure experiments revealed that at least three new iron-sulfur compounds, Fe3S2, Fe2S, and Fe3S, were formed at high pressures. In this study, we provide new information on their structure and stability.

Koch-Müller, M.; Fei, Y.; Wirth, R.; Bertka, C. M.

2002-03-01

392

6. Fire Protection (high pressure), view to the east. Located ...  

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

6. Fire Protection (high pressure), view to the east. Located on the pipe floor between Unit 3 and Unit 4, the high pressure CO2 tanks are connected to the generator barrel of all four units. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

393

Childhood Malnutrition Linked to High Blood Pressure Later in Life  

MedlinePLUS

... page, please enable JavaScript. Childhood Malnutrition Linked to High Blood Pressure Later in Life: Study Preventing childhood hunger might ... June 30, 2014 Related MedlinePlus Pages Child Nutrition High Blood Pressure Malnutrition MONDAY, June 30, 2014 (HealthDay News) -- Young ...

394

ANFIS for high-pressure waterjet cleaning prediction  

Microsoft Academic Search

The prediction of high pressure waterjet coating removal was very crucial to the optimization of cleaning parameters to save energy and improve productivity. This paper proposed a method of using an adaptive-network-based fuzzy inference system (ANFIS) for the modeling and predicting of high pressure cleaning process. A group of cleaning experiments was conducted for the removing of epoxy paint using

Gao Daoming; Chen Jie

2006-01-01

395

Structural and Elastic Properties of Strontium Selenide under High Pressure  

NASA Astrophysics Data System (ADS)

In the present paper we have investigated the high-pressure structural phase transition of strontium chalcogenides using the modified three-body potential (MTBP) incorporated by covalency effect. The phase transition pressures and associated volume collapses obtained from TBP show a reasonably good agreement with experimental data. It is observerd that Further more, the elastic constants and their combinations as a function of with pressure are also reported. It is found that MTBP incorporated by covalency effect has a promise to predict the phase transition pressure, the elastic constants and their pressure derivatives of other chalcogenides as well.

Bhardwaj, Purvee; Singh, Sadhna; Gaur, N. K.

2008-04-01

396

Development of a high temperature capacitive pressure transducer  

NASA Technical Reports Server (NTRS)

High temperature pressure transducers capable of continuous operation while exposed to 650 C were developed and evaluated over a full-scale differential pressure range of + or - 69 kPa. The design of the pressure transducers was based on the use of a diaphragm to respond to pressure, variable capacitive elements arranged to operate as a differential capacitor to measure diaphragm response and on the use of fused silica for the diaphragm and its supporting assembly. The uncertainty associated with measuring + or - 69 kPa pressures between 20C and 650C was less than + or - 6%.

Egger, R. L.

1977-01-01

397

Strong environmental tolerance of Artemia under very high pressure  

NASA Astrophysics Data System (ADS)

It was shown by the present authors group that a tardigrade in its tun-state can survive after exposed to 7.5 GPa for 13 hours. We have extended this experiment to other tiny animals searching for lives under extreme conditions of high hydrostatic pressure. Artemia, a kind of planktons, in its dried egg-state have strong environmental tolerance. Dozens of Artemia eggs were sealed in a small Teflon capsule together with a liquid pressure medium, and exposed to the high hydrostatic pressure of 7.5 GPa. After the pressure was released, they were soaked in seawater to observe hatching rate. It was proved that 80-90% of the Artemia eggs were alive and hatched into Nauplii after exposed to the maximum pressure of 7.5 GPa for up to 48 hours. Comparing with Tardigrades, Artemia are four-times stronger against high pressure.

Minami, K.; Ono, F.; Mori, Y.; Takarabe, K.; Saigusa, M.; Matsushima, Y.; Saini, N. L.; Yamashita, M.

2010-03-01

398

High-pressure Raman spectroscopy of tris(hydroxymethyl)aminomethane.  

PubMed

High-pressure Raman spectroscopy has been used to study tris(hydroxymethyl)aminomethane (C(CH(2)OH)(3)NH(2), Tris). Molecules with globular shapes such as Tris have been studied thoroughly as a function of temperature and are of fundamental interest because of the presence of thermal transitions from orientational order to disorder. In contrast, relatively little is known about their high-pressure behavior. Diamond anvil cell techniques were used to generate pressures in Tris samples up to approximately 10 GPa. A phase transition was observed at a pressure of approximately 2 GPa that exhibited relatively slow kinetics and considerable hysteresis, indicative of a first-order transition. The Raman spectrum becomes significantly more complex in the high-pressure phase, indicating increased correlation splitting and significant enhancement in the intensity of some weak, low-pressure phase Raman-active modes. PMID:20384383

Emmons, Erik D; Fallas, Juan C; Kamisetty, Vamsi K; Chien, Wen-Ming; Covington, Aaron M; Chellappa, Raja S; Gramsch, Stephen A; Hemley, Russell J; Chandra, Dhanesh

2010-05-01

399

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

400

Structure and stability of hydrous minerals at high pressure  

NASA Technical Reports Server (NTRS)

The presence of even small amounts of hydrogen in the Earth's deep interior may have profound effects on mantle melting, rheology, and electrical conductivity. The recent discovery of a large class of high-pressure H-bearing silicates further underscores the potentially important role for hydrous minerals in the Earth's mantle. Hydrogen may also be a significant component of the Earth's core, as has been recently documented by studies of iron hydride at high pressure. In this study, we explore the role of H in crystal structures at high pressure through detailed Raman spectroscopic and x ray diffraction studies of hydrous minerals compressed in diamond anvil cells. Brucite, Mg(OH)2, has a simple structure and serves as an analogue for the more complex hydrous silicates. Over the past five years, this material has been studied at high pressure using shock-compression, powder x ray diffraction, infrared spectroscopy, Raman spectroscopy, and neutron diffraction. In addition, we have recently carried out single-crystal synchrotron x-ray diffraction on Mg(OH)2 and Raman spectroscopy on Mg(OD)2 at elevated pressure. From all these studies, an interesting picture of the crystal chemical behavior of this material at high pressure is beginning to emerge. Some of the primary conclusions are as follows: First, hydrogen bonding is enhanced by the application of pressure. Second, layered minerals which are elastically anisotropic at low pressure may not be so at high pressure. Furthermore, the brucite data place constraints on the effect of hydrogen on seismic velocities and density at very high pressure. Third, the stability of hydrous minerals may be enhanced at high P by subtle structural rearrangements that are difficult to detect using traditional probes and require detailed spectroscopic analyses. Finally, brucite appears to be unique in that it undergoes pressure-induced disordering that is confined solely to the H-containing layers of the structure.

Duffy, T. S.; Fei, Y.; Meade, C.; Hemley, R. J.; Mao, H. K.

1994-01-01

401

Magnetic Properties of High Ti Titanomagnetite Under Pressure  

NASA Astrophysics Data System (ADS)

We present new data on the magnetic properties of titanium-rich titanomagnetite under pressures exceeding 7 GPa. The new data confirm that the piezoremanent response of titanomagnetite increases with Ti concentration; e.g., that lower pressures are needed to increase the magnetic remanence as Ti increases. We will also show results that pressure can transform high-Ti titanomagnetite that is paramagnetic at room temperature into a ferrimagnet. This coincides well with previous work suggesting the Curie temperature of high-Ti titanomagnetite increases about 15 degrees per gigapascal. Finally, we will address the question of the threshold pressure needed to saturate the piezoremanent effect in multidomain titanomagnetite.

Gilder, S. A.; Wei, Q.; Ertel-Ingrisch, W.; Church, N. S.

2013-12-01

402

High pressure and temperature sensing for the downhole applications  

NASA Astrophysics Data System (ADS)

Modern oil production in the oilfield management needs a sensor which enable fast, reliable and cost-effective through highly integrated optical measurement systems. A sensor for accurate and long-term fluid high pressure and temperature monitoring in oil down-hole based on optical fiber Bragg grating is presented. This sensor, using fiber Bragg grating written in side-hole single mode fiber, has small size and simple construct. At different temperature, the pressure measurements from atmospheric pressure to 40 Mpa has been made. It has very linear relationship between peak separation and pressure.

Li, Tianshu; Wang, Zhongguo; Wang, Qingfa; Wei, Xianfeng; Xu, BingHui; Hao, WeiDong; Meng, Fanyong; Dong, Susan

2007-10-01

403

Eclogite Rheology and Fabrics at High Temperature and High Pressure  

NASA Astrophysics Data System (ADS)

Eclogite plays an important role for mantle convection and geodynamics in subduction zones. An improved understanding of processes in the deeper levels of subduction zones and collision belts requires information on eclogite rheology. However, the deformation processes and associated fabrics in eclogite are not well understood. Incompatible views of deformation mechanism have been proposed for both garnet and omphacite. We investigated here the high temperature deformation behavior of eclogite reconstituted from powders of 50% garnet, 40% omphacite, 10% quartz and trace rutile at temperatures of 1000-1600 K, a confining pressure of 2.5-3.5 GPa, and strain rates of 10-4/s to 10-5/s. We obtained a power-law creep for the high temperature deformation of eclogite with n=3.4±0.5 and Q=420±70 KJ/mol. Microscopic fabrics of these experimental eclogites were analyzed with the Electron Back Scattered Diffraction (EBSD) technique. Our results show that: (I) Garnet displays complex pole figures with random distributions of misorientation angles in good agreement with rigid round garnets; (II) Omphacite shows a pronounced S-type crystallographic preferred orientation characterized by [001] axis forming a well-defined girdle near parallel to the foliation and poles of (010) normal to the foliation; suggesting a dislocation creep mechanism. Further investigation into the water effects on eclogite show: (I) Hydroxyl content does not induce a change in the microfabric of omphacite; (II) Grain boundary processes dominate the deformation of garnet under high water fugacity conditions, yielding a random crystallographic preferred orientation similar to that of nondeforming garnet. These results are remarkably similar to observations from deformed eclogites in nature.

Zhang, J.; Green, H. W.

2004-12-01

404

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

405

High-pressure amorphous phase of vanadium pentaoxide  

NASA Astrophysics Data System (ADS)

We have discovered a high-pressure amorphous state of vanadium pentaoxide based on the results of an in situ high-pressure Raman spectroscopic and synchrotron x-ray diffraction study in a diamond-anvil cell up to 53 GPa under nonhydrostatic conditions. The broadening of Raman spectra and the diminishing of diffraction intensities suggest the evolution of disorder in the high-pressure ? phase. The compound has been found to undergo amorphization around 40 GPa. Upon the release of pressure, the material remains amorphous; however, the changes in the shapes of the structure factor and pair correlation function suggest that a-V2O5 recovered after pressure cycling is different from that at high pressure, indicating possible polyamorphism. Raman investigations show that unlike ? and ? crystalline phases, the high-pressure amorphous phase contains only doubly coordinated oxygen. A comparison of the Raman spectrum of a-V2O5 recovered from high pressure with that of the vapor-deposited a-V2O5 film suggests that although both of these have disordered arrangements of V=O bonds, their structures are not identical.

Arora, A. K.; Sato, Tomoko; Okada, Taku; Yagi, Takehiko

2012-03-01

406

Low Level Pressure Oscillation Measurements in High, Varying DC Pressure Environments  

NASA Technical Reports Server (NTRS)

Passive motor stability diagnostics require high s/n measurements of low level (60 to 80 db below mean pressure) oscillatory pressures in environments with large and varying DC pressures. Three approaches are briefly examined relative to passive diagnostic demands. Although the high pass filter approach has been demonstrated by Hessler, the 'short time constant' approach is recommended because it enables the use of sensitive p-ducers (resolutions approx. 10(exp -4) psi). Pieso-electric transducers are described and a methodology for using high sensitivity designs for passive diagnostics measurements is presented.

Glick, R. L.; Hessler, R. O.

2000-01-01

407

Evaluation of candidate alloys for the construction of metal flex hoses in the STS launch environment  

NASA Technical Reports Server (NTRS)

Various vacuum jacketed cryogenic supply lines at the Shuttle launch site use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the flex hoses, which were made of 304L stainless steel. A search was done to find a more corrosion resistant replacement material. This study focused on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, long term exposure at the beach corrosion testing site, and pitting corrosion tests in ferric chloride solution. Based on the results of these tests, the most corrosion resistant alloys were found to be (in order) Hastelloy C-22, Inconel 625, Hastelloy C-276, Hastelloy C-4, and Inco Alloy G-3. Of these top five alloys, the Hastelloy C-22 stands out as being the best of those tested for this application.

Ontiveros, Cordelia

1988-01-01

408

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

409

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 8°C and the formation of staphylococcal enterotoxins were also

T. López-Pedemonte; A. X. Roig-Sagués; B. Guamis

2006-01-01

410

High pressure magnetic measurements on strongly correlated electron systems with a miniature ceramic anvil high pressure cell  

NASA Astrophysics Data System (ADS)

We have designed a miniature ceramic anvil high pressure cell (mCAC) for magnetic measurements at pressures up to 12.6 GPa in a commercial superconducting quantum interference (SQUID) magnetometer [1-3]. The simplified mCAC without anvil alignment mechanism is easy-to-use for researchers who are not familiar with high-pressure technology and magnetic measurements can be done above 10 GPa. Here, we show one additional modification in the mCAC. This modification enables more precise magnetic measurements on samples with smaller magnetization. We confirm the spontaneous dc magnetization in the pressure-induced ferromagnetic phase in YbCu2Si2 by high pressure magnetic measurements with the mCAC. The pressure-induced phase has the strong uniaxial Ising-type anisotropy.

Tateiwa, Naoyuki; Haga, Yoshinori; Matsuda, Tatsuma D.; Fisk, Zachary

2014-05-01

411

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

412

HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS  

SciTech Connect

The flow VLE apparatus designed and built for a previous project was upgraded and recalibrated for data measurements for this project. The modifications include better and more accurate sampling technique, addition of a digital recorder to monitor temperature and pressure inside the VLE cell, and a new technique for remote sensing of the liquid level in the cell. VLE data measurements for three binary systems, tetralin-quinoline, benzene--ethylbenzene and ethylbenzene--quinoline, have been completed. The temperature ranges of data measurements were 325 C to 370 C for the first system, 180 C to 300 C for the second system, and 225 C to 380 C for the third system. The smoothed data were found to be fairly well behaved when subjected to thermodynamic consistency tests. SETARAM C-80 calorimeter was used for incremental enthalpy and heat capacity measurements for benzene--ethylbenzene binary liquid mixtures. Data were measured from 30 C to 285 C for liquid mixtures covering the entire composition range. An apparatus has been designed for simultaneous measurement of excess volume and incremental enthalpy of liquid mixtures at temperatures from 30 C to 300 C. The apparatus has been tested and is ready for data measurements. A flow apparatus for measurement of heat of mixing of liquid mixtures at high temperatures has also been designed, and is currently being tested and calibrated.

Vinayak N. Kabadi

2000-05-01

413

Rotational viscometer for high-pressure, high-temperature fluids  

DOEpatents

The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer include a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. Means are provided to generate an output indicative of the phase difference between the two waveforms. The viscometer is comparatively simple, inexpensive, rugged, and does not require shaft seals.

Carr, K.R.

1983-06-06

414

Rotational viscometer for high-pressure high-temperature fluids  

DOEpatents

The invention is a novel rotational viscometer which is well adapted for use with fluids at high temperatures and/or pressures. In one embodiment, the viscometer includes a substantially non-magnetic tube having a closed end and having an open end in communication with a fluid whose viscosity is to be determined. An annular drive magnet is mounted for rotation about the tube. The tube encompasses and supports a rotatable shaft assembly which carries a rotor, or bob, for insertion in the fluid. Affixed to the shaft are (a) a second magnet which is magnetically coupled to the drive magnet and (b) a third magnet. In a typical operation, the drive magnet is rotated to turn the shaft assembly while the shaft rotor is immersed in the fluid. The viscous drag on the rotor causes the shaft assembly to lag the rotation of the drive magnet by an amount which is a function of the amount of viscous drag. A first magnetic pickup generates a waveform whose phase is a function of the angular position of the drive magnet. A second magnetic pickup generates a waveform whose phase is a function of the angular position of the third magnet. An output is generated indicative of the phase difference between the two waveforms.

Carr, Kenneth R. (Knoxville, TN)

1985-01-01

415

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

416

Disproportionation of nitric oxide at high pressure  

SciTech Connect

A facile pressure-induced disproportionation of nitric oxide occurs at 176 K and 1.5 GPa. The reaction products are N/sub 2/O/sub 4/, N/sub 2/O, and a small, variable amount of N/sub 2/O/sub 3/ as identified by infrared, Raman, and visible absorption spectroscopies. No free NO, N/sub 2/O/sub 2/ or NO/sub 2/ is observed after warming the sample to room temperature. The N/sub 2/O/sub 4/ product subsequently photolyzes to form N/sub 2/O/sub 3/ and NO/sub 2//sup +/NO/sub 3//sup -/, and evidence for the nitrite form of N/sub 2/O/sub 4/ is reported. The N/sub 2/PO product is stable, once formed, to 14.0 GPa. 27 references, 7 figures.

Agnew, S.F.; Swanson, B.I.; Jones, L.H.; Mills, R.L.

1985-04-25

417

High pressure compressor component performance report  

NASA Technical Reports Server (NTRS)

A compressor optimization study defined a 10 stage configuration with a 22.6:1 pressure ratio, an adiabatic efficiency goal of 86.1%, and a polytropic efficiency of 90.6%; the corrected airflow is 53.5 kg/s. Subsequent component testing included three full scale tests: a six stage rig test, a 10 stage rig test, and another 10 stage rig test completed in the second quarter of 1982. Information from these tests is used to select the configuration for a core engine test and an integrated core/low spool test. The test results will also provide data base for the flight propulsion system. The results of the test series with both aerodynamic and mechanical performance of each compressor build are presented. The second 10 stage compressor adiabatic efficiency was 0.848 at a cruise operating point versus a test goal of 0.846.

Cline, S. J.; Fesler, W.; Liu, H. S.; Lovell, R. C.; Shaffer, S. J.

1983-01-01

418

Snubbing yields high-pressure savings  

SciTech Connect

Producing wells become deficient because of mechanical problems within the well or depletion of the oil or gas reservoir. Workover is an operation within the well's bore to repair equipment malfunction or well situation, or to enhance the well's performance. Workover performed through existing tubing by means of smaller diameter tubing is called thru-tubing workover. Snubbing utilizes jointed tubing or drill pipe and a hydraulic snubbing unit to run tubing or pipe under pressure conditions without killing the well. Tubing is run either through the blowout preventers and bore of an uncompleted well or through the well-head and tubing of a completed well. Hydraulic snubbing units offer many advantages to well productivity. Some of these are discussed in this article.

Parkhill, T.; Loring, G.; Lirette, R.

1987-09-01

419

Cryogenic Transport of High-Pressure-System Recharge Gas  

NASA Technical Reports Server (NTRS)

A method of relatively safe, compact, efficient recharging of a high-pressure room-temperature gas supply has been proposed. In this method, the gas would be liquefied at the source for transport as a cryogenic fluid at or slightly above atmospheric pressure. Upon reaching the destination, a simple heating/expansion process would be used to (1) convert the transported cryogenic fluid to the room-temperature, high-pressure gaseous form in which it is intended to be utilized and (2) transfer the resulting gas to the storage tank of the system to be recharged. In conventional practice for recharging high-pressure-gas systems, gases are transported at room temperature in high-pressure tanks. For recharging a given system to a specified pressure, a transport tank must contain the recharge gas at a much higher pressure. At the destination, the transport tank is connected to the system storage tank to be recharged, and the pressures in the transport tank and the system storage tank are allowed to equalize. One major disadvantage of the conventional approach is that the high transport pressure poses a hazard. Another disadvantage is the waste of a significant amount of recharge gas. Because the transport tank is disconnected from the system storage tank when it is at the specified system recharge pressure, the transport tank still contains a significant amount of recharge gas (typically on the order of half of the amount transported) that cannot be used. In the proposed method, the cryogenic fluid would be transported in a suitably thermally insulated tank that would be capable of withstanding the recharge pressure of the destination tank. The tank would be equipped with quick-disconnect fluid-transfer fittings and with a low-power electric heater (which would not be used during transport). In preparation for transport, a relief valve would be attached via one of the quick-disconnect fittings (see figure). During transport, the interior of the tank would be kept at a near-ambient pressure far below the recharge pressure. As leakage of heat into the tank caused vaporization of the cryogenic fluid, the resulting gas would be vented through the relief valve, which would be set to maintain the pressure in the tank at the transport value. Inasmuch as the density of a cryogenic fluid at atmospheric pressure greatly exceeds that of the corresponding gas in a practical high-pressure tank at room temperature, a tank for transporting a given mass of gas according to the proposed method could be smaller (and, hence, less massive) than is a tank needed for transporting the same mass of gas according to the conventional method.

Ungar, Eugene K,; Ruemmele, Warren P.; Bohannon, Carl

2010-01-01

420

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

421

Effect of high hydrostatic pressure on lycopene stability  

Microsoft Academic Search

The stability and isomerization of lycopene by high hydrostatic pressure (HHP) were evaluated. Lycopene standard in hexane and tomato puree were pressurized at 100, 200, 300, 400, 500 and 600MPa for 12min at controlled temperature (20±1°C). After application of pressure, samples were stored at refrigerator temperature (4±1°C) and ambient laboratory temperature (24±1°C) under lightproof conditions. HPLC and spectral analysis were

Weifen Qiu; Hanhu Jiang; Haifeng Wang; Yulong Gao

2006-01-01

422

Structural Phase Transformations in Iron-Chalcogen under High Pressures  

Microsoft Academic Search

We report high pressure structural phase transformation sequence in a layered Iron-based superconducting compound FeSe0.3Te0.7 to 31 GPa at room temperature. The ambient pressure PbO type tetragonal phase (Space Group - P4\\/nmm) transforms to a monoclinic phase (Space group - P21\\/m) at a pressure of 7.3 \\\\pm 0.9 GPa. This monoclinic phase is similar to the one observed below 100

Andrew K. Stemshorn; Yogesh K. Vohra; Phillip M. Wu; F. C. Hsu; Y. L. Huang; M. K. Wu; K. W. Yeh

2011-01-01

423

Fiber optic photoelastic pressure sensor for high temperature gases  

NASA Technical Reports Server (NTRS)

A novel fiber optic pressure sensor based on the photoelastic effects has been developed for extremely high temperature gases. At temperatures varying from 25 to 650 C, the sensor experiences no change in the peak pressure of the transfer function and only a 10 percent drop in dynamic range. Refinement of the sensor has resulted in an optoelectronic interface and processor software which can calculate pressure values within 1 percent of full scale at any temperature within the full calibrated temperature range.

Wesson, Laurence N.; Redner, Alex S.; Baumbick, Robert J.

1990-01-01

424

High Pressure Treatment of Whey Protein \\/ Polysaccharide Systems  

Microsoft Academic Search

High hydrostatic pressure treatment can be used to change food structures, in particular to obtain weak or strong gels. In this study we have characterized the gelifying effect obtained by pressure treatments, at ambient and at 50°C, on whey protein\\/polysaccharide mixed systems. The polysaccharides studied were kappa-carrageenan, xanthan gum and HM-pectin. The pressures applied were 400, 600 and 800 MPa.

P. B. Fernandes; A. Raemy

1996-01-01

425

High-pressure Brillouin study on methane hydrate  

Microsoft Academic Search

Acoustic velocities and adiabatic elastic constants of structure I of methane hydrate (MH) have been determined as a function of pressure up to 0.6 GPa at 23°C by the high-pressure Brillouin spectroscopy developed for a single molecular crystal. The pressure dependence of the acoustic velocities of MH is very similar to that of ice-Ih except for the longitudinal acoustic (LA)

S. Sasaki; T. Kumazaki; I. Suwa; T. Kume; H. Shimizu

2002-01-01

426

Self-contained, single-use hose and tubing cleaning module  

NASA Technical Reports Server (NTRS)

A self contained, single use hose and tubing cleaning module which utilizes available water supplies without requiring access to precision cleaning facilities is presented. The module is attached to the water source at the inlet side and to the hose or tubing to be cleaned at the outlet side. The water flows through a water purification zone, a detergent dispensing zone, a filtration zone before the detergent laden water flows into the tubing to clean the tubing walls. The module contains an embedded pad which is impregnated with a pH indicator to indicate to the user when the detergent has dissolved and rinsing of the tubing begins.

Rollins, Fred P. (inventor); Glass, James S. (inventor)

1987-01-01

427

Criterion for Identifying Vortices in High-Pressure Flows  

NASA Technical Reports Server (NTRS)

A study of four previously published computational criteria for identifying vortices in high-pressure flows has led to the selection of one of them as the best. This development can be expected to contribute to understanding of high-pressure flows, which occur in diverse settings, including diesel, gas turbine, and rocket engines and the atmospheres of Jupiter and other large gaseous planets. Information on the atmospheres of gaseous planets consists mainly of visual and thermal images of the flows over the planets. Also, validation of recently proposed computational models of high-pressure flows entails comparison with measurements, which are mainly of visual nature. Heretofore, the interpretation of images of high-pressure flows to identify vortices has been based on experience with low-pressure flows. However, high-pressure flows have features distinct from those of low-pressure flows, particularly in regions of high pressure gradient magnitude caused by dynamic turbulent effects and by thermodynamic mixing of chemical species. Therefore, interpretations based on low-pressure behavior may lead to misidentification of vortices and other flow structures in high-pressure flows. The study reported here was performed in recognition of the need for one or more quantitative criteria for identifying coherent flow structures - especially vortices - from previously generated flow-field data, to complement or supersede the determination of flow structures by visual inspection of instantaneous fields or flow animations. The focus in the study was on correlating visible images of flow features with various quantities computed from flow-field data.

Bellan, Josette; Okong'o, Nora

2007-01-01

428

Non-Molecular Carbon Dioxide at High Pressure  

NASA Astrophysics Data System (ADS)

A brief review on the high pressure, non-molecular phases of CO2, which have been all discovered along the present decade, will be presented. It includes references to experimental studies, based on the XRD and optical spectroscopy techniques coupled to the diamond anvil cell (DAC), and to ab initio simulation studies. The matter is still under strong debate, and many open issues are left on the high pressure-high temperature phase diagram of this important substance.

Santoro, Mario

429

High pressure fabrication and processing of GaN:Mg  

Microsoft Academic Search

Results on introduction of magnesium to GaN by three methods are presented. They consists of (i) high pressure growth of bulk, single crystals of GaN from Ga+Mg melt, (ii) diffusion of Mg to bulk GaN and to layers of GaN\\/Al2O3 at high temperatures and high pressures and (iii) implantation of Mg to bulk, single crystals and to layers of GaN\\/Al2O3

T Suski; J Jun; M Leszczynski; H Teisseyre; I Grzegory; S Porowski; G Dollinger; K Saarinen; T Laine; J Nissilä; W Burkhard; W Kriegseis; B. K Meyer

1999-01-01

430

Fabrication of High Sensitivity Carbon Microcoil Pressure Sensors  

PubMed Central

This work demonstrates a highly sensitive pressure sensor that was fabricated using carbon microcoils (CMCs) and polydimethylsiloxane (PDMS). CMCs were grown by chemical vapor deposition using various ratios of Fe-Sn catalytic solution. The pressure sensor has a sandwiched structure, in which the as-grown CMCs were inserted between two PDMS layers. The pressure sensor exhibits piezo-resistivity changes in response to mechanical loading using a load cell system. The yields of the growth of CMCs at a catalyst proportion of Fe:Sn = 95:5 reach 95%. Experimental results show that the sensor achieves a high sensitivity of 0.93%/kPa from the CMC yield of 95%. The sensitivity of the pressure sensor increases with increasing yield of CMCs. The demonstrated pressure sensor shows the advantage of high sensitivity and is suitable for mass production.

Su, Chih-Chung; Li, Chen-Hung; Chang, Neng-Kai; Gao, Feng; Chang, Shuo-Hung

2012-01-01

431

Ignition of contaminants by impact of high-pressure oxygen  

NASA Technical Reports Server (NTRS)

The ignition of oil-film contaminants in high-pressure gaseous oxygen systems, caused by rapid pressurization, was investigated using the NASA/White Sands Test Facility's large-volume pneumatic impact test system. The test section consisted of stainless steel lines, contaminated on the inside surface with known amounts of Mobil DTE 24 oil and closed at one end, which was attached to a high-pressure oxygen system; the test section was pressurized to 48 MPa by opening a high-speed valve. Ignition of the oil was detected by a photocell attached to the closed end of the line. It was found that the frequency of ignition increased as a function of both the concentration of oil and of the pressure of the impacting oxygen. The threshold of ignition was between 25 and 65 mg/sq m. The results were correlated with the present NASA and Compressed Gas Association requirements for maximum levels of organic contaminants.

Pedley, Michael D.; Pao, Jenn-Hai; Bamford, Larry; Williams, Ralph E.; Plante, Barry

1988-01-01

432

Germination of vegetable seeds exposed to very high pressure  

NASA Astrophysics Data System (ADS)

Effects of high hydrostatic pressure were investigated on vegetable seeds in the GPa range to examine the potentialities of breed improvement by high-pressure processing. Specimens of several seeds of broccoli (Brassica oleracea var. italica), Turnip leaf (Brassica rapa var. perviridis) and Potherb Mustard (Brassica rapa var. nipposinica) were put in a teflon capsule with liquid high pressure medium, fluorinate, and inserted into a pyrophillite cube. By using a cubic anvil press a hydrostatic pressure of 5.5 GP a was applied to these seeds for 15 minutes. After being brought back to ambient pressure, they were seeded on humid soil in a plant pot. Many of these vegetable seeds began to germinate within 6 days after seeded.

Mori, Y.; Yokota, S.; Ono, F.

2012-07-01

433

The high pressure high shear stress rheology of liquid lubricants  

NASA Astrophysics Data System (ADS)

A limiting shear stress model of liquid lubricant shear rheology is offered which accurately represents all available primary data. The model is of the nonlinear Maxwell type with shear modulus taken into the time derivative and broadening of the viscous-plastic transition with pressure. Property relations for viscosity, limiting stress and shear modulus are refined for a polyphenyl ether in particular. The model, with simplifying assumptions, is compared with disk machine results. This model, with change of yield criterion, may be applicable to some shear thinning liquids at low pressure. Limiting shear stress varies with pressure in the same manner as the ultimate shear strength of solid polymers.

Bair, S.; Winer, W. O.

1992-01-01

434

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

435

High Pressure Structural Study of Quasicrystalline Al-Mn.  

National Technical Information Service (NTIS)

High pressure X-ray diffraction studies have been performed on rapidly solidified Al-Mn alloys (35 and 40 wt% Mn) containing the quasicrystalline phase. Pressure experiments were undertaken using a diamond anvil cell, and X-ray diffraction analysis in the...

E. Johnson J. Staun Olsen J. V. Wood L. Gerward

1987-01-01

436

Rotordynamic stability problems and solutions in high pressure turbocompressors  

NASA Technical Reports Server (NTRS)

The stability of a high pressure compressor is investigated with special regard to the self-exciting effects in oil seals and labyrinths. It is shown how to stabilize a rotor in spite of these effects and even increase its stability with increasing pressure.

Schmied, J.

1989-01-01

437

Detail view of unit 43 with high pressure stage compressor ...  

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

Detail view of unit 43 with high pressure stage compressor in left foreground and low pressure stage compressor in right background. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

438

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

439

High pressure phase transition kinetics of maize starch  

Microsoft Academic Search

In this paper, the impact of high hydrostatic pressure, temperature and time on the gelatinization of maize starch is reported. Starch transition has been assessed by microscopic inspections of the granule’s loss in birefringence which occurs during the first stage of gelatinization in consequence of the water uptake. Experiments have been carried out under combined pressure–temperature treatments in the range

Roman Buckow; Volker Heinz; Dietrich Knorr

2007-01-01

440

Pressure application technique for high-temperature composite fabrication  

NASA Technical Reports Server (NTRS)

Technique utilizes characteristic of room-temperature vulcanizing rubber (RTV) which expands readily when heated. RTV expansion can exert uniform pressure on filament-reinforced polymer materials during curing. Technology accommodates high-temperature pressure application for P13-N polyimide composite consolidation during cure.

Baucom, R. M.; Powers, J. F.

1974-01-01

441

High pressure crystal phases of benzene probed by infrared spectroscopy  

Microsoft Academic Search

In this work we present an infrared study of the high pressure phases of benzene crystal up to 25 GPa. The far infrared portion of the spectrum has been studied for the first time above 4 GPa. From the pressure behavior of the frequencies and the integrated peak absorptions we are able to confirm, beside the transition between phases II-III

Lucia Ciabini; Mario Santoro; Roberto Bini; Vincenzo Schettino

2001-01-01

442

Ontogenetic Development of Artemia Salina in Low and High Pressures.  

National Technical Information Service (NTIS)

The influence of different atmospheric pressures on the development of the eggs of Artemia salina was investigated. In a total of 65 experiments the animals were bred up to the stage of the first nauplius in low and high pressures as well as under normal ...

R. Peters

1976-01-01

443

High-Pressure Metallic Polymorph of Cadmium Arsenide.  

National Technical Information Service (NTIS)

A high pressure polymorph of Cd3As2 was retained at atmospheric pressure and temperatures below 150K. It is metallic, but no superconducting transition was found down to 1.1K. The crystal structure is D52 with a = 4.30A, c = 6.87A, and c/a = 1.60. (Author...

H. Katzman T. Donahue W. F. Libby

1968-01-01

444

High Blood Pressure May Up Psoriasis Risk for Women  

MedlinePLUS

... please enable JavaScript. High Blood Pressure May Up Psoriasis Risk for Women Long-term use of certain ... 2, 2014 Related MedlinePlus Pages Blood Pressure Medicines Psoriasis Women's Health WEDNESDAY, July 2, 2014 (HealthDay News) -- ...

445

High-pressure and temperature investigations of energetic materials  

NASA Astrophysics Data System (ADS)

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

Gump, J. C.

2014-05-01

446

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

447

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

448

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; Habán, Vladimír

2006-12-22

449

Digital pressure transducer for use at high temperatures  

DOEpatents

A digital pressure sensor for measuring fluid pressures at relatively high temperatures includes an electrically conducting fiber coupled to the fluid by a force disc that causes tension in the fiber to be a function of fluid pressure. The tension causes changes in the mechanical resonant frequency of the fiber, which is caused to vibrate in a magnetic field to produce an electrical signal from a positive-feedback amplifier at the resonant frequency. A count of this frequency provides a measure of the fluid pressure.

Karplus, Henry H. B. (Hinsdale, IL)

1981-01-01

450

Digital pressure transducer for use at high temperatures. [LMFBR  

SciTech Connect

A digital pressure sensor for measuring fluid pressures at relatively high temperatures includes an electrically conducting fiber coupled to the fluid by a force disc that causes tension in the fiber to be a function of fluid pressure. The tension causes changes in the mechanical resonant frequency of the fiber, which is caused to vibrate in a magnetic field to produce an electrical signal from a positive-feedback amplifier at the resonant frequency. A count of this frequency provides a measure of the fluid pressure.

Karplus, H.H.

1981-03-17

451

Low Cost, High Efficiency, High Pressure Hydrogen Storage  

SciTech Connect

A technical and design evaluation was carried out to meet DOE hydrogen fuel targets for 2010. These targets consisted of a system gravimetric capacity of 2.0 kWh/kg, a system volumetric capacity of 1.5 kWh/L and a system cost of $4/kWh. In compressed hydrogen storage systems, the vast majority of the weight and volume is associated with the hydrogen storage tank. In order to meet gravimetric targets for compressed hydrogen tanks, 10,000 psi carbon resin composites were used to provide the high strength required as well as low weight. For the 10,000 psi tanks, carbon fiber is the largest portion of their cost. Quantum Technologies is a tier one hydrogen system supplier for automotive companies around the world. Over the course of the program Quantum focused on development of technology to allow the compressed hydrogen storage tank to meet DOE goals. At the start of the program in 2004 Quantum was supplying systems with a specific energy of 1.1-1.6 kWh/kg, a volumetric capacity of 1.3 kWh/L and a cost of $73/kWh. Based on the inequities between DOE targets and Quantum’s then current capabilities, focus was placed first on cost reduction and second on weight reduction. Both of these were to be accomplished without reduction of the fuel system’s performance or reliability. Three distinct areas were investigated; optimization of composite structures, development of “smart tanks” that could monitor health of tank thus allowing for lower design safety factor, and the development of “Cool Fuel” technology to allow higher density gas to be stored, thus allowing smaller/lower pressure tanks that would hold the required fuel supply. The second phase of the project deals with three additional distinct tasks focusing on composite structure optimization, liner optimization, and metal.

Mark Leavitt

2010-03-31

452

Characterization of coaxial rocket injector sprays under high pressure environments  

NASA Technical Reports Server (NTRS)

The effect of elevated environment pressures on the atomization characteristics of a single element, scaled-down, shear-coaxial rocket injector has been investigated. In this study, the shear coaxial injector was operated with water and air as simulants for conventionally used liquid oxygen and hydrogen gas, respectively. The experiments were conducted in a specially designed high pressure rig. A two-component PDPA/DSA system was used to study the spray characteristics at different chamber pressures ranging from atmospheric to 100 psig. The study showed an overall increase in the droplet sizes at higher chamber pressures. This phenomenon is attributed to a decrease in the secondary atomization effects at higher chamber pressures which, in turn, is directly related to a decrease in the shear experienced by the droplets as they move axially through the pressure chamber.

Sankar, S. V.; Wang, G.; Brena De La Rosa, A.; Rudoff, R. C.; Isakovic, A.; Bachalo, W. D.

1992-01-01

453

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

454

Rubidium-xenon spin exchange and relaxation rates measured at high pressure and high magnetic field  

Microsoft Academic Search

The production of hyperpolarized Xe via spin exchange with optically pumped Rb atoms was studied at 47 000 G under high-pressure conditions. From variable pressure and temperature studies, the spin exchange efficiency was found to be pressure dependent and lower than comparable low-field measurements. Spin exchange due to short binary collisions is expected to be pressure independent, and the cross

Charles V. Rice; Daniel Raftery

2002-01-01

455

Hydrogen solubility in garnet at high pressures  

NASA Astrophysics Data System (ADS)

Garnet is the most important secondary mineral whose fraction ranges from ~ 20% in the shallow upper mantle for the pyrolite model to ~ 80% in the transition zone for the piclogite model. Therefore understanding the solubility and dissolution mechanisms of hydrogen in garnet is important for water budget as well as for understanding plastic properties of the mantle. However, there is little consensus on the solubility and dissolution mechanisms of hydrogen in garnet. For example, under deep upper mantle conditions (P>7 GPa), Withers et al. (1998) concluded virtually no hydrogen solubility in pyrope whereas Lu and Keppler (1997) showed small hydrogen solubility (~ 200 ppm wt of H2O). In order to address possible causes of such discrepancy, we have initiated a systematic study on hydrogen solubility under a broad range of pressure and controlled chemical environment. In contrast with the previous study, preliminary results indicate that natural garnet crystal surrounded by powder of olivine, orthopyroxene and clinopyroxene, could host around 1000 ppm wt of H2O at 9 GPa and 1100 °C conditions. Possible interpretation is that the enrichment of hydrogen is due to the increased Mg/Si ratio (activity of MgO) due to the coexistence of garnet with olivine. If hydrogarnet substitution (O4H4) is the dominant mechanism of hydrogen dissolution, then the increase in the activity of MgO will increase the hydrogen solubility. Further experiments are performed (i) to investigate the hydrogen solubility under deep upper mantle conditions (P=6-9 GPa T=1373-1573 K) where the previous results have a major discrepancy, and (ii) to investigate the kinetics and the influence of oxide buffer on hydrogen solubility.

Mookherjee, M.; Karato, S.-

2007-12-01

456

Applications and development of high pressure PEM systems  

SciTech Connect

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 bottles for space suits, to provide oxygen for space shuttle, to provide oxygen and/or reboost propellants to the space station, and to recharge oxygen bottles for commercial aviation. A long operating history has been generated for weight insensitive designs that serve as oxygen generators for submarines. Exciting future vehicle concepts and portable applications are enabled by carefully designing lightweight stacks which do not require additional pressure containment. These include high altitude long endurance solar rechargeable aircraft and airships, water refuelable spacecraft, and a variety of field portable systems. High pressure electrolyzers can refill compressed hydrogen storage tanks for fuel cell powered vehicles or portable fuel cells. Hamilton Standard has demonstrated many high pressure PEM water electrolyzer designs for a variety of applications. Electrolyzers with operational pressures up to 3000 psi (20.7 MPa) are currently used for US Navy submarine oxygen generators. An aerospace version has been demonstrated in the Integrated Propulsion Test Article (IPTA) program. Electrolyzers with operational pressures up to 6000 psi (41.4 MPa) have also been demonstrated in the High Pressure Oxygen Recharge System (HPORS). Onboard oxygen generator systems (OBOGS) that generate up to 2000 psi (13.8 MPa) oxygen and refill breathable oxygen tanks for commercial aviation have been designed and successfully demonstrated. Other hardware applications that require high pressure PEM devices are related to these proven applications.

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

1999-06-01

457

Structural study of helical polyfluorene under high quasihydrostatic pressure.  

PubMed

We report on an x-ray diffraction (XRD) study of helical poly[9,9-bis(2-ethylhexyl)fluorene] (PF2/6) under high quasihydrostatic pressure and show an effect of pressure on the torsion angle (dihedral angle) between adjunct repeat units and on the hexagonal unit cell. A model for helical backbone conformation is constructed. The theoretical position for the most prominent 00l x-ray reflection is calculated as a function of torsion angle. The XRD of high molecular weight PF2/6 (M(n)=30 kg/mol) is measured through a diamond anvil cell upon pressure increase from 1 to 10 GPa. The theoretically considered 00l reflection is experimentally identified, and its shift with the increasing pressure is found to be consistent with the decreasing torsion angle between 2 and 6 GPa. This indicates partial backbone planarization towards a more open helical structure. The h00 peak is identified, and its shift together with the broadening of 00l implies impairment of the ambient hexagonal order, which begins at or below 2 GPa. Previously collected high-pressure photoluminescence data are reanalyzed and are found to be qualitatively consistent with the XRD data. This paper provides an example of how the helical ?-conjugated backbone structure can be controlled by applying high quasihydrostatic pressure without modifications in its chemical structure. Moreover, it paves the way for wider use of high-pressure x-ray scattering in the research of ?-conjugated polymers. PMID:23496539

Knaapila, M; Konôpková, Z; Torkkeli, M; Haase, D; Liermann, H-P; Guha, S; Scherf, U

2013-02-01

458

Structural study of helical polyfluorene under high quasihydrostatic pressure  

NASA Astrophysics Data System (ADS)

We report on an x-ray diffraction (XRD) study of helical poly[9,9-bis(2-ethylhexyl)fluorene] (PF2/6) under high quasihydrostatic pressure and show an effect of pressure on the torsion angle (dihedral angle) between adjunct repeat units and on the hexagonal unit cell. A model for helical backbone conformation is constructed. The theoretical position for the most prominent 00l x-ray reflection is calculated as a function of torsion angle. The XRD of high molecular weight PF2/6 (Mn=30 kg/mol) is measured through a diamond anvil cell upon pressure increase from 1 to 10 GPa. The theoretically considered 00l reflection is experimentally identified, and its shift with the increasing pressure is found to be consistent with the decreasing torsion angle between 2 and 6 GPa. This indicates partial backbone planarization towards a more open helical structure. The h00 peak is identified, and its shift together with the broadening of 00l implies impairment of the ambient hexagonal order, which begins at or below 2 GPa. Previously collected high-pressure photoluminescence data are reanalyzed and are found to be qualitatively consistent with the XRD data. This paper provides an example of how the helical ?-conjugated backbone structure can be controlled by applying high quasihydrostatic pressure without modifications in its chemical structure. Moreover, it paves the way for wider use of high-pressure x-ray scattering in the research of ?-conjugated polymers.

Knaapila, M.; Konôpková, Z.; Torkkeli, M.; Haase, D.; Liermann, H.-P.; Guha, S.; Scherf, U.

2013-02-01

459

Anharmonicity in aluminum hydride at high pressures  

Microsoft Academic Search

Aluminum hydride has been predicted to be a superconductor with a transition temperature of 24 K at 110 GPa, in disagreement with the experimental observation. In this work, it is shown that the bulk of the electron–phonon coupling can be associated with modes that are highly anharmonic according to frozen phonon calculations. This large anharmonicity could partially explain the origin of the

Bruno Rousseau; Aitor Bergara

2011-01-01

460

Analysis of High Pressure Oil Shale Hugoniots.  

National Technical Information Service (NTIS)

A collection of low and high stress level Hugoniot data for a low kerogen content, porous Anvil Points oil shale are analyzed with the P- alpha model to give a Hugoniot for kerogen free shale. The P- alpha model suggests an ''elastic'' yield stress, P/sub...

D. E. Munson

1977-01-01

461

Materials for High Pressure Fuel Injection Systems.  

National Technical Information Service (NTIS)

The high-level goal of this multi-year effort was to facilitate the Advanced Combustion Engine goal of 20% improvement (compared to 2009 baseline) of commercial engine efficiency by 2015. A sub-goal is to increase the reliability of diesel fuel injectors ...

A. Shyam C. Hubbard J. Howe M. Pollard N. Yang P. J. Blau R. Trejo

2011-01-01

462

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

463

Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure  

NASA Astrophysics Data System (ADS)

Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

2014-05-01

464

High-pressure liquid chromatography of aromatic amines  

NASA Technical Reports Server (NTRS)

Analysis made on commercially available liquid chromatograph demonstrates high-pressure liquid chromatographic conditions for separation of approximately 50 aromatic amines ranging from simple aniline derivatives to complex multiring di- and tri-amines.

Young, P. R.

1979-01-01

465

High Blood Pressure - Multiple Languages: MedlinePlus  

MedlinePLUS

... Hmoob) Japanese (???) Khmer (Khmer) Korean (???) Portuguese (português) Russian (???????) Somali (af Soomaali) Spanish (español) Tagalog ( ... PDF Health Information Translations Return to top Portuguese (português) High Blood Pressure Pressão arterial alta - português (Portuguese) ...

466

High Blood Pressure in Pregnancy - Multiple Languages: MedlinePlus  

MedlinePLUS

... Japanese (???) Korean (???) Marshallese (kajin Majöl) Portuguese (português) Russian (???????) Somali (af Soomaali) Spanish (español) Ukrainian ( ... PDF Health Information Translations Return to top Portuguese (português) High Blood Pressure in Pregnancy Pressão arterial (PA) ...

467

High Pressure Working Mode of Hollow Cathode Arc Discharges.  

National Technical Information Service (NTIS)

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

468

High Blood Pressure Treatment in Children (Beyond the Basics)  

MedlinePLUS

... training. Sedentary activities (watching television and/or playing video and computer games) should be limited to less than two hours per day. Participation in sports — Children who have controlled high blood pressure are generally ...

469

Electron band theory and high pressure equation of state  

SciTech Connect

Calculations of the high pressure equation of state of selected materials are reviewed, in order to illustrate general trends which occur in the evolution of electronic structure with compression, and the consequences of these trends for material properties.

McMahan, A.K.

1981-07-21

470

People with High Blood Pressure Often Have a 'Salt Tooth'  

MedlinePLUS

... blood pressure are often "salt-seeking," said Dr. William White, current president of the American Society of ... case of a high-salt taste preference." SOURCES: William B. White, M.D., president, American Society of ...

471

Reactions of Carbon Dioxide with Silicates under High Pressures.  

National Technical Information Service (NTIS)

Reactions of carbon dioxide with molten glass under high pressures were studied. Two special types of apparatus were employed. The results supported the existence of equilibria between silicates and carbonates. No evidence was found for the existence of e...

W. Weyl

1975-01-01

472

DETAIL VIEW OF UNIT #3 WITH HIGH PRESSURE STAGE COMPRESSOR ...  

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

DETAIL VIEW OF UNIT #3 WITH HIGH PRESSURE STAGE COMPRESSOR IN LEFT FOREGROUND. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

473

Detail view of unit 43 with high pressure stage compressor ...  

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

Detail view of unit 43 with high pressure stage compressor in left foreground. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

474

Detail view of valve mechanisms and goverenor on high pressure ...  

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

Detail view of valve mechanisms and goverenor on high pressure stage engine of unit 43. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

475

Spectroscopic Research at High Pressure and Variable Temperature.  

National Technical Information Service (NTIS)

Work concentrated on the use of spectroscopic techniques to probe material held under high pressure at various temperatures with the objective of improving understanding of intermolecular forces and the material properties which depend on them. Included i...

W. F. Sherman

1984-01-01

476

143. MOBILE HIGH PRESSURE NITROGEN CART STORED IN CONTROL ROOM ...  

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

143. MOBILE HIGH PRESSURE NITROGEN CART STORED IN CONTROL ROOM (214), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

477