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1

30 CFR 56.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false High-pressure hose connections. 56...NONMETAL MINES Compressed Air and Boilers § 56.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2010-07-01

2

30 CFR 57.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false High-pressure hose connections. 57...NONMETAL MINES Compressed Air and Boilers § 57.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2010-07-01

3

30 CFR 56.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false High-pressure hose connections. 56...NONMETAL MINES Compressed Air and Boilers § 56.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2012-07-01

4

30 CFR 57.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false High-pressure hose connections. 57...NONMETAL MINES Compressed Air and Boilers § 57.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2012-07-01

5

30 CFR 57.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false High-pressure hose connections. 57...NONMETAL MINES Compressed Air and Boilers § 57.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2013-07-01

6

30 CFR 56.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false High-pressure hose connections. 56...NONMETAL MINES Compressed Air and Boilers § 56.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2013-07-01

7

30 CFR 57.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false High-pressure hose connections. 57...NONMETAL MINES Compressed Air and Boilers § 57.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2011-07-01

8

30 CFR 56.13021 - High-pressure hose connections.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false High-pressure hose connections. 56...NONMETAL MINES Compressed Air and Boilers § 56.13021 High-pressure hose connections. Except...connections to machines of high-pressure hose lines of 3/4...

2011-07-01

9

30 CFR 57.13021 - High-pressure hose connections.  

...AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains...

2014-07-01

10

30 CFR 56.13021 - High-pressure hose connections.  

...METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains...

2014-07-01

11

Lightweight, all-metal hose assembly has high flexibility and strength over wide range of temperature and pressure  

NASA Technical Reports Server (NTRS)

Lightweight flexible, metal braid reinforced hose assembly is used in high and low pressure oxygen, helium, and hydrogen systems. These hose assemblies have been successfully used on the Saturn-2 stage to provide joints of sufficient flexibility to absorb movement resulting from temperature variations.

Bessing, L. L.

1966-01-01

12

High-flexibility, noncollapsing lightweight hose  

DOEpatents

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

Williams, David A. (Pittsburgh, PA)

1993-01-01

13

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Pressure relief devices, piping, valves...Transportation § 178.337-9 Pressure relief devices, piping, valves, hoses, and fittings. (a) Pressure relief devices. (1) See §...

2011-10-01

14

Hand-tightened, high-pressure seal  

NASA Technical Reports Server (NTRS)

To provide flared tubing and hose connections for high-pressure hand tightened cryogenic service, a 1/4-inch male AN seal was modified by machining to receive a special, double-truncated-cone-shaped Kel-F washer between it and the flared flex hose connector.

Meyer, W. A.

1968-01-01

15

6. DETAIL OF HIGHPRESSURE COMPRESSED AIR HOSE IN SOUTHWEST CORNER ...  

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

6. DETAIL OF HIGH-PRESSURE COMPRESSED AIR HOSE IN SOUTHWEST CORNER OF SHIPPING AND RECEIVING ROOM (109) - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

16

33 CFR 154.500 - Hose assemblies.  

Code of Federal Regulations, 2010 CFR

... (a) The minimum design burst pressure for each hose assembly...plus the static head pressure of the transfer system...facility's operations manual or the vessel's transfer procedure...allowable working pressure; (2) Date...

2010-07-01

17

[Industrial standards of hose assemblies for use with medical gas systems: safety against collapsing loads].  

PubMed

We experienced troubles caused by mounting an anesthesia machine and a pump oxygenator on an oxygen pressure-resistant hose that connected the central piping system with the anesthesia machine. Therefore, we measured the resistance of 9 types of hose assemblies to collapsing loads by the method in the International Standardization Organization (ISO) 5359. Two types of hose made in the U.S. were highly resistant. On the other hand, 7 types of domestic hose tended to be obstructed with collapsing loads, and 3 of them did not fulfill ISO's criteria. To prevent anesthetic accidents, improvements in the property of hose assemblies and the establishment of their industrial standardization are urgently needed. PMID:1766126

Mizobe, T; Hatanaka, T; Nozuchi, S; Aoki, H; Murakami, T; Tanaka, Y

1991-11-01

18

Rotary Coupling Extends Life Of Hose  

NASA Technical Reports Server (NTRS)

Oscillating rotary coupling enables hose to withstand bending oscillations without leakage. Intended for use where hose connects to stationary structure at one end and to oscillating structure on other end. Coupling, (a sun-and-planetary pulley system), eliminates fatigue stress at fixed end. Pulley coupling requires less hose than conventional helical-wrap couplings, and its weight, pressure drop, heat loss or gain, and fluid contents also less. Conceived for use on Space Station to transfer vapors across rotary joints to directional radiators for condensation or to transfer liquids to gimballed payloads for evaporation. On Earth, used to carry working fluids to and from evaporative solar collectors following path of Sun.

Benner, Steve; Costello, Frederick; Swanson, Theodore

1991-01-01

19

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 ...

20

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 ...

21

Hypertension (High Blood Pressure)  

MedlinePLUS

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

22

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

Code of Federal Regulations, 2010 CFR

...tubing and hoses; hose assemblies and end fittings. 393.45 Section 393.45 Transportation Other Regulations Relating to...ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.45 Brake tubing and hoses; hose assemblies and...

2010-10-01

23

High Blood Pressure  

MedlinePLUS

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

24

High blood pressure - infants  

MedlinePLUS

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

25

The Garden-Hose Model  

E-print Network

We define a new model of communication complexity, called the garden-hose model. Informally, the garden-hose complexity of a function f:{0,1}^n x {0,1}^n to {0,1} is given by the minimal number of water pipes that need to be shared between two parties, Alice and Bob, in order for them to compute the function f as follows: Alice connects her ends of the pipes in a way that is determined solely by her input x \\in {0,1}^n and, similarly, Bob connects his ends of the pipes in a way that is determined solely by his input y \\in {0,1}^n. Alice turns on the water tap that she also connected to one of the pipes. Then, the water comes out on Alice's or Bob's side depending on the function value f(x,y). We prove almost-linear lower bounds on the garden-hose complexity for concrete functions like inner product, majority, and equality, and we show the existence of functions with exponential garden-hose complexity. Furthermore, we show a connection to classical complexity theory by proving that all functions computable in log-space have polynomial garden-hose complexity. We consider a randomized variant of the garden-hose complexity, where Alice and Bob hold pre-shared randomness, and a quantum variant, where Alice and Bob hold pre-shared quantum entanglement, and we show that the randomized garden-hose complexity is within a polynomial factor of the deterministic garden-hose complexity. Examples of (partial) functions are given where the quantum garden-hose complexity is logarithmic in n while the classical garden-hose complexity can be lower bounded by n^c for constant c>0. Finally, we show an interesting connection between the garden-hose model and the (in)security of a certain class of quantum position-verification schemes.

Harry Buhrman; Serge Fehr; Christian Schaffner; Florian Speelman

2011-09-12

26

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

27

High temperature pressure gauge  

DOEpatents

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

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

1981-01-01

28

Living with High Blood Pressure  

MedlinePLUS

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

29

Pre-assembled hoses aid marginal recovery projects  

Microsoft Academic Search

The use of pre-assembled hose strings is making feasible production from offshore oil wells where the water\\/oil ratio is sufficiently high to make uneconomic the transport of the mixture to a distant refinery for processing. The pre-assembled hoses cut costs and time when used on marginal recovery processing barges (MRPBs), those barges equipped with processing equipment to separate and dispose

Furness

1982-01-01

30

High Blood Pressure Medicines  

MedlinePLUS

... fluid. Renin inhibitors slow down your body’s production of renin, the enzyme that starts the many chemical reactions that raise your blood pressure. Do these medicines have any side effects? All medicines ... effects of high blood pressure medicines include the following: Chest ...

31

Fullerenes under high pressures  

Microsoft Academic Search

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

B. Sundqvist

1999-01-01

32

Investigation of Radiation and Chemical Resistance of Flexible HLW Transfer Hose  

SciTech Connect

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

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

2010-03-24

33

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

34

High Blood Pressure  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (;)

2004-01-01

35

30 CFR 18.39 - Hose conduit.  

Code of Federal Regulations, 2012 CFR

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction...Hose conduit shall be provided for mechanical protection of all machine cables that are exposed to damage. Hose conduit shall...

2012-07-01

36

30 CFR 18.39 - Hose conduit.  

Code of Federal Regulations, 2011 CFR

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction...Hose conduit shall be provided for mechanical protection of all machine cables that are exposed to damage. Hose conduit shall...

2011-07-01

37

30 CFR 18.39 - Hose conduit.  

Code of Federal Regulations, 2010 CFR

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction...Hose conduit shall be provided for mechanical protection of all machine cables that are exposed to damage. Hose conduit shall...

2010-07-01

38

30 CFR 18.39 - Hose conduit.  

Code of Federal Regulations, 2013 CFR

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction...Hose conduit shall be provided for mechanical protection of all machine cables that are exposed to damage. Hose conduit shall...

2013-07-01

39

High Blood Pressure in Pregnancy  

MedlinePLUS

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

40

High pressure gas target  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

41

What Causes High Blood Pressure?  

MedlinePLUS

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

42

What Is High Blood Pressure?  

MedlinePLUS

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

43

High Blood Pressure and Women  

MedlinePLUS

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

44

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

45

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

46

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

47

Controlling your high blood pressure  

MedlinePLUS

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

48

Pre-assembled hoses aid marginal recovery projects  

SciTech Connect

The use of pre-assembled hose strings is making feasible production from offshore oil wells where the water/oil ratio is sufficiently high to make uneconomic the transport of the mixture to a distant refinery for processing. The pre-assembled hoses cut costs and time when used on marginal recovery processing barges (MRPBs), those barges equipped with processing equipment to separate and dispose of the water produced and concentrate the crude for transport by tanker. In the Far East, one MRPB equipped with an assembled hose network has been operating successfully for more than a year. It was towed to the well and deployed over an existing well in a matter of a few hours, using only an existing loading tower crane.

Furness, R.

1982-03-01

49

Questions and Answers about High Blood Pressure  

MedlinePLUS

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

50

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

51

Stroke and High Blood Pressure  

MedlinePLUS

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

52

High blood pressure medications  

MedlinePLUS

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

53

High pressure, high temperature transducer  

NASA Technical Reports Server (NTRS)

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

Vrolyk, John J. (Inventor)

1977-01-01

54

46 CFR 154.1170 - Hand hose line: General.  

... 2014-10-01 2014-10-01 false Hand hose line: General. 154.1170 Section...Firefighting System: Dry Chemical § 154.1170 Hand hose line: General. Each dry chemical hand hose line must: (a) Not be longer...

2014-10-01

55

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 ...

56

Myths about High Blood Pressure  

MedlinePLUS

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

57

High Blood Pressure  

MedlinePLUS

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

58

High pressure storage vessel  

DOEpatents

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

Liu, Qiang

2013-08-27

59

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

60

Electrokinetically pumped high pressure sprays  

DOEpatents

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

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

2002-01-01

61

High-Pressure Transducer Package  

NASA Technical Reports Server (NTRS)

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

Wamstad, D.; Glenn, M.

1987-01-01

62

How Can High Blood Pressure Be Prevented?  

MedlinePLUS

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

63

High blood pressure tests (image)  

MedlinePLUS

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

64

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

65

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

66

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

67

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

SciTech Connect

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

Not Available

1993-05-01

68

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

69

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 ...

70

46 CFR 167.45-10 - Couplings on fire hose.  

Code of Federal Regulations, 2010 CFR

...Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be provided with suitable...

2010-10-01

71

46 CFR 167.45-10 - Couplings on fire hose.  

Code of Federal Regulations, 2012 CFR

...Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be provided with suitable...

2012-10-01

72

46 CFR 167.45-10 - Couplings on fire hose.  

Code of Federal Regulations, 2013 CFR

...Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be provided with suitable...

2013-10-01

73

46 CFR 167.45-10 - Couplings on fire hose.  

Code of Federal Regulations, 2011 CFR

...Firefighting and Fire Prevention Requirements § 167.45-10 Couplings on fire hose. The couplings on fire hose shall be of brass, copper, or composition material. All hydrants shall be provided with suitable...

2011-10-01

74

46 CFR 105.35-15 - Fire hose.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose shall be...

2012-10-01

75

46 CFR 105.35-15 - Fire hose.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose shall be...

2010-10-01

76

46 CFR 105.35-15 - Fire hose.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose shall be...

2011-10-01

77

46 CFR 105.35-15 - Fire hose.  

Code of Federal Regulations, 2013 CFR

...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Fire Extinguishing Equipment § 105.35-15 Fire hose. (a) One length of fire hose shall be...

2013-10-01

78

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

79

33 CFR 183.558 - Hoses and connections.  

Code of Federal Regulations, 2010 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...

2010-07-01

80

33 CFR 183.558 - Hoses and connections.  

Code of Federal Regulations, 2011 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...

2011-07-01

81

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

82

46 CFR 154.1155 - Hand hose line: Coverage.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 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...

2010-10-01

83

46 CFR 154.1155 - Hand hose line: Coverage.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 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...

2012-10-01

84

46 CFR 154.1155 - Hand hose line: Coverage.  

...2014-10-01 2014-10-01 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...

2014-10-01

85

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

86

46 CFR 154.1155 - Hand hose line: Coverage.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 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...

2011-10-01

87

30 CFR 18.65 - Flame test of hose.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Flame test of hose. 18.65 Section 18...ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen...wide by thickness of the hose. (b) Flame-test apparatus. The principal...

2013-07-01

88

30 CFR 18.65 - Flame test of hose.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Flame test of hose. 18.65 Section 18...ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen...wide by thickness of the hose. (b) Flame-test apparatus. The principal...

2011-07-01

89

30 CFR 18.65 - Flame test of hose.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Flame test of hose. 18.65 Section 18...ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen...wide by thickness of the hose. (b) Flame-test apparatus. The principal...

2012-07-01

90

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

91

How Is High Blood Pressure Treated?  

MedlinePLUS

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

92

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

93

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

94

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

95

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

96

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

97

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

98

High pressure heterogeneous catalysis in a low pressure UHV environment  

SciTech Connect

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

Ceyer, S.T.

1990-01-01

99

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

100

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

101

Ultra high pressure liquid chromatography  

Microsoft Academic Search

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

Fabrice Gritti; Georges A Guiochon

2008-01-01

102

46 CFR 108.425 - Fire hoses and associated equipment.  

Code of Federal Regulations, 2012 CFR

...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing...hose; or (2) Be a uniform design for each hose diameter throughout the vessel. (c) Each nozzle for a firehose in a fire main...stream and water spray firehose nozzle that is approve under...

2012-10-01

103

46 CFR 108.425 - Fire hoses and associated equipment.  

Code of Federal Regulations, 2011 CFR

...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing...hose; or (2) Be a uniform design for each hose diameter throughout the vessel. (c) Each nozzle for a firehose in a fire main...stream and water spray firehose nozzle that is approve under...

2011-10-01

104

46 CFR 108.425 - Fire hoses and associated equipment.  

Code of Federal Regulations, 2013 CFR

...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing...hose; or (2) Be a uniform design for each hose diameter throughout the vessel. (c) Each nozzle for a firehose in a fire main...stream and water spray firehose nozzle that is approve under...

2013-10-01

105

46 CFR 108.425 - Fire hoses and associated equipment.  

Code of Federal Regulations, 2010 CFR

...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing...hose; or (2) Be a uniform design for each hose diameter throughout the vessel. (c) Each nozzle for a firehose in a fire main...stream and water spray firehose nozzle that is approve under...

2010-10-01

106

33 CFR 183.540 - Hoses: Standards and markings.  

...J1527DEC85, Class 2. Note: SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square...

2014-07-01

107

33 CFR 183.540 - Hoses: Standards and markings.  

Code of Federal Regulations, 2012 CFR

...J1527DEC85, Class 2. Note: SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square...

2012-07-01

108

33 CFR 183.540 - Hoses: Standards and markings.  

Code of Federal Regulations, 2010 CFR

...J1527DEC85, Class 2. Note: SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square...

2010-07-01

109

33 CFR 183.540 - Hoses: Standards and markings.  

Code of Federal Regulations, 2011 CFR

...J1527DEC85, Class 2. Note: SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square...

2011-07-01

110

33 CFR 183.540 - Hoses: Standards and markings.  

Code of Federal Regulations, 2013 CFR

...J1527DEC85, Class 2. Note: SAE Class 1 hose has a permeation rating of 100 grams or less fuel loss per square meter of interior surface in 24 hours. SAE Class 2 hose has a permeation rating of 300 grams or less fuel loss per square...

2013-07-01

111

33 CFR 183.560 - Hose clamps: Installation.  

Code of Federal Regulations, 2010 CFR

...used with hose designed for clamps; (b) [Reserved] (c) Be beyond the bead, flare, or over the serrations of the mating spud, pipe, or hose fitting; and (d) Not depend solely on the spring tension of the clamp for compressive force....

2010-07-01

112

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

113

Electron-hose instability in an annular plasma sheath  

E-print Network

such as ion-hose5 and resistive hose.6 Until recently less attention has been given to the transverse two-stream Center Stanford University, Stanford CA 94309 (Received ) A relativistic electron beam propagating electron beams through plasma. Stability against transverse beam break-up1 is critical in such applications

114

30 CFR 18.65 - Flame test of hose.  

... 2014-07-01 2014-07-01 false Flame test of hose. 18.65 Section 18.65 Mineral Resources...MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Inspections and Tests § 18.65 Flame test of hose. (a) Size of test specimen....

2014-07-01

115

High pressure synthesis gas conversion. Final report  

SciTech Connect

The purpose of this research project is to build and test a high pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system were procured or fabricated and assembled in our laboratory. This system was then used to determine the effects of high pressure on growth and ethanol production by Clostridium ljungdahlii. The limits of cell concentration and mass transport relationships were found in CSTR and immobilized cell reactors (ICR). The minimum retention times and reactor volumes were found for ethanol production in these reactors. A maximum operating pressure of 150 psig has been shown to be possible for C. ljungdahlli with the medium of Phillips et al. This medium was developed for atmospheric pressure operation in the CSTR to yield maximum ethanol concentrations and thus is not best for operation at elevated pressures. It is recommended that a medium development study be performed for C. ljungdahlii at increased pressure. Cell concentration, gas conversion and product concentration profiles were presented for C. ljungdahlii as a function of gas flow rate, the variable which affects bacterium performance the most. This pressure was chosen as a representative pressure over the 0--150 psig operating pressure range for the bacterium. Increased pressure negatively affected ethanol productivity probably due to the fact that medium composition was designed for atmospheric pressure operation. Medium development at increased pressure is necessary for high pressure development of the system.

Not Available

1993-05-01

116

High Pressure-Temperature Studies of Vanadium  

NASA Astrophysics Data System (ADS)

Vanadium, a seemingly simple metal, has captured the interest of high-pressure scientists following the discovery (Ding et al. PRL 2007) of a subtle pressure-induced phase transition from bcc to a rhombohedral phase. Recent first-principles electronic-structure studies (Lee et al. PRB 2007) are consistent with these experiments and extend beyond the range of the measurements, predicting a reentrant phase transition back to bcc at high pressure. Further experiments in the regime of these predictions can validate and advance the understanding of simple metals at high-pressures. We have made x-ray diffraction measurements of the crystal structure and lattice parameters of vanadium at high-pressure and temperature. Detailed comparisons will challenge/validate models and guide development of predictive codes. We will discuss our measurements including high temperature behavior, the EOS, and transitions of vanadium at high pressure.

Jenei, Z.; Baer, B. J.; Cynn, H.; Klepeis, J.-H.; Lipp, M. J.; Evans, W. J.; Liermann, H.-P.; Meng, Y.; Sinogeikin, S. V.; Yang, W.

2009-03-01

117

High-speed fiber grating pressure sensors  

NASA Astrophysics Data System (ADS)

Fiber grating pressure sensors have been used to support pressure measurements associated with burn, deflagration and detonation of energetic materials. This paper provides an overview of this technology and serves as a companion paper to the application of this technology to measuring pressure during high speed impacts.

Udd, Eric; Rodriguez, George; Sandberg, Richard L.

2014-06-01

118

High-pressure high-temperature transducer  

NASA Technical Reports Server (NTRS)

Compact instrument has active and reference sides consisting of tubes that elongate in response to increasing interior pressures. Relative displacement of tubes is measured by linear variable differential transformer to determine pressure on active side. Device needs no internal cooling, thus eliminating condensation problem with gases containing saturated steam.

Vrolyk, J. J.

1977-01-01

119

High-pressure fiber optic acoustic sensor  

Microsoft Academic Search

This paper describes a diaphragm-based external Fabry-Perot interferometric (EFPI) fiber acoustic sensor with pressure-isolation structure. The structure minimizes the crosstalk generated by environmental pressure while enables considerable amount of acoustic signal power being delivered to the sensor, which allows the sensor to work in high-pressure environment. The detailed analysis on sensor design, pressure isolation and sensor fabrication as well as

Zhengyu Huang; Jiangdong Deng; Wei Peng; Gary R. Pickrell; Anbo Wang

2004-01-01

120

High-gain high-pressure highly efficient COIL  

Microsoft Academic Search

The activity of development a COIL with high potential recovered pressure, high gain and efficiency is described. Two nozzle banks with conical supersonic nozzles for the driver nitrogen but with different nozzle arrangements have been developed for generation of the gain flow of chemical oxygen-iodine laser. The nozzle banks were supplied by oxygen flow from the cross-flow singlet oxygen generator

Marsel V. Zagidullin; Valery D. Nikolaev; Michael I. Svistun; Nikolai A. Khvatov; Gordon D. Hager

2004-01-01

121

Thermal Expansion at High Pressures  

Microsoft Academic Search

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

Francis Birch

1968-01-01

122

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

123

Multicomponent fuel vaporization at high pressures.  

SciTech Connect

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

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

2002-01-01

124

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

125

More Americans Controlling Their High Blood Pressure  

MedlinePLUS

... page, please enable JavaScript. More Americans Controlling Their High Blood Pressure Government researchers report the numbers are looking better, ... November 16, 2014 Related MedlinePlus Pages Health Statistics High Blood Pressure SUNDAY, Nov. 16, 2014 (HealthDay News) -- A growing ...

126

Structural behaviour of YGa under high pressure  

NASA Astrophysics Data System (ADS)

High pressure X-ray diffraction studies on rare-earth gallide YGa was carried up to a pressure of ˜ 33 GPa using rotating anode x-ray source in an angle dispersive mode. YGa exhibits CrB (B33) type orthorhombic structure (space group Cmcm) at ambient pressure. It undergoes a reversible structural phase transition from orthorhombic to tetragonal structure at ˜ 8.8 GPa. Both the phases coexist up to the highest pressure studied. The zero pressure bulk modulus and its derivative for parent phase have been estimated to be Bo = 60 ± 3 GPa, Bo' = 4.6 ± 1.5.

Sekar, M.; Shekar, N. V. Chandra; Sahu, P. Ch.; Babu, R.

2014-04-01

127

High frequency dynamic pressure calibration technique  

NASA Technical Reports Server (NTRS)

A high frequency dynamic calibration technique for pressure transducers has been developed using a siren pressure generator (SPG). The SPG is an inlet-area-modulated device generating oscillating waveforms with dynamic pressure amplitudes up to 58.6 kPa (8.5 psi) in a frequency range of 1 to 10 kHz. A description of the generator, its operating characteristics and instrumentation used for pressure amplitude and frequency measurements is given. Waveform oscillographs and spectral analysis of the pressure transducers' output signals are presented.

Davis, P. A.; Zasimowich, R. F.

1985-01-01

128

Laser techniques in high-pressure geophysics  

NASA Technical Reports Server (NTRS)

Laser techniques in conjunction with the diamond-anvil cell can be used to study high-pressure properties of materials important to a wide range of problems in earth and planetary science. Spontaneous Raman scattering of crystalline and amorphous solids at high pressure demonstrates that dramatic changes in structure and bonding occur on compression. High-pressure Brillouin scattering is sensitive to the pressure variations of single-crystal elastic moduli and acoustic velocities. Laser heating techniques with the diamond-anvil cell can be used to study phase transitions, including melting, under deep-earth conditions. Finally, laser-induced ruby fluorescence has been essential for the development of techniques for generating the maximum pressures now possible with the diamond-anvil cell, and currently provides a calibrated in situ measure of pressure well above 100 gigapascals.

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

1987-01-01

129

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 has no ... your risk for related health problems. Complications of High Blood Pressure When blood pressure stays high over time, it ...

130

High Pressure-Temperature Studies of Vanadium  

NASA Astrophysics Data System (ADS)

Vanadium, a seemingly simple metal, has captured the interest of high-pressure scientists following the discovery (Ding et al. PRL 2007) of a subtle pressure-induced phase transition from bcc to a rhombohedral phase. Recent first-principles electronic-structure studies (Lee et al. PRB 2008) are consistent with these experiments and extend beyond the range of the measurements, predicting a reentrant phase transition back to bcc at high pressure. We have made x-ray diffraction measurements of the crystal structure and lattice parameters of vanadium at high-pressure and temperature. Detailed comparisons will challenge/validate models and guide development of predictive codes. We will discuss our measurements including high temperature behavior, the EOS, and dependence of the transition pressure on the hydrostatic conditions of the compression/decompression.

Jenei, Zs.; Baer, B. J.; Cynn, H.; Klepeis, J.-H. P.; Lipp, M. J.; Evans, W. J.; Liermann, H.-P.; Sinogeikin, S. V.; Yang, W.

2010-03-01

131

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

132

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

133

Applaying of high pressure to yoghurt preservation.  

PubMed

Effects of the high pressure treatment in the range of 200 - 1000 MPa/15 min., at the room temperature, on survivability of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus was investigated. Sensorial characteristics of yoghurt was conducted by a panel of experts. Influence of yoghurt acidity on the effect of pressurization was also determined. In the experiment, we also attempted to extend shelf-life of yoghurt, subjecting it to the pressure of 550 MPa/15 min. Pressure treated yoghurt was stored for 4-weeks at room and refrigerated temperature; every seven days microbial number, acidity and sensory attributes of the beverage was determined. Addition of fruit jam on the effect of pressurization was also checked. Survivability of microorganisms depends on the value of pressure used in the experiment. The research displayed that yoghurt acidity did not influence the effect of pressurization. During 4-weeks of storage, yoghurt processed at 550 MPa maintained its beneficial characteristics longer compared to the non-pressurized one. Addition of fruit jam beneficially affected consistency of the pressure treated yoghurt. The conducted studies showed that there was possibility of preserving yoghurt by the method of high pressures. Thus, to preserve yoghurt, the complete inactivation of microflora is not necessary. PMID:24757790

Jankowska, A; Reps, A; Proszek, A; Krasowska, M

2003-01-01

134

Yield strength of molybdenum at high pressures  

Microsoft Academic Search

In the diamond anvil cell technology, the pressure gradient approach is one of the three major methods in determining the yield strength for various materials at high pressures. In the present work, by in situ measuring the thickness of the sample foil, we have improved the traditional technique in this method. Based on this modification, the yield strength of molybdenum

Qiumin Jing; Yan Bi; Qiang Wu; Fuqian Jing; Zhigang Wang; Jian Xu; Sheng Jiang

2007-01-01

135

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2011 CFR

...of this chapter. Firehose nozzles previously approved under...firehose having a combination nozzle previously approved under...testing. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2011-10-01

136

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2012 CFR

...of this chapter. Firehose nozzles previously approved under...firehose having a combination nozzle previously approved under...testing. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2012-10-01

137

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2013 CFR

...of this chapter. Firehose nozzles previously approved under...firehose having a combination nozzle previously approved under...testing. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2013-10-01

138

46 CFR 95.10-10 - Fire hydrants and hose.  

Code of Federal Regulations, 2010 CFR

...of this chapter. Firehose nozzles previously approved under...firehose having a combination nozzle previously approved under...testing. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2010-10-01

139

Design of high pressure waterjet nozzles  

NASA Technical Reports Server (NTRS)

The Hydroblast Research Cell at Marshall Space Flight Center is used to investigate the use of high pressure waterjets to strip paint, grease, adhesive and thermal spray coatings from various substrates. Current methods of cleaning often use ozone depleting chemicals (ODC) such as chlorinated solvents. High pressure waterjet cleaning has proven to be a viable alternative to the use of solvents. A popular method of waterjet cleaning involves the use of a rotating, multijet, high pressure water nozzle which is robotically controlled. This method enables rapid cleaning of a large area, but problems such as incomplete coverage and damage to the substrate from the waterjet have been observed. This report summarizes research consisting of identifying and investigating the basic properties of rotating, multijet, high pressure water nozzles, and how particular designs and modes of operation affect such things as stripping rate, standoff distance and completeness of coverage. The study involved computer simulations, an extensive literature review, and experimental studies of different nozzle designs.

Mazzoleni, Andre P.

1994-01-01

140

High Blood Pressure: The Science Inside  

NSDL National Science Digital Library

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

Healthy People Library Project;

2004-01-01

141

Binge Drinking and High Blood Pressure  

MedlinePLUS Videos and Cool Tools

... October 22, 2014 Related MedlinePlus Pages Alcoholism and Alcohol Abuse High Blood Pressure Underage Drinking Transcript New ... the study.The team looked at patterns of alcohol use, the amount of alcohol consumed, the age ...

142

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

143

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

144

Demixing of binary systems at high pressures  

NASA Astrophysics Data System (ADS)

Recently we have developed a diamond-anvil system for the investigation of phase equilibria in gaseous mixtures up to 100 kbar. The phase behaviour of binary systems at high pressures will be discussed and some experimental results will be presented for the systems neon-xenon and helium-hydrogen. It turns out that the three phase line and the critical line diverge for the system He?H 2 even at a pressure of 60 kbar, so that fluid-fluid equilibrium will persist up to very high pressures.

Schouten, J. A.; van den Bergh, L. C.

1986-05-01

145

High temperature, high pressure water level sensor  

SciTech Connect

A sensor was developed to measure water level over a range of 750 mm with an uncertainty of +- 20 mm at a temperature from 20 to 250/sup 0/C and pressure up to 15.2 MPa. The sensor is type 304, flattened stainless steel rod. Its cross section is 1.6 x 3.2 mm, and its measured torsional transit time is a function of water density rho, level L, and temperature T. To minimize the influence of T, the extensional transit time is also measured in the same sensor. To interrogate the sensor with both modes, Joule and Wiedemann transducers are multiplexed in an alternating sequence. Experimental results, problems, and remedies are discussed.

Miller, G.N.; Anderson, R.L.; Lynnworth, L.C.

1980-01-01

146

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

147

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

148

High Pressure Discharge Negative Ion Source  

NASA Astrophysics Data System (ADS)

A high pressure discharge negative ion source has been developed with the goals of high duty cycle, high current, and good reliability, with the ultimate aim of providing a source for a facility such as the Spallation Neutron Source. The discharge itself has been characterized running on hydrogen and helium over pressure ranges of 10s to 100s of torr, with the pressure varied both by changing the flow rate and exit orifice diameter. A key part of the characterization was the power required for the E-H transition as a function of the pressure and gas flow. Running on hydrogen, a biased grid set has been used to extract negative current from a negative ion production region downstream from the discharge exit orifice and an electromagnet has been used to separate electrons from the negative ions. Initial measured efficiency for negative ion current has been in the range of 1-2 mA/kW.

Olson, Lynn; Blandino, John; Gatsonis, Nikolaos

2012-10-01

149

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

150

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. PMID:14507734

Müller, Joachim D.; Gratton, Enrico

2003-01-01

151

Sample injector for high pressure liquid chromatography  

DOEpatents

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

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

2001-01-01

152

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

DOEpatents

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

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

2010-03-23

153

ALTERNATIVES FOR HIGH-TEMPERATURE/HIGH-PRESSURE PARTICULATE CONTROL  

EPA Science Inventory

The report gives the status of the most promising high-temperature/high-pressure (HTP) particulate control devices being developed. Data are presented and anticipated performance and development problems are discussed. HTP particulate control offers efficiency and potential econo...

154

High-temperature high-pressure magnetic pickup  

NASA Technical Reports Server (NTRS)

Magnetic-pickup transducers operate at temperature as high as 1,100 C and pressures in excess of 2.5 kilobars. Transducers obtain simulated seismic data in laboratory experiments at high temperatures and pressure. They also have potential applications in industrial instrumentation for measurements under similarly difficult conditions. Transducers use high-temperature cement to bond parts together and high-temperature-insulated copper or aluminum wire for windings.

Ahlberg, L. A.; Tittmann, B. R.

1980-01-01

155

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

156

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

157

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

158

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

159

Amorphization of Serpentine at High Pressure and High Temperature  

PubMed

Pressure-induced amorphization of serpentine was observed at temperatures of 200° to 300°C and pressures of 14 to 27 gigapascals with a combination of a multianvil apparatus and synchrotron radiation. High-pressure phases then crystallized rapidly when the temperature was increased to 400°C. These results suggest that amorphization of serpentine is an unlikely mechanism for generating deep-focus earthquakes, as the temperatures of subducting slabs are significantly higher than those of the rapid crystallization regime. PMID:8662470

Irifune; Kuroda; Funamori; Uchida; Yagi; Inoue; Miyajima

1996-06-01

160

Over-the-Counter Medications and High Blood Pressure  

MedlinePLUS

... along with all of our regular issues. Interactive High Blood Pressure Guide Find videos, quizzes, trackers and more with ... Get started ! Also available as a downloadable PDF . High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

161

76 FR 38697 - High Pressure Steel Cylinders From China  

Federal Register 2010, 2011, 2012, 2013

...731-TA-1188; Preliminary] High Pressure Steel Cylinders From China Determinations...reason of imports from China of high pressure steel cylinders, provided for in subheading...of LTFV and subsidized imports of high pressure steel cylinders from China....

2011-07-01

162

77 FR 37712 - High Pressure Steel Cylinders From China  

Federal Register 2010, 2011, 2012, 2013

...and 731-TA-1188 (Final)] High Pressure Steel Cylinders From China Determinations...injured by reason of imports of high pressure steel cylinders from China, provided...determinations by Commerce that imports of high pressure steel cylinders from China were...

2012-06-22

163

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

164

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

165

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

166

Superconducting high-pressure phases of disilane  

PubMed Central

High-pressure structures of disilane (Si2H6) are investigated extensively by means of first-principles density functional theory and a random structure-searching method. Three metallic structures with P-1, Pm-3m, and C2/c symmetries are found, which are more stable than those of XY3-type candidates under high pressure. Enthalpy calculations suggest a remarkably wide decomposition (Si and H2) pressure range below 135 GPa, above which three metallic structures are stable. Perturbative linear-response calculations for Pm-3m disilane at 275 GPa show a large electron-phonon coupling parameter ? of 1.397 and the resulting superconducting critical temperature beyond the order of 102 K. PMID:20479272

Jin, Xilian; Meng, Xing; He, Zhi; Ma, Yanming; Liu, Bingbing; Cui, Tian; Zou, Guangtian; Mao, Ho-kwang

2010-01-01

167

High Pressure High Temperature Study of B+Sb Mixture  

NASA Astrophysics Data System (ADS)

High pressure synthesis of BSb has been attempted using Laser Heated Diamond Anvil Cell facility with a CO2 laser. B:Sb in 3:1 atom ratio was laser heated at ˜7 GPa , 10 GPa and 30 GPa. In-situ characterization of the pressurized sample was done by micro-Raman technique. The micro-Raman results before and after laser heating at different pressures did not indicate compound formation. Also, Sb, which shows a series of structural transitions under pressure up to 30 GPa did not show any metastable phase in the P and T regime studied.

Kumar, N. R. Sanjay; Shekar, N. V. Chandra; Ravindran, T. R.; Sahu, P. Ch.

2011-07-01

168

High-pressure treatment of polytene chromosomes  

E-print Network

High-pressure treatment of polytene chromosomes improves structural resolution Dmitri V Novikov1, Igor Kireev1,2 & Andrew S Belmont1 The exceptional cytology provided by polytene chromosomes has made Drosophila melanogaster a premier model for chromosome studies, but full exploitation of polytene cytology

Cai, Long

169

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

170

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

E-print Network

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

Rodríguez, Fernando

171

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

Code of Federal Regulations, 2013 CFR

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

2013-10-01

172

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

173

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

174

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

175

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

Code of Federal Regulations, 2013 CFR

...stream and water spray firehose nozzle that meets the requirements...of this chapter. Firehose nozzles previously approved under...Each combination firehose nozzle previously approved under...hose; or (2) Be a uniform design for each hose diameter...

2013-10-01

176

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

Code of Federal Regulations, 2012 CFR

...stream and water spray firehose nozzle that meets the requirements...of this chapter. Firehose nozzles previously approved under...Each combination firehose nozzle previously approved under...hose; or (2) Be a uniform design for each hose diameter...

2012-10-01

177

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

Code of Federal Regulations, 2010 CFR

...stream and water spray firehose nozzle that meets the requirements...of this chapter. Firehose nozzles previously approved under...Each combination firehose nozzle previously approved under...hose; or (2) Be a uniform design for each hose diameter...

2010-10-01

178

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

Code of Federal Regulations, 2011 CFR

...stream and water spray firehose nozzle that meets the requirements...of this chapter. Firehose nozzles previously approved under...Each combination firehose nozzle previously approved under...hose; or (2) Be a uniform design for each hose diameter...

2011-10-01

179

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

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Fluid power hose and fittings. 58.30-20 ...AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-20 Fluid power hose and fittings. (a) The...

2010-10-01

180

Photographic analysis of high pressure fluidization phenomena  

SciTech Connect

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

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

1983-01-01

181

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

182

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

183

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

184

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

185

Small, high-pressure liquid oxygen turbopump  

NASA Technical Reports Server (NTRS)

A small, high-pressure, liquid oxygen turbopump was designed, fabricated, and tested. The pump was of a single-stage, centrifugal type; power to the pump was supplied by a single-stage, partial emission, axial-impulse turbine. Design conditions included an operating speed of 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 LO2/LH2 combustion products at 1041 K (1874 R) inlet temperature, and at a design pressure ratio of 1.424. The approaches used in the detail analysis and design of the turbopump are described, and fabrication methods are discussed. Data obtained from gas generator tests, turbine performance calibration, and turbopump testing are presented.

Csomor, A.; Sutton, R.

1977-01-01

186

High Pressure Behavior of FeOOH  

NASA Astrophysics Data System (ADS)

Understanding the stability and properties of simple hydroxides at high pressures and temperatures offers an important first step toward quantifying more complex hydrogen-bearing compounds relevant to the Earth's interior. We focus on iron-oxy-hydroxides because they may be an important Fe and water bearing component in the deep Earth. Goethite (?-FeOOH) transforms to a high-pressure phase, ?-FeOOH, which is isostructural with ?-AlOOH, a material which may transport hydrogen to the core-mantle boundary. Here we present XES spectroscopy data of powder samples of synthesized alpha-FeOOH, beta-FeOOH and gamma-FeOOH monitoring their electronic spin transition. The samples was loaded into a Beryllium gasket, where a 50 micron hole served as the sample chamber with 300 micron culet diamond paired with a beveled 150 micron diamond in a diamond-anvil cell (DAC) without a pressure transmitting medium. Pressure was determined using ruby fluorescence (Mao et al. 1978). Using the incident X-ray energy centered at 11.3 KeV from the Advanced Photon Source, beam line HPCAT 16-ID-D, we measured Fe K-? 13 emission to pressures greater than 73 GPa. For alpha-FeOOH, we saw a clear shift in the main peak to lower energy, and an increasingly diminishing K beta prime peak intensity, indicating the sample was undergoing an electronic spin transition. The K beta prime peak completely disappeared at a pressure greater than 73 GPa. Beta-FeOOH showed no evidence of the beginnings of a spin transition, while gamma- FeOOH underwent an incomplete transition.

Reagan, M. M.; Gleason, A. E.; Mao, W. L.

2013-12-01

187

Advances in high chamber pressure propulsion  

NASA Technical Reports Server (NTRS)

NASA has been involved in the development of improved high thrust booster rocket engines to meet the propulsion requirements of launch vehicles such as the Space Shuttle. Solutions that NASA/Marshall Space Flight Center pursued to accomplish the high performance, long life goals set for SSME are discussed. In addition, currently projected requirements for liquid rocket engines have identified liquid oxygen/hydrocarbon-fueled engines for booster application in the near future. These advanced hydrocarbon-fueled engines will require improvements in performance and life to be suitable for their projected missions. Raising chamber pressure to increase performance and reduce engine envelope are the key objectives in hydrocarbon-fueled engine technology. This paper traces the history of advances in high pressure rocket engine systems and the challenges it presents.

Mccool, A. A.; Richmond, R. J.

1986-01-01

188

Metallic and superconducting gallane under high pressure  

NASA Astrophysics Data System (ADS)

Using our newly developed particle swarm optimization algorithm on crystal structural prediction, we characterized the pressure-induced structural transition sequence of gallane (GaH3). As has been observed in alane (AlH3), enthalpy calculations reveal that the Pm3¯n structure of GaH3 becomes stable above 160 GPa, below which it is unstable with respect to elemental decomposition. Interestingly, the Pm3¯n structure is metallic, and the application of the Allen-Dynes modified McMillan equation reveals a high superconducting transition temperature (Tc), which reaches 86 K at 160 GPa and increases with decreasing pressure (Tc = 102 K at 120 GPa). Our band structure calculations demonstrate that GaH3 within the Pm3¯n structure is a highly ionic solid, where the ionicity of H atoms plays an important role in the predicted high temperature superconductivity.

Gao, Guoying; Wang, Hui; Bergara, Aitor; Li, Yinwei; Liu, Guangtao; Ma, Yanming

2011-08-01

189

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

2014-07-01

190

Performance of small high pressure cryogenic pumps  

NASA Astrophysics Data System (ADS)

Two small cryogenic pumps have been made and tested for use in LO2/LH2 rocket-engine turbopumps. Both the pumps have a small impeller and are characterized by high speed and high delivery pressure. The main design characteristics of the pumps are as follows: rotational speeds 45,000 and 80,000 rpm, delivery pressures 24.6 and 26.0 MPa, and flow rates 0.016 and 0.0439 cu m/s, for LO2 and LH2 pumps, respectively. The efficiencies of the test pumps were compared with previously reported results, and the adiabatic efficiency (usually used for compressors or gas turbines) was investigated in more detail to demonstrate its applicability to cryogenic pumps.

Kamijo, K.; Watanabe, M.; Hasegawa, S.

191

High-pressure investigations of Earth's interior  

NASA Astrophysics Data System (ADS)

In the first half of the talk, the electronic structure of iron in ferromagnesium silicate perovskite will be discussed. Knowledge of iron valences and spin states in silicate perovskite is relevant to our understanding of the physical and chemical properties of Earth's lower mantle such as transport properties, mechanical behavior, and element partitioning. In this study, we have measured the electronic structure of the iron component of an aluminous Fe-bearing silicate perovskite sample, (Mg0.88Fe0.09)(Si0.94Al0.10)O3, close to a pyrolite composition, using synchrotron M"ossbauer spectroscopy (SMS) and laser heated diamond anvil cells at high-pressure and temperatures at beamline 3-ID of the Advanced Photon Source. Evaluation of the spectra provided the isomer shift and the quadrupole splitting of the iron component in silicate perovskite, which gives information on valence and spin states under lower mantle conditions. In the second half of the talk, experiments on the melting curve of iron at high-pressures will be presented. Seismological observations indicate that Earth's iron-dominated core consists of a solid inner region surrounded by a liquid outer core. Previously, melting studies of iron metal at high-pressures and temperatures were performed by shock-compression, resistive- and laser-heating in diamond anvil cells using visual observations or synchrotron x-ray diffraction and theoretical methods. However, the melting curve of iron is still controversial. Here, we will present a new method of detecting the solid-liquid phase boundary of iron at high-pressure using ^57Fe SMS. The characteristic SMS time signature is observed by fast detectors and vanishes suddenly when melting occurs. This process is described by the Lamb-M"ossbauer factor f = exp(-k^2), where k is the wave number of the resonant x-rays and is the mean-square displacement of the iron atoms.

Jackson, Jennifer

2007-03-01

192

Small, high pressure liquid hydrogen turbopump  

NASA Technical Reports Server (NTRS)

A high pressure, low capacity, liquid hydrogen turbopump was designed, fabricated, and tested. The design configuration of the turbopump is summarized and the results of the analytical and test efforts are presented. Approaches used to pin point the cause of poor suction performance with the original design are described and performance data are included with an axial inlet design which results in excellent suction capability.

Csomor, A.; Warren, D. J.

1980-01-01

193

High pressure applications of ferroelectric polymers  

Microsoft Academic Search

Ferroelectric polymers are the most recent class piezoelectric and pyroelectric materials developed. The most common piezoelectric polymers are PVDF, based on the monomer CH2-CF2 and copolymers PVDF with C2F3H. Under high hydrostatic pressure, piezoelectric polymers exhibit well defined piezoelectric response. Piezoelectric response of shock compressed PVDF film prepared with attention to mechanical and electrical processing exhibits precise, well defined reproducible

F. Bauer

1994-01-01

194

High pressure resistivity of UPd3  

Microsoft Academic Search

Electrical resistivity of UPd3, the only known binary U-based intermetallic with localized 5f states, was studied under high pressures up to 10 GPa, testing a possible incipient delocalization due to the lattice compression. The data obtained revealed no tendency to any delocalization. The shoulder related to crystal-electric field effects between 10 and 15 K remains visible, being only shifted slightly towards higher

Ji?í Prchal; Ladislav Havela; Alexander V. Andreev

2012-01-01

195

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

196

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2013 CFR

...STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Firefighting System: Dry Chemical...a hose cabinet; (c) Be non-kinkable; (d) Have a nozzle with a valve to start and stop the flow of chemical;...

2013-10-01

197

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2011 CFR

...STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Firefighting System: Dry Chemical...a hose cabinet; (c) Be non-kinkable; (d) Have a nozzle with a valve to start and stop the flow of chemical;...

2011-10-01

198

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2010 CFR

...STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Firefighting System: Dry Chemical...a hose cabinet; (c) Be non-kinkable; (d) Have a nozzle with a valve to start and stop the flow of chemical;...

2010-10-01

199

46 CFR 154.1170 - Hand hose line: General.  

Code of Federal Regulations, 2012 CFR

...STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Firefighting System: Dry Chemical...a hose cabinet; (c) Be non-kinkable; (d) Have a nozzle with a valve to start and stop the flow of chemical;...

2012-10-01

200

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

201

166. ARAIII Fire hose houses (Probably numbered on site as ...  

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

166. ARA-III Fire hose houses (Probably numbered on site as ARA-624). Aerojet-general 880-area/GCRE-701-S-4. Date: February 1958. Ineel index code no. 063-0624-00-013-102695. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

202

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

E-print Network

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

Peng, Huei

203

Arun field high pressure gas reinjection facilities  

SciTech Connect

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

Giles, A.J.

1984-02-01

204

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

205

High Pressure Microwave Powered UV Light Sources  

NASA Astrophysics Data System (ADS)

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

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

1997-10-01

206

CDC Vital Signs: High Blood Pressure and Cholesterol  

MedlinePLUS

... Vital Signs Share Compartir 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 ...

207

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

208

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...

209

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

210

Treating High Blood Pressure in People with Diabetes  

MedlinePLUS

Treating High Blood Pressure in People with Diabetes American Diabetes Association? ? 1–800–DIABETES (342–2383)? ? www.diabetes.org ©2009 by ... having your blood pressure checked regularly. What is high blood pressure? Blood pressure is the force of blood flow ...

211

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

SciTech Connect

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

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

2009-01-01

212

High pressure applications of ferroelectric polymers  

NASA Astrophysics Data System (ADS)

Ferroelectric polymers are the most recent class piezoelectric and pyroelectric materials developed. The most common piezoelectric polymers are PVDF, based on the monomer CH2-CF2 and copolymers PVDF with C2F3H. Techniques to process PVDF and P(VDF-TrFE) copolymers such that their physical properties exhibit reproducibility approaching that of piezoelectric single crystals are presented. Instrinsic piezoelectric properties of such materials are presented in this paper. Under high hydrostatic pressure, piezoelectric polymers exhibit well defined piezoelectric response. Piezoelectric response of shock compresed PVDF film prepared with attention to mechanical and electrical processing exhibits precise, well defined reproducible behavior to 35 GPa. P(VDF-TrFE) copolymers exhibit unqiue piezoelectric properties over a wide range of temperature depending on the compositions. Under high shock pressure loading, unique piezoelectric response is also observed. In particular, thickness can range from one micron up to more than one mm. Small and large area sensors can be prepared. Charge mode and current mode sensors are presented. These copolymers have the potential for new shock wave sensors with unique characteristics.

Bauer, F.

1994-07-01

213

High pressure-resistant nonincendive emulsion explosive  

DOEpatents

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

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

1994-01-01

214

High pressure phases of alkali ternary borohydrides  

NASA Astrophysics Data System (ADS)

Insitu synchrotron x-ray diffraction experiments were carried out on MBH4 (M = K and Rb) borohydrides at high pressures up to 26 GPa using diamond anvil cells. KBH4 undergoes a structural transition at 4 GPa to a tetragonal phase from cubic and then to an orthorhombic phase around 7 GPa which are very similar to NaBH4 investigated earlier [1]. However, RbBH4 shows, a direct transition from the ambient cubic to an orthorhombic phase at 2.9 GPa, followed by a monoclinic phase at 8 GPa. Complementary high pressure Raman experiments, support the transitions observed in the diffraction experiments. The results will be presented in detail. [1]. Ravhi S. Kumar and Andrew L. Cornelius, Appl.Phys.Lett., 87,261916 (2005) This work is supported in part by the U.S. Department of Energy (DOE) under Award Number DE-FG36 05GO85028. HPCAT is supported by DOE-BES, DOE-NNSA,NSF, and the W.M. Keck Foundation.

Kumar, Ravhi; Cornelius, Andrew

2007-03-01

215

Dynamical stability of Mo under high pressure and high temperature  

NASA Astrophysics Data System (ADS)

Considering the phonon-phonon interactions, we obtain the high temperature phonons of Mo under high pressure. The dynamically stable regions of bcc and fcc Mo in the phase diagram are predicted. By comparing the anharmonic free energy, we determine the bcc-fcc boundary. The bcc Mo is the stable phase up to 700 GPa. Around 210 GPa, there is no bcc-fcc phase transition, which is different with the results from quasiharmonic approximation.

Zeng, Zhao-Yi; Hu, Cui-E.; Zhang, Wei; Niu, Zhen-Wei; Cai, Ling-Cang

2014-10-01

216

Model of current enhancement at high pressure  

SciTech Connect

A model is proposed to account for the phenomenon of net current enhancement at high pressures recently observed on the Experimental Test Accelerator. The proposed mechanism involves energetic secondary electrons (delta rays) which are pushed forward by the self-magnetic field of the electron beam. For high current beams, the forward delta ray current can build up to a significant fraction of the beam current. Analytic calculations of the steady-state solution as well as the rate of buildup of the delta ray current are presented in this paper. In addition, numerical results from a nonlocal Boltzmann code, NUTS, are presented. The analytic and numerical results have many features which are in qualitative agreement with the experiments, but quantitative discrepancies still exist.

Yu, S.S.; Melendez, R.E.

1983-04-05

217

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

PubMed

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

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

2010-03-23

218

varicose veins smoking obesity swine flu high blood pressure  

E-print Network

varicose veins smoking obesity swine flu high blood pressure parkinson's stress depression muscle smoking obesity swine flu high blood pressure parkinson's stress depression muscle stiffness heart attack arthritis prostate disease bladder infection incontinence cancer varicose veins smoking obesity swine flu

Diggle, Peter J.

219

High Blood Pressure and Children: What Parents Need to Know  

MedlinePLUS

... Parents Need to Know High Blood Pressure and Children: What Parents Need to Know Children can have high blood pressure. Did you know ... children, the sooner it can be treated. All children 3 years of age and older should have ...

220

7 CFR 58.219 - High pressure pumps and lines.  

...construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The high pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger...

2014-01-01

221

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2012 CFR

...construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The high pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger...

2012-01-01

222

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2011 CFR

...construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The high pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger...

2011-01-01

223

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2013 CFR

...construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The high pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger...

2013-01-01

224

7 CFR 58.219 - High pressure pumps and lines.  

Code of Federal Regulations, 2010 CFR

...construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The high pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger...

2010-01-01

225

High Blood Pressure, Afib and Your Risk of Stroke  

MedlinePLUS

... have a stroke for the first time have high blood pressure . And an irregular atrial heart rhythm — a condition ... 800,000 Americans suffer a stroke each year. High blood pressure is the chief culprit, and atrial fibrillation isn’ ...

226

Talk with Your Health Care Provider about High Blood Pressure  

MedlinePLUS

... nurse. Talk With Your Health Care Provider About High Blood Pressure Partnership for HEALTH Here are some questions to ... What can you do to prevent or control high blood pressure? 1. Quit smoking and/or chewing tobacco. Ask ...

227

A Nutritional Strategy for the Treatment of High Blood Pressure.  

ERIC Educational Resources Information Center

Some physicians wonder if high blood pressure can be controlled without the use of drugs and their potential side effects. Current findings concerning nutrition and high blood pressure are presented. (RM)

Podell, Richard N.

1984-01-01

228

High blood pressure - what to ask your doctor  

MedlinePLUS

What to ask your doctor about high blood pressure; Hypertension - what to ask your doctor ... problems? What medicines am I taking to treat high blood pressure? Do they have any side effects? What should ...

229

Barbershops Join Fight Against High Blood Pressure in Black Men  

MedlinePLUS

... Join Fight Against High Blood Pressure in Black Men Novel partnership detects "silent killer" in more than ... overlooked health concern: high blood pressure among black men. In a novel partnership, the U.S. Centers for ...

230

High pressure Hugoniot measurements using converging shocks  

NASA Astrophysics Data System (ADS)

Plate impact experiments are a powerful tool in equation of state development, but are inherently limited by the range of impact velocities accessible to the facility. In an effort to dramatically increase the range of pressures which can be studied with available impact velocities, a new experimental technique is examined. The target plate is replaced by a composite assembly consisting of two concentric cylinders. The target is designed such that the initial shock velocity in a well-characterized outer cylinder is higher than in the inner cylinder material of interest. Conically converging shocks will be generated at the interface due to the impedance mismatch between the two materials and axisymmetric geometry. Upon convergence, an irregular reflection occurs and the conical analog of a Mach reflection develops. This Mach reflection grows until it reaches a steady state, at which point the high pressure state in the Mach disk can be measured using velocity interferometry and impedance matching techniques. The technique is demonstrated by studying the shock response of copper. A strong confinement setup utilizes a low impedance 6061-T6 aluminum outer cylinder and the weak confinement case features a higher impedance molybdenum outer cylinder. The experimental results for copper are in good agreement with a simple analytical model, numerical simulations, and data in the literature. The possibility of utilizing full field measurements to make multiple Hugoniot measurements is also examined.

Brown, J. L.; Ravichandran, G.; Reinhart, W. D.; Trott, W. M.

2011-05-01

231

[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

232

Diffuse plasma effects on the ion-hose instability  

NASA Astrophysics Data System (ADS)

The transverse stability of a relativistic electron beam focused by an ion channel in the presence of a diffuse background plasma is investigated. The linear behavior of the ion-hose and electron two-stream instabilities is treated analytically using a spread-mass model for the beam and ion channel and a cold-fluid model for the plasma. The electron two-stream instability is found to be quite weak. As the plasma neutralization radius approaches the beam radius, the ion-hose growth rate is reduced up to 50 percent before the model's assumptions break down. Particle-in-cell simulations confirm the linear analytic theory and show that the electron two-stream instability can saturate nonlinearly with little beam emittance growth.

Welch, Dale R.; Hughes, Thomas P.

1993-02-01

233

High pressure fiber optic connector plug  

NASA Astrophysics Data System (ADS)

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

Morency, Roger L.; Holmberg, Gerald E.

1991-11-01

234

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

235

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

236

High-pressure melting curve of hydrogen  

Microsoft Academic Search

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

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

2008-01-01

237

High pressure hugoniot measurements using mach waves  

NASA Astrophysics Data System (ADS)

Traditionally, most dynamic shock compression experiments are conducted using a plane one-dimensional wave of uniaxial strain. In this case, the evaluation of the equation of state is simplified due to the geometry, but the amplitude of the induced shock wave is limited by the magnitude of the input load. In an effort to dramatically increase the range of pressures that can be accessed by traditional loading methods, a composite target assembly is examined. The target consists of two concentric cylinders aligned with the axial direction parallel to the loading. The target is designed such that on initial loading, the outer cylinder will have a higher shock velocity than the inner material of interest. Conically converging shocks will be generated at the interface between the two materials due to the impedance mismatch. Upon convergence, an irregular reflection occurs and the conical analog of a Mach reflection develops. The Mach reflection will grow until it reaches a steady state, at which point the wave configuration becomes self similar. The resulting high pressure Hugoniot state can then be measured using velocity interferometry and impedance matching. The technique is demonstrated using a planar mechanical impact generated by a powder gun to study the shock response of copper. Two systems are examined which utilize either a low impedance (6061-T6 aluminum) or a high impedance (molybdenum) outer cylinder. A multipoint VISAR experiment will be presented to validate the technique, and will be compared to numerical simulations. The feasibility of measuring an entire Hugoniot curve using full field velocity interferometry (ORVIS) will also be discussed.

Brown, Justin; Ravichandran, Guruswami

2012-03-01

238

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

239

Dynamical stability analysis of a hose to the sky  

NASA Astrophysics Data System (ADS)

The Stratospheric Shield was proposed as a geoengineering concept to control the Earth's climate and reverse global warming. This approach seeks to release sulphur dioxide (SO2) aerosols in the stratosphere to decrease the amount of sunlight that reaches the surface of the Earth. It was proposed that this can be done by pumping liquefied SO2 from the ground to the stratosphere in a 30 km long hose supported by aerostats.

Gosselin, Frédérick P.; Païdoussis, Michael P.

2014-01-01

240

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

241

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

242

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

243

High Pressure Studies on Nanocrystalline Graphite to 60 GPa  

Microsoft Academic Search

High pressure studies were performed on a nanocrystalline graphite sample in a diamond anvil cell to pressures of 60 GPa at room temperature. Energy dispersive x-ray diffraction studies were carried out at the X-17C beamline at the National Synchrotron Light Source (NSLS) to monitor the broad diffraction peaks from the nanocrystalline hexagonal phase at high pressures. Mechanical properties of the

Jeremy Patterson; Marc Fries; Nenad Velisavljevic; Yogesh Vohra

2002-01-01

244

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

245

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

246

High Blood Pressure May Protect the Very Old from Dementia  

MedlinePLUS

... Blood Pressure May Protect the Very Old From Dementia But it's too early to recommend any change ... 2014) Monday, July 14, 2014 Related MedlinePlus Pages Dementia High Blood Pressure MONDAY, July 14, 2014 (HealthDay ...

247

9. General view of engine between cylinders with high pressure ...  

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

9. General view of engine between cylinders with high pressure cylinder on left and low pressure cylinder on right. - Carnegie Steel-Ohio Works, Steam Engines, 912 Salt Springs Road, Youngstown, Mahoning County, OH

248

High pressure fiber optic connector plug  

NASA Astrophysics Data System (ADS)

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

Holmberg, Gerald; Morency, Roger

1990-12-01

249

Hydrogen solubility in cristobalite at high pressure.  

PubMed

Powder samples of cristobalite-I are loaded with hydrogen at pressures up to 90 kbar and T = 250 °C and quenched under pressure to the liquid N2 temperature. The quenched samples are examined at ambient pressure by X-ray diffraction, Raman spectroscopy, and thermal desorption analysis. The hydrogen content of the samples is found to increase with pressure and reach a molecular ratio of H2/SiO2 ? 0.10 at P = 90 kbar. At ambient pressure, the samples consist of a mixture of approximately 80% cristobalite-I phase and 20% cristobalite-II-like phase, the crystal lattices of both phases being slightly expanded due to the hydrogen uptake. According to Raman spectroscopy, the hydrogen is dissolved in these phases in the form of H2 molecules. PMID:25322160

Efimchenko, Vadim S; Fedotov, Vladimir K; Kuzovnikov, Mikhail A; Meletov, Konstantin P; Bulychev, Boris M

2014-11-01

250

Selected studies of magnetism at high pressure  

SciTech Connect

Most previous studies of magnetism in various compounds under extreme conditions have been conducted over a wide pressure range at room temperature or over a wide range of cryogenic temperatures at pressures below 20 GPa (200 kbar). We present some of the most recent studies of magnetism over an extended range of temperatures and pressures far beyond 20 GPa, i.e., in regions of pressure-temperature (P-T) where magnetism has been largely unexplored. Recent techniques have permitted investigations of magnetism in selected 3d transition metal compounds in regions of P-T where physical properties may be drastically modified; related effects have often been seen in selected doping studies at ambient pressures.

Hearne, G.R. [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Physics; Pasternak, M.P. [Tel-Aviv Univ. (Israel). School of Physics and Astronomy; Taylor, R.D. [Los Alamos National Lab., NM (United States)

1995-09-01

251

Effect of back pressure on emulsification of lipid nanodispersions in a high-pressure homogenizer.  

PubMed

We examined the effect of 0-20% back pressure, which functions as a resistance to emulsification in a high-pressure homogenizer, on emulsification of lipid nanodispersions (emulsion and liposomes) less than 100 nm in diameter. Back pressure in the range of 0.9-3.8% of the emulsification pressure enhanced the emulsification, and the particle diameter of lipid nanodispersion was the smallest at 2% back pressure. The back pressure effect was independent of the actual pressure, which was regarded as the difference between the emulsification and the back pressures. The mechanism of the back pressure effect was considered to be enhancement of emulsification by suppression of collapse cavitation in the high-pressure emulsification module. This back pressure effect appeared in emulsification of emulsion and liposomes, and was seen predominantly in the early emulsification phase (within 10 passages). The particles of lipid nanodispersions prepared at 2% back pressure with adequate re-circulation achieved physicochemically optimal diameter with a narrow size distribution, and were more stable at 60°C for 7 days than particles prepared with 20% back pressure. Our results indicate that emulsification with a low level of back pressure is effective for production of stable lipid nanodispersions with narrow size distribution. PMID:22108638

Saheki, Akira; Seki, Junzo; Nakanishi, Takeo; Tamai, Ikumi

2012-01-17

252

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

253

Two-Phase Flow and Heat Transfer During Chilldown of a Simulated Flexible Metal Hose Using Liquid Nitrogen  

NASA Astrophysics Data System (ADS)

For many industrial, medical and space technologies, cryogenic fluids play irreplaceable roles. When any cryogenic system is initially started, it must go through a transient chill down period prior to normal operation. Chilldown is the process of introducing the cryogenic liquid into the system, and allowing the system components to cool down to several hundred degrees below the ambient temperature. The chilldown process is an important initial stage before a system begins functioning. The objective of this paper is to investigate the chilldown process associated with a flexible hose that was simulated by a channel with saw-teeth inner wall surface structure in the current study. We have investigated the fundamental physics of the two-phase flow and quenching heat transfer during cryogenic chilldown inside the simulated flexible hose through flow visualization, data measurement and analysis. The flow pattern developed inside the channel was recorded by a high speed camera for flow pattern investigation. The experimental results indicate that the chilldown process that is composed of unsteady vapor-liquid two-phase flow and phase-change heat transfer is modified by the inner wall surface wavy structure. Based on the measurement of the channel wall temperature, the teeth structure and the associated cavities generally reduce the heat transfer efficiency compared to the straight hose. Furthermore, based on the measured data, a complete series of correlations on the heat transfer coefficient for each heat transfer regime was developed and reported.

Hu, Hong; Wijeratne, Thilan K.; Chung, J. N.

2014-03-01

254

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

255

Osmium Metal Studied under High Pressure and Nonhydrostatic Stress  

SciTech Connect

Interest in osmium as an ultra-incompressible material and as an analog for the behavior of iron at high pressure has inspired recent studies of its mechanical properties. We have measured elastic and plastic deformation of Os metal at high pressures using in situ high pressure x-ray diffraction in the radial geometry. We show that Os has the highest yield strength observed for any pure metal, supporting up to 10 GPa at a pressure of 26 GPa. Furthermore, our data indicate changes in the nonhydrostatic apparent c/a ratio and clear lattice preferred orientation effects at pressures above 15 GPa.

Weinberger,M.; Tolbert, S.; Kavner, A.

2008-01-01

256

Could Probiotics Help Tame High Blood Pressure?  

MedlinePLUS

... Pressure? Study suggests effect from helpful microbes in yogurt, supplements, but more research is needed (*this news ... of probiotics, such as those found in certain yogurts or supplements, may help ease the condition. Researchers ...

257

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

258

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

259

DEPARTMENT OF ENGINEERING SCIENCE High Pressure Laminar Burning  

E-print Network

of : Temperature gradient in burned gas Change in gas properties e.g. cp Effects of residuals Normally use 10 zones Baffle Plate Max initial pressure 4 bar Max initial temperature 470 K Max pressure 34 bar Max unburned temperature 725 K High Pressure Laminar Burning Velocity Measurements October 27, 2008 Page 3 #12;System

260

Al Coordination Changes in High-Pressure Aluminosilicate Liquids  

Microsoft Academic Search

Understanding the effect of pressure on aluminosilicate glass and liquid structure is critical to understanding magma flow at depth. Aluminum coordination has been predicted by mineral phase analysis and molecular dynamic calculations to change with increasing pressure. Nuclear magnetic resonance studies of glasses quenched from high pressure provide clear evidence for an increase in the average coordination of Al with

J. L. Yarger; K. H. Smith; R. A. Nieman; J. Diefenbacher; G. H. Wolf; B. T. Poe; P. F. McMillan

1995-01-01

261

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

262

High Pressure Studies on Nanocrystalline Graphite to 60 GPa  

NASA Astrophysics Data System (ADS)

High pressure studies were performed on a nanocrystalline graphite sample in a diamond anvil cell to pressures of 60 GPa at room temperature. Energy dispersive x-ray diffraction studies were carried out at the X-17C beamline at the National Synchrotron Light Source (NSLS) to monitor the broad diffraction peaks from the nanocrystalline hexagonal phase at high pressures. Mechanical properties of the pressure treated samples were also examined to investigate the possible formation of the hard carbon phases due to pressure treatment. Nanoindentation hardness measurements of the pressure treated nanocrystalline graphite reveal hardness values between 0.5 GPa to 1.0 GPa. These hardness values are only slightly higher than the hardness value of 0.14 GPa reported for similar pressure treated crystalline graphite. These hardness values are a lot lower than the 30 GPa hardness value achieved with pressure treated fullerenes. Equation of state data for nanocrystalline graphite will also be reported to 60 GPa.

Patterson, Jeremy; Fries, Marc; Velisavljevic, Nenad; Vohra, Yogesh

2002-03-01

263

Vitrification of emulsified dilute aqueous sucrose solutions at high pressures  

NASA Astrophysics Data System (ADS)

The supercooling and glass-forming behavior of aqueous sucrose solution was investigated using emulsified sucrose solutions at high pressures. It is shown that emulsified aqueous sucrose solution with the sucrose concentration being as low as 1 m (m: molality) is glass-forming at high pressures above 190 MPa. This finding may form the basis of a useful vitrification method for cryo-preservation of living cells and tissues at high pressures.

Kanno, H.; Miyata, K.; Hayakawa, S.; Kajiwara, K.

2008-12-01

264

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

265

High-pressure magic angle spinning nuclear magnetic resonance  

NASA Astrophysics Data System (ADS)

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 situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg 2SiO 4) reacted with supercritical CO 2 and H 2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

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

266

High-pressure melting curve of hydrogen  

NASA Astrophysics Data System (ADS)

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

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

2008-11-01

267

High-pressure melting curve of hydrogen.  

PubMed

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

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

2008-11-21

268

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

269

High Pressure Effects on Thermal Properties of MgO  

Microsoft Academic Search

Using the non-empirical Variational Induced Breathing (VIB) model, the thermal properties of periclase (MgO) under high pressures and temperatures are investigated using molecular dynamics, which includes all anharmonic effects. Equations of state for temperatures up to 3000K and pressures up to 310 GPa were calculated. Bulk modulus, thermal expansivity, Anderson-Gruneisen parameter, thermal pressure, Gruneisen parameter and their pressure and temperature

Iris Inbar; R. E. Cohen

1995-01-01

270

High-pressure melting of molybdenum.  

PubMed

The melting curve of the body-centered cubic (bcc) phase of Mo has been determined for a wide pressure range using both direct ab initio molecular dynamics simulations of melting as well as a phenomenological theory of melting. These two methods show very good agreement. The simulations are based on density functional theory within the generalized gradient approximation. Our calculated equation of state of bcc Mo is in excellent agreement with experimental data. However, our melting curve is substantially higher than the one determined in diamond anvil cell experiments up to a pressure of 100 GPa. An explanation is suggested for this discrepancy. PMID:15169417

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

2004-05-14

271

Mechanisms of endospore inactivation under high pressure.  

PubMed

It is well known that spore germination and inactivation can be achieved within a broad temperature and pressure range. The existing literature, however, reports contradictory results concerning the effectiveness of different pressure-temperature combinations and the underlying inactivation mechanism(s). Much of the published kinetic data are prone to error as a result of unstable process conditions or an incomplete investigation of the entire inactivation pathway. Here, we review this field of research, and also discuss an inactivation mechanism of at least two steps and propose an inactivation model based on current data. Further, spore resistance properties and matrix interactions are linked to spore inactivation effectiveness. PMID:23540831

Reineke, Kai; Mathys, Alexander; Heinz, Volker; Knorr, Dietrich

2013-06-01

272

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

273

Transient High-Pressure Fuel Injection  

NASA Astrophysics Data System (ADS)

Break-up and atomization of liquid fuel jet during transient injection process has a significant effect on the Diesel engine combustion efficiency and pollution. The mechanisms responsible for liquid jet instability and break-up at high pressure, during the transient start-up and steady mass flux periods, has been investigated using Navier-Stokes and level-set computations. Via post-processing, the role of vorticity dynamics is examined and shown to reveal crucial new insights. An unsteady, axisymmetric full-jet case is solved. Then, a less computationally intensive case is studied with a segment of the jet core undergoing temporal instability; agreement with the full-jet calculation is satisfactory justifying the segment analysis for three-dimensional computation. The results for surface-shape development are in agreement with experimental observations and other three-dimensional computations; the initial, axisymmetric waves at the jet surface created by Kelvin-Helmholtz instability distort to cone shapes; next, three-dimensional character develops through an azimuthal instability that leads to the creation of streamwise vorticity, lobe shapes on the cones, and formation of liquid ligaments which extend from lobes on the cones. The cause of this azimuthal instability has been widely described as a Rayleigh-Taylor instability. However, additional and sometimes more important causes are identified here. Counter-rotating, streamwise vortices within and around the ligaments show a relationship in the instability behavior for jets flowing into like-density fluid; thus, density difference cannot explain fully the three-dimensional instability as previously suggested. Furthermore, the formation of ligaments that eventually break into droplets and the formation of streamwise vorticity are caused by the same vortical dynamics. Waviness is identified on the ligaments which should result in droplet formation. The nonlinear development of the shorter azimuthal waves and ligament waves explains the experimental results that droplet sizes are usually smaller than KH wavelengths. The higher the relative velocity and/or the lower the surface tension the shorter are the values of the most unstable wavelengths.

Jarrahbashi, Dorrin

274

Provisioning Virtual Private Networks in the Hose Model with Delay Requirements  

Microsoft Academic Search

Virtual Private Networks (VPN) provide a cost- effective means of meeting the communication needs among several sites. The hose model for VPN configuration alleviates the scalability problem of the pipe model by reserving bandwidth for traffic aggregates instead of between every pair of endpoints. Existing studies on quality of service (QoS) guarantees in the hose model deal only with bandwidth

Lei Zhang; Jogesh K. Muppala; Samuel T. Chanson

2005-01-01

275

49 CFR 178.345-9 - Pumps, piping, hoses and connections.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Pumps, piping, hoses and connections...Transportation § 178.345-9 Pumps, piping, hoses and connections...in the lading retention system. (e) Any heating...that is not as strong and heat resistant as the cargo...of the lading retention system. [Amdt....

2013-10-01

276

49 CFR 178.345-9 - Pumps, piping, hoses and connections.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Pumps, piping, hoses and connections...Transportation § 178.345-9 Pumps, piping, hoses and connections...in the lading retention system. (e) Any heating...that is not as strong and heat resistant as the cargo...of the lading retention system. [Amdt....

2012-10-01

277

49 CFR 178.345-9 - Pumps, piping, hoses and connections.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Pumps, piping, hoses and connections...Transportation § 178.345-9 Pumps, piping, hoses and connections...in the lading retention system. (e) Any heating...that is not as strong and heat resistant as the cargo...of the lading retention system. [Amdt....

2011-10-01

278

Swaging process of power steering hose: Its finite element analysis considering the stress relaxation  

Microsoft Academic Search

Rubber layers in the power steering hose display the stress relaxation after the swaging forming load is released. This paper presents the nonlinear finite element analysis of the swaging process of the power steering hose by considering the stress relaxation in terms of a Prony series expansion. Numerical results illustrating the theoretical work confirm that the stress relaxation of rubber

J. R. Cho; J. I. Song

2007-01-01

279

HIGH PRESSURE RF CAVITIES IN MAGNETIC FIELDS  

Microsoft Academic Search

The RF breakdown of dense hydrogen gas between metallic electrodes has been studied as part of a program to develop gas-filled RF cavities to be used for muon ionization cooling. A pressurized 805 MHz test cell was used at Fermilab to measure the increase in the breakdown threshold as a function of gas density, known as the Paschen effect. The

P. Hanlet; M. Alsharo; R. E. Hartline; R. P. Johnson

280

Diamondoid Structure of Polymeric Nitrogen at High Pressures  

E-print Network

High-pressure polymeric structures of nitrogen have attracted great attention owing to their potential application as high-energy-density materials. We report the density functional structural prediction of the unexpected stabilization of a diamondoid (or N10-cage) structure of polymeric nitrogen at high pressures. The structure adopts a highly symmetric body-centered cubic form with lattice sites occupied by N10 tetracyclic cages, each of which consists of 10 atoms and is covalently bonded with its six next-nearest N10 cages. The prediction of this diamondoid structure rules out the earlier proposed helical tunnel phase and demonstrates the high-order nature of polymeric nitrogen at extreme high pressures. Diamondoid nitrogen is a wide-gap insulator and energetically more favorable than the experimental cubic gauche and previously predicted layered Pba2 phases above 263 GPa, a pressure which is accessible to high pressure experiment.

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

2012-01-01

281

Evaluation of high-pressure drilling fluid supply systems  

SciTech Connect

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

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

1981-10-01

282

Foil-like manganin gauges for dynamic high pressure measurements  

NASA Astrophysics Data System (ADS)

Foil-like manganin gauges with a variety of shapes used in different ranges of pressure for the one-dimensional strain mode and axisymmetric strain mode were designed for measuring the detonation pressures of explosives and high shock pressure in materials. In the stress range of 0-53.5 GPa, the pressure-piezoresistance relationships of the manganin gauges were calibrated by the light gas gun and the planar lens of explosive. The piezoresistance coefficients were obtained in different ranges of pressure. To verify the coefficients, the detonation pressure (CJ pressure) of TNT explosive was measured by the manganin gauges, which give similar CJ pressure values to those reported by Zhang et al (2009 Detonation Physics (Beijing: Ordnance Industry Press)) with the maximum relative deviation being less than 3%.

Duan, Zhuoping; Liu, Yan; Pi, Aiguo; Huang, Fenglei

2011-07-01

283

Recent progress in high pressure metrology in Europe  

NASA Astrophysics Data System (ADS)

Five European national metrology institutes in collaboration with a university, a research institute and five industrial companies are working on a joint research project within a framework of the European Metrology Research Programme aimed at development of 1.6 GPa primary and 1.5 GPa transfer pressure standards. Two primary pressure standards were realised as pressure-measuring multipliers, each consisting of a low pressure and a high pressure (HP) piston-cylinder assembly (PCA). A special design of the HP PCAs was developed in which a tungsten carbide cylinder is supported by two thermally shrunk steel sleeves and, additionally, by jacket pressure applied to the outside of the outer sleeve. Stress-strain finite element analysis (FEA) was performed to predict behaviour of the multipliers and a pressure generation system. With FEA, the pressure distortion coefficient was determined, taking into account irregularities of the piston-cylinder gap. Transfer pressure standards up to 1.5 GPa are developed on the basis of modern 1.5 GPa pressure transducers. This project shall solve a discrepancy between the growing needs of the industry demanding precise traceable calibrations of the high pressure transducers and the absence of adequate primary standards for pressures higher than 1 GPa in the European Union today.

Sabuga, Wladimir; Pražák, Dominik; Rabault, Thierry

2014-08-01

284

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

285

Structural stability of WS2 under high pressure  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

286

N reactor confinement system high-pressure test report  

SciTech Connect

This report presents the results of the High-Pressure Confiner Test (PT-N-605) performed at N Reactor in October 1987. This test pressurized the confiner building to a maximum design basis accident pressure of 3.9 psi. It utilized integrated leak rate tests before and after the pressurization to evaluate the damage done to the confiner by the pressure. The test demonstrated that the confiner structure and its penetration seals perform as designed when subjected to the maximum pressure postulated by a design basis accident. This report also reviews the N Reactor description, confinement concept, confinement system function, and safety analyses study done prior to the test. It describes and addresses some recommendations of the Accelerated Safety Enhancement program, and it reviews the development and performance of the High-Pressure Confiner Test. 36 refs., 12 figs., 6 tabs.

Galvin, M.R.; Holy, D.A.; Reed, R.W.

1987-10-01

287

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

288

Elastic constants of solids at high pressures  

SciTech Connect

The isothermal and adiabatic nth-order (n {>=} 2) elastic constants of a loaded crystal are defined. These constants fully determine the behavior of solids at an arbitrary load and are controlled by both an interatomic interaction and an applied load. Expressions that relate these constants (of the second, third, and fourth order) to Brugger elastic constants of the corresponding order, which are only determined by an inter-atomic interaction, are found for cubic symmetry crystals under hydrostatic pressure. These expressions are used to calculate the equation of state and the second- and third-order elastic constants of bcc tantalum at T = 0 K over a wide pressure range (0-600 GPa) using an electron density functional method. The results of calculating the equation of state and the second-order elastic constants agree with available experimental data and the calculation results obtained in other works.

Krasil'nikov, O. M., E-mail: omkras@mail.ru; Vekilov, Yu. Kh.; Mosyagin, I. Yu. [National Research Technological University MISiS (Russian Federation)

2012-08-15

289

MULTI-ROD BURNOUT AT HIGH PRESSURE  

Microsoft Academic Search

Thirty-two burnout points were obtained on an electrically heated ; assembly of nine simulated fuel rods in a square channel. The hydraulic diameter ; was 0.52 in., and the 0.375-in.-dia. rods were uniformly heated over an 18-in. ; length. Test conditions ranged from 0.01 to 0.35 in steam quality at pressures ; of 1000 and 1400 psia, and mass velocities

E. E. Polomik; E. P. Quinn

1962-01-01

290

High-pressure hollow cathode discharges  

NASA Astrophysics Data System (ADS)

Reducing the diameter of the cathode hole in a plane anode - hollow cathode geometry to 0963-0252/6/4/003/img1m has allowed us to generate direct current discharges in argon at atmospheric pressure. Up to pressure times cathode hole diameter (pD) values of approximately 5 Torr cm, and at sub-mA currents, glow discharges (predischarges) are observed with a shape which is determined by the vacuum electric field. In the same pD range, but at higher currents of up to approximately 4 mA, the discharges are of the hollow cathode discharge type. At pD values exceeding 5 Torr cm the predischarges turn into surface discharges along the mica spacer between the electrodes. At currents > 4 mA filamentary, pulsed discharges are observed. Qualitative information on the electron energy distribution in the microdischarges has been obtained by studying the VUV emission from ionized argon atoms and the argon excimer radiation at 130 nm. The results of the spectral measurements indicate the presence of a relatively large concentration of electrons with energies > 15 eV over the entire pressure range. The fact that the current - voltage characteristic of the microdischarges has a positive slope over much of the current range where excimer radiation is emitted indicates the possibility of forming arrays of these discharges and using them in flat panel excimer lamps.

Schoenbach, Karl H.; El-Habachi, Ahmed; Shi, Wenhui; Ciocca, Marco

1997-11-01

291

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

292

High Pressure Materials Research: Novel Extended Phases of Molecular Triatomics  

Microsoft Academic Search

Application of high pressure significantly alters the interatomic distance and thus the nature of intermolecular interaction, chemical bonding, molecular configuration, crystal structure, and stability of solid. With modern advances in high-pressure technologies, it is feasible to achieve a large (often up to a several-fold) compression of lattice, at which condition material can be easily forced into a new physical and

Yoo; Choong-Shik

2006-01-01

293

Dissociation of CH4 at High Pressures and Temperatures  

E-print Network

Dissociation of CH4 at High Pressures and Temperatures: Diamond Formation in Giant Planet Interiors. Dissociation of CH4 at high pressures and temperatures can influence the energy budgets of planets containing substantial amounts of CH4, water, and ammonia, such as Uranus and Neptune. The luminosities and strong

Kruger, Michael - Department of Physics, University of Missouri

294

High pressure cell for magneto-optical experiments  

Microsoft Academic Search

High pressure equipment designed for low temperature magneto-optical experiments is described. The piston and cylinder type of pressure vessel was adapted to allow photocurrent experiments to be carried out at low temperatures and high magnetic fields. With a sapphire window the cell can be used in the far infrared region (3 mm-25 mu m wavelength) and in the near infrared

Z. Wasilewski; S. Porowski; R. A. Stradling

1986-01-01

295

The use of high pressure in basic and materials science  

Microsoft Academic Search

There are at least three important applications of the high pressure technique in basic and materials science: (1) to synthesize novel materials not accessible by other techniques, (2) to transform a given material from one phase to another, and (3) to uncover underlying systematics and critically test theoretical concepts. High pressure studies currently enjoy an increasing popularity which is fueled

James S. Schilling

1998-01-01

296

High Blood Pressure in Acute Ischemic Stroke and Underlying Disorders  

Microsoft Academic Search

Background: The Acute Candesartan Cilexetil Therapy in Stroke Survivors (ACCESS) study indicated that early treatment with an angiotensin type 1 receptor blocker in acute stroke patients who had relatively high blood pressure improved cardiovascular morbidity and mortality in the chronic stage. To better interpret the findings of this study, we determined whether stroke patients with high acute blood pressure had

Kazunori Toyoda; Yasushi Okada; Juro Jinnouchi; Seiji Gotoh; Yoko Yokoyama; Shigeru Fujimoto; Setsuro Ibayashi

2006-01-01

297

High pressure spectroscopy of Ce doped YAG crystal  

NASA Astrophysics Data System (ADS)

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

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

2003-01-01

298

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

299

Journey to the Center of the Earth: Exploring High Pressure  

SciTech Connect

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

Mao, Wendy

2009-09-29

300

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

301

Pressure-volume-temperature relationship of Fe72Pt28 alloy under high pressure and temperature  

NASA Astrophysics Data System (ADS)

The pressure-volume relationship of Fe72Pt28 alloy was investigated at 300, 500, 700, 900, 1100, and 1300 K by performing energy-dispersive X-ray diffraction measurements using a white X-ray beam produced from synchrotron radiation at the High Energy Accelerator Organization, Japan. The pressure-volume relationship measurements were performed only along the decreasing the pressure path. Below 700 K and 3.5 GPa, the compressibility of Fe72Pt28 alloy increased with the pressure. Above 900 K, the pressure-volume relationship was almost linear. Further the temperature-volume relationship at high pressures was linear. An abrupt decrease in the volume or a thermal expansion coefficient anomaly, which was observed in the case of Fe69Ni31 alloy in previous experiments, was not observed in the case of Fe72Pt28 alloy,

Matsushita, M.; Inoue, T.; Yoshimi, I.; Yamaoka, E.; Irifune, T.; Ono, F.; Ogiyama, H.; Kikegawa, T.

2010-03-01

302

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

303

Amorphous diamond -- A high-pressure superhard carbon allotrope  

NASA Astrophysics Data System (ADS)

Compressing glassy carbon above 40 GPa, we have observed a new carbon allotrope with a fully sp^3-bonded amorphous structure and diamond-like strength. Synchrotron x-ray Raman spectroscopy revealed a continuous pressure-induced sp^2-to-sp^3 bonding change, while x-ray diffraction confirmed the perseverance of non-crystallinity. The transition was reversible upon releasing pressure. Used as an indenter, the glassy carbon ball demonstrated exceptional strength by reaching 130 GPa with a confining pressure of 60 GPa. Such an extremely large stress difference of >70 GPa has never been observed in any material besides diamond, indicating the high hardness of this high-pressure carbon allotrope. The nanoscale transmission x-ray microscopy is being utilized for accurate pressure-volume determination of glassy carbon and its high-pressure phase.

Lin, Yu; Zhang, Li; Mao, Ho-Kwang; Chow, Paul; Xiao, Yuming; Baldini, Maria; Shu, Jinfu; Mao, Wendy

2012-02-01

304

High pressure NMR studies of proteins and membranes  

NASA Astrophysics Data System (ADS)

Advanced high resolution NMR spectroscopy, including two-dimensional NMR techniques, combined with the high pressure capability represents a powerful new tool in studies of proteins and membranes. Selected results taken from recent studies illustrate the high information content and the range of problems that can be investigated. Three specific studies dealing with proteins are mentioned: pressure-induced reversible unfolding of lysozyme; investigation of conformation of the pressure-dissociated monomer of Arc repressor, and cold denaturation of several proteins performed at high pressure by taking advantage of the phase diagram of water. A brief overview of the recent multinuclear NMR studies of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) multilamellar aqueous dispersions and sonicated vesicles and DPPC bilayers containing the charged form of local anesthetic tetracaine (TTC) shows the type of unique information that can be obtained from high pressure NMR studies of model membranes.

Jonas, Jiri

1994-07-01

305

High-Pressure Oxygen Generation for Outpost EVA Study  

NASA Technical Reports Server (NTRS)

The amount of oxygen consumption for crew extravehicular activity (EVA) in future lunar exploration missions will be significant. Eight technologies to provide high pressure EVA O2 were investigated. They are: high pressure O2 storage, liquid oxygen (LOX) storage followed by vaporization, scavenging LOX from Lander followed by vaporization, LOX delivery followed by sorption compression, water electrolysis followed by compression, stand-alone high pressure water electrolyzer, Environmental Control and Life Support System (ECLSS) and Power Elements sharing a high pressure water electrolyzer, and ECLSS and In-Situ Resource Utilization (ISRU) Elements sharing a high pressure electrolyzer. A trade analysis was conducted comparing launch mass and equivalent system mass (ESM) of the eight technologies in open and closed ECLSS architectures. Technologies considered appropriate for the two architectures were selected and suggested for development.

Jeng, Frank F.; Conger, Bruce; Ewert, Michael K.; Anderson, Molly S.

2009-01-01

306

Migraine and tension headache in high-pressure and normal-pressure glaucoma  

Microsoft Academic Search

PURPOSE:To analyze the association of normal-pressure glaucoma and migraine.METHODS:In a prospective study, 154 patients with glaucoma (56 normal-pressure subgroup and 98 high-pressure glaucoma subgroup), 55 patients with ocular hypertension, and 75 control subjects were analyzed by means of a standardized questionnaire based on International Headache Society criteria.RESULTS:According to the questionnaire, 46 patients (17%) were classified as suffering from migraine and

Claus Cursiefen; Martin Wisse; Simone Cursiefen; Anselm Jünemann; Peter Martus; Matthias Korth

2000-01-01

307

Ultrasonic depth gauge for liquids under high pressure  

NASA Technical Reports Server (NTRS)

The invention relates to an ultrasonic depth gauge for liquids under high pressure and is particularly useful in the space industry where it is necessary to use a pressurized gas to transfer a liquid from one location to another. Conventional liquid depth gauges do not have the capability to operate under extreme high pressure (i.e., exceeding 300 psi). An ultrasonic depth gauge capable of withstanding high pressure according to the present invention is comprised of a transducer assembly and a supporting electronics unit. The former is mounted in to the bottom wall of a storage vessel with its resonating surface directly exposed to the highly pressurized liquid in the vessel. In operation, the ultrasonic pulse propagates upward through the liquid to the liquid-gas interface in the storage vessel. When the ultrasonic echo returns from the liquid-gas interface, it re-excites the composite resonator into vibration. The supporting electronics unit measures the round-trip transmit time for the ultrasonic pulse and its return echo to traverse the depth of the highly pressurized liquid. The novelty of the invention resides in the use of a conventional transducer rigidly bonded to the inside wall of a bored out conventional high-pressure plug to form a composite resonator capable of withstanding extremely high pressure.

Zuckerwar, Allan J. (inventor); Mazel, David S. (inventor)

1988-01-01

308

High Temperature High Bandwidth Fiber Optic Pressure Sensors.  

E-print Network

??Pressure measurements are required in various industrial applications, including extremely harsh environments such as turbine engines, power plants and material-processing systems. Conventional sensors are often… (more)

Xu, Juncheng

2006-01-01

309

Glasses under high pressure: a link to colloidal science?  

PubMed

Whether glass formation is mainly driven by temperature or by pressure is an open question that is now being addressed in high-pressure experiments. Here we propose that some insight into these questions could be gained by comparing in a suitable manner with colloidal glass-transition data. Based on such a comparison, a cross-over is found from the usual regime of molecular glasses (where temperature effects tend to be important) to a very-high-pressure regime (where density effects eventually take over). This regime is found to be located at pressures higher than commonly studied in today's glass-transition experiments. PMID:21690894

Voigtmann, Th; Poon, Wilson C K

2006-09-20

310

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

311

Amorphous Diamond: A High-Pressure Superhard Carbon Allotrope  

NASA Astrophysics Data System (ADS)

Compressing glassy carbon above 40 GPa, we have observed a new carbon allotrope with a fully sp3-bonded amorphous structure and diamondlike strength. Synchrotron x-ray Raman spectroscopy revealed a continuous pressure-induced sp2-to-sp3 bonding change, while x-ray diffraction confirmed the perseverance of noncrystallinity. The transition was reversible upon releasing pressure. Used as an indenter, the glassy carbon ball demonstrated exceptional strength by reaching 130 GPa with a confining pressure of 60 GPa. Such an extremely large stress difference of >70GPa has never been observed in any material besides diamond, indicating the high hardness of this high-pressure carbon allotrope.

Lin, Yu; Zhang, Li; Mao, Ho-Kwang; Chow, Paul; Xiao, Yuming; Baldini, Maria; Shu, Jinfu; Mao, Wendy L.

2011-10-01

312

Effect of high pressure on hydrocarbon-degrading bacteria  

PubMed Central

The blowout of the Deepwater Horizon in the Gulf of Mexico in 2010 occurred at a depth of 1500 m, corresponding to a hydrostatic pressure of 15 MPa. Up to now, knowledge about the impact of high pressure on oil-degrading bacteria has been scarce. To investigate how the biodegradation of crude oil and its components is influenced by high pressures, like those in deep-sea environments, hydrocarbon degradation and growth of two model strains were studied in high-pressure reactors. The alkane-degrading strain Rhodococcus qingshengii TUHH-12 grew well on n-hexadecane at 15 MPa at a rate of 0.16 h?1, although slightly slower than at ambient pressure (0.36 h?1). In contrast, the growth of the aromatic hydrocarbon degrading strain Sphingobium yanoikuyae B1 was highly affected by elevated pressures. Pressures of up to 8.8 MPa had little effect on growth of this strain. However, above this pressure growth decreased and at 12 MPa or more no more growth was observed. Nevertheless, S. yanoikuyae continued to convert naphthalene at pressure >12 MPa, although at a lower rate than at 0.1 MPa. This suggests that certain metabolic functions of this bacterium were inhibited by pressure to a greater extent than the enzymes responsible for naphthalene degradation. These results show that high pressure has a strong influence on the biodegradation of crude oil components and that, contrary to previous assumptions, the role of pressure cannot be discounted when estimating the biodegradation and ultimate fate of deep-sea oil releases such as the Deepwater Horizon event.

2014-01-01

313

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

314

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

315

The optical properties of HgS under high pressures  

NASA Astrophysics Data System (ADS)

The DOS (density of states) and the optical properties of HgS under high pressure are studied with the first-principle computations. The change of the imaginary part, ?2( ?), of the dielectric function shows that HgS tends to metallization with increasing pressure, and this well agrees with the band gap calculations and the conductivities measurement results in the previous work. Under the pressures below 15 GPa, ?2( ?) is relatively anisotropic and tends to be more anisotropic with increasing pressure; while under the pressures above 15 GPa, the anisotropy decreases and finally becomes almost absolutely isotropic after the phase transition. The behavior of ?2( ?) is strongly related to the structure change in the cinnabar to rocksalt phase transition process under high pressure.

Sun, Shao-Rui; Dong, Yu-Hui

2006-06-01

316

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

317

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

318

Recent developments in conventional high-pressure methods  

Microsoft Academic Search

Over the last decade, high-pressure-temperature experiments in mineral physics generally have employed either diamond anvil, shock wave, or conventional pressure generation methods. In the latter category, one would include standard hydrostatic fluid vessels, piston-cylinder devices, 'belt' and 'girdle' apparatus, and multianvil units. Recent emphasis in the use of such systems has centered on improvements in volume, pressure, and temperature capabilities,

E. K. Graham

1986-01-01

319

Response of four types of coliphages to high hydrostatic pressure  

Microsoft Academic Search

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

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

2006-01-01

320

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

SciTech Connect

The purpose of this research project was to build and test a high pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system were procured or fabricated and assembled in our laboratory. This system was then used to determine the effects of high pressure on growth and ethanol production by C. ljungdahlil. The limits of cell concentration and mass transport relationships were found in CSTR and immobilized cell reactors (ICR). The minimum retention times and reactor volumes were found for ethanol production in these reactors. The purpose of this report was to present the results of high pressure experiments aimed at determining the maximum operating pressure of C. ljungdahlil. Preliminary experiments carried out in approaching the pressure maximum are presented, as well as experimental results at the maximum pressure of 150 psig. This latter pressure was the maximum operating pressure when using the defined medium of Phillips et al., and is expected to change if alternative media are employed.

Not Available

1993-05-01

321

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

322

Underground storage systems for high-pressure air and gases  

NASA Technical Reports Server (NTRS)

This paper is a discussion of the safety and cost of underground high-pressure air and gas storage systems based on recent experience with a high-pressure air system installed at Moffett Field, California. The system described used threaded and coupled oil well casings installed vertically to a depth of 1200 ft. Maximum pressure was 3000 psi and capacity was 500,000 lb of air. A failure mode analysis is presented, and it is shown that underground storage offers advantages in avoiding catastrophic consequences from pressure vessel failure. Certain problems such as corrosion, fatigue, and electrolysis are discussed in terms of the economic life of such vessels. A cost analysis shows that where favorable drilling conditions exist, the cost of underground high-pressure storage is approximately one-quarter that of equivalent aboveground storage.

Beam, B. H.; Giovannetti, A.

1975-01-01

323

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. PMID:23112586

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

2012-01-01

324

Fabrication of high sensitivity carbon microcoil pressure sensors.  

PubMed

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. PMID:23112586

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

2012-01-01

325

SulA-dependent hypersensitivity to high pressure and hyperfilamentation after high-pressure treatment of Escherichia coli lon mutants.  

PubMed

High-pressure treatment (>100 MPa) is known to induce several heat shock proteins as well as an SOS response in Escherichia coli. In the current work, we have investigated properties with respect to high-pressure treatment of mutants-deficient in Lon, a pressure-induced ATP-dependent protease that belongs to the heat shock regulon but that also has a link to the SOS regulon. We report that lon mutants show increased pressure sensitivity and exhibit hyperfilamentation during growth after high-pressure treatment. Both phenotypes could be entirely attributed to the action of the SOS protein SulA, a potent inhibitor of the cell division ring protein FtsZ and a specific target of the Lon protease, since they were suppressed by knock-out of SulA. Introduction of the lexA1 allele, which effectively blocks the entire SOS response, also suppressed the high pressure hypersensitivity of lon mutants, but not their UV hypersensitivity. These results indicate the existence of a SulA-dependent pathway of high-pressure-induced cell filamentation, and suggest involvement of the SOS response, and particularly of SulA, in high-pressure-mediated cell death in E. coli strains which are compromised in Lon function. PMID:15748989

Aertsen, Abram; Michiels, Chris W

2005-03-01

326

High pressure testing of see-through labyrinth seals  

E-print Network

Detailed results are presented for teeth-on-stator labyrinth seals tested under high pressure of 70 bar-a (1015 psi-a) and 52 bar-a (754 psi-a) in the centered position. The seals were tested at pressure ratios of 0.52, 0.36 and 0.16, speeds of 10...

Picardo, Arthur Michael

2012-06-07

327

Neutron scattering at high pressure D. B. McWhan  

E-print Network

715 Neutron scattering at high pressure D. B. McWhan Room 1D-234, Murray Hill, New Jersey 07974, U scattering at steady-state and pulsed sources are reviewed. The pressure cells available at most neutron 10 GPa have been made. For elastic scattering, a comparison is made between neutron scattering and X

Paris-Sud XI, Université de

328

One Reading Specialist's Response to High-Stakes Testing Pressures  

ERIC Educational Resources Information Center

Pressures to help students pass high-stakes tests affect teachers' reading instruction, their responsiveness to students' learning needs, and their professional effectiveness. This article reports on how one reading specialist responded to testing pressures in her urban elementary school. She believed that what was "right" for her students was to…

Assaf, Lori

2006-01-01

329

High pressure gas permeability of microporous carbon membranes  

Microsoft Academic Search

Microporous carbon membranes are prepared, characterised structurally and tested in terms of high pressure CO2 permeability at temperatures around the critical. A maximum in the permeance versus relative pressure curve is observed in close analogy to the case of mesoporous membranes. This weakens considerably as the temperature is increased above the critical. The results offer significant input for an improved

F. K. Katsaros; T. A. Steriotis; A. K. Stubos; A. Mitropoulos; N. K. Kanellopoulos; S. Tennison

1997-01-01

330

Dissociation of silica at high pressure  

NASA Astrophysics Data System (ADS)

Measurements of the temperature and optical reflectivity of quartz and fused silica under shock loading from 100 to 1000 GPa have revealed evidence for dissociation of silica between ˜150 and 400 GPa. Using attenuating laser-driven shock waves a continuous record of the temperature and reflectivity dependence on pressure has been obtained in both materials allowing the specific heat capacity and electronic conductivity to be deduced. Results show that between 150 and 400 GPa the specific heat rises significantly above that expected from the Dulong-Petit law, indicating the presence of a latent energy. Coincident with this anomalous specific heat is a rapid rise in electronic conductivity. Both these observables suggest that dissociation is occurring in the dense fluid. In addition temperature measurements near 5000 K detect a discontinuity at the melt transition, as measured earlier on gas gun experiments. This work was performed under the auspices of the US DOE by LLNL under Contract No. W-7405-ENG-48 and by the University of Rochester under Cooperative Agreement No. DE-FC03-92SF19460.

Hicks, Damien; Boehly, Tom

2005-07-01

331

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

332

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

NASA Astrophysics Data System (ADS)

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

Koo, Juny; Czeslik, Claus

2012-08-01

333

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

SciTech Connect

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

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

2008-02-13

334

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

335

High pressure apparatus for transport properties study in high magnetic field  

SciTech Connect

We have designed a high pressure apparatus for measuring electrical-transport properties at low temperatures, high magnetic field and hydrostatic pressure up to 10 kbar. Details of the high-pressure cell and an exemplary study on UNiAI are described and discussed briefly.

Alsmadi, A. M. (Abdel M.); Nakotte, H. (Heinrich); Honda, F.; Sechovsky, V. (Vladimir); Mikulina, O. (Olga); Kamarad, J.; Lacerda, A. H. (Alex H.)

2002-01-01

336

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

337

Linear ruby scale and one megabar. [high pressure fluorescence  

NASA Technical Reports Server (NTRS)

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

Ruoff, A. L.

1979-01-01

338

Laser-Machined Microcavities for Simultaneous Measurement of High-Temperature and High-Pressure  

PubMed Central

Laser-machined microcavities for simultaneous measurement of high-temperature and high-pressure are demonstrated. These two cascaded microcavities are an air cavity and a composite cavity including a section of fiber and an air cavity. They are both placed into a pressure chamber inside a furnace to perform simultaneous pressure and high-temperature tests. The thermal and pressure coefficients of the short air cavity are ?0.0779 nm/°C and ?1.14 nm/MPa, respectively. The thermal and pressure coefficients of the composite cavity are ?32.3 nm/°C and ?24.4 nm/MPa, respectively. The sensor could be used to separate temperature and pressure due to their different thermal and pressure coefficients. The excellent feature of such a sensor head is that it can withstand high temperatures of up to 400 °C and achieve precise measurement of high-pressure under high temperature conditions. PMID:25106018

Ran, Zengling; Liu, Shan; Liu, Qin; Huang, Ya; Bao, Haihong; Wang, Yanjun; Luo, Shucheng; Yang, Huiqin; Rao, Yunjiang

2014-01-01

339

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

340

Electrostatic despersion of diesel fuel heats at high back pressure  

SciTech Connect

The authors report an experimental study of electrostactically atomized and dispersed fuel jets conducted in room temperature N2 gas for various back pressures to 41,8 atm. No.2 diesel fuel was injected through an electrostatic spray triode designed for high-pressure operatin. Charge density measurements were conducted at various combinations of injection velocities, electric potentials, and back pressures. The charge density of fuel drops increased up to 1.5/m3 with increasing electric potential until breakdown occurred. After breakdown occurred at higher voltages. At higher back pressure, lower charge density was obtained and breakdown occurred at higher voltages. Visual observations showed that significant electrostatic dispersion was accomplished at high back pressures, and that the average drop size was about the same as the spray triode orifice diameter.

Kwack, E.Y.; Back, L.H.; Bankston, C.P. (Jet Propulsion, California Institute of Technology Pasadena, CA (US))

1989-07-01

341

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

342

9. Photocopy of engineering drawing. LC 17 HIGH PRESSURE GAS ...  

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

9. Photocopy of engineering drawing. LC 17 HIGH PRESSURE GAS INSTALLATION: SITE & GRADING PLAN, APRIL 1969. - Cape Canaveral Air Station, Launch Complex 17, Facility 28419, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

343

2. SOUTHEAST SIDE. HIGH PRESSURE HELIUM STORAGE TANKS AT LEFT. ...  

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

2. SOUTHEAST SIDE. HIGH PRESSURE HELIUM STORAGE TANKS AT LEFT. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Helium Compression Plant, Test Area 1-115, intersection of Altair & Saturn Boulevards, Boron, Kern County, CA

344

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

345

Preparing Eighth Graders for the Social Pressures of High School.  

ERIC Educational Resources Information Center

Describes a program for eighth graders at West Hempstead (New York) Middle School that prepares students for social pressures of high school by building leadership qualities. Includes an overview of the program and a description of program sessions. (NB)

Sabatini, Lou

1989-01-01

346

High pressure working mode of hollow cathode arc discharges  

NASA Technical Reports Server (NTRS)

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

Minoo, H.; Popovici, C.

1985-01-01

347

High-pressure polarimetric sensor using birefringent optical fibers  

Microsoft Academic Search

A fiber-optic high-pressure sensor has been developed for a pressure range up to 200 MPa and for a standard range of temperatures. The sensor is based on the effect of polarization coupling between two orthogonally polarized eigenmodes of a highly birefringent, polarization-preserving optical fiber used as a sensing element. When linearly polarized light is launched into such a fiber at

W. J. Bock

1990-01-01

348

High-pressure polarimetric sensor using birefringent optical fibres  

Microsoft Academic Search

A novel fiber-optic high-pressure sensor has been developed for a pressure range up to 200 MPa and for a standard range of temperatures. The sensor is based on the effect of polarization coupling between two orthogonally polarized eigenmodes of the highly birefringent, polarization-preserving optical fiber used as a sensing element. When linearly polarized light, is launched into the fiber at

Wojtek J. Bock

1989-01-01

349

High-pressure hydrogen materials compatibility of piezoelectric films  

Microsoft Academic Search

Hydrogen is well known for materials compatibility issues, including blistering and embrittlement in metals, which are challenges for its use as the next-generation ``green'' fuel. Beyond metals, hydrogen also degrades piezoelectric materials used as actuators used in direct injection hydrogen internal combustion engines. We present the materials compatibility studies of piezoelectric films in high-pressure hydrogen environments. Absorption of high-pressure hydrogen

Kyle J. Alvine; V. Shutthanandan; Wendy D. Bennett; Charles C. Bonham; Daniel C. Skorski; Stan G. Pitman; Michael E. Dahl; Charles H. Henager

2010-01-01

350

Vitrification of emulsified dilute aqueous sucrose solutions at high pressures  

Microsoft Academic Search

The supercooling and glass-forming behavior of aqueous sucrose solution was investigated using emulsified sucrose solutions at high pressures. It is shown that emulsified aqueous sucrose solution with the sucrose concentration being as low as 1m (m: molality) is glass-forming at high pressures above 190MPa. This finding may form the basis of a useful vitrification method for cryo-preservation of living cells

H. Kanno; K. Miyata; S. Hayakawa; K. Kajiwara

2008-01-01

351

Screening of Hydrogen Storage Media Applying High Pressure Thermogravimetry  

Microsoft Academic Search

A number of commercially available hydride-forming alloys of the MmNi5–xSnx (Mm=mischmetal, a mixture of lanthanides) type were examined using a high pressure, high temperature microbalance,scanning electron\\u000a microscopy and X-ray diffraction. Activation conditions, reversible storage capacity, working pressures and temperatures,\\u000a sensitivity to impurities, and morphological changes were explored.

J. J. Bentzen; A. S. Pedersen; J. Kjøller

2001-01-01

352

Coherent diffractive imaging of gold crystal under high pressure  

NASA Astrophysics Data System (ADS)

Coherent Diffractive Imaging (CDI) with Bragg geometry is a unique method that is sensitive to strain distributions in crystals. With measured 3D diffraction intensities around Bragg peaks, 3D real-space images can be obtained by inverting these over-sampled diffraction pattern using phase retrieval algorithms. The reconstructed magnitude stands for physical electron density of the measured crystal, while the obtained phase structure represents lattice dislocations. We extend the capability of Bragg CDI to investigate crystal strains under high-pressure environment. We demonstrate the strain evolution of a gold crystal under various pressures. This technique opens the door to visualize strain-introduced phase transition driven by high pressure.

Huang, Xiaojing; Yang, Wenge; Harder, Ross; Robinson, Ian

2011-06-01

353

High-pressure test loop design and application  

SciTech Connect

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

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

1980-07-01

354

Effect of high pressure on physicochemical properties of meat.  

PubMed

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

Buckow, Roman; Sikes, Anita; Tume, Ron

2013-01-01

355

FBG pressure sensor of high pressure electric oil pumps for prestressing  

NASA Astrophysics Data System (ADS)

Prestressed concrete structure is getting more and more extensive application in architecture, hydraulic engineering and traffic engineering because of its significant advantages of crack later or not cracks completely. It is an internal stress concrete structure that a certain force relies on prestressing tendons. The effectivity of the prestressing tendon in concrete structure is directly related to the reliability, applicability and viability of the whole concrete structure. So it is a key program to apply accurate prestress to the prestressing tendon. According to the pressure sensing principle of the fiber Bragg grating (FBG), a circular plate diaphragm-based FBG sensor for high pressure electric oil pumps that is the pressure source device of the prestressed concrete structure was presented. To overcome the cross sensitivity of temperature and pressure, two FBGs were integrated in the sensor, one of the FBGs isolated from the pressure is used as temperature compensation grating, it is called temperature-FBG comparing to another FBG called pressure-FBG. The elastic diaphragm was chosen as the pressure sensing element whose distortion displace is proportional to the difference of the two sides' pressure of the diaphragm. A certain stress is applied to the pressure-FBG which is stuck to the center of the diaphragm, and then the reflection wavelength of the pressure-FBG is inverse proportional to load of the diaphragm. The results indicated that the linearity is up to 99.99%, and the pressure sensitivity coefficient is 0.024nm/MPa within the measurement scope of 0-70MPa.

Guo, Zhenwu; Liu, Guangwei; Meng, Qingbin; Ge, Fuwei; Li, Weixiang

2013-03-01

356

Hydrogen Storage in Mesoporous Materials under High Pressure  

NASA Astrophysics Data System (ADS)

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

Weinberger, Michelle; Somayazulu, Maddury; Hemley, Russell

2008-03-01

357

Testing theories for thermal transport using high pressure  

NASA Astrophysics Data System (ADS)

This dissertation focuses on experimental studies of thermal transport in various materials, such as heat transfer in crystals and amorphous polymers, and across interfaces, using an ultrafast pump-probe method, time-domain thermoreflectance (TDTR), combined with gem anvil cell techniques. I demonstrated that pressure tuning of physical properties of materials is an elegant approach to test the validity of theories for thermal transport. Pressure dependence of the cross-plane thermal conductivity ?( P) of a layered muscovite mica crystal was measured by TDTR combined with diamond anvil cell techniques. Under a simple relaxation time approximation, most of the ?(P) of muscovite mica can be described by the pressure dependence of the cross-plane sound velocity, indicating that the cross-plane sound velocity plays an important role in the thermal transport in a layered crystal. The validity of the minimum thermal conductivity model for amorphous polymers was verified by the good agreement between my measurements of the pressure dependent thermal conductivity of poly(methyl methacrylate) (PMMA) and the model prediction. The thermal energy exchange between non-propagating vibrational modes is the dominant mechanism of thermal transport in amorphous polymers. I also used high pressure to demonstrate the importance of interface stiffness on the interfacial thermal transport. By measuring the pressure dependence of thermal conductance G(P) of clean and modified Al/SiC interfaces, I found that G( P) of a clean interface with high interface stiffness is weakly dependent on pressure and can be well accounted for by the diffuse mismatch model (DMM). By contrast, G(P) of modified interfaces with low interface stiffness initially increase rapidly with pressure; as the interface stiffness is increased to be comparable to the stiffness of chemical bonds, G(P) saturate at the value for the clean interface and value predicted by the DMM. In order to extend the TDTR measurements to high pressures and high temperatures, I studied the pressure dependent thermoreflectance and piezo-optical coefficient of metal film transducers---Al, Ta, and Au(Pd) alloy (?5 at. % Pd) at a laser wavelength of 785 nm. The thermoreflectance of Ta and Au(Pd) are comparable to that of Al at ambient conditions and independent of pressure in the range 0 to that of Al at ambient conditions and independent of pressure in the range 0pressure range. I conclude that Ta and Au(Pd) films can replace Al as metal transducers and extend TDTR to higher pressures and temperatures.

Hsieh, Wen-Pin

358

Experimental study on pressure drop of bends in dense phase pneumatic conveying under high pressure  

NASA Astrophysics Data System (ADS)

The transport test using nitrogen as conveying gas are carried out at high operating pressure up to 4MPa in the experimental equipment for dense phase pneumatic conveying. The transport powders in the experiment are anthracite coal and petroleum coke. The pressure drop characteristics in bends are acquired with the different transport powder. The experimental results show that under the similar mass flow, the pressure drop of vertical upward bend is greater than the horizontal bend and the horizontal bend is greater than the vertical downward bend at the same superficial gas velocity, while there is a best superficial gas velocity minimizes the pressure drop of the bend. Under the similar mass flow rate and the similar particle size, the pressure drop of the bend with the petroleum coke is greater than the pressure drop with the anthracite coal as the same superficial gas velocity. According to Barth's additional pressure drop method, the pressure drop fitting formulas of the vertical upward bend, the horizontal bend and the vertical downward bend are obtained, and the predicted results are in accordance with that of the experiments.

Yuan, Gaoyang; Liang, Cai; Chen, Xiaoping; Xu, Pan; Xu, Guiling; Shen, Liu

2014-04-01

359

High blood pressure in pregnancy and coronary calcification.  

PubMed

A considerable proportion of pregnant women develop high blood pressure in pregnancy. Although it is assumed that this condition subsides after pregnancy, many of these women develop the metabolic syndrome later in life and are at increased risk to develop coronary heart disease. Atherosclerosis development is considered in between risk factors and occurrence of vascular symptoms. We set out to cross-sectionally study the relation of high blood pressure during pregnancy with risk of coronary calcification. The study population was composed 491 healthy postmenopausal women selected from a population-based cohort study. Information on high blood pressure during pregnancy was obtained using a questionnaire. Between 2004 and 2005, the women underwent a multidetector computed tomography (Philips Mx 8000 IDT 16) to assess coronary calcium. The Agatston score, volume, and mass measurements were used to quantify coronary calcium. A total of 30.7% of the women reported to have had high blood pressure in pregnancy. Body mass index (odds ratio [OR]: 1.05; 95% CI: 1.01 to 1.09) and diastolic blood pressure (OR: 1.03; 95% CI: 1.01 to 1.05) were significantly related to a history of high blood pressure in pregnancy. Age was significantly related to increased coronary calcification. Women with a history of high blood pressure during pregnancy had a 57% increased risk of having coronary calcification compared with those women without this condition (OR: 1.57; 95% CI: 1.04 to 2.37). After adjusting for age, the relation did not change (OR: 1.64; 95% CI: 1.07 to 2.53). We concluded that high blood pressure during pregnancy is associated with an increased risk of coronary calcification later in life. PMID:17283250

Sabour, Siamak; Franx, Arie; Rutten, Annemarieke; Grobbee, Diederick E; Prokop, Mathias; Bartelink, Marie-Louise; van der Schouw, Yvonne T; Bots, Michiel L

2007-04-01

360

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

Code of Federal Regulations, 2011 CFR

...of this chapter. Firehose nozzles previously approved under...Inspection. (k) Firehose nozzles previously approved under subpart...section. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2011-10-01

361

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

Code of Federal Regulations, 2013 CFR

...of this chapter. Firehose nozzles previously approved under...Inspection. (k) Firehose nozzles previously approved under subpart...section. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2013-10-01

362

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

Code of Federal Regulations, 2012 CFR

...of this chapter. Firehose nozzles previously approved under...Inspection. (k) Firehose nozzles previously approved under subpart...section. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2012-10-01

363

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

Code of Federal Regulations, 2010 CFR

...of this chapter. Firehose nozzles previously approved under...Inspection. (k) Firehose nozzles previously approved under subpart...section. (m) Fire hydrants, nozzles, and other fittings shall...or (ii) Be a uniform design for each hose diameter...

2010-10-01

364

Astronaut Donald McMonagle checks drainage hose on his life raft in training  

NASA Technical Reports Server (NTRS)

Astronaut Donald R. McMonagle, STS-66 mission commander, checks the drainage hose on his rapidly fashioned life raft during an emergency bailout training exercise in JSC's Weightless Environment Training Facility (WETF).

1994-01-01

365

Generalization of low pressure, gas-liquid, metastable sound speed to high pressures  

NASA Technical Reports Server (NTRS)

A theory is developed for isentropic metastable sound propagation in high pressure gas-liquid mixtures. Without simplification, it also correctly predicts the minimum speed for low pressure air-water measurements where other authors are forced to postulate isothermal propagation. This is accomplished by a mixture heat capacity ratio which automatically adjusts from its single phase values to approximately the isothermal value of unity needed for the minimum speed. Computations are made for the pure components parahydrogen and nitrogen, with emphasis on the latter. With simplifying assumptions, the theory reduces to a well known approximate formula limited to low pressure.

Bursik, J. W.; Hall, R. M.

1981-01-01

366

High-pressure trickle-bed reactors: A review  

SciTech Connect

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

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

1997-08-01

367

Chemical Vapor Deposition at High Pressure in a Microgravity Environment  

NASA Technical Reports Server (NTRS)

In this paper we present an evaluation of critical requirements of organometallic chemical vapor deposition (OMCVD) at elevated pressure for a channel flow reactor in a microgravity environment. The objective of using high pressure is to maintain single-phase surface composition for materials that have high thermal decomposition pressure at their optimum growth temperature. Access to microgravity is needed to maintain conditions of laminar flow, which is essential for process analysis. Based on ground based observations we present an optimized reactor design for OMCVD at high pressure and reduced gravity. Also, we discuss non-intrusive real-time optical monitoring of flow dynamics coupled to homogeneous gas phase reactions, transport and surface processes. While suborbital flights may suffice for studies of initial stages of heteroepitaxy experiments in space are essential for a complete evaluation of steady-state growth.

McCall, Sonya; Bachmann, Klaus; LeSure, Stacie; Sukidi, Nkadi; Wang, Fuchao

1999-01-01

368

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

SciTech Connect

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

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

1999-10-07

369

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Control of the pressure of gas delivered from high-pressure distribution systems. 192.197 Section...Pipeline Components § 192.197 Control of the pressure of gas delivered from high-pressure...

2010-10-01

370

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Control of the pressure of gas delivered from high-pressure distribution systems. 192.197 Section...Pipeline Components § 192.197 Control of the pressure of gas delivered from high-pressure...

2011-10-01

371

On Bandwidth Efficiency of the Hose Resource Management Model in Virtual Private Networks  

Microsoft Academic Search

Abstract— The hose resource provisioning model promises to provide an easy–to–use characterization framework for Virtual Private Network service offerings. Significant research effort has recently been spent on proposing new algorithms for provisioning cost–optimal networks specified according to this new model. However, a detailed comparison of the bandwidth requirement for networks designed based on the hose model and networks designed based

372

Vibro-acoustic characterization of flexible hose in CO2 car air conditioning systems  

Microsoft Academic Search

Following the EU directive 2006\\/40\\/EC proscribing from 2011 that refrigerant fluids must have a global warming potential not higher than 150, it will not be allowed anymore to employ the current R134a on car air conditioning systems. Maflow s.p.a (automotive hose maker) is developing products for each possible new refrigerant. This paper is focused on hoses for CO2 refrigerants operating

F. Angelini; A. Bergami; M. Martarelli; E. P. Tomasini

2008-01-01

373

Behavior of silver molybdate at high-pressure  

SciTech Connect

Behavior of cubic spinel phase of Ag{sub 2}MoO{sub 4} is investigated at high pressure using X-ray diffraction and Raman spectroscopy. The P-V data are fitted to a third order Birch-Murnaghan equation of state using a value of B{sub 0}=113 GPa and B Prime {sub 0}=4. The compound is also found to exhibit a phase transition around 5 GPa to a tetragonal structure and the two phases are found to coexist over a range of pressures. Raman spectra exhibit dramatic changes across the phase transition. Increase of X-ray background scattering and broadening of the Raman peaks associated with MoO{sub 4} tetrahedral ions in the high pressure phase suggest evolution of positional disorder. However, no evidence of pressure-induced amorphization was found up to 47 GPa. - Graphical abstract: Evolution of the integrated intensity of all the diffraction peaks between 12 and 18 degree 2{theta} as a function of pressure. The rapid decrease of the intensity suggests evolution of positional disorder in the high-pressure tetragonal phase. Highlights: Black-Right-Pointing-Pointer First in-situ X-ray diffraction and Raman study of cubic silver molybdate at high pressure. Black-Right-Pointing-Pointer Commencement of a structural transition to a tetragonal phase is found at 2.3 GPa. Black-Right-Pointing-Pointer The high-pressure phase is found to have positional disorder. Black-Right-Pointing-Pointer A bulk modulus of 113 GPa is obtained from the equation of state.

Arora, A.K., E-mail: akarora49@yahoo.co.in [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Nithya, R. [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)] [Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Misra, Sunasira [Liquid Metals and Structural Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)] [Liquid Metals and Structural Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Yagi, Takehiko [Institute for Solid State Physics, Tokyo University, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)] [Institute for Solid State Physics, Tokyo University, Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

2012-12-15

374

Microscopic Analysis of Bacterial Motility at High Pressure  

PubMed Central

The bacterial flagellar motor is a molecular machine that converts an ion flux to the rotation of a helical flagellar filament. Counterclockwise rotation of the filaments allows them to join in a bundle and propel the cell forward. Loss of motility can be caused by environmental factors such as temperature, pH, and solvation. Hydrostatic pressure is also a physical inhibitor of bacterial motility, but the detailed mechanism of this inhibition is still unknown. Here, we developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of applied pressures. We also characterized the pressure dependence of the motility of swimming Escherichia coli cells and the rotation of single flagellar motors. The fraction and speed of swimming cells decreased with increased pressure. At 80 MPa, all cells stopped swimming and simply diffused in solution. After the release of pressure, most cells immediately recovered their initial motility. Direct observation of the motility of single flagellar motors revealed that at 80 MPa, the motors generate torque that should be sufficient to join rotating filaments in a bundle. The discrepancy in the behavior of free swimming cells and individual motors could be due to the applied pressure inhibiting the formation of rotating filament bundles that can propel the cell body in an aqueous environment. PMID:22768943

Nishiyama, Masayoshi; Sowa, Yoshiyuki

2012-01-01

375

Experimental in situ investigations of turbulence under high pressure.  

PubMed

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

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

2010-02-01

376

A hydronitrogen solid: high pressure ab initio evolutionary structure searches.  

PubMed

High pressure ab initio evolutionary structure searches resulted in a hydronitrogen solid with a composition of (NH)(4). The structure searches also provided two molecular isomers, ammonium azide (AA) and trans-tetrazene (TTZ) which were previously discovered experimentally and can be taken as molecular precursors for high pressure synthesis of the hydronitrogen solid. The computed pressure versus enthalpy diagram showed that the transformation pressure to the hydronitrogen solid is 36 GPa from AA and 75 GPa from TTZ. Its metastability was analyzed by the phonon dispersion spectrum and room-temperature vibrational density of state together with the transformation energy barrier back to molecular phases at 298 K. The predicted energy barrier of 0.21 eV/atom means that the proposed hydronitrogen solid should be very stable at ambient conditions. PMID:21406836

Hu, Anguang; Zhang, Fan

2011-01-19

377

A hydronitrogen solid: high pressure ab initio evolutionary structure searches  

NASA Astrophysics Data System (ADS)

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

Hu, Anguang; Zhang, Fan

2011-01-01

378

Cooling and slowing in high-pressure jet expansions  

NASA Astrophysics Data System (ADS)

The mathematical term for the mean flow velocity in supersonic beams of ideal gases is extended to include real gas properties. This procedure yields an explicit dependence of the flow velocity on pressure, as observed in recent experiments of free jet expansions. Applied to stagnation conditions slightly above the critical point, the model suggests that seeded high-pressure jet expansions might be suitable for slowing down virtually any molecule with maximum efficiency. Moreover, we discuss the consequence of a pressure-dependent flow velocity v0 for the speed ratio S=v0/?v? with respect to collisional cooling and suggest to use the velocity spread ?v? as a more nonambiguous measure of translational temperature in high-pressure jet expansions.

Christen, Wolfgang; Rademann, Klaus

2008-01-01

379

Measurements of plasma potential in high-pressure microwave plasmas.  

PubMed

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

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

2009-04-01

380

Measurements of plasma potential in high-pressure microwave plasmas  

SciTech Connect

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

Tarasova, A. V.; Podder, N. K. [Department of Math and Physics, Troy University, Troy, Alabama 36082 (United States); Clothiaux, E. J. [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

2009-04-15

381

Chemical kinetics at very high pressures. I. Two experimental techniques  

NASA Astrophysics Data System (ADS)

Two methods of following chemical reaction rates at very high pressures by means of the electrical conductivity are described. In the first, opposed circular tungsten-carbide anvils are used, with 12-?m sheets of platinum silver soldered to them if the solution is too corrosive for unprotected carbide or if electrode polarization is too high, and the sample is confined by a gasket of epoxy resin and fiberglass. It can be used at pressures up to ˜100 kbar. In the second, a conductance cell was built into a hydraulic piston-cylinder apparatus, and the hydraulic fluid was pressurized by a piston. Measurements were made to 27 kbar and could be made to 45 or 50 kbar if a pressure vessel having a greater ratio of outside to inside diameter were used.

Saluja, Preet P. S.; Cameron, Colin; Floriano, M. Antonio; Lavergne, Aurele; McLaurin, Graham E.; Whalley, Edward

1986-11-01

382

Amorphous Diamond: A High-Pressure Superhard Carbon Allotrope  

SciTech Connect

Compressing glassy carbon above 40 GPa, we have observed a new carbon allotrope with a fully sp{sup 3}-bonded amorphous structure and diamondlike strength. Synchrotron x-ray Raman spectroscopy revealed a continuous pressure-induced sp{sup 2}-to-sp{sup 3} bonding change, while x-ray diffraction confirmed the perseverance of noncrystallinity. The transition was reversible upon releasing pressure. Used as an indenter, the glassy carbon ball demonstrated exceptional strength by reaching 130 GPa with a confining pressure of 60 GPa. Such an extremely large stress difference of >70 GPa has never been observed in any material besides diamond, indicating the high hardness of this high-pressure carbon allotrope.

Lin, Yu; Zhang, Li; Mao, Ho-kwang; Chow, Paul; Xiao, Yuming; Baldini, Maria; Shu, Jinfu; Mao, Wendy L. (Stanford); (CIW)

2011-12-09

383

High pressure melting curves of silver, gold and copper  

SciTech Connect

In this work, based on the Lindemann's formula of melting and the pressure-dependent Grüneisen parameter, we have investigated the pressure effect on melting temperature of silver, gold and copper metals. The analytical expression of melting temperature as a function of volume compression has been derived. Our results are compared with available experimental data as well as with previous theoretical studies and the good and reasonable agreements are found. We also proposed the potential of this approach on predicting melting of copper at very high pressure.

Hieu, Ho Khac, E-mail: hieuhk@duytan.edu.vn [Research and Development Center for Science and Technology, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Ha, Nguyen Ngoc [VNU-Hanoi University of Science, 334 Nguyen Trai, Hanoi (Viet Nam)] [VNU-Hanoi University of Science, 334 Nguyen Trai, Hanoi (Viet Nam)

2013-11-15

384

High-pressure study of tetramethylsilane by Raman spectroscopy  

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

385

Structural Behaviour of Uranium Sulfide under High Pressure  

SciTech Connect

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

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

2011-07-15

386

LOX vaporization in high-pressure, hydrogen-rich gas  

NASA Technical Reports Server (NTRS)

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

Litchford, Ron J.; Jeng, San-Mou

1990-01-01

387

Ground state energy of solid molecular hydrogen at high pressure  

NASA Technical Reports Server (NTRS)

The present status of the theoretical equation of state of solid molecular hydrogen is reviewed. Different quantum mechanical calculations by several groups lead to results which generally agree with each other but which disagree systematically with the measured pressure-volume curve at pressures larger than about 3000 atm. A new calculation of this curve is presented including the effect of the anisotropic interaction between H2 molecules within a completely quantum-mechanical formalism. The results show that inclusion of this interaction removes the discrepancy between theory and experiment at high pressures and that a quantum-mechanical treatment is necessary to realize its full effect.

Ebner, C.; Sung, C. C.

1972-01-01

388

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

PubMed

Total internal reflection fluorescence (TIRF) spectroscopy is a surface sensitive technique that is widely used to characterize the structure and dynamics of molecules at planar liquid-solid interfaces. In particular, biomolecular systems, such as protein adsorbates and lipid membranes can easily be studied by TIRF spectroscopy. Applying pressure to molecular systems offers access to all kinds of volume changes occurring during assembly of molecules, phase transitions, and chemical reactions. So far, most of these volume changes have been characterized in bulk solution, only. Here, we describe the design and performance of a high pressure sample cell that allows for TIRF spectroscopy under high pressures up to 2500 bar (2.5 × 10(8) Pa), in order to expand the understanding of volume effects from the bulk phase to liquid-solid interfaces. The new sample cell is based on a cylindrical body made of Nimonic 90 alloy and incorporates a pressure transmitting sample cuvette. This cuvette is composed of a fused silica prism and a flexible rubber gasket. It contains the sample solution and ensures a complete separation of the sample from the liquid pressure medium. The sample solution is in contact with the inner wall of the prism forming the interface under study, where fluorescent molecules are immobilized. In this way, the new high pressure TIRF sample cell is very useful for studying any biomolecular layer that can be deposited at a planar water-silica interface. As examples, high pressure TIRF data of adsorbed lysozyme and two phospholipid membranes are presented. PMID:22938334

Koo, Juny; Czeslik, Claus

2012-08-01

389

Modelling of Release of Gas from High-Pressure Pipelines  

Microsoft Academic Search

The problem investigated is the break of a high-pressure pipeline carrying natural single-phase gas which may condensate (retrograde) when the pressure drops. Single-phase non-ideal gas is assumed using a general- ized equation of state. Taking advantage of the choked massflow condition, the break is split into a pipe flow problem and a dispersion flow problem, both solved using a finite

Ivar Øyvind Sand; Karl Sjøen; Jan Roar Bakke

1996-01-01

390

The high pressure rheology of polymer-oil solutions  

Microsoft Academic Search

We present perhaps the most comprehensive work on the high-pressure shear-thinning of polymer-blended mineral oil. Three solutions of commercial polymer VI improver in mineral oil are characterized for the effect of pressure and shear rate on viscosity. We show that the film thinning measured in concentrated contact can be explained by ordinary shear-thinning of the power-law type. We present extended

S. Bair; F. Qureshi

2003-01-01

391

Effect of high pressure on the emulsifying behaviour of ?-lactoglobulin  

Microsoft Academic Search

The influence of high pressure (up to 800 MPa) on the emulsifying behaviour of ?-lactoglobulin has been investigated at neutral pH. Fine oil-in-water emulsions (0.4% w\\/w ?-lactoglobulin, 20% v\\/v oil) made with the pressure-treated protein were found to give substantially larger droplets than those made with the native protein. Visual creaming behaviour and changes in average droplet size have been

Vanda B. Galazka; Eric Dickinson; Dave A. Ledward

1996-01-01

392

Inactivation of a Norovirus by High-Pressure Processing  

Microsoft Academic Search

Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV-1

David H. Kingsley; Daniel R. Holliman; Kevin R. Calci; Haiqiang Chen; George J. Flick

2007-01-01

393

Patellofemoral contact pressure following high tibial osteotomy: a cadaveric study  

Microsoft Academic Search

Patella infera is a known complication of high tibial osteotomy (HTO) that can cause anterior knee pain due to excessive stresses\\u000a associated with abnormal patellofemoral (PF) joint biomechanics. However, the translation of these abnormal biomechanics to\\u000a native cartilage pressure has not been explored. The present study was designed to compare the PF contact pressures of three\\u000a different HTOs in a

Karl Stoffel; Craig Willers; Omar Korshid; Markus Kuster

2007-01-01

394

Elastic properties of hydrous wadsleyite at high pressures  

NASA Astrophysics Data System (ADS)

The cause of 410 km and 520 km seismic discontinuities is commonly explained by the phase tansitions among olivine and its high-pressure polymorphs, wadsleyite and ringwoodite. Establishing whether these discontinuities are associated with changes in composition requires that the velocity jumps calculated from experimental measurements of the elastic properties of these phases be compared with observed seismological jumps. To date, there have been a number of laboratory experiments and computer simulations on olivine, wadsleyite and ringwoodite. Recent studies demonstrate that wadsleyite and ringwoodite can contain up to 3% H2O by weight, thus making them large potential water reservoirs in the transition zone. Previous work has shown that the incorporation of water into the crystal structure of wadsleyite and ringwoodite results in a substantial decrease in their elastic moduli. We have also shown previously that there is a small but significant increase in the pressure derivatives of the elastic moduli of ringwoodite. However, there is little experimental data on the elasticity of hydrous wadsleyite under high-pressure and high temperature conditions. This is critical for understanding the nature of the 410 and 520 km discontinuities. We have therefore undertaken a study of the sound velocities and single-crystal elastic moduli of hydrous wadsleyite at high pressure by Brillouin spectroscopy. Single crystals of hydrous Mg end-member wadsleyite containing 2.16 (9) wt% H2O were synthesized in a multi-anvil press at 16 GPa and 1300°C. Samples were loaded into diamond anvil cells with methano-ethanol-water as a pressure medium. We have measured single-crystal elastic moduli, the bulk modulus KS0, and the shear modulus ?0 to 17.8 GPa. Our results for KS0 and its pressure derivative KS0' are consistent with those of Yusa et al. (1997) after refitting their pressure-volume data. Hydration has a similar influence on elastic moduli of wadsleyite as observed for ringwoodite at ambient conditions. High pressure results indicate that the pressure derivatives of KS0 and ?0 are slightly higher than the values for dry wadsleyite. Therefore, the velocity contrast between ? and ? polymorphs of Mg2SiO4 under wet condition will be lower than under dry condition. The velocity gradients of neither hydrous wadsleyite nor hydrous ringwoodite can explain high velocity gradient in the transition zone. Reference: H. Yusa and T. Inoue, Compressibility of hydrous wadsleyite (?-phase) in Mg2SiO4 by high-pressure X-ray diffraction. J. Geophys. Res., 24, 1831-1834, 1997.

Wang, J.; Sinogeikin, S.; Inoue, T.; Bass, J. D.

2006-12-01

395

A System for Incubations at High Gas Partial Pressure  

PubMed Central

High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial pressure, which can exceed 1?MPa at in situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in situ conditions, but the partial pressure of dissolved gasses has to be controlled as well. We developed an incubation system that allows for incubations at hydrostatic pressure up to 60?MPa, temperatures up to 120°C, and at high gas partial pressure. The composition and partial pressure of gasses can be manipulated during the experiment. To keep costs low, the system is mainly made from off-the-shelf components with only very few custom-made parts. A flexible and inert PVDF (polyvinylidene fluoride) incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow-through mode. The incubation system described here is usable for versatile purposes, not only the incubation of microorganisms and determination of growth rates, but also for chemical degradation or extraction experiments under high gas saturation, e.g., fluid–gas–rock-interactions in relation to carbon dioxide sequestration. As an application of the system we extracted organic compounds from sub-bituminous coal using H2O as well as a H2O–CO2 mixture at elevated temperature (90°C) and pressure (5?MPa). Subsamples were taken at different time points during the incubation and analyzed by ion chromatography. Furthermore we demonstrated the applicability of the system for studies of microbial activity, using samples from the Isis mud volcano. We could detect an increase in sulfate reduction rate upon the addition of methane to the sample. PMID:22347218

Sauer, Patrick; Glombitza, Clemens; Kallmeyer, Jens

2012-01-01

396

A system for incubations at high gas partial pressure.  

PubMed

High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial pressure, which can exceed 1?MPa at in situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in situ conditions, but the partial pressure of dissolved gasses has to be controlled as well. We developed an incubation system that allows for incubations at hydrostatic pressure up to 60?MPa, temperatures up to 120°C, and at high gas partial pressure. The composition and partial pressure of gasses can be manipulated during the experiment. To keep costs low, the system is mainly made from off-the-shelf components with only very few custom-made parts. A flexible and inert PVDF (polyvinylidene fluoride) incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow-through mode. The incubation system described here is usable for versatile purposes, not only the incubation of microorganisms and determination of growth rates, but also for chemical degradation or extraction experiments under high gas saturation, e.g., fluid-gas-rock-interactions in relation to carbon dioxide sequestration. As an application of the system we extracted organic compounds from sub-bituminous coal using H(2)O as well as a H(2)O-CO(2) mixture at elevated temperature (90°C) and pressure (5?MPa). Subsamples were taken at different time points during the incubation and analyzed by ion chromatography. Furthermore we demonstrated the applicability of the system for studies of microbial activity, using samples from the Isis mud volcano. We could detect an increase in sulfate reduction rate upon the addition of methane to the sample. PMID:22347218

Sauer, Patrick; Glombitza, Clemens; Kallmeyer, Jens

2012-01-01

397

Devitrification of Iron based metallic glasses at high pressures and high temperatures  

NASA Astrophysics Data System (ADS)

High pressure high temperature devitrification of a Fe85Si10B5 and a Fe78B13Si9 metallic glass was conducted at constant pressures with simultaneous in situ energy dispersive x-ray powder diffraction measurement. After the application of pressure a constant heating rate was applied. Heating the sample in each case resulted in crystallization with two distinct stages. Pressure is found to strongly affect crystallization temperature. Each stage of crystallization is identified using crystallographic analysis. Complementary high pressure room temperature studies were conducted for each sample.

Stemshorn, Andrew Kevin

398

An accurate high pressure scale from quantum Monte Carlo  

NASA Astrophysics Data System (ADS)

We have developed a fundamental high-temperature and high-pressure scale based on cubic boron nitride (cBN) using a combination of Quantum Monte Carlo (QMC) for the static contribution along with density functional perturbation theory (DFPT) for the thermal pressure. The anharmonic Raman frequency was determined as a function of pressure by solving the Schrodinger equation for the vibrational well determined using QMC with the frozen phonon method. The use of cBN as a pressure scale has a number of advantages. Unlike ruby, its structure is highly constrained by symmetry and stable well beyond 100 GPa, and it has a well-separated Raman spectrum with sufficient pressure dependence to allow accurate pressure calibration. While the cBN EOS from density functional theory (DFT) gives reasonable agreement with experiment, the results from different approximate functionals disagree. Quantum Monte Carlo is a first principles simulation method which circumvents approximate functionals and is widely regarded to provide the most accurate predictions of the properties of solids available. We utilize state-of-the-art QMC methods to obtain the static EOS with the QMCPACK code. We include a novel correction based on all-electron wave functions to eliminate pseudopotential error.

Esler, Kenneth; Cohen, R. E.; Militzer, Burkhard; Kim, Jeongnim

2009-03-01

399

Spontaneous Raman Scattering Diagnostics for High-pressure Gaseous Flames  

NASA Technical Reports Server (NTRS)

A high-pressure (up to 60 atm) gaseous burner facility with optical access that provides steady, reproducible flames with high precision, and the ability to use multiple fuel/oxidizer combinations has been developed. In addition, a high-performance spontaneous Raman scattering system for use in the above facility has also been developed. Together, the two systems will be used to acquire and establish a comprehensive Raman scattering spectral database for use as a quantitative high-pressure calibration of single-shot Raman scattering measurements in high-pressure combustion systems. Using these facilities, the Raman spectra of H2-Air flames were successfully measured at pressures up to 20 atm. The spectra demonstrated clear rotational and ro-vibrational Raman features of H2, N2, and H2O. theoretical Raman spectra of pure rotational H2, vibrational H2, and vibrational N2 were calculated using a classical harmonic-oscillator model with pressure broadening effects and fitted to the data. At a gas temperature of 1889 K for a phi = 1.34 H2-Air flame, the model and the data showed good agreement, confirming a ro-vibrational equilibrium temperature.

Kojima, Jun; Nguyen, Quang-Viet; Reddy, D. R. (Technical Monitor)

2002-01-01

400

Department of Energy Workshop High Pressure Hydrogen Tank Manufacturing  

E-print Network

over 1,600 hydrogen tanks · Awarded patent on injectors for dry gaseous fuels · Opened stateDepartment of Energy Workshop High Pressure Hydrogen Tank Manufacturing Mark Leavitt Quantum Fuel-composite lightweight, high capacity, low-cost fuel storage technologies. · Developed a series of robust, OEM compatible

401

PARTICULATE CONTROL HIGHLIGHTS: RESEARCH AT HIGH TEMPERATURE/PRESSURE  

EPA Science Inventory

The report gives highlights of EPA high-temperature and high-pressure programs aimed at demonstrating control technology to meet environmental standards for the ambient concentration of particles and the emission rate of particles from new sources. Among the control devices consi...

402

Vacuum assisted high pressure die casting of aluminium alloys  

Microsoft Academic Search

High pressure die castings usually contain gas porosity due mainly to the entrapment of air or gas in the melt during the very high speed injection of the molten metal into the cavity. In this paper, the advantages of using an evacuated die cavity during mould filling were evaluated. ASTM standard die casting tensile specimens of three Al alloys, Al–5%Si,

X. P. Niu; B. H. Hu; I. Pinwill; H. Li

2000-01-01

403

High pressure gas spheres for neutron and photon experiments  

Microsoft Academic Search

High pressure gas spheres have been designed and successfully used in several nuclear physics experiments on noble gases. The pros and cons of this solution are the simple design and the high reliability versus the fact that the density is limited to 40–60% of liquid or solid gas samples. Originally produced for neutron capture studies at keV energies, the comparably

G. Rupp; D. Petrich; F. Käppeler; J. Kaltenbaek; B. Leugers; R. Reifarth

2009-01-01

404

Ultra High Pressure Water Stream Characterization and Optimization  

Microsoft Academic Search

Ultra-high pressure (UHP) technology has proven to enhance the performance of firefighting equipment using water and aqueous film forming foam (AFFF). UHP systems are capable of producing small water droplets at high velocity. As droplet size is reduced, surface area relative to mass increases, improving heat transfer. Smaller droplets however, experience greater drag, reducing throw distance. Findings indicate that on

K. R. Grosskopf; Paul Oppenheim

2006-01-01

405

A novel high pressure, high temperature vessel used to conduct long-term stability measurements of silicon MEMS pressure transducers  

NASA Astrophysics Data System (ADS)

The need to quantify and to improve long-term stability of pressure transducers is a persistent requirement from the aerospace sector. Specifically, the incorporation of real-time pressure monitoring in aircraft landing gear, as exemplified in Tire Pressure Monitoring Systems (TPMS), has placed greater demand on the pressure transducer for improved performance and increased reliability which is manifested in low lifecycle cost and minimal maintenance downtime through fuel savings and increased life of the tire. Piezoresistive (PR) silicon MEMS pressure transducers are the primary choice as a transduction method for this measurement owing to their ability to be designed for the harsh environment seen in aircraft landing gear. However, these pressure transducers are only as valuable as the long-term stability they possess to ensure reliable, real-time monitoring over tens of years. The "heart" of the pressure transducer is the silicon MEMS element, and it is at this basic level where the long-term stability is established and needs to be quantified. A novel High Pressure, High Temperature (HPHT) vessel has been designed and constructed to facilitate this critical measurement of the silicon MEMS element directly through a process of mechanically "floating" the silicon MEMS element while being subjected to the extreme environments of pressure and temperature, simultaneously. Furthermore, the HPHT vessel is scalable to permit up to fifty specimens to be tested at one time to provide a statistically significant data population on which to draw reasonable conclusions on long-term stability. With the knowledge gained on the silicon MEMS element, higher level assembly to the pressure transducer envelope package can also be quantified as to the build-effects contribution to long-term stability in the same HPHT vessel due to its accommodating size. Accordingly, a HPHT vessel offering multiple levels of configurability and robustness in data measurement is presented, along with 10 year long-term stability results.

Wisniewiski, David

2014-03-01

406

High pressure generation using scaled-up Kawai-cell  

NASA Astrophysics Data System (ADS)

A scaled-up version of a 6-8 Kawai-type multianvil apparatus equipped with 47-mm WC anvils has been developed at the Institute for the Study of the Earth's Interior for operation over pressure ranging up to 19 and 24 GPa using the conventional system with larger compressional volumes between 1.2 and 0.4 cm 3, respectively. This system is used under uniaxial compression along cube diagonal of the Kawai-cell up to the press load of 19 MN. Experiments are performed using octahedral pressure media (PM) made of MgO- and ZrO 2-based semi-sintered ceramics and unfired pyrophyllite gaskets. In this study we used "Toshiba-F" grade WC anvils allowing pressure generation up to 24 GPa. We perform pressure calibrations at room and high temperatures, with octahedron/anvil truncation edge-length ratios ( a0/ b, mm) of 12.2/6, 14/6, 14/7, 16/7, 18/7, 18/9, and 18/10. Different configurations show that an increase in edge-length ratio of a0/b permits the achievement of higher pressure, which agrees with the results of Frost at al. (Frost, D.J., Poe, B.T., Tronnes, R.G., Liebske, C., Duba, A., Rubie, D.C., 2004. A new large-volume multianvil system. Phys. Earth Planet. Inter. 143, 507). However, it also shifts the pressure maximum to higher press loads, in some cases exceeding the capacity of a press. Our and Frost et al. (2004) data reveal that the 14/6, 18/8, and 18/10 assemblies are the most suitable in generating pressures of up to 19-24 GPa at 19 MN press load limits. The assemblies with a low a0/ b ratio have a lower upper pressure limit; however, they exhibit a systematically higher efficiency in pressure generation at low press loads. Consequently, assemblages with high and low a0/ b ratios should be used in high and low pressure experiments, respectively. For example, the 18/12 assembly is suitable for 5-11 GPa pressure range (Stoyanov, E., Haussermann, U., Leinenweber, K., 2010. Large-volume multianvil cells designed for chemical synthesis at high pressures. High Pressure Res., 30, 175), whereas the 14/6, 18/8 ( Frost et al., 2004), and 18/10 assemblies are suitable for 22-24, 19-23, and 11-19 GPa pressure ranges, respectively. The maximum pressure generation achieved in the present study is 24 GPa, using the 14/6 assembly. This appears to be the maximum pressure level attainable by using WC anvils.

Shatskiy, A.; Katsura, T.; Litasov, K. D.; Shcherbakova, A. V.; Borzdov, Y. M.; Yamazaki, D.; Yoneda, A.; Ohtani, E.; Ito, E.

2011-11-01

407

Conductivity of AgI under high pressure  

NASA Astrophysics Data System (ADS)

We carried out in situ conductivity measurements on silver iodide (AgI) under high pressure using a fabricated microcircuit on a diamond anvil cell (DAC). The result shows that the conductivity of AgI increases discontinuously by two orders of magnitude at 1.0 GPa, accompanying the transition from wurtzite/zinc-blende structure to AgI-III (NaCl structure). The conductivity gradually decreases with increasing pressure from 1.0 to 11 GPa, indicating the ionic conduction is impeded by the application of pressure. The conductivity changes very little with further pressure increase from 11 to 20 GPa, implying that the ionic conductivity decrease with pressure may be offset by the conductivity increase with pressure from the electronic process. Above 20 GPa, the conductivity starts to increase again, indicating that the electronic contribution becomes dominant. We calculated the ionic carrier concentration and the activation energy for ionic transport in AgI-III, and investigated the temperature and pressure dependence of conductivity above 20 GPa. Based on this experimental information, we predict that the metallization of AgI should occur at about 91 GPa.

Hao, Aimin; Gao, Chunxiao; Li, Ming; He, Chunyuan; Huang, Xiaowei; Zou, Guangtian; Tian, Yongjun; Ma, Yanzhang

2007-03-01

408

Recent developments in conventional high-pressure methods  

NASA Astrophysics Data System (ADS)

Over the last decade, high-pressure-temperature experiments in mineral physics generally have employed either diamond anvil, shock wave, or conventional pressure generation methods. In the latter category, one would include standard hydrostatic fluid vessels, piston-cylinder devices, 'belt' and 'girdle' apparatus, and multianvil units. Recent emphasis in the use of such systems has centered on improvements in volume, pressure, and temperature capabilities, as well as the achievement of more hydrostatic pressure environments. Because the pressure generation level of conventional equipment is rather limited, in comparison to diamond anvil and shock wave methods, focus has been placed on the usage of working volume in terms of material synthesis and the measurement of physical properties. In this regard, the design of internal pressure cell-specimen capsule arrangements has been improved to allow X-ray and ultrasonic measurements to hydrostatic pressures in excess of 6 GPa. Mineral data derived from such measurements should provide the bases for more accurate representations of the equation of state in the lower mantle and core by virtue of the inclusion of higher-order elastic properties.

Graham, E. K.

1986-04-01

409

Achieving unusual oxidation state of matter under high pressure  

NASA Astrophysics Data System (ADS)

Pressure has many effects to matter including the reduction of the volume, the increase of the coordination number and the broadening of the band-widths. In the past, most of the high-pressure studies focused on structural and electronic state phase transitions. Using first principles calculations and a bias-free structural search method, we will demonstrate that high pressure can lead to high oxidation state of elements that can never be achieved under ambient condition, making high pressure technique a nice tool to explore many traditional topics in solid state and molecular chemistry. As an example, we will show that Hg can transfer the electrons in its outmost d shell to F atoms and form HgF4 molecular crystals under pressure, thereby acting as a true transition metal. Group IIB elements, including Zn, Cd, and Hg are usually defined as post-transition metals because they are commonly oxidized only to the +2 state. Their d shells are completely filled and do not participate in the formation of chemical bonds. Although the synthesis of HgF4 molecules in gas phase was reported before, the molecules show strong instabilities and dissociate. Therefore, the transition metal propensity of Hg remains an open question.

Wang, Xiaoli; Lin, Haiqing; Ma, Yanming; Miao, Maosheng

2013-03-01

410

A high pressure modulated molecular beam mass spectrometric sampling system  

NASA Technical Reports Server (NTRS)

The current state of understanding of free-jet high pressure sampling is critically reviewed and modifications of certain theoretical and empirical considerations are presented. A high pressure, free-jet expansion, modulated molecular beam, mass spectrometric sampling apparatus was constructed and this apparatus is described in detail. Experimental studies have demonstrated that the apparatus can be used to sample high temperature systems at pressures up to one atmosphere. Condensible high temperature gaseous species have been routinely sampled and the mass spectrometric detector has provided direct identification of sampled species. System sensitivity is better than one tenth of a part per million. Experimental results obtained with argon and nitrogen beams are presented and compared to theoretical predictions. These results and the respective comparison are taken to indicate acceptable performance of the sampling apparatus. Results are also given for two groups of experiments related to hot corrosion studies. The formation of gaseous sodium sulfate in doped methane-oxygen flames was characterized and the oxidative vaporization of metals was studied in an atmospheric pressure flowing gas system to which gaseous salt partial pressures were added.

Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.; Miller, R. A.

1977-01-01

411

A High-Pressure Bi-Directional Cycloid Rotor Flowmeter  

PubMed Central

The measurement of the flow rate of various liquids and gases is critical in industrial automation. Rotary positive displacement meters (rotary PD meters) are highly accurate flowmeters that are widely employed in engineering applications, especially in custody transfer operations and hydraulic control systems. This paper presents a high pressure rotary PD meter containing a pair of internal cycloid rotors. It has the advantages of concise structure, low pressure loss, high accuracy and low noise. The curve of the internal rotor is designed as an equidistant curtate epicycloid curve with the external rotor curve as its conjugate. The calculation method used to determine the displacement of the cycloid rotor flowmeter is discussed. A prototype was fabricated, and experiments were performed to confirm measurements over a flow range of 1–100 L/min with relative errors of less than ±0.5%. The pressure loss through the flowmeter was about 3 bar at a flow rate of 100 L/min. PMID:25196162

Liu, Shuo; Ding, Fan; Ding, Chuan; Man, Zaipeng

2014-01-01

412

Structure of high-pressure KNO 3-IV  

NASA Astrophysics Data System (ADS)

Potassium nitrate has seven polymorphs in the pressure range to 40 kbar. The structures of the three phases obtainable at atmospheric pressure are known. Attempts to solve the structure of high pressure KNO 3 phase IV by X-ray diffraction have been unsuccessful. We have now solved this structure using time-of-flight neutron powder diffraction data taken at room temperature and 3.6 kbar on the SEPD at IPNS. High pressure KNO 3-IV has the same space group and point group symmetry as the low pressure KNO 3-II, but with different values for lattice parameters and atomic positions. The structure of KNO 3-IV is orthorhombic Pnma with a = 7.4867(2), b = 5.5648(2), and c = 6.7629(2) with four formula units per unit cell. The K, N, and one O atom are in special positions (4c) and the other O atoms are in the general position (8d) just as in the atmospheric pressure phase. The O-N-O bond angles are 120.4(1)°, and 119.3(2)°. The N-O bond lengths are 1.228(3) Å and 1.246(2) Å.

Worlton, T. G.; Decker**, D. L.; Jorgensen, J. D.; Kleb, R.

1986-02-01

413

Structure of high-pressure KNO3-4  

NASA Astrophysics Data System (ADS)

Potassium nitrate has seven polymorphs in the pressure range to 40 kbar. The structures of the three phases obtainable at atmospheric pressure are known. Attempts to solve the structure of high pressure KNO3 phase 4 by X-ray diffraction have been unsuccessful. We have now solved this structure using time-of-flight neutron powder diffraction data taken at room temperature and 3.6 kbar on the SEPD at IPNS. High pressure KNO3-4 has the same space group and point group symmetry as the low pressure KNO3-2, but with different values for lattice parameters and atomic positions. The structure of KNO3-4 is orthorhombic Pnma with a = 7.4867(2), b = 5.5648(2), and c = 6.7629(2) with four formula units per unit cell. The K, N, and one O atom are in special positions (4c) and the other O atoms are in the general position (8d) just as in the atmospheric pressure phase. The O-N-O bond angles are 120.4(1) deg, and 119.3(2) deg. The N-O bond lengths are 1.228(3)A and 1.246(2)A.

Worlton, T. G.; Decker, D. L.; Jorgensen, J. D.; Kleb, R.

1985-07-01

414

Structure of high-pressure KNO/sub 3/-IV  

SciTech Connect

Potassium nitrate has seven polymorphs in the pressure range to 40 kbar. The structures of the three phases obtainable at atmospheric pressure are known. Attempts to solve the structure of high pressure KNO/sub 3/ phase IV by x-ray diffraction have been unsuccessful. We have now solved this structure using time-of-flight neutron powder diffraction data taken at room temperature and 3.6 kbar on the SEPD at IPNS. High pressure KNO/sub 3/-IV has the same space group and point group symmetry as the low pressure KNO/sub 3/-II, but with different values for lattice parameters and atomic positions. The structure of KNO/sub 3/-IV is orthorhombic Pnma with a = 7.4867(2), b = 5.5648(2), and c = 6.7629(2) with four formula units per unit cell. The K, N, and one O atom are in special positions (4c) and the other O atoms are in the general position (8d) just as in the atmospheric pressure phase. The O-N-O bond angles are 120.4(1)/sup 0/, and 119.3(2)/sup 0/. The N-O bond lengths are 1.228(3)A and 1.246(2)A.

Worlton, T.G.; Decker, D.L.; Jorgensen, J.D.; Kleb, R.

1985-07-01

415

Characterization of Quench-Extracted High Pressure Stressed Microorganisms  

NASA Astrophysics Data System (ADS)

In-situ high pressure microbiology work by Sharma et al (2002) presented a unique approach with diamond anvil cells to the study of microbes under environmental stress. This study focused on high pressure exposure as the stress component and provided a technique to directly monitor microbial activity. However, it lacked the much desired biochemical and biophysical information that could reflect the state of surviving microorganisms with insights into the process of adaptation at extreme. More recent work (Sharma et al 2011) expands on the previous study by including synergistic effect of high temperature with increased pressures along variable time scale. With the cell extraction and subsequent cell growth demonstrated, Sharma et al. (2011) show that more than pressure, temperature remains the environmental variable that defines the limits of life's survival. In this study we have refined the extraction process from the diamond anvil cell such that the stressed microorganisms can be routinely available for in-depth physiological study using conventional and state-of-the-art high resolution imaging tools. Here we present some recent in-depth FESEM, AFM and optical spectroscopy data to study the effect of stress on Escherichia coli. Contrary to earlier studies where various cell membrane ruptures were reported after moderate pressure exposure, we find that most cells remain viable and except for some occasional anomalous morphology, the surviving cells were similar to the unstressed state. Preliminary results suggest that the stress response in Escherichia coli exposed to short term extreme pressures (ranging from 1 -24 hrs) seems rapidly reversible. Biophysical entities such as the cell membrane, therefore, remain intact in the whole organism (and colony of microorganisms) at significantly higher pressure conditions than 300 MPa as reported in previous biophysics literature.

Sharma, P.; Sharma, A.

2011-12-01

416

High pressure electrides: a predictive chemical and physical theory.  

PubMed

Electrides, in which electrons occupy interstitial regions in the crystal and behave as anions, appear as new phases for many elements (and compounds) under high pressure. We propose a unified theory of high pressure electrides (HPEs) by treating electrons in the interstitial sites as filling the quantized orbitals of the interstitial space enclosed by the surrounding atom cores, generating what we call an interstitial quasi-atom, ISQ. With increasing pressure, the energies of the valence orbitals of atoms increase more significantly than the ISQ levels, due to repulsion, exclusion by the atom cores, effectively giving the valence electrons less room in which to move. At a high enough pressure, which depends on the element and its orbitals, the frontier atomic electron may become higher in energy than the ISQ, resulting in electron transfer to the interstitial space and the formation of an HPE. By using a He lattice model to compress (with minimal orbital interaction at moderate pressures between the surrounding He and the contained atoms or molecules) atoms and an interstitial space, we are able to semiquantitatively explain and predict the propensity of various elements to form HPEs. The slopes in energy of various orbitals with pressure (s > p > d) are essential for identifying trends across the entire Periodic Table. We predict that the elements forming HPEs under 500 GPa will be Li, Na (both already known to do so), Al, and, near the high end of this pressure range, Mg, Si, Tl, In, and Pb. Ferromagnetic electrides for the heavier alkali metals, suggested by Pickard and Needs, potentially compete with transformation to d-group metals. PMID:24702165

Miao, Mao-Sheng; Hoffmann, Roald

2014-04-15

417

High-pressure Raman spectroscopy of phase change materials  

SciTech Connect

We used high-pressure Raman spectroscopy to study the evolution of vibrational frequencies of the phase change materials (PCMs) Ge{sub 2}Sb{sub 2}Te{sub 5}, GeSb{sub 2}Te{sub 4}, and SnSb{sub 2}Te{sub 4}. We found that the critical pressure for triggering amorphization in the PCMs decreases with increasing vacancy concentration, demonstrating that the presence of vacancies, rather than differences in the atomic covalent radii, is crucial for pressure-induced amorphization in PCMs. Compared to the as-deposited amorphous phase, the pressure-induced amorphous phase has a similar vibrational spectrum but requires much lower laser power to transform into the crystalline phase, suggesting different kinetics of crystallization, which may have implications for applications of PCMs in non-volatile data storage.

Hsieh, Wen-Pin, E-mail: wphsieh@stanford.edu; Mao, Wendy L. [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States) [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305 (United States); Zalden, Peter [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States)] [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Wuttig, Matthias [I. Physikalisches Institut (IA), RWTH Aachen University, 52056 Aachen (Germany) [I. Physikalisches Institut (IA), RWTH Aachen University, 52056 Aachen (Germany); JARA – Fundamentals of Future Information Technology, RWTH Aachen University, 52056 Aachen (Germany); Lindenberg, Aaron M. [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States) [SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Menlo Park, California 94025 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); SLAC National Accelerator Laboratory, PULSE Institute, Menlo Park, California 94025 (United States)

2013-11-04

418

Racial differences in hypertension: implications for high blood pressure management.  

PubMed

The racial disparity in hypertension and hypertension-related outcomes has been recognized for decades with African Americans with greater risks than Caucasians. Blood pressure levels have consistently been higher for African Americans with an earlier onset of hypertension. Although awareness and treatment levels of high blood pressure have been similar, racial differences in control rates are evident. The higher blood pressure levels for African Americans are associated with higher rates of stroke, end-stage renal disease and congestive heart failure. The reasons for the racial disparities in elevated blood pressure and hypertension-related outcomes risk remain unclear. However, the implications of the disparities of hypertension for prevention and clinical management are substantial, identifying African American men and women with excel hypertension risk and warranting interventions focused on these differences. In addition, focused research to identify the factors attributed to these disparities in risk burden is an essential need to address the evidence gaps. PMID:24983758

Lackland, Daniel T

2014-08-01

419

LX-17 Deflagration at High Pressures and Temperatures  

SciTech Connect

We measure the laminar deflagration rate of LX-17 (92.5 wt% TATB, 7.5 wt% Kel-F 800) at high pressure and temperature in a strand burner, thereby obtaining reaction rate data for prediction of thermal explosion violence. Simultaneous measurements of flame front time-of-arrival and temporal pressure history allow for the direct calculation of deflagration rate as a function of pressure. Additionally, deflagrating surface areas are calculated in order to provide quantitative insight into the dynamic surface structure during deflagration and its relationship to explosion violence. Deflagration rate data show that LX-17 burns in a smooth fashion at ambient temperature and is represented by the burn rate equation B = 0.2P{sup 0.9}. At 225 C, deflagration is more rapid and erratic. Dynamic deflagrating surface area calculations show that ambient temperature LX-17 deflagrating surface areas remain near unity over the pressure range studied.

Koerner, J; Maienschein, J; Black, K; DeHaven, M; Wardell, J

2006-10-23

420

High-pressure melting of MgSiO3.  

PubMed

The melting curve of MgSiO(3) perovskite has been determined by means of ab initio molecular dynamics complemented by effective pair potentials, and a new phenomenological model of melting. Using first principles ground state calculations, we find that the MgSiO(3) perovskite phase transforms into post perovskite at pressures above 100 GPa, in agreement with recent theoretical and experimental studies. We find that the melting curve of MgSiO(3), being very steep at pressures below 60 GPa, rapidly flattens on increasing pressure. The experimental controversy on the melting of the MgSiO(3) perovskite at high pressures is resolved, confirming the data by Zerr and Boehler. PMID:16090187

Belonoshko, A B; Skorodumova, N V; Rosengren, A; Ahuja, R; Johansson, B; Burakovsky, L; Preston, D L

2005-05-20

421

Microhole High-Pressure Jet Drill for Coiled Tubing  

SciTech Connect

Tempress Small Mechanically-Assisted High-Pressure Waterjet Drilling Tool project centered on the development of a downhole intensifier (DHI) to boost the hydraulic pressure available from conventional coiled tubing to the level required for high-pressure jet erosion of rock. We reviewed two techniques for implementing this technology (1) pure high-pressure jet drilling and (2) mechanically-assisted jet drilling. Due to the difficulties associated with modifying a downhole motor for mechanically-assisted jet drilling, it was determined that the pure high-pressure jet drilling tool was the best candidate for development and commercialization. It was also determined that this tool needs to run on commingled nitrogen and water to provide adequate downhole differential pressure and to facilitate controlled pressure drilling and descaling applications in low pressure wells. The resulting Microhole jet drilling bottomhole assembly (BHA) drills a 3.625-inch diameter hole with 2-inch coil tubing. The BHA consists of a self-rotating multi-nozzle drilling head, a high-pressure rotary seal/bearing section, an intensifier and a gas separator. Commingled nitrogen and water are separated into two streams in the gas separator. The water stream is pressurized to 3 times the inlet pressure by the downhole intensifier and discharged through nozzles in the drilling head. The energy in the gas-rich stream is used to power the intensifier. Gas-rich exhaust from the intensifier is conducted to the nozzle head where it is used to shroud the jets, increasing their effective range. The prototype BHA was tested at operational pressures and flows in a test chamber and on the end of conventional coiled tubing in a test well. During instrumented runs at downhole conditions, the BHA developed downhole differential pressures of 74 MPa (11,000 psi, median) and 90 MPa (13,000 psi, peaks). The median output differential pressure was nearly 3 times the input differential pressure available from the coiled tubing. In a chamber test, the BHA delivered up to 50 kW (67 hhp) hydraulic power. The tool drilled uncertified class-G cement samples cast into casing at a rate of 0.04 to 0.17 m/min (8 to 33 ft/hr), within the range projected for this tool but slower than a conventional PDM. While the tool met most of the performance goals, reliability requires further improvement. It will be difficult for this tool, as currently configured, to compete with conventional positive displacement downhole motors for most coil tubing drill applications. Mechanical cutters on the rotating nozzle head would improve cutting. This tool can be easily adapted for well descaling operations. A variant of the Microhole jet drilling gas separator was further developed for use with positive displacement downhole motors (PDM) operating on commingled nitrogen and water. A fit-for-purpose motor gas separator was designed and yard tested within the Microhole program. Four commercial units of that design are currently involved in a 10-well field demonstration with Baker Oil Tools in Wyoming. Initial results indicate that the motor gas separators provide significant benefit.

Ken Theimer; Jack Kolle

2007-06-30

422

Chemical dimerization of crystalline anthracene produced by transient high pressure  

SciTech Connect

We report the production of a chemically bound dimer of anthracene produced by the shock compression of crystalline anthracene. The experimental probe used to detect the dimer structure was time-of-flight (TOF) mass spectrometry. The principal method used to produce the shock compression was the impact of electrically accelerated flyers ( slappers'') with the surface of the anthracene crystals. Our work correlates well with earlier experimental and theoretical work concerning chemical processes that can occur in pressurized anthracene and other aromatic materials. We briefly review the earlier work. The anthracene crystals were shocked to various pressures in the interval 9 to 22 GPa. Also various crystal thicknesses were employed; this allowed us to control the time interval over which various anthracene particles'' in the crystal were held at high pressure and temperature. At a pressure of [similar to]22.1 GPa we observe dimer formation in 20 ns or less. For a shock pressure of 9 GPa no dimer is produced, whereas for shock pressures of 18.4 GPa or higher dimer production is always observed. Under some conditions significant conversion of monomer to dimer is seen (up to a conversion of over 50%). A remarkably simple experimental observation is that the [ital only] new chemical species observed in the experiments at 18.4 GPa and higher is the dimer species. We present evidence that the dimerization is the result of a pressure-driven Diels--Alder reaction and that such reactions are characteristic of materials containing aromatic rings when they are shocked to high pressure.

Engelke, R.; Blais, N.C. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))

1994-12-15

423

High Pressure Hydrogen Materials Compatibility of Piezoelectric Films  

SciTech Connect

Abstract: Hydrogen is being considered as a next-generation clean burning fuel. However, hydrogen has well known materials issues, including blistering and embrittlement in metals. Piezoelectric materials are used as actuators in hydrogen fuel technology. We present studies of materials compatibility of piezoelectric films in a high pressure hydrogen environment. Absorption of high pressure hydrogen was studied with Elastic Recoil Detection Analysis (ERDA) and Rutherford Back Scattering (RBS) in lead zirconate titanate (PZT) and barium titanate (BTO) thin films. Hydrogen surface degradation in the form of blistering and Pb mixing was also observed.

Alvine, Kyle J.; Shutthanandan, V.; Bennett, Wendy D.; Bonham, Charles C.; Skorski, Daniel C.; Pitman, Stan G.; Dahl, Michael E.; Henager, Charles H.

2010-12-02

424

Capillary toroid cavity detector for high pressure NMR  

DOEpatents

A Toroid Cavity Detector (TCD) is provided for implementing nuclear magnetic resonance (NMR) studies of chemical reactions under conditions of high pressures and temperatures. A toroid cavity contains an elongated central conductor extending within the toroid cavity. The toroid cavity and central conductor generate an RF magnetic field for NMR analysis. A flow-through capillary sample container is located within the toroid cavity adjacent to the central conductor to subject a sample material flowing through the capillary to a static magnetic field and to enable NMR spectra to be recorded of the material in the capillary under a temperature and high pressure environment.

Gerald, II, Rex E. (Brookfield, IL); Chen, Michael J. (Downers Grove, IL); Klingler, Robert J. (Glenview, IL); Rathke, Jerome W. (Honer Glen, IL); ter Horst, Marc (Chapel Hill, NC)

2007-09-11

425

Large volume high-pressure cell with supported moissanite anvils  

SciTech Connect

The recently developed moissanite anvil cell (MAC) has become a useful device for achieving both high-pressure and large sample volume in an anvil cell. We describe two improvements in the basic design of the MAC. First, the loading environment has been optimized by centering the load. Second, a variety of supported systems have been examined to provide anvil stability at high loads with large anvils. Sample volumes that are nearly three orders magnitude greater than allowed by conventional diamond anvil cells can be pressurized and characterized at {approx}50 GPa.

Xu, J.; Mao, H.-k.; Hemley, R.J.; Hines , E. (CIW/GL)

2010-11-16

426

High pressure crystal structure of PrN  

NASA Astrophysics Data System (ADS)

Compression of PrN yields a phase transformation to a tetragonal structure with ~8.8 % volume collapse at ~40 GPa at ambient temperature. A refinement reveals a distorted CsCl-like structure for the high pressure phase PrN(II), which is different from the high pressure phases seen among other lanthanide monopnictides. The space group of the new structure is P4/nmm (#129) with Pr in the 2c(0,1/2,0.3546) and N in the 2a(0,0,0) positions. PrN(II) persists to 85 GPa.

Cynn, Hyunchae; Lipp, Magnus; Evans, William; Ohishi, Yasuo

2010-03-01

427

Synthetic chemistry with periodic mesostructures at high pressure.  

PubMed

Over the last two decades, researchers have studied extensively the synthesis of mesostructured materials, which could be useful for drug delivery, catalytic cracking of petroleum, or reinforced plastics, among other applications. However, until very recently researchers used only temperature as a thermodynamic variable for synthesis, completely neglecting pressure. In this Account, we show how pressure can affect the synthetic chemistry of periodic mesoporous structures with desirable effects. In its simplest application, pressure can crystallize the pore walls of periodic mesoporous silicas, which are difficult to crystallize otherwise. The motivation for the synthesis of periodic mesoporous silica materials (with pore sizes from 2 to 50 nm) 20 years ago was to replace the microporous zeolites (which have pore sizes of <2 nm) in petroleum cracking applications, because the larger pore size of mesoporous materials allows for faster transport of larger molecules. However, these mesoporous materials could not replace zeolite materials because they showed lower hydrothermal stability and lower catalytic activity. This reduced performance has been attributed to the amorphous nature of the mesoporous materials' channel walls. To address this problem, we developed the concept of "nanocasting at high pressure". Through this approach, we produced hitherto-unavailable, periodic mesostructured silicas with crystalline pore walls. In nanocasting, we compress a periodic mesostructured composite (e.g. a periodic mesoporous silica with carbon-filled pores) and subsequently heat it to induce the selective crystallization of one of the two phases. We attain the necessary high pressure for synthesis using piston-cylinder and multianvil apparatuses. Using periodic mesostructured silica/carbon nanocomposites as starting material, we have produced periodic mesoporous coesite and periodic mesoporous quartz. The quartz material is highly stable under harsh hydrothermal conditions (800°C in pure steam), verifying that crystallinity in the channel walls of periodic mesoporous silicas increases their hydrothermal stability. Even without including the carbon phase in the silica pores, we could obtain mesoporous coesite materials. We found similar behavior for periodic mesoporous carbons, which convert into transparent, mesoporous, nanopolycrystalline diamond at high-pressure. We also show that periodic mesoporous materials can serve as precursors for nanocrystals of high-pressure phases. We obtained nearly monodisperse, discrete stishovite nanocrystals from periodic mesoporous silicas and coesite nanocrystals from periodic mesoporous organosilicas. The stishovite nanocrystals disperse in water and form colloidal solutions of individual stishovite nanocrystals. The stishovite nanocrystals could be useful for machining, drilling, and polishing. Overall, the results show that periodic mesoporous materials are suitable starting materials for the synthesis of nanoporous high-pressure phases and nanocrystals of high pressure phases. The substantially enhanced hydrothermal stability seen in periodic mesoporous silicas synthesized at high pressure demonstrates that high pressure can be a useful tool to produce porous materials with improved properties. We expect that synthesis using mesostructures at high pressure can be extended to many other materials beyond silicas and carbons. Presumably, this chemistry can also be extended from mesoporous to microporous and macroporous materials. PMID:23841843

Mandal, Manik; Landskron, Kai

2013-11-19

428

Anomalous Elasticity Behavior in Orthoenstatite at High Pressure: Onset of Phase Transition to High-Pressure Clinoenstatite  

NASA Astrophysics Data System (ADS)

(Mg,Fe)SiO3-pyroxene with ~10mol% of iron, is a major mineral component of the Earth's upper mantle. The orthoenstatite (Oen) end-member (MgSiO3) is often used as an analogue for the behavior of more complex mantle pyroxene compositions. Observation of Raman spectroscopy suggests that Oen (orthorhombic, space group Pbca) transforms to a high pressure phase of clinoenstatite (monoclinic, space group C2/c) above 12 GPa at room temperature. On the basis of observations in FeSiO3-orthoferrisilite, this transition is believed to be first-order in character. To date, there have been no elasticity measurements across this phase transition regime. Rapid advances in utilizing ultrasonic techniques in multi-anvil, high-pressure apparatus, in conjunction with in-situ synchrotron X-radiation, have made possible to perform elasticity measurements across such phase transitions; using these techniques, travel times (of P and S waves), length of the specimen and PVT-equation of state, can be collected simultaneously at high pressure and temperature conditions. Polycrystalline orthoenstatite specimens for this study were synthesized using the multi-anvil apparatus at the High Pressure Laboratory at Stony Brook. The high pressure ultrasonic experiments were performed using the 1000-ton press and T-cup apparatus at beamline 13ID at the Advanced Photon Source of the Argonne National Laboratory (supported by GSECARS). Three high-pressure runs were carried out, extending to a maximum pressure of ~17 GPa. Measured P and S wave velocities from all runs exhibited a decrease of velocity with increasing pressure above pressures of 9 GPa, reaching a minimum at 12~14 GPa and thereafter increasing with P. In the X-ray diffraction spectra from the polycrystalline specimen, the reflections characteristic of the monoclinic phase do not appear until the velocities reach their minimum values. The X-ray pattern of the orthorhombic phase does not totally disappear, even at the peak pressure of the experiment. In this paper, we will present the results of these elasticity measurements and discuss the relationship of anomalous elasticity behavior to the onset of the ortho-clino enstatite phase transition.

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

2003-04-01

429

Your garden hose: a potential health risk due to Legionella spp. growth facilitated by free-living amoebae.  

PubMed

Common garden hoses may generate aerosols of inhalable size (?10 ?m) during use. If humans inhale aerosols containing Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Clinical cases of these illnesses have been linked to garden hose use. The hose environment is ideal for the growth and interaction of Legionella and free-living amoebae (FLA) due to biofilm formation, elevated temperatures, and stagnation of water. However, the microbial densities and hose conditions necessary to quantify the human health risks have not been reported. Here we present data on FLA and Legionella spp. detected in water and biofilm from two types of garden hoses over 18 months. By culturing and qPCR, two genera of FLA were introduced via the drinking water supply and reached mean densities of 2.5 log10 amoebae·mL(-1) in garden hose water. Legionella spp. densities (likely including pathogenic L. pneumophila) were significantly higher in one type of hose (3.8 log10 cells·mL(-1), p < 0.0001). A positive correlation existed between Vermamoebae vermiformis densities and Legionella spp. densities (r = 0.83, p < 0.028). The densities of Legionella spp. identified in the hoses were similar to those reported during legionellosis outbreaks in other situations. Therefore, we conclude that there is a health risk to susceptible users from the inhalation of garden hose aerosols. PMID:25075763

Thomas, Jacqueline M; Thomas, Torsten; Stuetz, Richard M; Ashbolt, Nicholas J

2014-09-01

430

77 FR 37377 - High Pressure Steel Cylinders From the People's Republic of China: Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-977] High Pressure Steel Cylinders From the People's Republic...issuing an antidumping duty order on high pressure steel cylinders from the People's Republic...1\\ See High Pressure Steel Cylinders from China...

2012-06-21

431

78 FR 55059 - High Pressure Steel Cylinders from the People's Republic of China: Rescission of Countervailing...  

Federal Register 2010, 2011, 2012, 2013

...Administration [C-570-978] High Pressure Steel Cylinders from the People's Republic...the countervailing duty order on high pressure steel cylinders (cylinders) from the...the Countervailing Duty Order on High Pressure Steel Cylinders from the People's...

2013-09-09

432

77 FR 1060 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Final...  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-977] High Pressure Steel Cylinders From the People's Republic...antidumping duty investigation on high pressure steel cylinders from the People's Republic...1\\ See High Pressure Steel Cylinders from the People's...

2012-01-09

433

77 FR 37384 - High Pressure Steel Cylinders From the People's Republic of China: Countervailing Duty Order  

Federal Register 2010, 2011, 2012, 2013

...Administration [C-570-978] High Pressure Steel Cylinders From the People's Republic...issuing a countervailing duty order on high pressure steel cylinders (``steel cylinders...steel cylinders from the PRC. See High Pressure Steel Cylinders From the People's...

2012-06-21

434

77 FR 26738 - High Pressure Steel Cylinders From the People's Republic of China: Final Affirmative...  

Federal Register 2010, 2011, 2012, 2013

...Administration [C-570-978] High Pressure Steel Cylinders From the People's Republic...provided to producers and exporters of high pressure steel cylinders (steel cylinders) from...1\\ See High Pressure Steel Cylinders From the People's...

2012-05-07

435

76 FR 59658 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Preliminary...  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-977] High Pressure Steel Cylinders From the People's Republic...antidumping duty investigation on high pressure steel cylinders from the People's Republic...1\\ See High Pressure Steel Cylinders from the People's...

2011-09-27

436

A temperature compensated pressure transducer for high temperature, high pressure applications  

E-print Network

properttes 'l2' 5 Thermal analysts props rties 1&' 0& 3fitsubisht ME10D3 data . gg i (1RIN lens clata. . Photodiode data 0 Power and size of hght beam throughout transducer ig LIST OF FIGURES Figure Page 1 Dimensions of present extrusion pressure... aud conclusions. Light Beam Collimating Lens Photodeteetor Fig. 2. Solution configuratt CHAPTER II BACKGROUND 2. 1 Plastic Extruders Plastic extrusion machines are used to create plastic parts front pellets. The pellets are heated and uuxed...

Lippka, Sandra Margaret

2012-06-07

437

Chagas disease, a risk factor for high blood pressure.  

PubMed

Abstract Background. Chagas disease is a parasite infection caused by the protozoan Trypanosoma cruzi. Its most common complications is chronic Chagas heart disease but impairments of the systemic vasculature also has been observed. Although the different mechanisms that regulate blood pressure are disrupted, to our knowledge data on the association of hypertension and chronic Chagas disease are scarce. In this regard we evaluate whether Chagas disease constitutes a high blood pressure risk factor. Materials and methods. We recruited 200 individuals, half of them with positive serology for T. cruzi. They were subjected to a complete clinical examination. Results. The mean age of sampled individuals was 46.7 ± 12.3, and the mean of systolic and diastolic blood pressure were 124 ± 12 mmHg and 82 ± 10 mmHg, respectively. There were no between-group differences regarding age, sex distribution or body mass index. Chagas disease contributed significantly to high blood pressure (OR = 4, 95% CI 1.8323-7.0864, p = 0.0002). Conclusion. Our results reveal an important association between Chagas disease and high blood pressure, which should be contemplated by physicians in order to promote preventive cardiovascular actions in patients with Chagas disease. PMID:24738834

Vicco, Miguel Hernán; Rodeles, Luz; Yódice, Agustina; Marcipar, Iván

2014-12-01

438

A survey of compatibility of materials with high pressure oxygen service  

NASA Technical Reports Server (NTRS)

The available information on the compatibility of materials with oxygen as applied to the production, transport, and applications experience of high pressure liquid and gaseous oxygen is compiled. High pressure is defined as about 2000 to 3000 psia. Since high pressure projections sometimes can be made from lower pressure data, some low pressure data are also included. Low pressure data are included if they are considered helpful to a better understanding of the behavior at high pressures.

Hust, J. G.; Clark, A. F.

1972-01-01

439

Energy efficient engine: High pressure turbine uncooled rig technology report  

NASA Technical Reports Server (NTRS)

Results obtained from testing five performance builds (three vane cascades and two rotating rigs of the Energy Efficient Engine uncooled rig have established the uncooled aerodynamic efficiency of the high-pressure turbine at 91.1 percent. This efficiency level was attained by increasing the rim speed and annulus area (AN(2)), and by increasing the turbine reaction level. The increase in AN(2) resulted in a performance improvement of 1.15 percent. At the design point pressure ratio, the increased reaction level rig demonstrated an efficiency of 91.1 percent. The results of this program have verified the aerodynamic design assumptions established for the Energy Efficient Engine high-pressure turbine component.

Gardner, W. B.

1979-01-01

440

carbonate solid solution at high pressures up to 55 GPa  

NASA Astrophysics Data System (ADS)

Magnesite, siderite and ferromagnesites Mg1- x Fe x CO3 ( x = 0.05, 0.09, 0.2, 0.4) were characterized using in situ Raman spectroscopy at high pressures up to 55 GPa. For the Mg-Fe-carbonates, the Raman peak positions of six modes (T, L, ?4, ?1, ?3 and 2?2) in the dependence of iron content in the carbonates at ambient conditions are presented. High-pressure Raman spectroscopy shows that siderite undergoes a spin transition at ~40 GPa. The examination of the solid solutions with compositions Mg0.6Fe0.4CO3, Mg0.8Fe0.2CO3, Mg0.91Fe0.09CO3 and Mg0.95Fe0.05CO3 indicates that with increase in the amount of the Fe spin transition pressure increases up to ~45 GPa.

Spivak, Anna; Solopova, Natalia; Cerantola, Valerio; Bykova, Elena; Zakharchenko, Egor; Dubrovinsky, Leonid; Litvin, Yuriy

2014-09-01

441

Hybrid photonic crystal fiber sensing of high hydrostatic pressure  

NASA Astrophysics Data System (ADS)

The opto-mechanical response of Hybrid Photonic Crystal Fiber (HPCF) with Ge-doped inclusions is numerically modeled for high hydrostatic pressure sensing purpose. A typical photonic crystal fiber (PCF) consists of a silica solidcore and a cladding with a hexagonal lattice of air-holes. The HPCF is similar to the regular PCF, but a horizontal line of air-holes is substituted by solid high index rods of Ge-doped silica. The optical guidance in HPCFs is supported combining two physical effects: the modified total internal reflection and the photonic bandgap. In such fibers, the Gedoped inclusions induce residual birefringence. In our analysis, we evaluate the susceptibility of the phase modal birefringence and group birefringence to hydrostatic pressure. The analyses were performed at a photonic bandgap with central wavelength near to 1350 nm. The polarimetric pressure sensitivity is about 10 rad/MPa x m at ? = 1175 nm.

Franco, Marcos A. R.; Serrão, Valdir A.; Pitarello, Tânia R.; Cerqueira S., Arismar, Jr.

2011-05-01

442

Low pressure high speed Stirling air engine. Final technical report  

SciTech Connect

The purpose of this project was to design, construct and test a simple, appropriate technology low pressure, high speed, wood-fired Stirling air engine of 100 W output. The final design was a concentric piston/displacer engine of 454 in. bore and 1 in. stroke with a rhombic drive mechanism. The project engine was ultimately completed and tested, using a propane burner for all tests as a matter of convenience. The 100 W aim was exceeded, at atmospheric pressure, over a wide range of engine speed with the maximum power being 112 W at 1150 rpm. A pressure can was constructed to permit pressurization; however the grant funds were running out, and the only pressurized power test attempted was unsuccessful due to seal difficulties. This was a disappointment because numerous tests on the 4 cubic inch engine suggested power would be more than doubled with pressurization at 25 psig. A manifold was designed and constructed to permit operation of the engine over a standard No. 40 pot bellied stove. The engine was run successfully, but at reduced speed and power, over this stove. The project engine started out being rather noisy in operation, but modifications ultimately resulted in a very quiet engine. Various other difficulties and their solutions also are discussed. (LCL)

Ross, M.A.

1980-06-16

443

Pressure tuning of high-power laser diodes  

NASA Astrophysics Data System (ADS)

We demonstrate wide-range wavelength tunability of high-power laser diodes emitting at 660 nm, 808 nm, and 980 nm. Pressure shifts of the emission wavelength are due to the increase of bandgaps of III-V semiconductors under pressure with the rate of about 10 meV per kbar. For the 980 nm InGaAs/GaAs laser the threshold currents and the quantum efficiencies remain constant with pressure which allows for the constant operating current and the emitted power in the full tuning range. For 808 nm GaAs/AlGaAs and 660 nm InGaP/AlGaInP lasers there is an increase of threshold currents with pressure related to the direct-indirect crossover in the conduction band of AlGaAs and AlGaInP. This limits the tuning range unless we operate the laser at lower temperature. We designed the pressure cell with Peltier cooling allowing for independent control of temperature down to 0 Celsius and pressure up to 20 kbar. This device allows for the tuning of 980 nm laser down to 840 nm, 808 nm laser down to 720 nm, 660 nm laser down to 620 nm.

Adamiec, Pawel; Dybala, F.; Bercha, A.; Bohdan, R.; Trzeciakowski, W.

2003-11-01

444

Theoretical investigation of the high-pressure phases of Ce  

NASA Astrophysics Data System (ADS)

In order to shed light on the recent experimental controversy concerning the intermediate pressure phases of Ce we have made systematic electronic structure and total-energy studies on Ce in the experimentally reported low-pressure phase ?-Ce (fcc), the intermediate-pressure ?-U (?'), the body-centered monoclinic [?''(I)], and C-face-centered monoclinic [?''(II)] phases, together with the stable high-pressure body-centered tetragonal phase. We also included the body-centered cubic, hexagonal-close-packed, and ? (hP3) phases. In this study we used the accurate full-potential linear muffin-tin orbital (FPLMTO) method. The optimized structural parameters obtained from our total-energy studies for the ?' and ?''(II) phases are found to be in good agreement with corresponding experimental values. The structural optimization of the ?''(I) phase always yields the fcc or bct phase stable, depending upon the volume considered. Except for an improvement in the equilibrium volume, the generalized gradient correction reproduces the calculated relative stability between different phases of Ce at high pressure of the local-density approximation. Of the experimentally reported intermediate pressure structures [?', ?''(I) and ?''(II)] we find that the ?''(II) phase is the most stable. Among the contending phases, ?' and ?''(I), the latter is very close in energy to the ?'' phase whereas the former is substantially higher in energy. We thus rule out the ?-U structure as an intermediate pressure phase of Ce. Our work suggests that the most probable structural phase transition sequence of Ce metal is fcc(?)-->fcc(?)-->?''(II) --> bct, which is consistent with current experimental results.

Ravindran, P.; Nordström, L.; Ahuja, R.; Wills, J. M.; Johansson, B.; Eriksson, O.

1998-01-01

445

Inactivation of a Norovirus by High-Pressure Processing?  

PubMed Central

Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV-1 was enhanced when pressure was applied at an initial temperature of 5°C; a 5-min pressure treatment of 350 MPa at 30°C inactivated 1.15 log10 PFU of virus, while the same treatment at 5°C resulted in a reduction of 5.56 log10 PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5°C and 20°C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5°C was sufficient to inactivate 4.05 log10 PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. PMID:17142353

Kingsley, David H.; Holliman, Daniel R.; Calci, Kevin R.; Chen, Haiqiang; Flick, George J.

2007-01-01

446

Inactivation of a norovirus by high-pressure processing.  

PubMed

Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20 degrees C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log(10) PFU of MNV-1. The inactivation of MNV-1 was enhanced when pressure was applied at an initial temperature of 5 degrees C; a 5-min pressure treatment of 350 MPa at 30 degrees C inactivated 1.15 log(10) PFU of virus, while the same treatment at 5 degrees C resulted in a reduction of 5.56 log(10) PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5 degrees C and 20 degrees C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5 degrees C was sufficient to inactivate 4.05 log(10) PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. PMID:17142353

Kingsley, David H; Holliman, Daniel R; Calci, Kevin R; Chen, Haiqiang; Flick, George J

2007-01-01

447

High pressure flow gravimetric apparatus for supercritical fluid extraction studies  

NASA Astrophysics Data System (ADS)

An experimental apparatus has been developed for real time measurements of fluid-solid adsorption (or desorption) rates and equilibria at elevated pressures. In addition to controlling pressure and flow rates simultaneously, this setup is able to operate at higher flow rates than previously possible in supercritical fluid experiments. The system consists of a high pressure microbalance, two high pressure syringe pumps, and an absorbance detector. The microbalance enables the collection of data at a greater time resolution, resulting in a more accurate measurement of rate data. Because of the dual syringe pump design, there is no pressure drop in the system, making it possible to operate at a wide range of flow rates (at experimental conditions). The buoyancy force was measured with helium experiments, while the hydrodynamic forces were measured using a clean solid sample and supercritical carbon dioxide at different flow rates. It was found that the hydrodynamic force increased with flow rate as expected. The apparatus was tested by conducting two desorption experiments of phenol from activated carbon at 141±0.07 bar, 36.0±0.02 °C, and 0.47 ml/min (at experimental conditions). The amount of phenol removed was 16.4% and 18%, respectively, in the two runs which is consistent with previously published results and indicates the difficulty of regenerating activated carbon loaded with phenol.

Jwayyed, Alzubair M.; Humayun, Raashina; Tomasko, David L.

1997-12-01

448

Keep the Beat: Control Your High Blood Pressure  

E-print Network

Keep the Beat: Control Your High Blood Pressure Healthy Hearts, Healthy Homes #12;Read other booklets in the Healthy Hearts, Healthy Homes series: Are You at Risk for Heart Disease? Do You Need To Lose Weight? Do You Know Your Cholesterol Levels? Protect Your Heart Against Diabetes Enjoy Living

Bandettini, Peter A.

449

A robust flow sensor for high pressure automotive applications  

Microsoft Academic Search

In this paper, a micromachined mass flow sensor mounted on a high pressure stable substrate is presented to measure on board the different injection quantities needed in modern direct injection (DI) systems for optimum performance of the engine. To detect the injection end\\/begin as well as the injection rate as precisely and fast as possible, the sensor is completely integrated

U. Schmid

2002-01-01

450

Differences in evolutionary pressure acting within highly conserved ortholog groups  

Microsoft Academic Search

BACKGROUND: In highly conserved widely distributed ortholog groups, the main evolutionary force is assumed to be purifying selection that enforces sequence conservation, with most divergence occurring by accumulation of neutral substitutions. Using a set of ortholog groups from prokaryotes, with a single representative in each studied organism, we asked the question if this evolutionary pressure is acting similarly on different

Teresa M Przytycka; Raja Jothi; L Aravind; David J Lipman

2008-01-01

451

High-Pressure Inactivation of Hepatitis A Virus within Oysters  

Microsoft Academic Search

Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish

Kevin R. Calci; Gloria K. Meade; Robert C. Tezloff; David H. Kingsley

2005-01-01

452

3. SOUTHWEST REAR, WITH RAILROAD LINE AT RIGHT. HIGH PRESSURE ...  

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

3. SOUTHWEST REAR, WITH RAILROAD LINE AT RIGHT. HIGH PRESSURE HELIUM STORAGE TANKS AT LEFT. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Helium Compression Plant, Test Area 1-115, intersection of Altair & Saturn Boulevards, Boron, Kern County, CA

453

26. VIEW OF PUMP ROOM, SHOWING PORTIONS OF HIGH PRESSURE ...  

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

26. VIEW OF PUMP ROOM, SHOWING PORTIONS OF HIGH PRESSURE AIR SYSTEM AT LEFT AND CENTER AND OVERFLOW STORAGE TANK AT RIGHT, LOOKING NORTHWEST - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

454

High Pressure X-Ray Diffraction Study of V. Siruguria,*  

E-print Network

Shed, Bhabha Atomic Research Centre, Mumbai 400 085, India b Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India c Novel Materials & Structural Chemistry Division, Bhabha with the available instrument resolution. Key words: actinide intermetallics, high pressure, equation of state PACS

455

High Pressure Research Vol. 26, No. 3, September 2006, 185191  

E-print Network

. To this end, the determination of the composition and condition of the deep Earth is of extreme importance of Earth Sciences, University College London, Gower Street, London WC1E 6BT, U.K. (Received 24 May 2006; High pressure; Multi-anvil press 1. Introduction Although the basic structure of the deep Earth has

Vocadlo, Lidunka

456

National High Blood Pressure 12-Month Kit. May 1988.  

ERIC Educational Resources Information Center

Part I of this kit provides information for program planners and health professionals on ways to overcome barriers to health care among the medically underserved, promote high blood pressure control through the media and other community channels, and improve adherence to treatment among hypertensive patients. It lists additional resources for…

National Heart and Lung Inst. (DHHS/NIH), Bethesda, MD. National High Blood Pressure Education Program.

457

Potential applications of high pressures in pharmaceutical science and medicine  

Microsoft Academic Search

High pressure (HP) technology appears to be of paramount interest for valuable applications in pharmacy and medicine, owing to academic studies and industrial developments of this technology for food processing. The main potential application of HP between 100 MPa and 1200 MPa (1 kbar to 12kbar) is the inactivation of biological agents (bacteria, moulds, yeasts, virus and even prions) which

Patrick Masson; Carole Tonello

2000-01-01

458

JT8D high pressure compressor performance improvement  

Microsoft Academic Search

An improved performance high pressure compressor with potential application to all models of the JT8D engine was designed. The concept consisted of a trenched abradable rubstrip which mates with the blade tips for each of the even rotor stages. This feature allows tip clearances to be set so blade tips run at or near the optimum radius relative to the

Gaffin

1981-01-01

459

Advanced High Pressure O2/H2 Technology  

NASA Technical Reports Server (NTRS)

Activities in the development of advanced high pressure oxygen-hydrogen stage combustion rocket engines are reported. Particular emphasis is given to the Space Shuttle main engine. The areas of engine technology discussed include fracture and fatigue in engine components, manufacturing and producibility engineering, materials, bearing technology, structure dynamics, fluid dynamics, and instrumentation technology.

Morea, S. F. (editor); Wu, S. T. (editor)

1985-01-01

460

Arc Cathode Emission Mechanisms at High Currents and Pressures  

Microsoft Academic Search

Cathode emission was studied at over 1 atmosphere pressure into He and A plasmas at 100- to 500-A total current. The cathode spot temperature and current density were measured by a high speed photometric method developed for this purpose. A low vacuum thermionic work function was found to be a most important criterion for long cathode life. Emission current densities

Peter W. Neurath; Thomas W. Gibbs

1963-01-01

461

Hybrid photonic crystal fiber sensing of high hydrostatic pressure  

Microsoft Academic Search

The opto-mechanical response of Hybrid Photonic Crystal Fiber (HPCF) with Ge-doped inclusions is numerically modeled for high hydrostatic pressure sensing purpose. A typical photonic crystal fiber (PCF) consists of a silica solidcore and a cladding with a hexagonal lattice of air-holes. The HPCF is similar to the regular PCF, but a horizontal line of air-holes is substituted by solid high

Marcos A. R. Franco; Valdir A. Serrão; Tânia R. Pitarello; Arismar Cerqueira S. Jr.

2011-01-01

462

Design and testing of high-pressure railguns and projectiles  

SciTech Connect

The results of high-pressure tests of four railgun designs and four projectile types are presented. All tests were conducted at the Los Alamos explosive magnetic-flux compression facility in Ancho Canyon. The data suggest that the high-strength projectiles have lower resistance to acceleration than the low-strength projectiles, which expand against the bore during acceleration. The railguns were powered by explosive magnetic-flux compression generators. Calculations to predict railgun and power supply performance were performed.

Peterson, D.R.; Fowler, C.M.; Cummings, C.E.; Kerrisk, J.F.; Parker, J.V.; Marsh, S.P.; Adams, D.F.

1983-01-01

463

Application of the TraPPE Force Field to Predicting Isothermal Pressure Volume Curves at High Pressures and High Temperatures  

NASA Astrophysics Data System (ADS)

Knowledge of the thermophysical properties of materials at extreme pressure and temperature conditions is essential for improving our understanding of many planetary and detonation processes. Significant gaps in what is known about the behavior of materials at high density and high temperature exist, largely, due to the limitations and dangers of performing experiments at the necessary extreme conditions. Modeling these systems through the use of equations of state and particle-based simulation methods significantly extends the range of pressures and temperatures that can be safely studied. The reliability of such calculations depend on the accuracy of the models used. Here we present an assessment of the united-atom version of the TraPPE (transferable potentials for phase equilibria) force field and single-site exp-6 representations for methane, methanol, oxygen, and ammonia at extreme conditions. As shown by Monte Carlo simulations in the isobaric isothermal ensemble, the TraPPE models, despite being parameterized to the vapor liquid coexistence curve (i.e., relatively mild conditions), perform remarkably well in the high-pressure/high-temperature regime. The single-site exp-6 models can fit experimental data in the high-pressure/temperature regime very well, but the parameters are less transferable to conditions below the critical temperature.

Eggimann, Becky L.; Siepmann, J. Ilja; Fried, Laurence E.

2007-06-01

464

A possible molecular mechanism for the pressure reversal of general anaesthetics: Aggregation of halothane in POPC bilayers at high pressure  

NASA Astrophysics Data System (ADS)

We placed halothane, a general anaesthetic, inside palmitoyloleoylphosphatidylcholine (POPC) bilayers and performed molecular dynamics simulations at atmospheric and raised pressures. We demonstrated that halothane aggregated inside POPC membranes at 20 MPa but not at 40 MPa. The pressure range of aggregation matches that of pressure reversal in whole animals, and strongly suggests that this could be the mechanism for this effect. Combining these results with previous experimental data, we describe a testable hypothesis of how aggregation of general anaesthetics at high pressure can lead to pressure reversal, the effect whereby these drugs lose the efficacy at high pressure.

Tu, K. M.; Matubayasi, N.; Liang, K. K.; Todorov, I. T.; Chan, S. L.; Chau, P.-L.

2012-08-01

465

Raman spectroscopic studies on p-terphenyl under high pressure  

NASA Astrophysics Data System (ADS)

High-pressure Raman scattering studies are performed on p-terphenyl up to 5 GPa. The Raman activities of different symmetric molecules were analyzed by means of group theory methods. A phase transition was detected at 1.3 GPa from changes in the slope on plots of frequency versus pressure. The diminishing of internal modes indicated that the molecule symmetry transformed from C2 to D2h. This is an effective method for detecting planar molecular structure of p-terphenyl by ring-ring stretching vibration mode, which can provide a new spectroscopic evidence of planar conjugated polyphenyl molecular conformation.

Liu, Tianyuan; Xu, Shengnan; Sun, Chenglin; Zhou, Mi

2014-11-01

466

Performance of pneumatic conveying injection systems against high back pressures  

SciTech Connect

Considerable work has been performed in recent years on the pneumatic conveying of coal in conventional systems operating at atmospheric conditions. This work is well documented. However, many systems within the power generation industry involve high gas pressures and temperatures. These extreme operating conditions may have a significant effect on the performance of a pneumatic conveying system. Such systems are becoming more prevalent as they offer higher efficiencies, good environmental performance and lower costs. For example, developments in pressurised fluidised bed combustion and gasification. The aim of this paper is to present an insight into the possible effect of gas pressure or gas density on pneumatic conveying system performance.

Johnson, P.A.; Jones, M.G.; Mills, D. [Glasgow Caledonian Univ. (United Kingdom)

1994-12-31

467

High pressure phase transformation in iron under fast compression  

SciTech Connect

We present experimental results on the solid-solid, {alpha} to {epsilon} phase transformation kinetics of iron under high pressure dynamic compression. We observe kinetic features - velocity loops - similar with the ones recently reported to occur when water is frozen into its ice VII phase under comparable experimental conditions. We analyze this behavior in terms of general ideas coupling the steady sample compression with phase nucleation and growth with a pressure dependent phase interface velocity. The model is used to predict the response of iron when steadily driven across the {alpha} - {epsilon} phase boundary on very short time scales, including those envisioned to be achieved in ultra-fast laser experiments.

Bastea, M; Bastea, S; Becker, R

2009-07-07

468

Effects of high combustion chamber pressure on rocket noise environment  

NASA Technical Reports Server (NTRS)

The acoustical environment for a high combustion chamber pressure engine was examined in detail, using both conventional and advanced theoretical analysis. The influence of elevated chamber pressure on the rocket noise environment was established, based on increase in exit velocity and flame temperature, and changes in basic engine dimensions. Compared to large rocket engines, the overall sound power level is found to be 1.5 dB higher, if the thrust is the same. The peak Strouhal number shifted about one octave lower to a value near 0.01. Data on apparent sound source location and directivity patterns are also presented.

Pao, S. P.

1972-01-01

469

Theoretical investigation of high pressure phases of carbon dioxide  

PubMed

The recent discovery of a new solid phase of carbon dioxide ( CO2-V) has made it apparent that the properties of this vital chemical species are drastically altered under high pressure conditions. The reported transition at around 40 GPa from the Cmca phase ( CO2-III), which is a molecular solid, into the novel phase, which was observed to be quartzlike, clearly suggests a dramatic change of the chemical, electronic, and structural properties. We here present a theoretical analysis of the implications of this metamorphosis. At even higher pressures, we predict the existence of a very hard phase of the stishovite type. PMID:10991526

Holm; Ahuja; Belonoshko; Johansson

2000-08-01

470

Microfabricated Nickel Based Sensors for Hostile and High Pressure Environments  

NASA Astrophysics Data System (ADS)

This thesis outlines the development of two platforms for integrating microfabricated sensors with high pressure feedthroughs for application in hostile high temperature high pressure environments. An application in oil well production logging is explored and two sensors were implemented with these platforms for application in an oil well. The first platform developed involved microfabrication directly onto a cut and polished high pressure feedthrough. This technique enables a system that is more robust than the wire bonded silicon die technique used for MEMS integration in pressure sensors. Removing wire bonds from the traditional MEMS package allows for direct interface of a microfabricated sensor with a hostile high pressure fluid environment which is not currently possible. During the development of this platform key performance metrics included pressure testing to 70MPa and temperature cycling from 20°C to 200°C. This platform enables electronics integration with a variety of microfabricated electrical and thermal based sensors which can be immersed within the oil well environment. The second platform enabled free space fabrication of nickel microfabricated devices onto an array of pins using a thick tin sacrificial layer. This technique allowed microfabrication of metal MEMS that are released by distances of 1cm from their substrate. This method is quite flexible and allows for fabrication to be done on any pin array substrate regardless of surface quality. Being able to place released MEMS sensors directly onto traditional style circuit boards, ceramic circuit boards, electrical connectors, ribbon cables, pin headers, or high pressure feedthroughs greatly improves the variety of possible applications and reduces fabrication costs. These two platforms were then used to fabricate thermal conductivity sensors that showed excellent performance for distinguishing between oil, water, and gas phases. Testing was conducted at various flow rates and performance of the released platform was shown to be better than the performance seen in the anchored sensors while both platforms were significantly better than a simply fabricated wrapped wire sensor. The anchored platform was also used to demonstrate a traditional capacitance based fluid dielectric sensor which was found to work similarly to conventional commercial capacitance probes while being significantly smaller in size.

Holt, Christopher Michael Bjustrom

471

Low-pressure performance of annular, high-pressure (40 atm) high-temperature (2480 K) combustion system  

NASA Technical Reports Server (NTRS)

Experimental tests were conducted to develop a combustion system for a 40 atmosphere pressure, 2480 K exhaust gas temperature, turbine cooling facility. The tests were conducted in an existing facility with a maximum pressure capability of 10 atmospheres and where inlet air temperatures as high as 894 K could be attained. Exhaust gas temperatures were as high as 2365 K. Combustion efficiences were about 100 percent over a fuel air ratio range of 0.016 to 0.056. Combustion efficiency decreased at leaner and richer ratios when the inlet air temperature was 589 K. Data are presented that show the effect of fuel air ratio and inlet air temperature on liner metal temperature. Isothermal system pressure loss as a function of diffuser inlet Mach number is also presented. Data included exhaust gas pattern factors; unburned hydrocarbon, carbon monoxide, and oxides of nitrogen emission index values; and smoke numbers.

Wear, J. D.

1980-01-01

472

SAMPLING SYSTEM EVALUATION FOR HIGH-TEMPERATURE, HIGH-PRESSURE PROCESSES  

EPA Science Inventory

The report describes a sampling system designed for the high temperatures and high pressures found in pressurized fluidized-bed combustors (PFBC). The system uses an extractive sampling approach, withdrawing samples from the process stream for complete analysis of particulate siz...

473

Energy efficient engine high-pressure turbine detailed design report  

NASA Technical Reports Server (NTRS)

The energy efficient engine high-pressure turbine is a single stage system based on technology advancements in the areas of aerodynamics, structures and materials to achieve high performance, low operating economics and durability commensurate with commercial service requirements. Low loss performance features combined with a low through-flow velocity approach results in a predicted efficiency of 88.8 for a flight propulsion system. Turbine airfoil durability goals are achieved through the use of advanced high-strength and high-temperature capability single crystal materials and effective cooling management. Overall, this design reflects a considerable extension in turbine technology that is applicable to future, energy efficient gas-turbine engines.

Thulin, R. D.; Howe, D. C.; Singer, I. D.

1982-01-01

474

Aging study of boiling water reactor high pressure injection systems  

SciTech Connect

The purpose of high pressure injection systems is to maintain an adequate coolant level in reactor pressure vessels, so that the fuel cladding temperature does not exceed 1,200{degrees}C (2,200{degrees}F), and to permit plant shutdown during a variety of design basis loss-of-coolant accidents. This report presents the results of a study on aging performed for high pressure injection systems of boiling water reactor plants in the United States. The purpose of the study was to identify and evaluate the effects of aging and the effectiveness of testing and maintenance in detecting and mitigating aging degradation. Guidelines from the United States Nuclear Regulatory Commission`s Nuclear Plant Aging Research Program were used in performing the aging study. Review and analysis of the failures reported in databases such as Nuclear Power Experience, Licensee Event Reports, and the Nuclear Plant Reliability Data System, along with plant-specific maintenance records databases, are included in this report to provide the information required to identify aging stressors, failure modes, and failure causes. Several probabilistic risk assessments were reviewed to identify risk-significant components in high pressure injection systems. Testing, maintenance, specific safety issues, and codes and standards are also discussed.

Conley, D.A.; Edson, J.L.; Fineman, C.F. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

1995-03-01

475

Maintaining viability of white clover under very high pressure  

NASA Astrophysics Data System (ADS)

The high pressure technique developed in physics may give a new possibility if it is applied to a biological study. We have been studying the tolerance of small living samples such as planktons and mosses, and found that all of them were alive after exposed to extremely high hydrostatic pressure of 7.5 GPa. This technique has been extended to a higher plant Trifolium lepens L. (white clover). A few seeds of white clover were exposed to 7.5 GPa for up to 6 days. After the pressure was released, they were seeded on agar, or directly on sowing soil. Seventeen out of the total 22 seeds exposed to the high pressure were found to be alive. Those exposed for up to 1 day and seeded on agar germinated roots. Those exposed for up to 1 h and seeded on soil germinated stems and leaves. The present technique has the possibility of being applied to improve breed of plants and to discover a very strong species that stands against very severe environmental conditions.

Nishihira, N.; Iwasaki, T.; Shinpou, R.; Hara, A.; Ono, F.; Hada, Y.; Mori, Y.; Takarabe, K.; Saigusa, M.; Matsushima, Y.; Saini, N. L.; Yamashita, M.

2012-06-01