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Sample records for constructing integrable high-pressure

  1. High pressure synthesis gas conversion. Task 1, System construction

    SciTech Connect

    Not Available

    1992-01-01

    A high pressure gas phase fermentation system has been constructed for the biological production of ethanol from coal synthesis gas. The reactors in the system consist of a 650 mL continuous stirred tank reactor and a 1 L continuous column reactor. The reactors are designed for individual or dual operation in series or parallel, with continuous gas and liquid feed. The system is housed in a constant temperature, explosion-proof room, equipped with gas leak detectors.

  2. SMART composite high pressure vessels with integrated optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Blazejewski, Wojciech; Czulak, Andrzej; Gasior, Pawel; Kaleta, Jerzy; Mech, Rafal

    2010-04-01

    In this paper application of integrated Optical Fiber Sensors for strain state monitoring of composite high pressure vessels is presented. The composite tanks find broad application in areas such as: automotive industry, aeronautics, rescue services, etc. In automotive application they are mainly used for gaseous fuels storage (like CNG or compressed Hydrogen). In comparison with standard steel vessels, composite ones have many advantages (i.e. high mechanical strength, significant weight reduction, etc). In the present work a novel technique of vessel manufacturing, according to this construction, was applied. It is called braiding technique, and can be used as an alternative to the winding method. During braiding process, between GFRC layers, two types of optical fiber sensors were installed: point sensors in the form of FBGs as well as interferometric sensors with long measuring arms (SOFO®). Integrated optical fiber sensors create the nervous system of the pressure vessel and are used for its structural health monitoring. OFS register deformation areas and detect construction damages in their early stage (ensure a high safety level for users). Applied sensor system also ensured a possibility of strain state monitoring even during the vessel manufacturing process. However the main application of OFS based monitoring system is to detect defects in the composite structure. An idea of such a SMART vessel with integrated sensor system as well as an algorithm of defect detection was presented.

  3. High-pressure combinatorial process integrating hot isostatic pressing.

    PubMed

    Fujimoto, Kenjiro; Morita, Hiroki; Goshima, Yuji; Ito, Shigeru

    2013-12-01

    A high-pressure combinatorial process integrating hot isostatic pressing (HIP) was developed by providing a reaction vessel with a high-pressure tightness based on a commercial flange. The reaction vessel can be used up to 200 MPa and 500 °C under HIP processing condition. Preparation of spinel-type MgAl2O4 from Mg(OH)2, Al(OH)3 and AlOOH was performed using the reaction vessel under 200 MPa and 500 °C as demonstration. The entire powder library was characterized using powder X-ray diffraction patterns, and the single phase of spinel-type MgAl2O4 was obtained from Mg(OH)2+Al(OH)3. These assessments corresponded with previously published data. PMID:24168067

  4. High pressure ratio cryocooler with integral expander and heat exchanger

    NASA Astrophysics Data System (ADS)

    Crunkleton, J. A.; Smith, J. L., Jr.; Iwasa, Y.

    A new 1 W, 4.2 K cryocooler is under development that is intended to miniaturize helium temperature refrigeration systems using a high-pressure-ratio Collins-type cycle. The configuration resulted from optimization studies of a saturated vapor compression (SCV) cycle that employs miniature parallel-plate heat exchangers. The basic configuration is a long displacer in a close-fitting, thin-walled cylinder. The displacer-to-cylinder gap is the high-pressure passage of the heat exchanger, and the low-pressure passage is formed by a thin tube over the OD of the cylinder. A solenoid-operated inlet valve admits 40 atm helium to the displacer-to-cylinder gap at room temperature, while the solenoid-operated exhaust valve operates at 4 atm. The single-stage cryocooler produces 1 W of refrigeration at 40 K without precooling and at 20 K with liquid nitrogen precooling.

  5. Development of design criteria for a high pressure vessel construction code

    SciTech Connect

    Mraz, G.J.

    1987-05-01

    Out of concern for public safety, most legal jurisdictions now require unfired pressure vessel construction to comply with the ASME Boiler and Pressure Vessel Code. Because the present two divisions of Section VIII of that Code are not well suited for high pressure design, a new division is needed. The currently anticipated main design criteria of the proposed division are full plastic flow or full overstrain pressure, stress intensity in the bore, fatigue, and fracture mechanics. The rules are expected to allow better utilization of high strength steels already included in the present Section VIII. At the same time materials of even higher strength are introduced. The benefits of compressive prestress are recognized. Construction methods allowing it's achievement, such as autofrettage, shrink fitting and wire winding are included. Reasons for selection of the criteria are given.

  6. Calculations of High-Pressure Properties of Beryllium: Construction of a Multiphase Equation of State

    SciTech Connect

    Benedict, L; Ogitsu, T

    2008-07-24

    We describe the construction of a three-phase equation of state (EOS) for elemental beryllium. The phases considered are: the ambient hcp phase, the high-temperature bcc phase, and the liquid. The free energies of the solid phases are constructed from cold, ion-thermal, and electron-thermal components derived from ab initio electronic structure-based calculations. We find that the bcc phase is unstable near ambient conditions, and that even at high pressures at which the bcc phase is stable, the bcc-hcp energy barrier can be as small as a few hundred Kelvins. The liquid free energy is based on a model of Chisolm and Wallace and is constrained by using the melt curve (determined by ab initio 2-phase simulations) as a reference. The high-temperature plasma limit is addressed with an average-atom-in-jellium model. Comparisons to experimental results, both for the ambient hcp phase, and for the phase diagram as a whole, are discussed.

  7. Membrane integrity of Campylobacter jejuni subjected to high pressure is pH-dependent

    NASA Astrophysics Data System (ADS)

    Lerasle, M.; Guillou, S.; Simonin, H.; Laroche, M.; de Lamballerie, M.; Federighi, M.

    2012-03-01

    Our study focuses on a foodborne pathogen, Campylobacter, which is responsible for the most frequent bacterial enteritis worldwide. Membrane integrity of Campylobacter jejuni NCTC 11168 cells treated at high pressure (300 MPa, 20°C, 10 min) at pH 7.0 and pH 5.6 was measured by fluorescence spectroscopy of propidium iodide (PI) uptake. The percentage of membrane-damaged cells by high pressure, in which PI is allowed to penetrate, was determined using two calibration methods based on the PI fluorescence signal obtained with cells killed either by a heat treatment (80°C for 15 min) or by a pressure treatment (400 MPa, 20°C, 10 min). Both calibrations were shown to be statistically different (P<0.05), particularly at acidic pH, suggesting that a difference in the penetration of PI into bacterial cells might depend on the mode of cell inactivation. These results corroborate the fact that the mechanism of microbial inactivation by high pressure is pH-dependent.

  8. Integrated-fin gasket for palm cubic-anvil high pressure apparatus

    SciTech Connect

    Cheng, J.-G.; Matsubayashi, K.; Nagasaki, S.; Hisada, A.; Hirayama, T.; Uwatoko, Y.; Hedo, M.; Kagi, H.

    2014-09-15

    We described an integrated-fin gasket technique for the palm cubic-anvil apparatus specialized for the high-pressure and low-temperature measurements. By using such a gasket made from the semi-sintered MgO ceramics and the tungsten-carbide anvils of 2.5 mm square top, we successfully generate pressures over 16 GPa at both room and cryogenic temperatures down to 0.5 K. We observed a pressure self-increment for this specific configuration and further characterized the thermally induced pressure variation by monitoring the antiferromagnetic transition temperature of chromium up to 12 GPa. In addition to enlarge the pressure capacity, such a modified gasket also improves greatly the surviving rate of electrical leads hanging the sample inside a Teflon capsule filled with the liquid pressure-transmitting medium. These improvements should be attributed to the reduced extrusion of gasket materials during the initial compression.

  9. The design, construction and three dimensional modeling of a high pressure organometallic chemical vapor deposition reactor

    NASA Astrophysics Data System (ADS)

    McCall, Sonya Denise

    Two high pressure reactors have been designed, built and tested, in order to extend Organometallic Chemical Vapor Deposition (OMCVD) to materials that exhibit large thermal decomposition pressures at their optimum growth temperature. The Differentially Pressure Controlled (DPC) Reactor System was designed and built for use at pressures ≤10 atm. A second generation reactor, the Compact Hard Shell (CHS) Reactor was built in order to extend pressures ≤100 atm. A physico-chemical model of the High Pressure Organometallic Chemical Vapor Deposition (HPOMCVD) process that describes three dimensional transport phenomena as well as gas-phase and surface reactions underlying the growth of compound semiconductors is presented. A reduced-order model of the Organometallic Chemical Vapor Deposition of InN from trimethylindium and ammonia at elevated pressures has been developed and tested. The model describes the flow dynamics coupled to chemical reactions and transport in the flow channel of the Compact Hard Shell Reactor, as a function of substrate temperature, total pressure and centerline flow velocity.

  10. ¹H-NMR study of the impact of high pressure and thermal processing on cell membrane integrity of onions.

    PubMed

    Gonzalez, Maria E; Barrett, Diane M; McCarthy, Michael J; Vergeldt, Frank J; Gerkema, Edo; Matser, Ariette M; Van As, Henk

    2010-09-01

    Proton nuclear magnetic resonance (¹H-NMR) relaxometry was used to study the effects of high pressure and thermal processing on membrane permeability and cell compartmentalization, important components of plant tissue texture. High pressure treated onions were subjected to pressure levels from 20 to 200 MPa at 5 min hold time at initial temperatures of 5 and 20 °C. Thermally treated onions were exposed for 30 min at temperatures from 40 to 90 °C. Loss of membrane integrity was clearly shown by changes in transverse relaxation time (T(2)) of water at temperatures of 60 °C and above. Destabilization effects on membranes exposed to high pressure were observed at 200 MPa as indicated by T(2) measurements and cryo-scanning electron microscopy (Cryo-SEM). T(2) relaxation successfully discriminated different degrees of membrane damage based on the T(2) shift of the vacuolar component. Analyses of the average water self-diffusion coefficient indicated less restricted diffusion after membrane rupture occurred in cases of severe thermal treatments. Milder processing treatments yielded lower average diffusion coefficients than the controls. ¹H-NMR proved to be an effective method for quantification of cell membrane damage in onions and allowed for the comparison of different food processes based on their impact on tissue integrity.

  11. Investigation of the Livengood-Wu integral for modelling autoignition in a high-pressure bomb

    NASA Astrophysics Data System (ADS)

    Hu, Zhixin; Somers, Bart L. M. T.; Cracknell, Roger F.; Bradley, Derek

    2016-01-01

    The reaction progress variable, which is widely used in premixed and diffusion combustion studies, comprises a set of pre-selected intermediate species to denote reaction progress. Progress towards autoignition can also be traced by the Livengood-Wu (LW) integral. Autoignition occurs when the LW integral attains a value of unity. This concept is further explored by applying it to an inhomogeneous mixture scenario, to determine the time and place of autoignition occurrence. A semidetailed mechanism (137 species and 633 reactions) for n-heptane/iso-octane/toluene is used in this study. Two numerical schemes based on the LW integral are proposed and incorporated into a computational fluid dynamics platform, to model autoignition in a 3D configuration, when a spray is injected into a constant volume bomb under diesel engine conditions. Tabulated chemistry, a traditional method of modelling autoignition using information from pre-calculated igniting diffusion flames, is also used for comparison purposes. The associated predicted pressure profiles are compared with experimental measurements.

  12. Automated Microdosing System for Integration With a Miniaturized High-pressure Reactor System

    PubMed Central

    Hawali, Ihsan; Thurow, Kerstin

    2005-01-01

    We present a new automated dosing system developed by the Institute for Automation of the University of Rostock, Germany. The new system is designed for the dosing of chemical liquids in the range of 50 μL–2.5 mL. It is integrated into a miniaturized reactor system to be used in the field of combinatorial synthesis. The reactor system can be pressurized up to 150 bar and tempered up to 200^C. A wide range of liquids with different physical properties can be handled with the new dosing system. A detailed description of the new dosing system in terms of function and operation as well as the relevant features and potential benefits is provided. PMID:18924738

  13. Automated Microdosing System for Integration With a Miniaturized High-pressure Reactor System.

    PubMed

    Stoll, Norbert; Hawali, Ihsan; Thurow, Kerstin

    2005-01-01

    We present a new automated dosing system developed by the Institute for Automation of the University of Rostock, Germany. The new system is designed for the dosing of chemical liquids in the range of 50 muL-2.5 mL. It is integrated into a miniaturized reactor system to be used in the field of combinatorial synthesis. The reactor system can be pressurized up to 150 bar and tempered up to 200(;)C. A wide range of liquids with different physical properties can be handled with the new dosing system. A detailed description of the new dosing system in terms of function and operation as well as the relevant features and potential benefits is provided.

  14. The Impact of Maturity Stage on Cell Membrane Integrity and Enzymatic Browning Reactions in High Pressure Processed Peaches (Prunus persica).

    PubMed

    Techakanon, Chukwan; Gradziel, Thomas M; Zhang, Lu; Barrett, Diane M

    2016-09-28

    Fruit maturity is an important factor associated with final product quality, and it may have an effect on the level of browning in peaches that are high pressure processed (HPP). Peaches from three different maturities, as determined by firmness (M1 = 50-55 N, M2 = 35-40 N, and M3 = 15-20 N), were subjected to pressure levels at 0.1, 200, and 400 MPa for 10 min. The damage from HPP treatment results in loss of fruit integrity and the development of browning during storage. Increasing pressure levels of HPP treatment resulted in greater damage, particularly in the more mature peaches, as determined by shifts in transverse relaxation time (T2) of the vacuolar component and by light microscopy. The discoloration of peach slices of different maturities processed at the same pressure was comparable, indicating that the effect of pressure level is greater than that of maturity in the development of browning. PMID:27556337

  15. The Impact of Maturity Stage on Cell Membrane Integrity and Enzymatic Browning Reactions in High Pressure Processed Peaches (Prunus persica).

    PubMed

    Techakanon, Chukwan; Gradziel, Thomas M; Zhang, Lu; Barrett, Diane M

    2016-09-28

    Fruit maturity is an important factor associated with final product quality, and it may have an effect on the level of browning in peaches that are high pressure processed (HPP). Peaches from three different maturities, as determined by firmness (M1 = 50-55 N, M2 = 35-40 N, and M3 = 15-20 N), were subjected to pressure levels at 0.1, 200, and 400 MPa for 10 min. The damage from HPP treatment results in loss of fruit integrity and the development of browning during storage. Increasing pressure levels of HPP treatment resulted in greater damage, particularly in the more mature peaches, as determined by shifts in transverse relaxation time (T2) of the vacuolar component and by light microscopy. The discoloration of peach slices of different maturities processed at the same pressure was comparable, indicating that the effect of pressure level is greater than that of maturity in the development of browning.

  16. Thermal, High Pressure, and Electric Field Processing Effects on Plant Cell Membrane Integrity and Relevance to Fruit and Vegetable Quality

    PubMed Central

    Gonzalez, Maria E; Barrett, Diane M

    2010-01-01

    Advanced food processing methods that accomplish inactivation of microorganisms but minimize adverse thermal exposure are of great interest to the food industry. High pressure (HP) and pulsed electric field (PEF) processing are commercially applied to produce high quality fruit and vegetable products in the United States, Europe, and Japan. Both microbial and plant cell membranes are significantly altered following exposure to heat, HP, or PEF. Our research group sought to quantify the degree of damage to plant cell membranes that occurs as a result of exposure to heat, HP, or PEF, using the same analytical methods. In order to evaluate whether new advanced processing methods are superior to traditional thermal processing methods, it is necessary to compare them. In this review, we describe the existing state of knowledge related to effects of heat, HP, and PEF on both microbial and plant cells. The importance and relevance of compartmentalization in plant cells as it relates to fruit and vegetable quality is described and various methods for quantification of plant cell membrane integrity are discussed. These include electrolyte leakage, cell viability, and proton nuclear magnetic resonance (1H-NMR). PMID:20492210

  17. High pressure synthesis gas fermentation

    SciTech Connect

    Not Available

    1992-01-01

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

  18. High pressure furnace

    DOEpatents

    Morris, D.E.

    1993-09-14

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

  19. High pressure furnace

    DOEpatents

    Morris, Donald E.

    1993-01-01

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

  20. High pressure oxygen furnace

    DOEpatents

    Morris, D.E.

    1992-07-14

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

  1. High pressure oxygen furnace

    DOEpatents

    Morris, Donald E.

    1992-01-01

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

  2. Construction of integrated case environments.

    PubMed

    Losavio, Francisca; Matteo, Alfredo; Pérez, María

    2003-01-01

    The main goal of Computer-Aided Software Engineering (CASE) technology is to improve the entire software system development process. The CASE approach is not merely a technology; it involves a fundamental change in the process of software development. The tendency of the CASE approach, technically speaking, is the integration of tools that assist in the application of specific methods. In this sense, the environment architecture, which includes the platform and the system's hardware and software, constitutes the base of the CASE environment. The problem of tools integration has been proposed for two decades. Current integration efforts emphasize the interoperability of tools, especially in distributed environments. In this work we use the Brown approach. The environment resulting from the application of this model is called a federative environment, focusing on the fact that this architecture pays special attention to the connections among the components of the environment. This approach is now being used in component-based design. This paper describes a concrete experience in civil engineering and architecture fields, for the construction of an integrated CASE environment. A generic architectural framework based on an intermediary architectural pattern is applied to achieve the integration of the different tools. This intermediary represents the control perspective of the PAC (Presentation-Abstraction-Control) style, which has been implemented as a Mediator pattern and it has been used in the interactive systems domain. In addition, a process is given to construct the integrated CASE. PMID:15916171

  3. High pressure synthesis gas fermentation

    SciTech Connect

    Not Available

    1991-01-01

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

  4. Electrokinetic high pressure hydraulic system

    DOEpatents

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

    2003-06-03

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

  5. Electrokinetic high pressure hydraulic system

    DOEpatents

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

    2001-01-01

    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.

  6. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy.

    PubMed

    Bansode, Atul; Guilera, Gemma; Cuartero, Vera; Simonelli, Laura; Avila, Marta; Urakawa, Atsushi

    2014-08-01

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280 °C) conditions. As the first demonstration, the cell was used for CO2 hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al2O3 methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260 °C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO2 phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies.

  7. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy.

    PubMed

    Bansode, Atul; Guilera, Gemma; Cuartero, Vera; Simonelli, Laura; Avila, Marta; Urakawa, Atsushi

    2014-08-01

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280 °C) conditions. As the first demonstration, the cell was used for CO2 hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al2O3 methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260 °C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO2 phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies. PMID:25173285

  8. Performance and characteristics of a high pressure, high temperature capillary cell with facile construction for operando x-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Bansode, Atul; Guilera, Gemma; Cuartero, Vera; Simonelli, Laura; Avila, Marta; Urakawa, Atsushi

    2014-08-01

    We demonstrate the use of commercially available fused silica capillary and fittings to construct a cell for operando X-ray absorption spectroscopy (XAS) for the study of heterogeneously catalyzed reactions under high pressure (up to 200 bars) and high temperature (up to 280 °C) conditions. As the first demonstration, the cell was used for CO2 hydrogenation reaction to examine the state of copper in a conventional Cu/ZnO/Al2O3 methanol synthesis catalyst. The active copper component of the catalyst was shown to remain in the metallic state under supercritical reaction conditions, at 200 bars and up to 260 °C. With the coiled heating system around the capillary, one can easily change the length of the capillary and control the amount of catalyst under investigation. With precise control of reactant(s) flow, the cell can mimic and serve as a conventional fixed-bed micro-reactor system to obtain reliable catalytic data. This high comparability of the reaction performance of the cell and laboratory reactors is crucial to gain insights into the nature of actual active sites under technologically relevant reaction conditions. The large length of the capillary can cause its bending upon heating when it is only fixed at both ends because of the thermal expansion. The degree of the bending can vary depending on the heating mode, and solutions to this problem are also presented. Furthermore, the cell is suitable for Raman studies, nowadays available at several beamlines for combined measurements. A concise study of CO2 phase behavior by Raman spectroscopy is presented to demonstrate a potential of the cell for combined XAS-Raman studies.

  9. High pressure synthesis gas conversion

    SciTech Connect

    Not Available

    1992-01-01

    A high pressure gas phase fermentation system has been constructed for the biological production of ethanol from coal synthesis gas. The reactors in the system consist of a 650 mL continuous stirred tank reactor and a 1 L continuous column reactor. The reactors are designed for individual or dual operation in series or parallel, with continuous gas and liquid feed. The system is housed in a constant temperature, explosion-proof room, equipped with gas leak detectors.

  10. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false High pressure pumps and lines. 58.219 Section 58.219....219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and shall be of such construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The...

  11. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false High pressure pumps and lines. 58.219 Section 58.219....219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and shall be of such construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The...

  12. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false High pressure pumps and lines. 58.219 Section 58.219....219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and shall be of such construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The...

  13. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false High pressure pumps and lines. 58.219 Section 58.219....219 High pressure pumps and lines. High pressure lines may be cleaned-in-place and shall be of such construction that dead ends, valves and the high pressure pumps can be disassembled for hand cleaning. The...

  14. High-pressure microfluidics

    NASA Astrophysics Data System (ADS)

    Hjort, K.

    2015-03-01

    When using appropriate materials and microfabrication techniques, with the small dimensions the mechanical stability of microstructured devices allows for processes at high pressures without loss in safety. The largest area of applications has been demonstrated in green chemistry and bioprocesses, where extraction, synthesis and analyses often excel at high densities and high temperatures. This is accessible through high pressures. Capillary chemistry has been used since long but, just like in low-pressure applications, there are several potential advantages in using microfluidic platforms, e.g., planar isothermal set-ups, large local variations in geometries, dense form factors, small dead volumes and precisely positioned microstructures for control of reactions, catalysis, mixing and separation. Other potential applications are in, e.g., microhydraulics, exploration, gas driven vehicles, and high-pressure science. From a review of the state-of-art and frontiers of high pressure microfluidics, the focus will be on different solutions demonstrated for microfluidic handling at high pressures and challenges that remain.

  15. High pressure melt ejection

    SciTech Connect

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

    1983-01-01

    Recent probabilistic risk assessments have identified the potential for reactor pressure vessel failure while the reactor coolant system is at elevated pressure. The analyses postulate that the blowdown of steam and hydrogen into the reactor cavity will cause the core material to be swept from the cavity region into the containment building. The High Pressure Melt Streaming (HIPS) program is an experimental study of the high pressure ejection of molten material and subsequent interactions within a concrete cavity. The program focuses on using prototypic system conditions and scaled models of reactor geometries to accurately simulate the ex-vessel processes during high-pressure accident sequences. Scaling analyses of the experiment show that the criteria established for core debris removal from the cavity are met or exceeded. Tests are performed at two scales, representing 1/10th and 1/20th linear reproductions of the Zion reactor plant. Results of the 1/20th scale tests are presented.

  16. The analysis of cracks in high-pressure piping and their effects on strength and lifetime of construction components at the Ignalina nuclear plant

    SciTech Connect

    Aleev, A.; Petkevicius, K.; Senkus, V.

    1997-04-01

    A number of cracks and damages of other sorts have been identified in the high-pressure parts at the Ignalina Nuclear Plant. They are caused by inadequate production- and repair technologies, as well as by thermal, chemical and mechanical processes of their performance. Several techniques are available as predictions of cracks and other defects of pressurized vessels. The choice of an experimental technique should be based on the level of its agreement with the actual processes.

  17. High pressure ratio turbocharger

    SciTech Connect

    Woollenweber, W.E.

    1991-06-25

    This patent describes a turbocharger system for an internal combustion engine. It comprises means forming a turbine adapted to be driven by exhaust gas from an internal combustion engine comprising: a turbine wheel having a central core and outwardly extending vanes, the turbine wheel being rotatable about a central axis; a meridionally divided volute for exhaust gas surrounding the turbine wheel, the meridionally divided volute including a divider wall defining first and second volute passageways with openings at the turbine wheel; means forming a high-pressure compressor driven by the turbine means, the high-pressure compressor comprising: rotating compressor blades, the compressor blades adapted to be driven in rotation about the central axis by the turbine means to deliver a flow of air at high pressures for an internal combustion engine, and blades being moveable about longitudinal axes generally transverse to the central axis to impart positive or negative pre-whirl motion to the air leaving the stator blades prior to entering the rotating blades of the compressor stage; closure means for providing a flow of engine exhaust gas from one of the first and second volute passageways into the turbine wheel; and a control means for operating the closure means and the stator blades in synchronization.

  18. High pressure atomization

    NASA Astrophysics Data System (ADS)

    Bracco, F. V.

    1982-03-01

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

  19. HIGH PRESSURE DIES

    DOEpatents

    Wilson, W.B.

    1960-05-31

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

  20. Construction of a Direct Water-Injected Two-Stroke Engine for Phased Direct Fuel Injection-High Pressure Charging Investigations

    NASA Technical Reports Server (NTRS)

    Somsel, James P.

    1998-01-01

    The development of a water injected Orbital Combustion Process (OCP) engine was conducted to assess the viability of using the powerplant for high altitude NASA aircraft and General Aviation (GA) applications. An OCP direct fuel injected, 1.2 liter, three cylinder, two-stroke engine has been enhanced to independently inject water directly into the combustion chamber. The engine currently demonstrates low brake specific fuel consumption capability and an excellent power to weight ratio. With direct water injection, significant improvements can be made to engine power, to knock limits/ignition advance timing, and to engine NO(x) emissions. The principal aim of the testing was to validate a cyclic model developed by the Systems Analysis Branch at NASA Ames Research Center. The work is a continuation of Ames' investigations into a Phased Direct Fuel Injection Engine with High Pressure Charging (PDFI-ITPC).

  1. Fibre based integral field unit constructional techniques

    NASA Astrophysics Data System (ADS)

    Murray, Graham J.

    2006-06-01

    Presented here is a selected overview of constructional techniques and principles that have been developed and implemented at the University of Durham in the manufacture of successful fibre-based integral field units. The information contained herein is specifically intended to highlight the constructional methods that have been devised to assemble an efficient fibre bundle. Potential pitfalls that need to be considered when embarking upon such a deceptively simple instrument are also discussed.

  2. HIGH PRESSURE GAS REGULATOR

    DOEpatents

    Ramage, R.W.

    1962-05-01

    A gas regulator operating on the piston and feedback principle is described. The device is particularly suitable for the delicate regulation of high pressure, i.e., 10,000 psi and above, gas sources, as well as being perfectly adaptable for use on gas supplies as low as 50 psi. The piston is adjustably connected to a needle valve and the movement of the piston regulates the flow of gas from the needle valve. The gas output is obtained from the needle valve. Output pressure is sampled by a piston feedback means which, in turn, regulates the movement of the main piston. When the output is other than the desired value, the feedback system initiates movement of the main piston to allow the output pressure to be corrected or to remain constant. (AEC)

  3. High pressure mechanical seal

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  4. High pressure mechanical seal

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  5. [High Pressure Gas Tanks

    NASA Technical Reports Server (NTRS)

    Quintana, Rolando

    2002-01-01

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

  6. High pressure capillary connector

    DOEpatents

    Renzi, Ronald F.

    2005-08-09

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

  7. ITER Construction--Plant System Integration

    SciTech Connect

    Tada, E.; Matsuda, S.

    2009-02-19

    This brief paper introduces how the ITER will be built in the international collaboration. The ITER Organization plays a central role in constructing ITER and leading it into operation. Since most of the ITER components are to be provided in-kind from the member countries, integral project management should be scoped in advance of real work. Those include design, procurement, system assembly, testing, licensing and commissioning of ITER.

  8. High-pressure neutron diffraction

    SciTech Connect

    Xu, Hongwu

    2011-01-10

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

  9. High Pressure Electrolyzer System Evaluation

    NASA Technical Reports Server (NTRS)

    Prokopius, Kevin; Coloza, Anthony

    2010-01-01

    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.

  10. Electrokinetically pumped high pressure sprays

    DOEpatents

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2005-11-01

    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.

  11. Electrokinetically pumped high pressure sprays

    SciTech Connect

    Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

    2002-01-01

    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.

  12. Integrating in situ high pressure small and wide angle synchrotron x-ray scattering for exploiting new physics of nanoparticle supercrystals

    PubMed Central

    Wang, Zhongwu; Chen, Ou; Cao, Charles Y.; Finkelstein, Ken; Smilgies, Detlef-M.; Lu, Xianmao; Bassett, William A.

    2010-01-01

    Combined small and wide angle synchrotron x-ray scattering (SAXS and WAXS) techniques have been developed for in situ high pressure samples, enabling exploration of the atomic structure and nanoscale superstructure phase relations. These studies can then be used to find connections between nanoparticle surfaces and internal atomic arrangements. We developed a four-axis control system for the detector, which we then employed for the study of two supercrystals assembled from 5 nm Fe3O4 and 10 nm Au nanoparticles. We optimized the x-ray energy and the sample-to-detector distance to facilitate simultaneous collection of both SAXS and WAXS. We further performedin situ high pressure SAXS and WAXS on a cubic supercrystal assembled from 4 nm wurtzite-structure CdSe nanoparticles. While wurtzite-structure CdSe nanoparticles transform into a rocksalt structure at 6.2 GPa, the cubic superstructure develops into a lamellarlike mesostructure at 9.6 GPa. Nanoparticle coupling and interaction could be enhanced, thus reducing the compressibility of the interparticle spacing above ∼3 GPa. At ∼6.2 GPa, the wurtzite-to-rocksalt phase transformation results in a noticeable drop of interparticle spacing. Above 6.2 GPa, a combined effect from denser CdSe nanoparticle causes the interparticle spacing to expand. These findings could be related to a series of changes including the surface structure, electronic and mechanical properties, and strain distribution of CdSe under pressure. This technique opens the way for exploring the new physics of nanoparticles and self-assembled superlattices. PMID:20886989

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

    SciTech Connect

    Not Available

    1993-05-01

    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.

  14. High pressure liquid level monitor

    DOEpatents

    Bean, Vern E.; Long, Frederick G.

    1984-01-01

    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.

  15. Controlled ecological life support systems (CELSS) in high pressure environments.

    PubMed

    Thompson, B G

    1989-05-01

    Future space habitats may be constructed in high pressure environments. The biological components of any controlled ecological life support systems (CELSS) used in these habitats will have to be able to grow and metabolize normally for the CELSS to operate.

  16. Electrokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H.; Rakestraw, David J.

    2000-01-01

    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.

  17. Sample injector for high pressure liquid chromatography

    DOEpatents

    Paul, Phillip H.; Arnold, Don W.; Neyer, David W.

    2001-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Astrophysics Data System (ADS)

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

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

  20. New developments in high pressure x-ray spectroscopy beamline at High Pressure Collaborative Access Team

    SciTech Connect

    Xiao, Y. M. Chow, P.; Boman, G.; Bai, L. G.; Rod, E.; Bommannavar, A.; Kenney-Benson, C.; Sinogeikin, S.; Shen, G. Y.

    2015-07-15

    The 16 ID-D (Insertion Device - D station) beamline of the High Pressure Collaborative Access Team at the Advanced Photon Source is dedicated to high pressure research using X-ray spectroscopy techniques typically integrated with diamond anvil cells. The beamline provides X-rays of 4.5-37 keV, and current available techniques include X-ray emission spectroscopy, inelastic X-ray scattering, and nuclear resonant scattering. The recent developments include a canted undulator upgrade, 17-element analyzer array for inelastic X-ray scattering, and an emission spectrometer using a polycapillary half-lens. Recent development projects and future prospects are also discussed.

  1. High pressure neon arc lamp

    DOEpatents

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  2. High-pressure well design

    SciTech Connect

    Krus, H.; Prieur, J.M. )

    1991-12-01

    Shell U.K. E and P (Shell Expro), operator in the U.K. North Sea on behalf of Shell and Esso, plans to drill 20 high-pressure oil and gas wells during the next 2 years. This paper reports that the well design is based on new standards developed after the U.K. Dept. of Energy restriction on high-pressure drilling in the autumn of 1988. Studies were carried out to optimize casing design and drilling performance on these wells. Several casing schemes, including a slim-hole option, were analyzed. The material specifications for casing and drillpipe were reviewed to ensure that they met the loads imposed during drilling, well- control, and well-testing operations. The requirement for sour-service material was weighted against possible H{sub 2}S adsorption by the mud film. As a result, a new drillstring and two high-pressure casing schemes have been specified. The high-pressure casing scheme used depends on the maximum expected surface pressure.

  3. High-pressure water facility

    NASA Technical Reports Server (NTRS)

    2006-01-01

    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.

  4. High pressure rinsing system comparison

    SciTech Connect

    D. Sertore; M. Fusetti; P. Michelato; Carlo Pagani; Toshiyasu Higo; Jin-Seok Hong; K. Saito; G. Ciovati; T. Rothgeb

    2007-06-01

    High pressure rinsing (HPR) is a key process for the surface preparation of high field superconducting cavities. A portable apparatus for the water jet characterization, based on the transferred momentum between the water jet and a load cell, has been used in different laboratories. This apparatus allows to collected quantitative parameters that characterize the HPR water jet. In this paper, we present a quantitative comparison of the different water jet produced by various nozzles routinely used in different laboratories for the HPR process

  5. Electronic phenomena at high pressure

    SciTech Connect

    Drickamer, H.G.

    1981-01-01

    High pressure research is undertaken either to investigate intrinsically high pressure phenomena or in order to get a better understanding of the effect of the chemical environment on properties or processes at one atmosphere. Studies of electronic properties which fall in each area are presented. Many molecules and complexes can assume in the excited state different molecular arrangements and intermolecular forces depending on the medium. Their luminescence emission is then very different in a rigid or a fluid medium. With pressure one can vary the viscosity of the medium by a factor of 10/sup 7/ and thus control the distribution and rate of crossing between the excited state conformations. In rare earth chelates the efficiency of 4f-4f emission of the rare earth is controlled by the feeding from the singlet and triplet levels of the organic ligand. These ligand levels can be strongly shifted by pressure. A study of the effect of pressure on the emission efficiency permits one to understand the effect of ligand chemistry at one atmosphere. At high pressure electronic states can be sufficiently perturbed to provide new ground states. In EDA complexes these new ground states exhibit unusual chemical reactivity and new products.

  6. High-Pressure Lightweight Thrusters

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    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

  7. Electrokinetic high pressure hydraulic system

    SciTech Connect

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

    2000-01-11

    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.

  8. Brillouin scattering at high pressures

    SciTech Connect

    Grimsditch, M.; Polian, A.

    1988-02-01

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

  9. Spray patternation at high pressure

    NASA Astrophysics Data System (ADS)

    Cohen, J. M.; Rosfjord, T. J.

    1989-07-01

    The spatial distribution of the fuel spray created by a gas turbine fuel injector has been measured at high pressure and temperature. A patternation system for measuring fuel spray mass flux distributions at high power conditions has been designed and operated. The facility has been designed to simulate the environment inside a gas turbine combustor as closely as possible. Results for a full scale gas turbine fuel injector have been obtained at high levels of pressure, temperature and liquid flowrate and compared with visual observations.

  10. Electokinetic high pressure hydraulic system

    DOEpatents

    Paul, Phillip H.; Rakestraw, David J.

    2000-01-01

    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.

  11. Improved high pressure turbine shroud

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  12. High pressure xenon ionization detector

    DOEpatents

    Markey, J.K.

    1989-11-14

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

  13. High pressure xenon ionization detector

    DOEpatents

    Markey, John K.

    1989-01-01

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

  14. High pressure effects on the iron iron oxide and nickel nickel oxide oxygen fugacity buffers

    SciTech Connect

    Campbell, Andrew J; Danielson, Lisa; Righter, Kevin; Seagle, Christopher T; Wang, Yanbin; Prakapenka, Vitali B

    2009-09-25

    The chemical potential of oxygen in natural and experimental samples is commonly reported relative to a specific oxygen fugacity (fO{sub 2}) buffer. These buffers are precisely known at 1 bar, but under high pressures corresponding to the conditions of the deep Earth, oxygen fugacity buffers are poorly calibrated. Reference (1 bar) fO{sub 2} buffers can be integrated to high pressure conditions by integrating the difference in volume between the solid phases, provided that their equations of state are known. In this work, the equations of state and volume difference between the metal-oxide pairs Fe-FeO and Ni-NiO were measured using synchrotron X-ray diffraction in a multi-anvil press and laser heated diamond anvil cells. The results were used to construct high pressure fO{sub 2} buffer curves for these systems. The difference between the Fe-FeO and Ni-NiO buffers is observed to decrease significantly, by several log units, over 80 GPa. The results can be used to improve interpretation of high pressure experiments, specifically Fe-Ni exchange between metallic and oxide phases.

  15. Steam Oxidation at High Pressure

    SciTech Connect

    Holcomb, Gordon R.; Carney, Casey

    2013-07-19

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

  16. High pressure hollow electrode discharges

    SciTech Connect

    Schoenbach, K.H.; El-Habachi, A.; Shi, W.; Ciocca, M.

    1997-12-31

    Reduction of the cathode hole diameter into the submillimeter range has allowed the authors to extend the pressure range for hollow electrode discharge operation to values on the order of 50 Torr. In recent experiments with cathode holes of 0.2 mm diameter they obtained stable glow discharge operation up to approximately 900 Torr in argon. The current-voltage (I-V) characteristics of these discharges (with currents ranging from the ten`s of {micro}A to ten mA) show three distinct discharge modes: at low current, a discharge with positive differential resistivity, followed by a range with strong increase in current and reduction in voltage, and, at high current, again a resistive discharge mode. For low pressure (< 100 Torr) these modes correspond to the predischarge, hollow cathode discharge (sustained by pendulum electrons), and abnormal glow discharge, respectively. At higher pressure the discharge in the short gap system (anode-cathode distance: 0.25 mm) changes from a hollow cathode discharge to, what seems to be a pulseless partial glow discharge. In hollow cathode discharges operated in the torr range the electron energy distribution is known to be strongly non-maxwellian with a large concentration of electrons at energies greater than 30 eV. This holds also for hollow cathode discharge at high pressure and for partial discharges as indicated by the presence of strong excimer lines in the VUV spectrum of Ar-discharges at 128 nm and Xe-discharges at 172 nm. The resistive characteristic of high pressure hollow electrode discharges over a large range of current allows them to generate arrays of these discharges for use as flat panel, direct current, excimer lamps.

  17. High-pressure droplet combustion studies

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  18. High Pressure Hydrogen from First Principles

    NASA Astrophysics Data System (ADS)

    Morales, M. A.

    2014-12-01

    Typical approximations employed in first-principles simulations of high-pressure hydrogen involve the neglect of nuclear quantum effects (NQE) and the approximate treatment of electronic exchange and correlation, typically through a density functional theory (DFT) formulation. In this talk I'll present a detailed analysis of the influence of these approximations on the phase diagram of high-pressure hydrogen, with the goal of identifying the predictive capabilities of current methods and, at the same time, making accurate predictions in this important regime. We use a path integral formulation combined with density functional theory, which allows us to incorporate NQEs in a direct and controllable way. In addition, we use state-of-the-art quantum Monte Carlo calculations to benchmark the accuracy of more approximate mean-field electronic structure calculations based on DFT, and we use GW and hybrid DFT to calculate the optical properties of the solid and liquid phases near metallization. We present accurate predictions of the metal-insulator transition on the solid, including structural and optical properties of the molecular phase. This work was supported by the U.S. Department of Energy at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and by LDRD Grant No. 13-LW-004.

  19. Electrical Transport Experiments at High Pressure

    SciTech Connect

    Weir, S

    2009-02-11

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

  20. Assessing Knowledge Integration in Science: Construct, Measures, and Evidence

    ERIC Educational Resources Information Center

    Liu, Ou Lydia; Lee, Hee-Sun; Hofstetter, Carolyn; Linn, Marcia C.

    2008-01-01

    In response to the demand for sound science assessments, this article presents the development of a latent construct called knowledge integration as an effective measure of science inquiry. Knowledge integration assessments ask students to link, distinguish, evaluate, and organize their ideas about complex scientific topics. The article focuses on…

  1. Construction CAE; Integration of CAD, simulation, planning and cost control

    SciTech Connect

    Wickard, D.A. ); Bill, R.D.; Gates, K.H.; Yoshinaga, T.; Ohcoshi, S. )

    1989-01-01

    Construction CAE is a simulation, planning, scheduling, and cost control tool that is integrated with a computer aided design (CAD) system. The system uses a CAD model and allows the user to perform construction simulation on objects defined within the model. Initial cost/schedule reports as well as those required for project chronicling are supported through an interface to a work breakdown structure (WBS) and a client's existing schedule reporting system. By integrating currently available project control tools with a simulation system, Construction CAE is more effective than its individual components.

  2. High-pressure coal fuel processor development

    SciTech Connect

    Greenhalgh, M.L. )

    1992-12-01

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

  3. Comparison of Integrated Testlet and Constructed-Response Question Formats

    ERIC Educational Resources Information Center

    Slepkov, Aaron D.; Shiell, Ralph C.

    2014-01-01

    Constructed-response (CR) questions are a mainstay of introductory physics textbooks and exams. However, because of the time, cost, and scoring reliability constraints associated with this format, CR questions are being increasingly replaced by multiple-choice (MC) questions in formal exams. The integrated testlet (IT) is a recently developed…

  4. A Connectionist Extension to Kintsch's Construction--Integration Model

    ERIC Educational Resources Information Center

    Sanjose, Vicente; Vidal-Abarca, Eduardo; Padilla, Olga M.

    2006-01-01

    This article proposes an extension to Kintsch's Construction-Integration (CI) model of text comprehension, which changes its mathematical implementation and emphasizes the connectionist features of the model. Specifically, the extension proposed here (a) simulates the learning process in a connectionist manner by making explicit changes in the…

  5. NETL- High-Pressure Combustion Research Facility

    ScienceCinema

    None

    2016-07-12

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

  6. NETL- High-Pressure Combustion Research Facility

    SciTech Connect

    2013-07-08

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

  7. Infrared Spectra of High Pressure Carbon Monoxide

    SciTech Connect

    Evans, W J; Lipp, M J; Lorenzana, H E

    2001-09-21

    We report infrared (IR) spectroscopic measurements of carbon monoxide (CO) at high pressures. Although CO is one of the simplest heteronuclear diatomic molecules, it displays surprisingly complex behavior at high pressures and has been the subject of several studies [1-5]. IR spectroscopic studies of high pressures phases of CO provide data complementing results from previous studies and elucidating the nature of these phases. Though a well-known and widely utilized diagnostic of molecular systems, IR spectroscopy presents several experimental challenges to high pressure diamond anvil cell research. We present measurements of the IR absorption bands of CO at high pressures and experimentally illustrate the crucial importance of accurate normalization of IR spectra specially within regions of strong absorptions in diamond.

  8. High-Pressure Research in Mineral Physics

    NASA Astrophysics Data System (ADS)

    Hazen, Robert M.

    Advances in high-pressure science and technology have transformed solid Earth geophysics. In the last decade, high-pressure researchers have reproduced the full range of Earth pressure and temperature conditions in the laboratory, and they have synthesized single crystals of dense silicate phases, unknown at the Earth's surface yet suspected to comprise most of the Earth's volume. These and other extraordinary accomplishments are chronicled in High-Pressure Research in Mineral Physics, an outgrowth of the third U.S.-Japan High-Pressure seminar, held in Kahuku, Hawaii, January, 13-16, 1986. The well produced and reasonably priced volume is dedicated to Syun-iti Akimoto, dean of Japanese high-pressure research, who recently retired from the University of Tokyo. Akimoto's fascinating historical account of pressure research at the Institute for Solid State Physics at the University of Tokyo is the leadoff article.

  9. High pressure common rail injection system modeling and control.

    PubMed

    Wang, H P; Zheng, D; Tian, Y

    2016-07-01

    In this paper modeling and common-rail pressure control of high pressure common rail injection system (HPCRIS) is presented. The proposed mathematical model of high pressure common rail injection system which contains three sub-systems: high pressure pump sub-model, common rail sub-model and injector sub-model is a relative complicated nonlinear system. The mathematical model is validated by the software Matlab and a virtual detailed simulation environment. For the considered HPCRIS, an effective model free controller which is called Extended State Observer - based intelligent Proportional Integral (ESO-based iPI) controller is designed. And this proposed method is composed mainly of the referred ESO observer, and a time delay estimation based iPI controller. Finally, to demonstrate the performances of the proposed controller, the proposed ESO-based iPI controller is compared with a conventional PID controller and ADRC. PMID:27012440

  10. Opportunities and challenges in high pressure processing of foods.

    PubMed

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

    2007-01-01

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

  11. TENSILE TESTING OF CARBON STEEL IN HIGH PRESSURE HYDROGEN

    SciTech Connect

    Duncan, A; Thad Adams, T; Ps Lam, P

    2007-05-02

    An infrastructure of new and existing pipelines and systems will be required to carry and to deliver hydrogen as an alternative energy source under the hydrogen economy. Carbon and low alloy steels of moderate strength are currently used in hydrogen delivery systems as well as in the existing natural gas systems. It is critical to understand the material response of these standard pipeline materials when they are subjected to pressurized hydrogen environments. The methods and results from a testing program to quantify hydrogen effects on mechanical properties of carbon steel pipeline and pipeline weld materials are provided. Tensile properties of one type of steel (A106 Grade B) in base metal, welded and heat affected zone conditions were tested at room temperature in air and high pressure (10.34 MPa or 1500 psig) hydrogen. A general reduction in the materials ability to plastically deform was noted in this material when specimens were tested in hydrogen. Furthermore, the primary mode of fracture was changed from ductile rupture in air to cleavage with secondary tearing in hydrogen. The mechanical test results will be applied in future analyses to evaluate service life of the pipelines. The results are also envisioned to be part of the bases for construction codes and structural integrity demonstrations for hydrogen service pipeline and vessels.

  12. MECHANICAL TESTING OF CARBON STEEL IN HIGH PRESSURE HYDROGEN

    SciTech Connect

    Duncan, A

    2006-05-11

    The methods and interim results from a testing program to quantify hydrogen effects on mechanical properties of carbon steel pipeline and pipeline weld materials are provided. The scope is carbon steels commonly used for natural gas pipelines in the United States that are candidates for hydrogen service in the hydrogen economy. The mechanical test results will be applied in future analyses to evaluate service life of the pipelines. The results are also envisioned to be part of the bases for construction codes and structural integrity demonstrations for hydrogen service pipeline and vessels. Tensile properties of one type of steel (A106 Grade B) in base metal, welded and heat affected zone conditions were tested at room temperature in air and high pressure (1500 psig) hydrogen. A general reduction in the materials ability to plastically deform was noted in this material when specimens were tested in 1500 psig hydrogen. Furthermore, the primary mode of fracture was changed from ductile rupture in air to cleavage with secondary tearing in hydrogen. The mechanical test program will continue with tests to quantify the fracture behavior in terms of J-R curves for these materials at air and hydrogen pressure conditions.

  13. High pressure optical combustion probe

    SciTech Connect

    Woodruff, S.D.; Richards, G.A.

    1995-06-01

    The Department of Energy`s Morgantown Energy Technology Center has developed a combustion probe for monitoring flame presence and heat release. The technology involved is a compact optical detector of the OH radical`s UV fluorescence. The OH Monitor/Probe is designed to determine the flame presence and provide a qualitative signal proportional to the flame intensity. The probe can be adjusted to monitor a specific volume in the combustion zone to track spatial fluctuations in the flame. The probe is capable of nanosecond time response and is usually slowed electronically to fit the flame characteristics. The probe is a sapphire rod in a stainless steel tube which may be inserted into the combustion chamber and pointed at the flame zone. The end of the sapphire rod is retracted into the SS tube to define a narrow optical collection cone. The collection cone may be adjusted to fit the experiment. The fluorescence signal is collected by the sapphire rod and transmitted through a UV transmitting, fused silica, fiber optic to the detector assembly. The detector is a side window photomultiplier (PMT) with a 310 run line filter. A Hamamatsu photomultiplier base combined with a integral high voltage power supply permits this to be a low voltage device. Electronic connections include: a power lead from a modular DC power supply for 15 VDC; a control lead for 0-1 volts to control the high voltage level (and therefore gain); and a lead out for the actual signal. All low voltage connections make this a safe and easy to use device while still delivering the sensitivity required.

  14. Learning from nature: constructing integrated graphene-based artificial nacre.

    PubMed

    Cheng, Qunfeng; Duan, Jianli; Zhang, Qi; Jiang, Lei

    2015-03-24

    Natural nacre supplies a number of properties that can be used in designing high-performance bioinspired materials. Likewise, due to the extraordinary properties of graphene, a series of bioinspired graphene-based materials have recently been demonstrated. Compared to other approaches for constructing graphene-based materials, bioinspired concepts result in high-loading graphene, and the resultant high-performance graphene-based artificial nacres demonstrate isotropic mechanical and electrical properties. In this Perspective, we describe how to construct integrated graphene-based artificial nacre through the synergistic relationship between interface interactions and building blocks. These integrated graphene-based artificial nacres show promising applications in many fields, such as aerospace, flexible supercapacitor electrodes, artificial muscle, and tissue engineering. PMID:25763684

  15. Method of producing a high pressure gas

    DOEpatents

    Bingham, Dennis N.; Klingler, Kerry M.; Zollinger, William T.

    2006-07-18

    A method of producing a high pressure gas is disclosed and which includes providing a container; supplying the container with a liquid such as water; increasing the pressure of the liquid within the container; supplying a reactant composition such as a chemical hydride to the liquid under pressure in the container and which chemically reacts with the liquid to produce a resulting high pressure gas such as hydrogen at a pressure of greater than about 100 pounds per square inch of pressure; and drawing the resulting high pressure gas from the container.

  16. Design of high pressure waterjet nozzles

    NASA Technical Reports Server (NTRS)

    Mazzoleni, Andre P.

    1994-01-01

    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.

  17. Design of high pressure waterjet nozzles

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Andre P.

    1994-10-01

    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.

  18. Cagelike diamondoid nitrogen at high pressures.

    PubMed

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

    2012-10-26

    Under high pressure, triply bonded molecular nitrogen dissociates into singly bonded polymeric nitrogen, a potential high-energy-density material. The discovery of stable high-pressure forms of polymeric nitrogen is of great interest. We report the striking stabilization of cagelike diamondoid nitrogen at high pressures predicted by first-principles structural searches. The diamondoid structure of polymeric nitrogen has not been seen in any other elements, and it adopts a highly symmetric body-centered cubic structure with lattice sites occupied by diamondoids, each of which consists of ten nitrogen atoms, forming a N(10) tetracyclic cage. Diamondoid nitrogen possesses a wide energy gap and is energetically most stable among all known polymeric structures above 263 GPa, a pressure that is accessible to a high-pressure experiment. Our findings represent a significant step toward the understanding of the behavior of solid nitrogen at extreme conditions.

  19. Cagelike diamondoid nitrogen at high pressures.

    PubMed

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

    2012-10-26

    Under high pressure, triply bonded molecular nitrogen dissociates into singly bonded polymeric nitrogen, a potential high-energy-density material. The discovery of stable high-pressure forms of polymeric nitrogen is of great interest. We report the striking stabilization of cagelike diamondoid nitrogen at high pressures predicted by first-principles structural searches. The diamondoid structure of polymeric nitrogen has not been seen in any other elements, and it adopts a highly symmetric body-centered cubic structure with lattice sites occupied by diamondoids, each of which consists of ten nitrogen atoms, forming a N(10) tetracyclic cage. Diamondoid nitrogen possesses a wide energy gap and is energetically most stable among all known polymeric structures above 263 GPa, a pressure that is accessible to a high-pressure experiment. Our findings represent a significant step toward the understanding of the behavior of solid nitrogen at extreme conditions. PMID:23215200

  20. Applications and development of high pressure PEM systems

    SciTech Connect

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

    1999-06-01

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

  1. High pressure processing for food safety.

    PubMed

    Fonberg-Broczek, Monika; Windyga, B; Szczawiński, J; Szczawińska, M; Pietrzak, D; Prestamo, G

    2005-01-01

    Food preservation using high pressure is a promising technique in food industry as it offers numerous opportunities for developing new foods with extended shelf-life, high nutritional value and excellent organoleptic characteristics. High pressure is an alternative to thermal processing. The resistance of microorganisms to pressure varies considerably depending on the pressure range applied, temperature and treatment duration, and type of microorganism. Generally, Gram-positive bacteria are more resistant to pressure than Gram-negative bacteria, moulds and yeasts; the most resistant are bacterial spores. The nature of the food is also important, as it may contain substances which protect the microorganism from high pressure. This article presents results of our studies involving the effect of high pressure on survival of some pathogenic bacteria -- Listeria monocytogenes, Aeromonas hydrophila and Enterococcus hirae -- in artificially contaminated cooked ham, ripening hard cheese and fruit juices. The results indicate that in samples of investigated foods the number of these microorganisms decreased proportionally to the pressure used and the duration of treatment, and the effect of these two factors was statistically significant (level of probability, P high pressure treatment than L. monocytogenes and A. hydrophila. Mathematical methods were applied, for accurate prediction of the effects of high pressure on microorganisms. The usefulness of high pressure treatment for inactivation of microorganisms and shelf-life extention of meat products was also evaluated. The results obtained show that high pressure treatment extends the shelf-life of cooked pork ham and raw smoked pork loin up to 8 weeks, ensuring good micro-biological and sensory quality of the products.

  2. Multicomponent fuel vaporization at high pressures.

    SciTech Connect

    Torres, D. J.; O'Rourke, P. J.

    2002-01-01

    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.

  3. Manufacturing Diamond Under Very High Pressure

    NASA Technical Reports Server (NTRS)

    Voronov, Oleg

    2007-01-01

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

  4. High-pressure phase transitions of strontianite

    NASA Astrophysics Data System (ADS)

    Speziale, S.; Biedermann, N.; Reichmann, H. J.; Koch-Mueller, M.; Heide, G.

    2015-12-01

    Strontianite (SrCO3) is isostructural to aragonite, a major high-pressure polymorph of calcite. Thus it is a material of interest to investigate the high-pressure phase behavior of aragonite-group minerals. SrCO3 is a common component of natural carbonates and knowing its physical properties at high pressures is necessary to properly model the thermodynamic properties of complex carbonates, which are major crustal minerals but are also present in the deep Earth [Brenker et al., 2007] and control carbon cycling in the Earth's mantle. The few available high-pressure studies of SrCO3 disagree regarding both pressure stability and structure of the post-aragonite phase [Lin & Liu, 1997; Ono et al., 2005; Wang et al. 2015]. To clarify such controversies we investigated the high-pressure behavior of synthetic SrCO3 by Raman spectroscopy. Using a diamond anvil cell we compressed single-crystals or powder of strontianite (synthesized at 4 GPa and 1273 K for 24h in a multi anvil apparatus), and measured Raman scattering up to 78 GPa. SrCO3 presents a complex high-pressure behavior. We observe mode softening above 20 GPa and a phase transition at 25 - 26.9 GPa, which we interpret due to the CO3 groups rotation, in agreement with Lin & Liu [1997]. The lattice modes in the high-pressure phase show dramatic changes which may indicate a change from 9-fold coordinated Sr to a 12-fold-coordination [Ono, 2007]. Our results confirm that the high-pressure phase of strontianite is compatible with Pmmn symmetry. References Brenker, F.E. et al. (2007) Earth and Planet. Sci. Lett., 260, 1; Lin, C.-C. & Liu, L.-G. (1997) J. Phys. Chem. Solids, 58, 977; Ono, S. et al. (2005) Phys. Chem. Minerals, 32, 8; Ono, S. (2007) Phys. Chem. Minerals, 34, 215; Wang, M. et al. (2015) Phys Chem Minerals 42, 517.

  5. Fuel droplet burning rates at high pressures.

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    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.

  6. Ignition during hydrogen release from high pressure into the atmosphere

    NASA Astrophysics Data System (ADS)

    Oleszczak, P.; Wolanski, P.

    2010-12-01

    The first investigations concerned with a problem of hydrogen jet ignition, during outflow from a high-pressure vessel were carried out nearly 40 years ago by Wolanski and Wojcicki. The research resulted from a dramatic accident in the Chorzow Chemical Plant Azoty, where the explosion of a synthesis gas made up of a mixture composed of three moles of hydrogen per mole of nitrogen, at 300°C and 30 MPa killed four people. Initial investigation had excluded potential external ignition sources and the main aim of the research was to determine the cause of ignition. Hydrogen is currently considered as a potential fuel for various vehicles such as cars, trucks, buses, etc. Crucial safety issues are of potential concern, associated with the storage of hydrogen at a very high pressure. Indeed, the evidence obtained nearly 40 years ago shows that sudden rupture of a high-pressure hydrogen storage tank or other component can result in ignition and potentially explosion. The aim of the present research is identification of the conditions under which hydrogen ignition occurs as a result of compression and heating of the air by the shock wave generated by discharge of high-pressure hydrogen. Experiments have been conducted using a facility constructed in the Combustion Laboratory of the Institute of Heat Engineering, Warsaw University of Technology. Tests under various configurations have been performed to determine critical conditions for occurrence of high-pressure hydrogen ignition. The results show that a critical pressure exists, leading to ignition, which depends mainly on the geometric configuration of the outflow system, such as tube diameter, and on the presence of obstacles.

  7. Construction of Electrochemical Chiral Interfaces with Integrated Polysaccharides via Amidation.

    PubMed

    Bao, Liping; Chen, Xiaohui; Yang, Baozhu; Tao, Yongxin; Kong, Yong

    2016-08-24

    Polysaccharides of sodium carboxymethyl cellulose (CMC) and chitosan (CS) were integrated together via amidation reactions between the carboxyl groups on sodium CMC and the amino groups on CS. Compared with individual sodium CMC and CS, the integrated polysaccharides with a mass ratio of 1:1, CMC-CS (1:1), exhibited a three-dimensional (3D) porous network structure, resulting in a significantly enhanced hydrophility due to the exposed polar functional groups in the CMC-CS (1:1). Chiral interfaces were constructed with the integrated polysaccharides and used for electrochemical enantiorecognition of tryptophan (Trp) isomers. The CMC-CS (1:1) chiral interfaces exhibited excellent selectivity toward the Trp isomers owing to the highly hydrophilic feature of CMC-CS (1:1) and the different steric hindrance during the formation of H bonds between Trp isomers and CMC-CS (1:1). Also, the optimization in the preparation of integrated polysaccharides such as mass ratio and combination mode (amidation or electrostatic interactions) was investigated. The CMC-CS (1:1) presented the ability of determining the percentage of d-Trp in racemic mixtures, and thus, the proposed electrochemical chiral interfaces could be regarded as a potential biosensing platform for enantiorecognition of chiral compounds. PMID:27487166

  8. Curved and conformal high-pressure vessel

    DOEpatents

    Croteau, Paul F.; Kuczek, Andrzej E.; Zhao, Wenping

    2016-10-25

    A high-pressure vessel is provided. The high-pressure vessel may comprise a first chamber defined at least partially by a first wall, and a second chamber defined at least partially by the first wall. The first chamber and the second chamber may form a curved contour of the high-pressure vessel. A modular tank assembly is also provided, and may comprise a first mid tube having a convex geometry. The first mid tube may be defined by a first inner wall, a curved wall extending from the first inner wall, and a second inner wall extending from the curved wall. The first inner wall may be disposed at an angle relative to the second inner wall. The first mid tube may further be defined by a short curved wall opposite the curved wall and extending from the second inner wall to the first inner wall.

  9. High pressure electrical insulated feed thru connector

    DOEpatents

    Oeschger, Joseph E.; Berkeland, James E.

    1979-11-13

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

  10. High-pressure distillation is different

    SciTech Connect

    Brierley, R.J.P.

    1994-07-01

    Many fluid systems perform differently at higher pressures than at lower ones. This makes high-pressure distillation different, too. But it also offers significant opportunities to engineers, both those deciding on the types of equipment to specify at the design stage, and those responsible for making high-pressure columns work, getting the best out of them, and assessing whether they can be uprated. Indeed, in a number of cases, it has been possible to uprate columns substantially (in one case by 70%) by redesign of the trays, and by replacement of trays with packing. This article provides practical guidance, based on the author's 20 years of experience as a distillation specialist, on how to get the best out of high-pressure distillation.

  11. Laser techniques in high-pressure geophysics

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  12. Temperature control for high pressure processes up to 1400 MPa

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

  13. High pressure synthesis gas fermentation. [Quarterly status] report, October 15, 1991--January 14, 1992

    SciTech Connect

    Not Available

    1992-09-01

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

  14. High pressure water jet mining machine

    DOEpatents

    Barker, Clark R.

    1981-05-05

    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.

  15. High pressure water jet cutting and stripping

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.; Babai, Majid K.

    1991-01-01

    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.

  16. Superelastic carbon spheres under high pressure

    NASA Astrophysics Data System (ADS)

    Li, Meifen; Guo, Junjie; Xu, Bingshe

    2013-03-01

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

  17. High pressure freon decontamination of remote equipment

    SciTech Connect

    Wilson, C.E.

    1987-01-01

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

  18. Behavior of silver molybdate at high-pressure

    SciTech Connect

    Arora, A.K.; Nithya, R.; Misra, Sunasira; Yagi, Takehiko

    2012-12-15

    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.

  19. Graphical construction of a local perspective on differentiation and integration

    NASA Astrophysics Data System (ADS)

    Hong, Ye Yoon; Thomas, Michael O. J.

    2015-06-01

    Recent studies of the transition from school to university mathematics have identified a number of epistemological gaps, including the need to change from an emphasis on equality to that of inequality. Another crucial epistemological change during this transition involves the movement from the pointwise and global perspectives of functions usually established through the school curriculum to a view of function that includes a local, or interval, perspective. This is necessary for study of concepts such as continuity and limit that underpin calculus and analysis at university. In this study, a first-year university calculus course in Korea was constructed that integrated use of digital technology and considered the epistemic value of the associated techniques. The aim was to encourage versatile thinking about functions, especially in relation to properties arising from a graphical investigation of differentiation and integration. In this paper, the results of this approach for the learning of derivative and antiderivative, based on integrated technology use, are presented. They show the persistence of what Tall ( Mathematics Education Research Journal, 20(2), 5-24, 2008) describes as symbolic world algebraic thinking on the part of a significant minority of students, who feel the need to introduce algebraic methods, in spite of its disadvantages, even when no explicit algebra is provided. However, the results also demonstrate the ability of many of the students to use technology mediation to build local or interval conceptual thinking about derivative and antiderivative functions.

  20. Small, high-pressure liquid hydrogen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.; Sutton, R.

    1977-01-01

    A high pressure, liquid hydrogen turbopump was designed, fabricated, and tested to a maximum speed of 9739 rad/s and a maximum pump discharge pressure of 2861 N/sq. cm. The approaches used in the analysis and design of the turbopump are described, and fabrication methods are discussed. Data obtained from gas generator tests, turbine performance calibration, and turbopump testing are presented.

  1. High Pressure Solution Kinetics of Metal Complexes.

    ERIC Educational Resources Information Center

    Suvachittanont, Surapong

    1983-01-01

    Describes use of activation volumes derived from the effect of pressure reaction rates in aiding the understanding of reaction mechanism. Topics discussed include determination and interpretation of activation volumes, high pressure equipment/techniques, and application of activation volumes in mechanistic elucidation of several inorganic…

  2. High-pressure differential scanning microcalorimeter.

    PubMed

    Senin, A A; Dzhavadov, L N; Potekhin, S A

    2016-03-01

    A differential scanning microcalorimeter for studying thermotropic conformational transitions of biopolymers at high pressure has been designed. The calorimeter allows taking measurements of partial heat capacity of biopolymer solutions vs. temperature at pressures up to 3000 atm. The principles of operation of the device, methods of its calibration, as well as possible applications are discussed. PMID:27036806

  3. High Pressure Inactivation of HAV within Mussels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential of hepatitis A virus (HAV) to be inactivated within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) by high pressure processing was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contamina...

  4. Advanced Diagnostics for High Pressure Spray Combustion.

    SciTech Connect

    Skeen, Scott A.; Manin, Julien Luc; Pickett, Lyle M.

    2014-06-01

    The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.

  5. The ATLAS Liquid Argon Calorimeter: Construction, Integration, Commissioning

    SciTech Connect

    Aleksa, Martin

    2006-10-27

    The ATLAS liquid argon (LAr) calorimeter system consists of an electromagnetic barrel calorimeter and two end caps with electromagnetic, hadronic and forward calorimeters. The liquid argon sampling technique, with an accordion geometry was chosen for the barrel electromagnetic calorimeter (EMB) and adapted to the end cap (EMEC). The hadronic end cap calorimeter (HEC) uses a copper-liquid argon sampling technique with flat plate geometry and is subdivided in depth in two wheels per end-cap. Finally, the forward calorimeter (FCAL) is composed of three modules employing cylindrical electrodes with thin liquid argon gaps.The construction of the full calorimeter system is complete since mid-2004. Production modules constructed in the home institutes were integrated into wheels at CERN in 2003-2004, and inserted into the three cryostats. They passed their first complete cold test before the lowering into the ATLAS cavern. Results of quality checks (e.g. electrical, mechanical, ...) performed on all the 190304 read-out channels after cool down will be reported. End 2004 the ATLAS barrel electromagnetic (EM) calorimeter was installed in the ATLAS cavern and since summer 2005 the front-end electronics are being connected and tested. Results of this first commissioning phase will be shown to demonstrate the high standards of quality control for our detectors.

  6. Treating swine wastewater by integrating earthworms into constructed wetlands.

    PubMed

    Nuengjamnong, Chackrit; Chiarawatchai, Nathasith; Polprasert, Chongrak; Otterpohl, Ralf

    2011-01-01

    The aim of this study was to investigate the application of integrating earthworms (Pheretima peguana) into two-stage pilot-scale subsurface-flow constructed wetlands (SFCWs) receiving swine wastewater in terms of their treatment performance, namely organic content, total kjeldahl nitrogen (TKN), and solid reduction as well as the quantity of sludge production. There was a minor difference in terms of removal efficiency according to each parameter when comparing the unit with earthworms to the one without earthworms. Both achieved the TKN, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total volatile suspended solids (TVSS), suspended solids (SS), and total solids (TS) removal by more than 90 %. The earthworms helped in reducing the sludge production on the surface of constructed wetlands 40 % by volume, which resulted in lowering operational costs required to empty and treat the sludge. The plant biomass production was higher in the wetlands without earthworms. Further research could be undertaken in order to effectively apply earthworms inside the wetlands.

  7. Performance Evaluation of Integrated Constructed Wetland for Domestic Wastewater Treatment.

    PubMed

    Sehar, Shama; Naz, Iffat; Khan, Sumera; Naeem, Sana; Perveen, Irum; Ali, Naeem; Ahmed, Safia

    2016-03-01

    Simple, budget friendly, laboratory-scale integrated constructed wetland (ICW) was designed to assess domestic wastewater treatment performance at a loading rate of 75 mm/d, planted with native plant species: Veronica-angallis aquatica and compared with non-vegetative control system at various residence times of 4, 8, 12, 16, 20, 24, and 28 days. Results revealed that the vegetated ICW demonstrated superior performance over non-vegetated control: 69.12 vs 17.12%, 67.77 vs 16.04%, 68 vs 16.48%, 71.19 vs 6.56%, 71.54 vs 14.80%, and 72.04 vs 11.41% for total dissolved solids, total suspended solids, phosphates (PO4(-)), sulfate (SO4(-)), nitrate (NO3(-)), and nitrite (NO2(-)), respectively, at 20 days residence times. Reduction in bacterial counts (2.79 × 10(4) CFU/mL) and fecal pathogens (345.5 MPN index/100 mL) was observed in V. aquatica at 20 days residence time. Therefore, the present study highlights not only the presence of vegetation but also appropriate residence time in constructed wetlands for better performances. PMID:26931539

  8. Magnetic and Superconducting Materials at High Pressures

    SciTech Connect

    Struzhkin, Viktor V.

    2015-03-24

    The work concentrates on few important tasks in enabling techniques for search of superconducting compressed hydrogen compounds and pure hydrogen, investigation of mechanisms of high-Tc superconductivity, and exploring new superconducting materials. Along that route we performed several challenging tasks, including discovery of new forms of polyhydrides of alkali metal Na at very high pressures. These experiments help us to establish the experimental environment that will provide important information on the high-pressure properties of hydrogen-rich compounds. Our recent progress in RIXS measurements opens a whole field of strongly correlated 3d materials. We have developed a systematic approach to measure major electronic parameters, like Hubbard energy U, and charge transfer energy Δ, as function of pressure. This technique will enable also RIXS studies of magnetic excitations in iridates and other 5d materials at the L edge, which attract a lot of interest recently. We have developed new magnetic sensing technique based on optically detected magnetic resonance from NV centers in diamond. The technique can be applied to study superconductivity in high-TC materials, to search for magnetic transitions in strongly correlated and itinerant magnetic materials under pressure. Summary of Project Activities; development of high-pressure experimentation platform for exploration of new potential superconductors, metal polyhydrides (including newly discovered alkali metal polyhydrides), and already known superconductors at the limit of static high-pressure techniques; investigation of special classes of superconducting compounds (high-Tc superconductors, new superconducting materials), that may provide new fundamental knowledge and may prove important for application as high-temperature/high-critical parameter superconductors; investigation of the pressure dependence of superconductivity and magnetic/phase transformations in 3d transition metal compounds, including

  9. Combustion of liquid sprays at high pressures

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  10. Design guide for high pressure oxygen systems

    NASA Technical Reports Server (NTRS)

    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

    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.

  11. High pressure studies of potassium perchlorate

    NASA Astrophysics Data System (ADS)

    Pravica, Michael; Wang, Yonggang; Sneed, Daniel; Reiser, Sharissa; White, Melanie

    2016-09-01

    Two experiments are reported on KClO4 at extreme conditions. A static high pressure Raman study was first conducted to 18.9 GPa. Evidence for at least two new phases was observed: one between 2.4 and 7.7 GPa (possibly sluggish), and the second near 11.7 GPa. Then, the X-ray induced decomposition rate of potassium perchlorate (KClO4 → hν KCl + 2O2) was studied up to 15.2 GPa. The time-dependent growth of KCl and O2 was monitored. The decomposition rate slowed at higher pressures. We present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregate at high pressure.

  12. Wound cleansing by high pressure irrigation.

    PubMed

    Rodeheaver, G T; Pettry, D; Thacker, J G; Edgerton, M T; Edlich, R F

    1975-09-01

    All traumatic wounds are contaminated to some degree by both soil and bacteria. Specific infection potentiating factors in soil impair the defenses of the tissue and invite infection. These factors are small in size and resist removal by low pressure irrigation. The efficiency of wound irrigation is markedly improved by delivering the irrigant to the wound under continuous high pressure. Irrigation of the wound with saline solution delivered at 15 pounds per square inch removed 84.8 per cent of the soil infection potentiating factors from the wound. The residual infection potentiating factors remaining in the wound did not significantly impair tissue defenses. On the basis of these experimental studies, clinical studies are now being initiated to test the therapeutic value of high pressure irrigation in traumatic wounds in humans.

  13. High pressure hydrogen time projection chamber

    SciTech Connect

    Goulianos, K.

    1983-01-01

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

  14. High-pressure mechanical instability in rocks

    USGS Publications Warehouse

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

    1969-01-01

    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.

  15. Small, high pressure liquid hydrogen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.; Warren, D. J.

    1980-01-01

    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.

  16. Raman spectroscopy of triolein under high pressures

    NASA Astrophysics Data System (ADS)

    Tefelski, D. B.; Jastrzębski, C.; Wierzbicki, M.; Siegoczyński, R. M.; Rostocki, A. J.; Wieja, K.; Kościesza, R.

    2010-03-01

    This article presents results of the high pressure Raman spectroscopy of triolein. Triolein, a triacylglyceride (TAG) of oleic acid, is an unsaturated fat, present in natural oils such as olive oil. As a basic food component and an energy storage molecule, it has considerable importance for food and fuel industries. To generate pressure in the experiment, we used a high-pressure cylindrical chamber with sapphire windows, presented in (R.M. Siegoczyński, R. Kościesza, D.B. Tefelski, and A. Kos, Molecular collapse - modification of the liquid structure induced by pressure in oleic acid, High Press. Res. 29 (2009), pp. 61-66). Pressure up to 750 MPa was applied. A Raman spectrometer in "macro"-configuration was employed. Raman spectroscopy provides information on changes of vibrational modes related to structural changes of triolein under pressure. Interesting changes in the triglyceride C‒H stretching region at 2650-3100 cm-1 were observed under high-pressures. Changes were also observed in the ester carbonyl (C˭ O) stretching region 1700-1780 cm-1 and the C‒C stretching region at 1050-1150 cm-1. The overall luminescence of the sample decreased under pressure, making it possible to set longer spectrum acquisition time and obtain more details of the spectrum. The registered changes suggest that the high-pressure solid phase of triolein is organized as β-polymorphic, as was reported in (C. Akita, T. Kawaguchi, and F. Kaneko, Structural study on polymorphism of cis-unsaturated triacylglycerol: Triolein, J. Phys. Chem. B 110 (2006), pp. 4346-4353; E. Da Silva and D. Rousseau, Molecular order and thermodynamics of the solid-liquid transition in triglycerides via Raman spectroscopy, Phys. Chem. Chem. Phys. 10 (2008), pp. 4606-4613) (with temperature-induced phase transitions). The research has shown that Raman spectroscopy in TAGs under pressure reveals useful information about its structural changes.

  17. (High-pressure structural studies of promethium)

    SciTech Connect

    Haire, R.G.

    1988-11-15

    The primary object of the foreign travel was to carry out collaborative high-pressure structural studies at the European Institute for Transuranium Elements (EITU), Karlsruhe, Federal Republic of Germany. These studies reestablished previous collaborative investigations by ORNL and EITU that have been very productive scientifically during the past few years. The study during the present travel period was limited to a structural study of promethium metal under pressure.

  18. High-pressure mechanical instability in rocks.

    PubMed

    Byerlee, J D; Brace, W F

    1969-05-01

    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.

  19. High pressure synthesis gas conversion. Final report

    SciTech Connect

    Not Available

    1993-05-01

    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.

  20. Apparatus for testing high pressure injector elements

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  1. [The high pressure life of piezophiles].

    PubMed

    Oger, Philippe; Cario, Anaïs

    2014-01-01

    The deep biosphere is composed of very different biotopes located in the depth of the oceans, the ocean crust or the lithosphere. Although very different, deep biosphere biotopes share one common feature, high hydrostatic pressure. The deep biosphere is colonized by specific organisms, called piezophiles, that are able to grow under high hydrostatic pressure. Bacterial piezophiles are mainly psychrophiles belonging to five genera of γ-proteobacteria, Photobacterium, Shewanella, Colwellia, Psychromonas and Moritella, while piezophilic Archaea are mostly (hyper)thermophiles from the Thermococcales. None of these genera are specific for the deep biosphere. High pressure deeply impacts the activity of cells and cellular components, and reduces the activity of numerous key processes, eventually leading to cell death of piezosensitive organisms. Biochemical and genomic studies yield a fragmented view on the adaptive mechanisms in piezophiles. It is yet unclear whether piezophilic adaptation requires the modification of a few genes, or metabolic pathways, or a more profound reorganization of the genome, the fine tuning of gene expression to compensate the pressure-induced loss of activity of the proteins most affected by high pressure, or a stress-like physiological cell response. In contrast to what has been seen for thermophily or halophily, the adaptation to high pressure is diffuse in the genome and may concern only a small fraction of the genes. PMID:25474000

  2. Exotic stable cesium polynitrides at high pressure

    DOE PAGES

    Peng, Feng; Han, Yunxia; Liu, Hanyu; Yao, Yansun

    2015-11-19

    New polynitrides containing metastable forms of nitrogen are actively investigated as potential high energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN3, we identified five new stoichiometric compounds (Cs3N, Cs2N, CsN, CsN2, and CsN5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N2, N3 , N4, N5, N6) and chains (N∞). Polymeric chainsmore » of nitrogen were found in the high-pressure C2/c phase of CsN2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N44- anion. In conclusion, to our best knowledge, this is the first time a charged N4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure.« less

  3. Exotic stable cesium polynitrides at high pressure

    NASA Astrophysics Data System (ADS)

    Peng, Feng; Han, Yunxia; Liu, Hanyu; Yao, Yansun

    2015-11-01

    New polynitrides containing metastable forms of nitrogen are actively investigated as potential high-energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN3, we identified five new stoichiometric compounds (Cs3N, Cs2N, CsN, CsN2, and CsN5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N2, N3, N4, N5, N6) and chains (N∞). Polymeric chains of nitrogen were found in the high-pressure C2/c phase of CsN2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N44- anion. To our best knowledge, this is the first time a charged N4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure.

  4. Raman study of opal at high pressure

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  5. Single Molecule Raman Spectroscopy Under High Pressure

    NASA Astrophysics Data System (ADS)

    Fu, Yuanxi; Dlott, Dana

    2014-06-01

    Pressure effects on surface-enhanced Raman scattering spectra of Rhdoamine 6G adsorbed on silver nanoparticle surfaces was studied using a confocal Raman microscope. Colloidal silver nanoparticles were treated with Rhodamine 6G (R6G) and its isotopically substituted partner, R6G-d4. Mixed isotopomers let us identify single-molecule spectra, since multiple-molecule spectra would show vibrational transitions from both species. The nanoparticles were embedded into a poly vinyl alcohol film, and loaded into a diamond anvil cell for the high-pressure Raman scattering measurement. Argon was the pressure medium. Ambient pressure Raman scattering spectra showed few single-molecule spectra. At moderately high pressure ( 1GPa), a surprising effect was observed. The number of sites with observable spectra decreased dramatically, and most of the spectra that could be observed were due to single molecules. The effects of high pressure suppressed the multiple-molecule Raman sites, leaving only the single-molecule sites to be observed.

  6. Exotic stable cesium polynitrides at high pressure

    PubMed Central

    Peng, Feng; Han, Yunxia; Liu, Hanyu; Yao, Yansun

    2015-01-01

    New polynitrides containing metastable forms of nitrogen are actively investigated as potential high-energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN3, we identified five new stoichiometric compounds (Cs3N, Cs2N, CsN, CsN2, and CsN5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N2, N3, N4, N5, N6) and chains (N∞). Polymeric chains of nitrogen were found in the high-pressure C2/c phase of CsN2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N44− anion. To our best knowledge, this is the first time a charged N4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure. PMID:26581175

  7. Apparatus for testing high pressure injector elements

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  8. High pressure effects on allergen food proteins.

    PubMed

    Somkuti, Judit; Smeller, László

    2013-12-15

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

  9. Water solubility in pyrope at high pressures

    NASA Astrophysics Data System (ADS)

    Mookherjee, M.; Karato, S.-

    2006-12-01

    To address how much water is stored within the Earth's mantle, we need to understand the water solubility in the nominally anhydrous minerals. Much is known about olivine and pyroxene. Garnet is another important component, approaching 40% by volume in the transition zone. Only two studies on water solubility in pyrope at high-pressures exist which contradict each other. Lu and Keppler (1997) observed increase in water solubility in a natural pyrope up to 200 ppm wt of water, till 10 GPa. They concluded that the proton is located in the interstitial site. Withers et al. (1998) on the contrary, observed increasing water content in Mg-rich pyrope till 6 GPa, then sudden decrease of water, beyond detection, at 7 GPa. Based on infrared spectra, Withers et al. (1998), concluded hydrogarnet (Si^{4+} replaced by 4H+ to form O4H4) substitution in synthetic magnesium rich pyrope. They argued that at high pressure owing to larger volume, hydrogarnet substitution is unstable and water is expelled out of garnet. In transition zone conditions, however, majorite garnet seems to contain around 600-700 ppm wt of water (Bolfan-Casanova et al. 2000; Katayama et al. 2003). The cause for such discrepancy is not clear and whether garnet could store a significant amount of water at mantle condition is unconstrained. In order to understand the solubility mechanism of water in pyrope at high-pressure, we have conducted high- pressure experiments on naturally occurring single crystals of pyrope garnet (from Arizona, Aines and Rossman, 1984). To ascertain water-saturated conditions, we use olivine single-crystal as an internal standard. Preliminary results indicate that natural pyrope is capable of dissolving water at high-pressures, however, water preferentially enters olivine than in pyrope. We are undertaking systematic study to estimate the solubility of water in pyrope as a function of pressure. This will enable us to develop solubility models to understand the defect mechanisms

  10. Comparison of integrated testlet and constructed-response question formats

    NASA Astrophysics Data System (ADS)

    Slepkov, Aaron D.; Shiell, Ralph C.

    2014-12-01

    Constructed-response (CR) questions are a mainstay of introductory physics textbooks and exams. However, because of the time, cost, and scoring reliability constraints associated with this format, CR questions are being increasingly replaced by multiple-choice (MC) questions in formal exams. The integrated testlet (IT) is a recently developed question structure designed to provide a proxy of the pedagogical advantages of CR questions while procedurally functioning as set of MC questions. ITs utilize an answer-until-correct response format that provides immediate confirmatory or corrective feedback, and they thus allow not only for the granting of partial credit in cases of initially incorrect reasoning, but, furthermore, the ability to build cumulative question structures. Here, we report on a study that directly compares the functionality of ITs and CR questions in introductory physics exams. To do this, CR questions were converted to concept-equivalent ITs, and both sets of questions were deployed in midterm and final exams. We find that both question types provide adequate discrimination between stronger and weaker students, with CR questions discriminating slightly better than the ITs. There is some indication that any difference in discriminatory power may result from the baseline score for guessing that is inherent in MC testing. Meanwhile, an analysis of interrater scoring of the CR questions raises serious concerns about the reliability of the granting of partial credit when this traditional assessment technique is used in a realistic (but nonoptimized) setting. Furthermore, we show evidence that partial credit is granted in a valid manner in the ITs. Thus, together with consideration of the vastly reduced costs of administering IT-based examinations compared to CR-based examinations, our findings indicate that ITs are viable replacements for CR questions in formal examinations where it is desirable both to assess concept integration and to reward partial

  11. Exotic stable cesium polynitrides at high pressure

    SciTech Connect

    Peng, Feng; Han, Yunxia; Liu, Hanyu; Yao, Yansun

    2015-11-19

    New polynitrides containing metastable forms of nitrogen are actively investigated as potential high energy-density materials. Using a structure search method based on the CALYPSO methodology, we investigated the stable stoichiometries and structures of cesium polynitrides at high pressures. Along with the CsN3, we identified five new stoichiometric compounds (Cs3N, Cs2N, CsN, CsN2, and CsN5) with interesting structures that may be experimentally synthesizable at modest pressures (i.e., less than 50 GPa). Nitrogen species in the predicted structures have various structural forms ranging from single atom (N) to highly endothermic molecules (N2, N3 , N4, N5, N6) and chains (N). Polymeric chains of nitrogen were found in the high-pressure C2/c phase of CsN2. This structure contains a substantially high content of single N-N bonds that exceeds the previously known nitrogen chains in pure forms, and also exhibit metastability at ambient conditions. We also identified a very interesting CsN crystal that contains novel N44- anion. In conclusion, to our best knowledge, this is the first time a charged N4 species being reported. Results of the present study suggest that it is possible to obtain energetic polynitrogens in main-group nitrides under high pressure.

  12. High pressure liquid chromatographic gradient mixer

    DOEpatents

    Daughton, Christian G.; Sakaji, Richard H.

    1985-01-01

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

  13. HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT

    SciTech Connect

    Stefano Orsino

    2005-03-30

    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

  14. High pressure luminescence probes in polymers

    SciTech Connect

    Drickamer, H.G.

    1980-01-01

    High pressure luminescence has proved to be a very powerful tool for characterizing crystalline solids and liquids. Two problems involving glassy polymers are analyzed. In the first problem the excited states of azulene and its derivatives are used to probe intermolecular interactions in PMMA and PS. In the second problem the change in emission intensity with pressure from two excimer states of polyvinylcarbazole as a pure polymer and in dilute solution in polystyrene (PS), polymethylmethacrylate (PMMA) and polyisoliutylene (PIB) is studied. The relative emission from the two states depends strongly on the possibility for motion of polymer segments. The observations are related to the proximity to the glass transition.

  15. High-pressure liquid chromatographic gradient mixer

    DOEpatents

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

    1982-09-08

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

  16. Very high-pressure orogenic garnet peridotites

    PubMed Central

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

    2007-01-01

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

  17. Sounding experiments of high pressure gas discharge

    SciTech Connect

    Biele, Joachim K.

    1998-07-10

    A high pressure discharge experiment (200 MPa, 5{center_dot}10{sup 21} molecules/cm{sup 3}, 3000 K) has been set up to study electrically induced shock waves. The apparatus consists of the combustion chamber (4.2 cm{sup 3}) to produce high pressure gas by burning solid propellant grains to fill the electrical pump chamber (2.5 cm{sup 3}) containing an insulated coaxial electrode. Electrical pump energy up to 7.8 kJ at 10 kV, which is roughly three times of the gas energy in the pump chamber, was delivered by a capacitor bank. From the current-voltage relationship the discharge develops at rapidly decreasing voltage. Pressure at the combustion chamber indicating significant underpressure as well as overpressure peaks is followed by an increase of static pressure level. These data are not yet completely understood. However, Lorentz forces are believed to generate pinching with subsequent pinch heating, resulting in fast pressure variations to be propagated as rarefaction and shock waves, respectively. Utilizing pure axisymmetric electrode initiation rather than often used exploding wire technology in the pump chamber, repeatable experiments were achieved.

  18. Stable Lithium Argon compounds under high pressure

    PubMed Central

    Li, Xiaofeng; Hermann, Andreas; Peng, Feng; Lv, Jian; Wang, Yanchao; Wang, Hui; Ma, Yanming

    2015-01-01

    High pressure can fundamentally alter the bonding patterns of chemical elements. Its effects include stimulating elements thought to be “inactive” to form unexpectedly stable compounds with unusual chemical and physical properties. Here, using an unbiased structure search method based on CALYPSO methodology and density functional total energy calculations, the phase stabilities and crystal structures of Li−Ar compounds are systematically investigated at high pressure up to 300 GPa. Two unexpected LimArn compounds (LiAr and Li3Ar) are predicted to be stable above 112 GPa and 119 GPa, respectively. A detailed analysis of the electronic structure of LiAr and Li3Ar shows that Ar in these compounds attracts electrons and thus behaves as an oxidizing agent. This is markedly different from the hitherto established chemical reactivity of Ar. Moreover, we predict that the P4/mmm phase of Li3Ar has a superconducting transition temperature of 17.6 K at 120 GPa. PMID:26582083

  19. Elasticity of Hydrogen at High Pressures

    NASA Astrophysics Data System (ADS)

    Goncharov, A. F.; Decremps, F.; Gauthier, M.; Ayrinhac, S.; Antonangeli, D.; Freiman, Y. A.; Grechnev, A.; Tretyak, S. M.

    2015-12-01

    High-pressure elastic properties of hydrogen give insight into anisotropy, equation of state, thermodynamic properties, and intermolecular potentials of this material providing an important link to ultrahigh pressure behavior approaching transformation to metallic monatomic or molecular state. Here we present picosecond acoustics measurements of compressional sound velocities [1] combined with optical interferometry and Raman spectroscopy of H2 and D2 at 295 K up to 55 GPa. Using the equation of state determined previously [2], we deduced the transverse sound velocities and the Poisson's ratio up to 55 GPa. The latter shows a broad minimum near 45 GPa (c.f. Ref. [3]) providing a new experimentally proven insight into lattice dynamics of hydrogen at high pressure that can be compared to theoretical calculations of various levels [4]. [1] F. Decremps, M. Gauthier, S. Ayrinhac, L. Bove, L. Belliard, B. Perrin, M. Morand, G. Le Marchand, F. Bergame, J. Philippe, Ultrasonics, 56 (2015) 129-140. [2] P. Loubeyre, R. LeToullec, D. Hausermann, M. Hanfland, R.J. Hemley, H.K. Mao, L.W. Finger, Nature, 383 (1996) 702-704. [3] C.-s. Zha, T.S. Duffy, H.-k. Mao, R.J. Hemley, Phys. Rev. B, 48 (1993) 9246-9255. [4] Y.A. Freiman, A. Grechnev, S.M. Tretyak, A.F. Goncharov, E. Gregoryanz, Fizika Nizkikh Temperatur, 41 (2015) 571.

  20. A picosecond high pressure gas switch

    SciTech Connect

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

    1992-06-01

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

  1. High pressure turbomachinery ground test facility

    NASA Technical Reports Server (NTRS)

    Scheuermann, Patrick E.

    1992-01-01

    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.

  2. 241-AY-101 Tank Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Gunter, Jason R.

    2013-08-26

    This report provides the results of an extent of condition construction history review for tank 241-AY-101. The construction history of tank 241-AY-101 has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In tank 241-AY-101, the second double-shell tank constructed, similar issues as those with tank 241-AY-102 construction reoccurred. The overall extent of similary and affect on tank 241-AY-101 integrity is described herein.

  3. 241-AW Tank Farm Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Gunter, Jason R.; Reeploeg, Gretchen E.

    2013-11-19

    This report provides the results of an extent of condition construction history review for the 241-AW tank farm. The construction history of the 241-AW tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AW tank farm, the fourth double-shell tank farm constructed, similar issues as those with tank 241-AY-102 construction occured. The overall extent of similary and affect on 241-AW tank farm integrity is described herein.

  4. (Ultra) high pressure homogenization for continuous high pressure sterilization of pumpable foods - a review.

    PubMed

    Georget, Erika; Miller, Brittany; Callanan, Michael; Heinz, Volker; Mathys, Alexander

    2014-01-01

    Bacterial spores have a strong resistance to both chemical and physical hurdles and create a risk for the food industry, which has been tackled by applying high thermal intensity treatments to sterilize food. These strong thermal treatments lead to a reduction of the organoleptic and nutritional properties of food and alternatives are actively searched for. Innovative hurdles offer an alternative to inactivate bacterial spores. In particular, recent technological developments have enabled a new generation of high pressure homogenizer working at pressures up to 400 MPa and thus, opening new opportunities for high pressure sterilization of foods. In this short review, we summarize the work conducted on (ultra) high pressure homogenization (U)HPH to inactivate endospores in model and food systems. Specific attention is given to process parameters (pressure, inlet, and valve temperatures). This review gathers the current state of the art and underlines the potential of UHPH sterilization of pumpable foods while highlighting the needs for future work.

  5. (Ultra) High Pressure Homogenization for Continuous High Pressure Sterilization of Pumpable Foods – A Review

    PubMed Central

    Georget, Erika; Miller, Brittany; Callanan, Michael; Heinz, Volker; Mathys, Alexander

    2014-01-01

    Bacterial spores have a strong resistance to both chemical and physical hurdles and create a risk for the food industry, which has been tackled by applying high thermal intensity treatments to sterilize food. These strong thermal treatments lead to a reduction of the organoleptic and nutritional properties of food and alternatives are actively searched for. Innovative hurdles offer an alternative to inactivate bacterial spores. In particular, recent technological developments have enabled a new generation of high pressure homogenizer working at pressures up to 400 MPa and thus, opening new opportunities for high pressure sterilization of foods. In this short review, we summarize the work conducted on (ultra) high pressure homogenization (U)HPH to inactivate endospores in model and food systems. Specific attention is given to process parameters (pressure, inlet, and valve temperatures). This review gathers the current state of the art and underlines the potential of UHPH sterilization of pumpable foods while highlighting the needs for future work. PMID:25988118

  6. Synthesis of sodium polyhydrides at high pressures.

    PubMed

    Struzhkin, Viktor V; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-Kwang; Pickard, Chris J; Needs, Richard J; Prakapenka, Vitali B; Goncharov, Alexander F

    2016-01-01

    The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials. PMID:27464650

  7. High pressure volumetric measurements in dipalmitoylphosphatidylcholine bilayers.

    PubMed

    Tosh, R E; Collings, P J

    1986-07-10

    The one previously reported high pressure volumetric experiment on a phospholipid bilayer investigated a region of pressure between 0 and 25 MPa and obtained isothermal compressibility values for the liquid crystal and intermediate phases which differed by more than a factor of ten. We report new volumetric measurements around the main transition in dipalmitoylphosphatidylcholine (DPPC) from 0 to 100 MPa. The isothermal compressibility data for the two phases are of the same order of magnitude, and the experimentally determined coexistence curve, specific volume dependence, and volume discontinuity values are compared with the predictions of the phenomenological theory according to Sugar and Tarjan ((1982) Sov. Phys. Crystallogr. 27, 4-5). Significant discrepancies between this theory and experiment are found. Finally, the data indicate that steric interactions play a more dominant role in the main transition of phospholipid bilayers than in transitions in most thermotropic liquid crystals.

  8. Synthesis of sodium polyhydrides at high pressures

    DOE PAGES

    Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-kwang; Pickard, Chris J.; Needs, Richard J.; Prakapenka, Vitali B.; Goncharov, Alexander F.

    2016-07-28

    Archetypal ionic NaH is the only known compound of sodium and hydrogen. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. Moreover, we combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formationmore » of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.« less

  9. Synthesis of sodium polyhydrides at high pressures

    NASA Astrophysics Data System (ADS)

    Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-Kwang; Pickard, Chris J.; Needs, Richard J.; Prakapenka, Vitali B.; Goncharov, Alexander F.

    2016-07-01

    The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.

  10. Safety improvements in high pressure thermal machines

    SciTech Connect

    Otters, J.L.

    1988-02-09

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

  11. Synthesis of sodium polyhydrides at high pressures.

    PubMed

    Struzhkin, Viktor V; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-Kwang; Pickard, Chris J; Needs, Richard J; Prakapenka, Vitali B; Goncharov, Alexander F

    2016-07-28

    The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials.

  12. Low energy high pressure miniature screw valve

    DOEpatents

    Fischer, Gary J.; Spletzer, Barry L.

    2006-12-12

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

  13. High pressure and high temperature apparatus

    DOEpatents

    Voronov, Oleg A.

    2005-09-13

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

  14. Small, high-pressure liquid oxygen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.; Sutton, R.

    1977-01-01

    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.

  15. High pressure study of acetophenone azine

    NASA Astrophysics Data System (ADS)

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

    2009-02-01

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

  16. High pressure combustion synthesis of aluminum nitride

    SciTech Connect

    Costantino, M.; Firpo, C. )

    1991-11-01

    We report initial results on the synthesis of monolithic aluminum nitride by burning Al--AlN mixtures in high pressure nitrogen. The objective is to synthesize economically large, near-theoretical density AlN parts. In this work, we begin with compacted mixtures of 10 {mu}m Al and 3 {mu}m AlN powder formed into 7.62 cm diameter by 3.81 cm thick disks having densities up to 60% of theoretical. Then, at N{sub 2} pressures up to 180 MPa (26 000 psi), we ignite the disk on one face. The fraction of Al converted to AlN, density, and severity of macroscopic cracking vary with N{sub 2} pressure and heat transfer from the sample. Presently, products are inhomogeneous, showing regions of relatively high porosity, regions with no porosity but with AlN in a matrix of Al, and regions of nearly theoretical density AlN.

  17. Ceramic high pressure gas path seal

    NASA Technical Reports Server (NTRS)

    Liotta, G. C.

    1987-01-01

    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.

  18. Synthesis of sodium polyhydrides at high pressures

    PubMed Central

    Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; Muramatsu, Takaki; Mao, Ho-kwang; Pickard, Chris J.; Needs, Richard J.; Prakapenka, Vitali B.; Goncharov, Alexander F.

    2016-01-01

    The only known compound of sodium and hydrogen is archetypal ionic NaH. Application of high pressure is known to promote states with higher atomic coordination, but extensive searches for polyhydrides with unusual stoichiometry have had only limited success in spite of several theoretical predictions. Here we report the first observation of the formation of polyhydrides of Na (NaH3 and NaH7) above 40 GPa and 2,000 K. We combine synchrotron X-ray diffraction and Raman spectroscopy in a laser-heated diamond anvil cell and theoretical random structure searching, which both agree on the stable structures and compositions. Our results support the formation of multicenter bonding in a material with unusual stoichiometry. These results are applicable to the design of new energetic solids and high-temperature superconductors based on hydrogen-rich materials. PMID:27464650

  19. High pressure chemistry of substituted acetylenes

    SciTech Connect

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

    2011-01-25

    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.

  20. Urea and deuterium mixtures at high pressures

    SciTech Connect

    Donnelly, M. Husband, R. J.; Frantzana, A. D.; Loveday, J. S.; Bull, C. L.; Klotz, S.

    2015-03-28

    Urea, like many network forming compounds, has long been known to form inclusion (guest-host) compounds. Unlike other network formers like water, urea is not known to form such inclusion compounds with simple molecules like hydrogen. Such compounds if they existed would be of interest both for the fundamental insight they provide into molecular bonding and as potential gas storage systems. Urea has been proposed as a potential hydrogen storage material [T. A. Strobel et al., Chem. Phys. Lett. 478, 97 (2009)]. Here, we report the results of high-pressure neutron diffraction studies of urea and D{sub 2} mixtures that indicate no inclusion compound forms up to 3.7 GPa.

  1. High Pressure Quick Disconnect Particle Impact Tests

    NASA Technical Reports Server (NTRS)

    Rosales, Keisa R.; Stoltzfus, Joel M.

    2009-01-01

    NASA Johnson Space Center White Sands Test Facility (WSTF) performed particle impact testing to determine whether there is a particle impact ignition hazard in the quick disconnects (QDs) in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). Testing included standard supersonic and subsonic particle impact tests on 15-5 PH stainless steel, as well as tests performed on a QD simulator. This paper summarizes the particle impact tests completed at WSTF. Although there was an ignition in Test Series 4, it was determined the ignition was caused by the presence of a machining imperfection. The sum of all the test results indicates that there is no particle impact ignition hazard in the ISS ECLSS QDs. KEYWORDS: quick disconnect, high pressure, particle impact testing, stainless steel

  2. Small, high-pressure, liquid oxygen turbopump

    NASA Technical Reports Server (NTRS)

    Csomor, A.

    1978-01-01

    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.

  3. High-pressure stabilization of argon fluorides.

    PubMed

    Kurzydłowski, Dominik; Zaleski-Ejgierd, Patryk

    2016-01-28

    On account of the rapid development of noble gas chemistry in the past half-century both xenon and krypton compounds can now be isolated in macroscopic quantities. The same does not hold true for the next lighter group 18 element, argon, which forms only isolated molecules stable solely in low temperature matrices or supersonic jet streams. Here we present theoretical investigations into a new high-pressure reaction pathway, which enables synthesis of argon fluorides in bulk and at room temperature. Our hybrid DFT calculations (employing the HSE06 functional) indicate that above 60 GPa ArF2-containing molecular crystals can be obtained by a reaction between argon and molecular fluorine. PMID:26742478

  4. High-Pressure Research Applications Seminar

    NASA Astrophysics Data System (ADS)

    Manghnani, Murli H.; Akimoto, Syun-iti; Ahrens, Thomas J.; Syono, Yasuhiko; Jeanloz, Raymond; Yagi, Takehiko

    The United States-Japan seminar on “High-Pressure Research Applications in Geophysics and Geochemistry” was held in Honolulu, Hawaii, January 13-16, 1986, under the auspices of the National Science Foundation (NSF) and the Japan Society for the Promotion of Science (JSPS). The seminar, the third in a series, was cocovened by Murli H. Manghnani (University of Hawaii, Honolulu) and Syun-iti Akimoto (University of Tokyo). Coming together for this symposium were 25 researchers from Japan, 22 from the United States, and four others, from Australia, the People's Republic of China, the Netherlands, and the Federal Republic of Germany. Of the 52 papers presented, 38 were presented orally at seven scientific sessions, and the rest were displayed at a poster session.

  5. High-pressure coal fuel processor development

    SciTech Connect

    Greenhalgh, M.L.

    1992-11-01

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

  6. Yield strength of molybdenum at high pressures.

    PubMed

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

    2007-07-01

    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 at pressures has been measured. Our main experimental conclusions are as follows: (1) The measured yield strength data for three samples with different initial thickness (100, 250, and 500 microm) are in good agreement above a peak pressure of 10 GPa. (2) The measured yield strength can be fitted into a linear formula Y=0.48(+/-0.19)+0.14(+/-0.01)P (Y and P denote the yield strength and local pressure, respectively, both of them are in gigapascals) in the local pressure range of 8-21 GPa. This result is in good agreement with both Y=0.46+0.13P determined in the pressure range of 5-24 GPa measured by the radial x-ray diffraction technique and the previous shock wave data below 10 GPa. (3) The zero-pressure yield strength of Mo is 0.5 GPa when we extrapolate our experimental data into the ambient pressure. It is close to the tensile strength of 0.7 GPa determined by Bridgman [Phys. Rev. 48, 825 (1934)] previously. The modified method described in this article therefore provides the confidence in determination of the yield strength at high pressures. PMID:17672772

  7. Topaz and Kyanite Luminescence Under High Pressure

    NASA Astrophysics Data System (ADS)

    O'Bannon, E. F., III; Williams, Q. C.

    2014-12-01

    The luminescence spectra of Cr3+ in heat-treated topaz Al2SiO4(OH,F)2 and natural kyanite Al2SiO5 were measured from 650 - 800 nm in a hydrostatic environment up to pressures of 15 GPa. The R1 and R2 peaks of topaz shift at average rates of 0.30 nm/GPa and 0.22 nm/GPa, respectively, implying that the deformation of the Cr3+ octahedra increases with pressure. Three peaks are fit under each R line of topaz at both room and high pressure, and these peaks are associated with different Al sites into which the Cr substitutes. The shift of the R lines in topaz under pressure is remarkably linear, which appears to be a general feature of many Cr3+-bearing oxides: the underlying cause of this linearity may lie in anharmonic coupling with lattice vibrations. In this context, we also characterize the frequency shifts of two vibronic peaks within topaz. The R1 and R2 peaks of kyanite shift at 0.37 nm/GPa and 0.88 nm/GPa respectively. Two peaks are fit under R1 and three peaks are fit under R2 of kyanite at both room and high pressure; this result is also consistent with three different Cr3+ sites in this material. The R lines in kyanite are notably optically anisotropic, depending strongly on crystallographic orientation: this is most strongly manifested in the R2 peak. The Cr3+ luminescence in these materials provides a sensitive probe of pressure-dependent shifts in the local geometry of the Al-sites in these materials, which are analyzed in the context of previous single-crystal x-ray diffraction measurements.

  8. Test facility for high pressure plasmas

    SciTech Connect

    Block, R.; Laroussi, M.; Schoenbach, K.H.

    1999-07-01

    High pressure nonthermal plasmas are gaining increasing importance because of their wide range of applications, e.g. in air plasma ramparts, gas processing, surface treatment, thin film deposition, and chemical and biological decontamination. In order to compare various methods of plasma generation with respect to efficiency, development of instabilities, homogeneity, lifetime etc., a central test facility for high pressure plasmas is being established. The facility will allow one to study large volume (> 100 cm{sup 3}), nonthermal (gas temperature: < 2,000 K) plasmas over a large pressure range (10{sup {minus}6} Torr up to more than 1 atmosphere) in a standardized discharge cell. The setup was designed to generate plasmas in air as well as in gas mixtures. The available voltage range extends to 25 kV dc (10 kW power). The electrodes can be water cooled. Electrical diagnostics include a 400 Mhz, 2 GS/s 4-channel oscilloscope for current and voltage measurements and the detection of the onset of instabilities. For optical diagnostics, a CCD video camera is used to record the appearance of dc discharges. A high-speed light intensified CCD-camera (25 mm MCP with photocathode, gating speed: 200 ps, adjustable in 10 ps steps) allows to study the development of instabilities and can also be utilized in temporally resolved spectroscopic measurements. Optical emission spectroscopy allows one to determine plasma parameters such as electron density (through Stark broadening measurements) and gas temperature measurements. Interferometry is well suited for electron density measurements especially in weakly ionized plasmas.

  9. High pressure microhollow cathode discharges in air

    SciTech Connect

    Khedr, M.A.; Stark, R.H.; Watson, B.; Schoenbach, K.H.

    1998-12-31

    Research on high pressure, large volume glow discharges in air is motivated by applications such as reflectors and absorbers for electromagnetic radiation, plasma processing, and the remediation of gaseous pollution. In order to prevent glow-to-arc transitions, which in high-pressure glow discharges start in the cathode region, it is proposed to use a plasma cathode consisting of an array of microhollow cathode discharges. To explore the conditions for stable operation of single 100 {micro}m microhollow cathode discharges in flowing air, the current-voltage characteristics, and the visual appearance of a 100 {micro}m microhollow cathode discharge were studied. The results show that the threshold current for the transition from a glow into a filamentary discharge varies inversely with pressure. At pressures of 400 Torr the current in the 100 {micro}m hollow cathode discharge must not exceed 0.5 mA in order for the discharge to be stable. The type of instability, which causes the transition from dc to fluctuating currents, is not known at this time, but the observed dependence of the threshold current from the gas pressure points to a thermal instability. Assuming that the White-Allis scaling law still holds for air discharges at pressures close to atmospheric, it is expected that reducing the cathode hole diameter to 50 {micro}m will allow us to operate microhollow cathode discharges at atmospheric air with currents of up to 0.25 mA. Experimental studies on the effect of the cathode dimensions and cathode material are underway and results will be discussed at the conference.

  10. Pulsed laser kinetic studies of liquids under high pressure

    SciTech Connect

    Eyring, E.M.

    1991-11-25

    A high pressure apparatus constructed for measuring the rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm has been used to measure the complexation kinetics of molybdenum hexacarbonyl reacting with 2,2-bipyridine, 4,4{prime}-dimethyl-2-2{prime}-bipyridine and 4,4{prime}-diphenyl-2-2{prime} bipyridine in toluene. Pentacarbonyl reaction intermediates are created by a 10 nsec flash of frequency tripled Nd:YAG laser light. Measured activation volumes for chelate ligand ring closure indicate a change in mechanism from associative interchange to dissociative interchange as steric hindrance increases. A similar high pressure kinetics study of molybdenum carbonyl complexation by several substituted phenanthrolines is now well advanced that indicates that with the more rigid phenanthroline ligands steric effects from bulky substituents have less effect on the ring closure mechanism than in the case of the bipyridine ligands. An experimental concentration dependence of the fluorescence quantum yield of cresyl violet has been harmonized with previously published contradictory reports. Fluorescence of cresyl violet in various solvents and in micellar systems has also been systematically explored.

  11. A high pressure modulated molecular beam mass spectrometric sampling system

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  12. High-Pressure Hydrogen from First-Principles

    NASA Astrophysics Data System (ADS)

    Morales, Miguel A.

    2014-03-01

    The main approximations typically employed in first-principles simulations of high-pressure hydrogen are the neglect of nuclear quantum effects (NQE) and the approximate treatment of electronic exchange and correlation, typically through a density functional theory (DFT) formulation. In this talk I'll present a detailed analysis of the influence of these approximations on the phase diagram of high-pressure hydrogen, with the goal of identifying the predictive capabilities of current methods and, at the same time, making accurate predictions in this important regime. We use a path integral formulation combined with density functional theory, which allows us to incorporate NQEs in a direct and controllable way. In addition, we use state-of-the-art quantum Monte Carlo calculations to benchmark the accuracy of more approximate mean-field electronic structure calculations based on DFT, and we use GW and hybrid DFT to calculate the optical properties of the solid and liquid phases near metallization. We present accurate predictions of the metal-insulator transition on the solid, including structural and optical properties of the molecular phase. MAM was supported by the U.S. Department of Energy at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and by LDRD Grant No. 13-LW-004.

  13. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  14. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  15. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  16. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  17. 30 CFR 57.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-pressure hose connections. 57.13021... Air and Boilers § 57.13021 High-pressure hose connections. Except where automatic shutoff valves are...-pressure hose lines of 3/4-inch inside diameter or larger, and between high-pressure hose lines of...

  18. 46 CFR 194.10-10 - Integral magazine construction.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., including the deck overhead, which are common with storerooms or workshops shall be of A-15 construction as... are permitted. (e) Piping, other than fresh or salt water service and drainage system, shall not...

  19. 46 CFR 194.10-10 - Integral magazine construction.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., including the deck overhead, which are common with storerooms or workshops shall be of A-15 construction as... are permitted. (e) Piping, other than fresh or salt water service and drainage system, shall not...

  20. High-pressure phase equilibria with compressed gases.

    PubMed

    Ren, Wei; Scurto, Aaron M

    2007-12-01

    An apparatus is described that is capable of determining high-pressure vapor-liquid equilibrium, liquid-liquid equilibrium, solid-liquid-vapor equilibrium, vapor-liquid-liquid equilibrium, and mixture critical points and transitions. The device is capable of temperatures to 150 degrees C and pressures to 300 bars (higher with slight modifications). The construction and operation are described in detail and do not require the use of mercury. This method requires very low sample volumes and no analytical equipment nor system-specific calibration. The apparatus was verified by comparison with literature data for the decane-CO(2) mixture and CO(2)-ionic liquid [1-hexyl-3-methyl-imidazolium bis(trifyl)imide)] systems. The experimental data have excellent agreement with the literature data that used different experimental methods. A rigorous error analysis of the system is also presented.

  1. Falling capillary tube viscometer suitable for liquids at high pressure

    NASA Astrophysics Data System (ADS)

    Kumagai, Akibumi; Kawase, Yasuo; Yokoyama, Chiaki

    1998-03-01

    A new high pressure viscometer based on a falling capillary tube was developed for the study of liquids and solutions. The viscometer was used to determine the viscosity of water containing 4.8 wt % CO2 at pressures up to 40 MPa and over the temperature range from 273.15 to 323.15 K. Measurements of methanol at 0.1 MPa and water at pressures up to 40 MPa and over the temperature range from 273 to 333 K were used to confirm the accuracy of the new viscometer. For the methanol and water, agreement to within 1.8% of the literature values was found. The new viscometer should be applicable up to 200 MPa as judged by the current apparatus and materials of construction.

  2. High-pressure Experimental Studies on Geo-liquids Using Synchrotron Radiation at the Advanced Photon Source

    SciTech Connect

    Wang, Yanbin; Shen, Guoyin

    2014-12-23

    Here, we review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Moreover, we describe experimental techniques, along with scientific highlights. Future developments are also discussed.

  3. High Pressure Electrochemistry: Application to silver halides

    NASA Astrophysics Data System (ADS)

    Havens, K.; Kavner, A.

    2007-12-01

    Electron and ion charge transfer processes help govern electrical conductivity and diffusive mass and heat transport properties in deep Earth minerals. In an attempt to understand how pressure influences charge transfer behavior, the halide silver bromide (AgBr) was studied under the influence of an electric potential difference applied across two electrodes in a diamond anvil cell. This study follows our previous work on AgI, which was found to dissociate to molecular iodine and silver metal due to pressure and voltage influences. We performed two sets of experiments on AgBr at high pressure in a diamond anvil cell: electrochemical dissociation and electrical resistance measurements. In our study, we were able to electrochemically dissociate AgBr at pressures of 0.25-1.6 GPa by applying a voltage across the electrodes in the diamond cell sample chamber. Ag metal grew visibly on the negatively-charged electrode when voltages varying from 0.1 V to 5 V were applied. Additionally, a dark blue color appeared in low pressure areas of the diamond cell and grew darker from both voltage application and light exposure, indicating photochemical effects. We found that the reaction area and growth rate of both metal and dark blue color strongly increased as voltage increased, but tended to decrease with greater pressure. The resistance across the cell was observed to be influenced by both pressure and light exposure. As the AgBr sample was exposed to visible light, the resistance dropped instantaneously, and after the light was turned off, the resistance increased on a timescale of 10's of seconds to minutes. Notably, at higher pressures, the AgBr showed less photosensitivity. Exploration of these metal halide systems has many potential applications. First, these experiments explore the pressure-dependence of photochemical and photovoltaic processes, and may spur development of pressure-tuned microscale electronic devices. Second, these experimental results can be used to

  4. High pressure waterjet cutting industrial needs survey

    NASA Astrophysics Data System (ADS)

    Klavuhn, John; Baker, Bruce

    1989-08-01

    The results are presented of a survey conducted by personnel of the National Center for Excellence in Metalworking Technology (NCEMT) to assess the industrial needs in high pressure water jet cutting (WJC) technology. Survey forms were mailed to approximately 1400 individuals obtained from three mailing lists. The respondents included approximately 200 individuals associated with a variety of industries: 12 percent were WJC equipment suppliers, 40 percent were WJC users, and 48 percent were neither suppliers nor users. The survey addressed five specific areas of WJC technology: research and development, standards, systems, new products, and training and service. Results show that the need having the highest priority is the establishment of a database on WJC that contains the cutting parameters for a wide range of materials. Associated with this objective is the expressed need for an independent demonstration and test center for testing, data generation and operator training. A further need was found for establishing organized efforts in hardware development and research in mechanisms of cutting.

  5. Stable magnesium peroxide at high pressure.

    PubMed

    Lobanov, Sergey S; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B; Oganov, Artem R; Goncharov, Alexander F

    2015-09-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth's lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O2(2-)) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions.

  6. Stable magnesium peroxide at high pressure

    NASA Astrophysics Data System (ADS)

    Lobanov, Sergey S.; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B.; Oganov, Artem R.; Goncharov, Alexander F.

    2015-09-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth’s lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O22-) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions.

  7. Dissociation of methane under high pressure

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    Methane is an extremely important energy source with a great abundance in nature and plays a significant role in planetary physics, being one of the major constituents of giant planets Uranus and Neptune. The stable crystal forms of methane under extreme conditions are of great fundamental interest. Using the ab initio evolutionary algorithm for crystal structure prediction, we found three novel insulating molecular structures with P212121, Pnma, and Cmcm space groups. Remarkably, under high pressure, methane becomes unstable and dissociates into ethane (C2H6) at 95 GPa, butane (C4H10) at 158 GPa, and further, carbon (diamond) and hydrogen above 287 GPa at zero temperature. We have computed the pressure-temperature phase diagram, which sheds light into the seemingly conflicting observations of the unusually low formation pressure of diamond at high temperature and the failure of experimental observation of dissociation at room temperature. Our results support the idea of diamond formation in the interiors of giant planets such as Neptune.

  8. Dissociation of methane under high pressure.

    PubMed

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

    2010-10-14

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

  9. Stable magnesium peroxide at high pressure.

    PubMed

    Lobanov, Sergey S; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B; Oganov, Artem R; Goncharov, Alexander F

    2015-01-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth's lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O2(2-)) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions. PMID:26323635

  10. Amorphous boron nitride at high pressure

    NASA Astrophysics Data System (ADS)

    Durandurdu, Murat

    2016-06-01

    The pressure-induced phase transformation in hexagonal boron nitrite and amorphous boron nitrite is studied using ab initio molecular dynamics simulations. The hexagonal-to-wurtzite phase transformation is successfully reproduced in the simulation with a transformation mechanism similar to one suggested in experiment. Amorphous boron nitrite, on the other hand, gradually transforms to a high-density amorphous phase with the application of pressure. This phase transformation is irreversible because a densified amorphous state having both sp3 and sp2 bonds is recovered upon pressure release. The high-density amorphous state mainly consists of sp3 bonds and its local structure is quite similar to recently proposed intermediate boron nitrite phases, in particular tetragonal structure (P42/mnm), rather than the known the wurtzite or cubic boron nitrite due to the existence of four membered rings and edge sharing connectivity. On the basis of this finding we propose that amorphous boron nitrite might be best candidate as a starting structure to synthesize the intermediate phase(s) at high pressure and temperature (probably below 800 °C) conditions.

  11. Stable magnesium peroxide at high pressure

    PubMed Central

    Lobanov, Sergey S.; Zhu, Qiang; Holtgrewe, Nicholas; Prescher, Clemens; Prakapenka, Vitali B.; Oganov, Artem R.; Goncharov, Alexander F.

    2015-01-01

    Rocky planets are thought to comprise compounds of Mg and O as these are among the most abundant elements, but knowledge of their stable phases may be incomplete. MgO is known to be remarkably stable to very high pressure and chemically inert under reduced condition of the Earth’s lower mantle. However, in exoplanets oxygen may be a more abundant constituent. Here, using synchrotron x-ray diffraction in laser-heated diamond anvil cells, we show that MgO and oxygen react at pressures above 96 GPa and T = 2150 K with the formation of I4/mcm MgO2. Raman spectroscopy detects the presence of a peroxide ion (O22−) in the synthesized material as well as in the recovered specimen. Likewise, energy-dispersive x-ray spectroscopy confirms that the recovered sample has higher oxygen content than pure MgO. Our finding suggests that MgO2 may be present together or instead of MgO in rocky mantles and rocky planetary cores under highly oxidized conditions. PMID:26323635

  12. High-pressure structural properties of tetramethylsilane

    NASA Astrophysics Data System (ADS)

    Zhen-Xing, Qin; Xiao-Jia, Chen

    2016-02-01

    High-pressure structural properties of tetramethylsilane are investigated by synchrotron powder x-ray diffraction at pressures up to 31.1 GPa and room temperature. A phase with the space group of Pnma is found to appear at 4.2 GPa. Upon compression, the compound transforms to two following phases: the phase with space groups of P21/c at 9.9 GPa and the phase with P2/m at 18.2 GPa successively via a transitional phase. The unique structural character of P21/c supports the phase stability of tetramethylsilane without possible decomposition upon heavy compression. The appearance of the P2/m phase suggests the possible realization of metallization for this material at higher pressure. Project supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project from Ministry of Education of China (Grant No. 708070), the Fundamental Research Funds for the Central Universities, South China University of Technology (Grant No. 2014ZZ0069), the National Natural Science Foundation of China (Grant No. 51502189), and the Doctoral Project of Taiyuan University of Science and Technology, China (Grant No. 20132010).

  13. Dissociation of methane under high pressure.

    PubMed

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

    2010-10-14

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

  14. Picosecond High Pressure Gas Switch experiment

    SciTech Connect

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

    1993-08-01

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

  15. Glow discharges in high pressure microhollow cathodes

    NASA Astrophysics Data System (ADS)

    Boeuf, J.-P.; Pitchford, L. C.; Schoenbach, K. H.

    2004-09-01

    We have developed a model of high-pressure, microhollow cathode discharges (MHCDs) which has been used to predict the electrical characteristics and other properties of these discharges for comparison with experiment. The configuration studied here is an anode/dielectric/cathode sandwich in which a cylindrical hole with a diameter of some 100's of microns is pierced in the dielectric and in the cathode. Results from the model calculations in xenon at 100 torr and higher pressures show that the positive V-I (voltage-current) characteristic observed experimentally at low current corresponds to an abnormal glow discharge inside the cathode hole. At higher current, the V-I characteristic is that of a normal to slightly abnormal glow discharge between the anode and the outer face of the cathode. The change in slope of the V-I characteristic is consistent with experiment (provided metastables are taken into account). This shape was previously attribed to the onset of the classical hollow cathode effect, but we find no hollow cathode effect for pressures above about 30 torr and for 200 micron hole diameters.

  16. 46 CFR 194.10-10 - Integral magazine construction.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Magazines § 194.10-10 Integral... are permitted. (e) Piping, other than fresh or salt water service and drainage system, shall not...

  17. High pressure phase transitions in lawsonite at simultaneous high pressure and temperature: A single crystal study

    NASA Astrophysics Data System (ADS)

    O'Bannon, E. F., III; Vennari, C.; Beavers, C. C. G.; Williams, Q. C.

    2015-12-01

    Lawsonite (CaAl2Si2O7(OH)2.H2O) is a hydrous mineral with a high overall water content of ~11.5 wt.%. It is a significant carrier of water in subduction zones to depths greater than ~150 km. The structure of lawsonite has been extensively studied under room temperature, high-pressure conditions. However, simultaneous high-pressure and high-temperature experiments are scarce. We have conducted synchrotron-based simultaneous high-pressure and temperature single crystal experiments on lawsonite up to a maximum pressure of 8.4 GPa at ambient and high temperatures. We used a natural sample of lawsonite from Valley Ford, California (Sonoma County). At room pressure and temperature lawsonite crystallizes in the orthorhombic system with Cmcm symmetry. Room temperature compression indicates that lawsonite remains in the orthorhombic Cmcm space group up to ~9.0 GPa. Our 5.0 GPa crystal structure is similar to the room pressure structure, and shows almost isotropic compression of the crystallographic axes. Unit cell parameters at 5.0 GPa are a- 5.7835(10), b- 8.694(2), and c- 13.009(3). Single-crystal measurements at simultaneous high-pressure and temperature (e.g., >8.0 GPa and ~100 oC) can be indexed to a monoclinic P-centered unit cell. Interestingly, a modest temperature increase of ~100 oC appears to initiate the orthorhombic to monoclinic phase transition at ~0.6-2.4 GPa lower than room temperature compression studies have shown. There is no evidence of dehydration or H atom disorder under these conditions. This suggests that the orthorhombic to monoclinic transition could be kinetically impeded at 298 K, and that monoclinic lawsonite could be the dominant water carrier through much of the depth range of upper mantle subduction processes.

  18. Pressure Dome for High-Pressure Electrolyzer

    NASA Technical Reports Server (NTRS)

    Norman, Timothy; Schmitt, Edwin

    2012-01-01

    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

  19. Cobalt ferrite nanoparticles under high pressure

    SciTech Connect

    Saccone, F. D.; Ferrari, S.; Grinblat, F.; Bilovol, V.; Errandonea, D.

    2015-08-21

    We report by the first time a high pressure X-ray diffraction and Raman spectroscopy study of cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles carried out at room temperature up to 17 GPa. In contrast with previous studies of nanoparticles, which proposed the transition pressure to be reduced from 20–27 GPa to 7.5–12.5 GPa (depending on particle size), we found that cobalt ferrite nanoparticles remain in the spinel structure up to the highest pressure covered by our experiments. In addition, we report the pressure dependence of the unit-cell parameter and Raman modes of the studied sample. We found that under quasi-hydrostatic conditions, the bulk modulus of the nanoparticles (B{sub 0} = 204 GPa) is considerably larger than the value previously reported for bulk CoFe{sub 2}O{sub 4} (B{sub 0} = 172 GPa). In addition, when the pressure medium becomes non-hydrostatic and deviatoric stresses affect the experiments, there is a noticeable decrease of the compressibility of the studied sample (B{sub 0} = 284 GPa). After decompression, the cobalt ferrite lattice parameter does not revert to its initial value, evidencing a unit cell contraction after pressure was removed. Finally, Raman spectroscopy provides information on the pressure dependence of all Raman-active modes and evidences that cation inversion is enhanced by pressure under non-hydrostatic conditions, being this effect not fully reversible.

  20. Integrated Sensor Architecture (ISA) for Live Virtual Constructive (LVC) environments

    NASA Astrophysics Data System (ADS)

    Moulton, Christine L.; Harkrider, Susan; Harrell, John; Hepp, Jared

    2014-06-01

    The Integrated Sensor Architecture (ISA) is an interoperability solution that allows for the sharing of information between sensors and systems in a dynamic tactical environment. The ISA created a Service Oriented Architecture (SOA) that identifies common standards and protocols which support a net-centric system of systems integration. Utilizing a common language, these systems are able to connect, publish their needs and capabilities, and interact with other systems even on disadvantaged networks. Within the ISA project, three levels of interoperability were defined and implemented and these levels were tested at many events. Extensible data models and capabilities that are scalable across multi-echelons are supported, as well as dynamic discovery of capabilities and sensor management. The ISA has been tested and integrated with multiple sensors, platforms, and over a variety of hardware architectures in operational environments.

  1. Construction of an integrated database to support genomic sequence analysis

    SciTech Connect

    Gilbert, W.; Overbeek, R.

    1994-11-01

    The central goal of this project is to develop an integrated database to support comparative analysis of genomes including DNA sequence data, protein sequence data, gene expression data and metabolism data. In developing the logic-based system GenoBase, a broader integration of available data was achieved due to assistance from collaborators. Current goals are to easily include new forms of data as they become available and to easily navigate through the ensemble of objects described within the database. This report comments on progress made in these areas.

  2. Design principles for high-pressure force fields: Aqueous TMAO solutions from ambient to kilobar pressures

    NASA Astrophysics Data System (ADS)

    Hölzl, Christoph; Kibies, Patrick; Imoto, Sho; Frach, Roland; Suladze, Saba; Winter, Roland; Marx, Dominik; Horinek, Dominik; Kast, Stefan M.

    2016-04-01

    Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures - while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields.

  3. Design principles for high-pressure force fields: Aqueous TMAO solutions from ambient to kilobar pressures.

    PubMed

    Hölzl, Christoph; Kibies, Patrick; Imoto, Sho; Frach, Roland; Suladze, Saba; Winter, Roland; Marx, Dominik; Horinek, Dominik; Kast, Stefan M

    2016-04-14

    Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures--while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields.

  4. Design principles for high-pressure force fields: Aqueous TMAO solutions from ambient to kilobar pressures.

    PubMed

    Hölzl, Christoph; Kibies, Patrick; Imoto, Sho; Frach, Roland; Suladze, Saba; Winter, Roland; Marx, Dominik; Horinek, Dominik; Kast, Stefan M

    2016-04-14

    Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures--while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields. PMID:27083705

  5. The construct of work commitment: testing an integrative framework.

    PubMed

    Cooper-Hakim, Amy; Viswesvaran, Chockalingam

    2005-03-01

    This study meta-analytically examined extensive literature associated with work commitment. The primary purposes were to (a) cumulate correlations among dimensions of work commitment to see which were intercorrelated and (b) determine impact of work commitment dimensions and subdimensions on specific outcome variables (job satisfaction, job performance, turnover intentions, and turnover). Results were cumulated across 997 articles. The positive manifold of correlations suggests the presence of a common psychological construct underlying different commitment forms, with the exception of calculative, continuance, and union commitment. Most of the 94 meta-analyzed correlations were small, suggesting that concept redundancy is not a major concern. Meta-analyses of the correlations of 24 commitment constructs with 4 outcome variables suggest that different commitment forms have similar patterns of correlations with outcome variables.

  6. Integrating the Development of Graduate Attributes through Constructive Alignment

    ERIC Educational Resources Information Center

    Treleaven, Lesley; Voola, Ranjit

    2008-01-01

    The importance of graduate attributes is increasingly recognized internationally in higher education and by industry, government, and accrediting bodies. However, integrating the development of graduate attributes, such as critical thinking and critical reflection, has proved challenging in business education. This article demonstrates the value…

  7. A High-Pressure Hollow Cathode Ionization Source for In-Situ Detection of Organic Molecules

    NASA Technical Reports Server (NTRS)

    Beegle, L. W.; Kanik, I.

    2001-01-01

    We have designed, constructed and characterized a new high-pressure (1-5 Torr) hollow cathode discharge source (HCDS) that can be utilized as an ionizer in a wide variety of mass analyzers. Additional information is contained in the original extended abstract.

  8. Hazardous waste retrieval strategies using a high-pressure water jet scarifier

    SciTech Connect

    Hatchell, B.K.; Rinker, M.W.; Mullen, O.D.

    1995-08-01

    The Waste Dislodging and Conveyance Program is sponsored by the US Department of Energy Office of Technology Development to investigate waste dislodging and conveyance processes suitable for the retrieval of high-level radioactive waste. This program, represented by industry, national laboratories, and academia, has proposed a baseline technology of high-pressure water jet dislodging and pneumatic conveyance integrated as a scarifier as a means of retrieval of waste inside Hanford single-shell tanks. A testing program has been initiated to investigate system deployment techniques to determine appropriate mining strategies, level of control, sensor requirements, and address integration issues associated with deploying the scarifier by a long robotic manipulator arm. A test facility denoted the Hydraulics Testbed (HTB) is being constructed to achieve these objectives and to allow longer-duration, multiple-pass tests on large waste fields using a versatile gantry-style manipulator. Mining strategy tests with materials simulating salt cake and sludge waste forms will be conducted to evaluate the effectiveness of mining strategies, forces related to scarifier and conveyance line, and retrieval rate. This paper will describe the testbed facility and testing program and present initial test results to date.

  9. OH defects in high-pressure kyanite

    NASA Astrophysics Data System (ADS)

    Wieczorek, A. K.; Beran, A.

    2003-04-01

    The close-packed mineral structures of nominally anhydrous minerals, likely to be present within the Earth's upper mantle, may offer important storage sites for trace hydrogen (Ingrin and Skogby, 2000). Kyanite may indeed incorporate essential amounts of hydrogen (Beran et al., 1993). The IR spectrum in the OH stretching vibrational region of a gem-quality kyanite from an eclogite xenolith in a kimberlite from the Roberts Victor mine, South Africa, is characterized by a band triplet consisting of sharp bands centered at 3440, 3410 and 3387 cm-1 showing similar intensities (band group I). In comparison with kyanites from crustal occurrences, the similar intensities of these bands is a characteristic feature of this high-pressure kyanite, probably related to the enhanced Mg and Ti contents (ca. 0.06 wt.% MgO, 0.09 wt.% TiO_2). A second group of bands (band group II) is characterized by a broad absorption centered around 3270 cm-1. Band deconvolution revealed two maxima at 3276 and 3260 cm-1. Heating experiments indicate diffusion processes of hydrogen to preferred structural oxygen positions. Up to temperatures of 600^oC, the band at 3387 cm-1 shows a significant increase of its intensity, while the intensities of the bands at 3440 and 3410 cm-1 slightly decrease. No changes of intensity were observed for the low-energy band group II. Above heating temperatures of 600^oC all bands show a decrease of their intensities. The two groups of bands suggest that at least two types of OH positions exist simultaneously in the structure of kyanite. The pleochroic scheme of the two band groups, measured on oriented sections cut parallel to (100) and perpendicular to b direction, allows to develop a model for the OH defect incorporation, where the two crystallographically different oxygen atoms, not bound to Si, are preferred candidates for the partial OH replacement. The analytical H_2O content was determined on the basis of Beer's law from polarized spectral data and amounts to

  10. Transient High-Pressure Fuel Injection

    NASA Astrophysics Data System (ADS)

    Jarrahbashi, Dorrin

    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

  11. 241-SY Tank Farm Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-25

    This report provides the results of an extent of condition construction history review for tanks 241-SY-101, 241-SY-102, and 241-SY-103. The construction history of the 241-SY tank farm has been reviewed to identify issues similar to those experienced during tank 241-AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank 241-AY-102 as the comparison benchmark. In the 241-SY tank farm, the third DST farm constructed, refractory quality and stress relief were improved, while similar tank and liner fabrication issues remained.

  12. 241-AZ Tank Farm Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-30

    This report provides the results of an extent of condition construction history review for tanks 241-AZ-101 and 241-AZ-102. The construction history of the 241-AZ tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AZ tank farm, the second DST farm constructed, both refractory quality and tank and liner fabrication were improved.

  13. 241-AP Tank Farm Construction Extent of Condition Review for Tank Integrity

    SciTech Connect

    Barnes, Travis J.; Gunter, Jason R.; Reeploeg, Gretchen E.

    2014-04-04

    This report provides the results of an extent of condition construction history review for the 241-AP tank farm. The construction history of the 241-AP tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AP tank farm, the sixth double-shell tank farm constructed, tank bottom flatness, refractory material quality, post-weld stress relieving, and primary tank bottom weld rejection were improved.

  14. High-pressure coal fuel processor development. Final report

    SciTech Connect

    Greenhalgh, M.L.

    1992-12-01

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

  15. Arts Based Environmental Integrated Curriculum Construction and Implementation Supported by Learning Communities

    ERIC Educational Resources Information Center

    Buda, Sharon Liddell

    2010-01-01

    A study of a three-year environmental curriculum project is documented with attention to the process of co-constructing and implementing the curriculum while exposing the hidden potential for thoughtfully aligned learning communities to strengthen curriculum construction. The curriculum project is integrated across all disciplinary subjects and…

  16. Calculating Mass Diffusion in High-Pressure Binary Fluids

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Harstad, Kenneth

    2004-01-01

    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.

  17. [Mutation effect of ultra high pressure on microbe].

    PubMed

    Wang, Sui-Lou; Wu, Xiao-Zong; Hao, Li-Hua; Sun, Jun-She

    2005-12-01

    (Ultra) high pressure had many influences on microbe. It could regulate the expression of gene and protein, influence DNA's structure and function as well as change cell morphology and cell component. These effects not only make (ultra) high pressure to be applied into food sterilization, conserving and some processing, but also indicate it would play an important role in mutagenic breeding of microbe. Pressure can change the structure and function of microbe, yet it is possible that (ultra) high pressure could induce mutation of microbe. Now the feasibility of (ultra) high pressure's mutation effect was discussed according to the effects of it on microbe, some examples and author's studying.

  18. Functional Sub-states by High-pressure Macromolecular Crystallography.

    PubMed

    Dhaussy, Anne-Claire; Girard, Eric

    2015-01-01

    At the molecular level, high-pressure perturbation is of particular interest for biological studies as it allows trapping conformational substates. Moreover, within the context of high-pressure adaptation of deep-sea organisms, it allows to decipher the molecular determinants of piezophily. To provide an accurate description of structural changes produced by pressure in a macromolecular system, developments have been made to adapt macromolecular crystallography to high-pressure studies. The present chapter is an overview of results obtained so far using high-pressure macromolecular techniques, from nucleic acids to virus capsid through monomeric as well as multimeric proteins.

  19. Quantitative nondestructive characterization of visco-elastic materials at high pressure

    SciTech Connect

    Aizawa, Tatsuhiko; Kihara, Junji; Ohno, Jun

    1995-11-01

    New anvil apparatus was developed to realize high pressure atmosphere suitable to investigation of viscoelastic behaviors of such soft materials as polymers, lubricants, proteins and so forth. In addition, ultrasonic spectroscopy system was also newly constructed to make quantitative nondestructive evaluation of elasticity and viscosity of soft materials at high pressure. In order to demonstrate the validity and effectiveness of the developed system and methodology for quantitative nondestructive visco-elastic characterization, various silicone oils are employed, and measured spectra are compared to the theoretical results calculated by the three linear element model.

  20. High pressure synthesis gas fermentation. [Quarterly status] report, July 15, 1991--October 14, 1991

    SciTech Connect

    Not Available

    1991-12-31

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

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

    SciTech Connect

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

    2010-07-20

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

  2. Exploring the Construct of Social Integration in a Community College Environment

    ERIC Educational Resources Information Center

    Mertes, Scott J.

    2013-01-01

    Among current retention models, Tinto's Interactionalist Model has reached near paradigmatic status. When his model has been applied to two-year college settings, the social integration results have been inconsistent. This has led Maxwell (2000) and Deil-Amen (2011) to suggest that a different construct of social integration exists in…

  3. Construction of classical superintegrable systems with higher order integrals of motion from ladder operators

    SciTech Connect

    Marquette, Ian

    2010-07-15

    We construct integrals of motion for multidimensional classical systems from ladder operators of one-dimensional systems. This method can be used to obtain new systems with higher order integrals. We show how these integrals generate a polynomial Poisson algebra. We consider a one-dimensional system with third order ladder operators and found a family of superintegrable systems with higher order integrals of motion. We obtain also the polynomial algebra generated by these integrals. We calculate numerically the trajectories and show that all bounded trajectories are closed.

  4. Constructing Worlds: Cosmovisions as Integral Parts of Human Ecosystems

    NASA Astrophysics Data System (ADS)

    Rappenglück, M. A.

    2009-08-01

    Archaeological and ethnological records worldwide give evidence that cosmovisions played an important role in the life of man since Paleolithic epochs. Parallel to the reduction of instincts man developed cultural systems to establish and maintain order and rhythm in his personal and social life and to organize the world into a meaningful system. Cosmovisions helped man to integrate and orientate himself within changing human ecosystems. These concepts were also useful to answer fundamental human questions about the whys and wherefores of man and the world. Some of the main features of archaic cosmovisions in different cultures across the world and throughout the epochs are discussed with focus on human ecosystems and the human mind.

  5. Construction, database integration, and application of an Oenothera EST library.

    PubMed

    Mrácek, Jaroslav; Greiner, Stephan; Cho, Won Kyong; Rauwolf, Uwe; Braun, Martha; Umate, Pavan; Altstätter, Johannes; Stoppel, Rhea; Mlcochová, Lada; Silber, Martina V; Volz, Stefanie M; White, Sarah; Selmeier, Renate; Rudd, Stephen; Herrmann, Reinhold G; Meurer, Jörg

    2006-09-01

    Coevolution of cellular genetic compartments is a fundamental aspect in eukaryotic genome evolution that becomes apparent in serious developmental disturbances after interspecific organelle exchanges. The genus Oenothera represents a unique, at present the only available, resource to study the role of the compartmentalized plant genome in diversification of populations and speciation processes. An integrated approach involving cDNA cloning, EST sequencing, and bioinformatic data mining was chosen using Oenothera elata with the genetic constitution nuclear genome AA with plastome type I. The Gene Ontology system grouped 1621 unique gene products into 17 different functional categories. Application of arrays generated from a selected fraction of ESTs revealed significantly differing expression profiles among closely related Oenothera species possessing the potential to generate fertile and incompatible plastid/nuclear hybrids (hybrid bleaching). Furthermore, the EST library provides a valuable source of PCR-based polymorphic molecular markers that are instrumental for genotyping and molecular mapping approaches. PMID:16829020

  6. Construction of an integrated genetic map for Capsicum baccatum L.

    PubMed

    Moulin, M M; Rodrigues, R; Ramos, H C C; Bento, C S; Sudré, C P; Gonçalves, L S A; Viana, A P

    2015-01-01

    Capsicum baccatum L. is one of the five Capsicum domesticated species and has multiple uses in the food, pharmaceutical and cosmetic industries. This species is also a valuable source of genes for chili pepper breeding, especially genes for disease resistance and fruit quality. However, knowledge of the genetic structure of C. baccatum is limited. A reference map for C. baccatum (2n = 2x = 24) based on 42 microsatellite, 85 inter-simple sequence repeat, and 56 random amplified polymorphic DNA markers was constructed using an F2 population consisting of 203 individuals. The map was generated using the JoinMap software (version 4.0) and the linkage groups were formed and ordered using a LOD score of 3.0 and maximum of 40% recombination. The genetic map consisted of 12 major and four minor linkage groups covering a total genome distance of 2547.5 cM with an average distance of 14.25 cM between markers. Of the 152 pairs of microsatellite markers available for Capsicum annuum, 62 were successfully transferred to C. baccatum, generating polymorphism. Forty-two of these markers were mapped, allowing the introduction of C. baccatum in synteny studies with other species of the genus Capsicum. PMID:26125877

  7. Construction of an integrated genetic map for Capsicum baccatum L.

    PubMed

    Moulin, M M; Rodrigues, R; Ramos, H C C; Bento, C S; Sudré, C P; Gonçalves, L S A; Viana, A P

    2015-06-18

    Capsicum baccatum L. is one of the five Capsicum domesticated species and has multiple uses in the food, pharmaceutical and cosmetic industries. This species is also a valuable source of genes for chili pepper breeding, especially genes for disease resistance and fruit quality. However, knowledge of the genetic structure of C. baccatum is limited. A reference map for C. baccatum (2n = 2x = 24) based on 42 microsatellite, 85 inter-simple sequence repeat, and 56 random amplified polymorphic DNA markers was constructed using an F2 population consisting of 203 individuals. The map was generated using the JoinMap software (version 4.0) and the linkage groups were formed and ordered using a LOD score of 3.0 and maximum of 40% recombination. The genetic map consisted of 12 major and four minor linkage groups covering a total genome distance of 2547.5 cM with an average distance of 14.25 cM between markers. Of the 152 pairs of microsatellite markers available for Capsicum annuum, 62 were successfully transferred to C. baccatum, generating polymorphism. Forty-two of these markers were mapped, allowing the introduction of C. baccatum in synteny studies with other species of the genus Capsicum.

  8. Construction of an integrated Raman- and angular-scattering microscope.

    PubMed

    Smith, Zachary J; Berger, Andrew J

    2009-04-01

    We report on the construction of a multimodal microscope platform capable of gathering both elastically and inelastically scattered light from a 38 mum(2) region in both epi- and transillumination geometries. Simultaneous monitoring of elastic and inelastic scattering from a microscopic region allows noninvasive characterization of the chemistry and morphology of a living sample without the need for exogenous dyes or labels, thus allowing measurements to be made longitudinally in time on the same sample as it evolves naturally. A sample is illuminated either from above or below with a focused 785 nm TEM(00) mode laser beam, with elastic and inelastic scattering collected by two separate measurement arms. The measurements may be made either simultaneously, if identical illumination geometries are used, or sequentially, if the two modalities utilize opposing illumination paths. In the inelastic arm, Stokes-shifted light is dispersed by a spectrograph onto a charge-coupled device (CCD) array. In the elastic scattering collection arm, a relay system images the microscope's back aperture onto a CCD array. Postprocessing of the inelastic scattering to remove fluorescence signals yields high quality Raman spectra that report on the sample's chemical makeup. Comparison of the elastically scattered pupil images to generalized Lorenz-Mie theory yields estimated size distributions of scatterers within the sample. PMID:19405678

  9. High-pressure autoclave for multipurpose nuclear magnetic resonance measurements up to 10 MPa

    NASA Astrophysics Data System (ADS)

    Behr, W.; Haase, A.; Reichenauer, G.; Fricke, J.

    1999-05-01

    High-pressure nuclear magnetic resonance (NMR) is an established method in NMR spectroscopy: on-line coupling of high-performance liquid chromatography with NMR, for example, reveals structural information which cannot be obtained with any other method. However, applications has been focused solely on high-pressure NMR spectroscopy, even though high-pressure NMR imaging allows in situ studies of processes such as the fluid exchange in porous media. A versatile high-pressure autoclave for NMR imaging is described in this article. The autoclave allows measurements in any horizontal NMR imager using magnetic field coil systems with an inside diameter of more than 70 mm. Any sample with a diameter up to 28 mm and a length of about 200 mm can be investigated. The autoclave is constructed for operating pressures up to 10 MPa and is temperature controlled between 10 and 60 °C. The materials of the high-pressure cell which are the thermoplastic polyetheretherketon (PEEK) for the pressure tube and brass (63% Cu, 37% Zn) for the caps also permit investigations with aggressive fluids such as supercritical carbon dioxide. Inlet and outlet valves allow replacement of fluids and pressure variations in the autoclave during the NMR measurement. FLASH NMR images of the fluid exchange of methanol for liquid carbon dioxide in silica alcogels at 6.5 MPa are presented in order to demonstrate possible applications.

  10. Towards a constructivist methodology: learning constructions by integrating in situ representations and productivity

    NASA Astrophysics Data System (ADS)

    van der Velde, Frank

    2013-01-01

    The ability to learn constructions may be important for the development of a self-organizing architecture for artificial general intelligence. Constructions are structural relations between more specific or more abstract conceptual representations. They can be derived from the processes of alignment, collocations and distributed equivalences. An architecture that integrates in situ grounded representations with cognitive productivity is ideally suited to learn constructions. This paper described such an architecture, based on neuronal assembly structures and neuronal ’blackboards’ for grounded compositional representations. The paper outlines how constructions could be learned in such an architecture and how the architecture could eventually develop into an autonomous self-organizing architecture for artificial general intelligence.

  11. Module-based construction of plasmids for chromosomal integration of the fission yeast Schizosaccharomyces pombe.

    PubMed

    Kakui, Yasutaka; Sunaga, Tomonari; Arai, Kunio; Dodgson, James; Ji, Liang; Csikász-Nagy, Attila; Carazo-Salas, Rafael; Sato, Masamitsu

    2015-06-01

    Integration of an external gene into a fission yeast chromosome is useful to investigate the effect of the gene product. An easy way to knock-in a gene construct is use of an integration plasmid, which can be targeted and inserted to a chromosome through homologous recombination. Despite the advantage of integration, construction of integration plasmids is energy- and time-consuming, because there is no systematic library of integration plasmids with various promoters, fluorescent protein tags, terminators and selection markers; therefore, researchers are often forced to make appropriate ones through multiple rounds of cloning procedures. Here, we establish materials and methods to easily construct integration plasmids. We introduce a convenient cloning system based on Golden Gate DNA shuffling, which enables the connection of multiple DNA fragments at once: any kind of promoters and terminators, the gene of interest, in combination with any fluorescent protein tag genes and any selection markers. Each of those DNA fragments, called a 'module', can be tandemly ligated in the order we desire in a single reaction, which yields a circular plasmid in a one-step manner. The resulting plasmids can be integrated through standard methods for transformation. Thus, these materials and methods help easy construction of knock-in strains, and this will further increase the value of fission yeast as a model organism.

  12. Module-based construction of plasmids for chromosomal integration of the fission yeast Schizosaccharomyces pombe

    PubMed Central

    Kakui, Yasutaka; Sunaga, Tomonari; Arai, Kunio; Dodgson, James; Ji, Liang; Csikász-Nagy, Attila; Carazo-Salas, Rafael; Sato, Masamitsu

    2015-01-01

    Integration of an external gene into a fission yeast chromosome is useful to investigate the effect of the gene product. An easy way to knock-in a gene construct is use of an integration plasmid, which can be targeted and inserted to a chromosome through homologous recombination. Despite the advantage of integration, construction of integration plasmids is energy- and time-consuming, because there is no systematic library of integration plasmids with various promoters, fluorescent protein tags, terminators and selection markers; therefore, researchers are often forced to make appropriate ones through multiple rounds of cloning procedures. Here, we establish materials and methods to easily construct integration plasmids. We introduce a convenient cloning system based on Golden Gate DNA shuffling, which enables the connection of multiple DNA fragments at once: any kind of promoters and terminators, the gene of interest, in combination with any fluorescent protein tag genes and any selection markers. Each of those DNA fragments, called a ‘module’, can be tandemly ligated in the order we desire in a single reaction, which yields a circular plasmid in a one-step manner. The resulting plasmids can be integrated through standard methods for transformation. Thus, these materials and methods help easy construction of knock-in strains, and this will further increase the value of fission yeast as a model organism. PMID:26108218

  13. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  14. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  15. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  16. 77 FR 37712 - High Pressure Steel Cylinders From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-22

    ... Commission, Washington, DC, and by publishing the notice in the Federal Register on January 23, 2012 (77 FR... COMMISSION High Pressure Steel Cylinders From China Determinations On the basis of the record \\1\\ developed... imports of high pressure steel cylinders from China, provided for in subheading 7311.00.00 of...

  17. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  18. 76 FR 38697 - High Pressure Steel Cylinders From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ..., 2011 (76 FR 28807). The conference was held in Washington, DC, on June 1, 2011, and all persons who... COMMISSION High Pressure Steel Cylinders From China Determinations On the basis of the record \\1\\ developed... injured by reason of imports from China of high pressure steel cylinders, provided for in subheading...

  19. 30 CFR 56.13021 - High-pressure hose connections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false High-pressure hose connections. 56.13021... and Boilers § 56.13021 High-pressure hose connections. Except where automatic shutoff valves are used, safety chains or other suitable locking devices shall be used at connections to machines of...

  20. 15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. ...

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

    15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. PROCESSES IN THIS MODULE OCCURRED UNDER HIGH PRESSURES AND TEMPERATURES. (5/70) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  1. 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

  2. High Pressure Inactivation of Food-borne Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past half dozen years or so, the USDA Seafood Safety laboratory has endeavored to evaluate the potential of high pressure processing (HPP) for inactivation of food-borne viruses. As a commercial food technology, high pressure processing is highly advantageous because it can inactivate path...

  3. High Pressure Cryocooling of Protein Crystals: The Enigma of Water

    NASA Astrophysics Data System (ADS)

    Gruner, Sol M.

    2010-03-01

    A novel high-pressure cryocooling technique for preparation biological samples for x-ray analysis is described. The method, high-pressure cryocooling, involves cooling samples to cryogenic temperatures (e.g., 100 K) in high-pressure Helium gas (up to 200 MPa). It bears both similarities and differences to high-pressure cooling methods that have been used to prepare samples for electron microscopy, and has been especially useful for cryocooling of macromolecular crystals for x-ray diffraction. Examples will be given where the method has been effective in providing high quality crystallographic data for difficult samples, such as cases where ligands needed to be stabilized in binding sites to be visualized, or where very high resolution data were required. The talk concludes with a discussion of data obtained by high-pressure cryocooling that pertains to two of the most important problems in modern science: the enigma of water and how water affects the activity of proteins.

  4. High-Pressure Oxygen Generation for Outpost EVA Study

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

    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.

  5. Continuous lipid extraction of microalgae using high-pressure carbon dioxide.

    PubMed

    Chen, Kuo-Ti; Cheng, Chen-Hsi; Wu, Yi-Huei; Lu, Wen-Chang; Lin, Yun-Huin; Lee, Hom-Ti

    2013-10-01

    Sequestering carbon, purifying water, and creating biofuel materials using microalgae are of global interest in the R&D field. However, extracting algal oil consumes a high amount of energy, which is an obstacle for the biofuel market. Nontoxic and recyclable high-pressure CO2 extraction processes are being developed by numerous researchers; however, most of these processes use batch operations mixed with a large amount of co-solvent and require improvement. We fabricated a continuous high-pressure CO2 extraction system, evaluating the optimal parameters for the extraction process. The various parameter tests included temperature, pressure, pretreatment methods, ratio, and the species of co-solvent. We integrated the optimal parameters from previous tests, using a 5-d continuous operation. Compared with traditional solvent extraction, a 90.56% extraction yield ratio was achieved using this continuous extraction method. This shows the stable, high extraction yields of this continuous high-pressure CO2 extraction system. PMID:23911813

  6. Continuous lipid extraction of microalgae using high-pressure carbon dioxide.

    PubMed

    Chen, Kuo-Ti; Cheng, Chen-Hsi; Wu, Yi-Huei; Lu, Wen-Chang; Lin, Yun-Huin; Lee, Hom-Ti

    2013-10-01

    Sequestering carbon, purifying water, and creating biofuel materials using microalgae are of global interest in the R&D field. However, extracting algal oil consumes a high amount of energy, which is an obstacle for the biofuel market. Nontoxic and recyclable high-pressure CO2 extraction processes are being developed by numerous researchers; however, most of these processes use batch operations mixed with a large amount of co-solvent and require improvement. We fabricated a continuous high-pressure CO2 extraction system, evaluating the optimal parameters for the extraction process. The various parameter tests included temperature, pressure, pretreatment methods, ratio, and the species of co-solvent. We integrated the optimal parameters from previous tests, using a 5-d continuous operation. Compared with traditional solvent extraction, a 90.56% extraction yield ratio was achieved using this continuous extraction method. This shows the stable, high extraction yields of this continuous high-pressure CO2 extraction system.

  7. High pressure compressor component performance report

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  8. Tank waste removal using a high pressure waterjet system

    SciTech Connect

    Randolph, J.D.; Rinker, M.W.; Summers, D.

    1996-10-01

    The Oak Ridge National Laboratory has several tank wastes that are currently stored in inactive tanks constructed of gunite concrete. A remediation program at ORNL and a development program at PNL and UMR are collaborating to develop a system that will utilize high pressure waterjet technology for cutting and dislodging sludge beds, and for conveyance of those materials to a treatment tank. This technology for waste removal has two major advantages. First, sludge will be retrieved from one or more high risk tanks, that is tanks with a high degree of uncertainty for failure, to a single treatment tank with lower risk. Second, sludges of similar nature will be consolidated for volume reduction. ORNL and PNL are currently pursuing this technology for waste removal and transport to a single immobilization treatment facility. The ORNL remediation program is known as the Gunite And Associated Tanks Treatability Study. The PNL development program is known as Retrieval Process Development and Enhancement. UMR is developing the waste dislodging/cutting tool. This paper will describe the waterjet technology for waste dislodging and conveyance of ORNL sludges from underground storage tanks.

  9. The effects of microbial fuel cell integration into constructed wetland on the performance of constructed wetland.

    PubMed

    Srivastava, Pratiksha; Yadav, Asheesh Kumar; Mishra, Barada Kanta

    2015-11-01

    The present work is the first detailed study, which is about the performance of CW after MFC integration with it. The experiments were run in open and closed circuit mode for assessment purpose. The findings of this study indicate towards a more practical application of MFC in wastewater treatment along with electricity production. The closed circuit operations of CW-MFCs have performed 12-20% better than open circuit operation and 27-49% better than Normal-CW for chemical oxygen demand (COD) removal. The maximum power density of 320.8 mW/m(3) and current density of 422.2 mA/m(3) have been achieved in granular graphite anode and Pt coated carbon cloth cathode based CW-MFC. PMID:26144020

  10. High-pressure magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    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

    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.

  11. High-pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    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

    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

  12. High-pressure magic angle spinning nuclear magnetic resonance

    SciTech Connect

    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

    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. Finally, as an application example, in situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

  13. High Pressure Oxygen A-Band Spectra

    NASA Astrophysics Data System (ADS)

    Drouin, Brian; Sung, Keeyoon; Yu, Shanshan; Lunny, Elizabeth M.; Bui, Thinh Quoc; Okumura, Mitchio; Rupasinghe, Priyanka; Bray, Caitlin; Long, David A.; Hodges, Joseph; Robichaud, David; Benner, D. Chris; Devi, V. Malathy; Hoo, Jiajun

    2015-06-01

    Composition measurements from remote sensing platforms require knowledge of air mass to better than the desired precision of the composition. Oxygen spectra allow determination of air mass since the mixing ratio of oxygen is fixed. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for air mass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the state-of-the-art for oxygen spectroscopy. To produce atmospheric pressure A-band cross-sections with this accuracy requires a sophisticated line-shape model (Galatry or Speed-Dependent) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, but an integrated self-consistent model must be developed to ensure accuracy. This presentation will describe the ongoing effort to parameterize these phenomena on a representative data set created from complementary experimental techniques. The techniques include Fourier transform spectroscopy (FTS), photo-acoustic spectroscopy (PAS) and cavity ring-down spectroscopy (CRDS). CRDS data allow long-pathlength measurements with absolute intensities, providing lineshape information as well as LM and CIA, however the subtleties of the lineshape are diminished in the saturated line-centers. Conversely, the short paths and large dynamic range of the PAS data allow the full lineshape to be discerned, but with an arbitrary intensity axis. Finally, the FTS data provides intermediate paths and consistency across a broad pressure range. These spectra are all modeled with the Labfit software using first the spectral line database HITRAN, and then model values are adjusted and fitted for better agreement with the data.

  14. Osmium Metal Studied under High Pressure and Nonhydrostatic Stress

    SciTech Connect

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

    2008-01-01

    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.

  15. Microstructural characteristics of Hadfield steel solidified under high pressure

    NASA Astrophysics Data System (ADS)

    Zhang, Yuzi; Li, Yanguo; Han, Bo; Zhang, Fucheng; Qian, Lihe

    2011-12-01

    Samples of Hadfield steel, high manganese austenite steel with 13 wt% manganese and 1.2 wt% carbon, were solidified under a pressure of 6 GPa. The microstructures of the samples were analyzed by metallography and X-ray diffraction. The results indicate that the solidification microstructure of the Hadfield steel was remarkably refined under high pressure. Additionally, the carbide of M23C6 was obtained in the Hadfield steel solidified under high pressure was different from the carbide of M3C obtained by solidification under normal pressure. Furthermore, high pressure promoted the formation of orientational solidified microstructure of the Hadfield steel.

  16. Safety analysis of high pressure gasous fuel container punctures

    SciTech Connect

    Swain, M.R.

    1995-09-01

    The following report is divided into two sections. The first section describes the results of ignitability tests of high pressure hydrogen and natural gas leaks. The volume of ignitable gases formed by leaking hydrogen or natural gas were measured. Leaking high pressure hydrogen produced a cone of ignitable gases with 28{degrees} included angle. Leaking high pressure methane produced a cone of ignitable gases with 20{degrees} included angle. Ignition of hydrogen produced larger overpressures than did natural gas. The largest overpressures produced by hydrogen were the same as overpressures produced by inflating a 11 inch child`s balloon until it burst.

  17. The high-pressure dimension in earth and planetary science

    SciTech Connect

    Mao, Ho-kwang; Hemley, Russell J.

    2008-06-17

    The bulk of our planet is hidden from view, within the earth, under high pressures and temperatures. The behavior of this material dictates the formation, evolution, and present state of the solid earth. Recent geophysical and geochemical studies of the planet present us with a rich array of large-scale processes and phenomena that are not fully understood. These range from the fate of deeply subducted slabs and the origin of plumes, to the nature of the core-mantle boundary; the differentiation of materials to form the present-day crust, mantle, and core; the distribution of trace elements; and the uptake and recycling of volatiles throughout earth's history. Addressing these questions experimentally has a long history, but it is only recently that the entire range of pressures that prevail within the earth could be produced in the laboratory and the materials probed with the necessary tools. Experiments have demonstrated that, under these extreme conditions, the physical and chemical behavior of materials can be profoundly altered, causing new and unforeseen reactions and giving rise to structural, elastic, electronic, and magnetic transitions not observed in rocks and minerals in the near-surface environment. Resolving new issues that have arisen requires an integrated approach involving subfields that include seismology, geochemistry, petrology, and geodynamics, as well as theoretical and experimental high-pressure mineral sciences. The collection of feature articles that follows, which were presented at a recent symposium, highlights an array of new developments in high-pressure geoscience. In ultrahigh-pressure metamorphic rocks, solid and fluid inclusions in phenocrysts contain rich information on deep-mantle processes. The structure, texture, strain, chemistry, and exsolution of these micrometer- to nanometer-sized inclusions indicate the formation environment of these rocks and contain rich information about the relevant physical and chemical processes

  18. 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

  19. 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

  20. The Combustion of HMX. [burning rate at high pressures

    NASA Technical Reports Server (NTRS)

    Boggs, T. L.; Price, C. F.; Atwood, A. I.; Zurn, D. E.; Eisel, J. L.

    1980-01-01

    The burn rate of HMX was measured at high pressures (p more than 1000 psi). The self deflagration rate of HMX was determined from 1 atmosphere to 50,000 psi. The burning rate shows no significant slope breaks.

  1. 5. INTERIOR, TWO 5' X 6' HIGH PRESSURE EMERGENCY GATES, ...

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

    5. INTERIOR, TWO 5' X 6' HIGH PRESSURE EMERGENCY GATES, FOR BUREAU OF RECLAIMATION, WITH HYDRAULIC HOISTS, INSIDE OF MACHINE SHOP (CA 1930S). - Hardie-Tynes Manufacturing Company, Workshop, 800 Twenty-eighth Street North, Birmingham, Jefferson County, AL

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

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

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

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

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

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

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

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

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

  5. 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

  6. 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

  7. High-pressure injection injury of the finger

    PubMed Central

    Saraf, Sanjay

    2012-01-01

    The high-pressure injection injuries are unusual injuries and the extent of tissue damage is often under estimated. They represent potentially disabling forms of trauma and have disastrous effects on tissues if not treated promptly. We present a case of high pressure injection injury to the finger from lubricant oil. The patient presented late with necrosis of volar tissue of left index finger. The patient was aggressively managed in stages, with delayed flap cover, with satisfactory functional and aesthetic outcome. PMID:23325982

  8. Structural behaviour of niobium oxynitride under high pressure

    SciTech Connect

    Sharma, Bharat Bhooshan Poswal, H. K. Pandey, K. K. Sharma, Surinder M.; Yakhmi, J. V.; Ohashi, Y.; Kikkawa, S.

    2014-04-24

    High pressure investigation of niobium oxynitrides (NbN{sub 0.98}O{sub 0.02}) employing synchrotron based angle dispersive x-ray diffraction experiments was carried out in very fine pressure steps using membrane driven diamond anvil cell. Ambient cubic phase was found to be stable up to ∼18 GPa. At further high pressure cubic phase showed rhombohedral distortion.

  9. High-pressure Raman spectroscopy of carbon onions and nanocapsules

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

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

  10. High pressure technology 1995. PVP-Volume 297

    SciTech Connect

    Lees, W.A.; Picqueur, L.

    1995-11-01

    The ASME conferences and in particular, the High Pressure sessions, have always encouraged participation from overseas contributors. This has greatly assisted the development of high pressure technology. This book is divided into the following topical sections: (1) design; (2) materials and testing; (3) applications and analysis; and (4) failure analysis and testing safety. Separate abstracts were prepared for some of the papers in this book.

  11. High-pressure injection injury with river water.

    PubMed

    Greenberg, M I

    1978-06-01

    A case of high pressure injection and laceration of the calf with river water is reported, the first such case appearing in the literature. As with high pressure injection of grease, paint, paint thinner, mineral spirits, diesel oil, gasoline, and turpentine, this injury is a surgical emergency. All patients must be admitted for surgical debridement, irrigation, parenteral antibiotics, and observation. River water, contaminated by sewage and industrial wastes, has great irritative and infective potential. PMID:661048

  12. Controllable synthesis of fullerene nano/microcrystals and their structural transformation induced by high pressure

    NASA Astrophysics Data System (ADS)

    Yao, Ming-Guang; Du, Ming-Run; Liu, Bing-Bing

    2013-09-01

    Fullerene molecules are interesting materials because of their unique structures and properties in mechanical, electrical, magnetic, and optical aspects. Current research is focusing on the construction of well-defined fullerene nano/microcrystals that possess desirable structures and morphologies. Further tuning the intermolecular interaction of the fullerene nano/microcrystals by use of pressure is an efficient way to modify their structures and properties, such as creation of nanoscale polymer structures and new hybrid materials, which expands the potential of such nanoscale materials for direct device components. In this paper, we review our recent progress in the construction of fullerene nanostructures and their structural transformation induced by high pressure. Fullerene nano/microcrystals with controllable size, morphology and structure have been synthesized through the self-assembly of fullerene molecules by a solvent-assisted method. By virtue of high pressure, the structures, components, and intermolecular interactions of the assemblied fullerene nano/microcrystals can be finely tuned, thereby modifying the optical and electronic properties of the nanostructures. Several examples on high pressure induced novel structural phase transition in typical fullerene nanocrystals with C60 or C70 cage serving as building blocks are presented, including high pressure induced amorphization of the nanocrystals and their bulk moduli, high pressure and high temperature (HPHT) induced polymerization in C60 nanocrystals, pressure tuned reversible polymerization in ferrocene-doped C60/C70 single crystal, as well as unique long-range ordered crystal with amorphous nanoclusters serving as building blocks in solvated C60 crystals, which brings new physical insight into the understanding of order and disorder concept and new approaches to the design of superhard carbon materials. The nanosize and morphology effects on the transformations of fullerene nanocrystals have also

  13. High-pressure crystallography of periodic and aperiodic crystals.

    PubMed

    Hejny, Clivia; Minkov, Vasily S

    2015-03-01

    More than five decades have passed since the first single-crystal X-ray diffraction experiments at high pressure were performed. These studies were applied historically to geochemical processes occurring in the Earth and other planets, but high-pressure crystallography has spread across different fields of science including chemistry, physics, biology, materials science and pharmacy. With each passing year, high-pressure studies have become more precise and comprehensive because of the development of instrumentation and software, and the systems investigated have also become more complicated. Starting with crystals of simple minerals and inorganic compounds, the interests of researchers have shifted to complicated metal-organic frameworks, aperiodic crystals and quasicrystals, molecular crystals, and even proteins and viruses. Inspired by contributions to the microsymposium 'High-Pressure Crystallography of Periodic and Aperiodic Crystals' presented at the 23rd IUCr Congress and General Assembly, the authors have tried to summarize certain recent results of single-crystal studies of molecular and aperiodic structures under high pressure. While the selected contributions do not cover the whole spectrum of high-pressure research, they demonstrate the broad diversity of novel and fascinating results and may awaken the reader's interest in this topic. PMID:25866659

  14. High-pressure crystallography of periodic and aperiodic crystals

    PubMed Central

    Hejny, Clivia; Minkov, Vasily S.

    2015-01-01

    More than five decades have passed since the first single-crystal X-ray diffraction experiments at high pressure were performed. These studies were applied historically to geochemical processes occurring in the Earth and other planets, but high-pressure crystallography has spread across different fields of science including chemistry, physics, biology, materials science and pharmacy. With each passing year, high-pressure studies have become more precise and comprehensive because of the development of instrumentation and software, and the systems investigated have also become more complicated. Starting with crystals of simple minerals and inorganic compounds, the interests of researchers have shifted to complicated metal–organic frameworks, aperiodic crystals and quasicrystals, molecular crystals, and even proteins and viruses. Inspired by contributions to the microsymposium ‘High-Pressure Crystallography of Periodic and Aperiodic Crystals’ presented at the 23rd IUCr Congress and General Assembly, the authors have tried to summarize certain recent results of single-crystal studies of molecular and aperiodic structures under high pressure. While the selected contributions do not cover the whole spectrum of high-pressure research, they demonstrate the broad diversity of novel and fascinating results and may awaken the reader’s interest in this topic. PMID:25866659

  15. High-pressure crystallography of periodic and aperiodic crystals.

    PubMed

    Hejny, Clivia; Minkov, Vasily S

    2015-03-01

    More than five decades have passed since the first single-crystal X-ray diffraction experiments at high pressure were performed. These studies were applied historically to geochemical processes occurring in the Earth and other planets, but high-pressure crystallography has spread across different fields of science including chemistry, physics, biology, materials science and pharmacy. With each passing year, high-pressure studies have become more precise and comprehensive because of the development of instrumentation and software, and the systems investigated have also become more complicated. Starting with crystals of simple minerals and inorganic compounds, the interests of researchers have shifted to complicated metal-organic frameworks, aperiodic crystals and quasicrystals, molecular crystals, and even proteins and viruses. Inspired by contributions to the microsymposium 'High-Pressure Crystallography of Periodic and Aperiodic Crystals' presented at the 23rd IUCr Congress and General Assembly, the authors have tried to summarize certain recent results of single-crystal studies of molecular and aperiodic structures under high pressure. While the selected contributions do not cover the whole spectrum of high-pressure research, they demonstrate the broad diversity of novel and fascinating results and may awaken the reader's interest in this topic.

  16. A new glove-box system for a high-pressure tritium pump

    SciTech Connect

    Wilson, S.W.; Borree, R.J.; Chambers, D.I.; Chang, Y.; Merrill, J.T.; Souers, P.C.; Wiggins, R.K.

    1988-05-26

    A new glove-box system that was designed around a high-pressure tritium pump is described. The system incorporates new containment ideas such as ''burpler'' passive pressure controls, valves that can be turned from outside the box, inflatable door seals, ferro-fluidic motor-shaft seals, and rapid box-to-hood conversion during cryostaging. Currently under construction, the system will contain nine separate sections with automatic pressure-balancing and venting systems. 3 refs., 5 figs.

  17. Self-Referent Constructs and Medical Sociology: In Search of an Integrative Framework

    ERIC Educational Resources Information Center

    Kaplan, Howard B.

    2007-01-01

    A theoretical framework centering on four classes of self-referent constructs is offered as a device for integrating the diverse areas constituting medical sociology. Guidance by this framework sensitizes the researcher to the occurrence of parallel processes in adjacent disciplines, facilitates recognition of the etiological significance of…

  18. Young African American Children Constructing Identities in an Urban Integrated Science-Literacy Classroom

    ERIC Educational Resources Information Center

    Kane, Justine M.

    2009-01-01

    This is a qualitative study of identities constructed and enacted by four 3rd-grade African American children (two girls and two boys) in an urban classroom that engaged in a year-long, integrated science-literacy project. Juxtaposing narrative and discursive identity lenses, coupled with race and gender perspectives, I examined the ways in which…

  19. A Descriptive and Co-Constructive Approach to Integrated Performance Assessment Feedback

    ERIC Educational Resources Information Center

    Adair-Hauck, Bonnie; Troyan, Francis J.

    2013-01-01

    This article presents a descriptive and Co-Constructive Approach to feedback related to performance in the interpersonal mode of communication on the Integrated Performance Assessment (IPA). The goal of this research study was to describe the discursive features of effective IPA feedback. To this end, critical discourse analysis of a feedback…

  20. BSM2 Plant-Wide Model construction and comparative analysis with other methodologies for integrated modelling.

    PubMed

    Grau, P; Vanrolleghem, P; Ayesa, E

    2007-01-01

    In this paper, a new methodology for integrated modelling of the WWTP has been used for the construction of the Benchmark Simulation Model N degrees 2 (BSM2). The transformations-approach proposed in this methodology does not require the development of specific transformers to interface unit process models and allows the construction of tailored models for a particular WWTP guaranteeing the mass and charge continuity for the whole model. The BSM2 PWM constructed as case study, is evaluated by means of simulations under different scenarios and its validity in reproducing water and sludge lines in WWTP is demonstrated. Furthermore the advantages that this methodology presents compared to other approaches for integrated modelling are verified in terms of flexibility and coherence. PMID:17978433

  1. High Pressure Gas Permeation and Liquid Diffusion Studies of Coflon and Tefzel Thermoplastics. Revision

    NASA Technical Reports Server (NTRS)

    Morgan, G. J.; Campion, R. P.

    1997-01-01

    The life of fluid-carrying flexible or umbilical pipes during service at elevated temperatures and pressures depends inter alia on their resistance to attack by the fluids present and the rate at which these fluids are absorbed by the pipe lining materials. The consequences of fluid ingress into the thermoplastic lining could mean a) a reduction in its mechanical strength, to increase chances of crack formation and growth and thus a loss of integrity, b) the occurrence of permeation right through the lining material, with pressure build- up in the outer pipe wall construction (of flexible pipes) or chemical attack (from a hostile permeant) on outer layers of reinforcements. Therefore it is important within this project to have relevant permeation data for Coflon and Tefzel thermoplastics: the former is plasticised, the latter is not. A previous report (CAPP/M.2) described experimental equipment and techniques used by MERL when measuring high pressure (up to 5000 psi) gas permeation and liquid diffusion through thermoplastic samples cut from extruded bar or pipe, and provided the basic theory involved. Norsk Hydro are also performing gas permeation tests on pipe sections, at up to 100 bars (1450 psi) pressure or so, and reporting separately. Some comparisons between data from Norsk Hydro and MERL have been made herein. The tests should be considered as complementary, as the Norsk Hydro test has the obvious benefit of using complete pipe sections, whilst MERL can test at much higher pressures, up to 1000 bar if necessary. The sophisticated analytical measuring equipment of Norsk Hydro can distinguish the individual components of mixed gases and hence the various permeation-linked coefficients whereas MERL, in using pressure increase at constant volume to determine permeation rate, is limited to obtaining single gas data, or apparent (or representative) coefficients for a mixed gas as a whole. Except for the initial fluid diffusion data for Tefzel described in CAPP

  2. Criterion for Identifying Vortices in High-Pressure Flows

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Okong'o, Nora

    2007-01-01

    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.

  3. Structure and stability of hydrous minerals at high pressure

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  4. High-pressure neutron diffraction studies at LANSCE

    NASA Astrophysics Data System (ADS)

    Zhao, Yusheng; Zhang, Jianzhong; Xu, Hongwu; Lokshin, Konstantin A.; He, Duanwei; Qian, Jiang; Pantea, Cristian; Daemen, Luke L.; Vogel, Sven C.; Ding, Yang; Xu, Jian

    2010-06-01

    on high-pressure neutron diffraction are important for multidisciplinary sciences, particularly for theoretical/computational modeling/simulations.

  5. High pressure rotating reverse osmosis for long term space missions

    NASA Astrophysics Data System (ADS)

    Christensen Pederson, Cynthia Lynn

    Rotating reverse osmosis, which uses reverse osmosis to purify water and rotating filtration to improve the efficacy of filtration, has great potential for wastewater recycling on a long term space mission. Previous investigations of a proof-of-concept device indicated that the most efficient method to improve rotating reverse osmosis performance is to increase the operational pressure. Thus, a second generation device and fluid circuit were designed, fabricated, and tested to permit high pressure operation for long time periods. The design overcame several obstacles including membrane attachment, rotating seal design, and fluid and pressure management. A theoretical model of rotating reverse osmosis was modified to properly account for the flow conditions in the new design. Tests lasting a week were conducted with a variety of model wastewaters. Significant fouling and a decrease in flux were observed after three days of testing regardless of the operational parameters. A semi-empirical model, the fouling potential, was added to the theoretical model to account for the fouling. This allowed the simulation of 48 hour cleaning cycles that significantly increased the flux of the device. Experimental investigation of the rotational speed and concentrate flow rate indicated that an increase in either parameter decreased the fouling slightly. A week long test of a wastewater ersatz with a biocide did not exhibit a decrease in flux around day three that otherwise occurred. Therefore, biofouling was identified as the primary mechanism of fouling. Rotating reverse osmosis was compared with conventional spiral wound reverse osmosis and displayed increased rejection under dead end filtration conditions. The rotating device exhibited similar rejection and increased flux compared to a tubular reverse osmosis device previously used in a NASA wastewater recovery system. The integration of the rotating device into a NASA water recovery management system was evaluated. Lastly, a

  6. Ultrasonic Guided Waves for Health Monitoring of High Pressure Composite Tanks

    NASA Astrophysics Data System (ADS)

    Castaings, M.; Hosten, B.

    2008-02-01

    Ultrasonic guided wave modes are proposed to control the integrity of high-pressure composite tanks produced by EADS—ASTRIUM, France. The purpose is to demonstrate the potentiality of air-coupled transducers to set-up a contact-less, single-sided technique for testing the moisture content and/or the micro-cracking of carbon epoxy composite wound around a Titanium liner.

  7. A 3D bioprinting system to produce human-scale tissue constructs with structural integrity.

    PubMed

    Kang, Hyun-Wook; Lee, Sang Jin; Ko, In Kap; Kengla, Carlos; Yoo, James J; Atala, Anthony

    2016-03-01

    A challenge for tissue engineering is producing three-dimensional (3D), vascularized cellular constructs of clinically relevant size, shape and structural integrity. We present an integrated tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape. Mechanical stability is achieved by printing cell-laden hydrogels together with biodegradable polymers in integrated patterns and anchored on sacrificial hydrogels. The correct shape of the tissue construct is achieved by representing clinical imaging data as a computer model of the anatomical defect and translating the model into a program that controls the motions of the printer nozzles, which dispense cells to discrete locations. The incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100-200 μm for cell survival in engineered tissues. We demonstrate capabilities of the ITOP by fabricating mandible and calvarial bone, cartilage and skeletal muscle. Future development of the ITOP is being directed to the production of tissues for human applications and to the building of more complex tissues and solid organs. PMID:26878319

  8. A 3D bioprinting system to produce human-scale tissue constructs with structural integrity.

    PubMed

    Kang, Hyun-Wook; Lee, Sang Jin; Ko, In Kap; Kengla, Carlos; Yoo, James J; Atala, Anthony

    2016-03-01

    A challenge for tissue engineering is producing three-dimensional (3D), vascularized cellular constructs of clinically relevant size, shape and structural integrity. We present an integrated tissue-organ printer (ITOP) that can fabricate stable, human-scale tissue constructs of any shape. Mechanical stability is achieved by printing cell-laden hydrogels together with biodegradable polymers in integrated patterns and anchored on sacrificial hydrogels. The correct shape of the tissue construct is achieved by representing clinical imaging data as a computer model of the anatomical defect and translating the model into a program that controls the motions of the printer nozzles, which dispense cells to discrete locations. The incorporation of microchannels into the tissue constructs facilitates diffusion of nutrients to printed cells, thereby overcoming the diffusion limit of 100-200 μm for cell survival in engineered tissues. We demonstrate capabilities of the ITOP by fabricating mandible and calvarial bone, cartilage and skeletal muscle. Future development of the ITOP is being directed to the production of tissues for human applications and to the building of more complex tissues and solid organs.

  9. The value of high-pressure hysterosalpingography with new cannula.

    PubMed

    Totani, R

    1982-01-01

    To achieve maximum dilatation of the Fallopian tubes so as to improve the pregnancy: non-pregnancy ratio of hysterosalpingography (HSG) treatment, a high-pressure injection technique was evaluated. For this purpose a disposable cannula and an adapted pair of tenacula were developed and a remote-control procedure using an auto-injector and an adapted pressure recorder was used to assure the safety of doctors and staff. 1780 cases who underwent 400 mmHg high-pressure HSG treatment were compared with 903 conventional HSG cases. Results indicated a higher pregnancy ratio for the high-pressure experimental group after treatment. In addition, it was found that side effects due to the use of disposable cannula and highly viscous water-soluble mediums developed for use in angiography were less common than for conventional materials.

  10. Deformation Twinning of a Silver Nanocrystal under High Pressure

    SciTech Connect

    Huang, Xiaojing; Yang, Wenge; Harder, Ross; Sun, Yugang; Liu, Ming; Chu, Yong S.; Robinson, Ian K.; Mao, Ho-kwang

    2015-11-01

    Within a high-pressure environment, crystal deformation is controlled by complex processes such as dislocation motion, twinning, and phase transitions, which change materials' microscopic morphology and alter their properties. Understanding a crystal's response to external stress provides a unique opportunity for rational tailoring of its functionalities. It is very challenging to track the strain evolution and physical deformation from a single nanoscale crystal under high-pressure stress. Here, we report an in situ three-dimensional mapping of morphology and strain evolutions in a single-crystal silver nanocube within a high-pressure environment using the Bragg Coherent Diffractive Imaging (CDI) method. We observed a continuous lattice distortion, followed by a deformation twining process at a constant pressure. The ability to visualize stress-introduced deformation of nanocrystals with high spatial resolution and prominent strain sensitivity provides an important route for interpreting and engineering novel properties of nanomaterials.

  11. High-pressure studies of pharmaceutical compounds and energetic materials.

    PubMed

    Fabbiani, Francesca P A; Pulham, Colin R

    2006-10-01

    The effects of high pressure on pharmaceutical compounds and energetic materials can have important implications for both the properties and performance of these important classes of material. Pharmaceutical compounds are frequently subjected to pressure during processing and formulation, causing interconversion between solid forms that may affect properties such as solubility and bio-availability. Energetic materials experience extremes of both pressure and temperature under conditions of detonation and deflagration, causing changes in properties such as sensitivity to shock and chemical reactivity. This tutorial review outlines the various methods used to study these materials at high pressure, describes how pressure can be used to explore polymorphism, and provides examples of compounds that have been studied at high pressure. PMID:17003899

  12. High pressure cosmochemistry applied to major planetary interiors: Experimental studies

    NASA Technical Reports Server (NTRS)

    Nicol, M. F.; Johnson, M.; Boone, S.

    1985-01-01

    The measurement of equilibria in binary fluid-solid systems in diamond anvil cells, represents a major advance of the art of high-pressure experimentation. Vibrational spectroscopy, direct visual observations, and X-ray diffraction crystallography of materials confined in externally heated cells are the primary experimental probes being used. Adiabats in these systems are being measured in order to constrain models of heat flow in these bodies and to detect phase transitions by thermal anomalies. Other studies are directed toward interpreting high pressure reactions in these systems that are suggested by shockwave measurements, and developing methods for reaching high temperatures and high pressures of planetary interest in diamond cells. The overall objective of this project is to determine the properties of the H2-He-H2O-HN3-CH4 system and related small-molecule systems that are needed to constrain theoretical models of the interiors of the major planets.

  13. High-pressure studies of pharmaceutical compounds and energetic materials.

    PubMed

    Fabbiani, Francesca P A; Pulham, Colin R

    2006-10-01

    The effects of high pressure on pharmaceutical compounds and energetic materials can have important implications for both the properties and performance of these important classes of material. Pharmaceutical compounds are frequently subjected to pressure during processing and formulation, causing interconversion between solid forms that may affect properties such as solubility and bio-availability. Energetic materials experience extremes of both pressure and temperature under conditions of detonation and deflagration, causing changes in properties such as sensitivity to shock and chemical reactivity. This tutorial review outlines the various methods used to study these materials at high pressure, describes how pressure can be used to explore polymorphism, and provides examples of compounds that have been studied at high pressure.

  14. Confinement of hydrogen at high pressure in carbon nanotubes

    DOEpatents

    Lassila, David H.; Bonner, Brian P.

    2011-12-13

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

  15. Evaluation of high pressure Freon decontamination. I. Preliminary tests

    SciTech Connect

    Rankin, W.N.

    1983-10-31

    High-pressure Freon blasting techniques are being evaluated for applications involving the removal of non-adherent radioactive particulate contamination at SRP. Very little waste is generated by this technique because the used Freon can be easily distilled and reused. One of the principle advantages of this technique is that decontaminated electrical equipment can be returned to service immediately without drying, unlike high-pressure water blasting techniques. Preliminary scoutin tests evaluating high-pressure Freon blasting for decontamination at SRP were carried out at Quadrex Co., Oak Ridge, TN, October 12 and 13. DWPF-type contamination (raw sludge plus volatiles) and separations area-type contamination (diluted boiling point (47.6/sup 0/C) allow it to rapidly separate from higher boiling contaminants via distillation with filtration to remove particulate material, and distillation with condensation, the solvent may be recovered for indefinite reuse while reducing the radioactive waste to a minimum. 3 references, 5 figures, 6 tables.

  16. High pressure rotary piston coal feeder for coal gasification applications

    DOEpatents

    Gencsoy, Hasan T.

    1977-05-24

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

  17. Experimental methods for phase equilibria at high pressures.

    PubMed

    Dohrn, Ralf; Fonseca, José M S; Peper, Stephanie

    2012-01-01

    Knowledge of high-pressure phase equilibria is crucial in many fields, e.g., for the design and optimization of high-pressure chemical and separation processes, carbon capture and storage, hydrate formation, applications of ionic liquids, and geological processes. This review presents the variety of methods to measure phase equilibria at high pressures and, following a classification, discusses the measurement principles, advantages, challenges, and error sources. Examples of application areas are given. A detailed knowledge and understanding of the different methods is fundamental not only for choosing the most suitable method for a certain task but also for the evaluation of experimental data. The discrepancy between the (sometimes low) true accuracy of published experimental data and the (high) accuracy claimed by authors is addressed. Some essential requirements for the generation of valuable experimental results are summarized.

  18. Deformation Twinning of a Silver Nanocrystal under High Pressure.

    PubMed

    Huang, Xiaojing; Yang, Wenge; Harder, Ross; Sun, Yugang; Lu, Ming; Chu, Yong S; Robinson, Ian K; Mao, Ho-Kwang

    2015-11-11

    Within a high-pressure environment, crystal deformation is controlled by complex processes such as dislocation motion, twinning, and phase transitions, which change materials' microscopic morphology and alter their properties. Understanding a crystal's response to external stress provides a unique opportunity for rational tailoring of its functionalities. It is very challenging to track the strain evolution and physical deformation from a single nanoscale crystal under high-pressure stress. Here, we report an in situ three-dimensional mapping of morphology and strain evolutions in a single-crystal silver nanocube within a high-pressure environment using the Bragg Coherent Diffractive Imaging (CDI) method. We observed a continuous lattice distortion, followed by a deformation twining process at a constant pressure. The ability to visualize stress-introduced deformation of nanocrystals with high spatial resolution and prominent strain sensitivity provides an important route for interpreting and engineering novel properties of nanomaterials. PMID:26484941

  19. High-Pressure Gaseous Burner (HPGB) Facility Became Operational

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet

    2003-01-01

    A gas-fueled high-pressure combustion facility with optical access, developed over the last 3 years, is now collecting research data in a production mode. The High-Pressure Gaseous Burner (HPGB) rig at the NASA Glenn Research Center can operate at sustained pressures up to 60 atm with a variety of gaseous fuels and liquid jet fuel. The facility is unique because it is the only continuous-flow, hydrogen-capable 60-atm rig in the world with optical access. It will provide researchers with new insights into flame conditions that simulate the environment inside the ultra-high-pressure-ratio combustion chambers of tomorrow s advanced aircraft engines. The facility provides optical access to the flame zone through four fused-silica optical windows, enabling the calibration of nonintrusive optical diagnostics to measure chemical species and temperature. The data from the HPGB rig enable the validation of numerical codes that simulate gas turbine combustors.

  20. High Pressure NMR Methods for Characterizing Functional Substates of Proteins.

    PubMed

    Kalbitzer, Hans Robert

    2015-01-01

    Proteins usually exist in multiple conformational states in solution. High pressure NMR spectroscopy is a well-suited method to identify these states. In addition, these states can be characterized by their thermodynamic parameters, the free enthalpies at ambient pressure, the partial molar volumes, and the partial molar compressibility that can be obtained from the analysis of the high pressure NMR data. Two main types of states of proteins exist, functional states and folding states. There is a strong link between these two types, the functional states represent essential folding states (intermediates), other folding states may have no functional meaning (optional folding states). In this chapter, this concept is tested on the Ras protein, an important proto-oncogen in humans where all substates required by theory can be identified experimentally by high pressure NMR spectroscopy. Finally, we show how these data can be used to develop allosteric inhibitors of proteins. PMID:26174382

  1. Ultra-high pressure water jet: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The technologies being tested for concrete decontamination are targeted for alpha contamination. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  2. An Ultra-High Pressure Proportional Counter for Hard X-Ray Astronomy.

    NASA Astrophysics Data System (ADS)

    Ye, Zongnan

    1992-01-01

    This thesis describes the successful development of ultra-high pressure proportional counters for balloon -borne hard X-ray astronomy. The proportional counters were filled with argon/xenon at pressures up to {~}30atm. The properties of proportional counters filled at such pressures have been studied by the author in the laboratory. The spatial response of these counters to X-rays and charged particles, and the energy response to X-rays up to 1MeV have been analysed. Gas gain measurements using the charge collection technique and analysis of the subsequent data show that simple extrapolation from low pressures cannot explain the observed behaviour (e.g. the mobility of positive ions and quenching efficiency) of these counters at high pressures. A hard X-ray telescope consisting of 32 such proportional counters filled at ultra-high pressures is being constructed, details of which are described. The sensitivity of this telescope for both continuum and narrow-line spectra is superb compared to contemporary balloon-and satellite-borne hard X-ray detectors. Together with an imaging phoswich Anger camera, it is scheduled for launch from Alice Springs in November 1992. An anticoincidence system for an X-ray detector, consisting of a combined passive and active shield, has been designed and constructed by the author, and flown on a balloon. The active shield, made of a plastic scintillator, has resulted in an additional reduction of 25% in the background registered at balloon altitudes.

  3. Experiment on wear behavior of high pressure gas seal faces

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Peng, Xudong; Bai, Shaoxian; Meng, Xiangkai; Li, Jiyun

    2014-11-01

    Current researches show that mechanical deformation of seal ring face makes fluid film clearance decrease at high pressure side, thus a divergent clearance is formed and face wear occurs more seriously at the high pressure side than that on the low pressure side. However, there is still lack of published experimental works enough to prove the theoretical results. In this paper, a spiral groove dry gas seal at high pressures is experimentally investigated so as to prove the face wear happened at the high pressure side of seal faces due to the face mechanical deformation, and the wear behavior affected by seal ring structure is also studied. The experimental results show that face wear would occur at the high pressure side of seal faces due to the deformation, thus the leakage and face temperature increase, which all satisfies the theoretical predictions. When sealed pressure is not less than 5 MPa, the pressure can provide enough opening force to separate the seal faces. The seal ring sizes have obvious influence on face wear. Face wear, leakage and face temperature of a dry gas seal with the smaller cross sectional area of seal ring are less than that of a dry gas seal with bigger one, and the difference of leakage rate between these two sizes of seal face width is in the range of 24%-25%. Compared with the effect of seal ring sizes, the effect of secondary O-ring seal position on face deformation and face wear is less. The differences between these two types of dry gas seals with different secondary O-ring seal positions are less than 5.9% when the rotational speed varies from 0 to 600 r/min. By linking face wear and sealing performance changes to the shift in mechanical deformation of seal ring, this research presents an important experimental method to study face deformation of a dry gas seal at high pressures.

  4. The construction and application of an atomistic J-integral via Hardy estimates of continuum fields

    NASA Astrophysics Data System (ADS)

    Jones, Reese E.; Zimmerman, Jonathan A.

    2010-09-01

    In this work we apply a Lagrangian kernel-based estimator of continuum fields to atomic data in order to estimate the J-integral for the analysis of cracks and dislocations. We show that this method has the properties of: consistency between the energy, stress and deformation fields; path independence of the contour integrals of the Eshelby stress; and excellent correlation with linear elastic fracture mechanics theory for appropriately constructed simulations. We discuss the appropriate reference configuration and reference energy for this type of analysis. Lastly, we use canonical examples to demonstrate that the proposed method is a direct and rational approach for estimating the configurational forces on atomic defects.

  5. High pressure and Multiferroics materials. A happy marriage

    SciTech Connect

    Gilioli, Edmondo; Ehm, Lars

    2014-10-31

    We found that the community of material scientists is strongly committed to the research area of multiferroic materials, both for the understanding of the complex mechanisms supporting the multiferroism and for the fabrication of new compounds, potentially suitable for technological applications. The use of high pressure is a powerful tool in synthesizing new multiferroic, in particular magneto-electric phases, where the pressure stabilization of otherwise unstable perovskite-based structural distortions may lead to promising novel metastable compounds. Moreover, the in situ investigation of the high-pressure behavior of multiferroic materials has provided insight into the complex interplay between magnetic and electronic properties and the coupling to structural instabilities.

  6. Equation of state of liquid Indium under high pressure

    SciTech Connect

    Li, Huaming E-mail: mo.li@gatech.edu; Li, Mo E-mail: mo.li@gatech.edu; Sun, Yongli

    2015-09-15

    We apply an equation of state of a power law form to liquid Indium to study its thermodynamic properties under high temperature and high pressure. Molar volume of molten indium is calculated along the isothermal line at 710K within good precision as compared with the experimental data in an externally heated diamond anvil cell. Bulk modulus, thermal expansion and internal pressure are obtained for isothermal compression. Other thermodynamic properties are also calculated along the fitted high pressure melting line. While our results suggest that the power law form may be a better choice for the equation of state of liquids, these detailed predictions are yet to be confirmed by further experiment.

  7. High pressure and multiferroics materials: a happy marriage.

    PubMed

    Gilioli, Edmondo; Ehm, Lars

    2014-11-01

    The community of material scientists is strongly committed to the research area of multiferroic materials, both for the understanding of the complex mechanisms supporting the multiferroism and for the fabrication of new compounds, potentially suitable for technological applications. The use of high pressure is a powerful tool in synthesizing new multiferroic, in particular magneto-electric phases, where the pressure stabilization of otherwise unstable perovskite-based structural distortions may lead to promising novel metastable compounds. The in situ investigation of the high-pressure behavior of multiferroic materials has provided insight into the complex interplay between magnetic and electronic properties and the coupling to structural instabilities.

  8. Very high pressure Moessbauer spectroscopy using diamond anvil cells

    SciTech Connect

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

    1988-01-01

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

  9. Carbon Nanotubes as High-Pressure Cylinders and Nanoextruders

    NASA Astrophysics Data System (ADS)

    Sun, L.; Banhart, F.; Krasheninnikov, A. V.; Rodríguez-Manzo, J. A.; Terrones, M.; Ajayan, P. M.

    2006-05-01

    Closed-shell carbon nanostructures, such as carbon onions, have been shown to act as self-contracting high-pressure cells under electron irradiation. We report that controlled irradiation of multiwalled carbon nanotubes can cause large pressure buildup within the nanotube cores that can plastically deform, extrude, and break solid materials that are encapsulated inside the core. We further showed by atomistic simulations that the internal pressure inside nanotubes can reach values higher than 40 gigapascals. Nanotubes can thus be used as robust nanoscale jigs for extruding and deforming hard nanomaterials and for modifying their properties, as well as templates for the study of individual nanometer-sized crystals under high pressure.

  10. High pressure and multiferroics materials: a happy marriage.

    PubMed

    Gilioli, Edmondo; Ehm, Lars

    2014-11-01

    The community of material scientists is strongly committed to the research area of multiferroic materials, both for the understanding of the complex mechanisms supporting the multiferroism and for the fabrication of new compounds, potentially suitable for technological applications. The use of high pressure is a powerful tool in synthesizing new multiferroic, in particular magneto-electric phases, where the pressure stabilization of otherwise unstable perovskite-based structural distortions may lead to promising novel metastable compounds. The in situ investigation of the high-pressure behavior of multiferroic materials has provided insight into the complex interplay between magnetic and electronic properties and the coupling to structural instabilities. PMID:25485138

  11. Equation of state of liquid Indium under high pressure

    NASA Astrophysics Data System (ADS)

    Li, Huaming; Sun, Yongli; Li, Mo

    2015-09-01

    We apply an equation of state of a power law form to liquid Indium to study its thermodynamic properties under high temperature and high pressure. Molar volume of molten indium is calculated along the isothermal line at 710K within good precision as compared with the experimental data in an externally heated diamond anvil cell. Bulk modulus, thermal expansion and internal pressure are obtained for isothermal compression. Other thermodynamic properties are also calculated along the fitted high pressure melting line. While our results suggest that the power law form may be a better choice for the equation of state of liquids, these detailed predictions are yet to be confirmed by further experiment.

  12. On some hydrogen bond correlations at high pressures

    NASA Astrophysics Data System (ADS)

    Sikka, S. K.

    2007-09-01

    In situ high pressure neutron diffraction measured lengths of O H and H O pairs in hydrogen bonds in substances are shown to follow the correlation between them established from 0.1 MPa data on different chemical compounds. In particular, the conclusion by Nelmes et al that their high pressure data on ice VIII differ from it is not supported. For compounds in which the O H stretching frequencies red shift under pressure, it is shown that wherever structural data is available, they follow the stretching frequency versus H O (or O O) distance correlation. For compounds displaying blue shifts with pressure an analogy appears to exist with improper hydrogen bonds.

  13. High-pressure-low-temperature x-ray power diffractometer.

    PubMed

    Syassen, K; Holzapfel, W B

    1978-08-01

    A high-pressure technique for x-ray diffraction studies at low temperatures is described. The system consists of a Bridgman anvil type high-pressure device with either tungsten carbide or boron carbide anvils, a liquid He cryostat, and x-ray diffractometer operating in Debye-Scherrer geometry. The newly developed boron carbide anvil cell is capable of containing a liquid pressure transmitting medium. The precision of the lattice parameter determination is discussed and the effect of nonisostatic stress components on the diffraction pattern is examined.

  14. Construction of two selectable markers for integrative/conjugative plasmids in Flavobacterium columnare

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Zou, Hong; Wang, Liangfa; Huang, Bei; Li, Nan; Wang, Guitang; Nie, Pin

    2012-03-01

    Flavobacterium columnare, the etiological agent of columnaris disease, is one of the most important and widespread bacterial pathogens of freshwater fish. In this study, we constructed two artificial selectable markers (chloramphenicol and spectinomycin resistance) for gene transfer in F. columnare. These two new artificial selectable markers, which were created by placing the chloramphenicol or spectinomycin resistance gene under the control of the native acs regulatory region of F. columnare, were functional in both F. columnare and Escherichia coli. The integrative/conjugative plasmids constructed by using these markers were introduced into F. columnare G4 via electroporation or conjugation. The integrated plasmid DNA was confirmed by Southern blotting and PCR analysis. These two markers can be employed in future investigations into gene deletion and the pathogenicity of virulence factors in F. columnare.

  15. Site-specific integration of bacteriophage VWB genome into Streptomyces venezuelae and construction of a VWB-based integrative vector.

    PubMed

    Van Mellaert, L; Mei, L; Lammertyn, E; Schacht, S; Anné, J

    1998-12-01

    The temperate bacteriophage VWB integrates into the chromosome of Streptomyces venezuelae ETH14630 via site-specific integration. Following recombination of the VWB attP region with the chromosomal attB sequence, the host-phage junctions attL and attR are formed. Nucleotide sequence analysis of attP, attB, attL and attR revealed a 45 bp common core sequence. In attB this 45 bp sequence consists of the 3' end of a putative tRNA Arg(AGG) gene with a 3'-terminal CCA sequence which is typical for prokaryotic tRNAs. Phage DNA integration restores the putative tRNA Arg(AGG) gene in attL. However, following recombination the CCA sequence is missing as is the case for most Streptomyces tRNA genes described so far. Adjacent to VWB attP, an ORF encoding a 427 aa protein was detected. The C-terminal region of this protein shows high similarity to the conserved C-terminal domain of site-specific recombinases belonging to the integrase family. To prove the functionality of this putative integrase gene (int), an integrative vector pKT02 was constructed. This vector consists of a 2.3 kb HindIII-SphI restriction fragment of VWB DNA containing attP and int cloned in a non-replicative Escherichia coli vector carrying a thiostrepton-resistance (tsr) gene. Integration of pKT02 was obtained after transformation of Streptomyces venezuelae ETH14630 and Streptomyces lividans TK24 protoplasts. This vector will thus be useful for a number of additional Streptomyces species in which a suitable tRNA gene can be functional as integration site.

  16. An Algebraic Construction of the First Integrals of the Stationary KdV Hierarchy

    NASA Astrophysics Data System (ADS)

    Matsushima, Masatomo; Ohmiya, Mayumi

    2009-09-01

    The stationary KdV hierarchy is constructed using a kind of recursion operator called Λ-operator. The notion of the maximal solution of the n-th stationary KdV equation is introduced. Using this maximal solution, a specific differential polynomial with the auxiliary spectral parameter called the spectral M-function is constructed as the quadratic form of the fundamental system of the eigenvalue problem for the 2-nd order linear ordinary differential equation which is related to the linearizing operator of the hierarchy. By calculating a perfect square condition of the quadratic form by an elementary algebraic method, the complete set of first integrals of this hierarchy is constructed.

  17. LIF measurements of turbulent premixed flames in a high pressure environment

    SciTech Connect

    Kobayashi, Hideaki; Oyachi, Yasuo; Maruta, Kaoru

    1999-07-01

    The effects of pressure on OH-LIF characteristics of laminar and turbulent premixed flames were investigated. OH-LIF experiments were performed for methane-air mixtures using burner flames stabilized in high-pressure chambers. An OPO tunable laser pumped by a Nd-YAG laser were used and A{sup 2}{Sigma}{sup +}-X{sup 2} II (0,0) and (1,0) band of OH radical were measured. For laminar flames, OH-LIF excitation spectrum was measured by scanning the laser wavelength at pressures up to 1.0 MPa. The overlap-integral profiles between Gaussian profiles of the laser and Voigt profiles of the absorption line were calculated, and the effects of pressure and laser linewidth on FWHM and intensities of the LIF excitation spectrum were compared with experimental data. Results show that the effects of pressure on the FWHM and peak intensity of overlap integral profiles agree qualitatively with those on the measured LIF excitation spectrum, indicating that the decrease in LIF intensity of the flame at high-pressure is dominated by the broadening of the absorption line shapes. The LIF intensity decreases with increasing linewidth of the laser. A narrow-band laser is effective in order to obtain higher LIF intensity at ordinary pressure but the linewidth of the laser has no significant effect at high pressures.

  18. X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

    SciTech Connect

    Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Shen, Guoyin; Shibazaki, Yuki; Wang, Yanbin

    2015-07-15

    Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10{sup 5} frames/second (fps) in air and up to ∼10{sup 4} fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures.

  19. 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

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

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

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

  1. Quantitative determination of phenol by high-pressure liquid chromatography.

    PubMed

    Musto, J D; Sane, J N; Warner, V D

    1977-08-01

    High-pressure liquid chromatography was used with a 5-micrometer silica gel column to quantitate the phenol in phenolated calamine lotion USP and a commercial antiseptic solution. This method requires less than 10 min/assay, and other compounds present in the products analyzed did not interfere.

  2. High-Pressure, Solid-State Experiments for NIF

    SciTech Connect

    Remington, B; Belak, J; Colvin, J; Edwards, J; Kalantar, D; Lasinski, B; Pollaine, S; Shay, H; Weber, S; Wolfer, B

    2001-02-15

    In this report, we summarize our plan for using NIF for measuring solid-state deformation physics at very high pressures, P >> 1 Mbar. There are several key uncertainties, the strength and phase being two of them. The deformation mechanisms at high pressure and high strain rate are also uncertain. The state, as well as strength, of a material that has first been melted, then dynamically refrozen by high-pressure compression is very uncertain. There is no single facility that can address all of these issues at all parameter regimes of interest. Rather, a coordinated plan involving multiple laboratories and universities and multiple facilities will ultimately be needed. We present here our first thoughts for the NIF component of this effort. In Sec. I, we motivate the physics of this regime, and point out the uncertainties, then describe in Sec. II the development work that we have done over the last 5 years in this area. In Sec. III, we describe several NIF designs we have developed to probe solid-state deformation physics at very high pressures.

  3. High-pressure applications in medicine and pharmacology

    NASA Astrophysics Data System (ADS)

    Silva, Jerson L.; Foguel, Debora; Suarez, Marisa; Gomes, Andre M. O.; Oliveira, Andréa C.

    2004-04-01

    High pressure has emerged as an important tool to tackle several problems in medicine and biotechnology. Misfolded proteins, aggregates and amyloids have been studied, which point toward the understanding of the protein misfolding diseases. High hydrostatic pressure (HHP) has also been used to dissociate non-amyloid aggregates and inclusion bodies. The diverse range of diseases that result from protein misfolding has made this theme an important research focus for pharmaceutical and biotech companies. The use of high pressure promises to contribute to identifying the mechanisms behind these defects and creating therapies against these diseases. High pressure has also been used to study viruses and other infectious agents for the purpose of sterilization and in the development of vaccines. Using pressure, we have detected the presence of a ribonucleoprotein intermediate, where the coat protein is partially unfolded but bound to RNA. These intermediates are potential targets for antiviral compounds. The ability of pressure to inactivate viruses, prions and bacteria has been evaluated with a view toward the applications of vaccine development and virus sterilization. Recent studies demonstrate that pressure causes virus inactivation while preserving the immunogenic properties. There is increasing evidence that a high-pressure cycle traps a virus in the 'fusion intermediate state', not infectious but highly immunogenic.

  4. Rotordynamic stability problems and solutions in high pressure turbocompressors

    NASA Technical Reports Server (NTRS)

    Schmied, J.

    1989-01-01

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

  5. Advanced High Pressure O2/H2 Technology

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  6. Effect of high pressure on physicochemical properties of meat.

    PubMed

    Buckow, Roman; Sikes, Anita; Tume, Ron

    2013-01-01

    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.

  7. Variable high pressure processing sensitivities for GII human noroviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cann...

  8. 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

  9. International Space Station (ISS) Oxygen High Pressure Storage Management

    NASA Technical Reports Server (NTRS)

    Lewis, John R.; Dake, Jason; Cover, John; Leonard, Dan; Bohannon, Carl

    2004-01-01

    High pressure oxygen onboard the ISS provides support for Extra Vehicular Activities (EVA) and contingency metabolic support for the crew. This high pressure 02 is brought to the ISS by the Space Shuttle and is transferred using the Oxygen Recharge Compressor Assembly (ORCA). There are several drivers that must be considered in managing the available high pressure 02 on the ISS. The amount of O2 the Shuttle can fly up is driven by manifest mass limitations, launch slips, and on orbit Shuttle power requirements. The amount of 02 that is used from the ISS high pressure gas tanks (HPGT) is driven by the number of Shuttle docked and undocked EVAs, the type of EVA prebreath protocol that is used and contingency use of O2 for metabolic support. Also, the use of the ORCA must be managed to optimize its life on orbit and assure that it will be available to transfer the planned amount of O2 from the Shuttle. Management of this resource has required long range planning and coordination between Shuttle manifest on orbit plans. To further optimize the situation hardware options have been pursued.

  10. Reducing peanut allergens by high pressure combined with polyphenol oxidase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyphenol oxidase (PPO) has been shown to reduce major peanut allergens (Ara h 1 and Ara h 2). Because high pressure (HP) can increase enzyme activity, we postulated that further reduction of peanut allergens can be achieved through HP combined with PPO. Peanut extracts were treated with each of th...

  11. Ultra-high pressure water jet: Baseline report

    SciTech Connect

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems.

  12. Quantitative high-pressure pair distribution function analysis of nanocrystalline gold

    NASA Astrophysics Data System (ADS)

    Martin, C. David; Antao, Sytle M.; Chupas, Peter J.; Lee, Peter L.; Shastri, Sarvjit D.; Parise, John B.

    2005-02-01

    Using a diamond anvil cell with high-energy monochromatic x rays, we have studied the total scattering of nanocrystalline gold to 20Å-1 at pressures up to 10GPa in a hydrostatic alcohol pressure-medium. Through direct Fourier transformation of the structure function [S(Q)], pair distribution functions (PDFs) [G(r)] are calculated without Kaplow-type iterative corrections. Quantitative high-pressure PDF (QHP-PDF) analysis is performed via full-profile least-squares modeling and confirmed through comparison of Rietveld analysis of Bragg diffraction. The quality of the high pressure PDFs obtained demonstrates the integrity of our technique and suggests the feasibility of future QHP-PDF studies of liquids, disordered solids, and materials at phase transition under pressure.

  13. Elementary reactions of nitrogen and oxygen with boron and carbon at high pressures and temperatures

    SciTech Connect

    Yoo, C.S.; Cynn, H.; Nicol, M.F.

    1997-08-01

    The direct elementary reactions among the first and second row elements often yield novel super hard, high energy density, and wide band-gap optical materials. The reactions of oxygen and nitrogen with boron and carbon have been investigated at high pressures and temperatures by using an integrated technique of diamond-anvil cell, laser-heating, x-ray diffraction, Raman spectroscopy. A wide range of products has been synthesized and characterized in-situ at high pressures, including {alpha}-CO{sub 2}, B{sub 2}0{sub 3}-I,B{sub 2}0{sub 3}-II, c-BN, h-BN, h{sup `}-B, amorphous carbon nitrides. The elementary reactions occur exothermically and result in highly polycrystallized products with an exception in carbon-nitrogen reactions. The implication of the elementary reactions to energetic materials applications is discussed.

  14. High Pressure Materials Research: Novel Extended Phases of Molecular Triatomics

    SciTech Connect

    Yoo, C

    2004-05-26

    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 [1]. With modern advances in high-pressure technologies [2], 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 chemical configuration [3]. The high-pressure thus offers enhanced opportunities to discover new phases, both stable and metastable ones, and to tune exotic properties in a wide-range of atomistic length scale, substantially greater than (often being several orders of) those achieved by other thermal (varying temperatures) and chemical (varying composition or making alloys) means. Simple molecular solids like H{sub 2}, C, CO{sub 2}, N{sub 2}, O{sub 2}, H{sub 2}O, CO, NH{sub 3}, and CH{sub 4} are bounded by strong covalent intramolecular bonds, yet relatively weak intermolecular bonds of van der Waals and/or hydrogen bonds. The weak intermolecular bonds make these solids highly compressible (i.e., low bulk moduli typically less than 10 GPa), while the strong covalent bonds make them chemically inert at least initially at low pressures. Carbon-carbon single bonds, carbon-oxygen double bonds and nitrogen-nitrogen triple bonds, for example, are among the strongest. These molecular forms are, thus, often considered to remain stable in an extended region of high pressures and high temperatures. High stabilities of these covalent molecules are also the basis of which their mixtures are often presumed to be the major detonation products of energetic materials as well as the major constituents of giant planets. However, their physical/chemical stabilities are not truly understood at those extreme pressure-temperature conditions. In fact, an increasing amount of experimental evidences contradict the assumed stability of these materials at high

  15. A hybrid simulation approach for integrating safety behavior into construction planning: An earthmoving case study.

    PubMed

    Goh, Yang Miang; Askar Ali, Mohamed Jawad

    2016-08-01

    One of the key challenges in improving construction safety and health is the management of safety behavior. From a system point of view, workers work unsafely due to system level issues such as poor safety culture, excessive production pressure, inadequate allocation of resources and time and lack of training. These systemic issues should be eradicated or minimized during planning. However, there is a lack of detailed planning tools to help managers assess the impact of their upstream decisions on worker safety behavior. Even though simulation had been used in construction planning, the review conducted in this study showed that construction safety management research had not been exploiting the potential of simulation techniques. Thus, a hybrid simulation framework is proposed to facilitate integration of safety management considerations into construction activity simulation. The hybrid framework consists of discrete event simulation (DES) as the core, but heterogeneous, interactive and intelligent (able to make decisions) agents replace traditional entities and resources. In addition, some of the cognitive processes and physiological aspects of agents are captured using system dynamics (SD) approach. The combination of DES, agent-based simulation (ABS) and SD allows a more "natural" representation of the complex dynamics in construction activities. The proposed hybrid framework was demonstrated using a hypothetical case study. In addition, due to the lack of application of factorial experiment approach in safety management simulation, the case study demonstrated sensitivity analysis and factorial experiment to guide future research.

  16. A hybrid simulation approach for integrating safety behavior into construction planning: An earthmoving case study.

    PubMed

    Goh, Yang Miang; Askar Ali, Mohamed Jawad

    2016-08-01

    One of the key challenges in improving construction safety and health is the management of safety behavior. From a system point of view, workers work unsafely due to system level issues such as poor safety culture, excessive production pressure, inadequate allocation of resources and time and lack of training. These systemic issues should be eradicated or minimized during planning. However, there is a lack of detailed planning tools to help managers assess the impact of their upstream decisions on worker safety behavior. Even though simulation had been used in construction planning, the review conducted in this study showed that construction safety management research had not been exploiting the potential of simulation techniques. Thus, a hybrid simulation framework is proposed to facilitate integration of safety management considerations into construction activity simulation. The hybrid framework consists of discrete event simulation (DES) as the core, but heterogeneous, interactive and intelligent (able to make decisions) agents replace traditional entities and resources. In addition, some of the cognitive processes and physiological aspects of agents are captured using system dynamics (SD) approach. The combination of DES, agent-based simulation (ABS) and SD allows a more "natural" representation of the complex dynamics in construction activities. The proposed hybrid framework was demonstrated using a hypothetical case study. In addition, due to the lack of application of factorial experiment approach in safety management simulation, the case study demonstrated sensitivity analysis and factorial experiment to guide future research. PMID:26456000

  17. Integrating Building Information Modeling and Health and Safety for Onsite Construction

    PubMed Central

    Ganah, Abdulkadir; John, Godfaurd A.

    2014-01-01

    Background Health and safety (H&S) on a construction site can either make or break a contractor, if not properly managed. The usage of Building Information Modeling (BIM) for H&S on construction execution has the potential to augment practitioner understanding of their sites, and by so doing reduce the probability of accidents. This research explores BIM usage within the construction industry in relation to H&S communication. Methods In addition to an extensive literature review, a questionnaire survey was conducted to gather information on the embedment of H&S planning with the BIM environment for site practitioners. Results The analysis of responses indicated that BIM will enhance the current approach of H&S planning for construction site personnel. Conclusion From the survey, toolbox talk will have to be integrated with the BIM environment, because it is the predominantly used procedure for enhancing H&S issues within construction sites. The advantage is that personnel can visually understand H&S issues as work progresses during the toolbox talk onsite. PMID:25830069

  18. A high pressure hollow cathode ionization source for in-situ detection of organic molecules on Mars

    NASA Technical Reports Server (NTRS)

    Beegle, Luther W.; Kanik, Isik

    2001-01-01

    We have designed, constructed and characterized a new high-pressure (1-5 Torr) hollow cathode discharge source (HCDSj that can be utilized as an ionizer in a wide variety of mass analyzers. It is able to function under ambient Martian atmospheric conditions without modification.

  19. Integrating affordability, energy and environmental efficiency, air quality and disaster resistance into residential design and construction

    SciTech Connect

    Cook, G.D.

    1995-12-31

    Much has been researched and written about the individual qualities of good home design and construction in terms of: energy efficiency; affordability; indoor air quality; sustainability; and wind, fire, and flood resistance. The real challenge is to integrate all these characteristics into the ideal house. The purpose of this paper is to review the characteristics of each of the above features and explore the integration of them into the ideal residential structure. The house would take the shape of a compact two story structure. A geometrically compact structure uses less construction materials per floor area, presents less area for improved thermal efficiency, and less profile for wind and flood resistance. The first floor would be constructed using insulated strong high thermal mass masonry system resistant to flood, wind, fire, and termite damage. The second story would be constructed using a lighter reinforced wood frame system with between stud insulation coupled with exterior insulated sheathing to minimize thermal bridging across studs. Optimizing floor plan such as separating living and sleeping areas present opportunities for efficient split HVAC zoning, natural ventilation, and solar passive adaptation. The design would emphasize the 4, 8, and 12 foot dimensioning for waste reduction; selection of environmentally friendly building materials, such as cellulose insulation; and efficient lighting and appliances. Features providing improved indoor air quality such as prudent duct selection, design and location, use of radon barriers, omission of carpeting, and control of moisture would be addressed. The design philosophy, concepts and rationale for the integration of these and many other features of the ideal residence will be addressed and illustrated.

  20. Synthetic chemistry with periodic mesostructures at high pressure.

    PubMed

    Mandal, Manik; Landskron, Kai

    2013-11-19

    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

  1. Methods for determining the CO2 sorption capacity of coal: Experimental and theoretical high pressure isotherms

    NASA Astrophysics Data System (ADS)

    Weishauptová, Zuzana; Přibyl, Oldřich

    2016-04-01

    volumetric sorption apparatus working within the temperature range of 30°C to 65°C at a pressure of 15 MPa was used for measuring the CO2 high pressure isotherms. The data for constructing the theoretical high pressure isotherm were obtained from a gravimetric sorption apparatus and a mercury porosimeter. The Dubinin, Langmuir, and Gibbs equations were used for evaluating the data. The measured experimental high pressure isotherms were compared with the theoretical isotherms using linearized Langmuir isotherms. The Langmuir parameters confirmed a reasonable correspondence between the sorption capacities derived using the two approaches applied here.

  2. Pyroxenes and olivines: Structural implications of shock-wave data for high pressure phases

    NASA Technical Reports Server (NTRS)

    Jeanloz, R.; Ahrens, T. J.

    1975-01-01

    The nature of the shock-induced, high-pressure phases of olivine and pyroxene rocks is examined in the light of data for the densities of a new class of perovskite-related silicate structures. Also examined are some new Hugoniot and release adiabat data for bronzite. Reexamining available shock data for magnesian pyroxenes and olivines leads to the conclusion that they define a mixed phase (or disequilibrium) region to about the 100 GPa range, related to the kinetics of phase transformation in these silicates. By recognizing this point, certain discrepancies in previous interpretations of shock data can be explained. A set of theoretical Hugonoits for pyroxene and olivine stoichiometry, perovskite-bearing assemblages was constructed based on their properties deduced from high-pressure work, showing that the shock data is compatible with transformations to perovskites in the 45-7GPa region. Finally, the shock data indicate very similar properties for olivine and pyroxene at high pressures making them both equally likely candidates for the lower mantle.

  3. Construction of an Ortholog Database Using the Semantic Web Technology for Integrative Analysis of Genomic Data

    PubMed Central

    Chiba, Hirokazu; Nishide, Hiroyo; Uchiyama, Ikuo

    2015-01-01

    Recently, various types of biological data, including genomic sequences, have been rapidly accumulating. To discover biological knowledge from such growing heterogeneous data, a flexible framework for data integration is necessary. Ortholog information is a central resource for interlinking corresponding genes among different organisms, and the Semantic Web provides a key technology for the flexible integration of heterogeneous data. We have constructed an ortholog database using the Semantic Web technology, aiming at the integration of numerous genomic data and various types of biological information. To formalize the structure of the ortholog information in the Semantic Web, we have constructed the Ortholog Ontology (OrthO). While the OrthO is a compact ontology for general use, it is designed to be extended to the description of database-specific concepts. On the basis of OrthO, we described the ortholog information from our Microbial Genome Database for Comparative Analysis (MBGD) in the form of Resource Description Framework (RDF) and made it available through the SPARQL endpoint, which accepts arbitrary queries specified by users. In this framework based on the OrthO, the biological data of different organisms can be integrated using the ortholog information as a hub. Besides, the ortholog information from different data sources can be compared with each other using the OrthO as a shared ontology. Here we show some examples demonstrating that the ortholog information described in RDF can be used to link various biological data such as taxonomy information and Gene Ontology. Thus, the ortholog database using the Semantic Web technology can contribute to biological knowledge discovery through integrative data analysis. PMID:25875762

  4. Construction of an ortholog database using the semantic web technology for integrative analysis of genomic data.

    PubMed

    Chiba, Hirokazu; Nishide, Hiroyo; Uchiyama, Ikuo

    2015-01-01

    Recently, various types of biological data, including genomic sequences, have been rapidly accumulating. To discover biological knowledge from such growing heterogeneous data, a flexible framework for data integration is necessary. Ortholog information is a central resource for interlinking corresponding genes among different organisms, and the Semantic Web provides a key technology for the flexible integration of heterogeneous data. We have constructed an ortholog database using the Semantic Web technology, aiming at the integration of numerous genomic data and various types of biological information. To formalize the structure of the ortholog information in the Semantic Web, we have constructed the Ortholog Ontology (OrthO). While the OrthO is a compact ontology for general use, it is designed to be extended to the description of database-specific concepts. On the basis of OrthO, we described the ortholog information from our Microbial Genome Database for Comparative Analysis (MBGD) in the form of Resource Description Framework (RDF) and made it available through the SPARQL endpoint, which accepts arbitrary queries specified by users. In this framework based on the OrthO, the biological data of different organisms can be integrated using the ortholog information as a hub. Besides, the ortholog information from different data sources can be compared with each other using the OrthO as a shared ontology. Here we show some examples demonstrating that the ortholog information described in RDF can be used to link various biological data such as taxonomy information and Gene Ontology. Thus, the ortholog database using the Semantic Web technology can contribute to biological knowledge discovery through integrative data analysis.

  5. Construction of an ortholog database using the semantic web technology for integrative analysis of genomic data.

    PubMed

    Chiba, Hirokazu; Nishide, Hiroyo; Uchiyama, Ikuo

    2015-01-01

    Recently, various types of biological data, including genomic sequences, have been rapidly accumulating. To discover biological knowledge from such growing heterogeneous data, a flexible framework for data integration is necessary. Ortholog information is a central resource for interlinking corresponding genes among different organisms, and the Semantic Web provides a key technology for the flexible integration of heterogeneous data. We have constructed an ortholog database using the Semantic Web technology, aiming at the integration of numerous genomic data and various types of biological information. To formalize the structure of the ortholog information in the Semantic Web, we have constructed the Ortholog Ontology (OrthO). While the OrthO is a compact ontology for general use, it is designed to be extended to the description of database-specific concepts. On the basis of OrthO, we described the ortholog information from our Microbial Genome Database for Comparative Analysis (MBGD) in the form of Resource Description Framework (RDF) and made it available through the SPARQL endpoint, which accepts arbitrary queries specified by users. In this framework based on the OrthO, the biological data of different organisms can be integrated using the ortholog information as a hub. Besides, the ortholog information from different data sources can be compared with each other using the OrthO as a shared ontology. Here we show some examples demonstrating that the ortholog information described in RDF can be used to link various biological data such as taxonomy information and Gene Ontology. Thus, the ortholog database using the Semantic Web technology can contribute to biological knowledge discovery through integrative data analysis. PMID:25875762

  6. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    SciTech Connect

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  7. DECOMMISSIONING THE HIGH PRESSURE TRITIUM LABORATORY AT LOS ALAMOS NATIONAL LABORATORY

    SciTech Connect

    Peifer, M.J.; Rendell, K.; Hearnsberger, D.W.

    2003-02-27

    In May 0f 2000, the Cerro Grande wild land fire burned approximately 48,000 acres in and around Los Alamos. In addition to the many buildings that were destroyed in the town site, many structures were also damaged and destroyed within the 43 square miles that comprise the Los Alamos National Laboratory (LANL). A special Act of Congress provided funding to remove Laboratory structures that were damaged by the fire, or that could be threatened by subsequent catastrophic wild land fires. The High Pressure Tritium Laboratory (HPTL) is located at Technical Area (TA) 33, building 86 in the far southeast corner of the Laboratory property. It is immediately adjacent to Bandelier National Park. Because it was threatened by both the Cerro Grande fire in 2000, and the 16,000- acre Dome fire in 1996, the former tritium processing facility was placed on the list of facilities scheduled for Decontamination and Decommissioning under the Cerro Grande Rehabilitation Project. The work was performed through the Facilities and Waste Operations (FWO) Division and is integrated with other Laboratory D&D efforts. The primary demolition contractor was Clauss Construction of San Diego, California. Earth Tech Global Environmental Services of San Antonio, Texas was sub-contracted to Clauss Construction, and provided radiological decontamination support to the project. Although the forty-seven year old facility had been in a state of safe-shutdown since operations ceased in 1990, a significant amount of tritium remained in the rooms where process systems were located. Tritium was the only radiological contaminant associated with this facility. Since no specific regulatory standards have been set for the release of volumetrically contaminated materials, concentration guidelines were derived in order to meet other established regulatory criteria. A tritium removal system was developed for this project with the goal of reducing the volume of tritium concentrated in the concrete of the building

  8. Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance

    SciTech Connect

    Turcu, Romulus V.F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 deg C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  9. Intermittently-fed high-pressure gasifier process

    DOEpatents

    Bailey, J.M.; Zadoks, A.L.

    1993-11-30

    An improved gasifier is described which is adapted for gasifying a predetermined charge of non-gaseous fuel into fuel gas. Each charge of non-gaseous fuel, which may have optional conditioning materials added to it, is intermittently fed to a gasifier chamber where each charge is partially burned with high-pressure air supplied thereto. High-pressure and temperature fuel gas is produced which is cleansed prior to passing out of the gasifier chamber. After gasification of the charge of fuel is ended, the gasifier chamber is vented. The residue of the burned charge in the gasifier chamber is removed, along with the contaminated or reacted conditioning materials, and replaced by a fresh charge. The subject invention provides a feasible way of continuously fueling an internal combustion engine with gasified fuel and is compact enough to be practical for even mobile applications. 3 figures.

  10. Intermittently-fed high-pressure gasifier process

    DOEpatents

    Bailey, John M.; Zadoks, Abraham L.

    1993-11-30

    An improved gasifier adapted for gasifying a predetermined charge of non-gaseous fuel into fuel gas. Each charge of non-gaseous fuel, which may have optional conditioning materials added to it, is intermittently fed to a gasifier chamber where each charge is partially burned with high-pressure air supplied thereto. High-pressure and temperature fuel gas is produced which is cleansed prior to passing out of the gasifier chamber. After gasification of the charge of fuel is is ended, the gasifier chamber is vented. The residue of the burned charge in the gasifier chamber is removed, along with the contaminated or reacted conditioning materials, and replaced by a fresh charge. The subject invention provides a feasible way of continuously fueling an internal combustion engine with gasified fuel and is compact enough to be practical for even mobile applications.

  11. Energy efficient engine: High pressure turbine uncooled rig technology report

    NASA Technical Reports Server (NTRS)

    Gardner, W. B.

    1979-01-01

    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.

  12. Rare-earth-metal nitridophosphates through high-pressure metathesis.

    PubMed

    Kloss, Simon David; Schnick, Wolfgang

    2015-09-14

    Developing a synthetic method to target an broad spectrum of unknown phases can lead to fascinating discoveries. The preparation of the first rare-earth-metal nitridophosphate LiNdP4 N8 is reported. High-pressure solid-state metathesis between LiPN2 and NdF3 was employed to yield a highly crystalline product. The in situ formed LiF is believed to act both as the thermodynamic driving force and as a flux to aiding single-crystal formation in dimensions suitable for crystal structure analysis. Magnetic properties stemming from Nd(3+) ions were measured by SQUID magnetometry. LiNdP4 N8 serves as a model system for the exploration of rare-earth-metal nitridophosphates that may even be expanded to transition metals. High-pressure metathesis enables the systematic study of these uncharted regions of nitride-based materials with unprecedented properties. PMID:26352033

  13. High-pressure synthesis and compressive behavior of tantalum nitrides

    SciTech Connect

    Yusa, Hitoshi Kawamura, Fumio; Taniguchi, Takashi; Hirao, Naohisa; Ohishi, Yasuo; Kikegawa, Takumi

    2014-03-14

    WC- and NaCl-type tantalum mononitrides and hexagonal Ta{sub 5}N{sub 6} were prepared at high pressure and temperature, and their compressive behaviors were examined using in situ high-pressure X-ray diffraction. Comparison of the formula volumes of the tantalum mononitrides indicated that the NaCl type was the densest phase. The P–V data showed that the WC-type structure had the highest bulk modulus value (K{sub 0} = 351(1) GPa). An analysis of the compression properties in terms of the crystallographic characteristics of the structures indicated that a prismatic polyhedral array with face-sharing connectivity was responsible for the incompressible nature of these tantalum nitrides.

  14. carbonate solid solution at high pressures up to 55 GPa

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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, ν4, ν1, ν3 and 2ν2) 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.

  15. Electronic Structure of Crystalline [superscript 4]He at High Pressures

    SciTech Connect

    Mao, Ho Kwang; Shirley, Eric L.; Ding, Yang; Eng, Peter; Cai, Yong Q.; Chow, Paul; Xiao, Yuming; Shu, Jinfu; Hemley, Russell J.; Kao, Chichang; Mao, Wendy L.

    2010-11-12

    Using inelastic x-ray scattering techniques, we have succeeded in probing the high-pressure electronic structure of helium at 300 K. Helium has the widest known valence-conduction band gap of all materials a property whose high-pressure response has been inaccessible to direct measurements. We observed a rich electron excitation spectrum, including a cutoff edge above 23 eV, a sharp exciton peak showing linear volume dependence, and a series of excitations and continuum at 26 to 45 eV. We determined the electronic dispersion along the {Gamma}-M direction over two Brillouin zones, and provided a quantitative picture of the helium exciton beyond the simplified Wannier-Frenkel description.

  16. A simplified model of high pressure spray combustion

    NASA Technical Reports Server (NTRS)

    Mao, C.-P.; Wakamatsu, Y.; Faeth, G. M.

    1981-01-01

    A simplified model of high-pressure spray combustion is examined. The analysis relies on a kappa-epsilon-g turbulence model in conjunction with the locally homogeneous flow (LHF) approximation of two-phase flow, which implies infinitely fast transport rates between the phases. High-pressure phenomena near the thermodynamic critical point are treated using the Redlich-Kwong equation of state. Predictions are compared with existing measurements of spray boundaries in a pressure-atomized n-pentane spray (Sauter mean diameter, approximately 30 microns) burning in stagnant air at 3, 6, and 9 MPa. The LHF model overestimates the rate of development of the flow, yielding spray lengths roughly 20% shorter than measured. Calibrated drop-life-history calculations suggest that finite interphase transport rates are the primary cause of the discrepancy.

  17. Plastic deformation and sintering of alumina under high pressure

    SciTech Connect

    Liu, Fangming; Liu, Pingping; Wang, Haikuo; Xu, Chao; Yin, Shuai; Yin, Wenwen; Li, Yong; He, Duanwei

    2013-12-21

    Plastic deformation of alumina (Al{sub 2}O{sub 3}) under high pressure was investigated by observing the shape changes of spherical particles, and the near fully dense transparent bulks were prepared at around 5.5 GPa and 900 °C. Through analyzing the deformation features, densities, and residual micro-strain of the Al{sub 2}O{sub 3} compacts prepared under high pressures and temperatures (2.0–5.5 GPa and 600–1200 °C), the effects of plastic deformation on the sintering behavior of alumina have been demonstrated. Under compression, the microscopic deviatoric stress caused by grain-to-grain contact could initiate the plastic deformation of individual particles, eliminate pores of the polycrystalline samples, and enhance the local atomic diffusion at the grain boundaries, thus produced transparent alumina bulks.

  18. Ultra high pressure liquid chromatography for crude plant extract profiling.

    PubMed

    Eugster, Philippe J; Guillarme, Davy; Rudaz, Serge; Veuthey, Jean-Luc; Carrupt, Pierre-Alain; Wolfender, Jean-Luc

    2011-01-01

    Ultra high pressure liquid chromatography (UHPLC) systems operating at very high pressures and using sub-2 microm packing columns have allowed a remarkable decrease in analysis time and increase in peak capacity, sensitivity, and reproducibility compared to conventional HPLC. This technology has rapidly been widely accepted by the analytical community and is being gradually applied to various fields of plant analysis such as QC, profiling and fingerprinting, dereplication, and metabolomics. For many applications, an important improvement of the overall performances has been reported. In this review, the basic principles of UHPLC are summarized, and practical information on the type of columns used and phase chemistry available is provided. An overview of the latest applications to natural product analysis in complex mixtures is given, and the potential and limitations as well as some new trends in the development of UHPLC are discussed.

  19. A scanning fluorescence spectroscopy of decorin under high pressure

    NASA Astrophysics Data System (ADS)

    Komoda, Takahito; Kim, Yun-Jung; Suzuki, Atsushi; Nishiumi, Tadayuki

    2013-06-01

    High pressure processing is able to tenderize not only meat but also intramuscular connective tissue, which is mainly composed of collagen. Decorin, one of the proteoglycans, binds to and stabilizes collagen fibrils. It has been suggested that structural weakening of intramuscular connective tissue may result from the disappearance of the decorin-collagen interaction. In this study, the fluorescence spectra and the surface hydrophobicity of decorin molecules were measured under high pressure in order to examine the resulting change in the tertiary structure. The fluorescence intensity and the surface hydrophobicity of decorin molecules both decreased with increasing applied pressure and with applied time at the constant applied pressure, respectively. The observations indicate that the native structure of decorin is maintained during 200 MPa pressurization for less than 30 min.

  20. Chemical Vapor Deposition at High Pressure in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  1. The effect of high pressure on nitrogen compounds of milk

    NASA Astrophysics Data System (ADS)

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

    2004-04-01

    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.

  2. Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  3. JT8D high pressure compressor performance improvement

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1981-01-01

    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 flowpath wall, without the danger of damaging the blades during transients and maneuvers. The improved compressor demonstrated thrust specific fuel consumption and exhaust gas temperature improvements of 1.0 percent and at least 10 C over the takeoff and climb power range at sea level static conditions, compared to a bill-of-material high pressure compressor. Surge margin also improved 4 percentage points over the high power operating range. A thrust specific fuel consumption improvement of 0.7 percent at typical cruise conditions was calculated based on the sea level test results.

  4. Large-Volume High-Pressure Mineral Physics in Japan

    NASA Astrophysics Data System (ADS)

    Liebermann, Robert C.; Prewitt, Charles T.; Weidner, Donald J.

    American high-pressure research with large sample volumes developed rapidly in the 1950s during the race to produce synthetic diamonds. At that time the piston cylinder, girdle (or belt), and tetrahedral anvil devices were invented. However, this development essentially stopped in the late 1950s, and while the diamond anvil cell has been used extensively in the United States with spectacular success for high-pressure experiments in small sample volumes, most of the significant technological advances in large-volume devices have taken place in Japan. Over the past 25 years, these technical advances have enabled a fourfold increase in pressure, with many important investigations of the chemical and physical properties of materials synthesized at high temperatures and pressures that cannot be duplicated with any apparatus currently available in the United States.

  5. High pressure intensification of cassava resistant starch (RS3) yields.

    PubMed

    Lertwanawatana, Proyphon; Frazier, Richard A; Niranjan, Keshavan

    2015-08-15

    Cassava starch, typically, has resistant starch type 3 (RS3) content of 2.4%. This paper shows that the RS3 yields can be substantially enhanced by debranching cassava starch using pullulanase followed by high pressure or cyclic high-pressure annealing. RS3 yield of 41.3% was obtained when annealing was carried out at 400MPa/60°C for 15 min, whereas it took nearly 8h to obtain the same yield under conventional atmospheric annealing at 60°C. The yield of RS3 could be further significantly increased by annealing under 400 MPa/60°C pressure for 15 min followed by resting at atmospheric pressure for 3h 45 min, and repeating this cycle for up to six times. Microstructural surface analysis of the product under a scanning electron microscope showed an increasingly rigid density of the crystalline structure formed, confirming higher RS3 content.

  6. High pressure differential conductance measurements of (Pb,Sn)Se

    NASA Astrophysics Data System (ADS)

    Paul, Tiffany; Vangennep, Derrick; Jackson, Daniel; Biswas, Amlan; Hamlin, James

    Topological transitions have been recognized as a new type of quantum phase transition. Recently, a number of papers have reported scanning tunneling microscope (STM) measurements of the Landau level spectra of topologically non-trivial materials. Such measurements can offer substantial insight into the nature of the transition between topologically distinct phases. Although applied pressure represents an attractive means to drive a topological quantum phase transition, STM measurements can not be performed under high pressure conditions. In this talk, I will discuss our recent attempts to observe Landau level spectra in compressed (Pb,Sn)Se using differential conductance measurements. Acknowledgements: TAP supported by REU NSF DMR-1461019. Pressure cell development and measurements at high magnetic fields supported by the National High Magnetic Field Laboratory User Collaboration Grants Program. Synthesis, characterization, and high pressure measurements supported by NSF DMR-1453752.

  7. Germination of vegetable seeds exposed to very high pressure

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  8. Rare-earth-metal nitridophosphates through high-pressure metathesis.

    PubMed

    Kloss, Simon David; Schnick, Wolfgang

    2015-09-14

    Developing a synthetic method to target an broad spectrum of unknown phases can lead to fascinating discoveries. The preparation of the first rare-earth-metal nitridophosphate LiNdP4 N8 is reported. High-pressure solid-state metathesis between LiPN2 and NdF3 was employed to yield a highly crystalline product. The in situ formed LiF is believed to act both as the thermodynamic driving force and as a flux to aiding single-crystal formation in dimensions suitable for crystal structure analysis. Magnetic properties stemming from Nd(3+) ions were measured by SQUID magnetometry. LiNdP4 N8 serves as a model system for the exploration of rare-earth-metal nitridophosphates that may even be expanded to transition metals. High-pressure metathesis enables the systematic study of these uncharted regions of nitride-based materials with unprecedented properties.

  9. High pressure and Multiferroics materials. A happy marriage

    DOE PAGES

    Gilioli, Edmondo; Ehm, Lars

    2014-10-31

    We found that the community of material scientists is strongly committed to the research area of multiferroic materials, both for the understanding of the complex mechanisms supporting the multiferroism and for the fabrication of new compounds, potentially suitable for technological applications. The use of high pressure is a powerful tool in synthesizing new multiferroic, in particular magneto-electric phases, where the pressure stabilization of otherwise unstable perovskite-based structural distortions may lead to promising novel metastable compounds. Moreover, the in situ investigation of the high-pressure behavior of multiferroic materials has provided insight into the complex interplay between magnetic and electronic properties andmore » the coupling to structural instabilities.« less

  10. High-pressure paint gun injection injury to the palm.

    PubMed

    Chaudhry, Sonia; Gould, Stephen; Gupta, Salil

    2013-08-01

    High-pressure injection injuries often have a misleadingly benign presentation. However, it is important to recognize the potential surgical urgency and long-term sequelae associated with these injuries. We present a case of paint gun injection to the palm and review the literature on high-pressure paint injection injuries. The 3 factors most important for the fate of the limb are material type, injection pressure, and injury site. The immediate use of antibiotics and tetanus prophylaxis, with or without steroids, is indicated. Urgent debridement in the operating room is imperative and can decompress the neurovascular structures and flexor tendon sheath by removing the irritating agents. Reported overall amputation rates have been as high as 30%.

  11. Electronic Structure of Crystalline 4He at High Pressure

    SciTech Connect

    Mao, H.K.; Cai, Y.; Shirley, E.L.; Ding, Y.; Eng, P.; Chow, P.; Xiao, Y.; Shu, J.; Hemley, R.J.; Kao, C.C.; Mao, W.L.

    2010-10-29

    Using inelastic x-ray scattering techniques, we have succeeded in probing the high-pressure electronic structure of helium at 300 K. Helium has the widest known valence-conduction band gap of all materials a property whose high-pressure response has been inaccessible to direct measurements. We observed a rich electron excitation spectrum, including a cutoff edge above 23 eV, a sharp exciton peak showing linear volume dependence, and a series of excitations and continuum at 26 to 45 eV. We determined the electronic dispersion along the {Gamma}-M direction over two Brillouin zones, and provided a quantitative picture of the helium exciton beyond the simplified Wannier-Frenkel description.

  12. Structural changes in thermoelectric SnSe at high pressures.

    PubMed

    Loa, I; Husband, R J; Downie, R A; Popuri, S R; Bos, J-W G

    2015-02-25

    The crystal structure of the thermoelectric material tin selenide has been investigated with angle-dispersive synchrotron x-ray powder diffraction under hydrostatic pressure up to 27 GPa. With increasing pressure, a continuous evolution of the crystal structure from the GeS type to the higher-symmetry TlI type was observed, with a critical pressure of 10.5(3) GPa. The orthorhombic high-pressure modification, β'-SnSe, is closely related to the pseudo-tetragonal high-temperature modification at ambient pressure. The similarity between the changes of the crystal structure at elevated temperatures and at high pressures suggests the possibility that strained thin films of SnSe may provide a route to overcoming the problem of the limited thermal stability of β-SnSe at high temperatures.

  13. Measurements of plasma potential in high-pressure microwave plasmas

    SciTech Connect

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

    2009-04-15

    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.

  14. High-pressure liquid chromatography of caffeine in coffee.

    PubMed

    Madison, B L; Kozarek, W J; Damo, C P

    1976-11-01

    A new method is described for the determination of caffeine in coffee, based on high-pressure liquid chromatography. The caffeine is extracted from the sample with water and/or methylene chloride, and then separated from interfering materials by passing an aliquot of the extract through a high-pressure column containing sulfonated cation exchange resin, using 0.01M nitric acid as the mobile phase. An ultraviolet detector measures the absorption of the solution directly. The method is rapid and eliminates the lengthy separations common to other methods. The procedure was applied successfully to decaffeinated and non-decaffeinated green, roasted, and instant coffees. This method gives a more accurate measure of the caffeine content in decaffeinated coffee samples than the micro Bailey-Andrew and modified Levine methods, with equal or better precision. This method gives results equal to those obtained by the official methods for non-decaffeinated samples. PMID:993180

  15. High pressure extraction of phenolic compounds from citrus peels†

    NASA Astrophysics Data System (ADS)

    Casquete, R.; Castro, S. M.; Villalobos, M. C.; Serradilla, M. J.; Queirós, R. P.; Saraiva, J. A.; Córdoba, M. G.; Teixeira, P.

    2014-10-01

    This study evaluated the effect of high pressure processing on the recovery of high added value compounds from citrus peels. Overall, the total phenolic content in orange peel was significantly (P < .05) higher than that in lemon peel, except when pressure treated at 500 MPa. However, lemon peel demonstrated more antioxidant activity than orange peel. Pressure-treated samples (300 MPa, 10 min; 500 MPa, 3 min) demonstrated higher phenolic content and antioxidant activity comparatively to the control samples. For more severe treatments (500 MPa, 10 min), the phenolic content and antioxidant activity decreased in both lemon and orange peels. This paper was presented at the 8th International Conference on High Pressure Bioscience & Biotechnology (HPBB 2014), in Nantes (France), 15-18 July 2014.

  16. High-pressure polymorphism of acetylsalicylic acid (aspirin): Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Crowell, Ethan L.; Dreger, Zbigniew A.; Gupta, Yogendra M.

    2015-02-01

    Micro-Raman spectroscopy was used to elucidate the high-pressure polymorphic behavior of acetylsalicylic acid (ASA), an important pharmaceutical compound known as aspirin. Using a diamond anvil cell (DAC), single crystals of the two polymorphic phases of aspirin existing at ambient conditions (ASA-I and ASA-II) were compressed to 10 GPa. We found that ASA-I does not transform to ASA-II, but instead transforms to a new phase (ASA-III) above ∼2 GPa. It is demonstrated that this transformation primarily introduces structural changes in the bonding and arrangement of the acetyl groups and is reversible upon the release of pressure. In contrast, a less dense ASA-II shows no transition in the pressure range studied, though it appears to exhibit a disordered structure above 7 GPa. Our results suggest that ASA-III is the most stable polymorph of aspirin at high pressures.

  17. Measurements of plasma potential in high-pressure microwave plasmas.

    PubMed

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

    2009-04-01

    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.

  18. Operating experience with gas-bearing circulators in a high-pressure helium loop

    SciTech Connect

    Sanders, J.P.; Gat, Uri; Young, H.C.

    1987-01-01

    A high-pressure engineering test loop has been designed and constructed at the Oak Ridge National Laboratory for circulating helium through a test chamber at temperatures to 1000/sup 0/C. The purpose of this loop is to determine the thermal and structural performance of proposed components for the primary loops of gas-cooled nuclear reactors. Five MW of power is available to provide the required gas temperature at the test chamber, and an air-cooled heat exchanger, rated at 4.4 MW, serves as a heat sink. This report contains results of tests performed on gas-bearing circulators.

  19. High pressure flame system for pollution studies with results for methane-air diffusion flames

    NASA Technical Reports Server (NTRS)

    Miller, I. M.; Maahs, H. G.

    1977-01-01

    A high pressure flame system was designed and constructed for studying nitrogen oxide formation in fuel air combustion. Its advantages and limitations were demonstrated by tests with a confined laminar methane air diffusion flame over the pressure range from 1 to 50 atm. The methane issued from a 3.06 mm diameter port concentrically into a stream of air contained within a 20.5 mm diameter chimney. As the combustion pressure is increased, the flame changes in shape from wide and convex to slender and concave, and there is a marked increase in the amount of luminous carbon. The height of the flame changes only moderately with pressure.

  20. Characterization of pores in high pressure die cast aluminum using active thermography and computed tomography

    NASA Astrophysics Data System (ADS)

    Maierhofer, Christiane; Myrach, Philipp; Röllig, Mathias; Jonietz, Florian; Illerhaus, Bernhard; Meinel, Dietmar; Richter, Uwe; Miksche, Ronald

    2016-02-01

    Larger high pressure die castings (HPDC) and decreasing wall thicknesses are raising the issue of casting defects like pores in aluminum structures. Properties of components are often strongly influenced by inner porosity. As these products are being established more and more in lightweight construction (e.g. automotive and other transport areas), non-destructive testing methods, which can be applied fast and on-site, are required for quality assurance. In this contribution, the application of active thermography for the direct detection of larger pores is demonstrated. The analysis of limits and accuracy of the method are completed by numerical simulation and the method is validated using computed tomography.

  1. Shockwave determination of the shear velocity at very high pressures.

    NASA Technical Reports Server (NTRS)

    Anderson, O. L.

    1972-01-01

    Description of a proposed shockwave experiment that may provide some understanding on the behavior of planet core materials in the presence of high temperatures and pressures. Shockwave experimentation is shown to offer promise of revealing some information on shear velocity behavior at high pressures, and its relevance to properties of planet interiors consists in that abrupt changes in shear velocities at boundary layers could be experimentally confirmed where abrupt changes in density are suspected from seismic interpretation.

  2. Effect of high pressure on hydrocarbon-degrading bacteria

    PubMed Central

    2014-01-01

    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. PMID:25401077

  3. High pressure phase transition in Pr-monopnictides

    SciTech Connect

    Raypuria, Gajendra Singh E-mail: gsraypuria@gmail.com; Gupta, Dinesh Chandra

    2015-06-24

    The Praseodymium-monopnictides compounds have been found to undergo transition from their initial NaCl-type structure to high pressure body centered tetragonal (BCT) structure (distorted CsCl-type P4/mmm) using CTIP model. The calculated values of cohesive energy, lattice constant, phase transition pressure, relative volume collapse agree well with the available measured data and better than those computed by earlier workers.

  4. High-pressure phase transition in {gamma}-hexanitrohexaazaisowurtzitane

    SciTech Connect

    Russell, T.P.; Miller, P.J.; Piermarini, G.J.; Block, S.

    1992-06-25

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

  5. High-Pressure Valve With Controlled Seating Force

    NASA Technical Reports Server (NTRS)

    Bradley, R. H.

    1987-01-01

    Poppet and seat less likely to be damaged by faulty operation. Improvements in widely-used high-pressure valve increase accuracy of preloading of poppet. Redesigned valve prevents metal shavings and other debris from developing during operation, installation, or removal. New features include secondary seal in cap. Belleville washers create precise value of seating force. If installer attempts to exceed force, torque limiter gives tactile and aural warning and makes further force increases difficult.

  6. Vibratory high pressure coal feeder having a helical ramp

    DOEpatents

    Farber, Gerald

    1978-01-01

    Apparatus and method for feeding powdered coal from a helical ramp into a high pressure, heated, reactor tube containing hydrogen for hydrogenating the coal and/or for producing useful products from coal. To this end, the helical ramp is vibrated to feed the coal cleanly at an accurately controlled rate in a simple reliable and trouble-free manner that eliminates complicated and expensive screw feeders, and/or complicated and expensive seals, bearings and fully rotating parts.

  7. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis.

    PubMed

    Vogel, R F; Pavlovic, M; Hörmann, S; Ehrmann, M A

    2005-08-01

    Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK), while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport. PMID:16082466

  8. Determination of the SSME high pressure oxidizer turbopump bearing temperature

    NASA Technical Reports Server (NTRS)

    Naerheim, Y.; Stocker, P. J.; Lumsden, J. B.

    1988-01-01

    The SSME high pressure liquid oxygen turbopump (HPOTP) bearings sometimes wear and experience heating and oxidation of the ball and raceway surfaces. So far it has been impossible to measure the temperature of the bearings directly during operation of the turbopumps. However, a method was developed for determining the surface temperature of the bearings from the composition of the oxides using oxidation samples for calibration and Auger Electron Spectroscopy (AES) for chemical analysis.

  9. Quantitative PLIF Imaging in High-Pressure Combustion

    NASA Technical Reports Server (NTRS)

    Hanson, R. K.

    1997-01-01

    This is the final report for a research project aimed at developing planar laser-induced fluorescence (PLIF) techniques for quantitative 2-D species imaging in fuel-lean, high-pressure combustion gases, relevant to modem aircraft gas turbine combustors. The program involved both theory and experiment. The theoretical activity led to spectroscopic models that allow calculation of the laser-induced fluorescence produced in OH, NO and 02 for arbitrary excitation wavelength, pressure, temperature, gas mixture and laser linewidth. These spectroscopic models incorporate new information on line- broadening, energy transfer and electronic quench rates. Extensive calculations have been made with these models in order to identify optimum excitation strategies, particularly for detecting low levels (ppm) of NO in the presence of large 02 mole fractions (10% is typical for the fuel-lean combustion of interest). A promising new measurement concept has emerged from these calculations, namely that excitation at specific wavelengths, together with detection of fluorescence in multiple spectral bands, promises to enable simultaneous detection of both NO (at ppm levels) and 02 or possibly NO, 02 and temperature. Calculations have been made to evaluate the expected performance of such a diagnostic for a variety of conditions and choices of excitation and detection wavelengths. The experimental effort began with assembly of a new high-pressure combustor to provide controlled high-temperature and high-pressure combustion products. The non-premixed burner enables access to postflame gases at high temperatures (to 2000 K) and high pressures (to 13 atm), and a range of fuel-air equivalence ratios. The chamber also allowed use of a sampling probe, for chemiluminescent detection of NO/NO2, and thermocouples for measurement of gas temperature. Experiments were conducted to confirm the spectroscopic models for OH, NO and 02.

  10. Design and testing of high-pressure railguns and projectiles

    SciTech Connect

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

    1983-01-01

    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.

  11. High pressure inactivation kinetics of a Thermomyces lanuginosus xylanase evaluated as a process indicator.

    PubMed

    Gogou, Eleni; Katapodis, Petros; Taoukis, Petros S

    2010-08-01

    The potential use of Thermomyces lanuginosus xylanase to develop a pressure-temperature-time integrator (PTTI) for high pressure processing was investigated. The combined effect of pressure and temperature on the inactivation of xylanase was studied in the pressure range of 100 to 600 MPa and temperature range of 50 to 70 degrees C. A synergistic effect of pressure and temperature was observed. Xylanase inactivation at the studied processing conditions followed first-order kinetics and was found to be very sensitive to changes in pressure and temperature. The values of activation energy and activation volume were estimated as 92.8 kJ/mol and -23.3 mL/mol at a reference pressure of 450 MPa and a reference temperature of 60 degrees C, respectively. A mathematical model of xylanase inactivation, having as variables time, pressure, and temperature allows the calculation of remaining enzyme activity at any combination of processing conditions within the studied domain. Practical Application: To ensure the optimization and control of high pressure processing, evaluation of the process impact on both safety and quality attributes of foods is essential. Enzymes can serve as effective tools in evaluating the impact of high pressure processes of foods.

  12. Theory and Practice: Measuring High-Pressure Electronic and Magnetic Properties

    SciTech Connect

    Hemley, R J; Struzhkin, V V; Cohen, R E

    2008-06-17

    Measurements of the electronic and magnetic properties of Earth and planetary materials at high pressure play a crucial role in modern geoscience. There have been numerous advances in the field, primarily as a result of developments in diamond-anvil cell methods. In particular, synchrotron radiation techniques play an especially important role. The chapter begins with a short review of fundamental properties of the relevant materials, with emphasis on how these are altered under very high pressures and temperatures of the Earth's deep interior, followed by a discussion of different classes of electronic and magnetic excitations. Various techniques currently used for high-pressure studies are then described, beginning with optical spectroscopies, Moessbauer spectroscopy, elastic X-ray and neutron scattering, many new X-ray spectroscopy and inelastic scattering methods, transport techniques, and finally resonance methods. Selected examples of the techniques are given, with a common theme being the high P-T behavior of iron-containing oxides, silicates, and metals at conditions found throughout the Earth's interior. Applications to upper-mantle phases, 'simple' oxides, silicate perovskite and post-perovskite, volatiles, and iron and iron alloys are discussed, with an emphasis given to integrated studies utilizing a combination of different techniques to understand high P-T electronic and magnetic phenomena.

  13. Preparation and evaluation of thiomer nanoparticles via high pressure homogenization.

    PubMed

    Hoyer, Herbert; Schlocker, Wolfgang; Greindl, Melanie; Ostermann, Thomas; Bernkop-Schnürch, Andreas

    2010-01-01

    The aim of this study was to establish and evaluate a high pressure homogenization method for the preparation of thiomer nanoparticles. Particles were formulated by incorporation of the model protein horseradish peroxidase in chitosan-glutathione (Ch-GSH) and poly(acrylic acid)-glutathione (PAA-GSH) via co-precipitation followed by air jet milling. The resulting microparticles were suspended in distilled water using an Ultraturax and subsequently micronized by high pressure homogenization. Finally, resulting particles were evaluated regarding size distribution, shape, zeta potential, drug load, protein activity and release behaviour. The mean particle size after 30 cycles with a pressure of 1500 bar was 538 +/- 94 nm for particles consisting of Ch-GSH and 638 +/- 94 nm for particles consisting of PAA-GSH. Nanoparticles of Ch-GSH had a positive zeta-potential of +1.03 mv, whereas nanoparticles from PAA-GSH had a negative zeta potential of -6.21 mv. The maximum protein load for nanoparticles based on Ch-GSH and based on PAA-GSH was 45 +/- 2% and 37 +/- %, respectively. The release profile of nanoparticles followed a first order release kinetic. Thiolated nanoparticles prepared by a high pressure homogenization technique were shown to be stable and provide controlled drug release characteristics. The preparation method described here might be a useful tool for a more upscaled production of nanoparticulate drug delivery systems. PMID:20367028

  14. Elasticity of methane hydrate phases at high pressure.

    PubMed

    Beam, Jennifer; Yang, Jing; Liu, Jin; Liu, Chujie; Lin, Jung-Fu

    2016-04-21

    Determination of the full elastic constants (cij) of methane hydrates (MHs) at extreme pressure-temperature environments is essential to our understanding of the elastic, thermodynamic, and mechanical properties of methane in MH reservoirs on Earth and icy satellites in the solar system. Here, we have investigated the elastic properties of singe-crystal cubic MH-sI, hexagonal MH-II, and orthorhombic MH-III phases at high pressures in a diamond anvil cell. Brillouin light scattering measurements, together with complimentary equation of state (pressure-density) results from X-ray diffraction and methane site occupancies in MH from Raman spectroscopy, were used to derive elastic constants of MH-sI, MH-II, and MH-III phases at high pressures. Analysis of the elastic constants for MH-sI and MH-II showed intriguing similarities and differences between the phases' compressional wave velocity anisotropy and shear wave velocity anisotropy. Our results show that these high-pressure MH phases can exhibit distinct elastic, thermodynamic, and mechanical properties at relevant environments of their respective natural reservoirs. These results provide new insight into the determination of how much methane exists in MH reservoirs on Earth and on icy satellites elsewhere in the solar system and put constraints on the pressure and temperature conditions of their environment. PMID:27389226

  15. A high-pressure carbon dioxide gasdynamic laser

    NASA Technical Reports Server (NTRS)

    Kuehn, D. M.

    1973-01-01

    A carbon dioxide gasdynamic laser was operated over a range of reservoir pressure and temperature, test-gas mixture, and nozzle geometry. A significant result is the dominant influence of nozzle geometry on laser power at high pressure. High reservoir pressure can be effectively utilized to increase laser power if nozzle geometry is chosen to efficiently freeze the test gas. Maximum power density increased from 3.3 W/cu cm of optical cavity volume for an inefficient nozzle to 83.4 W/cu cm at 115 atm for a more efficient nozzle. Variation in the composition of the test gas also caused large changes in laser power output. Most notable is the influence of the catalyst (helium or water vapor) that was used to depopulate the lower vibrational state of the carbon dioxide. Water caused an extreme deterioration of laser power at high pressure (100 atm), whereas, at low pressure the laser for the two catalysts approached similar values. It appears that at high pressure the depopulation of the upper laser level of the carbon dioxide by the water predominates over the lower state depopulation, thus destroying the inversion.

  16. Boundary Layer Ventilation Processes During a High Pressure Event

    NASA Astrophysics Data System (ADS)

    Gray, S. L.; Dacre, H. F.; Belcher, S. E.

    2006-12-01

    It is often assumed that ventilation of the atmospheric boundary layer is weak during high pressure events. But is this always true? Here we investigate the processes responsible for ventilation of the atmospheric boundary layer during a high pressure event that occured on the 9 May 2005 using the UK Met Office Unifed Model. Pollution sources are represented by the constant emission of a passive tracer everywhere over land. The ventilation processes observed include a sea breeze circulation, turbulent mixing across the top of the boundary layer followed by large-scale ascent, and shallow convection. Vertical distributions of tracer are validated with AMPEP (Aircraft Measurement of chemical Processing Export fluxes of Pollutants over the UK) CO aircraft measurements and are shown to agree impressively well. Budget calculations of tracers are performed in order to determine the relative importance of these ventilation processes. The sea breeze circulation was found to ventilate 26% of the boundary layer tracer by sunset of which 2% was above 2km. A combination of the sea breeze circulation and turbulent mixing ventilated 46% of the boundary layer tracer, of which 10% was above 2km. Finally, the sea breeze circulation, turbulent mixing and shallow convection processes together ventilated 52% of the tracer into the free troposphere, of which 26% was above 2km. Hence this study shows that signicant ventilation of the boundary layer can occur during high pressure events; turbulent mixing and convection processes can double the amount of pollution ventilated from the boundary layer.

  17. Elasticity of methane hydrate phases at high pressure

    NASA Astrophysics Data System (ADS)

    Beam, Jennifer; Yang, Jing; Liu, Jin; Liu, Chujie; Lin, Jung-Fu

    2016-04-01

    Determination of the full elastic constants (cij) of methane hydrates (MHs) at extreme pressure-temperature environments is essential to our understanding of the elastic, thermodynamic, and mechanical properties of methane in MH reservoirs on Earth and icy satellites in the solar system. Here, we have investigated the elastic properties of singe-crystal cubic MH-sI, hexagonal MH-II, and orthorhombic MH-III phases at high pressures in a diamond anvil cell. Brillouin light scattering measurements, together with complimentary equation of state (pressure-density) results from X-ray diffraction and methane site occupancies in MH from Raman spectroscopy, were used to derive elastic constants of MH-sI, MH-II, and MH-III phases at high pressures. Analysis of the elastic constants for MH-sI and MH-II showed intriguing similarities and differences between the phases' compressional wave velocity anisotropy and shear wave velocity anisotropy. Our results show that these high-pressure MH phases can exhibit distinct elastic, thermodynamic, and mechanical properties at relevant environments of their respective natural reservoirs. These results provide new insight into the determination of how much methane exists in MH reservoirs on Earth and on icy satellites elsewhere in the solar system and put constraints on the pressure and temperature conditions of their environment.

  18. Reinvestigation of high pressure polymorphism in hafnium metal

    SciTech Connect

    Pandey, K. K. Sharma, Surinder M.; Gyanchandani, Jyoti; Dey, G. K.; Somayazulu, M.; Sikka, S. K.

    2014-06-21

    There has been a recent controversy about the high pressure polymorphism of Hafnium (Hf). Unlike, the earlier known α→ω structural transition at 38 ± 8 GPa, at ambient temperature, Hrubiak et al. [J. Appl. Phys. 111, 112612 (2012)] did not observe it till 51 GPa. They observed this transition only at elevated temperatures. We have reinvestigated the room temperature phase diagram of Hf, employing x-ray diffraction (XRD) and DFT based first principles calculations. Experimental investigations have been carried out on several pure and impure Hf samples and also with different pressure transmitting media. Besides demonstrating the significant role of impurity levels on the high pressure phase diagram of Hf, our studies re-establish room temperature α→ω transition at high pressures, even in quasi-hydrostatic environment. We observed this transition in pure Hf with equilibrium transition pressure P{sub o} = 44.5 GPa; however, with large hysteresis. The structural sequence, transition pressures, the lattice parameters, the c/a ratio and its variation with compression for the α and ω phases as predicted by our ab-initio scalar relativistic (SR) calculations are found to be in good agreement with our experimental results of pure Hf.

  19. Spontaneous Raman Scattering Diagnostics for High-pressure Gaseous Flames

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  20. Reinvestigation of high pressure polymorphism in hafnium metal

    NASA Astrophysics Data System (ADS)

    Pandey, K. K.; Gyanchandani, Jyoti; Somayazulu, M.; Dey, G. K.; Sharma, Surinder M.; Sikka, S. K.

    2014-06-01

    There has been a recent controversy about the high pressure polymorphism of Hafnium (Hf). Unlike, the earlier known α→ω structural transition at 38 ± 8 GPa, at ambient temperature, Hrubiak et al. [J. Appl. Phys. 111, 112612 (2012)] did not observe it till 51 GPa. They observed this transition only at elevated temperatures. We have reinvestigated the room temperature phase diagram of Hf, employing x-ray diffraction (XRD) and DFT based first principles calculations. Experimental investigations have been carried out on several pure and impure Hf samples and also with different pressure transmitting media. Besides demonstrating the significant role of impurity levels on the high pressure phase diagram of Hf, our studies re-establish room temperature α→ω transition at high pressures, even in quasi-hydrostatic environment. We observed this transition in pure Hf with equilibrium transition pressure Po = 44.5 GPa; however, with large hysteresis. The structural sequence, transition pressures, the lattice parameters, the c/a ratio and its variation with compression for the α and ω phases as predicted by our ab-initio scalar relativistic (SR) calculations are found to be in good agreement with our experimental results of pure Hf.

  1. High-pressure phase transitions in rubidium and caesium hydroxides.

    PubMed

    Hermann, Andreas

    2016-06-28

    A computational investigation of the high-pressure phase sequence of the heaviest alkali hydroxides, RbOH and CsOH, shows that the phase diagram of both compounds is richer than hitherto thought. First-principles calculations suggest, based on energetics and comparisons to experimental diffraction and spectroscopy signatures, that the high-pressure phase RbOH-VI, stable above 6 GPa in experiment, should be assigned the KOH-VI structure type, and features localised hydrogen-bonded (OH)4 units. Meanwhile, a new high-pressure phase CsOH-VII is predicted to be stable above 10 GPa in an isosymmetric phase transition that, like RbOH-VI, marks the transition from layered to three-dimensional network structures under increased compression. Both new phases highlight an unexpected flexibility of hydrogen bond network formation in a series of compounds that seemingly only vary in the cation size, and potential consequences for similar systems, such as water-carrying minerals, are discussed briefly. PMID:27271485

  2. Exploration of the pyrazinamide polymorphism at high pressure.

    PubMed

    Tan, Xiao; Wang, Kai; Li, Shourui; Yuan, Hongsheng; Yan, Tingting; Liu, Jing; Yang, Ke; Liu, Bingbing; Zou, Guangtian; Zou, Bo

    2012-12-13

    We report the high-pressure response of three forms (α, δ, and γ) of pyrazinamide (C(5)H(5)N(3)O, PZA) by in situ Raman spectroscopy and synchrotron X-ray diffraction techniques with a pressure of about 14 GPa. These different forms are characterized by various intermolecular bonding schemes. High-pressure experimental results show that the γ phase undergoes phase transition to the β phase at a pressure of about 4 GPa, whereas the other two forms retain their original structures at a high pressure. We propose that the stabilities of the α and δ forms upon compression are due to the special dimer connection that these forms possess. On the other hand, the γ form, which does not have this connection, prefers to transform to the closely related β form when pressure is applied. The detailed mechanism of the phase transition together with the stability of the three polymorphs is discussed by taking molecular stacking into account. PMID:23176640

  3. Theoretical Predictions of Phase Transitions at Ultra-high Pressures

    NASA Astrophysics Data System (ADS)

    Boates, Brian

    2013-06-01

    We present ab initio calculations of the high-pressure phase diagrams of important planetary materials such as CO2, MgSiO3, and MgO. For CO2, we predict a series of distinct liquid phases over a wide pressure (P) and temperature (T) range, including a first-order transition to a dense polymer liquid. We have computed finite-temperature free energies of liquid and solid CO2 phases to determine the melting curve beyond existing measurements and investigate possible phase separation transitions. The interaction of these phase boundaries with the mantle geotherm will also be discussed. Furthermore, we find evidence for a vast pressure-temperature regime where molten MgSiO3 decomposes into liquid SiO2 and solid MgO, with a volume change of approximately 1.2 percent. The demixing transition is driven by the crystallization of MgO ? the reaction only occurs below the high-pressure MgO melting curve. The predicted transition pressure at 10,000 K is in close proximity to an anomaly reported in recent laser-driven shock experiments of MgSiO3. We also present new results for the high-pressure melting curve of MgO and its B1-B2 solid phase transition, with a triple point near 364 GPa and 12,000 K.

  4. Aging study of boiling water reactor high pressure injection systems

    SciTech Connect

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

    1995-03-01

    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.

  5. High-pressure Raman study of fully deuterated methane hydrate

    NASA Astrophysics Data System (ADS)

    Yabashi, Ryo; Yoshida, Masashi; Kume, Tetsuji; Sasaki, Shigeo

    2013-06-01

    Methane hydrate (MH: CH4- nH2O) crystallizes in a cubic structure I (sI) which consists of hydrogen-bonded water cages which enclathrate methane molecules as guests. With increasing pressure, the initial sI of MH transforms to a hexagonal structure H (sH) at 0.9 GPa, and eventually to an orthorhombic cage-less structure O at 1.9 GPa. The sH consists of three small S1, two small S2, and one large LL water cages in a hexagonal unit cell. The previous high-pressure Raman measurements for C-H stretching vibration of MH-sH indicated that the capacity of methane molecules in the large LL cage abruptly increased at 1.3 GPa, and its occupation number of methane molecule was about 2.5 above 1.3 GPa. However, this result disagrees with the previous high-pressure neutron diffraction experiments for sH of fully deutarated methane hydrate (FDMH: CD4- nD2O). To solve this discrepancy, we have carried out the high pressure Raman measurements for C-D stretching vibration in the sI and sH phases of FDMH. As a result, we have obtained the different Raman spectral patterns between FDMH and MH, which suggests that the occupancy of CD4 in water cages is somewhat different from CH4.

  6. Extended evolution: A conceptual framework for integrating regulatory networks and niche construction.

    PubMed

    Laubichler, Manfred D; Renn, Jürgen

    2015-11-01

    This paper introduces a conceptual framework for the evolution of complex systems based on the integration of regulatory network and niche construction theories. It is designed to apply equally to cases of biological, social and cultural evolution. Within the conceptual framework we focus especially on the transformation of complex networks through the linked processes of externalization and internalization of causal factors between regulatory networks and their corresponding niches and argue that these are an important part of evolutionary explanations. This conceptual framework extends previous evolutionary models and focuses on several challenges, such as the path-dependent nature of evolutionary change, the dynamics of evolutionary innovation and the expansion of inheritance systems.

  7. Tandem High-pressure Freezing and Quick Freeze Substitution of Plant Tissues for Transmission Electron Microscopy

    PubMed Central

    Bobik, Krzysztof; Dunlap, John R.; Burch-Smith, Tessa M.

    2014-01-01

    Since the 1940s transmission electron microscopy (TEM) has been providing biologists with ultra-high resolution images of biological materials. Yet, because of laborious and time-consuming protocols that also demand experience in preparation of artifact-free samples, TEM is not considered a user-friendly technique. Traditional sample preparation for TEM used chemical fixatives to preserve cellular structures. High-pressure freezing is the cryofixation of biological samples under high pressures to produce very fast cooling rates, thereby restricting ice formation, which is detrimental to the integrity of cellular ultrastructure. High-pressure freezing and freeze substitution are currently the methods of choice for producing the highest quality morphology in resin sections for TEM. These methods minimize the artifacts normally associated with conventional processing for TEM of thin sections. After cryofixation the frozen water in the sample is replaced with liquid organic solvent at low temperatures, a process called freeze substitution. Freeze substitution is typically carried out over several days in dedicated, costly equipment. A recent innovation allows the process to be completed in three hours, instead of the usual two days. This is typically followed by several more days of sample preparation that includes infiltration and embedding in epoxy resins before sectioning. Here we present a protocol combining high-pressure freezing and quick freeze substitution that enables plant sample fixation to be accomplished within hours. The protocol can readily be adapted for working with other tissues or organisms. Plant tissues are of special concern because of the presence of aerated spaces and water-filled vacuoles that impede ice-free freezing of water. In addition, the process of chemical fixation is especially long in plants due to cell walls impeding the penetration of the chemicals to deep within the tissues. Plant tissues are therefore particularly challenging, but

  8. Tandem high-pressure freezing and quick freeze substitution of plant tissues for transmission electron microscopy.

    PubMed

    Bobik, Krzysztof; Dunlap, John R; Burch-Smith, Tessa M

    2014-10-13

    Since the 1940s transmission electron microscopy (TEM) has been providing biologists with ultra-high resolution images of biological materials. Yet, because of laborious and time-consuming protocols that also demand experience in preparation of artifact-free samples, TEM is not considered a user-friendly technique. Traditional sample preparation for TEM used chemical fixatives to preserve cellular structures. High-pressure freezing is the cryofixation of biological samples under high pressures to produce very fast cooling rates, thereby restricting ice formation, which is detrimental to the integrity of cellular ultrastructure. High-pressure freezing and freeze substitution are currently the methods of choice for producing the highest quality morphology in resin sections for TEM. These methods minimize the artifacts normally associated with conventional processing for TEM of thin sections. After cryofixation the frozen water in the sample is replaced with liquid organic solvent at low temperatures, a process called freeze substitution. Freeze substitution is typically carried out over several days in dedicated, costly equipment. A recent innovation allows the process to be completed in three hours, instead of the usual two days. This is typically followed by several more days of sample preparation that includes infiltration and embedding in epoxy resins before sectioning. Here we present a protocol combining high-pressure freezing and quick freeze substitution that enables plant sample fixation to be accomplished within hours. The protocol can readily be adapted for working with other tissues or organisms. Plant tissues are of special concern because of the presence of aerated spaces and water-filled vacuoles that impede ice-free freezing of water. In addition, the process of chemical fixation is especially long in plants due to cell walls impeding the penetration of the chemicals to deep within the tissues. Plant tissues are therefore particularly challenging, but

  9. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    PubMed

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. PMID:24784452

  10. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    PubMed

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions.

  11. Cryogenic Transport of High-Pressure-System Recharge Gas

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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

  12. Material Strength at High Pressure LDRD Strategic Initiative Final Report

    SciTech Connect

    Lassila, D H; Bonner, B P; Bulatov, V V; Cazamias, J U; Chandler, E A; Farber, D L; Moriarty, J A; Zaug, J M

    2004-03-02

    Various aspects of the Laboratory's national security mission are now highly dependent on accurate computer code simulations of plastic flow (i.e., non-reversible deformation) of materials under conditions of high hydrostatic pressure. Strength models are typically dependent on pressure, temperature, and strain rate. Current strength models can not be extrapolated to high pressure because they are not based on the underlying mechanisms of plastic deformation. The critical need for predictive models of material strength, which describe flow stress in computer code simulations, has motivated LLNL's multiscale modeling efforts. Over the past three years, the ''Material Strength at High Pressure'' LDRD Strategic Initiative has established a framework for the development of predictive strength models for deformation of metals under conditions of high hydrostatic pressure. Deformation experiments have been developed to measure the effect of high pressure on the yield strength and work hardening behavior of high purity Mo and Ta single crystals. The over arching goal of the SI is to experimentally validate multiscale-modeling capabilities for deformation of metals under conditions of high pressure. The work performed and accomplished is a necessary next step in the development of predictive strength models. Our initial experimental results show that the influence of pressure is to dramatically increase the work hardening rate of Ta. Bridgman also observed this in experiments performed in the 1950's. Currently there is very little modern data on this phenomena, or theoretical understanding. The work started by this SI is a first step in a comprehensive understanding of plasticity under conditions of high pressure and we expect eventually to be able to incorporate the proper physics into dislocation dynamics (DD) simulations to capture the increase in work hardening that we observe experimentally. In the following sections we briefly describe the work that was performed in

  13. Construction and evaluation of an integrated dynamical model of visual motion perception.

    PubMed

    Tlapale, Émilien; Dosher, Barbara Anne; Lu, Zhong-Lin

    2015-07-01

    Although numerous models describe the individual neural mechanisms that may be involved in the perception of visual motion, few of them have been constructed to take arbitrary stimuli and map them to a motion percept. Here, we propose an integrated dynamical motion model (IDM), which is sufficiently general to handle diverse moving stimuli, yet sufficiently precise to account for a wide-ranging set of empirical observations made on a family of random dot kinematograms. In particular, we constructed models of the cortical areas involved in motion detection, motion integration and perceptual decision. We analyzed their parameters through dynamical simulations and numerical continuation to constrain their proper ranges. Then, empirical data from a family of random dot kinematograms experiments with systematically varying direction distribution, presentation duration and stimulus size, were used to evaluate our model and estimate corresponding model parameters. The resulting model provides an excellent account of a demanding set of parametrically varied behavioral effects on motion perception, providing both quantitative and qualitative elements of evaluation.

  14. Constructing and validating readability models: the method of integrating multilevel linguistic features with machine learning.

    PubMed

    Sung, Yao-Ting; Chen, Ju-Ling; Cha, Ji-Her; Tseng, Hou-Chiang; Chang, Tao-Hsing; Chang, Kuo-En

    2015-06-01

    Multilevel linguistic features have been proposed for discourse analysis, but there have been few applications of multilevel linguistic features to readability models and also few validations of such models. Most traditional readability formulae are based on generalized linear models (GLMs; e.g., discriminant analysis and multiple regression), but these models have to comply with certain statistical assumptions about data properties and include all of the data in formulae construction without pruning the outliers in advance. The use of such readability formulae tends to produce a low text classification accuracy, while using a support vector machine (SVM) in machine learning can enhance the classification outcome. The present study constructed readability models by integrating multilevel linguistic features with SVM, which is more appropriate for text classification. Taking the Chinese language as an example, this study developed 31 linguistic features as the predicting variables at the word, semantic, syntax, and cohesion levels, with grade levels of texts as the criterion variable. The study compared four types of readability models by integrating unilevel and multilevel linguistic features with GLMs and an SVM. The results indicate that adopting a multilevel approach in readability analysis provides a better representation of the complexities of both texts and the reading comprehension process.

  15. Theory of melting at high pressures: Amending density functional theory with quantum Monte Carlo

    SciTech Connect

    Shulenburger, L.; Desjarlais, M. P.; Mattsson, T. R.

    2014-10-01

    We present an improved first-principles description of melting under pressure based on thermodynamic integration comparing Density Functional Theory (DFT) and quantum Monte Carlo (QMC) treatments of the system. The method is applied to address the longstanding discrepancy between density functional theory (DFT) calculations and diamond anvil cell (DAC) experiments on the melting curve of xenon, a noble gas solid where van der Waals binding is challenging for traditional DFT methods. The calculations show excellent agreement with data below 20 GPa and that the high-pressure melt curve is well described by a Lindemann behavior up to at least 80 GPa, a finding in stark contrast to DAC data.

  16. High pressure melting curve of tin measured using an internal resistive heating technique to 45 GPa

    NASA Astrophysics Data System (ADS)

    Weir, S. T.; Lipp, M. J.; Falabella, S.; Samudrala, G.; Vohra, Y. K.

    2012-06-01

    The high pressure melting curve of tin was measured to 45 GPa using a designer diamond anvil cell with an integrated internal resistive heating element. Melting of the tin sample was detected by an abrupt increase in the electrical resistance of the sample and also by a change in the slope of the electrical heating power versus temperature curve. The melting temperatures determined by these two methods are in good agreement with each other. We find that the melting temperature of tin tends to monotonically increase with increasing pressure and reaches a temperature of about 2000 K at 45 GPa.

  17. Industrial & Engineering Systems Career Cluster ITAC for Career-Focused Education: Construction Sub-Cluster. Integrated Technical & Academic Competencies.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

    Designed for Ohio educators responsible for planning programs to prepare high school students for careers in construction, this document presents an overview of Ohio's Integrated Technical and Academic Competencies (ITAC) system of career-focused education and specific information about the construction subcluster of the industrial and engineering…

  18. Removal of antibiotics and antibiotic resistance genes in rural wastewater by an integrated constructed wetland.

    PubMed

    Chen, Jun; Liu, You-Sheng; Su, Hao-Chang; Ying, Guang-Guo; Liu, Feng; Liu, Shuang-Shuang; He, Liang-Ying; Chen, Zhi-Feng; Yang, Yong-Qiang; Chen, Fan-Rong

    2015-02-01

    Integrated constructed wetlands (ICWs) are regarded as one of the most important removal technology for pollutants in rural domestic wastewaters. This study investigated the efficiency of an ICW consisting of a regulating pool, four surface and subsurface flow-constructed wetlands, and a stabilization unit for removing antibiotics and antibiotic resistance genes (ARGs) from rural domestic wastewaters. The results showed that antibiotics leucomycin, ofloxacin, lincomycin, and sulfamethazine, and ARGs sul1, sul2, tetM, and tetO were the predominant antibiotics and ARGs in the influent, respectively. The ICW system could significantly reduce most of the detected antibiotics and ARGs with their aqueous removal rates of 78 to 100 % and >99 %, respectively. Based on the measured concentrations, the total pollution loadings of antibiotics were 3,479 μg/day in the influent and 199 μg/day in the final effluent. Therefore, constructed wetlands could be a promising technology for rural wastewater in removing contaminants such as antibiotics and ARGs.

  19. A database system for constructing, integrating, and displaying physical maps of chromosome 19

    SciTech Connect

    Slezak, T.; Wagner, M.; Yeh, Mimi; Ashworth, L.; Nelson, D.; Ow, D.; Branscomb, E.; Carrano, A.

    1994-06-01

    Efforts are underway at numerous sites around the world to construct physical maps of all human chromosomes. These maps will enable researchers to locate, characterize, and eventually understand the genes that control human structure and function. Accomplishing this goal will require a staggering amount of innovation and advancement of biological technology. The volume and complexity of the data already generated requires a sophisticated array of computational support to collect, store, analyze, integrate, and display it in biologically meaningful ways. The Human Genome Center at Livermore has spent the last 6 years constructing a database system to support its physical mapping efforts on human chromosome 19. Our computational support team is composed of experienced computer professionals who share a common pragmatic primary goal of rapidly supplying tools that meet the ever-changing needs of the biologists. Most papers describing computational support of genome research concentrate on mathematical details of key algorithms. However, in this paper we would like to concentrate on the design issues, tradeoffs, and consequences from the point of view of building a complex database system to support leading-edge genomic research. We introduce the topic of physical mapping, discuss the key design issues involved in our databases, and discuss the use of this data by our major tools (DNA fingerprint analysis and overlap computation, contig assembly, map integration, and database browsing.) Given the advantage of hindsight, we discuss what worked, what didn`t, and how we will evolve from here. As early pioneers in this field we hope that our experience may prove useful to others who are now beginning to design and construct similar systems.

  20. A framework for integrated, multi-scale model construction and uncertainty assessment

    NASA Astrophysics Data System (ADS)

    Schmitz, Oliver; de Kok, Jean-Luc; de Jong, Kor; Karssenberg, Derek

    2015-04-01

    The component-based software development practice promotes the construction of self-contained modules with defined input and output interfaces. In environmental modelling, we can adopt this development practice to construct more generic, reusable component models. Here, modellers need to implement a state transition function to describe a specific environmental process, and to specify the required external inputs and parameters to simulate the change of real-world processes over time. Depending on the usage of a component model, such as standalone execution or as part of an integrated model, the source of the external input needs to be specified. The required external inputs can thereby be obtained from disk by a file operation in case of a standalone execution; or inputs can be obtained from other component models, when the component model is used in an integrated model. Using different notations to specify input requirements, however, requires a modification of the state transition function per application case of a component model and therefore would reduce its generic nature. We propose the function object notation as a means to specify input sources of a component model and as a uniform syntax to express input requirements. At component initialisation, the function objects can be parametrised with different external sources. In addition to a uniform syntax, the function object notation allows modellers to specify a request-reply execution flow of the coupled models. We extended the request-reply execution approach to allow for Monte Carlo simulations, and implemented a software framework prototype in Python using the PCRaster module (http://www.pcraster.eu) for field-based modelling. We demonstrate the usage of the framework by building an exemplary integrated model by coupling components simulating land use change, hydrology and eucalyptus tree growth at different temporal discretisations to obtain the probability for bioenergy plantations in a hypothetical

  1. High-pressure open-channel on-chip electroosmotic pump for nanoflow high performance liquid chromatography.

    PubMed

    Wang, Wei; Gu, Congying; Lynch, Kyle B; Lu, Joann J; Zhang, Zhengyu; Pu, Qiaosheng; Liu, Shaorong

    2014-02-18

    Here, we construct an open-channel on-chip electroosmotic pump capable of generating pressures up to ∼170 bar and flow rates up to ∼500 nL/min, adequate for high performance liquid chromatographic (HPLC) separations. A great feature of this pump is that a number of its basic pump units can be connected in series to enhance its pumping power; the output pressure is directly proportional to the number of pump units connected. This additive nature is excellent and useful, and no other pumps can work in this fashion. We demonstrate the feasibility of using this pump to perform nanoflow HPLC separations; tryptic digests of bovine serum albumin (BSA), transferrin factor (TF), and human immunoglobulins (IgG) are utilized as exemplary samples. We also compare the performance of our electroosmotic (EO)-driven HPLC with Agilent 1200 HPLC; comparable efficiencies, resolutions, and peak capacities are obtained. Since the pump is based on electroosmosis, it has no moving parts. The common material and process also allow this pump to be integrated with other microfabricated functional components. Development of this high-pressure on-chip pump will have a profound impact on the advancement of lab-on-a-chip devices.

  2. High-pressure open-channel on-chip electroosmotic pump for nanoflow high performance liquid chromatography.

    PubMed

    Wang, Wei; Gu, Congying; Lynch, Kyle B; Lu, Joann J; Zhang, Zhengyu; Pu, Qiaosheng; Liu, Shaorong

    2014-02-18

    Here, we construct an open-channel on-chip electroosmotic pump capable of generating pressures up to ∼170 bar and flow rates up to ∼500 nL/min, adequate for high performance liquid chromatographic (HPLC) separations. A great feature of this pump is that a number of its basic pump units can be connected in series to enhance its pumping power; the output pressure is directly proportional to the number of pump units connected. This additive nature is excellent and useful, and no other pumps can work in this fashion. We demonstrate the feasibility of using this pump to perform nanoflow HPLC separations; tryptic digests of bovine serum albumin (BSA), transferrin factor (TF), and human immunoglobulins (IgG) are utilized as exemplary samples. We also compare the performance of our electroosmotic (EO)-driven HPLC with Agilent 1200 HPLC; comparable efficiencies, resolutions, and peak capacities are obtained. Since the pump is based on electroosmosis, it has no moving parts. The common material and process also allow this pump to be integrated with other microfabricated functional components. Development of this high-pressure on-chip pump will have a profound impact on the advancement of lab-on-a-chip devices. PMID:24495233

  3. Active and Engaged Citizenship: Multi-Group and Longitudinal Factorial Analysis of an Integrated Construct of Civic Engagement

    ERIC Educational Resources Information Center

    Zaff, Jonathan; Boyd, Michelle; Li, Yibing; Lerner, Jacqueline V.; Lerner, Richard M.

    2010-01-01

    Civic participation does not necessarily equate to civic engagement. However, to date, integrated measures of civic engagement that go beyond civic behaviors have not been developed. In this article, we propose an integrated construct of civic engagement, active and engaged citizenship (AEC), that includes behavioral, cognitive, and socioemotional…

  4. Analysis, design and testing of high pressure waterjet nozzles

    NASA Technical Reports Server (NTRS)

    Mazzoleni, Andre P.

    1996-01-01

    The Hydroblast Research Cell at MSFC is both a research and a processing facility. The cell is used to investigate fundamental phenomena associated with waterjets as well as to clean hardware for various NASA and contractor projects. In the area of research, investigations are made regarding the use of high pressure waterjets to strip paint, grease, adhesive and thermal spray coatings from various substrates. Current industrial methods of cleaning often use ozone depleting chemicals (ODC) such as chlorinated solvents, and high pressure waterjet cleaning has proven to be a viable alternative. Standard methods of waterjet cleaning use hand held or robotically controlled nozzles. The nozzles used can be single-stream or multijet nozzles, and the multijet nozzles may be mounted in a rotating head or arranged in a fan-type shape. We consider in this paper 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 (e.g. the formation of 'islands' of material not cleaned) and damage to the substrate from the waterjet have been observed. In addition, current stripping operations require the nozzle to be placed at a standoff distance of approximately 2 inches in order to achieve adequate performance. This close proximity of the nozzle to the target to be cleaned poses risks to the nozzle and the target in the event of robot error or the striking of unanticipated extrusions on the target surface as the nozzle sweeps past. Two key motivations of this research are to eliminate the formation of 'coating islands' and to increase the allowable standoff distance of the nozzle.

  5. Rapid prototyping polymers for microfluidic devices and high pressure injections.

    PubMed

    Sollier, Elodie; Murray, Coleman; Maoddi, Pietro; Di Carlo, Dino

    2011-11-21

    Multiple methods of fabrication exist for microfluidic devices, with different advantages depending on the end goal of industrial mass production or rapid prototyping for the research laboratory. Polydimethylsiloxane (PDMS) has been the mainstay for rapid prototyping in the academic microfluidics community, because of its low cost, robustness and straightforward fabrication, which are particularly advantageous in the exploratory stages of research. However, despite its many advantages and its broad use in academic laboratories, its low elastic modulus becomes a significant issue for high pressure operation as it leads to a large alteration of channel geometry. Among other consequences, such deformation makes it difficult to accurately predict the flow rates in complex microfluidic networks, change flow speed quickly for applications in stop-flow lithography, or to have predictable inertial focusing positions for cytometry applications where an accurate alignment of the optical system is critical. Recently, other polymers have been identified as complementary to PDMS, with similar fabrication procedures being characteristic of rapid prototyping but with higher rigidity and better resistance to solvents; Thermoset Polyester (TPE), Polyurethane Methacrylate (PUMA) and Norland Adhesive 81 (NOA81). In this review, we assess these different polymer alternatives to PDMS for rapid prototyping, especially in view of high pressure injections with the specific example of inertial flow conditions. These materials are compared to PDMS, for which magnitudes of deformation and dynamic characteristics are also characterized. We provide a complete and systematic analysis of these materials with side-by-side experiments conducted in our lab that also evaluate other properties, such as biocompatibility, solvent compatibility, and ease of fabrication. We emphasize that these polymer alternatives, TPE, PUMA and NOA, have some considerable strengths for rapid prototyping when bond

  6. Development of a high pressure micromechanical force apparatus.

    PubMed

    Lee, Bo Ram; Koh, Carolyn A; Sum, Amadeu K

    2014-09-01

    The formation of gas hydrates and subsequent plugging of pipelines are risks that need to be well understood during the production and transportation of oil and gas in subsea flowlines. These flowlines are typically operating at low temperature and high pressure conditions, which are well within the hydrate formation stability region. One of the key processes for hydrate plugs to develop is the agglomeration of hydrates. To obtain a more comprehensive understanding on this problem, we have developed a high-pressure micromechanical force (MMF) apparatus to directly measure cohesive forces between gas hydrate particles. The MMF system is housed in a stainless steel vessel that can withstand pressures of up to 10 MPa, thereby facilitating studies on a broad spectrum of hydrate formers and conditions. The MMF apparatus comprises of two cantilever fibers: one is stationary and another is manipulated via a nano-manipulator. Water droplets (~500 μm in diameter) are placed at the end of the each cantilever fiber so that they can be converted to hydrate. In order to demonstrate the stability of this apparatus, CH4/C2H6 (74.7 mol. %/25.3 mol. %) mixed hydrates were prepared at 2 MPa and -5 °C and annealed at 0 °C for 15 h. Subsequently, the hydrate particle cohesive force was measured at 2 °C. Compared with the cohesive force of cyclopentane hydrates in cyclopentane liquid (~4.3 mN/m), the average cohesive force of gas hydrates was about 10 times higher, ~43 mN/m. Studies using this new high pressure MMF apparatus will be central to better understand the agglomeration of hydrates in multiphase flowlines. PMID:25273785

  7. Development of a high pressure micromechanical force apparatus

    NASA Astrophysics Data System (ADS)

    Lee, Bo Ram; Koh, Carolyn A.; Sum, Amadeu K.

    2014-09-01

    The formation of gas hydrates and subsequent plugging of pipelines are risks that need to be well understood during the production and transportation of oil and gas in subsea flowlines. These flowlines are typically operating at low temperature and high pressure conditions, which are well within the hydrate formation stability region. One of the key processes for hydrate plugs to develop is the agglomeration of hydrates. To obtain a more comprehensive understanding on this problem, we have developed a high-pressure micromechanical force (MMF) apparatus to directly measure cohesive forces between gas hydrate particles. The MMF system is housed in a stainless steel vessel that can withstand pressures of up to 10 MPa, thereby facilitating studies on a broad spectrum of hydrate formers and conditions. The MMF apparatus comprises of two cantilever fibers: one is stationary and another is manipulated via a nano-manipulator. Water droplets (˜500 μm in diameter) are placed at the end of the each cantilever fiber so that they can be converted to hydrate. In order to demonstrate the stability of this apparatus, CH4/C2H6 (74.7 mol. %/25.3 mol. %) mixed hydrates were prepared at 2 MPa and -5 °C and annealed at 0 °C for 15 h. Subsequently, the hydrate particle cohesive force was measured at 2 °C. Compared with the cohesive force of cyclopentane hydrates in cyclopentane liquid (˜4.3 mN/m), the average cohesive force of gas hydrates was about 10 times higher, ˜43 mN/m. Studies using this new high pressure MMF apparatus will be central to better understand the agglomeration of hydrates in multiphase flowlines.

  8. Pulsed particle beam high pressure/shock research in India

    NASA Astrophysics Data System (ADS)

    Shyam, Anurag; Shukla, Rohit

    2012-07-01

    We have two major facilities for particle beam driven shock wave/high pressure generation. One being AMBA and the other being 1.2MJ capacitor bank RUDRA. Apparatus for Mega-Ampere Beam Application which is known as AMBA is now with India and the experiments are being planned from the facility for the shock wave and high pressure studies using the AMBA for intense light-ion beam generation and then bombarding them on a flyer target. To enhance the AMBA machine to double the output current is also under consideration. AMBA is a pulsed power source which delivers 50kJ of energy in 50ns with 1.7 MV minimum peak voltages maintained as an average of various shots in the case of positive polarity output in a suitable ion-diode. The output impedance of the AMBA machine is 2.25ohms and hence it is a 1.5 TW machine. With peak power densities up to ~1TW/cm2, and proton ranges in condensed matter of 10 to 20 μm, specific energy depositions of several MJ/g at deposition rates of the order of 100 TW/g are obtained. This way the AMBA system can be used as a shock wave generator in both, direct drive and impact experiments. We also have 1.2MJ capacitor bank capable of delivering 3.6MA peak current at 44kV charging voltage to be used for Magnetized target fusion based on z-pinch regime of target material compression. The related diagnostics for the system, which are currently being developed, are mentioned in the present paper. Both the systems and the high pressure experiments to be conducted are described in the paper. A brief detail on the plasma focus devices, which also produce shock waves using particle beams, is also presented in the paper.

  9. System Study: High-Pressure Core Spray 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at eight U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  10. System Study: High-Pressure Coolant Injection 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  11. System Study: High-Pressure Safety Injection 1998-2014

    SciTech Connect

    Schroeder, John Alton

    2015-12-01

    This report presents an unreliability evaluation of the high-pressure safety injection system (HPSI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPSI results.

  12. Availability of high-pressure safety injection system in PWRs

    SciTech Connect

    Sun, Y.H.; Fresco, A.; Papazoglou, I.A.

    1983-01-01

    This paper presents an evaluation of the impact of typical variations in configuration of the design of the High Pressure Injection (HPSI) System on system unavailability. The HPSI systems in seventeen nuclear power plants were reviewed for variations in design, systems operation, testing and maintenance policies, and possible sources for common cause failures. The power plants reviewed include PWRs with two, three and four loop Reactor Coolant Systems and cover all three PWR vendors. As a result of this effort, the following five representative configurations (along with some variations) were identified and their unavailability to initiate injection was estimated.

  13. Internal hysteresis experienced on a high pressure syn gas compressor

    NASA Technical Reports Server (NTRS)

    Zeidan, F. Y.

    1984-01-01

    A vibration instability phenomenon experienced in operating high pressure syn gas centrifugal compressors in two ammonia plants is described. The compressors were monitored by orbit and spectrum analysis for changes from baseline readings. It is found that internal hysteresis was the major destabilizing force; however, the problem was further complicated by seal lockup at the suction end of the compressor. A coupling lockup problem and a coupling fit problem, which frettage of the shaft, are also considered as contributors to the self excited vibrations.

  14. Energy efficient engine high-pressure turbine detailed design report

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  15. LOX vaporization in high-pressure, hydrogen-rich gas

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Jeng, San-Mou

    1990-01-01

    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.

  16. Design and testing of high-pressure railguns and projectiles

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Attention is given to the results of high-pressure tests involving four railgun designs and four projectile types. Explosive magnetic-flux compression generators were employed to power the railguns. On the basis of the experimental data, it appears that the high-strength projectiles have lower resistance to acceleration than low-strength projectiles, which expand against the bore during acceleration. While confined in the bore, polycarbonate projectiles can be subjected to pressures as high as 1.3 GPa without shattering. In multishot railguns, it is important to prevent an accumulation of sooty material from the plasma armature in railgun seams.

  17. Investigation of Acrylic Acid at High Pressure Using Neutron Diffraction

    PubMed Central

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalized using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new phase at ∼0.8 GPa and remains molecular to 7.2 GPa before polymerizing on decompression to ambient pressure. The resulting product is analyzed via Raman and FT-IR spectroscopy and differential scanning calorimetry and found to possess a different molecular structure compared with polymers produced via traditional routes. PMID:24650085

  18. Transition in fluctuation behaviour of normal liquids under high pressures

    NASA Astrophysics Data System (ADS)

    Postnikov, Eugene B.; Chora&zcedildot; ewski, Mirosław

    2016-05-01

    We explore the behaviour of the inverse reduced density fluctuations and the isobaric expansion coefficient using α , ω-dibromoalkanes as an example. Two different states are revealed far from the critical point: the region of exponentially decaying fluctuations near the coexistence curve and the state with longer correlations under sufficiently high pressures. The crossing of the isotherms of the isobaric expansion coefficient occurs within the PVT range of the mentioned transition. We discuss the interplay of this crossing with the changes in molecular packing structure connected with the analysed function of the density, which represents inverse reduced volume fluctuations.

  19. Study of mechanical properties of nanomaterials under high pressure

    NASA Astrophysics Data System (ADS)

    Sharma, Jyoti; Kaur, Namrat; Srivastava, A. K.

    2015-08-01

    In the present work, the study of physical properties and behaviour of nanomaterials i.e. n-γ- Al2O3and n-Si3C4 under high pressure is done. For this purpose Murnaghan equation of state is used. The applicability of Murnaghan equation of state is fully tested by calculating mechanical properties of nano materials i.e. volume compression (V/Vo), bulk modulus (KT) and relative isothermal compression coefficient (α(P)/α0) at different pressures. The present calculated values of compression curve for the cited nanomaterials come out to be in reasonable good agreement with the available experimental data.

  20. System Study: High-Pressure Safety Injection 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure safety injection system (HPSI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPSI results.

  1. High pressure and high temperature behaviour of ZnO

    SciTech Connect

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

    2014-04-24

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

  2. Design of high pressure vessels with radial crossbores

    NASA Astrophysics Data System (ADS)

    Chaaban, A.; Burns, D. J.

    1986-05-01

    Three dimensional finite element methods have been used to investigate the stress fields around radial crossbores in cylindrical high pressure vessels. Elastic analyses have been used to show the effects of crossbore and main cylinder diameter ratios on stress concentration factors. Elastic-plastic analyses have been used to study residual stress fields in crossbores overstained during autofrettage, proof-testing or the first operational cycle. The very beneficial influence of these residual stresses on fatigue performance is discussed. Other factors influencing fatigue life are briefly reviewed.

  3. High-pressure cryogenic valves for the Vulcain rocket motor

    NASA Astrophysics Data System (ADS)

    Garceau, P.; Meyer, F.

    The high-pressure valve developed to control the flow of liquid oxygen or hydrogen into the gas generator of the ESA Vulcain rocket motor is described. The spherical ball-seal design employed provides high reliability over a service lifetime of 5000 on-off actuations at temperatures 20-350 K and pressures up to 200 bar. Leakage is limited to a few cu cm/sec of hydrogen at 20 K. The steps in the development process, from the definition of the valve specifications to the fabrication and testing phase are reviewed, and the final design is shown in drawings, diagrams, and photographs.

  4. Surface roughening of superalloys by high pressure pure waterjet

    SciTech Connect

    Taylor, T.A.

    1995-12-31

    A high pressure waterjet has been used to study the surface roughening of superalloys as preparation for thermal spraying. Designed experiments for Mar-M 509 and Rene 80 were carried out for the effects of jet pressure and mass of water delivered per unit area. Comparisons were made of several superalloys in terms of erosion, surface roughness and topology. The mechanism of jet erosion of Rene 80 was studied in relation to its metallurgical microstructure. An MCrAlY coating by shrouded plasma spray was made over a waterjet prepared surface with excellent bonding and having an ideally clean interface.

  5. System Study: High-Pressure Core Spray 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at 8 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  6. High pressure far infrared spectroscopy of ionic solids

    NASA Technical Reports Server (NTRS)

    Lowndes, R. P.

    1974-01-01

    A high-pressure far-infrared cell operating at up to truly hydrostatic pressures of 8 kbar is described and used to determine the anharmonic self-energies associated with the transverse optic modes of ionic solids in which q approximately equals zero. The cell allows far-infrared studies in the spectral range below 120 reciprocal cm. The transverse optic modes were investigated to determine their mode Gruneisen constants and the pressure dependence of their inverse lifetimes in RbI, CsI, and TlCl.

  7. Piston cylinder cell for high pressure ultrasonic pulse echo measurements.

    PubMed

    Kepa, M W; Ridley, C J; Kamenev, K V; Huxley, A D

    2016-08-01

    Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe2. PMID:27587156

  8. High pressure melting curves of silver, gold and copper

    SciTech Connect

    Hieu, Ho Khac

    2013-11-15

    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.

  9. High Pressure Regenerative Turbine Engine: 21st Century Propulsion

    NASA Technical Reports Server (NTRS)

    Lear, W. E.; Laganelli, A. L.; Senick, Paul (Technical Monitor)

    2001-01-01

    A novel semi-closed cycle gas turbine engine was demonstrated and was found to meet the program goals. The proof-of-principle test of the High Pressure Regenerative Turbine Engine produced data that agreed well with models, enabling more confidence in designing future prototypes based on this concept. Emission levels were significantly reduced as predicted as a natural attribute of this power cycle. Engine testing over a portion of the operating range allowed verification of predicted power increases compared to the baseline.

  10. High pressure structural studies on nanophase praseodymium oxide

    NASA Astrophysics Data System (ADS)

    Saranya, L.; Chandra Shekar, N. V.; Amirthapandian, S.; Hussain, Shamima; Arulraj, A.; Sahu, P. Ch.

    2014-09-01

    The phase stability of nanocrystalline Pr2O3 has been investigated under pressure by in-situ high pressure X-ray diffraction using Mao-Bell type diamond anvil cell. The ambient structure and phase of the praseodymium oxide have been resolved unambiguously using x-ray diffraction, SEM and TEM techniques. Under the action of pressure the cubic phase of the system is retained up to 15 GPa. This is unusual as other isostructural rare earth oxides show structural transformations even at lower pressures. From the best fit to the P-V data with the Murnaghan equation of state yields a bulk modulus of 171 GPa.

  11. CF6 jet engine performance improvement: High pressure turbine roundness

    NASA Technical Reports Server (NTRS)

    Howard, W. D.; Fasching, W. A.

    1982-01-01

    An improved high pressure turbine stator reducing fuel consumption in current CF6-50 turbofan engines was developed. The feasibility of the roundness and clearance response improvements was demonstrated. Application of these improvements will result in a cruise SFC reduction of 0.22 percent for new engines. For high time engines, the improved roundness and response characteristics results in an 0.5 percent reduction in cruise SFC. A basic life capability of the improved HP turbine stator in over 800 simulated flight cycles without any sign of significant distress is shown.

  12. High-pressure /sup 3/He gas scintillation neutron spectrometer

    SciTech Connect

    Derzon, M.S.; Slaughter, D.R.; Prussin, S.G.

    1985-10-01

    A high-pressure, /sup 3/He-Xe gas scintillation spectrometer has been developed for neutron spectroscopy on D-D fusion plasmas. The spectrometer exhibits an energy resolution of (121 +- 20 keV) keV (FWHM) at 2.5 MeV and an efficiency of (1.9 +- 0.4) x 10/sup -3/ (n/cm/sup 2/)/sup -1/. The contribution to the resolution (FWHM) from counting statistics is only (22 +- 3 keV) and the remainder is due predominantly to the variation of light collection efficiency with location of neutron events within the active volume of the detector.

  13. α-Glycine under high pressures: a Raman scattering study

    NASA Astrophysics Data System (ADS)

    Murli, Chitra; Sharma, Surinder M.; Karmakar, S.; Sikka, S. K.

    2003-11-01

    High-pressure behaviour of α-glycine has been investigated up to ∼23 GPa using Raman scattering technique. The experimental results show slope change in the CO 2 bending, NH 3 torsional and NH 3 rocking modes around 3 GPa and are interpreted in terms of change in the nature of an N-H⋯O-C intra-layer hydrogen bond at this pressure. Several other spectral features seem to arise from pressure-induced variations in the inter-molecular coupling.

  14. Pasteurization of food by hydrostatic high pressure: chemical aspects.

    PubMed

    Tauscher, B

    1995-01-01

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

  15. Cf6 jet engine performance improvement: high pressure turbine roundness

    SciTech Connect

    Howard, W.D.; Fasching, W.A.

    1982-01-01

    An improved high pressure turbine stator reducing fuel consumption in current CF6-50 turbofan engines was developed. The feasibility of the roundness and clearance response improvements was demonstrated. Application of these improvements will result in a cruise SFC reduction of 0.22 percent for new engines. For high time engines, the improved roundness and response characteristics results in an 0.5 percent reduction in cruise SFC. A basic life capability of the improved HP turbine stator in over 800 simulated flight cycles without any sign of significant distress is shown.

  16. High pressure phase transformation in iron under fast compression

    SciTech Connect

    Bastea, M; Bastea, S; Becker, R

    2009-07-07

    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.

  17. System Study: High-Pressure Coolant Injection 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 25 U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  18. System Study: High-Pressure Core Spray 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-01-31

    This report presents an unreliability evaluation of the high-pressure core spray (HPCS) at eight U.S. commercial boiling water reactors. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCS results.

  19. System Study: High-Pressure Safety Injection 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-02-01

    This report presents an unreliability evaluation of the high-pressure safety injection system (HPSI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPSI results.

  20. High Pressure X-Ray Diffraction Studies of Nanocrystalline Materials

    NASA Technical Reports Server (NTRS)

    Palosz, B.; Stel'makh, S.; Grzanka, E.; Gierlotka, S.; Palosz, W.

    2004-01-01

    Experimental evidence obtained for a variety of nanocrystalline materials suggest that the crystallographic structure of a very small size particle deviates from that in the bulk crystals. In this paper we show the effect of the surface of nanocrystals on their structure by the analysis of generation and distribution of macro- and micro-strains at high pressures and their dependence on the grain size in nanocrystalline powders of Sic. We studied the structure of Sic nanocrystals by in-situ high-pressure powder diffraction technique using synchrotron and neutron sources and hydrostatic or isostatic pressure conditions. The diffraction measurements were done in HASYLAB at DESY using a Diamond Anvil Cell (DAC) in the energy dispersive geometry in the diffraction vector range up to 3.5 - 4/A and under pressures up to 50 GPa at room temperature. In-situ high pressure neutron diffraction measurements were done at LANSCE in Los Alamos National Laboratory using the HIPD and HIPPO diffractometers with the Paris-Edinburgh and TAP-98 cells, respectively, in the diffraction vector range up to 26 Examination of the response of the material to external stresses requires nonstandard methodology of the materials characterization and description. Although every diffraction pattern contains a complete information on macro- and micro-strains, a high pressure experiment can reveal only those factors which contribute to the characteristic diffraction patterns of the crystalline phases present in the sample. The elastic properties of powders with the grain size from several nm to micrometers were examined using three methodologies: (l), the analysis of positions and widths of individual Bragg reflections (used for calculating macro- and micro-strains generated during densification) [I], (2). the analysis of the dependence of the experimental apparent lattice parameter, alp, on the diffraction vector Q [2], and (3), the atomic Pair Distribution Function (PDF) technique [3]. The results

  1. Effect of high pressure on mesophilic lactic fermentation streptococci

    NASA Astrophysics Data System (ADS)

    Reps, A.; Kuźmicka, M.; Wiśniewska, K.

    2008-07-01

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

  2. System Study: High-Pressure Coolant Injection 1998-2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    This report presents an unreliability evaluation of the high-pressure coolant injection system (HPCI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2012 for selected components were obtained from the Equipment Performance and Information Exchange (EPIX). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPCI results.

  3. Piston cylinder cell for high pressure ultrasonic pulse echo measurements

    NASA Astrophysics Data System (ADS)

    Kepa, M. W.; Ridley, C. J.; Kamenev, K. V.; Huxley, A. D.

    2016-08-01

    Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe2.

  4. High Pressure Micro-Slot Hollow Cathode Discharge

    NASA Astrophysics Data System (ADS)

    Wang, Xinbing; Zhou, Lina; Yao, Xilin

    2005-12-01

    A direct current glow discharge source structure operating at high pressure based on the micro-slot hollow cathode is presented in this article. A 100 μm width slot cathode was fabricated of copper, and a stable DC glow discharge with an area of 0.5 mm2 was produced in noble gases (He, Ne) and air over a wide pressure range (kPa-10 kPa). The current-voltage characteristics and the near UV radiation emission of the discharge were studied.

  5. New findings in static high-pressure science

    SciTech Connect

    Hemley, R.J.; Mao, H.-k.

    2010-11-16

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

  6. Amorphous diamond: A high-pressure superhard carbon allotrope

    SciTech Connect

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

    2011-01-01

    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 >70 GPa has never been observed in any material besides diamond, indicating the high hardness of this high-pressure carbon allotrope.

  7. Superconductivity in the metallic elements at high pressures

    NASA Astrophysics Data System (ADS)

    Hamlin, J. J.

    2015-07-01

    Although the highest superconducting critical temperature, Tc , found in an elemental solid at ambient pressure is 9.2 K (niobium), under the application of ultra-high pressures, several elements exhibit Tc values near or above 20 K. This review includes a survey of the occurrence and understanding of pressure-induced superconductivity in the subset of elements that are metallic at ambient pressure. A particular focus is directed towards those elements that display the highest superconducting critical temperatures or exhibit substantial increases in Tc with pressure. A separate article in this issue by Shimizu will cover pressure-induced superconductivity in elements that are insulating at ambient pressure.

  8. Poisson's Ratio and the Densification of Glass under High Pressure

    SciTech Connect

    Rouxel, T.; Ji, H.; Hammouda, T.; Moreac, A.

    2008-06-06

    Because of a relatively low atomic packing density, (C{sub g}) glasses experience significant densification under high hydrostatic pressure. Poisson's ratio ({nu}) is correlated to C{sub g} and typically varies from 0.15 for glasses with low C{sub g} such as amorphous silica to 0.38 for close-packed atomic networks such as in bulk metallic glasses. Pressure experiments were conducted up to 25 GPa at 293 K on silica, soda-lime-silica, chalcogenide, and bulk metallic glasses. We show from these high-pressure data that there is a direct correlation between {nu} and the maximum post-decompression density change.

  9. The sound velocity measurement in diacylglycerol oil under high pressure

    NASA Astrophysics Data System (ADS)

    Rostocki, A. J.; Malanowski, A.; Tarakowski, R.; Szlachta, K.; Kiełczyński, P.; Szalewski, M.; Balcerzak, A.; Ptasznik, S.

    2013-03-01

    In this article, the influence of high pressure on sound velocity at 293 K has been presented. The investigated diacylglycerol oil (DAG - [D82T18]AG) was composed of 82% DAGs and 18% triacylglycerols. The variation of sound velocity with hydrostatic pressure for DAG was evaluated up to 400 MPa. The phase transformation in DAG has been observed as a discontinuity of the dependence of sound velocity on pressure. The sound velocity during the phase transition has shown distinct increment. Also the volume changes have been measured. It has shown the rapid drop of the volume at the phase transformation pressure due to the possible crystallization of DAG oil.

  10. LHDAC setup for high temperature and high pressure studies

    SciTech Connect

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

    2014-04-24

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

  11. Journey to the Center of the Earth: Exploring High Pressure

    SciTech Connect

    Mao, Wendy

    2009-09-29

    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.

  12. Correlation of theory and experiment for high-pressure hydrogen

    NASA Technical Reports Server (NTRS)

    Hoover, W. G.; Ross, M.; Bender, C. F.; Rogers, F. J.; Olness, R. J.

    1972-01-01

    Recent quantum calculations and high-pressure experiments both agree on the magnitude of the forces with which hydrogen molecules interact. The calculated forces have to be determined in two steps: the repulsion is determined by Hartree-Fock calculations while the attraction is deduced semiempirically. The experimental forces are inferred from recent data on hydrogen shockcompressed to 214 kbar. The agreement indicates the usefulness of a pair-potential description of dense hydrogen and suggests, using potentials consistent with both theory and experiment, that pressures of at least 1.7 Mbar will be required to make metallic hydrogen. The expected lifetime of the metal at atmospheric pressure is very short.

  13. Structural Behaviour of Uranium Sulfide under High Pressure

    SciTech Connect

    Shareef, F.; Singh, S.; Gour, A.; Bhardwaj, P.; Sarwan, M.; Dubey, R.; Singh, R. K.

    2011-07-15

    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.

  14. Miniature cryogenic diamond-anvil high-pressure cell

    NASA Astrophysics Data System (ADS)

    Dunstan, D. J.; Scherrer, W.

    1988-04-01

    A novel diamond-anvil cell is described which measures 19-mm diameter by 28 mm long to fit the Oxford Instruments CF 1204 flow cryostat, while providing full axial and tilt adjustment of the diamonds. The drive mechanism provides for pressure changes while the cell is in the cryostat. The small dimensions are achieved because the drive force is not transmitted through the tilt mechanism, and by the Bowden cable technique used for the drive mechanism. This cell makes high pressure a readily portable technique that can be brought to many already existing experimental apparatuses.

  15. Serum theophylline analysis by high-pressure liquid chromatography.

    PubMed

    Evenson, M A; Warren, B L

    1976-06-01

    We have developed and evaluated a rapid, high-pressure liquid-chromatographic method for theophylline in serum. Only 0.2 ml of serum is required for each determination, and the sensitivity of this method is 0.5 mg/liter. This method, involving liquid extraction and silica adsorption chromatography, provides adequate selectivity, accuracy, and precision for routine or research applications. Little sample preparation is required before chromatography. We found no endogenous or exogenous interferences. Use of beta-hydroxypropyl theophylline as the internal standard provides reproducible results for this micro-scale method.

  16. High-pressure structural study of MnF2

    DOE PAGES

    Stavrou, Elissaios; Yao, Yansun; Goncharov, Alexander F.; Konopkova, Zuzana; Raptis, Constantine

    2015-02-01

    In this study, manganese fluoride (MnF2) with the tetragonal rutile-type structure has been studied using a synchrotron angle-dispersive powder x-ray diffraction and Raman spectroscopy in a diamond anvil cell up to 60 GPa at room temperature combined with first-principles density functional calculations. The experimental data reveal two pressure-induced structural phase transitions with the following sequence: rutile → SrI2 type (3 GPa)→ α–PbCl2 type (13 GPa). Complete structural information, including interatomic distances, has been determined in the case of MnF2 including the exact structure of the debated first high-pressure phase. First-principles density functional calculations confirm this phase transition sequence, and themore » two calculated transition pressures are in excellent agreement with the experiment. Lattice dynamics calculations also reproduce the experimental Raman spectra measured for the ambient and high-pressure phases. The results are discussed in line with the possible practical use of rutile-type fluorides in general and specifically MnF2 as a model compound to reveal the HP structural behavior of rutile-type SiO2 (Stishovite).« less

  17. Processing Raman Spectra of High-Pressure Hydrogen Flames

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet; Kojima, Jun

    2006-01-01

    The Raman Code automates the analysis of laser-Raman-spectroscopy data for diagnosis of combustion at high pressure. On the basis of the theory of molecular spectroscopy, the software calculates the rovibrational and pure rotational Raman spectra of H2, O2, N2, and H2O in hydrogen/air flames at given temperatures and pressures. Given a set of Raman spectral data from measurements on a given flame and results from the aforementioned calculations, the software calculates the thermodynamic temperature and number densities of the aforementioned species. The software accounts for collisional spectral-line-broadening effects at pressures up to 60 bar (6 MPa). The line-broadening effects increase with pressure and thereby complicate the analysis. The software also corrects for spectral interference ("cross-talk") among the various chemical species. In the absence of such correction, the cross-talk is a significant source of error in temperatures and number densities. This is the first known comprehensive computer code that, when used in conjunction with a spectral calibration database, can process Raman-scattering spectral data from high-pressure hydrogen/air flames to obtain temperatures accurate to within 10 K and chemical-species number densities accurate to within 2 percent.

  18. High-pressure structural study of MnF2

    NASA Astrophysics Data System (ADS)

    Stavrou, Elissaios; Yao, Yansun; Goncharov, Alexander F.; Konôpková, Zuzana; Raptis, Constantine

    2016-02-01

    Manganese fluoride (MnF2) with the tetragonal rutile-type structure has been studied using a synchrotron angle-dispersive powder x-ray diffraction and Raman spectroscopy in a diamond anvil cell up to 60 GPa at room temperature combined with first-principles density functional calculations. The experimental data reveal two pressure-induced structural phase transitions with the following sequence: rutile → SrI2 type (3 GPa)→ α -PbCl2 type (13 GPa). Complete structural information, including interatomic distances, has been determined in the case of MnF2 including the exact structure of the debated first high-pressure phase. First-principles density functional calculations confirm this phase transition sequence, and the two calculated transition pressures are in excellent agreement with the experiment. Lattice dynamics calculations also reproduce the experimental Raman spectra measured for the ambient and high-pressure phases. The results are discussed in line with the possible practical use of rutile-type fluorides in general and specifically MnF2 as a model compound to reveal the HP structural behavior of rutile-type SiO2 (Stishovite).

  19. Thermal conductance of metal-diamond interfaces at high pressure.

    PubMed

    Hohensee, Gregory T; Wilson, R B; Cahill, David G

    2015-01-01

    The thermal conductance of interfaces between metals and diamond, which has a comparatively high Debye temperature, is often greater than can be accounted for by two-phonon processes. The high pressures achievable in a diamond anvil cell (DAC) can significantly extend the metal phonon density of states to higher frequencies, and can also suppress extrinsic effects by greatly stiffening interface bonding. Here we report time-domain thermoreflectance measurements of metal-diamond interface thermal conductance up to 50 GPa in the DAC for Pb, Au0.95Pd0.05, Pt and Al films deposited on type 1A natural [100] and type 2A synthetic [110] diamond anvils. In all cases, the thermal conductances increase weakly or saturate to similar values at high pressure. Our results suggest that anharmonic conductance at metal-diamond interfaces is controlled by partial transmission processes, where a diamond phonon that inelastically scatters at the interface absorbs or emits a metal phonon. PMID:25744853

  20. Optical calibration of pressure sensors for high pressures and temperatures

    SciTech Connect

    Goncharov, A F; Gregoryanz, E; Zaug, J M; Crowhurst, J C

    2004-10-04

    We present the results of Raman scattering measurements of diamond ({sup 12}C) and of cubic boron nitride (cBN), and fluorescence measurements of ruby, Sm:YAG, and SrB{sub 4}O{sub 7}:Sm{sup 2+} in the diamond anvil cell (DAC) at high pressures and temperatures. These measurements were accompanied by synchrotron x-ray diffraction measurements on gold. We have extended the room-temperature calibration of Sm:YAG in a quasihydrostatic regime up to 100 GPa. The ruby scale is shown to systematically underestimate pressure at high pressures and temperatures compared with all other sensors. On this basis, we propose a new high-temperature ruby pressure scale that should be valid to at least 100 GPa and 850 K. Historically, the accurate determination of pressure at high temperature and ultrahigh pressure has been extremely difficult. In fact, the lack of a general pressure scale nullifies, to a significant extent, the great innovations that have been made in recent years in DAC experimental techniques [1]. Now, more than ever a scale is required whose accuracy is comparable with that of the experimental data. Since pressure in the DAC is dependent on temperature (due to thermal pressure and also to changes in the properties of the materials that constitute the DAC) such a scale requires quantitative, and separate measurements of pressure and temperature.