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Sample records for high-pressure xenon tpc

  1. AXEL-a high pressure xenon gas TPC for neutrinoless double beta decay search

    NASA Astrophysics Data System (ADS)

    Nakamura, Kiseki; Ichikawa, Atsuko K.; Nakaya, Tsuyoshi; Minamino, Akihiro; Ban, Sei; Yanagita, Saori; Tanaka, Shunsuke; Hirose, Masanori; Sekiya, Hiroyuki; Ueshima, Kota; Miuchi, Kentaro

    2017-02-01

    To search for neutrinoless double beta decay, we have started developing a high pressure xenon gas time projection chamber as the AXEL (A Xenon ElectroLuminescence detector) project since 2014. We proposed a new scheme to measure energy deposit using electroluminescence lights to achieve high energy resolution, large mass and strong background rejection power. Important performances of compositions of our new readout scheme are shown: electric field simulation, VUV sensitivity of MPPC in high pressure gaseous xenon, response of MPPC for large amount of photons. To demonstrate as a whole system, we constructed a small prototype detector using 64 MPPCs filled with 4 bar xenon gas. Result of measurement with a 57Co gamma-ray source are shown.

  2. Improved background rejection in neutrinoless double beta decay experiments using a magnetic field in a high pressure xenon TPC

    NASA Astrophysics Data System (ADS)

    Renner, J.; Cervera, A.; Hernando, J. A.; Imzaylov, A.; Monrabal, F.; Muñoz, J.; Nygren, D.; Gomez-Cadenas, J. J.

    2015-12-01

    We demonstrate that the application of an external magnetic field could lead to an improved background rejection in neutrinoless double-beta (0νββ) decay experiments using a high-pressure xenon (HPXe) TPC. HPXe chambers are capable of imaging electron tracks, a feature that enhances the separation between signal events (the two electrons emitted in the 0νββ decay of 136Xe) and background events, arising chiefly from single electrons of kinetic energy compatible with the end-point of the 0νββ decay (0Qββ). Applying an external magnetic field of sufficiently high intensity (in the range of 0.5-1 Tesla for operating pressures in the range of 5-15 atmospheres) causes the electrons to produce helical tracks. Assuming the tracks can be properly reconstructed, the sign of the curvature can be determined at several points along these tracks, and such information can be used to separate signal (0νββ) events containing two electrons producing a track with two different directions of curvature from background (single-electron) events producing a track that should spiral in a single direction. Due to electron multiple scattering, this strategy is not perfectly efficient on an event-by-event basis, but a statistical estimator can be constructed which can be used to reject background events by one order of magnitude at a moderate cost (about 30%) in signal efficiency. Combining this estimator with the excellent energy resolution and topological signature identification characteristic of the HPXe TPC, it is possible to reach a background rate of less than one count per ton-year of exposure. Such a low background rate is an essential feature of the next generation of 0νββ experiments, aiming to fully explore the inverse hierarchy of neutrino masses.

  3. First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment

    DOE PAGES

    Ferrario, P.

    2016-01-19

    The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure 136Xe gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qββ. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of 22Na 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the 228Th decay chain were used tomore » represent the background and the signal in a double beta decay. Furthermore, these data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 ± 1.4 (stat.)%, while maintaining an efficiency of 66.7 ± 1% for signal events.« less

  4. First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment

    SciTech Connect

    Ferrario, P.

    2016-01-19

    The NEXT experiment aims to observe the neutrinoless double beta decay of xenon in a high-pressure 136Xe gas TPC using electroluminescence (EL) to amplify the signal from ionization. One of the main advantages of this technology is the possibility to reconstruct the topology of events with energies close to Qββ. This paper presents the first demonstration that the topology provides extra handles to reject background events using data obtained with the NEXT-DEMO prototype. Single electrons resulting from the interactions of 22Na 1275 keV gammas and electron-positron pairs produced by conversions of gammas from the 228Th decay chain were used to represent the background and the signal in a double beta decay. Furthermore, these data were used to develop algorithms for the reconstruction of tracks and the identification of the energy deposited at the end-points, providing an extra background rejection factor of 24.3 ± 1.4 (stat.)%, while maintaining an efficiency of 66.7 ± 1% for signal events.

  5. High-pressure Xenon Gas Electroluminescent TPC Concept for Simultaneous Searches for Neutrino-less Double Beta Decay & WIMP Dark Matter

    NASA Astrophysics Data System (ADS)

    Nygren, David

    2013-04-01

    Xenon is an especially attractive candidate for both direct WIMP and 0- decay searches. Although the current trend has exploited the liquid phase, gas phase xenon offers some remarkable performance advantages for energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now beginning construction in the Canfranc Underground Laboratory, Spain, will operate at 12 bars with 100 kg of ^136Xe for the 0- decay search. I will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay 2457.83 keV Q-value, as well as rejection of -rays by topology. However, sensitivity goals for WIMP dark matter and 0- decay searches indicate the need for ton-scale active masses; NEXT-100 provides the springboard to reach this scale with xenon gas. I describe a scenario for performing both searches in a single high-pressure ton-scale xenon gas detector, without significant compromise to either. In addition, -- even in a single, ton-scale, high-pressure xenon gas TPC, an intrinsic sensitivity to the nuclear recoil direction may exist -- plausibly offering an advance of more than two orders of magnitude relative to current low-pressure TPC concepts. I argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible, at acceptable cost, within the time frame of interest, and deserves our collective attention.

  6. 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.

  7. 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.

  8. Stability of xenon oxides at high pressures.

    PubMed

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

    2013-01-01

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

  9. Structures of xenon oxides at high pressures

    NASA Astrophysics Data System (ADS)

    Worth, Nicholas; Pickard, Chris; Needs, Richard; Dewaele, Agnes; Loubeyre, Paul; Mezouar, Mohamed

    2014-03-01

    For many years, it was believed that noble gases such as xenon were entirely inert. It was only in 1962 that Bartlett first synthesized a compound of xenon. Since then, a number of other xenon compounds, including oxides, have been synthesized. Xenon oxides are unstable under ambient conditions but have been predicted to stabilize under high pressure. Here we present the results of a combined theoretical and experimental study of xenon oxides at pressures of 80-100 GPa. We have synthesized new xenon oxides at these pressures and they have been characterized with X-ray diffraction and Raman spectroscopy. Calculations were performed with a density-functional theory framework. We have used the ab-initio random structure searching (AIRSS) method together with a data-mining technique to determine the stable compounds in the xenon-oxygen system in this pressure range. We have calculated structural and optical properties of these phases, and a good match between theoretical and experimental results has been obtained. Funding for computational research provided by the engineering and physical sciences research council (EPSRC; UK). Computing resources provided by Cambridge HPC and HECToR. X-ray diffraction experiments performed at ESRF.

  10. Imaging in (high pressure) Micromegas TPC detectors

    NASA Astrophysics Data System (ADS)

    Luzón, G.; Cebrián, S.; Castel, J.; Dafni, Th.; Galán, J.; Garza, J. G.; Irastorza, I. G.; Iguaz, F. J.; Mirallas, H.; Ruíz-Choliz, E.

    2016-11-01

    The T-REX project of the group of the University of Zaragoza includes a number of R&D and prototyping activities to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches where the pattern recognition of the signal is crucial for background discrimination. In the CAST experiment (CERN Axion Solar Telescope) a background level as low as 0.8 × 10-6 counts keV-1 cm-2 s-1 was achieved. Prototyping and simulations promise a 105 better signal-to-noise ratio than CAST for the future IAXO (International Axion Observatory) using x-ray telescopes. A new strategy is also explored in the search of WIMPS based on high gas pressure: the TREX-DM experiment, a low energy threshold detector. In both cases, axion and WIMP searches, the image of the expected signal is quite simple: a one cluster deposition coming from the magnet bore in the case of axions and, if possible, with a tadpole form in the case of WIMPs. It is the case of double beta decay (DBD) where imaging and pattern recognition play a major role. Results obtained in Xe + trimethylamine (TMA) mixture point to a reduction in electron diffusion which improves the quality of the topological pattern, with a positive impact on the discrimination capability, as shown in TREX-ββ prototype. Microbulk Micromegas are able to image the DBD ionization signature with high quality while, at the same time, measuring its energy deposition with a resolution of at least a ~ 3% FWHM at the transition energy Qββ and even better (up to ~ 1% FWHM) as extrapolated from low energy events. That makes Micromegas-based HPXe TPC a very competitive technique for the next generation DBD experiments (as PANDAX-III). Here, it will be shown the last results of the TREX project detectors and software concerning Axions, Dark matter and double beta decay.

  11. High-pressure transformations in xenon hydrates

    PubMed Central

    Sanloup, Chrystèle; Mao, Ho-kwang; Hemley, Russell J.

    2002-01-01

    A high-pressure investigation of the Xe⋅H2O chemical system was conducted by using diamond-anvil cell techniques combined with in situ Raman spectroscopy, synchrotron x-ray diffraction, and laser heating. Structure I xenon clathrate was observed to be stable up to 1.8 GPa, at which pressure it transforms to a new Xe clathrate phase stable up to 2.5 GPa before breaking down to ice VII plus solid xenon. The bulk modulus and structure of both phases were determined: 9 ± 1 GPa for Xe clathrate A with structure I (cubic, a = 11.595 ± 0.003 Å, V = 1,558.9 ± 1.2 Å3 at 1.1 GPa) and 45 ± 5 GPa for Xe clathrate B (tetragonal, a = 8.320 ± 0.004 Å, c = 10.287 ± 0.007 Å, V = 712.1 ± 1.2 Å3 at 2.2 GPa). The extended pressure stability field of Xe clathrate structure I (A) and the discovery of a second Xe clathrate (B) above 1.8 GPa have implications for xenon in terrestrial and planetary interiors. PMID:11756690

  12. Stable xenon nitride at high pressures

    NASA Astrophysics Data System (ADS)

    Peng, Feng; Wang, Yanchao; Wang, Hui; Zhang, Yunwei; Ma, Yanming

    2015-09-01

    Nitrides in many ways are fascinating since they often appear as superconductors, high-energy density, and hard materials. Though there exist a large variety of nitrides, noble gas nitrides are missing in nature. Pursuit of noble gas nitrides has therefore become the subject of topical interests, but remains as a great challenge since molecular nitrogen (N2, a major form of nitrogen) and noble gases are both inert systems and do not interact at normal conditions. We show through a first-principles swarm-structure search that high pressure enables a direct interaction of N2 and xenon (Xe) above 146 GPa. The resultant Xe nitride has a peculiar stoichiometry of XeN6, possessing a high-energy density of approximately 2.4 kJg -1, rivaling that of the modern explosives. Structurally, XeN6 is intriguing with the appearance of chaired N6 hexagons and unusually high 12-coordination of Xe bonded with N. Our work opens up the possibility of achieving Xe nitride with superior high-energy density whose formation is long sought as impossible.

  13. Scintillation luminescence for high-pressure xenon gas

    NASA Astrophysics Data System (ADS)

    Kobayashi, S.; Hasebe, N.; Igarashi, T.; Kobayashi, M.-N.; Miyachi, T.; Miyajima, M.; Okada, H.; Okudaira, O.; Tezuka, C.; Yokoyama, E.; Doke, T.; Shibamura, E.; Dmitrenko, V. V.; Ulin, S. E.; Vlasik, K. F.

    2004-09-01

    Scintillation and ionization yields in xenon gas for 5.49MeV alpha-particles were measured in the range of pressure from 0.35 to 3.7MPa and the electric field strength (E) over the number density of xenon atoms (N), E/N from 0 to 5×10-18Vcm2. When our data are normalized at the data point measured by Saito et al., the number of scintillation photons is 2.3×105 while the number of ionization electrons is 2.0×105 at 2.6MPa and at 3.7×10-18Vcm2. The scintillation and ionization yields of xenon doped with 0.2% hydrogen, High-Pressure Xenon gas[H2-0.2%], at 2.6MPa was also measured. Scintillation yield of the Xe-H2 mixture gas is 80% as high as that of pure xenon. It is found that the scintillation yield is luminous enough to generate a trigger pulse of the high-pressure xenon time projection chamber, which is expected as a promising MeV Compton gamma-ray camera.

  14. Commissioning of a dual-phase xenon TPC at Nikhef

    NASA Astrophysics Data System (ADS)

    Hogenbirk, E.; Aalbers, J.; Bader, M.; Breur, P. A.; Brown, A.; Decowski, M. P.; Tunnell, C.; Walet, R.; Colijn, A. P.

    2016-12-01

    A dual-phase xenon time-projection chamber was built at Nikhef in Amsterdam as a direct dark matter detection R&D facility. In this paper, the setup is presented and the first results from a calibration with a 22Na gamma-ray source are presented. The results show an average light yield of (5.6 ± 0.3) photoelectrons/keV (calculated to 122 keV and zero field) and an electron lifetime of (429±26) μs. The best energy resolution σE / E is (5.8 ± 0.2)% at an energy of 511 keV. This was achieved using a combination of the scintillation and the ionization signals. A photomultiplier tube gain calibration technique, based on the electroluminescence signals occurring from isolated electrons, is presented and its advantages and limitations are discussed.

  15. Advantages of using high-pressure short-arc xenon lamps for display systems

    NASA Astrophysics Data System (ADS)

    Yeralan, Serdar; Doughty, Douglas; Blondia, Rudi; Hamburger, Rick

    2005-04-01

    Xenon produces a brilliant white flash of light when it is excited electrically. The characteristics Xenon brings to short arc, high-pressure xenon lamps are substantial, particularly in display systems. The broadband and relatively flat profile of the xenon emission in the visible spectrum generates superior metameric matching to life-like colors, whereby the visible spectrums of other lamps generally contain spikes requiring additional adjustment. Xenon-powered lamps generate a native color point of 5900K to 6200K - very near the optimal D65 point - increasing efficiency and minimizing the need for filtering. Filtering often results in an undesirable loss of luminous efficacy. Instant turn-on/turn-off is possible since the xenon is in its gaseous state at the operating pressures of the lamp. This is an improvement over most ultra-high pressure mercury lamps requiring warm-up times. The DC drive of the lamp provides a compact arc near one of the electrodes that produces a very small volume of light that is ideal for coupling to elliptical reflectors. The light output can be dimmed by controlling the applied electrical power. Xenon-powered short arc, high-pressure lamps operate safely within the specified parameters, and incorporating a reflector within the lamp body provides alignment-free replacement. The xenon lamps also eliminate the use of mercury, an important benefit in today's environmentally-conscious industry.

  16. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    DOE PAGES

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; ...

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at themore » 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.« less

  17. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    SciTech Connect

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A.B.; Nygren, D.

    2015-03-24

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase offers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  18. A plan for directional dark matter sensitivity in high-pressure xenon detectors through the addition of wavelength shifting gaseous molecules

    NASA Astrophysics Data System (ADS)

    Gehman, V. M.; Goldschmidt, A.; Nygren, D.; Oliveira, C. A. B.; Renner, J.

    2013-10-01

    Xenon is an especially attractive candidate for both direct WIMP and 0νββ decay searches. Although the current trend has exploited the liquid phase, the gas phase xenon offers remarkable performance advantages for: energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now under construction in the Canfranc Underground Laboratory, Spain, will operate at ~ 15 bars with 100 kg of 136Xe for the 0νββ decay search. We will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay's Q value (2457.83 keV), as well as rejection of γ-rays with topological cuts. However, sensitivity goals for WIMP dark matter and 0νββ decay searches indicate the probable need for ton-scale active masses. NEXT-100 provides the springboard to reach this scale with xenon gas. We describe a scenario for performing both searches in a single, high-pressure, ton-scale xenon gas detector, without significant compromise to either. In addition, even in a single ton-scale, high-pressure xenon gas TPC, an intrinsic sensitivity to the nuclear recoil direction may exist. This plausibly offers an advance of more than two orders of magnitude relative to current low-pressure TPC concepts. We argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible at acceptable cost, within the time frame of interest, and deserves our collective attention.

  19. Formation of xenon-nitrogen compounds at high pressure

    PubMed Central

    Howie, Ross T.; Turnbull, Robin; Binns, Jack; Frost, Mungo; Dalladay-Simpson, Philip; Gregoryanz, Eugene

    2016-01-01

    Molecular nitrogen exhibits one of the strongest known interatomic bonds, while xenon possesses a closed-shell electronic structure: a direct consequence of which renders both chemically unreactive. Through a series of optical spectroscopy and x-ray diffraction experiments, we demonstrate the formation of a novel van der Waals compound formed from binary Xe-N2 mixtures at pressures as low as 5 GPa. At 300 K and 5 GPa Xe(N2)2-I is synthesised, and if further compressed, undergoes a transition to a tetragonal Xe(N2)2-II phase at 14 GPa; this phase appears to be unexpectedly stable at least up to 180 GPa even after heating to above 2000 K. Raman spectroscopy measurements indicate a distinct weakening of the intramolecular bond of the nitrogen molecule above 60 GPa, while transmission measurements in the visible and mid-infrared regime suggest the metallisation of the compound at ~100 GPa. PMID:27748357

  20. Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

    SciTech Connect

    TROYER, G.L.

    2000-08-25

    High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% {at} 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse rise time versus photo peak position and resolution. These data were collected to investigate the effect of pulse rise time compensation on resolution and efficiency.

  1. A Monte Carlo analysis of the liquid xenon TPC as gamma ray telescope

    NASA Technical Reports Server (NTRS)

    Aprile, E.; Bolotnikov, A.; Chen, D.; Mukherjee, R.

    1992-01-01

    Extensive Monte Carlo modeling of a coded aperture x ray telescope based on a high resolution liquid xenon TPC has been performed. Results on efficiency, background reduction capability and source flux sensitivity are presented. We discuss in particular the development of a reconstruction algorithm for events with multiple interaction points. From the energy and spatial information, the kinematics of Compton scattering is used to identify and reduce background events, as well as to improve the detector response in the few MeV region. Assuming a spatial resolution of 1 mm RMS and an energy resolution of 4.5 percent FWHM at 1 MeV, the algorithm is capable of reducing by an order of magnitude the background rate expected at balloon altitude, thus significantly improving the telescope sensitivity.

  2. Identification of hidden fissile materials using high-pressure xenon gamma-ray detectors

    NASA Astrophysics Data System (ADS)

    Ulin, Sergey E.; Dmitrenko, Valery V.; Grachev, V. M.; Sokolov, D. V.; Uteshev, Z. M.; Chernysheva, I. V.; Vlasik, K. F.

    2001-12-01

    The description of the High Pressure Xenon Gamma-Ray Detector (HPXeD) and its main characteristics are considered in the context of the search for hidden fissile materials. The results of HPXeD measurements of gamma-radiation from radioactive sources, which are covered by lead, iron and aluminium shields, are analyzed and discussed. The use of special software for processing data is shown to improve the potential of radioactive material detection, including the identification and estimation of the main protective shield parameters.

  3. Characteristics of a high pressure gas proportional counter filled with xenon

    NASA Technical Reports Server (NTRS)

    Sakurai, H.; Ramsey, B. D.

    1991-01-01

    The characteristics of a conventional cylindrical geometry proportional counter filled with high pressure xenon gas up to 10 atm. were fundamentally investigated for use as a detector in hard X-ray astronomy. With a 2 percent methane gas mixture the energy resolutions at 10 atm. were 9.8 percent and 7.3 percent for 22 keV and 60 keV X-rays, respectively. From calculations of the Townsend ionization coefficient, it is shown that proportional counters at high pressure operate at weaker reduced electric field than low pressure counters. The characteristics of a parallel grid proportional counter at low pressure showed similar pressure dependence. It is suggested that this is the fundamental reason for the degradation of resolution observed with increasing pressure.

  4. Iterative Boltzmann plot method for temperature and pressure determination in a xenon high pressure discharge lamp

    SciTech Connect

    Zalach, J.; Franke, St.

    2013-01-28

    The Boltzmann plot method allows to calculate plasma temperatures and pressures if absolutely calibrated emission coefficients of spectral lines are available. However, xenon arcs are not very well suited to be analyzed this way, as there are only a limited number of lines with atomic data available. These lines have high excitation energies in a small interval between 9.8 and 11.5 eV. Uncertainties in the experimental method and in the atomic data further limit the accuracy of the evaluation procedure. This may result in implausible values of temperature and pressure with inadmissible uncertainty. To omit these shortcomings, an iterative scheme is proposed that is making use of additional information about the xenon fill pressure. This method is proved to be robust against noisy data and significantly reduces the uncertainties. Intentionally distorted synthetic data are used to illustrate the performance of the method, and measurements performed on a laboratory xenon high pressure discharge lamp are analyzed resulting in reasonable temperatures and pressures with significantly reduced uncertainties.

  5. First results of a large-area cryogenic gaseous photomultiplier coupled to a dual-phase liquid xenon TPC

    NASA Astrophysics Data System (ADS)

    Arazi, L.; Coimbra, A. E. C.; Erdal, E.; Israelashvili, I.; Rappaport, M. L.; Shchemelinin, S.; Vartsky, D.; dos Santos, J. M. F.; Breskin, A.

    2015-10-01

    We discuss recent advances in the development of cryogenic gaseous photomultipliers (GPM), for possible use in dark matter and other rare-event searches using noble-liquid targets. We present results from a 10 cm diameter GPM coupled to a dual-phase liquid xenon (LXe) TPC, demonstrating—for the first time—the feasibility of recording both primary (``S1'') and secondary (``S2'') scintillation signals. The detector comprised a triple Thick Gas Electron Multiplier (THGEM) structure with cesium iodide photocathode on the first element; it was shown to operate stably at 180 K with gains above 105, providing high single-photon detection efficiency even in the presence of large α particle-induced S2 signals comprising thousands of photoelectrons. S1 scintillation signals were recorded with a time resolution of 1.2 ns (RMS). The energy resolution (σ/E) for S2 electroluminescence of 5.5 MeV α particles was ~ 9%, which is comparable to that obtained in the XENON100 TPC with PMTs. The results are discussed within the context of potential GPM deployment in future multi-ton noble-liquid detectors.

  6. Dark matter directionality revisited with a high pressure xenon gas detector

    SciTech Connect

    Mohlabeng, Gopolang; Kong, Kyoungchul; Li, Jin; Para, Adam; Yoo, Jonghee

    2015-07-20

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect in a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below ~50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.

  7. Dark matter directionality revisited with a high pressure xenon gas detector

    DOE PAGES

    Mohlabeng, Gopolang; Kong, Kyoungchul; Li, Jin; ...

    2015-07-20

    An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect inmore » a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below ~50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.« less

  8. Implementation of a Noise Mitigation Strategy for a High-Pressure Xenon Detector

    SciTech Connect

    Seifert, Allen; Milbrath, Brian D.; Pitts, W. K.; Smith, Leon E.

    2005-10-23

    High-pressure xenon (HPXe) detectors have historically been unable to achieve or even approach the theoretically predicted energy resolution, a phenomenon usually attributed to problems with microphonic, vibrational, or acoustic noise. All these noises are expected to have characteristic frequency signatures. We have determined the effects of external acoustic noise signals on the resolution of HPXe spectrometers and implemented a technique to reduce or eliminate the resolution loss caused by external acoustic noise in real time. Using a precision waveform generator as the driver on a 400-watt speaker, we determined the response of a commercial HPXe detector to a variety of constant frequency acoustic noise signals by performing a fast Fourier transform on a buffered detector output signal and noting distortions to the spectral response of the frequency domain. A data acquisition package was developed using the frequency response information to perform real time digital signal noise filtering on each gamma-ray pulse. With external acoustic noise, the measured resolution of HPXe gamma-ray energy spectra was degraded by a factor of 2 to 3. With the noise mitigating data acquisition package the spectroscopic resolution was restored to values comparable to the resolution measured under ideal (non-noisy) conditions.

  9. Herman Feshbach Prize in Theoretical Nuclear Physics Xiangdong Ji, University of Maryland PandaX-III: high-pressure gas TPC for Xe136 neutrinoless double beta decay at CJPL

    NASA Astrophysics Data System (ADS)

    Ji, Xiangdong; PandaX-III Collaboration

    2016-03-01

    The PandaX-III in China's Jinping Underground Lab is a new neutrinoless double beta decay experiment using Xe136 high-pressure gas TPC. The first phase of the experiment uses a 4 m3 gas detector with symmetric Micromegas charge readout planes. The gas TPC allows full reconstruction of the event topology, capable of distinguishing the two electron events from gamma background with high confidence level. The energy resolution can reach about 3% FWHM at the beta decay Q-value. The detector construction and the experimental lab is currently under active development. In this talk, the current status and future plan are reported.

  10. Influence of xenon on the self-reversal maxima of the Na-D emission lines in high-pressure sodium lamps

    NASA Astrophysics Data System (ADS)

    Jongerius, M. J.

    1987-10-01

    We report on the influence of xenon buffer gas on the shape of the self-reversed Na-D lines emitted by high-pressure sodium (HPS) arcs. In a previous paper we have reported experimental results on the collisional broadening of the Na-D line wings by xenon at high temperatures [M. J. Jongerius, J. Phys. B 20, 3345 (1987)]. These results are used to calculate the relative wavelength positions Δλr and Δλb of the red and blue Na-D self-reversal maximum, respectively, as functions of the Na/Hg amalgam temperature. The additional broadening by xenon leads to a strong asymmetry in the shape of the Na-D emission lines and a distinct maximum in Δλr/Δλb because of the Na-Xe satellite at 590.9 nm. The presence of this maximum in Δλr/Δλb is confirmed by experiments in which the shape of the Na-D emission lines is measured as a function of the arc power. The maximum value of Δλr/Δλb can be used as a measure of the xenon pressure in the arc. Furthermore, Δλr and Δλb can be used to obtain values for the sodium and mercury pressures in the burning arc. In the conventional method (J. J. de Groot and J. A. J. M. van Vliet, in Proceedings of the 2nd International Symposium on Incoherent Light Sources, Enschede, 1979, summary p. 30), the Na-D line broadening by the xenon buffer gas is not taken into account. We propose a modification of the conventional method to account for the influence of the collisional Na-D line broadening by xenon.

  11. Performance of a Small High-Pressure Xenon Detector at Sub-MeV Photon Energies with an Example Application to Ion Beam Analysis

    SciTech Connect

    Pallone, Arthur K.; Beyerle, Al; Demaree, John D.

    2009-03-10

    Ion beam analysis (IBA) is a nondestructive method that provides nondestructive compositional information of a sample. Many IBA techniques derive the information from high-energy photons produced by the interaction of the ion beam with the sample. The performance of a 1.53.8-inch cm diameter by 37.6-inch cm long high-pressure xenon (HPXe) detector is investigated at photon energies useful to IBA. The results for the HPXe detector are then used to predict the performance of larger HPXe detectors at those energies and recommendations are made for an HPXe system for IBA.

  12. The Impact of Multiple-Site Interactions on the Energy Resolution of a High-Pressure Xenon Gamma-Ray Spectrometer

    SciTech Connect

    Kiff, Scott D.; He, Zhong

    2007-11-30

    High-pressure xenon (HPXe) ionization chambers have generated interest as a radiation detection medium for purposes requiring good energy resolution, high detection efficiency, and uniform response over a broad temperature range, such as homeland security and well logging applications. These chambers generally exhibit a substantial degradation of the measured energy resolution relative to theoretical limits. This investigation studies the impact of the number of interaction sites in an event sequence on the measured energy resolution using a benchmarked simulation package. The prominence of single and multiple-site interactions is investigated in addition to the photopeak broadening due to each event class. A radial position-sensing technique developed for coplanar-anode HPXe chambers is shown to have benefit for only single-site events.

  13. Absorption spectroscopy of xenon and ethylene-noble gas mixtures at high pressure: towards Bose-Einstein condensation of vacuum ultraviolet photons

    NASA Astrophysics Data System (ADS)

    Wahl, Christian; Brausemann, Rudolf; Schmitt, Julian; Vewinger, Frank; Christopoulos, Stavros; Weitz, Martin

    2016-12-01

    Bose-Einstein condensation is a phenomenon well known for material particles as cold atomic gases, and this concept has in recent years been extended to photons confined in microscopic optical cavities. Essential for the operation of such a photon condensate is a thermalization mechanism that conserves the average particle number, as in the visible spectral regime can be realized by subsequent absorption re-emission processes in dye molecules. Here we report on the status of an experimental effort aiming at the extension of the concept of Bose-Einstein condensation of photons towards the vacuum ultraviolet spectral regime, with gases at high-pressure conditions serving as a thermalization medium for the photon gas. We have recorded absorption spectra of xenon gas at up to 30 bar gas pressure of the 5p^6-5p^56s transition with a wavelength close to 147 nm. Moreover, spectra of ethylene noble gas mixtures between 158 and 180 nm wavelength are reported.

  14. The XENON1T Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    de Perio, Patrick; Xenon Collaboration

    2017-01-01

    Recent results and status of the XENON1T direct dark matter detector will be presented. XENON1T is a two-phase xenon TPC using 248 low radioactivity PMTs to detect scintillation signals in a 2-ton active liquid xenon target. The detector has been fully operational at the Laboratori Nazionale del Gran Sasso since May 2016, with continuously improving xenon purity and reduction of the internal Kr-85 background source. This talk will summarize the detector performance, calibration, and background studies, discussed in more detail in the following XENON1T talks, which are paving the way towards the world's most sensitive dark matter search.

  15. Modeling High Pressure Micro Hollow Cathode Discharges

    DTIC Science & Technology

    2007-11-02

    calculations in glow discharge in argon and neon . A Monte Carlo simulation of the ions and Grant 033083 – Final report 7 the fast neutrals generated...in high pressure xenon or in rare gas mixtures containing xenon are of interest in the context of UV and VUV generation. Numerical experiments on...The shape of the calculated characteristic is similar to those measured by Schoenbach et al1 in argon and by Moselhy and Schoenbach9 in xenon . There

  16. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of liquid xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Resembling a tiny bit of window screen, the oscillator at the heart of CVX-2 will vibrate between two pairs of paddle-like electrodes. The slight bend in the shape of the mesh has no effect on the data. What counts are the mesh's displacement in the xenon fluid and the rate at which the displacement dampens. The unit shown here is encased in a small test cell and capped with a sapphire windown to contain the xenon at high pressure.

  17. Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy γ-rays

    NASA Astrophysics Data System (ADS)

    Álvarez, V.; Borges, F. I. G. M.; Cárcel, S.; Castel, J.; Cebrián, S.; Cervera, A.; Conde, C. A. N.; Dafni, T.; Dias, T. H. V. T.; Díaz, J.; Egorov, M.; Esteve, R.; Evtoukhovitch, P.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Gehman, V. M.; Gil, A.; Goldschmidt, A.; Gómez, H.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Hauptman, J.; Hernando Morata, J. A.; Herrera, D. C.; Iguaz, F. J.; Irastorza, I. G.; Jinete, M. A.; Labarga, L.; Laing, A.; Liubarsky, I.; Lopes, J. A. M.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez, A.; Martínez-Lema, G.; Miller, T.; Moiseenko, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Natal da Luz, H.; Navarro, G.; Nebot-Guinot, M.; Nygren, D.; Oliveira, C. A. B.; Palma, R.; Pérez, J.; Pérez Aparicio, J. L.; Renner, J.; Ripoll, L.; Rodríguez, A.; Rodríguez, J.; Santos, F. P.; dos Santos, J. M. F.; Segui, L.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J. F.; Tomás, A.; Torrent, J.; Tsamalaidze, Z.; Vázquez, D.; Veloso, J. F. C. A.; Villar, J. A.; Webb, R. C.; White, J. T.; Yahlali, N.; Aznar, F.; Calvet, D.; Druillole, F.; Ferrer-Ribas, E.; García, J. A.; Giomataris, I.; Gracia, J.; Le Coguie, A.; Mols, J. P.; Pons, P.; Ruiz, E.

    2014-04-01

    NEXT-MM is a general-purpose high pressure (10 bar, ~ 25 l active volume) Xenon-based TPC, read out in charge mode with an 0.8 cm × 0.8 cm-segmented 700 cm2 plane (1152 ch) of the latest microbulk-Micromegas technology. It has been recently commissioned at University of Zaragoza as part of the R&D of the NEXT 0νββ experiment, although the experiment's first stage is currently being built based on a SiPM/PMT-readout concept relying on electroluminescence. Around 2 million events were collected during the last months, stemming from the low energy γ-rays emitted by a 241Am source when interacting with the Xenon gas (Eγ = 26, 30, 59.5 keV). The localized nature of such events around atmospheric pressure, the long drift times, as well as the possibility to determine their production time from the associated α particle in coincidence, allow the extraction of primordial properties of the TPC filling gas, namely the drift velocity, diffusion and attachment coefficients. In this work we focus on the little explored combination of Xe and trimethylamine (TMA) for which, in particular, such properties are largely unknown. This gas mixture offers potential advantages over pure Xenon when aimed at Rare Event Searches, mainly due to its Penning characteristics, wave-length shifting properties and reduced diffusion, and it is being actively investigated by our collaboration. The chamber is currently operated at 2.7 bar, as an intermediate step towards the envisaged 10 bar. We report here its performance as well as a first implementation of the calibration procedures that have allowed the extension of the previously reported energy resolution to the whole readout plane (10.6% FWHM@30 keV).

  18. Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations

    SciTech Connect

    Gómez-Cadenas, J.J.; Martín-Albo, J.; Vidal, J. Muñoz; Peña-Garay, C. E-mail: jmalbos@ific.uv.es E-mail: penya@ific.uv.es

    2013-03-01

    The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Σm{sub ν} = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m{sub ββ} involved in neutrinoless double beta decay (ββ0ν) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ββ0ν experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ββ0ν events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely.

  19. TPC magnet cryogenic system

    SciTech Connect

    Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

    1980-03-01

    The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system.

  20. The Gap-Tpc

    NASA Astrophysics Data System (ADS)

    Rossi, B.; Anastasio, A.; Boiano, A.; Catalanotti, S.; Cocco, A. G.; Covone, G.; Di Meo, P.; Longo, G.; Vanzanella, A.; Walker, S.; Wang, H.; Wang, Y.; Fiorillo, G.

    2016-02-01

    Several experiments have been conducted worldwide, with the goal of observing low-energy nuclear recoils induced by WIMPs scattering off target nuclei in ultra-sensitive, low-background detectors. In the last few decades noble liquid detectors designed to search for dark matter in the form of WIMPs have been extremely successful in improving their sensitivities and setting the best limits. One of the crucial problems to be faced for the development of large size (multi ton-scale) liquid argon experiments is the lack of reliable and low background cryogenic PMTs: their intrinsic radioactivity, cost, and borderline performance at 87 K rule them out as a possible candidate for photosensors. We propose a brand new concept of liquid argon-based detector for direct dark matter search: the Geiger-mode Avalanche Photodiode Time Projection Chamber (GAP-TPC) optimized in terms of residual radioactivity of the photosensors, energy and spatial resolution, light and charge collection efficiency.

  1. Studies of basic mechanisms in high pressure gases: Applications to high efficiency high power lasers

    NASA Technical Reports Server (NTRS)

    Verdeyen, J. T.; Cherrington, B. E.; Leslie, S. G.; Millar, W. S.; Edwards, B. E.

    1976-01-01

    A high power pulsed dye laser was used to optically excite high pressure cesium-xenon mixtures and the resulting measurements are presented. A microwave discharge in rubidium at relatively high xenon pressure was achieved. Preliminary studies of cadium-rare gas mixtures are discussed and a detailed description of the entire experimental apparatus is given.

  2. Crystal structures at high pressures and temperatures

    NASA Astrophysics Data System (ADS)

    Caldwell, Wendel Alexander

    2000-10-01

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

  3. 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.

  4. Recovering Residual Xenon Propellant for an Ion Propulsion System

    NASA Technical Reports Server (NTRS)

    Ganapathi, Gani; Skakkottai, P.; wu, Jiunn Jeng

    2006-01-01

    Future nuclear-powered Ion-Propulsion- System-propelled spacecraft such as Jupiter Icy Moon Orbiter (JIMO) will carry more than 10,000 kg of xenon propellant. Typically, a small percentage of this propellant cannot be used towards the end of the mission because of the pressure drop requirements for maintaining flow. For large missions such as JIMO, this could easily translate to over 250 kg of unusable xenon. A proposed system, the Xenon Recovery System (XRS), for recovering almost all of the xenon remaining in the tank, would include a cryopump in the form of a condenser/evaporator that would be alternatively cooled by a radiator, then heated electrically. When the pressure of the xenon in the tank falls below 0.7 MPa (100 psia), the previously isolated XRS will be brought online and the gas from the tank would enter the cryopump that is initially cooled to a temperature below saturation temperature of xenon. This causes xenon liquefaction and further cryopumping from the tank till the cryopump is full of liquid xenon. At this point, the cryopump is heated electrically by small heaters (70 to 80 W) to evaporate the liquid that is collected as high-pressure gas (<7 MPa; 1,000 psia) in an intermediate accumulator. Check valves between the tank and the XRS prevent the reverse flow of xenon during the heating cycle. The accumulator serves as the high-pressure source of xenon gas to the Xenon Feed System (XFS) downstream of the XRS. This cycle is repeated till almost all the xenon is recovered. Currently, this system is being baselined for JIMO.

  5. Absolute Electron Extraction Efficiency of Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Kamdin, Katayun; Mizrachi, Eli; Morad, James; Sorensen, Peter

    2016-03-01

    Dual phase liquid/gas xenon time projection chambers (TPCs) currently set the world's most sensitive limits on weakly interacting massive particles (WIMPs), a favored dark matter candidate. These detectors rely on extracting electrons from liquid xenon into gaseous xenon, where they produce proportional scintillation. The proportional scintillation from the extracted electrons serves to internally amplify the WIMP signal; even a single extracted electron is detectable. Credible dark matter searches can proceed with electron extraction efficiency (EEE) lower than 100%. However, electrons systematically left at the liquid/gas boundary are a concern. Possible effects include spontaneous single or multi-electron proportional scintillation signals in the gas, or charging of the liquid/gas interface or detector materials. Understanding EEE is consequently a serious concern for this class of rare event search detectors. Previous EEE measurements have mostly been relative, not absolute, assuming efficiency plateaus at 100%. I will present an absolute EEE measurement with a small liquid/gas xenon TPC test bed located at Lawrence Berkeley National Laboratory.

  6. High Pressure Biomass Gasification

    SciTech Connect

    Agrawal, Pradeep K

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  7. Xenon Feed System Progress

    DTIC Science & Technology

    2006-01-01

    From - To) 13-06-2006 Technical Paper 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER F04611-00-C-0055 Xenon Feed System Progress (Preprint) 5b. GRANT...propulsion xenon feed system for a flight technology demonstration program. Major accomplishments include: 1) Utilization of the Moog...successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology Demonstration Program. The feed system has demonstrated throttling of xenon

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Thermal neutrons registration by xenon gamma-ray detector

    NASA Astrophysics Data System (ADS)

    Shustov, A. E.; Chernysheva, I. V.; Dmitrenko, V. V.; Dukhvalov, A. G.; Krivova, K. V.; Novikov, A. S.; Petrenko, D. V.; Vlasik, K. F.; Ulin, S. E.; Uteshev, Z. M.

    2016-02-01

    Experimental results of thermal neutrons detection by high pressure xenon gamma- ray spectrometers are presented. The study was performed with two devices with sensitive volumes of 0.2 and 2 litters filled with compressed mixture of xenon and hydrogen without neutron-capture additives. Spectra from Pu-Be neutron source were acquired using both detectors. Count rates of the most intensive prompt neutron-capture gamma-ray lines of xenon isotopes were calculated in order to estimate thermal neutrons efficiency registration for each spectrometer.

  14. The Electron Recoil Response of the XENON1T Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    Shockley, Evan; Xenon1T Collaboration

    2017-01-01

    XENON1T employs a two-phase xenon TPC to search for dark matter by detecting scintillation light produced by nuclear recoils in a 2 ton active volume of liquid xenon. However, nuclear recoils are not the only recoils that can occur since radiogenic electronic recoils are possible. Our only way of differentiating nuclear and electronic recoils is by comparing the relative fraction of scintillation (S1) and ionization (S2) signals. For the first Science Run of XENON1T, we must understand the response of our detector to S1 and S2 signals at the low keV energies where dark matter will present itself. Therefore, I will be discussing the current understanding of our signal and detection mechanisms at these energies. This work includes work using sources such as the Rn220 technique developed by XENON collaborators for understanding our rejection of electronic recoils.

  15. Xenon lighting adjusted to plant requirements

    NASA Technical Reports Server (NTRS)

    Koefferlein, M.; Doehring, T.; Payer, Hans D.; Seidlitz, H. K.

    1994-01-01

    Xenon lamps are available as low and high power lamps with relatively high efficiency and a relatively long lifetime up to several thousand hours. Different construction types of short-arc and long-arc lamps permit a good adaptation to various applications in projection and illumination techniques without substantial changes of the spectral quality. Hence, the xenon lamp was the best choice for professional technical purposes where high power at simultaneously good spectral quality of the light was required. However, technical development does not stand still. Between the luminous efficacy of xenon lamps of 25-50 lm/W and the theoretical limit for 'white light' of 250 lm/W is still much room for improvement. The present development mainly favors other lamp types, like metal halide lamps and fluorescent lamps for commercial lighting purposes. The enclosed sections deal with some of the properties of xenon lamps relevant to plant illumination; particularly the spectral aspects, the temporal characteristics of the emission, and finally the economy of xenon lamps will be addressed. Due to radiation exceeding the natural global radiation in both the ultraviolet (UV) and the infrared (IR) regions, filter techniques have to be included into the discussion referring to the requirements of plant illumination. Most of the presented results were obtained by investigations in the GSF phytotron or in the closed Phytocell chambers of the University of Erlangen. As our experiences are restricted to area plant illumination rather than spot lights our discussion will concentrate on low pressure long-arc xenon lamps which are commonly used for such plant illuminations. As the spectral properties of short-arc lamps do not differ much from those of long-arc lamps most of our conclusions will be valid for high pressure xenon lamps too. These lamps often serve as light sources for small sun simulators and for monochromators which are used for action spectroscopy of plant responses.

  16. A FORWARD TPC FOR STAR.

    SciTech Connect

    SCHUTTAUF,A. AND THE STAR COLLABORATION

    1999-05-10

    Two Forward Time Projection Chambers (FTPC) provide charge and momentum information in the pseudorapidity range between 2.5 < |{eta}| < 4.0. A radial TPC scheme is used, where ionization electrons drift in an electric field perpendicular to the axial solenoidal magnetic field. Curved proportional wire chambers with pad readout record the track information via 19200 electronic channels. We report on measurements with various gas mixtures in a prototype chamber with and without magnetic field. The design and construction of a curved readout chamber is described. Based on the prototype measurements and the final layout of the detector the expected performance in measuring accuracy and two-track-separation is given.

  17. 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.

  18. 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.

  19. 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)

  20. Chromium at High Pressure

    NASA Astrophysics Data System (ADS)

    Jaramillo, Rafael

    2012-02-01

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

  1. [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

  2. Is xenon eldest?

    NASA Technical Reports Server (NTRS)

    Zahnle, K.

    1994-01-01

    It is well known that the solubility of noble gases in magmas decreases with increasing atomic weight. Xenon, the weightiest of the stable noble gases, is the least soluble atmospheric gas in magma. It is not unreasonable to suppose that the noble gases should have degassed from (or equilibrated with) a bubbling mantle in order of increasing solubility, such that xenon was the most rapidly degassed and helium the least. The apparent relative ages of the famous radiogenic noble gas isotopes agrees, at least qualitatively, with this premise. When atmospheric loss processes are assigned their proper place, several long-standing xenonological puzzles become added evidence for xenon's relative antiquity. Xenon being the afore-mentioned sense the oldest atmospheric gas, will have been most greatly subject to escape, be it impact-driven or EUV-driven. Nonradiogenic xenon's pronounced isotopic fractionation has already been attributed to escape; why it should be more fractionated than krypton would be assigned to xenon's greater atmospheric age. The small atmospheric inventory of xenon relative to the other nonradiogenic noblegases, known as the 'missing xenon' problem, could easily be explained by differential escape. The relatively tiny atmospheric inventories of the radiogenic daughter products of 129 Iodine and 244 Plutonium, both much smaller than would be expected from the inferred abundances of the parents in meteorites, offer a third and fourth data to support the hypothesis that Earth has lost most of its xenon.

  3. 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.

  4. The Light Response of the XENON100 Time Projection Chamber and the Measurements of the Optical Parameters with the Xenon Scintillation Light

    NASA Astrophysics Data System (ADS)

    Choi, Bin

    The XENON program is a phased project using liquid xenon as a sensitive detector medium in search for weakly interacting massive particles (WIMPs). These particles are the leading candidates to explain the non-baryonic, cold dark matter in our Universe. XENON100, the successor experiment of XENON10, has increased the target liquid xenon mass to 61 kg with a 100 times reduction in background rate enabling a large increase in sensitivity to WIMP-nucleon interaction cross-section. To-date, the most stringent limit on this cross-section over a wide range of WIMP masses have been obtained with XENON100. XENON100 is a detector responding to the scintillation of xenon and the work of this thesis will mainly focus on the light response of the detector. Chapter 1 describes the evidences for dark matter and some of the detection methods, roughly divided by the indirect and the direct detection. In the section 1.2.2 for direct detection, a treatment of interaction rate of WIMPs is introduced. Chapter 2 is a description of the XENON100 detector, some of the main characteristics of liquid xenon, followed by the detector design. In Chapter 3, the light response of the XENON100 time projection chamber (TPC) is explained, including the Monte Carlo simulation work that was carried out prior to the main data taking. The Monte Carlo provided the basic idea of understanding the detector in the early stage of design and calibration, but the actual corrections of the light signals were determined later with the real data. Several optical parameters are critical in explaining the light response, such as the quantum efficiency (QE) of the photomultipliers (PMTs) used in the detector and the reflectivity of the teflon (Polytetrafluoroethylene, PTFE) material that surrounds the liquid xenon target volume and defines the TPC. Since the few existing measurements of reflectivity of PTFE in liquid xenon were performed in different conditions and thus could not be applied, the XENON

  5. The ALICE TPC: Status and perspectives

    NASA Astrophysics Data System (ADS)

    Schmidt, Hans Rudolf; ALICE Experiment

    2010-06-01

    The ALICE TPC is the largest Time Projection Chamber ever built. Given the performance requirements it is also, and justifiably so, dubbed the most challenging one. In this paper we browse through the often contradictory optimization strategies and outline the solutions taken to meet the specifications. Mainly on the basis of the commissioning data taken in 2008 and 2009 we will examine to which extend the ALICE TPC came up to its performance expectations, which were outlined elsewhere [1, 14]. First results on the performance of the TPC with proton-proton collisions in December 2009 are presented.

  6. Purging means and method for Xenon arc lamps

    NASA Technical Reports Server (NTRS)

    Miller, C. G. (Inventor)

    1973-01-01

    High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.

  7. 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.

  8. 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.

  9. Electrokinetically pumped high pressure sprays

    DOEpatents

    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.

  10. Effects of high beam rates on TPC's

    SciTech Connect

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C. ); Lindenbaum, S.J. City Coll., New York, NY ); Hallman, T.J. ); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. (C

    1992-02-06

    The TPC's (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchroton) were exposed to silicon ion fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to measure the distortion of the electric field caused by positive ions in the drift region. Results of these tests are presented and the consequences for the TPC based experiment at RHIC (Relativistic Heavy Ion Collider) are discussed.

  11. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The sample cell at the heart of CVX-2 will sit inside a thermostat providing three layers of insulation. The cell itself comprises a copper body that conducts heat efficiently and smoothes out thermal variations that that would destroy the xenon's uniformity. Inside the cell, the oscillating screen viscometer element is supported between two pairs of electrodes that deflect the screen and then measure screen motion.

  12. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Because xenon near the critical point will collapse under its own weight, experiments on Earth (green line) are limited as they get closer (toward the left) to the critical point. CVX in the microgravity of space (red line) moved into unmeasured territory that scientists had not been able to reach.

  13. Xenon ion propulsion for orbit transfer

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Patterson, M. J.; Gruber, R. P.

    1990-01-01

    The status of critical ion propulsion system elements is reviewed. Electron bombardment ion thrusters for primary propulsion have evolved to operate on xenon in the 5-10 kW power range. Thruster efficiencies of 0.7 and specific impulse values of 4000 s have been documented. The baseline thruster currently under development by NASA LeRC includes ring-cusp magnetic field plasma containment and dished two-grid ion optics. Based on past experience and demonstrated simplifications, power processors for these thrusters should have approximately 500 parts, a mass of 40 kg, and an efficiency near 0.94. Thrust vector control, via individual thruster gimbals, is a mature technology. High pressure, gaseous xenon propellant storage and control schemes, using flight qualified hardware, result in propellant tankage fractions between 0.1 and 0.2. In-space and ground integration testing has demonstrated that ion propulsion systems can be successfully integrated with their host spacecraft.

  14. Hollow cathodes in high pressure arc discharges. [for arcjet thrusters

    NASA Technical Reports Server (NTRS)

    Hardy, T. L.; Curran, F. M.

    1985-01-01

    An orified hallow cathode was tested at high pressure to improve lifetime and efficiency in arcjet thrusters. It is indicated that the arc would not operate with emission from the insert above 200 torr in nitrogen regardless of insert material, orifice diameter, or gas flow direction. Emission occurred from the insert in argon and xenon although it could not be ascertained whether diffuse or spot emission existed within the cathode. Over the extended range of configurations and operating parameters explored the desired diffuse emission mode could not be obtained at high enough pressures for orified hollow cathodes to operate in the range which is considered for arcjet applications.

  15. Xenon International Automated Control

    SciTech Connect

    2016-08-05

    The Xenon International Automated Control software monitors, displays status, and allows for manual operator control as well as fully automatic control of multiple commercial and PNNL designed hardware components to generate and transmit atmospheric radioxenon concentration measurements every six hours.

  16. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Shear thirning will cause a normally viscous fluid -- such as pie filling or whipped cream -- to deform and flow more readily under high shear conditions. In shear thinning, a pocket of fluid will deform and move one edge forward, as depicted here.

  17. High Pressure Industrial Water Facility

    NASA Technical Reports Server (NTRS)

    1992-01-01

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

  18. 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.

  19. High-Pressure Vibrational Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Pogson, Mark

    1987-09-01

    Available from UMI in association with The British Library. Requires signed TDF. The study of solids at high pressure and variable temperature enables development of accurate interatomic potential functions over wide ranges of interatomic distances. A review of the main models used in the determination of these potentials is given in Chapter one. A discussion of phonon frequency as a variable physical parameter reflecting the interatomic potential is given. A high pressure Raman study of inorganic salts of the types MSCN, (M = K,Rb,Cs & NH_4^+ ) and MNO_2, (M = K,Na) has been completed. The studies have revealed two new phases in KNO_2 and one new phase in NaNO _2 at high pressure. The accurate phonon shift data have enabled the determination of the pure and biphasic stability regions of the phases of KNO _2. A discussion of the B1, B2 relationship of univalent nitrites is also given. In the series of thiocyanates studied new phases have been found in all four materials. In both the potassium and rubidium salts two new phases have been detected, and in the ceasium salt one new phase has been detected, all at high pressure, from accurate phonon shift data. These transitions are discussed in terms of second-order mechanisms with space groups suggested for all phases, based on Landau's theory of second-order phase transitions. In the ammonium salt one new phase has been detected. This new phase transition has been interpreted as a second-order transition. The series of molecular crystals CH_3 HgX, (X = Cl,Br & I) has been studied at high pressure and at variable temperature. In Chapter five, their phase behaviour at high pressure is detailed along with the pressure dependencies of their phonon frequencies. In the chloride and the bromide two new phases have been detected. In the bromide one has been detected at high temperature and one at high pressure, and latter being interpreted as the stopping of the methyl rotation. In the chloride one phase has been found at

  20. [Xenon light therapy].

    PubMed

    Kanai, Akifumi

    2012-07-01

    The xenon light, generated by high-intensity electrical stimulation of xenon gas, is used to sterilize wounds, aid tissue repair, and relieve pain as a low-level light therapy. The light produced consists of non-coherent beams of multiple wavelengths in the ultraviolet to infrared spectrum. This broad-band light can be emitted in a continuous wave or pulsed mode, with the wave band chosen and the energy distribution controlled for the purpose. Specifically, wavelengths in the 500-700 nm range are suitable for treating superficial tissue, and wavelengths between 800 and 1,000 nm are suitable for deeper-seated tissues, due to longer optical penetration distances through tissue. One of the most common benefits in the xenon light therapy is considered to be the wide and deep irradiation of optimal rays to living tissue. Research into the use of xenon light for tissue repair and pain reduction is restricted within open-label studies and case reports. The present review expounded the effects of xenon light therapy on the basis of the available evidence in vitro and in vivo studies using a laser beam of single wavelength.

  1. 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.

  2. 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.

  3. Scalability study of solid xenon

    SciTech Connect

    Yoo, J.; Cease, H.; Jaskierny, W. F.; Markley, D.; Pahlka, R. B.; Balakishiyeva, D.; Saab, T.; Filipenko, M.

    2015-04-01

    We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employed a cryostat cooled by liquid nitrogen combined with a xenon purification and chiller system. A modified {\\it Bridgeman's technique} reproduces a large scale optically transparent solid xenon.

  4. Separation and purification of xenon

    DOEpatents

    Schlea, deceased, Carl Solomon

    1978-03-14

    Xenon is separated from a mixture of xenon and krypton by extractive distillation using carbon tetrafluoride as the partitioning agent. Krypton is flushed out of the distillation column with CF.sub.4 in the gaseous overhead stream while purified xenon is recovered from the liquid bottoms. The distillation is conducted at about atmospheric pressure or at subatmospheric pressure.

  5. 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.

  6. Nanomaterials under high-pressure.

    PubMed

    San-Miguel, Alfonso

    2006-10-01

    The use of high-pressure for the study and elaboration of homogeneous nanostructures is critically reviewed. Size effects, the interaction between nanostructures and guest species or the interaction of the nanosystem with the pressure transmitting medium are emphasized. Phase diagrams and the possibilities opened by the combination of pressure and temperature for the elaboration of new nanomaterials is underlined through the examination of three different systems: nanocrystals, nano-cage materials which include fullerites and group-14 clathrates, and single wall nanotubes. This tutorial review is addressed to scientist seeking an introduction or a panoramic view of the study of nanomaterials under high-pressure.

  7. 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.

  8. Critical Viscosity of Xenon

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2001 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure that is placed inside a pressure canister. A similar canister holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD. This is a detail view of MSFC 0100143.

  9. Performance study of the neutron-TPC

    NASA Astrophysics Data System (ADS)

    Huang, Meng; Li, Yulan; Niu, Libo; Deng, Zhi; Cheng, Xiaolei; He, Li; Zhang, Hongyan; Fu, Jianqiang; Yan, Yangyang; Cai, Yiming; Li, Yuanjing

    2017-02-01

    Fast neutron spectrometers will play an important role in the future of the nuclear industry and nuclear physics experiments, in tasks such as fast neutron reactor monitoring, thermo-nuclear fusion plasma diagnostics, nuclear reaction cross-section measurement, and special nuclear material detection. Recently, a new fast neutron spectrometer based on a GEM (Gas Electron Multiplier amplification)-TPC (Time Projection Chamber), named the neutron-TPC, has been under development at Tsinghua University. It is designed to have a high energy resolution, high detection efficiency, easy access to the medium material, an outstanding n/γ suppression ratio, and a wide range of applications. This paper presents the design, test, and experimental study of the neutron-TPC. Based on the experimental results, the energy resolution (FWHM) of the neutron-TPC can reach 15.7%, 10.3% and 7.0% with detection efficiency higher than 10‑5 for 1.2 MeV, 1.81 MeV and 2.5 MeV neutrons respectively. Supported by National Natural Science Foundation of China (11275109)

  10. Data links for the EOS TPC

    SciTech Connect

    Bieser, F.; Jones, R.; McParland, C.

    1990-10-01

    We report on the design and performance of high speed data links and slower configuration control links used between the EOS TPC detector and the data processing electronics. Data rates of 5MBytes/s/link are maintained over 30m with optical isolation. Pedestal subtraction, hit detection, and data reordering are performed online. 3 refs., 1 fig.

  11. High pressure paint gun injuries.

    PubMed

    Booth, C M

    1977-11-19

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

  12. 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.

  13. 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.

  14. High-pressure optical studies

    SciTech Connect

    Drickamer, H.G.

    1981-01-01

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

  15. Requirements for Xenon International

    SciTech Connect

    Hayes, James C.; Ely, James H.

    2013-09-26

    This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

  16. Requirements for Xenon International

    SciTech Connect

    Hayes, James C.; Ely, James H.; Haas, Derek A.; Harper, Warren W.; Heimbigner, Tom R.; Hubbard, Charles W.; Humble, Paul H.; Madison, Jill C.; Morris, Scott J.; Panisko, Mark E.; Ripplinger, Mike D.; Stewart, Timothy L.

    2015-12-30

    This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

  17. Liquid xenon time projection chamber for gamma rays in the MeV region: Development status

    NASA Technical Reports Server (NTRS)

    Aprile, E.; Bolotnikov, A.; Chen, D.; Mukherjee, R.

    1992-01-01

    The feasibility of a large volume Liquid Xenon Time Projection Chamber (LXe-TPC) for three dimensional imaging and spectroscopy of cosmic gamma ray sources, was tested with a 3.5 liter prototype. The observation of induction signals produced by MeV gamma rays in liquid xenon is reported, with a good signal-to-noise ratio. The results represent the first experimental demonstration with a liquid xenon ionization chamber of a nondestructive readout of the electron image produced by point-like charges, using a sense wire configuration of the type originally proposed in 1970 by Gatti et al. An energy resolution as good as that previously measured by the millimeter size chambers, was achieved with the large prototype of 4.4 cm drift gap.

  18. Liquid xenon time projection chamber for gamma rays in the MeV region: Development status

    NASA Astrophysics Data System (ADS)

    Aprile, E.; Bolotnikov, A.; Chen, D.; Mukherjee, R.

    1992-12-01

    The feasibility of a large volume Liquid Xenon Time Projection Chamber (LXe-TPC) for three dimensional imaging and spectroscopy of cosmic gamma ray sources, was tested with a 3.5 liter prototype. The observation of induction signals produced by MeV gamma rays in liquid xenon is reported, with a good signal-to-noise ratio. The results represent the first experimental demonstration with a liquid xenon ionization chamber of a nondestructive readout of the electron image produced by point-like charges, using a sense wire configuration of the type originally proposed in 1970 by Gatti et al. An energy resolution as good as that previously measured by the millimeter size chambers, was achieved with the large prototype of 4.4 cm drift gap.

  19. Diffusive nature of xenon anesthetic changes properties of a lipid bilayer: molecular dynamics simulations.

    PubMed

    Yamamoto, Eiji; Akimoto, Takuma; Shimizu, Hiroyuki; Hirano, Yoshinori; Yasui, Masato; Yasuoka, Kenji

    2012-08-02

    Effects of general anesthesia can be controllable by the ambient pressure. We perform molecular dynamics simulations for a 1-palmitoyl-2-oleoyl phosphatidylethanolamine lipid bilayer with or without xenon molecules by changing the pressure to elucidate the mechanism of the pressure reversal of general anesthesia. According to the diffusive nature of xenon molecules in the lipid bilayer, a decrease in the orientational order of the lipid tails, an increase in the area and volume per lipid molecule, and an increase in the diffusivity of lipid molecules are observed. We show that the properties of the lipid bilayer with xenon molecules at high pressure come close to those without xenon molecules at 0.1 MPa. Furthermore, we find that xenon molecules are concentrated in the middle of the lipid bilayer at high pressures by the pushing effect and that the diffusivity of xenon molecules is suppressed. These results suggest that the pressure reversal originates from a jamming and suppression of the diffusivity of xenon molecules in lipid bilayers.

  20. High-pressure injection injuries.

    PubMed

    Neal, N C; Burke, F D

    1991-11-01

    A retrospective review of the 11 patients attending the Hand Unit at the Derbyshire Royal Infirmary over the last 5 years with high-pressure injection injuries is presented. The machines and materials that cause these injuries are outlined and the methods of treatment and rehabilitation are described in detail. The study demonstrates the morbidity of high-pressure injection injuries, particularly those inflicted by paint spray guns, and highlights a frequent delay between injury and decompression of the injured part. We wish to emphasize the importance of early diagnosis, referral, exploration and rehabilitation to ensure an optimal outcome, and to point out that failure to refer early is becoming an increasing focus of negligence claims.

  1. Cryogenic High Pressure Sensor Module

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  2. Cryogenic, Absolute, High Pressure Sensor

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  3. 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

  4. 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.

  5. The XENON dark matter experiment

    NASA Astrophysics Data System (ADS)

    Aprile, Elena; Xenon Collaboration

    The XENON experiment aims at the direct detection of dark matter in the form of WIMPs (Weakly Interacting Massive Particles) via their elastic scattering off Xenon nuclei. With a fiducial mass of 1000 kg of liquid xenon, a sufficiently low threshold of 16 keV recoil energy and an un-rejected background rate of 10 events per year, XENON would be sensitive to a WIMP-nucleon interaction cross section of ~10-46cm2, for WIMPs with masses above 50 GeV. The 1 tonne scale experiment (XENON1T) will be realized with an array of ten identical 100 kg detector modules (XENON100). The detectors are time projection chambers operated in dual (liquid/gas) phase, to detect simultaneously the ionization, through secondary scintillation in the gas, and primary scintillation in the liquid produced by low energy recoils. The distinct ratio of primary to secondary scintillation for nuclear recoils from WIMPs (or neutrons), and for electron recoils from background, is key to the event-by-event discrimination capability of XENON. A 3kg dual phase detector with light readout provided by an array of 7 photomultipliers is currently being tested, along with other prototypes dedicated to various measurements relevant to the XENON program. We present some of the results obtained to-date and briefly discuss the next step in the phased approach to the XENON experiment, i.e. the development and underground deployment of a 10 kg detector (XENON10) during 2005.

  6. Results from the STAR TPC system test

    SciTech Connect

    Betts, W.; Bieser, F.; Bossingham, R.

    1996-12-31

    A system test of various components of the Solenoidal Tracker at RHIC (STAR) detector, operating in concern, has recently come on-line. Communication between a major sub-detector, a sector of the Time Projection Chamber (TPC), and the trigger, data acquisition and slow controls systems has been established, enabling data from cosmic ray muons to be collected. First results from an analysis of the TPC data are presented. These include measurements of system noise, electronic parameters such as amplifier gains and pedestal values, and tracking resolution for cosmic ray muons and laser induced ionization tracks. A discussion on the experience gained in integrating the different components for the system test is also given.

  7. Mobility and fluorescence of barium ions in xenon gas for the exo experiment

    NASA Astrophysics Data System (ADS)

    Benitez Medina, Julio Cesar

    The Enriched Xenon Observatory (EXO) is an experiment which aims to observe the neutrinoless double beta decay of 136Xe. The measurement of this decay would give information about the absolute neutrino mass and whether or not the neutrino is its own antiparticle. Since this is a very rare decay, the ability to reject background events by detecting the barium ion daughter from the double beta decay would be a major advantage. EXO is currently operating a detector with 200 kg of enriched liquid xenon, and there are plans to build a ton scale xenon detector. Measurements of the purity of liquid xenon in our liquid xenon test cell are reported. These results are relevant to the research on detection of single barium ions by our research group at Colorado State University. Details of the operation of the purity monitor are described. The effects of using a purifier, recirculation and laser ablation on the purity of liquid xenon are discussed. Mobility measurements of barium in xenon gas are reported for the first time. The variation of mobility with xenon gas pressure suggests that a significant fraction of molecular ions are formed when barium ions interact with xenon gas at high pressures. The measured mobility of Ba+ in Xe gas at different pressures is compared with the predicted theoretical value, and deviations are explained by a model that describes the fraction of molecular ions in Xe gas as a function of pressure. The results are useful for the analysis of experiments of fluorescence of Ba+ in xenon gas. It is also important to know the mobility of the ions in order to calculate the time they interact with an excitation laser in fluorescence experiments and in proposed 136 Ba+ daughter detection schemes. This thesis presents results of detection of laser induced fluorescence of Ba+ ions in Xe gas. Measurements of the pressure broadening of the excitation spectra of Ba+ in xenon gas are presented. Nonradiative decays due to gas collisions and optical pumping

  8. Solid Xenon Project

    NASA Astrophysics Data System (ADS)

    Balakishiyeva, Durdana N.; Mahapatra, Rupak; Saab, Tarek; Yoo, Jonghee

    2010-08-01

    Crystals like Germanium and Silicon need to be grown in specialized facilities which is time and money costly. It takes many runs to test the detector once it's manufactured and mishaps are very probable. It is of a great challenge to grow big germanium crystals and that's why stacking them up in a tower is the only way at the moment to increase testing mass. Liquid Noble gas experiments experiencing contamination problems, their predicted energy resolution at 10 keV and lower energy range is not as good as predicted. Every experiment is targeting one specific purpose, looking for one thing. Why not to design an experiment that is diverse and build a detector that can search for Dark Matter, Solar Axions, Neutrinoless Double Beta decay, etc. Solid Xenon detector is such detector. We designed a simple Xenon crystal growing chamber that was put together at Fermi National Accelerator Laboratory. The first phase of this experiment was to demonstrate that a good, crack free Xenon crystal can be grown (regardless of many failed attempts by various groups) and our first goal, 1 kg crystal, was successful.

  9. Solid Xenon Project

    SciTech Connect

    Balakishiyeva, Durdana N.; Saab, Tarek; Mahapatra, Rupak; Yoo, Jonghee

    2010-08-30

    Crystals like Germanium and Silicon need to be grown in specialized facilities which is time and money costly. It takes many runs to test the detector once it's manufactured and mishaps are very probable. It is of a great challenge to grow big germanium crystals and that's why stacking them up in a tower is the only way at the moment to increase testing mass. Liquid Noble gas experiments experiencing contamination problems, their predicted energy resolution at 10 keV and lower energy range is not as good as predicted. Every experiment is targeting one specific purpose, looking for one thing. Why not to design an experiment that is diverse and build a detector that can search for Dark Matter, Solar Axions, Neutrinoless Double Beta decay, etc. Solid Xenon detector is such detector. We designed a simple Xenon crystal growing chamber that was put together at Fermi National Accelerator Laboratory. The first phase of this experiment was to demonstrate that a good, crack free Xenon crystal can be grown (regardless of many failed attempts by various groups) and our first goal, 1 kg crystal, was successful.

  10. Highly integrated electronics for the star TPC

    SciTech Connect

    Arthur, A.A.; Bieser, F.; Hearn, W.; Kleinfelder, S.; Merrick, T.; Millaud, J.; Noggle, T.; Rai, G.; Ritter, H.G.; Wieman, H.

    1991-12-31

    The concept for the STAR TPC front-end electronics is presented and the progress toward the development of a fully integrated solution is described. It is the goal of the R+D program to develop the complete electronics chain for the STAR central TPC detector at RHIC. It is obvious that solutions chosen e.g. for ALEPH are not adequate for the 150000 channels that need to be instrumented for readout. It will be necessary to perform all the signal processing, digitization and multiplexing directly on the detector in order to reduce per channel cost and the amount of cabling necessary to read out the information. We follow the approach chosen by the EOS TPC project, where the readout electronics on the detector consists of an integrated preamplifier, a hybrid shaping amplifier, an integrated switched capacitor array and a highly multiplexed ADC. The STAR electronics will be further integrated so that approximately 16 channels of the preamplifier, the shaper, the analog store and the ADC will be contained in two integrated circuits located directly on the pad plane.

  11. Design and construction of the spirit TPC

    NASA Astrophysics Data System (ADS)

    Tangwancharoen, Suwat

    The nuclear symmetry energy, the density dependent term of the nuclear equation of state (EOS), governs important properties of neutron stars and dense nuclear matter. At present, it is largely unconstrained in the supra-saturation density region. This dissertation concerns the design and construction of the SpiRIT Time Projection Chamber (SpiRIT-TPC) at Michigan State University as part of an international collaborations to constrain the symmetry energy at supra-saturation density. The SpiRIT-TPC has been constructed during the dissertation and transported to Radioactive Isotope Beam Factory (RIBF) at RIKEN, Japan where it will be used in conjunction with the SAMURAI Spectrometer. The detector will measure yield ratios for pions and other light charged particles produced in central collisions of neutron-rich heavy ions such as 132Sn + 124Sn. The dissertation describes the design and solutions to the problem presented by the measurement. This also compares some of the initial fast measurement of the TPC to calculation of the performance characteristics.

  12. Electrochemical studies at high pressure

    SciTech Connect

    Cruanes, M.T.

    1993-01-01

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

  13. 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.

  14. 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.

  15. Xenon ion propulsion for orbit transfer

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Patterson, M. J.; Gruber, R. P.

    1990-01-01

    For more than 30 years, NASA has conducted an ion propulsion program which has resulted in several experimental space flight demonstrations and the development of many supporting technologies. Technologies appropriate for geosynchronous stationkeeping, earth-orbit transfer missions, and interplanetary missions are defined and evaluated. The status of critical ion propulsion system elements is reviewed. Electron bombardment ion thrusters for primary propulsion have evolved to operate on xenon in the 5 to 10 kW power range. Thruster efficiencies of 0.7 and specific impulse values of 4000 s were documented. The baseline thruster currently under development by NASA LeRC includes ring-cusp magnetic field plasma containment and dished two-grid ion optics. Based on past experience and demonstrated simplifications, power processors for these thrusters should have approximately 500 parts, a mass of 40 kg, and an efficiency near 0.94. Thrust vector control, via individual thruster gimbals, is a mature technology. High pressure, gaseous xenon propellant storage and control schemes, using flight qualified hardware, result in propellant tankage fractions between 0.1 and 0.2. In-space and ground integration testing has demonstrated that ion propulsion systems can be successfully integrated with their host spacecraft. Ion propulsion system technologies are mature and can significantly enhance and/or enable a variety of missions in the nation's space propulsion program.

  16. 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.

  17. High pressure synthesis gas fermentation

    SciTech Connect

    Not Available

    1991-01-01

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

  18. Xenon Feed System Progress (Postprint)

    DTIC Science & Technology

    2006-06-13

    development, assembly and test of an electric propulsion xenon feed system for a flight technology demonstration program. Major accomplishments...pressure transducer feedback, the PFCV has successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology Demonstration Program. The feed

  19. Shear Thinning in Xenon

    NASA Technical Reports Server (NTRS)

    Bergm Robert F.; Moldover, Michael R.; Yao, Minwu; Zimmerli, Gregory A.

    2009-01-01

    We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids such as molten plastics or ketchup, near the critical point of xenon. The data span a wide range of dimensionless shear rate: the product of the shear rate and the relaxation time of critical fluctuations was greater than 0.001 and was less than 700. As predicted by theory, shear thinning occurred when this product was greater than 1. The measurements were conducted aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity.

  20. How to Advance TPC Benchmarks with Dependability Aspects

    NASA Astrophysics Data System (ADS)

    Almeida, Raquel; Poess, Meikel; Nambiar, Raghunath; Patil, Indira; Vieira, Marco

    Transactional systems are the core of the information systems of most organizations. Although there is general acknowledgement that failures in these systems often entail significant impact both on the proceeds and reputation of companies, the benchmarks developed and managed by the Transaction Processing Performance Council (TPC) still maintain their focus on reporting bare performance. Each TPC benchmark has to pass a list of dependability-related tests (to verify ACID properties), but not all benchmarks require measuring their performances. While TPC-E measures the recovery time of some system failures, TPC-H and TPC-C only require functional correctness of such recovery. Consequently, systems used in TPC benchmarks are tuned mostly for performance. In this paper we argue that nowadays systems should be tuned for a more comprehensive suite of dependability tests, and that a dependability metric should be part of TPC benchmark publications. The paper discusses WHY and HOW this can be achieved. Two approaches are introduced and discussed: augmenting each TPC benchmark in a customized way, by extending each specification individually; and pursuing a more unified approach, defining a generic specification that could be adjoined to any TPC benchmark.

  1. Design and performance of TOPAZ TPC-trigger

    SciTech Connect

    Enomoto, R.; Tsukada, K.; Ujiie, N.; Shirahashi, A.

    1988-02-01

    The Time Projection Chamber (TPC) is widely used in the high energy physics experiment. The authors developed the new track finding algorithm by using the TOPAZ-TPC. The logic not only finds the number of tracks, but also calculates their vertex positions. It also takes care of the sector boundary crossing tracks. The proto-type TPC-Trigger has been tested at the in-beam experiment and has shown good performance. The authors achieved the vertex resolution of less than 10cm (r.m.s.) in the beam direction. The improved TPC-Trigger system is being used in October 1987 beam run.

  2. Investigation of Laser Driven Charge Clusters in Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Njoya, Oumarou; Tsang, Thomas; Tarka, Michal; Fairbank, William; Kumar, Krishna; Rao, Triveni; nEXO Collaboration

    2017-01-01

    We report on progress made in testing the concept of a laser driven in-situ electron lifetime monitoring system for a large Liquid Xenon Time Projection Chamber (LXe TPC). In our setup we use a 150-ns, 262-nm UV pulse (4th harmonic of YLF laser) to generate electrons from a gold photocathode; the laser couples to the photocathode via a 600- μm optical fiber. The electrons drift 20-mm in a uniform electric field inside the LXe-filled cell. The drift velocity and effects of diffusion are measured. Our setup is able to distinguish photo-emission due to gold from the multi-photon ionization of LXe by different drift times; this allows us to infer the cross section of the two-photon ionization process in LXe. Finally, we discuss preliminary studies of the stability, quantum efficiency, and work function of gold in a Xe environment. Department of Energy.

  3. Optical pumping and xenon NMR

    SciTech Connect

    Raftery, M.D.

    1991-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping {sup 129}Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the {sup 131}Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

  4. Optical pumping and xenon NMR

    SciTech Connect

    Raftery, M.D.

    1991-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping [sup 129]Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the [sup 131]Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.

  5. 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.

  6. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    SciTech Connect

    Benilov, M. S.; Hechtfischer, U.

    2012-04-01

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  7. Xe-129 NMR of xenon dissolved in biological media.

    NASA Astrophysics Data System (ADS)

    Mazitov, R. K.; Kuzma, N. N.; Happer, W.; Driehuys, B.; Merrill, G. F.

    2002-03-01

    The high solubility and large chemical shift of ^129Xe in various tissues makes it an ideal, non-invasive probe for pathological conditions such as cancer or atherosclerosis. To this end, we report NMR measurements of lineshapes, chemical shifts, and relaxation times of ^129Xe dissolved in the following biological tissues in vitro: heart, muscle, sinew, stomach(R.K. Mazitov, K. M. Enikeev, et al., Dokl. Akad. Nauk) 365, 396 (1999)., and the white and yolk of egg. NMR measurements of xenon dissolved in olive and sunflower oils are also reported. Tissues weighing 160--250 mg, not exposed to freezing, were studied in a 11.75 T field at the ^129Xe resonance frequency of 138.4 MHz; the pressure of xenon in the sealed-sample ampoules was ~20 bar. The influence of drugs and water content on tissues was studied. No xenon-water clathrates(J.A. Ripmeester and D.W. Davidson, J. Mol. Struct. ) 75, 67 (1981). were observed in the tissues, even at the high pressures used. The aim of this study is to establish possible correlations between the NMR parameters of dissolved xenon and the state of the tissue.

  8. 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.

  9. A liquid xenon imaging telescope for gamma ray astrophysics: Design and expected performance

    NASA Technical Reports Server (NTRS)

    Aprile, E.; Mukherjee, R.; Chen, D.; Bolotnikov, A.

    1992-01-01

    A high resolution telescope for imaging cosmic x ray sources in the MeV region, with an angular resolution better than 0.5 deg is being developed as balloon-borne payload. The instrument consists of a 3-D liquid xenon TPC as x ray detector, coupled with a coded aperture at a distance of 1 meter. A study of the actual source distribution of the 1.809 MeV line from the decay of Al-26 and the 511 keV positron-electron annihilation line is among the scientific objectives, along with a search for new x ray sources. The telescope design parameters and expected minimum flux sensitivity to line and continuum radiation are presented. The unique capablity of the LXe-TPC as a Compton Polarimeter is also discussed.

  10. An RF-only ion-funnel for extraction from high-pressure gases

    SciTech Connect

    Brunner, T.; Fudenberg, D.; Varentsov, V.; Sabourov, A.; Gratta, G.; Dilling, J.; DeVoe, R.; Sinclair, D.; Fairbank, W.; Albert, J. B.; Auty, D. J.; Barbeau, P. S.; Beck, D.; Benitez-Medina, C.; Breidenbach, M.; Cao, G. F.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Daniels, T.; Daugherty, S. J.; Didberidze, T.; Dolinski, M. J.; Dunford, M.; Fabris, L.; Farine, J.; Feldmeier, W.; Fierlinger, P.; Gornea, R.; Graham, K.; Heffner, M.; Hughes, M.; Jewell, M.; Jiang, X. S.; Johnson, T. N.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Killick, R.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Leonard, D. S.; Leonard, F.; Licciardi, C.; Lin, Y. H.; Ling, J.; MacLellan, R.; Marino, M. G.; Mong, B.; Moore, D.; Odian, A.; Ostrovskiy, I.; Ouellet, C.; Piepke, A.; Pocar, A.; Retiere, F.; Rowson, P. C.; Rozo, M. P.; Schubert, A.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tosi, D.; Twelker, K.; Vuilleumier, J. -L.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Yang, L.; Yen, Y. -R.

    2015-01-27

    An RF ion-funnel technique has been developed to extract ions from a high-pressure (10 bar) noble-gas environment into a vacuum (10-6 mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting 136Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to simulations. This demonstration of extraction of ions, with mass comparable to that of the gas generating the high-pressure, has applications to Ba tagging from a Xe-gas time-projection chamber for double-beta decay, as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m > 40 u) carrier gas.

  11. An RF-only ion-funnel for extraction from high-pressure gases

    DOE PAGES

    Brunner, T.; Fudenberg, D.; Varentsov, V.; ...

    2015-01-27

    An RF ion-funnel technique has been developed to extract ions from a high-pressure (10 bar) noble-gas environment into a vacuum (10-6 mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting 136Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to simulations. This demonstration of extraction of ions, with mass comparable to that of the gas generating the high-pressure, has applications to Ba tagging from a Xe-gas time-projectionmore » chamber for double-beta decay, as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m > 40 u) carrier gas.« less

  12. Liquid-xenon time-projection chamber for gamma rays in the MeV region: development status

    NASA Astrophysics Data System (ADS)

    Aprile, Elena; Bolotnikov, Aleksey E.; Chen, D.; Mukherjee, Reshmi

    1992-12-01

    The feasibility of a large volume liquid xenon time projection chamber (LXe-TPC) for three- dimensional imaging and spectroscopy of cosmic gamma-ray sources, was tested with a 3.5 liter prototype. The observation of induction signals produced by MeV gamma rays in liquid xenon is reported, with a good signal-to-noise ratio. The results represent the first experimental demonstration with a liquid xenon ionization chamber of a non-destructive read- out of the electron image produced by point-like charges, using a sense wire configuration of the type originally proposed in 1970 by Gatti et al. An energy resolution as good as that previously measured by us with millimeter size chambers, was achieved with the large prototype of 4.4 cm drift gap.

  13. Venus, Earth, Xenon

    NASA Astrophysics Data System (ADS)

    Zahnle, K. J.

    2013-12-01

    Xenon has been regarded as an important goal of many proposed missions to Venus. This talk is intended to explain why. Despite its being the heaviest gas found in natural planetary atmospheres, there is more evidence that Xe escaped from Earth than for any element apart from helium: (i) Atmospheric Xe is very strongly mass fractionated (at about 4% per amu) from any known solar system source. This suggests fractionating escape that preferentially left the heavy Xe isotopes behind. (ii) Xe is underabundant compared to Kr, a lighter noble gas that is not strongly mass fractionated in air. (iii) Radiogenic Xe is strongly depleted by factors of several to ~100 compared to the quantities expected from radioactive decay of primordial solar system materials. In these respects Xe on Mars is similar to Xe on Earth, but with one key difference: Xe on Mars is readily explained by a simple process like hydrodynamic escape that acts on an initially solar or meteoritic Xe. This is not so for Earth. Earth's Xe cannot be derived by an uncontrived mass fractionating process acting on any known type of Solar System Xe. Earth is a stranger, made from different stuff than any known meteorite or Mars or even the Sun. Who else is in Earth's family? Comets? We know nothing. Father Zeus? Data from Jupiter are good enough to show that jovian Xe is not strongly mass-fractionated but not good enough to determine whether Jupiter resembles the Earth or the Sun. Sister Venus? Noble gas data from Venus are incomplete, with Kr uncertain and Xe unmeasured. Krypton was measured by several instruments on several spacecraft. The reported Kr abundances are discrepant and were once highly controversial. These discrepancies appear to have been not so much resolved as forgotten. Xenon was not detected on Venus. Upper limits were reported for the two most abundant xenon isotopes 129Xe and 132Xe. From the limited data it is not possible to tell whether Venus's affinities lie with the solar wind, or with

  14. Team Primacy Concept (TPC) Based Employee Evaluation and Job Performance

    ERIC Educational Resources Information Center

    Muniute, Eivina I.; Alfred, Mary V.

    2007-01-01

    This qualitative study explored how employees learn from Team Primacy Concept (TPC) based employee evaluation and how they use the feedback in performing their jobs. TPC based evaluation is a form of multirater evaluation, during which the employee's performance is discussed by one's peers in a face-to-face team setting. The study used Kolb's…

  15. Critical Viscosity of Xenon investigators

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Dr. Dr. Robert F. Berg (right), principal investigator and Dr. Micheal R. Moldover (left), co-investigator, for the Critical Viscosity of Xenon (CVX/CVX-2) experiment. They are with the National Institutes of Standards and Technology, Gaithersburg, MD. The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Although it does not easily combine with other chemicals, its viscosity at the critical point can be used as a model for a range of chemicals.

  16. Prototype sector production for the STAR inner TPC upgrade

    NASA Astrophysics Data System (ADS)

    Yang, Chi; STAR Collaboration

    2017-01-01

    The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) is upgrading the Inner TPC sectors (iTPC). By increasing the number of inner pad rows from 13 to 40 and renewing the inner sector wires, this major detector upgrade will improve the rapidity coverage from |η| < 1 to |η| < 1.5, provide better momentum resolution, and better energy loss (dE/dx) resolution. The iTPC upgrade is crucial to STAR Beam Energy Scan Phase II (BES- II) program, which will provide in-depth understanding on QCD phase diagram and in-medium modification. In this paper we report on progress on the iTPC sector construction. The iTPC module fabrication techniques and testing results from the first full size prototype are presented.

  17. Development of a high resolution liquid xenon imaging chamber for gamma-ray astronomy

    NASA Technical Reports Server (NTRS)

    Aprile, Elena

    1991-01-01

    The objective was to develop the technology of liquid xenon (LXe) detectors for spectroscopy and imaging of gamma rays from astrophysical sources emitting in the low to medium energy regime. In particular, the technical challenges and the physical processes relevant to the realization of the LXe detector operated as a Time Projection Chamber (TPC) were addressed and studied. Experimental results were obtained on the following topics: (1) long distance drift of free electrons in LXe (purity); (2) scintillation light yield for electrons and alphas in LXe (triggering); and (3) ionization yield for electrons and gamma rays in LXe (energy resolution). The major results from the investigations are summarized.

  18. Solubilized xenon 133 lung scintigraphy

    SciTech Connect

    Oates, E.; Sarno, R.C.

    1988-11-01

    Lung scanning using solubilized xenon 133 can provide important information concerning both pulmonary perfusion and ventilation. This technique proved valuable in establishing the diagnosis of congenital lobar emphysema in a 7-month-old baby.

  19. A Decade of Xenon Chemistry

    ERIC Educational Resources Information Center

    Moody, G. J.

    1974-01-01

    Presents reactions for the formation of xenon compounds and compounds of the other inert gases. Provides bonding and structure theories for noble gas compounds and speculates on possible applications. (GS)

  20. Martensitic fcc-to-hcp transformation observed in xenon at high pressure.

    PubMed

    Cynn, H; Yoo, C S; Baer, B; Iota-Herbei, V; McMahan, A K; Nicol, M; Carlson, S

    2001-05-14

    Angle-resolved x-ray diffraction patterns of Xe to 127 GPa indicate that the fcc-to-hcp transition occurs martensitically between 3 and 70 GPa in diamond-anvil cells without an intermediate phase. These data also reveal that the transition occurs by the introduction of stacking disorder in the fcc lattice at low pressure, which grows into hcp domains with increasing pressure. The small energy difference between the hcp and the fcc structures may allow the two phases to coexist over a wide pressure range. Evidence of similar stacking disorder and incipient growth of an hcp phase are also observed in solid Kr.

  1. Irreversible xenon insertion into a small-pore zeolite at moderate pressures and temperatures

    SciTech Connect

    Seoung, Donghoon; Cynn, Hyunchae; Park, Changyong; Choi, Kwang -Yong; Blom, Douglas A.; Evans, William J.; Kao, Chi -Chang; Vogt, Thomas; Lee, Yongjae

    2014-09-01

    Pressure drastically alters the chemical and physical properties of materials and allows structural phase transitions and chemical reactions to occur that defy much of our understanding gained under ambient conditions. Particularly exciting is the high-pressure chemistry of xenon, which is known to react with hydrogen and ice at high pressures and form stable compounds. Here, we show that Ag16Al16Si24O8·16H2O (Ag-natrolite) irreversibly inserts xenon into its micropores at 1.7 GPa and 250 °C, while Ag+ is reduced to metallic Ag and possibly oxidized to Ag2+. In contrast to krypton, xenon is retained within the pores of this zeolite after pressure release and requires heat to desorb. This irreversible insertion and trapping of xenon in Ag-natrolite under moderate conditions sheds new light on chemical reactions that could account for the xenon deficiency relative to argon observed in terrestrial and Martian atmospheres.

  2. Irreversible xenon insertion into a small-pore zeolite at moderate pressures and temperatures

    DOE PAGES

    Seoung, Donghoon; Cynn, Hyunchae; Park, Changyong; ...

    2014-09-01

    Pressure drastically alters the chemical and physical properties of materials and allows structural phase transitions and chemical reactions to occur that defy much of our understanding gained under ambient conditions. Particularly exciting is the high-pressure chemistry of xenon, which is known to react with hydrogen and ice at high pressures and form stable compounds. Here, we show that Ag16Al16Si24O8·16H2O (Ag-natrolite) irreversibly inserts xenon into its micropores at 1.7 GPa and 250 °C, while Ag+ is reduced to metallic Ag and possibly oxidized to Ag2+. In contrast to krypton, xenon is retained within the pores of this zeolite after pressure releasemore » and requires heat to desorb. This irreversible insertion and trapping of xenon in Ag-natrolite under moderate conditions sheds new light on chemical reactions that could account for the xenon deficiency relative to argon observed in terrestrial and Martian atmospheres.« less

  3. 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

  4. Reflectance measurements of PTFE, Kapton, and PEEK for xenon scintillation light for the LZ detector.

    NASA Astrophysics Data System (ADS)

    Arthurs, M.; Batista, E.; Haefner, J.; Lorenzon, W.; Morton, D.; Neff, A.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; LZ Collaboration

    2017-01-01

    LZ (LUX-Zeplin) is an international collaboration that will look for dark matter candidates, WIMPs (Weakly Interacting Massive Particles), through direct detection by dual-phase time projection chamber (TPC) using liquid xenon. The LZ detector will be located nearly a mile underground at SURF, South Dakota, shielded from cosmic background radiation. Seven tons active mass of liquid xenon will be used for detecting the weak interaction of WIMPs with ordinary matter. Over three years of operation it is expected to reach the ultimate sensitivity of 2x10-48 cm2 for a WIMP mass of 50 GeV. As for many other rare event searches, high light collection efficiency is essential for LZ detector. Moreover, in order to achieve greater active volume for detection as well as reduce potential backgrounds, thinner detector walls without significant loss in reflectance are desired. Reflectance measurements of polytetrafluoroethylene (PTFE), Kapton, and PEEK for xenon scintillation light (178 nm), conducted at the University of Michigan using the Michigan Xenon Detector (MiX) will be presented. The University of Michigan, LZ Collaboration, The US Department of Energy.

  5. Elastomers Compatible With High-Pressure Oxygen

    NASA Technical Reports Server (NTRS)

    Martin, Jon W.

    1987-01-01

    Compatibility increased by fluorination. Report describes experiments aimed at improving compatibility of some fluorinated elastomers with high-pressure oxygen. Such elastomers needed for seals, gaskets, and positive-expulsion devices used with high-pressure oxygen. Oxygen - compatibility tests carried out on five elastomers chosen on the basis of literature survey.

  6. 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.

  7. 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.

  8. Development of a functionalized Xenon biosensor

    SciTech Connect

    Spence, Megan M.; Ruiz, E. Janette; Rubin, Seth M.; Lowery, Thomas J.; Winssinger, Nicolas; Schultz, Peter G.; Wemmer, David E.; Pines, Alexander

    2004-03-25

    NMR-based biosensors that utilize laser-polarized xenon offer potential advantages beyond current sensing technologies. These advantages include the capacity to simultaneously detect multiple analytes, the applicability to in vivo spectroscopy and imaging, and the possibility of remote amplified detection. Here we present a detailed NMR characterization of the binding of a biotin-derivatized caged-xenon sensor to avidin. Binding of functionalized xenon to avidin leads to a change in the chemical shift of the encapsulated xenon in addition to a broadening of the resonance, both of which serve as NMR markers of ligand-target interaction. A control experiment in which the biotin-binding site of avidin was blocked with native biotin showed no such spectral changes, confirming that only specific binding, rather than nonspecific contact, between avidin and functionalized xenon leads to the effects on the xenon NMR spectrum. The exchange rate of xenon (between solution and cage) and the xenon spin-lattice relaxation rate were not changed significantly upon binding. We describe two methods for enhancing the signal from functionalized xenon by exploiting the laser-polarized xenon magnetization reservoir. We also show that the xenon chemical shifts are distinct for xenon encapsulated in different diastereomeric cage molecules. This demonstrates the potential for tuning the encapsulated xenon chemical shift, which is a key requirement for being able to multiplex the biosensor.

  9. Development of a TPC for an ILC Detector

    NASA Astrophysics Data System (ADS)

    Diener, R.; LCTPC Collaboration

    The ILD concept, one of two proposed detector concepts for the planned International Linear Collider (ILC), foresees a Time Projection Chamber (TPC) as the main tracking detector. The LCTPC (Linear Collider TPC) collaboration pursues R&D to develop such a TPC based on the best state-of-the-art technology. After tests with smaller prototypes, the current efforts focus on studies using a large prototype with a diameter of 770 mm and a length of 610 mm. This prototype can accommodate seven read-out modules of a size comparable to the onesthatwouldbeusedinthe finalTPC.Several prototypesof modulesusing MicromegasorGEM structuresasgas amplification were constructedand tested. Besidesthe traditionalpad read-out,apixel read-out basedontheTimePix chipis studiedinthese testswithupto8TimePixchipsona board.The current statusand futureplansoftheR&Dare presented.

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

    NASA Astrophysics Data System (ADS)

    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. The method is applied to address the longstanding discrepancy between 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 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, in contrast to DAC data.

  11. 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.

  12. Behavior of TPC's in a high particle flux environment

    SciTech Connect

    Etkin, A.; Eisemann, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C. ); Lindenbaum, S.J. City Coll., New York, NY ); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. ); Hallman, T.J.; Madansky, L

    1991-12-13

    TPC's (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  13. [Xenon: From rare gaz to doping product].

    PubMed

    Tassel, Camille; Le Daré, Brendan; Morel, Isabelle; Gicquel, Thomas

    2016-04-01

    Doping is defined as the use of processes or substances to artificially increase physical or mental performance. Xenon is a noble gas used as an anesthetic and recently as a doping agent. Xenon is neuroprotective as an antagonist of NMDA glutamate receptors. Xenon stimulates the synthesis of erythropoietin (EPO) by increase of hypoxia inducible factor (HIF). Xenon would be a new doping product, maintaining doping methods ahead of detection.

  14. 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.

  15. Critical Viscosity of Xenon team

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure (at left) that is placed inside a pressure canister. A similar canister (right) holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (left) of the National Institutes of Standards and Technology, Gaithersburg, MD.

  16. Critical Viscosity of Xenon team

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure (at left) that is placed inside a pressure canister. A similar canister (right) holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD.

  17. CARS Diagnostics of High Pressure Combustion.

    DTIC Science & Technology

    1982-11-01

    e) 8. CONTRACT OR GRANT NUMBER(e) J. H. Stufflebeam t JDAAG29- 79-C-0008J %A,, Shirley R,,. Hall 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10...also the work in N2 at elevated tem- perature up to 30 atmospheres. John H. Stufflebeam continued the high pressure CARS work under the contract...Spectroscopy, Bordeaux, France, September 1982. 12. J. H. Stufflebeam , J. F. Verdieck, and R. J. Hall: CARS Diagnostics of High Pressure and

  18. Ultra High Pressure (UHP) Technology (BRIEFING SLIDES)

    DTIC Science & Technology

    2008-08-25

    AFRL-RX-TY-TP-2008-4600 POSTPRINT ULTRA HIGH PRESSURE ( UHP ) TECHNOLOGY (BRIEFING SLIDES) Patrick D. Sullivan Air Force Research...Since the discovery of the unprecedented effectiveness of 1500 psi Ultra High Pressure ( UHP ) technology in September of 2002 , AFRL scientists and... engineers have sought to increase Aircraft Rescue Fire Fighting (ARFF) performance by moving to higher flow rates to obtain greater throw distance and

  19. 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.

  20. 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.

  1. Simulation studies on performance parameters of a TPC polarimeter

    NASA Astrophysics Data System (ADS)

    Rakhee, K.; Koushal, V.; Radhakrishna, V.; Baishali, G.; A. M., Vinodkumar

    2014-07-01

    X-ray polarimeters based on Time Projection Chamber (TPC) geometry are currently being studied and developed to make sensitive measurement of polarization in 2-10keV energy range. TPC soft X-ray polarimeters exploit the fact that emission direction of the photoelectron ejected via photoelectric effect in a gas proportional counter carries the information of the polarization of the incident X-ray photon. Operating parameters such as pressure, drift field and driftgap affect the performance of a TPC polarimeter. Simulations presented here showcase the effect of these operating parameters on the modulation factor of the TPC polarimeter. Models of Garfield are used to study photoelectron interaction in gas and drift of electron cloud towards Gas Electron Multiplier (GEM). The emission direction is reconstructed from the image and modulation factor is computed. Our study has shown that Ne/DME (50/50) at lower pressure and drift field can be used for a TPC polarimeter with modulation factor of 50-65%.

  2. Thermal Transport at Static High-Pressures

    NASA Astrophysics Data System (ADS)

    Pangilinan, G. I.; Ladouceur, H. D.; Russell, T. P.

    2000-03-01

    Static properties and dynamic processes at high pressures and high temperatures are critically dependent on thermal properties of materials. Measurements of thermal properties at high pressures have only slowly developed through the years. Here we present a novel method, utilizing gem anvil cells, to measure specific heat, thermal conductivity and thermal diffusivity. The method involves launching a thermal wave in a sample. Subsequently, a localized sensor measures the temporal behavior of the temperature at a fixed point downstream in the material. A pulsed laser is used to deliver the heating pulse, while time-resolved fluorescence from a ruby sphere is used to measure the temperature. The thermal properties are inferred from the temporal behavior of the temperature and the heat conduction equations with appropriate boundary conditions. The thermal properties of table salt (NaCl) are obtained using this method. Impact to current and future high-pressure research, including materials science and geophysics will be addressed.

  3. 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.

  4. 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.

  5. Curved and conformal high-pressure vessel

    SciTech Connect

    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.

  6. Drift parameters optimization of a TPC polarimeter: a simulation study

    NASA Astrophysics Data System (ADS)

    Rakhee, K.; Radhakrishna, V.; Koushal, V.; Baishali, G.; Vinodkumar, A. M.

    2015-06-01

    Time Projection Chamber (TPC) based X-ray polarimeters using Gas Electron Multiplier (GEM) are currently being developed to make sensitive measurement of polarization in 2-10 keV energy range. The emission direction of the photoelectron ejected via photoelectric effect carries the information of the polarization of the incident X-ray photon. Performance of a gas based polarimeter is affected by the operating drift parameters such as gas pressure, drift field and drift-gap. We present simulation studies carried out in order to understand the effect of these operating parameters on the modulation factor of a TPC polarimeter. Models of Garfield are used to study photoelectron interaction in gas and drift of electron cloud towards GEM. Our study is aimed at achieving higher modulation factors by optimizing drift parameters. Study has shown that Ne/DME (50/50) at lower pressure and drift field can lead to desired performance of a TPC polarimeter.

  7. Hydrogen at high pressure and temperatures

    SciTech Connect

    Nellis, W J

    1999-09-30

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

  8. 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.

  9. 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.

  10. 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.

  11. Synthesis and stability of xenon oxides Xe2O5 and Xe3O2 under pressure.

    PubMed

    Dewaele, Agnès; Worth, Nicholas; Pickard, Chris J; Needs, Richard J; Pascarelli, Sakura; Mathon, Olivier; Mezouar, Mohamed; Irifune, Tetsuo

    2016-08-01

    The noble gases are the most inert group of the periodic table, but their reactivity increases with pressure. Diamond-anvil-cell experiments and ab initio modelling have been used to investigate a possible direct reaction between xenon and oxygen at high pressures. We have now synthesized two oxides below 100 GPa (Xe2O5 under oxygen-rich conditions, and Xe3O2 under oxygen-poor conditions), which shows that xenon is more reactive under pressure than predicted previously. Xe2O5 was observed using X-ray diffraction methods, its structure identified through ab initio random structure searching and confirmed using X-ray absorption and Raman spectroscopies. The experiments confirm the recent prediction of Xe3O2 as a stable xenon oxide under high pressure. Xenon atoms adopt mixed oxidation states of 0 and +4 in Xe3O2 and +4 and +6 in Xe2O5. Xe3O2 and Xe2O5 form extended networks that incorporate oxygen-sharing XeO4 squares, and Xe2O5 additionally incorporates oxygen-sharing XeO5 pyramids. Other xenon oxides (XeO2, XeO3) are expected to form at higher pressures.

  12. Synthesis and stability of xenon oxides Xe2O5 and Xe3O2 under pressure

    NASA Astrophysics Data System (ADS)

    Dewaele, Agnès; Worth, Nicholas; Pickard, Chris J.; Needs, Richard J.; Pascarelli, Sakura; Mathon, Olivier; Mezouar, Mohamed; Irifune, Tetsuo

    2016-08-01

    The noble gases are the most inert group of the periodic table, but their reactivity increases with pressure. Diamond-anvil-cell experiments and ab initio modelling have been used to investigate a possible direct reaction between xenon and oxygen at high pressures. We have now synthesized two oxides below 100 GPa (Xe2O5 under oxygen-rich conditions, and Xe3O2 under oxygen-poor conditions), which shows that xenon is more reactive under pressure than predicted previously. Xe2O5 was observed using X-ray diffraction methods, its structure identified through ab initio random structure searching and confirmed using X-ray absorption and Raman spectroscopies. The experiments confirm the recent prediction of Xe3O2 as a stable xenon oxide under high pressure. Xenon atoms adopt mixed oxidation states of 0 and +4 in Xe3O2 and +4 and +6 in Xe2O5. Xe3O2 and Xe2O5 form extended networks that incorporate oxygen-sharing XeO4 squares, and Xe2O5 additionally incorporates oxygen-sharing XeO5 pyramids. Other xenon oxides (XeO2, XeO3) are expected to form at higher pressures.

  13. 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...

  14. Hurricane risk mitigation - High Pressure Gas Facility

    NASA Technical Reports Server (NTRS)

    2008-01-01

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

  15. 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…

  16. Feedthrough Seal For High-Pressure Vessel

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  17. 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.

  18. 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.

  19. Elasticity of orthoenstatite at high-pressure

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  20. Xenon Fractionation and Archean Hydrogen Escape

    NASA Technical Reports Server (NTRS)

    Zahnle, K. J.

    2015-01-01

    Xenon is the heaviest gas found in significant quantities in natural planetary atmospheres. It would seem the least likely to escape. Yet there is more evidence for xenon escape from Earth than for any element other than helium and perhaps neon. The most straightforward evidence is that most of the radiogenic Xe from the decay of (129)I (half-life 15.7 Myr) and (244)Pu (half-life 81 Myr) that is Earth's birthright is missing. The missing xenon is often attributed to the impact erosion of early atmospheres of Earth and its ancestors. It is obvious that if most of the radiogenic xenon were driven off by impacts, most of the rest of the atmophiles fared the same fate. The other line of evidence is in the nonradiogenic isotopes of xenon and its silent partner, krypton. Atmospheric xenon is strongly mass fractionated (at about 4% per amu) compared to any known solar system source (Figure 1). This is in stark contrast to krypton, which may not be fractionated at all: atmospheric Kr is slightly heavier than solar Kr (at about 0.5% per amu), but it is the same as in carbonaceous chondrites. Nonradiogenic xenon is also under abundant relative to krypton (the so-called "missing xenon" problem). Together these observations imply that xenon has been subject to fractionating escape and krypton not.

  1. 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

  2. Stellar Helium Burning Studied with an Optical Readout TPC (O-TPC) at HIγS

    NASA Astrophysics Data System (ADS)

    Gai, Moshe; UConn-Yale-Duke-Weizmann-PTB-UCL Collaboration

    2011-09-01

    An Optical Readout Time Projection Chamber (O-TPC) operating with the gas mixture of CO2(80%) + N2(20%) at 100 torr with gamma beams from the HIγS facility of TUNL at Duke University were used to study the formation of carbon and oxygen during helium burning. Measurements were carried out with circularly polarized gamma-ray beams at energies: Eγ = 9.08, 9.38, 9.58, 9.78, 10.08, 10.38 and 10.68 MeV. We have begun the process of extracting complete angular distributions for the 16O(γ,α)12C reaction and the 12C(γ,3α) reaction (eventually with energy bins of approximately 100 keV) in order to determine the values of SE1, SE2 and the mixing phase phi12 of the 16O(γ, α)12C reaction. The rate of carbon formation at high temperatures (T > 3 GK) was suggested to increase due to contributions from a higher lying 2+ state. We have measured an angular distribution of (essentially) pure E2 transition at Eγ = 9.78 MeV of the 12C(γ, 3α) reaction, providing conclusive evidence for the elusive 2+2 state in 12C.

  3. Studies in Nuclear Astrophysics with an Optical Readout TPC (O-TPC) at HIγS

    NASA Astrophysics Data System (ADS)

    Gai, Moshe; UConn-Yale-Duke-Weizmann-PTB-UCL Collaboration

    2012-02-01

    An Optical Readout Time Projection Chamber (O-TPC) operating with the gas mixture of CO2(80%) + N2(20%) at 100 torr with gamma beams from the HIγS facility of TUNL at Duke University were used to study the formation of carbon and oxygen during helium burning. Measurements were carried out with circularly polarized gamma-ray beams at energies: Eγ = 9.08, 9.38, 9.58, 9.78, 10.08, 10.38 and 10.68 MeV. We have begun the process of extracting complete angular distributions for the 16O(γ, α)12C reaction and the 12C(γ, 3α) reaction (eventually with energy bins of approximately 100 keV) in order to determine the values of SE1, SE2 and the mixing phase phi12 of the 16O(γ, α)12C reaction. The rate of carbon formation at high temperatures (T > 3 GK) was suggested to increase due to contributions from a higher lying 2+ state. We have measured an angular distribution of (essentially) pure E2 transition at Eγ = 9.78 MeV of the 12C(γ, 3α) reaction, providing conclusive evidence for the elusive 2+2 state in 12C.

  4. High pressure studies of potassium perchlorate

    SciTech Connect

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

    2016-07-29

    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 hv→ 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. As a result, we present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregate at high pressure.

  5. High pressure injection injuries: an overview.

    PubMed

    Fialkov, J A; Freiberg, A

    1991-01-01

    Injuries resulting from the use of high pressure injectors and spray guns are relatively rare; however, the potential tissue damage caused by the injury as well as the extent of the injury itself may go unrecognized by the primary physician. The purpose of this paper is to inform the emergency physician of the nature and standard management of this type of injury. A basic understanding of the pathophysiology of the high pressure injection injury (HPII) is essential in avoiding the mistakes in management that have been reported in the literature. The emergency management of the HPII includes: evaluation and immobilization, tetanus and antimicrobial prophylaxis, supportive and resuscitative measures, analgesia, and minimizing the time to definitive surgical treatment.

  6. 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.

  7. Novel chemistry of matter under high pressure

    NASA Astrophysics Data System (ADS)

    Miao, Maosheng

    2015-03-01

    The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry, rooted in the atomic shell structure. Within compounds, Group I elements, for example, invariably assume the +1 oxidation state, and their chemical properties differ completely from those of the p-block elements. These general rules govern our understanding of chemical structures and reactions. Using first principles calculations, we demonstrate that under high pressure, the above doctrines can be broken. We show that both the inner shell electrons and the outer shell empty orbitals of Cs and other elements can involve in chemical reactions. Furthermore, we show that the quantized orbitals of the enclosed interstitial space may play the same role as atomic orbitals, an unprecedented view that led us to a unified theory for the recently observed high-pressure electride phenomenon.

  8. 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.

  9. 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.

  10. High pressure studies of potassium perchlorate

    DOE PAGES

    Pravica, Michael; Wang, Yonggang; Sneed, Daniel; ...

    2016-07-29

    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 hv→ 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. As a result, we present the first direct evidence for O2 crystallization at higher pressures, demonstrating that O2 molecules aggregatemore » at high pressure.« less

  11. (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.

  12. Efficient High-Pressure State Equations

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  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. Introduction to High-Pressure Science

    NASA Astrophysics Data System (ADS)

    Dera, Przemyslaw

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

  1. Exotic stable cesium polynitrides at high pressure

    DOE PAGES

    Peng, Feng; Han, Yunxia; Liu, Hanyu; ...

    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

  2. High pressure effects in anaesthesia and narcosis.

    PubMed

    Wlodarczyk, Agnieszka; McMillan, Paul F; Greenfield, Susan A

    2006-10-01

    There is growing interest in determining the effects of high pressure on biological functions. Studies of brain processes under hyperbaric conditions can give a unique insight into phenomena such as nitrogen narcosis, inert gas anaesthesia, and pressure reversal of the effects of anaesthetic and narcotic agents. Such research may shed light on the action of anaesthetics, which remains poorly understood, and on the nature of consciousness itself. Various studies have established the behavioural response of organisms to hyperbaric conditions, in the presence or absence of anaesthetic agents. At the molecular level, X-ray crystallography has been used to investigate the incorporation of species like Xe in hydrophobic pockets within model ion channels that may account for pressure effects on neuronal transmission. New magnetic resonance imaging techniques are providing tomographic three-dimensional images that detail brain structure and function, and that can be correlated with behavioural studies and psychological test results. Such whole organ techniques are linked to the molecular scale via voltage-sensitive dye (VSD) imaging studies on brain slices that provide time-resolved images of the dynamic formation and interconnection of inter-neuronal complexes. The VSD experiments are readily adapted to in situ studies under high pressure conditions. In this tutorial review we review the current state of knowledge of hyperbaric effects on brain processes: anaesthesia and narcosis, recent studies at the molecular level via protein crystallography at high pressure in a Xe atmosphere, and we also present some preliminary results of VSD imaging of brain slices under hyperbaric conditions.

  3. Application of Two Phase (Liquid/Gas) Xenon Gamma-Camera for the Detection of Special Nuclear Material and PET Medical Imaging

    SciTech Connect

    McKinsey, Daniel Nicholas

    2013-08-27

    The McKinsey group at Yale has been awarded a grant from DTRA for the building of a Liquid Xenon Gamma Ray Color Camera (LXe-GRCC), which combines state-of-the-art detection of LXe scintillation light and time projection chamber (TPC) charge readout. The DTRA application requires a movable detector and hence only a single phase (liquid) xenon detector can be considered in this case. We propose to extend the DTRA project to applications that allow a two phase (liquid/gas) xenon TPC. This entails additional (yet minimal) hardware and extension of the research effort funded by DTRA. The two phase detector will have better energy and angular resolution. Such detectors will be useful for PET medical imaging and detection of special nuclear material in stationary applications (e.g. port of entry). The expertise of the UConn group in gas phase TPCs will enhance the capabilities of the Yale group and the synergy between the two groups will be very beneficial for this research project as well as the education and research projects of the two universities. The LXe technology to be used in this project has matured rapidly over the past few years, developed for use in detectors for nuclear physics and astrophysics. This technology may now be applied in a straightforward way to the imaging of gamma rays. According to detailed Monte Carlo simulations recently performed at Yale University, energy resolution of 1% and angular resolution of 3 degrees may be obtained for 1.0 MeV gamma rays, using existing technology. With further research and development, energy resolution of 0.5% and angular resolution of 1.3 degrees will be possible at 1.0 MeV. Because liquid xenon is a high density, high Z material, it is highly efficient for scattering and capturing gamma rays. In addition, this technology scales elegantly to large detector areas, with several square meter apertures possible. The Yale research group is highly experienced in the development and use of noble liquid detectors for

  4. 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

  5. Overview of TPC Benchmark E: The Next Generation of OLTP Benchmarks

    NASA Astrophysics Data System (ADS)

    Hogan, Trish

    Set to replace the aging TPC-C, the TPC Benchmark E is the next generation OLTP benchmark, which more accurately models client database usage. TPC-E addresses the shortcomings of TPC-C. It has a much more complex workload, requires the use of RAID-protected storage, generates much less I/O, and is much cheaper and easier to set up, run, and audit. After a period of overlap, it is expected that TPC-E will become the de facto OLTP benchmark.

  6. 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...

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

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 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...

  8. Xenon fluoride solutions effective as fluorinating agents

    NASA Technical Reports Server (NTRS)

    Hyman, H. H.; Quarterman, L. A.; Sheft, I.

    1967-01-01

    Solutions of xenon fluorides in anhydrous hydrogen fluoride have few disruptive effects and leave a residue consisting of gaseous xenon, which can be recovered and refluorinated. This mild agent can be used with materials which normally must be fluorinated with fluorine alone at high temperatures.

  9. 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.

  10. 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

  11. Efficient High Pressure MixtureState Equations

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  12. 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.

  13. 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

  14. 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".

  15. High-Pressure Oxygen Test Evaluations

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.; Key, C. F.

    1974-01-01

    The relevance of impact sensitivity testing to the development of the space shuttle main engine is discussed in the light of the special requirements for the engine. The background and history of the evolution of liquid and gaseous oxygen testing techniques and philosophy is discussed also. The parameters critical to reliable testing are treated in considerable detail, and test apparatus and procedures are described and discussed. Materials threshold sensitivity determination procedures are considered and a decision logic diagram for sensitivity threshold determination was plotted. Finally, high-pressure materials sensitivity test data are given for selected metallic and nonmetallic materials.

  16. 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.

  17. Submarine High Pressure Dehydrator Performance Test

    DTIC Science & Technology

    1988-06-07

    Hatala of September 1985. Prepared for NAVSEA 05N under contract number N00024-33-C-2111. 13. General Dynamics Corporation, High Pressure Air Filtration...Cooling Water Pump Gear Ratio ............... 4:1 Cooling Water Pump Full Load Speed .......... 3500 rpm Water Pump TDH @ 3400 RPM & 15 GPM...Temperature Monitor Thomas A. Edison, Inc. 12-1/2" x 7-1/4" x 9" 25 lbs. Motor Electro Dynamic 2𔄁-1/16" x 2𔃾-1/4" x 2𔃻-1/4" 1150 lbs. S Pressure

  18. Xenon Gamma Detector Project Support

    SciTech Connect

    Vanier,P.E.; Forman, L.

    2008-04-01

    This project provided funding of $48,500 for part of one year to support the development of compressed xenon spectrometers at BNL. This report describes upgrades that were made to the existing detector system electronics during that period, as well as subsequent testing with check sources and Special Nuclear Materials. Previous testing of the equipment extended only up to the energy of 1.3 MeV, and did not include a spectrum of Pu-239. The new electronics allowed one-button activation of the high voltage ramp that was previously controlled by manual adjustments. Mechanical relays of the charging circuit were replaced by a tera-ohm resistor chain and an optical switch. The preamplifier and shaping amplifier were replaced by more modern custom designs. We found that the xenon purity had not been degraded since the chamber was filled 10 years earlier. The resulting spectra showed significantly better resolution than sodium iodide spectra, and could be analyzed quite effectively by methods using peak area templates.

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

    DOE PAGES

    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, amore » finding in stark contrast to DAC data.« less

  20. Simplified Ion Thruster Xenon Feed System for NASA Science Missions

    NASA Technical Reports Server (NTRS)

    Snyder, John Steven; Randolph, Thomas M.; Hofer, Richard R.; Goebel, Dan M.

    2009-01-01

    The successful implementation of ion thruster technology on the Deep Space 1 technology demonstration mission paved the way for its first use on the Dawn science mission, which launched in September 2007. Both Deep Space 1 and Dawn used a "bang-bang" xenon feed system which has proven to be highly successful. This type of feed system, however, is complex with many parts and requires a significant amount of engineering work for architecture changes. A simplified feed system, with fewer parts and less engineering work for architecture changes, is desirable to reduce the feed system cost to future missions. An attractive new path for ion thruster feed systems is based on new components developed by industry in support of commercial applications of electric propulsion systems. For example, since the launch of Deep Space 1 tens of mechanical xenon pressure regulators have successfully flown on commercial spacecraft using electric propulsion. In addition, active proportional flow controllers have flown on the Hall-thruster-equipped Tacsat-2, are flying on the ion thruster GOCE mission, and will fly next year on the Advanced EHF spacecraft. This present paper briefly reviews the Dawn xenon feed system and those implemented on other xenon electric propulsion flight missions. A simplified feed system architecture is presented that is based on assembling flight-qualified components in a manner that will reduce non-recurring engineering associated with propulsion system architecture changes, and is compared to the NASA Dawn standard. The simplified feed system includes, compared to Dawn, passive high-pressure regulation, a reduced part count, reduced complexity due to cross-strapping, and reduced non-recurring engineering work required for feed system changes. A demonstration feed system was assembled using flight-like components and used to operate a laboratory NSTAR-class ion engine. Feed system components integrated into a single-string architecture successfully operated

  1. Is sodium a superconductor under high pressure?

    PubMed

    Tutchton, Roxanne; Chen, Xiaojia; Wu, Zhigang

    2017-01-07

    Superconductivity has been predicted or measured for most alkali metals under high pressure, but the computed critical temperature (Tc) of sodium (Na) at the face-centered cubic (fcc) phase is vanishingly low. Here we report a thorough, first-principles investigation of superconductivity in Na under pressures up to 260 GPa, where the metal-to-insulator transition occurs. Linear-response calculations and density functional perturbation theory were employed to evaluate phonon distributions and the electron-phonon coupling for bcc, fcc, cI16, and tI19 Na. Our results indicate that the maximum electron-phonon coupling parameter, λ, is 0.5 for the cI16 phase, corresponding to a theoretical peak in the critical temperature at Tc≈1.2 K. When pressure decreases or increases from 130 GPa, Tc drops quickly. This is mainly due to the lack of p-d hybridization in Na even at 260 GPa. Since current methods based on the Eliashberg and McMillian formalisms tend to overestimate the Tc (especially the peak values) of alkali metals, we conclude that under high pressure-before the metal-to-insulator transition at 260 GPa-superconductivity in Na is very weak, if it is measurable at all.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. The atmosphere of Mars - Detection of krypton and xenon

    NASA Technical Reports Server (NTRS)

    Owen, T.; Biemann, K.; Biller, J. E.; Lafleur, A. L.; Rushneck, D. R.; Howarth, D. W.

    1976-01-01

    Krypton and xenon have been discovered in the Martian atmosphere with the mass spectrometer on the second Viking lander. Krypton is more abundant than xenon. The relative abundances of the krypton isotopes appear normal, but the ratio of xenon-129 to xenon-132 is enhanced on Mars relative to the terrestrial value for this ratio. Some possible implications of these findings are discussed.

  7. A High Resolution Liquid Xenon Imaging Telescope for 0.3-10 MeV Gamma Ray Astrophysics: Construction and Initial Balloon Flights

    NASA Technical Reports Server (NTRS)

    Aprile, Elena

    1993-01-01

    The results achieved with a 3.5 liter liquid xenon time projection chamber (LXe-TPC) prototype during the first year include: the efficiency of detecting the primary scintillation light for event triggering has been measured to be higher than 85%; the charge response has been measured to be stable to within 0.1% for a period of time of about 30 hours; the electron lifetime has been measured to be in excess of 1.3 ms; the energy resolution has been measured to be consistent with previous results obtained with small volume chambers; X-Y gamma ray imaging has been demonstrated with a nondestructive orthogonal wires readout; Monte Carlo simulation results on detection efficiency, expected background count rate at balloon altitude, background reduction algorithms, telescope response to point-like and diffuse sources, and polarization sensitivity calculations; and work on a 10 liter LXe-TPC prototype and gas purification/recovery system.

  8. The iTPC upgrade for BES-II

    NASA Astrophysics Data System (ADS)

    Videbaek, Flemming; STAR Collaboration

    2015-10-01

    STAR has proposed to upgrade the inner sectors of the STAR TPC to increase the segmentation on the inner padplane and to renew the inner sector wires. The upgrade will provide better momentum resolution, better dE/dx resolution and, most importantly, it will provide improved acceptance at high rapidity to | η| <= 1.5 compared to the current TPC configuration of | η| <= 1 and to extend the pt coverage towards lower pt. The enhanced measurement capabilities of STAR after the iTPC upgrade are a vital part of the BES-II effort for 2019-2020. The expanded rapidity coverage provides a major benefit for many analyses, especially those sensitive to changes in correlation lengths near a critical point, like the net-proton Kurtosis which exhibits interesting energy trends that only appear near the edge of the current STAR acceptance. In the area of dielectron measurements it reduces hadron contamination from a dominant source of uncertainty to an expected statistical uncertainty of only 10%, and will enable significantly improved understanding of in-medium modifications. In this talk I will discuss the physics impact and give a technical overview of the detector upgrade. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science.

  9. Readout system of TPC/MPD NICA project

    SciTech Connect

    Averyanov, A. V.; Bajajin, A. G.; Chepurnov, V. F.; Cheremukhina, G. A.; Fateev, O. V.; Korotkova, A. M.; Levchanovskiy, F. V.; Lukstins, J.; Movchan, S. A.; Razin, S. V.; Rybakov, A. A.; Vereschagin, S. V. Zanevsky, Yu. V.; Zaporozhets, S. A.; Zruyev, V. N.

    2015-12-15

    The time-projection chamber (TPC) is the main tracking detector in the MPD/NICA. The information on charge-particle tracks in the TPC is registered by the MWPG with cathode pad readout. The frontend electronics (FEE) are developed with use of modern technologies such as application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), and data transfer to a concentrator via a fast optical interface. The main parameters of the FEE are as follows: total number of channels, ∼95 000; data stream from the whole TPC, 5 GB/s; low power consumption, less than 100 mW/ch; signal to noise ratio (S/N), 30; equivalent noise charge (ENC), <1000e{sup –} (C{sub in} = 10–20 pF); and zero suppression (pad signal rejection ∼90%). The article presents the status of the readout chamber construction and the data acquisition system. The results of testing FEE prototypes are presented.

  10. A continuous read-out TPC for the ALICE upgrade

    NASA Astrophysics Data System (ADS)

    Lippmann, C.

    2016-07-01

    The largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb-Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at rates up to 1 TByte/s. A fractional ion feedback of below 1% is required to keep distortions due to space charge in the TPC drift volume at a tolerable level. The new read-out chambers will consist of quadruple stacks of Gas Electron Multipliers (GEM), combining GEM foils with a different hole pitch. Other key requirements such as energy resolution and operational stability have to be met as well. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.63%, a local energy resolution of 11.3% (sigma) and a discharge probability comparable to that of standard triple GEM detectors.

  11. Pad Plane Design and Readout for SAMURAI TPC

    NASA Astrophysics Data System (ADS)

    Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Estee, J.; Gilbert, J.; Lu, F.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yenello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    The SAMURAI TPC is being built at Michigan State University to be used in the SAMURAI spectrometer at RIKEN in Japan, as part of the Symmetry Energy project, which focuses on obtaining constraints on the symmetry energy at supra-saturation densities. The presentation will discuss the development of the TPC as well as design for readout plane design for the TPC. These involve enabling the use of existing and future front end electronics (FEE), making the most of limited space, designing a circuit board for the pad plane, and techniques to glue the pad plane. The pad plane has been designed to work with either STAR or AGET electronics. The pad plane is made of a circuit board designed to minimize crosstalk and capacitance. The board must be built in smaller pieces and tiled, using alignment pins and precision gluing. Prototypes for the pad plane to FEE connection, pad plane gluing and STAR card mounting will be presented. Supported by the Department of Energy under Grant DE-SC0004835.

  12. Materials Testing and Performance Optimization for the SAMURAI-TPC

    NASA Astrophysics Data System (ADS)

    Long, K. D.; Lynch, W. G.; Barney, J.; Chajecki, Z.; Estee, J.; Shane, R.; Tangwanchareon, S.; Tsang, M. B.; Yurkon, J.

    2012-10-01

    The SAMURAI time-projection chamber (TPC) will be used to make measurements of pion spectra from heavy ion collisions at RIBF in Japan. Such research provides an opportunity to study supra-saturation density neutron-rich matter in the laboratory, and is critical to understanding the structure of neutron stars. It will provide a complete, 3D picture of the ionization deposited in a gas volume, from which particle types and momenta can be determined. The gas-containment volume is composed of surfaces of aluminum and plastic, as well as halogen-free printed circuit board. During multiplication of the ionized electrons at the anode wire plane of the TPC, UV photons are produced. These cause unwanted discharges when they interact with oxidized aluminum surfaces, which have low work functions. This problem can be addressed by application of a suitable conductive paint or epoxy. Paints were investigated to insure they did not contain any materials capable of inhibiting the performance of the detector gas. These investigations were cross-checked by tests carried out using an existing BRAHMS-TPC. Details on these tests and the materials chosen will be shown. The design and optimization of the gating grid, used to limit data collection to triggered events, will also be discussed.

  13. Non-Uniform Electromagnetic Fields in the SAMURAI TPC

    NASA Astrophysics Data System (ADS)

    Estee, J.; Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Gilbert, J.; Lu, F.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yennello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    A Time Projection Chamber (TPC) is being developed for the SAMURAI dipole magnet at RIKEN. The main scientific objective for the TPC is to provide constraints on the nuclear symmetry at supra-saturation density. The poster presentation will discuss the design of the TPC field cage and the external electrodes that shape the high electric fields near the cathode. Garfield calculations of the electric field as well as TOSCA calculations of the magnetic field of the SAMURAI dipole will be shown and the impact of the non-uniformity of both fields on electron transport will be discussed. These non-uniformities can introduce components into the electron drift velocity in directions other than the expected vertical direction. This poster presentation will discuss the initial design of a laser calibration system, which will be used to calibrate away the influence of these non-uniformities in the electric and magnetic fields. This work is supported by the DOE under Grant DE-SC0004835.

  14. (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

  15. (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.

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

    SciTech Connect

    Yoo, Choong-Shik

    2006-01-27

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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Structural behaviour of YGa under high pressure

    SciTech Connect

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

    2014-04-24

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

  2. 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.

  3. Synthesis of sodium polyhydrides at high pressures

    DOE PAGES

    Struzhkin, Viktor V.; Kim, Duck Young; Stavrou, Elissaios; ...

    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

  4. 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.

  5. 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.

  6. Model of current enhancement at high pressure

    SciTech Connect

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

    1983-04-05

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

  7. 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

  8. 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.

  9. 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.

  10. Synthesis of sodium polyhydrides at high pressures

    SciTech Connect

    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 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Xenon clusters in intense VUV laser fields.

    PubMed

    Santra, Robin; Greene, Chris H

    2003-12-05

    A simple model is developed that quantitatively describes intense interactions of a vacuum ultraviolet (VUV) laser pulse with a xenon cluster. We find good agreement with a recent experiment [Nature (London) 420, 482 (2002)

  16. Xenon Blocks Neuronal Injury Associated with Decompression.

    PubMed

    Blatteau, Jean-Eric; David, Hélène N; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H

    2015-10-15

    Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS.

  17. Surface diffusion of xenon on Pt(111)

    NASA Astrophysics Data System (ADS)

    Meixner, D. Laurence; George, Steven M.

    1993-06-01

    The surface diffusion of xenon on the Pt(111) surface was investigated using laser induced thermal desorption (LITD) and temperature programmed desorption (TPD) techniques. The surface diffusion coefficient at 80 K decreased dramatically from D=8×10-7 cm2/s at θ=0.05θs to approximately D=2×10-8 cm2/s at θ=θs, where θs denotes the saturation coverage at 85 K, corresponding to a commensurate monolayer coverage of 5.0×1014 xenon atoms/cm2. This coverage dependence was consistent with attractive interactions between the adsorbed xenon atoms and the existence of two-dimensional condensed phases of xenon on Pt(111). The kinetic parameters for surface diffusion at θ=θs were Edif=1.3±0.1 kcal/mol and D0=1.1×10-4±0.2 cm2/s. The magnitude of Edif at θ=θs represented the combined effect of the intrinsic corrugation of the adsorbate-surface potential and attractive interactions between the adsorbed xenon atoms. LITD experiments at θ=0.25 θs revealed diffusion kinetic parameters of Edif=1.2±0.2 kcal/mol and D0=3.4×10-4±0.5 cm2/s. The constant Edif at low and high coverage was attributed to the ``breakaway'' of xenon atoms from the edges of condensed phase xenon islands. The coverage dependence of the surface diffusion coefficient for Xe/Pt(111) was explained by a multiple site diffusion mechanism, where collisions with xenon islands limit diffusional motion. Thermal desorption kinetics for xenon on Pt(111) were determined using TPD experiments. Using the variation of heating rates method, the desorption parameters were Edes=6.6±0.2 kcal/mol and νdes=1.3×1013±0.4 s-1, in good agreement with previous studies. The xenon TPD peak shifted to higher temperature versus initial coverage at a fixed heating rate, providing further evidence for attractive interactions between the adsorbed xenon atoms.

  18. Transportable Xenon Laboratory (TXL-1) Operations Manual

    SciTech Connect

    Thompson, Robert C.; Stewart, Timothy L.; Willett, Jesse A.; Woods, Vincent T.

    2011-03-07

    The Transportable Xenon Laboratory Operations Manual is a guide to set up and shut down TXL, a fully contained laboratory made up of instruments to identify and measure concentrations of the radioactive isotopes of xenon by taking air samples and analyzing them. The TXL is housed in a standard-sized shipping container. TXL can be shipped to and function in any country in the world.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger Type. ... 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...

  5. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger Type. ... 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...

  6. 7 CFR 58.219 - High pressure pumps and lines.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... pressure pump shall comply with the 3-A Sanitary Standard for Homogenizers and Pumps of the Plunger Type. ... 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...

  7. 77 FR 37712 - High Pressure Steel Cylinders From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-22

    ... 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 the... following notification of preliminary determinations by Commerce that imports of high pressure...

  8. TPC2 controls pigmentation by regulating melanosome pH and size

    PubMed Central

    Ambrosio, Andrea L.; Boyle, Judith A.; Aradi, Al E.; Christian, Keith A.; Di Pietro, Santiago M.

    2016-01-01

    Melanin is responsible for pigmentation of skin and hair and is synthesized in a specialized organelle, the melanosome, in melanocytes. A genome-wide association study revealed that the two pore segment channel 2 (TPCN2) gene is strongly linked to pigmentation variations. TPCN2 encodes the two-pore channel 2 (TPC2) protein, a cation channel. Nevertheless, how TPC2 regulates pigmentation remains unknown. Here, we show that TPC2 is expressed in melanocytes and localizes to the melanosome-limiting membrane and, to a lesser extent, to endolysosomal compartments by confocal fluorescence and immunogold electron microscopy. Immunomagnetic isolation of TPC2-containing organelles confirmed its coresidence with melanosomal markers. TPCN2 knockout by means of clustered regularly interspaced short palindromic repeat/CRISPR-associated 9 gene editing elicited a dramatic increase in pigment content in MNT-1 melanocytic cells. This effect was rescued by transient expression of TPC2-GFP. Consistently, siRNA-mediated knockdown of TPC2 also caused a substantial increase in melanin content in both MNT-1 cells and primary human melanocytes. Using a newly developed genetically encoded pH sensor targeted to melanosomes, we determined that the melanosome lumen in TPC2-KO MNT-1 cells and primary melanocytes subjected to TPC2 knockdown is less acidic than in control cells. Fluorescence and electron microscopy analysis revealed that TPC2-KO MNT-1 cells have significantly larger melanosomes than control cells, but the number of organelles is unchanged. TPC2 likely regulates melanosomes pH and size by mediating Ca2+ release from the organelle, which is decreased in TPC2-KO MNT-1 cells, as determined with the Ca2+ sensor tyrosinase-GCaMP6. Thus, our data show that TPC2 regulates pigmentation through two fundamental determinants of melanosome function: pH and size. PMID:27140606

  9. TPC2 controls pigmentation by regulating melanosome pH and size.

    PubMed

    Ambrosio, Andrea L; Boyle, Judith A; Aradi, Al E; Christian, Keith A; Di Pietro, Santiago M

    2016-05-17

    Melanin is responsible for pigmentation of skin and hair and is synthesized in a specialized organelle, the melanosome, in melanocytes. A genome-wide association study revealed that the two pore segment channel 2 (TPCN2) gene is strongly linked to pigmentation variations. TPCN2 encodes the two-pore channel 2 (TPC2) protein, a cation channel. Nevertheless, how TPC2 regulates pigmentation remains unknown. Here, we show that TPC2 is expressed in melanocytes and localizes to the melanosome-limiting membrane and, to a lesser extent, to endolysosomal compartments by confocal fluorescence and immunogold electron microscopy. Immunomagnetic isolation of TPC2-containing organelles confirmed its coresidence with melanosomal markers. TPCN2 knockout by means of clustered regularly interspaced short palindromic repeat/CRISPR-associated 9 gene editing elicited a dramatic increase in pigment content in MNT-1 melanocytic cells. This effect was rescued by transient expression of TPC2-GFP. Consistently, siRNA-mediated knockdown of TPC2 also caused a substantial increase in melanin content in both MNT-1 cells and primary human melanocytes. Using a newly developed genetically encoded pH sensor targeted to melanosomes, we determined that the melanosome lumen in TPC2-KO MNT-1 cells and primary melanocytes subjected to TPC2 knockdown is less acidic than in control cells. Fluorescence and electron microscopy analysis revealed that TPC2-KO MNT-1 cells have significantly larger melanosomes than control cells, but the number of organelles is unchanged. TPC2 likely regulates melanosomes pH and size by mediating Ca(2+) release from the organelle, which is decreased in TPC2-KO MNT-1 cells, as determined with the Ca(2+) sensor tyrosinase-GCaMP6. Thus, our data show that TPC2 regulates pigmentation through two fundamental determinants of melanosome function: pH and size.

  10. Nucleation and droplet growth at high pressure

    NASA Astrophysics Data System (ADS)

    Luijten, Carlo Cornelis Maria

    Homogeneous nucleation, the first stage of droplet formation in the absence of foreign particles, usually takes place in the presence of one or more supercritical carrier gases. The present work aimed at a systematic investigation of the effects of carrier gas pressure on nucleation and droplet growth. Using the so-called nucleation pulse method, nucleation and droplet growth can be separated in time, which facilitates quantitative study of these processes using Constant Angle Mie Scattering and light extinction. The method was implemented in a modified shock tube, using gas dynamic principles to create the pulse. In this way, nucleation and growth rates were measured as a function of temperature, pressure, and composition. Composition measurement at high pressure was achieved along two different routes. Water vapour concentrations were determined using a commercial humidity sensor, after calibration with total pressure as an independent parameter. Gas chromatography was used to determine hydrocarbon concentrations, after pressure reduction of the mixture over a thermostatic capillary tube. Using the above analysis techniques, nucleation and droplet growth experiments were performed for several vapour-gas mixtures, at pressures between 1 and 40 bar. Mixtures with a varying degree of interaction were selected, to allow for a systematic investigation of carrier gas influence. Besides these binary mixtures, the first quantitative nucleation and growth rates for- multicomponent-natural gas were obtained. Theoretical models for both nucleation and droplet growth were adapted to take into account the presence of a carrier gas, under condition of small carrier gas solubility. The main effects involved are the increase of saturated vapour density and decrease of surface tension with pressure. On the basis of our experiments, these effects were demonstrated to play important and counteracting roles in high pressure nucleation. Using Density Functional Theory, both effects

  11. Structure, stability, and superconductivity of new Xe-H compounds under high pressure.

    PubMed

    Yan, Xiaozhen; Chen, Yangmei; Kuang, Xiaoyu; Xiang, Shikai

    2015-09-28

    Application of high pressure can substantially enhance the chemical reactivity of xenon and has recently extended the Xe-compounds to unexpected elements such as Fe and H. Using unbiased structure searching techniques combined with first-principles calculations, we predict novel compounds of stable XeH2 and XeH4, and metastable XeH, XeH3, XeH5, XeH6, XeH7, and XeH8 under high pressure. Rather than van der Waals complexes, these are weakly covalent or ionic compounds stabilized by a pressure-induced increase in charge transfer from Xe to H atoms. The calculated electronic structures with hybrid exchange-correlation functionals reveal that only XeH and XeH2 are metalized under 300 GPa. For the metallic XeH and XeH2 at certain pressures, the superconducting critical temperatures are finally studied, by using Allen-Dynes modified McMillan equation combined with the calculated electron-phonon coupling parameter.

  12. Structure, stability, and superconductivity of new Xe-H compounds under high pressure

    NASA Astrophysics Data System (ADS)

    Yan, Xiaozhen; Chen, Yangmei; Kuang, Xiaoyu; Xiang, Shikai

    2015-09-01

    Application of high pressure can substantially enhance the chemical reactivity of xenon and has recently extended the Xe-compounds to unexpected elements such as Fe and H. Using unbiased structure searching techniques combined with first-principles calculations, we predict novel compounds of stable XeH2 and XeH4, and metastable XeH, XeH3, XeH5, XeH6, XeH7, and XeH8 under high pressure. Rather than van der Waals complexes, these are weakly covalent or ionic compounds stabilized by a pressure-induced increase in charge transfer from Xe to H atoms. The calculated electronic structures with hybrid exchange-correlation functionals reveal that only XeH and XeH2 are metalized under 300 GPa. For the metallic XeH and XeH2 at certain pressures, the superconducting critical temperatures are finally studied, by using Allen-Dynes modified McMillan equation combined with the calculated electron-phonon coupling parameter.

  13. Structure, stability, and superconductivity of new Xe–H compounds under high pressure

    SciTech Connect

    Yan, Xiaozhen; Chen, Yangmei; Kuang, Xiaoyu; Xiang, Shikai

    2015-09-28

    Application of high pressure can substantially enhance the chemical reactivity of xenon and has recently extended the Xe-compounds to unexpected elements such as Fe and H. Using unbiased structure searching techniques combined with first-principles calculations, we predict novel compounds of stable XeH{sub 2} and XeH{sub 4}, and metastable XeH, XeH{sub 3}, XeH{sub 5}, XeH{sub 6}, XeH{sub 7}, and XeH{sub 8} under high pressure. Rather than van der Waals complexes, these are weakly covalent or ionic compounds stabilized by a pressure-induced increase in charge transfer from Xe to H atoms. The calculated electronic structures with hybrid exchange-correlation functionals reveal that only XeH and XeH{sub 2} are metalized under 300 GPa. For the metallic XeH and XeH{sub 2} at certain pressures, the superconducting critical temperatures are finally studied, by using Allen-Dynes modified McMillan equation combined with the calculated electron-phonon coupling parameter.

  14. 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.

  15. 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.

  16. Raman Study of SWNT Under High Pressure

    NASA Astrophysics Data System (ADS)

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

    1998-03-01

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

  17. High pressure FAST of nanocrystalline barium titanate

    DOE PAGES

    Fraga, Martin B.; Delplanque, Jean -Pierre; Yang, Nancy; ...

    2016-06-01

    Here, this work studies the microstructural evolution of nanocrystalline (<1 µm) barium titanate (BaTiO3), and presents high pressure in field-assisted sintering (FAST) as a robust methodology to obtain >100 nm BaTiO3 compacts. Using FAST, two commercial ~50 nm powders were consolidated into compacts of varying densities and grain sizes. Microstructural inhomogeneities were investigated for each case, and an interpretation is developed using a modified Monte Carlo Potts (MCP) simulation. Two recurrent microstructural inhomogeneities are highlighted, heterogeneous grain growth and low-density regions, both ubiqutously present in all samples to varying degrees. In the worst cases, HGG presents an area coverage ofmore » 52%. Because HGG is sporadic but homogenous throughout a sample, the catalyst (e.g., the local segregation of species) must be, correspondingly, distributed in a homogenous manner. MCP demonstrates that in such a case, a large distance between nucleating abnormal grains is required—otherwise abnormal grains prematurely impinge on each other, and their size is not distinguishable from that of normal grains. Compacts sintered with a pressure of 300 MPa and temperatures of 900 °C, were 99.5% dense and had a grain size of 90±24 nm. These are unprecedented results for commercial BaTiO3 powders or any starting powder of 50 nm particle size—other authors have used 16 nm lab-produced powder to obtain similar results.« less

  18. High pressure FAST of nanocrystalline barium titanate

    SciTech Connect

    Fraga, Martin B.; Delplanque, Jean -Pierre; Yang, Nancy; Lavernia, Enrique J.; Monson, Todd C.

    2016-06-01

    Here, this work studies the microstructural evolution of nanocrystalline (<1 µm) barium titanate (BaTiO3), and presents high pressure in field-assisted sintering (FAST) as a robust methodology to obtain >100 nm BaTiO3 compacts. Using FAST, two commercial ~50 nm powders were consolidated into compacts of varying densities and grain sizes. Microstructural inhomogeneities were investigated for each case, and an interpretation is developed using a modified Monte Carlo Potts (MCP) simulation. Two recurrent microstructural inhomogeneities are highlighted, heterogeneous grain growth and low-density regions, both ubiqutously present in all samples to varying degrees. In the worst cases, HGG presents an area coverage of 52%. Because HGG is sporadic but homogenous throughout a sample, the catalyst (e.g., the local segregation of species) must be, correspondingly, distributed in a homogenous manner. MCP demonstrates that in such a case, a large distance between nucleating abnormal grains is required—otherwise abnormal grains prematurely impinge on each other, and their size is not distinguishable from that of normal grains. Compacts sintered with a pressure of 300 MPa and temperatures of 900 °C, were 99.5% dense and had a grain size of 90±24 nm. These are unprecedented results for commercial BaTiO3 powders or any starting powder of 50 nm particle size—other authors have used 16 nm lab-produced powder to obtain similar results.

  19. 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.

  20. 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

  1. 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.

  2. High-pressure promoted combustion chamber

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  3. High-pressure Raman study of Terephthalonitrile

    NASA Astrophysics Data System (ADS)

    Li, DongFei; Zhang, KeWei; Song, MingXing; Zhai, NaiCui; Sun, ChengLin; Li, HaiBo

    2017-02-01

    The in situ high-pressure Raman spectra of Terephthalonitrile (TPN) have been investigated from ambient to 12.6 GPa at room temperature. All the fundamental vibrational modes of TPN at ambient were assigned based on the first-principle calculations. A detailed Raman spectroscopy analysis revealed that TPN underwent a phase transition at 5.3 GPa. The frequencies of the TPN Raman peaks increase with increasing the pressure which can be attributed to the reduction in the interatomic distances and the escalation of effective force constants. The intensity of the C-C-C ring-out-plane deformation mode increases gradually as the frequency remains almost constant during the compression which can be explained by the existence of π-π interactions in TPN molecules. Additionally, the pressure-induced structural changes of TPN on the Fermi resonance between the C ≡ N out-of-plane vibration mode and the C - CN out-of-plane vibration mode have been analyzed.

  4. SAMURAI-TPC: Field Cage Design and Prototyping

    NASA Astrophysics Data System (ADS)

    Lu, F.; Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Estee, J.; Gilbert, J.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yenello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    The SAMURAI-TPC is a time-projection chamber to be used in conjunction with the SAMURAI spectrometer being built at the Radioactive Isotope Beam Facility at RIKEN, Japan. It will be used to measure charged pions, protons and light ions. The pi+/pi- ratios from heavy-ion collisions should provide constraints on the asymmetry term in the nuclear equation of state at densities about twice saturation density. In this talk, the design and operation of the field cage, an essential part of the detector, will be discussed, along with the results of prototype testing. This work is supported by the Department of Energy under Grant DE-SC0004835.

  5. A 4. pi. tracking TPC magnetic spectrometer for RHIC

    SciTech Connect

    Danby, G.; Eiseman, S.E.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Van Dijk, J.H. ); Lindenbaum, S.J. City Coll., New York, NY ); Chan, C.S.; Kramer, M.A.; Zhao, K. ); Biswas, N.; Kenney, P.; Piekarz, J. (Notre Dame Univ

    1990-01-01

    The primary physics objective of the 4{pi} TPC magnetic spectrometer proposal is to search for the Quark-Gluon Plasma. In previous workshops we have discussed what the possible hadronic signatures of such a state of matter would be. Succinctly, the QGP is a direct prediction of non-perturbative QCD. Therefore the question of the existence of this new state of matter bears directly on the validity of non-perturbative QCD. However, since non-perturbative QCD has never been established, it is apparent that what may await us is a host of new phenomena that will go beyond the standard model.

  6. Stevia rebaudiana Bertoni as a natural antioxidant/antimicrobial for high pressure processed fruit extract: processing parameter optimization.

    PubMed

    Barba, Francisco José; Criado, María Nieves; Belda-Galbis, Clara Miracle; Esteve, María José; Rodrigo, Dolores

    2014-04-01

    Response surface methodology was used to evaluate the optimal high pressure processing treatment (300-500 MPa, 5-15 min) combined with Stevia rebaudiana (Stevia) addition (0-2.5% (w/v)) to guarantee food safety while maintaining maximum retention of nutritional properties. A fruit extract matrix was selected and Listeria monocytogenes inactivation was followed from the food safety point of view while polyphenoloxidase (PPO) and peroxidase (POD) activities, total phenolic content (TPC) and antioxidant capacity (TEAC and ORAC) were studied from the food quality point of view. A combination of treatments achieved higher levels of inactivation of L. monocytogenes and of the oxidative enzymes, succeeding in completely inactivating POD and also increasing the levels of TPC, TEAC and ORAC. A treatment of 453 MPa for 5 min with a 2.5% (w/v) of Stevia succeeded in inactivating over 5 log cycles of L. monocytogenes and maximizing inactivation of PPO and POD, with the greatest retention of bioactive components.

  7. 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.

  8. XENON dark matter searches: Results and the future

    SciTech Connect

    Brown, Andrew; Collaboration: XENON Collaboration

    2014-06-24

    XENON100 is a dark matter search experiment looking for elastic WIMP scattering using a 62 kg liquid target. WIMP search data from XENON100 published in 2012 has set the world's strongest limits on WIMP-nucleus spinindependent, elastic scattering. It has also set the strongest limits on WIMP-nucleus spin-dependent scattering considering neutron scattering only, and competitive limits considering proton scattering only. The successor experiment to XENON100, XENON1T, is currently under construction, with commissioning scheduled to begin in 2014. XENON1T's design goal is a 100 fold increase in sensitivity for elastic WIMP searches over XENON100.

  9. The XENON100 Dark Matter Experiment: Design, Construction, Calibration and 2010 Search Results with Improved Measurement of the Scintillation Response of Liquid Xenon to Low-Energy Nuclear Recoils

    NASA Astrophysics Data System (ADS)

    Plante, Guillaume

    An impressive array of astrophysical observations suggest that 83% of the matter in the universe is in a form of non-luminous, cold, collisionless, non-baryonic dark matter. Several extensions of the Standard Model of particle physics aimed at solving the hierarchy problem predict stable weakly interacting massive particles (WIMPs) that could naturally have the right cosmological relic abundance today to compose most of the dark matter if their interactions with normal matter are on the order of a weak scale cross section. These candidates also have the added benefit that their properties and interaction rates can be computed in a well defined particle physics model. A considerable experimental effort is currently under way to uncover the nature of dark matter. One method of detecting WIMP dark matter is to look for its interactions in terrestrial detectors where it is expected to scatter off nuclei. In 2007, the XENON10 experiment took the lead over the most sensitive direct detection dark matter search in operation, the CDMS II experiment, by probing spin-independent WIMP-nucleon interaction cross sections down to sigmachi N ˜ 5 x 10-44 cm 2 at 30 GeV/c2. Liquefied noble gas detectors are now among the technologies at the forefront of direct detection experiments. Liquid xenon (LXe), in particular, is a well suited target for WIMP direct detection. It is easily scalable to larger target masses, allows discrimination between nuclear recoils and electronic recoils, and has an excellent stopping power to shield against external backgrounds. A particle losing energy in LXe creates both ionization electrons and scintillation light. In a dual-phase LXe time projection chamber (TPC) the ionization electrons are drifted and extracted into the gas phase where they are accelerated to amplify the charge signal into a proportional scintillation signal. These two signals allow the three-dimensional localization of events with millimeter precision and the ability to

  10. 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

  11. 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.

  12. High Pressure Microwave Powered UV Light Sources

    NASA Astrophysics Data System (ADS)

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

    1997-10-01

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

  13. The Xenon record of Earth's early differentiaiton

    NASA Astrophysics Data System (ADS)

    Peto, M. K.; Mukhopadhyay, S.; Kelley, K. A.

    2011-12-01

    Xenon isotopes in mantle derived rocks provide information on the early differentiation of the silicate mantle of our planet. {131,132 134,136}Xe isotopes are produced by the spontaneous fission of two different elements: the now extinct radionuclide 244Pu, and the long-lived 238U. These two parent nuclides, however, yield rather different proportion of fissiogenic Xenon isotopes. Hence, the proportion of Pu- to U-derived fission xenon is indicative of the degree and rate of outgassing of a mantle reservoir. Recent data obtained from Iceland in our lab confirm that the Xenon isotopic composition of the plume source(s) is characterized by lower 136Xe/130Xe ratios than the MORB source and the Iceland plume is more enriched in the Pu-derived Xenon component. These features are interpreted as reflecting different degrees of outgassing and appear not to be the result of preferential recycling of Xenon to the deep mantle. To further investigate how representative the Icelandic measurements might be of other mantle plumes, we measured noble gases (He, Ne, Ar, Xe) in gas-rich basalt glasses from the Rochambeau Ridge (RR) in the Northern Lau Basin. Recent work suggests the presence of a "Samoan-like" OIB source in the northern Lau Basin and our measurements were performed on samples with plume-like 3He/4He ratios (15-28 RA) [1]. The Xenon isotopic measurements indicate that the maximum measured 136Xe/130Xe ratios in the Rochambeau samples are similar to Iceland. In particular, for one of the gas rich samples we were able to obtain 77 different isotopic measurements through step-crushing. Preliminary investigation of this sample suggests higher Pu- to U-derived fission Xenon than in MORBs. To quantitatively evaluate the degree and rate of outgassing of the plume and MORB reservoirs, particularly during the first few hundred million years of Earth's history, we have modified a geochemical reservoir model that was previously developed to investigate mantle overturn and mixing

  14. Direct Dark Matter search with XENON100

    NASA Astrophysics Data System (ADS)

    Orrigo, S. E. A.

    2016-07-01

    The XENON100 experiment is the second phase of the XENON program for the direct detection of the dark matter in the universe. The XENON100 detector is a two-phase Time Projection Chamber filled with 161 kg of ultra pure liquid xenon. The results from 224.6 live days of dark matter search with XENON100 are presented. No evidence for dark matter in the form of WIMPs is found, excluding spin-independent WIMP-nucleon scattering cross sections above 2 × 10-45 cm2 for a 55 GeV/c2 WIMP at 90% confidence level (C.L.). The most stringent limit is established on the spin-dependent WIMP-neutron interaction for WIMP masses above 6 GeV/c2, with a minimum cross section of 3.5 × 10-40 cm2 (90% C.L.) for a 45 GeV/c2 WIMP. The same dataset is used to search for axions and axion-like-particles. The best limits to date are set on the axion-electron coupling constant for solar axions, gAe < 7.7 × 10-12 (90% C.L.), and for axion-like-particles, gAe < 1 × 10-12 (90% C.L.) for masses between 5 and 10 keV/c2.

  15. MicroBooNE, A Liquid Argon Time Projection Chamber (LArTPC) Neutrino Experiment

    SciTech Connect

    Katori, Teppei

    2011-07-01

    Liquid Argon time projection chamber (LArTPC) is a promising detector technology for future neutrino experiments. MicroBooNE is a upcoming LArTPC neutrino experiment which will be located on-axis of Booster Neutrino Beam (BNB) at Fermilab, USA. The R&D efforts on this detection method and related neutrino interaction measurements are discussed.

  16. Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

    SciTech Connect

    Wieman, H.H.; EOS Collaboration

    1994-05-01

    The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z.

  17. 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

  18. Material Composite Behavior Under High-Pressure

    NASA Astrophysics Data System (ADS)

    Conil, N.; Kavner, A.

    2004-12-01

    In situ x-ray diffraction techniques under relevant pressure and temperature conditions provide unique information about phase stability, elasticity and deformation behavior of Earth materials. Often samples consist of a calibrated standard intermixed with the material of interest. Accurate measurements of equation of state are based on two assumptions: that the equation of state of the calibrant is known precisely, and that the pressures of these two materials are the same. However, except under strict conditions of hydrostaticity, pressures are not necessary equal. To provide a detailed examination of the pressure relationship in the diamond anvil cell sample chamber, we analyzed two standard materials mixed together in a controlled geometry. Our samples consisted of unidirectional Al2O3 ceramic fibers ( ˜ 1μ m diameter) distributed in an Al metal matrix. This was ideal because both materials are existing high-pressure standards and the oxide/metal mixture is similar to many experiments. We conducted room temperature radial x-ray diffraction experiments using a diamond anvil cell at the X17C beamline at National Synchrotron Light Source. We studied two different fiber orientations with respect to the diamond anvil cell compression axis: one with fibers oriented vertically and the second, horizontally. In each case we measured the d-spacing of lattice planes as a function of rotation angle between principle stress axes and diffraction geometry. From these data, we calculated pressure and supported differential stress of both Al and Al2O3. We found that geometry plays an important role in determining the relative pressure and strength behavior of the two materials. At comparable pressures, in the vertical fibers case, PAl ˜ 8.7 GPa, PAl2O3 ˜ 10.2 GPa and in the horizontal fibers case, PAl ˜ 9.6 GPa when PAl2O3 ˜ 10.2 GPa. Thus, when the fibers are oriented vertically, aluminum pressure is always smaller than alumina pressure; whereas in the horizontal case

  19. Anticonvulsant effect of xenon on neonatal asphyxial seizures.

    PubMed

    Azzopardi, Denis; Robertson, Nicola J; Kapetanakis, Andrew; Griffiths, James; Rennie, Janet M; Mathieson, Sean R; Edwards, A David

    2013-09-01

    Xenon, a monoatomic gas with very high tissue solubility, is a non-competitive inhibitor of N-methyl-D-aspartate (NMDA) glutamate receptor, has antiapoptotic effects and is neuroprotective following hypoxic ischaemic injury in animals. Xenon may be expected to have anticonvulsant effects through glutamate receptor blockade, but this has not previously been demonstrated clinically. We examined seizure activity on the real time and amplitude integrated EEG records of 14 full-term infants with perinatal asphyxial encephalopathy treated within 12 h of birth with 30% inhaled xenon for 24 h combined with 72 h of moderate systemic hypothermia. Seizures were identified on 5 of 14 infants. Seizures stopped during xenon therapy but recurred within a few minutes of withdrawing xenon and stopped again after xenon was restarted. Our data show that subanaesthetic levels of xenon may have an anticonvulsant effect. Inhaled xenon may be a valuable new therapy in this hard-to-treat population.

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

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

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

  1. 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.

  2. Reflectance of polytetrafluoroethylene for xenon scintillation light

    SciTech Connect

    Silva, C.; Pinto da Cunha, J.; Pereira, A.; Chepel, V.; Lopes, M. I.; Solovov, V.; Neves, F.

    2010-03-15

    Gaseous and liquid xenon particle detectors are being used in a number of applications including dark matter search and neutrino-less double beta decay experiments. Polytetrafluoroethylene (PTFE) is often used in these detectors both as electrical insulator and as a light reflector to improve the efficiency of detection of scintillation photons. However, xenon emits in the vacuum ultraviolet (VUV) wavelength region ({lambda}{approx_equal}175 nm) where the reflecting properties of PTFE are not sufficiently known. In this work, we report on measurements of PTFE reflectance, including its angular distribution, for the xenon scintillation light. Various samples of PTFE, manufactured by different processes (extruded, expanded, skived, and pressed) have been studied. The data were interpreted with a physical model comprising both specular and diffuse reflections. The reflectance obtained for these samples ranges from about 47% to 66% for VUV light. Other fluoropolymers, namely, ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and perfluoro-alkoxyalkane (PFA) were also measured.

  3. The Mechanism of High Pressure Oxidations of Aliphatic Acids.

    DTIC Science & Technology

    ACETIC ACID , *OXIDATION), (*CARBOXYLIC ACIDS, OXIDATION), CHROMIUM ALLOYS, REACTION KINETICS, COPPER ALLOYS, NICKEL ALLOYS, TEMPERATURE, HIGH PRESSURE, CATALYSTS, GAS CHROMATOGRAPHY, VOLUMETRIC ANALYSIS, THESES

  4. Analgesic Effect of Xenon in Rat Model of Inflammatory Pain.

    PubMed

    Kukushkin, M L; Igon'kina, S I; Potapov, S V; Potapov, A V

    2017-02-01

    The analgesic effects of inert gas xenon were examined on rats. The formalin model of inflammatory pain, tail-flick test, and hot-plate test revealed the antinociceptive effects of subanesthetizing doses of inhalation anesthetic xenon. Inhalation of 50/50 xenon/oxygen mixture moderated the nociceptive responses during acute and tonic phases of inflammatory pain.

  5. Nitrous Oxide at High Pressure and Temperature: any Silica-like Polymorphs at High Pressure?

    NASA Astrophysics Data System (ADS)

    Iota, V.; Yoo, C.; Cynn, H.

    2001-12-01

    The crystal structures and phase stabilities of both four and six-fold silicon dioxide (SiO2) polymorphs are fundamental to the Earth's mineral physics and chemistry. The recent discovery of extended-solid phases of carbon dioxide (structurally similar to SiO2 polymorphs), offer a tantalizing new concept of mineral and geo-chemistry, considering the richness of oxygen, carbon, and silicon in the Earth's mantle and crust. In this study, we ask if nitrous oxide (N2O), an isoelectronic molecular analog to CO2, forms similar SiO2-like polymorphs at high pressures and temperatures. Our results based on in-situ and ex-situ Raman and X-ray diffraction measurements indicate that N2O indeed behaves similarly to CO2 at relatively low temperatures below 1000 K at high pressures up to 100 GPa. However, at higher temperatures, we find no transition to a polymeric phase of N2O. Instead, it disproportionates into a novel ionic phase of NO2 dimer (NO+NO3-) and N2. In this paper, we will discuss about the systematic of the phase diagrams of these triatomics, CO2 and N2O, in comparison with the polymorphs of SiO2, the Earth most abundant mineral.

  6. HXeOBr in a xenon matrix

    SciTech Connect

    Khriachtchev, Leonid; Tapio, Salla; Domanskaya, Alexandra V.; Raesaenen, Markku; Isokoski, Karoliina; Lundell, Jan

    2011-03-28

    We report on a new noble-gas molecule HXeOBr prepared in a low-temperature xenon matrix from the HBr and N{sub 2}O precursors by UV photolysis and thermal annealing. This molecule is assigned with the help of deuteration experiments and ab initio calculations including anharmonic methods. The H-Xe stretching frequency of HXeOBr is observed at 1634 cm{sup -1}, which is larger by 56 cm{sup -1} than the frequency of HXeOH identified previously. The experiments show a higher thermal stability of HXeOBr molecules in a xenon matrix compared to HXeOH.

  7. Readout of TPC Tracking Chambers with GEMs and Pixel Chip

    SciTech Connect

    Kadyk, John; Kim, T.; Freytsis, M.; Button-Shafer, J.; Kadyk, J.; Vahsen, S.E.; Wenzel, W.A.

    2007-12-21

    Two layers of GEMs and the ATLAS Pixel Chip, FEI3, have been combined and tested as a prototype for Time Projection Chamber (TPC) readout at the International Linear Collider (ILC). The double-layer GEM system amplifies charge with gain sufficient to detect all track ionization. The suitability of three gas mixtures for this application was investigated, and gain measurements are presented. A large sample of cosmic ray tracks was reconstructed in 3D by using the simultaneous timing and 2D spatial information from the pixel chip. The chip provides pixel charge measurement as well as timing. These results demonstrate that a double GEM and pixel combination, with a suitably modified pixel ASIC, could meet the stringent readout requirements of the ILC.

  8. A TPC for sPHENIX at RHIC

    NASA Astrophysics Data System (ADS)

    Ramasubramanian, Niveditha; Dehmelt, Klaus; Sphenix Collaboration

    2016-09-01

    The sPHENIX detector is being proposed at the Relativistic Heavy Ion Collider to measure jets and upsilons for advancing our understanding of the quark gluon plasma formed in heavy ion collisions. It is also expected to form the basis of a day-1 detector for a future U.S. Electron Ion Collider. sPHENIX is based on a superconducting solenoidal magnet formerly used by the BaBar experiment, and of charged particle tracking, electromagnetic as well as hadronic calorimetry. It covers a large acceptance, 2 π in azimuth and pseudorapidities of | η | < 1, and allows to acquire data at a rate of up to 15 kHz. Furthermore, a Gas Electron Multiplier based Time Projection Chamber has been proposed to improve tracking resolution in a high multiplicity environment. In this talk we will present the current design and status of ongoing R&D and simulation studies for tracking with a TPC.

  9. CARS Diagnostics of High Pressure Combustion - 2. Measurements of NO, H2O and High Pressure Flames

    DTIC Science & Technology

    1985-12-01

    R85-956328-F CARS DIAGNOSTICS OF r HIGH PRESSURE COMBUSTION -I MEASUREMENTS OF NO, H 0 AND HIGH PRESSURE FLAMES Final Report J.H. Stufflebeam DTIC I7...High Pressure Flames Final Report ~ 5%~ J. H. Stufflebeam J. A. Shirley December 1985 𔃿** U. S. Army Research Office Contract: DAAG29-83-C-OOO1...ClaIiation, CARS Diagnostics of High Pressure Combustion II 12. PERSONAL AUTHOR(S) Stufflebeam , 7. H., ShirleyJA 113a. TYPE OF REPORT 13b. TIME COVERED

  10. Excimer emission from pulsed microhollow cathode discharges in xenon

    SciTech Connect

    Lee, B.-J.; Nam, S. H.; Rahaman, H.; Iberler, M.; Jacoby, J.; Frank, K.

    2013-12-15

    Direct current (dc) microhollow cathode discharge (MHCD) is an intense source for excimer radiation in vacuum ultraviolet at a wavelength of 172 nm in a high pressure xenon (Xe) gas. The concentration of precursors for the excimer formation, i.e., excited and ionized gas atoms, increases significantly by applying high voltage pulse onto the dc MHCD over the pulse duration range from 20 to 100 ns. The intensity of the excimer emission for the voltage pulse of 20 ns duration exceeds that of the emission intensity obtained from the same MHCD operated only in the dc mode, by one order of magnitude. In addition, the emission intensity increases by one order of magnitude over the pulse duration range from 20 to 100 ns. It can be assumed that the emission intensity of the MHCD source increases as long as the duration of the high voltage pulse is shorter than the electron relaxation time. For the high voltage pulse of 100 ns duration, the emission intensity has been found to be further enhanced by a factor of three when the gas pressure is increased from 200 to 800 mbar.

  11. Reactivity of xenon with ice at planetary conditions.

    PubMed

    Sanloup, Chrystèle; Bonev, Stanimir A; Hochlaf, Majdi; Maynard-Casely, Helen E

    2013-06-28

    We report results from high pressure and temperature experiments that provide evidence for the reactivity of xenon with water ice at pressures above 50 GPa and a temperature of 1500 K-conditions that are found in the interiors of Uranus and Neptune. The x-ray data are sufficient to determine a hexagonal lattice with four Xe atoms per unit cell and several possible distributions of O atoms. The measurements are supplemented with ab initio calculations, on the basis of which a crystallographic structure with a Xe4O12H12 primitive cell is proposed. The newly discovered compound is formed in the stability fields of superionic ice and η-O2, and has the same oxygen subnetwork as the latter. Furthermore, it has a weakly metallic character and likely undergoes sublattice melting of the H subsystem. Our findings indicate that Xe is expected to be depleted in the atmospheres of the giant planets as a result of sequestration at depth.

  12. Reactivity of Xenon with Ice at Planetary Conditions

    NASA Astrophysics Data System (ADS)

    Sanloup, Chrystèle; Bonev, Stanimir A.; Hochlaf, Majdi; Maynard-Casely, Helen E.

    2013-06-01

    We report results from high pressure and temperature experiments that provide evidence for the reactivity of xenon with water ice at pressures above 50 GPa and a temperature of 1500 K—conditions that are found in the interiors of Uranus and Neptune. The x-ray data are sufficient to determine a hexagonal lattice with four Xe atoms per unit cell and several possible distributions of O atoms. The measurements are supplemented with ab initio calculations, on the basis of which a crystallographic structure with a Xe4O12H12 primitive cell is proposed. The newly discovered compound is formed in the stability fields of superionic ice and η-O2, and has the same oxygen subnetwork as the latter. Furthermore, it has a weakly metallic character and likely undergoes sublattice melting of the H subsystem. Our findings indicate that Xe is expected to be depleted in the atmospheres of the giant planets as a result of sequestration at depth.

  13. 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...

  14. 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

  15. 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

  16. 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...

  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. 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...

  19. 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...

  20. 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...

  1. 76 FR 38697 - High Pressure Steel Cylinders From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... 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 7311... pressure steel cylinders from China. Accordingly, effective May 11, 2011, the Commission...

  2. Vacuum Surface Flashover And High Pressure Gas Streamers

    DTIC Science & Technology

    1997-06-01

    Optical Emission Characteristics of Polycrystalline Diamond During Surface Flashover in Vacuum ," 1996 IEEE 1~ International Symposium on... VACUUM SURFACE FLASHOVER AND HIGH PRESSURE GAS STREAMERS J. M. Elizondo, M. L. Krogh, D. Smith, D. Stoltz, and S. N. Wright AlliedSignal Federal...breakdown current traces obtained during high pressure gas breakdown and vacuum surface flashover show similar signatures. The initial

  3. The Low-Energy Background in XENON1T

    NASA Astrophysics Data System (ADS)

    Gao, Fei; Stein, Alec; Xenon1T Collaboration

    2017-01-01

    The XENON1T dark matter direct-detection experiment looks for hypothetical Weakly Interacting Massive Particles (WIMPs). WIMPs are expected to scatter off xenon nuclei at low energies, so understanding the low-energy background of the detector is crucial. In XENON1T, the background in the WIMP search region is due to radioactive decays stemming from the detector construction materials and impurities in the xenon itself. We show that our predicted low-energy background rate of 10-4events .kg-1 .day-1 .keV-1 matches XENON1T's design goals and is in agreement with the data taken during the commissioning of the detector.

  4. Transdermal diffusion of xenon in vitro using diffusion cells

    NASA Astrophysics Data System (ADS)

    Verkhovsky, A.; Petrov, E.

    2015-11-01

    The aim of this research was to study the diffusion rate of xenon through guinea pig skin and how viscosity of cosmetic component capryl/capric triglyceride (CCT) facilitates to deliver xenon to surface of skin patches. They were placed in Franz cell for 24 hours and diffusion rate and permeability of xenon were calculated. Thus diffusion rate was 0.031 mg/hour*cm2 and permeability was 0.003 cm/hour. Using Brookfield viscometer it was shown that viscosity of CCT decreased upon increasing xenon concentration. Obtained results can be utilized in developing of new xenon containing drugs for topical administration.

  5. TPC tracking software for NIFFTE: the Neutron Induced Fission Fragment Tracking Experiment

    NASA Astrophysics Data System (ADS)

    Kudo, Ryuho; Klay, J. L.

    2008-10-01

    Ever since the scientific community started analyzing and filtering data using computers, programming has become a crucial part for the success of many projects. The NIFFTE Collaboration, which is building a Time Projection Chamber (TPC) to study neutron-induced fission of the major actinides, naturally requires a comprehensive software framework to analyze the high volume of data it will collect. Following the traditional TPC reconstruction model, we have written a set of offline analysis algorithms to reconstruct tracks left by the fission fragments in the TPC and determine their (A,Z). We accomplish this by organizing the raw TPC voxel data into 2 dimensional planes, performing cluster and hit-finding within those planes and then connecting the hits to create 3-D tracks. Finally, track fitting and error correction are performed and the fragment A,Z are determined from the distribution of specific ionization along the track. Since one of the goals of this project is to create a re-usable library of TPC reconstruction code that can be adapted to other TPC projects, the software uses open source tools and is built as an object-oriented package in C++. This poster will present the current status of the TPC reconstruction algorithms and discuss the motivations behind our specific programming choices.

  6. 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.

  7. Antiapoptotic activity of argon and xenon.

    PubMed

    Spaggiari, Sabrina; Kepp, Oliver; Rello-Varona, Santiago; Chaba, Kariman; Adjemian, Sandy; Pype, Jan; Galluzzi, Lorenzo; Lemaire, Marc; Kroemer, Guido

    2013-08-15

    Although chemically non-reactive, inert noble gases may influence multiple physiological and pathological processes via hitherto uncharacterized physical effects. Here we report a cell-based detection system for assessing the effects of pre-defined gas mixtures on the induction of apoptotic cell death. In this setting, the conventional atmosphere for cell culture was substituted with gas combinations, including the same amount of oxygen (20%) and carbon dioxide (5%) but 75% helium, neon, argon, krypton, or xenon instead of nitrogen. The replacement of nitrogen with noble gases per se had no effects on the viability of cultured human osteosarcoma cells in vitro. Conversely, argon and xenon (but not helium, neon, and krypton) significantly limited cell loss induced by the broad-spectrum tyrosine kinase inhibitor staurosporine, the DNA-damaging agent mitoxantrone and several mitochondrial toxins. Such cytoprotective effects were coupled to the maintenance of mitochondrial integrity, as demonstrated by means of a mitochondrial transmembrane potential-sensitive dye and by assessing the release of cytochrome c into the cytosol. In line with this notion, argon and xenon inhibited the apoptotic activation of caspase-3, as determined by immunofluorescence microscopy coupled to automated image analysis. The antiapoptotic activity of argon and xenon may explain their clinically relevant cytoprotective effects.

  8. Atomistic study of stability of xenon nanoclusters in uranium oxide

    SciTech Connect

    Chartier, A.; Van Brutzel, L.; Freyss, M.

    2010-05-01

    Density-functional theory calculations of the xenon incorporation energies in point defects in urania have been done in order to fit empirical potentials. With this set of parameters, we have considered the incorporation of xenon in small and extended defects such as planar interstitials, grain boundaries, faceted, and spherical voids. The results show that xenon atoms are more likely to aggregate than to be homogeneously distributed in the urania grains. SIGMA5 grain boundary and spherical shape voids are the most favorable defects of xenon atom incorporation. The presence of xenon atoms in nanovoids affects their shape. The energy gain to aggregate xenon atoms into clusters saturates for cluster sizes of about 15-20 Schottky defects. This demonstrates that medium size defects are just as favorable as big size defects for xenon incorporation.

  9. TPC-V: A Benchmark for Evaluating the Performance of Database Applications in Virtual Environments

    NASA Astrophysics Data System (ADS)

    Sethuraman, Priya; Reza Taheri, H.

    For two decades, TPC benchmarks have been the gold standards for evaluating the performance of database servers. An area that TPC benchmarks had not addressed until now was virtualization. Virtualization is now a major technology in use in data centers, and is the number one technology on Gartner Group's Top Technologies List. In 2009, the TPC formed a Working Group to develop a benchmark specifically intended for virtual environments that run database applications. We will describe the characteristics of this benchmark, and provide a status update on its development.

  10. A Large Liquid Argon TPC for Off-axis NuMI Neutrino Physics

    SciTech Connect

    Menary, Scott

    2006-07-11

    The ICARUS collaboration has shown the power of the liquid argon time projection chamber (LArTPC) technique to image events with bubble-chamber-like quality. I will describe a proposed long-baseline {nu}e appearance experiment utilizing a large ({>=} 15 kton1) LArTPC placed off-axis of Fermilab's NuMI {nu}{mu} beam. The total LArTPC program as it presently stands, which includes a number of smaller R and D projects designed to examine the key design issues, will be outlined.

  11. SAMURAI-TPC: A Time Projection Chamber for Constraining the Asymmetry Energy at High Density

    NASA Astrophysics Data System (ADS)

    McIntosh, A. B.; Maass, N.; Yennello, S. J.; Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Estee, J.; Gilbert, J.; Lu, F.; Lynch, W. G.; Shane, R.; Tsang, M. B.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    The SAMURAI-TPC is a time projection chamber designed to measure pions and light charged particles. By measuring pion yield ratios and particle flow in heavy ion collisions around E = 200A MeV, we expect to constrain the behavior of the nuclear asymmetry energy around twice saturation density. In this talk, the design and construction of the TPC components will be discussed. Upon completion, the SAMURAI-TPC will be installed in the SAMURAI spectrometer at the Radioactive Isotope Beam Facility at RIKEN, Japan. This work is supported by the Department of Energy (DE-SC0004835).

  12. 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.

  13. 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.

  14. 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.

  15. Molecular dynamics simulation of solvated protein at high pressure.

    PubMed

    Kitchen, D B; Reed, L H; Levy, R M

    1992-10-20

    We have completed a molecular dynamics simulation of protein (bovine pancreatic trypsin inhibitor, BPTI) in solution at high pressure (10 kbar). The structural and energetic effects of the application of high pressure to solvated protein are analyzed by comparing the results of the high-pressure simulation with a corresponding simulation at low pressure. The volume of the simulation cell containing one protein molecule plus 2943 water molecules decreases by 24.7% at high pressure. This corresponds to a compressibility for the protein solution of beta = 1.8 x 10(-2) kbar-1. The compressibility of the protein is estimated to be about one-tenth that of bulk water, while the protein hydration layer water is found to have a greater compressibility as compared to the bulk, especially for water associated with hydrophobic groups. The radius of gyration of BPTI decreases by 2% and there is a one third decrease in the protein backbone atomic fluctuations at high pressure. We have analyzed pressure effects on the hydration energy of the protein. The total hydration energy is slightly (4%) more favorable at high pressure even though the surface accessibility of the protein has decreased by a corresponding amount. Large pressure-induced changes in the structure of the hydration shell are observed. Overall, the solvation shell waters appear more ordered at high pressure; the pressure-induced ordering is greatest for nonpolar surface groups. We do not observe evidence of pressure-induced unfolding of the protein over the 100-ps duration of the high-pressure simulation. This is consistent with the results of high-pressure optical experiments on BPTI.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. 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.

  17. High-pressure saline washing of allografts reduces bacterial contamination.

    PubMed

    Hirn, M Y; Salmela, P M; Vuento, R E

    2001-02-01

    60 fresh-frozen bone allografts were contaminated on the operating room floor. No bacterial growth was detected in 5 of them after contamination. The remaining 55 grafts had positive bacterial cultures and were processed with three methods: soaking in saline, soaking in antibiotic solution or washing by high-pressure saline. After high-pressure lavage, the cultures were negative in three fourths of the contaminated allografts. The corresponding figures after soaking grafts in saline and antibiotic solution were one tenth and two tenths, respectively. High-pressure saline cleansing of allografts can be recommended because it improves safety by reducing the superficial bacterial bioburden.

  18. Investigation of High-Pressure Hydraulic Vortex Rate Sensor

    DTIC Science & Technology

    stability - augmentation system . The feasibility of low-pressure fluid stabilization systems was demonstrated. The primary component that requires development for implementation in a high pressure system is the vortex rate sensor. The high-pressure hydraulic vortex rate sensor has an on-board built-in supply of hydraulic fluid which is used in the primary hydro-mechanical flight control of the vehicle. A small amount of hydraulic fluid under high pressure can be diverted from the main system to the vortex rate sensor, used to perform a sensing function, and

  19. 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.

  20. Surfactant mediated extraction of total phenolic contents (TPC) and antioxidants from fruits juices.

    PubMed

    Sharma, Shweta; Kori, Shivpoojan; Parmar, Ankush

    2015-10-15

    The aim of this study was to enhance the extraction of total phenolic contents (TPC) and antioxidants from fruit juices by the application of surfactants formulations instead of conventional solvents (methanol, ethanol and acetone). A variety of fruit infusions: apple red delicious (apple (rd)) (Malus domestica), Mcintosh apple (apple (i)) (Malus pumila), sweet lemon (Citrus limetta) and mango (Magnifera indica) were studied. Effect of water, organic solvents and five different aqueous surfactant formulations viz. SDS, Brij-35, Brij-58, Triton X-100 and Span-40 were explored for the extraction of TPC and determining the antioxidant activity (AA). The TPC and AA (%) were determined using Folin-Ciocalteu (FCA) and DPPH assay, respectively. The effect of surfactant type, concentration and common organic solvents on the extraction of TPC and AA (%) was studied using UV-visible spectrophotometric technique. Among all the extracting systems employed, Brij-58 showed the highest extraction efficiency.

  1. Status and Plans for the XENON Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    Gaitskell, R. J.; Collaborotion, Xenon

    2005-04-01

    The XENON experiment aims at the direct detection of dark matter in the form of WIMPs (Weakly Interacting Massive Particles) via their elastic scattering off Xenon nuclei. With a fiducial mass of 1000 kg of liquid xenon, a sufficiently low threshold of 16 keV recoil energy and an un-rejected background rate of 10 events per year, XENON would be sensitive to a WIMP-nucleon interaction cross section of ~ 10-46cm2, for WIMPs with masses above 50 GeV. A 1 tonne scale experiment (XENON1T) would be realized with an array of ten identical 100 kg detector modules (XENON100). The detectors are time projection chambers operated in dual (liquid/gas) phase, to detect simultaneously the ionization, through secondary scintillation in the gas, and primary scintillation in the liquid produced by low energy recoils. The distinct ratio of primary to secondary scintillation for nuclear recoils from WIMPs (or neutrons), and for electron recoils from background, is key to the event-by-event discrimination capability of XENON. A 3kg dual phase detector with light readout provided by an array of 7 photomultipliers is currently being tested, along with other prototypes dedicated to various measurements relevant to the XENON program. We present some of the results obtained to-date and briefly discuss the next step in the phased approach to the XENON experiment, i.e. the development and underground deployment of a 10 kg detector (XENON10) during 2005.

  2. Xenon adsorption in NaA zeolite cavities

    NASA Astrophysics Data System (ADS)

    McCormick, A. V.; Chmelka, B. F.

    Adsorption of xenon atoms in the α-cages of NaA zeolite has been studied using 129Xe NMR spectroscopy to probe directly the distribution and configuration of molecules in confined, microporous environments. The 129Xe NMR spectrum is sensitive to subtle changes in xenon environment, so relative populations of α-cages containing different numbers of xenon guests can be determined and the effects of other co-adsorbed species monitored. On the basis of 129Xe NMR spectra, the distribution of xenon atoms among NaA α-cages is shown to exhibit a marked dependence on the pressure at which the xenon guests are introduced. 129Xe NMR spectra recorded at 200 K reveal that xenon atoms in the NaA α-cages experience diminished mobility (resembling condensation phenomena) at higher temperatures than in the bulk gas of equivalent density. Thus, the chemical potential of adsorbed xenon can be investigated experimentally as a function of both temperature and guest density. The density dependence of the 129Xe chemical shift in Xe/NaA and in bulk xenon gas shows that Xe-Xe interactions in the proximity of the NaA cage wall are important in α-cages containing more than five xenon guests. This trend is linked to entropic effects which may enhance xenon adsorption in the confined environment of the NaA α-cages.

  3. Behavior of TPC`s in a high particle flux environment

    SciTech Connect

    Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J.; Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y.; Hallman, T.J.; Madansky, L.; Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B.

    1991-12-31

    TPC`s (Time Projection Chamber) used in E-810 at the TAGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10 minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  4. Behavior of TPC`s in a high particle flux environment

    SciTech Connect

    Etkin, A.; Eisemann, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J. |; Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y.; Hallman, T.J.; Madansky, L.; Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B.

    1991-12-13

    TPC`s (Time Projection Chamber) used in E-810 at the AGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10{sup 7} minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

  5. A TPC detector for the study of high multiplicity heavy ion collisions

    SciTech Connect

    Rai, G.; Arthur, A.; Beiser, F.; Harnden, C.W.; Jones, R.; Kleinfelder, S.; Lee, K.; Matis, H.S.; Nakamura, M.; McParland, C.; Nesbitt, D.; Odyniec, G.; Olson, D.; Pugh, H.G.; Ritter, H.G.; Symons, T.J.M.; Weiman, H.; Wright, R. ); Rudge, A. )

    1990-04-01

    The design of the time projection chamber (TPC) detector with complete pad coverage is presented. The TPC will allow the measurements of high multiplicity ({approx}200 tracks) relativistic nucleus-nucleus collisions initiated with the heaviest, most energetic projectiles available at the LBL BEVALAC accelerator facility. The front end electronics, composed of over 15,000 time sampling channels, will be located on the chamber. The highly integrated, custom designed, electronics and the VME based data acquisition system are described.

  6. High pressure-induced structural effects in plastic packaging

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Today, flexible vacuum packages are predominantly used for products to be subjected to high pressure treatment. However, tray packages with a modified atmosphere are in demand, which provide a high failure rate with respect to gas and water vapour permeability and packaging integrity. Methods to follow permeation processes under high pressure were developed and used together with optical microscopy, confocal scanning laser microscopy, Raman spectroscopy and atomic force microscopy to identify the mechanisms for changes in permeability and damage to the packaging materials. Single film samples and pouch packages filled with model products were studied. Results indicate a reversible decrease in the coefficients of diffusion and permeation under the impact of high pressure, due to the compression of the polymeric bulk. Irreversible changes in the polymeric materials are associated with gases in the packaging head space, which cause high local temperatures and create damage due to rapid deliberation upon the pressure drop at the end of the high pressure cycle.

  7. 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

  8. 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

  9. Development of high pressure gas cells at ISIS

    NASA Astrophysics Data System (ADS)

    Kirichek, O.; Done, R.; Goodway, C. M.; Kibble, M. G.; Evans, B.; Bowden, Z. A.

    2012-02-01

    High-pressure research is one of the fastest-growing areas of natural science, and one that attracts as diverse communities as those of physics, bio-physics, chemistry, materials science and earth science. In condensed matter physics there are a number of highly topical areas, such as quantum criticality, pressure-induced superconductivity or non-Fermi liquid behaviour, where pressure is a fundamental parameter. Reliable, safe and user-friendly high pressure gas handling systems with gas pressures up to 1GPa should make a significant impact on the range of science possible. The ISIS facility is participating in the NMI3 FP7 sample environment project supported by the European Commission which includes high pressure gas cell development. In this paper the progress in designing, manufacturing and testing a new generation of high pressure gas cells for neutron scattering experiments is discussed.

  10. 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

  11. Evaluation of high-pressure drilling fluid supply systems

    SciTech Connect

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

    1981-10-01

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

  12. 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

  13. High-pressure liquid chromatography of aromatic amines

    NASA Technical Reports Server (NTRS)

    Young, P. R.

    1979-01-01

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

  14. High pressure working mode of hollow cathode arc discharges

    NASA Technical Reports Server (NTRS)

    Minoo, H.; Popovici, C.

    1985-01-01

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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. Muon tomography of rock density using Micromegas-TPC telescope

    NASA Astrophysics Data System (ADS)

    Hivert, Fanny; Busto, José; Gaffet, Stéphane; Ernenwein, Jean-Pierre; Brunner, Jurgen; Salin, Pierre; Decitre, Jean-Baptiste; Lázaro Roche, Ignacio; Martin, Xavier

    2014-05-01

    The knowledge of the subsurface properties is essentially obtained by geophysical methods, e.g., seismic imaging, electric prospection or gravimetry. The current work is based on a recently developed method to investigate in situ the density of rocks using a measurement of the muon flux, whose attenuation depends on the quantity of matter the particles travel through and hence on the rock density and thickness. The present project (T2DM2) aims at performing underground muon flux measurements in order to characterize spatial and temporal rock massif density variations above the LSBB underground research facility in Rustrel (France). The muon flux will be measured with a new muon telescope device using Micromegas-Time Projection Chamber (TPC) detectors. The first step of the work presented covers the muon flux simulation based on the Gaisser model (Gaisser T., 1990), for the muon flux at the ground level, and on the MUSIC code (Kudryavtsev V. A., 2008) for the propagation of muons through the rock. The results show that the muon flux distortion caused by density variations is enough significant to be observed at 500 m depth for measurement times of about one month. This time-scale is compatible with the duration of the water transfer processes within the unsaturated Karst zone where LSBB is located. The work now focuses on the optimization of the detector layout along the LSBB galleries in order to achieve the best sensitivity.

  20. XENON100 Dark Matter Search: Scintillation Response of Liquid Xenon to Electronic Recoils

    NASA Astrophysics Data System (ADS)

    Lim, Kyungeun Elizabeth

    Dark matter is one of the missing pieces necessary to complete the puzzle of the universe. Numerous astrophysical observations at all scales suggest that 23 % of the universe is made of nonluminous, cold, collisionless, nonbaryonic, yet undiscovered dark matter. Weakly Interacting Massive Particles (WIMPs) are the most well-motivated dark matter candidates and significant efforts have been made to search for WIMPs. The XENON100 dark matter experiment is currently the most sensitive experiment in the global race for the first direct detection of WIMP dark matter. XENON100 is a dual-phase (liquid-gas) time projection chamber containing a total of 161 kg of liquid xenon (LXe) with a 62kg WIMP target mass. It has been built with radiopure materials to achieve an ultra-low electromagnetic background and operated at the Laboratori Nazionali del Gran Sasso in Italy. WIMPs are expected to scatter off xenon nuclei in the target volume. Simultaneous measurement of ionization and scintillation produced by nuclear recoils allows for the detection of WIMPs in XENON100. Data from the XENON100 experiment have resulted in the most stringent limits on the spin-independent elastic WIMP-nucleon scattering cross sections for most of the significant WIMP masses. As the experimental precision increases, a better understanding of the scintillation and ionization response of LXe to low energy (< 10 keV) particles is crucial for the interpretation of data from LXe based WIMP searches. A setup has been built and operated at Columbia University to measure the scintillation response of LXe to both electronic and nuclear recoils down to energies of a few keV, in particular for the XENON100 experiment. In this thesis, I present the research carried out in the context of the XENON100 dark matter search experiment. For the theoretical foundation of the XENON100 experiment, the first two chapters are dedicated to the motivation for and detection medium choice of the XENON100 experiment

  1. 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.

  2. 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

  3. Pulse plasma carburizing and high pressure gas quenching -- Industrial applications

    SciTech Connect

    Preisser, F.; Schnatbaum, F.

    1995-12-31

    Pulse plasma carburizing with high pressure gas quenching up to 20 bar is the newly developed case hardening process now available in production size equipment. The first part of results demonstrates the tremendous potential of high pressure gas quenching for successful hardening of case hardening steels. The second part opens a window to glance at the pulse plasma carburizing of complex shaped parts. Both processes improve economical data and performance of carburizing processes.

  4. 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.

  5. Xenon and iodine reveal multiple distinct exotic xenon components in Efremovka "nanodiamonds"

    NASA Astrophysics Data System (ADS)

    Gilmour, J. D.; Holland, G.; Verchovsky, A. B.; Fisenko, A. V.; Crowther, S. A.; Turner, G.

    2016-03-01

    We identify new xenon components in a nanodiamond-rich residue from the reduced CV3 chondrite Efremovka. We demonstrate for the first time that these, and the previously identified xenon components Xe-P3 and Xe-P6, are associated with elevated I/Xe ratios. The 129I/127I ratio associated with xenon loss from these presolar compositions during processing on planetesimals in the early solar system was (0.369 ± 0.019) × 10-4, a factor of 3-4 lower than the canonical value. This suggests either incorporation of iodine into carbonaceous grains before the last input of freshly synthesized 129I to the solar system's precursor material, or loss of noble gases during processing of planetesimals around 30 Myr after solar system formation. The xenon/iodine ratios and model closure ages were revealed by laser step pyrolysis analysis of a neutron-irradiated, coarse-grained nanodiamond separate. Three distinct low temperature compositions are identified by characteristic I/Xe ratios and 136Xe/132Xe ratios. There is some evidence of multiple compositions with distinct I/Xe ratios in the higher temperature releases associated with Xe-P6. The presence of iodine alongside Q-Xe and these components in nanodiamonds constrains the pathway by which extreme volatiles entered the solid phase and may facilitate the identification of their carriers. There is no detectable iodine contribution to the presolar Xe-HL component, which is released at intermediate temperatures; this suggests a distinct trapping process. Releases associated with the other components all include significant contributions of 128Xe produced from iodine by neutron capture during reactor irradiation. We propose a revised model relating the origin of Xe-P3 (which exhibits an s-process deficit) through a ;Q-process; to the Q component (which makes the dominant contribution to the heavy noble gas budget of primitive material). The Q-process incorporates noble gases and iodine into specific carbonaceous phases with mass

  6. Background Discrimination Capability of a Dual Phase Xenon Detector for the XENON Dark Matter Experiment

    NASA Astrophysics Data System (ADS)

    Ni, Kaixuan

    2005-04-01

    The XENON experiment aims at searching for dark matter WIMPs via their elastic scattering off Xe nuclei. The detector is a dual phase (liquid/gas) xenon time projection chamber, which allows event-by-event discrimination through the different ratio of ionization (charge) and scintillation (light) signals produced in liquid xenon by nuclear recoils (WIMPs and neutrons) and by electron recoils (electrons and gammas). In the dual phase detector, the ionization signal is detected via proportional scintillation light produced by accelerated electrons extracted from the liquid to the gas. I will demonstrate the performance of event type discrimination of a dual phase xenon prototype with seven photomultiplier-tubes (PMTs) for detecting direct scintillation (S1) and proportional scintillation (S2) signals simultaneously. The values of S2/S1 were measured for electron (Co-57) and alpha (Po-210) recoils, with a difference about a factor of 30. A preliminary result of S2/S1 from nuclear recoils (Am-Be) will also be presented. Based on the distribution of S2 signals over the seven PMTs, an algorithm was developed to reconstruct the event positions, which shows promising capability to further reject background events from the detector surface. The background discrimination capability of a larger scale (10 kg) detector (XENON10) will be shown from detailed Monte Carlo simulations.

  7. 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

  8. Advances and synergy of high pressure sciences at synchrotron sources

    SciTech Connect

    Liu, H.; Ehm, L.; Duffy, T.; Crichton, W.; Aoki, K.

    2009-01-01

    Introductory overview to the special issue papers on high-pressure sciences and synchrotron radiation. High-pressure research in geosciences, materials science and condensed matter physics at synchrotron sources is experiencing growth and development through synergistic efforts around the world. A series of high-pressure science workshops were organized in 2008 to highlight these developments. One of these workshops, on 'Advances in high-pressure science using synchrotron X-rays', was held at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, USA, on 4 October 2008. This workshop was organized in honour of Drs Jingzhu Hu and Quanzhong Guo in celebration of their retirement after up to 18 years of dedicated service to the high-pressure community as beamline scientists at X17 of NSLS. Following this celebration of the often unheralded role of the beamline scientist, a special issue of the Journal of Synchrotron Radiation on Advances and Synergy of High-Pressure Sciences at Synchrotron Sources was proposed, and we were pleased to invite contributions from colleagues who participated in the workshop as well as others who are making similar efforts at synchrotron sources worldwide.

  9. Two pore channel 2 (TPC2) inhibits autophagosomal-lysosomal fusion by alkalinizing lysosomal pH.

    PubMed

    Lu, Yingying; Hao, Bai-Xia; Graeff, Richard; Wong, Connie W M; Wu, Wu-Tian; Yue, Jianbo

    2013-08-16

    Autophagy is an evolutionarily conserved lysosomal degradation pathway, yet the underlying mechanisms remain poorly understood. Nicotinic acid adenine dinucleotide phosphate (NAADP), one of the most potent Ca(2+) mobilizing messengers, elicits Ca(2+) release from lysosomes via the two pore channel 2 (TPC2) in many cell types. Here we found that overexpression of TPC2 in HeLa or mouse embryonic stem cells inhibited autophagosomal-lysosomal fusion, thereby resulting in the accumulation of autophagosomes. Treatment of TPC2 expressing cells with a cell permeant-NAADP agonist, NAADP-AM, further induced autophagosome accumulation. On the other hand, TPC2 knockdown or treatment of cells with Ned-19, a NAADP antagonist, markedly decreased the accumulation of autophagosomes. TPC2-induced accumulation of autophagosomes was also markedly blocked by ATG5 knockdown. Interestingly, inhibiting mTOR activity failed to increase TPC2-induced autophagosome accumulation. Instead, we found that overexpression of TPC2 alkalinized lysosomal pH, and lysosomal re-acidification abolished TPC2-induced autophagosome accumulation. In addition, TPC2 overexpression had no effect on general endosomal-lysosomal degradation but prevented the recruitment of Rab-7 to autophagosomes. Taken together, our data demonstrate that TPC2/NAADP/Ca(2+) signaling alkalinizes lysosomal pH to specifically inhibit the later stage of basal autophagy progression.

  10. Port and harbor patrol car loaded Xenon search light

    NASA Astrophysics Data System (ADS)

    Amoh, Hiroshi; Takenami, Takashi

    2005-05-01

    The container ship yard is brighten by the lighting, but after Sunset of the sea side is dark during a crescent. On the sea side lighting, we propose to use to patrol car loaded Xenon search light. Generally, the Pacific Ocean of a surface of the sea swimming fishes such as Samma (Mackerel pike) likes strong visible light as a Xenon search light beam. In the feeling of the human eyes and brains with a strong visible light beam such as Xenon search light, the reaction is divided two kind of types, to avoid reaction's humans have a feeling that bad conscience, and no reaction's humans tend to have a feeling of good mind. For the black painted unmanned objects of visible watching is needed as possible as strong visible light beam of the Xenon search light. The optical system of the Xenon search light consists of a Xenon lamp, a parabolic mirror and the filters.

  11. Optimization of Xenon Biosensors for Detection of ProteinInteractions

    SciTech Connect

    Lowery, Thomas J.; Garcia, Sandra; Chavez, Lana; Ruiz, E.Janette; Wu, Tom; Brotin, Thierry; Dutasta, Jean-Pierre; King, David S.; Schultz, Peter G.; Pines, Alex; Wemmer, David E..

    2005-08-03

    Hyperpolarized 129Xe NMR can detect the presence of specific low-concentration biomolecular analytes by means of the xenon biosensor, which consists of a water-soluble, targeted cryptophane-A cage that encapsulates xenon. In this work we use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical shift anisotropy, xenon exchange, and biosensor conformational exchange on protein-bound biosensor signal were assessed. It was found that optimal protein-bound biosensor signal can be obtained by minimizing the number of biosensor diastereomers and using a flexible linker of appropriate length. Both the linewidth and sensitivity of chemical shift to protein binding of the xenon biosensor were found to be inversely proportional to linker length.

  12. Boiling heat transfer characteristics of liquid xenon

    NASA Astrophysics Data System (ADS)

    Haruyama, T.

    2002-05-01

    Liquid xenon is one of the excellent media for high-energy particle calorimeter. In order to detect a scintillation light effectively, a large number of photo-multipliers (PMTs) will be immersed in liquid xenon. Many chip-resistors equipped with the PMTs dissipate heat into liquid and possibly generate thermal turbulence, such as bubbles, convection flow under a certain operating condition. There is, however, no heat transfer curve (q-ΔT curve) in the literature. Boiling heat transfer characteristics of liquid xenon were measured at a saturated pressure of 0.1 MPa for the first time by using a small pulse tube refrigerator. The heat transfer surface is a thin platinum wire of 0.1 mm diameter and 25 mm long. The measured results were in good agreement with the calculated values both in natural convection and nucleate boiling condition. The film boiling state was difficult to obtain due to its poor reproducibility, and only one data was obtained. The relationship between the heat flux q and temperature difference ΔT was in good agreement with the Morgan's empirical equation in the natural convection region, and with the Kutateladze's equation in the nucleate boiling region.

  13. Relaxation channels of multi-photon excited xenon clusters

    SciTech Connect

    Serdobintsev, P. Yu.; Melnikov, A. S.; Rakcheeva, L. P. Murashov, S. V.; Khodorkovskii, M. A.; Lyubchik, S.; Timofeev, N. A.; Pastor, A. A.

    2015-09-21

    The relaxation processes of the xenon clusters subjected to multi-photon excitation by laser radiation with quantum energies significantly lower than the thresholds of excitation of atoms and ionization of clusters were studied. Results obtained by means of the photoelectron spectroscopy method showed that desorption processes of excited atoms play a significant role in the decay of two-photon excited xenon clusters. A number of excited states of xenon atoms formed during this process were discovered and identified.

  14. Relaxation channels of multi-photon excited xenon clusters.

    PubMed

    Serdobintsev, P Yu; Rakcheeva, L P; Murashov, S V; Melnikov, A S; Lyubchik, S; Timofeev, N A; Pastor, A A; Khodorkovskii, M A

    2015-09-21

    The relaxation processes of the xenon clusters subjected to multi-photon excitation by laser radiation with quantum energies significantly lower than the thresholds of excitation of atoms and ionization of clusters were studied. Results obtained by means of the photoelectron spectroscopy method showed that desorption processes of excited atoms play a significant role in the decay of two-photon excited xenon clusters. A number of excited states of xenon atoms formed during this process were discovered and identified.

  15. Relaxation channels of multi-photon excited xenon clusters

    NASA Astrophysics Data System (ADS)

    Serdobintsev, P. Yu.; Rakcheeva, L. P.; Murashov, S. V.; Melnikov, A. S.; Lyubchik, S.; Timofeev, N. A.; Pastor, A. A.; Khodorkovskii, M. A.

    2015-09-01

    The relaxation processes of the xenon clusters subjected to multi-photon excitation by laser radiation with quantum energies significantly lower than the thresholds of excitation of atoms and ionization of clusters were studied. Results obtained by means of the photoelectron spectroscopy method showed that desorption processes of excited atoms play a significant role in the decay of two-photon excited xenon clusters. A number of excited states of xenon atoms formed during this process were discovered and identified.

  16. Initial evaluation of proportional scintillation in liquid Xenon for direct dark matter detection

    NASA Astrophysics Data System (ADS)

    Ye, T.; Giboni, K. L.; Ji, X.

    2014-12-01

    The Liquid Xenon Time Projection Chamber (LXeTPC) is often seen as an ideal detector for the direct Dark Matter (DM) search. In such experiments an efficient γ-ray background discrimination is essential. This can be achieved by distinguishing the ionization density, different for γ-rays and Nuclear Recoils. Two quantities are used for this measurement, the direct scintillation light generated by the ionizing event, and the free charges swept away by an electric field before recombination occurs. Present LXe detectors apply the Dual Phase principle, i.e. the charges are extracted into the gas phase and are measured by the proportional light they produce in a strong electric field in the gas. With ever growing dimensions of the detectors it is difficult to meet the tight mechanical tolerances required. Proportional scintillation also occurs in the liquid phase, although at much higher field strengths. Such field strengths can be reached in the 1/r field close to thin wires. All the limitations due to the extraction of electrons into the gas phase are avoided. Since the liquid level has not to be crossed, the design of the detector becomes simpler with many advantages over Dual Phase detectors. Our initial tests clearly show the pulses. They are much shorter, and their length is limited by longitudinal diffusion of the drifting charges. The threshold for proportional light production seems significantly lower, and estimates of the gain are more favorable than previously predicted. We attribute these discrepancies to our improved liquid purity.

  17. 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.

  18. Structure and stability of hydrous minerals at high pressure

    NASA Astrophysics Data System (ADS)

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

    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.

  19. 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.

  20. Magnetic resonance imaging of convection in laser-polarized xenon

    NASA Technical Reports Server (NTRS)

    Mair, R. W.; Tseng, C. H.; Wong, G. P.; Cory, D. G.; Walsworth, R. L.

    2000-01-01

    We demonstrate nuclear magnetic resonance (NMR) imaging of the flow and diffusion of laser-polarized xenon (129Xe) gas undergoing convection above evaporating laser-polarized liquid xenon. The large xenon NMR signal provided by the laser-polarization technique allows more rapid imaging than one can achieve with thermally polarized gas-liquid systems, permitting shorter time-scale events such as rapid gas flow and gas-liquid dynamics to be observed. Two-dimensional velocity-encoded imaging shows convective gas flow above the evaporating liquid xenon, and also permits the measurement of enhanced gas diffusion near regions of large velocity variation.

  1. Xenon preconditioning reduces brain damage from neonatal asphyxia in rats.

    PubMed

    Ma, Daqing; Hossain, Mahmuda; Pettet, Garry K J; Luo, Yan; Lim, Ta; Akimov, Stanislav; Sanders, Robert D; Franks, Nicholas P; Maze, Mervyn

    2006-02-01

    Xenon attenuates on-going neuronal injury in both in vitro and in vivo models of hypoxic-ischaemic injury when administered during and after the insult. In the present study, we sought to investigate whether the neuroprotective efficacy of xenon can be observed when administered before an insult, referred to as 'preconditioning'. In a neuronal-glial cell coculture, preexposure to xenon for 2 h caused a concentration-dependent reduction of lactate dehydrogenase release from cells deprived of oxygen and glucose 24 h later; xenon's preconditioning effect was abolished by cycloheximide, a protein synthesis inhibitor. Preconditioning with xenon decreased propidium iodide staining in a hippocampal slice culture model subjected to oxygen and glucose deprivation. In an in vivo model of neonatal asphyxia involving hypoxic-ischaemic injury to 7-day-old rats, preconditioning with xenon reduced infarction size when assessed 7 days after injury. Furthermore, a sustained improvement in neurologic function was also evident 30 days after injury. Phosphorylated cAMP (cyclic adenosine 3',5'-monophosphate)-response element binding protein (pCREB) was increased by xenon exposure. Also, the prosurvival proteins Bcl-2 and brain-derived neurotrophic factor were upregulated by xenon treatment. These studies provide evidence for xenon's preconditioning effect, which might be caused by a pCREB-regulated synthesis of proteins that promote survival against neuronal injury.

  2. Liquid xenon detectors for particle physics and astrophysics

    SciTech Connect

    Aprile, E.; Doke, T.

    2010-07-15

    This article reviews the progress made over the last 20 years in the development and applications of liquid xenon detectors in particle physics, astrophysics, and medical imaging experiments. A summary of the fundamental properties of liquid xenon as radiation detection medium, in light of the most current theoretical and experimental information is first provided. After an introduction of the different type of liquid xenon detectors, a review of past, current, and future experiments using liquid xenon to search for rare processes and to image radiation in space and in medicine is given. Each application is introduced with a survey of the underlying scientific motivation and experimental requirements before reviewing the basic characteristics and expected performance of each experiment. Within this decade it appears likely that large volume liquid xenon detectors operated in different modes will contribute to answering some of the most fundamental questions in particle physics, astrophysics, and cosmology, fulfilling the most demanding detection challenges. From detectors based solely on liquid xenon (LXe) scintillation, such as in the MEG experiment for the search of the rare ''{mu}{yields}e{gamma}'' decay, currently the largest liquid xenon detector in operation, and in the XMASS experiment for dark matter detection, to the class of time projection chambers which exploit both scintillation and ionization of LXe, such as in the XENON dark matter search experiment and in the Enriched Xenon Observatory for neutrinoless double beta decay, unrivaled performance and important contributions to physics in the next few years are anticipated.

  3. High-Rydberg Xenon Submillimeter-Wave Detector

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara

    1987-01-01

    Proposed detector for infrared and submillimeter-wavelength radiation uses excited xenon atoms as Rydberg sensors instead of customary beams of sodium, potassium, or cesium. Chemically inert xenon easily stored in pressurized containers, whereas beams of dangerously reactive alkali metals must be generated in cumbersome, unreliable ovens. Xenon-based detector potential for infrared astronomy and for Earth-orbiter detection of terrestrial radiation sources. Xenon atoms excited to high energy states in two stages. Doubly excited atoms sensitive to photons in submillimeter wavelength range, further excited by these photons, then ionized and counted.

  4. Relative scintillation efficiency of liquid xenon in the XENON10 direct dark matter search

    NASA Astrophysics Data System (ADS)

    Manzur, Angel

    There is almost universal agreement that most of the mass in the Universe consists of dark matter. Many lines of reasoning suggest that the dark matter consists of a weakly interactive massive particle (WIMP) with mass ranging from 10 GeV/c 2 to a few TeV/c 2 . Today, numerous experiments aim for direct or indirect dark matter detection. XENON10 is a direct detection experiment using a xenon dual phase time projection chamber. Particles interacting with xenon will create a scintillation signal ( S 1) and ionization. The charge produced is extracted into the gas phase and converted into a proportional scintillation light ( S 2), with an external electric field. The dominant background, b particles and g rays, will undergo an electron recoil (ER) interaction, while WIMPs and neutrons will undergo a nuclear recoil (NR) interaction. Event-by-event discrimination of background signals is based on log 10 ( S 2/ S 1) NR < log 10 ( S 2/ S 1) ER and the 3-D position reconstruction. In 2006 the XENON10 detector started underground operations at laboratorio Nazionali del Gran Sasso in Italy. After 6 months of operations, totaling 58.6 live days and 5.4 kg of fiducial mass, XENON10 set the best upper limits at the time. Finding a spin- independent WIMP-nucleon cross-section s h = 8.8 × 10^-44 cm 2 and a spin- dependent WIMP-neutron cross-section s h = 1.0 × 10^-38 cm 2 for a WIMP mass of 100 GeV/c 2 (90% C.L.). In this work I give an overview of the dark matter evidence and review the requirements for a dark matter search. In particular I discuss the XENON10 detector, deployment, operation, calibrations, analysis and WIMP-nucleon cross- section limits. Finally, I present our latest results for the relative scintillation efficiency ([Special characters omitted.] ) for nuclear recoils in liquid xenon, which was the biggest source of uncertainty in the XENON10 limit. This quantity is essential to determine the nuclear energy scale and to determine the WIMP-nucleon cross

  5. Method for the simultaneous preparation of Radon-211, Xenon-125, Xenon-123, Astatine-211, Iodine-125 and Iodine-123

    DOEpatents

    Mirzadeh, Saed; Lambrecht, Richard M.

    1987-01-01

    A method for simultaneously preparing Radon-211, Astatine-211, Xenon-125, Xenon-123, Iodine-125 and Iodine-123 in a process that includes irradiating a fertile metal material then using a one-step chemical procedure to collect a first mixture of about equal amounts of Radon-211 and Xenon-125, and a separate second mixture of about equal amounts of Iodine-123 and Astatine-211.

  6. Causes of high pressure compressor deterioration in service

    NASA Technical Reports Server (NTRS)

    Richardson, J. H.; Sallee, G. P.; Smakula, F. K.

    1979-01-01

    The high mechanical reliability and low deterioration rate of the JT9D high-pressure compressor results in long utilization without exceeding engine operational limits. The increasing cost and decreasing supply of fuel have focused attention on the fuel burned implications of such high time use without refurbishment. The paper presents the results of JT9D high pressure compressor studies. The mechanical deterioration of the JT9D high-pressure compressor gaspath parts versus increasing service usage, documented from inspection of service parts, is presented and discussed including changes in airfoil roughness, blade length, airfoil contour and outer air seal trench characteristics. An estimate of the performance loss versus usage is related to each type of damage. The combined estimated high-pressure compressor performance loss for all mechanisms determined from part inspection is compared to historical engine test data to establish the validity of the predicted loss levels. The effect of cold section refurbishment on engine fuel consumption recovery and the results of an optimization study to determine the appropriate interval for high pressure compressor refurbishment are also reported.

  7. Hydrogen Storage in Mesoporous Materials under High Pressure

    NASA Astrophysics Data System (ADS)

    Weinberger, Michelle; Somayazulu, Maddury; Hemley, Russell

    2008-03-01

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

  8. Transport properties of silicate melts at high pressure

    NASA Astrophysics Data System (ADS)

    Lesher, C. E.; Gaudio, S. J.; Clark, A. N.; O'Dwyer-Brown, L.

    2012-12-01

    It is well appreciated that the transport properties (e.g., diffusion, viscosity) of silicate melts are intimately linked by melt structure and the time scales of structural relaxation. These linkages have been explored exten-sively at low pressure, but our understanding is more limited for high-pressure conditions relevant to the Earth's deep interior. Transport property models based on free-volume, activation energy and/or configurational entropy have merits, but their validity in extrapolation is uncertain. Moreover, the structural implications at high pressure are conflicting and lack experimental support. We examine these issues and review theoretical efforts to model transport properties at high pressure, as well as, those constraints provided by laboratory experiments and simulations. We emphasis the need to consider the properties of melt not only for high-pressure superheated conditions, but also for supercooled conditions in the vicinity of the glass transition. For example, the time scales for density relaxation traversing the glass transition at high pressure can be monitored using in situ X-ray miroctomography/absorption and ex vivo by the Archimedes' method combined with spectroscopy. These approaches are amenable to both strong and fragile liquids. Taken together with superliquidus data, we can greatly improve the interpolation of melt properties within the melting interval for refractory mantle compositions.

  9. A New Wide-Range Equation of State for Xenon

    NASA Astrophysics Data System (ADS)

    Carpenter, John H.

    2011-06-01

    We describe the development of a new wide-range equation of state (EOS) for xenon. Three different prior EOS models predicted significant variations in behavior along the high pressure Hugoniot from an initial liquid state at 163.5 K and 2.97 g/cm3, which is near the triple point. Experimental measurements on Sandia's Z machine as well as density functional theory based molecular dynamics calculations both invalidate the prior EOS models in the pressure range from 200 to 840 GPa. The reason behind these EOS model disagreements is found to lie in the contribution from the thermal electronic models. A new EOS, based upon the standard separation of the Helmholtz free energy into ionic and electronic components, is constructed by combining the successful parts of prior models with a semi-empirical electronic model. Both the fluid and fcc solid phases are combined in a wide-range, multi-phase table. The new EOS is tabulated on a fine temperature and density grid, to preserve phase boundary information, and is available as table number 5191 in the LANL SESAME database. Improvements over prior EOS models are found not only along the Hugoniot, but also along the melting curve and in the region of the liquid-vapor critical point. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. SIGN, a WIMP detector based on high pressure gaseous neon

    NASA Astrophysics Data System (ADS)

    White, J. T.; Gao, J.; Maxin, J.; Miller, J.; Salinas, G.; Wang, H.

    A new WIMP detector concept based on the measurement of Scintillation and Ionization in Gaseous Neon (SIGN) is presented. The detector employs room temperature gaseous neon at a pressure of ≥100 bars as the WIMP target. The ionization is readout using either charge gain or electrofluorescence or both in a modified cylindrical proportional chamber geometry. The primary scintillation is detected by placing a CsI photocathode on the inside wall of the cylindrical chamber. The neon is doped with xenon (≤0.5%) for signal enhancement. Theoretical considerations suggest that the measurement of both scintillation and ionization will provide discrimination between nuclear and electron recoils in this gas mixture.

  11. High-resolution, high-pressure NMR studies of proteins.

    PubMed Central

    Jonas, J; Ballard, L; Nash, D

    1998-01-01

    Advanced high-resolution NMR spectroscopy, including two-dimensional NMR techniques, combined with high pressure capability, represents a powerful new tool in the study of proteins. This contribution is organized in the following way. First, the specialized instrumentation needed for high-pressure NMR experiments is discussed, with specific emphasis on the design features and performance characteristics of a high-sensitivity, high-resolution, variable-temperature NMR probe operating at 500 MHz and at pressures of up to 500 MPa. An overview of several recent studies using 1D and 2D high-resolution, high-pressure NMR spectroscopy to investigate the pressure-induced reversible unfolding and pressure-assisted cold denaturation of lysozyme, ribonuclease A, and ubiquitin is presented. Specifically, the relationship between the residual secondary structure of pressure-assisted, cold-denatured states and the structure of early folding intermediates is discussed. PMID:9649405

  12. 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.

  13. 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.

  14. 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.

  15. Confinement of hydrogen at high pressure in carbon nanotubes

    DOEpatents

    Lassila, David H [Aptos, CA; Bonner, Brian P [Livermore, CA

    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.

  16. Underground storage systems for high-pressure air and gases

    NASA Technical Reports Server (NTRS)

    Beam, B. H.; Giovannetti, A.

    1975-01-01

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

  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. High-pressure cryogenic seals for pressure vessels

    NASA Technical Reports Server (NTRS)

    Buggele, A. E.

    1977-01-01

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

  19. High-Pressure Design of Advanced BN-Based Materials.

    PubMed

    Kurakevych, Oleksandr O; Solozhenko, Vladimir L

    2016-10-20

    The aim of the present review is to highlight the state of the art in high-pressure design of new advanced materials based on boron nitride. Recent experimental achievements on the governing phase transformation, nanostructuring and chemical synthesis in the systems containing boron nitride at high pressures and high temperatures are presented. All these developments allowed discovering new materials, e.g., ultrahard nanocrystalline cubic boron nitride (nano-cBN) with hardness comparable to diamond, and superhard boron subnitride B13N₂. Thermodynamic and kinetic aspects of high-pressure synthesis are described based on the data obtained by in situ and ex situ methods. Mechanical and thermal properties (hardness, thermoelastic equations of state, etc.) are discussed. New synthetic perspectives, combining both soft chemistry and extreme pressure-temperature conditions are considered.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Veterinary high pressure injection injuries with inoculations for larger animals.

    PubMed

    Couzens, G; Burke, F D

    1995-08-01

    Equipment used in the mass vaccination of farm stock is a source of high pressure injection injury. We present four cases due to chicken vaccine, and one due to pig vaccine. Unlike injuries caused by paint or oil guns the vaccination delivers a fixed volume. Although the vaccine is in a mineral oil carrier it appears to elicit little inflammatory reaction in a small dose. The outcome is related to the volume injected. In chicken vaccine the dose is small enough to allow conservative or minimally invasive management. The large volume in pig vaccine requires treatment as for conventional high pressure injection injuries.

  7. Capillary toroid cavity detector for high pressure NMR

    DOEpatents

    Gerald, II, Rex E.; Chen, Michael J.; Klingler, Robert J.; Rathke, Jerome W.; ter Horst, Marc

    2007-09-11

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

  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. Recent Results on High-Pressure Axial Blowers

    NASA Technical Reports Server (NTRS)

    Eckert, B.

    1947-01-01

    Considerable progress has, in recent times, been attained in the development of the high-pressure axial blower by well-planned research. The efforts are directed toward improving the efficiencies, which are already high for the axial blower, and in particular the delivery pressure heads. For high pressures multistage arrangements are used. Of fundamental importance is the careful design of all structural parts of the blower that are subject to the effects of the flow. In the present report, several recent results and experiences are reported, which are based on results of German engine research.

  11. 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.

  12. High pressure and multiferroics materials: a happy marriage

    PubMed Central

    Gilioli, Edmondo; Ehm, Lars

    2014-01-01

    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

  13. Enhanced trigger for the NIFFTE fissionTPC in presence of high-rate alpha backgrounds

    NASA Astrophysics Data System (ADS)

    Bundgaard, Jeremy; Niffte Collaboration

    2015-10-01

    Nuclear physics and nuclear energy communities call for new, high precision measurements to improve existing fission models and design next generation reactors. The Neutron Induced Fission Fragment Tracking experiment (NIFFTE) has developed the fission Time Projection Chamber (fissionTPC) to measure neutron induced fission with unrivaled precision. The fissionTPC is annually deployed to the Weapons Neutron Research facility at Los Alamos Neutron Science Center where it operates with a neutron beam passing axially through the drift volume, irradiating heavy actinide targets to induce fission. The fissionTPC was developed at the Lawrence Livermore National Laboratory's TPC lab, where it measures spontaneous fission from radioactive sources to characterize detector response, improve performance, and evolve the design. To measure 244Cm, we've developed a fission trigger to reduce the data rate from alpha tracks while maintaining a high fission detection efficiency. In beam, alphas from 239Pu are a large background when detecting fission fragments; implementing the fission trigger will greatly reduce this background. The implementation of the cathode fission trigger in the fissionTPC will be presented along with a detailed study of its efficiency.

  14. Chondritic xenon in the Earth's mantle.

    PubMed

    Caracausi, Antonio; Avice, Guillaume; Burnard, Peter G; Füri, Evelyn; Marty, Bernard

    2016-05-05

    Noble gas isotopes are powerful tracers of the origins of planetary volatiles, and the accretion and evolution of the Earth. The compositions of magmatic gases provide insights into the evolution of the Earth's mantle and atmosphere. Despite recent analytical progress in the study of planetary materials and mantle-derived gases, the possible dual origin of the planetary gases in the mantle and the atmosphere remains unconstrained. Evidence relating to the relationship between the volatiles within our planet and the potential cosmochemical end-members is scarce. Here we show, using high-precision analysis of magmatic gas from the Eifel volcanic area (in Germany), that the light xenon isotopes identify a chondritic primordial component that differs from the precursor of atmospheric xenon. This is consistent with an asteroidal origin for the volatiles in the Earth's mantle, and indicates that the volatiles in the atmosphere and mantle originated from distinct cosmochemical sources. Furthermore, our data are consistent with the origin of Eifel magmatism being a deep mantle plume. The corresponding mantle source has been isolated from the convective mantle since about 4.45 billion years ago, in agreement with models that predict the early isolation of mantle domains. Xenon isotope systematics support a clear distinction between mid-ocean-ridge and continental or oceanic plume sources, with chemical heterogeneities dating back to the Earth's accretion. The deep reservoir now sampled by the Eifel gas had a lower volatile/refractory (iodine/plutonium) composition than the shallower mantle sampled by mid-ocean-ridge volcanism, highlighting the increasing contribution of volatile-rich material during the first tens of millions of years of terrestrial accretion.

  15. Distillation purification and radon assay of liquid xenon

    SciTech Connect

    Takeuchi, Yasuo

    2005-09-08

    We succeeded to reduce the Kr contamination in liquid xenon by a factor of 1/1000 with a distillation system in Kamioka mine. Then, the remaining radioactivities (Radon and Kr) in purified liquid xenon were measured with the XMASS prototype detector. In this talk, the distillation system and the remaining internal radioactivity levels are reported.

  16. Radon concentration monitoring using xenon gamma-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Novikov, A.; Ulin, S.; Dmitrenko, V.; Chernysheva, I.; Grachev, V.; Vlasik, K.; Uteshev, Z.; Shustov, A.; Petrenko, D.; Bychkova, O.

    2017-01-01

    A method for 222Rn concentration monitoring by means of intensity measurement of its daughter nuclei (214Pb and 214Bi) gamma-ray emission using xenon gamma-ray spectrometer is presented. Testing and calibration results for a gamma-spectrometric complex based on xenon gamma-ray detector are described.

  17. A xenon gas purity monitor for EXO

    NASA Astrophysics Data System (ADS)

    Dobi, A.; Hall, C.; Herrin, S.; Odian, A.; Prescott, C. Y.; Rowson, P. C.; Ackerman, N.; Aharmin, B.; Auger, M.; Barbeau, P. S.; Barry, K.; Benitez-Medina, C.; Breidenbach, M.; Cook, S.; Counts, I.; Daniels, T.; DeVoe, R.; Dolinski, M. J.; Donato, K.; Fairbank, W.; Farine, J.; Giroux, G.; Gornea, R.; Graham, K.; Gratta, G.; Green, M.; Hagemann, C.; Hall, K.; Hallman, D.; Hargrove, C.; Karelin, A.; Kaufman, L. J.; Kuchenkov, A.; Kumar, K.; Lacey, J.; Leonard, D. S.; LePort, F.; Mackay, D.; MacLellan, R.; Mong, B.; Montero Díez, M.; Müller, A. R.; Neilson, R.; Niner, E.; O'Sullivan, K.; Piepke, A.; Pocar, A.; Pushkin, K.; Rollin, E.; Sinclair, D.; Slutsky, S.; Stekhanov, V.; Twelker, K.; Voskanian, N.; Vuilleumier, J.-L.; Wichoski, U.; Wodin, J.; Yang, L.; Yen, Y.-R.

    2011-12-01

    We discuss the design, operation, and calibration of two versions of a xenon gas purity monitor (GPM) developed for the EXO double beta decay program. The devices are sensitive to concentrations of oxygen well below 1 ppb at an ambient gas pressure of one atmosphere or more. The theory of operation of the GPM is discussed along with the interactions of oxygen and other impurities with the GPM's tungsten filament. Lab tests and experiences in commissioning the EXO-200 double beta decay experiment are described. These devices can also be used on other noble gases.

  18. Environmental application of stable xenon and radioxenonmonitoring

    SciTech Connect

    Dresel, P. Evan; Olsen, Khris B.; Hayes, James C.; McIntyre,Justin I.; Waichler, Scott R.; Milbrath, Brian D.; Cooper, Matt; Kennedy,B. Mack

    2006-09-05

    Characterization of transuranic waste is needed to makedecisions about waste site remediation. Soil-gas sampling for xenonisotopes can be used to define the locations of spent fuel andtransuranic wastes. Radioxenon in the subsurface is characteristic oftransuranic waste and can be measured with extreme sensitivity usinglarge-volume soilgas samples. Measurements at the Hanford Site showed133Xe and 135Xe levels indicative of 240Pu spontaneous fission. Stablexenon isotopic ratios from fission are distinct from atmospheric xenonbackground. Neutron capture by 135Xe produces an excess of 136Xe inreactor-produced xenon providing a means of distinguishing spent fuelfrom separated transuranic materials.

  19. Ionization of excited xenon atoms by electrons

    NASA Astrophysics Data System (ADS)

    Erwin, Daniel A.; Kunc, Joseph A.

    2004-08-01

    Measured cross sections for electron-impact ionization of excited Xe atoms are not presently available. Therefore, we combine in this work the formalisms of the binary encounter approximation and Sommerfeld’s quantization of atomic orbits and derive from first-principles cross sections for ionization of excited atoms by electrons of low and moderate energies (up to a few hundred eV ). The approach of this work can be used to calculate the cross sections for electron-impact ionization of excited atoms and atomic ions other than xenon.

  20. Xenon-Ion Drilling of Tungsten Films

    NASA Technical Reports Server (NTRS)

    Garner, C. E.

    1986-01-01

    High-velocity xenon ions used to drill holes of controlled size and distribution through tungsten layer that sheaths surface of controlled-porosity dispenser cathode of traveling wave-tube electron emitter. Controlled-porosity dispenser cathode employs barium/calcium/ aluminum oxide mixture that migrates through pores in cathode surface, thus coating it and reducing its work function. Rapid, precise drilling technique applied to films of other metals and used in other applications where micron-scale holes required. Method requires only few hours, as opposed to tens of hours by prior methods.

  1. Solubilities of krypton and xenon in dichlorodifluoromethane

    SciTech Connect

    Shaffer, J.H.; Shockley, W.E.; Greene, C.W.

    1984-07-01

    The solubility behavior of krypton and xenon in dichlorodifluoromethane was investigated for the Consolidated Fuel Reprocessing Program (CFRP) in support of the fluorocarbon absorption process. The solubility data derived from solute radioisotopes had uncertainties of approx. 0.1%. Values for Henry's law constants were initially determined under equilibrium conditions at infinite solute dilution. Based on these results, the study was extended to finite solute concentrations. Nonidealities in the two binary systems were expressed as gas phase fugacity coefficients for each solute at 10/sup 0/ intervals over the range -30 to +50/sup 0/C. 22 references, 4 figures, 2 tables.

  2. Temperature effects for high pressure processing of Picornaviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Investigation of the effects of pre-pressurization temperature on the high pressure inactivation for single strains of aichivirus (AiV), coxsackievirus A9 (CAV9) and B5 (CBV5) viruses, as well as human parechovirus -1 (HPeV), was performed. For CAV9, an average 1.99 log10 greater inactivation was ...

  3. 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

  4. High-pressure injection injuries of the hand.

    PubMed

    Flotre, M

    1992-05-01

    Various types of high-pressure equipment, including airless paint sprayers, hydraulic apparatus and grease guns, are used in industry, in farming and in the home. Injection injuries from this equipment usually involve the hand and may initially appear benign. However, these injuries must be treated quickly and aggressively to prevent significant long-term disability.

  5. High pressure injection injuries: a serious occupational hazard.

    PubMed

    Mrvos, R; Dean, B S; Krenzelok, E P

    1987-01-01

    High pressure injection equipment such as airless paint sprayers, high pressure grease guns, and fuel injection apparatus constitute a serious safety hazard resulting in significant morbidity. These devices are capable of delivering contaminants such as paint, solvents, and grease at pressures ranging from 600-12,000 psi. This allows the substance to penetrate through a minute skin wound and to spread widely through fascial planes and tendon sheaths and to produce significant vascular compression and systemic toxicity. High pressure injection injuries frequently result in amputation. Fifty-five suspected high pressure injection injury cases were evaluated. Twenty were determined to be actual injection injuries from equipment producing pressures in the range of 1,500-12,000 psi. The injected contaminants included latex paint, mineral spirits, and concrete sealer. Fourteen injuries involved digits. Digital amputation was necessary in three patients. Hospital admissions averaged 6.5 days. Successful management of these cases involves awareness of the impending problem and rapid referral of the patient to an emergency department and to a competent orthopedic or plastic surgeon.

  6. 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.

  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. High-pressure ignition plasma torch for aerospace testing facilities

    NASA Astrophysics Data System (ADS)

    Yusupov, D. I.; Kulikov, Yu M.; Gadzhiev, M. Kh; Tyuftyaev, A. S.; Son, E. E.

    2016-11-01

    The present paper discusses the issues of implementation of high-pressure ignition plasma torch in terms of discharge phenomena in compressed gases, dense nitrogen plasma properties and stable arcing power requirements. Contact ignition has been tested in a pressure range p = 1-25 bar and has proved to be a reliable solution for pilot arc burning.

  9. 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...

  10. 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.

  11. Density functional theory investigation of sodium azide at high pressure

    NASA Astrophysics Data System (ADS)

    Steele, B. A.; Landerville, A. C.; Oleynik, I. I.

    2014-05-01

    High pressure experiments utilizing Raman spectroscopy indicate that the a phase of sodium azide undergoes a polymeric phase transition at high pressure. In this work, the structural and vibrational properties, including the first order Raman and infrared spectra, of the a phase of sodium azide are calculated using first-principles density functional theory up to 92 GPa. The equation of state of α NaN3 is obtained within the quasi-harmonic approximation at various temperatures. Each Raman-active mode blue shifts under compression whereas the doubly degenerate IR-active azide bending mode red-shifts under compression. However, at 70 GPa, the intensity of the Bu IR-active bending mode decreases substantially, and a new distorted azide bending lattice mode appears in the IR spectrum. In contrast to the bending mode, this new mode blue-shifts under compression. No new modes appear in the Raman spectra at high pressure, indicating that the changes in the Raman spectrum seen in experiment at high pressure are signs of new high nitrogen content structures, but not due to sodium azide.

  12. 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

  13. 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

  14. High Pressure Oxidizer Turbopump (HPOTP) inducer dynamic design environment

    NASA Technical Reports Server (NTRS)

    Herda, D. A.; Gross, R. S.

    1995-01-01

    The dynamic environment must be known to evaluate high pressure oxidizer turbopump inducer fatigue life. This report sets the dynamic design loads for the alternate turbopump inducer as determined by water-flow rig testing. Also, guidelines are given for estimating the dynamic environment for other inducer and impeller applications.

  15. High pressure processing inactivates human norovirus within oysters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of raw bivalve mollusks can result in norovirus infection. One potential intervention for virus-contaminated shellfish is high pressure processing (HPP). Currently HPP is known to inactivate Vibrio bacteria, hepatitis A virus, and murine norovirus within oysters. To evaluate the potentia...

  16. 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.

  17. Major vascular injury from high-pressure water jet.

    PubMed

    Harvey, R L; Ashley, D A; Yates, L; Dalton, M L; Solis, M M

    1996-01-01

    High-pressure water jets are used in industry as a cleaning and cutting tool. Penetrating injuries by these devices can produce minimal external evidence of extensive internal damage. We report a literature review and the case of a limb-threatening injury to the lower extremity caused by such a device.

  18. 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.

  19. Electron drift in a large scale solid xenon

    SciTech Connect

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.

  20. Electron drift in a large scale solid xenon

    DOE PAGES

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

  1. Biophysical changes induced by xenon on phospholipid bilayers.

    PubMed

    Booker, Ryan D; Sum, Amadeu K

    2013-05-01

    Structural and dynamic changes in cell membrane properties induced by xenon, a volatile anesthetic molecule, may affect the function of membrane-mediated proteins, providing a hypothesis for the mechanism of general anesthetic action. Here, we use molecular dynamics simulation and differential scanning calorimetry to examine the biophysical and thermodynamic effects of xenon on model lipid membranes. Our results indicate that xenon atoms preferentially localize in the hydrophobic core of the lipid bilayer, inducing substantial increases in the area per lipid and bilayer thickness. Xenon depresses the membrane gel-liquid crystalline phase transition temperature, increasing membrane fluidity and lipid head group spacing, while inducing net local ordering effects in a small region of the lipid carbon tails and modulating the bilayer lateral pressure profile. Our results are consistent with a role for nonspecific, lipid bilayer-mediated mechanisms in producing xenon's general anesthetic action.

  2. 76 FR 33239 - High Pressure Steel Cylinders From the People's Republic of China; Initiation of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China; Initiation...'') petition concerning imports of high pressure steel cylinders (``steel cylinders'') from the People's... Petitions for the Imposition of Antidumping and Countervailing Duties Against High Pressure Steel...

  3. 77 FR 37384 - High Pressure Steel Cylinders From the People's Republic of China: Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-21

    ... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China... duty order on high pressure steel cylinders (``steel cylinders'') from the People's Republic of China.... See High Pressure Steel Cylinders From the People's Republic of China: Final...

  4. Noise Filtering and Signal Calibration in the MicroBooNE LArTPC

    NASA Astrophysics Data System (ADS)

    Joshi, Jyoti; Qian, Xin; MicroBooNE Collaboration Collaboration

    2017-01-01

    In large liquid argon time projection chambers (LArTPCs), TPC signal processing, which recovers the number of ionized electrons arriving at anode wire planes from the raw digitized induction signals, is a crucial step towards automated event reconstruction. The first stage of signal processing is the identification and removal of any excess TPC noise with minimal impact on the true signal. In this talk, first I will describe the characterization and software filtering techniques of various TPC noise observed in the raw digital signal data in MicroBooNE. I will then describe a novel drifted-charge extraction method based on 2D deconvolution technique. These techniques significantly enhance the performance of the induction wire planes in MicroBooNE.

  5. Studies on GEM modules for a Large Prototype TPC for the ILC

    NASA Astrophysics Data System (ADS)

    Tsionou, Dimitra

    2017-02-01

    The International Linear Collider (ILC) is a future electron-positron collider with centre of mass energy of 500-1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1-6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

  6. Research on viscosity of metal at high pressure

    NASA Astrophysics Data System (ADS)

    Li, Y.; Liu, F.; Ma, X.; Zhang, M.

    2016-11-01

    A new experimental technique, the flyer-impact method, is proposed in this article to investigate the viscosity coefficient of shocked metals. In this technique, a shock wave with a sinusoidal perturbation on the front is induced by the sinusoidal profile of the impact surface of the sample by use of a two-stage light-gas gun, and the oscillatory damping process of the perturbation amplitude is monitored by electric pins. The damping processes of aluminum at 78 and 101 GPa and iron at 159 and 103 GPa are obtained by this technique, which supplement the existing data by measuring the viscosity coefficient via a dynamic high-pressure method. Applying the formula of Miller and Ahrens to fit the experimental data, the shear viscosity coefficients of aluminum at 78 and 101 GPa are 1350 ± 500 and 1200 ± 500 Pa s, respectively, and those of iron at 159 and 103 GPa are 1150 ± 1000 and 4800 ± 1000 Pa s, respectively. The values measured by the flyer-impact method, approximately 103 Pa s, are consistent with those measured by Sakharov's method, while still greatly differing from those measured by static high-pressure methods. In dynamic high-pressure experiments, the shear viscosity is related to dislocation motion in the solid material, while that in static high-pressure experiments is related to the diffusion motion of atoms or molecules in liquids. Therefore, there are different physical meanings of shear viscosity in dynamic and static high-pressure experiments, and there is no comparability among these results.

  7. 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.

  8. 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

  9. 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.

  10. Toward molecular mechanism of xenon anesthesia: a link to studies of xenon complexes with small aromatic molecules.

    PubMed

    Andrijchenko, Natalya N; Ermilov, Alexander Yu; Khriachtchev, Leonid; Räsänen, Markku; Nemukhin, Alexander V

    2015-03-19

    The present study illustrates the steps toward understanding molecular mechanism of xenon anesthesia by focusing on a link to the structures and spectra of intermolecular complexes of xenon with small aromatic molecules. A primary cause of xenon anesthesia is attributed to inhibition of N-methyl-D-aspartate (NMDA) receptors by an unknown mechanism. Following the results of quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) calculations we report plausible xenon action sites in the ligand binding domain of the NMDA receptor, which are due to interaction of xenon atoms with aromatic amino-acid residues. We rely in these calculations on computational protocols adjusted in combined experimental and theoretical studies of intermolecular complexes of xenon with phenol. Successful reproduction of vibrational shifts in molecular species upon complexation with xenon measured in low-temperature matrices allowed us to select a proper functional form in density functional theory (DFT) approach for use in QM subsystems, as well as to calibrate force field parameters for MD simulations. The results of molecular modeling show that xenon atoms can compete with agonists for a place in the corresponding protein cavity, thus indicating their active role in anesthetic action.

  11. Peach Bottom Turbine Trip Simulations with RETRAN Using INER/TPC BWR Transient Analysis Method

    SciTech Connect

    Kao Lainsu; Chiang, Show-Chyuan

    2005-03-15

    The work described in this paper is benchmark calculations of pressurization transient turbine trip tests performed at the Peach Bottom boiling water reactor (BWR). It is part of an overall effort in providing qualification basis for the INER/TPC BWR transient analysis method developed for the Kuosheng and Chinshan plants. The method primarily utilizes an advanced system thermal hydraulics code, RETRAN02/MOD5, for transient safety analyses. Since pressurization transients would result in a strong coupling effect between core neutronic and system thermal hydraulics responses, the INER/TPC method employs the one-dimensional kinetic model in RETRAN with a cross-section data library generated by the Studsvik-CMS code package for the transient calculations. The Peach Bottom Turbine Trip (PBTT) tests, including TT1, TT2, and TT3, have been successfully performed in the plant and assigned as standards commonly for licensing method qualifications for years. It is an essential requirement for licensing purposes to verify integral capabilities and accuracies of the codes and models of the INER/TPC method in simulating such pressurization transients. Specific Peach Bottom plant models, including both neutronics and thermal hydraulics, are developed using modeling approaches and experiences generally adopted in the INER/TPC method. Important model assumptions in RETRAN for the PBTT test simulations are described in this paper. Simulation calculations are performed with best-estimated initial and boundary conditions obtained from plant test measurements. The calculation results presented in this paper demonstrate that the INER/TPC method is capable of calculating accurately the core and system transient behaviors of the tests. Excellent agreement, both in trends and magnitudes between the RETRAN calculation results and the PBTT measurements, shows reliable qualifications of the codes/users/models involved in the method. The RETRAN calculated peak neutron fluxes of the PBTT

  12. Perovskites with the Framework-Forming Xenon.

    PubMed

    Britvin, Sergey N; Kashtanov, Sergei A; Krzhizhanovskaya, Maria G; Gurinov, Andrey A; Glumov, Oleg V; Strekopytov, Stanislav; Kretser, Yury L; Zaitsev, Anatoly N; Chukanov, Nikita V; Krivovichev, Sergey V

    2015-11-23

    The Group 18 elements (noble gases) were the last ones in the periodic system to have not been encountered in perovskite structures. We herein report the synthesis of a new group of double perovskites KM(XeNaO6) (M = Ca, Sr, Ba) containing framework-forming xenon. The structures of the new compounds, like other double perovskites, are built up of the alternating sequence of corner-sharing (XeO6) and (NaO6) octahedra arranged in a three-dimensional rocksalt order. The fact that xenon can be incorporated into the perovskite structure provides new insights into the problem of Xe depletion in the atmosphere. Since octahedrally coordinated Xe(VIII) and Si(IV) exhibit close values of ionic radii (0.48 and 0.40 Å, respectively), one could assume that Xe(VIII) can be incorporated into hyperbaric frameworks such as MgSiO3 perovskite. The ability of Xe to form stable inorganic frameworks can further extend the rich and still enigmatic chemistry of this noble gas.

  13. Tracking electrons from double beta decay - How far can you push the TPC?

    NASA Astrophysics Data System (ADS)

    Moe, M. K.; Nelson, M. A.; Vient, M. A.

    New results are reported from time-projection-chamber measurements of the double beta decay of 100Mo and 150Nd. A previously-observed high-energy anomaly has been eliminated by improved energy resolution. Kurie plots of the two-neutrino spectra show end-point energies close to the reported parent-daughter mass differences. The 150Nd source has produced a new direct-counting 90% confidence neutrino-majoron coupling limit of < gν, χ> < 7.0 × 10 -5. The strengths and weaknesses of the TPC, and the feasibility of a larger TPC for neutrinoless double beta decay are discussed.

  14. DETECTORS AND EXPERIMENTAL METHODS: Study on the TU gas for the GEM-TPC detector

    NASA Astrophysics Data System (ADS)

    Qi, Hui-Rong; Li, Yu-Lan; Li, Jin; Gao, Yuan-Ning; Li, Yuan-Jing

    2009-04-01

    In this paper several different working gas mixtures for GEM-TPC were evaluated based on a Garfield simulation. Among them, Ar:CH4:CF4 = 90:7:3 (named herein TU gas) was selected for a detailed study because of its better performance. Some performances of drift velocity, transverse diffusion, spatial resolution and the effective number of electrons in various electric fields were obtained. The performance of a GEM-TPC prototype working in the TU gas was studied and compared with that in Ar:CH4 = 90:10 (P10 gas).

  15. A TPC (Time Projection Chamber) detector for the study of high multiplicity heavy ion collisions

    SciTech Connect

    Rai, G.; Arthur, A.; Bieser, F.; Harnden, C.W.; Jones, R.; Klienfelder, S.; Lee, K.; Matis, H.S.; Nakamura, M.; McParland, C.; Nesbitt, D.; Odyniec, G.; Olson, D.; Pugh, H.G.; Ritter, H.G.; Symons, T.J.M.; Wieman, H.; Wright, M.; Wright, R. ); Rudge, A. )

    1990-01-01

    The design of a Time Projection Chamber (TPC) detector with complete pad coverage is presented. The TPC will allow the measurements of high multiplicity ({approx} 200 tracks) relativistic nucleus-nucleus collisions initiated with the heaviest, most energetic projectiles available at the LBL BEVALAC accelerator facility. The front end electronics, composed of over 15,000 time sampling channels, will be located on the chamber. The highly integrated, custom designed, electronics and the VME based data acquisition system are described. 10 refs., 8 figs., 1 tab.

  16. Structural transitions in full-length human prion protein detected by xenon as probe and spin labeling of the N-terminal domain

    PubMed Central

    Narayanan, Sunilkumar Puthenpurackal; Nair, Divya Gopalakrishnan; Schaal, Daniel; Barbosa de Aguiar, Marisa; Wenzel, Sabine; Kremer, Werner; Schwarzinger, Stephan; Kalbitzer, Hans Robert

    2016-01-01

    Fatal neurodegenerative disorders termed transmissible spongiform encephalopathies (TSEs) are associated with the accumulation of fibrils of misfolded prion protein PrP. The noble gas xenon accommodates into four transiently enlarged hydrophobic cavities located in the well-folded core of human PrP(23–230) as detected by [1H, 15N]-HSQC spectroscopy. In thermal equilibrium a fifth xenon binding site is formed transiently by amino acids A120 to L125 of the presumably disordered N-terminal domain and by amino acids K185 to T193 of the well-folded domain. Xenon bound PrP was modelled by restraint molecular dynamics. The individual microscopic and macroscopic dissociation constants could be derived by fitting the data to a model including a dynamic opening and closing of the cavities. As observed earlier by high pressure NMR spectroscopy xenon binding influences also other amino acids all over the N-terminal domain including residues of the AGAAAAGA motif indicating a structural coupling between the N-terminal domain and the core domain. This is in agreement with spin labelling experiments at positions 93 or 107 that show a transient interaction between the N-terminus and the start of helix 2 and the end of helix 3 of the core domain similar to that observed earlier by Zn2+-binding to the octarepeat motif. PMID:27341298

  17. Structural transitions in full-length human prion protein detected by xenon as probe and spin labeling of the N-terminal domain.

    PubMed

    Narayanan, Sunilkumar Puthenpurackal; Nair, Divya Gopalakrishnan; Schaal, Daniel; Barbosa de Aguiar, Marisa; Wenzel, Sabine; Kremer, Werner; Schwarzinger, Stephan; Kalbitzer, Hans Robert

    2016-06-24

    Fatal neurodegenerative disorders termed transmissible spongiform encephalopathies (TSEs) are associated with the accumulation of fibrils of misfolded prion protein PrP. The noble gas xenon accommodates into four transiently enlarged hydrophobic cavities located in the well-folded core of human PrP(23-230) as detected by [(1)H, (15)N]-HSQC spectroscopy. In thermal equilibrium a fifth xenon binding site is formed transiently by amino acids A120 to L125 of the presumably disordered N-terminal domain and by amino acids K185 to T193 of the well-folded domain. Xenon bound PrP was modelled by restraint molecular dynamics. The individual microscopic and macroscopic dissociation constants could be derived by fitting the data to a model including a dynamic opening and closing of the cavities. As observed earlier by high pressure NMR spectroscopy xenon binding influences also other amino acids all over the N-terminal domain including residues of the AGAAAAGA motif indicating a structural coupling between the N-terminal domain and the core domain. This is in agreement with spin labelling experiments at positions 93 or 107 that show a transient interaction between the N-terminus and the start of helix 2 and the end of helix 3 of the core domain similar to that observed earlier by Zn(2+)-binding to the octarepeat motif.

  18. 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

  19. TPC1 has two variant isoforms, and their removal has different effects on endo-lysosomal functions compared to loss of TPC2.

    PubMed

    Ruas, Margarida; Chuang, Kai-Ting; Davis, Lianne C; Al-Douri, Areej; Tynan, Patricia W; Tunn, Ruth; Teboul, Lydia; Galione, Antony; Parrington, John

    2014-11-01

    Organelle ion homeostasis within the endo-lysosomal system is critical for physiological functions. Two-pore channels (TPCs) are cation channels that reside in endo-lysosomal organelles, and overexpression results in endo-lysosomal trafficking defects. However, the impact of a lack of TPC expression on endo-lysosomal trafficking is unknown. Here, we characterize Tpcn1 expression in two transgenic mouse lines (Tpcn1(XG716) and Tpcn1(T159)) and show expression of a novel evolutionarily conserved Tpcn1B transcript from an alternative promoter, raising important questions regarding the status of Tpcn1 expression in mice recently described to be Tpcn1 knockouts. We show that the transgenic Tpcn1(T159) line lacks expression of both Tpcn1 isoforms in all tissues analyzed. Using mouse embryonic fibroblasts (MEFs) from Tpcn1(-/-) and Tpcn2(-/-) animals, we show that a lack of Tpcn1 or Tpcn2 expression has no significant impact on resting endo-lysosomal pH or morphology. However, differential effects in endo-lysosomal function were observed upon the loss of Tpcn1 or Tpcn2 expression; thus, while Tpcn1(-/-) MEFs have impaired trafficking of cholera toxin from the plasma membrane to the Golgi apparatus, Tpcn2(-/-) MEFs show slower kinetics of ligand-induced platelet-derived growth factor receptor β (PDGFRβ) degradation, which is dependent on trafficking to lysosomes. Our findings indicate that TPC1 and TPC2 have important but distinct roles in the endo-lysosomal pathway.

  20. Advanced Synchrotron Techniques at High Pressure Collaborative Access Team (HPCAT)

    NASA Astrophysics Data System (ADS)

    Shen, G.; Sinogeikin, S. V.; Chow, P.; Kono, Y.; Meng, Y.; Park, C.; Popov, D.; Rod, E.; Smith, J.; Xiao, Y.; Mao, H.

    2012-12-01

    High Pressure Collaborative Access Team (HPCAT) is dedicated to advancing cutting-edge, multidisciplinary, high-pressure science and technology using synchrotron radiation at Sector 16 of the Advanced Photon Source (APS) of Argonne National Laboratory. At HPCAT an array of novel x-ray diffraction and spectroscopic techniques has been integrated with high pressure and extreme temperature instrumentation for studies of structure and materials properties at extreme conditions.. HPCAT consists of four active independent beamlines performing a large range of various experiments at extreme conditions. 16BM-B beamline is dedicated to energy dispersive and white Laue X-ray diffraction. The majority of experiments are performed with a Paris-Edinburgh large volume press (to 7GPa and 2500K) and include amorphous and liquid structure measurement, white beam radiography, elastic sound wave velocity measurement of amorphous solid materials, with viscosity and density measurement of liquid being under development. 16BM-D is a monochromatic diffraction beamline for powder and single crystal diffraction at high pressure and high (resistive heating) / low (cryostats) temperature. The additional capabilities include high-resolution powder diffraction and x-ray absorption near edge structure (XANES) spectroscopy. The insertion device beamline of HPCAT has two undulators in canted mode (operating independently) and LN cooled Si monochromators capable of providing a large range of energies. 16IDB is a microdiffraction beamline mainly focusing on high-pressure powder and single crystal diffraction in DAC at high temperatures (double-sided laser heating and resistive heating) and low temperature (various cryostats). The modern instrumentation allows high-quality diffraction at megabar pressures from light element, fast experiments with pulsed laser heating, fast dynamic experiments with Pilatus detector, and so on. 16ID-D beamline is dedicated to x-ray scattering and spectroscopy research

  1. Measurements of charge and light in pure high pressure Xe towards the study of Xe+TMA mixtures with dark matter directionality sensitivity and supra-intrinsic energy resolution for 0νββ decay searches

    SciTech Connect

    Oliveira, C. A.B.; Gehman, V.; Goldschmidt, A.; Nygren, D.; Renner, J.

    2015-03-24

    Trimethylamine (TMA) may improve the energy resolution of gaseous xenon based detectors for 0νββ decay searches through the reduction of the Fano factor by the Penning effect. This molecule may also be the key for sensing directionality of nuclear recoils induced by Weakly Interacting Massive Particles (WIMPs) in monolithic massive (ton-scale) detectors, without the need of track imaging, by making use of columnar recombination. Nuclear recoil directionality may be the path for a definite discovery of the WIMP nature of Dark Matter. An ionization chamber has been constructed and operated to explore the properties of high pressure gaseous Xe + TMA mixtures for particle detection in rare-event experiments. The ionization, scintillation and electroluminescence (EL) signals are measured as function of pressure and electric field. We present results for pure xenon at pressures up to 8 bar. This work has been carried out within the context of the NEXT collaboration.

  2. Guest disorder and high pressure behavior of argon hydrates

    SciTech Connect

    Yang, L.; Tulk, C.A.; Klug, D.D.; Chakoumakos, B.C.; Ehm, L.; Molaison, J.J.; Parise, J.B.; Simonson, J.M.

    2010-03-29

    The structure of argon hydrate was studied at ambient pressure and low temperature, and between 1.7 and 4.2 GPa at 295 K. This analysis produced a single Ar guest atom, positionally disordered off-center in the large cages of sII. Above 1.7 GPa Ar clathrate transformed to a mixture of a body-centered orthorhombic filled-ice phase, which can be viewed as a polytype of ice-Ih, and high pressure forms of pure ice. The guest disorder is further substantiated by analysis of the guest to host ratio in this high pressure filled-ice structure. The bulk modulus of Ar filled-ice found to be 11.7 {+-} 0.4 GPa.

  3. 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.

  4. 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.

  5. 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.

  6. Microstructures define melting of molybdenum at high pressures

    PubMed Central

    Hrubiak, Rostislav; Meng, Yue; Shen, Guoyin

    2017-01-01

    High-pressure melting anchors the phase diagram of a material, revealing the effect of pressure on the breakdown of the ordering of atoms in the solid. An important case is molybdenum, which has long been speculated to undergo an exceptionally steep increase in melting temperature when compressed. On the other hand, previous experiments showed nearly constant melting temperature as a function of pressure, in large discrepancy with theoretical expectations. Here we report a high-slope melting curve in molybdenum by synchrotron X-ray diffraction analysis of crystalline microstructures, generated by heating and subsequently rapidly quenching samples in a laser-heated diamond anvil cell. Distinct microstructural changes, observed at pressures up to 130 gigapascals, appear exclusively after melting, thus offering a reliable melting criterion. In addition, our study reveals a previously unsuspected transition in molybdenum at high pressure and high temperature, which yields highly textured body-centred cubic nanograins above a transition temperature. PMID:28248309

  7. 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.

  8. 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.

  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. High-pressure injection injuries to the hand.

    PubMed

    Hayes, C W; Pan, H C

    1982-12-01

    Analysis of 14 cases of high-pressure injection injury to the hand revealed that the mechanism of injury, the nature of the injected substance, the site of injection, delay in treatment, and treatment specifics all influence prognosis. Injuries from paint or spray guns appear to be the most devastating; injuries to digits are worse than those to the hand. Paint, thinners, and solvents cause great impairment. Delay in treatment likely compromises the outcome; steroids may be effective in some cases in reducing eventual impairment. Early recognition of the gravity of these wounds is important and early decompression, tetanus prophylaxis, antibiotics, and judicious steroid usage are advocated. Significant impairment results from many high-pressure injuries despite seemingly adequate treatment.

  11. High-Pressure Microscopy for Studying Molecular Motors.

    PubMed

    Nishiyama, Masayoshi

    2015-01-01

    Movement is a fundamental characteristic of all living things. This biogenic function is carried out by various nanometer-sized molecular machines. Molecular motor is a typical molecular machinery in which the characteristic features of proteins are integrated; these include enzymatic activity, energy conversion, molecular recognition and self-assembly. These biologically important reactions occur with the association of water molecules that surround the motors. Applied pressures can alter the intermolecular interactions between the motors and water. In this chapter we describe the development of a high-pressure microscope and a new motility assay that enables the visualization of the motility of molecular motors under conditions of high-pressure. Our results demonstrate that applied pressure dynamically changes the motility of molecular motors such as kinesin, F1-ATPase and bacterial flagellar motors.

  12. The therapeutic use of high-pressure oxygen.

    PubMed

    TRAPP, W G

    1963-02-16

    The therapeutic use of a high-pressure oxygen atmosphere is of current research interest. Accounts of this means of treatment have come mainly from Amsterdam and Glasgow, but also from the United States. Reports indicate its value in treatment of coronary artery disease, severe shock, cerebral vascular accidents, gangrene, infections, carbon monoxide poisoning and bowel infarction. Hyaline membrane disease responds dramatically. The treatment has demonstrated value in conjunction with the operation of heart-lung machines, for patients with severe injuries of the extremities where blood supply is impaired, and in the treatment of rest pain in ischemic limbs. Converted hospital autoclaves have been used as an inexpensive means of initiating research projects in this field. One American supplier already has orders for construction of eight high-pressure oxygen treatment tanks in U.S. centres.

  13. 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.

  14. The high-pressure compressibility of B12P2

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Zhou, Mi; Wang, Haiyan; Ji, Cheng; Whiteley, C. E.; Edgar, J. H.; Liu, Haozhe; Ma, Yanzhang

    2017-03-01

    In situ high pressure synchrotron X-ray diffraction measurements were performed on icosahedral boron phosphide (B12P2) to 43.2 GPa. No structural phase transition occurs over this pressure range. The bulk modulus of B12P2 is KOT = 207 ± 7 GPa with pressure derivative of K'OT = 6.6 ± 0.8 . The structure is most compressible along the chain formed by phosphorus and boron atoms in the crystal structure. It is believed that the compressibility of boron-rich compounds at close to ambient pressure is determined by the boron icosahedral structure, while the inclusive atoms (both boron and non-boron) between the icosahedra determine the high-pressure compressibility and structure stability.

  15. High pressure as a probe of the solid state

    NASA Astrophysics Data System (ADS)

    Ruoff, Arthur L.

    1994-07-01

    It is a great pleasure and honor to receive the Percy Williams Bridgman Award. Henry Eyring, my Ph.D. advisor, instilled in me a desire to unravel the secrets of nature in the chemical and physical world. He continued what my mother had begun. From my father I learned the virtue and satisfaction of hard work. In reading Percy Bridgman's The Physics of High Pressure [1] after I came to Cornell, I became intrigued by the high-pressure variable, so I owe much to him. I received valuable assistance and encouragement from George Kennedy and Harry Drickamer (the first winner of the Bridgman Award) and later from Alvin Van Valkenburg (a co-inventor with three others of the diamond anvil cell). Most importantly, I received encouragement from my wife, Enid Seaton Ruoff, to carry out what is sometimes the arduous pursuit of science—a pursuit that involves long working hours—and I want especially to thank her.

  16. 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

  17. 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.

  18. JT8D high pressure compressor performance improvement

    SciTech Connect

    Gaffin, W.O.

    1981-11-01

    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% and at least 10/sup 0/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% at typical cruise conditions was calculated based on the sea level test results.

  19. 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.

  20. Microstructures define melting of molybdenum at high pressures

    NASA Astrophysics Data System (ADS)

    Hrubiak, Rostislav; Meng, Yue; Shen, Guoyin

    2017-03-01

    High-pressure melting anchors the phase diagram of a material, revealing the effect of pressure on the breakdown of the ordering of atoms in the solid. An important case is molybdenum, which has long been speculated to undergo an exceptionally steep increase in melting temperature when compressed. On the other hand, previous experiments showed nearly constant melting temperature as a function of pressure, in large discrepancy with theoretical expectations. Here we report a high-slope melting curve in molybdenum by synchrotron X-ray diffraction analysis of crystalline microstructures, generated by heating and subsequently rapidly quenching samples in a laser-heated diamond anvil cell. Distinct microstructural changes, observed at pressures up to 130 gigapascals, appear exclusively after melting, thus offering a reliable melting criterion. In addition, our study reveals a previously unsuspected transition in molybdenum at high pressure and high temperature, which yields highly textured body-centred cubic nanograins above a transition temperature.

  1. 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.

  2. 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%.

  3. 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.

  4. 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.

  5. Proposal for high pressure RF cavity test in the MTA

    SciTech Connect

    Yonehara, K.; /Fermilab

    2010-09-01

    In order to demonstrate the feasibility of high pressure hydrogen gas filled RF (HPRF) cavities for muon ionization cooling, an HPRF cavity must be tested with a high intensity charged beam. When an HPRF cavity is irradiated with an intense beam each incident particle generates about 1000 electrons and ions per cubic centimeter in a high pressure cavity via ionization. These ionization electrons are influenced by the RF field and the RF quality factor goes down. This Q factor reduction will be a problem with a multi bunch beam, e.g., a muon beam for a muon collider consists of a 12 to 20 bunch train beam with 5 ns timing gap. Thus, the RF field must recover in few nano seconds. We propose to use a 400 MeV proton beam in the MTA and measure a beam loading effect in the HPRF cavity and study the recovery mechanism of the RF field.

  6. The Calibrations of Space Shuttle Main Engines High Pressure Transducers

    NASA Technical Reports Server (NTRS)

    Steward, Christopher S.

    1995-01-01

    Previously, high pressure transducers that were used on the Space Shuttles Main Engine (SSME) exhibited a severe drift after being tested on the SSME. The Experimental Testing Technology Division (ETTD) designed some new transducers that would not exhibit a severe drift over a short period of time. These transducers were calibrated at the Test Bed at Marshall Space Flight Center (MSFC). After the high pressure transducers were calibrated, the transducers were placed on the SSME and fired. The transducers were then sent to the NASA LaRC to be recalibrated. The main objectives of the recalibrations was to make sure that the transducers possessed the same qualities as they did before they were fired on the SSME. Other objectives of the project were to determine the stability of the transducers and to determine whether the transducers exhibited a severe drift.

  7. High pressure elasticity and thermal properties of depleted uranium

    NASA Astrophysics Data System (ADS)

    Jacobsen, M. K.; Velisavljevic, N.

    2016-04-01

    Studies of the phase diagram of uranium have revealed a wealth of high pressure and temperature phases. Under ambient conditions the crystal structure is well defined up to 100 gigapascals (GPa), but very little information on thermal conduction or elasticity is available over this same range. This work has applied ultrasonic interferometry to determine the elasticity, mechanical, and thermal properties of depleted uranium to 4.5 GPa. Results show general strengthening with applied load, including an overall increase in acoustic thermal conductivity. Further implications are discussed within. This work presents the first high pressure studies of the elasticity and thermal properties of depleted uranium metal and the first real-world application of a previously developed containment system for making such measurements.

  8. 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.

  9. Electrical Resistivity and Thermodynamic Properties of Iron Under High Pressure

    NASA Astrophysics Data System (ADS)

    Hieu, Ho Khac; Hai, Tran Thi; Hong, Nguyen Thi; Sang, Ngo Dinh; Tuyen, Nguyen Viet

    2017-03-01

    In this work, the electrical resistivity and thermodynamic properties of iron under high pressure have been investigated by using the semi-empirical approach. The recently well-established Grüneisen parameter expressions have been applied to derive the Debye frequency and temperature under compression. Using these results combined with the Bloch-Grüneisen law, the resistivity of iron has also been determined up to Earth's core pressures. We show that the electrical resistivity diminished gradually with pressure and saturates at high pressure. Our model gives low electrical resistivity values which are in agreement with the recent experimental measurements. The low resistivity may be attributed to the well-known resistivity saturation effect at high temperature, which was not considered in earlier models of core conductivity.

  10. Introduction to high-pressure bioscience and biotechnology.

    PubMed

    Bartlett, Douglas H

    2010-02-01

    The manipulation of biological materials using elevated pressure is providing an ever-growing number of opportunities in both the applied and basic sciences. Manipulation of pressure is a useful parameter for enhancing food quality and shelf life; inactivating microbes, viruses, prions, and deleterious enzymes; affecting recombinant protein production; controlling DNA hybridization; and improving vaccine preparation. In biophysics and biochemistry, pressure is used as a tool to study intermediates in protein folding, enzyme kinetics, macromolecular interactions, amyloid fibrous protein aggregation, lipid structural changes, and to discern the role of solvation and void volumes in these processes. Biologists, including many microbiologists, examine the utility and basis of pressure inactivation of cells and cellular processes, and conversely seek to discover how deep-sea life has evolved a preference for high-pressure environments. This introduction and the papers that follow provide information on the nature and promise of the highly interdisciplinary field of high-pressure bioscience and biotechnology (HPBB).

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Strength coupling in mixed phases under high pressure

    NASA Astrophysics Data System (ADS)

    Yan, Xiaozhi; Dong, Haini; Sun, Guangai; Ren, Xiangting; He, Duanwei; Yang, Wenge

    2016-10-01

    The strength of a material can be altered by temperature, pressure, grain size, and orientation distributions. At the microscale, neighboring grains often play important roles in the elastic and plastic deformation process. By applying high pressure to a mixture of germanium and gold powder in the vicinity of the germanium phase transition pressure, we found that the deformation behavior of gold largely correlates with that of the surrounding germanium. The deviatoric strain and compressibility of Au behaves anomalously when Ge undergoes a diamond to β-tin structure transition, accompanying a large volume and strength drop. The results demonstrate that the intrinsic strength of a mixed phase could be largely controlled by the other surrounding phase, which is fundamentally important in understanding the deformation mechanism of multiphase materials, especially when one phase undergoes dramatic changes in strength under high pressure conditions.

  16. Generation of high pressure and temperature by converging detonation waves

    NASA Astrophysics Data System (ADS)

    Singh, V. P.; Shukla, S. K.

    1987-07-01

    Generation of high pressure and temperature has various applications in defense. Several techniques, viz flying plate method, collapsing of linear, convergence of detonation waves in solid explosives, have been established in this connection. In this paper, converging detonation waves in solid explosives, where variable heat of detonation is being added to the front, are studied by using Whitham's characteristics rule. Results are compared with those reported elsewhere.

  17. High-pressure two temperature equations of state

    NASA Astrophysics Data System (ADS)

    Eliezer, S.

    1989-01-01

    A phenomenological approach is suggested for calculating two temperature equations of state at high pressures. The Thomas-Fermi Dirac model and the SESAME equation of state are used to calculate the electron contribution while the solid gas interpolation method is used for ions. An algorithm to calculate the first and higher moments of the charge distribution within the framework of the Thomas-Fermi-Dirac model is proposed.

  18. 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.

  19. Survey of High-Pressure Effects in Solids.

    DTIC Science & Technology

    1979-11-01

    Target, and Optical Diagnostics ................................ 65 3.19. Rail Gun ............................................. 66 4.1. Tungsten Carbide ...displacement;5 𔄀 high-pressure x-ray diffraction using tungsten - carbide , boron- carbide , or diamond anvils and sodium chloride or aluminum markers to...used to study a number of other materials over the same pressure range. The cell consists of one tungsten - carbide anvil and one boron- carbide anvil

  20. 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.