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Sample records for high pressure synthesized

  1. First-principles calculations of a high-pressure synthesized compound PtC

    International Nuclear Information System (INIS)

    Li Linyan; Yu Wen; Jin Changqing

    2005-01-01

    The first-principles density-functional method is used to study the recently high-pressure synthesized compound PtC. It is confirmed by our calculations that platinum carbide has a zinc-blende ground-state phase at zero pressure and that the rock-salt structure is a high-pressure phase. The theoretical transition pressure from zinc-blende to rock-salt structure is determined to be 52 GPa. Furthermore, our calculation shows the possibility that the PtC experimentally synthesized under high pressure conditions might undergo a transition from rock-salt to zinc-blende structure after a pressure quench to ambient conditions

  2. Thermoelectric properties of high pressure synthesized lithium and calcium double-filled CoSb3

    Directory of Open Access Journals (Sweden)

    Xiaohui Li

    2017-01-01

    Full Text Available Lithium and calcium are inefficient filling elements of CoSb3 at ambient pressure, but show nice filling behavior under high pressure. In this work, we synthesized Li/Ca double-filled CoSb3 with high pressure synthesis method. The products show the skutterudite structure of Im3¯ symmetry. Thermoelectric properties were effectively enhanced through Li and Ca co-filling. For the optimal Li0.08Ca0.18Co4Sb12 sample, the power factor maintains a relatively high value over the whole measurement temperature range and peaks at 4700μWm−1K−2, meanwhile the lattice thermal conductivity is greatly suppressed, leading to a maximal ZT of 1.18 at 700 K. Current work demonstrates high pressure synthesis as an effective method to produce multiple elemental filled CoSb3 skutterudites.

  3. Ferroelectric and magnetic properties in high-pressure synthesized BiFeO3 compound

    International Nuclear Information System (INIS)

    Zhai, L.; Shi, Y.G.; Gao, J.L.; Tang, S.L.; Du, Y.W.

    2011-01-01

    Highlights: → A high-density polycrystalline BiFeO 3 compound was synthesized by high-pressure annealing method. → The sample showed weak ferromagnetic at room temperature, which could be attributed to the lattice distortion induced by the high-pressure annealing. → Irregular domains were observed on the surface of the sample by piezoresponse force microscopy, and a typical hysteresis loop was obtained. - Abstract: High-density polycrystalline BiFeO 3 compound was synthesized by high-pressure annealing. Measurements of crystal structure, magnetic, and ferroelectric properties were made on the sample. It was found that the sample was almost single phase with a distorted R3c structure. The results of the X-ray photoelectron spectra demonstrate that the oxidation state of Fe in the sample is Fe 3+ . The room-temperature field dependence of magnetization for BiFeO 3 exhibits a hysteretic behavior. The observed weak ferromagnetism could be ascribed to the lattice distortion induced by the high-pressure annealing. In addition, the local ferroelectric performance of the sample was studied by piezoresponse force microscopy.

  4. High quality graphene synthesized by atmospheric pressure CVD on copper foil

    OpenAIRE

    Trinsoutrot, Pierre; Rabot, Caroline; Vergnes, Hugues; Delamoreanu, Alexandru; Zenasni, Aziz; Caussat, Brigitte

    2013-01-01

    International audience; Graphene was synthesized at 1000 °C by Atmospheric Pressure Chemical Vapor Deposition on copper foil from methane diluted in argon and hydrogen. The influence of the main synthesis parameters was studied on 2 × 2 cm2 foils in order to obtain continuous monolayer graphenewithout crystalline defect. The uniformity, crystal quality and number of layers of graphenewere analyzed by Raman spectroscopy and Scanning Electronic Microscopy. First, an increase of the annealing pr...

  5. XPS analysis for cubic boron nitride crystal synthesized under high pressure and high temperature using Li3N as catalysis

    International Nuclear Information System (INIS)

    Guo, Xiaofei; Xu, Bin; Zhang, Wen; Cai, Zhichao; Wen, Zhenxing

    2014-01-01

    Highlights: • The cBN was synthesized by Li 3 N as catalyst under high pressure and high temperature (HPHT). • The film coated on the as-grown cBN crystals was studied by XPS. • The electronic structure variation in the film was investigated. • The growth mechanism of cubic boron nitride crystal was analyzed briefly. - Abstract: Cubic boron nitride (cBN) single crystals are synthesized with lithium nitride (Li3N) as catalyst under high pressure and high temperature. The variation of electronic structures from boron nitride of different layers in coating film on the cBN single crystal has been investigated by X-ray photoelectron spectroscopy. Combining the atomic concentration analysis, it was shown that from the film/cBN crystal interface to the inner, the sp 2 fractions are decreasing, and the sp 3 fractions are increasing in the film at the same time. Moreover, by transmission electron microscopy, a lot of cBN microparticles are found in the interface. For there is no Li 3 N in the film, it is possible that Li 3 N first reacts with hexagonal boron nitride to produce Li 3 BN 2 during cBN crystals synthesis under high pressure and high temperature (HPHT). Boron and nitrogen atoms, required for cBN crystals growth, could come from the direct conversion from hexagonal boron nitride with the catalysis of Li 3 BN 2 under high pressure and high temperature, but not directly from the decomposition of Li 3 BN 2

  6. The thermal expansion of a highly crystalline hexagonal BC2N compound synthesized under high temperature and pressure

    International Nuclear Information System (INIS)

    Wu Qinghua; Liu Zhongyuan; Hu Qianku; Li Hui; He Julong; Yu Dongli; Li Dongchun; Tian Yongjun

    2006-01-01

    The thermal expansion has been investigated for a highly crystalline hexagonal BC 2 N compound synthesized by the compression of a turbostratic B-C-N precursor with iron catalyst at the high temperature of 1500 deg. C and the high pressure of 5.5 GPa. The thermal expansion in the c direction is large and linear with an expansion coefficient of 35.86 x 10 -6 K -1 up to 1000 deg. C, while in the basal plane, the a dimension displays a slight linear contraction up to 750 deg. C with a contraction coefficient of -8.76 x 10 -7 K -1 , but above 750 deg. C a linear expansion is observed with a larger expansion coefficient of 1.52 x 10 -6 K -1

  7. Syntheses and properties of several metastable and stable hydrides derived from intermetallic compounds under high hydrogen pressure

    Energy Technology Data Exchange (ETDEWEB)

    Filipek, S.M., E-mail: sfilipek@unipress.waw.pl [Institute of High Pressure Physics PAS, ul. Sokolowska 29, 01-142 Warsaw (Poland); Paul-Boncour, V. [ICMPE-CMTR, CNRS-UPEC, 2-8 rue Henri Dunant, 94320 Thiais (France); Liu, R.S. [Department of Chemistry, National Taiwan University, Taipei 106, Taiwan (China); Jacob, I. [Unit Nuclear Eng., Ben Gurion University of the Negev, Beer-Sheva (Israel); Tsutaoka, T. [Dept. of Sci. Educ., Grad. School of Educ., Hiroshima University, Hiroshima (Japan); Budziak, A. [Institute of Nuclear Physics PAS, 31-342 Kraków (Poland); Morawski, A. [Institute of High Pressure Physics PAS, ul. Sokolowska 29, 01-142 Warsaw (Poland); Sugiura, H. [Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027 (Japan); Zachariasz, P. [Institute of Electron Technology Cracow Division, ul. Zablocie 39, 30-701 Krakow (Poland); Dybko, K. [Institute of Physics, PAS, 02-668 Warsaw (Poland); Diduszko, R. [Tele and Radio Research Institute, ul. Ratuszowa 11, Warsaw (Poland)

    2016-12-01

    Brief summary of our former work on high hydrogen pressure syntheses of novel hydrides and studies of their properties is supplemented with new results. Syntheses and properties of a number of hydrides (unstable, metastable or stable in ambient conditions) derived under high hydrogen pressure from intermetallic compounds, like MeT{sub 2}, MeNi{sub 5}, Me{sub 7}T{sub 3}, Y{sub 6}Mn{sub 23} and YMn{sub 12} (where Me = zirconium, yttrium or rare earth; T = transition metal) are presented. Stabilization of ZrFe{sub 2}H{sub 4} due to surface phenomena was revealed. Unusual role of manganese in hydride forming processes is pointed out. Hydrogen induced phase transitions, suppression of magnetism, antiferromagnetic-ferromagnetic and metal-insulator or semimetal-metal transitions are described. Equations of state (EOS) of hydrides submitted to hydrostatic pressures up to 30 GPa are presented and discussed.

  8. Auger electron spectroscopy analysis for growth interface of cubic boron nitride single crystals synthesized under high pressure and high temperature

    Science.gov (United States)

    Lv, Meizhe; Xu, Bin; Cai, Lichao; Guo, Xiaofei; Yuan, Xingdong

    2018-05-01

    After rapid cooling, cubic boron nitride (c-BN) single crystals synthesized under high pressure and high temperature (HPHT) are wrapped in the white film powders which are defined as growth interface. In order to make clear that the transition mechanism of c-BN single crystals, the variation of B and N atomic hybrid states in the growth interface is analyzed with the help of auger electron spectroscopy in the Li-based system. It is found that the sp2 fractions of B and N atoms decreases, and their sp3 fractions increases from the outer to the inner in the growth interface. In addition, Lithium nitride (Li3N) are not found in the growth interface by X-ray diffraction (XRD) experiment. It is suggested that lithium boron nitride (Li3BN2) is produced by the reaction of hexagonal boron nitride (h-BN) and Li3N at the first step, and then B and N atoms transform from sp2 into sp3 state with the catalysis of Li3BN2 in c-BN single crystals synthesis process.

  9. Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

    International Nuclear Information System (INIS)

    Nistor, L C; Nistor, S V; Dinca, G; Georgeoni, P; Landuyt, J van; Manfredotti, C; Vittone, E

    2002-01-01

    High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp 3 bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 pm, 15 mJ m -2 is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond

  10. Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nistor, L C [National Institute for Materials Physics, Bucharest (Romania); Nistor, S V [National Institute for Materials Physics, Bucharest (Romania); Dinca, G [Dacia Synthetic Diamonds Factory, Bucharest (Romania); Georgeoni, P [Dacia Synthetic Diamonds Factory, Bucharest (Romania); Landuyt, J van [University of Antwerpen - RUCA, EMAT, Antwerpen (Belgium); Manfredotti, C [Experimental Physics Department, University of Turin, Turin (Italy); Vittone, E [Experimental Physics Department, University of Turin, Turin (Italy)

    2002-11-11

    High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp{sup 3} bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 pm, 15 mJ m{sup -2} is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond.

  11. Boron doped diamond synthesized from detonation nanodiamond in a C-O-H fluid at high pressure and high temperature

    Science.gov (United States)

    Shakhov, Fedor M.; Abyzov, Andrey M.; Takai, Kazuyuki

    2017-12-01

    Boron doped diamond (BDD) was synthesized under high pressure and high temperature (HPHT) of 7 GPa, 1230 °C in a short time of 10 s from a powder mixtures of detonation nanodiamond (DND), pentaerythritol C5H8(OH)4 and amorphous boron. SEM, TEM, XRD, XPS, FTIR and Raman spectroscopy indicated that BDD nano- and micro-crystals have formed by consolidation of DND particles (4 nm in size). XRD showed the enlargement of crystallites size to 6-80 nm and the increase in diamond lattice parameter by 0.02-0.07% without appearance of any microstrains. Raman spectroscopy was used to estimate the content of boron atoms embedded in the diamond lattice. It was found that the Raman diamond peak shifts significantly from 1332 cm-1 to 1290 cm-1 without appearance of any non-diamond carbon. The correlation between Raman peak position, its width, and boron content in diamond is proposed. Hydrogenated diamond carbon in significant amount was detected by IR spectroscopy and XPS. Due to the doping with boron content of about 0.1 at%, the electrical conductivity of the diamond achieved approximately 0.2 Ω-1 cm-1. Reaction mechanism of diamond growth (models of recrystallization and oriented attachment) is discussed, including the initial stages of pentaerythritol pyrolysis and thermal desorption of functional groups from the surface of DND particles with the generation of supercritical fluid of low-molecular substances (H2O, CH4, CO, CO2, etc.), as well as byproducts formation (B2O3, B4C).

  12. A novel magnesium-vanadium hydride synthesized by a gigapascal-high-pressure technique

    Energy Technology Data Exchange (ETDEWEB)

    Kyoi, Daisuke; Sato, Toyoto; Roennebro, Ewa; Tsuji, Yasufumi; Kitamura, Naoyuki; Ueda, Atsushi; Ito, Mikio; Katsuyama, Shigeru; Hara, Shigeta; Noreus, Dag; Sakai, Tetsuo

    2004-07-28

    A magnesium-based vanadium-doped hydride was prepared in a high-pressure anvil cell by reacting a MgH{sub 2}-25%V molar mixture at 8 GPa and 873 K. The new magnesium-vanadium hydride has a cubic F-centred substructure (a=4.721(1) Angst), with an additional superstructure, which could be described by a doubling of the cubic cell axis and a magnesium atom framework, including an ordered arrangement of both vanadium atoms and vacancies (a=9.437(3) Angst, space group Fm3-bar m (no. 225), Z=4, V=840.55 Angst{sup 3}). The metal atom structure is related to the Ca{sub 7}Ge type structure but the refined metal atom composition with vacancies on one of the magnesium sites corresponding to Mg{sub 6}V nearly in line with EDX analysis. The thermal properties of the new compound were also studied by TPD analysis and TG-DTA. The onset of the hydrogen desorption for the new Mg{sub 6}V hydride occurred at a 160 K lower temperature when compared to magnesium hydride at a heating rate of 10 K/min.

  13. Whole ceramic-like microreactors from inorganic polymers for high temperature or/and high pressure chemical syntheses.

    Science.gov (United States)

    Ren, Wurong; Perumal, Jayakumar; Wang, Jun; Wang, Hao; Sharma, Siddharth; Kim, Dong-Pyo

    2014-02-21

    Two types of whole ceramic-like microreactors were fabricated from inorganic polymers, polysilsesquioxane (POSS) and polyvinylsilazane (PVSZ), that were embedded with either perfluoroalkoxy (PFA) tube or polystyrene (PS) film templates, and subsequently the templates were removed by physical removal (PFA tube) or thermal decomposition (PS). A POSS derived ceramic-like microreactor with a 10 cm long serpentine channel was obtained by an additional "selective blocking of microchannel" step and subsequent annealing at 300 °C for 1 h, while a PVSZ derived ceramic-like microreactor with a 14 cm long channel was yielded by a co-firing process of the PVSZ-PS composite at 500 °C for 2 h that led to complete decomposition of the film template leaving a microchannel behind. The obtained whole ceramic-like microfluidic devices revealed excellent chemical and thermal stabilities in various solvents, and they were able to demonstrate unique chemical performance at high temperature or/and high pressure conditions such as Michaelis-Arbuzov rearrangement at 150-170 °C, Wolff-Kishner reduction at 200 °C, synthesis of super-paramagnetic Fe3O4 nanoparticles at 320 °C and isomerisation of allyloxybenzene to 2-allylphenol (250 °C and 400 psi). These economic ceramic-like microreactors fabricated by a facile non-lithographic method displayed excellent utility under challenging conditions that is superior to any plastic microreactors and comparable to glass and metal microreactors with high cost.

  14. The inclusions of Mg-B (MgB12?) as potential pinning centres in high-pressure-high-temperature-synthesized or sintered magnesium diboride

    International Nuclear Information System (INIS)

    Prikhna, T A; Gawalek, W; Savchuk, Ya M; Habisreuther, T; Wendt, M; Sergienko, N V; Moshchil, V E; Nagorny, P; Schmidt, Ch; Dellith, J; Dittrich, U; Litzkendorf, D; Melnikov, V S; Sverdun, V B

    2007-01-01

    A systematic study of the structure and superconductive characteristics of high-pressure-high-temperature (2 GPa, 700-1000 deg. C )-synthesized and sintered MgB 2 without additions from different initial powders was performed. Among various secondary phases Mg-B inclusions with a stoichiometry close to MgB 12 were identified. With an increasing amount of these inclusions the critical current density increased. So these inclusions can be feasible pinning centres in MgB 2 . The highest j c values in zero field were 1300 kA cm -2 at 10 K, 780 kA cm -2 at 20 K and 62 kA cm -2 at 35 K and in 1 T field were 1200 kA cm -2 at 10 K, 515 kA cm -2 at 20 K and 0.1 kA cm -2 at 35 K for high-pressure-synthesized magnesium diboride and the field of irreversibility at 20 K reached 8 T. The average grain sizes calculated from x-ray examinations in materials having high j c were 15-37 nm

  15. Neutron diffraction study, magnetic properties and thermal stability of YMn2D6 synthesized under high deuterium pressure

    International Nuclear Information System (INIS)

    Paul-Boncour, V.; Filipek, S.M.; Dorogova, M.; Bouree, F.; Andre, G.; Marchuk, I.; Percheron-Guegan, A.; Liu, R.S.

    2005-01-01

    A new phase YMn 2 D 6 was synthesized by submitting YMn 2 to 1.7kbar deuterium pressure at 473K. According to X-ray and neutron powder diffraction experiments, YMn 2 D 6 crystallizes in the Fm3-bar m space group with a=6.709(1)A at 300K. The Y and half of the Mn atoms occupy statistically the 8c site whereas the other Mn atoms are located in 4a site and surrounded by 6D atoms (24e). This corresponds to a K 2 PtCl 6 -type structure with a partially disordered substructure which can be written as [YMn]MnH 6 . No ordered magnetic moment is observed in the NPD patterns and the magnetization measurements display a paramagnetic behavior. The study of the thermal stability by Differential Scanning Calorimetry and XRD experiments indicates that this phase decomposes in YD 2 and Mn at 625K, and is more stable than YMn 2 H 4.5

  16. Magnetic properties of the filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 synthesized under high pressure

    OpenAIRE

    Sekine, C; Uchiumi, T; Shirotani, I; Matsuhira, kazuyuki; Sakakibara, T; Goto, T; Yagi, T

    2000-01-01

    We have succeeded in synthesizing filled skutterudite-type structure compounds GdRu4P12 and TbRu4P12 under high pressure. The magnetic properties of GdRu4P12 and TbRu4P12 have been studied by means of electrical resistivity, magnetic susceptibility, and magnetization measurements. Magnetic experiments suggest that the Gd and Tb ions in the compounds have trivalent state. The compound GdRu4P12 displays features that suggest the occurrence of antiferromagnetic ordering below TN=22 K. In TbRu4P1...

  17. Identification of paramagnetic nitrogen centers (P1) in diamond crystallites synthesized via the sintering of detonation nanodiamonds at high pressure and temperature

    Science.gov (United States)

    Osipov, V. Yu.; Shakhov, F. M.; Efimov, N. N.; Minin, V. V.; Kidalov, S. V.; Vul', A. Ya.

    2017-06-01

    Diamond single crystals synthesized from powder detonation nanodiamonds (DNDs) by means of treatment at high pressures ( P 7 GPa) and temperatures ( T > 1300°C) have been studied by electron paramagnetic resonance (EPR). A key feature of treatment (high-pressure high-temperature (HPHT) sintering) is the use of low molecular weight alcohols in the process. The appearance of a hyperfine EPR signal structure due to "paramagnetic nitrogen" (P1 centers) is explained by the growth of submicron and micron diamond single crystals from DND nanocrystals by the oriented attachment and coalescence mechanism. Such growth and coarsening of crystals appreciably decreases the concentration of paramagnetic centers, the presence of which hinders the detection of a hyperfine structure in the EPR signal from P1 centers, in the near-surface areas of coalesced and grown together DND particles. It has been shown that the concentration of paramagnetic defects of all types decreases to 3.1 × 1018 g-1 ( 60 ppm) during HPHT treatment at T = 1650°C. This causes the successful identification of P1 centers, whose fraction is no less than 40% of the total amount of paramagnetic centers in microcrystals synthesized by HPHT sintering.

  18. High-pressure syntheses of lanthanide polysulfides and polyselenides LnX_1_._9 (Ln = Gd-Tm, X = S, Se)

    International Nuclear Information System (INIS)

    Mueller, Carola J.; Schwarz, Ulrich; Doert, Thomas

    2012-01-01

    The polysulfides LnS_1_._9 and polyselenides LnSe_1_._9 of the lanthanide metals from gadolinium to thulium were prepared by high-pressure high-temperature synthesis. The compounds adopt the tetragonal CeSe_1_._9 structure type in space group P4_2/n (No. 86) with lattice parameters of 8.531 Aa ≤ a ≤ 8.654 Aa and 15.563 Aa ≤ c ≤ 15.763 Aa for the sulfides and 8.869 Aa ≤ a ≤ 9.076 Aa and 16.367 Aa ≤ c ≤ 16.611 Aa for the selenides. The atomic pattern consists of puckered double slabs [LnX]"+ and planar chalcogenide layers with ten possible chalcogen positions, of which eight are occupied by chalcogen atoms forming dinuclear X_2"2"- dianions, one by a single X"2"- ion and one remaining vacant. This resembles a √5 x √5 x 2 superstructure of the ZrSSi aristotype. Structural relationships to the aristotype and the related lanthanide polychalcogenides LnX_2_-_δ (Ln = La-Tm, X = S-Te, δ = 0 - 0.3) are discussed. The samples synthesized under high-pressure conditions (p > 1 GPa) decompose slowly under release of sulfur or selenium at ambient conditions. The crystal structure of a partially degraded thulium-polysulfide sample can be described as an incommensurate variant of the original TmS_1_._9 motif. Additionally, the isostructural ternary compound Gd(S_1_-_xSe_x)_1_._9 was synthesized and characterized by powder X-ray diffraction. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Characterization of the Materials Synthesized by High Pressure-High Temperature Treatment of a Polymer Derived t-BC2N Ceramic

    OpenAIRE

    Matizamhuka, Wallace R.; Sigalas, Iakovos; Herrmann, Mathias; Dubronvinsky, Leonid; Dubrovinskaia, Natalia; Miyajima, Nobuyoshi; Mera, Gabriela; Riedel, Ralf

    2011-01-01

    Bulk B-C-N materials were synthesized under static high thermobaric conditions (20 GPa and 2,000 °C) in a multianvil apparatus from a polymer derived t-BC1.97N ceramic. The bulk samples were characterised using X-ray synchrotron radiation and analytical transmission electron microscopy in combination with electron energy loss spectroscopy. Polycrystalline B-C-N materials with a cubic type structure were formed under the applied reaction conditions, but the formation of a ternary cubic diamond...

  20. Characterization of the Materials Synthesized by High Pressure-High Temperature Treatment of a Polymer Derived t-BC2N Ceramic

    Directory of Open Access Journals (Sweden)

    Gabriela Mera

    2011-11-01

    Full Text Available Bulk B-C-N materials were synthesized under static high thermobaric conditions (20 GPa and 2,000 °C in a multianvil apparatus from a polymer derived t-BC1.97N ceramic. The bulk samples were characterised using X-ray synchrotron radiation and analytical transmission electron microscopy in combination with electron energy loss spectroscopy. Polycrystalline B-C-N materials with a cubic type structure were formed under the applied reaction conditions, but the formation of a ternary cubic diamond-like c-BC2N compound, could not be unambiguously confirmed.

  1. Characterization of the Materials Synthesized by High Pressure-High Temperature Treatment of a Polymer Derived t-BC₂N Ceramic.

    Science.gov (United States)

    Matizamhuka, Wallace R; Sigalas, Iakovos; Herrmann, Mathias; Dubronvinsky, Leonid; Dubrovinskaia, Natalia; Miyajima, Nobuyoshi; Mera, Gabriela; Riedel, Ralf

    2011-11-29

    Bulk B-C-N materials were synthesized under static high thermobaric conditions (20 GPa and 2,000 °C) in a multianvil apparatus from a polymer derived t-BC 1.97 N ceramic. The bulk samples were characterised using X-ray synchrotron radiation and analytical transmission electron microscopy in combination with electron energy loss spectroscopy. Polycrystalline B-C-N materials with a cubic type structure were formed under the applied reaction conditions, but the formation of a ternary cubic diamond-like c-BC₂N compound, could not be unambiguously confirmed.

  2. Characterization of the Materials Synthesized by High Pressure-High Temperature Treatment of a Polymer Derived t-BC2N Ceramic

    Science.gov (United States)

    Matizamhuka, Wallace R.; Sigalas, Iakovos; Herrmann, Mathias; Dubronvinsky, Leonid; Dubrovinskaia, Natalia; Miyajima, Nobuyoshi; Mera, Gabriela; Riedel, Ralf

    2011-01-01

    Bulk B-C-N materials were synthesized under static high thermobaric conditions (20 GPa and 2,000 °C) in a multianvil apparatus from a polymer derived t-BC1.97N ceramic. The bulk samples were characterised using X-ray synchrotron radiation and analytical transmission electron microscopy in combination with electron energy loss spectroscopy. Polycrystalline B-C-N materials with a cubic type structure were formed under the applied reaction conditions, but the formation of a ternary cubic diamond-like c-BC2N compound, could not be unambiguously confirmed. PMID:28824124

  3. High Blood Pressure

    Science.gov (United States)

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

  4. High Blood Pressure Facts

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    ... Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN High Blood Pressure Facts Recommend on Facebook Tweet Share Compartir On ... Top of Page CDC Fact Sheets Related to High Blood Pressure High Blood Pressure Pulmonary Hypertension Heart Disease Signs ...

  5. High Blood Pressure (Hypertension)

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    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  6. Hypertension (High Blood Pressure)

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  7. High blood pressure - children

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    ... this page: //medlineplus.gov/ency/article/007696.htm High blood pressure - children To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  8. Preventing High Blood Pressure

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    ... Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share ... meal and snack options can help you avoid high blood pressure and its complications. Be sure to eat plenty ...

  9. High blood pressure - infants

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    ... this page: //medlineplus.gov/ency/article/007329.htm High blood pressure - infants To use the sharing features on this page, please enable JavaScript. High blood pressure (hypertension) is an increase in the force of ...

  10. High blood pressure medications

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    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  11. High-pressure microbiology

    National Research Council Canada - National Science Library

    Michiels, Chris; Bartlett, Douglas Hoyt; Aertsen, Abram

    2008-01-01

    ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. High Hydrostatic Pressure Effects in the Biosphere: from Molecules to Microbiology * Filip Meersman and Karel Heremans . . . . . . . . . . . . 2. Effects...

  12. High-pressure apparatus

    NARCIS (Netherlands)

    Schepdael, van L.J.M.; Bartels, P.V.; Berg, van den R.W.

    1999-01-01

    The invention relates to a high-pressure device (1) having a cylindrical high-pressure vessel (3) and prestressing means in order to exert an axial pressure on the vessel. The vessel (3) can have been formed from a number of layers of composite material, such as glass, carbon or aramide fibers which

  13. High blood pressure - adults

    Science.gov (United States)

    ... pressure is found. This is called essential hypertension. High blood pressure that is caused by another medical condition or medicine you are taking is called secondary hypertension. Secondary hypertension may be due to: Chronic ...

  14. Structural characterization of Mg{sub 3}MnH{sub {approx}}{sub 6}--a new high-pressure phase synthesized in a multi-anvil cell at 6 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Blomqvist, Helen; Roennebro, Ewa; Kyoi, Daisuke; Sakai, Tetsuo; Noreus, Dag

    2003-08-25

    With modern X-ray diffraction refinement methods it was shown to be possible to identify a new Mg{sub 3}MnH{sub {approx}}{sub 6} phase from a minute sample volume in spite of poor crystallinity and coexisting impurity phases. The new hydride was synthesized at 6 GPa in a high-pressure multi-anvil cell at 873 K. A monoclinic unit cell was found with a=8.827(2), b=4.657(2), c=4.676(2) A and {beta}=105.74(2) deg., space group P2{sub 1}/m (no. 11), Z=2, V=184.99 A{sup 3}. Manganese is surrounded by a distorted cube of magnesium with average Mn-Mg distances of 2.78(2) A. The cubes share edges in the b and c directions of the unit cell but are separated by a distance of {approx}3.6 A along a, forming a layered structure. The hydrogen positions were not possible to determine, as only a small sample amount could be prepared. If the metal atom structure of the title compound is compared to the already known Mg{sub 3}MnH{sub 7} it can be concluded that Mg{sub 3}MnH{sub {approx}}{sub 6} also consists of manganese hydrido complexes counterbalanced by magnesium ions, but with a different alignment of the magnesium cubes.

  15. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... other risk factors, like diabetes, you may need treatment. How does high blood pressure affect pregnant women? A few women will get ... HIV, Birth Control Heart Health for Women Pregnancy Menopause More Women's Health ... High Blood Pressure--Medicines to Help You Women and Diabetes Heart ...

  16. High-pressure crystallography

    Science.gov (United States)

    Katrusiak, A.

    2008-01-01

    The history and development of high-pressure crystallography are briefly described and examples of structural transformations in compressed compounds are given. The review is focused on the diamond-anvil cell, celebrating its 50th anniversary this year, the principles of its operation and the impact it has had on high-pressure X-ray diffraction.

  17. High Blood Pressure

    Science.gov (United States)

    ... kidney disease, diabetes, or metabolic syndrome Read less Unhealthy lifestyle habits Unhealthy lifestyle habits can increase the risk of high blood pressure. These habits include: Unhealthy eating patterns, such as eating too much sodium ...

  18. High Blood Pressure

    Science.gov (United States)

    ... factors Diabetes High blood pressure Family history Obesity Race/ethnicity Full list of causes and risk factors ... give Give monthly Memorials and tributes Donate a car Donate gently used items Stock donation Workplace giving ...

  19. High-pressure tritium

    International Nuclear Information System (INIS)

    Coffin, D.O.

    1976-01-01

    Some solutions to problems of compressing and containing tritium gas to 200 MPa at 700 0 K are discussed. The principal emphasis is on commercial compressors and high-pressure equipment that can be easily modified by the researcher for safe use with tritium. Experience with metal bellows and diaphragm compressors has been favorable. Selection of materials, fittings, and gauges for high-pressure tritium work is also reviewed briefly

  20. Deuterium high pressure target

    International Nuclear Information System (INIS)

    Perevozchikov, V.V.; Yukhimchuk, A.A.; Vinogradov, Yu.I.

    2001-01-01

    The design of the deuterium high-pressure target is presented. The target having volume of 76 cm 3 serves to provide the experimental research of muon catalyzed fusion reactions in ultra-pure deuterium in the temperature range 80-800 K under pressures of up to 150 MPa. The operation of the main systems of the target is described: generation and purification of deuterium gas, refrigeration, heating, evacuation, automated control system and data collection system

  1. High pressure synthesis of bismuth disulfide

    DEFF Research Database (Denmark)

    Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

    In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure contains Bi atoms in distorted square-based pyramidal coordination to five surrounding...

  2. Aeon: Synthesizing Scheduling Algorithms from High-Level Models

    Science.gov (United States)

    Monette, Jean-Noël; Deville, Yves; van Hentenryck, Pascal

    This paper describes the aeon system whose aim is to synthesize scheduling algorithms from high-level models. A eon, which is entirely written in comet, receives as input a high-level model for a scheduling application which is then analyzed to generate a dedicated scheduling algorithm exploiting the structure of the model. A eon provides a variety of synthesizers for generating complete or heuristic algorithms. Moreover, synthesizers are compositional, making it possible to generate complex hybrid algorithms naturally. Preliminary experimental results indicate that this approach may be competitive with state-of-the-art search algorithms.

  3. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    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

  4. Fascination at high pressures

    International Nuclear Information System (INIS)

    Chidambaram, R.

    1992-01-01

    Research at high pressures has developed into an interdisciplinary area which has important implications for and applications in the areas of physics, chemistry, materials sciences, planetary sciences, biology, engineering sciences and technology. The state of-the-art in this field is reviewed and future directions are indicated. (M.G.B.)

  5. Cryogenic, Absolute, High Pressure Sensor

    Science.gov (United States)

    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.

  6. Cryogenic High Pressure Sensor Module

    Science.gov (United States)

    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.

  7. Investigation of the Mesostructure of Transition-Metal Monogermanides Synthesized under Pressure

    Science.gov (United States)

    Safiulina, I. A.; Altynbaev, E. V.; Iashina, E. G.; Heinemann, A.; Fomicheva, L. N.; Tsvyashchenko, A. V.; Grigoriev, S. V.

    2018-04-01

    The mesostructure of transition-metal monogermanides Mn1 - x Co x Ge is studied by small-angle neutron scattering in a wide range of concentrations x = 0-0.95. These compounds were synthesized under high pressure and are metastable under normal conditions. The experimental dependences I( Q) obtained for the whole series of samples in the range of transferred momenta (6 × 10-2 nm-1 interesting to note that such defects are absent in the isostructural FeGe compound, i.e., the experimental dependences of the intensity are described well by the expression Q - n with an exponent n = 4.1 ± 0.1, which demonstrates the presence of crystallites with a uniform density distribution inside and a sharp boundary characterizing the surface.

  8. Pressure Dome for High-Pressure Electrolyzer

    Science.gov (United States)

    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

  9. Improvement of the Water Resistance of a Narrow-Band Red-Emitting SrLiAl3 N4 :Eu(2+) Phosphor Synthesized under High Isostatic Pressure through Coating with an Organosilica Layer.

    Science.gov (United States)

    Tsai, Yi-Ting; Nguyen, Hoang-Duy; Lazarowska, Agata; Mahlik, Sebastian; Grinberg, Marek; Liu, Ru-Shi

    2016-08-08

    A SrLiAl3 N4 :Eu(2+) (SLA) red phosphor prepared through a high-pressure solid-state reaction was coated with an organosilica layer with a thickness of 400-600 nm to improve its water resistance. The observed 4f(6) 5d→4f(7) transition bands are thought to result from the existence of Eu(2+) at two different Sr(2+) sites. Luminescence spectra at 10 K revealed two zero-phonon lines at 15377 (for Eu(Sr1)) and 15780 cm(-1) (for Eu(Sr2)). The phosphor exhibited stable red emission under high pressure up to 312 kbar. The configurational coordinate diagram gave a theoretical explanation for the Eu(2+/3+) result. The coated samples showed excellent moisture resistance while retaining an external quantum efficiency (EQE) of 70 % of their initial EQE after aging for 5 days under harsh conditions. White-light-emitting diodes of the SLA red phosphor and a commercial Y3 Al5 O12 :Ce(3+) yellow phosphor on a blue InGaN chip showed high color rendition (CRI=89, R9=69) and a low correlated color temperature of 2406 K. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. High pressure mechanical seal

    Science.gov (United States)

    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.

  11. Common High Blood Pressure Myths

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Common High Blood Pressure Myths Updated:May 4,2018 Knowing the facts ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  12. Medications for High Blood Pressure

    Science.gov (United States)

    ... Consumers Home For Consumers Consumer Updates Medications for High Blood Pressure Share Tweet Linkedin Pin it More sharing options ... age and you cannot tell if you have high blood pressure by the way you feel, so have your ...

  13. High blood pressure and diet

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007483.htm High blood pressure and diet To use the sharing features on ... diet is a proven way to help control high blood pressure . These changes can also help you lose weight ...

  14. Controlling your high blood pressure

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000101.htm Controlling your high blood pressure To use the sharing features on this page, ... JavaScript. Hypertension is another term used to describe high blood pressure. High blood pressure can lead to: Stroke Heart ...

  15. Superconductivity at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, N B; Ginzburg, N I

    1969-07-01

    Work published during the last 3 or 4 yrs concerning the effect of pressure on superconductivity is reviewed. Superconducting modifications of Si, Ge, Sb, Te, Se, P and Ce. Change of Fermi surface under pressure for nontransition metals. First experiments on the influence of pressure on the tunneling effect in superconductors provide new information on the nature of the change in phonon and electron energy spectra of metals under hydrostatic compression. 78 references.

  16. High Blood Pressure in Pregnancy

    Science.gov (United States)

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

  17. Characterization of tin selenides synthesized by high-energy milling

    Directory of Open Access Journals (Sweden)

    Marcela Achimovičová

    2011-12-01

    Full Text Available Tin selenides SnSeX (x=1,2 were synthesized from tin and selenium powder precursors by high-energy milling in the planetary ballmill Pulverisette 6 (Fritsch, Germany. The orthorhombic tin selenide SnSe and the hexagonal tin diselenide SnSe2 phases were formed after4 min and 5 min of milling, respectively. Specific surface area of both selenides increased with increasing time of mechanochemicalsynthesis. The particle size distribution analysis demonstrated that the synthesized products contain agglomerated selenide particlesconsisting of numerous idiomorphic tin selenide crystals, measuring from 2 to more than 100 nm in diameter, which were also documentedby TEM. UV-Vis spectrophotometry confirmed that tin selenide particles do not behave as quantum dots.

  18. High-pressure phase transitions of strontianite

    Science.gov (United States)

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

    2015-12-01

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

  19. What Is High Blood Pressure?

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More What is High Blood Pressure? Updated:Feb 27,2018 First, let’s define high ... resources . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP Introduction What ...

  20. High pressure shaft seal

    International Nuclear Information System (INIS)

    Martinson, A.R.; Rogers, V.D.

    1980-01-01

    In relation to reactor primary coolant pumps, mechanical seal assembly for a pump shaft is disclosed which features a rotating seal ring mounting system which utilizes a rigid support ring loaded through narrow annular projections in combination with centering non-sealing O-rings which effectively isolate the rotating seal ring from temperature and pressure transients while securely positioning the ring to adjacent parts. A stationary seal ring mounting configuration allows the stationary seal ring freedom of motion to follow shaft axial movement up to 3/4 of an inch and shaft tilt about the pump axis without any change in the hydraulic or pressure loading on the stationary seal ring or its carrier. (author)

  1. Electrochemically synthesized nanocrystalline spinel thin film for high performance supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinay [Carbon Technology Unit, Engineering Materials Division, National Physical Laboratory, New-Delhi, 110012 (India); Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan); Japan Science and Technology Agency, Kawaguchi-shi, Saitama, 332-0012 (Japan); Gupta, Shubhra; Miura, Norio [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan)

    2010-06-01

    Spinels are not known for their supercapacitive nature. Here, we have explored electrochemically synthesized nanostructured NiCo{sub 2}O{sub 4} spinel thin-film electrode for electrochemical supercapacitors. The nanostructured NiCo{sub 2}O{sub 4} spinel thin film exhibited a high specific capacitance value of 580 F g{sup -1} and an energy density of 32 Wh kg{sup -1} at the power density of 4 kW kg{sup -1}, accompanying with good cyclic stability. (author)

  2. High Blood Pressure - Multiple Languages

    Science.gov (United States)

    ... Being 8 - High Blood Pressure - Amarɨñña / አማርኛ (Amharic) MP3 Siloam Family Health Center Arabic (العربية) Expand Section ... Being 8 - High Blood Pressure - myanma bhasa (Burmese) MP3 Siloam Family Health Center Chinese, Simplified (Mandarin dialect) ( ...

  3. Fundamentals of high pressure adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.P.; Zhou, L. [Tianjin University, Tianjin (China). High Pressure Adsorption Laboratory

    2009-12-15

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

  4. Effects of two newly synthesized analogues of lidocaine on rat arterial blood pressure and heart rate.

    Science.gov (United States)

    Al Rasheed, N M; Al Sayed, M I; Al Zuhair, H H; Al Obaid, A R; Fatani, A J

    2001-04-01

    Two new analogues of lidocaine were synthesized at the College of Pharmacy, King Saud University: compound I (Methyl-2-[2-(N,N-diethylamino) acetamido]-3-cyano-4,5-dimethylbenzoate) and compound II (Methyl-2-[2-(piperidino) acetamido]-3-cyano-4,5-dimethylbenzoate). Their influence on the arterial blood pressure and the heart rate of urethane-anaesthetized rats was studied and compared with the actions of lidocaine. Compounds I, II and lidocaine induced significant dose-dependent decreases in the arterial blood pressure and heart rate, which usually returned to basal values within 3-5 min. There were significant differences in the potency of the three compounds in producing their effects on blood pressure and heart rate (Plidocaine and compound I, respectively. The results of this study also indicated the ineffectiveness of antagonists of autonomic, histaminergic and 5-HT receptor, and various vasodilators in blocking the actions of the three compounds on blood pressure and heart rate. Pretreatment with CaCl(2)significantly reduced the hypotension and bradycardia induced by the three compounds, suggesting the involvement of calcium channels, probably of the L type. Several possible mechanisms are postulated. In conclusion, the results direct attention to the capability of the two new compounds to decrease blood pressure and heart rate; affects that may have clinical potential. Copyright 2001 Academic Press.

  5. High pressure phase transformations revisited.

    Science.gov (United States)

    Levitas, Valery I

    2018-04-25

    High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges. This field is critically compared with fields of phase transformations under normal pressure in steels and shape memory alloys, as well as plastic deformation of materials. The main reason for the above mentioned discrepancy is the lack of understanding that there is a fundamental difference between pressure-induced transformations under hydrostatic conditions, stress-induced transformations under nonhydrostatic conditions below yield, and strain-induced transformations during plastic flow. Each of these types of transformations has different mechanisms and requires a completely different thermodynamic and kinetic description and experimental characterization. In comparison with other fields the following challenges are indicated for high pressure phase transformation: (a) initial and evolving microstructure is not included in characterization of transformations; (b) continuum theory is poorly developed; (c) heterogeneous stress and strain fields in experiments are not determined, which leads to confusing material transformational properties with a system behavior. Some ways to advance the field of high pressure phase transformations are suggested. The key points are: (a) to take into account plastic deformations and microstructure evolution during transformations; (b) to formulate phase transformation criteria and kinetic equations in terms of stress and plastic strain tensors (instead of pressure alone); (c) to develop multiscale continuum

  6. High pressure phase transformations revisited

    Science.gov (United States)

    Levitas, Valery I.

    2018-04-01

    High pressure phase transformations play an important role in the search for new materials and material synthesis, as well as in geophysics. However, they are poorly characterized, and phase transformation pressure and pressure hysteresis vary drastically in experiments of different researchers, with different pressure transmitting media, and with different material suppliers. Here we review the current state, challenges in studying phase transformations under high pressure, and the possible ways in overcoming the challenges. This field is critically compared with fields of phase transformations under normal pressure in steels and shape memory alloys, as well as plastic deformation of materials. The main reason for the above mentioned discrepancy is the lack of understanding that there is a fundamental difference between pressure-induced transformations under hydrostatic conditions, stress-induced transformations under nonhydrostatic conditions below yield, and strain-induced transformations during plastic flow. Each of these types of transformations has different mechanisms and requires a completely different thermodynamic and kinetic description and experimental characterization. In comparison with other fields the following challenges are indicated for high pressure phase transformation: (a) initial and evolving microstructure is not included in characterization of transformations; (b) continuum theory is poorly developed; (c) heterogeneous stress and strain fields in experiments are not determined, which leads to confusing material transformational properties with a system behavior. Some ways to advance the field of high pressure phase transformations are suggested. The key points are: (a) to take into account plastic deformations and microstructure evolution during transformations; (b) to formulate phase transformation criteria and kinetic equations in terms of stress and plastic strain tensors (instead of pressure alone); (c) to develop multiscale continuum

  7. High pressure experimental water loop

    International Nuclear Information System (INIS)

    Grenon, M.

    1958-01-01

    A high pressure experimental water loop has been made for studying the detection and evolution of cladding failure in a pressurized reactor. The loop has been designed for a maximum temperature of 360 deg. C, a maximum of 160 kg/cm 2 and flow rates up to 5 m 3 /h. The entire loop consists of several parts: a main circuit with a canned rotor circulation pump, steam pressurizer, heating tubes, two hydro-cyclones (one de-gasser and one decanter) and one tubular heat exchanger; a continuous purification loop, connected in parallel, comprising pressure reducing valves and resin pots which also allow studies of the stability of resins under pressure, temperature and radiation; following the gas separator is a gas loop for studying the recombination of the radiolytic gases in the steam phase. The preceding circuits, as well as others, return to a low pressure storage circuit. The cold water of the low pressure storage flask is continuously reintroduced into the high pressure main circuit by means of a return pump at a maximum head of 160 kg /cm 2 , and adjusted to the pressurizer level. This loop is also a testing bench for the tight high pressure apparatus. The circulating pump and the connecting flanges (Oak Ridge type) are water-tight. The feed pump and the pressure reducing valves are not; the un-tight ones have a system of leak recovery. To permanently check the tightness the circuit has been fitted with a leak detection system (similar to the HRT one). (author) [fr

  8. Psoriasis and high blood pressure.

    Science.gov (United States)

    Salihbegovic, Eldina Malkic; Hadzigrahic, Nermina; Suljagic, Edin; Kurtalic, Nermina; Sadic, Sena; Zejcirovic, Alema; Mujacic, Almina

    2015-02-01

    Psoriasis is a chronic skin ailment which can be connected with an increased occurrence of other illnesses, including high blood pressure. A prospective study has been conducted which included 70 patients affected by psoriasis, both genders, older than 18 years. Average age being 47,14 (SD= ±15,41) years, from that there were 36 men or 51,43 and 34 women or 48,57%. Average duration of psoriasis was 15,52 (SD=±12,54) years. Frequency of high blood pressure in those affected by psoriasis was 54,28%. Average age of the patients with psoriasis and high blood pressure was 53,79 year (SD=±14,15) and average duration of psoriasis was 17,19 years (SD=±13,51). Average values of PASI score were 16,65. Increase in values of PASI score and high blood pressure were statistically highly related (r=0,36, p=0,0001). Psoriasis was related to high blood pressure and there was a correlation between the severity of psoriasis and high blood pressure.

  9. High Blood Pressure and Women

    Science.gov (United States)

    ... is known as gestational hypertension, a form of secondary hypertension caused by the pregnancy that usually disappears after delivery. If the mother is not treated, high blood pressure can be dangerous to both the mother ...

  10. High Pressure Industrial Water Facility

    Science.gov (United States)

    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.

  11. High Pressure Research on Materials

    Indian Academy of Sciences (India)

    example, represents the stress on the x plane in the y direction. There are three .... optical studies and studying compressibility of fluids. 3.2 Opposed ..... [4] G N Peggs, High Pressure Measurement Techniques, Applied Science. Publishers ...

  12. Condensed matter at high shock pressures

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  13. High Blood Pressure (Hypertension) (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Hypertension (High Blood Pressure) KidsHealth / For Parents / Hypertension (High Blood Pressure) What's ... High Blood Pressure) Treated? Print What Is Hypertension (High Blood Pressure)? Blood pressure is the pressure of blood against ...

  14. Terbium oxide at high pressures

    International Nuclear Information System (INIS)

    Dogra, Sugandha; Sharma, Nita Dilawar; Singh, Jasveer; Bandhyopadhyay, A.K.

    2011-01-01

    In this work we report the behaviour of terbium oxide at high pressures. The as received sample was characterized at ambient by X-ray diffraction and Raman spectroscopy. The X-ray diffraction showed the sample to be predominantly cubic Tb 4 O 7 , although a few peaks also match closely with Tb 2 O 3 . In fact in a recent study done on the same sample, the sample has been shown to be a mixture of Tb 4 O 7 and Tb 2 O 3 . The sample was subjected to high pressures using a Mao-Bell type diamond anvil cell upto a pressure of about 42 GPa with ruby as pressure monitor

  15. High Pressure Treatment in Foods

    OpenAIRE

    Edwin Fabian Torres Bello; Gerardo González Martínez; Bernadette F. Klotz Ceberio; Dolores Rodrigo; Antonio Martínez López

    2014-01-01

    Abstract: High hydrostatic pressure (HHP), a non-thermal technology, which typically uses water as a pressure transfer medium, is characterized by a minimal impact on food characteristics (sensory, nutritional, and functional). Today, this technology, present in many food companies, can effectively inactivate bacterial cells and many enzymes. All this makes HHP very attractive, with very good acceptance by consumers, who value the organoleptic characteristics of products processed by this non...

  16. High-pressure-assisted synthesis of high-volume ZnGeP2 polycrystalline

    Science.gov (United States)

    Huang, Changbao; Wu, Haixin; Xiao, Ruichun; Chen, Shijing; Ma, Jiaren

    2018-06-01

    The pnictide and chalcogenide semiconductors are promising materials for the applications in the field of photoelectric. High-purity and high-volume polycrystalline required in the real-world applications is hard to be synthesized due to the high vapor pressure of phosphorus and sulfur components at high temperature. A new high-pressure-resisted method was used to investigate the synthesis of the nonlinear-optical semiconductor ZnGeP2. The high-purity ZnGeP2 polycrystalline material of approximately 500 g was synthesized in one run, which enables the preparation of nominally stoichiometric material. Since increasing internal pressure resistance of quartz crucible and reducing the reaction space, the high-pressure-resisted method can be used to rapidly synthesize other pnictide and chalcogenide semiconductors and control the components ratio.

  17. Pressure vessel failure at high internal pressure

    International Nuclear Information System (INIS)

    Laemmer, H.; Ritter, B.

    1995-01-01

    A RPV failure due to plastic instability was investigated using the ABAQUS finite element code together with a material model of thermal plasticity for large deformations. Not only rotational symmetric temperature distributions were studied, but also 'hot spots'. Calculations show that merely by the depletion of strength of the material - even at internal wall temperatures well below the melting point of the fuel elements of about 2000/2400 C - the critical internal pressure can decrease to values smaller than the operational pressure of 16 Mpa. (orig.)

  18. Computer simulation at high pressure

    International Nuclear Information System (INIS)

    Alder, B.J.

    1977-11-01

    The use of either the Monte Carlo or molecular dynamics method to generate equations-of-state data for various materials at high pressure is discussed. Particular emphasis is given to phase diagrams, such as the generation of various types of critical lines for mixtures, melting, structural and electronic transitions in solids, two-phase ionic fluid systems of astrophysical interest, as well as a brief aside of possible eutectic behavior in the interior of the earth. Then the application of the molecular dynamics method to predict transport coefficients and the neutron scattering function is discussed with a view as to what special features high pressure brings out. Lastly, an analysis by these computational methods of the measured intensity and frequency spectrum of depolarized light and also of the deviation of the dielectric measurements from the constancy of the Clausius--Mosotti function is given that leads to predictions of how the electronic structure of an atom distorts with pressure

  19. Anxiety: A Cause of High Blood Pressure?

    Science.gov (United States)

    ... of high blood pressure? Can anxiety cause high blood pressure? Answers from Sheldon G. Sheps, M.D. Anxiety doesn't cause long-term high blood pressure (hypertension). But episodes of anxiety can cause dramatic, ...

  20. African Americans and High Blood Pressure

    Science.gov (United States)

    ANSWERS by heart Lifestyle + Risk Reduction High Blood Pressure What About African Americans and High Blood Pressure? African Americans in the U.S. have a higher prevalence of high blood pressure (HBP) than ...

  1. High Blood Pressure: Medicines to Help You

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women High Blood Pressure--Medicines to Help You Share Tweet Linkedin Pin ... Click here for the Color Version (PDF 533KB) High blood pressure is a serious illness. High blood pressure is ...

  2. High-pressure sodium lamp

    NARCIS (Netherlands)

    1996-01-01

    A high pressure sodium lamp of the invention is provided with a discharge vessel (20) which is enclosed with intervening space (1) by an outer bulb (10), which space contains a gas-fill with at least 70 mol. % nitrogen gas. Electrodes (30a, 30b) are positioned in the discharge vessel (20) and are

  3. Intermolecular Interactions at high pressure

    DEFF Research Database (Denmark)

    Eikeland, Espen Zink

    2016-01-01

    In this project high-pressure single crystal X-ray diffraction has been combined with quantitative energy calculations to probe the energy landscape of three hydroquinone clathrates enclosing different guest molecules. The simplicity of the hydroquinone clathrate structures together with their st...

  4. High-pressure water facility

    Science.gov (United States)

    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.

  5. Vital Signs - High Blood Pressure

    Centers for Disease Control (CDC) Podcasts

    2012-10-02

    In the U.S., nearly one third of the adult population have high blood pressure, the leading risk factor for heart disease and stroke - two of the nation's leading causes of death.  Created: 10/2/2012 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/17/2012.

  6. High Pressure Treatment in Foods

    Science.gov (United States)

    Torres Bello, Edwin Fabian; González Martínez, Gerardo; Klotz Ceberio, Bernadette F.; Rodrigo, Dolores; Martínez López, Antonio

    2014-01-01

    High hydrostatic pressure (HHP), a non-thermal technology, which typically uses water as a pressure transfer medium, is characterized by a minimal impact on food characteristics (sensory, nutritional, and functional). Today, this technology, present in many food companies, can effectively inactivate bacterial cells and many enzymes. All this makes HHP very attractive, with very good acceptance by consumers, who value the organoleptic characteristics of products processed by this non-thermal food preservation technology because they associate these products with fresh-like. On the other hand, this technology reduces the need for non-natural synthetic additives of low consumer acceptance. PMID:28234332

  7. High Pressure Treatment in Foods

    Directory of Open Access Journals (Sweden)

    Edwin Fabian Torres Bello

    2014-08-01

    Full Text Available High hydrostatic pressure (HHP, a non-thermal technology, which typically uses water as a pressure transfer medium, is characterized by a minimal impact on food characteristics (sensory, nutritional, and functional. Today, this technology, present in many food companies, can effectively inactivate bacterial cells and many enzymes. All this makes HHP very attractive, with very good acceptance by consumers, who value the organoleptic characteristics of products processed by this non-thermal food preservation technology because they associate these products with fresh-like. On the other hand, this technology reduces the need for non-natural synthetic additives of low consumer acceptance.

  8. Phase transitions in solids under high pressure

    CERN Document Server

    Blank, Vladimir Davydovich

    2013-01-01

    Phase equilibria and kinetics of phase transformations under high pressureEquipment and methods for the study of phase transformations in solids at high pressuresPhase transformations of carbon and boron nitride at high pressure and deformation under pressurePhase transitions in Si and Ge at high pressure and deformation under pressurePolymorphic α-ω transformation in titanium, zirconium and zirconium-titanium alloys Phase transformations in iron and its alloys at high pressure Phase transformations in gallium and ceriumOn the possible polymorphic transformations in transition metals under pressurePressure-induced polymorphic transformations in АIBVII compoundsPhase transformations in AIIBVI and AIIIBV semiconductor compoundsEffect of pressure on the kinetics of phase transformations in iron alloysTransformations during deformation at high pressure Effects due to phase transformations at high pressureKinetics and hysteresis in high-temperature polymorphic transformations under pressureHysteresis and kineti...

  9. Substitution of conventional high-temperature syntheses of inorganic compounds by near-room-temperature syntheses in ionic liquids

    KAUST Repository

    Groh, Matthias Friedrich; Mü llera, Ulrike; Ahmed, Ejaz; Rothenberger, Alexander; Ruck, Michael J.

    2013-01-01

    The high-temperature syntheses of the low-valent halogenides P2I4, Te2Br, α-Te4I4, Te4(Al2Cl7)2, Te4(Bi6Cl20), Te8(Bi4Cl14),Bi8(AlCl4)2, Bi6Cl7,and Bi6Br7, as well as of WSCl4 andWOCl4 have been replaced by resource-efficient low

  10. High Blood Pressure: Unique to Older Adults

    Science.gov (United States)

    ... our e-newsletter! Aging & Health A to Z High Blood Pressure Hypertension Unique to Older Adults This section provides ... Pressure Targets are Different for Very Old Adults High blood pressure (also called hypertension) increases your chance of having ...

  11. Properties of solvent-borne acrylic pressure-sensitive adhesives synthesized by a simple approach

    Directory of Open Access Journals (Sweden)

    2009-12-01

    Full Text Available Acrylic polymers are widely used for fabricating pressure-sensitive adhesives (PSAs with the inherent unique advantages of transparency and superior intrinsic adhesive properties over other polymer-based adhesives. In this study, we have developed and evaluated a method of obtaining by radical copolymerization PSAs for liquid crystalline (LCD applications. Various factors including the amount of monomers, amount of cross-linker, coating weight, dwell time and thermal treatment are investigated for further optimizing the properties of acrylic polymer based PSAs to meet the emerging strict requirements for practical uses related mainly to holding powder and peel strength. The results illustrate that novel crosslinking reagents coupled with the thermal treatment at 70°C can make the resultant PSAs with the improved adhesive properties. The coating weight variation from 10 to 40 g/m2 can significantly enhance the peel strength from 4.0 g/25 mm to 12.5 g/25 mm with about 310% increment. If the dwell time of PSAs with cross-linking reagent is more than 10 hrs, the peel strength can be reduced down to a suitable value to meet the criterion for use. Therefore, acrylic PSAs with peel strength less than 20 g/25 mm and holding power above 120 hrs were successfully synthesized by elaborately designing the reaction system, which are practically applicable for advanced industrial applications.

  12. High pressure effects on fruits and vegetables

    OpenAIRE

    Timmermans, R.A.H.; Matser, A.M.

    2016-01-01

    The chapter provides an overview on different high pressure based treatments (high pressure pasteurization, blanching, pressure-assisted thermal processing, pressure-shift freezing and thawing) available for the preservation of fruits and vegetable products and extending their shelf life. Pressure treatment can be used for product modification through pressure gelatinization of starch and pressure denaturation of proteins. Key pressure–thermal treatment effects on vitamin, enzymes, flavor, co...

  13. Brillouin scattering at high pressures

    International Nuclear Information System (INIS)

    Grimsditch, M.; Polian, A.

    1988-02-01

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

  14. High pressure effects on fruits and vegetables

    NARCIS (Netherlands)

    Timmermans, R.A.H.; Matser, A.M.

    2016-01-01

    The chapter provides an overview on different high pressure based treatments (high pressure pasteurization, blanching, pressure-assisted thermal processing, pressure-shift freezing and thawing) available for the preservation of fruits and vegetable products and extending their shelf life. Pressure

  15. Condensed matter at high shock pressures

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-07-12

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

  16. Substitution of conventional high-temperature syntheses of inorganic compounds by near-room-temperature syntheses in ionic liquids

    KAUST Repository

    Groh, Matthias Friedrich

    2013-01-01

    The high-temperature syntheses of the low-valent halogenides P2I4, Te2Br, α-Te4I4, Te4(Al2Cl7)2, Te4(Bi6Cl20), Te8(Bi4Cl14),Bi8(AlCl4)2, Bi6Cl7,and Bi6Br7, as well as of WSCl4 andWOCl4 have been replaced by resource-efficient low-temperature syntheses in room temperature ionic liquids (RTILs). The simple one-pot syntheses generally do not require elaborate equipment such as twozone furnaces or evacuated silica ampoules. Compared to the published conventional approaches, reduction of reaction time (up to 80%) and temperature (up to 500 K) and, simultaneously, an increase in yield were achieved. In the majority of cases, the solid products were phase-pure. X-Ray diffraction on single crystals (redetermination of 11 crystal structures) has demonstrated that the quality of the crystals from RTILs is comparable to that of products obtained by chemical transport reactions. © 2013 Verlag der Zeitschrift für Naturforschung, Tübingen.

  17. High Pressure Electrolyzer System Evaluation

    Science.gov (United States)

    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.

  18. High pressure research at CHESS

    International Nuclear Information System (INIS)

    Brister, K.

    1992-01-01

    Since February 1990 there has been a dedicated high pressure line at the Cornell High Energy Synchrotron Source (CHESS). This facility provides X-ray instrumentation for energy dispersive X-ray diffraction and Laue diffraction using diamond anvil cells. Both hard-bend magnet and wiggler radiation are available as well as focused monochromatic radiation. In addition, support instrumentation is also available; a ruby system, laser heating, sample loading, and data analysis software. Experienced users need only to bring their diamond anvil cells and samples and can leave with the initial data analysis finished. Research using diamond anvil cells will be introduced and the facility will be described. Some of the diamond anvil cell research done at CHESS will be reviewed, including crystalline to amorphous transitions (R.R. Winters et al., Chem. Phys, in press), properties of C 6 0 under stress (S.J. Duclos et al., Nature 351 (1991) 380), deep earthquakes (T.C. Wu et al., submitted to J. Geophys. Res.)l, and reaching pressures of the center of Earth (A.L. Ruoff et al., Rev. Sci. Instr. 61 (1990) 3830). (orig.)

  19. High-pressure microhydraulic actuator

    Science.gov (United States)

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

    2008-06-10

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

  20. Nuclear magnetic resonance studies at high pressures

    International Nuclear Information System (INIS)

    Jonas, J.

    1980-01-01

    Recent advances in the field of NMR spectroscopy at high pressure are reviewed. After a brief discussion of two novel experimental techniques, the main focus of this review is on several specific studies which illustrate the versatility and power of this high pressure field. Experimental aspects of NMR measurements at high pressure and high temperature and the techniques for the high resolution NMR spectroscopy at high pressure are discussed. An overview of NMR studies of the dynamic structure of simple polyatomic liquids and hydrogen bonded liquids is followed by a discussion of high resolution spectroscopy at high pressure. Examples of NMR studies of disordered organic solids and polymers conclude the review. (author)

  1. DASH diet to lower high blood pressure

    Science.gov (United States)

    ... patientinstructions/000770.htm DASH diet to lower high blood pressure To use the sharing features on this page, ... Hypertension. The DASH diet can help lower high blood pressure and cholesterol and other fats in your blood. ...

  2. What Is High Blood Pressure Medicine?

    Science.gov (United States)

    ... a medicine calendar. • Set a reminder on your smartphone. What types of medicine may be prescribed? One ... High Blood Pressure Medicine? What are their side effects? For many people, high blood pressure medicine can ...

  3. High blood pressure - medicine-related

    Science.gov (United States)

    Drug-induced hypertension is high blood pressure caused by using a chemical substance or medicine. ... of the arteries There are several types of high blood pressure : Essential hypertension has no cause that can be ...

  4. High blood pressure and eye disease

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000999.htm High blood pressure and eye disease To use the sharing features on this page, please enable JavaScript. High blood pressure can damage blood vessels in the retina . The ...

  5. Experimental vibroacoustic testing of plane panels using synthesized random pressure fields.

    Science.gov (United States)

    Robin, Olivier; Berry, Alain; Moreau, Stéphane

    2014-06-01

    The experimental reproduction of random pressure fields on a plane panel and corresponding induced vibrations is studied. An open-loop reproduction strategy is proposed that uses the synthetic array concept, for which a small array element is moved to create a large array by post-processing. Three possible approaches are suggested to define the complex amplitudes to be imposed to the reproduction sources distributed on a virtual plane facing the panel to be tested. Using a single acoustic monopole, a scanning laser vibrometer and a baffled simply supported aluminum panel, experimental vibroacoustic indicators such as the Transmission Loss for Diffuse Acoustic Field, high-speed subsonic and supersonic Turbulent Boundary Layer excitations are obtained. Comparisons with simulation results obtained using a commercial software show that the Transmission Loss estimation is possible under both excitations. Moreover and as a complement to frequency domain indicators, the vibroacoustic behavior of the panel can be studied in the wave number domain.

  6. High pressure metrology for industrial applications

    Science.gov (United States)

    Sabuga, Wladimir; Rabault, Thierry; Wüthrich, Christian; Pražák, Dominik; Chytil, Miroslav; Brouwer, Ludwig; Ahmed, Ahmed D. S.

    2017-12-01

    To meet the needs of industries using high pressure technologies, in traceable, reliable and accurate pressure measurements, a joint research project of the five national metrology institutes and the university was carried out within the European Metrology Research Programme. In particular, finite element methods were established for stress-strain analysis of elastic and nonlinear elastic-plastic deformation, as well as of contact processes in pressure-measuring piston-cylinder assemblies, and high-pressure components at pressures above 1 GPa. New pressure measuring multipliers were developed and characterised, which allow realisation of the pressure scale up to 1.6 GPa. This characterisation is based on research including measurements of material elastic constants by the resonant ultrasound spectroscopy, hardness of materials of high pressure components, density and viscosity of pressure transmitting liquids at pressures up to 1.4 GPa and dimensional measurements on piston-cylinders. A 1.6 GPa pressure system was created for operation of the 1.6 GPa multipliers and calibration of high pressure transducers. A transfer standard for 1.5 GPa pressure range, based on pressure transducers, was built and tested. Herewith, the project developed the capability of measuring pressures up to 1.6 GPa, from which industrial users can calibrate their pressure measurement devices for accurate measurements up to 1.5 GPa.

  7. A potential route to synthesize imporous MgB{sub 2} bulks by pretreatment of B powder at ambient pressure

    Energy Technology Data Exchange (ETDEWEB)

    Pan, X F; Zhou, J D; Zhao, Y [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C H [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)], E-mail: yzhao@home.swjtu.edu.cn

    2009-04-15

    Imporous MgB{sub 2} bulks with a density of 1.82 g cm{sup -3} have been synthesized by pretreatment of B powder in an in situ solid-state reaction at ambient pressure. The results show that the MgB{sub 2} with B powder pretreatment has a significant improvement in J{sub c}, B{sub irr}, microstructure and intergranular coupling, but with no decrease of T{sub c}. At 20 K and 4 T, the J{sub c} is enhanced by 4 times by the pretreatment of the B powder. For the B pretreated MgB{sub 2}, the B{sub irr} at 20 K reaches 5 T and J{sub c} at 10 K and 6 T reaches 2200 A cm{sup -2}, compared to 4.2 T and 670 A cm{sup -2} for the B-not-pretreated MgB{sub 2}. It is argued that the small amounts of highly dispersed carbon in B powder may enhance the mobility of B particles during the reaction of B and Mg, which avoids the formation of voids in the positions of Mg particles.

  8. High-Pressure Lightweight Thrusters

    Science.gov (United States)

    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

  9. Evaluation of high temperature pressure sensors

    International Nuclear Information System (INIS)

    Choi, In-Mook; Woo, Sam-Yong; Kim, Yong-Kyu

    2011-01-01

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

  10. Superhard MgB sub 2 bulk material prepared by high-pressure sintering

    CERN Document Server

    Ma, H A; Chen, L X; Zhu, P W; Ren, G Z; Guo, W L; Fu, X Q; Zou Guang Tian; Ren, Z A; Che, G C; Zhao, Z X

    2002-01-01

    Superhard MgB sub 2 bulk material with a golden metallic shine was synthesized by high-pressure sintering for 8 h at 5.5 GPa and different temperatures. Appropriate pressure and temperature conditions for synthesizing polycrystalline MgB sub 2 with high hardness were investigated. The samples were characterized by means of atomic force microscopy and x-ray diffraction. The Vickers hardness, bulk density, and electrical resistivity were measured at room temperature.

  11. Simple syntheses of 3-substituted indoles and their application for high yield 14C-labelling

    International Nuclear Information System (INIS)

    Schallenberg, J.; Meyer, E.

    1983-01-01

    Methods are described which allow the synthesis of several plant indole alkaloids and their metabolites at different scales. Compounds synthesized include gramine (1) (3-dimethylaminomethylindole) which is directly derived from indole, while its biosynthetic precursors 3-aminomethylindole (3) and 3-methylaminomethylindole (2) as well as indole3-carboxylic acid (7) are synthesized via indole-3-aldehyde (6). Slight changes of the experimental conditions allow syntheses with high yields not only at the molar but also at the μmolar level. This is extremely useful when isotope labelled compounds of high specific radioactivity are required for studies of plant metabolism. (orig.)

  12. HIGH BLOOD PRESSURE: DOES THIS CONCERN ME?

    CERN Multimedia

    2007-01-01

    To find out, the Medical Service's nurses are organising A HIGH BLOOD PRESSURE SCREENING AND PREVENTION CAMPAIGN from Monday, 26th to Thursday, 29th March 2007 at the Infirmary - Building 57 - ground floor A blood pressure test, advice, information and, if necessary, referral for specialist medical treatment will be offered to any person working on the CERN site. High blood pressure is a silent threat to health. So come and get your blood pressure checked.

  13. HIGH BLOOD PRESSURE: DOES THIS CONCERN ME?

    CERN Multimedia

    2007-01-01

    To find out, the Medical Service's nurses are organising A HIGH BLOOD PRESSURE SCREENING AND PREVENTION CAMPAIGN from Monday, 26th to Thursday, 29th March 2007 at the Infirmary - Building 57 - ground floor A blood pressure test, advice, information and, if necessary, referral for specialist medical treatment will be offered to any person working on the CERN site. High blood pressure is a stealth threat to health. So come and get your blood pressure checked.

  14. High pressure effect for high-Tc superconductors

    International Nuclear Information System (INIS)

    Takahashi, Hiroki; Tomita, Takahiro

    2011-01-01

    A number of experimental and theoretical studies have been performed to understand the mechanism of high-T c superconductivity and to enhance T c . High-pressure techniques have played a very important role for these studies. In this paper, the high-pressure techniques and physical properties of high-T c superconductor under high pressure are presented. (author)

  15. Pressure pressure-balanced pH sensing system for high temperature and high pressure water

    International Nuclear Information System (INIS)

    Tachibana, Koji

    1995-01-01

    As for the pH measurement system for high temperature, high pressure water, there have been the circumstances that first the reference electrodes for monitoring corrosion potential were developed, and subsequently, it was developed for the purpose of maintaining the soundness of metallic materials in high temperature, high pressure water in nuclear power generation. In the process of developing the reference electrodes for high temperature water, it was clarified that the occurrence of stress corrosion cracking in BWRs is closely related to the corrosion potential determined by dissolved oxygen concentration. As the types of pH electrodes, there are metal-hydrogen electrodes, glass electrodes, ZrO 2 diaphragm electrodes and TiO 2 semiconductor electrodes. The principle of pH measurement using ZrO 2 diaphragms is explained. The pH measuring system is composed of YSZ element, pressure-balanced type external reference electrode, pressure balancer and compressed air vessel. The stability and pH response of YSZ elements are reported. (K.I.)

  16. High Performance Shape Memory Polyurethane Synthesized with High Molecular Weight Polyol as the Soft Segment

    Directory of Open Access Journals (Sweden)

    Manzoor Ahmad

    2012-05-01

    Full Text Available Shape memory polyurethanes (SMPUs are typically synthesized using polyols of low molecular weight (MW~2,000 g/mol as it is believed that the high density of cross-links in these low molecular weight polyols are essential for high mechanical strength and good shape memory effect. In this study, polyethylene glycol (PEG-6000 with MW ~6000 g/mol as the soft segment and diisocyanate as the hard segment were used to synthesize SMPUs, and the results were compared with the SMPUs with polycaprolactone PCL-2000. The study revealed that although the PEG-6000-based SMPUs have lower maximum elongations at break (425% and recovery stresses than those of PCL-based SMPUs, they have much better recovery ratios (up to 98% and shape fixity (up to 95%, hence better shape memory effect. Furthermore, PEG-based SMPUs showed a much shorter actuation time of < 10 s for up to 90% shape recovery compared to typical actuation times of tens of seconds to a few minutes for common SMPUs, demonstrated their great potential for applications in microsystems and other engineering components.

  17. High pressure synthesis of amorphous TiO2 nanotubes

    Directory of Open Access Journals (Sweden)

    Quanjun Li

    2015-09-01

    Full Text Available Amorphous TiO2 nanotubes with diameters of 8-10 nm and length of several nanometers were synthesized by high pressure treatment of anatase TiO2 nanotubes. The structural phase transitions of anatase TiO2 nanotubes were investigated by using in-situ high-pressure synchrotron X-ray diffraction (XRD method. The starting anatase structure is stable up to ∼20GPa, and transforms into a high-density amorphous (HDA form at higher pressure. Pressure-modified high- to low-density transition was observed in the amorphous form upon decompression. The pressure-induced amorphization and polyamorphism are in good agreement with the previous results in ultrafine TiO2 nanoparticles and nanoribbons. The relationship between the LDA form and α-PbO2 phase was revealed by high-resolution transmission electron microscopy (HRTEM study. In addition, the bulk modulus (B0 = 158 GPa of the anatase TiO2 nanotubes is smaller than those of the corresponding bulks and nanoparticles (180-240 GPa. We suggest that the unique open-ended nanotube morphology and nanosize play important roles in the high pressure phase transition of TiO2 nanotubes.

  18. Effect of sintering pressure on structure and magnetic properties of Zn0.99Ni0.01O bulk samples synthesized under different pressures

    International Nuclear Information System (INIS)

    Wang, Yongqiang; Yuan, Chaosheng; Su, Lei; Wang, Zheng; Hao, Junhong; Ren, Yufen

    2015-01-01

    A series of Zn 0.99 Ni 0.01 O bulk samples were prepared by a coprecipitation method, and then sintered at 600 °C under various pressures from normal pressure(NP) to 3 GPa. The effects of sintering pressure (P S ) on the structure, morphology and magnetic properties of the doping samples were investigated in detail. The XRD and HRTEM results reveal that all samples are of single-phase hexagonal structure. Compared with the sample sintered at normal pressure, the lattice parameters a and c of the samples sintered at high pressures (HP) show a sharply decrease. With the increase of sintering pressure, the particle size gradually increases as well as the particles get closer to each other. At 300 K, the sample sintered at normal pressure shows a superparamagnetic-like behavior, while the samples sintered at high pressures display typical ferromagnetic behaviors. The saturation magnetization of the samples sintered at high pressures is three orders of magnitude larger than that of the one sintered at normal pressure. Our results reveal that an appropriate sintering pressure can tune the magnetic properties of Ni-doped ZnO system by changing the lattice parameters, particle size and inter-particle spacing, which may be helpful to the practical applications. - Highlights: • A series of Zn 0.99 Ni 0.01 O bulk samples were sintered in different pressures. • The lattice constants of the samples sintered at high pressure clearly decrease. • The particle size increases gradually with the increase of sintering pressure. • The samples sintered at different pressures show different magnetic behaviors. • Appropriate sintering pressure can tune the magnetic properties of Zn–Ni–O system

  19. High pressure gas reinjection unit

    Energy Technology Data Exchange (ETDEWEB)

    1976-03-01

    Nuovo Pignone has built for gas reinjection at Ekofisk the highest pressure injection unit to date: suction pressure 246 bar, discharge 647 bar, for 5.7 million cu m/day of natural gas, and driven by a GE MS 5001 gas turbine of 24,000 hp. The barrel-type compressor has been used already in Algeria at Hassi Messaoud. Full scale tests have shown that the unit is satisfactory; special attention being paid to the stability of the rotor. Air cooled heat exchangers were used in the test loop to cool the discharge gas; at Ekofisk, heat exchangers with sea water will be used. The valves in the test loop were of a special, low- noise type. Vibrations of the rotor system and changes in gas pressure monitored, showing that a pressure of 680 bars can be achieved without instability. Economic considerations lead to preference for rotary compressors driven by gas turbines for similar applications in the exploitation of oil fields. A graph of the characteristics of the unit is given.

  20. High-pressure boron hydride phases

    International Nuclear Information System (INIS)

    Barbee, T.W. III; McMahan, A.K.; Klepeis, J.E.; van Schilfgaarde, M.

    1997-01-01

    The stability of boron-hydrogen compounds (boranes) under pressure is studied from a theoretical point of view using total-energy methods. We find that the molecular forms of boranes known to be stable at ambient pressure become unstable at high pressure, while structures with extended networks of bonds or metallic bonding are energetically favored at high pressures. If such structures are metastable on return to ambient pressure, they would be energetic as well as dense hydrogen storage media. An AlH 3 -like structure of BH 3 is particularly interesting in that it may be accessible by high-pressure diamond anvil experiments, and should exhibit both second-order structural and metal-insulator transitions at lower pressures. copyright 1997 The American Physical Society

  1. High-pressure torsion of hafnium

    International Nuclear Information System (INIS)

    Edalati, Kaveh; Horita, Zenji; Mine, Yoji

    2010-01-01

    Pure Hf (99.99%) is processed by high-pressure torsion (HPT) under pressures of 4 and 30 GPa to form an ultrafine-grained structure with a gain size of ∼180 nm. X-ray diffraction analysis shows that, unlike Ti and Zr, no ω phase formation is detected after HPT processing even under a pressure of 30 GPa. A hydride formation is detected after straining at the pressure of 4 GPa. The hydride phase decomposes either by application of a higher pressure as 30 GPa or by unloading for prolong time after HPT processing. Microhardness, tensile and bending tests show that a high hardness (360 Hv) and an appreciable ductility (8%) as well as high tensile and bending strength (1.15 and 2.75 GPa, respectively) are achieved following the high-pressure torsion.

  2. Highly sensitive and selective detection of dopamine using one-pot synthesized highly photoluminescent silicon nanoparticles.

    Science.gov (United States)

    Zhang, Xiaodong; Chen, Xiaokai; Kai, Siqi; Wang, Hong-Yin; Yang, Jingjing; Wu, Fu-Gen; Chen, Zhan

    2015-03-17

    A simple and highly efficient method for dopamine (DA) detection using water-soluble silicon nanoparticles (SiNPs) was reported. The SiNPs with a high quantum yield of 23.6% were synthesized by using a one-pot microwave-assisted method. The fluorescence quenching capability of a variety of molecules on the synthesized SiNPs has been tested; only DA molecules were found to be able to quench the fluorescence of these SiNPs effectively. Therefore, such a quenching effect can be used to selectively detect DA. All other molecules tested have little interference with the dopamine detection, including ascorbic acid, which commonly exists in cells and can possibly affect the dopamine detection. The ratio of the fluorescence intensity difference between the quenched and unquenched cases versus the fluorescence intensity without quenching (ΔI/I) was observed to be linearly proportional to the DA analyte concentration in the range from 0.005 to 10.0 μM, with a detection limit of 0.3 nM (S/N = 3). To the best of our knowledge, this is the lowest limit for DA detection reported so far. The mechanism of fluorescence quenching is attributed to the energy transfer from the SiNPs to the oxidized dopamine molecules through Förster resonance energy transfer. The reported method of SiNP synthesis is very simple and cheap, making the above sensitive and selective DA detection approach using SiNPs practical for many applications.

  3. High pressure X-ray studies

    International Nuclear Information System (INIS)

    Sikka, S.K.

    1981-01-01

    High pressure research has already led to new insights in the physical properties of materials and at times to the synthesis of new ones. In all this, X-ray diffraction has been a valuable diagnostic experimental tool. In particular, X-rays in high pressure field have been used (a) for crystallographic identification of high pressure polymorphs and (b) for study of the effect of pressure on lattice parameters and volume under isothermal conditions. The results in the area (a) are reviewed. The techniques of applying high pressures are described. These include both static and dynamic shockwave X-ray apparatus. To illustrate the effect of pressure, some of the pressure induced phase transitions in pure metals are described. It has been found that there is a clear trend for elements in any group of the periodic table to adopt similar structures at high pressures. These studies have enabled to construct generalized phase diagrams for many groups. In the case of alloys, the high pressure work done on Ti-V alloys is presented. (author)

  4. Managing Stress to Control High Blood Pressure

    Science.gov (United States)

    ... Aortic Aneurysm More Managing Stress to Control High Blood Pressure Updated:Jan 29,2018 The importance of stress ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  5. Application of High Pressure in Food Processing

    Directory of Open Access Journals (Sweden)

    Herceg, Z.

    2011-01-01

    Full Text Available In high pressure processing, foods are subjected to pressures generally in the range of 100 – 800 (1200 MPa. The processing temperature during pressure treatments can be adjusted from below 0 °C to above 100 °C, with exposure times ranging from a few seconds to 20 minutes and even longer, depending on process conditions. The effects of high pressure are system volume reduction and acceleration of reactions that lead to volume reduction. The main areas of interest regarding high-pressure processing of food include: inactivation of microorganisms, modification of biopolymers, quality retention (especially in terms of flavour and colour, and changes in product functionality. Food components responsible for the nutritive value and sensory properties of food remain unaffected by high pressure. Based on the theoretical background of high-pressure processing and taking into account its advantages and limitations, this paper aims to show its possible application in food processing. The paper gives an outline of the special equipment used in highpressure processing. Typical high pressure equipment in which pressure can be generated either by direct or indirect compression are presented together with three major types of high pressure food processing: the conventional (batch system, semicontinuous and continuous systems. In addition to looking at this technology’s ability to inactivate microorganisms at room temperature, which makes it the ultimate alternative to thermal treatments, this paper also explores its application in dairy, meat, fruit and vegetable processing. Here presented are the effects of high-pressure treatment in milk and dairy processing on the inactivation of microorganisms and the modification of milk protein, which has a major impact on rennet coagulation and curd formation properties of treated milk. The possible application of this treatment in controlling cheese manufacture, ripening and safety is discussed. The opportunities

  6. Effects of pressure and temperature on pore structure of ceramic synthesized from rice husk: A small angle neutron scattering investigation

    Energy Technology Data Exchange (ETDEWEB)

    Raut Dessai, R., E-mail: reshooin@yahoo.com [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Desa, J.A.E. [Department of Physics, Goa University, Taleigao Plateau, Goa 403 206 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2013-07-05

    Highlights: ► A porous ceramic has been prepared from silica obtained from rice husk. ► The ceramic has a hierarchical pore structure from micrometric to nano-metric. ► Small Angle Neutron Scattering data indicate nano-pore connectivity to micro-pores. ► Pore morphology can be tuned by compaction pressure and sintering temperature. -- Abstract: Ceramic powder has been synthesized from rice husk as the source of silica. In order to probe the evolution of its hierarchical mesoscopic and microscopic porous structure, the ceramic powder was compacted at different pressures and was sintered at different temperatures. A glassy ceramic to crystalline transition under thermal treatment (up to 1000 °C) was revealed by X-ray diffraction. Existence of pores in two widely separated length scales was indicated by small angle neutron scattering with the smaller ones having mass fractal arrangement. Although no significant change in small pore structure under thermal effect was indicated, a significant modification of the same has been revealed by small angle neutron scattering at different compaction pressures. Connectivity between the pores was ascertained from scattering experiments on the ceramic compact impregnated with heavy water. Scanning electron microscopy shows the microstructure to undergo appreciable coalescence of micrometric ceramic particles for sintering temperature and pressure changes.

  7. High pressure injection of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Glensvig, M.; Sorenson, S.C.; Abata, D.L.

    1997-08-01

    The purpose of this investigation was to achieve a better understanding of the fundamental spray behavior of DME (Dimenthyl Ether) using a standard diesel pump with pintle and hole nozzles. Fundamental spray behavior was characterized by determining fuel spray penetration and angle, atomization and evaporation. The influences of opening pressure, nozzle geometry and ambient pressure above and below the critical pressure of the fuel on the spray behavior were investigated. The influence of opening pressures on the spray characteristics for the hole nozzle was investigated. The results showed that for opening pressures of 120 bar and 180 bar the spray has a similar appearance. For the higher opening pressure (200 bar and 240 bar), the initial spray breaks up very rapidly giving a high initial spray angle. The opening pressure had little influence on spray penetration. The spray angle later in the injection increased as the opening pressure was decreased. Above the critical pressure, the spray from the hole nozzle had a more irregular shape. Penetration decreased and the spray angle increased above the critical pressure. Three pintle nozzles with different geometries and opening pressures were tested. The appearance of the three sprays were very similar. The sprays seemed to be more sharply pointed as the nozzle hole angle decreased. The nozzle with the 4 deg. hole nozzle angle and an opening pressure of 280 bar had the highest penetration and highest initial spray angle. The pintle nozzle with the 12 deg. hole nozzle angle and opening pressure of approx. 450 bar was tested above the critical ambient pressure. Penetration was very similar for injection above and below the critical ambient pressure, while the spray angle decreased for the spray above the critical ambient pressure. (au)

  8. High Pressure EVA Glove (HPEG), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Final Frontier Design's (FFD) High Pressure EVA Glove (HPEG) is a game changing technology enabling future exploration class space missions. The high operating...

  9. Techniques in high pressure neutron scattering

    CERN Document Server

    Klotz, Stefan

    2013-01-01

    Drawing on the author's practical work from the last 20 years, Techniques in High Pressure Neutron Scattering is one of the first books to gather recent methods that allow neutron scattering well beyond 10 GPa. The author shows how neutron scattering has to be adapted to the pressure range and type of measurement.Suitable for both newcomers and experienced high pressure scientists and engineers, the book describes various solutions spanning two to three orders of magnitude in pressure that have emerged in the past three decades. Many engineering concepts are illustrated through examples of rea

  10. Synthesis and stability of hydrogen selenide compounds at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Pace, Edward J.; Binns, Jack; Alvarez, Miriam Pena; Dalladay-Simpson, Philip; Gregoryanz, Eugene; Howie, Ross T. (Edinburgh); (CHPSTAR- China)

    2017-11-14

    The observation of high-temperature superconductivity in hydride sulfide (H2S) at high pressures has generated considerable interest in compressed hydrogen-rich compounds. High-pressure hydrogen selenide (H2Se) has also been predicted to be superconducting at high temperatures; however, its behaviour and stability upon compression remains unknown. In this study, we synthesize H2Se in situ from elemental Se and molecular H2 at pressures of 0.4 GPa and temperatures of 473 K. On compression at 300 K, we observe the high-pressure solid phase sequence (I-I'-IV) of H2Se through Raman spectroscopy and x-ray diffraction measurements, before dissociation into its constituent elements. Through the compression of H2Se in H2 media, we also observe the formation of a host-guest structure, (H2Se)2H2, which is stable at the same conditions as H2Se, with respect to decomposition. These measurements show that the behaviour of H2Se is remarkably similar to that of H2S and provides further understanding of the hydrogen chalcogenides under pressure.

  11. High-pressure mechanical instability in rocks.

    Science.gov (United States)

    Byerlee, J D; Brace, W F

    1969-05-09

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

  12. The Role of Ambient Gas and Pressure on the Structuring of Hard Diamond-Like Carbon Films Synthesized by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Andrei C. Popescu

    2015-06-01

    Full Text Available Hard carbon thin films were synthesized on Si (100 and quartz substrates by the Pulsed Laser Deposition (PLD technique in vacuum or methane ambient to study their suitability for applications requiring high mechanical resistance. The deposited films’ surface morphology was investigated by scanning electron microscopy, crystalline status by X-ray diffraction, packing and density by X-ray reflectivity, chemical bonding by Raman and X-ray photoelectron spectroscopy, adherence by “pull-out” measurements and mechanical properties by nanoindentation tests. Films synthesized in vacuum were a-C DLC type, while films synthesized in methane were categorized as a-C:H. The majority of PLD films consisted of two layers: one low density layer towards the surface and a higher density layer in contact with the substrate. The deposition gas pressure played a crucial role on films thickness, component layers thickness ratio, structure and mechanical properties. The films were smooth, amorphous and composed of a mixture of sp3-sp2 carbon, with sp3 content ranging between 50% and 90%. The thickness and density of the two constituent layers of a film directly determined its mechanical properties.

  13. Terahertz Frequency-Domain Spectroscopy of Low-Pressure Acetonitrile Gas by a Photomixing Terahertz Synthesizer Referenced to Dual Optical Frequency Combs

    Science.gov (United States)

    Hsieh, Yi-Da; Kimura, Hiroto; Hayashi, Kenta; Minamikawa, Takeo; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Iwata, Tetsuo; Inaba, Hajime; Minoshima, Kaoru; Hindle, Francis; Yasui, Takeshi

    2016-09-01

    A terahertz (THz) frequency synthesizer based on photomixing of two near-infrared lasers with a sub-THz to THz frequency offset is a powerful tool for spectroscopy of polar gas molecules due to its broad spectral coverage; however, its frequency accuracy and resolution are relatively low. To tune the output frequency continuously and widely while maintaining its traceability to a frequency standard, we developed a photomixing THz synthesizer phase-locked to dual optical frequency combs (OFCs). While the phase-locking to dual OFCs ensured continuous tuning within a spectral range of 120 GHz, in addition to the traceability to the frequency standard, use of a broadband uni-traveling carrier photodiode for photomixing enabled the generation of CW-THz radiation within a frequency range from 0.2 to 1.5 THz. We demonstrated THz frequency-domain spectroscopy of gas-phase acetonitrile CH3CN and its isotope CH3 13CN in the frequency range of 0.600-0.720 THz using this THz synthesizer. Their rotational transitions were assigned with a frequency accuracy of 8.42 × 10-8 and a frequency resolution of 520 kHz. Furthermore, the concentration of the CH3CN gas at 20 Pa was determined to be (5.41 ± 0.05) × 1014 molecules/cm3 by curve fitting analysis of the measured absorbance spectrum, and the mixture ratio of the mixed CH3CN/CH3 13CN gas was determined to be 1:2.26 with a gas concentration of 1014-1015 molecules/cm3. The developed THz synthesizer is highly promising for high-precision THz-FDS of low-pressure molecular gases and will enable the qualitative and quantitative analyses of multiple gases.

  14. Industrial high pressure applications. Processes, equipment and safety

    Energy Technology Data Exchange (ETDEWEB)

    Eggers, Rudolf (ed.) [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Inst. fuer Thermische Verfahrenstechnik

    2012-07-01

    Industrial high pressure processes open the door to many reactions that are not possible under 'normal' conditions. These are to be found in such different areas as polymerization, catalytic reactions, separations, oil and gas recovery, food processing, biocatalysis and more. The most famous high pressure process is the so-called Haber-Bosch process used for fertilizers and which was awarded a Nobel prize. Following an introduction on historical development, the current state, and future trends, this timely and comprehensive publication goes on to describe different industrial processes, including methanol and other catalytic syntheses, polymerization and renewable energy processes, before covering safety and equipment issues. With its excellent choice of industrial contributions, this handbook offers high quality information not found elsewhere, making it invaluable reading for a broad and interdisciplinary audience.

  15. Nucleation at high pressure I: Theoretical considerations.

    NARCIS (Netherlands)

    Luijten, C.C.M.; Dongen, van M.E.H.

    1999-01-01

    A theoretical approach is presented that accounts for the influence of high pressure background gases on the vapor-to-liquid nucleation process. The key idea is to treat the carrier gas pressure as a perturbation parameter that modifies the properties of the nucleating substance. Two important

  16. High-pressure differential scanning microcalorimeter.

    Science.gov (United States)

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

    2016-03-01

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

  17. High-pressure oxidation of ethane

    DEFF Research Database (Denmark)

    Hashemi, Hamid; G. Jacobsen, Jon; Rasmussen, Christian T.

    2017-01-01

    Ethane oxidation at intermediate temperatures and high pressures has been investigated in both a laminar flow reactor and a rapid compression machine (RCM). The flow-reactor measurements at 600–900 K and 20–100 bar showed an onset temperature for oxidation of ethane between 700 and 825 K, depending...... on pressure, stoichiometry, and residence time. Measured ignition delay times in the RCM at pressures of 10–80 bar and temperatures of 900–1025 K decreased with increasing pressure and/or temperature. A detailed chemical kinetic model was developed with particular attention to the peroxide chemistry. Rate...

  18. Magnetic and Superconducting Materials at High Pressures

    Energy Technology Data Exchange (ETDEWEB)

    Struzhkin, Viktor V. [Carnegie Inst. of Washington, Washington, DC (United States)

    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

  19. High pressure processing of meat

    DEFF Research Database (Denmark)

    Grossi, Alberto; Christensen, Mette; Ertbjerg, Per

    the rheological properties of pork meat batters by inducing formation of protein gels. HP induced protein gels are suggested to be formed by high molecular weight myofibrillar protein aggregates and by peptides formed by lysosomal enzyme-induced cleavage of myofibrillar proteins. Perspectives: The data presented...

  20. Studies on synthesis of diamond at high pressure and temperature

    Science.gov (United States)

    Kailath, Ansu J.

    Diamond is an essential material of modern industry and probably the most versatile abrasive available today. It also has many other industrial applications attributable to its unique mechanical, optical, thermal and electrical properties. Its usage has grown to the extent that there is hardly a production process in modern industry in which industrial diamond does not play a part. Bulk diamond production today is a major industry. Diamonds can be produced in its thermodynamically stable regions either by direct static conversion, or shock-wave conversion. The pressures and temperatures required for direct static conversion are very high. In the catalyst-solvent method, the material used establishes a reaction path with lower activation energy than for direct transformation. This helps in a quicker transformation under more benign conditions. Hence, catalyst-solvent synthesis is readily accomplished and is now a viable and successful industrial process. Diamonds produced by shock wave are very small (approximately 60mu). Therefore this diamond is limited to applications such as polishing compounds only. The quality, quantity, size and morphology of the crystals synthesized by catalyst-solvent process depend on different conditions employed for synthesis. These details, because of commercial reasons are not disclosed in published literature. Hence, systematic studies have been planned to investigate the effect of various growth parameters on the synthesized crystals. During the growth of synthetic diamond crystals, some catalyst-solvent is retained into the crystals in some form and behaves like an impurity. Several physico-mechanical properties of the crystals are found to depend on the total quantity and distribution of these inclusions. Thus, detailed investigation of the crystallization medium and inclusions in synthesized diamonds was also undertaken in the present work. The work incorporated in this thesis has been divided into seven chapters. The first

  1. Raman spectroscopy of triolein under high pressures

    Science.gov (United States)

    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.

  2. Fast, High-Precision Optical Polarization Synthesizer for Ultracold-Atom Experiments

    Science.gov (United States)

    Robens, Carsten; Brakhane, Stefan; Alt, Wolfgang; Meschede, Dieter; Zopes, Jonathan; Alberti, Andrea

    2018-03-01

    We present a technique for the precision synthesis of arbitrary polarization states of light with a high modulation bandwidth. Our approach consists of superimposing two laser light fields with the same wavelength, but with opposite circular polarizations, where the phase and the amplitude of each light field are individually controlled. We find that the polarization-synthesized beam reaches a degree of polarization of 99.99%, which is mainly limited by static spatial variations of the polarization state over the beam profile. We also find that the depolarization caused by temporal fluctuations of the polarization state is about 2 orders of magnitude smaller. In a recent work, Robens et al. [Low-Entropy States of Neutral Atoms in Polarization-Synthesized Optical Lattices, Phys. Rev. Lett. 118, 065302 (2017), 10.1103/PhysRevLett.118.065302] demonstrated an application of the polarization synthesizer to create two independently controllable optical lattices which trap atoms depending on their internal spin state. We use ultracold atoms in polarization-synthesized optical lattices to give an independent, in situ demonstration of the performance of the polarization synthesizer.

  3. High pressure semiconductor physics I

    CERN Document Server

    Willardson, R K; Paul, William; Suski, Tadeusz

    1998-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise indeed that this tra...

  4. Modeling High Pressure Micro Hollow Cathode Discharges

    National Research Council Canada - National Science Library

    Boeuf, Jean-Pierre; Pitchford, Leanne

    2004-01-01

    This report results from a contract tasking CPAT as follows: The Grantee will perform theoretical modeling of point, surface, and volume high-pressure plasmas created using Micro Hollow Cathode Discharge sources...

  5. Foaming Glass Using High Pressure Sintering

    DEFF Research Database (Denmark)

    Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

    Foam glass is a high added value product which contributes to waste recycling and energy efficiency through heat insulation. The foaming can be initiated by a chemical or physical process. Chemical foaming with aid of a foaming agent is the dominant industrial process. Physical foaming has two...... to expand. After heat-treatment foam glass can be obtained with porosities of 80–90 %. In this study we conduct physical foaming of cathode ray tube (CRT) panel glass by sintering under high pressure (5-25 MPa) using helium, nitrogen, or argon at 640 °C (~108 Pa s). Reheating a sample in a heating...... variations. One way is by saturation of glass melts with gas. The other involves sintering of powdered glass under a high gas pressure resulting in glass pellets with high pressure bubbles entrapped. Reheating the glass pellets above the glass transition temperature under ambient pressure allows the bubbles...

  6. Preeclampsia and High Blood Pressure During Pregnancy

    Science.gov (United States)

    ... Gynecologists f AQ FREQUENTLY ASKED QUESTIONS FAQ034 PREGNANCY Preeclampsia and High Blood Pressure During Pregnancy • What is ... is chronic hypertension during pregnancy managed? • What is preeclampsia? • When does preeclampsia occur? • What causes preeclampsia? • What ...

  7. Teaming Up Against High Blood Pressure

    Centers for Disease Control (CDC) Podcasts

    This podcast is based on the September 2012 CDC Vital Signs report. A team-based approach by patients, health care systems, and health care providers is one of the best ways to treat uncontrolled high blood pressure.

  8. High-pressure portable pneumatic drive unit.

    Science.gov (United States)

    Hete, B F; Savage, M; Batur, C; Smith, W A; Golding, L A; Nosé, Y

    1989-12-01

    The left ventricular assist device (LVAD) of the Cleveland Clinic Foundation (CCF) is a single-chamber assist pump, driven by a high-pressure pneumatic cylinder. A low-cost, portable driver that will allow cardiac care patients, with a high-pressure pneumatic ventricle assist, more freedom of movement has been developed. The compact and light-weight configuration can provide periods of 2 h of freedom from a fixed position driver and does not use exotic technology.

  9. High Pressure Physics at Brigham Young University

    Science.gov (United States)

    Decker, Daniel

    2000-09-01

    I will discuss the high pressure research of Drs. J. Dean Barnett, Daniel L. Decker and Howard B. Vanfleet of the department of Physics and Astronomy at Brigham Young University and their many graduate students. I will begin by giving a brief history of the beginning of high pressure research at Brigham Young University when H. Tracy Hall came to the University from General Elecrtric Labs. and then follow the work as it progressed from high pressure x-ray diffraction experiments, melting curve measurements under pressure to pressure effects on tracer diffusion and Mossbauer effect spectra. This will be followed by showing the development of pressure calibration techniques from the Decker equation of state of NaCl to the ruby fluorescence spectroscopy and a short discussion of using a liquid cell for hydrostatic measurements and temperature control for precision high pressure measurements. Then I will conclude with a description of thermoelectric measuremnts, critical phenomena at the magnetic Curie point, and the tricritical point of BaTiO_3.

  10. Holographic interferometry of high pressure

    International Nuclear Information System (INIS)

    McIlwain, M.E.

    1987-01-01

    Measurements in turbulent flows have been historically performed using various types of probes and optical diagnostic methods. In general, probes suffer from plasma perturbation effects and are single point determination methods. Optical methods appear to be better suited to determinations in turbulent flows, however interpretation of the resulting data can often be complex. Methods such as laser Doppler anemometry, which relies on entrained particles, suffers from the fact that particles small enough to be swept along by the plasma are usually melted or sublimed in the plasma. Light refraction or diffraction methods such as shadow photography, interferometry, and holography have also been used to observe plasma flows. These methods typically suffer from the difficulty of interpreting line of sight images and obtaining quantitative data. A new method based on multi-pass holographic interferometry will be discussed. This method has certain advantages which can significantly simplify the complexity of line of sight interferometry image deconvolution. When the method employs high speed cinematography, time resolved images of the plasma flow can be obtained. This method has been applied to both transferred and non-transferred arcs and various types of DC-plasma torch produced jets. These studies and conclusions as to the usefulness of the technique are presented

  11. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: uu_gg_oo@yahoo.com.mx [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico) and Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM, Circuito de la Investigacion Cientifica s/n, C.U. Del. Coyoacan (Mexico); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico)

    2011-10-15

    Highlights: {yields} PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. {yields} During high-energy milling oxygen has to be chemically reduced from the lead oxide. {yields} Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  12. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    International Nuclear Information System (INIS)

    Rojas-Chavez, H.; Reyes-Carmona, F.; Jaramillo-Vigueras, D.

    2011-01-01

    Highlights: → PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. → During high-energy milling oxygen has to be chemically reduced from the lead oxide. → Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  13. High-pressure oxidation of methane

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Christensen, Jakob Munkholt; Gersen, Sander

    2016-01-01

    Methane oxidation at high pressures and intermediate temperatures was investigated in a laminar flow reactor and in a rapid compression machine (RCM). The flow-reactor experiments were conducted at 700–900 K and 100 bar for fuel-air equivalence ratios (Φ) ranging from 0.06 to 19.7, all highly...... diluted in nitrogen. It was found that under the investigated conditions, the onset temperature for methane oxidation ranged from 723 K under reducing conditions to 750 K under stoichiometric and oxidizing conditions. The RCM experiments were carried out at pressures of 15–80 bar and temperatures of 800......–1250 K under stoichiometric and fuel-lean (Φ=0.5) conditions. Ignition delays, in the range of 1–100 ms, decreased monotonically with increasing pressure and temperature. A chemical kinetic model for high-pressure methane oxidation was established, with particular emphasis on the peroxide chemistry...

  14. On high-pressure melting of tantalum

    Science.gov (United States)

    Luo, Sheng-Nian; Swift, Damian C.

    2007-01-01

    The issues related to high-pressure melting of Ta are discussed within the context of diamond-anvil cell (DAC) and shock wave experiments, theoretical calculations and common melting models. The discrepancies between the extrapolations of the DAC melting curve and the melting point inferred from shock wave experiments, cannot be reconciled either by superheating or solid-solid phase transition. The failure to reproduce low-pressure DAC melting curve by melting models such as dislocation-mediated melting and the Lindemann law, and molecular dynamics and quantum mechanics-based calculations, undermines their predictions at moderate and high pressures. Despite claims to the contrary, the melting curve of Ta (as well as Mo and W) remains inconclusive at high pressures.

  15. Pressure sensor for high-temperature liquids

    International Nuclear Information System (INIS)

    Forster, G.A.

    1978-01-01

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

  16. Facile approach to synthesize Ni(OH)2 nanoflakes on MWCNTs for high performance electrochemical supercapacitors

    International Nuclear Information System (INIS)

    Shahid, Muhammad; Liu Jingling; Shakir, Imran; Warsi, Muhammad Farooq; Nadeem, Muhammad; Kwon, Young-Uk

    2012-01-01

    Highlights: ► Deposition of ultra-thin Ni(OH) 2 nanoflakes on MWCNTs. ► Full utilization of the Ni(OH) 2 nanoflakes which provide maximum pseudocapacitance while minimizing the high surface area. ► The ultra-thin layer of Ni(OH) 2 nanoflakes on highly conductive MWCNTs is favorable for fast ion and electron transfer. ► The ultra-thin layer of Ni(OH) 2 nanoflakes on MWCNTs exhibited good cycling stability and lifetime. - Abstract: Ultrathin nanoflakes of Ni(OH) 2 were synthesized onto multi-walled carbon nanotubes (MWCNTs) by simple low cost chemically precipitation method for high performance electrochemical supercapacitor applications. The synthesized ultrathin Ni(OH) 2 exhibit high specific capacitance of 1735 Fg −1 at a scan rate of 5 mV s −1 with excellent rate capability. This high performance of Ni(OH) 2 nanoflakes was attributed to its complete accessibility to the electrolyte and maximum utilization of metal hydroxides. Findings of this work suggest that synthesized electrodes offer low-cost and scalable solution for high-performance energy storage devices.

  17. Solids, liquids, and gases under high pressure

    Science.gov (United States)

    Mao, Ho-Kwang; Chen, Xiao-Jia; Ding, Yang; Li, Bing; Wang, Lin

    2018-01-01

    Pressure has long been recognized as a fundamental thermodynamic variable but its application was previously limited by the available pressure vessels and probes. The development of megabar diamond anvil cells and a battery of associated in-laboratory and synchrotron techniques at the turn of the century have opened a vast new window of opportunities. With the addition of the pressure dimension, we are facing a new world with an order of magnitude more materials to be discovered than all that have been explored at ambient pressure. Pressure drastically and categorically alters all elastic, electronic, magnetic, structural, and chemical properties, and pushes materials across conventional barriers between insulators and superconductors, amorphous and crystalline solids, ionic and covalent compounds, vigorously reactive and inert chemicals, etc. In the process, it reveals surprising high-pressure physics and chemistry and creates novel materials. This review describes the principles and methodology used to reach ultrahigh static pressure: the in situ probes, the physical phenomena to be investigated, the long-pursued goals, the surprising discoveries, and the vast potential opportunities. Exciting examples include the quest for metallic hydrogen, the record-breaking superconducting temperature of 203 K in HnS , the complication of "free-electron gas" alkali metals, the magnetic collapse in 3 d transition elements, the pressure-induced superconductivity from topological insulators, the novel stoichiometry in simple compounds, the interaction of nanoscience, the accomplishment of 750 GPa pressure, etc. These highlights are the integral results of technological achievements, specific measurements, and theoretical advancement; therefore, the same highlights will appear in different sections corresponding to these different aspects. Overall, this review demonstrates that high-pressure research is a new dimension in condensed-matter physics.

  18. Radioresistance increase in polymers at high pressures

    International Nuclear Information System (INIS)

    Milinchuk, V.; Kirjukhin, V.; Klinshpont, E.

    1977-01-01

    The effect was studied of very high pressures ranging within 100 and 2,700 MPa on the radioresistance of polytetrafluoroethylene, polypropylene and polyethylene in gamma irradiation. For experiments industrial polymers in the shape of blocks, films and fibres were used. It is shown that in easily breakable polymers, such as polytetrafluoroethylene and polypropylene 1.3 to 2 times less free radicals are formed as a result of gamma irradiation and a pressure of 150 MPa than at normal pressure. The considerably reduced radiation-chemical formation of radicals and the destruction suppression by cross-linking in polymers is the evidence of the polymer radioresistance in irradiation at high pressures. (J.B.)

  19. observed by high pressure NMR and NQR

    Indian Academy of Sciences (India)

    Akogun, Hyogo 678-1297, Japan. ∗. Email: kohara@sci.himeji tech.ac.jp. Abstract. NMR and NQR studies on two interesting systems (URu2Si2, CeTIn5) were performed under high pressure. (1) URu2Si2: In the pressure range 3.0 to 8.3 kbar, we have observed new 29Si. NMR signals arising from the antiferromagnetic ...

  20. A power scalable PLL frequency synthesizer for high-speed Δ—Σ ADC

    International Nuclear Information System (INIS)

    Han Siyang; Chi Baoyong; Zhang Xinwang; Wang Zhihua

    2014-01-01

    A 35–130 MHz/300–360 MHz phase-locked loop frequency synthesizer for Δ—Σ analog-to-digital converter (ADC) in 65 nm CMOS is presented. The frequency synthesizer can work in low phase-noise mode (300–360 MHz) or in low-power mode (35–130 MHz) to satisfy the ADC's requirements. To switch between these two modes, a high frequency GHz LC VCO followed by a divided-by-four frequency divider and a low frequency ring VCO followed by a divided-by-two frequency divider are integrated on-chip. The measured results show that the frequency synthesizer achieves a phase-noise of −132 dBc/Hz at 1 MHz offset and an integrated RMS jitter of 1.12 ps with 1.74 mW power consumption from a 1.2 V power supply in low phase-noise mode. In low-power mode, the frequency synthesizer achieves a phase-noise of −112 dBc/Hz at 1 MHz offset and an integrated RMS jitter of 7.23 ps with 0.92 mW power consumption from a 1.2 V power supply. (semiconductor integrated circuits)

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

    Science.gov (United States)

    Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

    2010-03-23

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

  2. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

    2014-01-01

    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  3. High-Pressure Polymorphism in Orthoamphiboles

    Science.gov (United States)

    Finkelstein, G. J.; Zhang, D.; Shelton, H.; Dera, P.

    2017-12-01

    Amphiboles are double-chain silicate minerals that are the structurally hydrated counterpart to single-chain, anhydrous pyroxenes. They may play an important role in the earth as a carrier for volatiles in subduction zones, as well as a generator for seismic anisotropy in the upper mantle. Recent work has described previously unrecognized high-pressure polymorphism at low temperatures in a variety of pyroxene minerals, which may be relevant for the structure and dynamics of thick, cold, subducted slabs. However, high-pressure polymorphism in amphiboles above a few GPa in pressure has not been well explored, and if similar polymorphism to pyroxenes exists in this mineral family, it may affect the extent and depth of volatile transport in amphiboles, as well as their rheological properties. At low temperatures and high pressures, orthopyroxenes undergo crystal structure transitions at lower pressures than clinopyroxenes (10-30 GPa vs. > 50 GPa), so for this study we have investigated polymorphism in the anthophyllite-gedrite (Al-free and Al rich) orthoamphibole solid solution series. Using neon gas-loaded diamond anvil cells, we compressed both phases to a maximum pressure of 31 GPa, and observed transitions to new monoclinic structures in both endmembers. In this presentation, we will discuss the details of these transitions and implications for the earth's interior.

  4. High-pressure oxidation of methane

    NARCIS (Netherlands)

    Hashemi, Hamid; Christensen, Jakob M.; Gersen, Sander; Levinsky, Howard; Klippenstein, Stephen J.; Glarborg, Peter

    2016-01-01

    Methane oxidation at high pressures and intermediate temperatures was investigated in a laminar flow reactor and in a rapid compression machine (RCM). The flow-reactor experiments were conducted at 700–900 K and 100 bar for fuel-air equivalence ratios (Φ) ranging from 0.06 to 19.7, all highly

  5. High-purity aluminium creep under high hydrostatic pressure

    International Nuclear Information System (INIS)

    Zajtsev, V.I.; Lyafer, E.I.; Tokij, V.V.

    1977-01-01

    The effect of the hydrostatic pressure on the rate of steady-state creep of high-purity aluminium was investigated. It is shown that the hydrostatic pressure inhibits the creep. The activation volume of the creep is independent of the direction in the range of (4.7-6.2) kg/mm 2 and of the pressure in the range of (1-7.8000) atm. It is concluded that self-diffusion does not control the creep of high-purity aluminium at room temperature in the investigated stress and pressure range

  6. The increase in T sub c for MgB sub 2 superconductor under high pressure

    CERN Document Server

    Liu, Z X; You, J Y; Li, S C; Zhu, J L; Yu, R C; Li, F Y; Su, S K

    2002-01-01

    We report in situ high-pressure studies up to 1.0 GPa on MgB sub 2 superconductor which had been synthesized at high pressure. The as-prepared sample is of high quality as regards having a sharp superconducting transition (T sub c) at 39 K. The in situ high-pressure measurements were carried out using a Be-Cu piston-cylinder-type instrument with a mixed oil as the pressure-transmitting medium, which provides a quasi-hydrostatic pressure environment at low temperature. The superconducting transitions were measured using the electrical conductance method. It is found that T sub c increases with pressure in the initial pressure range, leading to a parabolic-like T sub c -P evolution.

  7. The increase in Tc for MgB2 superconductor under high pressure

    International Nuclear Information System (INIS)

    Liu, Z-X; Jin, C-Q; You, J-Y; Li, S-C; Zhu, J-L; Yu, R-C; Li, F-Y; Su, S-K

    2002-01-01

    We report in situ high-pressure studies up to 1.0 GPa on MgB 2 superconductor which had been synthesized at high pressure. The as-prepared sample is of high quality as regards having a sharp superconducting transition (T c ) at 39 K. The in situ high-pressure measurements were carried out using a Be-Cu piston-cylinder-type instrument with a mixed oil as the pressure-transmitting medium, which provides a quasi-hydrostatic pressure environment at low temperature. The superconducting transitions were measured using the electrical conductance method. It is found that T c increases with pressure in the initial pressure range, leading to a parabolic-like T c -P evolution

  8. Hydrogen - High pressure production and storage

    International Nuclear Information System (INIS)

    Lauretta, J.R

    2005-01-01

    The development of simple, safe and more and more efficient technologies for the production and the storage of hydrogen is necessary condition for the transition towards the economy of hydrogen.In this work the hydrogen production studies experimentally to high pressure by electrolysis of alkaline solutions without the intervention of compressing systems and its direct storage in safe containers.The made tests show that the process of electrolysis to high pressure is feasible and has better yield than to low pressure, and that is possible to solve the operation problems, with relatively simple technology.The preliminary studies and tests indicate that the system container that studied is immune to the outbreak and can have forms and very different sizes, nevertheless, to reach or to surpass the efficiency of storage of the conventional systems the investments necessary will be due to make to be able to produce aluminum alloy tubes of high resistance

  9. High-Tc superconductors under very high pressure

    International Nuclear Information System (INIS)

    Wijngaarden, R.J.; Scholtz, J.J.; Eenige, E.N. van; Griessen, R.

    1991-01-01

    High pressure has played a crucial role in the short history of high T c superconductors. Soon after the discovery of superconductivity by Bednorz and Muller in La-Ba-Cu-O, Chu et al. showed that the critical temperature T c could be significantly increased by pressure. This observation led to the discovery of YBa 2 Cu 3 O 7 by Wu et al. with a T c above 90 K. Incidentally, this high T c is probably also due to the fact that YBa 2 Cu 3 O 7 has two CuO 2 layers per unit cell instead of a single one in La-Ba-Cu-O. The authors discuss the high pressure dependence of the oxide superconductors, particularly at pressures above 10 GPa, and the nonmonotonic dependence of transition temperature on pressure

  10. High pressure freon decontamination of remote equipment

    International Nuclear Information System (INIS)

    Wilson, C.E.

    1987-01-01

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

  11. High pressure water jet cutting and stripping

    Science.gov (United States)

    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.

  12. High pressure water jet mining machine

    Science.gov (United States)

    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.

  13. Raman study of opal at high pressure

    Science.gov (United States)

    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.

  14. HIGH PRESSURE COAL COMBUSTON KINETICS PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    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

  15. Dynamism or Disorder at High Pressures?

    Science.gov (United States)

    Angel, R. J.; Bismayer, U.; Marshall, W. G.

    2002-12-01

    Phase transitions in minerals at elevated temperatures typically involve dynamics as a natural consequence of the increase in thermal energy available to the system. Classic examples include quartz, cristobalite, and carbonates in which the high-temperature, high symmetry phase is dynamically disordered. This disorder has important thermodynamic consequences, including displacement and curvature of phase boundaries (e.g. calcite-aragonite). In other minerals such as clinopyroxenes and anorthite feldspar, the dynamic behaviour is restricted to the neighbourhood of the phase transition. The fundamental question is whether increasing pressure generally suppresses such dynamic behaviour (as in anorthite; Angel, 1988), or not. In the latter case it must be included in thermodynamic models of high-pressure phase equilibria and seismological modelling of the mantle; the potential dynamics and softening in stishovite may provide the critical observational constraint on the presence or otherwise of free silica in the lower mantle. We have continued to use the lead phosphate as a prototype ferroelastic in which to understand dynamic behaviour, simply because its dynamics and transition behaviour is far better characterised than any mineral. Furthermore, the phase transition is at a pressure where experimental difficulties do not dominate the experimental results. Our previous neutron diffraction study (Angel et al., 2001) revealed that some disorder, either dynamic or static, is retained in the high-symmetry, high-pressure phase just above the phase transition. New neutron diffraction data on the pure material now suggests that this disorder slowly decreases with increasing pressure until at twice the transition pressure it is ordered. Further data for doped material provides insights into the nature of this disorder. Angel (1988) Amer. Mineral. 73:1114. Angel et al (2001) J PhysC 13: 5353.

  16. Acoustically enhanced microfluidic mixer to synthesize highly uniform nanodrugs without the addition of stabilizers.

    Science.gov (United States)

    Le, Nguyen Hoai An; Van Phan, Hoang; Yu, Jiaqi; Chan, Hak-Kim; Neild, Adrian; Alan, Tuncay

    2018-01-01

    This article presents an acoustically enhanced microfluidic mixer to generate highly uniform and ultra-fine nanoparticles, offering significant advantages over conventional liquid antisolvent techniques. The method employed a 3D microfluidic geometry whereby two different phases - solvent and antisolvent - were introduced at either side of a 1 μm thick resonating membrane, which contained a through-hole. The vibration of the membrane rapidly and efficiently mixed the two phases, at the location of the hole, leading to the formation of nanoparticles. The versatility of the device was demonstrated by synthesizing budesonide (a common asthma drug) with a mean diameter of 135.7 nm and a polydispersity index of 0.044. The method offers a 40-fold reduction in the size of synthesized particles combined with a substantial improvement in uniformity, achieved without the need of stabilizers.

  17. Fabrication of fluorescent composite with ultrafast aqueous synthesized high luminescent CdTe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lei, E-mail: mejswu@ust.hk; Chen, Haibin, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk; Wu, Jingshen, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk [Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong and Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong); Bi, Xianghong, E-mail: takubatch@gmail.com [Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong)

    2014-05-15

    Without precursor preparation, inert gas protection and enormous amount of additives and reductants, CdTe quantum dots (QDs) can be rapidly synthesized with high quality. A 600 nm photoluminescence peak wavelength could be obtained within 1 hour's refluxing through minimal addition of 1,2-diaminoethane (DAE). The theoretical design for the experiments are illustrated and further proved by the characterization results with different concentrations and reagents. On the other hand, generation of CdTe QDs was found even under room temperature by applying droplet quantity of DAE. This indicates that QDs can be synthesized with simply a bottle and no enormous additives required. The QDs were mixed into the epoxy matrix through solution casting method with cetyltrimethylammonium (CTA) capping for phase transfer. The acquired epoxy based nanocomposite exhibits good transparency, compatibility and fluorescence.

  18. High pressure photoinduced ring opening of benzene

    International Nuclear Information System (INIS)

    Ciabini, Lucia; Santoro, Mario; Bini, Roberto; Schettino, Vincenzo

    2002-01-01

    The chemical transformation of crystalline benzene into an amorphous solid (a-C:H) was induced at high pressure by employing laser light of suitable wavelengths. The reaction was forced to occur at 16 GPa, well below the pressure value (23 GPa) where the reaction normally occurs. Different laser sources were used to tune the pumping wavelength into the red wing of the first excited singlet state S 1 ( 1 B 2u ) absorption edge. Here the benzene ring is distorted, presenting a greater flexibility which makes the molecule unstable at high pressure. The selective pumping of the S 1 level, in addition to structural considerations, was of paramount importance to clarify the mechanism of the reaction

  19. Advanced Diagnostics for High Pressure Spray Combustion.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Cobalt ferrite nanoparticles under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Saccone, F. D.; Ferrari, S.; Grinblat, F.; Bilovol, V. [Instituto de Tecnologías y Ciencias de la Ingeniería, “Ing. H. Fernández Long,” Av. Paseo Colón 850 (1063), Buenos Aires (Argentina); Errandonea, D., E-mail: daniel.errandonea@uv.es [Departamento de Fisica Aplicada, Institut Universitari de Ciència dels Materials, Universitat de Valencia, c/ Doctor Moliner 50, E-46100 Burjassot, Valencia (Spain); Agouram, S. [Departamento de Física Aplicada y Electromagnetismo, Universitat de València, 46100 Burjassot, Valencia (Spain)

    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.

  1. Non-equilibrium plasma chemistry at high pressure and its applications

    International Nuclear Information System (INIS)

    Bai Xiyao; Zhang Zhitao; Bai Mindong; Zhu Qiaoying

    2000-01-01

    A review is presented of research and development of gas discharge and non-equilibrium plasma including, new ideas of non-equilibrium plasma at high gas pressure. With special technology, strong electric fields (>400 Td) can be achieved by which electrons are accelerated suddenly, becoming high energy electrons (> 10 eV) at high pressure. On impact with the electrons, the gas molecules dissociate into ions, atomic ions, atoms and free radicals, and new substances or molecules can be synthesized through custom design. Chemical reaction difficult to achieve by conventional method can be realized or accelerated. Non-equilibrium plasma chemistry at high pressure has wide application prospects

  2. Sounding experiments of high pressure gas discharge

    International Nuclear Information System (INIS)

    Biele, Joachim K.

    1998-01-01

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

  3. High Pressure Inactivation of HAV within Mussels

    Science.gov (United States)

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

  4. Teaming Up Against High Blood Pressure

    Centers for Disease Control (CDC) Podcasts

    2012-09-04

    This podcast is based on the September 2012 CDC Vital Signs report. A team-based approach by patients, health care systems, and health care providers is one of the best ways to treat uncontrolled high blood pressure.  Created: 9/4/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 9/4/2012.

  5. High pressure and synchrotron radiation satellite workshop

    Energy Technology Data Exchange (ETDEWEB)

    Bass, J.; Guignot, N.; Morard, G.; Mezouar, M.; Andrault, D.; Bolfan-Casanova, N.; Sturhahn, W.; Daniel, I.; Reynard, B.; Simionovici, A.; Sanchez Valle, C.; Martinez, I.; Kantor, I.; Dubrovinsky, I.; Mccammon, C.; Dubrovinskaia, N.; Kurnosiv, A.; Kuznetsov, A.; Goncharenko, I.; Loubeyre, P.; Desgreniers, S.; Weck, G.; Yoo, C.S.; Iota, V.; Park, J.; Cynn, H.; Gorelli, F.; Toulemonde, P.; Machon, D.; Merlen, A.; San Miguel, A.; Amboage, M.; Aquilanti, G.; Mathon, O.; Pascarelli, S.; Itie, J.P.; Mcmillan, P.F.; Trapananti, A.; Di Cicco, A.; Panfilis, S. de; Filipponi, A.; Kreisel, J.; Bouvier, P.; Dkhil, B.; Chaabane, B.; Rosner, H.; Koudela, D.; Schwarz, U.; Handestein, A.; Hanfland, M.; Opahle, I.; Koepernik, K.; Kuzmin, M.; Mueller, K.H.; Mydosh, J.; Richter, M.; Hejny, C.; Falconi, S.; Lundegaard, L.F.; Mcmahon, M.I; Loa, I.; Syassen, K.; Wang, X.; Roth, H.; Lorenz, T.; Farber Daniel, I.; Antonangeli Daniele, I.; Krisch, M.; Badro, J.; Fiquet, G.; Occelli, F.; Mao, W.L.; Mao, H.K.; Eng, P.; Kao, C.C.; Shu, J.F.; Hemley, R.J.; Tse, J.S.; Yao, Y.; Deen, P.P.; Paolasini, I.; Braithwaite, D.; Kernavanois, N.; Lapertot, G.; Rupprecht, K.; Leupold, O.; Ponkratz, U.; Wortmann, G.; Beraud, A.; Krisch, M.; Farber, D.; Antonangeli, D.; Aracne, C.; Zarestky, J.L.; Mcqueeney, R.; Mathon, O.; Baudelet, F.; Decremps, F.; Itie, J.P.; Nataf, I.; Pascarelli, S.; Polian, A

    2006-07-01

    The workshop is dedicated to recent advances on science at high pressure at third generation synchrotron sources. A variety of experiments using synchrotron radiation techniques including X-ray diffraction, EXAFS (extended X-ray absorption fine structure), inelastic X-ray scattering, Compton scattering and Moessbauer spectroscopy of crystalline, liquid or amorphous samples, are reported. This document gathers the abstracts of the presentations.

  6. Study of ceramics sintering under high pressures

    International Nuclear Information System (INIS)

    Kunrath Neto, A.O.

    1990-01-01

    A systematic study was made on high pressure sintering of ceramics in order to obtain materials with controlled microstructure, which are not accessible by conventional methods. Some aspects with particular interest were: to achieve very low porosity, with fine grains; to produce dispersed metastable and denser phases which can act as toughening agents; the study of new possibilities for toughening enhancement. (author)

  7. Analysis of high-pressure safety valves

    NARCIS (Netherlands)

    Beune, A.

    2009-01-01

    In presently used safety valve sizing standards the gas discharge capacity is based on a nozzle flow derived from ideal gas theory. At high pressures or low temperatures real gas effects can no longer be neglected, so the discharge coefficient corrected for flow losses cannot be assumed constant

  8. High pressure studies of planetary matter

    International Nuclear Information System (INIS)

    Ross, M.

    1989-06-01

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

  9. High pressure and synchrotron radiation satellite workshop

    International Nuclear Information System (INIS)

    Bass, J.; Guignot, N.; Morard, G.; Mezouar, M.; Andrault, D.; Bolfan-Casanova, N.; Sturhahn, W.; Daniel, I.; Reynard, B.; Simionovici, A.; Sanchez Valle, C.; Martinez, I.; Kantor, I.; Dubrovinsky, I.; Mccammon, C.; Dubrovinskaia, N.; Kurnosiv, A.; Kuznetsov, A.; Goncharenko, I.; Loubeyre, P.; Desgreniers, S.; Weck, G.; Yoo, C.S.; Iota, V.; Park, J.; Cynn, H.; Gorelli, F.; Toulemonde, P.; Machon, D.; Merlen, A.; San Miguel, A.; Amboage, M.; Aquilanti, G.; Mathon, O.; Pascarelli, S.; Itie, J.P.; Mcmillan, P.F.; Trapananti, A.; Di Cicco, A.; Panfilis, S. de; Filipponi, A.; Kreisel, J.; Bouvier, P.; Dkhil, B.; Chaabane, B.; Rosner, H.; Koudela, D.; Schwarz, U.; Handestein, A.; Hanfland, M.; Opahle, I.; Koepernik, K.; Kuzmin, M.; Mueller, K.H.; Mydosh, J.; Richter, M.; Hejny, C.; Falconi, S.; Lundegaard, L.F.; Mcmahon, M.I; Loa, I.; Syassen, K.; Wang, X.; Roth, H.; Lorenz, T.; Farber Daniel, I.; Antonangeli Daniele, I.; Krisch, M.; Badro, J.; Fiquet, G.; Occelli, F.; Mao, W.L.; Mao, H.K.; Eng, P.; Kao, C.C.; Shu, J.F.; Hemley, R.J.; Tse, J.S.; Yao, Y.; Deen, P.P.; Paolasini, I.; Braithwaite, D.; Kernavanois, N.; Lapertot, G.; Rupprecht, K.; Leupold, O.; Ponkratz, U.; Wortmann, G.; Beraud, A.; Krisch, M.; Farber, D.; Antonangeli, D.; Aracne, C.; Zarestky, J.L.; Mcqueeney, R.; Mathon, O.; Baudelet, F.; Decremps, F.; Itie, J.P.; Nataf, I.; Pascarelli, S.; Polian, A.

    2006-01-01

    The workshop is dedicated to recent advances on science at high pressure at third generation synchrotron sources. A variety of experiments using synchrotron radiation techniques including X-ray diffraction, EXAFS (extended X-ray absorption fine structure), inelastic X-ray scattering, Compton scattering and Moessbauer spectroscopy of crystalline, liquid or amorphous samples, are reported. This document gathers the abstracts of the presentations

  10. High hydrostatic pressure processing of tropical fruits.

    Science.gov (United States)

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

    2010-02-01

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

  11. High pressure neutron powder diffraction at LANSCE

    International Nuclear Information System (INIS)

    Von Dreele, R.B.

    1994-01-01

    By making use of the recently developed ''Paris-Edinburgh'' high pressure cell, the author has successfully performed neutron powder experiments to 10GPa at ambient temperature. Results for the structural compression of the high Tc 1223-Hg superconductor to 9.2 GPa, the compression and possible hydrogen bond formation in brucite, Mg(OD) 2 , to 9.3 GPa, and the molecular reorientation in nitromethane to 5.5 GPa will be presented

  12. High temperature and high pressure equation of state of gold

    International Nuclear Information System (INIS)

    Matsui, Masanori

    2010-01-01

    High-temperature and high-pressure equation of state (EOS) of Au has been developed using measured data from shock compression up to 240 GPa, volume thermal expansion between 100 and 1300 K and 0 GPa, and temperature dependence of bulk modulus at 0 GPa from ultrasonic measurements. The lattice thermal pressures at high temperatures have been estimated based on the Mie-Grueneisen-Debye type treatment with the Vinet isothermal EOS. The contribution of electronic thermal pressure at high temperatures, which is relatively insignificant for Au, has also been included here. The optimized EOS parameters are K' 0T = 6.0 and q = 1.6 with fixed K 0T = 167 GPa, γ 0 = 2.97, and Θ 0 = 170 K from previous investigations. We propose the present EOS to be used as a reliable pressure standard for static experiments up to 3000K and 300 GPa.

  13. Blue emitting organic semiconductors under high pressure

    DEFF Research Database (Denmark)

    Knaapila, Matti; Guha, Suchismita

    2016-01-01

    This review describes essential optical and emerging structural experiments that use high GPa range hydrostatic pressure to probe physical phenomena in blue-emitting organic semiconductors including π-conjugated polyfluorene and related compounds. The work emphasizes molecular structure and inter......This review describes essential optical and emerging structural experiments that use high GPa range hydrostatic pressure to probe physical phenomena in blue-emitting organic semiconductors including π-conjugated polyfluorene and related compounds. The work emphasizes molecular structure...... and intermolecular self-organization that typically determine transport and optical emission in π-conjugated oligomers and polymers. In this context, hydrostatic pressure through diamond anvil cells has proven to be an elegant tool to control structure and interactions without chemical intervention. This has been...... and intermolecular interactions on optical excitations, electron–phonon interaction, and changes in backbone conformations. This picture is connected to the optical high pressure studies of other π-conjugated systems and emerging x-ray scattering experiments from polyfluorenes which provides a structure-property map...

  14. The high-pressure behavior of bloedite

    DEFF Research Database (Denmark)

    Comodi, Paola; Nazzareni, Sabrina; Balic Zunic, Tonci

    2014-01-01

    High-pressure single-crystal synchrotron X‑ray diffraction was carried out on a single crystal of bloedite [Na2Mg(SO4)24H2O] compressed in a diamond-anvil cell. The volume-pressure data, collected up to 11.2 GPa, were fitted by a second- and a third-order Birch-Murnaghan equation of state (EOS....... Pressure decreases significantly the distortion of Na coordination. Up to 10 GPa, the donor-acceptor oxygen distances decrease significantly and the difference between the two water molecules decreases with an increase in the strengths of hydrogen bonds. At the same time, the bond lengths from Na and Mg...... to O atoms of the water molecules decrease faster than other bonds to these cations suggesting that there is a coupling between the Na-Ow and Mg-Ow bond strengths and the “hydrogen transfer” to acceptor O atoms....

  15. High-pressure torsion for new hydrogen storage materials.

    Science.gov (United States)

    Edalati, Kaveh; Akiba, Etsuo; Horita, Zenji

    2018-01-01

    High-pressure torsion (HPT) is widely used as a severe plastic deformation technique to create ultrafine-grained structures with promising mechanical and functional properties. Since 2007, the method has been employed to enhance the hydrogenation kinetics in different Mg-based hydrogen storage materials. Recent studies showed that the method is effective not only for increasing the hydrogenation kinetics but also for improving the hydrogenation activity, for enhancing the air resistivity and more importantly for synthesizing new nanostructured hydrogen storage materials with high densities of lattice defects. This manuscript reviews some major findings on the impact of HPT process on the hydrogen storage performance of different titanium-based and magnesium-based materials.

  16. The high-pressure phase of CePtAl

    International Nuclear Information System (INIS)

    Heymann, Gunter; Heying, Birgit; Rodewald, Ute C.; Janka, Oliver; Univ. Oldenburg

    2017-01-01

    The intermetallic aluminum compound HP-CePtAl was synthesized by arc melting of the elements with subsequent high-pressure/high-temperature treatment at 1620 K and 10.5 GPa in a multianvil press. The compound crystallizes in the hexagonal MgZn_2-type structure (P6_3/mmc) with lattice parameters of a=552.7(1) and c=898.8(2) pm refined from powder X-ray diffraction data. With the help of single crystal investigations (wR=0.0527, 187 F"2 values, 13 variables), the proposed structure type was confirmed and the mixed Pt/Al site occupations could be refined. Magnetic susceptibility measurements showed a disappearance of the complex magnetic ordering phenomena, which are observed in NP-CePtAl.

  17. The high-pressure phase of CePtAl

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, Gunter [Univ. Innsbruck (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Heying, Birgit; Rodewald, Ute C. [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie; Janka, Oliver [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie; Univ. Oldenburg (Germany). Inst. fuer Chemie

    2017-03-01

    The intermetallic aluminum compound HP-CePtAl was synthesized by arc melting of the elements with subsequent high-pressure/high-temperature treatment at 1620 K and 10.5 GPa in a multianvil press. The compound crystallizes in the hexagonal MgZn{sub 2}-type structure (P6{sub 3}/mmc) with lattice parameters of a=552.7(1) and c=898.8(2) pm refined from powder X-ray diffraction data. With the help of single crystal investigations (wR=0.0527, 187 F{sup 2} values, 13 variables), the proposed structure type was confirmed and the mixed Pt/Al site occupations could be refined. Magnetic susceptibility measurements showed a disappearance of the complex magnetic ordering phenomena, which are observed in NP-CePtAl.

  18. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Directory of Open Access Journals (Sweden)

    Smolen D

    2013-02-01

    Full Text Available Dariusz Smolen1, Tadeusz Chudoba1, Iwona Malka1, Aleksandra Kedzierska1, Witold Lojkowski1, Wojciech Swieszkowski2, Krzysztof Jan Kurzydlowski2, Malgorzata Kolodziejczyk-Mierzynska3, Malgorzata Lewandowska-Szumiel31Polish Academy of Science, Institute of High Pressure Physics, Warsaw, Poland; 2Faculty of Materials Engineering, Warsaw University of Technology, Warsaw, Poland; 3Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, Warsaw, PolandAbstract: A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM. The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 µmol/dm3 in the tris(hydroxymethylaminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material

  19. High-pressure effects in hydrofullerene C60H36 studied by Raman spectroscopy

    International Nuclear Information System (INIS)

    Meletov, K.P.; Rossijskaya Akademiya Nauk, Chernogolovka; Tsilika, I.; Assimopoulos, S.; Kourouklis, G.A.; Ves, S.; Bashkin, I.O.; Kulakov, V.I.; Khasanov, S.S.

    2001-01-01

    The effect of hydrostatic pressure on the Raman spectrum of hydrofullerene C 60 H 36 , at room temperature has been investigated up to 12 GPa. The samples were synthesized by means of high-pressure hydrogenation. The pressure dependence of the phonon frequencies exhibits two reversible changes one at ∝0.6 GPa and another one at ∝6 GPa. The first may be probably related to a phase transition from the initial orientationally disordered bcc structure to an orientationally ordered one. The second one, at ∝6 GPa, is probably driven by pressure-induced bonding of hydrogen to a carbon atom of a neighboring hydrofullerene cage. (orig.)

  20. A microbial-mineralization approach for syntheses of iron oxides with a high specific surface area.

    Science.gov (United States)

    Yagita, Naoki; Oaki, Yuya; Imai, Hiroaki

    2013-04-02

    Of minerals and microbes: A microbial-mineralization-inspired approach was used to facilitate the syntheses of iron oxides with a high specific surface area, such as 253 m(2)g(-1) for maghemite (γ-Fe(2)O(3)) and 148 m(2)g(-1) for hematite (α-Fe(2)O(3)). These iron oxides can be applied to electrode material of lithium-ion batteries, adsorbents, and catalysts. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Strain engineered pyrochlore at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rittman, Dylan R.; Turner, Katlyn M.; Park, Sulgiye; Fuentes, Antonio F.; Park, Changyong; Ewing, Rodney C.; Mao, Wendy L.

    2017-05-22

    Strain engineering is a promising method for next-generation materials processing techniques. Here, we use mechanical milling and annealing followed by compression in diamond anvil cell to tailor the intrinsic and extrinsic strain in pyrochlore, Dy2Ti2O7 and Dy2Zr2O7. Raman spectroscopy, X-ray pair distribution function analysis, and X-ray diffraction were used to characterize atomic order over short-, medium-, and long-range spatial scales, respectively, under ambient conditions. Raman spectroscopy and X-ray diffraction were further employed to interrogate the material in situ at high pressure. High-pressure behavior is found to depend on the species and concentration of defects in the sample at ambient conditions. Overall, we show that defects can be engineered to lower the phase transformation onset pressure by ~50% in the ordered pyrochlore Dy2Zr2O7, and lower the phase transformation completion pressure by ~20% in the disordered pyrochlore Dy2Zr2O7. These improvements are achieved without significantly sacrificing mechanical integrity, as characterized by bulk modulus.

  2. High Pressure and Temperature Effects in Polymers

    Science.gov (United States)

    Bucknall, David; Arrighi, Valeria; Johnston, Kim; Condie, Iain

    Elastomers are widely exploited as the basis for seals in gas and fluid pipelines. The underlying behaviour of these elastomer at the high pressure, elevated temperatures they experience in operation is poorly understood. Consequently, the duty cycle of these materials is often deliberately limited to a few hours, and in order to prevent failure, production is stopped in order to change the seals in critical joints. The result is significant time lost due to bringing down production to change the seals as well as knock on financial costs. In order to address the fundamental nature of the elastomers at their intended operating conditions, we are studying the gas permeation behaviour of hydrogenated natural butyl rubber (HNBR) and fluorinated elastomers (FKM) at a high pressure and elevated temperature. We have developed a pressure system that permits gas permeation studies at gas pressures of up to 5000 psi and operating temperatures up to 150° C. In this paper, we will discuss the nature of the permeation behaviour at these extreme operating conditions, and how this relates to the changes in the polymer structure. We will also discuss the use of graphene-polymer thin layer coatings to modify the gas permeation behaviour of the elastomers.

  3. 7 CFR 58.219 - High pressure pumps and lines.

    Science.gov (United States)

    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 high...

  4. Inspection technology for high pressure pipes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae H.; Lee, Jae C.; Eum, Heung S.; Choi, Yu R.; Moon, Soon S.; Jang, Jong H

    2000-02-01

    Various kinds of defects are likely to be occurred in the welds of high pressure pipes in nuclear power plants. Considering the recent accident of Zuruga nuclear power plant in Japan, reasonable policy is strongly requested for the high pressure pipe integrity. In this study, we developed the technologies to inspect pipe welds automatically. After development of scanning robot prototype in the first research year, we developed and implemented the algorithm of automatic tracking of the scanning robot along the weld line of the pipes. We use laser slit beam on weld area and capture the image using digital camera. Through processing of the captures image, we finally determine the weld line automatically. In addition, we investigated a new technology on micro systems for developing micro scanning robotic inspection of the pipe welds. The technology developed in this study is being transferred to the industry. (author)

  5. High pressure injection injuries: an overview.

    Science.gov (United States)

    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. Stress concentration effects in high pressure components

    International Nuclear Information System (INIS)

    Aller, J.E.

    1990-01-01

    This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

  7. High Pressure Multicomponent Adsorption in Porous Media

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1999-01-01

    We analyse adsorption of a multicomponent mixture at high pressure on the basis of the potential theory of adsorption. The adsorbate is considered as a segregated mixture in the external field produced by a solid adsorbent. we derive an analytical equation for the thickness of a multicomponent fi...... close to a dew point. This equation (asymptotic adsorption equation, AAE) is a first order approximation with regard to the distance from a phase envelope....

  8. Path Dependency of High Pressure Phase Transformations

    Science.gov (United States)

    Cerreta, Ellen

    2017-06-01

    At high pressures titanium and zirconium are known to undergo a phase transformation from the hexagonal close packed (HCP), alpha-phase to the simple-hexagonal, omega-phase. Under conditions of shock loading, the high-pressure omega-phase can be retained upon release. It has been shown that temperature, peak shock stress, and texture can influence the transformation. Moreover, under these same loading conditions, plastic processes of slip and twinning are also affected by similar differences in the loading path. To understand this path dependency, in-situ velocimetry measurements along with post-mortem metallographic and neutron diffraction characterization of soft recovered specimens have been utilized to qualitatively understand the kinetics of transformation, quantify volume fraction of retained omega-phase and characterize the shocked alpha and omega-phases. Together the work described here can be utilized to map the non-equilibrium phase diagram for these metals and lend insight into the partitioning of plastic processes between phases during high pressure transformation. In collaboration with: Frank Addesssio, Curt Bronkhorst, Donald Brown, David Jones, Turab Lookman, Benjamin Morrow, Carl Trujillo, Los Alamos National Lab.; Juan Pablo Escobedo-Diaz, University of New South Wales; Paulo Rigg, Washington State University.

  9. High pressure phase transitions in Europous oxide

    International Nuclear Information System (INIS)

    Kremser, D.T.

    1982-01-01

    The pressure-volume relationship for EuO was investigated to 630 kilobars at room temperature with a diamond-anvil, high-pressure cell. Volumes were determined by x-ray diffraction; pressures were determined by the ruby R 1 fluorescence method. The preferred interpretation involves normal compression behavior for EuO, initially in the B1 (NaCl-type) structure, to about 280 kilobars. Between approx. =280 and approx. =350 kilobars a region of anomalous compressibility in which the volume drops continuously by approximately 2% is observed. A second-order electronic transition is proposed with the 6s band overlapping with the 4f levels, thereby reducing the volume of EuO without changing the structure. This is not a semiconductor-to-metal transition. In reflected light, this transition is correlated with a subtle and continuous change in color from brown-black to a light brown. The collapsed B1 phase (postelectronic transition) is stable between approx. =350 and approx. =400 kilobars. At about 400 kilobars the collapsed B1 structure transforms to the B2 (CsCl-type) structure, with a zero pressure-volume change of approximately 12 +/- 1.5%

  10. The influence of high pressure and high temperature on the structure of ZrO sub 2 nanosolids

    CERN Document Server

    Xu Da Peng; LiuShue; Wang Quan Yong; Su Wen Hui

    2002-01-01

    Using nanoparticles of ZrO sub 2 (disordered structure) prepared by the method of precipitation as starting materials, ZrO sub 2 nanosolids have been synthesized under different pressures and at different temperatures. The x-ray diffraction results show that the crystallization temperature of the nanoparticles and the temperature at which the structural cubic-monoclinic transformation occurs are obviously reduced for the nanosolids synthesized under high pressure. X-ray photoelectron spectroscopy and EPR measurements indicate that there are some Zr sup 3 sup + ions in nanosolids. With increasing pressure, the number of Zr sup 3 sup + ions in the nanosolids essentially does not vary, and yet the content of oxygen ions with unsaturated bonds and dangling bonds in the interfacial region gradually decreases. The effect of synthesis pressure on the structure and interface states is mainly due to the decrease of the interatomic distance and the increasing interdiffusion of atoms in the interface phase.

  11. Energy Systems High-Pressure Test Laboratory | Energy Systems Integration

    Science.gov (United States)

    Facility | NREL Energy Systems High-Pressure Test Laboratory Energy Systems High-Pressure Test Laboratory In the Energy Systems Integration Facility's High-Pressure Test Laboratory, researchers can safely test high-pressure hydrogen components. Photo of researchers running an experiment with a hydrogen fuel

  12. Synthesis and properties of selenium trihydride at high pressures

    Science.gov (United States)

    Zhang, Xiao; Xu, Wan; Wang, Yu; Jiang, Shuqing; Gorelli, Federico A.; Greenberg, Eran; Prakapenka, Vitali B.; Goncharov, Alexander F.

    2018-02-01

    The chemical reaction products of molecular hydrogen (H2) with selenium (Se) are studied by synchrotron x-ray diffraction (XRD) and Raman spectroscopy at high pressures. We find that a common H2Se is synthesized at 0.3 GPa using laser heating. Upon compression at 300 K, a crystal of the theoretically predicted Cccm H3Se has been grown at 4.6 GPa. At room temperature, H3Se shows a reversible phase decomposition after laser irradiation above 8.6 GPa, but remains stable up to 21 GPa. However, at 170 K Cccm H3Se persists up to 39.5 GPa based on XRD measurements, while low-temperature Raman spectra weaken and broaden above 23.1 GPa. At these conditions, the sample is visually nontransparent and shiny suggesting that metallization occurred.

  13. Hydrogen high pressure proportional drift detector

    International Nuclear Information System (INIS)

    Arefiev, A.; Balaev, A.

    1983-01-01

    The design and operation performances of a proportional drift detector PDD are described. High sensitivity of the applied PAD makes it possible to detect the neutron-proton elastic scattering in the energy range of recoil protons as low as 1 keV. The PDD is filled with hydrogen up to the pressure at 40 bars. High purity of the gas is maintained by a continuously operating purification system. The detector has been operating for several years in a neutron beam at the North Area of the CERN SPS

  14. High pressure synthesis of BiS2

    DEFF Research Database (Denmark)

    Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

    crystal structures and electrical properties.1,2 Up until now, the most sulfur rich phase in the Bi-S phase diagram was Bi2S3.3 For BiS2 the Bi atoms have anisotropic charge distribution and more complex structures are expected when comparing the layered structures of transition metal dichalcogenides....... The possibilities of using high pressure synthesis to discover new phases in the Bi-S binary system were investigated as early as the 1960’s.4 The research led to discovery of a compound with BiS2 stoichiometry, but no structure solution of BiS2 was reported. A reason behind making this new phase is to study...... the physical properties since the related compound Bi2S3 is known to be a thermoelectric material.5 In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure...

  15. Superconductivity from magnetic elements under high pressure

    International Nuclear Information System (INIS)

    Shimizu, Katsuya; Amaya, Kiichi; Suzuki, Naoshi; Onuki, Yoshichika

    2006-01-01

    Can we expect the appearance of superconductivity from magnetic elements? In general, superconductivity occurs in nonmagnetic metal at low temperature and magnetic impurities destroy superconductivity; magnetism and superconductivity are as incompatible as oil and water. Here, we present our experimental example of superconducting elements, iron and oxygen. They are magnetic at ambient pressure, however, they become nonmagnetic under high pressure, then superconductor at low temperature. What is the driving force of the superconductivity? Our understanding in the early stages was a simple scenario that the superconductive state was obtained as a consequence of an emergence of the nonmagnetic states. In both cases, we may consider another scenario for the appearance of superconductivity; the magnetic fluctuation mechanism in the same way as unconventional superconductors

  16. Sizing of high-pressure restriction orifices

    International Nuclear Information System (INIS)

    Casado Flores, E.

    1995-01-01

    Constant up-grading of power plants sometimes requires the modification of components which form part of suppliers' packages. In order to protect technology they have developed, however, the suppliers do not supply their calculation criteria. In order to reduce the costs of such improvements, and so as to be able to undertake the modification without having to rely on the original supplier, this paper describes the basic criteria applicable to the study of high-pressure restriction orifices, which can be considered to be representative of the components in question. The restriction orifices discussed are: - Insert - Multiplates in series with one perforation in each plate - Multiplates in series with several perforations in each plate For each type, an explanation of their sizing is given, together with the equations relating the corresponding flow and pressure drop. (Author)

  17. High temperature and pressure electrochemical test station

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Allebrod, Frank; Mogensen, Mogens Bjerg

    2013-01-01

    An electrochemical test station capable of operating at pressures up to 100 bars and temperatures up to 400 ◦C has been established. It enables control of the partial pressures and mass flow of O2, N2, H2, CO2, and H2O in a single or dual environment arrangement, measurements with highly corrosive...... media, as well as localized sampling of gas evolved at the electrodes for gas analysis. A number of safety and engineering design challenges have been addressed. Furthermore, we present a series of electrochemical cell holders that have been constructed in order to accommodate different types of cells...... and facilitate different types of electrochemical measurements. Selected examples of materials and electrochemical cells examined in the test station are provided, ranging from the evaluation of the ionic conductivity of liquid electrolytic solutions immobilized in mesoporous ceramic structures...

  18. SrWO4 at high pressures

    International Nuclear Information System (INIS)

    Grzechnik, A.; Crichton, W.A.; Hanfland, M.

    2005-01-01

    Room-temperature high-pressure behaviour of SrWO 4 scheelite (I4 1 /a, Z=4) has been studied to 20.7 GPa in a diamond anvil cell using synchrotron angle-dispersive X-ray powder diffraction. Above 10 GPa, it transforms to the fergusonite structure (I2/a, Z=4). Both scheelite and fergusonite types are ordered superstructures of fluorite (Fm anti 3m, Z=4). There is no significant volume collapse at the scheelite-fergusonite phase transition. However, the compression data including both phases of strontium tungstate cannot be fitted by a common Birch-Murnaghan equation of state. An onset of decomposition into component oxides occurs at about 15 GPa. The pressure-induced transformations are irreversible. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. High pressure study of high-temperature superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Souliou, Sofia-Michaela

    2014-09-29

    The current thesis studies experimentally the effect of high external pressure on high-T{sub c} superconductors. The structure and lattice dynamics of several members of the high-T{sub c} cuprate and Fe-based superconductors families were investigated by means of Raman spectroscopy and X-ray diffraction under well-controlled, hydrostatic high pressure and low temperature conditions. The lattice dynamics of the high-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 6+x} have been investigated systematically by Raman spectroscopy as a function of doping (x = 0.95, 0.75, 0.60, 0.55, and 0.45) and external pressure. Under ambient pressure conditions, in addition to the Raman modes expected from group theory, we observe new Raman active phonons upon cooling the underdoped samples, at temperatures well above the superconducting transition temperature. The doping dependence and the onset temperatures of the new Raman features suggest that they are associated with the incommensurate charge density wave (CDW) state recently discovered in underdoped cuprates using synchrotron X-ray scattering techniques. Under high pressure conditions (from 2 to 12 GPa), our Raman measurements on highly ordered underdoped YBa{sub 2}Cu{sub 3}O{sub 6.55} samples do not show any of the new Raman phonons seen at ambient pressure. High pressure and low temperature Raman measurements have been performed on the underdoped superconductor YBa{sub 2}Cu{sub 4}O{sub 8}. A clear renormalization of some of the Raman phonons is seen below T{sub c} as a result of the changes in the phonon self-energy upon the opening of the superconducting gap, with the most prominent one being that of the B{sub 1g}-like buckling phonon mode. The amplitude of this renormalization strongly increases with pressure, resembling the effect of hole doping in YBa{sub 2}Cu{sub 3}O{sub 6+x}. At ∝ 10 GPa, the system undergoes a reversible pressure-induced structural phase transition to a non-centrosymmmetric structure (space group

  20. High pressure study of high-temperature superconductors

    International Nuclear Information System (INIS)

    Souliou, Sofia-Michaela

    2014-01-01

    The current thesis studies experimentally the effect of high external pressure on high-T c superconductors. The structure and lattice dynamics of several members of the high-T c cuprate and Fe-based superconductors families were investigated by means of Raman spectroscopy and X-ray diffraction under well-controlled, hydrostatic high pressure and low temperature conditions. The lattice dynamics of the high-T c superconductor YBa 2 Cu 3 O 6+x have been investigated systematically by Raman spectroscopy as a function of doping (x = 0.95, 0.75, 0.60, 0.55, and 0.45) and external pressure. Under ambient pressure conditions, in addition to the Raman modes expected from group theory, we observe new Raman active phonons upon cooling the underdoped samples, at temperatures well above the superconducting transition temperature. The doping dependence and the onset temperatures of the new Raman features suggest that they are associated with the incommensurate charge density wave (CDW) state recently discovered in underdoped cuprates using synchrotron X-ray scattering techniques. Under high pressure conditions (from 2 to 12 GPa), our Raman measurements on highly ordered underdoped YBa 2 Cu 3 O 6.55 samples do not show any of the new Raman phonons seen at ambient pressure. High pressure and low temperature Raman measurements have been performed on the underdoped superconductor YBa 2 Cu 4 O 8 . A clear renormalization of some of the Raman phonons is seen below T c as a result of the changes in the phonon self-energy upon the opening of the superconducting gap, with the most prominent one being that of the B 1g -like buckling phonon mode. The amplitude of this renormalization strongly increases with pressure, resembling the effect of hole doping in YBa 2 Cu 3 O 6+x . At ∝ 10 GPa, the system undergoes a reversible pressure-induced structural phase transition to a non-centrosymmmetric structure (space group Imm2). The structural transition is clearly reflected in the high pressure

  1. Synthesizing Zno Nanoparticles by High-Energy Milling and Investigating Their Antimicrobial Effect

    Directory of Open Access Journals (Sweden)

    N Mohammadi

    2015-07-01

    Results: The study results demonstrated that size of the synthesized nanoparticles was within the range of 20 -90 nm and their morphology was reported as nanorod and nanoparticles with multifaceted cross-section. An increase in the density of nanoparticles resulted in a rise in the antimicrobial effect. Moreover, Staphylococcus aureus bacteria inhibition zone was 3±0.5 and 7±0.5 mm respectively at the density of 6 and 10 mM. The MIC and MBC of ZnO nanoparticles provided for Staphylococcus aureus were observed 3±3 and 2.5±0 mg/ml, whereas they were reported 7.5±0 and 8±0 mg/ml for Escherichia coli bacteria. Conclusion: The findings of the present study revealed that ZnO nanomaterials could be synthesized by applying high-energy milling on micron-scaled ZnO particles. In addition, they can be utilized in food packaging and preservation process.

  2. 30 CFR 57.13021 - High-pressure hose connections.

    Science.gov (United States)

    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 3/4-inch...

  3. High-pressure-high-temperature treatment of natural diamonds

    CERN Document Server

    Royen, J V

    2002-01-01

    The results are reported of high-pressure-high-temperature (HPHT) treatment experiments on natural diamonds of different origins and with different impurity contents. The diamonds are annealed in a temperature range up to 2000 sup o C at stabilizing pressures up to 7 GPa. The evolution is studied of different defects in the diamond crystal lattice. The influence of substitutional nitrogen atoms, plastic deformation and the combination of these is discussed. Diamonds are characterized at room and liquid nitrogen temperature using UV-visible spectrophotometry, Fourier transform infrared spectrophotometry and photoluminescence spectrometry. The economic implications of diamond HPHT treatments are discussed.

  4. Characterization of diamond-like carbon thin film synthesized by RF atmospheric pressure plasma Ar/CH4 jet

    Science.gov (United States)

    Sohbatzadeh, Farshad; Safari, Reza; Etaati, G. Reza; Asadi, Eskandar; Mirzanejhad, Saeed; Hosseinnejad, Mohammad Taghi; Samadi, Omid; Bagheri, Hanieh

    2016-01-01

    The growth of diamond like carbon (DLC) on a Pyrex glass was investigated by a radio frequency (RF) atmospheric pressure plasma jet (APPJ). The plasma jet with capacitive configuration ran by a radio frequency power supply at 13.56 MHz. Alumina ceramic was used as dielectric barrier. Ar and CH4 were used in atmospheric pressure as carrier and precursor gases, respectively. Diamond like carbon thin films were deposited on Pyrex glass at substrate temperature and applied power of 130 °C and 250 Watts, respectively. Performing field emission scanning electron microscope (FE-SEM) and laser Raman spectroscopy analysis resulted in deposition rate and the ID/IG ratio of 21.31 nm/min and 0.47, respectively. The ID/IG ratio indicated that the coating possesses relative high sp3 content The optical emission spectroscopy (OES) diagnostic was applied to diagnose plasma jet species. Estimating electron temperature and density of the RF-APPJ resulted in 1.36 eV and 2.75 × 1014 cm-3 at the jet exit, respectively.

  5. Multi-morphological growth of nano-structured In{sub 2}Se{sub 3} by ambient pressure triethylene glycol based solution syntheses

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tongfei; Wang, Jian; Lai, Junyun; Zheng, Xuerong; Liu, Weiyan; Ji, Junna [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Liu, Hui [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401 (China); Jin, Zhengguo, E-mail: zhgjin@tju.edu.cn [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-10-15

    In{sub 2}Se{sub 3} nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized by a new, facile, ambient pressure triethylene glycol based solution chemical route using indium(III) chloride and selenium powder as precursors. The growing morphology, crystallization, chemical stoichiometry and light absorption property of the In{sub 2}Se{sub 3} products synthesized were characterized by TEM, HRTEM, FESEM, XRD, EDX and UV–vis–NIR measurements. Multi-morphological growth of the nano-structured In{sub 2}Se{sub 3} in triethylene glycol based solution syntheses with changed assisting agents and reaction styles was demonstrated. - Highlights: • Multimorphological growth of In{sub 2}Se{sub 3} was demonstrated based on solution chemistry. • A new, facile, low cost and fast air pressure TEG based solution process was used. • Nanoparticles, flower-like shaped and sheet-shaped nanocrystals were synthesized. • Morphology, crystallization, stoichiometry and light absorption was characterized. • Solution growth of β-In{sub 2}Se{sub 3} nanosheets was firstly reported by this submission.

  6. 49 CFR 192.621 - Maximum allowable operating pressure: High-pressure distribution systems.

    Science.gov (United States)

    2010-10-01

    ... STANDARDS Operations § 192.621 Maximum allowable operating pressure: High-pressure distribution systems. (a) No person may operate a segment of a high pressure distribution system at a pressure that exceeds the... segment of a distribution system otherwise designed to operate at over 60 p.s.i. (414 kPa) gage, unless...

  7. Recent progress in high-pressure studies on organic conductors

    Directory of Open Access Journals (Sweden)

    Syuma Yasuzuka and Keizo Murata

    2009-01-01

    Full Text Available Recent high-pressure studies of organic conductors and superconductors are reviewed. The discovery of the highest Tc superconductivity among organics under high pressure has triggered the further progress of the high-pressure research. Owing to this finding, various organic conductors with the strong electron correlation were investigated under high pressures. This review includes the pressure techniques using the cubic anvil apparatus, as well as high-pressure studies of the organic conductors up to 10 GPa showing extraordinary temperature and pressure dependent transport phenomena.

  8. Commentary on differential-pressure measurements at high reference pressures

    International Nuclear Information System (INIS)

    Hasbrouck, R.T.; Noyes, R.P.

    1981-01-01

    Some practical approaches to the difficult problems in calibrating and implementing differential-pressure measurements are discussed. The data presented were gathered several years ago in separate investigations. An attempt is made to compare the results of these investigations to the common mode concept as described by Peter K. Stein in his publication, The Measurement of Differential Quantities - Problems and Approaches. Although one of these investigations involed a 10,000- to 20,000-psi reference-pressure gas measured at an ambient temperature and the other a classic /sup Δ/P flow measurement of cryogenic temperature, the problems encountered were the same

  9. Conformable pressure vessel for high pressure gas storage

    Science.gov (United States)

    Simmons, Kevin L.; Johnson, Kenneth I.; Lavender, Curt A.; Newhouse, Norman L.; Yeggy, Brian C.

    2016-01-12

    A non-cylindrical pressure vessel storage tank is disclosed. The storage tank includes an internal structure. The internal structure is coupled to at least one wall of the storage tank. The internal structure shapes and internally supports the storage tank. The pressure vessel storage tank has a conformability of about 0.8 to about 1.0. The internal structure can be, but is not limited to, a Schwarz-P structure, an egg-crate shaped structure, or carbon fiber ligament structure.

  10. An ultra-high-speed direct digital frequency synthesizer implemented in GaAs HBT technology

    International Nuclear Information System (INIS)

    Chen Gaopeng; Wu Danyu; Jin Zhi; Liu Xinyu

    2010-01-01

    This paper presents a 10-GHz 8-bit direct digital synthesizer (DDS) microwave monolithic integrated circuit implemented in 1 μm GaAs HBT technology. The DDS takes a double-edge-trigger (DET) 8-stage pipeline accumulator with sine-weighted DAC-based ROM-less architecture, which can maximize the utilization ratio of the GaAs HBT's high-speed potential. With an output frequency up to 5 GHz, the DDS gives an average spurious free dynamic range of 23.24 dBc through the first Nyquist band, and consumes 2.4 W of DC power from a single -4.6 V DC supply. Using 1651 GaAs HBT transistors, the total area of the DDS chip is 2.4 x 2.0 mm 2 . (semiconductor integrated circuits)

  11. Generalized syntheses of nanocrystal-graphene hybrids in high-boiling-point organic solvents.

    Science.gov (United States)

    Pang, Danny Wei-Ping; Yuan, Fang-Wei; Chang, Yan-Cheng; Li, Guo-An; Tuan, Hsing-Yu

    2012-08-07

    Nanocrystal-graphene have been proposed as a new kind of promising hybrid for a wide range of application areas including catalysts, electronics, sensors, biomedicine, and energy storage, etc. Although a variety of methods have been developed for the preparation of hybrids, a facile and general synthetic approach is still highly required. In this study, nanocrystal-graphene hybrids were successfully synthesized in high-boiling-point organic solvents. Graphene oxide (GO) nanosheets were modified by oleylamine (OLA) to form a OLA-GO complex in order to be readily incorporated into hydrophobic synthesis. A rich library of highly crystalline nanocrystals, with types including noble metal, metal oxide, magnetic material and semiconductor were successfully grown on chemically converted graphene (CCG), which is simultaneously reduced from GO during the synthesis. High boiling-point solvents afford sufficient thermal energy to assure the high-quality crystalline nature of NCs, therefore the post-annealing process is obviated. Controlled experiments revealed that OLA-GO triggers heterogeneous nucleation and serves as excellent nuclei anchorage media. The protocol developed here brings one step closer to achieve "unity in diversity" on the preparation of nanocrystal-graphene hybrids.

  12. Experimental Compressibility of Molten Hedenbergite at High Pressure

    Science.gov (United States)

    Agee, C. B.; Barnett, R. G.; Guo, X.; Lange, R. A.; Waller, C.; Asimow, P. D.

    2010-12-01

    Experiments using the sink/float method have bracketed the density of molten hedenbergite (CaFeSi2O6) at high pressures and temperatures. The experiments are the first of their kind to determine the compressibility of molten hedenbergite at high pressure and are part of a collaborative effort to establish a new database for an array of silicate melt compositions, which will contribute to the development of an empirically based predictive model that will allow calculation of silicate liquid density and compressibility over a wide range of P-T-X conditions where melting could occur in the Earth. Each melt composition will be measured using: (i) double-bob Archimedean method for melt density and thermal expansion at ambient pressure, (ii) sound speed measurements on liquids to constrain melt compressibility at ambient pressure, (iii) sink/float technique to measure melt density to 15 GPa, and (iv) shock wave measurements of P-V-E equation of state and temperature between 10 and 150 GPa. Companion abstracts on molten fayalite (Waller et al., 2010) and liquid mixes of hedenbergite-diopside and anorthite-hedenbergite-diopside (Guo and Lange, 2010) are also presented at this meeting. In the present study, the hedenbergite starting material was synthesized at the Experimental Petrology Lab, University of Michigan, where melt density, thermal expansion, and sound speed measurements were also carried out. The starting material has also been loaded into targets at the Caltech Shockwave Lab, and experiments there are currently underway. We report here preliminary results from static compression measurement performed at the Department of Petrology, Vrije Universiteit, Amsterdam, and the High Pressure Lab, Institute of Meteoritics, University of New Mexico. Experiments were carried out in Quick Press piston-cylinder devices and a Walker-style multi-anvil device. Sink/float marker spheres implemented were gem quality synthetic forsterite (Fo100), San Carlos olivine (Fo90), and

  13. High blood pressure and visual sensitivity

    Science.gov (United States)

    Eisner, Alvin; Samples, John R.

    2003-09-01

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

  14. Method transfer from high-pressure liquid chromatography to ultra-high-pressure liquid chromatography. II. Temperature and pressure effects.

    Science.gov (United States)

    Åsberg, Dennis; Samuelsson, Jörgen; Leśko, Marek; Cavazzini, Alberto; Kaczmarski, Krzysztof; Fornstedt, Torgny

    2015-07-03

    The importance of the generated temperature and pressure gradients in ultra-high-pressure liquid chromatography (UHPLC) are investigated and compared to high-pressure liquid chromatography (HPLC). The drug Omeprazole, together with three other model compounds (with different chemical characteristics, namely uncharged, positively and negatively charged) were used. Calculations of the complete temperature profile in the column at UHPLC conditions showed, in our experiments, a temperature difference between the inlet and outlet of 16 °C and a difference of 2 °C between the column center and the wall. Through van't Hoff plots, this information was used to single out the decrease in retention factor (k) solely due to the temperature gradient. The uncharged solute was least affected by temperature with a decrease in k of about 5% while for charged solutes the effect was more pronounced, with k decreases up to 14%. A pressure increase of 500 bar gave roughly 5% increase in k for the uncharged solute, while omeprazole and the other two charged solutes gave about 25, 20 and 15% increases in k, respectively. The stochastic model of chromatography was applied to estimate the dependence of the average number of adsorption/desorption events (n) and the average time spent by a molecule in the stationary phase (τs) on temperature and pressure on peak shape for the tailing, basic solute. Increasing the temperature yielded an increase in n and decrease in τs which resulted in less skew at high temperatures. With increasing pressure, the stochastic modeling gave interesting results for the basic solute showing that the skew of the peak increased with pressure. The conclusion is that pressure effects are more pronounced for both retention and peak shape than the temperature effects for the polar or charged compounds in our study. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Thermal Plasma Spheroidization of High-Nitrogen Stainless Steel Powder Alloys Synthesized by Mechanical Alloying

    Science.gov (United States)

    Razumov, Nikolay G.; Popovich, Anatoly A.; Wang, QingSheng

    2018-03-01

    This paper presents the results of experimental studies on the treatment of Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys, synthesized by the mechanical alloying (MA) of elemental powders in the flow of a thermal plasma. Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys were prepared by MA in the attritor under an argon atmosphere. For spheroidization of Fe-23Cr-11Mn-1N high-nitrogen stainless steel powder alloys, the TekSphero 15 plant manufactured by Tekna Plasma Systems Inc was used. The studies have shown the possibility of obtaining Fe-23Cr-11Mn-1N high-nitrogen spherical powders steel alloys from the powder obtained by MA. According to the results of a series of experiments, it was found that the results of plasma spheroidization of powders essentially depend on the size of the fraction due to some difference in the particle shape and flowability, and on the gas regime of the plasma torch. It is established that during the plasma spheroidization process, some of the nitrogen leaves the alloy. The loss rate of nitrogen depends on the size of the initial particles.

  16. HIGH YIELD AND RAPID SYNTHESES METHODS FOR PRODUCING METALLO-ORGANIC SALTS

    DEFF Research Database (Denmark)

    2005-01-01

    A new method for preparing salts of metal cations and organic acids, especially divalent salts of alkaline earth metal ions from group II of the periodic system and carboxylic acids. The method comprising the use of a high temperature (about 90° or more) and, optionally. high pressure, in order...... to obtain a higher yield, purity and faster reaction speed than obtained with known synthesis methods. In particular, the present invention relates to the production of strontium salts of carboxylic acids. Novel strontium salts are also provided by the present method....

  17. The compact mirrors with high pressure plasmas

    International Nuclear Information System (INIS)

    Anikeev, A.V.; Bagryansky, P.A.; Ivanov, A.A.; Lizunov, A.A.; Murakhtin, S.V.; Prikhodko, V.V.; Collatz, S.; Noack, K.

    2004-01-01

    The gas dynamic trap (GDP) experimental facility at the Budker Institute Novosibirsk is a long axial-symmetric mirror system with a high mirror ratio variable in the range of 12.5 - 100 for the confinement of a two-component plasma. One component is a collisional plasma with ion and electron temperatures up to 100 eV and density up to 10 14 cm -3 . The second component is the population of high-energetic fast ions with energies of 2-18 keV and a density up to 10 13 cm -3 which is produced by neutral beam injection (NBI). GDP is currently undergoing an upgrade whose first stage is the achievement of the synthesized hot ion plasmoid experiment (SHIP). This experiment aims at the investigation of plasmas and at the knowledge of plasma parameters that have never been achieved before in magnetic mirrors. The paper presents the physical concept of the SHIP experiment, the results of numerical pre-calculations and draws conclusions regarding possible scenarios of experiments. The simulation of a maximal NBI power regime with hydrogen injection gave a fast ion density of 1.2*10 14 cm -3 with a mean energy of 14 keV. The calculation of the deuterium injection regime with 2 MW NBI power gave a maximal fast ion density of 1.9*10 14 cm -3 with a beam energy of 9 keV. The calculation of an experimental scenario with reduced magnetic field resulted in a maximal β-value of 62%, so this regime is recommended for the study of high-β effects in plasmas confined in axial-symmetric mirrors

  18. Food processing by high hydrostatic pressure.

    Science.gov (United States)

    Yamamoto, Kazutaka

    2017-04-01

    High hydrostatic pressure (HHP) process, as a nonthermal process, can be used to inactivate microbes while minimizing chemical reactions in food. In this regard, a HHP level of 100 MPa (986.9 atm/1019.7 kgf/cm 2 ) and more is applied to food. Conventional thermal process damages food components relating color, flavor, and nutrition via enhanced chemical reactions. However, HHP process minimizes the damages and inactivates microbes toward processing high quality safe foods. The first commercial HHP-processed foods were launched in 1990 as fruit products such as jams, and then some other products have been commercialized: retort rice products (enhanced water impregnation), cooked hams and sausages (shelf life extension), soy sauce with minimized salt (short-time fermentation owing to enhanced enzymatic reactions), and beverages (shelf life extension). The characteristics of HHP food processing are reviewed from viewpoints of nonthermal process, history, research and development, physical and biochemical changes, and processing equipment.

  19. Observation of high coercive fields in chemically synthesized coated Fe-Pt nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Dalavi, Shankar B.; Panda, Rabi N., E-mail: rnp@goa.bits-pilani.ac.in

    2017-04-15

    Nanocrystalline Fe-Pt alloys have been synthesized via chemical reduction route using various capping agents; such as: oleic acid/oleylamine (route-1) and oleic acid/CTAB (route-2). We could able to synthesize Fe50Pt and Fe54Pt alloys via route 1 and 2, respectively. As-prepared Fe-Pt alloys crystallize in disordered fcc phase with crystallite sizes of 2.3 nm and 6 nm for route-1 and route-2, respectively. Disordered Fe-Pt alloys were transformed to ordered fct phase after annealing at 600 °C. SEM studies confirm the spherical shape morphologies of annealed Fe-Pt nanoparticles with SEM particle sizes of 24.4 nm and 21.2 nm for route-1 and route-2, respectively. TEM study confirms the presence of 4.6 nm particles for annealed Fe50Pt alloys with several agglomerating clusters of bigger size and appropriately agrees well with the XRD study. Room temperature magnetization studies of as-prepared Fe-Pt alloys (fcc) show ferromagnetism with negligible coercivities. Average magnetic moments per particle for as-prepared Fe-Pt alloys were estimated to be 753 μ{sub B} and 814 μ{sub B}, for route 1 and 2, respectively. Ordered fct Fe-Pt alloys show high values of coercivities of 10,000 Oe and 10,792 Oe for route-1 and route-2, respectively. Observed magnetic properties of the fct Fe-Pt alloys nps were interpreted with the basis of order parameters, size, surface, and composition effects. - Highlights: • Synthesis of capped nanocrystalline Fe-Pt alloys via chemical routes. • Ordered fct phase were obtained at 600 °C. • Microstructural studies were carried out using SEM and TEM. • Investigation on evolution of magnetic properties from fcc to fct state. • Maximum values of coercivities up to 10,792 Oe were observed.

  20. Rheological assessment of nanofluids at high pressure high temperature

    Science.gov (United States)

    Kanjirakat, Anoop; Sadr, Reza

    2013-11-01

    High pressure high temperature (HPHT) fluids are commonly encountered in industry, for example in cooling and/or lubrications applications. Nanofluids, engineered suspensions of nano-sized particles dispersed in a base fluid, have shown prospective as industrial cooling fluids due to their enhanced rheological and heat transfer properties. Nanofluids can be potentially utilized in oil industry for drilling fluids and for high pressure water jet cooling/lubrication in machining. In present work rheological characteristics of oil based nanofluids are investigated at HPHT condition. Nanofluids used in this study are prepared by dispersing commercially available SiO2 nanoparticles (~20 nm) in a mineral oil. The basefluid and nanofluids with two concentrations, namely 1%, and 2%, by volume, are considered in this investigation. The rheological characteristics of base fluid and the nanofluids are measured using an industrial HPHT viscometer. Viscosity values of the nanofluids are measured at pressures of 100 kPa to 42 MPa and temperatures ranging from 25°C to 140°C. The viscosity values of both nanofluids as well as basefluid are observed to have increased with the increase in pressure. Funded by Qatar National Research Fund (NPRP 08-574-2-239).

  1. Synthesis of copolymerized porous organic frameworks with high gas storage capabilities at both high and low pressures

    KAUST Repository

    Pei, Cuiying

    2014-01-01

    A series of copolymerized porous organic frameworks (C-POFs) were synthesized with monomers of tetrakis(4-bromophenyl)methane and tris(4-bromophenyl)amine in different ratios by a Yamamoto-type Ullmann cross-coupling reaction. These C-POFs exhibit high physicochemical stability, large surface areas and excellent H2, CH4 and CO 2 adsorption properties both at low and high pressures. This journal is © the Partner Organisations 2014.

  2. Chemically synthesized metal-oxide-metal segmented nanowires with high ferroelectric response

    Energy Technology Data Exchange (ETDEWEB)

    Herderick, Edward D; Padture, Nitin P [Department of Materials Science and Engineering, Center for Emergent Materials, Ohio State University, Columbus, OH 43210 (United States); Polomoff, Nicholas A; Huey, Bryan D, E-mail: padture.1@osu.edu [Department of Chemical, Materials, and Biomolecular Engineering, Institute of Materials Science, University of Connecticut, Storrs, CT 06269 (United States)

    2010-08-20

    A chemical synthesis method is presented for the fabrication of high-definition segmented metal-oxide-metal (MOM) nanowires in two different ferroelectric oxide systems: Au-BaTiO{sub 3}-Au and Au-PbTiO{sub 3}-Au. This method entails electrodeposition of segmented nanowires of Au-TiO{sub 2}-Au inside anodic aluminum oxide (AAO) templates, followed by topotactic hydrothermal conversion of the TiO{sub 2} segments into BaTiO{sub 3} or PbTiO{sub 3} segments. Two-terminal devices from individual MOM nanowires are fabricated, and their ferroelectric properties are measured directly, without the aid of scanning probe microscopy (SPM) methods. The MOM nanowire architecture provides high-quality end-on electrical contacts to the oxide segments, and allows direct measurement of properties of nanoscale volume, strain-free oxide segments. Unusually high ferroelectric responses, for chemically synthesized oxides, in these MOM nanowires are reported, and are attributed to the lack of residual strain in the oxides. The ability to measure directly the active properties of nanoscale volume, strain-free oxides afforded by the MOM nanowire architecture has important implications for fundamental studies of not only ferroelectric nanostructures but also nanostructures in the emerging field of multiferroics.

  3. Chemically synthesized metal-oxide-metal segmented nanowires with high ferroelectric response

    International Nuclear Information System (INIS)

    Herderick, Edward D; Padture, Nitin P; Polomoff, Nicholas A; Huey, Bryan D

    2010-01-01

    A chemical synthesis method is presented for the fabrication of high-definition segmented metal-oxide-metal (MOM) nanowires in two different ferroelectric oxide systems: Au-BaTiO 3 -Au and Au-PbTiO 3 -Au. This method entails electrodeposition of segmented nanowires of Au-TiO 2 -Au inside anodic aluminum oxide (AAO) templates, followed by topotactic hydrothermal conversion of the TiO 2 segments into BaTiO 3 or PbTiO 3 segments. Two-terminal devices from individual MOM nanowires are fabricated, and their ferroelectric properties are measured directly, without the aid of scanning probe microscopy (SPM) methods. The MOM nanowire architecture provides high-quality end-on electrical contacts to the oxide segments, and allows direct measurement of properties of nanoscale volume, strain-free oxide segments. Unusually high ferroelectric responses, for chemically synthesized oxides, in these MOM nanowires are reported, and are attributed to the lack of residual strain in the oxides. The ability to measure directly the active properties of nanoscale volume, strain-free oxides afforded by the MOM nanowire architecture has important implications for fundamental studies of not only ferroelectric nanostructures but also nanostructures in the emerging field of multiferroics.

  4. Characterization of dip-coated ITO films derived from nanoparticles synthesized by low-pressure spray pyrolysis

    International Nuclear Information System (INIS)

    Ogi, Takashi; Iskandar, Ferry; Itoh, Yoshifumi; Okuyama, Kikuo

    2006-01-01

    In 2 O 3 :Sn (Indium Tin Oxide; ITO) films were prepared from a sol solution with highly crystalline ITO nanoparticles (less than 20 nm in size with 10 at.% Sn) which had been prepared by low-pressure spray pyrolysis (LPSP) in a single step. The ITO sol solution was prepared by dispersing LPSP-prepared ITO nanoparticles into ultra pure water. The nanoparticle ITO film was deposited on a glass substrate using a dip-coating method and then annealed in air at various temperatures. The optical transmittances of the ITO films were measured by UV-Vis spectrometry, and the films were found to have a high transparency to visible light (in the case of a film thickness of 250 nm annealed at 400 deg. C, the transparency was in excess of 95% over the range λ=450-800 nm, with a maximum value near 100% at wavelengths above λ=700 nm). The optical transmittances of the films were influenced by the size of the ITO particle used, the film thickness and the annealing temperature. The ITO films showed a minimum resistivity of 9.5x10 -2 Ω cm, and their resistivity was affected by both the ITO particle size and the annealing temperature used

  5. Engineering Model of High Pressure Moist Air

    Directory of Open Access Journals (Sweden)

    Hyhlík Tomáš

    2017-01-01

    Full Text Available The article deals with the moist air equation of state. There are equations of state discussed in the article, i.e. the model of an ideal mixture of ideal gases, the model of an ideal mixture of real gases and the model based on the virial equation of state. The evaluation of sound speed based on the ideal mixture concept is mentioned. The sound speed calculated by the model of an ideal mixture of ideal gases is compared with the sound speed calculated by using the model based on the concept of an ideal mixture of real gases. The comparison of enthalpy end entropy based on the model of an ideal mixture of ideal gases and the model of an ideal mixture of real gases is performed. It is shown that the model of an ideal mixture of real gases deviates from the model of an ideal mixture of ideal gases only in the case of high pressure. An impossibility of the definition of partial pressure in the mixture of real gases is discussed, where the virial equation of state is used.

  6. [High blood pressure and physical exercise].

    Science.gov (United States)

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

    2014-06-01

    High blood pressure is a frequent pathology with many cardiovascular complications. As highlighted in guidelines, the therapeutic management of hypertension relies on non-pharmacological measures, which are diet and regular physical activity, but both patients and physicians are reluctant to physical activity prescription. To acquire the conviction that physical activity is beneficial, necessary and possible, we can take into account some fundamental and clinical studies, as well as the feedback of our clinical practice. Physical inactivity is a major risk factor for cardiovascular morbidity and mortality, and hypertension contributes to increase this risk. Conversely, regular practice of physical activity decreases very significantly the risk by up to 60%. The acute blood pressure changes during exercise and post-exercise hypotension differs according to the dynamic component (endurance or aerobic and/or strength exercises), but the repetition of the sessions leads to the chronic hypotensive benefit of physical activity. Moreover, physical activity prescription must take into account the assessment of global cardiovascular risk, the control of the hypertension, and the opportunities and desires of the patient in order to promote good adherence and beneficial lifestyle change. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. High pressure fiber optic sensor system

    Science.gov (United States)

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

    2013-11-26

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

  8. Highly biocompatible, nanocrystalline hydroxyapatite synthesized in a solvothermal process driven by high energy density microwave radiation

    Science.gov (United States)

    Smolen, Dariusz; Chudoba, Tadeusz; Malka, Iwona; Kedzierska, Aleksandra; Lojkowski, Witold; Swieszkowski, Wojciech; Kurzydlowski, Krzysztof Jan; Kolodziejczyk-Mierzynska, Małgorzata; Lewandowska-Szumiel, Małgorzata

    2013-01-01

    A microwave, solvothermal synthesis of highly biocompatible hydroxyapatite (HAp) nanopowder was developed. The process was conducted in a microwave radiation field having a high energy density of 5 W/mL and over a time less than 2 minutes. The sample measurements included: powder X-ray diffraction, density, specific surface area, and chemical composition. The morphology and structure were investigated by scanning electron microscopy as well as transmission electron microscopy (TEM). The thermal behavior analysis was conducted using a simultaneous thermal analysis technique coupled with quadruple mass spectrometry. Additionally, Fourier transform infrared spectroscopy tests of heated samples were performed. A degradation test and a biocompatibility study in vitro using human osteoblast cells were also conducted. The developed method enables the synthesis of pure, fully crystalline hexagonal HAp nanopowder with a specific surface area close to 240 m2/g and a Ca/P molar ratio equal to 1.57. TEM measurements showed that this method results in particles with an average grain size below 6 nm. A 28-day degradation test conducted according to the ISO standard indicated a 22% loss of initial weight and a calcium ion concentration at 200 μmol/dm3 in the tris(hydroxymethyl)aminomethane hydrochloride test solution. The cytocompatibility of the obtained material was confirmed in a culture of human bone derived cells, both in an indirect test using the material extract, and in direct contact. A quantitative analysis was based on the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide. Viability assay as well as on DNA content measurements in the PicoGreen test. Indirect observations were performed at one point in time according to the ISO standard for in vitro cytotoxicity (ie, after 24 hours of cell exposure to the extracts). The direct contact tests were completed at three time points: after 24 hours, on day 7, and on day 14 of a culture in an osteogenic

  9. Computer simulations of high pressure systems

    International Nuclear Information System (INIS)

    Wilkins, M.L.

    1977-01-01

    Numerical methods are capable of solving very difficult problems in solid mechanics and gas dynamics. In the design of engineering structures, critical decisions are possible if the behavior of materials is correctly described in the calculation. Problems of current interest require accurate analysis of stress-strain fields that range from very small elastic displacement to very large plastic deformation. A finite difference program is described that solves problems over this range and in two and three space-dimensions and time. A series of experiments and calculations serve to establish confidence in the plasticity formulation. The program can be used to design high pressure systems where plastic flow occurs. The purpose is to identify material properties, strength and elongation, that meet the operating requirements. An objective is to be able to perform destructive testing on a computer rather than on the engineering structure. Examples of topical interest are given

  10. Urea and deuterium mixtures at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, M., E-mail: m.donnelly-2@sms.ed.ac.uk; Husband, R. J.; Frantzana, A. D.; Loveday, J. S. [Centre for Science at Extreme Conditions and School of Physics and Astronomy, The University of Edinburgh, Erskine Williamson Building, Peter Guthrie Tait Road, The King’s Buildings, Edinburgh EH9 3FD (United Kingdom); Bull, C. L. [ISIS, Rutherford Appleton Laboratory, Oxford Harwell, Didcot OX11 0QX (United Kingdom); Klotz, S. [IMPMC, CNRS UMR 7590, Université P and M Curie, 4 Place Jussieu, 75252 Paris (France)

    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.

  11. Recent developments in high pressure water technology

    International Nuclear Information System (INIS)

    Johnson, N.A.; Johnson, T.

    1992-01-01

    High Pressure Water Jetting has advanced rapidly in the last decade to a point where the field is splitting into specialised areas. This has left the end user or client in the dark as to whether water jetting will work and if so what equipment is best suited to their particular application. The aim of this paper is to give an overview of:-1. The way water is delivered to the surface and the parameters which control the concentration of energy available on impact. 2. The factors governing application driven selection of equipment. 3. The effects to technical advances in pumps and delivery systems on equipment selection with reference to their to their application to concrete removal and nuclear decontamination. (Author)

  12. High-pressure structures of methane hydrate

    International Nuclear Information System (INIS)

    Hirai, H; Uchihara, Y; Fujihisa, H; Sakashita, M; Katoh, E; Aoki, K; Yamamoto, Y; Nagashima, K; Yagi, T

    2002-01-01

    Three high-pressure structures of methane hydrate, a hexagonal structure (str. A) and two orthorhombic structures (str. B and str. C), were found by in situ x-ray diffractometry and Raman spectroscopy. The well-known structure I (str. I) decomposed into str. A and fluid at 0.8 GPa. Str. A transformed into str. B at 1.6 GPa, and str. B further transformed into str. C at 2.1 GPa which survived above 7.8 GPa. The fluid solidified as ice VI at 1.4 GPa, and the ice VI transformed to ice VII at 2.1 GPa. The bulk moduli, K 0 , for str. I, str. A, and str. C were calculated to be 7.4, 9.8, and 25.0 GPa, respectively

  13. High Pressure Quick Disconnect Particle Impact Tests

    Science.gov (United States)

    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

  14. A Nutritional Strategy for the Treatment of High Blood Pressure.

    Science.gov (United States)

    Podell, Richard N.

    1984-01-01

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

  15. Stress and High Blood Pressure: What's the Connection?

    Science.gov (United States)

    Stress and high blood pressure: What's the connection? Stress and long-term high blood pressure may not be linked, but taking steps to reduce your stress can improve your general health, including your blood ...

  16. High blood pressure - what to ask your doctor

    Science.gov (United States)

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

  17. High Blood Pressure, Afib and Your Risk of Stroke

    Science.gov (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More High Blood Pressure, AFib and Your Risk of Stroke Updated:Aug ... have a stroke for the first time have high blood pressure . And an irregular atrial heart rhythm — a condition ...

  18. Effect of high pressure on mesophilic lactic fermentation streptococci

    Energy Technology Data Exchange (ETDEWEB)

    Reps, A; Kuzmicka, M; Wisniewska, K [Chair of Food Biotechnology, University of Warmia and Mazury, ul. Heweliusza 1, 10-724 Olsztyn (Poland)], E-mail: arnold.reps@uwm.edu.pl

    2008-07-15

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

  19. Novel high pressure hexagonal OsB2 by mechanochemistry

    Science.gov (United States)

    Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

    2014-07-01

    Hexagonal OsB2, a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from -225 °C to 1050 °C. The hexagonal OsB2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods.

  20. Subnanosecond breakdown in high-pressure gases

    Science.gov (United States)

    Naidis, George V.; Tarasenko, Victor F.; Babaeva, Natalia Yu; Lomaev, Mikhail I.

    2018-01-01

    Pulsed discharges in high-pressure gases are of considerable interest as sources of nonequilibrium plasma for various technological applications: pollution control, pumping of laser media, plasma-assisted combustion, etc. Recently, attention has been attracted to the use of subnanosecond voltage fronts, producing diffuse discharges with radii of several millimeters. Such plasma structures, similar to pulsed glow discharges, are of special interest for applications due to quasi-uniformity of plasma parameters in relatively large gas volumes. This review presents the results of experimental and computational study of subnanosecond diffuse discharge formation. A description of generators of short high-voltage pulses with subnanosecond fronts and of discharge setups is given. Diagnostic methods for the measurement of various discharge parameters with high temporal and spatial resolution are described. Obtained experimental data on plasma properties for a wide range of governing factors are discussed. A review of various theoretical approaches used for computational study of the dynamics and structure of fast ionization waves is given; the applicability of conventional fluid streamer models for simulation of subnanosecond ionization waves is discussed. Calculated spatial-temporal profiles of plasma parameters during streamer propagation are presented. The efficiency of subnanosecond discharges for the production of reactive species is evaluated. On the basis of the comparison of simulation results and experimental data the effects of various factors (voltage rise time, polarity, etc.) on discharge characteristics are revealed. The major physical phenomena governing the properties of subnanosecond breakdown are analyzed.

  1. High pressure apparatus transport properties study in high magnetic field

    Czech Academy of Sciences Publication Activity Database

    Honda, F.; Sechovský, V.; Mikulina, O.; Kamarád, Jiří; Alsmadi, A. M.; Nakotte, H.; Lacerda, A. H.

    2002-01-01

    Roč. 16, 20, 21 & 22 (2002), s. 3330-3333 ISSN 0217-9792 R&D Projects: GA ČR GP202/01/D045; GA ČR GA202/00/1217; GA MŠk ME 165 Grant - others:NSF(XX) DMR-0094241 Institutional research plan: CEZ:AV0Z1010914 Keywords : high-pressure apparatus Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.604, year: 2002

  2. 30 CFR 56.13021 - High-pressure hose connections.

    Science.gov (United States)

    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 high-pressure...

  3. 76 FR 38697 - High Pressure Steel Cylinders From China

    Science.gov (United States)

    2011-07-01

    ... imports from China of high pressure steel cylinders, provided for in subheading 7311.00.00 of the... threatened with material injury by reason of LTFV and subsidized imports of high pressure steel cylinders... contained in USITC Publication 4241 (July 2011), entitled High Pressure Steel Cylinders from China...

  4. 77 FR 37712 - High Pressure Steel Cylinders From China

    Science.gov (United States)

    2012-06-22

    ...), that an industry in the United States is materially injured by reason of imports of high pressure steel... preliminary determinations by Commerce that imports of high pressure steel cylinders from China were... Publication 4328 (June 2012), entitled High Pressure Steel Cylinders from China: Investigation Nos. 701-TA-480...

  5. Development of manufacturing method of thermal-resisting concrete with highly synthesizing xonotolite

    International Nuclear Information System (INIS)

    Yamamoto, Takeshi; Hironaga, Michihiko

    2006-01-01

    Xonotolite is one of the most stable Ca-Si hydration compounds in the cementitious material. The authors have been developing anti-drying shrinkage concrete with focusing on the stable compounds, i.e. Tobermorite and Xonotolite. In this study, we proposed the manufacturing method of anti-drying shrinkage concrete with using low calcium/silica ratio cementitious material and applying autoclave curing. The compressive strength of proposed concrete was about 40N/mm 2 , and drying shrinkage under 110degC for 1 year was ranged from 0.04 to 0.06%. There was no amount released of combined water from the proposed concrete during exposure, so the stability of main synthesized compound in the proposed concrete was clarified. On the other hand, the conventional cementitious mortar showed from 0.1 to 0.13% of drying shrinkage and high amount release of combined water from the surface area of C-S-H colloid with resulting to widen the volume of pore among the colloid particle of C-S-H. (author)

  6. Highly Luminescent, Water-Soluble Lanthanide Fluorobenzoates: Syntheses, Structures and Photophysics, Part I: Lanthanide Pentafluorobenzoates.

    Science.gov (United States)

    Kalyakina, Alena S; Utochnikova, Valentina V; Bushmarinov, Ivan S; Ananyev, Ivan V; Eremenko, Igor L; Volz, Daniel; Rönicke, Franziska; Schepers, Ute; Van Deun, Rik; Trigub, Alexander L; Zubavichus, Yan V; Kuzmina, Natalia P; Bräse, Stefan

    2015-12-01

    Highly luminescent, photostable, and soluble lanthanide pentafluorobenzoates have been synthesized and thoroughly characterized, with a focus on Eu(III) and Tb(III) complexes as visible emitters and Nd(III) , Er(III) , and Yb(III) complexes as infrared emitters. Investigation of the crystal structures of the complexes in powder form and as single crystals by using X-ray diffraction revealed five different structural types, including monomeric, dimeric, and polymeric. The local structure in different solutions was studied by using X-ray absorption spectroscopy. The photoluminescence quantum yields (PLQYs) of terbium and europium complexes were 39 and 15 %, respectively; the latter value was increased almost twice by using the heterometallic complex [Tb0.5 Eu0.5 (pfb)3 (H2 O)] (Hpfb=pentafluorobenzoic acid). Due to the effectively utilized sensitization strategy (pfb)(-) →Tb→Eu, a pure europium luminescence with a PLQY of 29 % was achieved. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Generation of Bright, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses.

    Science.gov (United States)

    Jin, Cheng; Stein, Gregory J; Hong, Kyung-Han; Lin, C D

    2015-07-24

    We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser pulses, optimized such that highest harmonic yields are emitted from each atom. Optimization of the gas pressure and waveguide configuration has enabled us to produce bright and spatially coherent harmonics extending from the extreme ultraviolet to soft x rays. Our study on the interplay among waveguide mode, atomic dispersion, and plasma effect uncovers how dynamic phase matching is accomplished and how an optimized waveform is maintained when optimal waveguide parameters (radius and length) and gas pressure are identified. Our analysis should help laboratory development in the generation of high-flux bright coherent soft x rays as tabletop light sources for applications.

  8. Novel composite materials synthesized by the high-temperature interaction of pyrrole with layered oxide matrices

    Science.gov (United States)

    Pavel, Alexandru Cezar

    The initial goal of the research presented herein was to develop the very first synthetic metal---high-temperature superconductor ceramic composite material, in the specific form of a polypyrrole---Bi2Sr2CaCu 2O8+delta nanocomposite. In the course of scientific investigation, this scope was broadened to encompass structurally and compositionally similar layered bismuthates and simpler layered oxides. The latter substrates were prepared through novel experimental procedures that enhanced the chance of yielding nanostructured morphologies. The designed novel synthesis approaches yielded a harvest of interesting results that may be further developed upon their dissemination in the scientific community. High-temperature interaction of pyrrole with molybdenum trioxide substrates with different crystalline phases and morphologies led to the formation of the first members of a new class of heterogeneous microcomposites characterized by incomplete occupancy by the metal oxide core of the volume encapsulated by the rigid, amorphous permeable polymeric membrane that reproduces the volume of the initial grain of precursor substrate. The method may be applied for various heterogeneous catalyst substrates for the precise determination of the catalytically active crystallographic planes. In a different project, room-temperature, templateless impregnation of molybdenum trioxide substrates with different crystalline phases and morphologies by a large excess of silver (I) cations led to the formation of 1-D nanostructured novel Ag-Mo-O ternary phase in what may be the simplest experimental procedure available to date that has yielded a 1-D nanostructure, regardless the nature of the constituent material. Interaction of this novel ternary phase with pyrrole vapors at high reaction temperatures led to heterogeneous nanostructured composites that exhibited a silver nanorod core. Nanoscrolls of vanadium pentoxide xerogel were synthesized through a novel, facile reflux-based method that

  9. a Thz Photomixing Synthesizer Based on a Fiber Frequency Comb for High Resolution Rotational Spectroscopy

    Science.gov (United States)

    Hindle, Francis; Mouret, Gael; Cuisset, Arnaud; Yang, Chun; Eliet, Sophie; Bocquet, Robin

    2010-06-01

    To date the principal application for photomixing sources has been for high resolution spectroscopy of gases due to the large tuning range and spectral purity. New Developments of the Opto-Electronic THz Spectrometer have been performed in order to obtain a powerful tool for High-Resolution Spectroscopy. The combination of two extended cavity laser diodes and fast charge carrier lifetime semiconductor materials has allowed a continuous-wave THz spectrometer to be constructed based on optical heterodyning. Unlike many THz sources, this instrument gives access to all frequencies in the range 0.3 to 3.5 THz with a resolution of 1 MHz. The main spectroscopic applications of this spectrometer were dedicated to line profile analysis of rotational transitions referenced in the spectroscopic databases. One limitation of the THz spectrometer was accuracy with which the generated frequency is known. Recently, this obstacle has been circled with the construction of a photomixing spectrometer where the two pump lasers are phase locked to two modes of a repetition rate stabilized frequency doubled fiber laser frequency comb. In order to achieve a tuning range in excess to 100 MHz a third cw laser was required in the new configuration of the THz spectrometer. To assess the performances of this instrument, the frequencies of the pure rotational transitions of OCS molecules have been measured between 0,8 to 1,2 THz. A rms inferior to 100 kHz, deduced from the frequencies measured, demonstrates that the THz photomixing synthesizer is now able to be competitive with microwave and submillimeter techniques. S. Matton, F. Rohart, R. Bocquet, D. Bigourd, A. Cuisset, F. Hindle, G. Mouret, J. Mol. Spectrosc., 2006, 239: 182. C. Yang, J. Buldyreva, I. E. Gordon, F. Rohart, A. Cuisset, G. Mouret, R. Bocquet, F. Hindle, J. Quant. Spectrosc. Radiat. Transfer, 2008, 109: 2857. G. Mouret, F. Hindle, A. Cuisset, C. Yang, R. Bocquet, M. Lours, D. Rovera, Opt. Express, 2009, 17: 22031.

  10. Single stage high pressure centrifugal slurry pump

    Science.gov (United States)

    Meyer, John W.; Bonin, John H.; Daniel, Arnold D.

    1984-03-27

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

  11. Recombination times in germanium under high pressure

    International Nuclear Information System (INIS)

    Kuyt, J.H.

    1975-01-01

    The influence of pressure on a well defined recombination process was studied. The centres were introduced by γirradiation and the lifetime determined by the decay time of photoconductivity. An optical pressure vessel is described which allows for a hydrostatic variation of 3000 bars. The diffusion constant and lifetime measurements are presented and analysed. (V.J.C.)

  12. High Pressure Laminates with Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    Sandra Magina

    2016-02-01

    Full Text Available High-pressure laminates (HPLs are durable, resistant to environmental effects and good cost-benefit decorative surface composite materials with special properties tailored to meet market demand. In the present work, polyhexamethylene biguanide (PHMB was incorporated for the first time into melamine-formaldehyde resin (MF matrix on the outer layer of HPLs to provide them antimicrobial properties. Chemical binding of PHMB to resin matrix was detected on the surface of produced HPLs by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR. Antimicrobial evaluation tests were carried out on the ensuing HPLs doped with PHMB against gram-positive Listeria innocua and gram-negative Escherichia coli bacteria. The results revealed that laminates prepared with 1.0 wt % PHMB in MF resin were bacteriostatic (i.e., inhibited the growth of microorganisms, whereas those prepared with 2.4 wt % PHMB in MF resin exhibited bactericidal activity (i.e., inactivated the inoculated microorganisms. The results herein reported disclose a promising strategy for the production of HPLs with antimicrobial activity without affecting basic intrinsic quality parameters of composite material.

  13. Automated high pressure cell for pressure jump x-ray diffraction.

    Science.gov (United States)

    Brooks, Nicholas J; Gauthe, Beatrice L L E; Terrill, Nick J; Rogers, Sarah E; Templer, Richard H; Ces, Oscar; Seddon, John M

    2010-06-01

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

  14. Automated high pressure cell for pressure jump x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  15. Automated high pressure cell for pressure jump x-ray diffraction

    International Nuclear Information System (INIS)

    Brooks, Nicholas J.; Gauthe, Beatrice L. L. E.; Templer, Richard H.; Ces, Oscar; Seddon, John M.; Terrill, Nick J.; Rogers, Sarah E.

    2010-01-01

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

  16. High cost of stage IV pressure ulcers.

    Science.gov (United States)

    Brem, Harold; Maggi, Jason; Nierman, David; Rolnitzky, Linda; Bell, David; Rennert, Robert; Golinko, Michael; Yan, Alan; Lyder, Courtney; Vladeck, Bruce

    2010-10-01

    The aim of this study was to calculate and analyze the cost of treatment for stage IV pressure ulcers. A retrospective chart analysis of patients with stage IV pressure ulcers was conducted. Hospital records and treatment outcomes of these patients were followed up for a maximum of 29 months and analyzed. Costs directly related to the treatment of pressure ulcers and their associated complications were calculated. Nineteen patients with stage IV pressure ulcers (11 hospital-acquired and 8 community-acquired) were identified and their charts were reviewed. The average hospital treatment cost associated with stage IV pressure ulcers and related complications was $129,248 for hospital-acquired ulcers during 1 admission, and $124,327 for community-acquired ulcers over an average of 4 admissions. The costs incurred from stage IV pressure ulcers are much greater than previously estimated. Halting the progression of early stage pressure ulcers has the potential to eradicate enormous pain and suffering, save thousands of lives, and reduce health care expenditures by millions of dollars. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Sleep Deprivation: A Cause of High Blood Pressure?

    Science.gov (United States)

    ... it true that sleep deprivation can cause high blood pressure? Answers from Sheldon G. Sheps, M.D. Possibly. It's thought that ... hours a night could be linked to increased blood pressure. People who sleep five hours or less a ...

  18. High Pressure Electrochemical Oxygen Generation for ISS, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Giner, Inc. has developed an advanced high pressure electrochemical oxygen concentrator (EOC) that offers a simple alternative to the use of pressure swing...

  19. High-temperature fiber optic pressure sensor

    Science.gov (United States)

    Berthold, J. W.

    1984-01-01

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

  20. Novel high pressure hexagonal OsB2 by mechanochemistry

    International Nuclear Information System (INIS)

    Xie, Zhilin; Graule, Moritz; Orlovskaya, Nina; Andrew Payzant, E.; Cullen, David A.; Blair, Richard G.

    2014-01-01

    Hexagonal OsB 2 , a theoretically predicted high-pressure phase, has been synthesized for the first time by a mechanochemical method, i.e., high energy ball milling. X-ray diffraction indicated that formation of hexagonal OsB 2 begins after 2.5 h of milling, and the reaction reaches equilibrium after 18 h of milling. Rietveld refinement of the powder data indicated that hexagonal OsB 2 crystallizes in the P63/mmc space group (No. 194) with lattice parameters of a=2.916 Å and c=7.376 Å. Transmission electron microscopy confirmed the appearance of the hexagonal OsB 2 phase after high energy ball milling. in situ X-ray diffraction experiments showed that the phase is stable from −225 °C to 1050 °C. The hexagonal OsB 2 powder was annealed at 1050 °C for 6 days in vacuo to improve crystallinity and remove strain induced during the mechanochemical synthesis. The structure partially converted to the orthorhombic phase (20 wt%) after fast current assisted sintering of hexagonal OsB 2 at 1500 °C for 5 min. Mechanochemical approaches to the synthesis of hard boride materials allow new phases to be produced that cannot be prepared using conventional methods. - Graphical abstract: High resolution transmission electron micrograph of hexagonal OsB 2 nanocrystallite with corresponding fast Fourier transform and simulated diffraction pattern. - Highlights: • Hexagonal OsB 2 has been synthesized for the first time by mechanochemical method. • Hexagonal OsB 2 crystallizes in P63/mmc space group (No. 194), a=2.916 Å and c=7.376 Å. • The hexagonal structure was confirmed by a transmission electron microscope. • No phase transformation was observed after being annealed at 1050 °C for 6 days. • 20 wt% of h-OsB 2 was transformed to o-OsB 2 after being sintered at 1500 °C for 5 min

  1. GENERATION OF HIGH SHOCK PRESSURES BY LASER PULSES

    OpenAIRE

    Romain , J.

    1984-01-01

    Aspects of laser generated high shock pressures and results obtained over the last years are reviewed. Shock pressures up to 5 TPa inferred from shock velocity measurements are reported. Effects of laser wavelength, intensity and 2-D plasma expansion on the generated shock pressure are discussed. The hydrodynamic efficiency determined from various data including new results at 0,26 µm wavelength outlines the advantage of short wavelengths for producing very high pressures. The possibility of ...

  2. High Temperature Characterization of Ceramic Pressure Sensors

    National Research Council Canada - National Science Library

    Fonseca, Michael A; English, Jennifer M; Von Arx, Martin; Allen, Mark G

    2001-01-01

    This work reports functional wireless ceramic micromachined pressure sensors operating at 450 C, with demonstrated materials and readout capability indicating potential extension to temperatures in excess of 600 C...

  3. Hydraulic High Pressure Valve Controller Using the In-Situ Pressure Difference

    Science.gov (United States)

    Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor); Hall, Jeffery L. (Inventor)

    2016-01-01

    A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.

  4. High-Pressure Synthesis and Study of NO+NO3− and NO2+NO3− Ionic Solids

    Directory of Open Access Journals (Sweden)

    A. Yu. Kuznetsov

    2009-01-01

    Full Text Available Nitrosonium-nitrate NO+NO3− and dinitrogen pentoxide NO2+NO3− ionic crystals were synthesized by laser heating of a condensed oxygen-rich O2-N2 mixture compressed to different pressures, up to 40 GPa, in a diamond anvil cell (DAC. High-pressure/high-temperature Raman and X-ray diffraction studies of synthesized samples disclosed a transformation of NO+NO3− compound to NO2+NO3− crystal at temperatures above ambient and pressures below 9 GPa. High-pressure experiments revealed previously unreported bands in Raman spectra of NO+NO3− and NO2+NO3− ionic crystals. Structural properties of both ionic compounds are analyzed. Obtained experimental results support a hypothesis of a rotational disorder of NO+ complexes in NO+NO3− and indicate a rotational disorder of ionic complexes in NO2+NO3− solid.

  5. High Resolution Spectroscopy Using a Tunable Thz Synthesizer Based on Photomixing

    Science.gov (United States)

    Cuisset, Arnaud; Hindle, Francis; Mouret, Gael; Eliet, Sophie; Guinet, Mickael; Bocquet, Robin

    2011-06-01

    Optical heterodyning, also know as photomixing is an attractive solution as a single device able to cover the entire frequency range from 300 GHz to 3 THz. As the THz frequency is extracted from the difference frequency of two lasers, the accuracy with which the generated frequency is known is directly determined by the frequency accuracy of the lasers. In order to fully characterize the spectral fingerprint of a given molecule an accuracy approximately one order of magnitude finer than the Doppler linewidth is required, around 100 kHz for smaller polar compounds. To generate accurate cw-THz the frequency spacing of the modes of a Frequency Comb (FC) has been employed to constrain the emission frequency of a photomixing source.footnote{G. Mouret, F. Hindle, A. Cuisset, C. Yang, R. Bocquet, M. Lours, D. Rovera, Opt. Express, 2009, 17: 22031.} Two phase locked loops are implemented coherently locking the two cw-lasers (CW1 and CW2) to different modes of the FC. Although this solution allows accurate generation of narrowband THz the continuous tuning of the frequency presents some obstacles. To overcome these difficulties a system architecture with a third cw-laser (CW3) phase locked to CW2 has been implemented. The beatnote between CW2 and CW3 is free from the FC modes therefore the PLL frequency can be freely scanned over its entire operating range, in our case around 200 MHz. The most of polar compounds may be studied at high resolution in the THz domain with this synthesizer. Three different examples of THz analysis with atmospherical and astrophysical interests will be presented: The ground and vibrationnally excited states of H_2CO revisited in the 0.5-2 THz frequency region The rotational dependences of the broadening coefficients of CH_3Cl studied at high J and K values The molecular discrimination of a complex mixture containing methanol and ethanol. F. Hindle, A. Cuisset, G. Mouret, R. Bocquet Comptes Rendus Physique, 2008, 9: 262-275.

  6. Elasticity of stishovite at high pressure

    Science.gov (United States)

    Li, Baosheng; Rigden, Sally M.; Liebermann, Robert C.

    1996-08-01

    The elastic-wave velocities of stishovite, the rutile-structured polymorph of SiO 2, were measured to 3 GPa at room temperature in a piston cylinder apparatus using ultrasonic interferometry on polycrystalline samples. These polycrystalline samples (2-3 mm in length and diameter) were hot-pressed at 14 GPa and 1050°C in a 2000 ton uniaxial split-sphere apparatus (USSA-2000) using fused silica rods as starting material. They were characterized as low porosity (less than 1%), single phase, fine grained, free of cracks and preferred orientation, and acoustically isotropic by using density measurement, X-ray diffraction, scanning electron microscopy, and bench-top velocity measurements. On the basis of subsequent in situ X-ray diffraction study at high P and T on peak broadening on similar specimens, it is evident that the single crystal grains within these polycrystalline aggregates are well equilibrated and that these specimens are free of residual strain. P- and S-wave velocities measured at 1 atm are within 1.5% of the Hashin-Shtrikman bounds calculated from single-crystal elastic moduli. Measured pressure derivatives of the bulk and shear moduli, K' 0 = 5.3 ± 0.1 and G' 0 = 1.8 ± 0.1, are not unusual compared with values measured for other transition zone phases such as silicate spinel and majorite garnet. Isothermal compression curves calculated with the measured values of K0 and K' 0 agree well with experimental P-V data to 16 GPa. The experimental value of dG /dP is in excellent agreement with predictions based on elasticity systematics. Theoretical models are not yet able to replicate the measured values of K' 0 and G' 0.

  7. High quantum yield ZnO quantum dots synthesizing via an ultrasonication microreactor method.

    Science.gov (United States)

    Yang, Weimin; Yang, Huafang; Ding, Wenhao; Zhang, Bing; Zhang, Le; Wang, Lixi; Yu, Mingxun; Zhang, Qitu

    2016-11-01

    Green emission ZnO quantum dots were synthesized by an ultrasonic microreactor. Ultrasonic radiation brought bubbles through ultrasonic cavitation. These bubbles built microreactor inside the microreactor. The photoluminescence properties of ZnO quantum dots synthesized with different flow rate, ultrasonic power and temperature were discussed. Flow rate, ultrasonic power and temperature would influence the type and quantity of defects in ZnO quantum dots. The sizes of ZnO quantum dots would be controlled by those conditions as well. Flow rate affected the reaction time. With the increasing of flow rate, the sizes of ZnO quantum dots decreased and the quantum yields first increased then decreased. Ultrasonic power changed the ultrasonic cavitation intensity, which affected the reaction energy and the separation of the solution. With the increasing of ultrasonic power, sizes of ZnO quantum dots first decreased then increased, while the quantum yields kept increasing. The effect of ultrasonic temperature on the photoluminescence properties of ZnO quantum dots was influenced by the flow rate. Different flow rate related to opposite changing trend. Moreover, the quantum yields of ZnO QDs synthesized by ultrasonic microreactor could reach 64.7%, which is higher than those synthesized only under ultrasonic radiation or only by microreactor. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Surface chemical properties of novel high surface area solids synthesized from coal fly ash

    CSIR Research Space (South Africa)

    Pretorius, PJ

    2003-07-23

    Full Text Available The zeolite, Na-P1, was synthesized from fly ash samples originating from coal-fired power stations in South Africa by hydrothermal treatment of the raw ash with concentrated aqueous NaOH solutions. The zeolite was then further modified by acid...

  9. High-pressure system for Compton scattering experiments

    International Nuclear Information System (INIS)

    Oomi, G.; Honda, F.; Kagayama, T.; Itoh, F.; Sakurai, H.; Kawata, H.; Shimomura, O.

    1998-01-01

    High-pressure apparatus for Compton scattering experiments has been developed to study the momentum distribution of conduction electrons in metals and alloys at high pressure. This apparatus was applied to observe the Compton profile of metallic Li under pressure. It was found that the Compton profile at high pressure could be obtained within several hours by using this apparatus and synchrotron radiation. The result on the pressure dependence of the Fermi momentum of Li obtained here is in good agreement with that predicted from the free-electron model

  10. Effect of ambient pressure on the crystalline phase of nano TiO2 particles synthesized by a dc thermal plasma reactor

    International Nuclear Information System (INIS)

    Banerjee, I.; Karmakar, Soumen; Kulkarni, Naveen V.; Nawale, Ashok B.; Mathe, V. L.; Das, A. K.; Bhoraskar, S. V.

    2010-01-01

    The synthesis of nanoparticles of titanium dioxide (TiO 2 ) with varying percentages of anatase and rutile phases is reported. This was achieved by controlling the operating pressure in a transferred-arc, direct current thermal plasma reactor in which titanium vapors are evaporated, and then exposed to ambient oxygen. The average particle size remained around 15 nm in each case. The crystalline structure of the as-synthesized nanoparticles of TiO 2 was studied with X-ray diffraction analysis; whereas the particle morphology was investigated with the help of transmission electron microscopy. The precursor species responsible for the growth of these nanoparticles was studied with the help of optical emission spectroscopy. As inferred from the X-ray diffraction analysis, the relative abundance of anatase TiO 2 was found to be dominant when synthesized at 760 Torr, and the same showed a decreasing trend with decreasing chamber pressure. The study also reveals that anatase TiO 2 is a more effective photocatalytic agent in degrading methylene blue by comparison to its rutile phase.

  11. Defects of diamond single crystal grown under high temperature and high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Su, Qingcai, E-mail: suqc@sdu.edu.cn [Key Laboratory of Liquid Structure and Heredity of Materials (Ministry of Education), Shandong University, Jinan, P. R. China, 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Shandong Engineering Research Center for Superhard Materials, Zoucheng, P. R. China 273500 (China); Zhang, Jianhua [School of Mechanical Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Li, Musen [Key Laboratory of Liquid Structure and Heredity of Materials (Ministry of Education), Shandong University, Jinan, P. R. China, 250061 (China); School of Materials Science and Engineering, Shandong University, Jinan, P. R. China, 250061 (China); Shandong Engineering Research Center for Superhard Materials, Zoucheng, P. R. China 273500 (China)

    2013-11-01

    The diamond single crystal, synthesized with Fe–Ni–C–B system of catalyst under high temperature and high pressure, had been observed by field emission scanning electron microscope and transmission electron microscope. The presence of a cellular structure suggested that the diamond grew from melted catalyst solution and there existed a zone of component supercooling zone in front of the solid–liquid interface. The main impurities in the diamond crystal was (FeNi){sub 23}C{sub 6}. The triangle screw pit revealed on the (111) plane was generated by the screw dislocation meeting the diamond (111) plane at the points of emergence of dislocations. A narrow twin plane was formed between the two (111) plane. - Highlights: • High pressure, high temperature synthesis of diamond single crystal. • Fe–Ni–C–B used as catalyst, graphite as carbon source. • The main impurity in the diamond crystal was (FeNi){sub 23}C{sub 6}. • Surface defects arose from screw dislocations and stacking faults.

  12. Advances in high pressure science and technology: proceedings of the fourth national conference on high pressure science and technology

    International Nuclear Information System (INIS)

    Yousuf, Mohammad; Subramanian, N.; Govinda Rajan, K.

    1997-09-01

    The proceedings of the fourth National Conference on High Pressure Science and Technology covers a wide area of research and development activities in the field of high pressure science and technology, broadly classified into the following themes: mechanical behaviour of materials; instrumentation and methods in high pressure research; pressure calibration, standards and safety aspects; phase transitions; shock induced reactions; mineral science, geophysics, geochemistry and planetary sciences; optical, electronic and transport properties; synthesis of materials; soft condensed matter physics and liquid crystals; computational methods in high pressure research. Papers relevant to INIS are indexed separately

  13. Modeling, Parameters Identification, and Control of High Pressure Fuel Cell Back-Pressure Valve

    Directory of Open Access Journals (Sweden)

    Fengxiang Chen

    2014-01-01

    Full Text Available The reactant pressure is crucial to the efficiency and lifespan of a high pressure PEMFC engine. This paper analyses a regulated back-pressure valve (BPV for the cathode outlet flow in a high pressure PEMFC engine, which can achieve precisely pressure control. The modeling, parameters identification, and nonlinear controller design of a BPV system are considered. The identified parameters are used in designing active disturbance rejection controller (ADRC. Simulations and extensive experiments are conducted with the xPC Target and show that the proposed controller can not only achieve good dynamic and static performance but also have strong robustness against parameters’ disturbance and external disturbance.

  14. Neutron powder diffraction under high pressure at J-PARC

    International Nuclear Information System (INIS)

    Utsumi, Wataru; Kagi, Hiroyuki; Komatsu, Kazuki; Arima, Hiroshi; Nagai, Takaya; Okuchi, Takuo; Kamiyama, Takashi; Uwatoko, Yoshiya; Matsubayashi, Kazuyuki; Yagi, Takehiko

    2009-01-01

    It is expected that high-pressure material science and the investigation of the Earth's interior will progress greatly using the high-flux pulse neutrons of J-PARC. In this article, we introduce our plans for in situ neutron powder diffraction experiments under high pressure at J-PARC. The use of three different types of high-pressure devices is planned; a Paris-Edinburgh cell, a new opposed-anvil cell with a nano-polycrystalline diamond, and a cubic anvil high-pressure apparatus. These devices will be brought to the neutron powder diffraction beamlines to conduct a 'day-one' high-pressure experiment. For the next stage of research, we propose construction of a dedicated beamline for high-pressure material science. Its conceptual designs are also introduced here.

  15. High-pressure catalytic chemical vapor deposition of ferromagnetic ruthenium-containing carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Khavrus, Vyacheslav O., E-mail: V.Khavrus@ifw-dresden.de; Ibrahim, E. M. M.; Bachmatiuk, Alicja; Ruemmeli, Mark H.; Wolter, A. U. B.; Hampel, Silke; Leonhardt, Albrecht [IFW Dresden (Germany)

    2012-06-15

    We report on the high-pressure catalytic chemical vapor deposition (CCVD) of ruthenium nanoparticles (NPs) and single-walled carbon nanotubes (SWCNTs) by means of gas-phase decomposition of acetonitrile and ruthenocene in a tubular quartz flow reactor at 950 Degree-Sign C and at elevated pressures (between 2 and 8 bar). The deposited material consists of Ru metal cores with sizes ranging between 1 and 3 nm surrounded by a carbon matrix. The high-pressure CCVD seems to be an effective route to obtain composite materials containing metallic NPs, Ru in this work, inside a nanostructured carbon matrix protecting them from oxidation in ambient air. We find that in contradiction to the weak paramagnetic properties characterizing bulk ruthenium, the synthesized samples are ferromagnetic as predicted for nanosized particles of nonmagnetic materials. At low pressure, the very small ruthenium catalyst particles are able to catalyze growth of SWCNTs. Their yield decreases with increasing reaction pressure. Transmission electron microscopy, selected area energy-dispersive X-ray analysis, Raman spectroscopy, and magnetic measurements were used to analyze and confirm properties of the synthesized NPs and nanotubes. A discussion on the growth mechanism of the Ru-containing nanostructures is presented.

  16. High Pressure, High Gradient RF Cavities for Muon Beam Cooling

    CERN Document Server

    Johnson, R P

    2004-01-01

    High intensity, low emittance muon beams are needed for new applications such as muon colliders and neutrino factories based on muon storage rings. Ionization cooling, where muon energy is lost in a low-Z absorber and only the longitudinal component is regenerated using RF cavities, is presently the only known cooling technique that is fast enough to be effective in the short muon lifetime. RF cavities filled with high-pressure hydrogen gas bring two advantages to the ionization technique: the energy absorption and energy regeneration happen simultaneously rather than sequentially, and higher RF gradients and better cavity breakdown behavior are possible than in vacuum due to the Paschen effect. These advantages and some disadvantages and risks will be discussed along with a description of the present and desired RF R&D efforts needed to make accelerators and colliders based on muon beams less futuristic.

  17. Pressure effects on high temperature steam oxidation of Zircaloy-4

    International Nuclear Information System (INIS)

    Park, Kwangheon; Kim, Kwangpyo; Ryu, Taegeun

    2000-01-01

    The pressure effects on Zircaloy-4 (Zry-4) cladding in high temperature steam have been analyzed. A double layer autoclave was made for the high pressure, high temperature oxidation tests. The experimental test temperature range was 700 - 900 deg C, and pressures were 0.1 - 15 MPa. Steam partial pressure turns out to be an important one rather than total pressure. Steam pressure enhances the oxidation rate of Zry-4 exponentially. The enhancement depends on the temperature, and the maximum exists between 750 - 800 deg C. Pre-existing oxide layer decreases the enhancement about 40 - 60%. The acceleration of oxidation rate by high pressure team seems to be originated from the formation of cracks by abrupt transformation of tetragonal phase in oxide, where the un-stability of tetragonal phase comes from the reduction of surface energy by steam. (author)

  18. Molecular nanomagnets: Syntheses and characterization of high nuclearity transition metal complexes

    Science.gov (United States)

    Foguet-Albiol, Maria D.

    2006-12-01

    High nuclearity transition metal complexes have attracted a lot of attention because of their aesthetically pleasant structures and/or their potential applications. The fusion of the world of magnetism with the exciting research in physics and chemistry led to the realization of interesting types of materials that can function as nanoscale magnetic particles. The study of the magnetism of inorganic complexes and especially the study of these molecular nanomagnets (or single-molecule magnets, SMMs) is a field that has generated intense interest in the scientific community. Interest in these molecular nanomagnets arises as part of a broader investigation of nanomagnetism (and nanotechnology), as these represent the ultimate step in device miniaturization. The primary purpose of this dissertation is the development of new synthetic methods intended for the preparation of novel single-molecule magnets (SMMs). The definition of the "bottom-up approach" is to increase the size of molecules by adding new magnetic centers; this is attractive but does not actually reflect how the chemistry takes place. Various strategies have been employed in developing the aforementioned synthetic methods which include the use of mononuclear as well as preformed clusters as starting materials; and the introduction of new alcohol based ligands as N-methyldiethanolamine (mdaH2) and triethanolamine (teaH3), since currently only a few alcohol based ligands have been used by different research groups. Many of these efforts have led to the isolation of new polynuclear Mn clusters with nuclearities ranging all the way from four to thirty-one. Additionally, a family of related Fe7 complexes has been synthesized. The transition metal cluster chemistry has also been extended to nickel-containing species. Many of these polynulear transition metal complexes function as single-molecule magnets. An additional research direction discussed herein is the study of the exchange-coupled dimer of single

  19. Evaluation of the game Synthesizing Proteins addressed to high school students

    Directory of Open Access Journals (Sweden)

    C.C.P. da Silva

    2006-07-01

    Full Text Available Studies demonstrate that a good strategy in education is the use of games in the school atmosphere, intensifying the teaching and learning process. The game as educational tool motivates the students in an emotional, motor, social and cognitive way, helping them to create mental outlines, to develop the reasoning and in the construction of the knowledge. In this context, the dissemination team of the Centre for Structural Molecular Biotechnology (CBME, in partnership with the Centre for Scientific and Cultural Dissemination (CDCC-USP, developed a board game entitled Synthesizing Proteins, in order to help the learning and the comprehension of the transcription and translation processes, and of the synthesis of proteins, using examples of human proteins. The game was applied and evaluated in a systematic way, in order to validate it as an educational tool of teaching-learning as well as to correctly disseminate it.            The CBME dissemination team planned activities like workshops, where the game was applied for high school students of public and private schools of São Carlos city (SP. As evaluation tool a questionnaire was elaborated containing questions regarding the concepts involved in the proteins synthesis process. This questionnaire was applied before (pre-test and two weeks after the end of the activity (post-test, in order to check the previous and the acquired knowledge of the students after the manipulation of the educational material.            Analyzing the results of these pre- and post-tests, it was observed that, although most of the students has presented difficulties regarding the nomenclature and the details of the biochemical processes, these students were able to understand satisfactorily the following aspects: DNA is located in the nucleus of animal cells; the proteins are constituted of amino acids; the dynamics of the molecules of DNA, RNA and proteins during the interactions

  20. High pressure apparatus for neutron scattering at low temperature

    International Nuclear Information System (INIS)

    Munakata, Koji; Uwatoko, Yoshiya; Aso, Naofumi

    2010-01-01

    Effects of pressure on the physical properties are very important for understanding highly correlated electron systems, in which pressure-induced attractive phenomena such as superconductivity and magnetically ordered non-Fermi liquid have been observed. Up to now, many scientists have developed a lot of high pressure apparatus for each purpose. The characteristic features of various materials and pressure transmitting media for use of high pressure apparatus are reported. Then, two kinds of clamp type high-pressure cell designed for low-temperature neutron diffraction measurements are shown; one is a piston cylinder type high-pressure cell which can be attached to the dilution refrigerator, and the other one is a newly-developed cubic anvil type high-pressure cell which can generate pressure above 7GPa. We also introduce the results of magnetic neutron scattering under pressure on a pressure-induced superconducting ferromagnet UGe 2 in use of the piston cylinder type clamp cell, and those on an iron arsenide superconductor SrFe 2 As 2 in use of the cubic anvil type clamp cell. (author)

  1. Gold nanoparticle-polymer nanocomposites synthesized by room temperature atmospheric pressure plasma and their potential for fuel cell electrocatalytic application

    Science.gov (United States)

    Zhang, Ri-Chao; Sun, Dan; Zhang, Ruirui; Lin, Wen-Feng; Macias-Montero, Manuel; Patel, Jenish; Askari, Sadegh; McDonald, Calum; Mariotti, Davide; Maguire, Paul

    2017-04-01

    Conductive polymers have been increasingly used as fuel cell catalyst support due to their electrical conductivity, large surface areas and stability. The incorporation of metal nanoparticles into a polymer matrix can effectively increase the specific surface area of these materials and hence improve the catalytic efficiency. In this work, a nanoparticle loaded conductive polymer nanocomposite was obtained by a one-step synthesis approach based on room temperature direct current plasma-liquid interaction. Gold nanoparticles were directly synthesized from HAuCl4 precursor in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The resulting AuNPs/PEDOT:PSS nanocomposites were subsequently characterized under a practical alkaline direct ethanol fuel cell operation condition for its potential application as an electrocatalyst. Results show that AuNPs sizes within the PEDOT:PSS matrix are dependent on the plasma treatment time and precursor concentration, which in turn affect the nanocomposites electrical conductivity and their catalytic performance. Under certain synthesis conditions, unique nanoscale AuNPs/PEDOT:PSS core-shell structures could also be produced, indicating the interaction at the AuNPs/polymer interface. The enhanced catalytic activity shown by AuNPs/PEDOT:PSS has been attributed to the effective electron transfer and reactive species diffusion through the porous polymer network, as well as the synergistic interfacial interaction at the metal/polymer and metal/metal interfaces.

  2. High pressure synthesis of amorphous TiO{sub 2} nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Quanjun; Liu, Ran; Wang, Tianyi; Xu, Ke; Dong, Qing; Liu, Bo; Liu, Bingbing, E-mail: liubb@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Liu, Jing [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2015-09-15

    Amorphous TiO{sub 2} nanotubes with diameters of 8-10 nm and length of several nanometers were synthesized by high pressure treatment of anatase TiO{sub 2} nanotubes. The structural phase transitions of anatase TiO{sub 2} nanotubes were investigated by using in-situ high-pressure synchrotron X-ray diffraction (XRD) method. The starting anatase structure is stable up to ∼20GPa, and transforms into a high-density amorphous (HDA) form at higher pressure. Pressure-modified high- to low-density transition was observed in the amorphous form upon decompression. The pressure-induced amorphization and polyamorphism are in good agreement with the previous results in ultrafine TiO{sub 2} nanoparticles and nanoribbons. The relationship between the LDA form and α-PbO{sub 2} phase was revealed by high-resolution transmission electron microscopy (HRTEM) study. In addition, the bulk modulus (B{sub 0} = 158 GPa) of the anatase TiO{sub 2} nanotubes is smaller than those of the corresponding bulks and nanoparticles (180-240 GPa). We suggest that the unique open-ended nanotube morphology and nanosize play important roles in the high pressure phase transition of TiO{sub 2} nanotubes.

  3. Electrochromic Ni–Fe oxide thin films synthesized by an atmospheric pressure plasma jet for flexible electrochromic application

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yun-Sen, E-mail: yslin@fcu.edu.tw; Chuang, Pei-Ying; Shie, Ping-Shiun

    2014-11-03

    Flexible-electrochromic organo-nickel-iron oxide (NiFe{sub x}O{sub y}C{sub z}) films deposited onto flexible polyethylene terephthalate (PET)/indium tin oxide (ITO) substrates using atmospheric-pressure plasma-enhanced chemical vapor deposition with an atmospheric pressure plasma jet under various flow rates of oxygen gases are investigated. Precursors [nickelocence, Ni(C{sub 5}H{sub 5}){sub 2}] and [ferrocence, Fe(C{sub 5}H{sub 5}){sub 2}] vapors are carried by argon gas, mixed by oxygen gas and injected into air plasma torch for a rapid synthesis of NiFe{sub x}O{sub y}C{sub z} films by a short duration of the substrate, 32 s, in the plasmas. Uniform light modulation on PET/ITO/NiFe{sub x}O{sub y}C{sub z} is produced while the moving PET/ITO substrate is exposed to plasma torch at room temperature (∼ 23 °C) and atmospheric pressure. Light modulation with up to a 43.2% transmittance variation at a wavelength of 708 nm even after 200 cycles of Li{sup +} intercalation and de-intercalation in a 1 M LiClO{sub 4}-propylene carbonate electrolyte is accomplished. - Highlights: • Rapid deposition of electrochromic organo-nickel–iron oxide (NiFe{sub x}O{sub y}C{sub z}) films • Enhanced electrochromic performance of NiFe{sub x}O{sub y}C{sub z} films by oxygen gas addition • Uniform light modulation on NiFe{sub x}O{sub y}C{sub z} films produced by air plasma jet • Porous surfaces allow reversible Li{sup +} intercalation and deintercalation.

  4. Cavitation-induced reactions in high-pressure carbon dioxide

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; van Eck, D.; Kemmere, M.F.; Keurentjes, J.T.F.

    2002-01-01

    The feasibility of ultrasound-induced in situ radical formation in liquid carbon dioxide was demonstrated. The required threshold pressure for cavitation could be exceeded at a relatively low acoustic intensity, as the high vapor pressure of CO2 counteracts the hydrostatic pressure. With the use of

  5. Viscosity of liquid sulfur under high pressure

    International Nuclear Information System (INIS)

    Terasaki, Hidenori; Kato, T; Funakoshi, K; Suzuki, A; Urakawa, S

    2004-01-01

    The viscosity of liquid sulfur up to 9.7 GPa and 1067 K was measured using the in situ x-ray radiography falling sphere method. The viscosity coefficients were found to range from 0.11 to 0.69 Pa s, and decreased continuously with increasing pressure under approximately constant homologous temperature conditions. The observed viscosity variation suggests that a gradual structural change occurs in liquid sulfur with pressure up to 10 GPa. The L-L' transition in liquid sulfur proposed by Brazhkin et al (1991 Phys. Lett. A 154 413) from thermobaric measurements has not been confirmed by the present viscometry

  6. Announcement: National High Blood Pressure Education Month - May 2016.

    Science.gov (United States)

    2016-05-27

    May is National High Blood Pressure Education Month. High blood pressure (hypertension) is a major contributor to heart disease and stroke, two leading causes of death in the United States.* High blood pressure affects one third of U.S. adults, or approximately 75 million persons, yet approximately 11 million of these persons are not aware they have hypertension, and approximately 18 million are not being treated (unpublished data) (1,2).

  7. Safety regulation on high-pressure gas and gas business

    International Nuclear Information System (INIS)

    Kim, Du Yeoung; An, Dae Jun

    1978-09-01

    This book is divided into two parts. The first part introduces safety regulation on high-pressure gas, enforcement ordinance on safety regulation about high-pressure gas and enforcement regulation on safety regulation about high-pressure gas. The second part indicates regulations on gas business such as general rules, gas business gas supplies, using land, supervision, supple mentary rules and penalty. It has two appendixes on expected questions and questions during last years.

  8. Teaming Up Against High Blood Pressure PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    Nearly one-third of American adults have high blood pressure, and more than half of them don’t have it under control. Simply seeing a doctor and taking medications isn’t enough for many people who have high blood pressure. A team-based approach by patients, health care systems, and health care providers is one of the best ways to treat uncontrolled high blood pressure.

  9. Transportable, small high-pressure preservation vessel for cells

    International Nuclear Information System (INIS)

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

    2010-01-01

    We have previously reported that the survival rate of astrocytes increases under high-pressure conditions at 4 0 C. However, pressure vessels generally have numerous problems for use in cell preservation and transportation: (1) they cannot be readily separated from the pressurizing pump in the pressurized state; (2) they are typically heavy and expensive due the use of materials such as stainless steel; and (3) it is difficult to regulate pressurization rate with hand pumps. Therefore, we developed a transportable high-pressure system suitable for cell preservation under high-pressure conditions. This high-pressure vessel has the following characteristics: (1) it can be easily separated from the pressurizing pump due to the use of a cock-type stop valve; (2) it is small and compact, is made of PEEK and weighs less than 200 g; and (3) pressurization rate is regulated by an electric pump instead of a hand pump. Using this transportable high-pressure vessel for cell preservation, we found that astrocytes can survive for 4 days at 1.6 MPa and 4 0 C.

  10. Magnetic structures of erbium under high pressure

    DEFF Research Database (Denmark)

    Kawano, S.; Lebech, B.; Achiwa, N.

    1993-01-01

    Neutron diffraction studies of the magnetic structures of erbium metal at 4.5 K and 11.5 kbar hydrostatic pressure have revealed that the transition to a conical structure at low temperatures is suppressed and that the cycloidal structure, with modulation vector Q congruent-to (2/7 2pi/c)c persists...

  11. Generation of high shock pressures by laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Romain, J.P. (GRECO ILM, Laboratoire d' Energetique et Detonique, E.N.S.M.A., 86 - Poitiers (France))

    1984-11-01

    Aspects of laser generated high shock pressures and results obtained over the last years are reviewed. Shock pressures up to 5 TPa inferred from shock velocity measurements are reported. Effects of laser wavelength, intensity and 2-D plasma expansion on the generated shock pressure are discussed. The hydrodynamic efficiency determined from various data including new results at 0,26 ..mu..m wavelength outlines the advantage of short wavelengths for producing very high pressures. The possibility of achieving shock pressures in the 10 TPa range with the use of the impedance match technique is examined.

  12. Generation of high shock pressures by laser pulses

    International Nuclear Information System (INIS)

    Romain, J.P.

    1984-01-01

    Aspects of laser generated high shock pressures and results obtained over the last years are reviewed. Shock pressures up to 5 TPa inferred from shock velocity measurements are reported. Effects of laser wavelength, intensity and 2-D plasma expansion on the generated shock pressure are discussed. The hydrodynamic efficiency determined from various data including new results at 0,26 μm wavelength outlines the advantage of short wavelengths for producing very high pressures. The possibility of achieving shock pressures in the 10 TPa range with the use of the impedance match technique is examined

  13. Vibrational spectroscopy at high external pressures the diamond anvil cell

    CERN Document Server

    Ferraro, John R

    1984-01-01

    Vibrational Spectroscopy at High External Pressures: The Diamond Anvil Cell presents the effects of high pressure on the vibrational properties of materials as accomplished in a diamond anvil cell (DAC). The DAC serves the dual purpose of generating the pressures and being transparent to infrared radiation, allowing the observation of changes caused by pressure. The optical probes highlighted will deal principally with infrared and Raman scattering, although some observations in the visible region will also be presented. The book begins with a discussion of the effects of pressure and pres

  14. Magnetization at high pressure in CeP

    Science.gov (United States)

    Naka, T.; Matsumoto, T.; Okayama, Y.; Môri, N.; Haga, Y.; Suzuki, T.

    1995-02-01

    We have investigated the pressure dependence of magnetization below 60 K up to 1.6 GPa in the low-carrier concentration system CeP showing two step transitions at T = TL and TH under high pressure. At high pressure, M( P, T) exhibits a maximum at around the lower transition temperature TL. This behavior implies that the magnetic state changes at TL. The pressure dependence of isothermal magnetization M( P) is different above and below TL. In fact, M( P) below TL exhibits a maximum at around 1.4 GPa, whereas M( P) above TL increases steeply with pressure up to 1.6 GPa.

  15. High pressure studies of fluorenone emission in plastic media

    International Nuclear Information System (INIS)

    Mitchell, D.J.; Schuster, G.B.; Drickamer, H.G.

    1977-01-01

    The energy and the quantum efficiency for fluorenone fluorescence in the crystalline state and in polymeric matrices was measured as a function of external pressure over the range 0--140 kbar. The application of high pressure induces changes in the quantum yield, which ranges from 0.001 at low pressure to a maximum of approx.0.1 at high pressure in hydrocarbon plastics. These results are interpreted as arising from the decrease in the energy of the lowest ππ excited singlet state relative to other relevant states as the external pressure is increased

  16. Proposed dedicated high pressure beam lines at CHESS

    International Nuclear Information System (INIS)

    Ruoff, A.L.; Vohra, Y.K.; Bassett, W.A.; Batterman, B.W.; Bilderback, D.H.

    1988-01-01

    An instrumentation proposal for dedicated high pressure beam lines at CHESS is described. It is the purpose of this proposed program to provide researchers in high pressure science with beam lines for X-ray diffraction studies in the megabar regime. This will involve radiation from a bending magnet as well as from a wiggler. Examples of the high pressure results up to 2.16 Mbar are shown. Diffraction patterns from bending magnet and wiggler beams are shown and compared. The need for this facility by the high pressure community is discussed. (orig.)

  17. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  18. High pressure argon detector of high energy neutrinos

    International Nuclear Information System (INIS)

    Vishnevskii, A.V.; Golutvin, I.A.; Sarantsev, V.L.; Sviridov, V.A.; Dolgoshein, B.A.; Kalinovskii, A.N.; Sosnovtsev, V.V.; Chernyatin, V.K.; Kaftanov, V.S.; Khovanskii, V.D.; Shevchenko, V.G.

    1979-01-01

    In the present paper, we suggest an electron neutrino detector of a new type where track information is available for all charged particles. As a working medium we use Argon compressed up to a pressure of 100 to 150 atm (approximately 0.2-0.3 g/cm 3 ). The spatial reconstruction of tracks are accomplished with an accuracy not inferior to that of bubble chambers. The detector has a high sensitivity in ionization measurements. An assembly with a working medium mass of approximately 100 tons seem to be realisable. This makes it possible to perform tasks with cross-sections of (10 -5 + 10 -3 ) x delty tot at an intensity of the neutrino beam which is available in present-day accelerators. (orig.)

  19. Blood pressure in childhood : epidemiological probes into the aetiology of high blood pressure

    NARCIS (Netherlands)

    A. Hofman (Albert)

    1983-01-01

    textabstractHigh arterial blood pressure takes a heavy toll in western populations (1 ). Its causes are still largely unknown, but its sequelae, a variety of cardiovascular and renal diseases, have been referred to as "a modern scourge" (2). High blood pressure of unknown cause, or

  20. High pressure behaviour of uranium mono pnictides

    International Nuclear Information System (INIS)

    Pagare, Gitanjali; Ojha, Poonam; Sanyal, S.P.; Aynyas, Mahendra

    2006-01-01

    The pressure induced structural phase transition of three actinide mono pnictides AX (A=U and X=As, Sb, Bi), have been studied theoretically using two body interionic potential with necessary modifications to include the effect of Coulomb screening by the delocalized 5f electrons of the actinide (uranium) ion. The peculiar properties of these compounds have been interpreted in terms of the hybridization of f electrons with the conduction band. The calculated compression curves are compared with the experimental results. These compounds exhibits first order crystallographic phase transition from their NaCl (B 1 ) phase to CsCl (B 2 ) phase at 17GPa, 9.5GPa and 5.3 GPa respectively. The NaCl phase possesses lower energy than CsCl phase and stable at ambient pressure. (author)

  1. High pressure multiple shock response of aluminum

    International Nuclear Information System (INIS)

    Lawrence, R.J.; Asay, J.R.

    1977-01-01

    It is well known that both dynamic yield strength and rate-dependent material response exert direct influence on the development of surface and interface instabilities under conditions of strong shock loading. A detailed understanding of these phenomena is therefore an important aspect of the analysis of dynamic inertial confinement techniques which are being used in such applications as the generation of controlled thermonuclear fusion. In these types of applications the surfaces and interfaces under consideration can be subjected to cyclic loading characterized by shock pressures on the order of 100 GPa or more. It thus becomes important to understand how rate effects and material strength differ from the values observed in the low pressure regime where they are usually measured, as well as how they are altered by the loading history

  2. Single-catalyst high-weight% hydrogen storage in an N-heterocycle synthesized from lignin hydrogenolysis products and ammonia.

    Science.gov (United States)

    Forberg, Daniel; Schwob, Tobias; Zaheer, Muhammad; Friedrich, Martin; Miyajima, Nobuyoshi; Kempe, Rhett

    2016-10-20

    Large-scale energy storage and the utilization of biomass as a sustainable carbon source are global challenges of this century. The reversible storage of hydrogen covalently bound in chemical compounds is a particularly promising energy storage technology. For this, compounds that can be sustainably synthesized and that permit high-weight% hydrogen storage would be highly desirable. Herein, we report that catalytically modified lignin, an indigestible, abundantly available and hitherto barely used biomass, can be harnessed to reversibly store hydrogen. A novel reusable bimetallic catalyst has been developed, which is able to hydrogenate and dehydrogenate N-heterocycles most efficiently. Furthermore, a particular N-heterocycle has been identified that can be synthesized catalytically in one step from the main lignin hydrogenolysis product and ammonia, and in which the new bimetallic catalyst allows multiple cycles of high-weight% hydrogen storage.

  3. Nanographene synthesized in triple-phase plasmas as a highly durable support of catalysts for polymer electrolyte fuel cells

    Science.gov (United States)

    Amano, Tomoki; Kondo, Hiroki; Takeda, Keigo; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

    2018-04-01

    Nanographene was synthesized in triple-phase plasmas comprising a gaseous phase, a gas-liquid boundary layer, and an in-liquid phase using a setup in which one electrode was placed in the gaseous phase while the other was immersed in the liquid phase. The triple-phase plasmas were generated using a pure alcohol, such as ethanol, 1-propanol, or 1-butanol, by applying a high voltage to a pair of electrodes made of copper or graphite. The nanographene synthesized using ethanol had high durability and thus could serve as a catalyst support in polymer electrolyte fuel cells (PEFCs). The PEFCs exhibited low degradation rates in the high-potential cycle test of a half-cell, as a result of which, a loss of only 10% was observed in the effective electrochemical surface area of Pt, even after 10,000 cycles.

  4. Designing high pressure containers for research- principles and applications

    International Nuclear Information System (INIS)

    Anandkumar, V.

    1997-01-01

    The high pressure scientist looks for a well engineered pressure apparatus for high pressure experiments for 1 kbar (0.1 GPa) and above. Often, a variety of difficulties including the choice of materials, design configuration, optimum utilisation of the strength of materials used in the design, are encountered. This article is intended to help the high pressure scientist to select the design approach for pressure retaining container. The limitations imposed by the strength of available materials and engineering standards in building high pressure containers are discussed. Engineering solutions to overcome these limitations with optimal utilisation of the strength of the materials are also discussed. Novel methods to boost up the pressure retaining capacity like multilayered design and autofrettaging are compared along with their relative advantages and disadvantages. Special methods by which it is possible to attain pressures which are several times the yield strength of the materials of construction are presented. In this aspects such as the basis of the codes and their relevance in the design of high pressure equipment will also be described. Discussions are centered around the methods to tackle situations where experimental constraints dictate requirements of pressures higher than those permitted by design codes. Safety features are also discussed. (author)

  5. The use of high pressure in basic, materials, and life sciences

    International Nuclear Information System (INIS)

    Schilling, James S.

    2000-01-01

    Four of the most important applications of the high pressure technique in today's science are: (1) to help identify the materials which reside deep within our earth or other heavenly bodies and determine their properties, (2) to uncover underlying systematics and critically test theoretical models, (3) to synthesize novel and useful materials not readily available by other means, and (4) to determine the effect of pressure on living organisms and explore the conditions favorable for the origin of life itself. High pressure studies currently enjoy an increasing popularity which is fueled by recent advances in the notably difficult experimental techniques. In this paper I will attempt to capture some of the current excitement in this field by offering brief synopses of selected experiments in the basic, materials, and life sciences

  6. Solid gas reaction phase diagram under high gas pressure

    International Nuclear Information System (INIS)

    Ishizaki, K.

    1992-01-01

    This paper reports that to evaluate which are the stable phases under high gas pressure conditions, a solid-gas reaction phase diagram under high gas pressure (HIP phase diagram) has been proposed by the author. The variables of the diagram are temperature, reactant gas partial pressure and total gas pressure. Up to the present time the diagrams have been constructed using isobaric conditions. In this work, the stable phases for a real HIP process were evaluated assuming an isochoric condition. To understand the effect of the total gas pressure on stability is of primary importance. Two possibilities were considered and evaluated, those are: the total gas pressure acts as an independent variable, or it only affects the fugacity values. The results of this work indicate that the total gas pressure acts as an independent variable, and in turn also affects the fugacity values

  7. Portable laser synthesizer for high-speed multi-dimensional spectroscopy

    Science.gov (United States)

    Demos, Stavros G [Livermore, CA; Shverdin, Miroslav Y [Sunnyvale, CA; Shirk, Michael D [Brentwood, CA

    2012-05-29

    Portable, field-deployable laser synthesizer devices designed for multi-dimensional spectrometry and time-resolved and/or hyperspectral imaging include a coherent light source which simultaneously produces a very broad, energetic, discrete spectrum spanning through or within the ultraviolet, visible, and near infrared wavelengths. The light output is spectrally resolved and each wavelength is delayed with respect to each other. A probe enables light delivery to a target. For multidimensional spectroscopy applications, the probe can collect the resulting emission and deliver this radiation to a time gated spectrometer for temporal and spectral analysis.

  8. Practical conditions in the neutron diffraction under high pressure

    International Nuclear Information System (INIS)

    Kamigaki, Kazuo; Ohashi, Masayoshi

    1993-01-01

    Practical analysis is made on some conditions in utilizing neutrons for the study of atomistic structure of materials under high pressure. Investigation is made on the geometrical conditions; size of the specimen, width of slits, and the rate of extra-scattering. Experiments are performed on the effects of absorption by high pressure cell and the disturbance due to an overlapping of diffraction peaks. An observation is presented on the pressure-induced transformation in RbBr. (author)

  9. Pressurizer pump reliability analysis high flux isotope reactor

    International Nuclear Information System (INIS)

    Merryman, L.; Christie, B.

    1993-01-01

    During a prolonged outage from November 1986 to May 1990, numerous changes were made at the High Flux Isotope Reactor (HFIR). Some of these changes involved the pressurizer pumps. An analysis was performed to calculate the impact of these changes on the pressurizer system availability. The analysis showed that the availability of the pressurizer system dropped from essentially 100% to approximately 96%. The primary reason for the decrease in availability comes because off-site power grid disturbances sometimes result in a reactor trip with the present pressurizer pump configuration. Changes are being made to the present pressurizer pump configuration to regain some of the lost availability

  10. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    against conventional technologies for hydrogen production, such as natural gas reforming, the production and investment costs have to be reduced. A reduction of the investment costs may be achieved by increasing the operational pressure and temperature of the electrolyzer, as this will result in: 1.......3 A cm-2 combined with relatively small production costs may lead to both reduced investment and operating costs for hydrogen and oxygen production. One of the produced electrolysis cells was operated for 350 h. Based on the successful results a patent application covering this novel cell was filed...

  11. Surface stabilized GMR nanorods of silver coated CrO2 synthesized via a polymer complex at ambient pressure

    Science.gov (United States)

    Biswas, S.; Singh, G. P.; Ram, S.; Fecht, H.-J.

    2013-08-01

    Stable anisotropic nanorods of surface modified CrO2 (˜18 nm diameter) with a correlated diamagnetic layer (2-3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr4+ ions by Ag atoms on the CrO2 surface (topotactic surface layer) via an etching reaction of a CrO2-polymer complex with Ag+ ions in hot water followed by heating the dried sample at 300-400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO2 such that it no longer converts to Cr2O3 in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO2 structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d5/2 and 3d3/2 X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (-) 7.6% at 77 K, than reported values in compacted CrO2 powders or composites. Such a large MR-value in the Coulomb blockade regime (<100 K) arises not only due to the suppressed spin flipping at low temperature but also from a spin dependent co-tunneling through an interlinked structure of silver and silver coated CrO2 nanorods.

  12. Surface stabilized GMR nanorods of silver coated CrO2 synthesized via a polymer complex at ambient pressure

    International Nuclear Information System (INIS)

    Biswas, S.; Singh, G.P.; Ram, S.; Fecht, H.-J.

    2013-01-01

    Stable anisotropic nanorods of surface modified CrO 2 (∼18 nm diameter) with a correlated diamagnetic layer (2–3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr 4+ ions by Ag atoms on the CrO 2 surface (topotactic surface layer) via an etching reaction of a CrO 2 -polymer complex with Ag + ions in hot water followed by heating the dried sample at 300–400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO 2 such that it no longer converts to Cr 2 O 3 in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO 2 structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d 5/2 and 3d 3/2 X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (−) 7.6% at 77 K, than reported values in compacted CrO 2 powders or composites. Such a large MR-value in the Coulomb blockade regime ( 2 nanorods. - Highlights: • Synthesis and structural studies of a novel GMR material of Ag coated CrO 2 . • Tailoring useful GMR property in CrO 2 nanorods of controlled shape and anisotropy. • Enhanced GMR is explained in correlation to the surface structure of CrO 2 nanorods

  13. High-Performance Pressure Sensor for Monitoring Mechanical Vibration and Air Pressure

    Directory of Open Access Journals (Sweden)

    Yancheng Meng

    2018-05-01

    Full Text Available To realize the practical applications of flexible pressure sensors, the high performance (sensitivity and response time as well as more functionalities are highly desired. In this work, we fabricated a piezoresistive pressure sensor based on the micro-structured composites films of multi-walled carbon nanotubes (MWCNTs and poly (dimethylsiloxane (PDMS. In addition, we establish efficient strategies to improve key performance of our pressure sensor. Its sensitivity is improved up to 474.13 kPa−1 by minimizing pressure independent resistance of sensor, and response time is shorten as small as 2 μs by enhancing the elastic modulus of polymer elastomer. Benefiting from the high performance, the functionalities of sensors are successfully extended to the accurate detection of high frequency mechanical vibration (~300 Hz and large range of air pressure (6–101 kPa, both of which are not achieved before.

  14. Lithium iron phosphate with high-rate capability synthesized through hydrothermal reaction in glucose solution

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Guangchuan; Wang, Li; Ou, Xiuqin; Zhao, Xia; Xu, Shengzhao [Institute of Power Source and Ecomaterials Science, Box 1055, Hebei University of Technology, 300130 Tianjin (China)

    2008-10-01

    Carbon-coated lithium iron phosphate (LiFePO{sub 4}/C) was hydrothermally synthesized from commercial LiOH, FeSO{sub 4} and H{sub 3}PO{sub 4} as raw materials and glucose as carbon precursor in aqueous solution at 180 C for 6 h followed by being fired at 750 C for 6 h. The samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and constant current charge-discharge cycling test. The results show that the synthesized powders are in situ coated with carbon precursor produced from glucose. At ambient temperature (25{+-}2 C), the specific discharge capacities are 154 mAh g{sup -1} at 0.2C and 136 mAh g{sup -1} at 5 C rate, and the cycling capacity retention rate reaches 98% over 90 cycles. The excellent electrochemical performance can be correlated with the in situ formation of carbon precursor/carbon, thus leading to the even distribution of carbon and the enhancement of conductibility of individual grains. (author)

  15. What You Should Know About High Blood Pressure and Medications

    Science.gov (United States)

    ... Aortic Aneurysm More What You Should Know About High Blood Pressure and Medications Updated:Jan 18,2017 Is medication ... resources . This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  16. How Potassium Can Help Control High Blood Pressure

    Science.gov (United States)

    ... Aneurysm More How Potassium Can Help Control High Blood Pressure Updated:Jan 29,2018 Understanding the heart-healthy ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  17. How High Blood Pressure Can Lead to Stroke

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More How High Blood Pressure Can Lead to Stroke Updated:Jan 29,2018 ... This content was last reviewed October 2016. High Blood Pressure • Home • Get the Facts About HBP • Know Your ...

  18. High Blood Pressure and Cold Remedies: Which Are Safe?

    Science.gov (United States)

    ... counter cold remedies safe for people who have high blood pressure? Answers from Sheldon G. Sheps, M.D. Over- ... remedies aren't off-limits if you have high blood pressure, but it's important to make careful choices. Among ...

  19. High pressure discharges in cavities formed by microfabrication techniques

    International Nuclear Information System (INIS)

    Khan, B.A.; Cammack, D.A.; Pinker, R.D.; Racz, J.

    1997-01-01

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

  20. Impurity trapped excitons under high hydrostatic pressure

    Science.gov (United States)

    Grinberg, Marek

    2013-09-01

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

  1. Microstructures define melting of molybdenum at high pressures

    Science.gov (United States)

    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.

  2. High-Pressure Oxygen Generation for Outpost EVA Study

    Science.gov (United States)

    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.

  3. Surface stabilized GMR nanorods of silver coated CrO{sub 2} synthesized via a polymer complex at ambient pressure

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, S., E-mail: drsomnathbiswas@gmail.com [The LNM Institute of Information Technology, Jaipur-302031 (India); Singh, G.P. [Centre for Nanotechnology, Central University of Jharkhand, Ranchi-835205 (India); Ram, S. [Materials Science Centre, Indian Institute of Technology, Kharagpur-721302 (India); Fecht, H.-J. [Insitut für Micro-und Nanomaterialien, Universität Ulm, Albert Einstein Allee-47, Ulm, D-89081, and Forschungszentrum Karlsruhe, Institute of Nanotechnology, Karlsruhe, D-76021 (Germany)

    2013-08-15

    Stable anisotropic nanorods of surface modified CrO{sub 2} (∼18 nm diameter) with a correlated diamagnetic layer (2–3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr{sup 4+} ions by Ag atoms on the CrO{sub 2} surface (topotactic surface layer) via an etching reaction of a CrO{sub 2}-polymer complex with Ag{sup +} ions in hot water followed by heating the dried sample at 300–400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO{sub 2} such that it no longer converts to Cr{sub 2}O{sub 3} in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO{sub 2} structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d{sub 5/2} and 3d{sub 3/2} X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (−) 7.6% at 77 K, than reported values in compacted CrO{sub 2} powders or composites. Such a large MR-value in the Coulomb blockade regime (<100 K) arises not only due to the suppressed spin flipping at low temperature but also from a spin dependent co-tunneling through an interlinked structure of silver and silver coated CrO{sub 2} nanorods. - Highlights: • Synthesis and structural studies of a novel GMR material of Ag coated CrO{sub 2}. • Tailoring useful GMR property in CrO{sub 2} nanorods of controlled shape and anisotropy. • Enhanced GMR is explained in correlation to the surface structure of CrO{sub 2} nanorods.

  4. High blood pressure in acute ischemic stroke and clinical outcome.

    Science.gov (United States)

    Manabe, Yasuhiro; Kono, Syoichiro; Tanaka, Tomotaka; Narai, Hisashi; Omori, Nobuhiko

    2009-11-16

    This study aimed to evaluate the prognostic value of acute phase blood pressure in patients with acute ischemic stroke by determining whether or not it contributes to clinical outcome. We studied 515 consecutive patients admitted within the first 48 hours after the onset of ischemic strokes, employing systolic and diastolic blood pressure measurements recorded within 36 hours after admission. High blood pressure was defined when the mean of at least 2 blood pressure measurements was ≥200 mmHg systolic and/or ≥110 mmHg diastolic at 6 to 24 hours after admission or ≥180 mmHg systolic and/or ≥105 mmHg diastolic at 24 to 36 hours after admission. The high blood pressure group was found to include 16% of the patients. Age, sex, diabetes mellitus, hypercholesterolemia, atrial fibrillation, ischemic heart disease, stroke history, carotid artery stenosis, leukoaraiosis, NIH Stroke Scale (NIHSS) on admission and mortality were not significantly correlated with either the high blood pressure or non-high blood pressure group. High blood pressure on admission was significantly associated with a past history of hypertension, kidney disease, the modified Rankin Scale (mRS) on discharge and the length of stay. On logistic regression analysis, with no previous history of hypertension, diabetes mellitus, atrial fibrillation, and kidney disease were independent risk factors associated with the presence of high blood pressure [odds ratio (OR), 1.85 (95% confidence interval (CI): 1.06-3.22), 1.89 (95% CI: 1.11-3.22), and 3.31 (95% CI: 1.36-8.04), respectively]. Multi-organ injury may be presented in acute stroke patients with high blood pressure. Patients with high blood pressure had a poor functional outcome after acute ischemic stroke.

  5. Radioresistance increase in polymers at high pressures. [. gamma. rays

    Energy Technology Data Exchange (ETDEWEB)

    Milinchuk, V; KIRJUKHIN, V; KLINSHPONT, E

    1977-06-01

    The effect was studied of very high pressures ranging within 100 and 2,700 MPa on the radioresistance of polytetrafluoroethylene, polypropylene and polyethylene in gamma irradiation. For experiments industrial polymers in the shape of blocks, films and fibers were used. It is shown that in easily breakable polymers, such as polytetrafluoroethylene and polypropylene, 1.3 to 2 times less free radicals are formed as a result of gamma irradiation and a pressure of 150 MPa than at normal pressure. The considerably reduced radiation-chemical formation of radicals and the destruction suppression by cross-linking in polymers is the evidence of the polymer radioresistance in irradiation at high pressures.

  6. Protection against high intravascular pressure in giraffe legs

    DEFF Research Database (Denmark)

    Petersen, Karin K; Hørlyck, Arne; Østergaard, Kristine Hovkjær

    2013-01-01

    The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination....... All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure....... revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along...

  7. CARS diagnostics of high pressure discharges

    International Nuclear Information System (INIS)

    Uhlenbusch, J.

    2001-01-01

    After a short description of the principles of the CARS, RECARS and POLCARS techniques and a discussion of setups for CARS experiments some experimental results are summarized. The results concern mainly plasma under atmospheric pressure, in particular the determination of temperature in a CO 2 laser-induced pyrolysis flame burning in a silane-acetylene gas mixture, the measurements of N 2 vibrational and rotational temperatures as well as the electron density by CARS and of an NO minority by POLCARS in an atmospheric microwave discharge, and finally RECARS experiments on indium iodide, Which is present in metal halide discharge lamps. Guided by these examples some problems and difficulties arising when performing CARS measurements are discussed

  8. Development of high pressure pipe scanners

    International Nuclear Information System (INIS)

    Kim, Jae H.; Lee, Jae C.; Moon, Soon S.; Eom, Heung S.; Choi, Yu R.

    1998-12-01

    This report describes an automatic ultrasonic scanning system for pressure pipe welds, which was developed in this project using recent advanced technologies on mobile robot and computer. The system consists of two modules: a robot scanner module which navigates and manipulates scanning devices, and a data acquisition module which generates ultrasonic signal and processes the data from the scanner. The robot has 4 magnetic wheels and 2 -axis manipulator on which ultrasonic transducer attached. The wheeled robot can navigate curved surface such as outer wall of circular pipes. Magnetic wheels were optimally designed through magnetic field analysis. Free surface sensing and line tracking control algorithm were developed and implemented, and the control devices and software can be used in practical inspection works. We expect our system can contribute to reduction of inspection time, performance enhancement, and effective management of inspection results

  9. LDH nanocages synthesized with MOF templates and their high performance as supercapacitors

    Science.gov (United States)

    Jiang, Zhen; Li, Zhengping; Qin, Zhenhua; Sun, Haiyan; Jiao, Xiuling; Chen, Dairong

    2013-11-01

    Layered double hydroxides (LDHs) are currently attracting intense research interest for their various applications. Three LDH hollow nano-polyhedra are synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the templates. The nanocages well inherit the rhombic dodecahedral shape of the ZIF-67 templates, and the shell is composed of nanosheets assembled with an edge-to-face stacking. This is the first synthesis of the LDH non-spherical structures. And the mechanism of utilizing metal-organic framework (MOF) nanocrystals as templates is explored. Control of the simultaneous reactions, the precipitation of the shells and the template etching, is extremely crucial to the preparation of the perfect nanocages. And the Ni-Co LDH nanocages exhibit superior pseudocapacitance property due to their novel hierarchical and submicroscopic structures.Layered double hydroxides (LDHs) are currently attracting intense research interest for their various applications. Three LDH hollow nano-polyhedra are synthesized with zeolitic imidazolate framework-67 (ZIF-67) nanocrystals as the templates. The nanocages well inherit the rhombic dodecahedral shape of the ZIF-67 templates, and the shell is composed of nanosheets assembled with an edge-to-face stacking. This is the first synthesis of the LDH non-spherical structures. And the mechanism of utilizing metal-organic framework (MOF) nanocrystals as templates is explored. Control of the simultaneous reactions, the precipitation of the shells and the template etching, is extremely crucial to the preparation of the perfect nanocages. And the Ni-Co LDH nanocages exhibit superior pseudocapacitance property due to their novel hierarchical and submicroscopic structures. Electronic supplementary information (ESI) available: Experimental details, XRD, TEM, SEM, and XPS images. See DOI: 10.1039/c3nr03829g

  10. Characterization and Thermal Dehydration Kinetics of Highly Crystalline Mcallisterite, Synthesized at Low Temperatures

    Directory of Open Access Journals (Sweden)

    Emek Moroydor Derun

    2014-01-01

    Full Text Available The hydrothermal synthesis of a mcallisterite (Mg2(B6O7(OH62·9(H2O mineral at low temperatures was characterized. For this purpose, several reaction temperatures (0–70°C and reaction times (30–240 min were studied. Synthesized minerals were subjected to X-ray diffraction (XRD, fourier transform infrared (FT-IR, and Raman spectroscopies and scanning electron microscopy (SEM. Additionally, experimental analyses of boron trioxide (B2O3 content and reaction yields were performed. Furthermore, thermal gravimetry and differential thermal analysis (TG/DTA were used for the determination of thermal dehydration kinetics. According to the XRD results, mcallisterite, which has a powder diffraction file (pdf number of “01-070-1902,” was formed under certain reaction parameters. Pure crystalline mcallisterite had diagnostic FT-IR and Raman vibration peaks and according to the SEM analysis, for the minerals which were synthesized at 60°C and 30 min of reaction time, particle size was between 398.30 and 700.06 nm. Its B2O3 content and reaction yield were 50.80±1.12% and 85.80±0.61%, respectively. Finally, average activation energies (conversion values (α that were selected between 0.1 and 0.6 were calculated as 100.40 kJ/mol and 98.31 kJ/mol according to Ozawa and Kissinger-Akahira-Sunose (KAS methods, respectively.

  11. Various high precision measurements of pressure in atomic energy industry

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Inoue, Akira; Hosoma, Takashi; Tanaka, Izumi; Gabane, Tsunemichi.

    1987-01-01

    As for the pressure measurement in atomic energy industry, it is mostly the measurement using differential pressure transmitters and pressure transmitters for process measurement with the general accuracy of measurement of 0.2 - 0.5 % FS/year. However, recently for the development of nuclear fusion reactors and the establishment of nuclear fuel cycle accompanying new atomic energy technology, there are the needs of the pressure measurement having higher accuracy of 0.01 % FS/year and high resolution, and quartz vibration type pressure sensors appeared. New high accuracy pressure measurement techniques were developed by the advance of data processing and the rationalization of data transmission. As the results, the measurement of the differential pressure of helium-lithium two-phase flow in the cooling system of nuclear fusion reactors, the high accuracy measuring system for the level of plutonium nitrate and other fuel substance in tanks in fuel reprocessing and conversion, the high accuracy measurement of atmospheric pressure and wind velocity in ducts, chimneys and tunnels in nuclear facilities and so on became feasible. The principle and the measured data of quartz vibration type pressure sensors are shown. (Kako, I.)

  12. High-pressure applications in medicine and pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jerson L; Foguel, Debora; Suarez, Marisa; Gomes, Andre M O; Oliveira, Andrea C [Centro Nacional de Ressonancia Magnetica Nuclear, Departamento de Bioquimica Medica, Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590 (Brazil)

    2004-04-14

    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.

  13. High-pressure applications in medicine and pharmacology

    International Nuclear Information System (INIS)

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

    2004-01-01

    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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  15. A novel SOI pressure sensor for high temperature application

    International Nuclear Information System (INIS)

    Li Sainan; Liang Ting; Wang Wei; Hong Yingping; Zheng Tingli; Xiong Jijun

    2015-01-01

    The silicon on insulator (SOI) high temperature pressure sensor is a novel pressure sensor with high-performance and high-quality. A structure of a SOI high-temperature pressure sensor is presented in this paper. The key factors including doping concentration and power are analyzed. The process of the sensor is designed with the critical process parameters set appropriately. The test result at room temperature and high temperature shows that nonlinear error below is 0.1%, and hysteresis is less than 0.5%. High temperature measuring results show that the sensor can be used for from room temperature to 350 °C in harsh environments. It offers a reference for the development of high temperature piezoresistive pressure sensors. (semiconductor devices)

  16. High pressure Moessbauer spectroscopy of perovskite iron oxide

    CERN Document Server

    Nasu, S; Morimoto, S; Kawakami, T; Kuzushita, K; Takano, M

    2003-01-01

    High-pressure sup 5 sup 7 Fe Moessbauer spectroscopy using a diamond anvil cell has been performed for perovskite iron oxides SrFeO sub 3 , CaFeO sub 3 and La sub 1 sub / sub 3 Sr sub 2 sub / sub 3 O sub 3. The charge states and the magnetic dependency to pressure were determined. Pressure magnetic phase diagrams of these perovskite iron oxides are determined up to about 70 GPa. To be clear the magnetic ordered state, they are measured up to 7.8 T external magnetic fields at 4.5K. The phase transition of these perovskite oxides to ferromagnetisms with high magnetic ordered temperature is observed. In higher pressure, high spin-low spin transition of oxides besides CaFeO sub 3 is generated. The feature of Moessbauer spectroscopy, perovskite iron oxide and Moessbauer spectroscopy under high pressure are explained. (S.Y.)

  17. High pressure processing reaches the U.S. market

    International Nuclear Information System (INIS)

    Mermelstein, N.H.

    1997-01-01

    The first food product commercially produced by a U.S. company using high-pressure processing has had successful test market results. High-pressure processing permits food to be preserved by subjecting it to pressures in the range of 60,000-100,000 psi for a short time instead of exposing the food to heat, freezing, chemicals, or irradiation. To produce Classic Guacamole, Avomex of Keller, Texas, uses a batch isostatic press to deactivate the enzymes in the avocado and to kill bacteria, obtaining a refrigerated shelf life of over 30 days. The guacamole is then vacuum packed and processed again. The product undergoes no heat treatment and does not contain preservatives, and the high pressure does not affect its texture, color, or taste. Meanwhile, a continuous system for high-pressure processing of pumpable foods is currently being developed by Flow International of Kent, Washington, and will be used for testing and applications work at Oregon State University

  18. High pressure orthorhombic structure of CuInSe2

    International Nuclear Information System (INIS)

    Bovornratanaraks, T; Saengsuwan, V; Yoodee, K; McMahon, M I; Hejny, C; Ruffolo, D

    2010-01-01

    The structural behaviour of CuInSe 2 under high pressure has been studied up to 53 GPa using angle-dispersive x-ray powder diffraction techniques. The previously reported structural phase transition from its ambient pressure tetragonal structure to a high pressure phase with a NaCl-like cubic structure at 7.6 GPa has been confirmed. On further compression, another structural phase transition is observed at 39 GPa. A full structural study of this high pressure phase has been carried out and the high pressure structure has been identified as orthorhombic with space group Cmcm and lattice parameters a = 4.867(8) A, b = 5.023(8) A and c = 4.980(3) A at 53.2(2) GPa. This phase transition behaviour is similar to those of analogous binary and trinary semiconductors, where the orthorhombic Cmcm structure can also be viewed as a distortion of the cubic NaCl-type structure.

  19. High pressure Moessbauer spectroscopy of perovskite iron oxide

    International Nuclear Information System (INIS)

    Nasu, Saburo; Suenaga, Tomoya; Morimoto, Shotaro; Kawakami, Takateru; Kuzushita, Kaori; Takano, Mikio

    2003-01-01

    High-pressure 57 Fe Moessbauer spectroscopy using a diamond anvil cell has been performed for perovskite iron oxides SrFeO 3 , CaFeO 3 and La 1/3 Sr 2/3 O 3 . The charge states and the magnetic dependency to pressure were determined. Pressure magnetic phase diagrams of these perovskite iron oxides are determined up to about 70 GPa. To be clear the magnetic ordered state, they are measured up to 7.8 T external magnetic fields at 4.5K. The phase transition of these perovskite oxides to ferromagnetisms with high magnetic ordered temperature is observed. In higher pressure, high spin-low spin transition of oxides besides CaFeO 3 is generated. The feature of Moessbauer spectroscopy, perovskite iron oxide and Moessbauer spectroscopy under high pressure are explained. (S.Y.)

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

    International Nuclear Information System (INIS)

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

    2003-01-01

    Fluorinert is a liquid pressure-transmitting medium that is widely used in high-pressure diffraction work. A systematic study of five different fluorinerts was carried out using single-crystal x-ray diffraction in a diamond-anvil cell in order to determine the pressure range over which they provide a hydrostatic stress state to the sample. It was found that none of the fluorinerts studied can be considered hydrostatic above 1.2 GPa, a lower pressure than reported previously

  1. Moessbauer study of phase transitions under high hydrostatic pressures. 1

    International Nuclear Information System (INIS)

    Kapitanov, E.V.; Yakovlev, E.N.

    1979-01-01

    Experimental results of the hydrostatic pressure influence on Moessbauer spectrum parameters are obtained over the pressure range including the area of structural phase transition. A linear increase of the Moessbauer effect probability (recoilless fraction) is accompanied by a linear decrease of the electron density at tin nuclei within the pressure range foregoing the phase transition. The electric resistance and the recoilless fraction of the new phase of Mg 2 Sn are lower, but the electron density at tin nuclei is greater than the initial phase ones. Hydrostatic conditions allow to fix clearly the diphasic transition area and to determine the influence of the pressure on the Moessbauer line position and on the recoilless fraction of the high pressure phase. The phase transition heat Q = 415 cal mol -1 is calculated using recoilless fractions of the high and low pressure phases at 25 kbar. The present results are qualitatively and quantitatively different from the results, obtained at nonhydrostatic conditions. (author)

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

    International Nuclear Information System (INIS)

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

    2004-01-01

    The effect of pressurization at different pressures (from 200 to 1000 MPa, at 200 MPa intervals, t const. = 15 min) and periods of time (from 15 to 35 min, at 10 min intervals, p const. = 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

  3. Low Power and High Sensitivity MOSFET-Based Pressure Sensor

    International Nuclear Information System (INIS)

    Zhang Zhao-Hua; Ren Tian-Ling; Zhang Yan-Hong; Han Rui-Rui; Liu Li-Tian

    2012-01-01

    Based on the metal-oxide-semiconductor field effect transistor (MOSFET) stress sensitive phenomenon, a low power MOSFET pressure sensor is proposed. Compared with the traditional piezoresistive pressure sensor, the present pressure sensor displays high performances on sensitivity and power consumption. The sensitivity of the MOSFET sensor is raised by 87%, meanwhile the power consumption is decreased by 20%. (cross-disciplinary physics and related areas of science and technology)

  4. High temperature pressure water's blowdown into water. Experimental results

    International Nuclear Information System (INIS)

    Ishida, Toshihisa; Kusunoki, Tsuyoshi; Kasahara, Yoshiyuki; Iida, Hiromasa

    1994-01-01

    The purpose of the present experimental study is to clarify the phenomena in blowdown of high temperature and pressure water in pressure vessel into the containment water for evaluation of design of an advanced marine reactor(MRX). The water blown into the containment water flushed and formed steam jet plume. The steam jet condensed in the water, but some stream penetrated to gas phase of containment and contributed to increase of containment pressure. (author)

  5. Phase transformations of high-purity PbI{sub 2} nanoparticles synthesized from lead-acid accumulator anodes

    Energy Technology Data Exchange (ETDEWEB)

    Malevu, T.D., E-mail: malevutd@ufs.ac.za; Ocaya, R.O.; Tshabalala, K.G.

    2016-09-01

    High-purity hexagonal lead iodide nanoparticles have been synthesized from a depleted sealed lead acid battery anode. The synthesized product was found to consist of the rare 6R polytype form of PbI{sub 2} that is thought to have good potential in photovoltaic applications. We investigate the effects of annealing time and post-melting temperature on the structure and optical properties using 1.5418 Å CuKα radiation. Photoluminescence measurements were done under 150 W/221 nm wavelength xenon excitation. Phase transformation was observed through XRD peaks when annealing time increased from 0.5–5 h. The nanoparticle grain size and inter-planar distance appeared to be independent of annealing time. PL measurements show three broad peaks in a range of 400 nm to 700 nm that are attributed to excitonic, donor–acceptor pair and luminescence bands from the deep levels.

  6. Ab initio pseudopotential studies of cubic BC2N under high pressure

    International Nuclear Information System (INIS)

    Pan Zicheng; Sun Hong; Chen Changfeng

    2005-01-01

    We present the results of a systematic study of the structural, electronic, and vibrational properties of various cubic BC 2 N phases under high pressure. Ab initio pseudopotential total-energy and phonon calculations have been carried out to examine the changes in the structural parameters, bonding behaviours, band structures, and dynamic instabilities caused by phonon softening in these phases. We find that an experimentally synthesized high-density phase of cubic BC 2 N exhibits outstanding stability in the structural and electronic properties up to very high pressures. On the other hand, another experimentally identified phase with lower density and lower symmetry undergoes a dramatic structural transformation with a volume and bond-length collapse and a concomitant semi-metal to semiconductor transition. A third phase is predicted to be favourable over the above-mentioned lower-density phase by the enthalpy calculations. However, the dynamic phonon calculations reveal that it develops imaginary phonon modes and, therefore, is unstable in the experimental pressure range. The calculations indicate that its synthesis may be achieved at reduced pressures. These results provide a comprehensive understanding for the high-pressure behaviour of the cubic BC 2 N phases and reveal their interesting properties that can be verified by experiments

  7. One-step green synthesis of cuprous oxide crystals with truncated octahedra shapes via a high pressure flux approach

    International Nuclear Information System (INIS)

    Li Benxian; Wang Xiaofeng; Xia Dandan; Chu Qingxin; Liu Xiaoyang; Lu Fengguo; Zhao Xudong

    2011-01-01

    Cuprous oxide (Cu 2 O) was synthesized via reactions between cupric oxide (CuO) and copper metal (Cu) at a low temperature of 300 deg. C. This progress is green, environmentally friendly and energy efficient. Cu 2 O crystals with truncated octahedra morphology were grown under high pressure using sodium hydroxide (NaOH) and potassium hydroxide (KOH) with a molar ratio of 1:1 as a flux. The growth mechanism of Cu 2 O polyhedral microcrystals are proposed and discussed. - Graphical Abstract: The Cu 2 O crystals with truncated octahedral shape were one-step synthesized in high yield via high pressure flux method for the first time, which is green and environmentally friendly. The mechanisms of synthesis and crystal growth were discussed in this paper. Highlights: → Cuprous oxide was one-step green synthesized by high pressure flux method. → The approach was based on the reverse dismutation reactions between cupric oxide and copper metal. → This progress is green, environmentally friendly and energy efficient. → The synthesized Cu2O crystals were of truncated octahedra morphology.

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

    Science.gov (United States)

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

    2016-04-14

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

  9. Decomposition of silicon carbide at high pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Daviau, Kierstin; Lee, Kanani K. M.

    2017-11-01

    We measure the onset of decomposition of silicon carbide, SiC, to silicon and carbon (e.g., diamond) at high pressures and high temperatures in a laser-heated diamond-anvil cell. We identify decomposition through x-ray diffraction and multiwavelength imaging radiometry coupled with electron microscopy analyses on quenched samples. We find that B3 SiC (also known as 3C or zinc blende SiC) decomposes at high pressures and high temperatures, following a phase boundary with a negative slope. The high-pressure decomposition temperatures measured are considerably lower than those at ambient, with our measurements indicating that SiC begins to decompose at ~ 2000 K at 60 GPa as compared to ~ 2800 K at ambient pressure. Once B3 SiC transitions to the high-pressure B1 (rocksalt) structure, we no longer observe decomposition, despite heating to temperatures in excess of ~ 3200 K. The temperature of decomposition and the nature of the decomposition phase boundary appear to be strongly influenced by the pressure-induced phase transitions to higher-density structures in SiC, silicon, and carbon. The decomposition of SiC at high pressure and temperature has implications for the stability of naturally forming moissanite on Earth and in carbon-rich exoplanets.

  10. High-pressure phase transition in Ho2O3

    International Nuclear Information System (INIS)

    Lonappan, Dayana; Shekar, N.V. Chandra; Ravindran, T.R.; Sahu, P. Ch.

    2010-01-01

    High-pressure X-ray diffraction and Raman studies on holmium sesquioxide (Ho 2 O 3 ) have been carried out up to a pressure of ∼17 GPa in a diamond-anvil cell at room temperature. Holmium oxide, which has a cubic or bixbyite structure under ambient conditions, undergoes an irreversible structural phase transition at around 9.5 GPa. The high-pressure phase has been identified to be low symmetry monoclinic type. The two phases coexist to up to about 16 GPa, above which the parent phase disappears. The high-pressure laser-Raman studies have revealed that the prominent Raman band ∼370 cm -1 disappears around the similar transition pressure. The bulk modulus of the parent phase is reported.

  11. Mechanically recovered poultry meat sausages manufactured with high hydrostatic pressure.

    Science.gov (United States)

    Yuste, J; Mor-Mur, M; Capellas, M; Guamis, B; Pla, R

    1999-06-01

    The effect of high pressure processing at high temperature on texture and color of frankfurter-type sausages made with different contents of mechanically recovered poultry meat (MRPM) was evaluated and compared with that of a standard cooking process. Five types of sausages containing 100, 75, 50, 25, and 0% MRPM and 0, 25, 50, 75, and 100% of minced pork meat (MPM), respectively, were manufactured. They were pressurized at 500 MPa for 30 min at 50, 60, 70, and 75 C or cooked at 75 C for 30 min. Pressure-treated sausages were less springy and firm, but more cohesive. Moreover, color of pressurized sausages was lighter and more yellow than that of conventionally cooked sausages. Addition of MPM increased cohesiveness, hardness, and force at 80% compression. Minced pork meat also caused the appearance of sausages to be lighter, less red, and less yellow. Cooked sausages made with MRPM can have an attractive appearance and texture via high pressure processing.

  12. Germination of vegetable seeds exposed to very high pressure

    Science.gov (United States)

    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.

  13. Germination of vegetable seeds exposed to very high pressure

    International Nuclear Information System (INIS)

    Mori, Y; Yokota, S; Ono, F

    2012-01-01

    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.

  14. HIGH HYDROSTATIC PRESSURE SYSTEMS USE IN FOOD INDUSTRY

    OpenAIRE

    Yahya TÜLEK; Gökçe FİLİZAY

    2006-01-01

    Food preservation is a continuous fight against microorganisms spoiling the food or making it unsafe. The last decade, non-thermal inactivation techniques have been a major research issue, driven by an increased consumer demand for nutritious, fresh like food products with a high organoleptical quality and an acceptable shelf life. Investigated inactivation technologies are ionisation radiation, high hydrostatic pressure (HHP), pulsed electrical fields, high pressure homogenisation, UV decont...

  15. Glassy selenium at high pressure: Le Chatelier's principle still works

    Science.gov (United States)

    Brazhkin, V. V.; Tsiok, O. B.

    2017-10-01

    Selenium is the only easily vitrified elementary substance. Numerous experimental studies of glassy Se (g -Se) at high pressures show a large spread in the data on the compressibility and electrical resistivity of g -Se. Furthermore, H. Liu et al. [Proc. Natl. Acad. Sci. USA 105, 13229 (2008), 10.1073/pnas.0806857105] have arrived at the surprising conclusion that the volume of glass increases during pressure-induced crystallization. We have performed high-precision measurements of the specific volume and electrical resistivity of glassy selenium (g -Se) at high hydrostatic pressures up to 9 GPa. The measured bulk modulus at normal pressure is B =(9.0 5 ±0.15 ) GPa and its pressure derivative is BP'=6.4 ±0.2 . In the pressure range P <3 GPa, glassy selenium has an anomalously large negative second derivative of the bulk modulus. The electrical resistivity of g -Se decreases almost exponentially with increasing pressure and reaches 20 Ω cm at a pressure of 8.75 GPa. The inelastic behavior and weak relaxation of the volume for g -Se begin at pressures above 3.5 GPa; the volume and logarithm of the electrical resistivity relax significantly (logarithmically with the time) at pressures above 8 GPa. Bulk measurements certainly indicate that the volume of g -Se glass in the crystallization pressure range is larger than the volumes of both appearing crystalline phases (by 2% and 4%). Therefore, the "volume expansion phenomenon" suggested in [H. Liu et al., Proc. Natl. Acad. Sci. USA 105, 13229 (2008), 10.1073/pnas.0806857105] is not observed, and the pressure-induced crystallization of glassy selenium is consistent with the laws of thermodynamics.

  16. Low Cost, High Efficiency, High Pressure Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mark Leavitt

    2010-03-31

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

  17. High hydrostatic pressure extraction of phenolic compounds from ...

    African Journals Online (AJOL)

    High hydrostatic pressure processing (HHPP) is a food processing method, in which food is subjected to the elevated pressure which is mostly between 100 to 800 MPa. HHPP is seen not only in food engineering, but also have other application areas, such as extraction of active ingredients from natural biomaterials.

  18. Growth and high pressure studies of zirconium sulphoselenide ...

    Indian Academy of Sciences (India)

    Growth and high pressure studies of zirconium sulphoselenide single ... tance was monitored in a Bridgman opposed anvil set-up up to 8 GPa pressure to identify .... The optical band gaps of the as-grown crystals were obtained by optical ab-.

  19. Investigation of Methacrylic Acid at High Pressure Using Neutron Diffraction

    DEFF Research Database (Denmark)

    Marshall, William G.; Urquhart, Andrew; Oswald, Iain D. H.

    2015-01-01

    This article shows that pressure can be a low-intensity route to the synthesis of polymethacrylic acid. The exploration of perdeuterated methacrylic acid at high pressure using neutron diffraction reveals that methacrylic acid exhibits two polymorphic phase transformations at relatively low...

  20. High pressure phases of terbium: Possibility of a thcp phase

    International Nuclear Information System (INIS)

    Staun Olsen, J.; Steenstrup, S.; Gerward, L.

    1985-01-01

    High pressure phases of trivalent Tb studied by energy dispersive X-ray diffraction with synchrotron radiation exhibits the closed packed sequence (hcp -> Sm -> dhcp -> fcc) typical of the trivalent rare earth metals. Furthermore, a phase consistent with a triple hexagonal closed packed (thcp) structure was observed in a narrow pressure range around 30 GPa. (orig.)

  1. Two-Dimensional Polymer Synthesized via Solid-State Polymerization for High-Performance Supercapacitors.

    Science.gov (United States)

    Liu, Wei; Ulaganathan, Mani; Abdelwahab, Ibrahim; Luo, Xin; Chen, Zhongxin; Rong Tan, Sherman Jun; Wang, Xiaowei; Liu, Yanpeng; Geng, Dechao; Bao, Yang; Chen, Jianyi; Loh, Kian Ping

    2018-01-23

    Two-dimensional (2-D) polymer has properties that are attractive for energy storage applications because of its combination of heteroatoms, porosities and layered structure, which provides redox chemistry and ion diffusion routes through the 2-D planes and 1-D channels. Here, conjugated aromatic polymers (CAPs) were synthesized in quantitative yield via solid-state polymerization of phenazine-based precursor crystals. By choosing flat molecules (2-TBTBP and 3-TBQP) with different positions of bromine substituents on a phenazine-derived scaffold, C-C cross coupling was induced following thermal debromination. CAP-2 is polymerized from monomers that have been prepacked into layered structure (3-TBQP). It can be mechanically exfoliated into micrometer-sized ultrathin sheets that show sharp Raman peaks which reflect conformational ordering. CAP-2 has a dominant pore size of ∼0.8 nm; when applied as an asymmetric supercapacitor, it delivers a specific capacitance of 233 F g -1 at a current density of 1.0 A g -1 , and shows outstanding cycle performance.

  2. Safety analysis of high pressure gasous fuel container punctures

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.R. [Univ. of Miami, Coral Gables, FL (United States)

    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.

  3. Teaming Up Against High Blood Pressure PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2012-09-04

    Nearly one-third of American adults have high blood pressure, and more than half of them don’t have it under control. Simply seeing a doctor and taking medications isn’t enough for many people who have high blood pressure. A team-based approach by patients, health care systems, and health care providers is one of the best ways to treat uncontrolled high blood pressure.  Created: 9/4/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 9/4/2012.

  4. Safety supervision on high-pressure gas regulations

    International Nuclear Information System (INIS)

    Lee, Won Il

    1991-01-01

    The first part lists the regulation on safety supervision of high-pressure gas, enforcement ordinance on high-pressure gas safety supervision and enforcement regulations about high-pressure gas safety supervision. The second part indicates safety regulations on liquefied petroleum gas and business, enforcement ordinance of safety on liquefied petroleum gas and business, enforcement regulation of safety supervision over liquefied petroleum gas and business. The third part lists regulation on gas business, enforcement ordinance and enforcement regulations on gas business. Each part has theory and explanation for questions.

  5. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  6. High pressure structural studies on nanophase praseodymium oxide

    International Nuclear Information System (INIS)

    Saranya, L.; Chandra Shekar, N.V.; Amirthapandian, S.; Hussain, Shamima; Arulraj, A.; Sahu, P. Ch.

    2014-01-01

    The phase stability of nanocrystalline Pr 2 O 3 has been investigated under pressure by in-situ high pressure X-ray diffraction using Mao-Bell type diamond anvil cell. The ambient structure and phase of the praseodymium oxide have been resolved unambiguously using x-ray diffraction, SEM and TEM techniques. Under the action of pressure the cubic phase of the system is retained up to 15 GPa. This is unusual as other isostructural rare earth oxides show structural transformations even at lower pressures. From the best fit to the P–V data with the Murnaghan equation of state yields a bulk modulus of 171 GPa

  7. High-pressure structural behaviour of nanocrystalline Ge

    International Nuclear Information System (INIS)

    Wang, H; Liu, J F; He, Y; Wang, Y; Chen, W; Jiang, J Z; Olsen, J Staun; Gerward, L

    2007-01-01

    The equation of state and the pressure of the I-II transition have been studied for nanocrystalline Ge using synchrotron x-ray diffraction. The bulk modulus and the transition pressure increase with decreasing particle size for both Ge-I and Ge-II, but the percentage volume collapse at the transition remains constant. Simplified models for the high-pressure structural behaviour are presented, based on the assumption that a large fraction of the atoms reside in grain boundary regions of the nanocrystalline material. The interface structure plays a significant role in affecting the transition pressure and the bulk modulus

  8. Trends in high pressure developments for new perspectives

    Science.gov (United States)

    Largeteau, Alain; Prakasam, Mythili

    2018-06-01

    Temperature and Pressure are two parameters in the universe, where pressure represents the largest scale in comparison to temperature. The design of high pressure equipment depends mainly on the media used which could be gas, liquid or solid and the objective could be synthesis of materials or in situ characterization. The development of new research fields requiring high pressure equipment which are currently in Bordeaux - France are based on the historical development of high pressure domain initiated by Professor Gerard DEMAZEAU and his team during the last half century, which is discussed here. The main concepts governing the effect of pressure on materials synthesis is by the combination of high pressure and high temperature which are described with apt examples. There is an upsurge in various technologies for strong development for the synthesis of materials to drive several possibilities, for example: to reach very high density to obtain optical ceramics (by conventional SPS), to diminish parameters (P, T, t) of synthesis (by HP-SPS), to sinter at low temperature thermal sensitive composition (by HyS), to consolidate porous materials (by FIP), to densify biocomposite with cold decontamination (by HHP) simultaneously, etc.

  9. High-pressure behavior of CaMo O4

    Science.gov (United States)

    Panchal, V.; Garg, N.; Poswal, H. K.; Errandonea, D.; Rodríguez-Hernández, P.; Muñoz, A.; Cavalli, E.

    2017-09-01

    We report a high-pressure study of tetragonal scheelite-type CaMo O4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density functional theory calculations. We have found evidence of a pressure-induced phase transition near 15 GPa. Experiments and calculations agree in assigning the high-pressure phase to a monoclinic fergusonite-type structure. The reported results are consistent with previous powder x-ray-diffraction experiments, but are in contradiction with the conclusions obtained from earlier Raman measurements, which support the existence of more than one phase transition in the pressure range covered by our studies. The observed scheelite-fergusonite transition induces significant changes in the electronic band gap and phonon spectrum of CaMo O4 . We have determined the pressure evolution of the band gap for the low- and high-pressure phases as well as the frequencies and pressure dependencies of the Raman-active and infrared-active modes. In addition, based on calculations of the phonon dispersion of the scheelite phase, carried out at a pressure higher than the transition pressure, we propose a possible mechanism for the reported phase transition. Furthermore, from the calculations we determined the pressure dependence of the unit-cell parameters and atomic positions of the different phases and their room-temperature equations of state. These results are compared with previous experiments showing a very good agreement. Finally, information on bond compressibility is reported and correlated with the macroscopic compressibility of CaMo O4 . The reported results are of interest for the many technological applications of this oxide.

  10. Effect of High Pressure and Heat on Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Dirk Margosch

    2005-01-01

    Full Text Available Even though the inactivation of microorganisms by high pressure treatment is a subject of intense investigations, the effect of high pressure on bacterial toxins has not been studied so far. In this study, the influence of combined pressure/temperature treatment (0.1 to 800 MPa and 5 to 121 °C on bacterial enterotoxins was determined. Therefore, heat-stable enterotoxin (STa of cholera toxin (CT from Vibrio cholerae, staphylococcal enterotoxins A-E, haemolysin BL (HBL from Bacillus cereus, and Escherichia coli (STa were subjected to different treatment schemes. Structural alterations were monitored in enzyme immunoassays (EIAs. Cytotoxicity of the pressure treated supernatant of toxigenic B. cereus DSM 4384 was investigated with Vero cells. High pressure of 200 to 800 MPa at 5 °C leads to a slight increase of the reactivity of the STa of E. coli. However, reactivity decreased at 800 MPa and 80 °C to (66±21 % after 30 min and to (44±0.3 % after 128 min. At ambient pressure no decrease in EIA reactivity could be observed after 128 min. Pressurization (0.1 to 800 MPa of heat stable monomeric staphylococcal toxins at 5 and 20 °C showed no effect. A combined heat (80 °C and pressure (0.1 to 800 MPa treatment lead to a decrease in the immuno-reactivity to 20 % of its maximum. For cholera toxin a significant loss in latex agglutination was observable only at 80 °C and 800 MPa for holding times higher than 20 min. Interestingly, the immuno-reactivity of B. cereus HBL toxin increased with the increase of pressure (182 % at 800 MPa, 30 °C, and high pressure showed only minor effects on cytotoxicity to Vero cells. Our results indicate that pressurization can increase inactivation observed by heat treatment, and combined treatments may be effective at lower temperatures and/or shorter incubation time.

  11. A low-jitter RF PLL frequency synthesizer with high-speed mixed-signal down-scaling circuits

    International Nuclear Information System (INIS)

    Tang Lu; Wang Zhigong; Xue Hong; He Xiaohu; Xu Yong; Sun Ling

    2010-01-01

    A low-jitter RF phase locked loop (PLL) frequency synthesizer with high-speed mixed-signal down-scaling circuits is proposed. Several techniques are proposed to reduce the design complexity and improve the performance of the mixed-signal down-scaling circuit in the PLL. An improved D-latch is proposed to increase the speed and the driving capability of the DMP in the down-scaling circuit. Through integrating the D-latch with 'OR' logic for dual-modulus operation, the delays associated with both the 'OR' and D-flip-flop (DFF) operations are reduced, and the complexity of the circuit is also decreased. The programmable frequency divider of the down-scaling circuit is realized in a new method based on deep submicron CMOS technology standard cells and a more accurate wire-load model. The charge pump in the PLL is also realized with a novel architecture to improve the current matching characteristic so as to reduce the jitter of the system. The proposed RF PLL frequency synthesizer is realized with a TSMC 0.18-μm CMOS process. The measured phase noise of the PLL frequency synthesizer output at 100 kHz offset from the center frequency is only -101.52 dBc/Hz. The circuit exhibits a low RMS jitter of 3.3 ps. The power consumption of the PLL frequency synthesizer is also as low as 36 mW at a 1.8 V power supply. (semiconductor integrated circuits)

  12. Experiments on aerosol removal by high-pressure water spray

    Energy Technology Data Exchange (ETDEWEB)

    Corno, Ada del, E-mail: delcorno@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Morandi, Sonia, E-mail: morandi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Parozzi, Flavio, E-mail: parozzi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Araneo, Lucio, E-mail: lucio.araneo@polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy); CNR-IENI, via Cozzi 53, I-20125 Milano (Italy); Casella, Francesco, E-mail: francesco2.casella@mail.polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy)

    2017-01-15

    Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m{sup 3}. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m{sup 3}. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was

  13. Experiments on aerosol removal by high-pressure water spray

    International Nuclear Information System (INIS)

    Corno, Ada del; Morandi, Sonia; Parozzi, Flavio; Araneo, Lucio; Casella, Francesco

    2017-01-01

    Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO_2 particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m"3. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO_2 particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m"3. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was detected with 1

  14. High Efficient Dye-Sensitized Solar Cells Based on Synthesized SnO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    W. M. N. M. B. Wanninayake

    2016-01-01

    Full Text Available In this study, SnO2 semiconductor nanoparticles were synthesized for DSC applications via acid route using tin(ii chloride as a starting material and hydrothermal method through the use of tin(iv chloride. Powder X-ray diffraction studies confirmed the formation of the rutile phase of SnO2 with nanoranged particle sizes. A quasi-solid-state electrolyte was employed instead of a conventional liquid electrolyte in order to overcome the practical limitations such as electrolyte leakage, solvent evaporation, and sealing imperfections associated with liquid electrolytes. The gel electrolytes were prepared incorporating lithium iodide (LiI and tetrapropylammonium iodide (Pr4N+I− salts, separately, into the mixture which contains polyacrylonitrile as a polymer, propylene carbonate and ethylene carbonate as plasticizers, iodide/triiodide as the redox couple, acetonitrile as the solvent, and 4-tertiary butylpyridine as an electrolyte additive. In order to overcome the recombination problem associated with the SnO2 due to its higher electron mobility, ultrathin layer of CaCO3 coating was used to cover the surface recombination sites of SnO2 nanoparticles. Maximum energy conversion efficiency of 5.04% is obtained for the device containing gel electrolyte incorporating LiI as the salt. For the same gel electrolyte, the ionic conductivity and the diffusion coefficient of the triiodide ions are 4.70 × 10−3 S cm−1 and 4.31 × 10−7 cm2 s−1, respectively.

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

    Science.gov (United States)

    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.

  16. High-pressure Raman investigation of the semiconductor antimony oxide

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Aihui; Cao, Lihua [State Key Lab on High Power Semiconductor Laser, Changchun University of Science and Technology, 130022 Changchun (China); Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130012 Changchun (China); Wan, Chunming [State Key Lab on High Power Semiconductor Laser, Changchun University of Science and Technology, 130022 Changchun (China); Ma, Yanmei [Department of Agronomy, Jilin University, 130062 Changchun (China)

    2011-05-15

    The in situ high-pressure behavior of the semiconductor antimony trioxide (Sb{sub 2}O{sub 3}) has been investigated by Raman spectroscopy techniques in a diamond anvil cell up to 20 GPa at room temperature. New peaks in the external lattice mode range emerged at a pressure above 8.6-15 GPa, suggesting that the structural phase transition occurred. The pressure dependence of Raman frequencies was obtained. The band at 139 cm{sup -1} (assigned to group mode) has a pressure dependence of -0.475 cm{sup -1}/GPa and reveals significant softening at high pressure. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Laser-machined microcavities for simultaneous measurement of high-temperature and high-pressure.

    Science.gov (United States)

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

    2014-08-07

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

  18. Baking and coking properties of hard coal under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, H.D.

    1981-09-01

    For a better assessment of the baking and coking properties of hard coal under high pressure as in modern coal beneficiation processes, the determination of the swelling index and the dilatation curve are investigated.

  19. The high pressure gas Cerenkov counter at the Omega Facility.

    CERN Multimedia

    1975-01-01

    The high-pressure gas Cerenkov was used to measure reactions as pion (or kaon)- hydrogen --> forward proton - X. It was built by the Ecole Polytechnique (Palaiseu). Here Peter Sonderegger and Patrick Fleury,

  20. Use of genetic algorithms for high hydrostatic pressure inactivation ...

    African Journals Online (AJOL)

    ) for high hydrostatic pressure (HHP) inactivation of Bacillus cereus spores, Bacillus subtilis spores and cells, Staphylococcus aureus and Listeria monocytogenes, all in milk buffer, were used to demonstrate the utility of genetic algorithms ...

  1. Bio-Hemostat-Acute Treatment Modality for High Pressure Hemorrhage

    National Research Council Canada - National Science Library

    Carr, Marcus

    2002-01-01

    Bleeding from an artery is difficult to control due to the high pressures found in the arterial system Hemorrhage is especially problematic in penetrating wounds where the bleeding source may not be...

  2. Applicable technical method for freeze-substitution of high pressure ...

    African Journals Online (AJOL)

    bmshsj

    2011-11-02

    Quintana, 1994) are available for the microscopic visualization of intracellular organelles. Cryo- fixation, plunge freezing, propane jet freezing, cold metal block freezing, and high pressure freezing provide advantages over chemical ...

  3. Beam steering effects in turbulent high pressure flames

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The propagation of a laser beam through a flame is influenced by variations of the optical density. Especially in turbulent high pressure flames this may seriously limit the use of laser diagnostic methods. (author) 1 fig., 2 refs.

  4. Electronic structure and optical properties of AIN under high pressure

    International Nuclear Information System (INIS)

    Li Zetao; Dang Suihu; Li Chunxia

    2011-01-01

    We have calculated the electronic structure and optical properties of Wurtzite structure AIN under different high pressure with generalized gradient approximation (GGA) in this paper. The total energy, density of state, energy band structure and optical absorption and reflection properties under high pressure are calculated. By comparing the changes of the energy band structure, we obtained AIN phase transition pressure for 16.7 GPa, which is a direct band structure transforming to an indirect band structure. Meanwhile, according to the density of states distribution and energy band structure, we analyzed the optical properties of AIN under high-pressure, the results showed that the absorption spectra moved from low-energy to high-energy. (authors)

  5. Evidence for photo-induced monoclinic metallic VO2 under high pressure

    International Nuclear Information System (INIS)

    Hsieh, Wen-Pin; Mao, Wendy L.; Trigo, Mariano; Reis, David A.; Andrea Artioli, Gianluca; Malavasi, Lorenzo

    2014-01-01

    We combine ultrafast pump-probe spectroscopy with a diamond-anvil cell to decouple the insulator-metal electronic transition from the lattice symmetry changing structural transition in the archetypal strongly correlated material vanadium dioxide. Coherent phonon spectroscopy enables tracking of the photo-excited phonon vibrational frequencies of the low temperature, monoclinic (M 1 )-insulating phase that transforms into the metallic, tetragonal rutile structured phase at high temperature or via non-thermal photo-excitations. We find that in contrast with ambient pressure experiments where strong photo-excitation promptly induces the electronic transition along with changes in the lattice symmetry, at high pressure, the coherent phonons of the monoclinic (M 1 ) phase are still clearly observed upon the photo-driven phase transition to a metallic state. These results demonstrate the possibility of synthesizing and studying transient phases under extreme conditions

  6. Evidence for photo-induced monoclinic metallic VO{sub 2} under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Wen-Pin, E-mail: wphsieh@stanford.edu; Mao, Wendy L. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305 (United States); Trigo, Mariano [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Reis, David A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Photon Science and Applied Physics, Stanford University, Stanford, California 94305 (United States); Andrea Artioli, Gianluca; Malavasi, Lorenzo [Dipartimento di Chimica, Sezione di Chimica Fisica, INSTM (UdR Pavia), Università di Pavia, Viale Taramelli 16, 27100 Pavia (Italy)

    2014-01-13

    We combine ultrafast pump-probe spectroscopy with a diamond-anvil cell to decouple the insulator-metal electronic transition from the lattice symmetry changing structural transition in the archetypal strongly correlated material vanadium dioxide. Coherent phonon spectroscopy enables tracking of the photo-excited phonon vibrational frequencies of the low temperature, monoclinic (M{sub 1})-insulating phase that transforms into the metallic, tetragonal rutile structured phase at high temperature or via non-thermal photo-excitations. We find that in contrast with ambient pressure experiments where strong photo-excitation promptly induces the electronic transition along with changes in the lattice symmetry, at high pressure, the coherent phonons of the monoclinic (M{sub 1}) phase are still clearly observed upon the photo-driven phase transition to a metallic state. These results demonstrate the possibility of synthesizing and studying transient phases under extreme conditions.

  7. Model of Structural Fragmentation Induced by High Pressure Torsion

    Czech Academy of Sciences Publication Activity Database

    Kratochvíl, J.; Kružík, Martin; Sedláček, R.

    2010-01-01

    Roč. 25, č. 1 (2010), s. 88-98 ISSN 1606-5131 Institutional research plan: CEZ:AV0Z10750506 Keywords : High-pressure torsion * intergranular glide * homogeneous deformation mode Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.649, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/kruzik-model of structural fragmentation induced by high pressure torsion.pdf

  8. Thermal neutron scattering studies of condensed matter under high pressures

    International Nuclear Information System (INIS)

    Carlile, C.J.; Salter, D.C.

    1978-01-01

    Although temperature has been used as a thermodynamic variable for samples in thermal neutron scattering experiments since the inception of the neutron technique, it is only in the last decade that high pressures have been utilised for this purpose. In the paper the problems particular to this field of work are outlined and a review is made of the types of high-pressure cells used and the scientific results obtained from the experiments. 103 references. (author)

  9. Signal processing in urodynamics: towards high definition urethral pressure profilometry.

    Science.gov (United States)

    Klünder, Mario; Sawodny, Oliver; Amend, Bastian; Ederer, Michael; Kelp, Alexandra; Sievert, Karl-Dietrich; Stenzl, Arnulf; Feuer, Ronny

    2016-03-22

    Urethral pressure profilometry (UPP) is used in the diagnosis of stress urinary incontinence (SUI) which is a significant medical, social, and economic problem. Low spatial pressure resolution, common occurrence of artifacts, and uncertainties in data location limit the diagnostic value of UPP. To overcome these limitations, high definition urethral pressure profilometry (HD-UPP) combining enhanced UPP hardware and signal processing algorithms has been developed. In this work, we present the different signal processing steps in HD-UPP and show experimental results from female minipigs. We use a special microtip catheter with high angular pressure resolution and an integrated inclination sensor. Signals from the catheter are filtered and time-correlated artifacts removed. A signal reconstruction algorithm processes pressure data into a detailed pressure image on the urethra's inside. Finally, the pressure distribution on the urethra's outside is calculated through deconvolution. A mathematical model of the urethra is contained in a point-spread-function (PSF) which is identified depending on geometric and material properties of the urethra. We additionally investigate the PSF's frequency response to determine the relevant frequency band for pressure information on the urinary sphincter. Experimental pressure data are spatially located and processed into high resolution pressure images. Artifacts are successfully removed from data without blurring other details. The pressure distribution on the urethra's outside is reconstructed and compared to the one on the inside. Finally, the pressure images are mapped onto the urethral geometry calculated from inclination and position data to provide an integrated image of pressure distribution, anatomical shape, and location. With its advanced sensing capabilities, the novel microtip catheter collects an unprecedented amount of urethral pressure data. Through sequential signal processing steps, physicians are provided with

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

    Science.gov (United States)

    Buckow, Roman; Sikes, Anita; Tume, Ron

    2013-01-01

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

  11. High-pressure test loop design and application

    International Nuclear Information System (INIS)

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

    1980-07-01

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

  12. Very high pressure Moessbauer spectroscopy using diamond anvil cells

    International Nuclear Information System (INIS)

    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 151 Eu, 119 Sn and 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

  13. High pressure processing's potential to inactivate norovirus and other fooodborne viruses

    Science.gov (United States)

    High pressure processing (HPP) can inactivate human norovirus. However, all viruses are not equally susceptible to HPP. Pressure treatment parameters such as required pressure levels, initial pressurization temperatures, and pressurization times substantially affect inactivation. How food matrix ...

  14. In Situ Raman Study of Liquid Water at High Pressure.

    Science.gov (United States)

    Romanenko, Alexandr V; Rashchenko, Sergey V; Goryainov, Sergey V; Likhacheva, Anna Yu; Korsakov, Andrey V

    2018-06-01

    A pressure shift of Raman band of liquid water (H 2 O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H 2 O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H 2 O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H 2 O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H 2 O at this pressure. The most convenient approach for pressure calibration is the use of "a linear background + one Gaussian" decomposition (the pressure can be measured using the formula P (GPa) = -0.0317(3)·Δν G (cm -1 ), where Δν G represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

  15. Association between parity and breastfeeding with maternal high blood pressure.

    Science.gov (United States)

    Lupton, Samantha J; Chiu, Christine L; Lujic, Sanja; Hennessy, Annemarie; Lind, Joanne M

    2013-06-01

    The objective of this study was to determine how parity and breastfeeding were associated with maternal high blood pressure, and how age modifies this association. Baseline data for 74,785 women were sourced from the 45 and Up Study, Australia. These women were 45 years of age or older, had an intact uterus, and had not been diagnosed with high blood pressure before pregnancy. Odds ratios (ORs) and 99% confidence intervals (CIs) for the association between giving birth, breastfeeding, lifetime breastfeeding duration, and average breastfeeding per child with high blood pressure were estimated using logistic regression. The combination of parity and breastfeeding was associated with lower odds of having high blood pressure (adjusted OR, 0.89; 99% CI, 0.82-0.97; P high blood pressure when compared with parous women who never breastfed. The odds were lower with longer breastfeeding durations and were no longer significant in the majority of women over the age of 64 years. Women should be encouraged to breastfeed for as long as possible and a woman's breastfeeding history should be taken into account when assessing her likelihood of high blood pressure in later life. Copyright © 2013 Mosby, Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    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.

  17. High blood pressure in older subjects with cognitive impairment.

    Science.gov (United States)

    Mossello, Enrico; Simoni, David

    2016-06-22

    High blood pressure and cognitive impairment often coexist in old age, but their pathophysiological association is complex. Several longitudinal studies have shown that high blood pressure at midlife is a risk factor for cognitive impairment and dementia, although this association is much less clear in old age. The effect of blood pressure lowering in reducing the risk of dementia is only borderline significant in clinical trials of older subjects, partly due to the insufficient follow-up time. Conversely, dementia onset is associated with a decrease of blood pressure values, probably secondary to neurodegeneration. Prognostic effect of blood pressure values in cognitively impaired older subjects is still unclear, with aggressive blood pressure lowering being potentially harmful in this patients category. Brief cognitive screening, coupled with simple motor assessment, are warranted to identify frail older subjects who need a more cautious approach to antihypertensive treatment. Values obtained with ambulatory blood pressure monitoring seem more useful than clinical ones to predict the outcome of cognitively impaired older subjects. Future studies should identify the most appropriate blood pressure targets in older subjects with cognitive impairment.

  18. High-performance macroporous bulk silicon anodes synthesized by template-free chemical etching

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Byoung Man; Lee, Jung-In; Kim, Hyunjung; Cho, Jaephil; Park, Soojin [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST), Ulsan (Korea, Republic of)

    2012-07-15

    Three-dimensional porous silicon particles can be produced via the combination of a galvanic displacement reaction and a metal-assisted chemical etching process. This simple synthetic route can be applied to make high-performance anode materials, including high specific capacity, stable cycling retention, and high rate capability, in lithium-ion batteries. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis

    Directory of Open Access Journals (Sweden)

    R.F. Vogel

    2005-08-01

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

  20. Diamonds: powerful tools for high-pressure physics

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Diamond-anvil high-pressure studies have progressed to the point where they complement shock-wave studies. Because they operate at static high pressure, they permit time-consuming procedures, such as x-ray diffraction measurements for determining crystal structure. The sample material is completely recoverable and the method is adaptable to minute advantage when dealing with rare or hazardous materials. One of our goals in investigating the high-pressure behavior of iridium was to test the theoretical prediction that iridium would exhibit a phase transformation from the face-centered cubic crystal structure at about 9 GPa. Our finding that no such transformation takes place even at pressures up to 30 GPa will need to be taken into account by physicsts working to improve solid-state theory

  1. Confinement of hydrogen at high pressure in carbon nanotubes

    Science.gov (United States)

    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.

  2. Modification of enzymes by use of high-pressure homogenization.

    Science.gov (United States)

    Dos Santos Aguilar, Jessika Gonçalves; Cristianini, Marcelo; Sato, Helia Harumi

    2018-07-01

    High-pressure is an emerging and relatively new technology that can modify various molecules. High-pressure homogenization (HPH) has been used in several studies on protein modification, especially in enzymes used or found in food, from animal, plant or microbial resources. According to the literature, the enzymatic activity can be modulated under pressure causing inactivation, stabilization or activation of the enzymes, which, depending on the point of view could be very useful. Homogenization can generate changes in the structure of the enzyme modifying various chemical bonds (mainly weak bonds) causing different denaturation levels and, consequently, affecting the catalytic activity. This review aims to describe the various alterations due to HPH treatment in enzymes, to show the influence of high-pressure on proteins and to report the HPH effects on the enzymatic activity of different enzymes employed in the food industry and research. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Security of bottle to fill in a high pressure air

    Science.gov (United States)

    Todic, M.; Latinovic, T.; Golubovic-Bugarski, V.; Majstorovic, A.

    2018-01-01

    Charging the bottle of high pressure air isolation devices is performed by a high-pressure compressor. The charging time is in function of the compressor capacity and the intensity of the nominal pressure of the air in the bottle. However, in accident situations this time is long and therefore high-pressure accumulators are used where the filling time of the bottle of isolation apparatus has been drastically reduced. Due to the short filling time of the bottle through the air flow, there is a thermodynamic load of bottle material that could endanger the safety of users and other participants in the area. It is therefore necessary to determine the critical parameters of the rapid charge and their intensity.

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

    Science.gov (United States)

    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. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Performance characterization of solid oxide cells under high pressure

    DEFF Research Database (Denmark)

    Sun, Xiufu; Bonaccorso, Alfredo Damiano; Graves, Christopher R.

    2014-01-01

    in both fuel cell mode and electrolysis mode. In electrolysis mode at low current density, the performance improvement was counteracted by the increase in open circuit voltage, but it has to be born in mind that the pressurised gas contains higher molar free energy. Operating at high current density...... hydrocarbon fuels, which is normally performed at high pressure to achieve a high yield. Operation of SOECs at elevated pressure will therefore facilitate integration with the downstream fuel synthesis and is furthermore advantageous as it increases the cell performance. In this work, recent pressurised test...... results of a planar Ni-YSZ (YSZ: Yttria stabilized Zirconia) supported solid oxide cell are presented. The test was performed at 800 °C at pressures up to 15 bar. A comparison of the electrochemical performance of the cell at 1 and 3 bar shows a significant and equal performance gain at higher pressure...

  6. Condensation heat transfer on natural convection at the high pressure

    International Nuclear Information System (INIS)

    Jong-Won, Kim; Hyoung-Kyoun, Ahn; Goon-Cherl, Park

    2007-01-01

    The Regional Energy Research Institute for the Next Generation is to develop a small scale electric power system driven by an environment-friendly and stable small nuclear reactor. REX-10 has been developed to assure high system safety in order to be placed in densely populated region and island. REX-10 adopts the steam-gas pressurizer to assure the inherent safety. The thermal-hydraulic phenomena in the steam-gas pressurizer are very complex. Especially, the condensation heat transfer with noncondensable gas on the natural convection is important to evaluate the pressurizer behavior. However, there have been few investigations on the condensation in the presence of noncondensable gas at the high pressure. In this study, the theoretical model is developed to estimate the condensation heat transfer at the high pressure using heat and mass transfer analogy. The analysis results show good agreement with correlations and experimental data. It is found that the condensation heat transfer coefficient increases as the total pressure increases or the mass fraction of the non-condensable gas decreases. In addition, the heat transfer coefficient no more increases over the specific pressure

  7. Structural stability of high entropy alloys under pressure and temperature

    DEFF Research Database (Denmark)

    Ahmad, Azkar S.; Su, Y.; Liu, S. Y.

    2017-01-01

    The stability of high-entropy alloys (HEAs) is a key issue before their selection for industrial applications. In this study, in-situ high-pressure and high-temperature synchrotron radiation X-ray diffraction experiments have been performed on three typical HEAs Ni20Co20Fe20Mn20Cr20, Hf25Nb25Zr25Ti...

  8. Effect of high pressure hydrogen on low-cycle fatigue

    International Nuclear Information System (INIS)

    Rie, K.T.; Kohler, W.

    1979-01-01

    It has been shown that the fatigue life can be influenced in low-cycle range by high pressure hydrogen while the effect of high pressure hydrogen on high-cycle fatigue will not be as significant. The paper reports the details and the results of the investigations of the effect of high pressure hydrogen on the low-cycle endurance of commercially pure titanium. The results of this study indicate that: 1. The degradation of the fatigue life in low-cycle region for commercially pure titanium under high pressure hydrogen can be described by Nsub(cr)sup(α x Δepsilon)sub(pl)sup(=c) 2. The fatigue life decreases with decreasing strain rate. 3. The fatigue life decreases with increasing hydrogen pressure. It was found that the semilogarithmic plot of the fatigue life versus the hydrogen pressure gives a linear relationship. The Sievert's law does not hold in low-cycle fatigue region. 4. HAC in titanium in low-cycle fatigue region is the result of the disolution of hydrogen at the crack tip and of the strain-induced hybride formation. (orig.) 891 RW/orig. 892 RKD [de

  9. High-temperature transient creep properties of CANDU pressure tubes

    International Nuclear Information System (INIS)

    Fong, R.W.L.; Chow, C.K.

    2002-06-01

    During a hypothetical large break loss-of-coolant accident (LOCA), the coolant flow would be reduced in some fuel channels and would stagnate and cause the fuel temperature to rise and overheat the pressure tube. The overheated pressure tube could balloon (creep radially) into contact with its moderator-cooled calandria tube. Upon contact, the stored thermal energy in the pressure tube is transferred to the calandria tube and into the moderator, which acts as a heat sink. For safety analyses, the modelling of fuel channel deformation behaviour during a large LOCA requires a sound knowledge of the high-temperature creep properties of Zr-2.5Nb pressure tubes. To this extent, a ballooning model to predict pressure-tube deformation was developed by Shewfelt et al., based on creep equations derived using uniaxial tensile specimens. It has been recognized, however, that there is an inherent variability in the high-temperature creep properties of CANDU pressure tubes. The variability, can be due to different tube-manufacturing practices, variations in chemical compositions, and changes in microstructure induced by irradiation during service in the reactor. It is important to quantify the variability of high-temperature creep properties so that accurate predictions on pressure-tube creep behaviour can be made. This paper summarizes recent data obtained from high-temperature uniaxial creep tests performed on specimens taken from both unirradiated (offcut) and irradiated pressure tubes, suggesting that the variability is attributed mainly to the initial differences in microstructure (grain size, shape and preferred orientation) and also from tube-to-tube variations in chemical composition, rather than due to irradiation exposure. These data will provide safety analysts with the means to quantify the uncertainties in the prediction of pressure-tube contact temperatures during a postulated large break LOCA. (author)

  10. High-pressure tolerance of earthworm fibrinolytic and digestive enzymes.

    Science.gov (United States)

    Akazawa, Shin-Ichi; Tokuyama, Haruka; Sato, Shunsuke; Watanabe, Toshinori; Shida, Yosuke; Ogasawara, Wataru

    2018-02-01

    Earthworms contain several digestive and therapeutic enzymes that are beneficial to our health and useful for biomass utilization. Specifically, earthworms contain potent fibrinolytic enzymes called lumbrokinases, which are highly stable even at room temperature and remain active in dried earthworm powder. However, the high-temperature sterilization method leads to the inactivation of enzymes. Therefore, we investigated the effect of high-pressure treatment (HPT) (from 0.1 MPa to 500 MPa at 25°C and 50°C) on the enzymatic activity of lumbrokinase (LK), α-amylase (AMY), endoglucanase (EG), β-glucosidase (BGL), and lipase (LP) of the earthworm Eisenia fetida, Waki strain, and its sterilization ability in producing dietary supplement. LK showed thermo- and high-pressure tolerance. In addition, HPT may have resulted in pressure-induced stabilization and activation of LK. Although AMY activity was maintained up to 400 MPa at 25°C, the apparent activity decreased slightly at 50°C with HPT. EG showed almost the same pattern as AMY. However, it is possible that the effects of temperature and pressure compensated each other under 100 MPa at 50°C. BGL was shown to be a pressure- and temperature-sensitive enzyme, and LP showed a thermo- and high-pressure tolerance. The slight decrease in apparent activity occurred under 200 MPa at both temperatures. Furthermore, the low-temperature and pressure treatment completely sterilized the samples. These results provide a basis for the development of a novel earthworm dietary supplement with fibrinolytic and digestive activity and of high-pressure-tolerant enzymes to be used for biomass pretreatment. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Enhancement of anaerobic sludge digestion by high-pressure homogenization.

    Science.gov (United States)

    Zhang, Sheng; Zhang, Panyue; Zhang, Guangming; Fan, Jie; Zhang, Yuxuan

    2012-08-01

    To improve anaerobic sludge digestion efficiency, the effects of high-pressure homogenization (HPH) conditions on the anaerobic sludge digestion were investigated. The VS and TCOD were significantly removed with the anaerobic digestion, and the VS removal and TCOD removal increased with increasing the homogenization pressure and homogenization cycle number; correspondingly, the accumulative biogas production also increased with increasing the homogenization pressure and homogenization cycle number. The optimal homogenization pressure was 50 MPa for one homogenization cycle and 40 MPa for two homogenization cycles. The SCOD of the sludge supernatant significantly increased with increasing the homogenization pressure and homogenization cycle number due to the sludge disintegration. The relationship between the biogas production and the sludge disintegration showed that the accumulative biogas and methane production were mainly enhanced by the sludge disintegration, which accelerated the anaerobic digestion process and improved the methane content in the biogas. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Vibrational properties of ZnTe at high pressures

    International Nuclear Information System (INIS)

    Camacho, J.; Loa, I.; Syassen, K.; Cantarero, A.

    2002-01-01

    Raman spectra of ZnTe were measured under hydrostatic pressures up to 15 GPa at T=300 K. Results for the frequencies of first- and second-order Raman features of the zincblende phase (0-9.5 GPa) are used to set up a rigid-ion model of the phonon dispersion relations under pressure. Calculated phonon densities of states, mode Grueneisen parameters and the thermal expansion coefficient as a function of pressure are discussed. The effect of pressure on the widths and intensities of Raman spectral features is considered. Raman spectra of high-pressure phases of ZnTe are reported. These spectra indicate the possible existence of a new phase near 13 GPa, intermediate between the cinnabar and orthorhombic (Cmcm) phases of ZnTe. (author)

  13. Vibrational properties of ZnTe at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, J. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany) and Instituto de Ciencia de Materiales, Universidad de Valencia, Valencia (Spain)]. E-mail: Juana.Camacho@uv.es; Loa, I.; Syassen, K. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Cantarero, A. [Instituto de Ciencia de Materiales, Universidad de Valencia, Valencia (Spain)

    2002-02-04

    Raman spectra of ZnTe were measured under hydrostatic pressures up to 15 GPa at T=300 K. Results for the frequencies of first- and second-order Raman features of the zincblende phase (0-9.5 GPa) are used to set up a rigid-ion model of the phonon dispersion relations under pressure. Calculated phonon densities of states, mode Grueneisen parameters and the thermal expansion coefficient as a function of pressure are discussed. The effect of pressure on the widths and intensities of Raman spectral features is considered. Raman spectra of high-pressure phases of ZnTe are reported. These spectra indicate the possible existence of a new phase near 13 GPa, intermediate between the cinnabar and orthorhombic (Cmcm) phases of ZnTe. (author)

  14. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    DEFF Research Database (Denmark)

    Varzandeh, Farhad

    properties like saturation pressures, densities at reservoir temperature and Stock TankviOil (STO) densities, while keeping the n-alkane limit of the correlations unchanged. Apart from applying this general approach to PC-SAFT, we have also shown that the approach can be applied to classical cubic models...... approach to characterizing reservoir fluids for any EoS. The approach consists in developing correlations of model parameters first with a database for well-defined components and then adjusting the correlations with a large PVT database. The adjustment is made to minimize the deviation in key PVT...... method to SRK and PR improved the saturation pressure calculation in comparisonto the original characterization method for SRK and PR. Using volume translationtogether with the new characterization approach for SRK and PR gives comparable results for density and STO density to that of original...

  15. A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2018-03-01

    Full Text Available With the development of energetic materials (EMs and microelectromechanical systems (MEMS initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor’s sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa−1. The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size.

  16. High Pressure and High Temperature State of Oxygen Enriched Ice

    Science.gov (United States)

    LI, M.; Zhang, S.; Jeanloz, R.; Militzer, B.

    2016-12-01

    Interior models for Uranus and Neptune include a hydrogen/helium/water outer envelope and a core of rock and metal at the center, with superionic water-rich ice proposed as comprising an intermediate layer. Here we consider an oxygen-enriched ice, such as H2O2 hydrogen peroxide (± water), that could form through chemical reaction between water-rich and underlying rocky (i.e., oxygen-rich) layers. As oxygen and its compounds (e.g., H2O, SiO2) form metallic fluids at pressures above 100-150 GPa, the problem amounts to considering oxygen alloying of semiconducting or metallic water. The density of H2O2 is 1.45 g/cc at ambient pressure and 0° C, increasing to 1.71 g/cc in the solid state at about -20° C. There are no Hugoniot data beyond 30 GPa, so we estimated Hugoniots for H2O2 with different initial densities, using both a mixing model based on Hugoniot data for H2O2 and 1/2 O2 (molar volume summation under pressure) and ab initio calculations for unreacted H2O2. The results agree with each other to pressures of about 200 GPa, and the ab initio calculations show evidence of a superionic state at temperatures as low as 500 K, much lower than for water ice. Hydrogen peroxide is expected to be liquid along planetary isentropes for Uranus and Neptune, suggesting that H2O2 may not be present as a pure compound in these planets. Instead, oxygen-enriched H2O ice may be the relevant form of water and oxygen, and might be produced in the laboratory by way of dynamic compression of H2O2 or laser-heating of statically compressed H2O + O2 and/or H2O2.

  17. High pressure {sup 31}P NMR spectroscopy on guanine nucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Spoerner, Michael; Karl, Matthias; Lopes, Pedro; Hoering, Marcus; Loeffel, Karoline; Nuehs, Andrea; Adelsberger, Joseph; Kremer, Werner; Kalbitzer, Hans Robert, E-mail: hans-robert.kalbitzer@ur.de [University of Regensburg, Centre of Magnetic Resonance in Chemistry and Biomedicine, Institute of Biophysics and Physical Biochemistry (Germany)

    2017-01-15

    The {sup 31}P NMR pressure response of guanine nucleotides bound to proteins has been studied in the past for characterizing the pressure perturbation of conformational equilibria. The pressure response of the {sup 31}P NMR chemical shifts of the phosphate groups of GMP, GDP, and GTP as well as the commonly used GTP analogs GppNHp, GppCH{sub 2}p and GTPγS was measured in the absence and presence of Mg{sup 2+}-ions within a pressure range up to 200 MPa. The pressure dependence of chemical shifts is clearly non-linear. For all nucleotides a negative first order pressure coefficient B{sub 1} was determined indicating an upfield shift of the resonances with pressure. With exception of the α-phosphate group of Mg{sup 2+}·GMP and Mg{sup 2+}·GppNHp the second order pressure coefficients are positive. To describe the data of Mg{sup 2+}·GppCH{sub 2}p and GTPγS a Taylor expansion of 3rd order is required. For distinguishing pH effects from pressure effects a complete pH titration set is presented for GMP, as well as GDP and GTP in absence and presence of Mg{sup 2+} ions using indirect referencing to DSS under identical experimental conditions. By a comparison between high pressure {sup 31}P NMR data on free Mg{sup 2+}-GDP and Mg{sup 2+}-GDP in complex with the proto-oncogene Ras we demonstrate that pressure induced changes in chemical shift are clearly different between both forms.

  18. High Accuracy, Miniature Pressure Sensor for Very High Temperatures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SiWave proposes to develop a compact, low-cost MEMS-based pressure sensor for very high temperatures and low pressures in hypersonic wind tunnels. Most currently...

  19. Design Concepts for Low Aspect Ratio High Pressure Turbines for High Bypass Ratio Turbofans, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The performance gains and weight reductions from using Ceramic Matrix Composite(CMC) turbine blades in both the High Pressure Turbine(HPT) and Low Pressure...

  20. Soft Functional Silicone Elastomers with High Dielectric Permittivty: Simple Additives vs. Cross-Linked Synthesized Copolymers

    DEFF Research Database (Denmark)

    Madsen, Frederikke Bahrt; Yu, Liyun; Skov, Anne Ladegaard

    Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity of the elas......Though dielectric elastomers (DEs) have many favorable properties, the issue of high driving voltages limits the commercial viability of the technology. Improved actuation at lower voltages can be obtained by decreasing the Young’s modulus and/or decreasing the dielectric permittivity...... of the elastomer. A decrease in Young’s modulus, however, is often accompanied by the loss of mechanical stability and thereby the lifetime of the DE whereas addition of high permittivity fillers such as metal oxides often increases Young’s modulus such that improved actuation is not accomplished. New soft...... silicone elastomers with high dielectric permittivity were prepared through the use of chloropropyl-functional silicones. One method was through the synthesis of modular cross-linkable chloropropyl-functional copolymers that allow for a high degree of chemical freedom such that a tuneable silicone...

  1. Strength-toughness requirements for thick walled high pressure vessels

    International Nuclear Information System (INIS)

    Kapp, J.A.

    1990-01-01

    The strength and toughness requirements of materials for use in high pressure vessels has been the subject of some discussion in the meetings of the Materials Task Group of the Special Working Group High Pressure Vessels. A fracture mechanics analysis has been performed to theoretically establish the required toughness for a high pressure vessel. This paper reports that the analysis performed is based on the validity requirement for plane strain fracture of fracture toughness test specimens. This is that at the fracture event, the crack length, uncracked ligament, and vessel length must each be greater than fifty times the crack tip plastic zone size for brittle fracture to occur. For high pressure piping applications, the limiting physical dimension is the uncracked ligament, as it can be assumed that the other dimensions are always greater than fifty times the crack tip plastic zone. To perform the fracture mechanics analysis several parameters must be known: these include vessel dimensions, material strength, degree of autofrettage, and design pressure. Results of the analysis show, remarkably, that the effects of radius ratio, pressure and degree of autofrettage can be ignored when establishing strength and toughness requirements for code purposes. The only parameters that enter into the calculation are yield strength, toughness and vessel thickness. The final results can easily be represented as a graph of yield strength against toughness on which several curves, one for each vessel thickness, are plotted

  2. The influence of defects on the transport properties of AgSbPb18Te20 prepared at high pressure and high temperature

    International Nuclear Information System (INIS)

    Wang Yi; Zhu Pinwen; Jiao Hujun; Chen Haiyong; Ma Yanming; Niu Yingli; Li Yingai; Zhang Lijun; Zhang Tiechen; Gao Chunxiao; Zou Guangtian

    2007-01-01

    We synthesized polycrystal AgSbPb 18 Te 20 by using the method of high pressure and high temperature, and found that the defects produced by high pressure and high temperature caused the changes of transport properties. X-ray diffraction patterns showed that the cell parameters did not change obviously with synthesis at high pressure, apart from a small fluctuation. The electrical resistivity first increased, and then decreased to one quarter of the original value, as the synthesis pressure changed from low to high. The Seebeck coefficient decreased with the increase of synthesis pressure, and then changed from positive to negative. High pressure and high temperature could cause AgSbPb 18 Te 20 to change from a p-type to n-type semiconductor, increase the carrier concentration at maximum by two orders of magnitude, and shift the infrared absorption edge to a higher energy range. All of these phenomena were regarded as showing that high pressure and high temperature favored the formation of certain defects which could change the band structure and thereby change the transport properties

  3. Characterization of high-pressure, underexpanded hydrogen-jet flames

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, R.W.; Houf, W.G.; Williams, T.C. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Bourne, B.; Colton, J. [SRI International, 333 Ravenwood Ave., Menlo Park, CA 94025 (United States)

    2007-08-15

    Measurements were performed to characterize the dimensional and radiative properties of large-scale, vertical hydrogen-jet flames. This data is relevant to the safety scenario of a sudden leak in a high-pressure hydrogen containment vessel and will provide a technological basis for determining hazardous length scales associated with unintended hydrogen releases at storage and distribution centers. Jet flames originating from high-pressure sources up to 413 bar (6000 psi) were studied to verify the application of correlations and scaling laws based on lower-pressure subsonic and choked-flow jet flames. These higher pressures are expected to be typical of the pressure ranges in future hydrogen storage vessels. At these pressures the flows exiting the jet nozzle are categorized as underexpanded jets in which the flow is choked at the jet exit. Additionally, the gas behavior departs from that of an ideal-gas and alternate formulations for non-ideal gas must be introduced. Visible flame emission was recorded on video to evaluate flame length and structure. Radiometer measurements allowed determination of the radiant heat flux characteristics. The flame length results show that lower-pressure engineering correlations, based on the Froude number and a non-dimensional flame length, also apply to releases up to 413 bar (6000 psi). Similarly, radiative heat flux characteristics of these high-pressure jet flames obey scaling laws developed for low-pressure, smaller-scale flames and a wide variety of fuels. The results verify that such correlations can be used to a priori predict dimensional characteristics and radiative heat flux from a wide variety of hydrogen-jet flames resulting from accidental releases. (author)

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  5. Photoconductivity studies of the ferrocyanide ion under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Finston, M. I.

    1979-01-01

    The photoaquation of the ferrocyanide ion was studied using a high-pressure photoconductivity apparatus and a steady-state high-pressure mercury lamp. The first-order photocurrent rise-time could be related to the relative quantum efficiency of the photoaquation process, while the dark decay of the photocurrent yielded a relative value of the bimolecular rate-constant for the reverse reaction. Kinetic measurements were carried out on dilute solutions of potassium ferrocyanide in pure water, and in 20% ethanol. The photocurrent yield in aqueous solution was dependent upon secondary chemical equilibria which were sensitive to pressure in a predictable way. In ethanolic solution, the dependence of photocurrent yield on pressure followed the variation of the reciprocal solvent vicosity. In both aqueous and alcoholic solution, the photoaquation quantum efficiency decreased exponentially with pressure, as did the biomolecular rate-constant for the dark reaction in aqueous solution. The pressure dependence of the bimolecular rate-constant in the alcoholic solution indicated a diffusion-limited process. The pressure dependence of the photoaquation quantum yield, and of the bimolecular rate-constant in aqueous solution, was interpreted in terms of an activation volume model. The photoaquation data for both the aqueous and the alcoholic solutions agreed with a hypothetical mechanism whereby ligand-to-metal bond-breaking, and solvent-to-metal bond-formation, are effectively simultaneous. The results for the aqueous dark reaction strongly indicated breaking of the solvent-to-metal bond as the rate-limiting step.

  6. Microwave Wire Interrogation Method Mapping Pressure under High Temperatures

    Directory of Open Access Journals (Sweden)

    Xiaoyong Chen

    2017-12-01

    Full Text Available It is widely accepted that wireless reading for in-situ mapping of pressure under high-temperature environments is the most feasible method, because it is not subject to frequent heterogeneous jointing failures and electrical conduction deteriorating, or even disappearing, under heat load. However, in this article, we successfully demonstrate an in-situ pressure sensor with wire interrogation for high-temperature applications. In this proof-of-concept study of the pressure sensor, we used a microwave resonator as a pressure-sensing component and a microwave transmission line as a pressure characteristic interrogation tunnel. In the sensor, the line and resonator are processed into a monolith, avoiding a heterogeneous jointing failure; further, microwave signal transmission does not depend on electrical conduction, and consequently, the sensor does not suffer from the heat load. We achieve pressure monitoring under 400 °C when employing the sensor simultaneously. Our sensor avoids restrictions that exist in wireless pressure interrogations, such as environmental noise and interference, signal leakage and security, low transfer efficiency, and so on.

  7. Experimental in situ investigations of turbulence under high pressure.

    Science.gov (United States)

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

    2010-02-01

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

  8. Microscopic Analysis of Bacterial Motility at High Pressure

    Science.gov (United States)

    Nishiyama, Masayoshi; Sowa, Yoshiyuki

    2012-01-01

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

  9. How to Prevent High Blood Pressure: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Understanding Blood Pressure Readings (American Heart Association) Weightlifting: Bad for Your Blood Pressure? (Mayo Foundation for ... High Blood Pressure High Blood Pressure in Pregnancy Nutrition Quitting Smoking Stress National Institutes of Health The ...

  10. Reverse martensitic transformation in alumina-15 vol% zirconia nanostructured powder synthesized by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Maneshian, M.H. [Department of Materials Science and Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9466, Tehran (Iran, Islamic Republic of)], E-mail: mh_maneshian@yahoo.com; Banerjee, M.K. [National Institute of Foundry and Forge Technology, Hatia, Ranchi 834003 (India)

    2008-07-14

    In the present work, three alumina-15 vol% zirconia composites with Y{sub 2}O{sub 3}, MgO as dopants and without oxide as dopant have been investigated. High energy ball milling (HEBM) provides the positive thermodynamic driving force for monoclinic to tetragonal transformation and it reduces starting temperature for the reverse martensitic transformation, meanwhile mobility of zirconium cations and oxygen anions are enhanced in zirconia by HEBM. The general, albeit heuristic, reasoning is corroborated by nanocrystallity, particle size and also the retained monoclinic seem to play an important role. After 10 h HEBM, approximately 28% zirconia tetragonal phase is achieved. Non-stoichiometric tetragonal zirconia phase; Zr{sub 0.95}O{sub 2} is seen to have been achieved by high energy ball milling (HEBM). The structural and compositional evolutions during HEBM have been investigated using X-ray diffraction method (XRD) and scanning electron microscopy (SEM). High resolution transmission electron microscope (TEM) is also used for further understanding about the phenomenological changes taking place during high energy ball milling.

  11. High corrosion resistance of magnesium coated with hydroxyapatite directly synthesized in an aqueous solution

    International Nuclear Information System (INIS)

    Hiromoto, Sachiko; Yamamoto, Akiko

    2009-01-01

    Anticorrosion coatings are crucial for practical applications of magnesium alloys, which are used to reduce the weight of vehicles, aircraft, electronics enclosures etc. Hydroxyapatite (HAp) potentially offers high corrosion resistance and no environmental toxicity because its thermodynamic structural stability is high and it is a basic component of bone. However, direct synthesis of HAp on magnesium in aqueous solutions has been a scientific challenge because Mg ions prevent HAp crystallization. A new method of direct synthesis of HAp on magnesium was developed using a Ca chelate compound, which can maintain a sufficiently high concentration of Ca ions on the magnesium surface to overcome prevention of HAp crystallization with Mg ions. Highly crystallized HAp coatings were successfully formed on pure magnesium and AZ series alloys. Corrosion behavior of HAp-coated pure magnesium was examined by cyclic dry and wet tests with 1 g m -2 NaCl on the surface and polarization tests in a 3.5 wt% NaCl solution. A HAp-coated pure magnesium showed no noticeable corrosion pits after the dry and wet test. HAp-coated specimens showed 10 3 -10 4 times lower anodic current density than as-polished specimen in the polarization test. The results demonstrate the remarkable anticorrosion performance of HAp coatings on magnesium for the first time.

  12. High corrosion resistance of magnesium coated with hydroxyapatite directly synthesized in an aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Hiromoto, Sachiko [Biomaterials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)], E-mail: hiromoto.sachiko@nims.go.jp; Yamamoto, Akiko [Biomaterials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2009-11-30

    Anticorrosion coatings are crucial for practical applications of magnesium alloys, which are used to reduce the weight of vehicles, aircraft, electronics enclosures etc. Hydroxyapatite (HAp) potentially offers high corrosion resistance and no environmental toxicity because its thermodynamic structural stability is high and it is a basic component of bone. However, direct synthesis of HAp on magnesium in aqueous solutions has been a scientific challenge because Mg ions prevent HAp crystallization. A new method of direct synthesis of HAp on magnesium was developed using a Ca chelate compound, which can maintain a sufficiently high concentration of Ca ions on the magnesium surface to overcome prevention of HAp crystallization with Mg ions. Highly crystallized HAp coatings were successfully formed on pure magnesium and AZ series alloys. Corrosion behavior of HAp-coated pure magnesium was examined by cyclic dry and wet tests with 1 g m{sup -2} NaCl on the surface and polarization tests in a 3.5 wt% NaCl solution. A HAp-coated pure magnesium showed no noticeable corrosion pits after the dry and wet test. HAp-coated specimens showed 10{sup 3}-10{sup 4} times lower anodic current density than as-polished specimen in the polarization test. The results demonstrate the remarkable anticorrosion performance of HAp coatings on magnesium for the first time.

  13. High pressure fracturing in Colombia: a quantum leap

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, Juan C. [BP Exploration (United Kingdom); Gutierrez, Jim; Ham, Ernesto; Castro, Alberto [BJ Services Company (United States)

    2004-07-01

    Fracturing has become one of the most common stimulation and well completion techniques in petroleum production. Due to the deeper depths and high frac gradients encountered in some areas, various treatments have resulted in early screen outs or aborted operations due to insufficient rate limited by the available treating pressures. A state of the art technology and high pressure equipment including the largest frac pumps (rated at 2,700 hhp) in the world, were used in Colombian fields to overcome these limitations. The reliability of this equipment has allowed the treatment of these wells to operating pressures of up to 18,000 psi and rates in excess of 40 bpm, placing up to 400,000 lbs of bauxite. Bottom hole treating pressures of 25,000 psi also were reached. This paper describes the development of the fracture campaign and relates the jobs performed to date, including the results and lessons learned (author)

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

    International Nuclear Information System (INIS)

    Hu Anguang; Zhang Fan

    2011-01-01

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

  15. High-pressure needle interface for thermoplastic microfluidics.

    Science.gov (United States)

    Chen, C F; Liu, J; Hromada, L P; Tsao, C W; Chang, C C; DeVoe, D L

    2009-01-07

    A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

  16. Pressure Amplification Off High Impedance Barriers in DDT

    Energy Technology Data Exchange (ETDEWEB)

    Heatwole, Eric Mann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Broilo, Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kistle, Trevin Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Gary Robert Jr. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-04-23

    The Deflagration-to-Detonation Transition (DDT) in one-dimensional porous explosive, where combustion in an explosive transitions to detonation, can be described by the following model. This simplified model proceeds in five steps, as follows: 1) Ignition of the explosive, surface burning. 2) Convective burning, with the flame front penetrating through the porous network of the explosive. This proceeds until the pressure grows high enough to result in choked flow in the pores restricting the convective burn. 3) The choked flow results in the formation of a high-density compact of explosive. This compact is driven into undisturbed material by the pressure of the burning explosive. See Figure1. 4) The compression of the undisturbed porous explosive by the compact leads to the ignition of a compressive burn. This builds in pressure until a supported shock forms. 5) The shock builds in pressure until detonation occurs. See Figure 2 for an overview streak of the proceeding steps.

  17. High pressure transport properties of Yb2Cu9

    International Nuclear Information System (INIS)

    Spendeler, L.; Jaccard, D.; Sierro, J.; Flouquet, J.

    1992-01-01

    The electrical resistivity (ρ) and the absolute thermopower (S) of high-purity Yb 2 Cu 9 have been measured between 1.2 and 300 K at pressures up to 17 kbar and in magnetic fields up to 6 T. At zero pressure the three measured samples show a Kondo peak in the resistivity at 17 K. Furthermore for one of them the resistivity rises below 5 K. Under pressure, the Kondo peak in ρ slowly moves towards lower temperatures indicating a decrease of the Kondo temperature T K , in good agreement with specific heat results. The increase of ρ below 5 K disappears completely for pressure lower than 1 kbar and the residual resistivity remains high. The thermopower S exhibits similar trends. Magnetic field dependences of both ρ and S are weak. No evidence of magnetic ordering has been detected up to 17.6 kbar

  18. Foam glass obtained through high-pressure sintering

    DEFF Research Database (Denmark)

    Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

    2018-01-01

    Foam glasses are usually prepared through a chemical approach, that is, by mixing glass powder with foaming agents, and heating the mixture to a temperature above the softening point (106.6 Pa s) of the glass. The foaming agents release gas, enabling expansion of the sintered glass. Here, we use...... a physical foaming approach to prepare foam glass. First, closed pores filled with inert gases (He, Ar, or N2) are physically introduced into a glass body by sintering cathode ray tube (CRT) panel glass powder at high gas pressure (5‐25 MPa) at 640°C and, then cooled to room temperature. The sintered bodies...... are subjected to a second heat treatment above the glass transition temperature at atmospheric pressure. This heat treatment causes expansion of the pores due to high internal gas pressure. We found that the foaming ability strongly depends on the gas pressure applied during sintering, and on the kinetic...

  19. High-pressure phase transitions - Examples of classical predictability

    Science.gov (United States)

    Celebonovic, Vladan

    1992-09-01

    The applicability of the Savic and Kasanin (1962-1967) classical theory of dense matter to laboratory experiments requiring estimates of high-pressure phase transitions was examined by determining phase transition pressures for a set of 19 chemical substances (including elements, hydrocarbons, metal oxides, and salts) for which experimental data were available. A comparison between experimental and transition points and those predicted by the Savic-Kasanin theory showed that the theory can be used for estimating values of transition pressures. The results also support conclusions obtained in previous astronomical applications of the Savic-Kasanin theory.

  20. Synergistic effect of high pressure processing and Lactobacillus casei antimicrobial activity against pressure resistant Listeria monocytogenes.

    Science.gov (United States)

    Chung, Hyun-Jung; Yousef, Ahmed E

    2010-09-30

    The purpose of this study was to evaluate combinations of high pressure processing (HPP) and Lactobacillus casei antimicrobial activity against Listeria monocytogenes strains with variation in pressure resistance in culture and in a food model. In culture, combination of HPP (350 MPa, for 1-20 min) and Lb. casei cell extract (CE, 32 CEAU/ml) showed a significant synergistic bactericidal effect (P5 log(10)CFU/ml. Synergy between CE and HPP was most evident in the pressure-resistant strain, OSY-8578. Similar result was observed in meat products where high pressure (500 MPa for 1 min), and high-activity CE (100 CEAU/g) caused >5 log reduction in the viability of L. monocytogenes Scott A. The combination treatment resulted in the absence of peaks associated with cellular components in DSC thermogram suggesting that the presence of CE may have caused a considerable damage to cellular components during the high pressure treatment. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Advances in high pressure research in condensed matter: proceedings of the international conference on condensed matter under high pressures

    International Nuclear Information System (INIS)

    Sikka, S.K.; Gupta, Satish C.; Godwal, B.K.

    1997-01-01

    The use of pressure as a thermodynamic variable for studying condensed matter has become very important in recent years. Its main effect is to reduce the volume of a substance. Thus, in some sense, it mimics the phenomena taking place during the cohesion of solids like pressure ionization, modifications in electronic properties and phase changes etc. Some of the phase changes under pressure lead to synthesis of new materials. The recent discovery of high T c superconductivity in YBa 2 Cu 3 O 7 may be indirectly attributed to the pressure effect. In applied fields like simulation of reactor accident, design of inertial confinement fusion schemes and for understanding the rock mechanical effects of shock propagation in earth due to underground nuclear explosions, the pressure versus volume relations of condensed matter are a vital input. This volume containing the proceedings of the International Conference on Condensed Matter Under High Pressure covers various aspects of high pressure pertaining to equations of state, phase transitions, electronic, optical and transport properties of solids, atomic and molecular studies, shock induced reactions, energetic materials, materials synthesis, mineral physics, geophysical and planetary sciences, biological applications and food processing and advances in experimental techniques and numerical simulations. Papers relevant to INIS are indexed separately

  2. High pressure phase transition in Pr-monopnictides

    Energy Technology Data Exchange (ETDEWEB)

    Raypuria, Gajendra Singh, E-mail: sosfizix@gmail.com, E-mail: gsraypuria@gmail.com; Gupta, Dinesh Chandra [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior - 474011 (India); Department of Physics, Govt. K.R.G. P.G. Autonomous College, Gwalior - 474001 (India)

    2015-06-24

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

  3. Phase transition of La- chalcogenides under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dinesh Chandra [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior - 474 011 (India); Raypuria, Gajendra Singh, E-mail: gsraypuria@gmail.com [Department of Physics, Govt. K.R.G. P.G. Autonomous College, Gwalior - 474 001 (India)

    2014-04-24

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

  4. A system for incubations at high gas partial pressure

    Directory of Open Access Journals (Sweden)

    Patrick eSauer

    2012-02-01

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

  5. Anomalous phase transition of InN nanowires under high pressure

    International Nuclear Information System (INIS)

    Tang Shun-Xi; Zhu Hong-Yang; Jiang Jun-Ru; Wu Xiao-Xin; Dong Yun-Xuan; Zhang Jian; Cui Qi-Liang; Yang Da-Peng

    2015-01-01

    Uniform InN nanowires were studied under pressures up to 35.5 GPa by using in situ synchrotron radiation x-ray diffraction technique at room temperature. An anomalous phase transition behavior has been discovered. Contrary to the results in the literature, which indicated that InN undergoes a fully reversible phase transition from the wurtzite structure to the rocksalt type structure, the InN nanowires in this study unusually showed a partially irreversible phase transition. The released sample contained the metastable rocksalt phase as well as the starting wurtzite one. The experimental findings of this study also reveal the potentiality of high pressure techniques to synthesize InN nanomaterials with the metastable rocksalt type structure, in addition to the generally obtained zincblende type one. (paper)

  6. Nb effect on Zr-alloy oxidation under high pressure steam at high temperatures

    International Nuclear Information System (INIS)

    Park, Kwangheon; Yang, Sungwoo; Kim, Kyutae

    2005-01-01

    The high-pressure steam effects on the oxidation of Zircaloy-4 (Zry-4) and Zirlo (Zry-1%Nb) claddings at high temperature have been analyzed. Test temperature range was 700-900degC, and pressures were 1-150 bars. High pressure-steam enhances oxidation of Zry-4, and the dependency of enhancement looks exponential to steam pressure. The origin of the oxidation enhancement turned out to be the formation of cracks in oxide. The loss of tetragonal phase by high-pressure steam seems related to the crack formation. Addition of Nb as an alloying element to Zr alloy reduces significantly the steam pressure effects on oxidation. The higher compressive stresses and the smaller fraction of tetragonal oxides in Zry-1%Nb seem to be the diminished effect of high-pressure steam on oxidation. (author)

  7. Elasticity of methane hydrate phases at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Beam, Jennifer; Yang, Jing; Liu, Jin [Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78712 (United States); Liu, Chujie [Laboratory of Seismology and Physics of Earth’s Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Lin, Jung-Fu, E-mail: afu@jsg.utexas.edu [Department of Geological Sciences, Jackson School of Geosciences, The University of Texas at Austin, Austin, Texas 78712 (United States); Center for High Pressure Science and Advanced Technology Research (HPSTAR), Shanghai 201203 (China)

    2016-04-21

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

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

    Directory of Open Access Journals (Sweden)

    Oleksandr O. Kurakevych

    2016-10-01

    Full Text Available 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.

  9. Superconductivity of divalent Chevrel phases at very high pressures

    International Nuclear Information System (INIS)

    Yao, Y.S.; Guertin, R.P.; Hinks, D.G.; Jorgensen, J.; Capone II, D.W.

    1988-01-01

    The electrical resistivity and the superconducting transition temperatures were examined for three representative divalent Chevrel phase systems, SnMo 6 S 8 , EuMo 6 S 8 , and BaMo 6 S 8 , as a function of hydrostatic pressure to 2 GPa and in quasihydrostatic pressures to 10 GPa. In all systems, T/sub c/ is depressed to 0 K for sufficiently large pressures. For the Sn- and Eu-based systems, both highly purified samples and samples with controlled oxygen content were used. In an oxygenated SnMo 6 S 8 sample (less than 3% O 2 substituted for the S atoms) the pressure threshold and maximum T/sub c/ are 40% lower than in the pure sample, but for P>3.5 GPa the T/sub c/-P phase diagrams nearly coincide, with T/sub c/ reaching zero at an extrapolated pressure of about 12 GPa. In pure EuMo 6 S 8 , superconductivity appears only above a threshold pressure of about 1 GPa and is depressed to 0 K above 4.5 GPa. In an oxygenated sample the maximum T/sub c/ and the threshold pressure are depressed, and above about 3.5 GPa the T/sub c/-P phase diagrams coincide, as in the Sn-based system, although T/sub c/ is then rapidly depressed to 0 K at about 4.5 GPa. In a highly purified BaMo 6 S 8 sample superconductivity appears above about 2 GPa and is depressed to 0 K at extrapolated pressures above 12 GPa. A full transition to the zero-resistance superconducting state is observed in BaMo 6 S 8 . The data are discussed in terms of a model linking the rhombohedral-to-triclinic structural transition, the superconducting transition temperature, and the role of pressure in suppressing the structural transition

  10. Transient heating effects in high pressure Diesel injector nozzles

    International Nuclear Information System (INIS)

    Strotos, George; Koukouvinis, Phoevos; Theodorakakos, Andreas; Gavaises, Manolis; Bergeles, George

    2015-01-01

    Highlights: • Simulation of friction-induced heating in high pressure Diesel fuel injectors. • Injection pressures up to 3000 bar. • Simulations with variable fuel properties significantly affect predictions. • Needle motion affects flow and temperature fields. • Possible heterogeneous boiling as injection pressures increase above 2000 bar. - Abstract: The tendency of today’s fuel injection systems to reach injection pressures up to 3000 bar in order to meet forthcoming emission regulations may significantly increase liquid temperatures due to friction heating; this paper identifies numerically the importance of fuel pressurization, phase-change due to cavitation, wall heat transfer and needle valve motion on the fluid heating induced in high pressure Diesel fuel injectors. These parameters affect the nozzle discharge coefficient (C d ), fuel exit temperature, cavitation volume fraction and temperature distribution within the nozzle. Variable fuel properties, being a function of the local pressure and temperature are found necessary in order to simulate accurately the effects of depressurization and heating induced by friction forces. Comparison of CFD predictions against a 0-D thermodynamic model, indicates that although the mean exit temperature increase relative to the initial fuel temperature is proportional to (1 − C d 2 ) at fixed needle positions, it can significantly deviate from this value when the motion of the needle valve, controlling the opening and closing of the injection process, is taken into consideration. Increasing the inlet pressure from 2000 bar, which is the pressure utilized in today’s fuel systems to 3000 bar, results to significantly increased fluid temperatures above the boiling point of the Diesel fuel components and therefore regions of potential heterogeneous fuel boiling are identified

  11. HIGH HYDROSTATIC PRESSURE SYSTEMS USE IN FOOD INDUSTRY

    Directory of Open Access Journals (Sweden)

    Yahya TÜLEK

    2006-02-01

    Full Text Available Food preservation is a continuous fight against microorganisms spoiling the food or making it unsafe. The last decade, non-thermal inactivation techniques have been a major research issue, driven by an increased consumer demand for nutritious, fresh like food products with a high organoleptical quality and an acceptable shelf life. Investigated inactivation technologies are ionisation radiation, high hydrostatic pressure (HHP, pulsed electrical fields, high pressure homogenisation, UV decontamination, etc. Most research has focussed on HHP and is therefore discussed in detail here.

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

    Science.gov (United States)

    Wisniewiski, David

    2014-03-01

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

  13. Field-Effect Transistors Based on Networks of Highly Aligned, Chemically Synthesized N = 7 Armchair Graphene Nanoribbons.

    Science.gov (United States)

    Passi, Vikram; Gahoi, Amit; Senkovskiy, Boris V; Haberer, Danny; Fischer, Felix R; Grüneis, Alexander; Lemme, Max C

    2018-03-28

    We report on the experimental demonstration and electrical characterization of N = 7 armchair graphene nanoribbon (7-AGNR) field effect transistors. The back-gated transistors are fabricated from atomically precise and highly aligned 7-AGNRs, synthesized with a bottom-up approach. The large area transfer process holds the promise of scalable device fabrication with atomically precise nanoribbons. The channels of the FETs are approximately 30 times longer than the average nanoribbon length of 30 nm to 40 nm. The density of the GNRs is high, so that transport can be assumed well-above the percolation threshold. The long channel transistors exhibit a maximum I ON / I OFF current ratio of 87.5.

  14. Waveforms for optimal sub-keV high-order harmonics with synthesized two- or three-colour laser fields.

    Science.gov (United States)

    Jin, Cheng; Wang, Guoli; Wei, Hui; Le, Anh-Thu; Lin, C D

    2014-05-30

    High-order harmonics extending to the X-ray region generated in a gas medium by intense lasers offer the potential for providing tabletop broadband light sources but so far are limited by their low conversion efficiency. Here we show that harmonics can be enhanced by one to two orders of magnitude without an increase in the total laser power if the laser's waveform is optimized by synthesizing two- or three-colour fields. The harmonics thus generated are also favourably phase-matched so that radiation is efficiently built up in the gas medium. Our results, combined with the emerging intense high-repetition MHz lasers, promise to increase harmonic yields by several orders to make harmonics feasible in the near future as general bright tabletop light sources, including intense attosecond pulses.

  15. Extremely-high vacuum pressure measurement by laser ionization

    International Nuclear Information System (INIS)

    Kokubun, Kiyohide

    1991-01-01

    Laser ionization method has the very high sensitivity for detecting atoms and molecules. Hurst et al. successfully detected a single Cs atom by means of resonance ionization spectroscopy developed by them. Noting this high sensitivity, the authors have attempted to apply the laser ionization method to measure gas pressure, particularly in the range down to extremely high vacuum. At present, hot cathode ionization gauges are used for measuring gas pressure down to ultrahigh vacuum, however, those have a number of disadvantages. The pressure measurement using lasers does not have such disadvantages. The pressure measurement utilizing the laser ionization method is based on the principle that when laser beam is focused through a lens, the amount of atom or molecule ions generated in the focused space region is proportional to gas pressure. In this paper, the experimental results are presented on the nonresonant multiphoton ionization characteristics of various kinds of gases, the ion detection system with high sensitivity and an extremely high vacuum system prepared for the laser ionization experiment. (K.I.)

  16. Experimental studies on radiation effects under high pressure oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, E [Osaka Univ. (Japan). School of Dentistry

    1974-06-01

    The effect of oxygen tension on the radiosensitivity of tumor cells is well known, but its clinical application for radiotherapy is not yet established. Rabbits with V x 2 carcinoma in the maxilla were irradiated by /sup 60/Co under high pressure oxygen (experimental group), and compared with those treated in air (control group). For the purpose of examining the clinical effects of high pressure oxygen, an experiment was made in vivo. The following items were compared respectively: a) Tumor regression effect b) Tumor clearance rate c) Survival days d) Half size reduction time e) Inhibition of DNA synthesis in the tumor tissue. Results obtained were as follows: a) 56 per cent of animals showed tumor regression in the experimental group, whereas it occured 26 per cent in the control group. b) 53 per cent of animals showed tumor disappearance in the experimental group, while it was observed only in 13 per cent in the control group. c) Only 2 of 30 rabbits irradiated in air survived over 180 days, whereas 11 of 30 rabbits survived meanwhile in the group irradiated under high pressure oxygen. d) About 11 days were necessary to reduce the tumor size by half after irradiation in the group under high pressure oxygen, while it took 17 days in the group treated in normal air. e) DNA synthesis was inhibited more prominently in the group irradiated under high pressure oxygen in normal air.

  17. Thermal high pressure hydrogenolysis II. The thermal high pressure hydrocracking of fluorene

    NARCIS (Netherlands)

    Oltay, Ernst; Penninger, Johannes M.L.; Konter, Willem A.N.

    1973-01-01

    The thermal hydrocracking of fluorene was investigated in the temperature range of 400 to 480 °C and hydrogen pressures of up to 375 atm. As main reaction products were found 2-methylbiphenyl, biphenyl, toluene and benzene. They account for about 90% of the converted fluorene. Only very low

  18. High dose thermoluminescence dosimetry performance of Sol-gel synthesized TiO{sub 2} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Salas J, Ch. J.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Castillo U, D. M.; Flores M, K. [Universidad de Sonora, Departamento de Ciencias Quimico Biologicas, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: castillouzeta@gmail.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, Queretaro, Qro. (Mexico)

    2015-10-15

    Full text: TiO{sub 2} is a ceramic material with many applications due to their different crystalline phases (rutile, anatase and brookite). It has attracted attention in several fields because their high mechanical strength, chemical stability and ion-conducting properties. Moreover, in recent years, some research groups gained interest in the thermoluminescence features of TiO{sub 2} concerning their potential use as thermoluminescence dosimeter. In this work, we present experimental results obtained in the first stage of a long-term research project focused in the synthesis of TiO{sub 2} phosphors for dosimetric applications. The thermoluminescent characterization of samples was carried out after being exposed to beta particle irradiation. TiO{sub 2} was prepared by alkoxide sol-gel route using titanium tetrabutoxide as precursor, ethanol, water and ammonia as catalyst. Pellet-shaped samples were annealed at 700 degrees C for 6 h in air atmosphere followed by slow cooling, and then were exposed to radiation doses from 25 to 400 Gy. The glow curves display maxima located at 103 and 238 degrees C when a 5 C/s heating rate is used. From the experimental results here presented, we conclude that TiO{sub 2} is a promising material to develop high dose Tl dosimeters. (Author)

  19. Application and possible benefits of high hydrostatic pressure or high-pressure homogenization on beer processing: A review.

    Science.gov (United States)

    Santos, Lígia Mr; Oliveira, Fabiano A; Ferreira, Elisa Hr; Rosenthal, Amauri

    2017-10-01

    Beer is the most consumed beverage in the world, especially in countries such as USA, China and Brazil.It is an alcoholic beverage made from malted cereals, and the barley malt is the main ingredient, added with water, hops and yeast. High-pressure processing is a non-traditional method to preserve food and beverages. This technology has become more interesting compared to heat pasteurization, due to the minimal changes it brings to the original nutritional and sensory characteristics of the product, and it comprises two processes: high hydrostatic pressure, which is the most industrially used process, and high-pressure homogenization. The use of high pressure almost does not affect the molecules that are responsible for the aroma and taste, pigments and vitamins compared to the conventional thermal processes. Thus, the products processed by high-pressure processing have similar characteristics compared to fresh products, including beer. The aim of this paper was to review what has been investigated about beer processing using this technology regarding the effects on physicochemical, microbiology and sensory characteristics and related issues. It is organized by processing steps, since high pressure can be applied to malting, mashing, boiling, filtration and pasteurization. Therefore, the beer processed with high-pressure processing may have an extended shelf-life because this process can inactivate beer spoilage microorganisms and result in a superior sensory quality related to freshness and preservation of flavors as it does to juices that are already commercialized. However, beyond this application, high-pressure processing can modify protein structures, such as enzymes that are present in the malt, like α- and β-amylases. This process can activate enzymes to promote, for example, saccharification, or instead inactivate at the end of mashing, depending on the pressure the product is submitted, besides being capable of isomerizing hops to raise beer bitterness

  20. Screening of hydrogen storage media applying high pressure thermogravimetry

    DEFF Research Database (Denmark)

    Bentzen, J.J.; Pedersen, Allan Schrøder; Kjøller, J.

    2001-01-01

    A number of commercially available hydride-forming alloys of the MmNi5–xSnx (Mm=mischmetal, a mixture of lanthanides) type were examined using a high pressure, high temperature microbalance,scanning electron microscopy and X-ray diffraction. Activation conditions, reversible storage capacity...

  1. High pressure gas laser technology for atmospheric remote sensing

    Science.gov (United States)

    Javan, A.

    1980-01-01

    The development of a fixed frequency chirp-free and highly stable intense pulsed laser made for Doppler wind velocity measurements with accurate ranging is described. Energy extraction from a high pressure CO2 laser at a tunable single mode frequency is also examined.

  2. High-pressure phase transitions of deep earth materials

    International Nuclear Information System (INIS)

    Hirose, Kei

    2009-01-01

    Recent developments in synchrotron XRD measurements combined with laser-heated diamond-anvil cell (LHDAC) techniques have enabled us to search for a novel phase transition at extremely high pressure and temperature. A phase transition from MgSiO 3 perovskite to post-perovskite was discovered through a drastic change in XRD patterns above 120 GPa and 2500 K, corresponding to the condition in the lowermost mantle (Murakami et al., 2004; Oganov and Ono, 2004). A pressure-induced phase transformation from ABO 3 -type perovskite to any denser structures was not known at that time. This new MgSiO 3 polymorph called post-perovskite has an orthorhombic symmetry (space group: Cmcm) with a sheet-stacking structure. The Mg site in post-perovskite is smaller than that in perovskite, which results in a volume reduction by 1.0-1.5% from perovskite structure. The electrical conductivity of post-perovskite is higher by three orders of magnitude than that of perovskite at similar pressure range (Ohta et al., 2008). This is likely due to a shorter Fe-Fe distance in post-perovskite structure, while conduction mechanism is yet to be further examined. Phase transition boundary between perovskite and post-perovskite has been determined in a wide temperature range up to 4400 K at 170 GPa (Tateno et al., 2008). Phase relations of Fe alloys have been also studied at core pressures (>135 GPa), although the generation of high temperature is more difficult at higher pressures. A new high-pressure B2 phase of B2 phase of FeS was recently discovered above 180 GPa (Sata et al., 2008). The Fe-Ni alloys have a wide pressure-temperature stability field of fcc phase at the core pressure range, depending on the Ni content (Kuwayama et al., 2008). (author)

  3. An innovative approach to synthesize highly-ordered TiO2 nanotubes.

    Science.gov (United States)

    Isimjan, Tayirjan T; Yang, D Q; Rohani, Sohrab; Ray, Ajay K

    2011-02-01

    An innovative route to prepare highly-ordered and dimensionally controlled TiO2 nanotubes has been proposed using a mild sonication method. The nanotube arrays were prepared by the anodization of titanium in an electrolyte containing 3% NH4F and 5% H2O in glycerol. It is demonstrated that the TiO2 nanostructures has two layers: the top layer is TiO2 nanowire and underneath is well-ordered TiO2 nanotubes. The top layer can easily fall off and form nanowires bundles by implementing a mild sonication after a short annealing time. We found that the dimensions of the TiO2 nanotubes were only dependent on the anodizing condition. The proposed technique may be extended to fabricate reproducible well-ordered TiO2 nanotubes with large area on other metals.

  4. Organosilica hybrid nanomaterials with a high organic content: syntheses and applications of silsesquioxanes

    KAUST Repository

    Croissant, Jonas G.

    2016-11-07

    Organic-inorganic hybrid materials garner properties from their organic and inorganic matrices as well as synergistic features, and therefore have recently attracted much attention at the nanoscale. Non-porous organosilica hybrid nanomaterials with a high organic content such as silsesquioxanes (R-SiO, with R organic groups) and bridged silsesquioxanes (OSi-R-SiO) are especially attractive hybrids since they provide 20 to 80 weight percent of organic functional groups in addition to the known chemistry and stability of silica. In the organosilica family, silsesquioxanes (R-SiO) stand between silicas (SiO) and silicones (RSiO), and are variously called organosilicas, ormosil (organically-modified silica), polysilsesquioxanes and silica hybrids. Herein, we comprehensively review non-porous silsesquioxane and bridged silsesquioxane nanomaterials and their applications in nanomedicine, electro-optics, and catalysis.

  5. Modulating fluorescence quantum yield of highly concentrated fluorescein using differently shaped green synthesized gold nanoparticles

    International Nuclear Information System (INIS)

    John, Jisha; Thomas, Lincy; Kurian, Achamma; George, Sajan D.

    2016-01-01

    The interaction of dye molecules with differently shaped nanoparticles is of great interest owing to the potential applications in areas of bioimaging, sensing and photodynamic therapy (biology) as well as solar cells (photonics) applications. For such applications, noble metallic nanoparticles are commonly employed to either enhance or quench the luminescence of a nearby fluorophore. However, in most of the studies, the dye concentration is limited to avoid self-quenching. This paper reports the influence of differently shaped gold nanoparticles (spherical, bean and star), prepared via green synthesis, on the emission behavior as well as on the fluorescence quantum yield of fluorescein dye at concentrations for which self-quenching occurs. The emission behavior is probed via laser based steady state fluorescence whereas quantum yield is measured using a dual beam laser based thermal lens technique. The experimentally observed fluorescence quenching with a concomitant increase in thermal lens signal in the vicinity of nanoparticles are explained in terms of nonradiative energy transfer between the donor and the acceptor. Further, the influence of pH of the prepared gold nanofluid on the absorption, emission as well as quantum yield are also accounted. These studies elucidate that even at high concentrations of dye, the gold nanoparticle and its shape clearly influences the optical properties of nearby dye molecules and thus can be exploited for future applications. - Highlights: • Green synthesis of differently shaped gold nanoparticles. • Tailoring emission properties of fluorescein with respect to nanoparticle concentration and shape. • Tailoring the quantum yield of highly concentrated fluorescein with nanoparticles.

  6. Releasable, high-pressure seal and method of forming same

    International Nuclear Information System (INIS)

    Holman, R.R.; Turkail, D.N.

    1980-01-01

    An inexpensive releaseable, high-pressure seal was developed, which can withstand pressures over 70 atm, and is particularly useful for nuclear reactors where remote-handling equipment must be used to access the flanged connections. It is smaller than existing high-pressure seals and does not require as many bolts. The fail-safe quality of the seal does not depend on close tolerances or high-quality surface finishes. The seal comprises two conduits through which the high-pressure fluid flows, each fitted with flanges. The second flange has a periphery attached to the second conduit. Each flange has a central opening for the fluid to flow through. The second flange is frustoconical in shape and is resilient so that a portion of it near its central opening can be resiliently biased towards the first flange. A seal ring between the end flanges seals the interior of the conduits from the exterior. A force is applied to the seal ring which acts nearly parallel to the axis of the conduits and varies as a function of the fluid pressure inside of the conduits. The flanges are attached to each other with peripheral collars via a circumferential clamp. (DN)

  7. Ultra-high pressure water jet: Baseline report

    International Nuclear Information System (INIS)

    1997-01-01

    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

  8. Iron based superconductors and related compounds synthesized by solid state metathesis and high temperature reactions

    International Nuclear Information System (INIS)

    Frankovsky, Rainer

    2013-01-01

    The results of this thesis can be divided into three major topics, which can also be seen as different approaches of solid state chemistry to reveal interesting features of known and unknown compounds and to develop alternative synthesis routes. Firstly, known compounds with related structural motifs to the superconducting iron-arsenides were investigated regarding their structural and physical properties. In case of La 3 Pd 4 Ge 4 the influence of Fe doping on the properties was studied, whereas in the series ZrMAs (M=Ti,V) the physical properties have not yet been reported at all and were investigated for the first time. Secondly, an alternative synthesis route has been developed for the synthesis of superconducting LaFeAsO 1-x F x . This solid state metathesis reaction distinctly increased the quality of the samples compared to conventionally prepared products. Furthermore, the reaction pathway was investigated and clarified, which helps to understand the processes during high temperature solid state metathesis reactions in general. Thirdly, this alternative synthesis route was expanded to other systems and new compounds like co-substituted LaFe 1-x Mn x AsO 1-y F y were prepared and thoroughly investigated. This led to a complex study of the interplay of magnetism, electronic and structural conditions and the occurrence of superconducting properties. The investigation and understanding of such complex coherences will probably be decisive for the further understanding of the superconducting mechanism in iron based superconductors.

  9. Haemocompatibility of iron oxide nanoparticles synthesized for theranostic applications: a high-sensitivity microfluidic tool

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Raquel O. [Polytechnic Institute of Bragança, Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM) (Portugal); Bañobre-López, Manuel; Gallo, Juan [INL-International Iberian Nanotechnology Laboratory, Advanced (Magnetic) Theranostic Nanostructures Lab (Portugal); Tavares, Pedro B. [Universidade de Trás-os-Montes e Alto Douro, CQVR-Centro de Química-Vila Real (Portugal); Silva, Adrián M. T. [Universidade do Porto, Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia (Portugal); Lima, Rui, E-mail: rl@dem.uminho.pt [MEtRiCS, University of Minho, Mechanical Engineering Department (Portugal); Gomes, Helder T. [Polytechnic Institute of Bragança, Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM) (Portugal)

    2016-07-15

    The poor heating efficiency of the most reported magnetic nanoparticles (MNPs), allied to the lack of comprehensive biocompatibility and haemodynamic studies, hampers the spread of multifunctional nanoparticles as the next generation of therapeutic bio-agents in medicine. The present work reports the synthesis and characterization, with special focus on biological/toxicological compatibility, of superparamagnetic nanoparticles with diameter around 18 nm, suitable for theranostic applications (i.e. simultaneous diagnosis and therapy of cancer). Envisioning more insights into the complex nanoparticle-red blood cells (RBCs) membrane interaction, the deformability of the human RBCs in contact with magnetic nanoparticles (MNPs) was assessed for the first time with a microfluidic extensional approach, and used as an indicator of haematological disorders in comparison with a conventional haematological test, i.e. the haemolysis analysis. Microfluidic results highlight the potential of this microfluidic tool over traditional haemolysis analysis, by detecting small increments in the rigidity of the blood cells, when traditional haemotoxicology analysis showed no significant alteration (haemolysis rates lower than 2 %). The detected rigidity has been predicted to be due to the wrapping of small MNPs by the bilayer membrane of the RBCs, which is directly related to MNPs size, shape and composition. The proposed microfluidic tool adds a new dimension into the field of nanomedicine, allowing to be applied as a high-sensitivity technique capable of bringing a better understanding of the biological impact of nanoparticles developed for clinical applications.

  10. Investigation of a high pressure oxy-coal process

    Energy Technology Data Exchange (ETDEWEB)

    Renz, U. [RWTH Aachen Univ. (Germany). Inst. of Heat and Mass Transfer

    2013-07-01

    A study was conducted to investigate the feasibility of an oxy-coal process, which is pressurized to a combustion pressure of 80 bar. At that pressure the water-vapor can be separated economically from the CO{sub 2}/H{sub 2}O flue gases, either by nucleate condensation or by condensation on cooled surfaces in condenser heat exchangers at a temperature of about 300 C. The heat of condensation can be recaptured to preheat the boiler feed water. So the number of economizers is drastically reduced compared to a conventional steam cycle. Another interesting feature of the high pressure oxy-coal process is the fact, that low rank coal with high moisture content can be fired. Such a process at a pressure of about 80 bar is currently investigated by Babcock, USA, as the ThermoEnergy Integrated Power System (TIPS) and will be analyzed in the present paper. A known disadvantage of the oxy-coal processes is the large recirculating flue gas stream to control the combustion temperature, and which need large pipes and heavy recirculation fans. This disadvantage could be avoided if instead of flue gas a part of the condensed water from the condenser heat exchangers is recirculated. Within the present study both types of processes have been simulated and for an electric power output of about 220 MW. Furthermore, results of CFD simulations of a pressurized 250 MW combustor with a single swirl burner and flue gas recirculation will be presented.

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

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1983-01-01

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

  12. Bonding pathways of high-pressure chemical transformations

    International Nuclear Information System (INIS)

    Hu Anguang; Zhang Fan

    2013-01-01

    A three-stage bonding pathway towards high-pressure chemical transformations from molecular precursors or intermediate states has been identified by first-principles simulations. With the evolution of principal stress tensor components in the response of chemical bonding to compressive loading, the three stages can be defined as the van der Waals bonding destruction, a bond breaking and forming reaction, and equilibrium of new bonds. The three-stage bonding pathway leads to the establishment of a fundamental principle of chemical bonding under compression. It reveals that during high-pressure chemical transformation, electrons moving away from functional groups follow anti-addition, collision-free paths to form new bonds in counteracting the local stress confinement. In applying this principle, a large number of molecular precursors were identified for high-pressure chemical transformations, resulting in new materials. (fast track communication)

  13. High pressure gas driven liquid metal MHD homopolar generator

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki

    1988-01-01

    A liquid metal MHD homopolar generator is proposed to be used as a high repetition rate pulsed power supply. In the generator, the thermal energy stored in a high pressure gas (He) reservoir is rapidly converted into kinetic energy of a rotating liquid metal (NaK) cylinder which is contracted by a gas driven annular free piston. The rotational kinetic energy is converted into electrical energy by making use of the homopolar generator principle. The conversion efficiency is calculated to be 47% in generating electrical energy of 20 kJ/pulse (1.7 MW peak power) at a repetition rate of 7 Hz. From the viewpoint of energy storage, the high pressure gas reservoir with a charging pressure of 15 MPa is considered to ''electrically'' store the energy at a density of 10 MJ/m 3 . (author)

  14. Diagnostics and modeling of high pressure streamer induced discharges

    International Nuclear Information System (INIS)

    Marode, E.; Dessante, P.; Deschamps, N.; Deniset, C.

    2001-01-01

    A great variety of diagnostic has been applied to gain information on basic parameter governing high pressure nonthermal filamentary plasmas (and namely streamer induced filamentary discharges). Apart from electrical diagnostics, gas discharge, in contrast with solid state physics, can greatly benefit from all optical techniques owing to its ''transparent'' state. Emission and absorption spectroscopy, as well as LIF or CARS (talk are given during this meeting on these two techniques) are among such specific possibilities. The figures gained from these diagnostic measurements has generally no meaning by itself. They must be worked out, by means of calibrated former results, and/or by using them as input in high pressure plasma modeling. Mixing experimental and modeling approach is necessary for reaching relevant physical knowledge of the high pressure filamentary discharges processes. It is shown that diffusion, and thermal space and time distribution, must fully be taken into account

  15. Transformations in refractory compounds, caused by high pressures and temperatures

    International Nuclear Information System (INIS)

    Zajnulin, Yu.G.; Alyamovskij, S.I.; Shvejkin, G.P.

    1979-01-01

    Considered is the effect of high pressures and temperatures on structural features of refractory carbides, nitrides and monooxides of transition metals. The results are discussed on the basis of one component of the theory on daltonides and bertollides by N.S. Kurnakov - the theory of imaginary compounds, developed by G.B. Bokij. Several new ideas, resulting from this consideration, are formulated, It is shown that at high pressures and temperatures it is possible to obtain new electron modifications of compounds and to expand sufficiently the region of the existance of variable composition phases. The concept on imaginary compounds is shown to be true. A supposition is made on realization of numerous imaginary compounds at high pressures and temperatures. Other ways of production of imaginary compounds are recommended

  16. Equation of state of liquid Indium under high pressure

    Directory of Open Access Journals (Sweden)

    Huaming Li

    2015-09-01

    Full Text Available 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.

  17. Synthesis and Structural Study of Sr2CuO3+δ Superconductor under High Pressure

    International Nuclear Information System (INIS)

    Qing-Qing, Liu; Fu-Ren, Wang; Feng-Ying, Li; Liang-Chen, Chen; Ri-Cheng, Yu; Chang-Qing, Jin; Yan-Chun, Li; Jing, Liu

    2008-01-01

    A single-phase Sr 2 CuO 3+δ superconductor is synthesized under high temperature and high pressure, in which oxygen atoms only partially occupy the apical sites next to the CuO 2 planes and act as hole-dopants. The superconducting transition temperature with T c max = 75 K is achieved in the material. Structure analysis from x-ray powder diffraction data show that this material crystallizes into a K 2 NiF 4 structure with tetragonal unit cell of a = 3. 795(3) Å and c = 12. 507(1) Å. Energy-dispersive synchrotron x-ray-diffraction studies at ambient are performed on powder samples of Sr 2 CuO 3+δ in a diamond-anvil cell at pressure up to 35 GPa. Anisotropic compressibility is found. Pressure-induced isostructural phase transition might exist as revealed by the discontinuous change of crystal cell volume V with pressure. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  18. Thermopower measurement under high pressure using 'seesaw heating method'

    International Nuclear Information System (INIS)

    Hedo, M; Nakamura, D; Takaesu, Y; Yagasaki, K; Nakama, T; Fujiwara, T; Uchima, K

    2010-01-01

    We have developed a set-up with modified 'seesaw heating method' for the thermopower measurement under pressures P up to 3 GPa at the temperature range between 2 K and 300 K. By using this set-up, the thermopower and electrical resistivity of the single crystalline YbMn 2 Ge 2 under high pressure were measured with enough accuracy. S(T) curve shows the characteristic feature at the magnetic transition in all pressure range, while no evidence of the magnetic phase transition is observed in ρ(T) at P > 1.25 GPa. The measurement results indicate that the simultaneous measurement of the thermopower and electrical resistivity is a useful tool to study the pressure-induced phase transitions.

  19. High-pressure Raman spectroscopy of phase change materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-04

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

  20. NATO Advanced Study Institute on High-Pressure Crystallography

    CERN Document Server

    Boldyreva, Elena; High-Pressure Crystallography

    2010-01-01

    This book is devoted to the theme of crystallographic studies at high pressure, with emphasis on the phenomena characteristic to the compressed state of matter, as well as experimental and theoretical techniques used to study these phenomena. As a thermodynamic parameter, pressure is remarkable in many ways. In the visible universe its value spans over sixty orders of magnitude, from the non-equilibrium pressure of hydrogen in intergalactic space, to the kind of pressure encountered within neutron stars. In the laboratory, it provides the unique possibility to control the structure and properties of materials, to dramatically alter electronic properties, and to break existing, or form new chemical bonds. This agenda naturally encompasses elements of physics (properties, structure and transformations), chemistry (reactions, transport), materials science (new materials) and engineering (mechanical properties); in addition it has direct applications and implications for geology (minerals in deep Earth environmen...