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  1. Dissociative attachment from vibrationally and rotationally excited HCl and HF

    International Nuclear Information System (INIS)

    Allan, M.; Wong, S.F.

    1981-01-01

    An electron impact mass spectrometer is used to study dissociative attachment in HCl, DCl, and HF at incident energies 0--4 eV. Target molecules in different excited nuclear states are prepared with an iridium oven source. The cross sections for Cl - /HCl, Cl - /DCl, and F - /HF all show an order of magnitude increase with each increase of vibrational quantum (v=0, 1, and 2). In Cl - /HCl the threshold cross section for the v=2 level at 0.1 eV reaches (7.8 +- 4.7) x 10 -15 cm 2 . Together, this large cross section and the recent potential-energy-curve calculations of HCl and HCl - show that the conventional theory of dissociative attachment may not be applicable here. A new mechanism for dissociative attachment is suggested

  2. Detection of HCl and HF by TTFMS and WMS.

    Science.gov (United States)

    De Luca, Anna Chiara; Pesce, Giuseppe; Rusciano, Giulia; Sasso, Antonio

    2006-04-01

    In this work we discuss on a compact spectrometer based on DFB diode lasers for detection of chloridric and fluoridric acids. HCl and HF concentrations are determined through optical absorption of the P(4) line (lambda=1.7 microm) and the R(3) line (lambda=1.3 microm), respectively. Both lines belong to first overtone vibrational bands and their line strengths are 7.8 x 10(-21)cm/molecule for HCl and 2.8 x 10(-20)cm/molecule for HF. We chose these lines for their relative high intensities and because they are quite far from water vapour lines which represent the main interfering gas for trace-gases analysis. To detect these species we used two different high frequency modulation techniques: two-tone frequency modulation spectroscopy (f(1)=800 MHz and f(2)=804 MHz) was used for HCl while for HF we followed a simpler approach based on wavelength modulation spectroscopy (f=600 kHz). We demonstrate that the two techniques provide comparable detection limit of about 80 ppbV at atmospheric pressure. Positive testing of our spectrometer makes it suitable for in situ measurements of exhaust gases coming from waste incinerators.

  3. First results on the sorption behaviour of Rutherfordium from HCl/HF containing aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, D.; Nitsche, H. [Technische Univ. Dresden (Germany); Taut, S. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany); Jost, D.T.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Yakushev, A.B.; Buklanov, G.V.; Domanov, V.P.; Lien Din Thi [Joint Inst. for Nuclear Research, Dubna (Russian Federation); Kubica, B.; Misiak, R.; Szeglowski, Z. [NINP Cracow (Poland)

    1997-09-01

    Rutherfordium shows strong sorption on the cation exchanger DOWEX 50x8 at a concentration of 0.1 M HCl/10{sup -2} M HF. This shows that Rf behaves under these conditions differently from Hf and Zr and more like Th under these conditions. (author) 1 fig., 5 refs.

  4. Effect of CH3COOH on Hydrometallurgical Purification of Metallurgical-Grade Silicon Using HCl-HF Leaching

    Science.gov (United States)

    Tian, Chunjin; Lu, Haifei; Wei, Kuixian; Ma, Wenhui; Xie, Keqiang; Wu, Jijun; Lei, Yun; Yang, Bin; Morita, Kazuki

    2018-04-01

    The present study investigated the effects of adding CH3COOH to HCl and HF used to purify metallurgical-grade Si (MG-Si). After 6 h of leaching MG-Si with an acid mixture consisting of 4 mol L-1 HCl, 3 mol L-1 HF, and 3 mol L-1 CH3COOH at 348 K, the total impurity removal efficiency was 88.5%, exceeding the 81.5% removal efficiency obtained without addition of CH3COOH. The microstructural evolution of Si after etching with the two lixiviants indicated better dissolution of metal impurities in MG-Si when using the HCl-HF-CH3COOH mixture. Furthermore, the leaching kinetics of Fe using the HCl-HF and HCl-HF-CH3COOH mixtures were observed to depend on the interfacial chemical reactions.

  5. Theoretical predictions of hydrolysis and complex formation of group-4 elements Zr, Hf and Rf in HF and HCl solutions

    International Nuclear Information System (INIS)

    Pershina, V.; Trubert, D.; Le Naour, C.; Kratz, J.V.

    2002-01-01

    Fully relativistic molecular density-functional calculations of the electronic structures of hydrated, hydrolyzed and fluoride/chloride complexes have been performed for group-4 elements Zr, Hf, and element 104, Rf. Using the electronic density distribution data, relative values of the free energy change for hydrolysis and complex formation reactions were defined. The results show the following trend for the first hydrolysis step of the cationic species: Zr>Hf>Rf in agreement with experiments. For the complex formation in HF solutions, the trend to a decrease from Zr to Hf is continued with Rf, provided no hydrolysis takes place. At pH>0, further fluorination of hydrolyzed species or fluoro-complexes has an inversed trend in the group Rf≥Zr>Hf, with the difference between the elements being very small. For the complex formation in HCl solutions, the trend is continued with Rf, so that Zr>Hf>Rf independently of pH. A decisive energetic factor in hydrolysis or complex formation processes proved to be a predominant electrostatic metal-ligand interaction. Trends in the K d (distribution coefficient) values for the group-4 elements are expected to follow those of the complex formation

  6. QTAIM analysis of the HF, HCl, HBr, and HOH elimination reactions of halohydrocarbons and halohydroalcohols.

    Science.gov (United States)

    Parworth, Caroline L; Tucker, Mary K; Holmes, Bert E; Heard, George L

    2011-11-17

    The 1,2-HX elimination reaction (where X = F, Cl, Br, OH) has been established as an important reaction in the degradation of compounds introduced into the upper atmosphere, including common CFC replacement compounds. By analyzing the electron densities of the transition state geometries of these reactions using QTAIM, we see that we can divide these reactions into two types. For HF and HOH elimination, the transition state is a complete ring of bonds, and neither the C-H nor the C-X bonds have been broken at the maximum of energy. There is very little accumulation of electron density on the X atom, with the majority of charge being lost by the hydrogen atom undergoing elimination, being transferred on to the two carbon atoms. In HCl and HBr elimination, a similar loss of electron density of the hydrogen atom is accompanied by significant accumulation of electron density on the X atom and a smaller change in electron density on the carbon atoms. The C-X bond is broken in the transition state geometry, with no ring critical point being present. This may explain the relative stabilities of halohydrocarbons and haloalcohols with respect to loss of H-X.

  7. Kinetics studies of the F + HClHF + Cl reaction on an accurate potential energy surface

    Science.gov (United States)

    Lu, Dandan; Zhang, Ying; Li, Jun

    2018-02-01

    A full-dimensional electronic ground state potential energy surface for the hydrogen abstraction reaction F + HClHF + Cl is developed by using the permutation invariant polynomial neural network approach based on 6509 points computed at the level of CCSD(T)-F12a/AVTZ. Spin-orbit correction is also taken into account at the complete active space self-consistent field level. Theoretical thermal rate coefficients determined by the ring polymer molecular dynamics (RPMD) approach agree well with experiment, validating the accuracy of the PES. Kinetic isotope effect is also investigated.

  8. Observed and simulated time evolution of HCl, ClONO2, and HF total column abundances

    Directory of Open Access Journals (Sweden)

    B.-M. Sinnhuber

    2012-04-01

    Full Text Available Time series of total column abundances of hydrogen chloride (HCl, chlorine nitrate (ClONO2, and hydrogen fluoride (HF were determined from ground-based Fourier transform infrared (FTIR spectra recorded at 17 sites belonging to the Network for the Detection of Atmospheric Composition Change (NDACC and located between 80.05° N and 77.82° S. By providing such a near-global overview on ground-based measurements of the two major stratospheric chlorine reservoir species, HCl and ClONO2, the present study is able to confirm the decrease of the atmospheric inorganic chlorine abundance during the last few years. This decrease is expected following the 1987 Montreal Protocol and its amendments and adjustments, where restrictions and a subsequent phase-out of the prominent anthropogenic chlorine source gases (solvents, chlorofluorocarbons were agreed upon to enable a stabilisation and recovery of the stratospheric ozone layer. The atmospheric fluorine content is expected to be influenced by the Montreal Protocol, too, because most of the banned anthropogenic gases also represent important fluorine sources. But many of the substitutes to the banned gases also contain fluorine so that the HF total column abundance is expected to have continued to increase during the last few years. The measurements are compared with calculations from five different models: the two-dimensional Bremen model, the two chemistry-transport models KASIMA and SLIMCAT, and the two chemistry-climate models EMAC and SOCOL. Thereby, the ability of the models to reproduce the absolute total column amounts, the seasonal cycles, and the temporal evolution found in the FTIR measurements is investigated and inter-compared. This is especially interesting because the models have different architectures. The overall agreement between the measurements and models for the total column abundances and the seasonal cycles is good. Linear trends of HCl, ClONO2, and HF are calculated from both

  9. Relativistic and correlation effects on molecular properties .2. The hydrogen halides HF, HCl, HBr, HI, and HAt

    NARCIS (Netherlands)

    Visscher, L; Styszynski, J.; Nieuwpoort, W.C

    1996-01-01

    A benchmark study of a number of four-component relativistic correlation methods is presented. Bond lengths, harmonic frequencies, and dissociation energies of the molecules HF, HCl, HBr, HI, and HAt are calculated at various levels of theory, using both the Schrodinger and the Dirac-Coulomb-(Gaunt)

  10. Observed and simulated time evolution of HCl, ClONO2, and HF total columns

    Science.gov (United States)

    Ruhnke, Roland; Geomon, Ndacc Infrared, Modelling Working Group

    2010-05-01

    Institute of Technology (KIT), IMK-IFU, Garmisch-Partenkirchen, Germany, (16) University of Denver, Dept. of Physics and Astronomy, Denver, CO, USA, (17) National Center for Atmospheric Research (NCAR), Boulder, CO, USA, (18) NASA Langley Research Center, Hampton, VA, USA, (19) Karlsruhe Institute of Technology (KIT), Steinbuch Centre for Computing, Karlsruhe, Germany Total column abundances of HCl and ClONO2, the primary components of the stratospheric inorganic chlorine (Cly) budget, and of HF have been retrieved from ground-based, high-resolution infrared solar absorption spectra recorded at 17 sites of the Network for the Detection of Atmospheric Composition Change (NDACC) located at latitudes between 80.05°N and 77.82°S. These data extend over more than 20 years (through 2007) during a period when the growth in atmospheric halogen loading has slowed in response to the Montreal Protocol (and ammendments). These observed time series are interpreted with calculations performed with a 2-D model, the 3-D chemistry-transport models (CTMs) KASIMA and SLIMCAT, and the 3-D chemistry-climate models (CCMs) EMAC and SOCOLv2.0. The observed Cly and in particular HCl column abundances decreases significantely since the end of the nineties at all stations, which is consistent with the observed changes in the halocarbon source gases, with an increasing rate in the last years. In contrast to Cly, the trend values for total column HF at the different stations show a less consistent behaviour pointing to the fact that the time development of the HF columns is peaking. There is a good overall qualitative agreement regarding trends between models and data. With respect to the CTMs the agreement improves if simulation results for measurement days only are used in the trend analysis instead of simulation results for each day.

  11. Rotational structure of small 4He clusters seeded with HF, HCl, and HBr molecules.

    Science.gov (United States)

    Ramilowski, Jordan A; Mikosz, Aleksandra A; Farrelly, David; Fajín, José Luis Cagide; Fernandez, Berta

    2007-12-13

    Diffusion Monte Carlo calculations are performed for ground and excited rotational states of HX(4He)N, complexes with NHBr in a 4He nanodroplet will be smaller than that observed for HF, despite HF's having the largest (by far) gas-phase rotational constant of the three molecules. This suggests that the specifics of the solvation dynamics of a molecule in a 4He cluster are the result of a delicate interplay between the magnitude of the gas-phase rotational constant of the molecule and the anisotropic contributions to the atom-molecule potential energy.

  12. Real-time, high frequency (1 Hz), in situ measurement of HCl and HF gases in volcanic plumes with a novel cavity-enhanced, laser-based instrument

    Science.gov (United States)

    Kelly, P. J.; Sutton, A. J.; Elias, T.; Kern, C.; Clor, L. E.; Baer, D. S.

    2017-12-01

    Primary magmatic halogen-containing gases (HCl, HF, HBr, HI in characteristic order of abundance) are of great interest for volcano monitoring and research because, in general, they are more soluble in magma than other commonly-monitored volcanic volatiles (e.g. CO2, SO2, H2S) and thereby can offer unique insights into shallow magmatic processes. Nevertheless, difficulties in obtaining observations of primary volcanic halogens in gas plumes with traditional methods (e.g. direct sampling, Open-Path Fourier Transform Infrared spectroscopy, filter packs) have limited the number of observations reported worldwide, especially from explosive arc volcanoes. With this in mind, the USGS and Los Gatos Research, Inc. collaborated to adapt a commercially-available industrial in situ HCl-HF analyzer for use in airborne and ground-based measurements of volcanic gases. The new, portable instrument is based around two near-IR tunable diode lasers and uses a vibration-tolerant, enhanced-cavity approach that is well-suited for rugged field applications and yields fast (1 Hz) measurements with a wide dynamic range (0 -2 ppm) and sub-ppb precision (1σ: HCl: <0.4 ppb; HF: <0.1 ppb). In spring 2017 we conducted field tests at Kīlauea Volcano, Hawaii, to benchmark the performance of the new instrument and to compare it with an accepted method for halogen measurements (OP-FTIR). The HCl-HF instrument was run in parallel with a USGS Multi-GAS to obtain in situ H2O-CO2-SO2-H2S-HCl-HF plume compositions. The results were encouraging and quasi-direct comparisons of the in situ and remote sensing instruments showed good agreement (e.g. in situ SO2/HCl = 72 vs. OP-FTIR SO2/HCl = 88). Ground-based and helicopter-based measurements made 0 - 12 km downwind from the vent (plume age 0 - 29 minutes) show that plume SO2/HCl ratios increase rapidly from 60 to 300 around the plume edges, possibly due to uptake of HCl onto aerosols.

  13. Semiclassical study of the collision of a highly excited Rydberg atom with the molecules HF and HCl

    International Nuclear Information System (INIS)

    Kimura, M.; Lane, N.F.

    1990-01-01

    The semiclassical impact-parameter method is applied to the processes of state changing and energy transfer in the collision of a highly excited Rydberg atom (n≥20) with the polar molecules HF and HCl. The relative motion of the molecule and atomic nucleus is taken to be rectilinear; the electron-molecule and ion core-molecule interactions are represented by cutoff dipole forms. Cross sections for transitions involving quantum numbers n and l of the atom and rotational quantum number j of the molecule are obtained for a range of collision energies and initial atomic and molecular states. Comparisons are made with the results of earlier classical studies and with the quantum-mechanical impulse approximation. Collision rates are calculated and compared with experimental values for l mixing and n and j changing. The agreement between experiment and theory is shown to be satisfactory, within the uncertainties of both the measurements and the theory. Cases of agreement and disagreement between various theories are examined. One finding of the present work is that the quantum-mechanical impulse approximation appears to significantly overestimate the values of various state-changing cross sections when the internal energy defect is small. The validity of the impulse approximation for collisions of Rydberg atoms with polar molecules is discussed

  14. Sorption behaviour of W, Hf, Lu, U, and Th on ion exchangers from HCl/H2O2 solutions. Model experiments for chemical studies of seaborgium (Sg)

    International Nuclear Information System (INIS)

    Schumann, D.; Andrassy, M.; Nitsche, H.; Misiak, R.; Schaedel, M.; Bruechle, W.; Schausten, B.; Kratz, J.V.

    1997-08-01

    In model experiments with W, Hf, Th, and U radionuclides, a chemical system was developed for the separation of seaborgium from element 104 and heavy actinides, i.e., cation exchange on DOWEX 50 x 8 from solutions containing 0.1-1.0 M HCl and 0.5-2.0 vol.% H 2 O 2 . The system should be suitable for fast on-line experiments if seaborgium exibits a non-uranium-like behaviour. Adding hydrogen peroxide to mixed HCl/HF solutions suppresses the partial sorption of W and, presumably seaborgium, on the cation exchanger. This way, the elution volume can be minimized. Prospects for anion exchange separations of group 6 from 4 elements are also briefly discussed. (orig.)

  15. Product rotational angular momentum polarization of H+FCl (v=0-5; j=0, 3, 6, 9) → HF+Cl and HCl+F at Erel=0.5-20 kcal mol(-1).

    Science.gov (United States)

    Chao Wu, Victor Wei-Keh

    2015-12-01

    The rotational angular momentum polarizations of product molecules of the title reactions on the ground potential energy surface 1 (2)A' of DHTSN [Deskevic et al. J Chem Phys 2006, 124, 224303] have been studied using the quasi-classical trajectory method. Reaction dynamic results of the HF product channel comparing with another channel of HCl with 100,000 trajectories can be accurately resolved. We show the value of the polar p(ϑr) in the range of 0° ≤ ϑr ≤ 180(°), azimuthal p(φr) in the range of 0° ≤ φr ≤ 360(°), and dihedral p(ϑr, φr) in the ranges of 0(°) ≤ ϑr ≤ 180(°) and 0(°) ≤ φr ≤ 360(°); the angular distributions of the product molecules HF and HCl at relative Erel = 0.5, 1, 2, 5, 10, 15, and 20 kcal mol(-1); and four polarization-dependent differential cross sections (PDDCSs) of HF and HCl at Erel = 0.5, 1, 2, 5, 10, and 15 kcal mol(-1). p(φr) distributions at v = 0-5, and j = 0, 3, 6, 9 at every Erel are plotted cylindrically together. The stereo dynamic transformation reaction dependent upon the rovibrational states of the reactant molecule FCl and its relative translational energies around 0.5-5 kcal mol(-1) can be significantly differentiated. Translational and rovibrational enhancements of the title reactions on both early barrier potential energy surfaces have been shown in great detail and clarified. Reaction mechanisms of forward and backward scattering of the product molecules HF and HCl, respectively, have been obtained. Graphical Abstract H + FCl → either HF + Cl (left) or HCl + F (right) is moving along a trajectory on the respective PES.

  16. Qualification of a Multi-Channel Infrared Laser Absorption Spectrometer for Monitoring CO, HCl, HCN, HF, and CO2 Aboard Manned Spacecraft

    Science.gov (United States)

    Briggs, Ryan M.; Frez, Clifford; Forouhar, Siamak; May, Randy D.; Meyer, Marit E.; Kulis, Michael J.; Berger, Gordon M.

    2015-01-01

    Monitoring of specific combustion products can provide early-warning detection of accidental fires aboard manned spacecraft and also identify the source and severity of combustion events. Furthermore, quantitative in situ measurements are important for gauging levels of exposure to hazardous gases, particularly on long-duration missions where analysis of returned samples becomes impractical. Absorption spectroscopy using tunable laser sources in the 2 to 5 micrometer wavelength range enables accurate, unambiguous detection of CO, HCl, HCN, HF, and CO2, which are produced in varying amounts through the heating of electrical components and packaging materials commonly used aboard spacecraft. Here, we report on calibration and testing of a five-channel laser absorption spectrometer designed to accurately monitor ambient gas-phase concentrations of these five compounds, with low-level detection limits based on the Spacecraft Maximum Allowable Concentrations. The instrument employs a two-pass absorption cell with a total optical pathlength of 50 cm and a dedicated infrared semiconductor laser source for each target gas. We present results from testing the five-channel sensor in the presence of trace concentrations of the target compounds that were introduced using both gas sources and oxidative pyrolysis (non-flaming combustion) of solid material mixtures.

  17. Dipole and quadrupole moment functions of the hydrogen halides HF, HCl, HBr, and HI: a Hirshfeld interpretation.

    Science.gov (United States)

    Harrison, James F

    2008-03-21

    The dipole and quadrupole moment functions of the hydrogen halides are calculated using a large polarized basis and correlated wavefunctions and compared to experiment and previous calculations. These functions are analyzed in terms of local moments constructed using the Hirshfeld method. The dipole moment is the sum of the functions q(H)R+mu(H) and mu(X) with q(H) being the charge on the hydrogen atom, R the internuclear separation, mu(H) and mu(X) the atomic dipoles on the hydrogen and halogen atoms. We find that q(H)R+mu(H) is always positive and has a maximum at bond lengths larger than the equilibrium. In HF, mu(F) is slightly positive at the maximum in q(H)R+mu(H) and has little effect on the resultant maximum in the dipole moment function (DMF). mu(Cl), mu(Br), and mu(I), on the other hand, are increasingly more negative at the maximum of q(H)R+mu(H) and have a profound effect on the width of the maximum of the resulting DMF, successively broadening it and completely eliminating it at HI. The quadrupole moment function (QMF) (with the halogen as origin) is given by Theta(HX)=Theta(HX) (proto)+deltaTheta(X)+deltaTheta(H)+2mu(H)R+q(H)R(2), where Theta(HX) (proto) is the quadrupole moment of the separated atoms (the halogen in this instance) and deltaTheta(X)+deltaTheta(H) the change in the in situ quadrupole moments of the halogen and hydrogen atoms. The maximum in the QMF and its slope at equilibrium are determined essentially by 2mu(H)R+q(H)R(2), which is known once the DMF is known. deltaTheta(X)+deltaTheta(H) is always negative while Theta(HX) (proto) is positive, so one can approximate the molecular quadrupole moment to within 10% as Theta(HX)>Theta(HX) (proto)+2mu(H)R+q(H)R(2).

  18. Ground-based remote sensing of volcanic CO2 and correlated SO2, HF, HCl, and BrO, in safe-distance from the crater

    Science.gov (United States)

    Butz, Andre; Solvejg Dinger, Anna; Bobrowski, Nicole; Kostinek, Julian; Fieber, Lukas; Fischerkeller, Constanze; Giuffrida, Giovanni Bruno; Hase, Frank; Klappenbach, Friedrich; Kuhn, Jonas; Lübcke, Peter; Tirpitz, Lukas; Tu, Qiansi

    2017-04-01

    Remote sensing of CO2 enhancements in volcanic plumes can be a tool to estimate volcanic CO2 emissions and thereby, to gain insight into the geological carbon cycle and into volcano interior processes. However, remote sensing of the volcanic CO2 is challenged by the large atmospheric background concentrations masking the minute volcanic signal. Here, we report on a demonstrator study conducted in September 2015 at Mt. Etna on Sicily, where we deployed an EM27/SUN Fourier Transform Spectrometer together with a UV spectrometer on a mobile remote sensing platform. The spectrometers were operated in direct-sun viewing geometry collecting cross-sectional scans of solar absorption spectra through the volcanic plume by operating the platform in stop-and-go patterns in 5 to 10 kilometers distance from the crater region. We successfully detected correlated intra-plume enhancements of CO2 and volcanic SO2, HF, HCl, and BrO. The path-integrated volcanic CO2 enhancements amounted to about 0.5 ppm (on top of the ˜400 ppm background). Key to successful detection of volcanic CO2 was A) the simultaneous observation of the O2 total column which allowed for correcting changes in the CO2 column caused by changes in observer altitude and B) the simultaneous measurement of volcanic species co-emitted with CO2 which allowed for discriminating intra-plume and extra-plume observations. The latter were used for subtracting the atmospheric CO2 background. The field study suggests that our remote sensing observatory is a candidate technique for volcano monitoring in safe distance from the crater region.

  19. Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl3F and CCl2F2 using space-, balloon- and ground-based instrument observations

    Directory of Open Access Journals (Sweden)

    C. Servais

    2008-10-01

    Full Text Available Hydrogen chloride (HCl and hydrogen fluoride (HF are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F and CFC-12 (CCl2F2, during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and -12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10% above 20 km altitude, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences

  20. Emissions monitoring in conveyed gas flow: (a) sulfur oxides and nitrogen oxides expressed respectively as SO{sub 2} and NO{sub 2}, (b) inorganic chlorine and fluorine compounds as gases and vapours expressed as HCl and HF; Rilevamento delle emissioni in flussi gassosi convogliati: (a) ossidid di zolfo e ossidi di azoto espressi rispettivamente come SO{sub 2} e NO{sub 2}, (b) composti inorganici del cloro e del fluoro sotto forma di gas e vapore espressi rispettivamente come HCl e HF

    Energy Technology Data Exchange (ETDEWEB)

    Ziemacki, G.; Viviano, G. [ed.] [Isituto Superiore di Sanita`, Rome (Italy). Gruppo di lavoro `Modifiche per il rilevamento delle emissioni in atmosfera da impianti industriali`

    1998-03-01

    The method (a) enables the determination of sulfur oxides (SO{sub 2}) and nitrogen oxides (NO{sub 2}) in conveyed atmospheric emissions. A stream of flue gas is a sampled by a heated with a filter housing and absorbed by an alkaline solution of potassium permanganate. The absorption solution is analyzed by ion-exchange chromatography for the determination of sulfate ion and nitrate ion as SO{sub 2} and NO{sub 2}. The method (b) enables the determination of hydrochloric acid (HCl) and hydrofluoric acid (HF) in conveyed atmospheric emissions. A stream of flue gas is sampled by a heated probe with a filter housing and absorbed by an alkaline solution (NaOH). The absorption solution is analyzed by ion-exchange chromatography for the determination of chloride ion and fluoride ion as HCl and HF. [Italiano] Il metodo a) consente la determinazione, in emissioni atmosferiche convogliate, degli ossidi di zolfo (SO{sub 2}) e degli ossidi di azoto (NO{sub 2}). Il campionamento viene effettuato mediante sonda riscaldata, munita di sistema filtrante, e sistema di assorbimento in soluzione alcalina di permanganato di potassio. La soluzione di assorbimento viene analizzata mediante cromatografia a scambio ionico, determinando le concentrazioni di ioni solfato e nitrato come SO{sub 2} ed NO{sub 2}. Il metodo b) consente la determinazione, in emissioni atmosferiche convogliate, dell`acido cloridrico (HCl) e dell`acido fluoridrico (HF). Il campionamento viene effettuato mediante sonda riscaldata, munita di sistema filtrante, e sistema di assorbimento in soluzione alcalina (NaOH). La soluzione alcalina viene quindi analizzata mediante cromatografia a scambio ionico, deter,mminando le concentrazioni di ioni cloro e fluoro come HCl e HF.

  1. HF laser

    International Nuclear Information System (INIS)

    Suzuki, Kazuya; Iwasaki, Matae

    1977-01-01

    A review is made of the research and development of HF chemical laser and its related work. Many gaseous compounds are used as laser media successfully; reaction kinetics and technological problems are described. The hybrid chemical laser of HF-CO 2 system and the topics related to the isotope separation are also included. (auth.)

  2. Estudo das ligações de hidrogênio para dímeros formados pelas moléculas de H2O, NH3, HF, HCl e HBr através de cálculos baseados em primeiros princípios

    Directory of Open Access Journals (Sweden)

    Sergio Duvoisin Jr

    2011-09-01

    Full Text Available Hydrogen bond energies of fifteen dimers were calculated using the large basis set 6-311++G(3df,3pd, at Hartree-Fock (HF level including Møller-Plesset (MP2 calculations. The procedure for obtaining such energies were based on the dimer's energy rise provoked by increasing in intermolecular distance of the system component units. Deviations from a strictly linear hydrogen bond were investigated and rotational barriers were also computed allowing the calculation of the second order attractive interactions. In order to provide a more objective definition of hydrogen bond, a lower energy limit was proposed in place of the merely empirical parameters employed in the classical definition

  3. Survivable HF communications

    Science.gov (United States)

    Randerson, John T.

    Robust HF uses a noncoherent FSK (frequency-shift-keyed) signal. It uses fast pseudorandom frequency hopping and a rugged modulation format which makes it impervious to multipath, atmospheric, and man-made noise. It is optimized as an antijam system. The robust-HF operating frequency range is 2-30 MHz. The pseudorandom frequency hopping uses variable bandwidth and adapts to the best frequencies between the lowest usable frequency and the maximum usable frequency. The system operates skywave (long distance) or ground wave (up to 100 km, or even more over water). Buried hard antennas have been tested and show almost no degradation in system performance. Robust HF uses powerful error coding with variable code rates and code combining, which automatically adapt according to link conditions. The result is exceptional processing gain. A powerful cyclic redundancy check (CRC) is included to prevent delivery of corrupt data. System bit rates run as high as 600 b/s, with average throughput of about 75 b/s, depending on the code rate.

  4. HF-laser program

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The HF laser is an attractive candidate driver for a large-system ICF scientific demonstration facility, for an ICF experimental power reactor and for a commercial laser--fusion power reactor. Previous accomplishments of the program have included demonstrations of high efficiency and high energy capability, efficient energy extraction from HF amplifiers, good beam quality and focusability, and short-pulse generation and amplification. In the reporting period, beam quality has been determined to be near-diffraction limited for a short pulsewidth (6 ns to 25 ns) oscillator-amplifier chain, suppression of amplified spontaneous emission has been demonstrated on an individual spectral line, high-pressure characteristics have been determined for the Phoenix I amplifier, and detailed comparisions between the kinetic code and experiments have been made. Details of two major upcoming experiments are also included. The first is energy extraction and beam quality measurements on the Phoenix I amplifier operating under saturated output power conditions. The second experiment, using a newly designed amplifier (Phoenix II), is designed to demonstrate the concept of angular-multiplexing: a pulse width-compression scheme

  5. Study on the adducts formation of Zr and Hf chelates

    International Nuclear Information System (INIS)

    Ree, Chin Taik; Jung, Young Sam; Park, Jun Kown

    1986-01-01

    The synergistic effect observed in Zr(IV) and Hf(IV) extraction from strong perchloric acid solutions by the mixtures of 2-Thenoyltri-fluoroacetone(TTA) and Octanols is shown to be caused by the formation of a mixed complex, M(TTA) 3 XS (M=Zr(IV), HF(IV), X=ClO 4 - , S=Octanol). One of the four TTA molecules coordinated at lower HClO 4 concentration to the metal as bidendate ligand seems to be changed to monodendate due to increasing HClO 4 concentration. The monodenate TTA ligand leaves the coordination site, finally, due to the activity of perchlorate at higher concentration and the additional coordination of an Octanol molecule seems to be allowed to the vaccant site which shows the synergistic extraction phenomena. (Author)

  6. Microhardness evaluation alloys Hf-Si-B; Avaliacao de microdureza de ligas Hf-Si-B

    Energy Technology Data Exchange (ETDEWEB)

    Gigolotti, Joao Carlos Janio; Costa, Eliane Fernandes Brasil [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil); Nunes, Carlos Angelo; Rocha, Elisa Gombio; Coelho, Gilberto Carvalho, E-mail: carlosjanio@uol.com.br, E-mail: eliane-costabrasi@hotmail.com, E-mail: cnunes@demar.eel.usp.br, E-mail: elisarocha@alunos.eel.usp.br, E-mail: coelho@demar.eel.usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil)

    2014-08-15

    The technological advance has generated increasing demand for materials that can be used under high temperature, what includes intermetallic MR-Si-B (MR = refractory metal) alloys with multiphase structures, that can also be applied in oxide environments. Thus, this work had for objective the micro hardness study of the Hf-Si-B system alloys, heat treated at 1600 deg C, in the Hf rich region. Hf-Si-B alloys had been produced with blades of Hf (min. 99.8%), Si (min. 99.998%) and B (min. 99.5%), in the voltaic arc furnace and heat treated at 1600 deg C under argon atmosphere. The relationship of the phases had been previously identified by X-ray diffraction and contrast in backscattered electron imaging mode. The alloys had their hardness analyzed by method Vickers (micro hardness) with load of 0.05 kgf and 0.2 kgf and application time of 20 s. The results, obtained from the arithmetic mean of measurements for each alloy on the heterogeneous region, showed a mean hardness of 11.08 GPA, with small coefficient of variation of 3.8%. The borides HfB2 (19.34 GPa) e HfB - 11.76 GPa, showed the hardness higher than the silicides Hf2Si (8.57 GPa), Hf5Si3 (9.63 GPa), Hf3Si2 (11.66 GPa), Hf5Si4 (10.00 GPa), HfSi (10.02 GPa) e HfSi2 (8.61 GPa). (author)

  7. Application of the Zr/Hf ratio in the determination of hafnium in geochemical samples by high-resolution inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Liu, Ya Xuan; Li, Qing Xia; Ma, Na; Sun, Xiao Ling; Bai, Jin Feng; Zhang, Qin

    2014-12-02

    Hafnium content and its change are of significance in geochemistry and cosmochemistry; however, the determination of hafnium has always been problematic in analytical chemistry. In this paper, a new idea is proposed for the determination of hafnium in geochemical samples, including rocks, soils, and stream sediments. Through the comparison of two conventional open-type acid digestion methods (HF-HNO3-HClO4 and HF-HNO3-H2SO4), it was found that although neither of these methods could fully digest the zirconium and hafnium in a sample, the zirconium and hafnium digestion behaviors in one sample were consistent in the 60 experimental geochemical reference materials with different properties, so the experimentally determined Zr/Hf ratio in solution could be used to calculate the hafnium content in a sample. In addition, possible mass spectral interferences during the determination of zirconium and hafnium by high resolution inductively coupled plasma mass spectrometry (HR-ICPMS) were studied, and it was found that the mass spectral interferences of the selected isotopes (90)Zr and (178)Hf could be neglected. The mass spectral behaviors of (90)Zr and (178)Hf were also very consistent during the determination by HR-ICPMS. Since the hafnium content was calculated using the ratio value, all of the errors (including the errors in weighing process, the accidental errors during operation and the instrument fluctuation in the determination) of the Zr/Hf ratio could be effectively reduced or even eliminated. The relative standard deviation of the actual samples was lower than 3.2%, and the detection limit of the method (considering the dilution effect and matrix effect during measurement of the Zr/Hf ratio and zirconium content) was 0.04 μg/g. The proposed method could satisfy the requirement for the determination of hafnium in geochemical samples.

  8. HF-laser program

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Sandia's HF-laser program for FY 77 and FY 78 was revised in June 1977 in order to meet several new program milestones. Research progress is reported on: objective of HF oscillator-amplifier studies using H 2 -F 2 gas mixtures; characteristics of large-volume oscillator using H 2 -F 2 mixtures; characteristics of large-volume amplifier using H 2 -F 2 mixtures; experimental results of the oscillator-amplifier study; objective of high-quality discharge-initiated SF 6 -HI oscillator-preamplifier system; pin-discharge-initiated oscillator and first beam expander; fast-discharge-initiated preamplifiers; reflecting beam expanders for oscillator-preamplifier system; beam quality of discharge-initiated oscillator-preamplifier system; short pulse option for discharge initiated SF 6 -HI system; H 2 -F 2 electron-beam-initiated oscillator-preamplifier system; chamber for HF-laser focusing experiments; computer study of parasitic oscillations in HF amplifiers and oscillators; kinetics upgrade of HF-laser code; repetitivey ignited flowing H 2 -F 2 -O 2 mixtures; spontaneous detonations in multiatmosphere H 2 -F 2 -O 2 mixtures; high-pressure H 2 -F 2 laser studies; and time sequenced energy extraction on the high xenon laser

  9. On the stabilization of NbV-solutions by ZrIV and HfIV

    International Nuclear Information System (INIS)

    Soerensen, E.; Bjerre, A.B.

    1987-11-01

    Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as Cl- and SO 4 --. This is ascribed to the copolymerisation of Nb v and the hydrolyzed ionic species of Zr IV v and Hf IV by which the colloidal particles are masked as Zr- and Hf-compounds. In HCl the particles are positively charged as opposed to when they are in sulphate solution where the Zr- and Hf- sulphate complexes confer a negative charge. The two cases are considered separately. (author)

  10. ExtraHF survey

    DEFF Research Database (Denmark)

    Piepoli, Massimo F; Binno, Simone; Corrà, Ugo

    2015-01-01

    AIMS: In heart failure (HF), exercise training programmes (ETPs) are a well-recognized intervention to improve symptoms, but are still poorly implemented. The Heart Failure Association promoted a survey to investigate whether and how cardiac centres in Europe are using ETPs in their HF patients...... for 36,385 (48%) patients] did not implement an ETP. This was mainly attributed to the lack of resources (25%), largely due to lack of staff or lack of financial provision. The lack of a national or local pathway for such a programme was the reason in 13% of the cases, and in 12% the perceived lack...

  11. Formulation and Evaluation of Tramadol HCl Matrix Tablets Using ...

    African Journals Online (AJOL)

    Purpose: To formulate and prepare controlled release (CR) matrix tablets of tramadol HCl using Carbopol 974P and 934 polymers as rate-controlling agents. Methods: The tablets were prepared by direct compression method using various drug to polymer (D:P) ratios. Co-excipients, including carboxymethylcellulose, starch ...

  12. LU-HF Age and Isotope Systematics of ALH84001

    Science.gov (United States)

    Righter, M.; Lapen, T. J.; Brandon, A. D.; Beard, B. L.; Shafer, J. T.; Peslier, A. H.

    2009-01-01

    Allan Hills (ALH) 84001 is an orthopyroxenite that is unique among the Martian meteorites in having the oldest inferred crystallization age (approx..4.5 to 4.0 Gyr) [e.g., 1-6 and references therein 7]. Its ancient origin makes this stone a critical constraint on early history of Mars, in particular the evolution of different planetary crust and mantle reservoirs. However, because there is significant variability in reported crystallization ages, determination of initial isotope compositions is imprecise making assessment of planetary reservoirs difficult. Here we report a new Lu-Hf mineral isochron age, initial Hf-176/Hf-177 isotope composition, and inferred Martian mantle source compositions for ALH84001 that place constraints on longlived source reservoirs for the enriched shergottite suite of Martian meteorites including Shergotty, Zagami, NWA4468, NWA856, RBT04262, LAR06319, and Los Angeles. Sm-Nd isotope analyses are under way for the same mineral aliquots analyzed for Lu-Hf. The Lu-Hf system was utilized because Lu and Hf are both lithophile and refractory and are not easily redistributed during short-lived thermal pulses associated with shock metamorphism. Moreover, chromite has relatively modest Hf concentrations with very low Lu/Hf ratios [9] yielding tight constraints on initial Hf-176/Hf-177 isotope compositions

  13. The CMS HF status

    CERN Document Server

    Rahmat, Rahmat

    2012-01-01

    The experiments at the Large Hadron Collider will have to deal with unprecedented radiation levels. The design of the CMS forward calorimetry detector (HF) is now finalized. The present design of CMS calls for the HF calorimeter to be based on quartz fiber technology. It consists of two modules, located symmetrically at about 11 meters from either side of interaction point. They cover the pseudorapidity range 3-5. The length along the beam is 1.65m or 10 nuclear interaction lenghts. Each calorimeter consists of a large steel block that serves as the absorber. Embedded quartz fibers in the steel absorber run parallel to the beam and constitute the active component of the detector. In order to optimize energy resolution for E and ET flows and forward jets, the calorimeter is effectively segmented longitudinally by using two different fiber lengths. The present status will be discussed.

  14. FT-IR and FT-Raman spectra, molecular structure and first-order molecular hyperpolarizabilities of a potential antihistaminic drug, cyproheptadine HCl

    Science.gov (United States)

    Sagdinc, Seda G.; Erdas, Dilek; Gunduz, Ilknur; Sahinturk, Ayse Erbay

    2015-01-01

    Cyproheptadine hydrochloride (CYP HCl) {4-(5H-dibenzo[a,d]-cyclohepten-5-ylidene)-1-methylpiperidine hydrochloride} is a first-generation antihistamine with additional anticholinergic, antiserotonergic, and local-anesthetic properties. The geometry optimization, Mulliken atomic charges and wavenumber and intensity of the vibrational bands of all of the possible modes of CYP HCl have been calculated using ab initio Hartree-Fock (HF) and density functional theory (DFT) employing the B3LYP functional with the 6-311G(d,p) basis set. We have compared the calculated IR and Raman wavenumbers with experimental data. Quantum-chemical calculations of the geometrical structure, energies, and molecular electrostatic potential and NBO analysis of CYP HCl have been performed using the B3LYP/6-311G(d,p) method. The electric dipole moment (μ), static polarizability (α) and the first hyperpolarizability (β) values of the title compound have been computed using HF and DFT methods. The study reveals that the antihistaminic pharmacological property of CYP HCl has a large β value and, hence, may in general have potential applications in the development of non-linear optical materials. The experimental and calculated results for CYP HCl have also been compared with those for mianserin HCl.

  15. Conductimetric determination of phenylpropanolamine HCl, ranitidine HCl, hyoscyamine HBr and betaine HCl in their pure state and pharmaceutical preparations.

    Science.gov (United States)

    Issa, Yousry M; Youssef, Ahmed F A; Mutair, Ali A

    2005-01-01

    Sodium tetraphenylborate and phosphotungstic acid were used as titrants for the conductimetric determination of phenylpropanolamine HCl (PPA.Cl), ranitidine HCl (Ra.Cl), hyoscyamine HBr (Hy.Br) and betaine HCl (Be.Cl) through ion-associate complex formation. The molar combining ratio and the solubility products of the formed ion-associates were studied and calculated. The suggested method has been applied to the determination of the mentioned drugs in their pure state and pharmaceutical preparations with mean recovery values of 97.71-102.97% and relative standard deviations 0.25-0.85%. The accuracy of the method is indicated by excellent recovery and low standard deviation. The results are compared with the pharmacopoeial or the official methods.

  16. A new digestion and chemical separation technique for rapid and highly reproducible determination of Lu/Hf and Hf isotope ratios in geological materials by mc-ICP-MS

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Baker, J.A.; Ulfbeck, D.

    2003-01-01

    A new digestion procedure and chemical separation technique has been developed for measurement of Lu/Hf and Hf isotope ratios that does not require high-pressure bombs or use of HF or HClO acids. Samples are digested in dilute HCl or HNO after flux-fusion at 1100 °C in the presence of lithium....... The relative simplicity of this technique, coupled with the ease of digestion (and samplespike equilibration) of large difficult-to-dissolve samples, and the speed (2 days) with which samples can be digested and processed through the chemical separation scheme makes it an attractive new method for preparing...... REE (Lu+Yb), and the middle-light REE and HFSE (Hf). The middle-light REE and individual HFSE are then separated (10.5, 9 and 6 mol l HCl) using a miniaturized column containing TEVA spec resin which provides a REE-, Ti- and Zr-free Hf cut. This chemical separation scheme can also be readily adapted...

  17. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    2016-09-07

    Sep 7, 2016 ... Many H-abstraction reactions in chemistry involve halides like HCl, HBr and HI. And they often need to undergo coherent vibrational excitation to promote the reaction (for instance, the late-barrier reactions in chemistry require vibrationally hot reactant molecules to have the reaction promoted) efficiently.

  18. Antioxidant assessment on promethazinr HCl decomposition using ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the effect of different sodium metabisulfite (SMBS) concentrations under a variety of ICH recommended test conditions. An attempt was made to test the feasibility of increasing shelf life when stored under different conditions. The promethazine hydrochloride (HCL) sample ...

  19. Optimal control of vibrational transitions of HCl

    Indian Academy of Sciences (India)

    Control of fundamental and overtone transitions of a vibration are studied for the diatomic molecule, HCl. Specifically, the results of the effect of variation of the penalty factor on the physical attributes of the system (i.e., probabilities) and pulse (i.e., amplitudes) considering three different pulse durations for each value of the ...

  20. Behaviour at the indicator scale of the elements Zr, Hf and 104, Nb,Ta and Pa (105) in very complexation media; Comportement a l`echelle des indicateurs des elements Zr, Hf, et 104, Nb, Ta, et Pa (105) en milieux tres complexants

    Energy Technology Data Exchange (ETDEWEB)

    Monroy Guzman, F. [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

    1997-12-31

    In order to determine the chemical properties of the trans-actinide elements of Z = 104 and 105 in aqueous solutions we studied their behaviour to ion exchange resin in different complex media. Due to the very short lifetimes (some tens of seconds) et to the low yield of these elements (a few atoms per irradiation hour) only very fast radiochemical techniques can be used. These severe constraints impose comparative studies of these elements with their most likely homologues to be carried out. The corresponding homologues were the elements of group 4 (Zr and Hf) for the element 104 and the elements of group 5 (Nb and Ta) and also Pa for the element 105. The complexation properties of the elements at indicator scale were determined in the media of HF, NH{sub 4}/HClO{sub 4}, NH{sub 4}SCN/HClO{sub 4}, NH{sub 4}SCN/HF and HCl/HF by ion exchange chromatography. The studies in fluorides media allowed us to identify the complexes in solution and to explain the shape of the experimentally observed sorption curves. The decrease of sorption for higher acid concentration in case of HF/HCl medium was interpreted by formation of chloro-fluoro-complexes. In case of the mixture NH{sub 4}SCN/HF, the particularly pronounced anti-synergic effects were observed and discussed. At the same time studies of the Hf and Ta short-lived isotopes were carried out by means of the RACHEL facility operating by the Orsay Tandem accelerator. These realistic simulations allowed optimization of different production, transportation and separation stages of the trans-actinide elements. The two experiments of 104 element production showed that this element forms in HF very stable anionic complexes similarly to its homologues Zr and Hf. (authors). 181 refs.

  1. Magnetic properties of Hf177 and Hf180 in the strong-coupling deformed model

    Science.gov (United States)

    Muto, S.; Stone, N. J.; Bingham, C. R.; Stone, J. R.; Walker, P. M.; Audi, G.; Gaulard, C.; Köster, U.; Nikolov, J.; Nishimura, K.; Ohtsubo, T.; Podolyak, Z.; Risegari, L.; Simpson, G. S.; Veskovic, M.; Walters, W. B.

    2014-04-01

    This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2-, 51.4 m, 2740 keV state in Hf177 and the 8-, 5.5 h, 1142 keV state in Hf180 by the method of on-line nuclear orientation. Also included are results on the angular distributions of γ transitions in the decay of the Hf177 isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2+, 1.1 s, isomer at 1315 keV and on the 9/2+, 0.663 ns, isomer at 321 keV. The new results are discussed in the light of the recently reported finding of systematic dependence of the behavior of the gR parameter upon the quasiproton and quasineutron make up of high-K isomeric states in this region.

  2. Scalable overtone HF chemical laser

    International Nuclear Information System (INIS)

    Jeffers, W.O.

    1988-01-01

    A method of producing essentially coherent electromagnetic emissions with high efficiency from excited HF molecules at overtone frequencies is described comprising the steps of: thermally dissociating a molecular gas containing fluorine to produce F atoms; reacting the F atoms with a gas containing hydrogen to produce excited HF molecules; preferentially depleting Δv=2 overtone vibrational transitions of the excited HF molecules to produce the electromagnetic emissions at overtone frequencies such that the electromagnetic emissions from the Δv=2 overtone vibrational transitions have an output power which is a significant percentage of the output power obtainable from Δv=1 fundamental vibrational transitions of excited HF molecules so that the electromagnetic emissions produced by the Δv=2 overtone vibrational transitions can be efficiently scaled to high output powers

  3. Marburg Hemorrhagic Fever (Marburg HF)

    Science.gov (United States)

    ... Controls Cancel Submit Search the CDC Marburg hemorrhagic fever (Marburg HF) Note: Javascript is disabled or is ... first recognized in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, ...

  4. Hf på VUC

    DEFF Research Database (Denmark)

    Pless, Mette; Hansen, Niels-Henrik Møller

    . Konkret har forskningsprojektet 3 mål: At afdække hf-kursisternes tidligere uddannelsesforløb og -erfaringer, før de starter på hf på VUC.At afdække, hvordan mødet med uddannelsens studiemiljø opleves af kursisterne, og ikke mindst kursisternes oplevelse af undervisningsformer, lærere mm.At afdække, hvad...

  5. Determination of traces of HCl in the troposphere and stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Baechmann, K.; Vierkorn-Rudolph, B.

    1981-05-01

    The difference between total HCl and HCl in aerosols was determined by sampling with the aid of adsorption tubes; the derivatization of HCl was carried out with 7-oxabicyclo-(4.1.0.)-heptane and by separating the occurring 2-chlorocyclohexanol using gas chromatography. Sampling was done from airplanes and balloons.

  6. Aspects of HF radio propagation

    Directory of Open Access Journals (Sweden)

    Stephane Saillant

    2009-06-01

    Full Text Available

    radio systems. From the point of view Working Group 2 of the COST 296 Action, interest lies with effects associated

    with propagation via the ionosphere of signals within the HF band. Several aspects are covered in this paper:

    a The directions of arrival and times of flight of signals received over a path oriented along the trough have

    been examined and several types of propagation effects identified. Of particular note, combining the HF observations

    with satellite measurements has identified the presence of irregularities within the floor of the trough that

    result in propagation displaced from the great circle direction. An understanding of the propagation effects that

    result in deviations of the signal path from the great circle direction are of particular relevance to the operation

    of HF radiolocation systems.

    b Inclusion of the results from the above mentioned measurements into a propagation model of the northerly

    ionosphere (i.e. those regions of the ionosphere located poleward of, and including, the mid-latitude trough

    and the use of this model to predict the coverage expected from transmitters where the signals impinge on the

    northerly ionosphere

  7. The magnetic properties of $^{\\rm 177}$Hf and $^{\\rm 180}$Hf in the strong coupling deformed model

    OpenAIRE

    Muto, S.; Stone, N. J.; Bingham, C. R.; Stone, J. R.; Walker, P. M.; Audi, G.; Gaulard, C.; Köster, U.; Nikolov, J.; Nishimura, K.; Ohtsubo, T.; Podolyak, Z.; Risegari, L.; Simpson, G. S.; Veskovic, M.

    2014-01-01

    This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2$^-$, 51.4 m, 2740 keV state in $^{\\rm 177}$Hf and the 8$^-$, 5.5 h, 1142 keV state in $^{\\rm 180}$Hf by the method of on-line nuclear orientation. Also included are results on the angular distributions of gamma transitions in the decay of the $^{\\rm 177}$Hf isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2$^+$, 1.1 s, isomer at 1315 keV ...

  8. 78 FR 22911 - HCL America, Inc., a Subsidiary of HCL Technologies Limited, Including On-Site Leased Workers...

    Science.gov (United States)

    2013-04-17

    ... insurance (UI) tax account under the name Genuent IT Fluency, also known as Genuent, formerly known as... acquisition of application support and development services and infrastructure services from India. The...

  9. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO{sub 2}(cr)

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Dhanpat [Rai Enviro-Chem, LLC, Yachats, OR (United States); Kitamura, Akira [Japan Atomic Energy Agency, Ibaraki (Japan); Rosso, Kevin M. [Pacific Northwest National Laboratory, Richland, WA (United States); Sasaki, Takayuki; Kobayashi, Taishi [Kyoto Univ. (Japan)

    2016-11-01

    Solubility studies were conducted with HfO{sub 2}(cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg{sup -1}. These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO{sub 2}(am) suspensions to 90 C to ascertain whether the HfO{sub 2}(am) converts to HfO{sub 2}(cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO{sub 2}(cr) contains a small fraction of less crystalline, but not amorphous, material [HfO{sub 2}(lcr)] and this, rather than the HfO{sub 2}(cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log{sub 10} K{sup 0} values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO{sub 2}(lcr)[HfO{sub 2}(lcr) + 2H{sub 2}O ↔ Hf{sup 4+} + 4OH{sup -}]. The log{sub 10} of the solubility product of HfO{sub 2}(cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  10. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO2(cr)

    International Nuclear Information System (INIS)

    Rai, Dhanpat; Kitamura, Akira; Rosso, Kevin M.; Sasaki, Takayuki; Kobayashi, Taishi

    2016-01-01

    Solubility studies were conducted with HfO 2 (cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg -1 . These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO 2 (am) suspensions to 90 C to ascertain whether the HfO 2 (am) converts to HfO 2 (cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO 2 (cr) contains a small fraction of less crystalline, but not amorphous, material [HfO 2 (lcr)] and this, rather than the HfO 2 (cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log 10 K 0 values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO 2 (lcr)[HfO 2 (lcr) + 2H 2 O ↔ Hf 4+ + 4OH - ]. The log 10 of the solubility product of HfO 2 (cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  11. Cinacalcet HCl attenuates parathyroid hyperplasia in a rat model of secondary hyperparathyroidism.

    Science.gov (United States)

    Colloton, Matthew; Shatzen, Edward; Miller, Gerald; Stehman-Breen, Catherine; Wada, Michihito; Lacey, David; Martin, David

    2005-02-01

    Secondary hyperparathyroidism (HPT) in chronic kidney disease (CKD) is a physiologic response to kidney failure characterized by elevated serum parathyroid hormone (PTH) levels and parathyroid gland enlargement. Calcimimetic agents acting through allosteric modification of the calcium-sensing receptor (CaR) can attenuate parathyroid hyperplasia in rats with secondary HPT. The present study explores the effects of the calcimimetic cinacalcet HCl on parathyroid hyperplasia, apoptosis, and PTH secretion in a rat model of secondary HPT. Cinacalcet HCl was gavaged daily (1, 5, or 10 mg/kg) for 4 weeks starting 6 weeks post-5/6 nephrectomy. After dosing, hyperplasia was determined using parathyroid weight and proliferating cell nuclear antigen (PCNA) immunochemistry. Apoptosis was determined using in situ techniques. Serum PTH((1-34)) and blood chemistries were determined throughout the course of the study. Administration of cinacalcet HCl (5 or 10 mg/kg) significantly reduced the number of PCNA-positive cells and decreased parathyroid weight compared with vehicle-treated 5/6 nephrectomized rats. There was no difference in apoptosis from cinacalcet HCl-treated or vehicle-treated animals. Serum PTH and blood ionized calcium levels decreased in cinacalcet HCl-treated animals compared with vehicle-treated controls. The results confirm previous work demonstrating that calcimimetic agents attenuate the progression of parathyroid hyperplasia in subtotally nephrectomized rats, extending earlier observations to now include cinacalcet HCl. These results support a role for the CaR in regulating parathyroid cell proliferation. Therefore, cinacalcet HCl may represent a novel therapy for improving the management of secondary HPT.

  12. Zirconium Zr and hafnium Hf

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for extracting and determining Zr(4) and Hf(4) are described. Diantipyrinemethane and its alkyl homologs selectively extract Zr and Hf from HNO 3 solutions in the presence of nitrates. Zr is selectively extracted with tetraethyldiamide of heptyl phosphoric acid (in benzene) as well as with 2-thenoyltrifluoroacetone (in an acid). The latter reagents is suitable for rapid determination of 95 Zr in a mixture with 95 Nb and other fragments. The complexometric determination of Zr is based on formation of a stable complex of Zr with EDTA. The titration is carried out in the presence of n-sulfobenzene-azo-pyrocatechol, eriochrome black T. The determination is hindered by Hf, fluoride-, phosphate-, oxalate- and tartrate-ions. The method is used for determining Zr in zircon and eudialyte ore. Zr is determined photometrically with the aid of xylenol orange, arsenazo 3 and pyrocatechol violet (in phosphorites). Hf is determined in the presence of Zr photometrically with the aid of xylenol orange or methyl-thymol blue. The method is based on Zr being masked with hydrogen peroxide in the presence of sulfate-ions

  13. Spectrophotometric determination of traces of Ti, Zr, Hf, Nb, Ta and V after selective separation with B.P.H.A. - Application to uranium compounds

    International Nuclear Information System (INIS)

    Lamarque, Gerard

    1971-08-01

    The extraction of traces of Ti, Zr, Hf, Nb and Ta using 0.1 per cent, 0. 2 per cent and 0.5 per cent HCl-N-benzoylphenyl-hydroxylamine in benzene was investigated. A further extraction with HCl-HF allowed the concentration of each component to be obtained by spectrophotometric means. The proposed techniques, which are simple and selective, applied to uranium solutions enabled the detection down to 0.15 ppm Ti, 0.08 ppm Zr, 0.12 ppm Hf, 0.05 ppm Nb and 0.15 ppm Ta with two 5 gram uranium test samples. A further 4 gram test sample enabled V to be detected down to 0. 25 ppm [fr

  14. Validation of Aura Microwave Limb Sounder HCl Measurements

    Science.gov (United States)

    Froidevaux, L.; Jiang, Y. B.; Lambert, A.; Livesey, N. J.; Read, W. G.; Waters, J. W.; Fuller, R. A.; Marcy, T. P.; Popp, P. J.; Gao, R. S.; hide

    2008-01-01

    The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within approximately 5%, on average), but the MLS HCl abundances are generally larger (by 10-20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon-borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (approximately 0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraftHCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.

  15. Space-based measurements of HCl: Intercomparison and historical context

    Science.gov (United States)

    Lary, D. J.; Aulov, O.

    2008-08-01

    The peak in stratospheric HCl was reached in the late 1990s. Between 1998 and 2004 the stratospheric loading of HCl was relatively constant, with some month to month fluctuation; this was followed by a more pronounced decrease in HCl since 2004. We use probability distribution functions (PDFs) and scatter diagrams for validation and bias characterization of Aura Microwave Limb Sounder (MLS) HCl retrievals. Both these methods allow us to use large statistical samples and do not require correlative measurements to be colocated in space and time. The bias between the Halogen Occultation Experiment (HALOE) and Aura MLS is greatest above the 525 K (˜21 km) isentropic surface. The global average mean bias between Aura and the Atmospheric Chemistry Experiment (ACE) for January 2005 was 2% and between Aura MLS and HALOE was 14%. The widths of the PDFs are a measure of the spatial variability and measurement precision. The Aura MLS HCl PDFs are consistently wider than those for ACE and HALOE, this reflects the retrieval uncertainties. The median observation uncertainty for Aura MLS v1.51 HCl is 12%, and the median ACE v2.2 uncertainty is 8%. We also connect Aura MLS HCl with the heritage of HALOE HCl by using neural networks to learn the interinstrument biases and provide a seamless HCl record from the launch of the Upper Atmosphere Research Satellite (UARS) in 1991 to the present.

  16. Empirical Study of the Multiaxial, Thermomechanical Behavior of NiTiHf Shape Memory Alloys

    Science.gov (United States)

    Shukla, Dhwanil; Noebe, Ronald D.; Stebner Aaron P.

    2013-01-01

    An empirical study was conducted to characterize the multiaxial, thermomechanical responses of new high temperature NiTiHf alloys. The experimentation included loading thin walled tube Ni(sub 50.3)Ti(sub 29.7)Hf(sub 20) alloy samples along both proportional and nonproportional axial-torsion paths at different temperatures while measuring surface strains using stereo digital image correlation. A Ni(sub 50.3)Ti(sub 33.7)Hf(sub 16) alloy was also studied in tension and compression to document the effect of slightly depleting the Hf content on the constitutive responses of NiTiHf alloys. Samples of both alloys were made from nearly texture free polycrystalline material processed by hot extrusion. Analysis of the data shows that very small changes in composition significantly alter NiTiHf alloy properties, as the austenite finish (Af) temperature of the 16-at Hf alloy was found to be approximately 60 C less than the 20-at Hf alloy (approximately 120 C vs. 180 C). In addition, the 16-at Hf alloy exhibited smaller compressive transformation strains (2 vs. 2.5 percent). Multi-axial characterization of the 20-at % Hf alloy showed that while the random polycrystal transformation strains in tension (4 percent) and compression (2.5 percent) are modest in comparison with binary NiTi (6 percent, 4 percent), the torsion performance is superior (7 vs. 4 shear strain width to the pseudoelastic plateau).

  17. HCl Vapour Pressures and Reaction Probabilities for ClONO2 + HCl on Liquid H2SO4-HNO3-HCl-H20 Solutions

    Science.gov (United States)

    Elrod, M. J.; Koch, R. E.; Kim, J. E.; Molina, M. J.

    1995-01-01

    Henry's Law solubility constants for HCl have been measured for liquid H2SO4-HNO3-HCl-H2O solutions; the results are in good agreement with predictions from published semiempirical models. The ClONO2 + HCl reaction on the surfaces of such solutions with compositions simulating those of stratospheric aerosols has been investigated; as the composition changes following the temperature drop characteristic of the high-latitude stratosphere the reaction probability gamma increases rapidly. Furthermore, the gamma values remain essentially unchanged when HN03 uptake is neglected; the controlling factor appears to be the solubility of HCl. These results corroborate our earlier suggestion that supercooled liquid sulfate aerosols promote chlorine activation at low temperatures as efficiently as solid polar stratospheric cloud particles.

  18. Solubility of HCL in sulfuric acid at stratospheric temperatures

    Science.gov (United States)

    Williams, Leah R.; Golden, David M.

    1993-01-01

    The solubility of HCl in sulfuric acid was measured using a Knudsen cell technique. Effective Henry's law constants are reported for sulfuric acid concentrations between 50 and 60 weight percent and for temperatures between 220 and 230 K. The measured values indicate that very little HCl will be dissolved in the stratospheric sulfate aerosol particles.

  19. THE HIGH-RESOLUTION INFRARED SPECTRUM OF HCl{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Doménech, J. L.; Herrero, V. J.; Tanarro, I. [Molecular Physics Department, Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, E-28006 Madrid (Spain); Drouin, B. J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Cernicharo, J., E-mail: jl.domenech@csic.es [Molecular Astrophysics Group, Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Sor Juana Inés de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain)

    2016-12-20

    The chloroniumyl cation, HCl{sup +}, has been recently identified in space from Herschel 's spectra. A joint analysis of extensive vis-UV spectroscopy emission data together with a few high-resolution and high-accuracy millimeter-wave data provided the necessary rest frequencies to support the astronomical identification. Nevertheless, the analysis did not include any infrared (IR) vibration–rotation data. Furthermore, with the end of the Herschel mission, IR observations from the ground may be one of the few available means to further study this ion in space. In this work, we provide a set of accurate rovibrational transition wavenumbers, as well as a new and improved global fit of vis-UV, IR, and millimeter-wave spectroscopy laboratory data, that will aid in future studies of this molecule.

  20. On averaged force acting on a particle in H.F electromagnetic field

    International Nuclear Information System (INIS)

    Ogunniyi, J.F.; Tskhakaya, D.D.

    1989-06-01

    A general expression is obtained for the time averaged force acting on a particle immersed in a magnetic field in the presence of H.F quasiplanar, quasimonochromatic electromagnetic wave. Here, averaging is done over the period of the H.F wave. It is shown that this averaged force is proportional to the time derivative of the squared H.F wave amplitude. The force also includes a term proportional to the gradient of the time constant magnetic field and is connected with the induced magnetic moment in the H.F field. (author). 7 refs

  1. HCl removal using cycled carbide slag from calcium looping cycles

    International Nuclear Information System (INIS)

    Xie, Xin; Li, Yingjie; Wang, Wenjing; Shi, Lei

    2014-01-01

    Highlights: • Cycled carbide slag from calcium looping cycles is used to remove HCl. • The optimum temperature for HCl removal of cycled carbide slag is 700 °C. • The presence of CO 2 restrains HCl removal of cycled carbide slag. • CO 2 capture conditions have important effects on HCl removal of cycled carbide slag. • HCl removal capacity of carbide slag drops with cycle number rising from 1 to 50. - Abstract: The carbide slag is an industrial waste from chlor-alkali plants, which can be used to capture CO 2 in the calcium looping cycles, i.e. carbonation/calcination cycles. In this work, the cycled carbide slag from the calcium looping cycles for CO 2 capture was proposed to remove HCl in the flue gas from the biomass-fired and RDFs-fired boilers. The effects of chlorination temperature, HCl concentration, particle size, presence of CO 2 , presence of O 2 , cycle number and CO 2 capture conditions in calcium looping cycles on the HCl removal behavior of the carbide slag experienced carbonation/calcination cycles were investigated in a triple fixed-bed reactor. The chlorination product of the cycled carbide slag from the calcium looping after absorbing HCl is not CaCl 2 but CaClOH. The optimum temperature for HCl removal of the cycled carbide slag from the carbonation/calcination cycles is 700 °C. The chlorination conversion of the cycled carbide slag increases with increasing the HCl concentration. The cycled carbide slag with larger particle size exhibits a lower chlorination conversion. The presence of CO 2 decreases the chlorination conversions of the cycled carbide slag and the presence of O 2 has a trifling impact. The chlorination conversion of the carbide slag experienced 1 carbonation/calcination cycle is higher than that of the uncycled calcined sorbent. As the number of carbonation/calcination cycles increases from 1 to 50, the chlorination conversion of carbide slag drops gradually. The high calcination temperature and high CO 2

  2. Anion exchange behaviour of Zr, Hf, Nb, Ta and Pa as homologues of RF and Db in fluoride medium

    Energy Technology Data Exchange (ETDEWEB)

    Monroy G, F. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Trubert, D.; Brillard, L.; Hussonnois, M.; Constantinescu, O.; Le Naour, C., E-mail: fabiola.monroy@inin.gob.m [Institut de Physique Nucleaire, F-91406 Orsay, France (France)

    2010-07-01

    Studies of the chemical property of trans actinide elements are very difficult due to their short half-lives and extremely small production yields. However it is still possible to obtain considerable information about their chemical properties, such as the most stable oxidation states in aqueous solution, complexing ability, etc., comparing their behaviour with their lighter homologous in the periodic table. In order to obtain a better knowledge of the behaviour of rutherfordium, RF (element 104), dub nium, Db (element 105) in HF medium, the sorption properties of Zr, Hf, Nb, Ta an Pa, homologues of RF and Db, were studied in NH{sub 4}F/HClO{sub 4} medium in this work. Stability constants of the fluoride complexes of these elements were experimentally obtained from K{sub d} obtained at different F{sup -} and H{sup +} concentrations. The anionic complexes: [Zr(Hf)F{sub 5}]{sup -}, [Zr(Hf)F{sub 6}]{sup 2-}, [Zr(Hf)F{sub 7}]{sup 3-}, [Ta(Pa)F{sub 6}]{sup -}, [Ta(Pa)F{sub 7}]{sup 2-}, [Ta(Pa)F{sub 8}]{sup 3-}, [NbOF{sub 4}]{sup -} and [NbOF{sub 5}]{sup 2-} are present as predominant species in the HF range over investigation. (Author)

  3. Anion exchange behaviour of Zr, Hf, Nb, Ta and Pa as homologues of RF and Db in fluoride medium

    International Nuclear Information System (INIS)

    Monroy G, F.; Trubert, D.; Brillard, L.; Hussonnois, M.; Constantinescu, O.; Le Naour, C.

    2010-01-01

    Studies of the chemical property of trans actinide elements are very difficult due to their short half-lives and extremely small production yields. However it is still possible to obtain considerable information about their chemical properties, such as the most stable oxidation states in aqueous solution, complexing ability, etc., comparing their behaviour with their lighter homologous in the periodic table. In order to obtain a better knowledge of the behaviour of rutherfordium, RF (element 104), dub nium, Db (element 105) in HF medium, the sorption properties of Zr, Hf, Nb, Ta an Pa, homologues of RF and Db, were studied in NH 4 F/HClO 4 medium in this work. Stability constants of the fluoride complexes of these elements were experimentally obtained from K d obtained at different F - and H + concentrations. The anionic complexes: [Zr(Hf)F 5 ] - , [Zr(Hf)F 6 ] 2- , [Zr(Hf)F 7 ] 3- , [Ta(Pa)F 6 ] - , [Ta(Pa)F 7 ] 2- , [Ta(Pa)F 8 ] 3- , [NbOF 4 ] - and [NbOF 5 ] 2- are present as predominant species in the HF range over investigation. (Author)

  4. The rotational excitation of HF by H

    Science.gov (United States)

    Desrousseaux, Benjamin; Lique, François

    2018-03-01

    The HF molecule is a key tracer of molecular hydrogen in diffuse interstellar medium (ISM). Accurate modeling of the HF abundance in such media requires to model its excitation by both radiation and collisions. In diffuse ISM, the dominant collisional partners are atomic and molecular hydrogen. We report quantum time-independent calculations of collisional cross sections and rate coefficients for the rotational excitation of HF by H. The reactive hydrogen exchange channels are taken into account in the scattering calculations. For the first time, HF-H rate coefficients are provided for temperature ranging from 10 to 500 K. The strongest collision-induced rotational HF transitions are those with Δj = 1 and the order of magnitude of the new HF-H rate coefficients is similar to that of the HF-H2 ones previously computed. As a first application, we simulate the excitation of HF by both H and H2 in typical diffuse ISM. We show that, depending on the rotational transition, hydrogen atoms increase or decrease the simulated excitation temperatures compared to collisional excitation only due to H2 molecules. Such result suggest that the new HF-H collisional data have to be used for properly modeling the abundance of HF in diffuse ISM.

  5. Application of HF Radar in Hazard Management

    Directory of Open Access Journals (Sweden)

    Mal Heron

    2016-01-01

    Full Text Available A review is given of the impact that HF radars are having on the management of coastal hazards. Maps of surface currents can be produced every 10–20 minutes which, in real time, improve navigation safety in restricted areas commonly found near ports and harbours. The time sequence of surface current maps enables Lagrangian tracking of small parcels of surface water, which enables hazard mitigation in managing suspended sediments in dredging, in emergency situations where flotsam and other drifting items need to be found, and in pollution control. The surface current measurement capability is used to assist tsunami warnings as shown by the phased-array data from Chile following the Great Tohoku Earthquake in 2011. The newly launched Tsunami Warning Center in Oman includes a network of phased-array HF radars to provide real-time tsunami monitoring. Wind direction maps can be used to locate the position of cold fronts in the open ocean and to monitor the timing and strength of sea-breeze fronts in key locations.

  6. Reaction characteristics of Ca(OH)2, HCl and SO2 at low temperature in a spray dryer integrated with a fabric filter.

    Science.gov (United States)

    Liu, Zhen-Shu; Wey, Ming-Yen; Lin, Chiou-Liang

    2002-12-02

    The objective of this research was to evaluate the reaction characteristics of CaOH2, HCl and SO2 in the flue gas emitted by a laboratory incinerator. The amount of sulfur retained in the residues (including the spray dryer ash and baghouse ash) was also evaluated in this study. The experimental parameters included HCl concentration (500-2000 ppm), SO2 concentration (500-2000 ppm), relative humidity (40-80% RH), and the addition of CaCl2 (30 wt.%). The results indicated that an HCl concentration of 500-2000 ppm did not affect HCl removal efficiency in the spray dryer at 150 degrees C and 45+/-5% RH. On the other hand, increase in SO2 concentration from 500 to 2000 ppm enhanced SO2 removal at 150 degrees C and 75+/-5% RH. Moreover, increase in removal efficiency of SO2 was more obvious when the relative humidity was greater than 80%. When the flue gas contained both HCl and SO2 simultaneously, the removal efficiency of SO2 could increase from 56.7 to 90.33% at HCl concentration of 236 ppm. However, when the concentration of HCl exceeded 535 ppm, the removal efficiency of SO2 decreased with increasing concentration of HCl. The removal efficiency of SO2 could be increase to 97.7% with the addition of CaCl2.

  7. Effects of HfB2 and HfN Additions on the Microstructures and Mechanical Properties of TiB2-Based Ceramic Tool Materials

    Directory of Open Access Journals (Sweden)

    Jing An

    2017-04-01

    Full Text Available The effects of HfB2 and HfN additions on the microstructures and mechanical properties of TiB2-based ceramic tool materials were investigated. The results showed that the HfB2 additive not only can inhibit the TiB2 grain growth but can also change the morphology of some TiB2 grains from bigger polygons to smaller polygons or longer ovals that are advantageous for forming a relatively fine microstructure, and that the HfN additive had a tendency toward agglomeration. The improvement of flexural strength and Vickers hardness of the TiB2-HfB2 ceramics was due to the relatively fine microstructure; the decrease of fracture toughness was ascribed to the formation of a weaker grain boundary strength due to the brittle rim phase and the poor wettability between HfB2 and Ni. The decrease of the flexural strength and Vickers hardness of the TiB2-HfN ceramics was due to the increase of defects such as TiB2 coarse grains and HfN agglomeration; the enhancement of fracture toughness was mainly attributed to the decrease of the pore number and the increase of the rim phase and TiB2 coarse grains. The toughening mechanisms of TiB2-HfB2 ceramics mainly included crack bridging and transgranular fracture, while the toughening mechanisms of TiB2-HfN ceramics mainly included crack deflection, crack bridging, transgranular fracture, and the core-rim structure.

  8. New Insights into Solid Form Stability and Hydrate Formation: o-Phenanthroline HCl and Neocuproine HCl

    Directory of Open Access Journals (Sweden)

    Doris E. Braun

    2017-12-01

    Full Text Available The moisture- and temperature dependent stabilities and interrelation pathways of the practically relevant solid forms of o-phenanthroline HCl (1 and neocuproine HCl (2 were investigated using thermal analytical techniques (HSM, DSC and TGA and gravimetric moisture sorption/desorption studies. The experimental stability data were correlated with the structural changes observed upon dehydration and the pairwise interaction and lattice energies calculated. For 1 the monohydrate was identified as the only stable form under conditions of RH typically found during production and storage, but at RH values >80% deliquescence occurs. The second compound, 2, forms an anhydrate and two different hydrates, mono- (2-Hy1 and trihydrate (2-Hy3. The 2-Hy1 structure was solved from SCXRD data and the anhydrate structure derived from a combination of PXRD and CSP. Depending on the environmental conditions (moisture either 2-Hy1 or 2-Hy3 is the most sable solid form of 2 at RT. The monohydrates 1-Hy1 and 2-Hy1 show a high enthalpic stabilization (≥20 kJ mol−1 relative to the anhydrates. The anhydrates are unstable at ambient conditions and readily transform to the monohydrates even in the presence of traces of moisture. This study demonstrates how the right combination of experiment and theory can unravel the properties and interconversion pathways of solid forms.

  9. lambda-3, Sandia's 100-J HF laser system

    International Nuclear Information System (INIS)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results

  10. Hf isotope evidence for a hidden mantle reservoir

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Simonetti, A.; Stevenson, R.K.

    2002-01-01

    High-precision Hf isotopic analyses and U-Pb ages of carbonatites and kimberlites from Greenland and eastern North America, including Earth's oldest known carbonatite (3 Ga), indicate derivation from an enriched mantle source. This previously unidentified mantle reservoir-marked by an unradiogenic...

  11. Spin-rotation and NMR shielding constants in HCl

    International Nuclear Information System (INIS)

    Jaszuński, Michał; Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth; Garbacz, Piotr; Jackowski, Karol; Makulski, Włodzimierz

    2013-01-01

    The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of 1 H 35 Cl are C Cl   = −53.914 kHz and C H   = 42.672 kHz (for the lowest rovibrational level). For the chlorine shielding constant, the ab initio value computed including the relativistic corrections, σ(Cl) = 976.202 ppm, provides a new absolute shielding scale; for hydrogen we find σ(H) = 31.403 ppm (both at 300 K). Combining the theoretical results with our new gas-phase NMR experimental data allows us to improve the accuracy of the magnetic dipole moments of both chlorine isotopes. For the hydrogen shielding constant, including relativistic effects yields better agreement between experimental and computed values

  12. Development of HF-systems for electron storage systems

    International Nuclear Information System (INIS)

    Androsov, V.P.; Karnaukhov, I.M.; Popkov, Yu.P.; Reva, S.N.; Telegin, Yu.N.

    1999-01-01

    Development of HF systems for electron storages is described. Its final task is construction of 100 kW HF station at 699,3 MHz frequency consisting from low-power HF system, klystron amplifier, wave line for HF power transmission and accelerating section. Functional parameters of HF station are given

  13. Mechanical alloying of Hf and Fe powders

    International Nuclear Information System (INIS)

    Mendoza Zelis, L.; Crespo, E.; Creus, M.; Damonte, L.C.; Sanchez, F.H.; Punte, G.

    1994-01-01

    Pure crystalline Hf and Fe powders were mixed and milled under an argon atmosphere. The evolution of the system with milling time was followed with Moessbauer effect spectroscopy and X-ray diffraction. The results indicate that in the first stages an amorphous Fe-rich alloy was gradually formed together with a solid solution of Hf in Fe beyond the solubility limit. (orig.)

  14. Reliability assessment of ultra-thin HfO2 films deposited on silicon wafer

    International Nuclear Information System (INIS)

    Fu, Wei-En; Chang, Chia-Wei; Chang, Yong-Qing; Yao, Chih-Kai; Liao, Jiunn-Der

    2012-01-01

    Highlights: ► Nano-mechanical properties on annealed ultra-thin HfO 2 film are studied. ► By AFM analysis, hardness of the crystallized HfO 2 film significantly increases. ► By nano-indention, the film hardness increases with less contact stiffness. ► Quality assessment on the annealed ultra-thin films can thus be achieved. - Abstract: Ultra-thin hafnium dioxide (HfO 2 ) is used to replace silicon dioxide to meet the required transistor feature size in advanced semiconductor industry. The process integration compatibility and long-term reliability for the transistors depend on the mechanical performance of ultra-thin HfO 2 films. The criteria of reliability including wear resistance, thermal fatigue, and stress-driven failure rely on film adhesion significantly. The adhesion and variations in mechanical properties induced by thermal annealing of the ultra-thin HfO 2 films deposited on silicon wafers (HfO 2 /SiO 2 /Si) are not fully understood. In this work, the mechanical properties of an atomic layer deposited HfO 2 (nominal thickness ≈10 nm) on a silicon wafer were characterized by the diamond-coated tip of an atomic force microscope and compared with those of annealed samples. The results indicate that the annealing process leads to the formation of crystallized HfO 2 phases for the atomic layer deposited HfO 2 . The HfSi x O y complex formed at the interface between HfO 2 and SiO 2 /Si, where the thermal diffusion of Hf, Si, and O atoms occurred. The annealing process increases the surface hardness of crystallized HfO 2 film and therefore the resistance to nano-scratches. In addition, the annealing process significantly decreases the harmonic contact stiffness (or thereafter eliminate the stress at the interface) and increases the nano-hardness, as measured by vertically sensitive nano-indentation. Quality assessments on as-deposited and annealed HfO 2 films can be thereafter used to estimate the mechanical properties and adhesion of ultra-thin HfO 2

  15. Simulation studies of the influence of HCl absorption on the performance of a wet flue gas desulphurisation pilot plant

    DEFF Research Database (Denmark)

    Kiil, Søren; Nygaard, Helle; Johnsson, Jan Erik

    2002-01-01

    The mathematical model of Kiil et al, (Ind. Eng, Chem. Res. 37 (1998) 2792) for a wet flue gas desulphurisation (FGD) pilot plant was extended to include the simultaneous absorption of HCl. In contrast to earlier models for wet FGD plants, the inclusion of population balance equations for the lim......The mathematical model of Kiil et al, (Ind. Eng, Chem. Res. 37 (1998) 2792) for a wet flue gas desulphurisation (FGD) pilot plant was extended to include the simultaneous absorption of HCl. In contrast to earlier models for wet FGD plants, the inclusion of population balance equations...... for the limestone particles enabled a quantitative description of the influence of HCl absorption on essential process parameters such as the degree of desulphurisation and the residual limestone level of the gypsum produced. Simulations showed that the presence of 100 ppmv HCl in the flue gas reduced the degree...... gas concentration of SO2 on the degree of desulphurisation and the residual limestone level was found to be almost the same irrespective of HCl was present (100 ppmv) in the flue gas or not. The results presented are of importance in the analysis of the performance of wet FGD plants installed at power...

  16. Study of high-temperature multiplex HCl coherent anti-Stokes Raman spectroscopy spectra.

    Science.gov (United States)

    Singh, J P; Yueh, F Y; Kao, W; Cook, R L

    1993-02-20

    A feasibility study of temperature measurement with multiplex HCl coherent anti-Stokes Raman spectroscopy (CARS) is investigated. The HCl CARS spectra of a 100% HCl gas sample are recorded in a quartz sample cell placed in a furnace at 1 atm pressure and at different temperatures. The nonlinear susceptibility of HCl (chi(nr)(HCl)), which is measured with the present CARS experimental setup, is reported. The experimental spectra are fit by using a library of simulated HCl CARS spectra with a least-squares-fitting program to infer the temperature. The inferred temperatures from HCl CARS spectra are in agreement with thermocouple temperatures.

  17. High-temperature chemistry of HCl and Cl2

    DEFF Research Database (Denmark)

    Pelucchi, Matteo; Frassoldati, Alessio; Faravelli, Tiziano

    2015-01-01

    chemistry discussed in the paper was based on reference and experimental measurements of rate constants available in the literature. By coupling the new HCl/Cl2 subset with the Politecnico di Milano (POLIMI) syngas mechanism a kinetic mechanism consisting of 25 species and 102 reactions was obtained......The high temperature chlorine chemistry was updated and the inhibition mechanisms involving HCl and Cl2 were re-examined. The thermochemistry was obtained using the Active Thermochemical Tables (ATcT) approach, resulting in improved data for chlorine-containing species of interest. The HCl/Cl2....... The validation was carried out on selected experimental data from laminar flames, shock tubes and plug flow reactors. Systems containing Cl2 showed high sensitivity to Cl2 +M⇌Cl+Cl+M; the rate constant for this reaction has a significant uncertainty and there is a need for an accurate high...

  18. Concurrent administration of donepezil HCl and sertraline HCl in healthy volunteers: assessment of pharmacokinetic changes and safety following single and multiple oral doses

    Science.gov (United States)

    Nagy, Christa F; Kumar, Dinesh; Perdomo, Carlos A; Wason, Suman; Cullen, Edward I; Pratt, Raymond D

    2004-01-01

    Aim This study evaluated the safety and pharmacokinetics (PK) of donepezil HCl and sertraline HCl when administered separately and in combination. Methods This was a randomized, open-label, three-period crossover study. In consecutive dosing periods separated by washout periods of ≥3 weeks, healthy volunteers received either oral donepezil HCI 5 mg once daily for 15 days, oral sertraline HCl 50 mg once daily for 5 days followed by 10 days of once-daily sertraline HCl 100 mg, or the simultaneous administration of oral donepezil HCl and sertraline HCl. Plasma donepezil and sertraline concentrations were determined by high performance liquid chromatography/mass spectrometry. Safety was evaluated by physical and laboratory evaluations and the monitoring of adverse events (AEs). Results A total of 19 volunteers (16 male and three female) were enrolled. Three male subjects withdrew from the study prematurely due to AEs (one case of nausea/stomach cramps and one case of eosinophilia during combination treatment, and one upper respiratory tract infection during treatment with sertraline HCl alone). In subjects who completed all three treatment periods (n = 16), the concurrent administration of donepezil HCl and sertraline HCl did not alter the steady-state (day 15) PK parameters of donepezil HCl. A small (<12%) but statistically significant (P = 0.02) increase in donepezil Cmax was seen after single doses of sertraline HCl and donepezil HCl on day 1 but this was not thought to be clinically meaningful. No significant differences in the tmax or AUC0–24 h of donepezil were observed between the donepezil HCl only or donepezil HCl plus sertraline HCl groups on day 1. No significant changes in sertraline PK parameters were observed either on day 1 (single dose) or on day 15 (steady state) when sertraline HCl was co-administered with donepezil HCl. Generally, the concurrent administration of donepezil HCl and sertraline HCl was well tolerated, with no serious AEs reported

  19. The dissociation mechanism and thermodynamic properties of HCl(aq) in hydrothermal fluids (to 700 °C, 60 kbar) by ab initio molecular dynamics simulations

    Science.gov (United States)

    Mei, Yuan; Liu, Weihua; Brugger, Joël; Sherman, David M.; Gale, Julian D.

    2018-04-01

    HCl is one of the most significant volatiles in the Earth's crust. It is well established that chloride activity and acidity (pH) play important roles in controlling the solubility of metals in aqueous hydrothermal fluids. Thus, quantifying the dissociation of HCl in aqueous solutions over a wide range of temperature and pressure is crucial for the understanding and numerical modeling of element mobility in hydrothermal fluids. Here we have conducted ab initio molecular dynamics (MD) simulations to investigate the mechanism of HCl(aq) dissociation and to calculate the thermodynamic properties for the dissociation reaction at 25-700 °C, 1 bar to 60 kbar, i.e. including high temperature and pressure conditions that are geologically important, but difficult to investigate via experiments. Our results predict that HCl(aq) tends to associate with increasing temperature, and dissociate with increasing pressure. In particular, HCl(aq) is highly dissociated at extremely high pressures, even at high temperatures (e.g., 60 kbar, 600-700 °C). At 25 °C, the calculated logKd values (6.79 ± 0.81) are close to the value (7.0) recommended by IUPAC (International Union of Pure and Applied Chemistry) and some previous experimental and theoretical studies (Simonson et al.., 1990; Sulpizi and Sprik, 2008, 2010). The MD simulations indicate full dissociation of HCl at low temperature; in contrast, some experiments were interpreted assuming significant association at high HCl concentrations (≥1 m HCltot) even at room T (logKd ∼0.7; e.g., Ruaya and Seward, 1987; Sretenskaya, 1992; review in Tagirov et al., 1997). This discrepancy is most likely the result of difficulties in the experimental determination of minor (if any) concentration of associated HCl(aq) under ambient conditions, and thus reflects differences in the activity models used for the interpretation of the experiments. With increasing temperature, the discrepancy between our MD results and previous experimental

  20. Non-LTE calculation of HCL earthlimb emission and implication for detection of HCl in the atmosphere

    Science.gov (United States)

    Kumer, J. B.; James, T. C.

    1982-01-01

    Calculation results are presented for the contribution of the non-Local Thermodynamic Equilibrium process of resonant scattering of sunlight in the 1-0 band of HCl to the earthlimb radiance, for the case of tangent altitudes from 20 to 90 km. It is established that the mechanism in question is a significant contributor to radiance at altitudes as low as 20 km, and that it becomes greater than the Local Thermodynamic Equilibrium contribution above 40 km. Attention is given to the prospects for detection of HCl at altitudes approaching 80 km, by means of the Cryogenic Limb Array Etalon Spectrometer scheduled for deployment by the NASA Upper Atmospheric Research Satellite.

  1. Unusually low ozone, HCl, and HNO3 column measurements at Eureka, Canada during winter/spring 2011

    Directory of Open Access Journals (Sweden)

    R. L. Mittermeier

    2012-04-01

    Full Text Available As a consequence of dynamically variable meteorological conditions, springtime Arctic ozone levels exhibit significant interannual variability in the lower stratosphere. In winter 2011, the polar vortex was strong and cold for an unusually long time. Our research site, located at Eureka, Nunavut, Canada (80.05° N, 86.42° W, was mostly inside the vortex from October 2010 until late March 2011. The Bruker 125HR Fourier transform infrared spectrometer installed at the Polar Environment Atmospheric Research Laboratory at Eureka acquired measurements from 23 February to 6 April during the 2011 Canadian Arctic Atmospheric Chemistry Experiment Validation Campaign. These measurements showed unusually low ozone, HCl, and HNO3 total columns compared to the previous 14 yr. To remove dynamical effects, we normalized these total columns by the HF total column. The normalized values of the ozone, HCl, and HNO3 total columns were smaller than those from previous years, and confirmed the occurrence of chlorine activation and chemical ozone depletion. To quantify the chemical ozone loss, a three-dimensional chemical transport model, SLIMCAT, and the passive subtraction method were used. The chemical ozone depletion was calculated as the mean percentage difference between the measured ozone and the SLIMCAT passive ozone, and was found to be 35%.

  2. Clinical and Laboratory Presentation of Hairy Cell Leukemia (Hcl and Rate of Response to Cladribine

    Directory of Open Access Journals (Sweden)

    M Forat Yazdi

    2008-04-01

    Full Text Available Introduction: HCL is a rare malignant condition that is curable if diagnosed early. HCL can present with reduced blood cells and splenomegaly which maybe misdiagnosed with other conditions. The aim of the present study was to determine the frequency of early clinical and laboratory findings as well as the response rate of patients to the standard treatment regimen of Cladribine. Methods: The study was an uncontrolled clinical trial including 25 HCL patients referring to Oncology Clinics of Shahid Sadoughi (Yazd - Iran and Shahid Beheshti (Tehran - Iran between 1999 and 2005. Data was gathered by a pre–designed questionnaire. 21 out of 25 patients were treated with Cladribine and the clinical and laboratory response was assessed. Results: Of the 25 patients studied, 20 patients (80% were male and 5 patients (20% were female. Most of the patients at diagnosis were 55–67 years old and the most common presenting symptom was fatigue and lassitude secondary to anemia. Two patients were asymptomatic and were diagnosed incidentally. Splenomegaly was the main clinical finding which was present in about 80% of the males and all of the females. Accordingly, hairy cells in the peripheral blood smear, leukopenia and anemia were the most common laboratory findings. In contrast to previous results, pancytopenia was found in only 60% of the patients. Response rate was 90% (19 out of 21 of which 61.9% (13 patients and 28.5% (6 patients had complete remission (CR and partial remission (PR, respectively. Conclusion: According to the results, it can be concluded that HCL should be considered as a possible diagnosis in the context of fatigue, splenomegaly and reduced blood cell count. The results of the present study were similar to other similar international studies.

  3. Novel levocetirizine HCl tablets with enhanced palatability: synergistic effect of combining taste modifiers and effervescence technique

    Directory of Open Access Journals (Sweden)

    Labib GS

    2015-09-01

    Full Text Available Gihan S Labib1,2 1Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt Objectives: Levocetirizine HCl, a second-generation piperazine derivative and H1-selective antihistaminic agent, possesses few side effects. The first objective of the study was to compare and evaluate the taste-masking effect of different ratios of 2-hydroxypropyl-β-cyclodextrin and mannitol on levocetirizine HCl using an inclusion complex and solid dispersion, respectively. The second objective was to study the possibility of preparing and evaluating effervescent tablets from the best-chosen taste-masked blends for the purpose of their use either as orodispersible tablets or as water-soluble effervescent tablets, according to patients’ will.Materials and methods: Prepared taste-masked blends were prepared and subjected to palatability, Fourier-transform infrared spectroscopy, and differential scanning calorimetry studies. Tablets containing different percentages of effervescent mixtures were prepared by direct compression on the selected taste-modified blends. Evaluation tests were conducted, including flowability and compressibility on the precompressed blends and hardness, friability, wetting time, effervescent time, in vitro, in vivo disintegration time, and in vitro dissolution study on the compressed tablets. Formulated tablets were evaluated and compared to marketed orodispersible tablets for mouth feel and palatability.Results: All prepared tablets showed convenient physical and palatability properties compared to the selected brand. The in vitro drug-release study revealed fast release of levocetirizine HCl within 5 minutes from all prepared tablets.Conclusion: Levocetirizine HCl effervescent tablets are likely to increase patient compliance with drug administration. Moreover, the use of these

  4. Novel levocetirizine HCl tablets with enhanced palatability: synergistic effect of combining taste modifiers and effervescence technique

    Science.gov (United States)

    Labib, Gihan S

    2015-01-01

    Objectives Levocetirizine HCl, a second-generation piperazine derivative and H1-selective antihistaminic agent, possesses few side effects. The first objective of the study was to compare and evaluate the taste-masking effect of different ratios of 2-hydroxypropyl-β-cyclodextrin and mannitol on levocetirizine HCl using an inclusion complex and solid dispersion, respectively. The second objective was to study the possibility of preparing and evaluating effervescent tablets from the best-chosen taste-masked blends for the purpose of their use either as orodispersible tablets or as water-soluble effervescent tablets, according to patients’ will. Materials and methods Prepared taste-masked blends were prepared and subjected to palatability, Fourier-transform infrared spectroscopy, and differential scanning calorimetry studies. Tablets containing different percentages of effervescent mixtures were prepared by direct compression on the selected taste-modified blends. Evaluation tests were conducted, including flowability and compressibility on the precompressed blends and hardness, friability, wetting time, effervescent time, in vitro, in vivo disintegration time, and in vitro dissolution study on the compressed tablets. Formulated tablets were evaluated and compared to marketed orodispersible tablets for mouth feel and palatability. Results All prepared tablets showed convenient physical and palatability properties compared to the selected brand. The in vitro drug-release study revealed fast release of levocetirizine HCl within 5 minutes from all prepared tablets. Conclusion Levocetirizine HCl effervescent tablets are likely to increase patient compliance with drug administration. Moreover, the use of these effervescent tablets in an orodispersible dosage form can improve oral drug bioavailability and act as an attractive pediatric dosage form. PMID:26379426

  5. The influence of HCl concentration and demineralization temperature of Atrina pectinata shells on quality of chitin

    Science.gov (United States)

    Nugroho, Intan Lazuardi; Pursetyo, Kustiawan Tri; Masithah, Endang Dewi

    2017-02-01

    Atrina pectinata is one of shells species widely consumed by people, which means the high consumption will generate the availability of shells in the environment as waste. Chitin can be produced from the shells. Shells contain quite high minerals that it should be demineralized to reduce the mineral content from the shells. This study aimed to determine the effect of HCl concentration and temperature affect chitin characteristics as the result of demineralization process from pen shells. The method based on two steps, there were demineralization and deproteination. This study used Completely Randomized Design (CRD) with two factors, including HCl concentration (2N, 4N, and 6N) and temperature (33°C and 60°C) which consists six combination treatments and three replications. Data was analyzed by using Analysis of Variance (ANOVA) and followed by Duncan's Multiple Range Test. The results showed that interaction of HCl concentration and temperature has significant effect (pchitin. The use concentration of 6N and 33°C produced the lowest ash content. Characteristics chitin resulted from the treatment of 6N and 33°C produced ash content 25.33% ± 6.82, moisture content 3.67% ± 1.10, yield 0.72% ± 0.12 and protein content 5.86%.

  6. Modelling of Phase Equlibria in the Hf-V System\

    Czech Academy of Sciences Publication Activity Database

    Vřešťál, Jan; Pavlů, Jana; Wdowik, U. D.; Šob, Mojmír

    2017-01-01

    Roč. 53, č. 3 (2017), s. 239-247 ISSN 1450-5339 R&D Projects: GA ČR GA14-15576S; GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Laves phases * Hf-V system * Ab initio calculations * Phase diagram * Zero Kelvin * CALPHAD method Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.804, year: 2016

  7. Determining Energy Distributions of HF-Accelerated Electrons at HAARP

    Science.gov (United States)

    2015-11-18

    copper) over the HAARP facility in Gakona, Alaska. A wide-field imager located about 160 km north of HAARP measured the airglow intensity. MUIR ...from 250 km altitude to 150 km altitude. The altitude of the HF-enhanced ion line (HFIL) measured with the Modular UHF Ionosphere Radar ( MUIR ) co...km 250 km 200 km 200 km 150 km 150 km 44 al. [2014], including the 13 March 2002 experiment despite available MUIR measurements showing descent

  8. INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl) ACID ...

    African Journals Online (AJOL)

    2015-05-01

    May 1, 2015 ... the present work, the role of aniline as inhibitor for corrosion of zinc in (HNO3 + HCl) binary acid mixture ... and without inhibitor containing 230 ml test solution at 301 + 1 K for 24 h immersion period. After the ... rate was determined at various temperatures e.g.at 303, 313, 323 and 333 K for an immersion.

  9. The kinetics of titanium leaching of ilmenite using HCl

    International Nuclear Information System (INIS)

    MV Purwani; Herry Poernomo

    2015-01-01

    The research of ilmenite leaching of tailings processing zircon sand has been done. Tailings of processing zircon sand contain Zr, Ti, Nb and Fe. Determination of leaching kinetics of Ti on ilmenite using HCl was done on this research. Determination of reaction rate consist the influence of weight ratio of HCl to ilmenite, HCl molarity and temperature reaction. The experiment of kinetics was done by varying the temperature reaction from 70°C to 108°C and time parameter range 0 to 200 minutes. From data of research can be concluded that the greater of weight ratio of HCl with ilmenite, M HCl and reaction temperature, the faster rate of reaction. On weight ratio of HCl with ilmenite varied 4 - 20, average reaction rate along 50 minutes and instantaneous reaction rate in the first 50 minutes ranged from 0.0021 to 0.0032 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0005 to 0.0007 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). For M HCl = 8 to 12.23 M, average reaction rate and instantaneous reaction rate in the first 50 minutes ranged from 0.0012 to 0.0026 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0004 to 0.0006 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). On reaction temperature = 70 - 108°C, average reaction rate along 50 minutes and instantaneous reaction rate in the first 50 minutes ranged from 0.0012 to 0.0032 gmol/(l.minute). Average reaction rate along 250 minutes ranged from 0.0002 to 0.0006 gmol/(l.minute) and instantaneous reaction rate at 50 minutes latest ranged from 0.0000 to 0.0001 gmol/(l.minute). The leaching reaction of Ti in ilmenite was second order reaction. The relationship between temperature (T) with the reaction rate constant (k) are - ln k = 3333.2/T - 1.3685 or k = 1.3685. e-3333,2/T , frequency factor A = 1446 and activation energy E = 27.712 k

  10. Determination of the rate of HF hydration and the effects of HF on moisture condensation

    International Nuclear Information System (INIS)

    McCulla, W.H.

    1982-01-01

    There were four basic questions addressed in this report that relate to the HF interaction in the environment. As to whether HF hydrates in the vapor phase and what the rate of that hydration is, there seems ample evidence that HF hydrates readily in the vapor phase and the rate of that hydration is very fast, i.e., dHF/dt greater than or equal to 25 torr sec -1 . Concerning under what conditions condensation of the hydrate will occur and whether a third body is required for condensation, it was found that HF does effect the dew point or condensation of water and data was presented indicating the extent of that effect. It was also determined that condensation will occur without a third body present. Thus, in attempting to model an HF release for the Safety Analysis Report the hydration of HF and the subsequent heat released may be treated as occurring instantaneously; but the ultimate disposition of the HF will be strongly dependent upon the environmental conditions at the time of the release

  11. Determination of the rate of HF hydration and the effects of HF on moisture condensation

    Energy Technology Data Exchange (ETDEWEB)

    McCulla, W H

    1982-04-30

    There were four basic questions addressed in this report that relate to the HF interaction in the environment. As to whether HF hydrates in the vapor phase and what the rate of that hydration is, there seems ample evidence that HF hydrates readily in the vapor phase and the rate of that hydration is very fast, i.e., dHF/dt greater than or equal to 25 torr sec/sup -1/. Concerning under what conditions condensation of the hydrate will occur and whether a third body is required for condensation, it was found that HF does effect the dew point or condensation of water and data was presented indicating the extent of that effect. It was also determined that condensation will occur without a third body present. Thus, in attempting to model an HF release for the Safety Analysis Report the hydration of HF and the subsequent heat released may be treated as occurring instantaneously; but the ultimate disposition of the HF will be strongly dependent upon the environmental conditions at the time of the release.

  12. Ir Spectroscopic Studies on Microsolvation of HCl by Water

    Science.gov (United States)

    Mani, Devendra; Schwan, Raffael; Fischer, Theo; Dey, Arghya; Kaufmann, Matin; Redlich, Britta; van der Meer, Lex; Schwaab, Gerhard; Havenith, Martina

    2016-06-01

    Acid dissociation reactions are at the heart of chemistry. These reactions are well understood at the macroscopic level. However, a microscopic level understanding is still in the early stages of development. Questions such as 'how many H_2O molecules are needed to dissociate one HCl molecule?' have been posed and explored both theoretically and experimentally.1-5 Most of the theoretical calculations predict that four H_2O molecules are sufficient to dissociate one HCl molecule, resulting in the formation of a solvent separated H_3O+(H_2O)3Cl- cluster.1-3 IR spectroscopy in helium nanodroplets has earlier been used to study this dissociation process.3-5 However, these studies were carried out in the region of O-H and H-Cl stretch, which is dominated by the spectral features of undissociated (HCl)m-(H_2O)n clusters. This contributed to the ambiguity in assigning the spectral features arising from the dissociated cluster.4,5 Recent predictions from Bowman's group, suggest the presence of a broad spectral feature (1300-1360 wn) for the H_3O+(H_2O)3Cl- cluster, corresponding to the umbrella motion of H_3O+ moiety.6 This region is expected to be free from the spectral features due to the undissociated clusters. In conjunction with the FELIX laboratory, we have performed experiments on the (HCl)m(H_2O)n (m=1-2, n≥4) clusters, aggregated in helium nanodroplets, in the 900-1700 wn region. Mass selective measurements on these clusters revealed the presence of a weak-broad feature which spans between 1000-1450 wn and depends on both HCl as well as H_2O concentration. Measurements are in progress for the different deuterated species. The details will be presented in the talk. References: 1) C.T. Lee et al., J. Chem. Phys., 104, 7081 (1996). 2) H. Forbert et al., J. Am. Chem. Soc., 133, 4062 (2011). 3) A. Gutberlet et al., Science, 324, 1545 (2009). 4) S. D. Flynn et al., J. Phys. Chem. Lett., 1, 2233 (2010). 5) M. Letzner et al., J. Chem. Phys., 139, 154304 (2013). 6) J. M

  13. HF Radio Wave Production of Artificial Ionospheres

    Science.gov (United States)

    Carlson, Herbert

    In 1993 it was predicted that artificial ionospheres would be produced by high power HF radio waves, once HF transmitters approached a GWatt ERP. When that threshold was very recently achieved, such production was indeed detected and published at two high latitude high power HF facilities. Here we review: the first-principles logic behind that prediction, which aspects of such production are critically dependent on magnetic latitude, and which aspects of such production depend only on physical parameters independent of latitude. These distinctions follow directly from decomposition of the problem of ionization production into its components of: radio-wave propagation, wave-particle interactions, electron transport, and quantitative elastic/inelastic cross-sections. We outline this analysis to show that, within the context of early observations, the production of ionization is inevitable, and only a question of competing instability thresholds, and scale of ionization production. This illustrates complimentary aeronomy and plasma physics to advance understanding of both.

  14. High frequency titration in non-aqueous solvents. Application to HF and UF6

    International Nuclear Information System (INIS)

    Neveu, Claude

    1965-01-01

    In this research thesis, the author first presents the main theoretical notions regarding high frequency titration, notably by studying characteristic curves, i.e. the titration meter indication with respect to conductibility. He reports the use of this method for the study of various reactions in non-aqueous medium: reaction of AlCl 3 with pyridine in acetonitrile, of AlCl 3 with HCl in tetrachloroethane and in nitromethane. He also reports the attempt of application of this method to the titration of HF in presence of UF 6 in CCl 4 as solvent, or by using F acceptors like BF 3 , PF 5 or ClF 3 as reactants [fr

  15. Lu-Hf constraints on the evolution of lunar basalts

    International Nuclear Information System (INIS)

    Fujimaki, H.; Tatsumoto, M.

    1984-01-01

    Very low Ti basalts andd green glass samples from the moon show high Lu/Hf ratios and low Hf concentrations. Low-Ti lunar basalts show high and variable Lu/Hf ratios and higher Hf concentrations, whereas high-Ti lunar basalts show low Lu/Hf ratios and high Hf concentrations. KREEP basalts have constant Lu/Hf ratios and high but variable Hf concentrations. Using the Lu-Hf behavior as a constraint, we propose a model for the mare basalts evolution. This constraint requires extensive crystallization of the primary lunar magma ocean prior to formation of the lunar mare basalt sources and the KREEP basalts. Mare basalts are produced by the melting of the cumulate rocks, and KREEP basalts represent the residual liquid of the magma ocean

  16. Sr-Nd-Hf isotopic fingerprinting of transatlantic dust derived from North Africa

    Science.gov (United States)

    Zhao, Wancang; Balsam, William; Williams, Earle; Long, Xiaoyong; Ji, Junfeng

    2018-03-01

    Long-range transport of African dust plays an important role in understanding dust-climate relationships including dust source areas, dust pathways and associated atmospheric and/or oceanic processes. Clay-sized Sr-Nd-Hf isotopic compositions can be used as geochemical fingerprints to constrain dust provenance and the pathways of long-range transported mineral dust. We investigated the clay-sized Sr-Nd-Hf isotopic composition of surface samples along four transects bordering the Sahara Desert. The transects are from Mali, Niger/Benin/Togo, Egypt and Morocco. Our results show that the Mali transect on the West African Craton (WAC) produces lower εNd (εNd-mean = -16.38) and εHfHf-mean = -9.59) values than the other three transects. The Egyptian transect exhibits the lowest 87Sr/86Sr ratios (87Sr/86Srmean = 0.709842), the highest εHfHf-mean = -0.34) and εNd values of the four transects. Comparison of the clay-sized Sr-Nd-Hf isotopic values from our North African samples to transatlantic African dust collected in Barbados demonstrates that the dust's provenance is primarily the western Sahel and Sahara as well as the central Sahel. Summer emission dust is derived mainly from the western Sahel and Sahara regions. The source of transatlantic dust in spring and autumn is more varied than in the summer and includes dust not only from western areas, but also south central areas. Comparison of the Sr-Nd-Hf isotopic fingerprints between the source and sink of transatlantic dust also suggests that a northwestward shift in dust source occurs from the winter, through the spring and into the summer. The isotopic data we develop here provide another tool for discriminating changes in dust archives resulting from paleoenvironmental evolution of source regions.

  17. Synthetic smoke with acrolein but not HCl produces pulmonary edema.

    Science.gov (United States)

    Hales, C A; Barkin, P W; Jung, W; Trautman, E; Lamborghini, D; Herrig, N; Burke, J

    1988-03-01

    The chemical toxins in smoke and not the heat are responsible for the pulmonary edema of smoke inhalation. We developed a synthetic smoke composed of carbon particles (mean diameter of 4.3 microns) to which toxins known to be in smoke, such as HCl or acrolein, could be added one at a time. We delivered synthetic smoke to dogs for 10 min and monitored extravascular lung water (EVLW) accumulation thereafter with a double-indicator thermodilution technique. Final EVLW correlated highly with gravimetric values (r = 0.93, P less than 0.01). HCl in concentrations of 0.1-6 N when added to heated carbon (120 degrees C) and cooled to 39 degrees C produced airway damage but no pulmonary edema. Acrolein, in contrast, produced airway damage but also pulmonary edema, whereas capillary wedge pressures remained stable. Low-dose acrolein smoke (less than 200 ppm) produced edema in two of five animals with a 2- to 4-h delay. Intermediate-dose acrolein smoke (200-300 ppm) always produced edema at an average of 147 +/- 57 min after smoke, whereas high-dose acrolein (greater than 300 ppm) produced edema at 65 +/- 16 min after smoke. Thus acrolein but not HCl, when presented as a synthetic smoke, produced a delayed-onset, noncardiogenic, and peribronchiolar edema in a roughly dose-dependent fashion.

  18. Source Components and Mass Transfer in the Aleutian Arc from Hf, Nd and Pb Isotopes

    Science.gov (United States)

    Brown, S. T.; Yogodzinski, G. M.; Vervoort, J. D.; Kelemen, P. B.

    2008-12-01

    Hafnium, Nd and Pb isotopic and trace element data from the eastern Aleutian arc, including new samples from dredged back arc volcanoes, are used to evaluate the sources of Hf and other high field strength elements (HFSE) in island arc lavas. A relatively simple subduction system and on-going efforts to accurately characterize the subducting sediment make the Aleutian arc an ideal natural laboratory to test models of mass transfer from the subducting plate through the sub arc mantle and back to the surface. Aleutian lavas sampled from the arc front have less radiogenic Nd and Hf isotope ratios than estimates of the local mantle wedge, consistent with the addition of small amounts of subducting sediment to the melt source. In general ɛNd and ɛHf increase westward, apparently due to decreasing subduction rates and sediment flux to the trench. In detail, Nd and Hf isotopes are well correlated west of Seguam Island but are decoupled to the east, where ɛHf decreases continuously and ɛNd is weakly correlated with the sediment flux. Correlations between sediment flux, Nd and Hf isotopes indicate that sediment-derived Nd and Hf are incorporated into the source of Aleutian magmas. This implies that Hf (+ other HFSE's?) is not conserved in the subducted sediment. An eastward increase in the terrigenous component of subducting sediments, which likely include a greater proportion of detrital zircon, may be the source of relatively unradiogenic Hf in eastern Aleutian lavas. This suggests that Hf, derived in part from detrital zircon, may be transferred from the subducting plate to the sub arc mantle. Dredged lavas from submerged, back-arc volcanoes located between Umnak Island and the Islands of Four Mountains display stronger isotopic diversity (e.g.,ɛHf= 11.6-19.9, ɛNd= 5.8-9.4, and 206Pb/204Pb= 18.4-19.0) than nearby emergent and arc front volcanoes. This suggests that the small seafloor volcanoes effectively sample isotopic end-members, which likely originate from

  19. Kisilidjan hf - A unique diatomite plant

    International Nuclear Information System (INIS)

    Sigurdsson, F.

    1992-01-01

    This paper gives a short description of Kisilidjan hf. (The Icelandic Diatomite Plant, Ltd.), a description of the production, the use of geothermal steam in the plant, steam supply, steam use, steam price, experience associated with the use of steam, and some conclusions

  20. Searching triaxial superdeformation in 175Hf

    International Nuclear Information System (INIS)

    Li Xiaowei; Zhejiang Normal Univ., Jinhua; Yu Shaoying; Zhejiang Normal Univ., Jinhua; Chinese Academy of Sciences, Beijing; Shen Caiwan; National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou; Chen Yongshou; Chinese Academy of Sciences, Beijing; National Laboratory of Heavy Ion Accelerator of Lanzhou

    2006-01-01

    A two-dimensional Total Routhian Surface (TRS) calculation is carried out in order to ascertain if there is triaxial superdeformation in 175 Hf. A five quasi-particle configuration is chosen in the calculation. Unfortunately, the TRS minimum does not show up in the total potential energy surface. (authors)

  1. Resistive switching characteristics of Pt/TaOx/HfNx structure and its performance improvement

    Directory of Open Access Journals (Sweden)

    Qigang Zhou

    2013-03-01

    Full Text Available The refractory transition metal nitride (TMN film Hafnium nitride (HfNx was successfully prepared on silicon-based substrates as bottom electrodes for resistive random access memory (RRAM cells in Pt (top/metal oxide/ HfNx (bottom sandwich structure. The reproducible resistive switching (RS characteristics of the memory cells were studied systematically for RRAM applications. The advantages of adopting HfNx instead of Pt as bottom electrode material were demonstrated, including the improvement of the low resistive state value, the RS endurance and the uniformity of RS parameters. The composition and chemical bonding states of the prepared HfNx was analyzed by X-ray photoelectron spectroscopy (XPS technique. The nitrogen content in the HfNx and the Gibbs free energy of the corresponding metal oxide formation has great influences on the RS properties. The oxygen reservoir ability and diffusion barrier effect of the HfNx play a key role in the RS performance improvement of the RRAM devices.

  2. Ergonomics action research II: a framework for integrating HF into work system design.

    Science.gov (United States)

    Neumann, W P; Village, J

    2012-01-01

    This paper presents a conceptual framework that can support efforts to integrate human factors (HF) into the work system design process, where improved and cost-effective application of HF is possible. The framework advocates strategies of broad stakeholder participation, linking of performance and health goals, and process focussed change tools that can help practitioners engage in improvements to embed HF into a firm's work system design process. Recommended tools include business process mapping of the design process, implementing design criteria, using cognitive mapping to connect to managers' strategic goals, tactical use of training and adopting virtual HF (VHF) tools to support the integration effort. Consistent with organisational change research, the framework provides guidance but does not suggest a strict set of steps. This allows more adaptability for the practitioner who must navigate within a particular organisational context to secure support for embedding HF into the design process for improved operator wellbeing and system performance. There has been little scientific literature about how a practitioner might integrate HF into a company's work system design process. This paper proposes a framework for this effort by presenting a coherent conceptual framework, process tools, design tools and procedural advice that can be adapted for a target organisation.

  3. QAPP for Hydraulic Fracturing (HF) Surface Spills Data Analysis

    Science.gov (United States)

    This QAPP provides information concerning the analysis of spills associated with hydraulic fracturing. This project is relevant to both the chemical mixing and flowback and produced water stages of the HF water cycle as found in the HF Study Plan.

  4. Investigation of Modified Pumice with HCl and NaOH for Removal of Fluoride from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Mansur Zarrabi

    2014-06-01

    Full Text Available Background: Fluoride is an essential element for human health body, since in standard levels, it prevents the tooth decay. If fluoride concentration in drinking water exceeds from standard levels, it can leads to some diseases such as alzeimer syndrome, sterility, brittle bones, and thyroid disorder. So, removal of excess amounts of fluoride seems to be essential in order to health protection and prevention of the environment. Methods: In this work, modified pumice with HCl and NaOH were used for removal of fluoride from aqueous solution. Several experimental parameters including pH (2-10, temperature (20-60°C, adsorbent dosage (2-10 g/L, initial fluoride concentration (5-20 mg/L, and contact time were studied. All experiment were conducted in batch system by keeping constant one parameter and changing others. Results: Results showed that removal efficiency was increased with increase in contact time, initial fluoride concentration and adsorbent dosage. The maximum removal efficiency was observed at pH 6, 10 g/L adsorbent dosage, 20°C solution temperature, 90 min reaction time and 20 mg/L of fluoride concentration. Moreover, the maximum removal efficiency was observed by adsorbents modified with HCl. In general, results revealed that modified Pumice with HCL could remove 96% of fluoride at 90 min contact time, pH=6, 20°C and 20 mg/L of fluoride concentration. Conclusion: Results showed that pumice modified with HCl and NaOH had high capacity in removal of fluoride which the capacity was higher for pumice  modified with HCl.

  5. SINTESIS DIMETIL ASETAL SITRONELAL DENGAN KATALIS GAS HCL

    Directory of Open Access Journals (Sweden)

    E Cahyono

    2014-06-01

    Full Text Available Perlindungan gugus aldehida melalui pembentukan asetal umumnya dilakukan dengan metanol atau etanol terkatalis asam. Sitronelal memiliki gugus aldehida dan gugus alkena. Dalam lingkungan asam, sitronelal mudah mengalami siklisasi membentuk isopulegol dan isomernya. Penelitian ini bertujuan untuk mensintesis dimetil asetal sitronelal dengan katalis gas HCl. Penggunaan gas HCl secara terbatas dimaksudkan untuk menghindari siklisasi sitronelal. Dalam suatu reaktor, 10 mL sitronelal ditambah dengan 20 mL metanol absolut dan 2 g CaCl2 pada labu leher tiga. Gas HCl dialirkan dengan laju alir 12 mL/menit pada temperatur ruang hingga pH campuran menjadi 2-3. Kemudian dilakukan pengadukan pada 30°C selama 48 jam dan diambil sampel pada durasi reaksi 12, 24 dan 48 jam. Dalam penelitian ini dilakukan variasi temperatur dan jumlah CaCl2. Dimetil asetal sitronelal yang dihasilkan diisolasi dengan distilasi fraksinasi pengurangan tekanan dan diuji strukturnya dengan GC-MS, IR dan 1H-NMR. Peningkatan temperatur dan jumlah CaCl2 meningkatkan konversi sitronelal. Setelah 48 jam kuantitas dimetil asetal sitronelal mencapai 48,65%. Distilasi fraksinasi pengurangan tekanan (5 cmHg terbukti meningkatkan kemurnian dimetil asetal sitronelal menjadi 86,39% terhadap produk kasarnya. Elusidasi struktur dengan spektrofotometer infra merah (IR dan resonansi magnetik inti (1H-NMR pada hasil distilasi fraksinasi membuktikan adanya struktur asetal sitronelal.  Aldehyde group protection through acetal formation is generally performed by acid catalyzed methanol or ethanol. Citronellal that has aldehyde and alkene groups. In acidic environment, it is prone to do cyclization to form isopulegol and its isomers. This study aims to synthesize dimethyl acetal of citronellal with HCl gas catalysts. The limitation of HCl using gas was intended to avoid the citronellal cyclization. In a reactor, 10 mL citronellal was added with 20 mL of absolute methanol and 2 g CaCl2 in the three

  6. Quasiclassical R-matrix theory of inelastic processes in collisions of electrons with HCl molecules

    International Nuclear Information System (INIS)

    Fabrikant, I.I.

    1991-01-01

    The R-matrix theory for the vibrational excitation and dissociative attachment in e-HCl collisions is developed. Only one pole in the R-matrix expansion is included. This allows for making a connection between the R-matrix and the nonlocal-complex-potential theories, and for obtaining the expression for the dissociative-attachment cross section without using the R-matrix radius in the internuclear coordinate. All matrix elements in the equation for the vibrational-excitation and dissociative-attachment amplitudes are calculated using the quasiclassical approach. We study how the results depend on the number of vibrational levels of the neutral molecule included in the theory and show how to exclude the vibrational continuum by a modification of the nonlocal-complex potential. The results for the vibrational-excitation cross sections are extremely sensitive to the behavior of the R-matrix potential curve near the point of crossing this curve with the potential curve of the neutral molecule. Particularly in some cases the cross section at the threshold peak exhibits the boomerang oscillations earlier found for HCl by Domcke [in Aspects of Electron-Molecule Scattering and Photoionization, edited by A. Herzenberg (AIP, New Haven, 1989), p. 169]. The dissociative-attachment cross sections are in reasonable agreement with experiment and with other theories

  7. Activation cross section measurement for the 179Hf(n,2n)178m2Hf reaction

    International Nuclear Information System (INIS)

    Yu Weixiang; Lu Hanlin; Zhao Wenrong

    1992-01-01

    As an important data for a fusion reactor there are not any experimental results for the cross section of the 179 Hf(n,2n) 178m2 Hf reaction. So the cross section was measured in this work at neutron energy of 14 MeV. Meanwhile, we also gave the data for the cross section of the 180 Hf(n,2n) 179m2 Hf reaction. (author). 5 refs, 4 figs, 5 tabs

  8. Effects of pentoxifylline on TNF-alpha and lung histopathology in HCL-induced lung injury

    Directory of Open Access Journals (Sweden)

    Itamar Souza de Oliveira-Júnior

    2008-01-01

    Full Text Available OBJECTIVE: To evaluate the effects of pentoxifylline on hydrochloric acid-induced lung lesions in rats subjected to mechanical ventilation. METHODS: Twenty male, adult Wistar-EPM-1 rats were anesthetized and randomly grouped (n=5 animals per group as follows: control-MV (mechanical ventilation, MV group; bilateral instillation of HCl (HCl group; bilateral instillation of HCl followed by pentoxifylline (50 mg/kg bw infusion (HCl+PTX group and pentoxifylline infusion followed by bilateral instillation of HCl (PTX+HCl group. At 20, 30, 90 and 180 min after treatments, the blood partial pressures of CO2 and O2 were measured. The animals were euthanized, and bronchoalveolar lavages were taken to determine the contents of total proteins, corticosterone and TNF-alpha. Samples of lung tissue were used for histomorphometric studies and determining the wet-to-dry (W/D lung weight ratio. RESULTS: In the MV group, rats had alveolar septal congestion, and, in the HCl group, a remarkable recruitment of neutrophils and macrophages into the alveoli was noticed; these events were reduced in the animals with PTX+HCl. The partial pressure of oxygen increased in PTX+HCl animals (121±5 mmHg as compared with the HCl (62±6 mmHg and HCl+PTX (67±3 mmHg groups within 30 minutes. TNF-alpha levels in bronchoalveolar lavage were significantly higher in the HCl group (458±50 pg/mL, reduced in the HCl+PTX group (329±45 pg/mL and lowest in the PTX+HCl group (229±41 pg/mL. The levels of corticosterone in bronchoalveolar lavage were significantly lower in the HCl (8±1.3 ng/mL and HCl+PTX group (16±2 ng/mL and were highest in the PTX+HCl (27±1.9 ng/mL. CONCLUSION: Pretreatment with PTX improves oxygenation, reduces TNF-alpha concentration and increases the concentration of corticosterone in bronchoalveolar lavage upon lung lesion induced by HCl.

  9. Comparison of HfCl4, HfI4, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO2 films deposited by ALD: A DFT study

    International Nuclear Information System (INIS)

    Cortez-Valadez, M.; Fierro, C.; Farias-Mancilla, J.R.; Vargas-Ortiz, A.; Flores-Acosta, M.; Ramírez-Bon, R.; Enriquez-Carrejo, J.L.

    2016-01-01

    Highlights: • Hafnium oxide growth on Si(100) by atomic layer deposition was simulated. • The interface structure was considered as silicate and silicide. • The interface was studied employing DFT. • TDMA-Hf precursor show better interface stability. - Abstract: The final structure of HfO 2 films grown by atomic layer deposition (ALD) after reaction with OH − ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl 4 (hafnium tetrachloride), HfI 4 (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO–H was studied employing the B3LYP (Becke 3-parameter, Lee–Yang–Parr) hybrid functional and the PBE (Perdew–Burke–Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  10. Comparison of HfCl{sub 4}, HfI{sub 4}, TEMA-Hf, and TDMA-Hf as precursors in early growing stages of HfO{sub 2} films deposited by ALD: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Cortez-Valadez, M. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190 Hermosillo, Son. (Mexico); Fierro, C.; Farias-Mancilla, J.R. [Instituto de Ingeniería y Tecnología, Departamento de Física y Matemáticas, Universidad Autónoma de Ciudad Juárez, Av. del Charro 450, Cd. Juárez C.P. 32310, Chihuahua (Mexico); Vargas-Ortiz, A. [Universidad Autónoma de Sinaloa, Facultad de Ingeniería Mochis, Ciudad Universitaria, C.P. 81223 Los Mochis, Sinaloa (Mexico); Flores-Acosta, M. [Departamento de Investigación en Física, Universidad de Sonora, Apdo. Postal 5-88, 83190 Hermosillo, Son. (Mexico); Ramírez-Bon, R. [Centro de Investigación y Estudios Avanzados del IPN, Unidad Querétaro, Apdo. Postal 1-798, 76001 Querétaro, Qro. (Mexico); Enriquez-Carrejo, J.L. [Instituto de Ingeniería y Tecnología, Departamento de Física y Matemáticas, Universidad Autónoma de Ciudad Juárez, Av. del Charro 450, Cd. Juárez C.P. 32310, Chihuahua (Mexico); and others

    2016-06-15

    Highlights: • Hafnium oxide growth on Si(100) by atomic layer deposition was simulated. • The interface structure was considered as silicate and silicide. • The interface was studied employing DFT. • TDMA-Hf precursor show better interface stability. - Abstract: The final structure of HfO{sub 2} films grown by atomic layer deposition (ALD) after reaction with OH{sup −} ions has been analyzed by DFT (density functional theory). The interaction of the precursors: HfCl{sub 4} (hafnium tetrachloride), HfI{sub 4} (hafnium tetraiodide), TEMA-Hf (tetrakis-ethylmethylamino hafnium), and TDMA-Hf (tetrakis-dimethylamino hafnium) with HO–H was studied employing the B3LYP (Becke 3-parameter, Lee–Yang–Parr) hybrid functional and the PBE (Perdew–Burke–Ernzerhof) generalized gradient functional. The structural evolution at the Si(100) surface has been analyzed by LDA (local density approximation). The structural parameters: bond length and bond angle, and the vibrational parameters for the optimized structures are also reported. The presence of hafnium silicate at the interface was detected. The infrared spectra and structural parameters obtained in this work agree with previously reported experimental results.

  11. Self-diffusion of Er and Hf inpure and HfO2-doped polycrystalline Er2O3

    International Nuclear Information System (INIS)

    Scheidecker, R.W.

    1979-01-01

    Using a tracer technique, self-diffusion of Er and Hf was measured over the approximate temperature interval of 1600 to 1970 0 C in pure and HfO 2 -doped polycryatalline Er 2 O 3 . Up to about 10 m/o HfO 2 dopant level, the Er self-diffusion coefficients followed a relationship based on cation vacancies. Above 10 m/o HfO 2 , deviation from this relationship occurred, apparently due to clustering of cation vacancies and oxygen interstitials around the dopant hafnia ion. The activation energy for the self-diffusion of Er in pure Er 2 O 3 was 82.2 Kcal/mole and increased with the HfO 2 dopant level present. Self-diffusion of Hf was measured in pure Er 2 O 3 having two impurity levels, and a separation of the grain boundary. The volume diffusion of Hf showed both extrinsic and intrinsic behavior with the transition temperature increasing with the impurity level present in Er 2 O 3 . The activation energy for Hf volume diffusion in the intrinsic region was high, i.e. 235 -+ 9.5 Kcal/mole. The grain boundary diffusion was apparently extrinsic over the entire temperature interval Very low Hf self diffusion rates were found in both pure and HfO 2 doped Er 2 O 3 compositions. Despite a clustering effect, the HfO 2 dopant increased the Hf volume diffusion coefficients

  12. Characterization of the Hf-NTA complex

    International Nuclear Information System (INIS)

    Das, S.K.; Chatterjee, R.K.; Saha, S.K.

    2002-01-01

    Hafnium ion forms a strong complex with nitrilotriacetic acid (NTA). But there is a controversy about the nature of the complex on whether it is a 1:1 or a 1:2 complex. We have carried out an electrophoresis experiment and supplemented data to establish the nature of the complex. Our data indicates that it is a 1:2 complex i.e. [Hf(NTA) 2 ] 2- in which the coordination number 8 has been satisfied for hafnium. (author)

  13. RFID UHF i HF w bibliotekach

    Directory of Open Access Journals (Sweden)

    Gładysz Bartłomiej

    2015-06-01

    Full Text Available The potential of the innovative Radio Frequency Identification (RFID technology to be applied for support, acceleration and automation of the circulation process of library collection is presented. Technology basics, and hardware and software components are described. Two different radio standards used in libraries are compared. The goal is to present the potential of RFID technology for libraries, to highlight the differences and to build a basis for further consideration of UHF and HF alternatives.

  14. Fragmentation of HCl following excitation at the chlorine K edge

    International Nuclear Information System (INIS)

    Hansen, D.L.; Arrasate, M.E.; Cotter, J.P.

    1997-01-01

    A space-focused time-of-flight (TOF) mass spectrometer was used to study the relaxation dynamics of HCl following excitation in the vicinity of the Cl-K edge (∼2.8 keV) using x-rays from B.L. 9.3.1. At the lowest resonant excitation to a σ * antibonding orbital (1σ → 6σ), a significant fraction of the excited molecules decay by emission of a neutral H atom. While neutral-H emission has been observed for shallow core levels (e.g., Cl 2p in HCl), the authors believe this to be the first observation of neutral-atom emission as a significant decay channel following resonant excitation of a deep core hole. The dissociation of neutral hydrogen atoms raises the issue of how effectively dissociation competes with Auger decay in the relaxation of these deep core levels (i.e., Cl 1s). Graphical evidence is presented to support the dissociation agrument. In addition, trends in fractional ion yields from Photo-Ion Photo-Ion COincidence (PIPICO) spectra suggest the presence of post-collision interaction (PCI). While, electron spectroscopy studies are required to confirm the observation of this effect, the authors believe this to be the first evidence of PCI moderated dissociation in molecules

  15. Fragmentation of HCl following excitation at the chlorine K edge

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, D.L.; Arrasate, M.E. [Univ. of Nevada, Las Vegas, NV (United States); Cotter, J.P. [Univ. of Nevada, Reno, NV (United States)] [and others

    1997-04-01

    A space-focused time-of-flight (TOF) mass spectrometer was used to study the relaxation dynamics of HCl following excitation in the vicinity of the Cl-K edge ({approximately}2.8 keV) using x-rays from B.L. 9.3.1. At the lowest resonant excitation to a {sigma}{sup *} antibonding orbital (1{sigma} {r_arrow} 6{sigma}), a significant fraction of the excited molecules decay by emission of a neutral H atom. While neutral-H emission has been observed for shallow core levels (e.g., Cl 2p in HCl), the authors believe this to be the first observation of neutral-atom emission as a significant decay channel following resonant excitation of a deep core hole. The dissociation of neutral hydrogen atoms raises the issue of how effectively dissociation competes with Auger decay in the relaxation of these deep core levels (i.e., Cl 1s). Graphical evidence is presented to support the dissociation agrument. In addition, trends in fractional ion yields from Photo-Ion Photo-Ion COincidence (PIPICO) spectra suggest the presence of post-collision interaction (PCI). While, electron spectroscopy studies are required to confirm the observation of this effect, the authors believe this to be the first evidence of PCI moderated dissociation in molecules.

  16. Densities and apparent molar volumes of atmospherically important electrolyte solutions. 1. The solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50 °C, including extrapolations to very low temperature and to the pure liquid state, and NaHSO4, NaOH, and NH3 at 25 °C.

    Science.gov (United States)

    Clegg, S L; Wexler, A S

    2011-04-21

    Calculations of the size and density of atmospheric aerosols are complicated by the fact that they can exist at concentrations highly supersaturated with respect to dissolved salts and supercooled with respect to ice. Densities and apparent molar volumes of solutes in aqueous solutions containing the solutes H(2)SO(4), HNO(3), HCl, Na(2)SO(4), NaNO(3), NaCl, (NH(4))(2)SO(4), NH(4)NO(3), and NH(4)Cl have been critically evaluated and represented using fitted equations from 0 to 50 °C or greater and from infinite dilution to concentrations saturated or supersaturated with respect to the dissolved salts. Using extrapolated densities of high-temperature solutions and melts, the relationship between density and concentration is extended to the hypothetical pure liquid solutes. Above a given reference concentration of a few mol kg(-1), it is observed that density increases almost linearly with decreasing temperature, and comparisons with available data below 0 °C suggest that the fitted equations for density can be extrapolated to very low temperatures. As concentration is decreased below the reference concentration, the variation of density with temperature tends to that of water (which decreases as temperature is reduced below 3.98 °C). In this region below the reference concentration, and below 0 °C, densities are calculated using extrapolated apparent molar volumes which are constrained to agree at the reference concentrations with an equation for the directly fitted density. Calculated volume properties agree well with available data at low temperatures, for both concentrated and dilute solutions. Comparisons are made with literature data for temperatures of maximum density. Apparent molar volumes at infinite dilution are consistent, on a single ion basis, to better than ±0.1 cm(3) mol(-1) from 0 to 50 °C. Volume properties of aqueous NaHSO(4), NaOH, and NH(3) have also been evaluated, at 25 °C only. In part 2 of this work (ref 1 ) an ion interaction (Pitzer

  17. Amino acids modified konjac glucomannan as green corrosion inhibitors for mild steel in HCl solution.

    Science.gov (United States)

    Zhang, Kegui; Yang, Wenzhong; Yin, Xiaoshuang; Chen, Yun; Liu, Ying; Le, Jinxun; Xu, Bin

    2018-02-01

    Konjac glucomannan (KGM) was modified with amino acids to synthesize polysaccharide esters (KGMA and KGMH) which were evaluated as corrosion inhibitor for mild steel in 0.5M HCl solution by weight loss tests, Tafel curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The synthetic polymers were found to have the lower water absorbency and the higher water solubility than KGM. Gravimetric measurements showed the maximum efficiencies of KGMA and KGMH for decreasing the corrosion rate of metal at 2000ppm are up to 89.9% and 92.4%, respectively. Polarization curves indicated polysaccharide esters could retard both hydrogen evolution reaction and metal dissolution reaction and that the inhibitory effect was concentration dependent. Besides, EIS studies demonstrated the corrosion resistance of mild steel in hydrochloric acid was enhanced by polymer additives. The observations on mild steel surface by SEM suggested the metallic substrate obtained good protection against corrosion in inhibitor-containing HCl solution. The adsorptive behavior of polymer molecules including physisorption and chemisorption obeyed Langmuir isotherm and UV-vis spectra revealed the formation of inhibitor-ion complex. The better performance of KGMH on corrosion inhibition was attributed to the easier transfer of π-electron or n-electron, which was confirmed by quantum chemical calculations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The Influence of Variation in Time and HCl Concentration to the Glucose Produced from Kepok Banana

    Science.gov (United States)

    Widodo M, Rohman; Noviyanto, Denny; RM, Faisal

    2016-01-01

    Kepok banana (Musa paradisiaca) is a plant that has many advantagesfrom its fruit, stems, leaves, flowers and cob. However, we just tend to take benefit from the fruit. We grow and harvest the fruit without taking advantages from other parts. So they would be a waste or detrimental to animal nest if not used. The idea to take the benefit from the banana crop yields, especially cob is rarely explored. This study is an introduction to the use of banana weevil especially from the glucose it contains. This study uses current methods of hydrolysis using HCl as a catalyst with the concentration variation of 0.4 N, 0.6 N and 0.8 N and hydrolysis times variation of 20 minutes, 25 minutes and 30 minutes. The stages in the hydrolysis include preparation of materials, the process of hydrolysis and analysis of test results using Fehling and titrate with standard glucose solution. HCl is used as a catalyst because it is cheaper than the enzyme that has the same function. NaOH 60% is used for neutralizing the pH of the filtrate result of hydrolysis. From the results of analysis, known thatthe biggest yield of glucose is at concentration 0.8 N and at 30 minutes reaction, it contains 6.25 gram glucose / 20 gram dry sampel, and the convertion is 27.22% at 20 gram dry sampel.

  19. Oil Spill Trajectories from HF Radars: Applied Dynamical Systems Methods vs. a Lagrangian Stochastic Model

    Science.gov (United States)

    Emery, B. M.; Washburn, L.; Mezic, I.; Loire, S.; Arbabi, H.; Ohlmann, C.; Harlan, J.

    2016-02-01

    We apply several analysis methods to HF radar ocean surface current maps to investigate improvements in trajectory modeling. Results from a Lagrangian Stochastic Model (LSM) are compared with methods based on dynamical systems theory: hypergraphs and Koopman mode analysis. The LSM produces trajectories by integrating Eulerian fields from the HF radar, and accounts for sub-grid scale velocity variability by including a random component based on the Lagrangian decorrelation time. Hypergraphs also integrate the HF radar maps in time, showing areas of strain, strain-rotation, and mixing, by plotting the relative strengths of the eigenvalues of the gradient of the time-averaged Lagrangian velocity. Koopman mode analysis decomposes the velocity field into modes of variability, similarly to EOF or a Fourier analysis, though each Koopman mode varies in time with a distinct frequency. Each method simulates oil drift from a the oil spill of May, 2015 that occurred within the coverage area of the HF radars, in the Santa Barbara Channel near Refugio Beach, CA. Preliminary results indicate some skill in determining the transport of oil when compare to publicly available observations of oil in the Santa Barbara Channel. These simulations have not shown a connection between the Refugio spill site and oil observations in the Santa Monica Bay, near Los Angeles CA, though accumulation zones shown by the hypergraphs correlate in time and space with these observations. Improvements in the HF radar coverage and accuracy were observed during the spill by the deployment of an additional HF radar site near Gaviota, CA. Presently we are collecting observations of oil on beaches and in the ocean, determining the role of winds in the oil movement, and refining the methods. Some HF radar data is being post-processed to incorporate recent antenna calibrations for sites in Santa Monica Bay. We will evaluate effects of the newly processed data on analysis results.

  20. HCl-ractopamine level addition on reproductive response, carcass characteristics and meat quality of pork

    Directory of Open Access Journals (Sweden)

    Francisco Gerardo Ríos Rincón

    2010-12-01

    Full Text Available To determinate the effect of ractopamine hydrochloride (HCl-R in reproductive response, carcass characteristics, primary cuts yield and meat quality, 80 pork (Large White Landrace X Large White-Pietrain at end stage (Live weight 73.1 kg were feed during 31 days with an integral ration with 15.12% PC and 2.32 Mcal of ME/kg with different HCL-R levels (0, 5, 10, 15 and 20ppm. Pigs were randomly distributed in the different treatments. HCl-R inclusion had no effect on reproductive response and carcass weight. Rib eye area wee improved with 15 and 20 ppm HCL-R. HCL-R levels of 10 and 20 ppm increased red coloration. The pH24 and drip loss were also no affected. HCl-R in end stage pigs had no effect on reproductive response, but improved rib eye area, red coloration and leg weight.

  1. Validation of the Russian version of the Hypomania Checklist (HCL-32) for the detection of Bipolar II disorder in patients with a current diagnosis of recurrent depression.

    Science.gov (United States)

    Mosolov, S N; Ushkalova, A V; Kostukova, E G; Shafarenko, A A; Alfimov, P V; Kostyukova, A B; Angst, J

    2014-02-01

    There are no validated screening tools for Bipolar Disorder (BD) in Russia. To validate the Russian version of the HCL-32 for the detection of Bipolar II disorder (BD II) in patients with Recurrent Depressive Disorder (RDD). 409 patients with a current diagnosis of RDD were recruited. The diagnosis was confirmed by the validated Russian version of the Mini International Neuropsychiatric Interview (MINI). Another investigator interviewed the patients using the НСL-32 questions. The total HCL-32 score in patients with BD II was significantly higher than in patients with RDD: 18.2 (4.22) versus 10.85 (5.81) (pRussian version of the HCL-32 displayed a good ratio of sensitivity to specificity and can be recommended as a validated screening instrument. An 8-item version of HCL needs further research. Limitations include the specific nature of the sample, the HCL-32 assessment carried out by a psychiatrist, no comparison with other BD screening scales. The results of the 8-item version may be sample and culture dependent. © 2013 Elsevier B.V. All rights reserved.

  2. CW HF selected-line integral master oscillator power amplifier (IMOPA)

    Energy Technology Data Exchange (ETDEWEB)

    Chodzko, R.A.; Bernard, J.M.; Coffer, J.G.; Hofland, R. [Aerospace Corp., El Segundo, CA (United States)

    1994-12-31

    Efficient lasing on multiple-selected lines has been recently demonstrated experimentally on a CW HF chemical laser. Multiple-selected-line operation is required to both enhance atmospheric transmission, and to ensure high-power extraction efficiency on multiple vibrational HF levels. Seventy-five percent of the multiline power was measured on two selected HF lines using a confocal, unstable cavity with a high-efficiency (97%) intercavity diffraction grating. This measured fraction of the multiline power is consistent with theoretical calculations, which include the effect of rotational nonequilibrium. The two-selected-line HF unstable cavity was not prone to parasitic oscillations. A novel multiple-selected-line integral master oscillator power amplifier (IMOPA) concept was also evaluated. A line-selected inner master oscillator fed an outer amplifier region through a small hole in the concave mirror of a confocal cavity. Line selection on two HF lines was demonstrated with the IMOPA, although the hole diameter had to be made sufficiently large to prevent parasitic oscillations within the amplifier. It was concluded from the experiments and theoretical calculations that, although the IMOPA concept was demonstrated at relatively low power (400 W), parasitics may be a problem at much higher values of the single-pass gain.

  3. Photoelectron studies of autoionizing Rydberg states in HCl

    International Nuclear Information System (INIS)

    White, M.G.; Grover, J.R.

    1985-01-01

    The results of a systematic investigation of electronically autoionizing Rydberg states in HCl are discussed. Vibrationally resolved photoelectron spectroscopy was used to map out the non-radiative decay of vibronic levels of 3psigma → n(/sub d//sup s/)sigma Rydberg states converging to the A 2 Σ + (3psigma) -1 excited ionic state. The observed vibrational distributions of the resulting X 2 PI(1π) -1 ionic state are compared with the results of model calculations of Terwilliger and Smith based on spectral analysis of the absorption spectrum. Overall, the X 2 PI vibrational branching ratios are found to be in only rough qualitative agreement with the calculations and these results are discussed in relation to the approximations involved. 18 refs., 4 figs., 1 tab

  4. Impacts of post-metallization annealing on the memory performance of Ti/HfO2-based resistive memory

    International Nuclear Information System (INIS)

    Chen, Pang-Shiu; Chen, Yu-Sheng; Lee, Heng-Yuan

    2013-01-01

    Impacts of post-metallization annealing (PMA) on bipolar resistance switching of Ti/HfO x stacked films were investigated. A Ti capping film as a scavenging layer with assistance of PMA is used to tune the dielectric strength of the 10-nm-thick HfO x layer. The polycrystalline microstructure of 10-nm-thick HfO x seems immune to the temperature of PMA in this work. The initial resistance and forming voltage in the Ti/HfO x devices mitigate as the increment of the annealing temperature. With enough annealing temperature (>450 °C), the device shows a good on/off ratio, high temperature operation ability and robust endurance (>10 6 cycles). Through the reaction between Ti and HfO x at 500 °C, the abundant oxygen ions are depleted from the insulator and the left charge-defects building conductive percolative paths in the dielectric layer. The operation-polarity independence of the form-free HfO x device in initial state is demonstrated. The forming-free memory with initial low resistance of 800 Ω at 0.1 V can be operated with stable bipolar resistance switching via initially positive or negative voltage sweep. The formless device with 10 nm thick HfO x also exhibits excellent nonvolatile memory performances, including enough on/off ratio, improved HRS uniformity and good high temperature retention (3 × 10 4 s at 200 °C). The results of this work suggest that the PMA temperature will affect the memory window and cycling reliability of the Ti/HfO x -based resistive memory. Optimum temperature (450 °C) will improve the memory performance of the Ti/HfO x stacked layer. (paper)

  5. High-aspect-ratio HfC nanobelts accompanied by HfC nanowires: Synthesis, characterization and field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Song, E-mail: tiansong22@126.com [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); School of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Hejun, E-mail: lihejun@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072 (China)

    2017-04-30

    Highlights: • HfC naobelts accompanied by HfC nanowires were synthesized by a catalytic CVD method. • HfC nanobelts as a novel structure of HfC ceramic are reported for the first time. • HfC nanobelts have 100–200 μm in lengths and reach up to 10 μm in widths. • The synthesized product is promising field nanoemitters. - Abstract: As a key refractory carbide, hafnium carbide (HfC) is commonly used as structural materials while the field emission (FE) application of HfC in the field of vacuum microelectronics is almost the only one for functional material purposes. Based on its outstanding physical and chemical characteristics, HfC is identified as a potential candidate with satisfactory mechanical properties and long-term and/or high-temperature FE stability for future applications in high-performance field emitters. However, the development of HfC in various FE applications is hindered because it is not facile to fabricate large-scale low-dimensional HfC field nanoemitters. Herein, High-aspect-ratio HfC nanobelts accompanied by HfC nanowires were synthesized on a large scale by a traditional and simple catalytic chemical vapor deposition (CVD) method. Classical vapor–liquid–solid (VLS) theory was employed to explain the growth of the HfC nanowires and nanobelts along axial direction. The thin HfO{sub 2} shell and thin C layer surrounding the nanostructures might give rise to the diameter fluctuation of HfC nanowires and the width increase of HfC nanobelts in lateral direction. Field emission results show that the high-aspect-ratio HfC nanobelts accompanied by the nanowires are promising field nanoemitters, which exhibit excellent field emission properties with a fairly low turn-on field of ∼1.5 V μm{sup −1} and a low current fluctuation less than ∼10%. This suggests that HfC ceramics with high-aspect-ratio nanostructures are ideal cathode material for various field emission applications.

  6. Optimization of $^{178m2}$/Hf isomer production in spallation reactions at projectile energies up to 100 MeV using STAPRE and ALICE code simulations

    CERN Document Server

    Kirischuk, V I; Khomenkov, V P; Strilchuk, N V; Zheltonozhskij, V A

    2004-01-01

    /sup 178m2/Hf isomer production in different spallation reactions with protons, alpha particles and neutrons at projectile energies up to 100 MeV has been analyzed using both STAPRE and ALICE code simulations. The STAPRE code was used to calculate the isomeric ratios, while the ALICE code was used to simulate the excitation functions of the respective ground states. A number of spallation reactions have been compared taking into account not only /sup 178m2 /Hf isomer productivity but also, first, the isomeric ratios calculated by the STAPRE code; second, the accumulation of the most undesirable Hf isotopes and isomers, such as /sup 172/Hf, /sup 175 /Hf, and /sup 179m/Hf; and, third, the production of other admixtures and by-products that could degrade the quality of the produced /sup 178m2/Hf isomer sources, including all stable Hf isotopes as well. Possibilities and ways of optimizing /sup 178m2/Hf isomer production in spallation reactions at projectile energies up to 100 MeV are discussed. This can be consi...

  7. Preformulation studies and characterization of proposed chondroprotective agents: glucosamine HCl and chondroitin sulfate.

    Science.gov (United States)

    Ebube, Nkere K; Mark, William; Hahm, Huijeong

    2002-11-01

    Glucosamine HCl and chondroitin sulfate are proposed chondroprotective agents commonly used as dietary supplements. This study examined the physicochemical and mechanical properties of chondroitin sulfate, glucosamine HCl powder, and glucosamine HCl granulation obtained from various sources. The particle size distributions of the materials were determined using sieve analysis and time-of-flight techniques. Polarized light microscopy was used to examine particle morphology. Powder x-ray diffraction studies, moisture sorption isotherms, deformation behavior, powder flow, and compaction characteristics were also investigated. The polarized light microscopy and x-ray diffraction patterns showed that chondroitin sulfate is amorphous while glucosamine HCl is crystalline. Particle sizes of chondroitin sulfate and glucosamine HCl varied widely, depending on their source or manufacturing technique (e.g., granulation). The studied samples of shark-derived chondroitin sulfate had a small median particle size (4 microns) compared to that derived from bovine cartilage (17 microns). Different moisture sorption profiles were obtained for the glucosamine HCl granulations studied. Glucosamine HCl granulation from Supplier I showed no observable moisture sorption, while the granulation from Supplier II showed an approximately 5% weight gain. Conversely, chondroitin sulfate was extremely hygroscopic and deliquescent. The Carr's indices for glucosamine HCl samples ranged from 12.5 to 31.5; for chondroitin sulfate the values were 25.2 and 53.6. The compression analysis showed that all chondroitin sulfate samples exhibited plastic deformation behavior, with the shark-derived chondroitin sulfate forming superior compacts when compared to the bovine. The dominant mechanism of compression of glucosamine HCl powder was brittle fracture, whereas wet granulated glucosamine HCl exhibited plastic deformation with enhanced mechanical strength. The physicochemical and mechanical characteristics

  8. Deep inelastic neutron scattering from orthorhombic ordered HCl: Short-time proton dynamics and anomalous neutron cross sections

    International Nuclear Information System (INIS)

    Senesi, R.; Colognesi, D.; Pietropaolo, A.; Abdul-Redah, T.

    2005-01-01

    Deep inelastic neutron scattering measurements from orthorhombic ordered HCl are presented and analyzed in order to clarify the problem of an anomalous deficit in the neutron-proton cross section found in previous experiments on various materials. A reliable model for the HCl short-time single-particle dynamics, including atomic vibrational anisotropies and deviations from the impulsive approximation, is set up. The model HCl response function is transformed into simulated time-of-flight spectra, taking carefully into account the effects of instrumental resolution and the filter absorption profile used for neutron energy analysis. Finally, the experimental values of the anomalous reduction factor for the neutron-proton cross section are extracted by comparing simulated and experimental data. Results show a 34% reduction of the H cross section, varying with the scattering angle in a range centered at 53 deg. In addition, the same approximate procedure used in earlier studies is also employed, providing results in reasonable agreement with the more rigorous ones, and confirming the substantial reliability of the past work on this subject

  9. Experimental study of dissociation of HCl from 350 to 500°C and from 500 to 2500 bars: Thermodynamic properties of HCl° (aq)

    Science.gov (United States)

    Tagirov, B. R.; Zotov, A. V.; Akinfiev, N. N.

    1997-10-01

    New values of the dissociation constants of HCl° referring to low density supercritical solutions and near-critical temperatures of water (350-500°C and 500-2500 bars) have been obtained based on comparison of AgCl (s) solubility in NaCl or KCl solutions with Ag (s) solubility in HCl + NaCl or KCl solutions at controlled hydrogen fugacities. During the course of this study the thermodynamic properties of AgCl s- were refined with the aid of the revised HKF equation of state (Tanger and Helgeson, 1988). The dissociation constants of HCl° obtained in the present work are higher than that found from electrical conductance measurements (Frantz and Marshall, 1984) by more than an order of magnitude at pressures of about 500 bars, but the difference becomes smaller as the pressure increases. Both sets of dissociation constants agree well at high pressures where the isothermal compressibility of water is less than about 1.42·10 -4 bar -1. To reliably compare experimental data obtained by different methods, the Redlikh-Kwong equation of state was applied to available literature data as well as to the results of this study. Finally, the standard state thermodynamic properties and HKF parameters for HCl° (aq) were established. These results allow extrapolation of the thermodynamic properties of HCl° (aq) and consequently the HCl dissociation constant up to 700°C and 5000 bars.

  10. A Study of Anomalous Events in CMS-HF PMTs

    CERN Document Server

    Halu, A; Deliomeroglu, M

    2009-01-01

    In the 2004 HF test beam data, signals corresponding to unusually high energies compared to the beam energy were observed and later confirmed in the subsequent test beam study in 2007. These high energy signals most likely result from particles directly hitting the PMTs instead of passing through the fibers to produce Cherenkov radiation, which is the basis of the HF calorimeter. We studied these events using the 2004 HF test beam data confirming the previous results.

  11. Helium implanted AlHf as studied by Ta TDPAC

    Indian Academy of Sciences (India)

    Unknown

    ments beyond 650 K. On comparison of the present results with that reported in CuHf subjected to identical helium implantation, it is inferred that the Hf solute clusters in AlHf bind less ... the 133–482 keV γ –γ cascade of 181Ta was measured by a three-detector twin fast-slow coincidence setup using. NaI(Tl) detectors.

  12. Sugarbeet ( Beta vulgaris L.) seed pre-treatment with water and HCl ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the effects of pre-sowing seed treated by soaking in distilled water and two concentrates of hydrochloric Acid (0.03 N HCl and 0.3 N HCl) at three different time ( 2, 4 and 6 h) by factorial arrangement based on completely randomized design with three replications in the University of ...

  13. From items to syndromes in the Hypomania Checklist (HCL-32): Psychometric validation and clinical validity analysis

    DEFF Research Database (Denmark)

    Bech, P; Christensen, E M; Vinberg, M

    2011-01-01

    BACKGROUND: The Hypomania Checklist (HCL-32) was developed to identify subthreshold bipolarity in patients with major depression. An HCL-32 version with fewer items has been suggested. METHODS: Principal component analysis (PCA) without rotation was used to identify active/elevated mood versus ri...

  14. Anticoccidial activity of hydrochloric acid (HCl against Eimeria tenella in broiler chickens

    Directory of Open Access Journals (Sweden)

    Rao Z Abbas

    2011-05-01

    Full Text Available The present study was planned to evaluate the anticoccidial activity of the different concentrations of the HCl against Eimeria tenella infection in broiler chickens in comparison with the amprolium anticoccidial. For this purpose, a total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations of HCl (1000ppm, 2000ppm and 3000ppm and amproilum (at the dose rate of 125ppm were given to the experimental groups in drinking water from 10 to 19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. At the 12th day of age, all the groups were inoculated orally with 75,000 sporulated oocysts except non infected non medicated control. Anticoccidial activity was evaluated on the basis of performance (weight gain, feed conversion ratio and pathogenic (oocyst score, lesion score and mortality %age parameters. Among HCl medicated groups, the maximum anticoccidial effect was seen in the group medicated with 1000ppm HCl followed by 2000ppm and 3000ppm HCl medicated groups. Amprolium and 1000ppm HCl were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella challenge. In summary, the lower doses of HCl have the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. It is therefore suggested that further studies should be carried out to determine the possible minimum safe levels of HCl with least toxic effects to be used as anticoccidial.

  15. PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKAN MIXER SETTLER

    Directory of Open Access Journals (Sweden)

    Dwi Biyantoro

    2017-01-01

    Full Text Available ABSTRAK PEMISAHAN Zr – Hf SECARA SINAMBUNG MENGGUNAKANMIXER SETTLER. Telah dilakukan pemisahanZr – Hf secara sinambung menggunakan pengaduk pengenap (mixer settler 16 stage. Larutan umpan adalah zirkon nitrat dengan kadar Zr = 30786 ppm dan Hf = 499 ppm. Ekstraktan dipakai adalah solven 60 % TBP dalam kerosen dan larutan scrubbingyang dipakai adalah asam nitrat 1 M. Umpan masuk pada stageke 5 dikontakkan secara berlawanan arah dengan solven masuk pada stage ke 16 dan larutan scrubbing masuk pada stage ke 1. Tujuan penelitian ini adalah memisahkan unsur Zr dan Hf dari hasil olah pasir zirkon menggunakan solven TBP dengan alat mixer settler16 stage. Analisis umpan dan hasil proses pemisahan untuk zirkonium (Zr dilakukan dengan menggunakan alat pendar sinar-X, sedangkananalisis unsur hafnium (Hf menggunakan Analisis Pengaktifan Neutron (APN. Parameter penelitian dilakukan dengan variasi keasaman asam nitrat dalam umpan dan variasi waktu pada berbagai laju pengadukan. Hasil penelitian pemisahan unsur Zr dengan Hf diperolehkondisi optimum pada keasaman umpan 4 N HNO3, keseimbangan dicapai setelah 3jam dan laju pengadukan 3300 rpm. Hasil ekstrak  unsur zirkon (Zr diperoleh kadar sebesar 28577 ppm dengan efisiensi 92,76 % serta kadar pengotor hafnium (Hf sebesar 95 ppm. Kata Kunci: pemisahan Zr, Hf, ekstraksi, mixer settler, alat pendar sinar-X, APN. ABSTRACT SEPARATION of Zr - Hf CONTINUOUSLY USE THE MIXER SETTLER. Separation of Zr - Hf continuously using mixer settler 16 stage has been done. The feed solution is zircon nitrate concentration of Zr = 30786 ppm  and Hf = 499 ppm. As the solvent used extractant 60 % TBP in 40 % kerosene. Nitric acid solution used srubbing 1 M. The feed entered into stage to 5 is contacted with solvents direction on the stage to 16 and the scrubbing solution enter the stage to 1. The purpose of this study is to separate Zr and Hf of the results from the process of zircon sand using solvent TBP using 16 stage

  16. Microstructural characterization of as-cast hf-b alloys

    Directory of Open Access Journals (Sweden)

    João Carlos Jânio Gigolotti

    2012-04-01

    Full Text Available An accurate knowledge of several metal-boron phase diagrams is important to evaluation of higher order systems such as metal-silicon-boron ternaries. The refinement and reassessment of phase diagram data is a continuous work, thus the reevaluation of metal-boron systems provides the possibility to confirm previous data from an investigation using higher purity materials and better analytical techniques. This work presents results of rigorous microstructural characterization of as-cast hafnium-boron alloys which are significant to assess the liquid composition associated to most of the invariant reactions of this system. Alloys were prepared by arc melting high purity hafnium (minimum 99.8% and boron (minimum 99.5% slices under argon atmosphere in water-cooled copper crucible with non consumable tungsten electrode and titanium getter. The phases were identified by scanning electron microscopy, using back-scattered electron image mode and X-ray diffraction. In general, a good agreement was found between our data and those from the currently accepted Hafnium-Boron phase diagram. The phases identified are αHfSS and B-RhomSS, the intermediate compounds HfB and HfB2 and the liquide L. The reactions are the eutectic L ⇔ αHfSS + HfB and L ⇔ HfB2 + B-Rhom, the peritectic L + HfB2 ⇔ HfB and the congruent formation of HfB2.

  17. A 223-nm KrCl excimer laser on a He-Kr-HCl mixture

    International Nuclear Information System (INIS)

    Razhev, A M; Zhupikov, A A; Kargapol'tsev, E S

    2004-01-01

    The results of experimental studies of the parameters of a 223-nm electric-discharge KrCl excimer laser on a He-Kr-HCl mixture depending on the excitation conditions and the composition of the active gaseous medium are presented. To achieve the maximum values of the output energy and the efficiency of the KrCl laser on mixtures with buffer gaseous helium, an excitation system was used that included a circuit with an LC inverter with a high-voltage switch based on an RU-65 spark gap. An output energy of 320 mJ with an efficiency of 0.5% relative to the energy stored in the capacitors is obtained in a KrCl laser with an active medium based on the buffer He gas at a charging voltage of 30 kV. Radiation pulses with a duration of 22±1 ns and a pulse power of 15 MW are obtained. (lasers)

  18. Options in the HCl Process for the Production of Alumina from Clay

    Science.gov (United States)

    Shanks, D. E.; Thompson, D. C.; Arington, R. M.; Dan, G. L.; Eisele, J. A.

    The Bureau of Mines has conducted in-depth studies on the recovery of aluminum chloride hexa-hydrate and alumina from domestic kaolinitic clay. The original goal of the studies was to provide the technology for alumina production from domestic raw materials. Current research is focused on process modifications that would improve the economics of clay-HCl leaching and improve chances for transfer of the technology to commercial use. Options under investigation include direct leaching of raw clay, changes in leaching acid concentration and stoichi-ometry, decreased leaching duration, improved solid-liquid separations, elimination of solvent extraction for iron removal, and formation of basic aluminum chloride instead of aluminum chloride hexahydrate as an intermediate product. Implementation could decrease energy, equipment, and reagent costs by eliminating the calcination step, substituting filtration for thickening and washing circuits, and combining iron removal with aluminum chloride crystallization.

  19. More evidence for very short-lived substance contribution to stratospheric chlorine inferred from HCl balloon-borne in situ measurements in the tropics

    Directory of Open Access Journals (Sweden)

    Y. Mébarki

    2010-01-01

    Full Text Available Volume mixing ratio (vmr vertical profiles of hydrogen chloride (HCl are retrieved from in situ measurements performed by a balloon-borne infrared tunable diode laser absorption spectrometer (SPIRALE during two balloon flights in the tropics (Teresina, Brazil, 5.1° S–42.9° W in June 2005 and June 2008. HCl vertical profiles obtained from 15 to 31 km are presented and analysed to estimate the contribution of very short-lived substances (VSLS to total stratospheric chlorine. Both retrieved vertical profiles of HCl from these flights agree very well with each other, with estimated overall uncertainties of 6% on vmr between 23 and 31 km. Upper limits of HCl vmr as low as 20 pptv in June 2008 and 30 pptv in June 2005 are inferred in the upper part of the tropical tropopause layer (TTL. Backward trajectory calculations and such low amounts suggest that the air masses sampled correspond to typical background conditions, i.e. neither influenced by recent tropospheric nor stratospheric air. Taking into account the recently reported VSL source gas measurements obtained in similar conditions (Laube et al., 2008 and the main intermediate degradation product gas COCl2 (Fu et al., 2007, a total VSLS contribution of 85±40 pptv to stratospheric chlorine is inferred. This refines the WMO (2007 estimation of 50 to 100 pptv, which was not taking into account any HCl contribution. In addition, comparisons of HCl measurements between SPIRALE and the Aura MLS satellite instrument in the tropical lower and middle stratosphere lead to a very good agreement. The previous agreement between MLS-deduced upper stratospheric total chlorine content and modelled values including 100 pptv of VSLS (Froidevaux et al., 2006 is thus supported by our present result about the VSLS contribution.

  20. lambda-3, Sandia's 100-J HF laser system

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results.

  1. High-temperature x-ray diffraction study of HfTiO4-HfO2 solid solutions

    International Nuclear Information System (INIS)

    Carpenter, D.A.

    1975-01-01

    High-temperature x-ray diffraction techniques were used to determine the axial thermal expansion curves of HfTiO 4 -HfO 2 solid solutions as a function of composition. Data show increasing anisotropy with increasing HfO 2 content. An orthorhombic-to-monoclinic phase transformation was detected near room temperature for compositions near the high HfO 2 end of the orthorhombic phase field and for compositions within the two-phase region (HfTiO 4 solid solution plus HfO 2 solid solution). An orthorhombic-to-cubic phase transformation is indicated by data from oxygen-deficient materials at greater than 1873 0 K. (U.S.)

  2. LIX 860N-IC as an extractant for the extraction of HF(iv) from acidic chloride solutions

    International Nuclear Information System (INIS)

    Kumar, Rajesh J.; Ramachandra Reddy, B.; Varada Reddy, A.

    2004-01-01

    LIX 860N-IC as an extractant for the extraction of tetravalent hafnium from acidic chloride solutions has been investigated. Increase of acid concentration decreases the percentage extraction of metal indicating the ion exchange type mechanism. The plot of log D vs log [extractant], M is linear with slope 1.8 indicating the association of two moles of extractant with the extracted metal species. Plot of log D vs log [H + ] gave a straight line with a negative slope of ∼ 2 indicating the exchange of two moles of hydrogen ions for every mole of Hf(IV). Addition of sodium salts enhanced the percentage extraction of metal and follows the order NaSCN >NaCl >Na 2 SO 4 >NaNO 3 . Stripping of metal from the loaded organic (L.O) with HCl, H 2 SO 4 and extraction behavior of associated metals was studied. (author)

  3. Device Process and Circuit Application Interaction for Harsh Electronics: Hf-In-Zn-O Thin Film Transistors as an Example

    KAUST Repository

    Ho, Chih-Hsiang

    2017-06-27

    The effects of Hf content on the radiation hardness of Hf-In-Zn-O thin-film transistors (HIZO TFTs) and HIZO TFTbased circuits are systemically examined. The evaluated circuits, including current-starved ring oscillator, energy harvesting and RF circuits are essential for space electronic systems. It is shown that HIZO TFTs with low Hf concentration have better initial performance while TFTs with high Hf concentration are more stable against radiation. On the other hand, for circuit application, the stable HIZO TFTs are not necessarily preferred for all circuits. The work demonstrates that understanding the device-circuit interactions is necessary for device optimization and circuit reliability improvements for harsh electronic systems.

  4. Measurements of diurnal concentration variations of gaseous HCl in air in the subnanogram range

    Energy Technology Data Exchange (ETDEWEB)

    Matusca, P.; Schwarz, B.; Baechmann, K.

    1984-01-01

    A method of measuring gaseous HCl based on diffusion samplers has been developed. This sampling method allows a filterless dynamic gas-aerosol separation. After thermal desorption, HCl is converted into 2-chlorocyclohexanol by gas-phase reaction with 7-oxabicyclo(4.1.0)heptane. The derivatization product is analyzed by GC-separation using an electrolytic conductivity detector (HECD). The minimum concentration detectable is: 40 pptv HCl. Several results of measurements of gaseous HCl in air are reported. Gaseous HCl is present in concentrations between about 0.1 and 1.4 ng l/sup -1/ at STP in rural areas and 0.2 and 3.0 ng l/sup -1/ at STP in urban areas. Diurnal and spatial variations and the influence of climate were measured and are discussed.

  5. Measurements of diurnal concentration variations of gaseous HCl in air in the sub-nanogram range

    Science.gov (United States)

    Matusca, P.; Schwarz, B.; Bächmann, K.

    A method of measuring gaseous HCl based on diffusion samplers has been developed. This sampling method allows a filterless dynamic gas-aerosol separation. After thermal desorption, HCl is converted into 2-chlorocyclohexanol by gas-phase reaction with 7-oxabicyclo(4.1.0)heptane. The derivatization product is analysed by GC-separation using an electrolytic conductivity detector (HECD). The minimum concentration detectable is: 40 pptv HCl. Several results of measurements of gaseous HCl in air are reported. Gaseous HCl is present in concentrations between about 0.1 and 1.4 ngℓ -1 at STP in rural areas and 0.2 and 3.0 ng ℓ -1 at STP in urban areas. Diurnal and spatial variations and the influence of climate were measured and are discussed.

  6. First-principles study of the Hf-based Heusler alloys: Hf2CoGa and Hf2CoIn

    International Nuclear Information System (INIS)

    Hu, Yan; Zhang, Jian-Min

    2017-01-01

    The electronic structures and magnetic properties of the new Heusler alloys Hf 2 CoGa and Hf 2 CoIn have been studied by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation (GGA). Both Hf 2 CoGa and Hf 2 CoIn Heusler alloys have the half-metallic character and completely (100%) spin polarization at the Fermi level (E F ) and the indirect band gaps of 0.733 eV and 0.654 eV, respectively, in the minority spin channel. The total magnetic moments µ t are all 2µ B per formula unit, linearly scaled with the total number of valence electrons (Z t ) by µ t =Z t −18 and the atomic magnetic moments have localized character due to less affected by deformations. The origin of the indirect band gaps for these two new Heusler alloys is well understood. These two new Heusler alloys are the ideal candidates for spintronic devices. - Graphical abstract: The distribution of the magnetic charge density of the Hf 2 CoGa at equilibrium lattice constant. - Highlights: • The Hf 2 CoGa and Hf 2 CoIn are HM ferromagnets with large half-metallic gaps. • The indirect band gaps of Hf 2 CoGa and Hf 2 CoIn are located in minority spin channel. • The total magnetic moments of these two alloys obey the Slater–Pauling rule. • The atomic magnetic moments have the localized characters.

  7. Probing of medium-scale traveling ionospheric disturbances using HF-induced scatter targets

    Directory of Open Access Journals (Sweden)

    N. F. Blagoveshchenskaya

    2006-09-01

    Full Text Available Experimental results from the Tromsø and Sura heating experiments at high and mid-latitudes are examined. It is shown that the combination of HF-induced target and bi-static HF Doppler radio scatter observations is a profitable method for probing medium-scale traveling ionospheric disturbances (TIDs at high and mid-latitudes. HF ionospheric modification experiments provide a way of producing the HF-induced scatter target in a controlled manner at altitudes where the sensitivity to TIDs is highest. Bi-static HF Doppler radio scatter observations were carried out on the London-Tromsø-St. Petersburg path in the course of a Tromsø heating experiment on 16 November 2004 when the pump wave was reflected from an auroral Es-layer. During Sura heating experiments on 19 and 20 August 2004, when the HF pump wave was reflected from the F2 ionospheric layer, multi-position bi-static HF Doppler radio scatter observations were simultaneously performed at three reception points including St. Petersburg, Kharkov, and Rostov-on-Don. Ray tracing and Doppler shift simulations were made for all experiments. A computational technique has been developed allowing the reconstruction of the TID phase velocities from multi-position bi-static HF Doppler scatters. Parameters of medium-scale TIDs were found. In all experiments they were observed in the evening and pre-midnight hours. TIDs in the auroral E-region with periods of about 23 min were traveling southward at speeds of 210 m/s. TIDs in the mid-latitudinal F-region with periods from 20 to 45 min travelled at speeds between 40 and 150 m/s. During quiet magnetic conditions the waves were traveling in the north-east direction. In disturbed conditions the waves were moving in the south-west direction with higher speeds as compared with quiet conditions. Possible sources for the atmospheric gravity waves at middle and high latitudes are discussed.

  8. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path du...

  9. Study of {sup 179}Hf{sup m2} excitation

    Energy Technology Data Exchange (ETDEWEB)

    Vishnevsky, I. N.; Zheltonozhsky, V. A., E-mail: zhelton@kinr.kiev.ua; Savrasov, A. N. [National Academy of Sciences of Ukraine, Institute for Nuclear Research (Ukraine); Mazur, V. M. [National Academy of Sciences of Ukraine, Institute of Electronic Physics (Ukraine)

    2016-12-15

    Isomeric ratios of {sup 179}Hf{sup m2,g} yields in the (γ, n) reaction and the cross section for the {sup 179}Hf{sup m2} population in the (α, p) reaction are measured for the first time at the end-point energies of 15.1 and 17.5 MeV for bremsstrahlung photons and 26 MeV for alpha particles. The results are σ = (1.1 ± 0.11) × 10{sup −27} cm{sup 2} for the {sup 176}Lu(α, p){sup 179}Hf{sup m2} reaction and Y{sub m2}/Y{sub g} = (6.1 ± 0.3) × 10{sup −6} and (3.7 ± 0.2) × 10{sup −6} for the {sup 180}Hf(γ, n){sup 179}Hf{sup m22} reaction at E{sub ep} =15.1 and 17.5 MeV, respectively. The experimental data on the relative {sup 179}Hf{sup m2} yield indicate a single-humped shape of the excitation function for the {sup 180}Hf(γ, n){sup 179}Hf{sup m2} reaction. Simulation is performed using the TALYS-1.4 and EMPIRE-3.2 codes.

  10. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path...

  11. The Performance and Fouling Control of Submerged Hollow Fiber (HF Systems: A Review

    Directory of Open Access Journals (Sweden)

    Ebrahim Akhondi

    2017-07-01

    Full Text Available The submerged membrane filtration concept is well-established for low-pressure microfiltration (MF and ultrafiltration (UF applications in the water industry, and has become a mainstream technology for surface-water treatment, pretreatment prior to reverse osmosis (RO, and membrane bioreactors (MBRs. Compared to submerged flat sheet (FS membranes, submerged hollow fiber (HF membranes are more common due to their advantages of higher packing density, the ability to induce movement by mechanisms such as bubbling, and the feasibility of backwashing. In view of the importance of submerged HF processes, this review aims to provide a comprehensive landscape of the current state-of-the-art systems, to serve as a guide for further improvements in submerged HF membranes and their applications. The topics covered include recent developments in submerged hollow fiber membrane systems, the challenges and developments in fouling-control methods, and treatment protocols for membrane permeability recovery. The highlighted research opportunities include optimizing the various means to manipulate the hydrodynamics for fouling mitigation, developing online monitoring devices, and extending the submerged HF concept beyond filtration.

  12. The Influence of the multilayer ZnO-HfO x structure on the characteristics of a light-emitting device

    Science.gov (United States)

    Liu, Lingguang; Zhang, Xiaoning; Yu, Bojiang; Lin, Yuanyuan; Zhang, He

    2017-05-01

    A MOS structure device with a ZnO-HfO x layer was fabricated on a p-type silicon substrate. Current (i.e., conductive) paths formed after the breakdown of the dielectric layer under a voltage and thermal-induced emission of broadband light, including visible and near-IR wavelengths. To investigate the influence of the ZnO-HfO x layer on a device’s light-emitting characteristics, we prepared devices with one, two and three layers of ZnO-HfO x thin film on a p-type silicon substrate. We then measured the light emission, the emission spectrum, the I-V curves and the microstructure. The results show that the range and peak wavelength of the emission spectra from devices with different numbers of ZnO-HfO x layers are the same. Under the condition of a fixed total thickness of HfO x , luminous intensity increases with increasing number of ZnO-HfO x layers. Multilayer ZnO-HfO x can cause the ZnO grains to diffuse more into the HfO x layer, which is beneficial for the formation of current paths and increases the luminous intensity.

  13. Amount and composition of gases in the HF process

    Energy Technology Data Exchange (ETDEWEB)

    Welz, H.

    1944-04-04

    Gases arising from production of 50%-aromatics gasoline in an HF kiln installation are considered. Results from a naphthenic starting material are compared to those from a paraffinic starting material, with both starting materials being raw gasoline distilled to 165/sup 0/C. The figures gave 19 to 21% by weight for naphthenic versus 23 to 25% for paraffinnic materials. The author's superior, Dr. Kaufmann, made a marginal note that those figures were quite high under consideration of the fact that the yield of HF gasoline and gases would be only 71.5% versus 75.5% after losses to coking and redistillation residues. Figures are also included for the composition of the gases. Relative to the total amount of gas, the composition was given as 6 to 7% hydrogen, 14 to 20% methane, 24 to 32% ethane, 25 to 33% propane, 5 to 8% iso-butane, and 11.5 to 15.5% normal butane. Relative to the hydrocarbon content only, the composition was given as 15 to 21% methane, 25.5 to 34% ethane, 26.5 to 35% propane, 5.5 to 8.5% iso-butane, and 12.5 to 16.5% normal butane. The olefin content of the gases was less than 2%. Another marginal note gave compositions separated into naphthenic versus paraffinic materials, respectively, again relative to hydrocarbons only. These figures were 18.5 vs 18.2% methane, 28.4 vs. 29.6% ethane, 29.4 vs. 31.0% propane, 7.6 vs. 6.9% iso-butane, and 16.3 vs. 14.4% normal butane. Yields were given as 82 vs. 79.5% for this set of figures.

  14. QAPP for Analysis of Data Received from Nine Hydraulic Fracturing (HF) Service Companies

    Science.gov (United States)

    This QAPP provides information concerning the Water Acquisition, Chemical Mixing, Well Injection, and Flowback and Produced Water stages of the HF water cycle as found in Figure 1 of the HF QMP and as described in HF Study Plan.

  15. Tribological and wear behavior of HfN/VN nanomultilayer coated cutting tools

    Directory of Open Access Journals (Sweden)

    Willian Aperador Chaparro

    2014-01-01

    Full Text Available Wear and tribological behavior of [HfN/VN]n multinanolayers deposited via magnetron sputtering has been exhaustively studied in this work. Enhancement of both hardness and elastic modulus up to 37 GPa and 351 GPa, respectively, was observed as bilayer periods in the coatings were decreased. The sample with a bilayer period (Λ of 15 nm and bilayer number n = 80, showed the lowest friction coefficient (∼0.15 and the highest critical load (72 N, corresponding to 2.2 and 1.38 times better than those values for the coating deposited with n = 1, respectively. Taking into account the latest results of tungsten carbide (WC inserts were used as substrates to improve the mechanical and tribological properties of [HfN/VN]n coatings as a function of increased interface number and to manage higher efficiency of these coatings in different industrial applications, like machining and extrusion. Their physical, mechanical, and tribological characteristics were investigated, including cutting tests with AISI 1020 steel (workpiece to assess wear as a function of the bilayer number and bilayer period. A comparison of the tribological properties revealed a decrease of flank wear (approximately 24% for WC inserts coated with [HfN/VN]80 (Λ =15 nm, when compared to uncoated tungsten carbide inserts. These results demonstrate the possibility of using [HfN/VN] multilayers as new coatings for tool machining with excellent industrial performance.

  16. E-region decameter-scale plasma waves observed by the dual TIGER HF radars

    Directory of Open Access Journals (Sweden)

    B. A. Carter

    2009-01-01

    Full Text Available The dual Tasman International Geospace Environment Radar (TIGER HF radars regularly observe E-region echoes at sub-auroral magnetic latitudes 58°–60° S including during geomagnetic storms. We present a statistical analysis of E-region backscatter observed in a period of ~2 years (late 2004–2006 by the TIGER Bruny Island and Unwin HF radars, with particular emphasis on storm-time backscatter. It is found that the HF echoes normally form a 300-km-wide band at ranges 225–540 km. In the evening sector during geomagnetic storms, however, the HF echoes form a curved band joining to the F-region band at ~700 km. The curved band lies close to the locations where the geometric aspect angle is zero, implying little to no refraction during geomagnetic storms, which is an opposite result to what has been reported in the past. The echo occurrence, Doppler velocity, and spectral width of the HF echoes are examined in order to determine whether new HF echo types are observed at sub-auroral latitudes, particularly during geomagnetic storms. The datasets of both TIGER radars are found to be dominated by low-velocity echoes. A separate population of storm-time echoes is also identified within the datasets of both radars with most of these echoes showing similar characteristics to the low-velocity echo population. The storm-time backscatter observed by the Bruny Island radar, on the other hand, includes near-range echoes (r<405 km that exhibit some characteristics of what has been previously termed the High Aspect angle Irregularity Region (HAIR echoes. We show that these echoes appear to be a storm-time phenomenon and further investigate this population by comparing their Doppler velocity with the simultaneously measured F- and E-region irregularity velocities. It is suggested that the HAIR-like echoes are observed only by HF radars with relatively poor geometric aspect angles when electron density is low and when the electric field is particularly

  17. Emblica Officinalis (Indian Gooseberry Leaves Extract as Corrosion Inhibitor for Mild Steel in 1N HCl Medium

    Directory of Open Access Journals (Sweden)

    R. Saratha

    2010-01-01

    Full Text Available Corrosion inhibition efficiency of acid extract of dry Emblica officinalis leaves for mild steel in 1N HCl medium is investigated in the present study. Experimental methods include weight loss, potentiodynamic polarization and impedance studies. The results indicate Emblica officinalis leaves to be a good corrosion inhibitor of a mixed type and having efficiency of 87.9% at 2% v/v inhibitor concentration. Corrosion inhibition may be due to the spontaneous physical adsorption of the plant constituents on the mild steel surface. Experimental data fitted the Langmuir, Temkin, Freundlich and Flory-Huggins adsorption isotherms.

  18. Adaptive servoventilation in clinical practice: beyond SERVE-HF?

    Directory of Open Access Journals (Sweden)

    Winfried Randerath

    2017-10-01

    Full Text Available Adaptive servoventilation (ASV has proven effective at suppressing breathing disturbances during sleep, improving quality of life and cardiac surrogate parameters. Since the publication of the SERVE-HF-trial, ASV became restricted. The purpose of this study was to evaluate the clinical relevance of the SERVE-HF inclusion criteria in real life and estimate the portion of patients with these criteria with or without risk factors who are undergoing ASV treatment. We performed a retrospective study of all patients who were treated with ASV in a university-affiliated sleep laboratory. We reviewed the history of cardiovascular diseases, echocardiographic measurements of left ventricular ejection fraction (LVEF and polysomnography. From 1998 to 2015, 293 patients received ASV, of which 255 (87.0% had cardiovascular diseases and 118 (40.3% had HF. Among those with HF, the LVEF was ≤45% in 47 patients (16.0%. Only 12 patients (4.1% had LVEF <30%. The SERVE-HF inclusion criteria were present in 28 (9.6% ASV recipients. Of these patients, 3 died within 30–58 months of therapy, all with systolic HF and a LVEF <30%. In this study, only a small minority of ASV patients fell in the risk group. The number of fatalities did not exceed the expected mortality in optimally treated systolic HF patients.

  19. MLS/Aura L2 Hydrogen Chloride (HCl) Mixing Ratio V002

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HCL is the EOS Aura Microwave Limb Sounder (MLS) standard product for hydrogen chloride derived from radiances measured primarily by the 640 GHz radiometer. The...

  20. Magnetized solutions altered the absorbance of tramadol hcl: uv-spectrophotometer study.

    Science.gov (United States)

    Al-Nimer, Marwan S M; Neda, Fezaa Sh; Lateef, Zainab W Abdul

    2010-03-01

    Magnetized water showed alterations in the electrolyte potential and vibration modes. This study aimed to investigate the effect of magnetic water and physiological solutions on the UV-spectra of tramadol HCl. Distilled water as well as full strength or diluted physiological solutions are magnetized by magnetic disc. Then tramadol HCl was dissolved in each magnetic and in non-magnetic solution to obtain the following final concentrations: 0, 25, 50, 100, and 200μg/mL. The pH of each solution and the absorbance (O.D.) was recorded at wavelength 271 nm. Magnetized water or physiological solutions showed alterations in pH as well as in the absorbance (O.D.) of tramadol HCl detected by ultraviolet spectra at λ271 nm. It concludes that magnetized physiological solutions adversely altered the stability of tramadol HCl.

  1. The extraction of uranyl nitrate and chloride in octaethyltetraamidopyrophosphate (OETAPP)-HCl, HNO3 systems

    International Nuclear Information System (INIS)

    Jankowska, M.; Kulawik, J.; Mikulski, J.

    1975-01-01

    The extraction of uranium was studied in the system of 0.1 M OETAPP in CHCl 3 /HCl or HNO 3 . The distribution coefficients of HCl and HNO 3 were calculated as a function of OETAPP concentration. The amount of OETAPP in the aqueous phase containing HCl and HNO 3 was found from the measurements of surface tension of this phase. The distribution of HCl or HNO 3 between the organic and aqueous phases was studied as a function of the concentration of the acid used in the aqueous phase. The solvation energy of the extracted complexes was calculated from the measured potential differences. Cohesion and adhesion energies of the studied systems are also given. (author)

  2. Chlorine in dense interstellar clouds - The abundance of HCl in OMC-1

    Science.gov (United States)

    Blake, G. A.; Keene, J.; Phillips, T. G.

    1985-01-01

    The first detection of a chlorine-bearing molecular species in the interstellar medium via emission from the J = 1-0 transition of HCl at 625.9 GHz toward OMC-1 is reported. The relative strengths, widths, and velocities of the resolved hyperfine components are consistent with moderate optical depth emission originating from dense, quiescent molecular cloud material. The overall emission strength implies a fractional abundance of f(HCl/H2) of about (0.5-5.0) x 10 to the -8th, depending on the density of the emitting region. This is approximately an order of magnitude below previous theoretical estimates and a factor of 3-30 below the cosmic abundance of Cl. Recent laboratory work suggests that the lowered fractional abundance of HCl is caused by a combination of depletion onto grains with gas-phase loss processes such as the reaction of HCl with C(+).

  3. MLS/Aura L2 Hydrogen Chloride (HCl) Mixing Ratio V003

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HCL is the EOS Aura Microwave Limb Sounder (MLS) standard product for hydrogen chloride derived from radiances measured primarily by the 640 GHz radiometer. The...

  4. MLS/Aura Level 2 Hydrogen Chloride (HCl) Mixing Ratio V004

    Data.gov (United States)

    National Aeronautics and Space Administration — ML2HCL is the EOS Aura Microwave Limb Sounder (MLS) standard product for hydrogen chloride derived from radiances measured primarily by the 640 GHz radiometer. The...

  5. Measurements of diurnal concentration variations of gaseous HCl in air in the sub-nanogram range

    Energy Technology Data Exchange (ETDEWEB)

    Matusca, P.; Schwarz, B.; Baechmann, K.

    1984-01-01

    A diffusion sampling method, which allows a filterless dynamic gas-aerosol separation of HCl, has been developed. By gas-phase reaction with 7-oxabicyclo(4.1.0)heptane, HCl is converted into 2-chlorocyclohexanol and through the use of an electrolytic conductivity detector, the product is analyzed by GC-separation. A minimum HCl concentration of 40 pptv has been detected, and the gas has been found in rural areas at concentrations ranging between approximately 0.1 and 1.4 ng/l at STP, and in urban areas at concentrations of approximately 0.2 and 3.0 ng/l at STP. Consideration is also given to diurnal and spatial variations, and climate influence. The center of Darmstadt, a forest in the southeast of Darmstadt, and the Rhein-Main-Airport area of Frankfurt are the three areas where HCl measurements were made. 13 references.

  6. Critical Questions about PARADIGM-HF and the Future.

    Science.gov (United States)

    Chen, Chen-Huan

    2016-07-01

    Cardiovascular (CV) diseases in general and heart failure (HF) in particular are major contributors to death and morbidity and are also recognized as important drivers of health care expenditure. The PARADIGM-HF trial was a pivotal trial designed to compare the long-term effects of LCZ696 with enalapril in patients with symptomatic HF with reduced ejection fraction (HFrEF). This review article presents an in-depth view of the PARADIGM-HF trial and the implications of the results in the management of patients with HF and is based on peer reviewed manuscripts, editorials, perspectives and opinions written about the PARADIGM-HF trial. The article presents the key safety and efficacy results of the trial with specific emphasis on the clinical implications of these findings. The review highlights the highly statistically significant, 20% reduction in the primary composite endpoint of cardiovascular death or HF hospitalization, and a 16% reduction in the risk of death from any cause. It also provides an overview of the design, clinical findings, limitations and special areas of clinical interest. The review discusses the future of LCZ696 and additional trials that seek to answer questions in other sub-populations of patients with HF. The article reiterates what has been concluded by many experts in the field of HF- the introduction of LCZ696 into routine clinical care, while dependent on the regulatory approvals in various countries as well as acceptance by physicians, payers and patients, will change the treatment landscape for patients with HFrEF.

  7. Heavy metal pollution in topsoils near a cement plant: the role of organic matter and distance to the source to predict total and hcl-extracted heavy metal concentrations.

    Science.gov (United States)

    Bermudez, Gonzalo M A; Moreno, Mónica; Invernizzi, Rodrigo; Plá, Rita; Pignata, María Luisa

    2010-01-01

    Heavy metal and trace element concentrations were examined in topsoils to evaluate a cement plant and an industrial waste incinerator as pollution sources. As, Ba, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb and Zn were measured by Neutron Activation Analysis (NAA), and Co, Cu, Fe, Ni, Pb and Zn by a 0.5M-hydrochloric extraction technique using an Atomic Absorption Spectrophotometer (AAS). The Cr total concentration and HCl-extracted Co and Mn were possibly related to wind transportation from an industrial area in the north of Córdoba city (Argentina). Cu, Pb and Zn in partial HCl extraction were influenced by the cement plant and the industrial area in the north of Córdoba city. The mean total Ba concentration was above the residential and agricultural land use limits stated in national and international legislation and was related to the distance to the cement plant. The concentrations of HCl-extracted heavy metals could be predicted by the organic matter percentage and the distance to the cement plant (with R(2) values of 0.50-0.74). The Ca total concentration was seen to have little influence whereas the organic matter percentage strongly affected HCl-extracted heavy metals according to the correlation analysis and multiple regression models. According to soil quality guidelines for environmental health, the human and wildlife populations in Yocsina might be experiencing toxic Ba and Cr effects. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. The (178m2) Hf Controversy

    CERN Document Server

    Becker, J A; Schiffer, J P; Wilhelmy, J

    2003-01-01

    Since its discovery in the 1960's the sup 1 sup 7 sup 8 sup m sup 2 Hf isomer has garnered high attention from both the basic and applied communities in nuclear science. It's combination of high spin (16+), long half life (31 yrs), and high excitation energy (2.446 MeV) offer unique possibilities as an energy storage medium. Interest in the isomer was rekindled beginning in 1999 when a series of publications began to appear from a group (referred to here as the ''Texas collaboration'') primarily based at the University of Texas, Dallas [1]. They reported observations that some of the stored energy could be released (''triggered'') when the isomer was exposed to a fluence of photons in the energy range approx 10 to approx 60 keV. The implications of this observation are profound. Even though the claimed cross section for the process was approx 7 orders of magnitude greater than would be predicted from the known systematics of photon absorption by nuclei in this mass range [2], such a highly efficient method fo...

  9. The study of water + HCl + ethanol vapor-liquid equilibrium at 78 kPa

    International Nuclear Information System (INIS)

    Ojeda Toro, Juan Carlos; Dobrosz-Gómez, Izabela; Gómez García, Miguel Ángel

    2017-01-01

    Graphical abstract: Comparison between experimental and calculated saturation temperature of water + HCl + ethanol system using two rigorous electrolyte models. - Highlights: • Data for the water + HCl + ethanol VLE is reported at 78 kPa. • The VLE for the system water + HCl + ethanol was determined. • A new set of parameters for extended UNIQUAC model were correlated. • A new set of parameters for LIQUAC model were correlated. - Abstract: In this work, the isobaric vapor-liquid equilibrium (VLE) data obtained for the ternary system water + HCl + ethanol at 78 kPa, using an Ellis still, were studied. Two rigorous electrolyte models (extended UNIQUAC and LIQUAC) were fitted to the experimental data. Ethanol-H + , water-H + , ethanol-Cl − , water-Cl − , and Cl − -H + interaction parameters were determined. Likewise, Henry’s law constants for the volatile electrolyte were defined. A high goodness of fit was obtained for both electrolyte models; however, the extended UNIQUAC one showed better performance (AAD = 0.1326%). Two azeotropes observed in the system were accurately predicted (ethanol + water: x EtOH = 0.86 at 344.6 K; and HCl + water: x HCl = 0.11 at 375.5 K).

  10. Effect of HCl on the Formation of TiO2 Nanocrystallites

    Directory of Open Access Journals (Sweden)

    Nguyen Trong Tung

    2016-01-01

    Full Text Available TiO2 nanocrystals are prepared by pyrolysis of titanium tetrachloride (TiCl4 as precursor in HCl aqueous solution at 80°C. The experimental results show that the HCl concentrations in the synthesizing medium and the following aging are the essential factors affecting the phase formation and phase composition of the resulting TiO2 nanocrystals. The TiO2 suspended in the HCl media is predominant anatase in uniform cluster and the TiO2 deposited in the sedimentation is predominant rutile in the rod-like structure. In the anatase phase, TiO2 crystallites have particle structure of 4–11 nm in mean size depending on the HCl concentration and aging time. In the rutile phase, the mean size of rutile TiO2 is 12-13 nm and there is not much change with HCl environment and aging time. The mean size of TiO2 of around 11-12 nm is considered to be the critical point of phase transition from anatase to rutile in HCl media. Consequence, TiO2 nanocrystallites in pure anatase and rutile phase can be extracted and segregated from the colloidal suspension and the deposited parts in the synthesizing media.

  11. Ion-orbital coupling in Car-Parrinello calculations of hydrogen-bond vibrational dynamics: Case study with the NH3-HCl dimer

    Science.gov (United States)

    Ong, S. W.; Lee, B. X. B.; Kang, H. C.

    2011-09-01

    We have performed Car-Parrinello molecular dynamics (CPMD) calculations of the hydrogen-bonded NH3-HCl dimer. Our main aim is to establish how ionic-orbital coupling in CPMD affects the vibrational dynamics in hydrogen-bonded systems by characterizing the dependence of the calculated vibrational frequencies upon the orbital mass in the adiabatic limit of Car-Parrinello calculations. We use the example of the NH3-HCl dimer because of interest in its vibrational spectrum, in particular the magnitude of the frequency shift of the H-Cl stretch due to the anharmonic interactions when the hydrogen bond is formed. We find that an orbital mass of about 100 a.u. or smaller is required in order for the ion-orbital coupling to be linear in orbital mass, and the results for which can be accurately extrapolated to the adiabatic limit of zero orbital mass. We argue that this is general for hydrogen-bonded systems, suggesting that typical orbital mass values used in CPMD are too high to accurately describe vibrational dynamics in hydrogen-bonded systems. Our results also show that the usual application of a scaling factor to the CPMD frequencies to correct for the effects of orbital mass is not valid. For the dynamics of the dimer, we find that the H-Cl stretch and the N-H-Cl bend are significantly coupled, suggesting that it is important to include the latter degree of freedom in quantum dynamical calculations. Results from our calculations with deuterium-substitution show that both these degrees of freedom have significant anharmonic interactions. Our calculated frequency for the H-Cl stretch using the Becke-exchange Lee-Yang-Parr correlation functional compares reasonably well with a previous second-order Møller-Plesset calculation with anharmonic corrections, although it is low compared to the experimental value for the dimer trapped in a neon-matrix.

  12. Subduction Contributions in the Trans-Mexican Volcanic Belt: Implications from Lava Chemistry and Hf-Nd-Pb Isotopes

    Science.gov (United States)

    Cai, Y.; Goldstein, S. L.; Langmuir, C. H.; Gómez-Tuena, A.; Lagatta, A.; Straub, S. M.; Martín Del Pozzo, A.

    2007-05-01

    Despite thick continental crust, near primitive lavas erupt throughout the Trans-Mexican Volcanic Belt (TMVB). In order to distinguish and better constrain subduction contributions and effects of crustal contamination, we analyzed samples representing subducting sediments from DSDP Site 487, and Quaternary lavas from stratovolcanoes and cinder cones, including alkaline "high-Nb" lavas from the Sierra Chichinautzin Volcanic Field (SCVF) showing negligible subduction signature in its trace element chemistry and representing melts of the mantle wedge. Our primary observations and implications are: (1) The high-Nb SCVF `intraplate' lavas define a linear trend along the "Nd-Hf mantle-crust array", defining the composition of the mantle wedge. (2) Popocatepetl and Nevado de Toluca stratovolcanoes show the highest Nd and Hf isotope ratios, higher than the `intraplate' lavas, indicating their sources are more "depleted mantle-like" than the regional mantle wedge. (3) The Popo and Toluca chemical and isotopic trends sharply contrast with Pico de Orizaba, which shows classic indications of crustal contamination (e.g. high 207Pb/204Pb, low Nd-Hf isotope ratios), consistent with contamination by local Precambrian crust. (4) Higher Nd-Hf isotopes in Popo and Toluca lavas also correlate with lower Pb isotope ratios, and lower Lu/Hf and Zr/Hf. Together, these data indicate contributions from subducted Pacific oceanic crust and hydrothermal sediment. (5) Popo and Toluca are also enriched in Th/LREE compared with `intraplate' lavas, reflecting subducted sediment contributions. (6) Nd-Hf isotope ratios of hydrothermal sediment from DSDP Site 487 lie on the "seawater array", with high Hf isotope ratios compared to the "mantle-crust array". Popo and Toluca Nd-Hf isotopes display a shallower slope than the "intraplate lava Nd-Hf array", reflecting contributions from hydrothermal sediment. Popocatepetl and Toluca lavas therefore avoid substantial crustal contamination of mantle wedge

  13. Solvation behavior and sweetness response of carbohydrates, their derivatives and sugar alcohols in thiamine HCl (vitamin B1) and pyridoxine HCl (vitamin B6) at different temperatures.

    Science.gov (United States)

    Banipal, Parampaul K; Sharma, Mousmee; Banipal, Tarlok S

    2017-12-15

    Volumetric properties are important tools to study the solvation behavior of solutes and reveal valuable information about solute-solute/cosolute interactions. Therefore, standard partial molar volumes at infinite dilution have been calculated from density measurements for monosaccharides, their methoxy and deoxy derivatives, disaccharides and sugar alcohols in (0.05, 0.15, 0.25 and 0.35)molkg -1 thiamine HCl (aq) and pyridoxine HCl (aq) solutions over temperature range (288.15-318.15)K at pressure, p=0.1MPa. The corresponding transfer volumes, expansibilities and apparent massic volumes have been evaluated to examine the solvation behavior and the basic taste quality of studied solutes. UV-Vis absorption study of these solutes has also been carried out in 1.0×10 -4 molkg -1 thiamine HCl and pyridoxine HCl solutions. Results have been compared with our previously reported studies carried out in l-ascorbic acid (vitamin C). Stereochemical effects on hydration controlled by dominant conformations of studied solutes have also been discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. HF Surface Wave Radar Operation in Adverse Conditions

    National Research Council Canada - National Science Library

    Ponsford, Anthony M; Dizaji, Reza M; McKerracher, Richard

    2005-01-01

    ...) system based on HF Surface Wave Radar (HFSWR). the primary objective behind the programme was to demonstrate the capability of HFSWR to continuously detect and track surface targets (ships and icebergs...

  15. Theoretical Assessment of 178m2Hf De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Hartouni, E P; Chen, M; Descalle, M A; Escher, J E; Loshak, A; Navratil, P; Ormand, W E; Pruet, J; Thompson, I J; Wang, T F

    2008-10-06

    This document contains a comprehensive literature review in support of the theoretical assessment of the {sup 178m2}Hf de-excitation, as well as a rigorous description of controlled energy release from an isomeric nuclear state.

  16. Thermodynamic modeling of the Hf-N system

    Directory of Open Access Journals (Sweden)

    Pang M.

    2018-01-01

    Full Text Available Hf-N based alloys have been widely used and studied in the fields of electronic devices and cutting tools industry. A thermodynamic description of this system is essential for further materials development. By means of CALPHAD method, a thermodynamic modeling of the Hf-N system was carried out based on the available phase diagram data as well as thermodynamic property data. The Fcc phase is modeled as (Hf, Va1(N, Va1 to cover the composition range since the solubility of nitrogen in Fcc phase is reported up to about 52 at.%. A set of self-consistent thermodynamic parameters for the Hf-N system has been obtained. The computed phase diagrams and thermodynamic quantities using the present parameters agree well with the experimental data.

  17. HF band filter bank multi-carrier spread spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Laraway, Stephen Andrew; Moradi, Hussein; Farhang-Boroujeny, Behrouz

    2015-10-01

    Abstract—This paper describes modifications to the filter bank multicarrier spread spectrum (FB-MC-SS) system, that was presented in [1] and [2], to enable transmission of this waveform in the HF skywave channel. FB-MC-SS is well suited for the HF channel because it performs well in channels with frequency selective fading and interference. This paper describes new algorithms for packet detection, timing recovery and equalization that are suitable for the HF channel. Also, an algorithm for optimizing the peak to average power ratio (PAPR) of the FBMC- SS waveform is presented. Application of this algorithm results in a waveform with low PAPR. Simulation results using a wide band HF channel model demonstrate the robustness of this system over a wide range of delay and Doppler spreads.

  18. Directional Properties of Surface Waves Observed With HF Radar

    National Research Council Canada - National Science Library

    Wyatt, Lucy

    2003-01-01

    The goal of the work at Sheffield is to demonstrate that wave measurements obtained using HF radars are of sufficient accuracy and availability for them to contribute to the investigation of changes...

  19. Anomalous growth of HfAl3 in thin films

    International Nuclear Information System (INIS)

    Lever, R.F.; Howard, J.K.; Chu, W.K.; Smith, P.J.

    1977-01-01

    Anomalous growth of HfAl 3 is observed on 400degreeC annealing of evaporated thin-film samples consisting of 900 A aluminum, on 1000 A hafnium, 6000 A aluminum and SiO 2 substrates. A continuous layer of HfAl 3 forms at the aluminum--hafnium interface nearer the surface, but not at the deeper interface. The surface HfAl 3 layer then continues to grow, fed by diffusion of underlying aluminum through the intervening hafnium layer. Needlelike precipitates of HfAl 3 are formed along the underlying aluminum grain boundaries. Observations are made by nuclear backscattering, Auger electron spectroscopy, and transmission electron microscopy. Similar behavior is observed in Al--Zr--Al layers

  20. HF fiber stuffing in building 186 at CERN

    CERN Multimedia

    Tiziano Camporesi

    2003-01-01

    Each of the 36 HF wedges comprise ca 12000 quartz fibers which are the active element of the calorimeter. The fibers are produced by Polymicro (USA), cleaved and bundled at KFKI, Budapest, Hungary and inserted at CERN.

  1. Kinetika Hidrolisis Pati Biji Nangka (Artocarpus heterophyllus Menggunakan Katalisator Asam Klorida (HCl

    Directory of Open Access Journals (Sweden)

    Sri Endang

    2014-07-01

    Full Text Available The research of kinetic hydrolysis from the starch of jackfruit seed (Artocarpus heterophyllus used clorid acid catalyst (HCl aims to know the influence of variation of concentration HCl catalyst which give the maximum result of hydrolysis of the starch of jackfruit seed, determining the optimum concentration of HCl catalyst that produces the maximum value of the reaction rate constants, and determine the value of the reaction rate constant of hydrolysis the starch of jackfruit seed using catalyst. The method of this research has done in two stages that are the determination of the optimum catalyst concentration of HCl hydrolysis reaction of the starch of jackfruit seed using various concentration of catalyst HCl 0,5 M; 1,0 M; 1,5 M; 2,0 M and 2,5 M at the optimum temperature and stirring time (90oC during 70 minutes. Hydrolysis followed by neutralization process using sodium hydroxide solution and evaporated to get the form of glucose concentrated, that glucose is analyzed by qualitative and quantitative with Benedict experiment and fenol sulphate acid method, based on maximum degree of glucose which is gotten from the result of hydrolysis the starch of jackfruit seed variation concentration oh HCl is in HCl 1,5 M concentration with degree of glucose (% weight is 7,54% with percentage of starch conversion is 83,21%. Second step is determining the value of hydrolysis constant rate reaction which use time variation (30, 40,50, 60 and 70 minutes in 70 minutes optimum operation condition, 90oC te mperature and concentration catalyst of HCl 1,5 M. Based on statistic calculation date of ANOVA is gained F hitung < F tabel so Ho receive and reject HI  which shows that there is not influence catalyst variation concentration of HCl to the result of hydrolysis the starch of jackfruit seed which is gained. The result of the research shows that hydrolysis of kinetic of the starch of jackfruit seeduse HCl catalyst is reaction of the first apparent orde with

  2. Large Magnetic Anisotropy in HfMnP

    Science.gov (United States)

    Parker, David; Lamichhane, Tej; Taufour, Valentin; Masters, Morgan; Thimmaiah, Srinivasa; Bud'Ko, Ser'gey; Canfield, Paul

    We present a theoretical and experimental study of two little-studied manganese phosphide ferromagnets, HfMnP and ZrMnP, with Curie temperatures above room temperature. We find an anisotropy field in HfMnP approaching 10 T - larger than that of the permanent magnet workhorse NdFeB magnets. From theory we determine the source of this anisotropy. Our results show the potential of 3d-element-based magnetic materials for magnetic applications.

  3. Integrated magnetics design for HF-link power converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper deals with the design of integrated magnetics for HF-link converters, where the integrated magnetic components do not necessarily belong to the same voltage loop. Depending on the specific HF-link converter topology, the proposed integrated magnetics can either alleviate the derivation...... of independent auxiliary supply voltages from the main transformer or integrate other magnetic structures, thus saving board space and cutting costs....

  4. Integrated magnetics design for HF-link power converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper deals with the design of integrated magnetics for HF-link converters, where the two integrated magnetic components on the same core do not necessarily belong to the same voltage loop. Depending on the specific HF-link converter topology, the proposed integrated magnetics can either alleviate the derivation of independent auxiliary supply voltages from the main transformer or integrate other magnetic structures, thus saving board space and cutting costs. (au)

  5. Synthesis of freestanding HfO2 nanostructures

    Directory of Open Access Journals (Sweden)

    Boyle Kayla

    2011-01-01

    Full Text Available Abstract Two new methods for synthesizing nanostructured HfO2 have been developed. The first method entails exposing HfTe2 powders to air. This simple process resulted in the formation of nanometer scale crystallites of HfO2. The second method involved a two-step heating process by which macroscopic, freestanding nanosheets of HfO2 were formed as a byproduct during the synthesis of HfTe2. These highly two-dimensional sheets had side lengths measuring up to several millimeters and were stable enough to be manipulated with tweezers and other instruments. The thickness of the sheets ranged from a few to a few hundred nanometers. The thinnest sheets appeared transparent when viewed in a scanning electron microscope. It was found that the presence of Mn enhanced the formation of HfO2 by exposure to ambient conditions and was necessary for the formation of the large scale nanosheets. These results present new routes to create freestanding nanostructured hafnium dioxide. PACS: 81.07.-b, 61.46.Hk, 68.37.Hk.

  6. Thermoelectric properties of doped BaHfO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Chandra Kr., E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Dr. Shakuntala Misra National Rehabilitation University, Lucknow-229001, U.P India (India); Bhamu, K. C. [Department of Physics, Goa University, Goa-403 206 (India); Sharma, Ramesh, E-mail: ckparadise@gmail.com, E-mail: sharmarameshfgiet@gmail.com [Dept. of Physics, Feroze Gandhi Institute of Engineering & Technology, Raebareli-229001, U.P India (India)

    2016-05-06

    We have studied the structural stability, electronic structure, optical properties and thermoelectric properties of doped BaHfO{sub 3} by full potential linearized augmented plane wave (FP-LAPW) method. The electronic structure of BaHfO{sub 3} doped with Sr shows enhances the indirect band gaps of 3.53 eV, 3.58 eV. The charge density plots show strong ionic bonding in Ba-Hf, and ionic and covalent bonding between Hf and O. Calculations of the optical spectra, viz., the dielectric function, refractive index and extinction coefficient are performed for the energy range are calculated and analyzed. Thermoelectric properties of semi conducting are also reported first time. The doped BaHfO{sub 3} is approximately wide band gap semiconductor with the large p-type Seebeck coefficient. The power factor of BaHfO{sub 3} is increased with Sr doping, decreases because of low electrical resistivity and thermal conductivity.

  7. Sequential sputtered Co-HfO{sub 2} granular films

    Energy Technology Data Exchange (ETDEWEB)

    Chadha, M.; Ng, V.

    2017-03-15

    A systematic study of magnetic, magneto-transport and micro-structural properties of Co-HfO{sub 2} granular films fabricated by sequential sputtering is presented. We demonstrate reduction in ferromagnetic-oxide formation by using HfO{sub 2} as the insulting matrix. Microstructure evaluation of the films showed that the film structure consisted of discrete hcp-Co grains embedded in HfO{sub 2} matrix. Films with varying compositions were prepared and their macroscopic properties were studied. We correlate the variation in these properties to the variation in film microstructure. Our study shows that Co-HfO{sub 2} films with reduced cobalt oxide and varying properties can be prepared using sequential sputtering technique. - Highlights: • Co-HfO{sub 2} granular films were prepared using sequential sputtering. • A reduction in ferromagnetic-oxide formation is observed. • Co-HfO{sub 2} films display superparamagnetism and tunnelling magneto-resistance. • Varying macroscopic properties were achieved by changing film composition. • Applications can be found in moderate MR sensors and high –frequency RF devices.

  8. The isobutylene-isobutane alkylation process in liquid HF revisited.

    Science.gov (United States)

    Esteves, P M; Araújo, C L; Horta, B A C; Alvarez, L J; Zicovich-Wilson, C M; Ramírez-Solís, A

    2005-07-07

    Details on the mechanism of HF catalyzed isobutylene-isobutane alkylation were investigated. On the basis of available experimental data and high-level quantum chemical calculations, a detailed reaction mechanism is proposed taking into account solvation effects of the medium. On the basis of our computational results, we explain why the density of the liquid media and stirring rates are the most important parameters to achieve maximum yield of alkylate, in agreement with experimental findings. The ab initio Car-Parrinello molecular dynamics calculations show that isobutylene is irreversibly protonated in the liquid HF medium at higher densities, leading to the ion pair formation, which is shown to be a minimum on the potential energy surface after optimization using periodic boundary conditions. The HF medium solvates preferentially the fluoride anion, which is found as solvated [FHF](-) or solvated F(-.)(HF)(3). On the other hand, the tert-butyl cation is weakly solvated, where the closest HF molecules appear at a distance of about 2.9 Angstrom with the fluorine termination of an HF chain.

  9. Nickel and platinum in high-temperature H2O + HCl fluids: Implications for hydrothermal mobilization

    Science.gov (United States)

    Scholten, Lea; Watenphul, Anke; Beermann, Oliver; Testemale, Denis; Ames, Doreen; Schmidt, Christian

    2018-03-01

    The dissolution of NiS and NiAs (nickeline) in 0.1 and 1 molal HCl at 400 °C, 80 MPa, and of PtAs2 (sperrylite) and Pt metal in 1 and 6.86 molal HCl at 500 °C, 80 MPa was studied in-situ using synchrotron radiation X-ray fluorescence and absorption spectroscopy. The Pt concentration in the fluid averaged 8 · 10-5 molal (12.8 ppm) during dissolution of Pt metal in 6.86 molal HCl, and was below the minimum detection limit (mdl; 2.6 · 10-5 molal) in all other experiments. Dissolution of NiS was congruent or nearly congruent. Equilibrium was attained rapidly in about 250 min at an initial HCl concentration of 1 molal HCl, and in about 500 min at 0.1 molal HCl. Addition of HCl resulted in a large increase in the Ni solubility from 7.2 · 10-3 molal Ni (423 ppm) at 0.1 molal HCl to 8.72 · 10-2 molal Ni (4959 ppm) at 1 molal HCl. Dissolution of NiAs in 0.1 and 1 molal HCl was incongruent. A steady state was not reached even at a run duration of more than 16 h, and the maximum recorded Ni concentrations in the fluid were much lower than the Ni solubility in the corresponding experiments with NiS at the same HCl molality. Measured K-edge XANES spectra in comparison with literature data indicated that arsenic in the fluid was present as As(V) and that nickel complexed with Cl and H2O as tetrahedral [NiCl2(H2O)2]0 and [NiCl3(H2O)]- and octahedral [NiCl2(H2O)4]0 species. In addition, Raman spectra of H2O + NiCl2 and H2O + NiCl2 + HCl solutions and of H2O + HCl fluids reacted with NiS crystals were acquired at temperatures (T) up to 600 °C and pressures (P) up to 1.15 GPa. All spectra at T ≥ 300 °C and P Based on calculated vibrational frequencies available in the literature, it may stem from the species [NiCl4]2- or [NiCl2(H2O)4]0, although particularly the first assignment is in conflict with the information from published XAS data. The results of this study demonstrate that nickel is readily mobilized by acidic chloridic hydrothermal fluids, but platinum remains

  10. Vibrational relaxation and energy transfer of matrix isolated HCl and DCl

    International Nuclear Information System (INIS)

    Wiesenfeld, J.M.

    1977-12-01

    Vibrational kinetic and spectroscopic studies have been performed on matrix-isolated HCl and DCl between 9 and 20 K. Vibrational relaxation rates for v = 2 and v = 1 were measured by a tunable infrared laser-induced, time-resolved fluorescence technique. In an Ar matrix, vibrational decay times are faster than radiative and it is found that HCl relaxes about 35 times more rapidly than CCl, in spite of the fact that HCl must transfer more energy to the lattice than DCl. This result is explained by postulating that the rate-determining step for vibrational relaxation produces a highly rotationally excited guest in a V yield R step; rotational relaxation into lattice phonons follows rapidly. HCl v = 1, but not v = 2, excitation rapidly diffuses through the sample by a resonant dipole-dipole vibrational energy transfer process. Molecular complexes, and in particular the HCl dimer, relax too rapidly for direct observation, less than or approximately 1 μs, and act as energy sinks in the energy diffusion process. The temperature dependence for all these processes is weak--less than a factor of two between 9 and 20 K. Vibrational relaxation of HCl in N 2 and O 2 matrices is unobservable, presumably due to rapid V yield V transfer to the host. A V yield R binary collision model for relaxation in solids is successful in explaining the HCl(DCl)/Ar results as well as results of other experimenters. The model considers relaxation to be the result of ''collisions'' due to molecular motion in quantized lattice normal modes--gas phase potential parameters can fit the matrix kinetic data

  11. Vibrational relaxation and energy transfer of matrix isolated HCl and DCl

    Energy Technology Data Exchange (ETDEWEB)

    Wiesenfeld, J.M.

    1977-12-01

    Vibrational kinetic and spectroscopic studies have been performed on matrix-isolated HCl and DCl between 9 and 20 K. Vibrational relaxation rates for v = 2 and v = 1 were measured by a tunable infrared laser-induced, time-resolved fluorescence technique. In an Ar matrix, vibrational decay times are faster than radiative and it is found that HCl relaxes about 35 times more rapidly than CCl, in spite of the fact that HCl must transfer more energy to the lattice than DCl. This result is explained by postulating that the rate-determining step for vibrational relaxation produces a highly rotationally excited guest in a V yield R step; rotational relaxation into lattice phonons follows rapidly. HCl v = 1, but not v = 2, excitation rapidly diffuses through the sample by a resonant dipole-dipole vibrational energy transfer process. Molecular complexes, and in particular the HCl dimer, relax too rapidly for direct observation, less than or approximately 1 ..mu..s, and act as energy sinks in the energy diffusion process. The temperature dependence for all these processes is weak--less than a factor of two between 9 and 20 K. Vibrational relaxation of HCl in N/sub 2/ and O/sub 2/ matrices is unobservable, presumably due to rapid V yield V transfer to the host. A V yield R binary collision model for relaxation in solids is successful in explaining the HCl(DCl)/Ar results as well as results of other experimenters. The model considers relaxation to be the result of ''collisions'' due to molecular motion in quantized lattice normal modes--gas phase potential parameters can fit the matrix kinetic data.

  12. Predicting new-onset HF in patients undergoing coronary or peripheral angiography: results from the Catheter Sampled Blood Archive in Cardiovascular Diseases (CASABLANCA) study.

    Science.gov (United States)

    Ibrahim, Nasrien E; Lyass, Asya; Gaggin, Hanna K; Liu, Yuyin; van Kimmenade, Roland R J; Motiwala, Shweta R; Kelly, Noreen P; Gandhi, Parul U; Simon, Mandy L; Belcher, Arianna M; Harisiades, Jamie E; Massaro, Joseph M; D'Agostino, Ralph B; Januzzi, James L

    2018-02-09

    Methods to identify patients at risk for incident HF would be welcome as such patients might benefit from earlier interventions. From a registry of 1251 patients referred for coronary and/or peripheral angiography, we sought to identify independent predictors of incident HF during follow-up and develop a clinical and biomarker strategy to predict this outcome. There were 991 patients free of prevalent HF at baseline. Cox proportional hazard models were developed to predict adjudicated diagnosis of incident HF. Model discrimination and reclassification were evaluated. At follow-up, 177 (18%) developed new-onset HF. Independent predictors of new-onset HF included five clinical variables (age, male sex, heart rate, history of atrial fibrillation/flutter, and history of hypertension) and two biomarkers (amino-terminal pro-B type natriuretic peptide and ST2). The c-statistic for the model without biomarkers was 0.69; including biomarkers increased the c-statistic to 0.76 (P time to incident HF compared with lower quintiles (log-rank P < 0.001). Following 100 bootstrap iterations, internal validation was confirmed with Harrell's c-statistic of 0.77. Use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers at enrollment was associated with substantial attenuation of predictive value of the risk score. Patients undergoing coronary/peripheral angiographic procedures are a population at high risk for incident HF. We describe an accurate clinical and biomarker strategy for predicting incident HF and possibly intervening in such patients (NCT00842868). © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  13. Isothermal cross-sections of Hf-Sc-Ga(800 deg C) and Hf-Ti-Ga (750 deg C) phase diagrams

    International Nuclear Information System (INIS)

    Markiv, V.Ya.; Belyavina, N.N.

    1981-01-01

    Isothermal cross sections of Hf-Sc-Ga (800 deg C) and Hf-Ti-Ga (750 deg C) state diagrams are plotted. The existence of two ternary Hfsub(0.1-0.8)Scsub(0.9)-sub(0.2)Ga and Hfsub(0.8)Scsub(0.2)Gasub(3) phases is stated in the Hf-Sc-Ga system. The crystal structure of these compounds investigated by the powder method belongs to the structural α-MoB and ZrAl 3 types respectively. Continuous rows of (Hf, Sc 5 Ga 5 , (Hf, Ti)Ga 3 and (Hf, Ti)Ga 2 solid solutions are formed in the investigated systems. Essential quantity of the third component dissolve binary Sc 5 Ga 4 , Sc 2 Ga 3 (15 and 30 at % Hf respectively), Hf 5 Ga 4 , HfGa 2 (20, 10 at. % Sc), Hf 5 Ga 4 , HfGa, Hf 5 Ga 3 , Hf 2 Ga 3 (48, 30, 46, 20 at. % Ti) gallides [ru

  14. Relationship between CCR and NT-proBNP in Chinese HF patients, and their correlations with severity of HF.

    Science.gov (United States)

    Lu, Zhigang; Wang, Bo; Wang, Yunliang; Qian, Xueqing; Zheng, Wei; Wei, Meng

    2014-01-01

    To evaluate the relationship between creatinine clearance rate (CCR) and the level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure (HF) patients and their correlations with HF severity. Two hundred and one Chinese patients were grouped according to the New York Heart Association (NYHA) classification as NYHA 1-2 and 3-4 groups and 135 cases out of heart failure patients as control group. The following variables were compared among these three groups: age, sex, body mass index (BMI), smoking status, hypertension, diabetes, NT-proBNP, creatinine (Cr), uric acid (UA), left ventricular end-diastolic diameter (LVEDD), and CCR. The biomarkers of NT-proBNP, Cr, UA, LVEDD, and CCR varied significantly in the three groups, and these variables were positively correlated with the NHYA classification. The levels of NT-proBNP and CCR were closely related to the occurrence of HF and were independent risk factors for HF. At the same time, there was a significant negative correlation between the levels of NT-proBNP and CCR. The area under the receiver operating characteristic curve suggested that the NT-proBNP and CCR have high accuracy for diagnosis of HF and have clinical diagnostic value. NT-proBNP and CCR may be important biomarkers in evaluating the severity of HF.

  15. Investigation of thermal annealing effects on microstructural and optical properties of HfO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Modreanu, M. [Tyndall National Institute, Cork (Ireland)]. E-mail: mircea.modreanu@tyndall.ie; Sancho-Parramon, J. [Tyndall National Institute, Cork (Ireland); Durand, O. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France); Servet, B. [Thales Research and Technology France, Route Departementale 128, F-91767 Palaiseau Cedex (France); Stchakovsky, M. [Horiba Jobin-Yvon, Thin Film Division, Chilly-Mazarin (France); Eypert, C. [Horiba Jobin-Yvon, Thin Film Division, Chilly-Mazarin (France); Naudin, C. [HORIBA Jobin-Yvon Raman Division, Villeneuve d' Ascq (France); Knowles, A. [HORIBA Jobin-Yvon Ltd., Raman Division, Middlesex (United Kingdom); Bridou, F. [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS, Unite mixte de Recherche 85801, 91403 Orsay Cedex (France); Ravet, M.-F. [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS, Unite mixte de Recherche 85801, 91403 Orsay Cedex (France)

    2006-10-31

    In the present paper, we investigate the effect of thermal annealing on optical and microstructural properties of HfO{sub 2} thin films (from 20 to 190 nm) obtained by plasma ion assisted deposition (PIAD). After deposition, the HfO{sub 2} films were annealed in N{sub 2} ambient for 3 h at 300, 350, 450, 500 and 750 deg. C. Several characterisation techniques including X-ray reflectometry (XRR), X-ray diffraction (XRD), spectroscopic ellipsometry (SE), UV Raman and FTIR were used for the physical characterisation of the as-deposited and annealed HfO{sub 2} thin films. The results indicate that as-deposited PIAD HfO{sub 2} films are mainly amorphous and a transition to a crystalline phase occurs at a temperature higher than 450 deg. C depending on the layer thickness. The crystalline grains consist of cubic and monoclinic phases already classified in literature but this work provides the first evidence of amorphous-cubic phase transition at a temperature as low as 500 deg. C. According to SE, XRR and FTIR results, an increase in the interfacial layer thickness can be observed only for high temperature annealing. The SE results show that the amorphous phase of HfO{sub 2} (in 20 nm thick samples) has an optical bandgap of 5.51 eV. Following its transition to a crystalline phase upon annealing at 750 deg. C, the optical bandgap increases to 5.85 eV.

  16. A study of the inhibition of iron corrosion in HCl solutions by some amino acids

    International Nuclear Information System (INIS)

    Amin, Mohammed A.; Khaled, K.F.; Mohsen, Q.; Arida, H.A.

    2010-01-01

    The performance of three selected amino acids, namely alanine (Ala), cysteine (Cys) and S-methyl cysteine (S-MCys) as safe corrosion inhibitors for iron in aerated stagnant 1.0 M HCl solutions was evaluated by Tafel polarization and impedance measurements. Results indicate that Ala acts mainly as a cathodic inhibitor, while Cys and S-MCys function as mixed-type inhibitors. Cys, which contains a mercapto group in its molecular structure, was the most effective among the inhibitors tested, while Ala was less effective than S-MCys. The low inhibition efficiency recorded for S-MCys compared with that of Cys was attributed to steric effects caused by the substituent methyl on the mercapto group. Electrochemical frequency modulation (EFM) technique and inductively coupled plasma atomic emission spectrometry (ICP-AES), were also applied to make accurate determination of corrosion rates. Validation of the Tafel extrapolation method for measuring corrosion rates was tested. Rates of corrosion rates (in μm y -1 ) obtained from Tafel extrapolation method are in good agreement with those measured using EFM and ICP methods. Some theoretical studies, including molecular dynamics (MD) and density functional theory (DFT), were also employed to establish the correlation between the structure (molecular and electronic) of the three tested inhibitors and the inhibition efficiency. Adsorption via hydrogen bonding was discussed here based on some theoretical studies. Experimental and theoretical results were in good agreement.

  17. Laser Desorption of Tryptophan from Tryptophan-HCl Salt on a Graphite Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Jun; Kim, Jeong Jin; Kang, Hyuk [Ajou University, Suwon (Korea, Republic of)

    2016-03-15

    Laser spectroscopy of biological molecules in the gas phase has been pioneered by Levy and coworkers when they first produced a supersonic molecular beam of tryptophan (Trp) and obtained its electronic spectrum. They were able to obtain enough vapor pressure needed for spectroscopy by heating a powder sample of Trp, although a special thermal spray was used to minimize fragmentation during heating. Many amine compounds, including biomolecules like amino acids and peptides, are usually available only as HCl salt form in order to prevent oxidation in air. Chemical processing is required to recover a neutral amine compound from its salt, thus limiting the applicability of laser-desorption spectroscopy of biomolecules. The experimental setup is a standard molecular beam machine composed of a pulsed valve with a laser-desorption module in a vacuum chamber, a second buffer chamber, a skimmer that separates the first and the second chambers, and a third vacuum chamber that is a time-of-flight mass spectrometer (TOF MS)

  18. Biogenic corrosion inhibitor on mild steel protection in concentrated HCl medium.

    Science.gov (United States)

    Krishnan, Muthukumar; Subramanian, Harinee; Dahms, Hans-Uwe; Sivanandham, Vignesh; Seeni, Palanichamy; Gopalan, Subramanian; Mahalingam, Ashok; Rathinam, Arthur James

    2018-02-08

    Turbinaria ornata (TO) extract was tested as green corrosion inhibitor on mild steel (MS) coupons in conc. HCl medium with an efficiency of 100% at 25 g l -1 during 5 min exposure. Antibacterial efficacy performed against 16 S rDNA identified marine biofilming bacteria (MBB) and human pathogenic bacteria (HPB). Maximum inhibition growth was 16 mm on MBB observed in Bacillus megaterium (MBF14 - AB894827) and 20 mm on HPB in Escherichia coli (B5 - NCIM 2931). Similarly, minimum of 10 mm on MBB witnessed in Pseudomonas sp., (MBF9 - AB894829). Toxicity studies proved 50.0% LC 50 at 500 μg ml -1 in 24 hrs, whereas Balanus amphitrite resulted in 100% mortality within 12 hrs. Results including weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy, FT-IR and GC-MS confirm 10-Octadecaonic acid as a major corrosion inhibitor from T. ornata and is discovered as a novel antifoulant. Anticorrosion formulation will become available soon.

  19. Effect of the presence of HCl on cyclic CO2 capture of calcium-based sorbent in calcium looping process

    International Nuclear Information System (INIS)

    Wang, Wenjing; Li, Yingjie; Xie, Xin; Sun, Rongyue

    2014-01-01

    Highlights: • HCl improves CO 2 capture capacity of limestone in the previous a dozen cycles. • HCl sharply decreases limestone reactivity after a dozen cycles. • HCl intensifies effects of carbonation and calcination temperature on CO 2 capture. • HCl enlarges effects of particle size on CO 2 capture. • HCl severely aggravates the sintering of limestone after a dozen cycles. - Abstract: The effect of the presence of HCl on cyclic CO 2 capture behavior of calcium-based sorbent in the calcium looping process was investigated. When HCl was present in the carbonation atmosphere, the effects of carbonation temperature, calcination temperature, HCl concentration and particle size on CO 2 capture of the limestone in the multiple calcination/carbonation cycles were studied in a dual fixed-bed reactor. The presence of HCl in the carbonation atmosphere improves CO 2 capture capacity of the limestone in the previous a dozen cycles, but sharply decreases its reactivity with further increasing the cycle number above a dozen. The presence of HCl intensifies the effects of carbonation temperature and calcination temperature on CO 2 capture capacity of the limestone. The optimum carbonation temperature and the feasible calcination temperature for cyclic CO 2 capture of the limestone in the presence of HCl should be 700 °C and below 900 °C, respectively. The cyclic CO 2 capture capacity of the limestone in the previous a dozen cycles achieves the maximum in the presence of 300 ppm HCl with increasing the HCl concentration from 100 to 1000 ppm. The higher CO 2 capture capacity of the limestone is achieved with smaller particle size in the presence of HCl. The presence of HCl may destroy the compact CaCO 3 product layer and it is beneficial to CO 2 diffusion through the layer in the initial cycles. The chlorination conversion and the molten CaCl 2 –CaCO 3 product layer thickness of the limestone in the presence of HCl increase with the number of calcination

  20. Effects of Topical Phenylephrine HCl 2.5% used before Cataract Surgery on Systemic Blood Pressure

    Directory of Open Access Journals (Sweden)

    Emre Ayıntap

    2011-06-01

    Full Text Available Purpose: To evaluate the effect of topical phenylephrine HCl 2.5% (Mydfrin, used as a fast and effective mydriatic before cataract surgery, on systemic blood pressure. Material and Method: Topical phenylephrine HCl 2.5% was administered 3 times with 5-minute intervals before cataract surgery to 44 eyes of 44 patients. The systemic blood pressure was measured preoperatively and at 15 and 30 minutes. Results: The mean systolic blood pressure before the topical administration of phenylephrine HCl 2.5% was 119.7mmHg, while 15 and 30 minutes later, it was 125.3 mmHg and 121.2 mmHg, respectively. The mean diastolic blood pressure before the topical administration of phenylephrine HCl 2.5% was 75.9 mmHg; 15 and 30 minutes later, it was 76.9 mmHg and 75.3 mmHg, respectively. The increase in systolic blood pressure at 15 and 30 minutes was statistically significant (p=0.003 and p=0.042. The change in diastolic blood pressure was not statistically significant. Discussion: Phenylephrine HCl 2.5%, which is used preoperatively as a fast and effective mydriatic for cataract surgery, can increase the systolic blood pressure. This effect is most significant at 15 minutes and lasts at least 30 minutes. This agent should be used with care in hypertensive patients. (Turk J Ophthalmol 2011; 41: 164-6

  1. Penentuan Nilai Kalor Serta Pengaruh Asam Klorida (Hcl Terhadap Kadar Bioetanol Bonggol Pisang (Musa Paradisiacal

    Directory of Open Access Journals (Sweden)

    Asri Saleh

    2016-01-01

    Full Text Available The research of influence bioetanol degree to chlorine acid catalyst concentration (HCl in the hydrolysis process banana’s bump (Musa paradisiacal has the goal to know the influence of catalyst concentration variation HCl was given the result of banana’s bump hydrolysis which maximum on catalyst variation HCl 0,5 M; 1,0 M; 1,5 M; 2,0 M and 2,5 M on temperature 70oC, 150 rpm during 120 minute with appointment of calor percentage on optimum etanol degree. Based on the result of the research etanol degree highest on HCl with concentration 2,5 with bioetanol degree 5.29% per 10 gram banana’s bump. Based on the ANAVA calculation found out F calculate < F table so that H0 accepted and H1 refused. It’s mean that there were not influenced of concentration HCl to bioetanol degree significantly. Percentage of bioetanol calor which found out on concentration HC1 2,5 M (maximum concentration were 3461 (Sample I  and 3384 kkal (Sample II.

  2. Dynamics and mass accommodation of HCl molecules on sulfuric acid-water surfaces.

    Science.gov (United States)

    Behr, P; Scharfenort, U; Ataya, K; Zellner, R

    2009-09-28

    A molecular beam technique has been used to study the dynamics and mass accommodation of HCl molecules in collision with sulfuric acid-water surfaces. The experiments were performed by directing a nearly mono-energetic beam of HCl molecules onto a continuously renewed liquid film of 54-76 wt% sulfuric acid at temperatures between 213 K and 243 K. Deuterated sulfuric acid was used to separate sticking but non-reactive collisions from those that involved penetration through the phase boundary followed by dissociation and recombination with D+. The results indicate that the mass accommodation of HCl on sulfuric acid-water surfaces decreases sharply with increasing acidity over the concentration range 54-76 wt%. Using the capillary wave theory of mass accommodation this effect is explained by a change of the surface dynamics. Regarding the temperature dependence it is found that the mass accommodation of HCl increases with increasing temperature and is limited by the bulk phase viscosity and driven by the restoring forces of the surface tension. These findings imply that under atmospheric conditions the uptake of HCl from the gas phase depends crucially on the bulk phase parameters of the sulfuric acid aerosol.

  3. Hf Isotope Evidence for Subducted Basalt and Sediment Contributions to the Eastern Trans-Mexican Volcanic Belt

    Science.gov (United States)

    Cai, Y.; Tuena, A. G.; Capra, L.; Straub, S. M.; Goldstein, S. L.; Langmuir, C. H.

    2005-12-01

    Magmas generated at thick crust continental arcs often have enriched continental crust-like trace element patterns and Pb-Sr-Nd isotope ratios that are intermediate to both upper mantle and crustal compositions. Thus it is difficult to distinguish between contributions from (a) the subducted basalt and the upper mantle wedge, and (b) subducted sediment and the continental crust. These issues have been the focus of major controversy. Here we show evidence for subduction contributions to lavas in a classic thick crust environment. In Eastern Trans-Mexican Volcanic Belt, the upper continental crust is 30 km to 45 km thick. However, primitive mafic lavas erupt on many sites across the arc. We have analyzed the subducting sediments as represented by DSDP 487, located seaward of the trench, where the lower third of the sediment column has strongly hydrothermal pelagic features and the upper two-thirds is composed of terrigenous sediments. The pelagic sediments have distinctive features that could be used to identify a subduction component in the volcanics, including high REE/Hf, negative Ce anomalies, and Nd-Hf isotopes that lie on the "seawater array" and offset from the "mantle-crust" array. We have focused on a unique series of lavas from volcano Nevado de Toluca, located southwest of Mexico City. These lavas show negative Ce anomalies coupled with low REE/Hf and Zr/Nd ratios. Hf-Nd isotope ratios show a shallow trend compared to the mantle-crust array, consistent with a pelagic component. In addition, Hf isotopes show a striking positive correlation with Ce anomalies that trend toward the pelagic sediment compositions. These and other observations provide clear evidence for a component from subducted sediment in the lavas. In addition, there is a negative correlation of Lu/Hf and Hf isotopes that requires a mixing endmember with MORB-like Hf isotope ratios but with lower than MORB Lu/Hf. This indicates a melt from eclogitic subducted basalt. Compared to other

  4. Study of a novel agent for TCA precipitated proteins washing - comprehensive insights into the role of ethanol/HCl on molten globule state by multi-spectroscopic analyses.

    Science.gov (United States)

    Eddhif, Balkis; Lange, Justin; Guignard, Nadia; Batonneau, Yann; Clarhaut, Jonathan; Papot, Sébastien; Geffroy-Rodier, Claude; Poinot, Pauline

    2018-02-20

    Sample preparation for mass spectrometry-based proteomics is a key step for ensuring reliable data. In gel-free experimental workflows, protein purification often starts with a precipitation stage using trichloroacetic acid (TCA). In presence of TCA, proteins precipitate in a stable molten globule state making the pellet difficult to solubilize in aqueous buffer for proteolytic digestion and MS analysis. In this context, the objective of this work was to study the suitability of a novel agent, ethanol/HCl, for the washing of TCA-precipitated proteins. This method optimized the recovery of proteins in aqueous buffer (50 to 96%) while current organic solvents led to losses of material. Following a mechanistic study, the effect of ethanol/HCl on the conformation of TCA-precipitated proteins was investigated. It was shown that the reagent triggered the unfolding of TCA-stabilized molten globule into a reversible intermediate, characterized by a specific Raman signature, which favored protein subsequent resolubilization. Finally, the efficiency of ethanol/HCl for the washing of TCA-precipitated proteins extracted from a biofilm, a soil or a mouse liver was demonstrated (data available via ProteomeXchange with identifier PXD008110). Being versatile and simple, it could be of great interest to include an ethanol/HCl wash-step to produce high-quality protein extracts. In mass spectrometry-based proteomics workflows, proteins precipitation and/or washing usually involves the use of acetone. In fact, this solvent is effective for removing both biological interferences (e.g. lipids) and chemicals employed in protein extraction/purification protocols (e.g. TCA, SDS). However, the use of acetone can lead to significant protein losses. Moreover, when proteins are precipitated with TCA, the acetone-treated precipitate remains hard to disperse, leading to poor resolubilization of proteins in aqueous buffers. Here, we investigated the use of ethanol/HCl for washing TCA

  5. Experimental Research of HF Passive Radar Based on DRM Digital AM Broadcasting

    Directory of Open Access Journals (Sweden)

    Wan Xian-rong

    2012-03-01

    Full Text Available This paper gives the experimental research of HF Passive Bistatic Radar (HFPBR based on Digital Radio Mondiale (DRM digital AM broadcasting that have been first carried out in China, using the newly-developed all-digital active/passive integrated HF surface wave radar system. The principle, key techniques, experimental equipment, and preliminary results are introduced about this new radar system. Based on analysis of the measurement data, experimental results under different scenarios including surface-wave, sky-wave, and hybrid sky-surface propagation modes are presented, which have proved, for the first time worldwide, the technical feasibility of using DRM broadcasting signal for over-the-horizon detection by field experiment and formed the theoretical and experimental basis for the further development of HFPBR.

  6. Chromatographic study of element 104 in the system HCl/triisobutylphosphate (TBP)

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, R.; Paulus, W.; Kratz, J.V.; Seibert, A.; Thoerle, P.; Zauner, S. [Mainz Univ. (Germany); Bruechle, W.; Jaeger, E.; Schaedel, M.; Schausten, B. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Schumann, D. [Technische Univ. Dresden (Germany); Eichler, B.; Jost, D.T.; Tuerler, A.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    With the Automated Rapid Chemistry Apparatus ARCA chromatic experiments have been performed using the chemical system hydrochloric acid/tributylphosphate with element 104 (Rf). The results indicate that Rf behaves more like its homolog Hf. (author) 2 figs., 5 refs.

  7. A shrinking particle model at leaching of titanium in ilmenite use HCl

    International Nuclear Information System (INIS)

    MV Purwani; Suyanti

    2016-01-01

    The research of ilmenite leaching has conducted. Ilmenite was tailings of zircon sand processing. Zircon sand processing tailings containing Zr, Ti, Nb and Fe. This research will be conducted to determine the kinetic leaching of Ti in HCl based shrinking core models. From the research results ilmenite leaching of Ti in HCl wear, it can be concluded that the 50 grams of ilmenite leaching wear 11 M HCl leaching, the higher temperature was conducted the greater of the Ti conversion. The mechanism of the leaching process was controlled by Sphere Reaction with formula equation 1- (1-α)1/3 = k.C/r o ρ t = klt, the relationship between temperature (T) with the reaction rate constant (k), k = 61.744.e- 4553.3 / T or ln k = - 4553.3 / T + 4.123, the frequency factor A = 61.744, the activation energy E = 37.856 kJ/mol. (author)

  8. OPTIMASI PENGGUNAAN HCl SEBAGAI LARUTAN PENGELUSI ITRIUM-90 DALAM DOWEX® 50WX8-200

    Directory of Open Access Journals (Sweden)

    Sulaiman Sulaiman

    2015-07-01

    Full Text Available OPTIMASI PENGGUNAAN HCl SEBAGAI LARUTAN PENGELUSI ITRIUM-90 DALAM DOWEX® 50WX8-200. Itrium-90 merupakan radionuklida pemancar β yang mempunyai waktu paruh 64,1 jam dan memancarkan energi β maksimum 2280 keV. Itrium-90 digunakan dalam kedokteran nuklir untuk keperluan terapi. Sistem generator 90Sr/90Y telah dikembangkan untuk mendapatkan 90Y bebas pengemban. Itrium-90 yang diperoleh dari generator 90Sr/90Y berbentuk radiokimia 90Y-sitrat. Bentuk radiokimia 90Y yang ideal untuk penandaan berbagai macam ligan yaitu 90YCl3. Untuk mendapatkan bentuk radiokimia 90Y yang diinginkan dilakukan serangkaian proses dengan metode penukar ion menggunakan resin Dowex® 50WX8-200. Dalam penelitian ini telah dilakukan optimasi penggunaan HCl untuk elusi 90Y dari resin dengan variasi konsentrasi HCl dan waktu kontak saat elusi 90Y dari resin. Pelepasan 90Y dari resin Dowex® 50WX8-200 tergantung pada konsentrasi HCl yang digunakan. Konsentrasi HCl semakin besar laju pelepasan 90Y dari 90Y-Dowex semakin besar.  Waktu kontak optimummenggunakan 5 mL HCl 12 N adalah 60 menit dengan hasil  9,4 %. Hasil uji 90Y setelah dielusi dari Dowex® 50WX8-200 memberikan informasi radionuklida 90Y yang diperoleh dalam bentuk radiokimia 90YCl3.   OPTIMIZATION OF USE HCl AS SOLUTION FOR ELUTION ITRIUM-90 IN DOWEX® 50WX8- 200. Yttrium-90 is a β emitter radionuclide with a half life of 64.1 hours and emits the maximum β energy at 2280 keV. Yttrium-90 radionuclide is widely used in nuclear medicine for therapeutic purposes. 90Sr/90Y generator system has been developed to obtain carrier-free 90Y. Yttrium-90 were obtained from the 90Sr/90Y generator in the form of 90Y-citrate radiochemical. The 90Y ideal for tagging ligands is in the form of 90YCl3. To obtain the desired radiochemical a series of processes with ion exchange resin method is performed using Dowex® 50WX8-200. In this study optimization of the use of HCl for has been carried out 90Y elution from the resin with

  9. Beneficiation of titanium concentrate (anatase) by HCl/H2O2 leaching of impurities

    International Nuclear Information System (INIS)

    Trindade, R.B.E.; Teixeira, L.A.C.

    1988-01-01

    The HCl/H 2 O 2 leaching of impurities from a Brazilian anatase (TiO 2 ) concentrate has been investigated by factorial experimentations. The effects of the following variables were investigated: temperature (50-90 0 C), redox potential (with and without oxidizing agent-H 2 O 2 ) and HCl concentration (4-18,5%). The conclusions were based on the analyses of Fe, Ca, P, Al, Si, Th,Ce, La, U and Ti in the beneficiated concentrates. The final results recommended the following optimum operational conditions, in a four stage countercurrent leaching: in the 4 th reactor (discharge of beneficiated concentrate): HCl fed at 18.5%, T=75 0 C, and addition of H 2 O 2 at a potential (eH) of 850 mV; in the first three reactors: T=90 0 C; with no oxidizing agent. (author) [pt

  10. Hydro-fluorination device with 'in situ' HF generation

    International Nuclear Information System (INIS)

    Boussier, H.; Peron, F.

    2012-01-01

    The reference pyro-chemistry process studied by the DRCP is based on an actinide reductive extraction in fluoride media. At the front end of the process, a hydro-fluorination step is needed in order to convert the oxides present in irradiated fuel into fluorides. This hydro-fluorination is carried out with HF gas at 350-500 degrees C. Very few experimental facilities, hot cells, or glove-boxes are equipped with operational HF gas lines: the building and commissioning of such HF lines is very complicated and expensive. This experimental device offers an alternative, enabling hydro-fluorination of small samples (approximate to 5g) of oxide fission product (FP) elements through a chemical reaction involving 'in situ' HF gas generation. A specific gas line would no longer be required, and the hydro-fluorination reaction could therefore be carried out in conventional hot cells or glove-boxes. Ten inactive runs were carried out without any particular problem; there were no gas leaks and no temperature control issues. More than seventeen FP samples were tested. The reliability of the hydro-fluorination set-up through a chemical reaction involving 'in situ' HF gas generation has been demonstrated, and therefore this set-up could be implemented in a hot cell. (authors)

  11. Draft revision of human factors guideline HF-010

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Lee, Yong Hee; Oh, In Seok; Lee, Jung Woon; Cha, Woo Chang; Lee, Dhong Ha

    2003-05-01

    The Application of Human Factors to the design of Man-Machine Interfaces System(MMIS) in the nuclear power plant is essential to the safety and productivity of the nuclear power plants, human factors standards and guidelines as well as human factors analysis methods and experiments are weightily used to the design application. A Korean engineering company has developed a human factors engineering guideline, so-call HF-010, and has used it for human factors design, however the revision of HF-010 is necessary owing to lack of the contents related to the advanced MMI(Man-Machine Interfaces). As the results of the reviews of HF-010, it is found out that the revision of Section 9. Computer Displays of HF-010 is urgent, thus the revision was drafted on the basis of integrated human factors design guidelines for VDT, human factors design guidelines for PMAS SPADES display, human factors design guidelines for PMAS alarm display, and human factors design guidelines for electronic displays developed by the surveillance and operation support project of KOICS. The draft revision of HF-010 Section 9 proposed in this report can be utilized for the human factors design of the advanced MMI, and the high practical usability of the draft can be kept up through the continuous revision according to the advancement of digital technology

  12. Supplementation with rumen-protected L-arginine-HCl increased fertility in sheep with synchronized estrus.

    Science.gov (United States)

    de Chávez, Julio Agustín Ruiz; Guzmán, Adrian; Zamora-Gutiérrez, Diana; Mendoza, Germán David; Melgoza, Luz María; Montes, Sergio; Rosales-Torres, Ana María

    2015-08-01

    The aim of the present study was to evaluate the effects of L-arginine-HCl supplementation on ovulation rate, fertility, prolificacy, and serum VEGF concentrations in ewes with synchronized oestrus. Thirty Suffolk ewes with a mean body weight of 45 ± 3 kg and a mean body condition score (BCS) of 2.4 ± 0.28 were synchronized for estrus presentation with a progestin-containing sponge (20 mg Chronogest® CR) for 9 days plus PGF2-α (Lutalyse; Pfizer, USA) on day 7 after the insertion of the sponge. The ewes were divided into two groups; i.e., a control group (n = 15) that was fed on the native pasture (basal diet) and an L-arginine-HCl group (n = 15) that received 7.8 g of rumen-protected L-arginine-HCl from day 5 of the sponge insertion until day 25 after mating plus the basal diet. The L-arginine-HCl was administered daily via an esophageal probe between days 5 and 9 of the synchronization protocol and every third day subsequently. Blood samples were drawn from the jugular vein every 6 days throughout the entire experimental period. The results revealed that the L-arginine-HCl supplementation increased fertility during the synchronized estrus (P = 0.05). However, no effects were observed on the final BCS (P = 0.78), estrus presentation (P = 0.33), multiple ovulations (P = 0.24), prolificacy (P = 0.63), or serum VEGF concentration. In conclusion, L-arginine-HCl supplementation during the period used in this study increased fertility in sheep with synchronized estrus possibly due to improved embryo-fetal survival during early pregnancy.

  13. Sequential pyrolysis of plastic to recover polystyrene, HCl and terephthalic acid

    Science.gov (United States)

    Evans, R.J.; Chum, H.L.

    1995-11-07

    A process is described for pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene, HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons. 83 figs.

  14. Corrosion Inhibition Effect of Dicycloimine Hydrochloride (DCI on Mild Steel in 1M HCl

    Directory of Open Access Journals (Sweden)

    R. Rajalakshmi

    2010-01-01

    Full Text Available Addition of corrosion inhibitors is one of the widely used methods to control corrosion. In this work, an attempt has been made to explore the possibility of using dicycloimine hydrochloride (DCI as an inhibitor on mild steel in 1 M HCl. The inhibition efficiency of DCI has been evaluated by conventional weight loss method and electrochemical polarization studies. Experimental results are fitted to various adsorption isotherms. Thermodynamic parameters have also been studied from temperature studies. The results reveal that DCI acts as an effective inhibitor (around 90% of IE in HCl media.

  15. Determining characteristics of HF communications links using SuperDARN

    Directory of Open Access Journals (Sweden)

    J. M. Hughes

    Full Text Available Space weather effects can strongly influence high-frequency (HF communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for measuring high-latitude HF communications link parameters using data from SuperDARN radars. These techniques use ground-scatter returns to define the variation in skip distance with frequency. From these data, the maximum usable frequency (MUF as a function of range is determined and ionospheric critical frequencies are estimated. These calculations are made in near-real-time and the results are made available on the World Wide Web. F-region critical frequencies calculated using this method show good agreement with ionosonde data.

    Key words. Ionosphere (active experiments; instruments and techniques – Radio science (ionospheric propagation

  16. Determining characteristics of HF communications links using SuperDARN

    Directory of Open Access Journals (Sweden)

    J. M. Hughes

    2002-07-01

    Full Text Available Space weather effects can strongly influence high-frequency (HF communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for measuring high-latitude HF communications link parameters using data from SuperDARN radars. These techniques use ground-scatter returns to define the variation in skip distance with frequency. From these data, the maximum usable frequency (MUF as a function of range is determined and ionospheric critical frequencies are estimated. These calculations are made in near-real-time and the results are made available on the World Wide Web. F-region critical frequencies calculated using this method show good agreement with ionosonde data.Key words. Ionosphere (active experiments; instruments and techniques – Radio science (ionospheric propagation

  17. Lattice Thermal Conductivity from Atomistic Simulations: ZrB2 and HfB2

    Science.gov (United States)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  18. Thermal relaxation of magnetic clusters in amorphous Hf57Fe43 alloy

    International Nuclear Information System (INIS)

    Pajic, Damir; Zadro, Kreso; Ristic, Ramir; Zivkovic, Ivica; Skoko, Zeljko; Babic, Emil

    2007-01-01

    The magnetization processes in binary magnetic/non-magnetic amorphous alloy Hf 57 Fe 43 are investigated by the detailed measurement of magnetic hysteresis loops, temperature dependence of magnetization, relaxation of magnetization and magnetic ac susceptibility, including a nonlinear term. Blocking of magnetic moments at lower temperatures is accompanied by the slow relaxation of magnetization and magnetic hysteresis loops. All of the observed properties are explained by the superparamagnetic behaviour of the single domain magnetic clusters inside the non-magnetic host, their blocking by the anisotropy barriers and thermal fluctuation over the barriers accompanied by relaxation of magnetization. From magnetic viscosity analysis based on thermal relaxation over the anisotropy barriers it is found that magnetic clusters occupy the characteristic volume from 25 up to 200 nm 3 . The validity of the superparamagnetic model of Hf 57 Fe 43 is based on the concentration of iron in the Hf 100-x Fe x system that is just below the threshold for long range magnetic ordering. This work also throws more light on the magnetic behaviour of other amorphous alloys

  19. Oxidation behavior of Hf-modified platinum aluminide coatings during thermal cycling

    Directory of Open Access Journals (Sweden)

    Liya Ye

    2018-02-01

    Full Text Available Platinum aluminide coatings with different Hf contents were fabricated by using HfCl4. The oxidation kinetics and the rumpling behavior of oxide scale were investigated. After thermal cycling, the coating with 0.46 wt% Hf showed least weight gain. With the increase of Hf content, rumpling extent of the scale decreased. Meanwhile, HfO2 preferentially formed in the scale resulting in the increase of scale thickness. The oxidation of excessive Hf even caused the spallation of the scale. The results in the present study indicate that although Hf plays an important role in decreasing rumpling extent of TGO, the oxidation of Hf decreases the adhesion of the scale. Keywords: Pt-Al coating, Hf, Oxidation, Rumpling

  20. HF-START: A Regional Radio Propagation Simulator

    Science.gov (United States)

    Hozumi, K.; Maruyama, T.; Saito, S.; Nakata, H.; Rougerie, S.; Yokoyama, T.; Jin, H.; Tsugawa, T.; Ishii, M.

    2017-12-01

    HF-START (HF Simulator Targeting for All-users' Regional Telecommunications) is a user-friendly simulator developed to meet the needs of space weather users. Prediction of communications failure due to space weather disturbances is of high priority. Space weather users from various backgrounds with high economic impact, i.e. airlines, telecommunication companies, GPS-related companies, insurance companies, international amateur radio union, etc., recently increase. Space weather information provided by Space Weather Information Center of NICT is, however, too professional to be understood and effectively used by the users. To overcome this issue, I try to translate the research level data to the user level data based on users' needs and provide an immediate usable data. HF-START is positioned to be a space weather product out of laboratory based truly on users' needs. It is originally for radio waves in HF band (3-30 MHz) but higher frequencies up to L band are planned to be covered. Regional ionospheric data in Japan and southeast Asia are employed as a reflector of skywave mode propagation. GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) model will be used as ionospheric input for global simulation. To evaluate HF-START, an evaluation campaign for Japan region will be launched in coming months. If the campaign successes, it will be expanded to southeast Asia region as well. The final goal of HF-START is to provide the near-realtime necessary radio parameters as well as the warning message of radio communications failure to the radio and space weather users.

  1. Potential energy and dipole moment surfaces for HF@C60: Prediction of spectral and electric response properties

    Science.gov (United States)

    Kalugina, Yulia N.; Roy, Pierre-Nicholas

    2017-12-01

    We present a five-dimensional potential energy surface (PES) for the HF@C60 system computed at the DF-LMP2/cc-pVTZ level of theory. We also calculated a five-dimensional dipole moment surface (DMS) based on DFT(PBE0)/cc-pVTZ calculations. The HF and C60 molecules are considered rigid with bond length rHF = 0.9255 Å (gas phase ground rovibrational state geometry). The C60 geometry is of Ih symmetry. The ab initio points were fitted to obtain a PES in terms of bipolar spherical harmonics. The minimum of the PES corresponds to a geometry where the center of mass of HF is located 0.11 Å away from the center of the cage with an interaction energy of -6.929 kcal/mol. The DMS was also represented in terms of bipolar spherical harmonics. The PES was used to calculate the rotation-translation bound states of HF@C60, and good agreement was found relative to the available experimental data [A. Krachmalnicoff et al., Nat. Chem. 8, 953 (2016)] except for the splitting of the first rotational excitation levels. We propose an empirical adjustment to the PES in order to account for the experimentally observed symmetry breaking. The form of that effective PES is additive. We also propose an effective Hamiltonian with an adjusted rotational constant in order to quantitatively reproduce the experimental results including the splitting of the first rotational state. We use our models to compute the molecular volume polarizability of HF confined by C60 and obtain good agreement with experiment.

  2. HF-induced airglow at magnetic zenith: theoretical considerations

    Directory of Open Access Journals (Sweden)

    E. V. Mishin

    2005-01-01

    Full Text Available Observations of airglow at 630nm (red line and 557.7nm (green line during HF modification experiments at the High Frequency Active Auroral Research Program (HAARP heating facility are analyzed. We propose a theoretical framework for understanding the generation of Langmuir and ion acoustic waves during magnetic zenith injections. We show that observations of HF-induced airglow in an underdense ionosphere as well as a decrease in the height of the emitting volume are consistent with this scenario.

  3. New active load voltage clamp for HF-link converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, M.A.E.

    2005-07-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core. (au)

  4. European coordination for coastal HF radar data in EMODnet Physics

    Science.gov (United States)

    Mader, Julien; Novellino, Antonio; Gorringe, Patrick; Griffa, Annalisa; Schulz-Stellenfleth, Johannes; Montero, Pedro; Montovani, Carlo; Ayensa, Garbi; Vila, Begoña; Rubio, Anna; Sagarminaga, Yolanda

    2015-04-01

    Historically, joint effort has been put on observing open ocean, organizing, homogenizing, sharing and reinforcing the impact of the acquired information based on one technology: ARGO with profilers Argo floats, EuroSites, ESONET-NoE, FixO3 for deep water platforms, Ferrybox for stations in ships of opportunities, and GROOM for the more recent gliders. This kind of networking creates synergies and makes easier the implementation of this source of data in the European Data exchange services like EMODnet, ROOSs portals, or any applied services in the Blue economy. One main targeted improvement in the second phase of EMODnet projects is the assembling of data along coastline. In that sense, further coordination is recommended between platform operators around a specific technology in order to make easier the implementation of the data in the platforms (4th EuroGOOS DATAMEQ WG). HF radar is today recognized internationally as a cost-effective solution to provide high spatial and temporal resolution current maps (depending on the instrument operation frequency, covering from a few kilometres offshore up to 200 km) that are needed for many applications for issues related to ocean surface drift or sea state characterization. Significant heterogeneity still exists in Europe concerning technological configurations, data processing, quality standards and data availability. This makes more difficult the development of a significant network for achieving the needed accessibility to HF Radar data for a pan European use. EuroGOOS took the initiative to lead and coordinate activities within the various observation platforms by establishing a number of Ocean Observing Task Teams such as HF-Radars. The purpose is to coordinate and join the technological, scientific and operational HF radar communities at European level. The goal of the group is on the harmonization of systems requirements, systems design, data quality, improvement and proof of the readiness and standardization of

  5. Anisotropic etching of p-Si in HF solution

    International Nuclear Information System (INIS)

    Outemzabet, R.; Benzekour, N.; Gabouze, N.; Kesri, N.; Ait-Hamouda, K.

    2003-01-01

    In situ electrochemical attenuated total reflection Fourier transform infrared spectroscopy has been used to study the etching process on a Si (100), (110) and (111) surface in dilute HF solution. On the other hand I-V characteristic of the p-Si-HF system was used for the interface reactions and kinetics study. Infrared results show that monohydride (SiH) and hydroxyl (Si-OH) species surface concentration depend on the applied potential to the electrode. I-V characteristics show a relative variation in magnitude of the first peak as the substrate orientation is changed. A mechanism of silicon dissolution is proposed (Authors)

  6. Quasi-Classical Trajectory Study of Atom-Diatomic Molecule Collisions in Symmetric Hyperspherical Coordinates: The F + HCl Reaction as a Test Case.

    Science.gov (United States)

    Freixas-Lemus, Victor Manuel; Martínez-Mesa, Aliezer; Uranga-Piña, Llinersy

    2016-04-07

    We investigate the reactive dynamics of the triatomic system F + HClHF + Cl for total angular momentum equal zero and for different low-lying rovibrational states of the diatomic molecule. For each of the initial vibrational quantum numbers, the time evolution of the atom-diatom collision process is investigated for a wide range of impact angles and collision energies. To this purpose, the Quasi-Classical Trajectories (QCT) method was implemented in a hyperspherical configuration space. The Hamilton equations of motion are solved numerically in an intermediate effective Cartesian space to exploit the relative simplicity of this intermediate representation. Interatomic interactions are described by a London-Eyring-Polanyi-Sato potential energy surface, specifically developed for the title reaction, and the results of the QCT simulations are discussed in terms of the time-evolution of the hyperangles. The analysis of the collision dynamics using symmetric hyperspherical coordinates provides, in addition to the description in terms of a natural reaction coordinate (the hyperradius), a more striking representation of the exchange dynamics, in terms of the time-dependent probability distribution along the kinematic rotation hyperangle, and a precise distinction between direct and indirect mechanisms of the reaction.

  7. Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution

    Science.gov (United States)

    Patchett, P.J.

    1983-01-01

    The 176Lu-176Hf isotope method and its applications in earth sciences are discussed. Greater fractionation of Lu/Hf than Sm/Nd in planetary magmatic processes makes 176Hf 177Hf a powerful geochemical tracer. In general, proportional variations of 176Hf 177Hf exceed those of 143Nd l44Nd by factors of 1.5-3 in terrestrial and lunar materials. Lu-Hf studies therefore have a major contribution to make in understanding of terrestrial and other planetary evolution through time, and this is the principal importance of Lu-Hf. New data on basalts from oceanic islands show unequivocally that whereas considerable divergences occur in 176Hf 177Hf- 87Sr 86Sr and 143Nd l44Nd- 87Sr 86Sr diagrams, 176Hf 177Hf and 143Nd 144Nd display a single, linear isotopic variation in the suboceanic mantle. These discordant 87Sr 86Sr relationships may allow, with the acquisition of further Hf-Nd-Sr isotopic data, a distinction between processes such as mantle metasomatism, influence of seawater-altered material in the magma source, or recycling of sediments into the mantle. In order to evaluate the Hf-Nd isotopic correlation in terms of mantle fractionation history, there is a need for measurements of Hf distribution coefficients between silicate minerals and liquids, and specifically for a knowledge of Hf behavior in relation to rareearth elements. For studying ancient terrestrial Hf isotopic variations, the best quality Hf isotope data are obtained from granitoid rocks or zircons. New data show that very U-Pb discordant zircons may have upwardly-biased 176Hf 177Hf, but that at least concordant to slightly discordant zircons appear to be reliable carriers of initial 176Hf 177Hf. Until the controls on addition of radiogenic Hf to zircon are understood, combined zircon-whole rock studies are recommended. Lu-Hf has been demonstrated as a viable tool for dating of ancient terrestrial and extraterrestrial samples, but because it offers little advantage over existing methods, is unlikely to find

  8. High Frequency (HF) Radio Signal Amplitude Characteristics, HF Receiver Site Performance Criteria, and Expanding the Dynamic Range of HF Digital New Energy Receivers by Strong Signal Elimination

    Science.gov (United States)

    1990-06-21

    Commander (PMW-143/144) PROGRAM PROJECT TASK WORK UNIT Space and Naval Warfare Systems Command ELEMENT NO. NO. NO. CCESSION NO. Washinxton. DC 20363-5100 1A...Mean and Variance Estimation Using the Kolmogoroff -Smirnoff ...... 67 Method for All Tests 4.12 Comparison of Density Functions Using All Four Mean...and to minimize interference among spectrum users. Within the HF band, the ITU allocates space to the following services (with examples) [Ref. 2

  9. Rationale and methods of the multicenter randomised trial of a heart failure management programme among geriatric patients (HF-Geriatrics

    Directory of Open Access Journals (Sweden)

    Casado Jose

    2011-08-01

    Full Text Available Abstract Background Disease management programmes (DMPs have been shown to reduce hospital readmissions and mortality in adults with heart failure (HF, but their effectiveness in elderly patients or in those with major comorbidity is unknown. The Multicenter Randomised Trial of a Heart Failure Management Programme among Geriatric Patients (HF-Geriatrics assesses the effectiveness of a DMP in elderly patients with HF and major comorbidity. Methods/Design Clinical trial in 700 patients aged ≥ 75 years admitted with a primary diagnosis of HF in the acute care unit of eight geriatric services in Spain. Each patient should meet at least one of the following comorbidty criteria: Charlson index ≥ 3, dependence in ≥ 2 activities of daily living, treatment with ≥ 5 drugs, active treatment for ≥ 3 diseases, recent emergency hospitalization, severe visual or hearing loss, cognitive impairment, Parkinson's disease, diabetes mellitus, chronic obstructive pulmonary disease (COPD, anaemia, or constitutional syndrome. Half of the patients will be randomly assigned to a 1-year DMP led by a case manager and the other half to usual care. The DMP consists of an educational programme for patients and caregivers on the management of HF, COPD (knowledge of the disease, smoking cessation, immunizations, use of inhaled medication, recognition of exacerbations, diabetes (knowledge of the disease, symptoms of hyperglycaemia and hypoglycaemia, self-adjustment of insulin, foot care and depression (knowledge of the disease, diagnosis and treatment. It also includes close monitoring of the symptoms of decompensation and optimisation of treatment compliance. The main outcome variables are quality of life, hospital readmissions, and overall mortality during a 12-month follow-up. Discussion The physiological changes, lower life expectancy, comorbidity and low health literacy associated with aging may influence the effectiveness of DMPs in HF. The HF-Geriatrics study

  10. Cross validation with the mood disorder questionnaire (MDQ) of an instrument for the detection of hypomania in Spanish: the 32 item hypomania symptom check list (HCL-32).

    Science.gov (United States)

    Vieta, E; Sánchez-Moreno, J; Bulbena, A; Chamorro, L; Ramos, J L; Artal, J; Pérez, F; Oliveras, M A; Valle, J; Lahuerta, J; Angst, J

    2007-08-01

    The detection and diagnosis of present or past hypomanic episodes is of key importance for the differential diagnosis between depressive disorders and type II bipolar disorder. However, there are few instruments available to satisfactorily screen for the latter condition. The Hypomania Symptom Checklist-32 (HCL-32) is a self-applied questionnaire with 32 hypomania items and 8 severity and functional impact items which is being developed in several European countries for this purpose. Our aim was to develop and validate the psychometric properties of the HCL-32 scale in Spain in patients with bipolar disorder and to compare its properties with other instruments available for the detection of bipolar II disorder. Patients were selected from 15 psychiatric outpatient departments, diagnosed with type I or type II bipolar disorder (BDI and BDII) and unipolar major depression (MD) according to DSM-IV-TR criteria. A control group of healthy subjects (HS) was likewise assessed. The patient selection criteria included a well-established diagnosis and a stable disorder and pharmacological treatment. The HCL-32 was administered to 237 subjects distributed among the above groups, on two occasions four weeks apart. We analysed the internal consistency, test-retest reliability and discriminative capacity of the HCL-32. The internal consistency of the Spanish version of the HCL-32, evaluated by Cronbach's alpha, was 0.94. Mean of affirmative questions by group were 21.2 (SD 5.8) for BDI, 19.3 (SD 6.2) for BDII, 8.6 (SD 6.6) for MD and 6.6 (SD 6.1) for HS, with statistically significant differences between them (Kruskal-Wallis test, p<0.001). Concurrent validity using the diagnosis variable was 0.72. Test-retest reliability was 0.90. We analysed the best cut-off point by means of a ROC curve analysis; for 14 affirmative responses, a sensitivity of 0.85 95%CI (0.78, 0.91) and specificity of 0.79, 95%CI (0.72, 0.87) were obtained. The positive and negative probability ratios were 4

  11. Far infrared study of the Argon-HCl van der Waals molecule

    NARCIS (Netherlands)

    Boom, E.W.; Frenkel, D.; Elsken, J. van der

    1977-01-01

    Results of far infrared measurements on the system HCl–Ar at low density and temperature are presented. Distinct spectral features are observed that must be attributed to Ar–HCl van der Waals molecules. Possible explanations of the observed spectra in terms of a simple picture of the internal motion

  12. Optical sensing of HCl with phenol red doped sol-gels

    International Nuclear Information System (INIS)

    Wang Enju; Chow, Kwok-Fan; Wang Wenqun; Wong, Crystal; Yee, Cynthia; Persad, Alvin; Mann, Jonathan; Bocarsly, Andrew

    2005-01-01

    A dye doped sol-gel for the sensing of hydrochloric acid in solution and/or gaseous phase is described. The sol-gel is obtained by acidic hydrolysis of tetraethoxysilane (TEOS) and phenyltriethoxysilane (Ph-TriEOS) in the presence of phenol red (PR) and further spin-coating onto glass slides. The sensitive response is based on an increase of the absorption band at 510 nm of phenol red entrapped in the sol-gel casting when exposed to HCl solution or gas, due to protonation of the dye. The detection limit of the sol-gel response to moisturized gaseous HCl is below 12 ppm, and its response to HCl in solution falls in the range of 0.01-6 M. The sol-gel coating has a response time of less than 40 s in steady-state, and life-time of more than a year. Weak acids such as acetic acid, benzoic acid, salicylate acid, citrate acid, and carbonic acid do not interfere the response. The responses in acid solutions are completely reversible. In the gaseous phase, response of HCl appears to be moisture sensitive

  13. Optical sensing of HCl with phenol red doped sol-gels

    Energy Technology Data Exchange (ETDEWEB)

    Wang Enju [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States)]. E-mail: wange@stjohns.edu; Chow, Kwok-Fan [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Wang Wenqun [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Wong, Crystal [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Yee, Cynthia [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Persad, Alvin [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Mann, Jonathan [Department of Chemistry, Princeton University, Princeton, NJ 08540 (United States); Bocarsly, Andrew [Department of Chemistry, Princeton University, Princeton, NJ 08540 (United States)

    2005-04-08

    A dye doped sol-gel for the sensing of hydrochloric acid in solution and/or gaseous phase is described. The sol-gel is obtained by acidic hydrolysis of tetraethoxysilane (TEOS) and phenyltriethoxysilane (Ph-TriEOS) in the presence of phenol red (PR) and further spin-coating onto glass slides. The sensitive response is based on an increase of the absorption band at 510 nm of phenol red entrapped in the sol-gel casting when exposed to HCl solution or gas, due to protonation of the dye. The detection limit of the sol-gel response to moisturized gaseous HCl is below 12 ppm, and its response to HCl in solution falls in the range of 0.01-6 M. The sol-gel coating has a response time of less than 40 s in steady-state, and life-time of more than a year. Weak acids such as acetic acid, benzoic acid, salicylate acid, citrate acid, and carbonic acid do not interfere the response. The responses in acid solutions are completely reversible. In the gaseous phase, response of HCl appears to be moisture sensitive.

  14. Benzydamine HCl, a new agent for the treatment of radiation mucositis of the oropharynx

    International Nuclear Information System (INIS)

    Kim, J.H.; Chu, F.C.; Lakshmi, V.; Houde, R.

    1986-01-01

    Benzydamine HCl is a new nonsteroidal analgesic and anti-inflammatory compound which is not chemically related to local anesthetics such as procaine and xylocaine. A double-blind, randomized clinical investigation was carried out to determine the analgesic and anti-inflammatory effectiveness of benzydamine HCl in patients with radiation-induced mucositis of the oropharynx. Of the 67 patients in the study, 37 were on benzydamine and 30 on placebo. Patients developed radiation mucositis, hyperemia, and throat pain when the total radiation dose reached above 2000 rad over 2 weeks (200 rad per fraction, five treatments per week). Analysis of the data showed that benzydamine HCl used as a rinse/gargle provided a statistically significant and clinically meaningful alleviation of the symptoms of oropharyngeal mucositis. There was also significant improvement in terms of reduction in hyperemia and mucositis in benzydamine group. No systemic side effects associated with benzydamine medication were noted. In view of the relative ineffectiveness of systemic analgesics and topical anesthetics for these conditions, benzydamine HCl promises to be a useful addition to the therapeutic armamentarium

  15. Nanofiber-net-binary structured membranes for highly sensitive detection of trace HCl gas.

    Science.gov (United States)

    Wang, Xianfeng; Wang, Jialin; Si, Yang; Ding, Bin; Yu, Jianyong; Sun, Gang; Luo, Wenjing; Zheng, Gang

    2012-12-07

    This work describes the detection of trace hydrogen chloride (HCl) gas through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with polyaniline (PANI) functionalized polyamide 6 (PA 6) (PANI-PA 6) nanofiber-net-binary (NNB) structured membranes. The PA 6 NNB substrate comprising nanofibers and spider-web-like nano-nets fabricated by a versatile electro-spinning/netting (ESN) process offered an ideal interface for the uniform PANI functionalization and enhanced sensing performance. Benefiting from the large specific surface area, high porosity, and strong adhesive force to the QCM electrode of the PANI-PA 6 NNB membranes, the developed HCl-selective sensors exhibited a rapid response, good reproducibility and stability, and low detection limit (7 ppb) at room temperature. Additionally, the PANI-PA 6 NNB sensing membranes presented visible color changes upon cycled exposure to HCl and ammonia, suggesting their potential application in the development of colorimetric sensors. The PANI-PA 6 NNB coated QCM sensors are considered to be a promising candidate for trace HCl gas detection in practical applications.

  16. Ab initio potential-energy surface and rovibrational states of the HCN-HCl complex

    NARCIS (Netherlands)

    Avoird, A. van der; Pedersen, T.B.; Dhont, G.S.F.; Fernandez, B.; Koch, H.

    2006-01-01

    A four-dimensional intermolecular potential-energy surface has been calculated for the HCN-HCl complex, with the use of the coupled cluster method with single and double excitations and noniterative inclusion of triples. Data for more than 13 000 geometries were represented by an angular expansion

  17. The effect of conditioning with NaCl, KCl and HCl on the ...

    African Journals Online (AJOL)

    2+ and Co2+ was investigated in order to consider its viability in the removal of metal cations from aqueous solutions. The effect of chemical conditioning was investigated using sodium chloride (NaCl), hydrochloric acid (HCl) and potassium ...

  18. Effect of HCl doping on optoelectrical and LPG sensing properties of nanostructured polyaniline thin films

    Energy Technology Data Exchange (ETDEWEB)

    Upadhye, Deepak S., E-mail: deepaksu22@gmail.com; Huse, Nanasaheb P.; Sharma, Ramphal, E-mail: rps.phy@gmail.com [Thin Film and Nanotechnology Laboratory, Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (India)

    2016-05-06

    Nanostructure Polyaniline thin films doped with 0.5 M, 0.7 M, and 1 M of HCL were synthesized by simple and inexpensive chemical oxidative polymerization technique at room temperature. All prepared thin films of Polyaniline were characterized by optical absorbance study by UV-visible spectroscopy. The absorbance spectrum of Polyaniline shows three fundamental peaks at 356, 419 and 820 nm with increase in absorption intensity. The electrical study shows magnitude of resistance of HCL doped Polyaniline is dependent on doping level. Furthermore, the thin film of Polyaniline was investigated by Scanning electron microscopy for surface morphology study. The SEM micrograph represents irregular granular morphology. In order to investigate LPG sensing properties, I-V characteristics of the Polyaniline films doped with 0.5 M, 0.7 M, and 1 M of HCL were recorded at room temperature in presence of air and 100 ppm of LPG. The observed values of sensitivity found to be 7.21%, 9.85% and 17.46 % for 0.5 M, 0.75 M, and 1.0 M of HCL doped Polyaniline thin films respectively.

  19. Inhibition of Corrosion of Zinc in (HNO 3 + HCl) acid mixture by ...

    African Journals Online (AJOL)

    Corrosion of Zinc metal in (HNO3 + HCl) binary acid mixture and inhibition efficiency of aniline has been studied by weight loss method and polarization technique. Corrosion rate increases with the concentration of acid mixture and the temperature. Inhibition efficiency (I.E.) of aniline increases with the concentration of ...

  20. A theoretical investigation of gaseous absorption by water droplets from SO2-HNO3-NH3-CO2-HCl mixtures

    Science.gov (United States)

    Adewuyi, Y. G.; Carmichael, G. R.

    1982-01-01

    A physical-chemical model is developed and used to investigate gaseous absorption by water droplets from trace gas mixtures. The model is an extension of that of Carmichael and Peters (1979) and includes the simultaneous absorption of SO2, NH3, HNO3, CO2, and HCl. Gas phase depletion is also considered. Presented results demonstrate that the absorption behavior of raindrops is strongly dependent on drop size, fall distance, trace gas concentrations, and the chemical and physical properties of the constituents of the mixture. In addition, when gas phase depletion is considered, the absorption rates and equilibrium values are also dependent on the precipitation rate itself. Also, the trace constituents liquid phase concentrations may be a factor of six or more lower when gas depletion is considered then when the depletion is ignored. However, the hydrogen ion concentration may be insensitive to the gas phase depletion.

  1. Airway hyperresponsiveness induced by repeated esophageal infusion of HCl in guinea pigs.

    Science.gov (United States)

    Cheng, Yan-Mei; Cao, Ai-Li; Zheng, Jian-Pu; Wang, Hong-Wei; Sun, Yong-Shun; Liu, Chun-Fang; Zhang, Bei-Bei; Wang, Yi; Zhu, Sheng-Liang; Wu, Da-Zheng

    2014-11-01

    Gastroesophageal reflux is a common disorder closely related to chronic airway diseases, such as chronic cough, asthma, chronic bronchitis, and chronic obstructive disease. Indeed, gastroesophageal acid reflux into the respiratory tract causes bronchoconstriction, but the underlying mechanisms have still not been clarified. This study aimed to elucidate functional changes of bronchial smooth muscles (BSMs) isolated from guinea pigs in an animal model of gastroesophageal reflux. The marked airway inflammation, hyperresponsiveness and remodeling were observed after guinea pigs were exposed to intraesophageal HCl infusion for 14 days. In addition, contractile responses to acetylcholine (ACh), KCl, electrical field stimulation, and extracellular Ca(2+) were greater in guinea pigs infused with HCl compared with control groups. The L-type voltage-dependent Ca(2+) channels (L-VDCC) blocker, nicardipine, significantly inhibited ACh- and Ca(2+)-enhanced BSM contractions in guinea pigs infused with HCl. The Rho-kinase inhibitor, Y27632, attenuated ACh-enhanced BSM contractions in guinea pigs infused with HCl. Moreover, mRNA and protein expressions for muscarinic M2 and M3 receptors, RhoA, and L-VDCC in BSM were detected by real-time PCR and Western blot. Expressions of mRNA and protein for muscarinic M3 receptors, RhoA, and L-VDCC were greater than in BSM of HCl-infused guinea pigs, whereas levels of muscarinic M2 receptors were unchanged. We demonstrate that acid infusion to the lower esophagus and, subsequently, microaspiration into the respiratory tract in guinea pigs leads to airway hyperresponsiveness and overactive BSM. Functional and molecular results indicate that overactive BSM is the reason for enhancement of extracellular Ca(2+) influx via L-VDCC and Ca(2+) sensitization through Rho-kinase signaling.

  2. Local sustained delivery of bupivacaine HCl from a new castor oil-based nanoemulsion system.

    Science.gov (United States)

    Rachmawati, Heni; Arvin, Yang Aryani; Asyarie, Sukmadjaja; Anggadiredja, Kusnandar; Tjandrawinata, Raymond Rubianto; Storm, Gert

    2018-06-01

    Bupivacaine HCl (1-butyl-2',6'-pipecoloxylidide hydrochloride), an amide local anesthetic compound, is a local anesthetic drug utilized for intraoperative local anesthesia, post-operative analgesia and in the treatment of chronic pain. However, its utility is limited by the relative short duration of analgesia after local administration (approximately 9 h after direct injection) and risk for side effects. This work is aimed to develop a nanoemulsion of bupivacaine HCl with sustained local anesthetics release kinetics for improved pain management, by exhibiting extended analgesic action and providing reduced peak levels in the circulation to minimize side effects. Herein, biodegradable oils were evaluated for use in nanoemulsions to enable sustained release kinetics of bupivacaine HCl. Only with castor oil, a clear and stable nanoemulsion was obtained without the occurrence of phase separation over a period of 3 months. High loading of bupivacaine HCl into the castor oil-based nanoemulsion system was achieved with about 98% entrapment efficiency and the resulting formulation showed high stability under stress conditions (accelerated stability test) regarding changes in visual appearance, drug content, and droplet size. We show herein that the in vitro release and in vivo pharmacokinetic profiles as well as pharmacodynamic outcome (pain relief test) after subcutaneous administration in rats correlate well and clearly demonstrate the prolonged release and extended duration of activity of our novel nanoformulation. In addition, the lower C max value achieved in the blood compartment suggests the possibility that the risk for systemic side effects is reduced. We conclude that castor oil-based nanomulsion represents an attractive pain treatment possibility to achieve prolonged local action of bupivacaine HCl.

  3. Deciphering metamorphic evolution of rocks by means of Hf isotopes

    Czech Academy of Sciences Publication Activity Database

    Sláma, Jiří; Košler, J.; Pedersen, R. B.

    2006-01-01

    Roč. 70, 18 /S1/ (2006), A596-A596 ISSN 0046-564X. [Goldschmidt Conference /16./. 27.08.2006-01.09.2006, Melbourne] Institutional research plan: CEZ:AV0Z30130516 Keywords : Hafnium * Hf isotopes * granulite Subject RIV: DD - Geochemistry

  4. Lu-Hf and Sm-Nd garnet geochronology

    DEFF Research Database (Denmark)

    Smit, Matthijs Arjen; Scherer, Erik E.; Mezger, Klaus

    2013-01-01

    To investigate the systematics of the 176Lu–176Hf and 147Sm–143Nd garnet chronometers, we performed REE and isotope analyses on garnet crystals of different size (0.55–3.1 mm radius) from a single granulite specimen (Archean Pikwitonei Granulite Domain, Manitoba, Canada). The Lu–Hf dates are simi......To investigate the systematics of the 176Lu–176Hf and 147Sm–143Nd garnet chronometers, we performed REE and isotope analyses on garnet crystals of different size (0.55–3.1 mm radius) from a single granulite specimen (Archean Pikwitonei Granulite Domain, Manitoba, Canada). The Lu–Hf dates...... are similar among grains having radii larger than 1.3 mm (weighted mean: 2714±6 Ma2714±6 Ma; 2 s.d.) and up to 20 Myr younger for finer fractions. In contrast, Sm–Nd dates are equal to or younger than the 2641–2637 Ma age of peak metamorphism. The roles of concurrently digested inclusions and core–rim Lu/Sm...

  5. Rate coefficients for the reactions of OH and OD with HCl and DCl between 200 and 400 K

    Energy Technology Data Exchange (ETDEWEB)

    Battin-Leclerc, F. [CNRS, Nancy (France). Dept. de Chimie-Physique des Reactions; Talukdar, R.K. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Aeronomy Lab.]|[Univ. of Colorado, Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences; Kim, I.K.; Portmann, R.W.; Ravishankara, A.R. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Aeronomy Lab.]|[Univ. of Colorado, Boulder, CO (United States). Dept. of Chemistry and Biochemistry

    1999-04-29

    HCl is a principal reservoir of inorganic chlorine in the stratosphere. Rate coefficients for the reaction of OH radical with HCl ({kappa}{sub 1}) between 200 and 400 K, were measured to be 3.28 {times} 10{sup {minus}17} T{sup 1.66} exp [184/T]cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} by producing OH via pulsed laser photolysis and detecting it via laser induced fluorescence. The rate coefficients for the reactions of OH and DCl ({kappa}{sub 2}), OD with HCl ({kappa}{sub 3}), and OD with DCl ({kappa}{sub 4}) were also measured using the same method to be {kappa}{sub 2} = 2.9 {times} 10{sup {minus}12} exp [{minus}728/T], {kappa}{sub 3} = 8.1 {times} 10{sup {minus}18} T{sup 1.85} exp [300/T], and {kappa}{sub 4} = 2.5 {times} 10{sup {minus}12} exp [{minus}660/T] cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. {kappa}{sub 1}--{kappa}{sub 4} were computed for 200 < T < 400 K using the variational transition theory, including tunneling corrections, to be {kappa}{sub 1} = 1.49 {times} 10{sup {minus}16} T{sup 1.35} exp [262/T], {kappa}{sub 2} = 9.04 {times} 10{sup {minus}20} T{sup 2.34} exp[429/T], {kappa}{sub 3} = 1.01 {times} 10{sup {minus}16} T{sup 1.4} exp[309/T], and {kappa}{sub 4} = 1.64 {times} 10{sup {minus}19} T{sup 2.27} exp [385/T]cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, in reasonable agreement with experiments. They were also used to analyze the origin of the isotope effects. A two-dimensional chemical transport model calculation shows that the measured higher values of {kappa}{sub 1} at low temperatures do not significantly alter the calculated ozone abundance, or its trend, in the stratosphere.

  6. Self-diffusion of Er and Hf inpure and HfO/sub 2/-doped polycrystalline Er/sub 2/O/sub 3/. [Hf-175 and Er-169

    Energy Technology Data Exchange (ETDEWEB)

    Scheidecker, R.W.

    1979-01-01

    Using a tracer technique, self-diffusion of Er and Hf was measured over the approximate temperature interval of 1600 to 1970/sup 0/C in pure and HfO/sub 2/-doped polycryatalline Er/sub 2/O/sub 3/. Up to about 10 m/o HfO/sub 2/ dopant level, the Er self-diffusion coefficients followed a relationship based on cation vacancies. Above 10 m/o HfO/sub 2/, deviation from this relationship occurred, apparently due to clustering of cation vacancies and oxygen interstitials around the dopant hafnia ion. The activation energy for the self-diffusion of Er in pure Er/sub 2/O/sub 3/ was 82.2 Kcal/mole and increased with the HfO/sub 2/ dopant level present. Self-diffusion of Hf was measured in pure Er/sub 2/O/sub 3/ having two impurity levels, and a separation of the grain boundary. The volume diffusion of Hf showed both extrinsic and intrinsic behavior with the transition temperature increasing with the impurity level present in Er/sub 2/O/sub 3/. The activation energy for Hf volume diffusion in the intrinsic region was high, i.e. 235 -+ 9.5 Kcal/mole. The grain boundary diffusion was apparently extrinsic over the entire temperature interval Very low Hf self diffusion rates were found in both pure and HfO/sub 2/ doped Er/sub 2/O/sub 3/ compositions. Despite a clustering effect, the HfO/sub 2/ dopant increased the Hf volume diffusion coefficients.

  7. Nanosized Hydroxyapatite Precipitation on the Ti—30Ta—xHf Alloys.

    Science.gov (United States)

    Lee, Kang; Jang, Jae- In; Han-Cheol, Choe

    2017-04-01

    In this study, we prepared hydroxyapatite (HAp) layer on the alkali treated Ti–30Ta–xHf alloys using electrochemical deposition method. Ti–30Ta–xHf alloys was anodized in 5 M NaOH solution at 0.3 A for 10 min. Alkali treated Ti–30Ta–xHf surface formed by anodization step which acted as templates and anchorage for growth of the HAp during subsequent pulsed electrochemical deposition process at 85 °C. The phase and morphologies of deposited HAp layer were affected by the Hf contents of Ti–30Ta–xHf alloys. The nano-scale rod-like HAp layer was formed on untreated Ti–30Ta–xHf alloys with partially low crystallinity. In the case of alkali treated Ti–30Ta–xHf, nano-sized needle-like layers were transferred to nano-flake surface and denser morphology as Hf content increased.

  8. HF Radar observations of the Dardanelles outflow current in North Eastern Aegean using validated WERA HF radar data

    Directory of Open Access Journals (Sweden)

    Z. KOKKINI

    2014-12-01

    Full Text Available A two-site WERA HF radar station was installed in November 2009 at the eastern coast of Lemnos Island in North Aegean Sea, aiming to monitor the surface inflow of Black Sea waters exiting from the Dardanelles Strait, as well as to constitute a coastal management tool for incidents of oil-pollution or save-and-rescue operations. Strong interference by foreign transmissions is a source of noise deteriorating the quality of the backscattered signal, thus significantly reducing the HF radar’s effective data return rate. In order to ameliorate this problem, further quality-control and data gap interpolating procedures have been developed and applied, to be used in addition to the procedures incorporated and used by the manufacturer’s signal processing software. The second-level processing involves traditional despiking in the temporal domain, preceding Empirical Orthogonal Function analysis. The latter is used not only to filter high-frequency noise but also to fill data gaps in time and space. The data reconstruction procedure has been assessed via comparison of (a HF radial with CODE-type drifter radial velocities as well as (b HF-derived virtual drifter tracks with actual drifter tracks. The main circulation features and their variability, as revealed by the reconstructed fields, are presented.

  9. HF filter design and computer simulation

    CERN Document Server

    Rhea, Randall W

    1994-01-01

    A book for engineers who design and build filters of all types, including lumped element, coaxial, helical, dielectric resonator, stripline and microstrip types. A thorough review of classic and modern filter design techniques, containing extensive practical design information of passband characteristics, topologies and transformations, component effects and matching. An excellent text for the design and construction of microstrip filters.

  10. HfO2/Pr2O3 gate dielectric stacks

    Science.gov (United States)

    Sidorov, F.; Molchanova, A.; Rogozhin, A.

    2016-12-01

    Electrical properties of MOS structures based on molecular beam epitaxy formed HfO2/Pr2O3 gate dielectric stacks have been studied by CV, GV and IV characteristics. Electrical properties of the structures with HfO2/Pr2O3 and PEALD HfO2 dielectric layers were compared. Higher gate leakage current and lower interface trap level density in the structure with HfO2/Pr2O3 dielectric layer was observed.

  11. Material parameters from frequency dispersion simulation of floating gate memory with Ge nanocrystals in HfO2

    Science.gov (United States)

    Palade, C.; Lepadatu, A. M.; Slav, A.; Lazanu, S.; Teodorescu, V. S.; Stoica, T.; Ciurea, M. L.

    2018-01-01

    Trilayer memory capacitors with Ge nanocrystals (NCs) floating gate in HfO2 were obtained by magnetron sputtering deposition on p-type Si substrate followed by rapid thermal annealing at relatively low temperature of 600 °C. The frequency dispersion of capacitance and resistance was measured in accumulation regime of Al/HfO2 gate oxide/Ge NCs in HfO2 floating gate/HfO2 tunnel oxide/SiOx/p-Si/Al memory capacitors. For simulation of the frequency dispersion a complex circuit model was used considering an equivalent parallel RC circuit for each layer of the trilayer structure. A series resistance due to metallic contacts and Si substrate was necessary to be included in the model. A very good fit to the experimental data was obtained and the parameters of each layer in the memory capacitor, i.e. capacitances and resistances were determined and in turn the intrinsic material parameters, i.e. dielectric constants and resistivities of layers were evaluated. The results are very important for the study and optimization of the hysteresis behaviour of floating gate memories based on NCs embedded in oxide.

  12. Alloy 33: A new material for the handling of HNO3/HF media in reprocessing of nuclear fuel

    International Nuclear Information System (INIS)

    Koehler, M.; Heubner, U.; Eichenhofer, K.W.; Renner, M.

    1997-01-01

    Alloy 33, an austenitic 33Cr-32Fe-31Ni-1.6Mo-0.6Cu-0.4N material shows excellent resistance to corrosion when exposed to highly oxidizing media as e.g. HNO 3 and HNO 3 /HF mixtures which are encountered in reprocessing of nuclear fuel. According to the test results available so far, resistance to corrosion in boiling azeotropic (67%) HNO 3 is about 6 and 2 times superior to AISI 304 L and 310 L. In higher concentrated nitric acid it can be considered corrosion resistant up to 95% HNO 3 at 25 C, up to 90% HNO 3 at 50 C and up to somewhat less than 85% HNO 3 at 75 C. In 20% HNO 3 /7% HF at 50 C its resistance to corrosion is superior to AISI 316 Ti and Alloy 28 by factors of about 200 and 2.4. Other media tested with different results include 12% HNO 3 with up to 3.5% HF and 0.4% HF with 32 to 67.5% HNO 3 at 90 C. Alloy 33 is easily fabricated into all product forms required for chemical plants (e.g. plate, sheet, strip, wire, tube and flanges). Components such as dished ends and tube to tube sheet weldments have been successfully fabricated facilitating the use of Alloy 33 for reprocessing of nuclear fuel

  13. Preliminary results from the Arecibo Heating Experiment (HEX): HF to GNSS

    Science.gov (United States)

    Jackson-Booth, N.; Penney, R.; Bernhardt, P. A.; Martin, P. L.; Buckland, R.; Morton-Orr, T.; Nossa, E.; Buckland, R.

    2017-12-01

    The ionosphere is subject to many solar and terrestrial influences that can generate disturbances, causing degradation to modern communication and navigational systems. Whilst the disturbances are normally caused by natural phenomena such as hurricanes, earthquakes and solar storms; they can also be generated by artificially modifying the ionosphere. Artificial Ionospheric Modification (AIM) attempts to alter a small region of the ionosphere in order to perturb the RF propagation environment. This can be achieved through injecting the ionosphere with aerosols, chemicals or radio signals. The effects of any such modification can be detected through the deployment of sensors, including ground based high-frequency (HF) sounders and dual-band Global Navigation Satellite System (GNSS) receivers. HF sounders allow measurements of the bottom-side of the ionosphere. GNSS receivers offer a convenient means of obtaining information about the ionosphere, including ionospheric disturbances through changes in the derived total electron content information. The Heating EXperiment (HEX), which took place in March and May 2017, was designed to further our understanding of the phenomena caused by artificially heating a small region of the ionosphere, using the Arecibo facility in Puerto Rico. This was achieved by utilizing a HF measurement experiment spread between Texas and Trinidad and the deployment of a small scale travelling ionospheric disturbance (TID) network near the heater. The TID network comprised three GNSS receivers along baselines of approximately 4 km, located 20 km north of the heater. This paper presents preliminary results from the HEX campaign, including evidence of heating-induced disturbances enhancing propagation between Virginia and Trinidad. The implications of generated irregularities on GNSS will also be discussed.

  14. Nanotube formation and morphology change of Ti alloys containing Hf for dental materials use

    International Nuclear Information System (INIS)

    Jeong, Yong-Hoon; Lee, Kang; Choe, Han-Cheol; Ko, Yeong-Mu; Brantley, William A.

    2009-01-01

    In this paper, Ti-Hf (10, 20, 30 and 40 wt.%) alloys were prepared by arc melting, and subjected to heat treatment for 24 h at 1000 o C in an argon atmosphere. Formation of surface nanotubes was achieved by anodizing a Ti-Hf alloy in 1.0 M H 3 PO 4 electrolytes with small amounts of NaF at room temperature. Microstructures of the alloys and nanotube morphology were examined by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The homogenized Ti-Hf alloys had a needle-like microstructure of α phase, and nanotubes formed on Ti-xHf alloys had the anatase phase after treatment that promoted crystallization. Uniform nanotubes formed for Hf contents up to 20 wt.%. Irregular nanotubes formed on the Ti-30Hf and Ti-40Hf alloys. The structure of the irregular layers on the Ti-30Hf and Ti-40Hf alloys had nanotubes of two sizes. Increasing the Hf content in Ti led to the formation of nanotubes with more narrow size. The pores in the nanotubes typically had a diameter ranging from 80-120 nm and a length of approximately 1.7 μm. It is concluded that nanotube morphology on Ti-Hf alloys can controlled by varying the amount of Hf.

  15. Photon strength function in the Hf-181 nucleus by method of two-step cascade

    CERN Document Server

    Le Hong Khiem

    2003-01-01

    The applicability of sum-coincidence measurements of two-step cascade gamma ray spectra determining Photon Strength Function (PSF) of Hf-181 induced from Hf-180 (n,2 gamma) Hf-181 reaction is presented. Up to 80% intensity of the primary gamma ray transitions in a wide energy range have been deduced and compared to model calculation.

  16. EPR, Endor and DFT Studies on X-Irradiated Single Crystals of L-Lysine HCl 2 H 2O and L-Arginine HCl H2O

    Science.gov (United States)

    Zhou, Yiying; Nelson, William H.

    2011-03-01

    When proteins and DNA interact, arginine and lysine are the two amino acids most often in close contact with the DNA. In order to understand the radiation damage to DNA in vivo, which is always associated with protein, it is important to learn the radiation chemistry of arginine and lysine independently, and then complexed to DNA. This work studied X-irradiated single crystals of L- lysine . HCl . 2 H2 O and L- arginine . HCl . H2 O with EPR, ENDOR techniques and DFT calculations. In both crystal types irradiated at 66K, the carboxyl anion radical and the decarboxylation radical were identified. Specifically, the calculations performed on the cluster models for the carboxyl anion radicals reproduced the proton transfers to the carboxyl group from the neighboring molecules through the hydrogen bonds. Moreover, computations supported the identification of one radical type within irradiated arginine as the guanidyl radical anion with an electron trapped by the guanidyl group. Based on the radicals detected in the crystal irradiated at 66K and at 298K, and the annealing experiments from the irradiation at 66K, the mechanisms of the irradiation damage on lysine and arginine were proposed, and the possible effects of irradiated arginine and lysine to the DNA within chromatin were analyzed.

  17. Quantitation of cefepime.2HCl dihydrate in cefepime.2HCl monohydrate by diffuse reflectance IR and powder X-ray diffraction techniques.

    Science.gov (United States)

    Bugay, D E; Newman, A W; Findlay, W P

    1996-10-01

    The identification, characterization and quantitation of crystal forms is becoming increasingly important within the pharmaceutical industry. Multi-disciplinary, physical analytical techniques are necessary for this task. In this work, diffuse reflectance mid-infrared (IR) and powder X-ray diffraction (XRD) analyses were used to identify two different hydrated forms of cefepime.2HCl, a cephalosporin. Characterization of the mono- and dihydrate forms led to separate IR and XRD quantitative assays for the determination of dihydrate content in cefepime.2HCl monohydrate bulk material. For the IR assay, a working range of 1.0-8% (w/w) was established with a minimum quantifiable level (MQL) of 1.0% (w/w) and a limit of detection (LD) of 0.3% (w/w) dihydrate in monohydrate material. The XRD assay displayed a working range of 2.5-15% (w/w) with an MQL of 2.5% (w/w) and an LD of 0.75% (w/w). Cross validation was performed between the two techniques, with a good correlation displayed for each assay as compared with the known concentrations and as compared with each other. In addition, a full evaluation of potential assay errors was made.

  18. Action mechanism of hydrogen gas on deposition of HfC coating using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yalei, E-mail: yaleipm@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Li, Zehao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Xiong, Xiang, E-mail: xiongx@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China); Li, Xiaobin [School of Metallurgy and Environment, Central South University, Changsha, 410083 (China); Chen, Zhaoke; Sun, Wei [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083 (China)

    2016-12-30

    Highlights: • HfC coatings were deposited on C/C composites by LPCVD using HfCl4-CH4-H2-Ar system. • Action mechanism of H2 on structure and growth behavior of HfC coating was studied. • Increased H2 concentration leads to transformation in growth mechanism of coating. - Abstract: Hafnium carbide coatings were deposited on carbon/carbon composites by low pressure chemical vapor deposition using HfCl{sub 4}-CH{sub 4}-H{sub 2}-Ar system. The microstructure, mechanical and ablation resistance performance of HfC coatings deposited with various H{sub 2} concentrations were investigated. The effect of hydrogen gas on the deposition of HfC coating was also discussed. Results show that all of the deposited coatings are composed of single cubic HfC phase, the hydrogen gas acted as a crucial role in determining the preferred orientation, microstructure and growth behavior of HfC coatings. During the deposition process, the gas phase supersaturation of the reaction species can be controlled by adjusting the hydrogen gas concentration. When deposited with low hydrogen gas concentration, the coating growth was dominated by the nucleation of HfC, which results in the particle-stacked structure of HfC coating. Otherwise, the coating growth was dominated by the crystal growth at high hydrogen gas concentration, which leads to the column-arranged structure of HfC coating. Under the ablation environment, the coating C2 exhibits better configurational stability and ablation resistance. The coating structure has a significant influence on the mechanical and ablation resistance properties of HfC coating.

  19. HF Propagation sensitivity study and system performance analysis with the Air Force Coverage Analysis Program (AFCAP)

    Science.gov (United States)

    Caton, R. G.; Colman, J. J.; Parris, R. T.; Nickish, L.; Bullock, G.

    2017-12-01

    The Air Force Research Laboratory, in collaboration with NorthWest Research Associates, is developing advanced software capabilities for high fidelity simulations of high frequency (HF) sky wave propagation and performance analysis of HF systems. Based on the HiCIRF (High-frequency Channel Impulse Response Function) platform [Nickisch et. al, doi:10.1029/2011RS004928], the new Air Force Coverage Analysis Program (AFCAP) provides the modular capabilities necessary for a comprehensive sensitivity study of the large number of variables which define simulations of HF propagation modes. In this paper, we report on an initial exercise of AFCAP to analyze the sensitivities of the tool to various environmental and geophysical parameters. Through examination of the channel scattering function and amplitude-range-Doppler output on two-way propagation paths with injected target signals, we will compare simulated returns over a range of geophysical conditions as well as varying definitions for environmental noise, meteor clutter, and sea state models for Bragg backscatter. We also investigate the impacts of including clutter effects due to field-aligned backscatter from small scale ionization structures at varied levels of severity as defined by the climatologically WideBand Model (WBMOD). In the absence of additional user provided information, AFCAP relies on International Reference Ionosphere (IRI) model to define the ionospheric state for use in 2D ray tracing algorithms. Because the AFCAP architecture includes the option for insertion of a user defined gridded ionospheric representation, we compare output from the tool using the IRI and ionospheric definitions from assimilative models such as GPSII (GPS Ionospheric Inversion).

  20. Determination of prilocaine HCl in bulk drug and pharmaceutical formulation by GC-NPD method

    Directory of Open Access Journals (Sweden)

    Atila Alptug

    2013-01-01

    Full Text Available The novel analytical method was developed and validated for determination of prilocaine HCl in bulk drug and pharmaceutical formulation by gas chromatography-nitrogen phosphorus detection (GC-NPD. The chromatographic separation was performed using a HP-5MS column. The calibration curve was linear over the concentration range of 40-1000 ng ml-1 with a correlation coefficient of 0.9998. The limits of detection (LOD and quantification (LOQ of method were 10 ng ml-1 and 35 ng ml-1, respectively. The within-day and between-day precision, expressed as the percent relative standard deviation (RSD% was less than 5.0%, and accuracy (percent relative error was better than 4.0%. The developed method can be directly and easily applied for determination of prilocaine HCl in bulk drug and pharmaceutical formulation using internal standard methodology.

  1. Picture analysis in CT-HF and its CT photographs

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Kohirasawa, Hideo; Shinojima, Masayasu; Tokui, Mitsuru; Seo, Kunihiko.

    1980-01-01

    CT (computed tomography) apparatus is rarely used yet in the field of dentistry, though it seems useful. It is possibly because of the artefacts caused by the metallic parts attached to teeth, the large partial volume effect due to many bones and the problems of positioning and reproducibility. After considering the various requirements of the CT apparatuses in dental field, CT-HF (of T/R type) was chosen as such apparatus, and installed as the first in dentistry. In the CT-HF apparatus, the inner diameter of the gantry is up to 300 mm, and the position of a tomographic plane is only 40 mm away from the front of gantry. Mainly the usefulness of scanography in positioning and the usefulness of the CT apparatus in the picture analysis and processing in dental field are described. (J.P.N.)

  2. Accelerators for a Higgs Factory: Linear vs. Circular . (HF2012)

    CERN Document Server

    Blondel, A; Chou, W; Gao, J; Schulte, D; Yokoya, K

    2013-01-01

    The 4th of July 2012 was a historical moment for high-energy physics (HEP). On that day, CERN announced that both the ATLAS and CMS experiments had discovered a new Higgs-like boson. In this report, we shall assume that this newly found particle will turn out to be a Higgs boson, the key signature of the Standard Model. At the ICFA meeting on July 8 in Melbourne, an ICFA Beam Dynamics Workshop “Accelerators for a Higgs Factory: Linear vs. Circular” (HF2012) was approved. This workshop took place from November 14 to 16, 2012 at Fermilab, USA. (conferences.fnal.gov/hf2012) Seventy-one people from 31 institutions in Asia, Europe and North America attended.

  3. Present status of CMS HF quartz fiber calorimetry

    CERN Document Server

    Önel, Y M

    2002-01-01

    The experiments at the Large Hadron Collider will have to deal with unprecedented radiation levels. The design of the CMS forward calorimetry detector (HF) is now finalized. The present design of CMS calls for the HF calorimeter to be based on quartz fiber technology. It consists of two modules, located symmetrically at about 11 meters from either side of interaction point. They cover the pseudorapidity range 3-5. The length along the beam is 1.65 m or 10 nuclear interaction lengths. Each calorimeter consists of a large steel block that serves as the absorber. Embedded quartz fibers in the steel absorber run parallel to the beam and constitute the active component of the detector. In order to optimize energy resolution for E and E /sup T/ flows and forward jets, the calorimeter is effectively segmented longitudinally by using two different fiber lengths. The present status will be discussed. (6 refs).

  4. Performance Analysis of HF Band FB-MC-SS

    Energy Technology Data Exchange (ETDEWEB)

    Hussein Moradi; Stephen Andrew Laraway; Behrouz Farhang-Boroujeny

    2016-01-01

    Abstract—In a recent paper [1] the filter bank multicarrier spread spectrum (FB-MC-SS) waveform was proposed for wideband spread spectrum HF communications. A significant benefit of this waveform is robustness against narrow and partial band interference. Simulation results in [1] demonstrated good performance in a wideband HF channel over a wide range of conditions. In this paper we present a theoretical analysis of the bit error probably for this system. Our analysis tailors the results from [2] where BER performance was analyzed for maximum ration combining systems that accounted for correlation between subcarriers and channel estimation error. Equations are give for BER that closely match the simulated performance in most situations.

  5. Comparison between HF radar current data and moored ADCP currentmeter

    International Nuclear Information System (INIS)

    Cosoli, S.

    2005-01-01

    A preliminary assessment of accuracy of a two-sites shore-based HF Radar network along the Venice Lagoon littoral was attempted by means of comparison with a 57.5 day-long ADCP current time series for the period September-October 2002. Results showed that radar measurements were accurate ( O . The main differences between the HF radar and surface ADCP currents can be explained in terms of random errors affecting the measurement technique and the daily sea breeze forcing, since low-pass filtering of current time series significantly improved the correlation and decreased the RMS of the differences between the two measured data set. Comparison of the semidiurnal (M2, S2) tidal band suggested good agreement between tidal ellipse amplitudes. Wind forcing on a daily time-scale (sea-breeze) was associated with larger differences between radar and ADCP currents at a diurnal band due to the presence of a vertical shear in the surface layer

  6. Fe substitution and pressure effects on superconductor Re6Hf

    Science.gov (United States)

    Yang, Jinhu; Guo, Yang; Wang, Hangdong; Chen, Bin

    2018-04-01

    Polycrystalline samples of (Re1-xFex) 6Hf were synthesized by arc-melting method and the phase purity of the samples was confirmed by powder X-ray diffraction method. In this paper, we report the Fe substitution and pressure effect on non-centrosymmetric superconductor Re6Hf. The superconducting transition temperature, TC, is confirmed by the measurements of magnetic susceptibility, electrical resistivity for x ≤ 0.22 samples with the temperature down to 2 K. We find that the TC is suppressed with the increase of Fe content. The upper critical field Hc2 is larger than the value predicted by the WHH theory and shows a linear temperature dependence down to 2 K. When upon the application of external pressure up to 2.5 GPa, the TC decreases monotonically at a rate dlnTC/dP of 0.01 GPa-1.

  7. Formulation Design, Optimization and Pharmacodynamic Evaluation of Sustained Release Mucoadhesive Microcapsules of Venlafaxine HCl

    OpenAIRE

    Swain, S.; Behera, A.; Dinda, S. C.; Patra, C. N.; Jammula, Sruti; Beg, S.; Rao, M. E. B.

    2014-01-01

    The objective of present research work was to design and characterize the venlafaxine HCl-loaded sodium alginate-based mucoadhesive microcapsules by ionic gelation technique using HPMC K100M as mucoadhesive polymer. The Placket-Burman Design was applied for preliminary screening of the formulations and systematic optimization by using Box-Behnken Design. The prepared microcapsules were characterized for drug content, entrapment efficiency, micromeritic properties, particle size, swelling inde...

  8. UC oxidation with HNO2 in aqueous solutions of HNO3 and HClO4

    International Nuclear Information System (INIS)

    Maslennikov, A.; Genin, X.; Vermeleun, J.; Moisy, P.

    2009-01-01

    The oxidation of UC powder was studied in 0.5-6.0 M HNO 3 and HClO 4 , containing 0.01-0.1 M NaNO 2 , at ambient temperature. The addition of nitrous acid caused the oxidation potential to exceed 400 mV/SCE and thus accelerated the dissolution and increased the dissolution yield to exceed 95%. One hundred percent dissolution at room temperature was achieved within 30 to 40 min when 3.0-6.0 M HNO 3 was used that contained more than 0.005 M HNO 2 . The dissolution rate increased with increasing HNO 3 concentration and initial solid-to-liquid ratio. The effective dissolution rate constants and reaction orders were estimated for the UC oxidation with H + , NO 3 - and HNO 2 in 0.5-6.0 M HClO 4 . The rate of UC oxidation with HNO 2 exceeded 50-80 times its oxidation rates with NO 3 - ions. During UC oxidation with HNO 2 in 0.5-6.0 M HClO 4 . 60-85% carbon was oxidized to CO 2 . The C/U(VI) ratio in the dissolver solution decreased from 0.5 to 0.1 mg eq/mol with increasing of HClO 4 and HNO 2 solution concentration. Two to five percent of the carbon remained in the insoluble residue of the HNO 3 dissolver solutions, even when a 100% U(VI) yield was observed. Scanning electron microscopy of the insoluble residue showed the carbon particle size between 1.0 and 5.0 μm. (orig.)

  9. Resonant X-ray Raman scattering on molecules: A benchmark study on HCl

    International Nuclear Information System (INIS)

    Carniato, Stephane; Taieb, Richard; Journel, Loic; Guillemin, Renaud; Stolte, Wayne C.; Lindle, Dennis W.; Gel'mukhanov, Faris; Simon, Marc

    2010-01-01

    Resonant X-ray Raman scattering is a powerful tool to study molecular dynamics and subtle chemical effects like the molecular field beyond vibrational and lifetime limitations. Using this technique in the tender X-ray region, gas phase HCl is studied as a benchmark molecule for other compounds like freons, which play an important role in physical-chemical properties of the ozone layer of atmosphere.

  10. Resonant X-ray Raman scattering on molecules: A benchmark study on HCl

    Energy Technology Data Exchange (ETDEWEB)

    Carniato, Stephane [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); Taieb, Richard, E-mail: richard.taieb@upmc.f [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); Journel, Loic; Guillemin, Renaud [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); Stolte, Wayne C.; Lindle, Dennis W. [Department of Chemistry, University of Nevada, Las Vegas, NV 89154-4003 (United States); Gel' mukhanov, Faris [Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Simon, Marc [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matiere et Rayonnement, F-75005 Paris (France)

    2010-08-15

    Resonant X-ray Raman scattering is a powerful tool to study molecular dynamics and subtle chemical effects like the molecular field beyond vibrational and lifetime limitations. Using this technique in the tender X-ray region, gas phase HCl is studied as a benchmark molecule for other compounds like freons, which play an important role in physical-chemical properties of the ozone layer of atmosphere.

  11. Thermodynamics and Efficiency of a CuCl(aq)/HCl(aq) Electrolyzer

    International Nuclear Information System (INIS)

    Hall, Derek M.; Akinfiev, Nikolay N.; LaRow, Eric G.; Schatz, Richard S.; Lvov, Serguei N.

    2014-01-01

    The high ionic strength and complex speciation of the anolyte solution within the CuCl(aq)/HCl(aq) electrolytic cell have impeded predictions of the energy requirements for the cell's electrolytic reaction at 25 °C and 1 bar. After collecting experimental open circuit potential (OCP) data and comparing the values obtained with predictions from prospective thermodynamic models, an approach to predict thermodynamic values and the overall efficiency was formulated. The compositions of the experimental measurements ranged from 2-2.5 mol of CuCl(aq) with 8-9 mol of HCl(aq) per kilogram of water in anolyte solution and 8-9 mol of HCl(aq) per kilogram of water in catholyte solution. From the OCP data, it was found that activity coefficient and speciation effects were critical in predicting the Gibbs energy, entropy and thermodynamic (intrinsic maximum) efficiency of the electrolytic cell. At equilibrium, all thermodynamic functions of the anolyte redox reactions were the same after activity coefficients and speciation effects were taken into account. The electrochemical reactions’ Gibbs energy and entropy were found to be 9700 J/mol and 2.18 J/(mol K) at 25 °C and 1 bar, which indicated that the reactions required a small amount of electrical and thermal energy to proceed. With thermodynamic values for the electrolytic reaction and experimental data from a CuCl(aq)/HCl(aq) electrolytic cell, the voltage, current, thermodynamic and overall efficiency were calculated. The overall efficiency ranged from 15 to 95% depending on the current density

  12. Collision-Induced Dissociation Study of Strong Hydrogen-Bonded Cluster Ions Y-(HF) n (Y=F, O2) Using Atmospheric Pressure Corona Discharge Ionization Mass Spectrometry Combined with a HF Generator.

    Science.gov (United States)

    Sakamoto, Kenya; Sekimoto, Kanako; Takayama, Mitsuo

    2017-01-01

    Hydrogen fluoride (HF) was produced by a homemade HF generator in order to investigate the properties of strong hydrogen-bonded clusters such as (HF) n . The HF molecules were ionized in the form of complex ions associated with the negative core ions Y - produced by atmospheric pressure corona discharge ionization (APCDI). The use of APCDI in combination with the homemade HF generator led to the formation of negative-ion HF clusters Y - (HF) n (Y=F, O 2 ), where larger clusters with n ≥4 were not detected. The mechanisms for the formation of the HF, F - (HF) n , and O 2 - (HF) n species were discussed from the standpoints of the HF generator and APCDI MS. By performing energy-resolved collision-induced dissociation (CID) experiments on the cluster ions F - (HF) n ( n =1-3), the energies for the loss of HF from F - (HF) 3 , F - (HF) 2 , and F - (HF) were evaluated to be 1 eV or lower, 1 eV or higher, and 2 eV, respectively, on the basis of their center-of-mass energy ( E CM ). These E CM values were consistent with the values of 0.995, 1.308, and 2.048 eV, respectively, obtained by ab initio calculations. The stability of [O 2 (HF) n ] - ( n =1-4) was discussed on the basis of the bond lengths of O 2 H-F - (HF) n and O 2 - H-F(HF) n obtained by ab initio calculations. The calculations indicated that [O 2 (HF) 4 ] - separated into O 2 H and F - (HF) 3 .

  13. Clinical trials update from the Heart Failure Society of America Meeting 2009: FAST, IMPROVE-HF, COACH galectin-3 substudy, HF-ACTION nuclear substudy, DAD-HF, and MARVEL-1.

    Science.gov (United States)

    Lainscak, Mitja; Coletta, Alison P; Sherwi, Nasser; Cleland, John G F

    2010-02-01

    This article presents findings and a commentary on late-breaking trials presented during the meeting of the Heart Failure Society of America in September 2009. Unpublished reports should be considered as preliminary, since analyses may change in the final publication. The FAST trial showed somewhat better performance of intrathoracic impedance for prediction of deterioration in patients with heart failure (HF) when compared with daily weighing. The IMPROVE-HF study reported the benefits of education on the management of patients with systolic HF. Galectin-3 appeared a useful method for improving risk stratification of patients with chronic HF in a substudy of the COACH trial. A nuclear substudy of the HF-ACTION trial failed to demonstrate that resting myocardial perfusion imaging, a measure of myocardial scar and viability, was clinically useful. A small randomized controlled trial (DAD-HF) suggested that the use of low-dose dopamine in patients with acutely decompensated HF was associated with less deterioration in renal function and less hypokalaemia. The MARVEL-1 trial raises further concerns about the safety of myoblast transplantation in ischaemic HF.

  14. The phase diagram of a part of the system Ti-Hf-O

    International Nuclear Information System (INIS)

    Ruda, G.I.; Vavilova, V.V.

    1979-01-01

    Using the methods of physico-chemical analysis phase equilibria in Ti-Hf-O system in the concentration range up to 50 at.% Hf and 33 at.% O are investigated. Detected is the existence of wide region of ternary α-solid solutions Ti(Hf,O). The temperature increase reduces it due to extention of two-phase region (α+β). Alloy systems are subjected to transformations connected with Ti and Hf polymorphism. Solubility boundary α/α+γ(HfO 2 ) (20 - 25 at.% range) is constant from 40O to 1600 deg C

  15. Ionosphere Transient Response To Solar Flares: Hf Radio Monitoring Observations

    Science.gov (United States)

    Lebreton, J.-P.; Telljohann, U.; Witasse, O.; Sanderson, T. R.

    We use a simple and low cost method to monitor the ionospheric reflection of commer- cial HF radio transmissions. It only requires a standard HF radio receiver with Single Side Band capability, a computer with a sound card, and appropriate audio signal spectral analysis software. We tune the radio receiver such that the carrier frequency of the transmission appears as a ~ 1kHz tone at the output of the radio receiver. The output signal of the radio receiver is processed with appropriate software that allows real time recording of high frequency resolution dynamic spectrograms of the audio spectrum in the 0-5 kHz range. Voice modulation is also present in the audio spectrum and appears as both upper and lower side bands but it is not considered in this study. HF radio signals reach the receiving station after being reflected by ionospheric layers. Any change in the ionospheric layers that affects HF wave reflection is detectable. In this paper, we particularly discuss our observations related to the transient response of the ionosphere to solar flare ionizing radiation. Enhanced ionization due to EUV and soft X-rays may produce a transient perturbation of the ionosphere which lasts typically one to few minutes. The signature of the transient response depends upon local time, solar flare intensity and the rise time of the solar flare ionizing radiation. We discuss both a few typical examples and a preliminary analysis of our 1-year sta- tistical analysis of observed events at 17.640 MHz. The method is easily accessible to amateur scientists. Possible use of the method for spaceweather-related research and outreach and educational activities is discussed.

  16. Self-healing structural properties of thermoplastics in HF field

    Directory of Open Access Journals (Sweden)

    N. G. Filippenko

    2014-01-01

    Full Text Available The article concerns one of the possible ways for safe operation of polymer products with initiating a process of their self-healing. This is especially true for products from polymer materials, used in hard-to-reach areas and units of machines and mechanisms. In this regard, the aim of this study was to develop techniques for a self-healing process of the mechanical properties of products from polymer materials.To achieve this goal, the author has solved problems to define a complex method of HF self-healing of polymer material: damage detection in products from polymer materials, determination of signal initiating the recovery process, determining the efficiency of material regeneration. The present study uses proposed and developed by the author methods for the determination of necessary and sufficient indicators of the strength characteristics of products under realmeteorological and climatic conditions of their operation.To determine the practical results of the developed algorithm for self-healing the polymer products in the HF field, a series of experimental studies has been conducted to regenerate the polyamide cage fatigue destruction of the rolling stock axle equipment of Russian Railways JSC.The obtained results of the strength characteristics of the material under investigation prove the self-healing process of polymer materials in HF field.According to research results, the conclusion is drawn that it is required to provide a technological HF self-healing process of products from polymer materials. The created algorithm of regeneration enables a new approach to study the effects of electromagnetic fields on polymer and polymer-based composite materials when solving the practical tasks to improve the quality of repairing parts from thermoplastics.

  17. Silica Content and Structure from Corncob Ash with Various Acid Treatment (HCl, HBr, and Citric Acid

    Directory of Open Access Journals (Sweden)

    Gladys Ayu Paramita Kusumah Wardhani

    2017-11-01

    Full Text Available In this study, a simple method to obtain silica from corncob ash has been investigated using a nonthermal and thermal method. The Nonthermal method was done by various acid treatment with HCl, HBr and citric acid at room temperature. Thermal method was performed for HCl-leached, HBr-leached, and citric acid-leached corncob in the furnace at 750 ºC for 5 hours. Corncob ash was characterized by Energy Dispersive X-ray fluorescence spectroscopy (EDXRF, Fourier transforms infrared spectroscopy (FTIR, X-Ray diffraction (XRD, and Scanning electron microscope-electron dispersive X-ray (SEM-EDX. In this study silica content increase after acid treatment (leaching and combustion at high temperatures. The result established that silica is most obtained with HCl treatment that is equal to 79,95% with lower metallic oxide impurity content. The FTIR spectra with different intensity shows silanol group at 1636 – 1641 cm-1, whereas siloxane group at 1037 – 1106 cm-1, 616–797 cm-1, and 459–469 cm-1. X-Ray diffractogram shows silica transition pf amorphous (2θ = 21 - 25º to quartz crystalline (2θ = 26.66º phase. The surface morphology of silica that characterized with SEM-EDX shows amorphous and crystalline silica corresponds to XRD result. The high intensity spectra of Si and O in EDX shows the presence of silica in corncob ash.

  18. Development of pectinate-ispagula mucilage mucoadhesive beads of metformin HCl by central composite design.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2014-05-01

    Ionotropically-gelled mucoadhesive beads of metformin HCl composed of low methoxy (LM) pectin-ispaghula husk mucilage (IHM) polymer-blend was developed and optimized using central composite design (spherical type, single center point, and α=1.414). Effects of LM pectin and IHM amounts on drug encapsulation efficiency (DEE) and cumulative drug release at 10h (R10h) were analysed using response surface methodology. The optimized beads containing metformin HCl (F-O) showed DEE of 86.98 ± 3.26% and R10h of 47.20 ± 1.28%. All these beads exhibited suitable controlled in vitro sustained drug release pattern with super case-II transport mechanism over 10h. These beads were also characterized by SEM and FTIR. The optimized beads also exhibited pH-dependent swelling, good mucoadhesivity with goat intestinal mucosa and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration, which could possibly be lucrative in terms of prolonged systemic absorption of metformin HCl maintaining tight blood glucose level and advanced patient compliance. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Performance of Terminalia catappa on mild steel corrosion in HCl medium

    Science.gov (United States)

    Omotosho, Olugbenga Adeshola; Okeniyi, Joshua Olusegun; Loto, Cleophas Akintoye; Popoola, Abimbola Patricia Idowu; Obi, Chukwunonso Ezekiel; Sonoiki, Oluwatobi Oluwasegun Oluwagbenga; Oni, Adeoluwa Barnabas; Alabi, Ayomide Samuel; Olarewaju, Abisola Ebunoluwa

    2016-07-01

    This work investigates Terminalia catappa leaf-extract performance on mild steel corrosion in 0.5 M hydrochloric acid (HCl). Electrochemical linear-sweep-voltametry (LSV) and gravimetric techniques were employed for assessing the mild steel corrosion in the HCl test-environment of immersion having different concentrations of the leaf-extract. Results showed that all the concentrations of the Terminalia catappa leaf-extract employed inhibited mild steel corrosion from the electrochemical (potentiodynamic) and the gravimetric considerations. Also, corrosion rate from LSV exhibited excellent correlation (R = 95.77%, Nash-Sutcliffe Efficiency (NSE) = 91.72% and p-value = 0.02383) with linear function of the corrosion rate from gravimetric method, for the leaf-extract concentrations employed. From the experimental model, 6 g/L Terminalia catappa exhibited optimal inhibition efficiency, η = 78.07%, while 8 g/L Terminalia catappa was predicted as optimally effective, η = 75.41%, by the correlation fitting model, at inhibiting mild steel corrosion in the medium. However, adsorption isotherm modelling showed that the experimental gravimetric, experimental potentiodynamic and predicted potentiodynamic data exhibited agreements in following the Langmuir adsorption isotherm. All the three data models indicated favourable adsorption and identified physisorption as the prevalent adsorption mechanism of Terminalia catappa leaf-extract on mild steel immersed in the 0.5 M HCl medium.

  20. Ions in water: the microscopic structure of a concentrated HCl solution.

    Science.gov (United States)

    Botti, A; Bruni, F; Imberti, S; Ricci, M A; Soper, A K

    2004-10-22

    A neutron diffraction experiment with isotopic H/D substitution on a concentrated HCl/H2O solution is presented. The full set of partial structure factors is extracted, by combining the diffraction data with a Monte Carlo simulation. This allows us to investigate both the changes of the water structure in the presence of ions and their solvation shell, overcoming the limitations of standard diffraction experiments. It is found that the interaction with the solutes affects the tetrahedral network of hydrogen bonded water molecules, in a manner similar to the application of an external pressure to pure water, although HCl seems less effective than other solutes, such as NaOH, at the same concentration. Consistent with experimental and theoretical data, the number of water molecules in the solution is not sufficient to completely dissociate the acid molecule. As a consequence, both dissociated H+ and Cl- ions and undissociated HCl molecules coexist in the sample, and this mixture is correctly reproduced in the simulation box. In particular, the hydrated H+ ions, forming a H3O+ complex, participate in three strong and short hydrogen bonds, while a well-defined hydration shell is found around the chlorine ion. These results are not consistent with the findings of early diffraction experiments on the same system and could only be obtained by combining high quality experimental data with a proper computer simulation. (c) 2004 American Institute of Physics.

  1. Initial backscatter occurrence statistics from the CUTLASS HF radars

    Directory of Open Access Journals (Sweden)

    S. E. Milan

    Full Text Available A statistical study of the occurrence of ground and ionospheric backscatter within the fields-of-view of the CUTLASS HF radars, at an operating frequency of 10 MHz, during the first 20 months of operation has been undertaken. The diurnal variation of the occurrence of backscatter and the range at which such backscatter is observed is found to be highly dependent on seasonal changes of the ionospheric electron density in both the E and F region, determined from ionosonde observations. In general, ionospheric backscatter is observed at far ranges during the local day in winter months and at near ranges during the local night in summer months. The Iceland radar observes more near-range E region backscatter than the Finland radar as a consequence of its more zonal look-direction. The dependence of the occurrence of backscatter on geomagnetic activity and radar operating frequency are also investigated. The occurrence of ground and ionospheric backscatter is discussed in terms of HF propagation modes and ionospheric electron densities as well as geophysical processes. A brief assessment of the possible impact of solar cycle variations on the observations is made and frequency management is discussed. Such a study, with its focus on the `instrumental' aspect of backscatter occurrence, is essential for a full interpretation of HF coherent radar observations.

  2. TID measurement using oblique transmissions of HF pulses

    Science.gov (United States)

    Galkin, Ivan; Reinisch, Bodo; Huang, Xueqin; Paznukhov, Vadym; Hamel, Ryan; Kozlov, Alexander; Belehaki, Anna

    2017-04-01

    The Traveling Ionospheric Disturbance (TID), a wave-like signature of moving plasma density modulation in the ionosphere, is widely acknowledged for its utility in backtracking the anomalous events responsible for the TID generation, and as a major inconvenience to high-frequency (HF) operational systems because of its deleterious impact on the accuracy of navigation and geolocation. The pilot project "Net-TIDE" for the real-time detection and evaluation of TIDs began its operation in 2016 based on the remote-sensing data from synchronized, network-coordinated HF sounding between pairs of DPS4D ionosondes at five participating observatories in Europe. Measurement of all signal properties (Doppler frequency, angle of arrival, and time-of-flight from transmitter to receiver) proved to be instrumental in detecting the TID and deducing the TID parameters: amplitude, wavelength, phase velocity, and direction of propagation. Processing of the measured HF signal data required a specialized signal processing technique that is capable of consistently extracting different signals that have propagated along different ionospheric paths. The multi-path signal environment proved to be the greatest challenge for the reliable TID specification by Net-TIDE, demanding the development of an intelligent system for "signal tracking". The intelligent system is based on a neural network model of a pre-attentive vision capable of extracting continuous signal tracks from the multi-path signal ensemble. Specific examples of the Net-TIDE algorithm suite operation and its suitability for a fully automated TID warning service are discussed.

  3. Ash partitioning during the oxy-fuel combustion of lignite and its dependence on the recirculation of flue gas impurities (H{sub 2}O, HCl and SO{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Facun Jiao; Juan Chen; Lian Zhang; Yajuan Wei; Yoshihiko Ninomiya; Sankar Bhattacharya; Hong Yao [Monash University, Clayton, Vic. (Australia). Department of Chemical Engineering

    2011-06-15

    Oxy-fuel combustion of a brown coal (i.e. lignite) has been carried out at 1000{sup o}C to experimentally examine the vaporisation of organically bound metals and the agglomeration of ash particles as a function of the concentration of gaseous impurities including H{sub 2}O, HCl and SO{sub 2} in about 27% O{sub 2} balanced with CO{sub 2}. The properties of bulk ash and individual metals were investigated intensively. Particularly, attention was paid to Na which is notorious for fouling and to organically bound Al which has been less studied. The results indicate that, the organically bound metals, although possessing a very low content in the raw coal, are vital for the agglomeration of ash particles, which are also highly sensitive to the loading of gas impurities in flue gas. HCl recirculation is the most crucial factor promoting the vaporisation of metals via chlorination. Apart from alkali metals, the organically bound Al and Ti were also vaporised noticeably. Recirculation of SO{sub 2} promoted the sulfation of Na to condense into liquid droplet which increased fine ash yield. Co-existence of bulk HCl and SO{sub 2} played a synergetic role in the sulfation of Na via an initial chlorination of the char-bound Na. In contrast, co-existence of steam with HCl and SO{sub 2} favored the formation of Na alumino-silicates, which are favorable for ash agglomeration. 34 refs., 15 figs., 3 tabs.

  4. Investigation of new type Cu-Hf-Al bulk glassy alloys

    International Nuclear Information System (INIS)

    Nagy, E; Ronto, V; Solyom, J; Roosz, A

    2009-01-01

    In the last years new type Cu-Hf-Al ternary alloys were developed with high glass forming ability and ductility. The addition of Al to Cu-Hf alloys results in improvements in glass formation, thermal stability and mechanical properties of these alloys. We have investigated new Cu-based bulk amorphous alloys in Cu-Hf-Al ternary system. The alloys with Cu 49 Hf 42 Al 9 , Cu 46 Hf 45 Al 9 , Cu 50 Hf 42.5 Al 7.5 and Cu 50 Hf 45 Al 5 compositions were prepared by arc melting. The samples were made by centrifugal casting and were investigated by X-ray diffraction method. Thermodynamic properties were examined by differential scanning calorimetry and the structure of the crystallising phases by scanning electron microscopy. The determination of liquidus temperatures of alloys were measured by differential thermal analysis.

  5. Influenza Vaccination in Patients With Chronic Heart Failure: The PARADIGM-HF Trial.

    Science.gov (United States)

    Vardeny, Orly; Claggett, Brian; Udell, Jacob A; Packer, Milton; Zile, Michael; Rouleau, Jean; Swedberg, Karl; Desai, Akshay S; Lefkowitz, Martin; Shi, Victor; McMurray, John J V; Solomon, Scott D

    2016-02-01

    This study sought to examine the prevalence and predictors of influenza vaccination among participants in the PARADIGM-HF (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) study and investigate associations between receiving influenza vaccine and cardiovascular death or heart failure hospitalizations, all-cause hospitalizations, and cardiopulmonary or influenza-related hospitalizations. Influenza is associated with an increased risk for cardiovascular events in patients with heart failure. We used data from the PARADIGM-HF trial in which patients with heart failure were randomized to the angiotensin receptor neprilysin inhibitor LCZ696 (sacubitril/valsartan) or enalapril. We assessed predictors of receiving influenza vaccination, and examined the relationship between influenza vaccination and outcomes in a propensity-adjusted model. Of 8,099 study participants, 1,769 (21%) received influenza vaccination. We observed significant regional variation in vaccination rates, with highest rates in the Netherlands (77.5%), Great Britain (77.2%), and Belgium (67.5%), and lowest rates in Asia (2.6%), with intermediate rates in North America (52.8%). Top predictors of vaccination included enrolling country, white race, implanted defibrillator, older age, lower New York Heart Association functional class, lower heart rate, and a history of diabetes mellitus. Influenza vaccination was associated with a reduced risk for all-cause mortality in propensity-adjusted (hazard ratio: 0.81; 95% confidence interval: 0.67 to 0.97; p = 0.015) models. Influenza vaccination rates varied widely in patients with heart failure with reduced ejection fraction enrolled in the PARADIGM-HF trial, and vaccination was associated with reduced risk for death, although whether this association was causal cannot be determined. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. Nightside studies of coherent HF Radar spectral width behaviour

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

    2002-09-01

    Full Text Available A previous case study found a relationship between high spectral width measured by the CUTLASS Finland HF radar and elevated electron temperatures observed by the EISCAT and ESR incoherent scatter radars in the post-midnight sector of magnetic local time. This paper expands that work by briefly re-examining that interval and looking in depth at two further case studies. In all three cases a region of high HF spectral width (>200 ms-1 exists poleward of a region of low HF spectral width (<200 ms-1. Each case, however, occurs under quite different geomagnetic conditions. The original case study occurred during an interval with no observed electrojet activity, the second study during a transition from quiet to active conditions with a clear band of ion frictional heating indicating the location of the flow reversal boundary, and the third during an isolated sub-storm. These case studies indicate that the relationship between elevated electron temperature and high HF radar spectral width appears on closed field lines after 03:00 magnetic local time (MLT on the nightside. It is not clear whether the same relationship would hold on open field lines, since our analysis of this relationship is restricted in latitude. We find two important properties of high spectral width data on the nightside. Firstly the high spectral width values occur on both open and closed field lines, and secondly that the power spectra which exhibit high widths are both single-peak and multiple-peak. In general the regions of high spectral width (>200 ms-1 have more multiple-peak spectra than the regions of low spectral widths whilst still maintaining a majority of single-peak spectra. We also find that the region of ion frictional heating is collocated with many multiple-peak HF spectra. Several mechanisms for the generation of high spectral width have been proposed which would produce multiple-peak spectra, these are discussed in relation to the data presented here. Since the

  7. Nightside studies of coherent HF Radar spectral width behaviour

    Directory of Open Access Journals (Sweden)

    E. E. Woodfield

    Full Text Available A previous case study found a relationship between high spectral width measured by the CUTLASS Finland HF radar and elevated electron temperatures observed by the EISCAT and ESR incoherent scatter radars in the post-midnight sector of magnetic local time. This paper expands that work by briefly re-examining that interval and looking in depth at two further case studies. In all three cases a region of high HF spectral width (>200 ms-1 exists poleward of a region of low HF spectral width (<200 ms-1. Each case, however, occurs under quite different geomagnetic conditions. The original case study occurred during an interval with no observed electrojet activity, the second study during a transition from quiet to active conditions with a clear band of ion frictional heating indicating the location of the flow reversal boundary, and the third during an isolated sub-storm. These case studies indicate that the relationship between elevated electron temperature and high HF radar spectral width appears on closed field lines after 03:00 magnetic local time (MLT on the nightside. It is not clear whether the same relationship would hold on open field lines, since our analysis of this relationship is restricted in latitude. We find two important properties of high spectral width data on the nightside. Firstly the high spectral width values occur on both open and closed field lines, and secondly that the power spectra which exhibit high widths are both single-peak and multiple-peak. In general the regions of high spectral width (>200 ms-1 have more multiple-peak spectra than the regions of low spectral widths whilst still maintaining a majority of single-peak spectra. We also find that the region of ion frictional heating is collocated with many multiple-peak HF spectra. Several mechanisms for the generation of high spectral width have been proposed which would produce multiple-peak spectra, these are discussed in relation to

  8. Evaporation of water and uptake of HCl and HBr through hexanol films at the surface of supercooled sulfuric acid.

    Science.gov (United States)

    Glass, Samuel V; Park, Seong-Chan; Nathanson, Gilbert M

    2006-06-22

    Vacuum evaporation and molecular beam scattering experiments have been used to monitor the loss of water and dissolution of HCl and HBr in deuterated sulfuric acid at 213 K containing 0 to 100 mM hexanol. The addition of 1-hexanol to the acid creates a surface film of hexyl species. This film becomes more compact with decreasing acidity, ranging from approximately 62% to approximately 68% of maximum packing on 68 to 56 wt % D(2)SO(4), respectively. D(2)O evaporation from 68 wt % acid remains unaltered by the hexyl film, where it is most porous, but is impeded by approximately 20% from 56 and 60 wt % acid. H --> D exchange experiments further indicate that the hexyl film on 68 wt % acid enhances conversion of HCl and HBr into DCl and DBr, which is interpreted as an increase in HCl and HBr entry into the bulk acid. For this permeable hexyl film, the hydroxyl groups of surface hexanol molecules may assist uptake by providing extra sites for HCl and HBr hydrogen bonding and dissociation. In contrast, HCl --> DCl exchange in 60 wt % D(2)SO(4) at first rises with hexyl surface coverage but then drops back to the bare acid value as the hexyl species pack more tightly. HCl entry is actually diminished by the hexyl film on 56 wt % acid, where the film is most compact. These experiments reveal a transition from a porous hexanol film on 68 wt % sulfuric acid that enhances HCl and HBr uptake to one on 56 wt % acid that slightly impedes HCl and D(2)O transport.

  9. Optical oscillator strengths for valence-shell and Br-3d inner-shell excitations of HCl and HBr.

    Science.gov (United States)

    Li, Wen-Bin; Zhu, Lin-Fan; Yuan, Zhen-Sheng; Liu, Xiao-Jing; Xu, Ke-Zun

    2006-10-21

    Absolute optical oscillator strength density spectra for valence-shell excitations of HCl and HBr, as well as for Br-3d inner-shell excitations of HBr, have been determined by high-resolution electron-energy-loss-spectroscopy method in the dipole limit. Absolute optical oscillator strengths for the discrete transitions of HCl and HBr are reported and compared with the previous results determined by the photoabsorption method.

  10. Factor structure and reliability of the Arabic adaptation of the Hypomania Check List-32, second revision (HCL-32-R2).

    Science.gov (United States)

    Fornaro, Michele; Elassy, Mai; Mounir, Mina; Abd-Elmoneim, Noran; Ashour, Hala; Hamed, Rania; Al-Shehri, Abdullah; Bedir, Samir; Rashed, Ibrahem; Amer, Noha; Mohammed, Talal A; De Berardis, Domenico; Mazza, Monica; Pino, Mariachiara; Koshy, Ann Sarah; De Pasquale, Concetta; Okasha, Tarek; Angst, Jules

    2015-05-01

    To assess the psychometric properties of the Arabic adaptation of the Hypomania-Check-List 32-item, second revision (HCL-32-R2) for the detection of bipolarity in major depressive disorder (MDD) inpatients suffering a current major depressive episode (MDE). The "Bipolar Disorders: Improving Diagnosis, Guidance, and Education" Arabic module of the HCL-32-R2 was administered to mother-tongue Arabic MDE inpatients between March 2013 and October 2014. Diagnostic and Statistical Manual Fourth edition (DSM-IV) diagnoses were made adopting the mini-international neuropsychiatric interview, using bipolar disorder (BD) patients as controls. In our sample (n=500, of whom, BD-I=329; BD-II=70; MDD=101), using a cut-off of 17 allowed the HCL-32-R2 to discriminate DSM-IV-defined MDD patients between "true unipolar" (HCL-32-R2(-)) and "sub-threshold bipolar depression" (HCL-32-R2(+)) with sensitivity=82% and specificity=77%. Area under the curve was .883; positive and negative predictive values were 93.44% and 73.23% respectively. Owing to clinical interpretability considerations and consistency with previous adaptations of the HCL-32, a two-factor solution (F1="hyperactive/elated" vs. F2="irritable/distractible/impulsive") was preferred using exploratory and confirmatory factors analyses. Item n.33 ("I gamble more") and n.34 ("I eat more") introduced in the R2 version of the HCL-32 loaded onto F1, though very slightly. Cronbach's alphas were F1=.86 and F2=.60. No cross-validation with any additional validated screening tool. Inpatients only sample; recall bias; no systematic evaluation of eventual medical/psychiatric comorbidities, current/lifetime pharmacological history, or record of severity of current MDE. In our sample, the HCL-32 fairly discriminated between MDD and BD-I but not BD-II, therefore soliciting for replication studies for use in Arabic-speaking depressed inpatients. Copyright © 2015. Published by Elsevier Inc.

  11. Report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012)

    CERN Document Server

    Blondel, Alain; Chou, Weiren; Gao, Jie; Schulte, Daniel; Yokoya, Kaoru

    2013-01-01

    This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.

  12. Thermodynamics of HfCl4-KCl molten mixtures containing HfCl4 up to 33.3 mol. per cent

    International Nuclear Information System (INIS)

    Smirnov, M.V.; Salyulev, A.B.; Kudyakov, V.Ya.

    1980-01-01

    Based on measurements of saturated vapour pressure in components of melted mixtures of HfCl 4 -KCl, depending on temperature and concentration, calculated are the results of changes in activity coefficients of hafnium tetrachloride and potassium chloride on transition from diluted solutions, where the Henry law is met, to those concentrated where the law is disobeyed. Growth in the activity coefficient of HfCl 4 is due to dissociation of complex groups of HfCl 6 2- into complexes with a lesser number of ligands and decreasing relative binding energy of Hf 4+ -Cl - there. In this case, marked changes take place in partial enthalpy and entropy of hafnium tetrachloride mixing. Similar dependences are observed for potassium chloride, but they are expressed considerably weaker. Evaporation enthalpy and entropy are calculated for HfCl 4 and KCl monomers from their melted mixtures of various concentrations

  13. Theoretical predictions of properties and volatility of chlorides and oxychlorides of group-4 elements. II. Adsorption of tetrachlorides and oxydichlorides of Zr, Hf, and Rf on neutral and modified surfaces.

    Science.gov (United States)

    Pershina, V; Borschevsky, A; Iliaš, M; Türler, A

    2014-08-14

    With the aim to interpret results of gas-phase chromatography experiments on volatility of group-4 tetrachlorides and oxychlorides including those of Rf, adsorption enthalpies of these species on neutral, and modified quartz surfaces were estimated on the basis of relativistic, two-component Density Functional Theory calculations of MCl4, MOCl2, MCl6(-), and MOCl4(2) with the use of adsorption models. Several mechanisms of adsorption were considered. In the case of physisorption of MCl4, the trend in the adsorption energy in the group should be Zr > Hf > Rf, so that the volatility should change in the opposite direction. The latter trend complies with the one in the sublimation enthalpies, ΔH(sub), of the Zr and Hf tetrachlorides, i.e., Zr Hf. On the basis of a correlation between these quantities, ΔH(sub)(RfCl4) was predicted as 104.2 kJ/mol. The energy of physisorption of MOCl2 on quartz should increase in the group, Zr Hf Hf > Rf, as defined by the complex formation energies. In the case of adsorption of MCl4 on a chlorinated quartz surface, formation of the MCl6(2-) surface complexes can occur, so that the trend in the adsorption strength should be Zr ≤ Hf Hf, observed in the "one-atom-at-a-time" gas-phase chromatography experiments. Thus, currently no theoretical explanation can be found for the experimental observations.

  14. Resistive switching of Sn-doped In2O3/HfO2core-shell nanowire: geometry architecture engineering for nonvolatile memory.

    Science.gov (United States)

    Huang, Chi-Hsin; Chang, Wen-Chih; Huang, Jian-Shiou; Lin, Shih-Ming; Chueh, Yu-Lun

    2017-05-25

    Core-shell NWs offer an innovative approach to achieve nanoscale metal-insulator-metal (MIM) heterostructures along the wire radial direction, realizing three-dimensional geometry architecture rather than planar type thin film devices. This work demonstrated the tunable resistive switching characteristics of ITO/HfO 2 core-shell nanowires with controllable shell thicknesses by the atomic layer deposition (ALD) process for the first time. Compared to planar HfO 2 thin film device configuration, ITO/HfO 2 core-shell nanowire shows a prominent resistive memory behavior, including lower power consumption with a smaller SET voltage of ∼0.6 V and better switching voltage uniformity with variations (standard deviation(σ)/mean value (μ)) of V SET and V RESET from 0.38 to 0.14 and from 0.33 to 0.05 for ITO/HfO 2 core-shell nanowire and planar HfO 2 thin film, respectively. In addition, endurance over 10 3 cycles resulting from the local electric field enhancement can be achieved, which is attributed to geometry architecture engineering. The concept of geometry architecture engineering provides a promising strategy to modify the electric-field distribution for solving the non-uniformity issue of future RRAM.

  15. Synaptic Plasticity and Learning Behaviors Mimicked in Single Inorganic Synapses of Pt/HfOx/ZnOx/TiN Memristive System

    Science.gov (United States)

    Wang, Lai-Guo; Zhang, Wei; Chen, Yan; Cao, Yan-Qiang; Li, Ai-Dong; Wu, Di

    2017-01-01

    In this work, a kind of new memristor with the simple structure of Pt/HfOx/ZnOx/TiN was fabricated completely via combination of thermal-atomic layer deposition (TALD) and plasma-enhanced ALD (PEALD). The synaptic plasticity and learning behaviors of Pt/HfOx/ZnOx/TiN memristive system have been investigated deeply. Multilevel resistance states are obtained by varying the programming voltage amplitudes during the pulse cycling. The device conductance can be continuously increased or decreased from cycle to cycle with better endurance characteristics up to about 3 × 103 cycles. Several essential synaptic functions are simultaneously achieved in such a single double-layer of HfOx/ZnOx device, including nonlinear transmission properties, such as long-term plasticity (LTP), short-term plasticity (STP), and spike-timing-dependent plasticity. The transformation from STP to LTP induced by repetitive pulse stimulation is confirmed in Pt/HfOx/ZnOx/TiN memristive device. Above all, simple structure of Pt/HfOx/ZnOx/TiN by ALD technique is a kind of promising memristor device for applications in artificial neural network.

  16. Solidification Rate Dependence of Microstructures and Transformation Behavior of Ti-Ni-Hf Alloys.

    Science.gov (United States)

    Kim, Dong-Jo; Kim, Yeon-Wook; Nam, Tae-Hyun

    2018-09-01

    The microstructures and transformation behavior of Ti-49Ni-20Hf, Ti-49.5Ni-20Hf and Ti-50.3Ni- 20Hf alloys, when prepared by conventional casting, were investigated and compared with the properties of the alloys prepared by melt spinning. The area fraction of (Ti,Hf)2Ni in Ti-Ni-Hf alloys decreased to 3.9% from 9.4% as Ni content rose to 50.3 at% from 49 at%. Several cracks were observed in the hot-rolled Ti-49Ni-20Hf alloy sheet but none were found in the Ti-50.3Ni-20Hf alloy sheet. The B2-B19' transformation start temperature (Ms) decreased to 476 K from 580 K as Ni content increased to 50.3 at% from 49 at%. All the as-spun ribbons were amorphous, and the activation energy for crystallization ranged from 167.8 kJ/mol to 182.7 kJ/mol based on Ni content. When annealing temperature ranged from 810 K to 873 K, crystalline Ti-Ni-Hf alloys without (Ti,Hf)2Ni particles were obtained. At annealing temperatures higher than 873 K, very fine (Ti,Hf)2Ni particles, less than 20 nm in size, were found embedded in a crystalline matrix.

  17. Crystallography of the NiHfSi Phase in a NiAl (0.5 Hf) Single-Crystal Alloy

    Science.gov (United States)

    Garg, A.; Noebe, R. D.; Darolia, R.

    1996-01-01

    Small additions of Hf to conventionally processed NiAl single crystals result in the precipitation of a high density of cuboidal G-phase along with a newly identified silicide phase. Both of these phases form in the presence of Si which is not an intentional alloying addition but is a contaminant resulting from contact with the ceramic shell molds during directional solidification of the single-crystal ingots. The morphology, crystal structure and Orientation Relationship (OR) of the silicide phase in a NiAl (0.5 at.%Hf) single-crystal alloy have been determined using transmission electron microscopy, electron microdiffraction and energy dispersive X-ray spectroscopy. Qualitative elemental analysis and indexing of the electron microdiffraction patterns from the new phase indicate that it is an orthorhombic NiHfSi phase with unit cell parameters, a = 0.639 nm, b = 0.389 nm and c = 0.72 nm, and space group Pnma. The NiHfSi phase forms as thin rectangular plates on NiAl/111/ planes with an OR that is given by NiHfSi(100))(parallel) NiAl(111) and NiHfSi zone axes(010) (parallel) NiAl zone axes (101). Twelve variants of the NiHfSi phase were observed in the alloy and the number of variants and rectangular morphology of NiHfSi plates are consistent with symmetry requirements. Quenching experiments indicate that nucleation of the NiHfSi phase in NiAI(Hf) alloys is aided by the formation of NiAl group of zone axes (111) vacancy loops that form on the NiAl /111/ planes.

  18. Resolving Ambiguities in the LF/HF Ratio: LF-HF Scatter Plots for the Categorization of Mental and Physical Stress from HRV.

    Science.gov (United States)

    von Rosenberg, Wilhelm; Chanwimalueang, Theerasak; Adjei, Tricia; Jaffer, Usman; Goverdovsky, Valentin; Mandic, Danilo P

    2017-01-01

    It is generally accepted that the activities of the autonomic nervous system (ANS), which consists of the sympathetic (SNS) and parasympathetic nervous systems (PNS), are reflected in the low- (LF) and high-frequency (HF) bands in heart rate variability (HRV)-while, not without some controversy, the ratio of the powers in those frequency bands, the so called LF-HF ratio (LF/HF), has been used to quantify the degree of sympathovagal balance. Indeed, recent studies demonstrate that, in general: (i) sympathovagal balance cannot be accurately measured via the ratio of the LF- and HF- power bands; and (ii) the correspondence between the LF/HF ratio and the psychological and physiological state of a person is not unique. Since the standard LF/HF ratio provides only a single degree of freedom for the analysis of this 2D phenomenon, we propose a joint treatment of the LF and HF powers in HRV within a two-dimensional representation framework, thus providing the required degrees of freedom. By virtue of the proposed 2D representation, the restrictive assumption of the linear dependence between the activity of the autonomic nervous system (ANS) and the LF-HF frequency band powers is demonstrated to become unnecessary. The proposed analysis framework also opens up completely new possibilities for a more comprehensive and rigorous examination of HRV in relation to physical and mental states of an individual, and makes possible the categorization of different stress states based on HRV. In addition, based on instantaneous amplitudes of Hilbert-transformed LF- and HF-bands, a novel approach to estimate the markers of stress in HRV is proposed and is shown to improve the robustness to artifacts and irregularities, critical issues in real-world recordings. The proposed approach for resolving the ambiguities in the standard LF/HF-ratio analyses is verified over a number of real-world stress-invoking scenarios.

  19. Resolving Ambiguities in the LF/HF Ratio: LF-HF Scatter Plots for the Categorization of Mental and Physical Stress from HRV

    Directory of Open Access Journals (Sweden)

    Wilhelm von Rosenberg

    2017-06-01

    Full Text Available It is generally accepted that the activities of the autonomic nervous system (ANS, which consists of the sympathetic (SNS and parasympathetic nervous systems (PNS, are reflected in the low- (LF and high-frequency (HF bands in heart rate variability (HRV—while, not without some controversy, the ratio of the powers in those frequency bands, the so called LF-HF ratio (LF/HF, has been used to quantify the degree of sympathovagal balance. Indeed, recent studies demonstrate that, in general: (i sympathovagal balance cannot be accurately measured via the ratio of the LF- and HF- power bands; and (ii the correspondence between the LF/HF ratio and the psychological and physiological state of a person is not unique. Since the standard LF/HF ratio provides only a single degree of freedom for the analysis of this 2D phenomenon, we propose a joint treatment of the LF and HF powers in HRV within a two-dimensional representation framework, thus providing the required degrees of freedom. By virtue of the proposed 2D representation, the restrictive assumption of the linear dependence between the activity of the autonomic nervous system (ANS and the LF-HF frequency band powers is demonstrated to become unnecessary. The proposed analysis framework also opens up completely new possibilities for a more comprehensive and rigorous examination of HRV in relation to physical and mental states of an individual, and makes possible the categorization of different stress states based on HRV. In addition, based on instantaneous amplitudes of Hilbert-transformed LF- and HF-bands, a novel approach to estimate the markers of stress in HRV is proposed and is shown to improve the robustness to artifacts and irregularities, critical issues in real-world recordings. The proposed approach for resolving the ambiguities in the standard LF/HF-ratio analyses is verified over a number of real-world stress-invoking scenarios.

  20. A multicenter trial evaluating retaspimycin HCL (IPI-504) plus trastuzumab in patients with advanced or metastatic HER2-positive breast cancer.

    Science.gov (United States)

    Modi, Shanu; Saura, Cristina; Henderson, Charles; Lin, Nancy U; Mahtani, Reshma; Goddard, Jill; Rodenas, Eduardo; Hudis, Clifford; O'Shaughnessy, Joyce; Baselga, Jose

    2013-05-01

    Heat shock protein 90 (Hsp90) facilitates maturation and stability of HER2. Combining an Hsp90 inhibitor and trastuzumab has demonstrated anti-tumor effects in patients with HER2+ breast cancer. Adults with measurable, locally advanced or metastatic HER2+ breast cancer and prior trastuzumab treatment were enrolled in a phase 2 trial employing weekly 300 mg/m(2) retaspimycin HCl, a potent Hsp90 inhibitor, with 6 mg/kg trastuzumab every 3 weeks. A Simon's two-stage design determined trial expansion by dose-limiting toxicity (DLT) and response rates. Pharmacokinetics and electrocardiograms were evaluated. Twenty-six patients with median age 52.5 years (range 33-72) enrolled with a median of six prior chemotherapeutic regimens (range 2-20). On study, patients received a median of three treatment cycles (range 1-12). No DLTs were observed. Most adverse events (AEs) were grade 1 or 2; common treatment-related AEs included fatigue (46 %), nausea (31 %), and diarrhea (23 %). One patient had treatment-related serious AEs of grade 1 diarrhea and grade 3 hypokalemia. grade 3 transaminase elevation occurred in one patient (4 %) who also had metastatic liver disease. Sixteen patients (62 %) had stable disease, with a median on-study duration of 2.4 months (range 1.1-8.2). No confirmed responses were observed. Retaspimycin HCl at 300 mg/m² weekly in combination with trastuzumab was well tolerated and without significant toxicities. Modest clinical activity was observed, but did not meet criteria for trial expansion. The safety profile for patients on study raises the possibility of retaspimycin HCl underdosing that limited efficacy. Studies employing higher doses are ongoing.

  1. Impact of supersonic and subsonic aircraft on ozone: Including heterogeneous chemical reaction mechanisms

    International Nuclear Information System (INIS)

    Kinnison, D.E.; Wuebbles, D.J.

    1992-01-01

    Preliminary calculations suggest that heterogeneous reactions are important in calculating the impact on ozone from emissions of trace gases from aircraft fleets. In this study, three heterogeneous chemical processes that occur on background sulfuric acid aerosols are included and their effects on O 3 , NO x , Cl x , HCl, N 2 O 5 , ClONO 2 are calculated

  2. Impact of supersonic and subsonic aircraft on ozone: Including heterogeneous chemical reaction mechanisms

    Science.gov (United States)

    Kinnison, Douglas E.; Wuebbles, Donald J.

    1994-01-01

    Preliminary calculations suggest that heterogeneous reactions are important in calculating the impact on ozone from emissions of trace gases from aircraft fleets. In this study, three heterogeneous chemical processes that occur on background sulfuric acid aerosols are included and their effects on O3, NO(x), Cl(x), HCl, N2O5, ClONO2 are calculated.

  3. Two-dimensional spin-orbit Dirac point in monolayer HfGeTe

    Science.gov (United States)

    Guan, Shan; Liu, Ying; Yu, Zhi-Ming; Wang, Shan-Shan; Yao, Yugui; Yang, Shengyuan A.

    2017-10-01

    Dirac points in two-dimensional (2D) materials have been a fascinating subject of research, with graphene as the most prominent example. However, the Dirac points in existing 2D materials, including graphene, are vulnerable against spin-orbit coupling (SOC). Here, based on first-principles calculations and theoretical analysis, we propose a new family of stable 2D materials, the HfGeTe-family monolayers, which host so-called spin-orbit Dirac points (SDPs) close to the Fermi level. These Dirac points are special in that they are formed only under significant SOC, hence they are intrinsically robust against SOC. We show that the existence of a pair of SDPs are dictated by the nonsymmorphic space group symmetry of the system, which are very robust under various types of lattice strains. The energy, the dispersion, and the valley occupation around the Dirac points can be effectively tuned by strain. We construct a low-energy effective model to characterize the Dirac fermions around the SDPs. Furthermore, we find that the material is simultaneously a 2D Z2 topological metal, which possesses nontrivial Z2 invariant in the bulk and spin-helical edge states on the boundary. From the calculated exfoliation energies and mechanical properties, we show that these materials can be readily obtained in experiment from the existing bulk materials. Our result reveals HfGeTe-family monolayers as a promising platform for exploring spin-orbit Dirac fermions and topological phases in two-dimensions.

  4. 3-dimensional self-calibrating coastal oil spill trajectory tracking and contaminant transport using HF radar

    International Nuclear Information System (INIS)

    Ojo, T.O.; Bonner, J.S.

    2002-01-01

    A study was conducted to demonstrate the dynamic behaviour of the turbulent mixing process in coastal environments for both advection and dispersion transport. The spatial variability of the coefficients that characterize the process was also examined. Every transport model should be calibrated to include specific information regarding geomorphology and climatic conditions. HF-radar equipment eliminates the need for model-recalibration and validation for transport models of coefficients which have spatial-temporal variations. The HF-radar has a grid resolution of 1000 m, providing real-time velocity coefficients by measuring surface currents. Dispersion coefficients can be derived from velocity time-series using the principle of Autocorrelation Functions (ACF) for time series. This concept was applied to two Gulf of Mexico bays in Texas, Corpus Christi and Matagorda. It was determined that the within-bay spatial variability of dispersion coefficients were many orders of magnitude higher than between-bay variability. The proposed model effectively reduced model complexity. The results of a 3-D dimensional contaminant transport model was presented. It was successfully used in the simulation of a contaminant spill scenario in the two bays using spatially distributed time-dependent transport coefficients. 5 refs., 8 figs

  5. Ionosphere research with a HF/MF cubesat radio instrument

    Science.gov (United States)

    Kallio, Esa; Aikio, Anita; Alho, Markku; Fontell, Mathias; Harri, Ari-Matti; Kauristie, Kirsti; Kestilä, Antti; Koskimaa, Petri; Mäkelä, Jakke; Mäkelä, Miika; Turunen, Esa; Vanhamäki, Heikki; Verronen, Pekka

    2017-04-01

    New technology provides new possibilities to study geospace and 3D ionosphere by using spacecraft and computer simulations. A type of nanosatellites, CubeSats, provide a cost effective possibility to provide in-situ measurements in the ionosphere. Moreover, combined CubeSat observations with ground-based observations gives a new view on auroras and associated electromagnetic phenomena. Especially joint and active CubeSat - ground based observation campaigns enable the possibility of studying the 3D structure of the ionosphere. Furthermore using several CubeSats to form satellite constellations enables much higher temporal resolution. At the same time, increasing computation capacity has made it possible to perform simulations where properties of the ionosphere, such as propagation of the electromagnetic waves in the medium frequency, MF (0.3-3 MHz) and high frequency, HF (3-30 MHz), ranges is based on a 3D ionospheric model and on first-principles modelling. Electromagnetic waves at those frequencies are strongly affected by ionospheric electrons and, consequently, those frequencies can be used for studying the plasma. On the other hand, even if the ionosphere originally enables long-range telecommunication at MF and HF frequencies, the frequent occurrence of spatiotemporal variations in the ionosphere disturbs communication channels, especially at high latitudes. Therefore, study of the MF and HF waves in the ionosphere has both a strong science and technology interests. We introduce recently developed simulation models as well as measuring principles and techniques to investigate the arctic ionosphere by a polar orbiting CubeSat whose novel AM radio instrument measures HF and MF waves. The cubesat, which contains also a white light aurora camera, is planned to be launched in late 2017 (http://www.suomi100satelliitti.fi/eng). The new models are (1) a 3D ray tracing model and (2) a 3D full kinetic electromagnetic simulation. We also introduce how combining of the

  6. High Q-factor tunable superconducting HF circuit

    CERN Document Server

    Vopilkin, E A; Pavlov, S A; Ponomarev, L I; Ganitsev, A Y; Zhukov, A S; Vladimirov, V V; Letyago, A G; Parshikov, V V

    2001-01-01

    Feasibility of constructing a high Q-factor (Q approx 10 sup 5) mechanically tunable in a wide range of frequencies (12-63 MHz) vibration circuit of HF range was considered. The tunable circuit integrates two single circuits made using YBaCuO films. The circuit frequency is tuned by changing distance X (capacity) between substrates. Potentiality of using substrates of lanthanum aluminate, neodymium gallate and strontium titanate for manufacture of single circuits was considered. Q-factor of the circuit amounted to 68000 at resonance frequency of 6.88 MHz

  7. Atomic-level quantized reaction of HfOx memristor

    Science.gov (United States)

    Syu, Yong-En; Chang, Ting-Chang; Lou, Jyun-Hao; Tsai, Tsung-Ming; Chang, Kuan-Chang; Tsai, Ming-Jinn; Wang, Ying-Lang; Liu, Ming; Sze, Simon M.

    2013-04-01

    In this study, we have observed dynamic switching behaviors in a memristive device. There are only a few atoms in the resistive switching reaction which enables the high-speed resistive switching characteristics, which was analyzed dynamically by real-time analyzing tools. From fundamental conductance considerations, the resistance of the conductive path in HfOx memristor is found to be due to barriers which are atomically incremented during the RESET process. Simultaneously, we have demonstrated the quantized switching phenomena at ultra-cryogenic temperature (4 K), which are attributed to the atomic-level reaction in metallic filament.

  8. AFRL Field Campaign to study oblique HF propagation

    Science.gov (United States)

    Colman, J. J.; Parris, R.; Dao, E. V.; Hines, J.; Caton, R.; Holmes, J.; Ober, D. M.; Sciacca, J.

    2017-12-01

    AFRL is executing a field campaign overlapping with the upcoming total eclipse on August 21st, 2017. Three Digisonde-Portable-Sounder-4D (DPS4D) Ionosondes will be deployed by AFRL in the southeastern US from South Carolina to Key West, Florida. Two existing DPS4D's at the University of Florida Gainesville and Eglin AFB will also support the campaign. The goal is to investigate HF oblique propagation and its assimilation into ionospheric models. A description of the campaign will be presented along with preliminary observations and simulations. The image shows the physical layout of the ionospheric sounder network and their geographic midpoints.

  9. TEA HF laser with a high specific radiation energy

    Science.gov (United States)

    Puchikin, A. V.; Andreev, M. V.; Losev, V. F.; Panchenko, Yu. N.

    2017-01-01

    Results of experimental studies of the chemical HF laser with a non-chain reaction are presented. The possibility of the total laser efficiency of 5 % is shown when a traditional C-to-C pumping circuit with the charging voltage of 20-24 kV is used. It is experimentally shown that the specific radiation output energy of 21 J/l is reached at the specific pump energy of 350 J/l in SF6/H2 = 14/1 mixture at the total pressure of 0.27 bar.

  10. [Data from the IN-HF Outcome registry].

    Science.gov (United States)

    Misuraca, Gianfranco; Di Tano, Giuseppe; Camerini, Alberto; Cloro, Cosima; Gorini, Marco

    2012-05-01

    The IN-HF Outcome registry enrolled 1855 patients admitted for acute heart failure and 3755 outpatients with chronic heart failure seen at 64 cardiology units of the Italian Network-Heart Failure. We assessed gender-related differences in clinical characteristics, management, and short- and long-term mortality and morbidity outcomes. Women were older, more often hypertensive and with a higher prevalence of heart failure with preserved systolic function. Aggressive management was less frequent in women who underwent less often diagnostic and therapeutic procedures. We found no gender-related differences in either acute or long-term mortality nor in hospital readmissions.

  11. Fenugreek seed mucilage-alginate mucoadhesive beads of metformin HCl: Design, optimization and evaluation.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar; Pradhan, Jyotiprakash; Hasnain, M Saquib

    2013-03-01

    The work investigates the development and optimization of fenugreek (Trigonella foenum-graecum L.) seed mucilage (FSM)-alginate mucoadhesive beads containing metformin HCl through ionotropic gelation using 3(2) factorial design. The effect of polymer-blend ratio (sodium alginate to FSM) and cross-linker (CaCl(2)) concentration on the drug encapsulation efficiency (DEE, %), and cumulative drug release after 10h (R(10h), %) was optimized. The DEE (%) of all these beads was within the range of 71.63 ± 2.32 to 95.08 ± 3.73% with sustained in vitro drug release of 69.78 ± 2.43% to 95.70 ± 4.26% over 10h. The in vitro drug release from these beads was followed controlled-release (zero-order) pattern (R(2)=0.9910 to 0.9953) with super case-II transport mechanism. The average size of these beads was within the range of 0.92 ± 0.05 to 1.30 ± 0.14 mm. The beads were also characterized by SEM, FTIR and (1)H NMR. The swelling and degradation of FSM-alginate beads containing metformin HCl were influenced by pH of the test medium. These beads also exhibited good mucoadhesivity in wash-off test. The optimized FSM-alginate mucoadhesive beads containing metformin HCl showed significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Effect of glucosamine HCl on dissolution and solid state behaviours of piroxicam upon milling.

    Science.gov (United States)

    Al-Hamidi, Hiba; Edwards, Alison A; Douroumis, Dionysis; Asare-Addo, Kofi; Nayebi, Alireza Mohajjel; Reyhani-Rad, Siamak; Mahmoudi, Javad; Nokhodchi, Ali

    2013-03-01

    Piroxicam is a non-steroidal anti-inflammatory drug that is characterised by low solubility and high permeability. In order to improve the drug dissolution rate, the co-grinding method was used as an approach to prepare piroxicam co-ground in the carriers such as glucosamine hydrochloride. As, this amino sugar (glucosamine HCl) has been shown to decrease pain and improve mobility in osteoarthritis in joints, therefore, the incorporation of glucosamine in piroxicam formulations would be expected to offer additional benefits to patients. The effect of the order of grinding on the dissolution of piroxicam was also investigated. Co-ground drug and glucosamine were prepared in different ratios using a ball mill. The samples were then subjected to different grinding times. In order to investigate the effect of the grinding process on the dissolution behaviour of piroxicam, the drug was ground separately in the absence of glucosamine. Mixtures of ground piroxicam and unground D-glucosamine HCl were prepared. Physical mixtures of piroxicam and glucosamine were also prepared for comparison. The properties of prepared co-ground systems and physical mixtures were studied using a dissolution tester, FTIR, SEM, XRPD and DSC. These results showed that the presence of glucosamine HCl can increase dissolution rate of piroxicam compared to pure piroxicam. Generally, all dissolution profiles showed the fastest dissolution rate when ground piroxicam was mixed with unground glucosamine. This was closely followed by the co-grinding of piroxicam with glucosamine where lower grinding times showed the fastest dissolution. The solid state studies showed that the grinding of piroxicam for longer times had no effect on polymorphic form of piroxicam, whereas mixtures of piroxicam-glucosamine ground for longer times (60 min) converted piroxicam polymorph II to polymorph I. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. The release behavior and kinetic evaluation of tramadol HCl from chemically cross linked Ter polymeric hydrogels.

    Science.gov (United States)

    Malana, Muhammad A; Zohra, Rubab

    2013-01-18

    Hydrogels, being stimuli responsive are considered to be effective for targeted and sustained drug delivery. The main purpose for this work was to study the release behavior and kinetic evaluation of Tramadol HCl from chemically cross linked ter polymeric hydrogels. Ter-polymers of methacrylate, vinyl acetate and acrylic acid cross linked with ethylene glycol dimethacrylate (EGDMA) were prepared by free radical polymerization. The drug release rates, dynamic swelling behavior and pH sensitivity of hydrogels ranging in composition from 1-10 mol% EGDMA were studied. Tramadol HCl was used as model drug substance. The release behavior was investigated at pH 8 where all formulations exhibited non-Fickian diffusion mechanism. Absorbency was found to be more than 99% indicating good drug loading capability of these hydrogels towards the selected drug substance. Formulations designed with increasing amounts of EGDMA had a decreased equilibrium media content as well as media penetrating velocity and thus exhibited a slower drug release rate. Fitting of release data to different kinetic models indicate that the kinetic order shifts from the first to zero order as the concentration of drug was increased in the medium, showing gradual independency of drug release towards its concentration. Formulations with low drug content showed best fitness with Higuchi model whereas those with higher concentration of drug followed Hixson-Crowell model with better correlation values indicating that the drug release from these formulations depends more on change in surface area and diameter of tablets than that on concentration of the drug. Release exponent (n) derived from Korse-Meyer Peppas equation implied that the release of Tramadol HCl from these formulations was generally non-Fickian (n > 0.5 > 1) showing swelling controlled mechanism. The mechanical strength and controlled release capability of the systems indicate that these co-polymeric hydrogels have a great potential to

  14. Formulation and Evaluation of Microsphere Based Oro Dispersible Tablets of Itopride Hcl

    Directory of Open Access Journals (Sweden)

    S.S Agrawal

    2012-09-01

    Full Text Available Background The purpose of the present work is to mask the intensely bitter taste of Itopride HCl and to formulate an Oro dispersible tablet (ODT of the taste-masked drug by incorporation of microspheres in the tablets for use in specific populations viz. pediatrics, geriatrics and patients experiencing difficulty in swallowing.Methods:With this objective in mind, microspheres loaded with Itopride HCl were prepared by solvent evaporation method using acetone as solvent for pH-sensitive polymer, Eudragit EPO and light liquid paraffin as the encapsulating medium. The prepared microspheres were characterized with regard to yield, drug content, flow properties, particle size and size distribution, surface features, in vitro drug release and taste. The ODTs so prepared from these microspheres were evaluated for hardness, thickness, weight variation, friability, disintegration time, drug content, wetting time, water absorption ratio, moisture uptake, in vitro dispersion, in vitro disintegration, in vitro drug release and stability. Results:The average size of microspheres was found to be satisfactory in terms of the size and size distribution. Microspheres prepared were of a regular spherical shape. Comparison of the dissolution profiles of microspheres in different pH media showed that microspheres having drug: polymer ratio of 1:2 produced a retarding effect in simulated salivary fluid (pH 6.8 and were further used for formulation into ODTs after addition of suitable amounts of excipients such as superdisintegrant, diluent, sweetener and flavor of directly compressible grade. ConclusionsEffective taste-masking was achieved for Itopride HCl by way of preparation of microspheres and ODTs of acceptable characteristics.

  15. Formulation and evaluation of microsphere based oro dispersible tablets of itopride hcl

    Directory of Open Access Journals (Sweden)

    Shah Sanjay

    2012-09-01

    Full Text Available Abstract Background The purpose of the present work is to mask the intensely bitter taste of Itopride HCl and to formulate an Oro dispersible tablet (ODT of the taste-masked drug by incorporation of microspheres in the tablets for use in specific populations viz. pediatrics, geriatrics and patients experiencing difficulty in swallowing. Methods With this objective in mind, microspheres loaded with Itopride HCl were prepared by solvent evaporation method using acetone as solvent for pH-sensitive polymer, Eudragit EPO and light liquid paraffin as the encapsulating medium. The prepared microspheres were characterized with regard to yield, drug content, flow properties, particle size and size distribution, surface features, in vitro drug release and taste. The ODTs so prepared from these microspheres were evaluated for hardness, thickness, weight variation, friability, disintegration time, drug content, wetting time, water absorption ratio, moisture uptake, in vitro dispersion, in vitro disintegration, in vitro drug release and stability. Results The average size of microspheres was found to be satisfactory in terms of the size and size distribution. Microspheres prepared were of a regular spherical shape. Comparison of the dissolution profiles of microspheres in different pH media showed that microspheres having drug: polymer ratio of 1:2 produced a retarding effect in simulated salivary fluid (pH 6.8 and were further used for formulation into ODTs after addition of suitable amounts of excipients such as superdisintegrant, diluent, sweetener and flavor of directly compressible grade. Conclusions Effective taste-masking was achieved for Itopride HCl by way of preparation of microspheres and ODTs of acceptable characteristics.

  16. High performance organic nonvolatile memory transistors based on HfO2 and poly(α-methylstyrene) electret hybrid charge-trapping layers

    Science.gov (United States)

    Xu, W. C.; He, H. X.; Jing, X. S.; Wu, S. J.; Zhang, Z.; Gao, J. W.; Gao, X. S.; Zhou, G. F.; Lu, X. B.; Liu, J.-M.

    2017-08-01

    In this work, we fabricated a high performance flash-type organic nonvolatile memory transistor, which adopted polymer-electret poly(α-methylstyrene) (PαMS) and HfO2 films as hybrid charge trapping layer (CTL). Compared with a single HfO2 or PαMS CTL structure, the hybrid HfO2/PαMS CTL structure can provide enhanced charge trapping efficiency to increase the device operation speed and reduce the leakage current to boost the device reliability. The fabricated nonvolatile organic memory transistors with the hybrid CTL shows excellent electrical properties, including low operation voltage (8 V), high speed (erase cycles). The present work provides useful idea for the design of future low-power consumption and highly reliable organic nonvolatile memories.

  17. Ab initio study of mechanical and thermo-acoustic properties of tough ceramics: applications to HfO2 in its cubic and orthorhombic phase

    International Nuclear Information System (INIS)

    Ponce, C A; Casali, R A; Caravaca, M A

    2008-01-01

    By means of the ab initio all-electron new full-potential linear-muffin-tin orbitals method, calculations were made for elastic constants C 11 , C 12 and C 44 for Si, ZrO 2 and HfO 2 in their cubic phase, and constants C 11 , C 22 , C 33 , C 12 , C 13 , C 23 , C 44 , C 55 and C 66 for HfO 2 in its orthorhombic phase. Using the Voigt and Reuss theory, estimations were made for polycrystals of their bulk, shear and Young moduli, and Poisson coefficients. The speed of elastic wave propagations and Debye temperatures were estimated for polycrystals built from Si and the above mentioned compounds. The semicore 4f 14 electrons should be included in the valence set of Hf atom in this all-electron approach if accurate results for elastic properties under pressures are looked for

  18. Physical and Chemical Behaviors of HCl on Ice Surface: Insights from an XPS and NEXAFS Study

    Science.gov (United States)

    Kong, X.; Waldner, A.; Orlando, F.; Birrer, M.; Artiglia, L.; Ammann, M.; Bartels-Rausch, T.

    2016-12-01

    Ice and snow play active roles for the water cycle, the energy budget of the Earth, and environmental chemistry in the atmosphere and cryosphere. Trace gases can be taken up by ice, and physical and chemical fates of the impurities could modify surface properties significantly and consequently influence atmospheric chemistry and the climate system. However, the understanding of chemical behaviour of impurities on ice surface are very poor, which is largely limited by the difficulties to apply high sensitivity experimental approaches to ambient air conditions, e.g. studies of volatile surfaces, because of the strict requirements of vacuum experimental conditions. In this study, we employed synchrotron-based X-ray photoelectron spectroscopy (XPS) and partial electron yield Near Edge X-ray Absorption Fine Structure (NEXAFS) in a state-of-the-art near-ambient pressure photoelectron (NAPP) spectroscopy end station. The NAPP enables to utilize the surface sensitive experimental methods, XPS and NEXAFS, on volatile surfaces, i.e. ice at temperatures approaching 0°C. XPS and NEXAFS together provide unique information of hydrogen bonding network, dopants surface concentration, dopant depth profile, and acidic dissociation on the surfaces1. Taking the advantages of the highly sensitive techniques, the adsorption, dissociation and depth profile of Hydrogen Chloride (HCl) on ice were studied. In brief, two states of Chloride on ice surface are identified from the adsorbed HCl, and they are featured with different depth profiles along the ice layers. Combining our results and previously reported constants from literatures (e.g. HCl diffusion coefficients in ice)2, a layered kinetic model has been constructed to fit the depth profiles of two states of Chloride. On the other side, pure ice and doped ice are compared for their surface structure change caused by temperature and the presence of HCl, which shows how the strong acid affect the ice surface in turn. 1. Orlando, F., et

  19. A Solute's Perspective on How TMAO, Urea and GdnHCl Affect Water's Hydrogen Bonding Ability

    OpenAIRE

    Pazos, Ileana M.; Gai, Feng

    2012-01-01

    While the thermodynamic effects of trimethylamine oxide (TMAO), urea and guanidine hydrochloride (GdnHCl) on protein stability are well understood, the underlying mechanisms of action are less well characterized and, in some cases, even under debate. Herein, we employ the stretching vibration of two infrared (IR) reporters, i.e., nitrile (C≡N) and carbonyl (C=O), to directly probe how these cosolvents mediate the ability of water to form hydrogen bonds with the solute of interest, e.g., a pep...

  20. Thermal electron attachment processes in gas mixtures containing H/sub 2/S, HCl and HBr

    Energy Technology Data Exchange (ETDEWEB)

    Szamrej, I.; Janicka, H.; Chrzascik, I.; Forys, M.

    1989-01-01

    The kinetics of thermal electron capture reactions by H/sub 2/S, HCl and HBr in mixtures with CO/sub 2/ have been investigated using the electron swarm method. A mechanism involving van der Waals molecules (H/sub 2/S)/sub 2/, (HClcenter dotCO/sub 2/) and (HBrcenter dotCO/sub 2/) has been proposed and the rate constants have been calculated. Some tentative conclusions have been made concerning the influence of electronegativity and the dipole moment of the electron scavenger on the mechanism of the electron capture process.

  1. Increased coronary collateral blood flow. A possible mechanism of action for betahistine-HCl.

    Science.gov (United States)

    Terracio, L; Kubicek, W G

    1979-01-01

    beta-Histine-HCl has been shown to be effective in modifying the size of developing myocardial infarcts. In the present study the hypothesis that beta-histine increases the flow of blood through collateral channels and thus supplies blood to ligated areas of the myocardium was investigated in the dog. The methods used were measurement of retrograde coronary blood flow and angiography after coronary artery ligation. beta-Histine administration for 6 h increased retrograde blood flow 68.2--91.0% over controls. Coronary angiography demonstrated the existence of collateral channels 200--400 micrometer in diameter within the myocardium after ligation and 4 h of beta-histine administration.

  2. Spectrophotometric Methods for Simultaneous Determination of Oxytetracycline HCl and Flunixin Meglumine in Their Veterinary Pharmaceutical Formulation

    OpenAIRE

    Merey, Hanan A.; Abd-Elmonem, Mahmmoud S.; Nazlawy, Hagar N.; Zaazaa, Hala E.

    2017-01-01

    Four precise, accurate, selective, and sensitive UV-spectrophotometric methods were developed and validated for the simultaneous determination of a binary mixture of Oxytetracycline HCl (OXY) and Flunixin Meglumine (FLU). The first method, dual wavelength (DW), depends on measuring the difference in absorbance (ΔA 273.4–327 nm) for the determination of OXY where FLU is zero while FLU is determined at ΔA 251.7–275.7 nm. The second method, first-derivative spectrophotometric method (1D), depend...

  3. A multinational study to pilot the modified Hypomania Checklist (mHCL) in the assessment of mixed depression.

    Science.gov (United States)

    Altinbas, Kursat; Ozerdem, Aysegul; Prieto, Miguel L; Fuentes, Manuel E; Yalin, Nefize; Ersoy, Zeliha; Aydemir, Omer; Quiroz, Danilo; Oztekin, Signem; Geske, Jennifer R; Feeder, Scott E; Angst, Jules; Frye, Mark A

    2014-01-01

    Mixed depression is a common, dimensional phenomenon that is increasingly recognized in unipolar and bipolar disorders. We piloted a modified version of the Hypomania Checklist (mHCL-32) to assess the prevalence and clinical correlates of concurrent manic (hypo) symptoms in depressed patients. The mHCL-32, Young Mania Rating Scale (YMRS) and Hamilton Rating Scale for Depression (HAMD-24) were utilized in the assessment of unipolar (UP=61) and bipolar (BP=44) patients with an index major depressive episode confirmed by the Structured Clinical Interview for DSM-IV (SCID). Differential mHLC-32 item endorsement was compared between UP and BP. Correlation analyses assessed the association of symptom dimensions measured by mHCL-32, YMRS and HAMD-24. There was no significant difference between mood groups in the mean mHCL-32 and YMRS scores. Individual mHLC-32 items of increased libido, quarrels, and caffeine intake were endorsed more in BP vs. UP patients. The mHCL-32 active-elevated subscale score was positively correlated with the YMRS in BP patients and negatively correlated with HAMD-24 in UP patients. Conversely, the mHCL-32 irritable-risk taking subscale score was positively correlated with HAMD-24 in BP and with YMRS in UP patients. Small sample size and cross-sectional design. Modifying the HCL to screen for (hypo) manic symptoms in major depression may have utility in identifying mixed symptoms in both bipolar vs. unipolar depression. Further research is encouraged to quantify mixed symptoms with standardized assessments. © 2013 Published by Elsevier B.V.

  4. Factor structure and reliability of the Italian adaptation of the Hypomania Check List-32, second revision (HCL-32-R2).

    Science.gov (United States)

    Fornaro, Michele; De Berardis, Domenico; Mazza, Monica; Pino, Mariachiara; Favaretto, Ettore; Bedani, Fulvio; Wieser, Christian; Indelicato, Luisa; Paternò, Vito Fabio; Lo Monaco, Francesca; Dugo, Febronia; Ventriglio, Antonio; Mungo, Sergio; Selle, Valerio; Valchera, Alessandro; Elassy, Mai; Martinotti, Giovanni; De Bartolomeis, Andrea; Iasevoli, Felice; Tomasetti, Carmine; Avvisati, Livia; Tartaglione, Sergio; Perna, Giampaolo; Cattaneo, Carlo Ignazio; Consoli, Giorgio; Romano, Anna; Del Debbio, Alessandro; Martino, Matteo; D' Angelo, Emanuela; De Pasquale, Concetta; Koshy, Ann Sarah; Angst, Jules

    2015-06-01

    To assess the psychometric properties of the Italian adaptation of the Hypomania-Check-List 32-item, second revision (HCL-32-R2) for the detection of bipolarity in major depressive disorder (MDD) treatment-seeking outpatients. A back-to-back Italian adaption of the "Bipolar Disorders: Improving Diagnosis, Guidance, and Education" English module of the HCL-32-R2 was administered between March 2013 and October 2014 across twelve collaborating sites in Italy. Diagnostic and Statistical Manual Fourth edition (DSM-IV) diagnoses were made adopting the mini-international neuropsychiatric interview, using bipolar disorder (BD) patients as controls. In our sample (n=441, of whom, BD-I=68; BD-II=117; MDD=256), using a cut-off of 14 allowed the HCL-32-R2 to discriminate DSM-IV-defined MDD patients between "true unipolar" (HCL-32-R2(-)) and "sub-threshold bipolar depression" (HCL-32-R2(+)) with sensitivity=89% and specificity=79%. Area under the curve was .888; positive and negative predictive values were 75.34% and 90.99% respectively. Owing to clinical interpretability considerations and consistency with previous adaptations of the HCL-32, a two-factor solution (F1="hyperactive/elated" vs. F2="irritable/distractible/impulsive") was preferred using exploratory and confirmatory factor analyses, whereas items n.33 ("I gamble more") and n.34 ("I eat more") introduced in the R2 version of the scale slightly loaded onto F2 and F1 respectively. Cronbach׳s α=.88 for F1 and .71 for F2. No cross-validation with any additional validated screening tool; treatment-seeking outpatient sample; recall bias; no systematic evaluation of eventual medical/psychiatric comorbidities, current/lifetime pharmacological history, neither record of severity of current MDE. Our results seem to indicate fair accuracy of HCL-32 as a screening instrument for BD, though replication studies are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Depletion of chlorine into HCl ice in a protostellar core. The CHESS spectral survey of OMC-2 FIR 4

    Science.gov (United States)

    Kama, M.; Caux, E.; López-Sepulcre, A.; Wakelam, V.; Dominik, C.; Ceccarelli, C.; Lanza, M.; Lique, F.; Ochsendorf, B. B.; Lis, D. C.; Caballero, R. N.; Tielens, A. G. G. M.

    2015-02-01

    Context. The freezeout of gas-phase species onto cold dust grains can drastically alter the chemistry and the heating-cooling balance of protostellar material. In contrast to well-known species such as carbon monoxide (CO), the freezeout of various carriers of elements with abundances OMC-2 FIR 4. Methods: We observed transitions of HCl and H2Cl+ towards OMC-2 FIR 4 using the Herschel Space Observatory and Caltech Submillimeter Observatory facilities. Our analysis makes use of state of the art chlorine gas-grain chemical models and newly calculated HCl-H2 hyperfine collisional excitation rate coefficients. Results: A narrow emission component in the HCl lines traces the extended envelope, and a broad one traces a more compact central region. The gas-phase HCl abundance in FIR 4 is 9 × 10-11, a factor of only 10-3 that of volatile elemental chlorine. The H2Cl+ lines are detected in absorption and trace a tenuous foreground cloud, where we find no depletion of volatile chlorine. Conclusions: Gas-phase HCl is the tip of the chlorine iceberg in protostellar cores. Using a gas-grain chemical model, we show that the hydrogenation of atomic chlorine on grain surfaces in the dark cloud stage sequesters at least 90% of the volatile chlorine into HCl ice, where it remains in the protostellar stage. About 10% of chlorine is in gaseous atomic form. Gas-phase HCl is a minor, but diagnostically key reservoir, with an abundance of ≲10-10 in most of the protostellar core. We find the [35Cl]/[37Cl] ratio in OMC-2 FIR 4 to be 3.2 ± 0.1, consistent with the solar system value. Appendices are available in electronic form at http://www.aanda.org

  6. Oral Phenylephrine HCl for Nasal Congestion in Seasonal Allergic Rhinitis: A Randomized, Open-label, Placebo-controlled Study.

    Science.gov (United States)

    Meltzer, Eli O; Ratner, Paul H; McGraw, Thomas

    2015-01-01

    Phenylephrine hydrochloride (PE HCl) is widely used for the treatment of nasal congestion, but efficacy at the 10-mg dose is not known for certain. The Food and Drug Administration has requested that sufficiently powered, multicenter, dose-ranging studies be conducted to assess the efficacy and safety of PE HCl. To evaluate subjective nasal congestion symptom relief and safety of 4 different doses of PE HCl immediate-release 10-mg tablets and placebo in adults with seasonal allergic rhinitis (SAR). This multicenter, phase 2, parallel, open-label trial randomized 539 adults with SAR (but otherwise healthy) to 7 days of treatment with either PE HCl 10-mg tablets at fixed doses of 10, 20, 30, or 40 mg or placebo. The primary efficacy end point was the mean change from baseline over the entire treatment period in daily reflective nasal congestion score. Other efficacy end points and safety were also evaluated. None of the PE HCl treatment groups had a statistically significant change from baseline in instantaneous or reflective nasal congestion scores compared with the placebo group. PE HCl was well tolerated at doses of up to 30 mg. At least 1 treatment-emergent adverse event was experienced by 18.4% of the participants, the most common being headache (3.0%). PE HCl, at doses of up to 40 mg every 4 hours, is not significantly better than placebo at relieving nasal congestion in adults with SAR. The phenylephrine section of the Food and Drug Administration monograph on over-the-counter cold, cough, allergy, bronchodilator, and antiasthmatic products should be revised accordingly. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  7. The magnetic hyperfine field in the 181Ta site in the Co2HfAl and Co2HfGa Heusler alloys

    International Nuclear Information System (INIS)

    Silva, R. da.

    1979-01-01

    The hyperfine magnetic fields at 181 Ta nuclei in Heusler alloys Co 2 HfZ (Z=Al, Ga) have been measured using the time differential perturbed gamma-gamma angular correlation (TDPAC) method. The hyperfine fields obtained from these measurements at the liquid nitrogen temperature are -189 and +- 150 kOersted for Co 2 HfAl and Co 2 HfGa, respectively. The concept that the hyperfine field at the Y site is similar to the solute fields in Fe, Co, Ni and Gd matrices is corroborated. We have verified that ratios H sub(hf) sub(Ta)/T sub(c) and H sub(hf) sub(Ta)μ sub(Co) in Co 2 HfZ compounds (Z=Al, Ga, Sn) do not depend on the nature of Z element. However a dependence in the value of observed field with the s-p element in Z site was noticed. We feel that the samples are not completely ordered cubic as observed by the quadrupole interaction measurements. The results are interpreted in terms of the Campbell-Blandin formalism, and it is shown that the spin polarization of conduction electrons at Hf and Ta have opposite signs. (Author) [pt

  8. Development of Cu-Hf-Al ternary systems and tungsten wire/particle reinforced Cu48Hf43Al9 bulk metallic glass composites for strengthening

    International Nuclear Information System (INIS)

    Park, Joyoung; An, Jihye; Choi-Yim, Haein

    2010-01-01

    Stable bulk glass forming alloys can be developed over a wide range of compositions in Cu-Hf-Al ternary systems starting from the Cu 49 Hf 42 Al 9 bulk metallic glass. Ternary Cu-Hf-Al alloys can be cast directly from the melt into copper molds to form fully amorphous strips with thicknesses of 1 to 6 mm. The maximum critical diameter of the new Cu-Hf-Al ternary alloy was 6 mm. X-ray diffraction patterns were used to confirm the amorphous nature of the ternary Cu-Hf-Al alloys. To increase the toughness of these metallic glasses, we reinforced the Cu 48 Hf 43 Al 9 bulk metallic glass-forming liquid with a 50% volume fraction of tungsten particles and an 80% volume fraction of tungsten wires with diameters of 242.4 μm. Composites with a critical diameter of 7 mm and length 70 mm were synthesized. The structure of the composites was confirmed by using X-ray diffraction (XRD), and the scanning electron microscopy (SEM). The mechanical properties of the composites were studied in compression tests. The thermal stability and the crystallization processes of the Cu-Hf-Al alloys and composites were investigated by using differential scanning calorimetry (DSC). Values of the glass transition temperature (T g ), the crystallization temperature (T x ), and the supercooled liquid region (ΔT = T x - T g ) are given in this paper.

  9. Pre-assembly test of 3 HF wedges at a time

    CERN Multimedia

    Tiziano Camporesi

    2002-01-01

    To check the geometry of the individual HF wedges a special jig has been developed which allows mounting 3 HF wedges at a time. The jig simulates the exact geometry of the final shield where 9 wedges will be assembled forming the 'D' shaped half HF. Such pre-mounting has allowed to verify the accuracy of the construction of the individual wedges and made sure that the final assembly will not meet any structural problem.

  10. Simultaneous measurements of HF-enhanced plasma waves and artificial field-aligned irregularities at Arecibo

    International Nuclear Information System (INIS)

    Noble, S.T.; Djuth, F.T.

    1990-01-01

    Two radar systems with beams intersecting in the HF-modified F region were used to simultaneously measure HF-enhanced plasma lines (HFPLs) and artificial geomagnetic field-aligned irregularities (AFAIs). The Arecibo 430-MHz radar was used for the HFPL observations, and a portable 49.92-MHz backscatter radar was deployed on the island of Guadeloupe to monitor the AFAIs. The experiment was desgined to examine the degree to which HF-induced plasma turbulence influences the development of AFAIs. When the HF beam is stepped up in power, sustained HFPLs and AFAIs are first observed at the same HF power level, indicating that ponderomotively driven instabilities may be involved in the early time development of AFAIs. As the HF power is increased, the HFPL backscatter power begins to saturate at ∼70 MW effective radiated power (ERP). However, the backscatter from AFAIs is linearly dependent on HF power, even at the highest (120 MW ERP) HF power levels available at Arecibo. This suggests that additional processes may contribute to the development of AFAIs. For example, ponderomotively driven instabilities may give rise to weak geomagnetic field-aligned irregularities that are subsequently driven unstable by processes excited near the upper hybrid resonance. It is also likely that AFAIs greatly impact the development of HF-induced plasma turbulence at late times (>1 s) following HF turn-on. Once the ionosphere is preconditioned by high-power HF modifications, AFAIs and HFPLs can be simultaneously sustained at a much lower HF power level than that needed to originally excite them. The nature of the preconditioning process is currently not well understood. New theoretical initiatives are clearly needed to guide future experimental activity in this area

  11. Assembly of the CMS HF (hadron forward) calorimeter, April 2003 to June 2005

    CERN Multimedia

    Tejinder S. Virdee, CERN

    2005-01-01

    The forward calorimeters (HF) of the CMS hadron calorimeter system are located 11.2 m from the interaction point. Each HF module is composed by 18 wedges, made of steel absorbers and radiation-hard quartz fibers. The photogallery shows the wedges (Figs. 1-3, April 2003), the assembly of one HF module (Figs. 4-9, May and June 2004) and the assembly of the other (Figs. 10-11, June 2005)

  12. Reversible spin texture in ferroelectric Hf O2

    Science.gov (United States)

    Tao, L. L.; Paudel, Tula R.; Kovalev, Alexey A.; Tsymbal, Evgeny Y.

    2017-06-01

    Spin-orbit coupling effects occurring in noncentrosymmetric materials are known to be responsible for nontrivial spin configurations and a number of emergent physical phenomena. Ferroelectric materials may be especially interesting in this regard due to reversible spontaneous polarization making possible a nonvolatile electrical control of the spin degrees of freedom. Here, we explore a technologically relevant oxide material, Hf O2 , which has been shown to exhibit robust ferroelectricity in a noncentrosymmetric orthorhombic phase. Using theoretical modelling based on density-functional theory, we investigate the spin-dependent electronic structure of the ferroelectric Hf O2 and demonstrate the appearance of chiral spin textures driven by spin-orbit coupling. We analyze these spin configurations in terms of the Rashba and Dresselhaus effects within the k .p Hamiltonian model and find that the Rashba-type spin texture dominates around the valence-band maximum, while the Dresselhaus-type spin texture prevails around the conduction band minimum. The latter is characterized by a very large Dresselhaus constant λD= 0.578 eV Å, which allows using this material as a tunnel barrier to produce tunneling anomalous and spin Hall effects that are reversible by ferroelectric polarization.

  13. HF Radar Sea-echo from Shallow Water

    Directory of Open Access Journals (Sweden)

    Josh Kohut

    2008-08-01

    Full Text Available HF radar systems are widely and routinely used for the measurement of ocean surface currents and waves. Analysis methods presently in use are based on the assumption of infinite water depth, and may therefore be inadequate close to shore where the radar echo is strongest. In this paper, we treat the situation when the radar echo is returned from ocean waves that interact with the ocean floor. Simulations are described which demonstrate the effect of shallow water on radar sea-echo. These are used to investigate limits on the existing theory and to define water depths at which shallow-water effects become significant. The second-order spectral energy increases relative to the first-order as the water depth decreases, resulting in spectral saturation when the waveheight exceeds a limit defined by the radar transmit frequency. This effect is particularly marked for lower radar transmit frequencies. The saturation limit on waveheight is less for shallow water. Shallow water affects second-order spectra (which gives wave information far more than first-order (which gives information on current velocities, the latter being significantly affected only for the lowest radar transmit frequencies for extremely shallow water. We describe analysis of radar echo from shallow water measured by a Rutgers University HF radar system to give ocean wave spectral estimates. Radar-derived wave height, period and direction are compared with simultaneous shallow-water in-situ measurements.

  14. Interrogation zone determination in HF RFID systems with multiplexed antennas*

    Directory of Open Access Journals (Sweden)

    Jankowski-Mihułowicz Piotr

    2015-09-01

    Full Text Available The operation of an anti-collision RFID system is characterized by the interrogation zone which should be estimated in any direction of 3D space for a group of electronic transponders. The interrogation zone should be as large as possible. However, the many problems in this area are due to the fact that energy can be transferred to transponders only on a limited distance. The greatest flexibility in developing RFID applications and shaping the interrogation zone can be achieved using the system with an antenna multiplexer. Therefore the problem of the interrogation zone determination in HF RFID systems with two orthogonal RWD antennas is presented in the paper. The perceived issues have been effectively dealt with and the solution has been proposed on the basis of the elaborated model. Conducted studies have been used to develop the software tool JankoRFIDmuxHF in the Mathcad environment. The research results are analysed in an example system configuration. The specialized measuring stand has been used for experimental verification of the identification efficiency. The convergence of the measurements and calculations confirms a practical usefulness of the presented concept of interrogation zone determination in anti-collision systems. It also shows the practical utility of the developed model and software tools.

  15. Phase1 upgrade of the CMS-HF Calorimeter

    CERN Document Server

    Gulmez, Erhan

    2016-01-01

    In this presentation, results of the Phase I upgrade of the CMS Hadron Forward Calorimeter (HF) are discussed. The CMS-HF Calorimeter was using regular PMTs. Cherenkov light produced in the quartz fibers embedded in the iron absorber was read out with the PMTs. However, occasionally, stray muons hitting the PMT windows cause Cherenkov radiation in the PMT itself and produce large signals. These large signals mimic a very high-energy particle and are tagged as important by the trigger. To reduce this problem, PMTs had to be replaced. The four-anode PMTs that were chosen have thinner windows; thereby reducing the Cherenkov radiation in the PMT window. As part of the upgrade, the read-out electronics is to be replaced so that the PMTs are read out in two channels by connecting each pair of anodes to a single channel. Information provided by these two channels will help us reject the false signals due to the stray muons since the Cherenkov radiation in the PMT window is more likely to produce a signal only in one...

  16. Meteorite zircon constraints on the bulk Lu−Hf isotope composition and early differentiation of the Earth

    Science.gov (United States)

    Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

    2015-01-01

    Knowledge of planetary differentiation is crucial for understanding the chemical and thermal evolution of terrestrial planets. The 176Lu−176Hf radioactive decay system has been widely used to constrain the timescales and mechanisms of silicate differentiation on Earth, but the data interpretation requires accurate estimation of Hf isotope evolution of the bulk Earth. Because both Lu and Hf are refractory lithophile elements, the isotope evolution can be potentially extrapolated from the present-day 176Hf/177Hf and 176Lu/177Hf in undifferentiated chondrite meteorites. However, these ratios in chondrites are highly variable due to the metamorphic redistribution of Lu and Hf, making it difficult to ascertain the correct reference values for the bulk Earth. In addition, it has been proposed that chondrites contain excess 176Hf due to the accelerated decay of 176Lu resulting from photoexcitation to a short-lived isomer. If so, the paradigm of a chondritic Earth would be invalid for the Lu−Hf system. Herein we report the first, to our knowledge, high-precision Lu−Hf isotope analysis of meteorite crystalline zircon, a mineral that is resistant to metamorphism and has low Lu/Hf. We use the meteorite zircon data to define the Solar System initial 176Hf/177Hf (0.279781 ± 0.000018) and further to identify pristine chondrites that contain no excess 176Hf and accurately represent the Lu−Hf system of the bulk Earth (176Hf/177Hf = 0.282793 ± 0.000011; 176Lu/177Hf = 0.0338 ± 0.0001). Our results provide firm evidence that the most primitive Hf in terrestrial zircon reflects the development of a chemically enriched silicate reservoir on Earth as far back as 4.5 billion years ago. PMID:25870298

  17. Meteorite zircon constraints on the bulk Lu-Hf isotope composition and early differentiation of the Earth.

    Science.gov (United States)

    Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

    2015-04-28

    Knowledge of planetary differentiation is crucial for understanding the chemical and thermal evolution of terrestrial planets. The (176)Lu-(176)Hf radioactive decay system has been widely used to constrain the timescales and mechanisms of silicate differentiation on Earth, but the data interpretation requires accurate estimation of Hf isotope evolution of the bulk Earth. Because both Lu and Hf are refractory lithophile elements, the isotope evolution can be potentially extrapolated from the present-day (176)Hf/(177)Hf and (176)Lu/(177)Hf in undifferentiated chondrite meteorites. However, these ratios in chondrites are highly variable due to the metamorphic redistribution of Lu and Hf, making it difficult to ascertain the correct reference values for the bulk Earth. In addition, it has been proposed that chondrites contain excess (176)Hf due to the accelerated decay of (176)Lu resulting from photoexcitation to a short-lived isomer. If so, the paradigm of a chondritic Earth would be invalid for the Lu-Hf system. Herein we report the first, to our knowledge, high-precision Lu-Hf isotope analysis of meteorite crystalline zircon, a mineral that is resistant to metamorphism and has low Lu/Hf. We use the meteorite zircon data to define the Solar System initial (176)Hf/(177)Hf (0.279781 ± 0.000018) and further to identify pristine chondrites that contain no excess (176)Hf and accurately represent the Lu-Hf system of the bulk Earth ((176)Hf/(177)Hf = 0.282793 ± 0.000011; (176)Lu/(177)Hf = 0.0338 ± 0.0001). Our results provide firm evidence that the most primitive Hf in terrestrial zircon reflects the development of a chemically enriched silicate reservoir on Earth as far back as 4.5 billion years ago.

  18. Thermodynamic modeling of the Co–Hf system supported by key experiments and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xingxu [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Liu, Shuhong, E-mail: shhliu@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Sino-German Cooperation Group “Microstructure in Al alloys”, Central South University, Changsha, Hunan 410083 (China); Cheng, Kaiming; Tang, Ying [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Ou, Pengfei [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Nash, Philip [Thermal Processing Technology Center, Illinois Institute of Technology (IIT), 10 West 32nd Street, Chicago, IL 60616 (United States); Sundman, Bo [INSTN, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Du, Yong [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China); Sino-German Cooperation Group “Microstructure in Al alloys”, Central South University, Changsha, Hunan 410083 (China); Zheng, Feng [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China)

    2015-05-20

    Highlights: • Heat contents of Co{sub 2}Hf and CoHf{sub 2} were measured by drop calorimetry. • Enthalpy of formation for Co{sub 23}Hf{sub 6} was computed via first-principles calculations. • Co–Hf system was assessed by means of CALPHAD approach. • Order–disorder model is used to describe B2 (CoHf) and A2 (βHf). • Glass forming range of the Co–Hf amorphous alloys was predicted. - Abstract: Phase equilibria and thermodynamic properties of the Co–Hf system were investigated via calorimetric measurements, first-principles calculations and thermodynamic modeling. Heat contents of Co{sub 2}Hf and CoHf{sub 2} were measured by drop calorimetry from 300 to 1200 °C. The enthalpy of formation for Co{sub 23}Hf{sub 6} at 0 K was computed via first-principles calculations. Based on the experimental measurements and first-principles calculations from the present work and the literature, the Co–Hf system was assessed by means of CALPHAD (CALculation of PHAse Diagram) approach. The excess Gibbs energy of solution phases was modeled with Redlich–Kister polynomial. Sublattice models were employed to describe the homogeneity ranges of Co{sub 2}Hf, CoHf and CoHf{sub 2}. The order–disorder transition between B2 (CoHf) and A2 (βHf) phases was taken into account in the current optimization. Using the optimized parameters, glass forming range (GFR) of the Co–Hf amorphous alloys was predicted to be 15–75 at.% Hf, which is in satisfactory agreement with the experimental observation.

  19. Chemical stability and defect formation in CaHfO3

    KAUST Repository

    Alay-E-Abbas, Syed Muhammad

    2014-04-01

    Defects in CaHfO3 are investigated by ab initio calculations based on density functional theory. Pristine and anion-deficient CaHfO 3 are found to be insulating, whereas cation-deficient CaHfO 3 is hole-doped. The formation energies of neutral and charged cation and anion vacancies are evaluated to determine the stability in different chemical environments. Moreover, the energies of the partial and full Schottky defect reactions are computed. We show that clustering of anion vacancies in the HfO layers is energetically favorable for sufficiently high defect concentrations and results in metallicity. © 2014 EPLA.

  20. Efficient noble metal nanocatalysts supported on HfC(001 for O2 dissociation

    Directory of Open Access Journals (Sweden)

    Shiyan Wang

    2017-03-01

    Full Text Available The adsorption and dissociation of O2 on the M4 (M=Au, Pd, Pt clusters supported on HfC(001 (Hafnium Carbide are investigated using ab initio density functional theory calculations. The geometric and electronic structures are analyzed in detail. It is found that the dissociation barriers of O2 on Au4/HfC(001 (0.26 eV, Pd4/HfC(001 (0.49 eV and Pt4/HfC(001 (0.09 eV are much smaller than those on the clean surfaces of HfC(001 (1.60 eV, Au(111 (1.37 eV, Pd(111 (1.0 and 0.91 eV and Pt(111 (0.27–0.7 eV, respectively. The low dissociation barriers imply that the Pt4/HfC(001 exhibits the highest catalytic activity for O2 dissociation, and the Au4/HfC(001 and Pd4/HfC(001 may also be possible substitutes with lower cost for the current Pt/C catalyst for O2 dissociation. The present study is conductive to designing new efficient noble metal catalyst using HfC support for efficiently promoting O2 dissociation.

  1. Study of Direct-Contact HfO2/Si Interfaces

    Directory of Open Access Journals (Sweden)

    Noriyuki Miyata

    2012-03-01

    Full Text Available Controlling monolayer Si oxide at the HfO2/Si interface is a challenging issue in scaling the equivalent oxide thickness of HfO2/Si gate stack structures. A concept that the author proposes to control the Si oxide interface by using ultra-high vacuum electron-beam HfO2 deposition is described in this review paper, which enables the so-called direct-contact HfO2/Si structures to be prepared. The electrical characteristics of the HfO2/Si metal-oxide-semiconductor capacitors are reviewed, which suggest a sufficiently low interface state density for the operation of metal-oxide-semiconductor field-effect-transistors (MOSFETs but reveal the formation of an unexpected strong interface dipole. Kelvin probe measurements of the HfO2/Si structures provide obvious evidence for the formation of dipoles at the HfO2/Si interfaces. The author proposes that one-monolayer Si-O bonds at the HfO2/Si interface naturally lead to a large potential difference, mainly due to the large dielectric constant of the HfO2. Dipole scattering is demonstrated to not be a major concern in the channel mobility of MOSFETs.

  2. Lu-Hf total-rock age for the Amîtsoq gneisses, West Greenland

    Science.gov (United States)

    Pettingill, H.S.; Patchett, P.J.

    1981-01-01

    Lu-Hf total-rock data for the Amîtsoq gneisses of West Greenland yield an age of 3.55±0.22Gy(2σ), based on the decay constant λ176Lu=1.96×10−11y−1, and an initial176Hf/177Hf ratio of 0.280482±33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 Gy, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial176Hf/177Hf lies close to a chondritic Hf isotopic evolution curve from 4.55 Gy to present. This is consistent with the igneous precursors to the Amîtsoq gneisses having been derived from the mantle at or shortly before 3.6 Gy. Anomalous relationships between Hf concentration and the176Lu/177Hf ratio may suggest that trace element abundances in the Amîtsoq gneisses are partly controlled by processes related to metamorphism.

  3. Green luminescence of divalent europium in the hydride chloride EuHCl

    International Nuclear Information System (INIS)

    Kunkel, Nathalie; Kohlmann, Holger; Rudolph, Daniel; Schleid, Thomas; Meijerink, Andries; Rommel, Stefan; Weihrich, Richard

    2015-01-01

    Luminescence properties of divalent europium in the mixed-anion hydride chloride EuHCl were studied for the first time. Olive-green single crystals of EuHCl (PbFCl-type structure: tetragonal, P4/nmm, a = 406.58(3) pm, c = 693.12(5) pm, c/a = 1.705, Z = 2) resulted from the reaction of elemental europium (Eu), sodium hydride (NaH) and sodium chloride (NaCl), while powder samples were prepared from the binary components europium dihydride (EuH 2 ) and dichloride (EuCl 2 ). Low temperature X-ray powder diffraction proved the absence of phase transitions for 12(2) K ≤ T ≤ 295(2) K. Bright green emission was observed under UV-excitation and assigned to the 4f 6 5d 1 -4f 7 transition of divalent europium. Temperature-dependent luminescence absorption and emission, as well as lifetime measurements were carried out on single crystal and powder samples. Surprisingly, only limited concentration quenching was found. Additionally, two emission bands (485 and 510 nm) are observed, whose intensity ratio depends strongly on temperature. In order to explain this behavior for a single Eu 2+ site, we suggest either a dynamical Jahn-Teller effect in the excited 5d 1 state or emission from both a 4f 6 5d 1 state and a trapped exciton state. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Removal of Zn from Contaminated Sediment by FeCl3 in HCl Solution

    Directory of Open Access Journals (Sweden)

    Sang-hun Lee

    2015-10-01

    Full Text Available Harbor sediments contaminated with ZnS concentrate were treated by ferric chloride in HCl solution to remove Zn. The sediments were evaluated using Tessier’s sequential extraction method to determine the different metal phase associations of Zn. Leaching tests were performed to investigate the effects of experimental factors, such as agitation speed, ferric ion concentration, temperature, and pulp density, on the removal of Zn. The sequential extraction procedure revealed that about 17.7% of Zn in the sediment was associated with soluble carbonate and oxide phases. The results of the leaching tests indicated that higher ferric concentration and temperature increased the leaching efficiencies significantly, while the agitation speed has a negligible effect on the removal of Zn. The removal ratio increased to more than 99% within 120 min of treatment at 1 kmol·m−3 HCl solution with 1 kmol·m−3 Fe3+, 10% pulp density, and 400 rpm at 90 °C. The dissolution kinetics of Zn were discussed by comparing the two shrinking core models. It was determined that the kinetic data followed the diffusion controlled model well compared to the surface chemical reaction model. The activation energies were calculated to be 76.9 kJ/mol, 69.6 kJ/mol, and 58.5 kJ/mol for 0.25 kmol·m−3, 0.5 kmol·m−3, and 1 kmol·m−3 Fe3+, respectively.

  5. Development of calcium pectinate-tamarind seed polysaccharide mucoadhesive beads containing metformin HCl.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2014-01-30

    Novel mucoadhesive beads containing metformin HCl made of low methoxy (LM) pectin-tamarind seed polysaccharide (TSP) polymer-blend was developed through ionotropic-gelation technique and optimized using 3(2) factorial design. Effects of LM pectin and TSP amounts on drug encapsulation efficiency (DEE), and cumulative drug release at 10h (R10h) were analyzed using response surface methodology. The optimized calcium pectinate-TSP beads containing metformin HCl showed DEE of 95.12 ± 4.26%, R10h of 46.53 ± 3.28%, and mean diameter of 1.93 ± 0.26 mm. The in vitro drug release from these beads was followed controlled-release (zero-order) pattern with super case-II transport mechanism. These beads were also characterized by SEM and FTIR. The optimized beads also exhibited pH-dependent swelling, good mucoadhesivity with goat intestinal mucosa and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Tamarind seed polysaccharide-gellan mucoadhesive beads for controlled release of metformin HCl.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar; Santra, Kousik

    2014-03-15

    The paper describes the development, optimization and evaluation of tamarind seed polysaccharide (TSP)-blended gellan gum (GG) mucoadhesive beads containing metformin HCl through Ca(2+)-ion cross-linked ionic gelation for oral drug delivery. Effects of GG to TSP ratio and cross-linker (CaCl2) concentration on the drug encapsulation efficiency (DEE, %), and cumulative drug release after 10h (R10h, %) of TSP-GG mucoadhesive beads containing metformin HCl were optimized by 32 factorial design. The optimized mucoadhesive beads (F-O) showed DEE of 95.73 ± 4.02%, R10h of 61.22 ± 3.44% and mean diameter of 1.70 ± 0.24 mm.These beads were characterized by SEM and FTIR analyses. The in vitro drug release from these beads showed controlled-release (zero-order) pattern over a period of 10h.The optimized TSP-GG mucoadhesive beads also exhibited pH-dependent swelling, good mucoadhesivity with biological mucosal membrane and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Formulation Design, Optimization and Pharmacodynamic Evaluation of Sustained Release Mucoadhesive Microcapsules of Venlafaxine HCl.

    Science.gov (United States)

    Swain, S; Behera, A; Dinda, S C; Patra, C N; Jammula, Sruti; Beg, S; Rao, M E B

    2014-07-01

    The objective of present research work was to design and characterize the venlafaxine HCl-loaded sodium alginate-based mucoadhesive microcapsules by ionic gelation technique using HPMC K100M as mucoadhesive polymer. The Placket-Burman Design was applied for preliminary screening of the formulations and systematic optimization by using Box-Behnken Design. The prepared microcapsules were characterized for drug content, entrapment efficiency, micromeritic properties, particle size, swelling index, mucoadhesive strength, in vitro drug release and in vivo antidepressant activity. FTIR and differential scanning calorimetry studies showed no incompatibility. Surface morphology studies revealed spherical nature of the prepared microcapsules. In vitro drug release studies revealed sustained release by diffusion mechanism. Further, the microcapsules were effective in reducing the depression induced by forced swimming test in Sprague-Dawley rats compared to the pure drug. The microcapsules were found to be stable under accelerated stability conditions, which suggest them as better alternative delivery systems for enhanced therapeutic efficacy of antidepressant drug, venlafaxine HCl.

  8. [Hypomania Check List (HCL-32)--hypomania symptoms questionnaire: description and application].

    Science.gov (United States)

    Łojko, Dorota; Rybakowski, Janusz; Dudek, Dominika; Pawłowski, Tomasz; Siwek, Marcin; Kiejna, Andrzej

    2010-01-01

    In current diagnostic classifications such as the International Classification of Diseases (ICD-10) and the American Diagnostic and Statistical Manual (DSM-IV), unipolar and bipolar mood disorders are mentioned, where the differentiating factor is occurrence of mania or hypomania. In DSM-IV, bipolar mood disorder type I (bipolar I), with the episodes of mania, and bipolar mood disorder type II (bipolar II) with hypomania, have been separated. Clinical and epidemiological studies performed in recent decades using more sensitive measures of the assessment of hypomania suggest a marked prevalence of bipolar disorders of not-bipolar I type, amounting to about 3-5% of population. In 2005, Angst and collaborators introduced the Hypomania Check List-32 scale (HCL-32) aimed at a better identification of the occurrence of hypomania symptoms in patients with affective disorders. The studies carried out in many countries have demonstrated a significant sensitivity and specificity of the scale and its usefulness for the assessment of bipolar affective disorders. In the present paper, the Polish version of HCL-32 scale is presented. This version has been already employed in the all-country Polish project TRES-DEP where the features of bipolarity were assessed in depressive patients in whom treatment with antidepressant drugs was unsuccessful.

  9. Determination of polymorphic forms of ranitidine-HCl by DRIFTS and XRPD.

    Science.gov (United States)

    Agatonovic-Kustrin, S; Rades, T; Wu, V; Saville, D; Tucker, I G

    2001-07-01

    The identification, characterization and quantification of crystal forms are becoming increasingly important within the pharmaceutical industry. A combination of different physical analytical techniques is usually necessary for this task. In this work solid-state techniques, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and X-ray powder diffractometry (XRPD) were combined to analyze polymorphic purity of crystalline ranitidine-HCl, an antiulcer drug, H2 receptor antagonists. A series of 12 different mixtures of Form 1 and 2 was prepared by geometric mixing and their DRIFT spectra and XRD powder patterns were obtained and analyzed, either alone or combined together, using Artificial Neural Networks (ANNs). A standard feed-forward network, with back-propagation rule and with multi layer perceptron architecture (MPL) was chosen. A working range of 1.0-100% (w/w) of crystal Form 2 in Form 1 was established with a minimum quantifiable level (MQL) of 5.2% and limit of detection of 1.5% (w/w). The results demonstrate that DRIFTS combined with XRPD may be successfully used to distinguish between the ranitidine-HCl polymorphs and to quantify the composition of binary mixtures of the two.

  10. Differentially expressed microRNAs in diapausing versus HCl-treated Bombyx embryos

    Science.gov (United States)

    Qin, Mingyue; Lin, Bimin; Chen, Fangyan; Yan, Huichao; Li, Wenchu

    2017-01-01

    Differentially expressed microRNAs were detected to explore the molecular mechanisms of diapause termination. The total small RNA of diapause-destined silkworm eggs and HCl-treated eggs was extracted and then sequenced using HiSeq high-throughput method. 44 novel miRNAs were discovered. Compared to those in the diapause-destined eggs, 61 miRNAs showed significant changes in the acid-treated eggs, with 23 being up-regulated and 38 being down-regulated. The potential target genes of differentially expressed miRNAs were predicted by miRanda. Gene Ontology and KEGG pathway enrichment analysis of these potential target genes revealed that they were mainly located within cells and organelles, involved in cellular and metabolic processes, and participated in protein production, processing and transportation. Two differentially expressed genes, Bombyx mori SDH and Bmo-miR-2761-3p, were further analyzed with qRT-PCR. BmSDH was significantly up-regulated in the HCl-treated eggs, while Bmo-miR-2761-3p was down-regulated. These results suggested that these two genes were well coordinated in silkworm eggs. Dual luciferase reporter assay demonstrated that Bmo-miR-2761-3p inhibited the expression of BmSDH. PMID:28700597

  11. Identification and characterization of the HCl-DMS gas phase molecular complex via infrared spectroscopy and electronic structure calculations.

    Science.gov (United States)

    Bork, Nicolai; Du, Lin; Kjaergaard, Henrik G

    2014-02-27

    Models of atmospheric aerosol formation are dependent on accurate Gibbs free binding energies (ΔG°) of gaseous acids and bases, but for most acid–base pairs, only ab initio data are available. We report a combined experimental and theoretical study of the gaseous molecular complex of dimethylsulfide (DMS) and HCl. On the basis of infrared spectroscopy and anharmonic local mode calculations, we determine ΔG(295K)° to be between 6.2 and 11.1 kJ mol(–1). We test the performance of MP2 and five often used DFT functionals with respect to this result. M06-2X performs the best, but also the MP2 prediction is within the experimental range. We find that coupled cluster corrections to the electronic energy improves ΔG° estimates if and only if triple excitations are included. These estimates may be further improved by applying vibrational scaling factors to account for anharmonicity. Hereby, all but the PW91 based predictions are within the experimental range.

  12. Estimation of heterogeneous reaction rates for stratospheric trace gases with particular reference to the diffusional uptake of HCl and ClONO2 by polar stratospheric clouds

    Directory of Open Access Journals (Sweden)

    J. A. Pyle

    Full Text Available The stratosphere holds a variety of particulates like polar stratospheric clouds (PSCs and sulphate aerosols which catalyse chemical reactions. These reactions cause changes in the composition of the stratosphere, including the redistribution of active chlorine which might lead to ozone destruction. As a result during recent years a lot of effort has been directed towards the quantification of the uptake of trace gases like ClONO2, HCl, etc. into these particulates. However, it has been observed that many of the two and three dimensional models used in such studies are constrained by the lack of adequate rate constant data. This paper describes a theoretical approach to estimate the reaction rate constants for 23 gases on both types of polar stratospheric clouds (type I and II. It is found that for gases like N2O5, ClONO2 and HCl, diffusional uptake is important and contributes significantly to the heterogeneous reaction rate. A complete Lennard-Jones calculation is used to accurately compute the trace gas diffusion coefficients.

  13. Effects of high pressure nitrogen annealing on ferroelectric Hf0.5Zr0.5O2 films

    Science.gov (United States)

    Kim, Taeho; Park, Jinsung; Cheong, Byoung-Ho; Jeon, Sanghun

    2018-02-01

    The effect of high-pressure nitrogen annealing at up to 50 atmospheres (atm) on Hf0.5Zr0.5O2 films at relatively low temperatures (450 °C) is analyzed using polarization-electric field curves, bipolar switching endurance measurements, grazing angle incidence X-ray diffraction, and piezoelectric force microscopy. Hf0.5Zr0.5O2 films annealed at 450 °C/50 atm have excellent characteristics, including remanent polarizations greater than 20 μC/cm2, a switching speed of 200 ns, and reliability, measured by sustained performance after 1010 bipolar switching cycles. The enhanced device features are attributed to the transition to the orthorhombic-phase from the tetragonal-phase of Hf0.5Zr0.5O2 at high pressure, which is also consistent with the results of "wake-up" analysis, and the variations of the pure polarization curves, extracted from the total displacement field under pressure.

  14. Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation

    Science.gov (United States)

    Fry, C. D.; Adams, M.; Gallagher, D. L.; Habash Krause, L.; Rawlins, L.; Suggs, R. M.; Anderson, S. C.

    2017-12-01

    August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. The Amateur Radio community has developed several automated receiving and reporting networks that draw from widely-distributed, automated and manual radio stations to build a near-real time, global picture of changing radio propagation conditions. We used these networks and employed HF radio propagation modeling in our investigation. A Ham Radio Science Citizen Investigation (HamSCI) collaboration with the American Radio Relay League (ARRL) ensured that many thousands of amateur radio operators would be "on the air" communicating on eclipse day, promising an extremely large quantity of data would be collected. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Our expectations were the D-Region ionosphere would be most impacted by the eclipse, enabling over-the-horizon radio propagation on lower HF frequencies (3.5 and 7 MHz) that are typically closed during the middle of the day. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

  15. Changes in the structure of doped poly aniline (Pani-HCL) due to the process of de-doped

    International Nuclear Information System (INIS)

    Gomes, Everton Carlos; Oliveira, Maria Auxiliadora Silva de

    2009-01-01

    The poly aniline (PAni) is much studied, partly due to its relatively ease chemical or electrochemical synthesis, thermal stability in air and redox behavior. The chemical synthesis of poly aniline (PAni) was performed in a medium containing hydrochloric acid (HCl) as a doping agent. After that, the obtained polymer was de-doped in alkaline medium (NH4OH). Thermogravimetric analysis (TG) showed that the doped polymer, PAni-HCl, shows better thermal stability in comparison with the de-doped polymer (PAni-NH4OH). Differential scanning calorimetry (DSC) analyses show that the number of processes occurring during the heating of the polymer, as well as the complexity of them, is much higher in the PAni-HCl than the in the PAni-NH4OH. Through the spectra of FTIR and Raman could conclude that dedoping PAni-HCl was not complete, but the degree of doping of PAni-NH4OH decreased by treatment with ammonium hydroxide. XRD analysis pointed out that as the PAni-HCl as the PAni-NH4OH are partially crystalline. (author)

  16. Randomized control trial of benzydamine HCl versus sodium bicarbonate for prophylaxis of concurrent chemoradiation-induced oral mucositis.

    Science.gov (United States)

    Chitapanarux, Imjai; Tungkasamit, Tharatorn; Petsuksiri, Janjira; Kannarunimit, Danita; Katanyoo, Kanyarat; Chakkabat, Chakkapong; Setakornnukul, Jiraporn; Wongsrita, Somying; Jirawatwarakul, Naruemon; Lertbusayanukul, Chawalit; Sripan, Patumrat; Traisathit, Patrinee

    2018-03-01

    The purpose of the study is to compare the efficacy of benzydamine HCl with sodium bicarbonate in the prevention of concurrent chemoradiation-induced oral mucositis in head and neck cancer patients. Sixty locally advanced head and neck cancer patients treated with high-dose radiotherapy concurrently with platinum-based chemotherapy were randomly assigned to receive either benzydamine HCl or sodium bicarbonate from the first day of treatment to 2 weeks after the completion of treatment. The total score for mucositis, based on the Oral Mucositis Assessment Scale (OMAS), was used for the assessment, conducted weekly during the treatment period and at the fourth week of the follow-up. Pain score, all prescribed medications, and tube feeding needs were also recorded and compared. The median of total OMAS score was statistically significant lower in patients who received benzydamine HCl during concurrent chemo-radiotherapy (CCRT) than in those who received sodium bicarbonate, (p value sodium bicarbonate arm needed oral antifungal agents whereas none in the benzydamine HCl arm required such medications, (p value = 0.06). Tube feeding needs and the compliance of CCRT were not different between the two study arms. For patients undergoing high-dose radiotherapy concurrently with platinum-based chemotherapy, using benzydamine HCl mouthwash as a preventive approach was superior to basic oral care using sodium bicarbonate mouthwash in terms of reducing the severity of oral mucositis and encouraging trend for the less need of oral antifungal drugs.

  17. Screening for Bipolar Disorder Symptoms in Depressed Primary Care Attenders: Comparison between Mood Disorder Questionnaire and Hypomania Checklist (HCL-32

    Directory of Open Access Journals (Sweden)

    Anna Sasdelli

    2013-01-01

    Full Text Available Objective. To describe the prevalence of patients who screen positive for bipolar disorder (BD symptoms in primary care comparing two screening instruments: Mood Disorders Questionnaire (MDQ and Hypomania Checklist (HCL-32. Participants. Adult patients presenting to their primary care practitioners for any cause and reporting current depression symptoms or a depressive episode in the last 6 months. Methods. Subjects completed MDQ and HCL-32, and clinical diagnosis was assessed by a psychiatrist following DSM-IV criteria. Depressive symptoms were evaluated in a subgroup with the Patient Health Questionnaire (PHQ-9. Results. A total of 94 patients were approached to participate and 93 completed the survey. Among these, 8.9% screened positive with MDQ and 43.0% with HCL-32. MDQ positive had more likely features associated with BD: panic disorder and smoking habit (. The best test accuracy was performed by cut-off 5 for MDQ (sensitivity = .91; specificity = .67 and 15 for HCL-32 (sensitivity = .64; specificity = .57. Higher total score of PHQ-9 was related to higher total scores at the screening tests (. Conclusion. There is a significant prevalence of bipolar symptoms in primary care depressed patients. MDQ seems to have better accuracy and feasibility than HCL-32, features that fit well in the busy setting of primary care.

  18. Densities of L-Glutamic Acid HCl Drug in Aqueous NaCl and KCl Solutions at Different Temperatures

    Science.gov (United States)

    Ryshetti, Suresh; Raghuram, Noothi; Rani, Emmadi Jayanthi; Tangeda, Savitha Jyostna

    2016-04-01

    Densities (ρ ) of (0.01 to 0.07) {mol}{\\cdot } {kg}^{-1} L-Glutamic acid HCl (L-HCl) drug in water, and in aqueous NaCl and KCl (0.5 and 1.0) {mol}{\\cdot } {kg}^{-1} solutions have been reported as a function of temperature at T = (298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure. The accurate density (ρ ) values are used to estimate the various parameters such as the apparent molar volume (V_{2,{\\upphi }}), the partial molar volume (V2^{∞}), the isobaric thermal expansion coefficient (α 2), the partial molar expansion (E2^{∞}), and Hepler's constant (partial 2V2^{∞}/partial T2)P. The Cosphere overlap model is used to understand the solute-solvent interactions in a ternary mixture (L-HCl drug + NaCl or KCl + water). Hepler's constant (partial 2V2^{∞}/partial T2)_P is utilized to interpret the structure-making or -breaking ability of L-HCl drug in aqueous NaCl and KCl solutions, and the results are inferred that L-HCl drug acts as a structure maker, i.e., kosmotrope in aqueous NaCl solutions and performs as a structure breaker, i.e., chaotrope in aqueous KCl solutions.

  19. Inorganic Chlorine Partitioning in the Summer Lower Stratosphere: Modeled and Measured [ClONO2/HCl] During POLARIS

    Science.gov (United States)

    Voss, P. B.; Stimpfle, R. M.; Cohen, R. C.; Hanisco, T. F.; Bonne, G. P.; Perkins, K. K.; Lanzendorf, E. J.; Anderson, J. G.; Salawitch, R. J.

    2001-01-01

    We examine inorganic chlorine (Cly) partitioning in the summer lower stratosphere using in situ ER-2 aircraft observations made during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) campaign. New steady state and numerical models estimate [ClONO2]/[HCl] using currently accepted photochemistry. These models are tightly constrained by observations with OH (parameterized as a function of solar zenith angle) substituting for modeled HO2 chemistry. We find that inorganic chlorine photochemistry alone overestimates observed [ClONO2]/[HCl] by approximately 55-60% at mid and high latitudes. On the basis of POLARIS studies of the inorganic chlorine budget, [ClO]/[ClONO2], and an intercomparison with balloon observations, the most direct explanation for the model-measurement discrepancy in Cly partitioning is an error in the reactions, rate constants, and measured species concentrations linking HCl and ClO (simulated [ClO]/[HCl] too high) in combination with a possible systematic error in the ER-2 ClONO2 measurement (too low). The high precision of our simulation (+/-15% 1-sigma for [ClONO2]/[HCl], which is compared with observations) increases confidence in the observations, photolysis calculations, and laboratory rate constants. These results, along with other findings, should lead to improvements in both the accuracy and precision of stratospheric photochemical models.

  20. In-hospital resource use and medical costs in the last year of life by mode of death (from the HF-ACTION randomized controlled trial).

    Science.gov (United States)

    Reed, Shelby D; Li, Yanhong; Dunlap, Mark E; Kraus, William E; Samsa, Gregory P; Schulman, Kevin A; Zile, Michael R; Whellan, David J

    2012-10-15

    Patterns of medical resource use near the end of life may differ across modes of death. The aim of this study was to characterize patterns of inpatient resource use and direct costs for patients with heart failure (HF) who died of sudden cardiac death (SCD), HF, other cardiovascular causes, or noncardiovascular causes during the last year of life. Data were from a randomized trial of exercise training in patients with HF. Mode of death was adjudicated by an end point committee. Generalized estimating equations were used to compare hospitalizations, inpatient days, and inpatient costs incurred during the final year of life in patients who died of different causes, adjusting for clinical and treatment characteristics. Of 2,331 patients enrolled in the trial, 231 died after ≥1 year of follow-up with an adjudicated mode of death, including 72 of SCD, 80 of HF, 34 of other cardiovascular causes, and 45 of noncardiovascular causes. Patients who died of SCD were younger, had less severe HF, and incurred fewer hospitalizations, fewer inpatient days, and lower inpatient costs than patients who died of other causes. After adjustment for patient characteristics, inpatient resource use varied by 2 to 4 times across modes of death, suggesting that cost-effectiveness analyses of interventions that reduce mortality from SCD compared to other causes should incorporate mode-specific end-of-life costs. In conclusion, resource use and associated medical costs in the last year of life differed markedly in patients with HF who experienced SCD and patients who died of other causes. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. 182Hf-182W age dating of a 26Al-poor inclusion and implications for the origin of short-lived radioisotopes in the early Solar System.

    Science.gov (United States)

    Holst, Jesper C; Olsen, Mia B; Paton, Chad; Nagashima, Kazuhide; Schiller, Martin; Wielandt, Daniel; Larsen, Kirsten K; Connelly, James N; Jørgensen, Jes K; Krot, Alexander N; Nordlund, Ake; Bizzarro, Martin

    2013-05-28

    Refractory inclusions [calcium-aluminum-rich inclusions, (CAIs)] represent the oldest Solar System solids and provide information regarding the formation of the Sun and its protoplanetary disk. CAIs contain evidence of now extinct short-lived radioisotopes (e.g., (26)Al, (41)Ca, and (182)Hf) synthesized in one or multiple stars and added to the protosolar molecular cloud before or during its collapse. Understanding how and when short-lived radioisotopes were added to the Solar System is necessary to assess their validity as chronometers and constrain the birthplace of the Sun. Whereas most CAIs formed with the canonical abundance of (26)Al corresponding to (26)Al/(27)Al of ∼5 × 10(-5), rare CAIs with fractionation and unidentified nuclear isotope effects (FUN CAIs) record nucleosynthetic isotopic heterogeneity and (26)Al/(27)Al of Solar System, including the origin of short-lived radioisotopes. However, their chronology is unknown. Using the (182)Hf-(182)W chronometer, we show that a FUN CAI recording a condensation origin from a solar gas formed coevally with canonical CAIs, but with (26)Al/(27)Al of ∼3 × 10(-6). The decoupling between (182)Hf and (26)Al requires distinct stellar origins: steady-state galactic stellar nucleosynthesis for (182)Hf and late-stage contamination of the protosolar molecular cloud by a massive star(s) for (26)Al. Admixing of stellar-derived (26)Al to the protoplanetary disk occurred during the epoch of CAI formation and, therefore, the (26)Al-(26)Mg systematics of CAIs cannot be used to define their formation interval. In contrast, our results support (182)Hf homogeneity and chronological significance of the (182)Hf-(182)W clock.

  2. Structural, chemical and electrical characterization of HfNO-HfTiO high-k dielectric stack

    Energy Technology Data Exchange (ETDEWEB)

    Mikhelashvili, Visorian; Eisenstein, Gadi [Electrical Engineering Dept., Technion (Israel); Paramasivam, Thangadurai; Kaplan, Wayne [Material Engineering Dept., Technion (Israel)

    2008-07-01

    We study the influence of annealing temperature on structural, compositional and electrical characteristics of a MOS structure with a high-k dielectric based on a 5 nm HfNO-HfTiO nanolaminate stack. A common feature of all samples independent on annealing temperature is the observation of two distinct 2-2.5 and 2.3-2.5 nm thick layers, respectively for transition (close to Si substrate) and top layers. The transition layer is amorphous, while in the top layer some crystalline inclusions embedded into the amorphous matrix are observed. EDS line-scans and XPS analysis showed that the transition layer is similar to metal-Si-O-N or metal-Si-O. The minimum values of quantum mechanical corrected effective oxide thickness close to 1.29 and 0.86 nm, respectively for structures with Au and Cr electrodes. A large reduction of leakage current density to 1.5 x 10{sup -8} and 2.9 x 10{sup -7} A/cm{sup 2}, respectively for Au and Cr gate electrodes at an electric fields of 2 MV/cm was observed with annealing temperature and breakdown electric field as high as 10-12 MV/cm, was measured independently of the electrodes type.

  3. Atomic scale engineering of HfO2-based dielectrics for future DRAM applications

    International Nuclear Information System (INIS)

    Dudek, Piotr

    2011-01-01

    Modern dielectrics in combination with appropriate metal electrodes have a great potential to solve many difficulties associated with continuing miniaturization process in the microelectronic industry. One significant branch of microelectronics incorporates dynamic random access memory (DRAM) market. The DRAM devices scaled for over 35 years starting from 4 kb density to several Gb nowadays. The scaling process led to the dielectric material thickness reduction, resulting in higher leakage current density, and as a consequence higher power consumption. As a possible solution for this problem, alternative dielectric materials with improved electrical and material science parameters were intensively studied by many research groups. The higher dielectric constant allows the use of physically thicker layers with high capacitance but strongly reduced leakage current density. This work focused on deposition and characterization of thin insulating layers. The material engineering process was based on Si cleanroom compatible HfO 2 thin films deposited on TiN metal electrodes. A combined materials science and dielectric characterization study showed that Ba-added HfO 2 (BaHfO 3 ) films and Ti-added BaHfO 3 (BaHf 0.5 Ti 0.5 O 3 ) layers are promising candidates for future generation of state-of-the-art DRAMs. In especial a strong increase of the dielectric permittivity k was achieved for thin films of cubic BaHfO 3 (k∝38) and BaHf 0.5 Ti 0.5 O 3 (k∝90) with respect to monoclinic HfO 2 (k∝19). Meanwhile the CET values scaled down to 1 nm for BaHfO 3 and ∝0.8 nm for BaHf 0.5 Ti 0.5 O 3 with respect to HfO 2 (CET=1.5 nm). The Hf 4+ ions substitution in BaHfO 3 by Ti 4+ ions led to a significant decrease of thermal budget from 900 C for BaHfO 3 to 700 C for BaHf 0.5 Ti 0.5 O 3 . Future studies need to focus on the use of appropriate metal electrodes (high work function) and on film deposition process (homogeneity) for better current leakage control. (orig.)

  4. Atomic scale engineering of HfO{sub 2}-based dielectrics for future DRAM applications

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, Piotr

    2011-02-14

    Modern dielectrics in combination with appropriate metal electrodes have a great potential to solve many difficulties associated with continuing miniaturization process in the microelectronic industry. One significant branch of microelectronics incorporates dynamic random access memory (DRAM) market. The DRAM devices scaled for over 35 years starting from 4 kb density to several Gb nowadays. The scaling process led to the dielectric material thickness reduction, resulting in higher leakage current density, and as a consequence higher power consumption. As a possible solution for this problem, alternative dielectric materials with improved electrical and material science parameters were intensively studied by many research groups. The higher dielectric constant allows the use of physically thicker layers with high capacitance but strongly reduced leakage current density. This work focused on deposition and characterization of thin insulating layers. The material engineering process was based on Si cleanroom compatible HfO{sub 2} thin films deposited on TiN metal electrodes. A combined materials science and dielectric characterization study showed that Ba-added HfO{sub 2} (BaHfO{sub 3}) films and Ti-added BaHfO{sub 3} (BaHf{sub 0.5}Ti{sub 0.5}O{sub 3}) layers are promising candidates for future generation of state-of-the-art DRAMs. In especial a strong increase of the dielectric permittivity k was achieved for thin films of cubic BaHfO{sub 3} (k{proportional_to}38) and BaHf{sub 0.5}Ti{sub 0.5}O{sub 3} (k{proportional_to}90) with respect to monoclinic HfO{sub 2} (k{proportional_to}19). Meanwhile the CET values scaled down to 1 nm for BaHfO{sub 3} and {proportional_to}0.8 nm for BaHf{sub 0.5}Ti{sub 0.5}O{sub 3} with respect to HfO{sub 2} (CET=1.5 nm). The Hf{sup 4+} ions substitution in BaHfO{sub 3} by Ti{sup 4+} ions led to a significant decrease of thermal budget from 900 C for BaHfO{sub 3} to 700 C for BaHf{sub 0.5}Ti{sub 0.5}O{sub 3}. Future studies need to focus

  5. Do Hf isotopes in magmatic zircons represent those of their host rocks?

    Science.gov (United States)

    Wang, Di; Wang, Xiao-Lei; Cai, Yue; Goldstein, Steven L.; Yang, Tao

    2018-04-01

    Lu-Hf isotopic system in zircon is a powerful and widely used geochemical tracer in studying petrogenesis of magmatic rocks and crustal evolution, assuming that zircon Hf isotopes can represent initial Hf isotopes of their parental whole rock. However, this assumption may not always be valid. Disequilibrium partial melting of continental crust would preferentially melt out non-zircon minerals with high time-integrated Lu/Hf ratios and generate partial melts with Hf isotope compositions that are more radiogenic than those of its magma source. Dissolution experiments (with hotplate, bomb and sintering procedures) of zircon-bearing samples demonstrate this disequilibrium effect where partial dissolution yielded variable and more radiogenic Hf isotope compositions than fully dissolved samples. A case study from the Neoproterozoic Jiuling batholith in southern China shows that about half of the investigated samples show decoupled Hf isotopes between zircons and the bulk rocks. This decoupling could reflect complex and prolonged magmatic processes, such as crustal assimilation, magma mixing, and disequilibrium melting, which are consistent with the wide temperature spectrum from ∼630 °C to ∼900 °C by Ti-in-zircon thermometer. We suggest that magmatic zircons may only record the Hf isotopic composition of their surrounding melt during crystallization and it is uncertain whether their Hf isotopic compositions can represent the primary Hf isotopic compositions of the bulk magmas. In this regard, using zircon Hf isotopic compositions to trace crustal evolution may be biased since most of these could be originally from disequilibrium partial melts.

  6. Schirmwirkung von Hochfrequenz (HF-Schutzkleidung: Untersuchung verschiedener Konstruktionsmerkmale

    Directory of Open Access Journals (Sweden)

    V. Arps

    2005-01-01

    Full Text Available Die Messverfahren zur Bestimmung der Schutzwirkung von HF-Schutzkleidung sind in der Norm DIN 32780-100 festgelegt. Entsprechend diesen Anforderungen wird die elektrische und magnetische Schirmdämpfung bestimmt und daraus als Maß für die Schutzwirkung die elektromagnetische Schirmdämpfung berechnet. Diese ist eine der SAR vergleichbare Größe. In diesem Beitrag werden die Einflüsse verschiedener Konstruktionsmerkmale von HF-Schutzanzügen auf die elektromagnetische Schirmdämpfung untersucht. Zu diesen gehören die nach MIL STD 285 vermessene elektrische Schirmdämpfung der verwendeten Gewebe. Weiter werden verschiedene Teilbereiche der HF-Schutzkleidung auf ihre Schutzwirkung untersucht. Der Schwerpunkt liegt hierbei auf der Fragestellung inwieweit Verschlüsse, Reißverschlüsse oder leitfähiges Klettband, die Schutzwirkung beeinträchtigen. Zu diesem Zweck werden zwei Schutzanzüge unterschiedlicher Konstruktion vergleichend vermessen. Es handelt sich dabei um einen bereits im Handel befindlichen und entsprechend der Norm zertifizierten Anzug und einen neuen Prototyp, welcher nach verschiedenen Gesichtspunkten optimiert wurde. Schwachstellen der Konstruktion werden herausgearbeitet und Ansatzpunkte für weitere Verbesserungen erarbeitet. The measuring methods for determining the shielding effectiveness of radiofrequency (RF-protective clothing are defined in German Standard DIN 32780-100. According to this standard, both the electric and the magnetic shielding effectiveness are measured in order to calculate the electromagnetic shielding effectiveness. The electromagnetic shielding effectiveness is an adequate quality criterion for the degree of protection and also compares well with the Specific Absorption Rate (SAR. In this article, the impact of different design features on the electromagnetic shielding effectiveness is analyzed. The electric shielding effectiveness of the used shielding materials is measured according to MIL STD

  7. Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

    Energy Technology Data Exchange (ETDEWEB)

    Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K. [Synthetic and Surface Science Laboratory, Ajmer (India)

    2012-08-15

    Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E{sub B}), ocimum canum (E{sub C}) and ocimum sanctum (E{sub S}). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E{sub B} is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution.

  8. Experimental Research of HF Passive Radar Based on DRM Digital AM Broadcasting

    Directory of Open Access Journals (Sweden)

    Wan Xian-rong

    2012-03-01

    Full Text Available Radio Mondiale (DRM digital AM broadcasting that have been first carried out in China, using the newly-developed all-digital active/passive integrated HF surface wave radar system. The principle, key techniques, experimental equipment, and preliminary results are introduced about this new radar system. Based on analysis of the measurement data, experimental results under different scenarios including surface-wave, sky-wave, and hybrid sky-surface propagation modes are presented, which have proved, for the first time worldwide, the technical feasibility of using DRM broadcasting signal for over-the-horizon detection by field experiment and formed the theoretical and experimental basis for the further development of HFPBR.

  9. Digital hf radar observations of equatorial spread-F

    International Nuclear Information System (INIS)

    Argo, P.E.

    1984-01-01

    Modern digital ionosondes, with both direction finding and doppler capabilities can provide large scale pictures of the Spread-F irregularity regions. A morphological framework has been developed that allows interpretation of the hf radar data. A large scale irregularity structure is found to be nightward of the dusk terminator, stationary in the solar reference frame. As the plasma moves through this foehn-wall-like structure it descends, and irregularities may be generated. Localized upwellings, or bubbles, may be produced, and they drift with the background plasma. The spread-F irregularity region is found to be best characterized as a partly cloudy sky, due to the patchiness of the substructures. 13 references, 16 figures

  10. Direct electrochemical preparation of Nb-10Hf-1Ti alloy

    International Nuclear Information System (INIS)

    Abdelkader, Amr M.; Fray, Derek J.

    2010-01-01

    The preparation of 89Nb-10Hf-1Ti alloy by the electro-deoxidation of a porous precursor cathode made from a mixture of oxides containing the alloying elements has been investigated. The results confirmed the formation of the alloy, saturated with oxygen, after 4 h of the reduction. The X-ray diffraction (XRD) and microstructural analysis suggested that the reduction starts with the formation of niobium suboxides and calcium niobates. The calcium niobate slows down the reaction until some nonstoichiometric calcium niobate (Ca 3 Nb 2 O x-8 ) starts to form. Hafnium was also observed to be reduced through the formation of calcium hafnate without any side reactions with the other alloy constituents. Alloy with the target stoichiometry containing 390 ppm oxygen was obtained after 24 h of electro-deoxidation.

  11. Evaluation of pomegranate rind (Punica granatum hydroethanolic extract on blood parameters in male mice treated by Irinotecan Hcl

    Directory of Open Access Journals (Sweden)

    N Mirazi

    2015-05-01

    Full Text Available Background & aim: Irinotecan Hcl is the first order drug for some neoplasm treatment in patients. Irinotecan Hcl has side effects on blood such as anemia and leukopeny. The aim of this study was to evaluate erythropoetic effects of the pomegranate hydroethanolic extract were examined on mice which treated by irinotecan Hcl. Methods: In this experimental study, 49 male mice (25-30 g were divided in 7 groups (control, sham, treated by irinotecan Hcl (100 mg/kg, treated by pomegranate extract (100 and 400 mg/kg, i.p, daily for one week and treated by irinotecan Hcl plus pomegranate extract (100 and 400 mg/kg, i.p, daily for one week randomly. Anemia induced by administration of irinotecan in the experimental animal. At the end of experiment the blood samples were collected by cardiac puncture method and analized for RBC, WBC, Hb, Hct parameters. Data were analyzed using one-way ANOVA and Tukey’s test. Results: The results of this study showed that irinotecan has affected on blood factors and cause to significance decrese compared with control group (p<0.001. Also groups which treated with pomegranate extract (100 and 400 mg/kg significantly reduce the side effects of irinotecan and cause to increasing in blood factors (p<0.001. The number of WBC counts in the group which received Irinotecan (100 kg significantly decreased as compared with the control group (p<0.001. Irinotecan affected on blood Hb level and cause to significant decrease compared with control group. Groups which received pomegranate extract (100 and 400 kg had positive effect and significantly increased the blood Hb levels as compared to controls (p<0.001. Conclusion: These results showed that consumption of pomegranate rind extract in a dose-dependent manner has protective effect on blood parameters in mice which treated with Irinotecan Hcl.

  12. Phase transport of HCl, HFeCl4, water, and crude oil components in acid-crude oil systems.

    Science.gov (United States)

    Rietjens, Marcel; van Haasterecht, Menno

    2003-12-15

    A model describing the transport of HCl and HFeCl(4) from a water phase to a crude oil phase and subsequent sludge formation is proposed. Crude oil phase transfer compounds (PTCs) that are basic in nature facilitate transport of acid to the crude oil phase. These crude oil PTCs are able to migrate to the acid-oil interface and form acid-base complexes that can return to the oil phase. Once in the crude phase, these protonated compounds have a propensity to form aggregates. Growth of small aggregates into larger aggregates eventually generates a precipitate known as acid-sludge. Under certain conditions the model predicts the amount of acid-sludge formed to be proportional to the acid activity, or acidity function H(0), in the water phase. This relation was confirmed experimentally. Furthermore, the total amount of phase-transported acid is proportional to the base content of the crude oil. In strong HCl formulations containing Fe(3+), the acid HFeCl(4) is formed in small amounts that can be transported to the crude oil phase. In principle, the behavior of HFeCl(4) is similar to that of HCl. It was shown that HCl and HFeCl(4) compete for basic, or receptor, sites and that exchange between these two acids is reversible. The antisludging agent dodecylbenzenesulfonic acid, DBSA, intervenes through the same mechanism; that is, it competes for receptor sites with HCl and HFeCl(4). Exchange between HCl/HFeCl(4) and DBSA was also shown to be reversible.

  13. Enhancement removal of tartrazine dye using HCl-doped polyaniline and TiO2-decorated PANI particles

    Science.gov (United States)

    Elsayed, M. A.; Gobara, Mohamed

    2016-08-01

    HCl-doped polyaniline (HCl-PANI) and titanium dioxide decorated with polyaniline (TiO2-decorated PANI) with different TiO2:PANI ratios were chemically prepared and utilized for the removal of tartrazine (TZ) dye from a synthetic aqueous solution. The mechanism of preparation of the sample suggested that aniline was adsorbed on the TiO2 surface before the polymerization process took place. Samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy and x-ray diffraction. The results showed that HCl-PANI and TiO2-decorated PANI have an amorphous structure. The thermal stability of the prepared samples was characterized using thermo-gravimetric (TG) analysis. HCl-PANI is stable up to 200 °C and the relative weight per cent of PANI in the TiO2-decorated PANI was 20, 25, 40 and 45%. The removal activity of TiO2-decorated PANI via TZ azo dye was investigated under UV light irradiations and compared with HCl-PANI and TiO2 particles. The results indicated the superiority of the TiO2-decorated PANI over pure HCl-PANI and TiO2. However, the excessive PANI percentage tends to form a relatively thick layer, and even aggregates on the surface of TiO2. This hinders the migration of excited electrons from the outer PANI layer to the inner TiO2 particles, which consequently leads to a decrease in the removal efficiency. A possible mechanism for the removal oxidative degradation is also mentioned.

  14. Tsunami Arrival Detection with High Frequency (HF Radar

    Directory of Open Access Journals (Sweden)

    Donald Barrick

    2012-05-01

    Full Text Available Quantitative real-time observations of a tsunami have been limited to deep-water, pressure-sensor observations of changes in the sea surface elevation and observations of sea level fluctuations at the coast, which are essentially point measurements. Constrained by these data, models have been used for predictions and warning of the arrival of a tsunami, but to date no system exists for local detection of an actual incoming wave with a significant warning capability. Networks of coastal high frequency (HF-radars are now routinely observing surface currents in many countries. We report here on an empirical method for the detection of the initial arrival of a tsunami, and demonstrate its use with results from data measured by fourteen HF radar sites in Japan and USA following the magnitude 9.0 earthquake off Sendai, Japan, on 11 March 2011. The distance offshore at which the tsunami can be detected, and hence the warning time provided, depends on the bathymetry: the wider the shallow continental shelf, the greater this time. We compare arrival times at the radars with those measured by neighboring tide gauges. Arrival times measured by the radars preceded those at neighboring tide gauges by an average of 19 min (Japan and 15 min (USA The initial water-height increase due to the tsunami as measured by the tide gauges was moderate, ranging from 0.3 to 2 m. Thus it appears possible to detect even moderate tsunamis using this method. Larger tsunamis could obviously be detected further from the coast. We find that tsunami arrival within the radar coverage area can be announced 8 min (i.e., twice the radar spectral time resolution after its first appearance. This can provide advance warning of the tsunami approach to the coastline locations.

  15. Op soek na ’n gebalanseerde beeld van H.F. Verwoerd

    Directory of Open Access Journals (Sweden)

    Johannes D. Froneman

    2013-12-01

    Full Text Available Towards a balanced view of H.F. Verwoerd. Doctor H.F. Verwoerd is possibly the most controversial political figure in South African history. In life he was revered by his followers, but even critics acknowledged his stature. Today he is mostly depicted as a brutal symbol of racial suppression. This article first gives insight into various, contradictory views expressed in the press on Verwoerd during his life, immediately after his death and in recent years. This is discussed in view of some media-theoretical perspectives. It is followed by an overview of views expressed on Verwoerd in literature, including recent works by eminent historian Hermann Giliomee. Against this background of diverse and sometimes one-sided views, J.J. (Ponti Venter’s analysis of Verwoerdian thought, as published in a 1999 issue of Koers – Bulletin for Christian Scholarship, is presented as an example of a balanced intellectual contribution to an ongoing debate. It is argued that Venter’s contribution was important as it provides incisive criticism of Verwoerd not found elsewhere. Venter’s article, which was based on texts of speeches, however lacks some context. This is provided by other publications and press coverage. It is suggested that no assessment of an important historical figure is ever definitive, least so by consulting only the press. As is the case with Verwoerd, contemporaneous press coverage needs to be supplemented by solid research on the subject. In particular the sober analysis of public intellectuals such as J.J. Venter is needed and should be included in assesments of Verwoerd.

  16. A novel process for preparation of titanium dioxide from Ti-bearing electric furnace slag: NH4HF2-HF leaching and hydrolyzing process.

    Science.gov (United States)

    Zheng, Fuqiang; Guo, Yufeng; Qiu, Guanzhou; Chen, Feng; Wang, Shuai; Sui, Yulei; Jiang, Tao; Yang, Lingzhi

    2018-02-15

    A novel process to prepare titanium dioxide from Ti-bearing electric furnace slag by NH 4 HF 2 -HF leaching and hydrolyzing process has been developed. In this present study, the effects of [NH 4 + ]/[F] mXolar ratio, leaching temperature, [F] concentration, liquid/solid mass ratio, leaching time on the Ti extraction, and the phase transformations have been investigated to reveal the leaching mechanism of Ti-bearing electric furnace slag in NH 4 HF 2 -HF solution. In the NH 4 HF 2 -HF leaching process, the MgTi 2 O 5 and Al 2 TiO 5 are converted to TiF 6 2- and Mg-Al-bearing precipitate. Ti extraction rate reached 98.84% under the optimal conditions. In addition, 98.25% iron ions can be removed in the presence of NaCl prior to hydrolysis process. The effects of pH and temperature on the selective hydrolysis of TiF 6 2- during hydrolysis process were also studied. In the hydrolysis process, the TiF 6 2- is converted to (NH 4 ) 2 TiOF 4 . By calcination, high grade TiO 2 powder with its purity of 99.88% was obtained, using which the products, well crystallized anatase and rutile, were obtained through roasting at 800°C and 1000°C, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. HfSiO/SiO2- and SiO2/HfSiO/SiO2-gate stacks for non-volatile memories

    International Nuclear Information System (INIS)

    Erlbacher, T.; Jank, M.P.M.; Lemberger, M.; Bauer, A.J.; Ryssel, H.

    2008-01-01

    The use of hafnium silicate (HfSiO) as a charge trapping layer in charge-based non-volatile memory cells will be discussed. First, fundamental properties (e.g., dielectric constant, trap depths/levels) of the hafnium silicate layers, deposited from a single-source precursor, are deduced from capacitance-voltage and current density-voltage measurements. The oxide trap density of the analyzed HfSiO layers can be tuned to exceed that of silicon nitride. At the same time, a significant reduction of the write voltage is achieved due to a reduced effective oxide thickness. The erase operation, however, is hampered by the lower electric field at the HfSiO layer due to its high dielectric constant. Measurements also indicate that HfSiO exposed to a higher thermal budget during device fabrication results in fewer trapping centers. Retention measurements show that information can be reliably stored in memory cells with a trapping layer of HfSiO for more than 10 years similar to their silicon nitride counterparts. But the thickness of the top and bottom oxides must be increased for compensation of additional charge losses which are due to lower trap depth and free electron mass in HfSiO

  18. Addition of Liposome Bupivacaine to Bupivacaine HCl Versus Bupivacaine HCl Alone for Interscalene Brachial Plexus Block in Patients Having Major Shoulder Surgery.

    Science.gov (United States)

    Vandepitte, Catherine; Kuroda, Max; Witvrouw, Richard; Anne, Ludwig; Bellemans, Johan; Corten, Kristoff; Vanelderen, Pascal; Mesotten, Dieter; Leunen, Ine; Heylen, Micheline; Van Boxstael, Sam; Golebiewski, Monika; Van de Velde, Marc; Knezevic, Nebojsa Nick; Hadzic, Admir

    We examined whether liposome bupivacaine (Exparel) given in the interscalene brachial plexus block lowers pain in the setting of multimodal postoperative pain management for major shoulder surgery. Fifty-two adult patients were randomized to receive either 5 mL of 0.25% bupivacaine HCl immediately followed by 10 mL of liposome bupivacaine 133 mg (n = 26) or 15 mL of 0.25% standard bupivacaine alone (n = 26) in interscalene brachial plexus block. The primary outcome (worst pain in the first postoperative week) was assessed by the Modified Brief Pain Inventory short form. Secondary outcomes were overall satisfaction with analgesia (OBAS), functionality of the surgical arm, sleep duration, time to first opioid (tramadol) request and opioid consumption (mEq), sensory-motor block characteristics, and the occurrence of adverse effects. Worst pain was lower in patients given liposome bupivacaine added to standard bupivacaine than in patients given standard bupivacaine alone (generalized estimating equation [GEE] estimated marginal mean values, 3.6 ± 0.3 vs 5.3 ± 0.4 points on the Numeric Rating Scale, respectively, although the effect was modest, 1.6 ± 0.5; 95% confidence interval, 0.8-2.5). Total OBAS scores indicated greater satisfaction (GEE estimated marginal mean values, 1.8 ± 0.3 vs 3.3 ± 0.4 on total OBAS, respectively, with modest effect, difference, 1.4 ± 0.5; 95% confidence interval, 0.5-2.4). There were no differences in any of the other secondary outcomes. Liposome bupivacaine added to standard bupivacaine may lower pain and enhance patient's satisfaction in the first postoperative week even in the setting of multimodal analgesia for major shoulder surgery.This study was registered with clinicaltrials.gov (NCT02554357) on July 11, 2015, by Principal Investigator Catherine Vandepitte, MD.

  19. EURObservational Research Programme : The Heart Failure Pilot Survey (ESC-HF Pilot)

    NARCIS (Netherlands)

    Maggioni, Aldo P.; Dahlstrom, Ulf; Filippatos, Gerasimos; Chioncel, Ovidiu; Crespo Leiro, Marisa; Drozdz, Jaroslaw; Fruhwald, Friedrich; Gullestad, Lars; Logeart, Damien; Metra, Marco; Parissis, John; Persson, Hans; Ponikowski, Piotr; Rauchhaus, Mathias; Voors, Adriaan A.; Nielsen, Olav Wendelboe; Zannad, Faiez; Tavazzi, Luigi

    2010-01-01

    The primary objective of the new ESC-HF Pilot Survey was to describe the clinical epidemiology of outpatients and inpatients with heart failure (HF) and the diagnostic/therapeutic processes applied across 12 participating European countries. This pilot study was specifically aimed at validating the

  20. Decolourization and degradation of azo Dye, Synozol Red HF6BN ...

    African Journals Online (AJOL)

    Decolourization and degradation of azo Dye, Synozol Red HF6BN, by Pleurotus ostreatus. Sidra Ilyas, Skinder Sultan Sultan, Abdul Rehman. Abstract. The present paper focuses on the use of fungus, Pleurotus ostreatus, to decolorize and degrade azo dye, Synazol Red HF6BN. Decolorization study showed that P.

  1. Effects of sol aging on resistive switching behaviors of HfO{sub x} resistive memories

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Chih-Chieh, E-mail: cchsu@yuntech.edu.tw [Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliu 64002, Taiwan, ROC (China); Department of Electronic Engineering, National Yunlin University of Science and Technology, Douliu 64002, Taiwan, ROC (China); Graduate School of Electronic Engineering, National Yunlin University of Science and Technology, Douliu 64002, Taiwan, ROC (China); Sun, Jhen-Kai; Tsao, Che-Chang; Chen, Yu-Ting [Graduate School of Electronic Engineering, National Yunlin University of Science and Technology, Douliu 64002, Taiwan, ROC (China)

    2017-03-01

    This work investigates effects of long-term sol-aging time on sol-gel HfO{sub x} resistive random access memories (RRAMs). A nontoxic solvent of ethanol is used to replace toxic 2-methoxyethanol, which is usually used in sol-gel processes. The top electrodes are fabricated by pressing indium balls onto the HfO{sub x} surface rather than by using conventional sputtering or evaporation processes. The maximum process temperature is limited to be 100 ℃. Therefore, influences of plasma and high temperature on HfO{sub x} film can be avoided. Under this circumstance, effects of sol aging time on the HfO{sub x} films can be more clearly studied. The current conduction mechanisms in low and high electric regions of the HfO{sub x} RRAM are found to be dominated by Ohmic conduction and trap-filled space charge limited conduction (TF-SCLC), respectively. When the sol aging time increases, the resistive switching characteristic of the HfO{sub x} layer becomes unstable and the transition voltage from Ohmic conduction to TF-SCLC is also increased. This suggests that an exceedingly long aging time will give a HfO{sub x} film with more defect states. The XPS results are consistent with FTIR analysis and they can further explain the unstable HfO{sub x} resistive switching characteristic induced by sol aging.

  2. Torsemide Versus Furosemide in Patients With Acute Heart Failure (from the ASCEND-HF Trial)

    NARCIS (Netherlands)

    Mentz, Robert J.; Hasselblad, Vic; DeVore, Adam D.; Metra, Marco; Voors, Adriaan A.; Armstrong, Paul W.; Ezekowitz, Justin A.; Tang, W. H. Wilson; Schulte, Phillip J.; Anstrom, Kevin J.; Hernandez, Adrian F.; Velazquez, Eric J.; O'Connor, Christopher M.

    2016-01-01

    Furosemide is the most commonly used loop diuretic in patients with heart failure (HF) despite data suggesting potential pharmacologic and antifibrotic benefits with torsemide. We investigated patients with HF in Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure who

  3. EURObservational Research Programme: the Heart Failure Pilot Survey (ESC-HF Pilot)

    DEFF Research Database (Denmark)

    Maggioni, Aldo P; Dahlström, Ulf; Filippatos, Gerasimos

    2010-01-01

    The primary objective of the new ESC-HF Pilot Survey was to describe the clinical epidemiology of outpatients and inpatients with heart failure (HF) and the diagnostic/therapeutic processes applied across 12 participating European countries. This pilot study was specifically aimed at validating...... the structure, performance, and quality of the data set, for continuing the survey into a permanent registry....

  4. Ferromagnetic HfO2/Si/GaAs interface for spin-polarimetry applications

    Science.gov (United States)

    Tereshchenko, O. E.; Golyashov, V. A.; Eremeev, S. V.; Maurin, I.; Bakulin, A. V.; Kulkova, S. E.; Aksenov, M. S.; Preobrazhenskii, V. V.; Putyato, M. A.; Semyagin, B. R.; Dmitriev, D. V.; Toropov, A. I.; Gutakovskii, A. K.; Khandarkhaeva, S. E.; Prosvirin, I. P.; Kalinkin, A. V.; Bukhtiyarov, V. I.; Latyshev, A. V.

    2015-09-01

    In this letter, we present electrical and magnetic characteristics of HfO2-based metal-oxide-semiconductor capacitors (MOSCAPs), along with the effect of pseudomorphic Si as a passivating interlayer on GaAs(001) grown by molecular beam epitaxy. Ultrathin HfO2 high-k gate dielectric films (3-15 nm) have been grown on Si/GaAs(001) structures through evaporation of a Hf/HfO2 target in NO2 gas. The lowest interface states density Dit at Au/HfO2/Si/GaAs(001) MOS-structures were obtained in the range of (6 -13 )×1011 eV-1 cm-2 after annealing in the 400-500 °C temperature range as a result of HfO2 crystallization and the Si layer preservation in non-oxidized state on GaAs. HfO2-based MOSCAPs demonstrated the ferromagnetic properties which were attributed to the presence of both cation and anion vacancies according to the first-principle calculations. Room-temperature ferromagnetism in HfO2 films allowed us to propose a structure for the ferromagnetic MOS spin-detector.

  5. New PWM method and commutation strategy for HF-link converters for fuel cells and photovoltaics

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new PWM method and commutation strategy for HF-link converters, which leads to safe commutation of the load current in the output bidirectional bridge. The proposed implementation is independent of the particular HF-link converter topology and bidirectional switch selection ...

  6. Nanomechanical study of amorphous and polycrystalline ALD HfO2 thin films

    Science.gov (United States)

    K. Tapily; J.E. Jakes; D. Gu; H. Baumgart; A.A. Elmustafa

    2011-01-01

    Thin films of hafnium oxide (HfO2) were deposited by atomic layer deposition (ALD). The structural properties of the deposited films were characterised by transmission electron microscopy (TEM) and X-ray diffraction (XRD). We investigated the effect of phase transformations induced by thermal treatments on the mechanical properties of ALD HfO

  7. Mechanical properties of ultra-thin HfO2 films studied by nano scratches tests

    International Nuclear Information System (INIS)

    Fu, Wei-En; Chang, Yong-Qing; Chang, Chia-Wei; Yao, Chih-Kai; Liao, Jiunn-Der

    2013-01-01

    10-nm-thick atomic layer deposited HfO 2 films were characterized in terms of wear resistance and indentation hardness to investigate the thermal annealing induced impacts on mechanical properties. The wear resistance of ultra-thin films at low loads was characterized using nano-scratch tests with an atomic force microscope. The depth of the nano-scratches decreases with increasing annealing temperature, indicating that the hardness of the annealed films increases with the annealing temperatures. Surface nanoindentation was also performed to confirm the nanoscratch test results. The hardness variation of the annealed films is due to the generation of HfSi x O y induced by the thermal annealing. X-ray photoelectron spectroscopy measurements proved that the hardness of formed HfSi x O y with increasing annealing temperatures. The existence of HfSi x O y broadens the interface, and causes the increase of the interfacial layer thickness. As a result, the surface hardness increases with the increasing HfSi x O y induced by the thermal annealing. - Highlights: ► Mechanical properties of HfO 2 films were assessed by nano-scratch and indentation. ► Scratch depth of HfO 2 films decreased with the increase of annealing temperatures. ► Nano-hardness of HfO 2 films increased with the increase of annealing temperatures

  8. Helium implanted AlHf as studied by 181 Ta TDPAC

    Indian Academy of Sciences (India)

    Measurements on helium implanted sample indicate the binding of helium associated defects by Hf solute clusters. Isochronal annealing measurements indicate the dissociation of the helium implantation induced defects from Hf solute clusters for annealing treatments beyond 650 K. On comparison of the present results ...

  9. Kinetics of acid leaching of ilmenite decomposed by KOH part 1: decomposition by KOH and leaching by HCl

    International Nuclear Information System (INIS)

    Nayl, A.A; Aly, H.F.

    2010-01-01

    Decomposition of ilmenite by KOH solutions, to convert titanium to potassium titanate, was first studied . This was followed by leaching titanium from the ilmenite paste using HCl solutions in the temperature range 50-150 degree C for different periods up to 3 hr. The significant factors affecting the leaching process were studied. The experimental data of the decomposition rate of ilmenite by KOH and of the formed KOH paste by HCl under the relevant operating variables were interpreted with the shrinking core model under chemically controlled process. The apparent activation energy for leaching of titanium in both cases bas been evaluated and discussed.

  10. Analysis of HCl and ClO time series in the upper stratosphere using satellite data sets

    Directory of Open Access Journals (Sweden)

    A. Jones

    2011-06-01

    Full Text Available Previous analyses of satellite and ground-based measurements of hydrogen chloride (HCl and chlorine monoxide (ClO have suggested that total inorganic chlorine in the upper stratosphere is on the decline. We create HCl and ClO time series using satellite data sets extended to November 2008, so that an update can be made on the long term evolution of these two species. We use the HALogen Occultation Experiment (HALOE and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS data for the HCl analysis, and the Odin Sub-Millimetre Radiometer (SMR and the Aura Microwave Limb Sounder (Aura-MLS measurements for the study of ClO. Altitudes between 35 and 45 km and two mid-latitude bands: 30° S–50° S and 30° N–50° N, for HCl, and 20° S–20° N for ClO and HCl are studied. ACE-FTS and HALOE HCl anomaly time series (with QBO and seasonal contributions removed are combined to produce all instrument average time series, which show HCl to be reducing from peak 1997 values at a linear estimated rate of −5.1 % decade−1 in the Northern Hemisphere and −5.2 % decade−1 in the Southern Hemisphere, while the tropics show a linear trend of −5.8 % per decade (although we do not remove the QBO contribution there due to sparse data. Trend values are significantly different from a zero trend at the 2 sigma level. ClO is decreasing in the tropics by −7.1 % ± 7.8 % decade−1 based on measurements made from December 2001 to November 2008. The statistically significant downward trend found in HCl after 1997 and the apparent downward ClO trend since 2001 (although not statistically significant confirm how effective the 1987 Montreal protocol objectives and its amendments have been in reducing the total amount of inorganic chlorine.

  11. Investigation on Adsorption and the Corrosion Inhibition Effect of Some Novel Hydrazide Derivatives for Mild Steel in HCl Solution

    Science.gov (United States)

    Singh, Dharmendra Kumar; Behera, Debasis; Singh, Mantu Kumar; Udayabhanu, G.; John, Rohith P.

    2017-10-01

    Two hydrazide derivatives, namely, N'-(thiophene-2-ylmethylene)nicotinic hydrazone (TNH) and N'-(pyrrol-2-ylmethylene)nicotinic hydrazone (PNH), have been synthesized and investigated as corrosion inhibitors for mild steel in 1 M HCl solution by electrochemical, weight loss, field emission-scanning electron microscope (FE-SEM), atomic force microscope (AFM), and quantum chemical calculation methods. The experimental results show that both the compounds are good inhibitors for mild steel in 1 M HCl. They act as mixed type inhibitors with predominating cathodic character. The adsorption of inhibitors obeys the Langmuir adsorption isotherm. Correlation between quantum chemical parameters and experimental results is discussed.

  12. Interactions of aerosols (ammonium sulfate, ammonium nitrate and ammonium chloride) and of gases (HCl, HNO 3) with fogwater

    Science.gov (United States)

    Ruprecht, Heidi; Sigg, Laura

    The concentrations of aerosols (NH 4NO 3, (NH 4) 2SO 4 and NH 4Cl) and of gases (HCl (g), HNO 3(g), NH 3(g) were determined by denuder methods under different conditions (in the absence of fog, before, during and after fog events). At this site situated in an urban region, high concentrations of the gaseous strong acids HCl (g) and HNO 3(g) are observed. NH 4Cl and NH 4NO 3 aerosols represent a major fraction of the Cl - and NO 3- aerosols (fogwater and are released again after fog dissipation.

  13. Pengaruh Lama Hidrolisis Selulosa Tongkol Jagung (Zea mays) dengan HCl 1% terhadap Kadar Glukosa untuk Pembuatan Bioetanol

    OpenAIRE

    Putra, Adytia Anggara

    2016-01-01

    Have been done research about influence of hydrolysis time on bioethanol of hydrolysis glucose from cellulose corn cobs by HCl 1%. Cellulose insulation on baby corn cob with weight obtained 18.21 g. The cellulose obtained is hydrolyzed by HCl 1% with a variation of hydrolysis time 90, 120, and 150 minutes to produced glucose was analyzed by the Luff-Schoorl method. Glucose levels were obtained 7.37%, 9.2% and 6.64%. The result showed that the highest of bioethanol yield at hydrolysis time of ...

  14. Timescales and mechanisms of REE and Hf uptake in fossil bones

    Science.gov (United States)

    Herwartz, Daniel; Tütken, Thomas; Münker, Carsten; Jochum, Klaus Peter; Stoll, Brigitte; Sander, P. Martin

    2011-01-01

    Rare earth element (REE) patterns of fossil bones and teeth are widely used as proxies for provenance, taphonomy, and palaeoenvironment. In order to investigate if fossil bones behave as closed systems over geologic time, REE profiles were analysed by LA-ICPMS along cross sections of 54 bones from various well-characterised and well-dated settings. These include terrestrial and marine diagenetic environments, covering Early Triassic to Holocene ages. In general, all fossil bones exhibit the highest REE concentrations at the outer rim, gradually decreasing by up to four orders of magnitude toward the inner bone cortex. Intra-bone REE concentration gradients decrease significantly from Quaternary via Tertiary to Mesozoic specimens, suggesting long term REE uptake and open system behaviour of fossil bone. This view is further corroborated by 176Lu- 176Hf dating of selected samples, all yielding significantly younger ages than the known chronostratigraphic ages. Hence, there is clear evidence for long term open system behaviour of fossil bones with respect to REE, which is in marked contrast to currently accepted models suggesting that REE uptake is only early diagenetic. Although unexpected, statistically significant four to seven point isochrons are observed for four fossil dinosaur bone samples and one Upper Triassic Mastodonsaurus tooth with MSWDs ranging from 0.083 to 4.5. Notably, mobility of Lu alone cannot account for the observed age patterns. Assuming constant Lu uptake rates over time, the radiometric ages should only be as low as half of the chronostratigraphic age. However, a six-point isochron defined by subsamples of a single Upper Triassic Mastodonsaurus tooth yields an age of 65.2 ± 1.1 Ma (MSWD = 0.68), much younger than half of the stratigraphic age (ca. 234 Ma). Hence, Hf must also undergo late diagenetic exchange. Likely mechanisms to account for the presence of statistically meaningful isochrons as well as for the late diagenetic exchange of both

  15. Directionally solidified pseudo-binary eutectics of Ni-Cr-/Hf,Zr/

    Science.gov (United States)

    Kim, Y. G.; Ashbrook, R. L.

    1975-01-01

    This report is concerned with the experimental determination of pseudo binary eutectic compositions and the directional solidification of the Ni-Cr-Hf,Zr, and Ni-Cr-Zr eutectic alloys. To determine unknown eutectics, chemical analyses were made of material bled from near eutectic ingots during incipient melting. Nominal compositions in weight per cent of Ni-18.6Cr-24.0Hf, Ni-19.6Cr-12.8Zr-2.8Hf, and Ni-19.2Cr-14.8Zr formed aligned pseudo-binary eutectic structures. The melting points were about 1270 C. The reinforcing intermetallic phases were identified as noncubic (Ni,Cr)7Hf2 and (Ni,Cr)7(Hf,Zr)2, and face centered cubic (Ni,Cr)5Zr. The volume fraction of the reinforcing phases were about 0.5.

  16. Channel specific rate constants for reactions of O(1D) with HCl and HBr

    Science.gov (United States)

    Wine, P. H.; Wells, J. R.; Ravishankara, A. R.

    1986-01-01

    The absolute rate coefficients and product yields for reactions of O(1D) with HCl(1) and HBr(2) at 287 K are presently determined by means of the time-resolved resonance fluorescence detection of O(3P) and H(2S) in conjunction with pulsed laser photolysis of O3/HX/He mixtures. Total rate coefficients for O(1D) removal are found to be, in units of 10 to the -10th cu cm/molecule per sec, k(1) = 1.50 + or - 0.18 and k(2) 1.48 + or - 0.16; the absolute accuracy of these rate coefficients is estimated to be + or - 20 percent.

  17. Spectral studies related to dissociation of HBr, HCl and BrO

    Science.gov (United States)

    Ginter, M. L.

    1986-01-01

    Concern over halogen catalyzed decomposition of O3 in the upper atmosphere has generated need for data on the atomic and molecular species X, HX and XO (where X is Cl and Br). Of special importance are Cl produced from freon decomposition and Cl and Br produced from natural processes and from other industrial and agricultural chemicals. Basic spectral data is provided on HCl, HBr, and BrO necessary to detect specific states and energy levels, to enable detailed modeling of the processes involving molecular dissociation, ionization, etc., and to help evaluate field experiments to check the validity of model calculations for these species in the upper atmosphere. Results contained in four published papers and two major spectral compilations are summarized together with other results obtained.

  18. Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available Linear alkyl benzene sulfonic acid (L and three of its ester derivatives (L1, L2, L3 were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q. The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH∗, entropy (ΔS∗ of activation, adsorption–desorption equilibrium constant (Kads, standard free energy of adsorption (ΔGoads, heat (ΔHoads, and entropy of adsorption (ΔSoads were calculated to elaborate the corrosion inhibition mechanism.

  19. Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2012-01-01

    Full Text Available The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98% than the other leaves extract. Strychnos nuxvomica showed better inhibition (98% than the other seed extracts. Moringa oleifera is reflected as a good corrosion inhibitor of mild steel in 1 M HCl with 98% inhibition efficiency among the studied fruits extract. Bacopa monnieri showed its maximum inhibition performance to be 95% at 600 ppm among the investigated stem extracts. All the reported plant extracts were found to inhibit the corrosion of mild steel in acid media.

  20. Evaluation of stability of oxytetracycline-HCl to sterilization levels of gamma radiation.

    Science.gov (United States)

    Tawfik, Z S

    1985-01-01

    The effect of gamma irradiation at different dose levels (from 5 to 50 KGy) on the solid state of the antibiotic oxytetracycline-HCl was examined. The results obtained showed no effect on the biological activity of the compound, as investigated by the bioassay technique. The physicochemical properties of the antibiotic were not altered by irradiation dose levels up to 40 KGy. The UV-visible spectra of all irradiated samples showed no changes. The I.R. spectra of oxytetracycline, exposed to dose levels higher than 40 KGy, showed, however, definite destruction in the chemical structure of the antibiotic. HPLC separation of samples, irradiated at 45 KGy, showed the presence of new degradation products. Accordingly, sterilization of oxytetracycline by use of gamma irradiation could be considered safe and applicable, since sterilization doses are usually considered to be less than 30 KGy.

  1. EKSTRAKSI PEKTIN DARI KULIT PISANG KEPOK (Musa paradisiaca MENGGUNAKAN PELARUT HCl SEBAGAI EDIBLE FILM

    Directory of Open Access Journals (Sweden)

    Megawati Megawati

    2016-06-01

    Full Text Available Pisang merupakan buah yang sering dikonsumsi oleh manusia, baik secara langsung setelah buahnya matang ataupun diolah menjadi makanan lain. Kulit pisang biasanya hanya dibuang menjadi limbah, padahal didalam pisang terdapat kandungan pektin sebanyak 22,4%. Pada penelitian ini dilakukan ekstraksi pektin dengan bahan dasar kulit pisang yang bertujuan untuk mengetahui jenis pisang yang banyak mengandung pektin, pengaruh variasi bahan serta jenis pelarut yang menghasilkan pektin maksimum. Percobaan dilakukan memakai pisang kepok yang dikeringkan dan diekstraksi menggunakan pelarut dengan suhu ekstraksi 600 W, variasi berat bahan 10 dan 15 gram dengan waktu ekstraksi 20 menit. Dengan pelarut HCl. Hasil ekstraksi ditambahkan dengan etanol hingga terbentuk endapan, kemudian disaring dan di oven pada suhu 65 0C sampai berat konstan. Hasil penelitian menunjukkan bahwa menggunakan metode MAE kadar yield nya yaitu 16,53% lebih besar daripada menggunakan metode konvensional kadar yield nya yaitu 12,8%.

  2. Vibrational relaxation of matrix-isolated CH3F and HCl

    International Nuclear Information System (INIS)

    Young, L.

    1981-08-01

    Kinetic and spectroscopic studies have been performed on CH 3 F and HCl as a function of host matrix and temperature. Temporally and spectrally resolved infrared fluorescence was used to monitor the populations of both the initially excited state and the lower lying levels which participate in the relaxation process. For CH 3 F, relaxation from any of the levels near 3.5 μ, i.e. the CH stretching fundamentals or bend overtones, occurs via rapid ( 3 with subsequent relaxation of the ν 3 (CF stretch) manifold. Lifetimes of 2ν 3 and ν 3 were determined through overtone, ΔV = 2, and fundamental fluorescence. These lifetimes show a dramatic dependence on host lattice, an increase of two orders of magnitude in going from Xe and Ar matrices. Lifetimes depend only weakly on temperature. The relaxation of 2ν 3 and ν 3 is consistent with a model in which production of a highly rotationally excited guest via collisions with the repulsive wall of the host is the rate limiting step. For HCl, lifetimes of v = 1,2,3 have been determined. In all hosts, the relaxation is non-radiative. For a given vibrational state, v, the relaxation rate increases in the series k(Ar) < k(Kr) < k(Xe). The dependence of the relaxation rate; on v is superlinear in all matrices, the deviation from linearity increasng in the order Ar < Kr < Xe. The relaxation rates become more strongly temperature dependent with increasing vibrational excitation. The results are consistent with a mechanism in which complex formation introduces the anisotropy necessary to induce a near resonant V → R transition in the rate limiting step

  3. Hf and Nd Isotopic and REE Investigations of Magnetite in a Proterozoic IOCG system: Fingerprinting Sources and Timing of Mineralisation

    Science.gov (United States)

    Schaefer, B. F.

    2016-12-01

    The Stuart Shelf on the margin of the Gawler Craton, South Australia, contains numerous economic and sub-econmic IOCG mineralised systems, including the giant Olympic Dam Cu-Au-U deposit. Hematite and magnetite have played a critical in the genesis of all of these deposits, and increasingly it appears that magnetite has been in equilibrium with either the final mineralised assemblage or was critical in transporting metals during the ore forming event. 14 magnetites and one hematite from three separate styles of iron oxide mineralisation associated with the Prominent Hill Cu-Au deposit were selected for detailed analysis. The REE and isotopic separations were all conducted by low blank wet chemistry and isotopes determined by TIMS (Nd) and MC-ICPMS (Hf). Magnetites associated with skarn style mineralsiation proximal to the ore body are unformly depleted in REE, whereas hematite within the ore and magmatic magmatites and whole rock gabbros from the nearby 1590Ma White Hill Gabbro intrusion are all relatively LREE enriched and display a comparable range in REE. Significantly however, magnetite separates almost invariably display more evolved Hf isotopic signatures than the host lithologies adjacent the economic mineralisation (dacites and metasediments at Prominent Hill mine) implying that the magnetites were sourcing their REE inventory dominantly from the local crust rather than a mantle derived source. In contrast, the magmatic magnetites from the White Hill Complex display Nd and Hf isotopes which are slightly more primitive, recording a greater relative mantle component, however still requiring a significant crustal input. Significantly, the hematite which contains the Au mineralisation preserves ɛNd (1590) = -4.04 and ɛHf (1590) = -6.05 essentially identical to the magmatic magnetites and their host gabbros in the White Hill complex and the basalts and dacites of the host Gawler Range Volcanics (ɛNd (1590) = -7.10 - -3.72 and ɛHf (1590) = -7.69 - -1

  4. Single layer of Ge quantum dots in HfO2for floating gate memory capacitors.

    Science.gov (United States)

    Lepadatu, A M; Palade, C; Slav, A; Maraloiu, A V; Lazanu, S; Stoica, T; Logofatu, C; Teodorescu, V S; Ciurea, M L

    2017-04-28

    High performance trilayer memory capacitors with a floating gate of a single layer of Ge quantum dots (QDs) in HfO 2 were fabricated using magnetron sputtering followed by rapid thermal annealing (RTA). The layer sequence of the capacitors is gate HfO 2 /floating gate of single layer of Ge QDs in HfO 2 /tunnel HfO 2 /p-Si wafers. Both Ge and HfO 2 are nanostructured by RTA at moderate temperatures of 600-700 °C. By nanostructuring at 600 °C, the formation of a single layer of well separated Ge QDs with diameters of 2-3 nm at a density of 4-5 × 10 15 m -2 is achieved in the floating gate (intermediate layer). The Ge QDs inside the intermediate layer are arranged in a single layer and are separated from each other by HfO 2 nanocrystals (NCs) about 8 nm in diameter with a tetragonal/orthorhombic structure. The Ge QDs in the single layer are located at the crossing of the HfO 2 NCs boundaries. In the intermediate layer, besides Ge QDs, a part of the Ge atoms is segregated by RTA at the HfO 2 NCs boundaries, while another part of the Ge atoms is present inside the HfO 2 lattice stabilizing the tetragonal/orthorhombic structure. The fabricated capacitors show a memory window of 3.8 ± 0.5 V and a capacitance-time characteristic with 14% capacitance decay in the first 3000-4000 s followed by a very slow capacitance decrease extrapolated to 50% after 10 years. This high performance is mainly due to the floating gate of a single layer of well separated Ge QDs in HfO 2 , distanced from the Si substrate by the tunnel oxide layer with a precise thickness.

  5. Hardness and Second Phase Percentage of Ni-Ti-Hf Compounds After Heat Treatment at 700C

    Science.gov (United States)

    Stanford, Malcolm K.

    2017-01-01

    The Vickers hardness and second phase precipitation of three ternary intermetallic Ni-Ti-Hf compounds containing either 1, 3 or 5 at.% Hf were compared to 60-Nitinol (55 at.% Ni - 45 at.% Ti). Heat treatment either at 700 C or with a subsequent aging step, hardened the 3 and 5 at.% Hf-containing ternaries to approximately 620 HV (56 HRC). Heat treatment increased the hardness of the 1 at.% Hf compound by more than 25 percent. Average hardness of the 3 and 5 at.% Hf ternaries, though higher than that of the binary Ni-Ti or the Ni-Ti-Hf compound containing 1 at.% Hf, appeared to be fairly insensitive to the different heat treatments. There was a drastic reduction of fatigue-enhancing second phase precipitates for the 5 at.% Hf ternaries compared to the other compounds. These results should guide materials selection for development of aerospace componentry.

  6. Oxidation behavior of TiC, ZrC, and HfC dispersed in oxide matrices

    International Nuclear Information System (INIS)

    Arun, R.; Subramanian, M.; Mehrotra, G.M.

    1990-01-01

    The oxidation behavior of hot pressed TiC-Al 2 O 3 , TiC-ZrO 2 , ZrC-ZrO 2 , and HfC-HfO 2 composites has been investigated at 1273 K. The oxidation of TiC, ZrC, and HfC in hot-pressed composites containing ZrO 2 and HfO 2 has been found to be extremely rapid. The kinetics of oxidation of TiC and a 90 wt% TiC-Al 2 O 3 composite appear to be faster compared to that of pure TiC. X-ray diffraction results for hot-pressed ZrC-HfO 2 and HfC-HfO 2 composites indicate partial stabilization of tetragonal ZrO 2 and HfO 2 phases in these composites

  7. Minutes of a meeting in Leuna on April 27, 1942 concerning DHD and HF processes

    Energy Technology Data Exchange (ETDEWEB)

    Welz, H.

    1942-06-18

    This discussion centered on the most recent experiences with the two processes. In light of experiments and production experience, Ludwigshafen had decided on the following guidelines for operation o DHD: (1) sudden rises in temperature should be avoided, as should falls in temperature of more than 25/sup 0/C. (2) When possible, higher pressures, up to 50 atm total pressure, should be used. (3) Inputs of gas should be at least 1.0 cubic meter per kilogram of oil, but preferably 1.5 cbm/kg oil. (4) Throughputs of starting materials should be no more than 0.5 kg/liter/hr, and should be less if that would not decrease production. The report included tables giving data on which these recommendations were based, showing the principal advantages gained to be a lowering of coke buildup, an increase of yield of gasoline, or an increase of lower-boiling point components in the gasoline. The discussion of the HF process involved results of tests with two different types of oven systems (unheated kiln ovens versus heated tube ovens), three types of starting materials (naphthenic, paraffinic, mixed), various arrangements of patterns of temperature and catalyst activity through each oven and through the sequence of ovens, and various values of pressures and loading. There was discussion of points on which Ludwigshafen and Leuna still had differences of opinion and differing test results, such as optimum values for pressures, temperature distribution, and loadings, and optimum distribution of aromatics formation among the ovens. Finally there was discussion of Leuna's method of refining the HF gasoline using sulfuric acid and Ludwigshafen's method of fighting corrosion due to sulfur dioxide.

  8. Heavy ion radiation effects on TiN/HfO2/W resistive random access memory

    Science.gov (United States)

    He, Xiaoli; Geer, Robert E.

    Resistive random access memory (ReRAM) is an attractive candidate for application in next-generation nonvolatile memory (NVM) devices for both aerospace and conventional commercial applications. ReRAM has several intrinsic advantages over other NVM technologies due to its simple metal-insulator-metal structure, high storage density, low power consumption, high switching speed, and high endurance. Most importantly, there are indications that ReRAM is an intrinsically radiation-hard device due to its defect-moderated, resistive switching mechanism and potentially well suited for applications in aerospace or other radiation intensive environments. We present a study of the effects of radiation on TiN/HfO2/W ReRAM devices carried out with a variety of ion sources, including He, N, Ne, and Ar, at fluences ranging from 1012 to 1015 cm- 2. Multiple (15- 16) devices were employed in each irradiation experiment. Half of the devices were programmed into high resistance states (HRS, off states) and the other half were programmed into low resistance states (LRS, on states) before radiation exposure. After radiation, the resistance of ReRAM devices in each state decreased with higher influence and with heavier ions. We observed spontaneous switching of the high resistance states of all devices to low resistance states following Ne and Ar radiation at a fluence of 1015 cm- 2. However, most devices remained functional after radiation. Forming voltage and initial resistance of fresh non-formed devices were also compared with non-irradiated devices. The effects of radiation on ReRAM switching are attributed to modified defect distributions within the conducting filament. The radiation-induced defect densities and the associated dependence on ion mass are discussed in terms of current defect-mediated switching models for TiN/HfO2/W ReRAM devices.

  9. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  10. Structure, optical properties and thermal stability of HfErO films deposited by simultaneous RF and VHF magnetron sputtering

    International Nuclear Information System (INIS)

    Zhang, H.Y.; He, H.J.; Zhang, Z.; Jin, C.G.; Yang, Y.; Wang, Y.Y.; Ye, C.; Zhuge, L.J.; Wu, X.M.

    2015-01-01

    HfErO films are deposited on Si substrates by simultaneous radio frequency (RF) and very high frequency (VHF) magnetron sputtering technique. The content of the doped ingredient of Er and the body composition of HfO x are, respectively, controlled through the VHF and RF powers. Low content of Er doping in the HfErO films can be achieved, because the VHF source of 27.12 MHz has higher ion energy and lower ion flux than the RF source resulting in low sputtering rate in the magnetron sputtering system. The structure, optical properties and thermal stability of the HfErO films are investigated in this work. Results show that the doped content of Er is independently controlled by the VHF power. The oxygen vacancies are created by the Er incorporation. The hafnium in the HfErO films forms mixed valence of Hf 2+ and Hf 4+ . The HfErO films are composed with the structures of HfO 2 , HfO and ErO x , which can be optimized through the VHF power. At high VHF power, the Hf-Er-O bonds are formed, which demonstrates that the Er atoms are doped into the lattice of HfO 2 in the HfErO films. The HfErO films have bad thermal stability as the crystallization temperature decreases from 900 to 800 C. After thermal annealing, cubic phase of HfO 2 are stabilized, which is ascribed to the oxygen vacancies creation by the Er incorporation. The optical properties such as the refractive index and the optical band gap of the HfErO films are optimized by the VHF power. (orig.)

  11. Optical modulator including grapene

    Science.gov (United States)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  12. High-throughput micro-plate HCL-vanillin assay for screening tannin content in sorghum grain

    Science.gov (United States)

    Sorghum contains tannin which is a phenolic compound that offers health promoting antioxidant capacity. The HCl-vanillin assay is a common and time consuming method for determining tannin content, but is not efficient for screening large sample sets as seen in association mapping panels or breeding ...

  13. TEA CO2 laser-induced reaction of CH3NO2 with CF2HCl: A ...

    Indian Academy of Sciences (India)

    Unknown

    CH3NO2. Time-resolved infrared fluorescence from vibrationally excited CF2HCl and CH3NO2 molecules as well as ... nitromethane, dissociation into CH3 and NO2 radicals is the most efficient [φ = 0⋅6]. *For correspondence ... Quantitative analysis could not be done because of the complexity of the reaction products and ...

  14. Hydrogen bond symmetrization and superconducting phase of HBr and HCl under high pressure: An ab initio study.

    Science.gov (United States)

    Duan, Defang; Tian, Fubo; He, Zhi; Meng, Xing; Wang, Liancheng; Chen, Changbo; Zhao, Xiusong; Liu, Bingbing; Cui, Tian

    2010-08-21

    Ab initio calculations are performed to probe the hydrogen bonding, structural, and superconducting behaviors of HBr and HCl under high pressure. The calculated results show that the hydrogen bond symmetrization (Cmc2(1)-->Cmcm transition) of HBr and HCl occurs at 25 and 40 GPa, respectively, which can be attributed to the symmetry stretching A(1) mode softening. After hydrogen bond symmetrization, a pressure-induced soft transverse acoustic phonon mode of Cmcm phase is identified and a unique metallic phase with monoclinic structure of P2(1)/m (4 molecules/cell) for both compounds is revealed by ab initio phonon calculations. This phase preserves the symmetric hydrogen bond and is stable in the pressure range from 134 to 196 GPa for HBr and above 233 GPa for HCl, while HBr is predicted to decompose into Br(2)+H(2) above 196 GPa. Perturbative linear-response calculations predict that the phase P2(1)/m is a superconductor with T(c) of 27-34 K for HBr at 160 GPa and 9-14 K for HCl at 280 GPa.

  15. Acetone enhances the direct analysis of total condensed tannins in plant tissues by the butanol-HCl-iron assay

    Science.gov (United States)

    The butanol-HCl spectrophotometric assay is widely used to quantify extractable and insoluble forms of condensed tannin (CT, syn. proanthocyanidin) in foods, feeds, and foliage of herbaceous and woody plants. However, this method underestimates total CT content when applied directly to plant materia...

  16. Oral Ezatiostat HCl (TLK199) and Myelodysplastic syndrome: a case report of sustained hematologic response following an abbreviated exposure.

    Science.gov (United States)

    Quddus, Fahd; Clima, Jessica; Seedham, Helen; Sajjad, Ghulam; Galili, Naomi; Raza, Azra

    2010-04-23

    Treatment options for patients with lower risk non-del(5q) myelodysplastic syndromes (MDS) who fail erythroid stimulating agents are restricted to one of the hypomethylating drugs with an expected response rate of approximately 50%. Ezatiostat HCl, an agent with the potential for producing multi-lineage responses in this population is currently in clinical investigation phase. This case report describes a 77 year old male who received less than two cycles of therapy with ezatiostat HCl which had to be aborted due to intolerable side effects, but which produced a sustained normalization of all three blood counts. This trilineage response has now lasted for more than a year. Interestingly, the patient began with a del(5q) abnormality and responded briefly to lenalidomide. Upon relapse of the anemia, a bone marrow showed the disappearance of the del(5q) but the appearance of a new clonal abnormality t(2;3). Given that the patient had a complete cytogenetic response to a truncated exposure to lenalidomide followed by a trilineage response to an even briefer course of ezatiostat HCl suggests a potential role for ezatiostat HCl in del(5q) patients who relapse following lenalidomide.

  17. Corrosion inhibition of Q235 steel in 1 M HCl using quaternized tetraaniline as a corrosion inhibitor

    Science.gov (United States)

    Li, Xiangyu; Ye, Yuwei; Liu, Tong; Zheng, Wenru; Yang, Feng; Zhao, Haichao; Wang, Liping

    2017-12-01

    Novel quaternary ammonium cation containing tetraaniline (QATA) was successfully synthesized by condensation of amine-capped tetraaniline with 6-bromohexanoic acid, followed by quaternarization with triethylamine. The corrosion inhibition performance of QATA with their adsorption mechanisms for Q235 steel was studied in 1 M HCl solution by a series of methods such as weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM). The inhibition efficiency (IE%) increased with increasing concentrations of QATA, reaching a value up to 97.47% at a concentration of 150 mg l‑1. Potentiodynamic polarization curves showed that the QATA affected both cathodic and anodic protection and was a mixed type inhibitor in 1 M HCl corrosive medium. Adsorption isotherm studies confirmed that the absorption of QATA on the Q235 steel surface in 1 M HCl solution obeyed Langmuir adsorption isotherm, and the adsorption process of corrosion inhibition on Q235 steel surface involved both the physical and chemical adsorption. The EDS analysis determined the adsorption of QATA molecules on the steel surface, the surface morphologies before and after immersion in 1 M HCl medium were also investigated by SEM and AFM.

  18. TEA CO2 laser-induced reaction of CH3NO2 with CF2HCl: A ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 4. TEA CO2 laser-induced reaction of CH3NO2 with CF2HCl: A mechanistic study. Rajesh K Vatsa Sisir K Sarkar Jai P Mittal. Physical and Theoretical Volume 113 Issue 4 August 2001 pp 333-342 ...

  19. 76 FR 41250 - Formetanate HCl and Acephate; Notice of Receipt of Requests to Voluntarily Amend Registrations To...

    Science.gov (United States)

    2011-07-13

    ... registrations to delete uses. The requests would delete formetanate HCl use in or on apple, pear and peach...: Office of Pesticide Programs (OPP) Regulatory Public Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-0001. Delivery: OPP Regulatory Public Docket (7502P...

  20. HCl Flow-Induced Phase Change of α-, β-, and ε-Ga2O3 Films Grown by MOCVD

    KAUST Repository

    Sun, Haiding

    2018-03-06

    Precise control of the heteroepitaxy on a low-cost foreign substrate is often the key to drive the success of fabricating semiconductor devices in scale when a large low-cost native substrate is not available. Here, we successfully synthesized three different phases of Ga2O3 (α, β, and ε) films on c-plane sapphire by only tuning the flow rate of HCl along with other precursors in an MOCVD reactor. A 3-fold increase in the growth rate of pure β-Ga2O3 was achieved by introducing only 5 sccm of HCl flow. With continuously increased HCl flow, a mixture of β- and ε-Ga2O3 was observed, until the Ga2O3 film transformed completely to a pure ε-Ga2O3 with a smooth surface and the highest growth rate (∼1 μm/h) at a flow rate of 30 sccm. At 60 sccm, we found that the film tended to have a mixture of α- and ε-Ga2O3 with a dominant α-Ga2O3, while the growth rate dropped significantly (∼0.4 μm/h). The film became rough as a result of the mixture phases since the growth rate of ε-Ga2O3 is much higher than that of α-Ga2O3. In this HCl-enhanced MOCVD mode, the Cl impurity concentration was almost identical among the investigated samples. On the basis of our density functional theory calculation, we found that the relative energy between β-, ε-, and α-Ga2O3 became smaller, thus inducing the phase change by increasing the HCl flow in the reactor. Thus, it is plausible that the HCl acted as a catalyst during the phase transformation process. Furthermore, we revealed the microstructure and the epitaxial relationship between Ga2O3 with different phases and the c-plane sapphire substrates. Our HCl-enhanced MOCVD approach paves the way to achieving highly controllable heteroepitaxy of Ga2O3 films with different phases for device applications.

  1. HF and VHF Spectra of Fast Breakdown Processes

    Science.gov (United States)

    Liu, N.; Tilles, J.; Krehbiel, P. R.; Stanley, M. A.; Rison, W.; Dwyer, J. R.; Brown, R. G.; Wilson, J. G.

    2017-12-01

    The recent discovery of fast positive breakdown (FPB) as the underlying process of narrow bipolar events (NBEs) or compact intracloud discharges [Rison et al., Nat. Commun., 7, 10721, 2016] is an important step towards understanding why NBEs radiate strongly in high frequency (HF, 3-30 MHz) and very high frequency (VHF, 30-300 MHz) bands. Rison et al. [2016] has further hypothesized that fast positive breakdown is a system of volumetrically distributed streamers. The current theory of radio emissions from streamers is based on the concept of accelerating and expanding streamers. An expanding streamer carries an exponentially increasing current, and its resulting electromagnetic radiation extends to HF and VHF bands, when the external electric field supporting its propagation varies from 0.5Ek to 1.5Ek at 9 km altitude, where Ek is the conventional breakdown threshold field [Shi et al., J. Geophys. Res. Atmos., 121, 7284, 2016]. It should be noted that the spectrum of NBEs below 50 MHz is available in the literature [Willett et al., J. Geophys. Res., 94, 16255, 1989], but the spectrum beyond 50 MHz is not well known currently. The broadband, high-speed radio interferometer (INTF) used by Rison et al. [2016] was deployed at Kennedy Space Center, Florida to collect data from July to October in 2016. Many NBEs were recorded. The majority of the NBEs are caused by FPB, similar to those reported by Rison et al. [2016], but there exist a few cases, where the breakdown process propagates in the opposite direction expected of fast positive breakdown and is termed fast negative breakdown [Tilles et al., AE12A-03, AGU Fall Meeting, 2016]. In this talk, we will analyze the spectra of fast breakdown of both polarities in the frequency band of the INTF, 20-80 MHz, and compare the results with published NBE spectra. We will also apply the technique developed by Dwyer and Cummer [J. Geophys. Res., 118, 3769, 2013] to synthesize the radio pulse and spectrum of a system of streamers

  2. Effects of humidity on the quantitative determination of HCl, NOx, H2S, and NH3 using a three-stage filter pack with ion chromatography analysis

    International Nuclear Information System (INIS)

    Borek, T.T.; Wu, C.F.

    1993-01-01

    Low-level transuranic (TRU) waste to be stored underground at the Waste Isolation Pilot Plant (WIPP) has the potential to generate low levels of reactive gases such as HCl, NO x H 2 S, and NH 3 through radiological, biological, and chemical (corrosion) processes. Because of the low levels of gas expected to be produced (< 1 ppM), a method was developed which includes the simultaneous sampling of gases using chemically treated filter papers and analysis of the extracted ions by ion chromatography. To determine the effects of humidification on the collection and determination of reactive gases, a humidification system was added to the trace gas generator system to produce a relative humidity approximately equal to that in the Humid Test Bin. This humidification system consisted of gas washing bottles filled with saturated brine (NaCl) that has been shown to produce a relative humidity of approximately 75% in the temperature range of 68 degree F to 86 degree

  3. In-situ atomic layer deposition growth of Hf-oxide

    International Nuclear Information System (INIS)

    Karavaev, Konstantin

    2010-01-01

    We have grown HfO 2 on Si(001) by atomic layer deposition (ALD) using HfCl 4 , TEMAHf, TDMAHf and H 2 O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and X-ray absorption spectroscopy. We observed the changes occurring in the Si 2p, O 1s, Hf 4f, Hf 4d, and Cl 2p (for HfCl 4 experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO 2 . The investigation was carried out in situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages in-situ approach in comparison with ex-situ experiments. The study provides to follow the evolution of the important properties of HfO 2 : contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that in-situ XPS approach for ALD gives much more information than ex-situ experiments. (orig.)

  4. Directionally solidified pseudo-binary eutectics of Ni-Cr-(Hf, Zr)

    Science.gov (United States)

    Kim, Y. G.; Ashbrook, R. L.

    1975-01-01

    A pseudo-binary eutectic, in which the intermetallic Ni7Hf2 reinforces the Ni-Cr solid solution phase, was previously predicted in the Ni-Cr-Hf system by a computer analysis. The experimental determination of pseudo binary eutectic compositions and the directional solidification of the Ni-Cr-Hf, Zr, and Ni-Cr-Zr eutectic alloys are discussed. To determine unknown eutectics, chemical analyses were made of material bled from near eutectic ingots during incipient melting. Nominal compositions in weight percent of Ni-18.6Cr-24.0HF, Ni19.6Cr-12.8Zr-2.8Hf, and Ni-19.2Cr-14.8Zr formed aligned pseudo-binary eutectic structures. The melting points were about 1270 C. The reinforcing intermetallic phases were identified as noncubic (Ni,Cr)7Hf2 and (Ni,Cr)7(Hf,Zr)2, and face centered cubic (Ni,Cr)5Zr. The volume fraction of the reinforcing phases were about 0.5.

  5. In-situ atomic layer deposition growth of Hf-oxide

    Energy Technology Data Exchange (ETDEWEB)

    Karavaev, Konstantin

    2010-06-17

    We have grown HfO{sub 2} on Si(001) by atomic layer deposition (ALD) using HfCl{sub 4}, TEMAHf, TDMAHf and H{sub 2}O as precursors. The early stages of the ALD were investigated with high-resolution photoelectron spectroscopy and X-ray absorption spectroscopy. We observed the changes occurring in the Si 2p, O 1s, Hf 4f, Hf 4d, and Cl 2p (for HfCl{sub 4} experiment) core level lines after each ALD cycle up to the complete formation of two layers of HfO{sub 2}. The investigation was carried out in situ giving the possibility to determine the properties of the grown film after every ALD cycle or even after a half cycle. This work focused on the advantages in-situ approach in comparison with ex-situ experiments. The study provides to follow the evolution of the important properties of HfO{sub 2}: contamination level, density and stoichiometry, and influence of the experimental parameters to the interface layer formation during ALD. Our investigation shows that in-situ XPS approach for ALD gives much more information than ex-situ experiments. (orig.)

  6. Linear Trimeric Hafnium Clusters in Hf0.86(1I3

    Directory of Open Access Journals (Sweden)

    Jan Beekhuizen

    2011-05-01

    Full Text Available The reduction of hafnium tetraiodide, HfI4, with aluminum at 600 °C or 850 °C in the presence of a NaI flux resulted in black single crystals of Hf0.86(1I3. This composition corresponds well to the upper end of the non-stoichiometry range 0.89 ≤ x ≤ 1.00 previously reported for HfxI3. The crystal structure (a = 1250.3(2, c = 1999.6(3 pm, R-3m, Z = 18 is made up of hexagonal closest packed layers of iodide ions. One third of the octahedral holes would be filled as in TiI3 or ZrI3 if it were Hf1.00I3. In Hf0.86(1I3, one out of six octahedral holes along [001] are, however, only occupied by 16%. In contrast to TiI3-I and ZrI3, one striking structural feature is in the formation of linear hafnium trimers with identical Hf―Hf distances of 318.3(2 pm rather than the formation of dimers. These may be associated with Hf―Hf bonding although only 2.64 electrons are available for one Hf5.16I18 column.

  7. Superelasticity and Shape Memory Behavior of NiTiHf Alloys

    Science.gov (United States)

    Sehitoglu, H.; Wu, Y.; Patriarca, L.; Li, G.; Ojha, A.; Zhang, S.; Chumlyakov, Y.; Nishida, M.

    2017-06-01

    The NiTiHf high-temperature shape memory alloys represent a significant advancement in extending the functionality of binary NiTi to elevated temperatures above 100 °C. Despite this potential, the previous results in the literature point to a disappointingly low shape memory strains with addition of Hf. On the other hand, based on theoretical analysis using the lattice constants, the transformation strains should increase substantially with increase in Hf content. The present paper addresses this discrepancy, and using atomistic simulations, determination of twinning modes in martensite with transmission electron microscopy, digital image measurements of habit plane orientation, and strains in single-crystal specimens show that the experimental transformation strains in NiTiHf indeed increase with increasing Hf to unprecedented strain levels near 20%. The Hf contents considered were in the range 6.25-25 at.%, and NiTi (0% Hf) results are provided as the baseline. The current work represents more than 60 experiments representing an extremely thorough study on single crystals and polycrystals.

  8. Preparation, structure and properties of hafnium compounds in the system Hf-C-N-O

    International Nuclear Information System (INIS)

    Brundiers, G.D.

    1975-08-01

    Highly dense, homogenous and single phase hafnium carbonitride samples (with low oxygen content) were prepared in the whole concentration range of the ternary cubic carbonitrides. Stoichiometric hafnium oxicarbides were also prepared within the range of solubility. The procedure involved the hot pressing of powders of HfC, HfN, Hf, Hf-Oxide and carbon at temperatures of 3,000 0 C and pressures up to 550 kpf/cm 2 using a novel technique. Small single crystals of slightly substoichiometric HfN were also repared. The densification of the powders was studied as a function of the non-metal concentration. Carbonitrides with N/Hf ratio of 0.37 were prepared in a high temperature autoclave operating at medium pressures by the reaction of HfC with nitrogen. All the samples were characterized by density measurements, chemical, X-ray and metallographic analysis and in some cases with the aid of quantitative metallography and microprobe analysis. Typical properties investigated were lattice parameter, thermal expansion, microhardness and electrical resistivity as function of the non-metal content. For specific concentrations extreme values in the properties are attained. With the aid of the valence electron concentration (VEC) parameter, the properties can be correlated with the density of states of electrons at the Fermi level. (orig./HK) [de

  9. Identification of protein secondary structures by laser induced autofluorescence: A study of urea and GnHCl induced protein denaturation

    Science.gov (United States)

    Siddaramaiah, Manjunath; Satyamoorthy, Kapaettu; Rao, Bola Sadashiva Satish; Roy, Suparna; Chandra, Subhash; Mahato, Krishna Kishore

    2017-03-01

    In the present study an attempt has been made to interrogate the bulk secondary structures of some selected proteins (BSA, HSA, lysozyme, trypsin and ribonuclease A) under urea and GnHCl denaturation using laser induced autofluorescence. The proteins were treated with different concentrations of urea (3 M, 6 M, 9 M) and GnHCl (2 M, 4 M, 6 M) and the corresponding steady state autofluorescence spectra were recorded at 281 nm pulsed laser excitations. The recorded fluorescence spectra of proteins were then interpreted based on the existing PDB structures of the proteins and the Trp solvent accessibility (calculated using "Scratch protein predictor" at 30% threshold). Further, the influence of rigidity and conformation of the indole ring (caused by protein secondary structures) on the intrinsic fluorescence properties of proteins were also evaluated using fluorescence of ANS-HSA complexes, CD spectroscopy as well as with trypsin digestion experiments. The outcomes obtained clearly demonstrated GnHCl preferably disrupt helix as compared to the beta β-sheets whereas, urea found was more effective in disrupting β-sheets as compared to the helices. The other way round the proteins which have shown detectable change in the intrinsic fluorescence at lower concentrations of GnHCl were rich in helices whereas, the proteins which showed detectable change in the intrinsic fluorescence at lower concentrations of urea were rich in β-sheets. Since high salt concentrations like GnHCl and urea interfere in the secondary structure analysis by circular dichroism Spectrometry, the present method of analyzing secondary structures using laser induced autofluorescence will be highly advantageous over existing tools for the same.

  10. OBTENCIÓN DE RECUBRIMIENTOS COMPUESTOS DE HfN/HfO2 DUROS Y TRANSPARENTES POR SPUTTERING Y TRATAMIENTOS TÉRMICOS

    Directory of Open Access Journals (Sweden)

    Leandro García

    2017-01-01

    Full Text Available Se sintetizaron recubrimientos de HfN sobre vidrio Corning por la técnica de erosión catódica. Se realizaron tratamientos térmicos post-depósito a 300 °C, 400 °C y 500 °C para obtener recubrimientos compuestos de HfN/HfO2, y analizar cambios en la dureza y transmitancia en función de su microestructura. Los recubrimientos se caracterizaron por DRX, MEB-EC, EED, dureza Vickers y UV-vis. DRX mostró que los tratamientos térmicos cambian las fases en los recubrimientos, logrando obtener el recubrimiento compuesto de HfN/HfO2 para los tratamientos térmicos de 400 °C y 500 °C. Por MEB-EC se corroboraron los resultados de DRX mostrando cambios morfológicos con el aumento de la temperatura. La dureza Vickers y el porcentaje de transmitancia aumentaron conforme la temperatura aumentó, logrando alcanzar valores máximos de 22 GPa y 71 %, respectivamente. La tenacidad a la fractura disminuye con el aumento de temperatura, pero el band gap se mantiene constante en 4.17 eV.

  11. Ti insertion in the MTe5 (M = Zr, Hf structure type: Hf0.78Ti0.22Te5

    Directory of Open Access Journals (Sweden)

    Hoseop Yun

    2012-03-01

    Full Text Available The group 5 mixed-metal telluride, Hf0.78Ti0.22Te5 (hafnium titanium pentatelluride, is isostructural with the binary phases HfTe5 and ZrTe5 and forms a layered structure extending parallel to (010. The layers are made up from chains of bicapped metal-centered trigonal prisms and zigzag Te chains. The metal site (site symmetry m2m is occupied by statistically disordered Hf [78.1 (5%] and Ti [21.9 (5%]. In addition to the regular Te—Te pair [2.7448 (13 Å] forming the short base of the equilateral triangle of the trigonal prism, an intermediate Te...Te separation [2.9129 (9 Å] is also found. The classical charge balance of the compound can be described as [M4+][Te2−][Te22−][Te20] (M = Hf, Ti. The individual metal content can vary in different crystals, apparently forming a random substitutional solid solution (Hf1-xTixTe5, with 0.15 ≤ x ≤ 0.22.

  12. Effects of HfO{sub 2}/Co interface and Co/HfO{sub 2} interface on anomalous Hall behavior in perpendicular Co/Pt multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Long [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Yang, Guang [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Teng, Jiao, E-mail: tengjiao@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Guo, Qi-Xun; Liu, Yi-Wei; Li, Xu-Jing [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2017-07-01

    Highlights: • Anomalous Hall effect in perpendicular Co/Pt multilayers is studied. • Thermally stable AHE feature is obtained in [Pt/Co]{sub 3}/HfO{sub 2}/Pt multilayers. • Good thermal stability is due to enhanced intrinsic and side-jump contributions. - Abstract: Effects of the HfO{sub 2}/Co interface and the Co/HfO{sub 2} interface on thermal stability of anomalous Hall effect (AHE) in perpendicular Co/Pt multilayers have been studied. It is observed that thermally stable AHE behavior cannot be obtained in perpendicular Co/Pt multilayers with the HfO{sub 2}/Co interface, mainly due to Co-Pt interdiffusion during annealing. In contrast, thermally stable AHE feature is observed in perpendicular Co/Pt multilayers with the Co/HfO{sub 2} interface despite Co-Pt interdiffusion, which is owing to the enhancement of the side jump and intrinsic contributions to the AHE through interfacial modification after annealing.

  13. Multi-quasi-particles states in 173Hf

    International Nuclear Information System (INIS)

    Fabricius, B.; Dracoulis, G.D.; Kibedi, T.; Stuchbery, A.E.; Baxter, A.M.

    1990-10-01

    Rotational bands built on 1, 3 and 5 quasi-particle (qp) states in 173 Hf have been populated to medium and high spins through the 160 Gd ( 18 O,5n) reaction. The 1qp bands, previously identified as the 1/2 - [521], 5/2 - [512] and 7/2 + [633] (mixed i 1 3 /2 ) Nilsson configurations, have been extended past the first back-bend and show different alignment properties, possibly originating from deformation differences. The multi-particle states were identified from excitation energies, the properties of their associated band structures and decay patterns. The 3 qp states are the previously known K π 19/2 + and 23/2 - isomeric states originating from the 7/2 + [633] quasi-neutron coupled to the 6 + and 8 - , 2-quasi-proton excitations and a K π = (13/2 + ) state possibly containing the three lowest quasi-neutrons. A 5 qp state with K π = (29/2 - ) was identified as the same three lowest lying quasi-neutrons coupled to the 8 - , 2-quasi-proton excitation. The low excitation energies of these two related 3- and 5-quasi-particle states implies a reduced neutron pairing gap, which can be attributed to the effect of blocking. 28 refs., 2 tabs., 9 figs

  14. A New Method of Wave Mapping with HF Radar

    Directory of Open Access Journals (Sweden)

    Lijie Jin

    2016-01-01

    Full Text Available Study of wave height inversion with High-Frequency Surface Wave Radars (HFSWRs has been going on for more than 40 years. Various wave inversion methods have been proposed, and HFSWRs have achieved great success in local wave measurements. However, the method of wave mapping is still under development, especially for the broad-beam HF radars. Existing methods of wave mapping are based on narrow-beam radar with beamforming. This paper introduces a way of wave height inversion, using the ratio of the second-harmonic peak (SHP to the Bragg peak (RSB. A new wave mapping method is proposed, which can be used in both narrow and broad-beam radars, according to the way of wave inversion based on the RSB. In addition, radar wave measurements at the buoy position are compared with the in situ buoy, which show a good agreement. At last, the results of wave mapping on the two-hour timescale are given.

  15. Three band crossings in the yrast structure of 162Hf

    International Nuclear Information System (INIS)

    Bingham, C.R.; Riedinger, L.L.; Courtney, L.H.

    1988-01-01

    The yrast sequence of 162 Hf has been observed up to a level tentatively assigned as 38 + and reveals a continuing rotational character up to that spin. Sharp backbends at rotational frequencies of 0.27 and 0.42 MeV/ℎ are attributed to isub(13/2) neutron and hsub(11/2) proton alignments, respectively. A gradual increase in the aligned angular momentum of the yrast levels between these two sharp backbends is attributed to the rotational alignment of a pair of negative parity quasineutrons (mostly hsub(9/2) in character). The interpretation of this effect is supported by the failure of the negative parity bands, which already contain this aligned hsub(9/2) neutron, to gain alignment in the same rotational frequency range. While the alignment of the hsub(9/2) quasineutrons has been predicted in the cranked shell model to occur in the rare-earth region with a large interaction strength, this represents the first clear observation of such a band crossing. (author)

  16. Isotopic evidence for chondritic Lu/Hf and Sm/Nd of the Moon

    OpenAIRE

    Sprung Peter; Kleine Thorsten; Scherer Erik E.

    2013-01-01

    Refractory lithophile elements are generally considered to occur in chondritic relative abundances in terrestrial planets. This assumption forms the basis for using isotope systems such as 176Lu 176Hf and 146 147Sm 142 143Nd as tracers of planetary evolution. However on the basis of high precision 142Nd measurements higher than chondritic Sm/Nd and Lu/Hf values have been recently proposed for the Earth Moon and Mars. This hypothesis can be tested using the combined 147Sm 143Nd and 176Lu 176Hf...

  17. Crystal structure of Na2HfSi2O7 by Rietveld refinement

    Directory of Open Access Journals (Sweden)

    Nicolas Massoni

    2016-10-01

    Full Text Available The structure of triclinic disodium hafnium disilicate, Na2HfSi2O7, has been determined by laboratory powder X-ray diffraction and refined by the Rietveld refinement. The structure is a framework made of alternate layers of HfO6 octahedra and SiO4 tetrahedra linked by common O atoms. Sodium atoms are located in the voids of the framework, aligned into tunnels along the [010] direction. Na2HfSi2O7 is isostructural with the parakeldyshite Na2ZrSi2O7 phase.

  18. The role of phosphates for the Lu-Hf chronology of meteorites

    Science.gov (United States)

    Debaille, Vinciane; Van Orman, James; Yin, Qing-Zhu; Amelin, Yuri

    2017-09-01

    The 176Lu-176Hf isotopic system is widely used for dating and tracing cosmochemical and geological processes, but still suffers from two uncertainties. First, Lu-Hf isochrons for some early Solar System materials have excess slope of unknown origin that should not be expected for meteorites with ages precisely determined with other isotopic chronometers. This observation translates to an apparent Lu decay constant higher than the one calculated by comparing ages obtained with various dating methods on terrestrial samples. Second, unlike the well constrained Sm/Nd value (to within 2%) for the chondritic uniform reservoir (CHUR), the Lu/Hf ratios in chondrites vary up to 18% when considering all chondrites, adding uncertainty to the Lu/Hf CHUR value. In order to better understand the Lu-Hf systematics of chondrites, we analyzed mineral fractions from the Richardton H5 chondrite to construct an internal Lu-Hf isochron, and set up a numerical model to investigate the effect of preferential diffusion of Lu compared to Hf from phosphate, the phase with the highest Lu-Hf ratio in chondrites, to other minerals. The isochron yields an age of 4647 ± 210 million years (Myr) using the accepted 176Lu decay constant of 1.867 ± 0.008 ×10-11yr-1. Combining this study with the phosphate fractions measured in a previous study yields a slope of 0.08855 ± 0.00072, translating to a 176Lu decay constant of 1.862 ± 0.016 ×10-11yr-1 using the Pb-Pb age previously obtained, in agreement with the accepted value. The large variation of the Lu/Hf phosphates combined with observations in the present study identify phosphates as the key in perturbing Lu-Hf dating and generating the isochron slope discrepancy. This is critical as apatite has substantially higher diffusion rates of rare earth elements than most silicate minerals that comprise stony meteorites. Results of numerical modeling depending of temperature peak, size of the grains and duration of the metamorphic event, show that

  19. Comprehensive Pb-Sr-Nd-Hf isotopic, trace element, and mineralogical characterization of mafic to ultramafic rock reference materials

    Science.gov (United States)

    Fourny, Anaïs.; Weis, Dominique; Scoates, James S.

    2016-03-01

    Controlling the accuracy and precision of geochemical analyses requires the use of characterized reference materials with matrices similar to those of the unknown samples being analyzed. We report a comprehensive Pb-Sr-Nd-Hf isotopic and trace element concentration data set, combined with quantitative phase analysis by XRD Rietveld refinement, for a wide range of mafic to ultramafic rock reference materials analyzed at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. The samples include a pyroxenite (NIM-P), five basalts (BHVO-2, BIR-1a, JB-3, BE-N, GSR-3), a diabase (W-2), a dolerite (DNC-1), a norite (NIM-N), and an anorthosite (AN-G); results from a leucogabbro (Stillwater) are also reported. Individual isotopic ratios determined by MC-ICP-MS and TIMS, and multielement analyses by HR-ICP-MS are reported with 4-12 complete analytical duplicates for each sample. The basaltic reference materials have coherent Sr and Nd isotopic ratios with external precision below 50 ppm (2SD) and below 100 ppm for Hf isotopes (except BIR-1a). For Pb isotopic reproducibility, several of the basalts (JB-3, BHVO-2) require acid leaching prior to dissolution. The plutonic reference materials also have coherent Sr and Nd isotopic ratios (<50 ppm), however, obtaining good reproducibility for Pb and Hf isotopic ratios is more challenging for NIM-P, NIM-N, and AN-G due to a variety of factors, including postcrystallization Pb mobility and the presence of accessory zircon. Collectively, these results form a comprehensive new database that can be used by the geochemical community for evaluating the radiogenic isotope and trace element compositions of volcanic and plutonic mafic-ultramafic rocks.

  20. Rationale and design of the comParIson Of sacubitril/valsartaN versus Enalapril on Effect on nt-pRo-bnp in patients stabilized from an acute Heart Failure episode (PIONEER-HF) trial.

    Science.gov (United States)

    Velazquez, Eric J; Morrow, David A; DeVore, Adam D; Ambrosy, Andrew P; Duffy, Carol I; McCague, Kevin; Hernandez, Adrian F; Rocha, Ricardo A; Braunwald, Eugene

    2018-04-01

    The objective is to assess the safety, tolerability, and efficacy of sacubitril/valsartan compared with enalapril in patients with heart failure (HF) with a reduced ejection fraction (EF) stabilized during hospitalization for acute decompensated HF. Sacubitril/valsartan, a first-in-class angiotensin receptor-neprilysin inhibitor, improves survival among ambulatory HF patients with a reduced EF. However, there is very limited experience with the in-hospital initiation of sacubitril/valsartan in patients who have been stabilized following hospitalization for acute decompensated HF. PIONEER-HF is a 12-week, prospective, multicenter, double-blind, randomized controlled trial enrolling a planned 882 patients at more than 100 participating sites in the United States. Medically stable patients >18 years of age with an EF 1600 pg/mL or b-type natriuretic peptide >400 pg/mL are eligible for participation no earlier than 24 hours and up to 10 days from initial presentation while still hospitalized. Patients are randomly assigned 1:1 to in-hospital initiation of sacubitril/valsartan titrated to 97/103 mg by mouth twice daily versus enalapril titrated to 10 mg by mouth twice daily for 8 weeks. All patients receive open-label treatment with sacubitril/valsartan for the remaining 4 weeks of the study. The primary efficacy end point is the time-averaged proportional change in amino terminal-pro b-type natriuretic peptide from baseline through weeks 4 and 8. Secondary and exploratory end points include serum and urinary biomarkers as well as clinical outcomes. Safety end points include the incidence of angioedema, hypotension, renal insufficiency, and hyperkalemia. The PIONEER-HF trial will inform clinical practice by providing evidence on the safety, tolerability, and efficacy of in-hospital initiation of sacubitril/valsartan among patients who have been stabilized following an admission for acute decompensated HF with a reduced EF. Copyright © 2018 Elsevier Inc. All rights

  1. First principles study of structural, electronic and optical properties of Pb doped SrHfO3

    International Nuclear Information System (INIS)

    Luo Benhua; Wang Xueye; Zhang Yu; Xia Yong

    2012-01-01

    Highlights: ► Dopant formation energy results show that Pb enters the Sr site in SrHfO 3 . ► The bandgap of Sr 0.875 Pb 0.125 HfO 3 is slightly wider compared with SrHfO 3 . ► Bonding between Hf and O is covalent whereas Sr-HfO 3 and Pb-HfO 3 are ionic. ► O 2p states and Hf 5d states play a major role in optical transitions. - Abstract: The structural, electronic and optical properties of Sr 0.875 Pb 0.125 HfO 3 are investigated using the pseudo-potential plane wave method within the generalized gradient approximation (GGA) by first principles. The lattice constants obtained by minimization of the total energy are in agreement with the available experimental data. Dopant formation energy results show that Pb preferentially enters the Sr site in SrHfO 3 , which is in good agreement with experimental observations. The band structures indicate that both SrHfO 3 and Sr 0.875 Pb 0.125 HfO 3 are insulators. The density of states and charge density map indicate that bonding between Hf and O is mainly covalent, whereas bonding of Sr-HfO 3 and Pb-HfO 3 is ionic. In order to understand the optical properties of Sr 0.875 Pb 0.125 HfO 3 , the dielectric functions, loss function, refractive index, absorption coefficient and reflectivity are calculated for radiation up to 40 eV.

  2. Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl.

    Science.gov (United States)

    Noel, J A; Broxterman, R M; McCoy, G M; Craig, J C; Phelps, K J; Burnett, D D; Vaughn, M A; Barstow, T J; O'Quinn, T G; Woodworth, J C; DeRouchey, J M; Rozell, T G; Gonzalez, J M

    2016-06-01

    The objectives of this study were to determine the effects of dietary ractopamine HCl (RAC) on muscle fiber characteristics and electromyography (EMG) measures of finishing barrow exhaustion when barrows were subjected to increased levels of activity. Barrows ( = 34; 92 ± 2 kg initial BW) were assigned to 1 of 2 treatments: a conventional swine finishing diet containing 0 mg/kg ractopamine HCl (CON) or a diet formulated to meet the requirements of finishing barrows fed 10 mg/kg RAC (RAC+). After 32 d on feed, barrows were individually moved around a track at 0.79 m/s until subjectively exhausted. Wireless EMG sensors were affixed to the deltoideus (DT), triceps brachii lateral head (TLH), tensor fasciae latae (TFL), and semitendinosus (ST) muscles to measure median power frequency (MdPF) and root mean square (RMS) as indicators of action potential conduction velocity and muscle fiber recruitment, respectively. After harvest, samples of each muscle were collected for fiber type, succinate dehydrogenase (SDH), and capillary density analysis. Speed was not different ( = 0.82) between treatments, but RAC+ barrows reached subjective exhaustion earlier and covered less distance than CON barrows ( 0.29). There was a treatment × muscle interaction ( = 0.04) for end-point RMS values. The RAC diet did not change end-point RMS values in the DT or TLH ( > 0.37); however, the diet tended to decrease and increase end-point RMS in the ST and TFL, respectively ( 0.10). Muscles of RAC+ barrows tended to have less type I fibers and more capillaries per fiber ( < 0.07). Type I and IIA fibers of RAC+ barrows were larger ( < 0.07). Compared with all other muscles, the ST had more ( < 0.01) type IIB fibers and larger type I, IIA, and IIX fibers ( < 0.01). Type I, IIA, and IIX fibers of the ST also contained less SDH compared with the other muscles ( < 0.01). Barrows fed a RAC diet had increased time to subjective exhaustion due to loss of active muscle fibers in the ST, possibly due

  3. Influence of oxygen vacancies in ALD HfO2-x thin films on non-volatile resistive switching phenomena with a Ti/HfO2-x/Pt structure

    Science.gov (United States)

    Sokolov, Andrey Sergeevich; Jeon, Yu-Rim; Kim, Sohyeon; Ku, Boncheol; Lim, Donghwan; Han, Hoonhee; Chae, Myeong Gyoon; Lee, Jaeho; Ha, Beom Gil; Choi, Changhwan

    2018-03-01

    We report a modulation of oxygen vacancies profile in atomic layer deposition (ALD) HfO2-x thin films by reducing oxidant pulse time (0.7 s-0.1 s) and study its effect on resistive switching behavior with a Ti/HfO2-x/Pt structure. Hf 4f spectra of x-ray photoelectron microscopy (XPS) and depth profile confirm varied oxygen vacancies profiles by shifts of binding energies of Hf 4f5/2 and Hf 4f7/2 main peaks and its according HfO2-x sub-oxides for each device. The ultraviolet photoelectron spectroscopy (UPS) confirms different electron affinity (χ) of HfO2 and HfO2-x thin films, implying that barrier height at Ti/oxide interface is reduced. Current transport mechanism is dictated by Ohmic conduction in fully oxidized HfO2 thin films - Device A (0.7 s) and by Trap Filled Space Charge Limited Conduction (TF-SCLC) in less oxidized HfO2-x thin films - Device B (0.3 s) and Device C (0.1 s). A switching mechanism related to the oxygen vacancies modulation in Ti/HfO2-x/Pt based resistive random access memory (RRAM) devices is used to explain carefully notified current transport mechanism variations from device-to-device. A proper endurance and long-time retention characteristics of the devices are also obtained.

  4. A simple and efficient dispersion correction to the Hartree-Fock theory (3): A comprehensive performance comparison of HF-Dtq with MP2 and DFT-Ds.

    Science.gov (United States)

    Yoshida, Tatsusada; Hayashi, Takahisa; Mashima, Akira; Sasahara, Katsunori; Chuman, Hiroshi

    2016-01-15

    Accurate prediction of the intermolecular interaction energy (ΔEbind) has been a challenging and serious problem. Current in silico drug screening demands efficient and accurate evaluation of ΔEbind for ligands and their target proteins. It is desirable that ΔEbind including the dispersion interaction energy (Edisp) is calculated using a post-Hartree-Fock (HF) theory, such as the high-order coupled-cluster one, with a larger basis set. However, it remains computationally too expensive to apply such a one to large molecular systems. As another problem, it is necessary to consider the contribution of the basis set superposition error (BSSE) in calculation of ΔEbind. In Bioorg. Med. Chem. Lett. 2014 and 2015, we proposed simple and efficient corrections of dispersion and BSSE for the HF theory, which is not able to express the dispersion interaction energy correctly. The current Letter, as the final one in the series, aims to verify the HF theory enhanced by the dispersion correction (HF-Dtq) in the light of reproducibility of 'accurate' intermolecular ligand-protein interaction energy values, with comprehensive comparison with the MP2 and recently proposed various DFT-D theories. Taking ΔEbind calculated with the coupled-cluster theory coupled with a complete basis set as a reference, ΔEbind of over a hundred small sized noncovalent complexes as well as real ligand-protein complexes models was systematically examined in terms of accuracy and computational cost. The comprehensive comparison in the current work showed that HF-Dtq is a practical and reliable approach for in silico drug screening and quantitative structure-activity relationships. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Comparing LCZ696 with enalapril according to baseline risk using the MAGGIC and EMPHASIS-HF risk scores: an analysis of mortality and morbidity in PARADIGM-HF.

    Science.gov (United States)

    Simpson, Joanne; Jhund, Pardeep S; Silva Cardoso, Jose; Martinez, Felipe; Mosterd, Arend; Ramires, Felix; Rizkala, Adel R; Senni, Michele; Squire, Iain; Gong, Jianjian; Lefkowitz, Martin P; Shi, Victor C; Desai, Akshay S; Rouleau, Jean L; Swedberg, Karl; Zile, Michael R; McMurray, John J V; Packer, Milton; Solomon, Scott D

    2015-11-10

    Although most patients in the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial had mild symptoms, there is a poor correlation between reported functional limitation and prognosis in heart failure. The aim of this study was to examine the spectrum of risk in PARADIGM-HF and the effect of LCZ696 across that spectrum. This study analyzed rates of the primary composite outcome of cardiovascular death or heart failure hospitalization, its components, and all-cause mortality using the MAGGIC (Meta-Analysis Global Group in Chronic Heart Failure) and EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure) risk scores to categorize patients. The authors determined whether risk, on the basis of these scores, modified the treatment effect of LCZ696. The complete MAGGIC risk score was available for 8,375 of the 8,399 patients in PARADIGM-HF. The median MAGGIC score was 20 (IQR: 16 to 24). An increase of 1 point was associated with a 6% increased risk for the primary endpoint (p PARADIGM-HF patients had mild symptoms, many were at high risk for adverse outcomes and obtained a large absolute benefit from LCZ696, compared with enalapril, over a relatively short treatment period. LCZ696's benefit was consistent across the spectrum of risk. (PARADIGM-HF trial [Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure]; NCT01035255). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  6. Formation of Al2O3-HfO2 Eutectic EBC Film on Silicon Carbide Substrate

    Directory of Open Access Journals (Sweden)

    Kyosuke Seya

    2015-01-01

    Full Text Available The formation mechanism of Al2O3-HfO2 eutectic structure, the preparation method, and the formation mechanism of the eutectic EBC layer on the silicon carbide substrate are summarized. Al2O3-HfO2 eutectic EBC film is prepared by optical zone melting method on the silicon carbide substrate. At high temperature, a small amount of silicon carbide decomposed into silicon and carbon. The components of Al2O3 and HfO2 in molten phase also react with the free carbon. The Al2O3 phase reacts with free carbon and vapor species of AlO phase is formed. The composition of the molten phase becomes HfO2 rich from the eutectic composition. HfO2 phase also reacts with the free carbon and HfC phase is formed on the silicon carbide substrate; then a high density intermediate layer is formed. The adhesion between the intermediate layer and the substrate is excellent by an anchor effect. When the solidification process finished before all of HfO2 phase is reduced to HfC phase, HfC-HfO2 functionally graded layer is formed on the silicon carbide substrate and the Al2O3-HfO2 eutectic structure grows from the top of the intermediate layer.

  7. Radiation chemical behavior of Rh(III) in HClO4 and HNO3

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Khalkina, E.V.

    1995-01-01

    The radiation chemical behavior of Rh is very interesting since Rh accumulates in irradiated U but has not been reported in the literature. Scattered data do exist for the radiation chemical behavior of Rh(III) in weakly acidic and alkaline solutions. Pulsed radiolysis was used to investigate the formation of unstable oxidation states of Rh during reduction and oxidation of Rh(III) in neutral solutions. The rate constant of the reaction Rh(III) + e aq - was found to be 6·10 10 liter/mole·sec. The radiation chemical behavior of Rh(III) toward γ-radiolysis in neutral, weakly acidic (up to 0.1 N), and alkaline solutions was examined. In neutral solutions of [Rh(NH 3 ) 5 Cl]Cl 2 and RhCl 3 , metallic Rh is formed. The degree of reduction is ∼ 1%. In neutral and weakly acidic solutions of Rh(NO 3 ) 3 , Rh 2 O 3 ·xH 2 O is formed. Irradiation of Rh(ClO 4 ) 3 solutions produces no reduction. The radiation chemical behavior of Rh(III) in HClO 4 and HNO 3 solutions at concentrations > 1 M is studied in the present work

  8. The disposition and metabolism of /sup 14/C-tiaramide. HCl in man

    Energy Technology Data Exchange (ETDEWEB)

    Klunk, L.J.; Riska, P.S.; Maynard, D.E.

    The disposition and metabolism of /sup 14/C-tiaramide HCl was examined in four healthy male volunteers, after administration of a 200-mg dose in solution. The mean cumulative recovery of administered radioactivity was 91.3 +/- 2.9% (mean +/- SD) in urine an 6.0 +/- 1.5% in feces. The elimination was rapid, with 83.9% of the radioactivity extracted in urine in the first 12 hr. The unchanged tiaramide serum concentration curve showed monoexponential elimination with a half-life of 1.3 hr. Peak serum levels, of 1.6-2.2 micrograms/ml were attained between 0.5 and 1.5 hr after dosing. Tiaramide was extensively metabolized, with less than 1% excreted unchanged. Urinary metabolites (80-95% of the dose) were identified by mass-spectral comparison to authentic standards. Biotransformation resulted in production of the N-acetic acid N-oxide, N-acetic acid, O-glucuronide, N-oxide, and desethanol metabolites of tiaramide.

  9. Spectrophotometric Determination of Pipazethate HCl and Dextromethorphan HBr using Potassium Permanganate.

    Science.gov (United States)

    Gouda, Ayman Abou El-Fetouh; El-Sheikh, Ragaa; El Shafey, Zeineb; Hossny, Nagda; El-Azzazy, Rham

    2008-12-01

    Rapid, simple and sensitive validated spectrophotometric methods have been described for the assay of pipazethate HCl (PiCl) and dextromethorphan HBr (DEX) either in pure form or in pharmaceutical formulations. The proposed methods were based on the oxidation of the studied drugs by a known excess of potassium permanganate in acidic medium and estimating the unreacted permanganate with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. Beer's law is obeyed in the concentration range of 2.0-16 and 2.0-15 μg mL(-1) for PiCl and DEX, respectively with correlation coefficient (n=6) ≥ 0.9993. The apparent molar absorptivity and sandell sensitivity values are in the range 1.062-1.484 × 10(4), 3.35-4.51 × 10(4) L mol(-1) cm(-1) and 29.36-41.03, 8.21-11.06 ng cm(-2) for PiCl and DEX, respectively. Different variables affecting the reaction were studied and optimized. The proposed methods were applied successfully to the determination of the examined drugs either in a pure or pharmaceutical dosage forms with good accuracy and precision. No interferences were observed from excipients and the results obtained were in good agreement with those obtained using the official methods.

  10. Calcium pectinate-fenugreek seed mucilage mucoadhesive beads for controlled delivery of metformin HCl.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar; Das, Sabinesh

    2013-07-01

    Calcium pectinate-fenugreek seed mucilage (FSM) mucoadhesive beads containing metformin HCl was developed through ionic-gelation. Effects of pectin and FSM amounts on drug encapsulation efficiency (DEE) and cumulative drug release at 10h (R10 h) were optimized using 3(2) factorial design. The DEE (%) was within the range of 63.16 ± 2.88 to 96.03 ± 4.67% (w/w). The in vitro drug release from these beads (56.64 ± 1.47 to 93.63 ± 4.52% over 10h) was followed controlled-release (zero-order) pattern (R(2)=0.993 to 0.997) with super case-II transport mechanism. The average size of beads was within 1.47 ± 0.14 to 2.08 ± 0.18 mm. The beads were also characterized by SEM and FTIR. The swelling and mucoadhesivity of these beads were influenced by pH of the medium. The optimized beads also exhibited good mucoadhesivity and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Modification of the size of developing infarcts in the ligated dog heart by betahistine-HCL.

    Science.gov (United States)

    Terracio, L; Kubicek, W G

    1978-01-01

    The effectiveness of beta-histine-HCL in modifying the size of developing myocardial infarcts was tested in the surgically ligated dog. Branches of the left coronary artery were ligated and a 6-hour continuous intravenous infusion of 0.24 mg/kg/min of beta-histine was administered from 0 to 120 min after ligation. The effect of this treatment was evaluated histologically in studies on acute ischemia by the use of the hematoxylin-basic fuchsin-picric acid stain for early myocardial ischemia. The treatment was also evaluated grossly in a study on chronic ischemia where the dogs were permitted to survive for 30 days before sacrifice. In these experiments the size of infarcts found in the beta-histine-treated animals was compared with those found in the saline controls. Both studies showed that the control ligations produced a large uniform area of ischemia or infarction that was greatly reduced or prevented by immediate treatment with beta-histine. Also, beta-histine was capable of significantly reducing the size of developing infarcts for up to 120 min after ligation.

  12. Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles

    Science.gov (United States)

    Wang, Feng; Huang, Wei; Zhang, Shuai; Liu, Guokui; Li, Kexiang; Tang, Bo

    2011-03-01

    Ellagic acid (C 14H 6O 8), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0 × 10 -10 to 4.0 × 10 -5 mol L -1; and the detection limits are 3.2 × 10 -10 mol L -1 and 5.9 × 10 -10 mol L -1 excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

  13. Electrospun water soluble polymer mat for ultrafast release of Donepezil HCl

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available Electrostatic spinning (Electrospinning, ES was applied to prepare Donepezil HCl loaded nanofibers as a potential orally dissolving dosage form. Electrospinning of water solutions of different polymers were performed in order to fabricate a consistent and removable web on the collector with ultra-fast dissolution in water based media. Poly(vinyl-alcohol of low molecular weight was found to be the most appropriate for this purpose. Morphology of the prepared nanofibers was characterized by scanning electron microscope as a function of viscosity and drug content. Diameters of the fibers were between 100 and 300 nm with narrow distribution. In vitro drug release of the webs was immediate (less than 30 s after immersion independently of their drug content owing to the formed huge surface area, while cast films with the same compositions and commercial tablets needed 30 min or more for complete dissolution. The developed technology for the preparation of orally dissolving web (ODW formulations is a promising way for producing effective and acceptable dosage forms for children, older people and patients with dysphagia.

  14. CO- and HCl-free synthesis of acid chlorides from unsaturated hydrocarbons via shuttle catalysis

    Science.gov (United States)

    Fang, Xianjie; Cacherat, Bastien; Morandi, Bill

    2017-11-01

    The synthesis of carboxylic acid derivatives from unsaturated hydrocarbons is an important process for the preparation of polymers, pharmaceuticals, cosmetics and agrochemicals. Despite its industrial relevance, the traditional Reppe-type carbonylation reaction using pressurized CO is of limited applicability to laboratory-scale synthesis because of: (1) the safety hazards associated with the use of CO, (2) the need for special equipment to handle pressurized gas, (3) the low reactivity of several relevant nucleophiles and (4) the necessity to employ different, often tailor-made, catalytic systems for each nucleophile. Herein we demonstrate that a shuttle-catalysis approach enables a CO- and HCl-free transfer process between an inexpensive reagent, butyryl chloride, and a wide range of unsaturated substrates to access the corresponding acid chlorides in good yields. This new transformation provides access to a broad range of carbonyl-containing products through the in situ transformation of the reactive acid chloride intermediate. In a broader context, this work demonstrates that isodesmic shuttle-catalysis reactions can unlock elusive catalytic reactions.

  15. Preparation and characterization of polymeric and lipid nanoparticles of pilocarpine HCl for ocular application.

    Science.gov (United States)

    Lütfi, Genç; Müzeyyen, Demirel

    2013-01-01

    Pilocarpine is used topically in the treatment of glaucoma. Various studies were performed to improve the bioavailability and prolong the residence time of drugs in ocular drug delivery. Drug loaded polymeric and lipid nanoparticles offer several favourable biological properties, such as biodegradability, nontoxicity, biocompatibility and mucoadhesiveness. Therefore, preparing positively-charged pilocarpine HCl-loaded polymeric and lipid nanoparticles was the purpose of this study. Nanoparticles were prepared by quasi-emulsion solvent evaporation technique. The non-biodegradable positively-charged polymer Eudragit(®) RS 100 and semi-solid lipid excipient Gelucire(®) 44/14 were used as a vehicle, the cationic lipid octadecylamine was used as a cationic agent. The formulations were evaluated in terms of particle size, size distribution, zeta potential measurement, thermal behavior (Differential Scanning Calorimetry DSC), entrapment efficacy and pH. Characterizations of nanoparticles were analyzed during the storage period of 6 months for stability tests. Polymeric and lipid nanoparticles could be prepared successfully promising their use for ophthalmic delivery.

  16. PENGARUH KONSENTRASI HCl SEBAGAI PELARUT PADA EKSTRAKSI PEKTIN DARI LABU SIAM

    Directory of Open Access Journals (Sweden)

    Rinska Erwinda

    2014-10-01

    Full Text Available Labu siam (Sechium edule Sw merupakan salah satu jenis buah yang masih sangat terbatas penggunannya. Labu siam biasanya hanya dikonsumsi sebagai sayuran biasa seperti sayur labu dan sebagai lalapan. Untuk itu perlu dicari alternatif lain yang dapat lebih meningkatkan daya guna labu siam. Salah satu usaha yang dapat dilakukan adalah dengan mengekstrak pektinnya, karena pektin dapat digunakan secara luas pada berbagai industri. Penelitian ini bertujuan untuk mencari pengaruh konsentrasi pelarut terhadap rendemen pektin yang didapat dari buah labu siam. Pada penelitian ini, pengambilan pektin labu siam dilakukan dengan metode ekstraksi pelarut. Bahan baku sumber pektin adalah kulit dan daging buah labu siam. Variabel yang digunakan adalah perbandingan konsentrasi pelarut dengan berat kering buah labu siam konstan sebanyak 25 gram. Sebagai zat pengasam digunakan larutan HCl dengan konsentrasi 0,05; 0,1; 0,15; 0,2; 0,25 N. Hasil penelitian menunjukan bahwa rendemen pektin terbaik sebanyak  9,61% pada kondisi operasi ekstraksi sebagai berikut : konsentrasi pelarut 0,2 N, temperatur 90 oC dan waktu ekstraksi 120 menit.   Kata kunci :Pektin, Ekstraksi, Labu Siam, Pelarut, Asam Klorida

  17. Ionic exchange of Hf donor impurities in the wide-gap semiconductor Tm2O3

    International Nuclear Information System (INIS)

    Munoz, E.L.; Darriba, G.N.; Bibiloni, A.G.; Errico, L.A.; Renteria, M.

    2010-01-01

    The ionic exchange of Hf donor impurities in substitutional cationic sites of the cubic (bixbyite) phase of the wide-gap semiconductor Tm 2 O 3 was studied. The doping process was performed by ball-milling-assisted solid-state reaction of Tm 2 O 3 and neutron-activated m-HfO 2 . 181 Ta atoms, obtained by the β-decay of the 181 Hf-isotope, were used as probes in time-differential perturbed-angular-correlation (TDPAC) experiments carried out after each step of the doping process. The measured hyperfine interactions at 181 Ta sites enabled the electric-field gradient (EFG) characterization at representative Hf impurity sites of each step of the process. The efficiency and substitutional character of the exchange process is discussed and elucidated in the framework of an empirical EFG systematic established in isostructural rare-earth bixbyite sesquioxides.

  18. Luminescence and scintillation properties of Rb2HfCl6 crystals

    Science.gov (United States)

    Saeki, Keiichiro; Wakai, Yuki; Fujimoto, Yutaka; Koshimizu, Masanori; Yanagida, Takayuki; Nakauchi, Daisuke; Asai, Keisuke

    2016-11-01

    We developed a scintillator based on a Rb2HfCl6 crystal as a ternary halide crystal with intrinsic luminescence. In the photoluminescence spectra, two emission bands are observed at 383 and 434 nm. The 434 nm emission band for Rb2HfCl6 may be attributed to [HfCl6]2- complex ion or [ZrCl6]2- impurity, since the Rb2HfCl6 contained Zr as impurity at 0.62 mol %. The radioluminescence band is observed at 420 nm and can be attributed to the same origin as the photoluminescence band at 434 nm. The scintillation decay-time constants were 0.84 and 5.4 µs. The light yield was estimated to be 24,100 photons/MeV.

  19. Operational oil spill trajectory modelling using HF radar currents: A northwest European continental shelf case study.

    Science.gov (United States)

    Abascal, Ana J; Sanchez, Jorge; Chiri, Helios; Ferrer, María I; Cárdenas, Mar; Gallego, Alejandro; Castanedo, Sonia; Medina, Raúl; Alonso-Martirena, Andrés; Berx, Barbara; Turrell, William R; Hughes, Sarah L

    2017-06-15

    This paper presents a novel operational oil spill modelling system based on HF radar currents, implemented in a northwest European shelf sea. The system integrates Open Modal Analysis (OMA), Short Term Prediction algorithms (STPS) and an oil spill model to simulate oil spill trajectories. A set of 18 buoys was used to assess the accuracy of the system for trajectory forecast and to evaluate the benefits of HF radar data compared to the use of currents from a hydrodynamic model (HDM). The results showed that simulated trajectories using OMA currents were more accurate than those obtained using a HDM. After 48h the mean error was reduced by 40%. The forecast skill of the STPS method was valid up to 6h ahead. The analysis performed shows the benefits of HF radar data for operational oil spill modelling, which could be easily implemented in other regions with HF radar coverage. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  20. Reducing the stoichiometric excess of HF in the hydrofluorination of UO2

    International Nuclear Information System (INIS)

    Zhao Jun; Qiu Lufu; Zhong Xing; Xu Heqing

    1989-11-01

    In a fluidized bed, UO 2 obtained from the decomposition-reduction of AUC (Ammonium Uranyl Carbonate) was fed to absorb HF remaining in the exhaust gas of UF 4 production process. In the case of 60% conversion of UO 2 and the reaction temperature in the region of 300 deg C, HF remaining in the exhaust gas in absorbing fluidized bed was less than 7 ∼ 8% (w/w), i.e. apparent stoichiometric excess of HF had reduced to 0% more or less. Hence, with the high hydrofluorination reactivity of UO 2 obtained from the decomposition-reduction of AUC, it is possible to reduce evidently the stoichiometric excess of HF in the hydrofluorination process by two fluidized beds in series in which solids move against the gas flow

  1. HF183/BFDrev and HumM2 qPCR data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Concentration estimates for HF183/BFDrev and HumM2 qPCR genetic markers in raw sewage collected from 54 geographic locations across the United States. This dataset...

  2. Luminescence and scintillation properties of Rb2HfCl6 crystals

    International Nuclear Information System (INIS)

    Saeki, Keiichiro; Wakai, Yuki; Fujimoto, Yutaka; Koshimizu, Masanori; Asai, Keisuke; Yanagida, Takayuki; Nakauchi, Daisuke

    2016-01-01

    We developed a scintillator based on a Rb 2 HfCl 6 crystal as a ternary halide crystal with intrinsic luminescence. In the photoluminescence spectra, two emission bands are observed at 383 and 434 nm. The 434 nm emission band for Rb 2 HfCl 6 may be attributed to [HfCl 6 ] 2- complex ion or [ZrCl 6 ] 2- impurity, since the Rb 2 HfCl 6 contained Zr as impurity at 0.62 mol %. The radioluminescence band is observed at 420 nm and can be attributed to the same origin as the photoluminescence band at 434 nm. The scintillation decay-time constants were 0.84 and 5.4 μs. The light yield was estimated to be 24,100 photons/MeV. (author)

  3. Effects of Vitamin D on Cardiac Function in Patients With Chronic HF: The VINDICATE Study.

    Science.gov (United States)

    Witte, Klaus K; Byrom, Rowena; Gierula, John; Paton, Maria F; Jamil, Haqeel A; Lowry, Judith E; Gillott, Richard G; Barnes, Sally A; Chumun, Hemant; Kearney, Lorraine C; Greenwood, John P; Plein, Sven; Law, Graham R; Pavitt, Sue; Barth, Julian H; Cubbon, Richard M; Kearney, Mark T

    2016-06-07

    Patients with chronic heart failure (HF) secondary to left ventricular systolic dysfunction (LVSD) are frequently deficient in vitamin D. Low vitamin D levels are associated with a worse prognosis. The VINDICATE (VitamIN D treatIng patients with Chronic heArT failurE) study was undertaken to establish safety and efficacy of high-dose 25 (OH) vitamin D3 (cholecalciferol) supplementation in patients with chronic HF due to LVSD. We enrolled 229 patients (179 men) with chronic HF due to LVSD and vitamin D deficiency (cholecalciferol vitamin D3 supplementation (4,000 IU [100 μg] daily) or matching non-calcium-based placebo. The primary endpoint was change in 6-minute walk distance between baseline and 12 months. Secondary endpoints included change in LV ejection fraction at 1 year, and safety measures of renal function and serum calcium concentration assessed every 3 months. One year of high-dose vitamin D3 supplementation did not improve 6-min walk distance at 1 year, but was associated with a significant improvement in cardiac function (LV ejection fraction +6.07% [95% confidence interval (CI): 3.20 to 8.95; p vitamin D3 supplementation does not improve 6-min walk distance but has beneficial effects on LV structure and function in patients on contemporary optimal medical therapy. Further studies are necessary to determine whether these translate to improvements in outcomes. (VitamIN D Treating patIents With Chronic heArT failurE [VINDICATE]; NCT01619891). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc

    Energy Technology Data Exchange (ETDEWEB)

    Yogodzinski, Gene; Vervoort, Jeffery; Brown, Shaun Tyler; Gerseny, Megan

    2010-08-29

    The Hf and Nd isotopic compositions of 71 Quaternary lavas collected from locations along the full length of the Aleutian island arc are used to constrain the sources of Aleutian magmas and to provide insight into the geochemical behavior of Nd and Hf and related elements in the Aleutian subduction-magmatic system. Isotopic compositions of Aleutian lavas fall approximately at the center of, and form a trend parallel to, the terrestrial Hf-Nd isotopic array with {var_epsilon}{sub Hf} of +12.0 to +15.5 and {var_epsilon}{sub Nd} of +6.5 to +10.5. Basalts, andesites, and dacites within volcanic centers or in nearby volcanoes generally all have similar isotopic compositions, indicating that there is little measurable effect of crustal or other lithospheric assimilation within the volcanic plumbing systems of Aleutian volcanoes. Hafnium isotopic compositions have a clear pattern of along-arc increase that is continuous from the eastern-most locations near Cold Bay to Piip Seamount in the western-most part of the arc. This pattern is interpreted to reflect a westward decrease in the subducted sediment component present in Aleutian lavas, reflecting progressively lower rates of subduction westward as well as decreasing availability of trench sediment. Binary bulk mixing models (sediment + peridotite) demonstrate that 1-2% of the Hf in Aleutian lavas is derived from subducted sediment, indicating that Hf is mobilized out of the subducted sediment with an efficiency that is similar to that of Sr, Pb and Nd. Low published solubility for Hf and Nd in aqueous subduction fluids lead us to conclude that these elements are mobilized out of the subducted component and transferred to the mantle wedge as bulk sediment or as a silicate melt. Neodymium isotopes also generally increase from east to west, but the pattern is absent in the eastern third of the arc, where the sediment flux is high and increases from east to west, due to the presence of abundant terrigenous sediment in the

  5. Finishing and Commissioning the New Arecibo HF Facility

    Science.gov (United States)

    Sulzer, M. P.; Gonzalez, S. A.

    2011-12-01

    The imminent completion of the major tasks in the construction of the New Arecibo HF facility means that we must verify that the components are working as intended. The antenna system and the transmitters must be separately commissioned before they can be connected together so that we an be sure it will provide 83 dbW at 8.175 MHz, and 80 dbW at 5.1 MHz. The antenna system will be ready for initial testing in September. It Illuminates the 305 meter dish using dipoles near the surface of the dish transmitting upward to a wire mesh sub-reflector. There are three crossed dipoles for each of the two frequencies. The dipoles are supported on towers mounted on concrete pads underneath the dish. Each dipole element is connected to a transmitter through a three inch coax line. The tower foundations are nearly complete, and the towers will be erected in early September, and we expect to have at least one crossed dipole in place for initial testing by the end of September. We will need to make some measurements on the antenna system to ensure that it meets our requirements. One requirement is to match the antenna impedance to the transmission line and the transmitter closely enough to meet the transmitter specifications, the closer, the better. We have additional requirements; for example, it is necessary for efficient use of the facility that the polarization be close to circular. In most experiments, we want O mode excitation. If we were to transmit linear only half the power would reach the reflection height. The symmetry of the system assures that most of the conditions for achieving accurate circular polarization are met, but one condition is not: that exciting the transmitters driving the orthogonal elements at 90 degrees assures 90 degree separation in the corresponding antenna currents. One of the dipoles of each pair points toward the center of the array. If we think of the three crossed dipoles as consisting of a reference and two that are excited relative to it

  6. Theoretical predictions of properties and volatility of chlorides and oxychlorides of group-4 elements. II. Adsorption of tetrachlorides and oxydichlorides of Zr, Hf, and Rf on neutral and modified surfaces

    International Nuclear Information System (INIS)

    Pershina, V.; Borschevsky, A.; Iliaš, M.; Türler, A.

    2014-01-01

    With the aim to interpret results of gas-phase chromatography experiments on volatility of group-4 tetrachlorides and oxychlorides including those of Rf, adsorption enthalpies of these species on neutral, and modified quartz surfaces were estimated on the basis of relativistic, two-component Density Functional Theory calculations of MCl 4 , MOCl 2 , MCl 6 − , and MOCl 4 2 with the use of adsorption models. Several mechanisms of adsorption were considered. In the case of physisorption of MCl 4 , the trend in the adsorption energy in the group should be Zr > Hf > Rf, so that the volatility should change in the opposite direction. The latter trend complies with the one in the sublimation enthalpies, ΔH sub , of the Zr and Hf tetrachlorides, i.e., Zr < Hf. On the basis of a correlation between these quantities, ΔH sub (RfCl 4 ) was predicted as 104.2 kJ/mol. The energy of physisorption of MOCl 2 on quartz should increase in the group, Zr < Hf < Rf, as defined by increasing dipole moments of these molecules along the series. In the case of adsorption of MCl 4 on quartz by chemical forces, formation of the MOCl 2 or MOCl 4 2− complexes on the surface can take place, so that the sequence in the adsorption energy should be Zr > Hf > Rf, as defined by the complex formation energies. In the case of adsorption of MCl 4 on a chlorinated quartz surface, formation of the MCl 6 2− surface complexes can occur, so that the trend in the adsorption strength should be Zr ≤ Hf < Rf. All the predicted sequences, showing a smooth change of the adsorption energy in the group, are in disagreement with the reversed trend Zr ≈ Rf < Hf, observed in the “one-atom-at-a-time” gas-phase chromatography experiments. Thus, currently no theoretical explanation can be found for the experimental observations

  7. Physical and electrical characteristics of atomic-layer-deposited Hf-silicate thin films using Hf[N(CH{sub 3})(C{sub 2}H{sub 5})]{sub 4} and SiH[N(CH{sub 3}){sub 2}]{sub 3} precursors

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K. B.; Whang, C. N.; Yim, C. J.; Ko, D. H. [Yonsei University, Seoul (Korea, Republic of); Cho, M. H. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Y. S.; Kim, M. J.; Lee, J. H.; Lee, N. I. [Samsung Electronics Co. Ltd., Yongin (Korea, Republic of)

    2006-04-15

    Hf-silicate films were grown by using atomic layer deposition with Hf[N(CH{sub 3})(C{sub 2}H{sub 5})]{sub 4} and SiH[N(CH{sub 3}){sub 2}]{sub 3} precursors. The composition of the Hf-silicate films was excellently well controlled by using the ratio of the deposition cycles of HfO{sub 2} and SiO{sub 2} (Hf/Si). The physical and the electrical characteristics of the Hf-silicate films were compared for Hf/Si = 3/1, Hf/Si = 1/1, and Hf/Si = 1/3. The relative Hf/(Hf+Si) compositions were 58 %, 41 %, and 25 % for Hf/Si = 3/1, Hf/Si = 1/1, and Hf/Si = 1/3, respectively. The binding characteristics of the Hf-silicate films were shifted in the direction of higher binding energy with increasing of SiO{sub 2} portion, resulting in electric charging. The molecular structure of the Hf-silicate films was changed by the relative compositions of HfO{sub 2} and SiO{sub 2}. In addition, the dielectric characteristics of the Hf-silicate films were directly proportional to the HfO{sub 2} portion.

  8. Low modulus Ti–Nb–Hf alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    González, M., E-mail: Marta.Gonzalez.Colominas@upc.edu [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Peña, J. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Materials Science, Elisava Escola Superior de Disseny i Enginyeria de Barcelona, La Rambla 30-32, 08002 Barcelona (Spain); Gil, F.J.; Manero, J.M. [Department of Materials Science and Metallurgy, Universitat Politècnica de Catalunya (UPC), Avda. Diagonal 647, 08028 Barcelona (Spain); Ciber-BBN (Spain)

    2014-09-01

    β-Type titanium alloys with a low elastic modulus are a potential strategy to reduce stress shielding effect and to enhance bone remodeling in implants used to substitute failed hard tissue. For biomaterial application, investigation on the mechanical behavior, the corrosion resistance and the cell response is required. The new Ti25Nb16Hf alloy was studied before and after 95% cold rolling (95% C.R.). The mechanical properties were determined by tensile testing and its corrosion behavior was analyzed by potentiostatic equipment in Hank's solution at 37 °C. The cell response was studied by means of cytotoxicity evaluation, cell adhesion and proliferation measurements. The stress–strain curves showed the lowest elastic modulus (42 GPa) in the cold worked alloy and high tensile strength, similar to that of Ti6Al4V. The new alloy exhibited better corrosion resistance in terms of open circuit potential (E{sub OCP}), but was similar in terms of corrosion current density (i{sub CORR}) compared to Ti grade II. Cytotoxicity studies revealed that the chemical composition of the alloy does not induce cytotoxic activity. Cell studies in the new alloy showed a lower adhesion and a higher proliferation compared to Ti grade II presenting, therefore, mechanical features similar to those of human cortical bone and, simultaneously, a good cell response. - Highlights: • Presents low elastic modulus and high strength and elastic deformability. • Exhibits good biocompatibility in terms of cytotoxicity and cell response. • Corrosion resistance of this alloy is good, similar to that of Ti grade II. • Potential candidate for implants used to substitute failed hard tissue.

  9. Hydrogen fluoride (HF) substance flow analysis for safe and sustainable chemical industry.

    Science.gov (United States)

    Kim, Junbeum; Hwang, Yongwoo; Yoo, Mijin; Chen, Sha; Lee, Ik-Mo

    2017-11-01

    In this study, the chemical substance flow of hydrogen fluoride (hydrofluoric acid, HF) in domestic chemical industries in 2014 was analyzed in order to provide a basic material and information for the establishment of organized management system to ensure safety during HF applications. A total of 44,751 tons of HF was made by four domestic companies (in 2014); import amount was 95,984 tons in 2014 while 21,579 tons of HF was imported in 2005. The export amount of HF was 2180 tons, of which 2074 ton (China, 1422 tons, U.S. 524 tons, and Malaysia, 128 tons) was exported for the manufacturing of semiconductors. Based on the export and import amounts, it can be inferred that HF was used for manufacturing semiconductors. The industries applications of 161,123 tons of HF were as follows: manufacturing of basic inorganic chemical substance (27,937 tons), manufacturing of other chemical products such as detergents (28,208 tons), manufacturing of flat display (24,896 tons), and manufacturing of glass container package (22,002 tons). In this study, an analysis of the chemical substance flow showed that HF was mainly used in the semiconductor industry as well as glass container manufacturing. Combined with other risk management tools and approaches in the chemical industry, the chemical substance flow analysis (CSFA) can be a useful tool and method for assessment and management. The current CSFA results provide useful information for policy making in the chemical industry and national systems. Graphical abstract Hydrogen fluoride chemical substance flows in 2014 in South Korea.

  10. The production of Hf and the fluoride industry in South Africa

    International Nuclear Information System (INIS)

    Du Preez, D.J.

    1988-01-01

    The production, properties and handling of hydrofluoric acid is sketched. The present and potential uses of HF and its by products in South Africa is given. An overview of the use of HF in the nuclear industry is given with specific emphasis on the local development of technology. A brief look is taken at possible future development vis-a-vis the Atomic Energy Corporation and local industry

  11. Effects of high-latitude atmospheric gravity wave disturbances on artificial HF radar backscatter

    OpenAIRE

    A. Senior; M. J. Kosch; T. K. Yeoman; M. T. Rietveld; I. W. McCrea

    2006-01-01

    International audience; Observations of HF radar backscatter from artificial field-aligned irregularities in an ionosphere perturbed by travelling disturbances due to atmospheric gravity waves are presented. Some features of the spatio-temporal structure of the artificial radar backscatter can be explained in terms of the distortion of the ionosphere resulting from the travelling disturbances. The distorted ionosphere can allow the HF pump wave to access upper-hybrid resonance at larger dista...

  12. The Farsi version of the Hypomania Check-List 32 (HCL-32): applicability and indication of a four-factorial solution.

    Science.gov (United States)

    Haghighi, Mohammad; Bajoghli, Hafez; Angst, Jules; Holsboer-Trachsler, Edith; Brand, Serge

    2011-01-20

    Data from the Iranian population for hypomania core symptom clusters are lacking. The aim of the present study was therefore to apply the Farsi version of the Hypomania-Check-List 32 (HCL-32), and to explore its factorial structure. A total of 163 Iranian out-patients took part in the study; 61 suffered from Major Depressive Disorder (MDD), and 102 suffered from Bipolar Disorders (BP). Participants completed the Mood Disorder Questionnaire (MDQ) and the Hypomania Checklist (HCL-32). Exploratory factor analyses were used to examine the properties of the HCL-32. A ROC-curve analysis was performed to calculate sensitivity and specificity. The HCL-32 differentiated between patients with MDD and with BP. Psychometric properties were satisfactory: sensitivity: 73%; specificity: 91%. MDQ and HCL-32 did correlate highly. No differences were found between patients suffering from BP I and BP II. Instead of the two-factorial structure of the HCL-32 reported previously, the present pattern of factorial results suggest a distinction between four factors: two broadly positive dimensions of hypomania ("physically and mentally active"; "positive social interactions") and two rather negative dimensions ("risky behavior and substance use"; "difficulties in social interaction and impatience"). The Farsi version of the HCL-32 proved to be applicable, and therefore easy to introduce within a clinical context. The pattern of results suggests a four factorial solution.

  13. Density functional study of S(N) 2 substitution reactions for CH(3) Cl + CX(1) X(2•-) (X(1) X(2) = HH, HF, HCl, HBr, HI, FF, ClCl, BrBr, and II).

    Science.gov (United States)

    Liang, Jun-Xi; Geng, Zhi-Yuan; Wang, Yong-Cheng

    2012-03-05

    A systematic investigation on the S(N) 2 displacement reactions of nine carbene radical anions toward the substrate CH(3) Cl has been theoretically carried out using the popular density functional theory functional BHandHLYP level with different basis sets 6-31+G (d, p)/relativistic effective core potential (RECP), 6-311++G (d, p)/RECP, and aug-cc-pVTZ/RECP. The studied models are CX(1) X(2•-) + CH(3) Cl → X(2) X(1) CH(3) C(•) + Cl(-) , with CX(1) X(2•-) = CH(2) (•-) , CHF(•-) , CHCl(•-) , CHBr(•-) , CHI(•-) , CF(2) (•-) , CCl(2) (•-) , CBr(2) (•-) , and CI(2) (•-) . The main results are proposed as follows: (a) Based on natural bond orbital (NBO), proton affinity (PA), and ionization energy (IE) analysis, reactant CH(2) (•-) should be a strongest base among the anion-containing species (CX(1) X(2•-) ) and so more favorable nucleophile. (b) Regardless of frontside attacking pathway or backside one, the S(N) 2 reaction starts at an identical precomplex whose formation with no barrier. (c) The back-S(N) 2 pathway is much more preferred than the front-S(N) 2 one in terms of the energy gaps [ΔE cent≠(front)-ΔE cent≠(back)], steric demand, NBO population analysis. Thus, the back-S(N) 2 reaction was discussed in detail. On the one hand, based on the energy barriers (ΔE cent≠ and ΔE ovr≠) analysis, we have strongly affirmed that the stabilization of back attacking transition states (b-TSs) presents increase in the order: b-TS-CI(2) < b-TS-CBr(2) < b-TS-CCl(2) < b-TS-CHI < b-TS-CHBr < b-TS-CHCl < b-TS-CF(2) < b-TS-CHF < b-TS-CH(2) . On the other hand, depended on discussions of the correlations of ΔE ovr≠ with influence factors (PA, IE, bond order, and ΔE def≠), we have explored how and to what extent they affect the reactions. Moreover, we have predicted that the less size of substitution (α-atom) required for the gas-phase reaction with α-nucleophile is related to the α-effect and estimated that the reaction with the stronger PA nucleophile, holding the lighter substituted atom, corresponds to the greater exothermicity given out from reactants to products. Copyright © 2012 Wiley Periodicals, Inc.

  14. HfCo7-Based Rare-Earth-Free Permanent-Magnet Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Das, B; Balamurugan, B; Kumar, P; Skomski, R; Shah, VR; Shield, JE; Kashyap, A; Sellmyer, DJ

    2013-07-01

    This study presents the structural and magnetic properties of melt-spun HfCo7, HfCo7-xFex (0.25 <= x <=), and HfCo7Six (0.2 <= x <= 1.2) alloys. Appreciable permanent-magnet properties with a magnetocrystalline anisotropy of about 9.6-16.5, Mergs/cm(3), a magnetic polarization J(s) approximate to 7.2-10.6 kG, and coercivities H-c = 0.5-3.0 kOe were obtained by varying the composition of these alloys. Structural analysis reveals that the positions of x-ray diffraction peaks of HfCo7 show good agreement with those corresponding to an orthorhombic structure having lattice parameters of about a = 4.719 angstrom, b = 4.278 angstrom, and c = 8.070 angstrom. Based on these results, a model crystal structure for HfCo7 is developed and used to estimate the magnetic properties of HfCo7 using density-functional calculations, which agree with the experimental results.

  15. Positions of sources of lightning-related HF signatures measured by the DEMETER satellite

    Science.gov (United States)

    Pisa, D.; Santolik, O.; Parrot, M.

    2010-12-01

    We present results of a systematic analysis of high-frequency pulses observed by the HF instrument on-board the DEMETER satellite. These broadband pulses extend from a lower frequency cutoff up to the upper frequency limit of the HF instrument (3.3 MHz). We can observe them only during the night-time since during the day-time the cutoff frequency is above the upper frequency limit of the HF instrument. These signatures are mostly observed between June and August above South America and South Africa. We have composed a database of these events observed between 2005 and 2010. For several events observed during the burst mode, we show connection between lightning discharges and HF signatures based on the plane wave analysis of the waveforms in the ELF/VLF range. We use a reverse ray tracing method for calculation of the expected position of the causative lightning discharges for the selected HF signatures. We also present examples of the signatures and their global distribution. This investigation covers the lower part of the frequency range of the HF wave instrument which is being prepared for the TARANIS mission.

  16. Electric field gradients at 181Ta sites in HfOx

    International Nuclear Information System (INIS)

    Darriba, G.N.; Rodriguez, A.M.; Saitovitch, H.; Silva, P.R.J.; Pasquevich, A.F.

    2007-01-01

    In the present work we report preliminary results about the possibility to study properties of the order-disorder transition in HfO x solid solutions via the determination of the electric field gradient (EFG) at 181 Ta radioactive probes. Oxygen solution into the metal was achieved by arc melting stoichiometric amounts of metallic Hf and HfO 2 under argon atmosphere. Samples of HfO x with x=0.1 and 0.2 were prepared. Two types of samples were used for the perturbed angular correlation (PAC) experiments by doping alternatively with 181 Ta, by neutron irradiation, the metallic Hf or the hafnium oxide. The PAC results on both samples were identical, with disappearing hyperfine signals of the metal and the oxide, showing a complete diffusion of the probes independent of the way of doping. The PAC signal of the HfO x solid solution consisted in a wide distribution of EFGs due to the oxygen disorder. This scheme held even after long thermal treatments at high temperature (several days at 1273K). Annealing treatments at moderate temperature (600K) were also made. In these cases the samples were cooling at a very low rate. These results, together with those obtained by measuring samples below and above the order temperature are reported

  17. Oxidation Study of an Ultra High Temperature Ceramic Coatings Based on HfSiCN

    Science.gov (United States)

    Sacksteder, Dagny; Waters, Deborah L.; Zhu, Dongming

    2018-01-01

    High temperature fiber-reinforced ceramic matrix composites (CMCs) are important for aerospace applications because of their low density, high strength, and significantly higher-temperature capabilities compared to conventional metallic systems. The use of the SiCf/SiC and Cf/SiC CMCs allows the design of lighter-weight, more fuel efficient aircraft engines and also more advanced spacecraft airframe thermal protection systems. However, CMCs have to be protected with advanced environmental barrier coatings when they are incorporated into components for the harsh environments such as in aircraft engine or spacecraft applications. In this study, high temperature oxidation kinetics of an advanced HfSiCN coating on Cf/SiC CMC substrates were investigated at 1300 C, 1400 C, and 1500 C by using thermogravimetric analysis (TGA). The coating oxidation reaction parabolic rate constant and activation energy were estimated from the experimental results. The oxidation reaction studies showed that the coatings formed the most stable, predominant HfSiO4-HfO2 scales at 1400 C. A peroxidation test at 1400 C then followed by subsequent oxidation tests at various temperatures also showed more adherent scales and slower scale growth because of reduced the initial transient oxidation stage and increased HfSiO4-HfO2 content in the scales formed on the HfSiCN coatings.

  18. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    2003-04-01

    Full Text Available Peculiar near range echoes observed in summer with the SuperDARN HF radar in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant ranges of 105–250 km for about 100 min. Interferometer measurements indicate that the echoes are returned from 80–100 km altitudes with elevation angles of 20°–60°. Echo power (< 16 dB, Doppler velocity (between –30 and + 30 ms-1 and spectral width (< 60 ms-1 fluctuate with periods of several to 20 min, perhaps due to short–period atmospheric gravity waves. When the HF radar detected the echoes, a vertical incidence MST radar, located at Esrange in Sweden (650 km north of the HF radar site, observed polar mesosphere summer echoes (PMSE at altitudes of 80–90 km. This fact suggests that the near range HF echoes are PMSE at HF band, although both radars did not probe a common volume. With increasing radar frequency, HF echo ranges are closer to the radar site and echo power becomes weaker. Possible mechanisms to explain these features are discussed.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides; instruments and techniques

  19. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    Directory of Open Access Journals (Sweden)

    T. Ogawa

    Full Text Available Peculiar near range echoes observed in summer with the SuperDARN HF radar in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant ranges of 105–250 km for about 100 min. Interferometer measurements indicate that the echoes are returned from 80–100 km altitudes with elevation angles of 20°–60°. Echo power (< 16 dB, Doppler velocity (between –30 and + 30 ms-1 and spectral width (< 60 ms-1 fluctuate with periods of several to 20 min, perhaps due to short–period atmospheric gravity waves. When the HF radar detected the echoes, a vertical incidence MST radar, located at Esrange in Sweden (650 km north of the HF radar site, observed polar mesosphere summer echoes (PMSE at altitudes of 80–90 km. This fact suggests that the near range HF echoes are PMSE at HF band, although both radars did not probe a common volume. With increasing radar frequency, HF echo ranges are closer to the radar site and echo power becomes weaker. Possible mechanisms to explain these features are discussed.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; thermospheric dynamics; waves and tides; instruments and techniques

  20. 1,25-Dihydroxyvitamin D3 but not cinacalcet HCl (Sensipar/Mimpara) treatment mediates aortic calcification in a rat model of secondary hyperparathyroidism.

    Science.gov (United States)

    Henley, Charles; Colloton, Matt; Cattley, Russell C; Shatzen, Edward; Towler, Dwight A; Lacey, David; Martin, David

    2005-07-01

    Calcitriol treatment of secondary hyperparathyroidism (HPT) in chronic kidney disease (CKD) patients can lead to increased serum calcium and phosphorus, which have been associated as risk factors for vascular calcification. Cinacalcet HCl (Sensipar/Mimpara) {(alphaR)-(-)-alpha-methyl-N-[3-[3-(trifluoromethylphenyl)propyl]-1-napthalenemethanamine hydrochloride} lowers serum parathyroid hormone (PTH), calcium, phosphorus and calcium-phosphorous (CaxP) product in stage 5 CKD dialysis patients; however, its effects on vascular calcification are unknown. Cinacalcet HCl (10 or 1 mg/kg, p.o. gavage), 1,25-dihydroxyvitamin D(3) (0.1 microg, s.c, calcitriol) or the combination was administered daily for 26 days in a rat model of secondary HPT [5/6 nephrectomy]. After dosing, aortic calcification was determined using the von Kossa staining method. Serum PTH and blood chemistries were determined on days 0, 26 and 0, 14, 26, respectively, prior to and after dosing. Calcitriol-treated rats had moderate to marked aortic calcification, whereas no significant calcification was observed in vehicle- or cinacalcet HCl-only treated groups. Co-administration of cinacalcet HCl with calcitriol did not attenuate the calcitriol-mediated increase in CaxP product or calcitriol-mediated aortic calcification. Both calcitriol and cinacalcet HCl therapy significantly reduced serum PTH levels. Calcitriol significantly elevated serum calcium, serum phosphorous and CaxP product above pretreatment levels, or those seen with vehicle or cinacalcet HCl. Cinacalcet HCl (10 or 1 mg/kg) decreased serum ionized calcium and decreased calcitriol-induced hypercalcaemia. Cinacalcet HCl and calcitriol both effectively reduce PTH, albeit via different mechanisms, but unlike calcitriol, cinacalcet HCl did not produce hypercalcaemia, an increased CaxP product or vascular calcification.

  1. Laser detection of spin-polarized hydrogen from HCl and HBr photodissociation: comparison of H- and halogen-atom polarizations.

    Science.gov (United States)

    Sofikitis, Dimitris; Rubio-Lago, Luis; Bougas, Lykourgos; Alexander, Andrew J; Rakitzis, T Peter

    2008-10-14

    Thermal HCl and HBr molecules were photodissociated using circularly polarized 193 nm light, and the speed-dependent spin polarization of the H-atom photofragments was measured using polarized fluorescence at 121.6 nm. Both polarization components, described by the a(0)(1)(perpendicular) and Re[a(1)(1)(parallel, perpendicular)] parameters which arise from incoherent and coherent dissociation mechanisms, are measured. The values of the a(0)(1)(perpendicular) parameter, for both HCl and HBr photodissociation, are within experimental error of the predictions of both ab initio calculations and of previous measurements of the polarization of the halide cofragments. The experimental and ab initio theoretical values of the Re[a(1)(1)(parallel, perpendicular)] parameter show some disagreement, suggesting that further theoretical investigations are required. Overall, good agreement occurs despite the fact that the current experiments photodissociate molecules at 295 K, whereas previous measurements were conducted at rotational temperatures of about 15 K.

  2. State-to-state inelastic scattering of OH by HI: a comparison with OH-HCl and OH-HBr.

    Science.gov (United States)

    Moise, A; Parker, D H; ter Meulen, J J

    2007-03-28

    Relative state-to-state cross sections and steric asymmetries have been measured for the scattering process: OH (X (2)Pi(32),v=0,J=32,M(J)=32,f)+HI ((1)Sigma,v=0,JOH (X (2)Pi,v=0,Omega=12,J=12-52 and Omega=32,J=32-92,ef)+HI, at 690 cm(-1) collision energy. Comparison with the previously studied systems OH-HCl and OH-HBr reveals relevant features of the potential energy surfaces of these molecular systems. Some measured differences concerning the internal energy distribution after collision and the propensities for the impact with one or the other side of the OH molecule in scattering by HCl, HBr, and HI molecules are discussed.

  3. Evaluation of Resin Regeneration Using HCl and H2SO4 for the Ion Exchanger of Copper

    International Nuclear Information System (INIS)

    Prayitno; Djoko Sardjono

    2002-01-01

    The experimental investigation on the regeneration of resin using HCl and H 2 SO 4 with its varian concentration of 1; 2.5; 2; 2.5 and 3 N and the stirring time was 5; 10; 15; 20; and 25 minutes. For evaluating their effectiveness on the separation of ion copper in the waste with concentration 500 ppm. Experimentally this investigation is the first step of resin results of regeneration process usage as an alternative resin for the treatment of liquid waste containing especially copper. The experimental resulted by mixing the feed copper waste with resin after regeneration. Therefore it could be concluded that the most effective regeneration was obtained with HCl as the regeneration of concentration 2 N and the stirring time 15 minutes with the percentage of separation used of 85.1 %. (author)

  4. Unusual mechanisms can dominate reactions at hyperthermal energies: an example from O(3P) + HCl --> ClO + H.

    Science.gov (United States)

    Zhang, Jianming; Camden, Jon P; Brunsvold, Amy L; Upadhyaya, Hari P; Minton, Timothy K; Schatz, George C

    2008-07-16

    An unusual mechanism in the reaction, O(3P) + HCl --> ClO + H, dominates at hyperthermal collision energies. This mechanism applies to collision geometries in which the H atom in the HCl molecule is oriented toward the reagent O atom. As the Cl-O bond forms, the H atom experiences a strong repulsive force from both the O and Cl atoms. The ClO product scatters forward with respect to the initial velocity of the O atom, and the H atom scatters backward. This mechanism accounts for more than half the reactive trajectories at energies >110 kcal mol-1, but it does not involve motion near the minimum energy path, which favors an SN2-like reaction mechanism where the H atom is oriented away from the reagent O atom during the collision.

  5. Complexing of rhenium(5) with 4-methyl-1,2,4-triazolethiol-5 in the medium of 6 M HCl

    International Nuclear Information System (INIS)

    Amindzhanov, A.A.; Safarmamadov, S.M.

    1993-01-01

    Reversibility of R-S-S-R/RS redox system, where RS -4-methyl-1,2,4-triazolethiol-5, on platinum electrode was established. Values of the real system potential in 273-338 K range were determined. Potentiometric method was used to determine the stepwise stability contants of oxochloro-4-methyl-1,2,4-triazolethiol rhenium(5) complexes in the medium of 6 M HCl at different temperatures. It was established that introduction of triazole ring of methyl group to position 4 resulted to decrease of complex stability. Thermodynamic functions of complexing process in H 2 ReOCl 5 -4-methyl-1,2,4-triazolethiol-5 - 6 M HCl system were evaluated

  6. Flow-injection chemiluminometric determination of pioglitazone HCl by its sensitizing effect on the cerium-sulfite reaction.

    Science.gov (United States)

    Al-Arfaj, Nawal A; Al-Abdulkareem, Eman A; Aly, Fatma A

    2009-03-01

    A flow injection chemiluminescent (FI-CL) method was developed for the determination of pioglitazone HCl. It is based on the sensitizing effect of the drug on the oxidation reaction of sulfite with cerium(IV). The different experimental parameters affecting the chemiluminescence intensity, such as concentration of reagents and some physical parameters of the manifold, were carefully studied and incorporated into the procedure. The method permits the determination of 0.05 - 3.0 microg ml(-1) of pioglitazone HCl with correlation coefficient r = 0.9999. The lower limit of detection (LOD) is 0.01 microg ml(-1) (S/N = 2) and the lower limit of quantitation (LOQ) is 0.05 microg ml(-1). The proposed method was compared with other reported methods and was found to be equally accurate and precise. It was successfully applied to the determination of the drug in pharmaceutical preparations and in biological fluids.

  7. Luminescence and charge trapping in Cs.sub.2./sub.HfCl.sub.6./sub. single crystals: optical and magnetic resonance spectroscopy study

    Czech Academy of Sciences Publication Activity Database

    Král, Robert; Babin, Vladimir; Mihóková, Eva; Buryi, Maksym; Laguta, Valentyn; Nitsch, Karel; Nikl, Martin

    2017-01-01

    Roč. 121, č. 22 (2017), s. 12375-12382 ISSN 1932-7447 R&D Projects: GA MŠk LO1409; GA ČR GA17-09933S Institutional support: RVO:68378271 Keywords : Cs2HfCl6 * single crystal * luminescence * temperature dependence * EPR spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 4.536, year: 2016

  8. Evidence for Slab Melt Contributions to the Mexican Volcanic Belt and Other Young Hot Slab Arcs from Lu-Hf Isotopes

    Science.gov (United States)

    Goldstein, S. L.; Cai, Y. M.; Langmuir, C. H.; Lagatta, A.; Straub, S. M.; Gomez-Tuena, A.; Martin Del Pozzo, A.

    2007-12-01

    Despite major advances in delineating the processes that govern magma generation at convergent margins, the problem persists of distinguishing slab, mantle wedge, and crustal contributions. A corrollary question is whether there is significant melting of subducted ocean crust. Especially in thick crust regions, the importance of crustal versus mantle contributions to lavas represents a long-standing fundamental issue in arc magma geochemistry. We show that frontal arc magmas from the Central Mexican Volcanic Belt (CMVB), including the large andesitic stratovolcanoes Popocatepetl and Nevado de Toluca, display negligible crustal contamination, and contain substantial contributions from melting of subducted Pacific ocean crust. Despite ca. 50 km thick continental crust, the CMVB erupts near primitive lavas including "high-Nb" alkaline basalts that show negligible "subduction signatures" in their trace element patterns. These "high-Nb" basalts define the regional mantle wedge composition in isotope-trace element space. The "normal" calcalkaline lavas form a negative correlation between Hf isotopes and Lu/Hf. One endmember is like the high Nb basalts representing the regional mantle wedge. The other endmember has higher Hf isotopes (approaching values of Pacific MORB) and very low Lu/Hf of less than 0.04 (e.g. compared to typical values of ca. 0.2 in Pacific MORB). The low Lu/Hf values require low degree partial melting of a source rich in garnet. The high Hf isotopes require a depleted mantle source with isotopes like Pacific MORB. Together the Lu-Hf data indicate a substantial component derived from melting of eclogitic Pacific ocean crust. A key feature of the data is that the stratovolcano lavas showing the largest slab melt signature also show the highest Hf isotope ratios and thus are more "depleted mantle-like" than the regional mantle wedge. Thus, the integrated data allow us to clearly distinguish between mantle and crustal sources in the CMVB and point to

  9. Reaction kinetics of nitrous acid with acetohydroxamic acid in HClO4 and HNO3 medium

    International Nuclear Information System (INIS)

    Zheng Weifang; Yan Taihong; Bian Xiaoyan; Zhang Yu

    2007-01-01

    The presence of nitrous acid in feed solution of PUREX process is unavoidable. Owing to its effect on the valence of plutonium and other nuclides, nitrous acid should be scavenged. The kinetics of reaction of AHA with nitrous acid was studied in HClO 4 and HNO 3 medium. The reaction rate equation in HClO 4 and HNO 3 medium is obtained as. --dc(HNO 2 )/dr= k·c(HNO 2 ) 1 ·c(AHA) 0.75 ·c(HClO 4 ) 0.5 and --dc(HNO 2 )/dt=k·c(HNO 2 ) 1 ·c(AHA) 0.25 .· c(HNO 3 ) 1 , respectively. In HClO 4 medium, the reaction rate constant (k) is found to be (2.37±0.21) L 1.25 /(mol 1.25 ·s) at θ=5 degree C, I=0.5 mol/kg. Reaction rate constant is increased slightly with the increased ion strength in the range of 0.5-2.0 mol/kg. In HNO 3 medium, the reaction rate constant (k) is found to be (0.482±0.048) L 1.25 /(mol 1.25 ·s) at θ=10 degree C and I= 0.5 mol/kg. Reaction rate constant is also increased slightly with the increased ion strength in the range of 0.5-3.0 mol/kg. The effect of temperature to the reaction rate is also studied. The results show that with the increase of temperature, the reaction rate increases quickly. And the activation energy is found to be 99.0 kJ/mol and 46.9 kJ/mol respectively in HNO 3 . (authors)

  10. Investigation of inhibition effect of rhodanine-N-acetic acid on mild steel corrosion in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Yuece, Ayse Ongun [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330 Adana (Turkey); Solmaz, Ramazan [Bingoel University, Science and Letters Faculty, Chemistry Department, 12000 Bingoel (Turkey); Kardas, Guelfeza, E-mail: gulfeza@cu.edu.tr [Cukurova University, Science and Letters Faculty, Chemistry Department, 01330 Adana (Turkey)

    2012-01-05

    Highlights: Black-Right-Pointing-Pointer R-NA inhibits corrosion of mild steel in 0.1 M HCl solution. Black-Right-Pointing-Pointer The inhibition efficiency or R-NA is concentration and exposure time dependent. Black-Right-Pointing-Pointer The inhibitor molecules form a good protective film on the mild steel surface. - Abstract: Corrosion inhibition effect of rhodanine-N-acetic acid (R-NA) on mild steel (MS) corrosion in 0.1 M HCl solution was investigated. For this purpose, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) as well as hydrogen gas evolution (V{sub H{sub 2}}-t) and the change of open circuit potential as a function of immersion time (E{sub ocp} - t) were used. The MS surfaces exposed to 0.1 M HCl solution in the absence and presence of inhibitor were examined by scanning electron microscopy (SEM). The thermodynamic parameters of adsorption were calculated and discussed. In order to gain more information about the adsorption mechanism, the EIS technique was used to evaluate the potential of zero charge (PZC) and a mechanism of adsorption process was proposed. It was found that, R-NA is a good corrosion inhibitor for the MS corrosion in 0.1 M HCl solution. The inhibition efficiency increased with increasing inhibitor concentration and reached 98% at 1.0 Multiplication-Sign 10{sup -2} M R-NA. The high inhibition efficiency was related to adsorption of R-NA on steel surface. Surface SEM images showed a good surface coverage of inhibitor on the metal surface.

  11. The technique for calculation of equilibrium in heterogeneous systems of the InP-GaP-HCl type

    International Nuclear Information System (INIS)

    Voronin, V.A.; Prokhorov, V.A.; Goliusov, V.A.; Chuchmarev, S.K.

    1983-01-01

    Technique for calculation of equilibrium in heterogeneous systems based on A 1 3 B 5 -A 2 3 B 5 solid solutions implying the use of structural-topological models of chemical equilibrium in the investigated systems, is developed. Chemical equilibrium in the InP-GaP-HCl systems is analyzed by means of the suggested technique and the equilibrium composition of the gas phase is calculated

  12. Detection of residues in urine and tissues of sheep treated with trace levels of dietary ractopamine HCl

    Science.gov (United States)

    Ractopamine HCl was fed to sheep at 0 (Z), 0.001 (L), 0.01 (M), or 0.1 (H) mg/kg of diet (n = 4 per level, 0.5 kg of feed/day) for seven consecutive days and urine was collected daily about ~16 h post exposure. On-site lateral flow assays were able to reliably (0% false negatives) detect 20 ng of r...

  13. Evaluation of a Novel, Natural Locust Bean Gum as a Sustained Release and Mucoadhesive Component of Tizanidine Hcl Buccal Tablets

    OpenAIRE

    Harikrishnan.V

    2015-01-01

    Mucoadhesive polymers that bind to the gastric mucin or epithelial cell surface are useful in drug delivery for the purpose of increasing the intimacy and duration of contact of drug with the absorbing membrane. Mainly synthetic polymers are in use for this purpose. Probably the biodegradability of the synthetic polymers are questionable, In the present work mucoadhesive buccal tablets of Tizanidine hydrochloride (TZD HCl) were prepared by using locust bean gum that have better mucoadhesive p...

  14. A study of the structure of the ν1(HF) absorption band of the СH3СN…HF complex

    Science.gov (United States)

    Gromova, E. I.; Glazachev, E. V.; Bulychev, V. P.; Koshevarnikov, A. M.; Tokhadze, K. G.

    2015-09-01

    The ν1(HF) absorption band shape of the CH3CN…HF complex is studied in the gas phase at a temperature of 293 K. The spectra of gas mixtures CH3CN/HF are recorded in the region of 4000-3400 cm-1 at a resolution from 0.1 to 0.005 cm-1 with a Bruker IFS-120 HR vacuum Fourier spectrometer in a cell 10 cm in length with wedge-shaped sapphire windows. The procedure used to separate the residual water absorption allows more than ten fine-structure bands to be recorded on the low-frequency wing of the ν1(HF) band. It is shown that the fine structure of the band is formed primarily due to hot transitions from excited states of the low-frequency ν7 librational vibration. Geometrical parameters of the equilibrium nuclear configuration, the binding energy, and the dipole moment of the complex are determined from a sufficiently accurate quantum-chemical calculation. The frequencies and intensities for a number of spectral transitions of this complex are obtained in the harmonic approximation and from variational solutions of anharmonic vibrational problems.

  15. Two-dimensional simulation of the development of an inhomogeneous volume discharge in a Ne/Xe/HCl gas mixture

    International Nuclear Information System (INIS)

    Bychkov, Yu. I.; Yampolskaya, S. A.; Yastremskii, A. G.

    2013-01-01

    The kinetic processes accompanying plasma column formation in an inhomogeneous discharge in a Ne/Xe/HCl gas mixture at a pressure of 4 atm were investigated by using a two-dimensional model. Two cathode spots spaced by 0.7 cm were initiated by distorting the cathode surface at local points, which resulted in an increase in the field strength in the cathode region. Three regimes differing in the charging voltage, electric circuit inductance, and electric field strength at the local cathode points were considered. The spatiotemporal distributions of the discharge current; the electron density; and the densities of excited xenon atoms, HCl(v = 0) molecules in the ground state, and HCl(v > 0) molecules in vibrational levels were calculated. The development of the discharge with increasing the electron density from 10 4 to 10 16 cm −3 was analyzed, and three characteristic stages in the evolution of the current distribution were demonstrated. The width of the plasma column was found to depend on the energy deposited in the discharge. The width of the plasma column was found to decrease in inverse proportion to the deposited energy due to spatiotemporal variations in the rates of electron production and loss. The calculated dependences of the cross-sectional area of the plasma column on the energy deposited in the discharge agree with the experimental results.

  16. A comparison between the 2N and 4N HCl acid-insoluble ash methods for digestibility trials in horses.

    Science.gov (United States)

    Bergero, D; Préfontaine, C; Miraglia, N; Peiretti, P G

    2009-12-01

    The digestibility of horse feeds and rations can be determined using different techniques such as calculations based on the chemical composition, in vivo or in vitro methods. The marker methods overcome difficulties like discomfort for the animals and longer experimental times encountered using the ingesta/egesta method. In field conditions, a natural indigestible marker like acid-insoluble ash (AIA), with no changes in the normal ration, could be a very useful tool for digestibility trials. A group of six standardbred horses was used in a set of seven apparent digestibility trials. The diets were based on a first-cut meadow hay added to three different cereals (barley for trials 1 and 2; oats for trials 3 and 5 and corn for trials 6 and 7), the hay : concentrate ratio being 60 : 40 or 70 : 30 on a dry matter basis. Feedstuffs and faeces were analysed to determine the AIA content, using 2N HCl or 4N HCl technique. No differences about AIA concentration were found between the two methods for means and accuracy in each diet. Digestion coefficients for each diet did not differ with AIA method, even if in some trials interfering factors consistently lowered the overall values. Consequently, the AIA 2N HCl can be considered the easier and cheaper method to state apparent digestibility in field conditions, and a good tool for digestibility trials in horses fed hay-based diets.

  17. Trigonella foenum-graecum L. seed mucilage-gellan mucoadhesive beads for controlled release of metformin HCl.

    Science.gov (United States)

    Nayak, Amit Kumar; Pal, Dilipkumar

    2014-07-17

    Fenugreek (Trigonella foenum-graecum L.) seed mucilage (FSM)-gellan gum (GG) mucoadhesive beads containing metformin HCl for oral use were developed through ionotropic-gelation technique. Effects of GG to FSM ratio and cross-linker (CaCl2) concentration on the drug encapsulation efficiency (DEE, %), and cumulative drug release after 10h (R10h, %) of ionotropically-gelled FSM-GG mucoadhesive beads containing metformin HCl were optimized by 3(2) factorial design. The optimized mucoadhesive beads showed DEE of 92.53 ± 3.85% and R10h of 55.28 ± 1.58% and mean diameter of 1.62 ± 0.22 mm. The in vitro metformin HCl release from these ionotropically-gelled FSM-GG beads was prolonged over 10h and followed zero-order model with super case-II transport mechanism. The optimized mucoadhesive beads also exhibited pH-dependent swelling, good mucoadhesivity with biological mucosal membrane and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Recovery of actinides from actinide-aluminium alloys by chlorination: Part III - Chlorination with HCl(g)

    Science.gov (United States)

    Meier, Roland; Souček, Pavel; Walter, Olaf; Malmbeck, Rikard; Rodrigues, Alcide; Glatz, Jean-Paul; Fanghänel, Thomas

    2018-01-01

    Two steps of a pyrochemical route for the recovery of actinides from spent metallic nuclear fuel are being investigated at JRC-Karlsruhe. The first step consists in electrorefining the fuel in molten salt medium implying aluminium cathodes. The second step is a chlorination process for the separation of actinides (An) from An-Al alloys formed on the cathodes. The chlorination process, in turn, consists of three steps; the distillation of adhered salt (1), the chlorination of An-Al by HCl/Cl2 under formation of AlCl3 and An chlorides (2), and the subsequent sublimation of AlCl3 (3). In the present work UAl2, UAl3, NpAl2, and PuAl2 were chlorinated with HCl(g) in a temperature range between 300 and 400 °C forming UCl4, NpCl4 or PuCl3 as the major An containing phases, respectively. Thermodynamic calculations were carried out to support the experimental work. The results showed a high chlorination efficiency for all used starting materials and indicated that the sublimation step may not be necessary when using HCl(g).

  19. The nucleation of HCl and Cl{sub 2}-based HVPE GaN on mis-oriented sapphire substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bohnen, Tim; Dreumel, Gerbe W.G. van; Enckevort, Willem J.P. van; Ashraf, Hina; Jong, Aryan E.F. de; Hageman, Paul R.; Vlieg, Elias [IMM, Radboud University, Nijmegen (Netherlands); Weyher, Jan L. [Institute of High Pressure Physics, Polish Academy of Sciences, Warsaw (Poland)

    2010-07-15

    The nucleation of both classic HCl-based and novel Cl{sub 2{sup -}} based HVPE GaN on mis-oriented sapphire substrates was investigated. The use of Cl{sub 2}in HVPE increases the growth rate by a factor of 4-5 and strongly reduces the parasitic deposition, allowing for the growth of much thicker wafers than HCl-based HVPE. Morphological SEM surface studies of the HCl-based HVPE sample surface show that at 600 C a nanocrystalline layer is deposited on the sapphire. During the subsequent annealing phase, the morphology changes to a {mu}m-sized island structure. During overgrowth at 1080 C, the islands coalesce. Small voids or pinholes are then formed in between the coalescing GaN islands. These pinholes lead to numerous pits on the surface of the GaN at thicknesses of 5 {mu}m. The pits disappear during continued overgrowth and can no longer be found on the surface, when the GaN film reaches a thickness of 45 {mu}m. This particular coalescence mechanism also applies to Cl{sub 2}-based HVPE GaN on sapphire (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. C6H5NH2 effect on the corrosion inhibition of aluminium in 0.5 M HCl

    Science.gov (United States)

    Omotosho, Olugbenga Adeshola; Okeniyi, Joshua Olusegun; Loto, Cleophas Akintoye; Popoola, Abimbola Patricia Idowu; Fademi, Ekundayo Oluwademilade Jacob; Oladipupo, Segun Isaac; Alabi, Ayomide Samuel; Ajibola, Omokolade Bamidele; Emelieze, Alex Nwabunor

    2017-02-01

    In this paper, C6H6NH2 (aniline) effect on the corrosion of aluminium in 0.5 M (i.e. mol/L) HCl medium was studied using gravimetric method by weight loss measurements and electrochemical technique of corrosion potential and potentiodynamic polarization by cyclic voltamery (CV) instrumentation. By these techniques, corrosion rate obtained from aluminium specimens, in 0.5 HCl test-solution having different concentrations of the hydrogen-containing C6H6NH2 chemical, were requisitely analysed. Results showed that the potentiodynamic corrosion rate excellently correlated (R = 98.94%, Nash-Sutcliffe efficiency = 97.89% and ANOVA p-value = 0.0314) with function of the gravimetric corrosion rate and C6H5NH2 concentration. Both experimental and correlated prediction models identified 0.043 mol/L C6H5NH2 with optimal inhibition efficiency performance η = 84.11% by the experimental or η = 81.15% by the predicted models. Fittings of experimental and correlated data showed the data models followed the Langmuir adsorption isotherm from which favourable adsorption and prevalent physisorption were indicated as the C6H5NH2 corrosion-protection on aluminium metal in the 0.5 M HCl medium.